TTK. Typical flow chart for the installation and installation of internal ventilation and air conditioning systems with air handling units and equipment for refrigeration systems
TYPICAL TECHNOLOGICAL CHART (TTK)
INSTALLATION OF REFRIGERATION SYSTEMS. INSTALLATION OF SPLIT SYSTEMS, FAN COILS AND CHILLERS
1 AREA OF USE
A typical flow chart has been developed for the installation of refrigeration systems, split systems, fan coil units and chillers.
General information
An autonomous air conditioner is a unit with a built-in refrigeration machine. Such units require installation directly in the room.
Local air conditioners include split systems, consisting of an external unit, which includes a compressor and condenser unit, and an internal evaporative unit. The indoor unit is installed directly in the air-conditioned room. It is designed for cooling, heating and air filtration, as well as creating the necessary mobility of air flows.
The advantages of split systems include simplicity of design and low labor costs during installation; to the disadvantages - circulation without mixing fresh air into the room. Only high-power models allow you to organize the supply of a small amount of fresh air (up to 10%).
The outdoor unit can be installed on the wall of the building, on the roof, in the attic, etc., that is, where the heated condenser can be blown with air at a lower temperature. The indoor unit can be mounted on the wall, on the floor, on the ceiling, behind a false ceiling (cassette type), as well as be designed in the form of column cabinets up to 500x800x400 mm in size.
Split-system air conditioners with supply ventilation have more opportunities. Such a system is designed to be installed in places where fresh air supply is required.
With a significant number of serviced premises, the use of a system with chillers and fan coils is recommended. A chiller is a refrigerating machine designed to reduce (increase) the temperature of the liquid, which, under the pressure of the pump, is supplied to the air conditioner (fan coil) installed in the room. In this case, the air in the room is cooled or heated.
Features of installation of refrigeration systems
air conditioning (SLE)
General information about SCR refrigeration units
Among the processes carried out in air conditioners, one of the most important is the process of air cooling. To carry out this process, refrigeration units (XU) are used. Refrigeration units are considered as subsystems serving the ACS that produce "cold".
Compressor refrigeration units are the most common CW operating as part of SCR. These units consist of the following main elements: compressor, condenser, expansion valve (or capillary tube), evaporator and pipelines connecting the listed elements into a closed system in which the refrigerant circulates.
The cooling of the conditioned air takes place in air coolers, which are air conditioners. Two types of air conditioner air coolers are used. One of them is a surface recuperative heat exchanger, through the internal channels of which an intermediate coolant passes, which also circulates through the XY evaporator, located at some distance from the air conditioner.
Liquids (antifreeze, water, etc.) are used as a coolant. This cooling option is used, for example, in systems with chillers and fan coil units. Another type of air coolers for air conditioners should include heat exchangers, through the internal channels of which freon (freon) moves, and the outer surfaces of the channels are washed with air. These direct expansion air coolers are both elements of a refrigeration unit and an air conditioner. They are used in autonomous air conditioners.
Intercooler air conditioner coolers receive refrigerant pre-cooled in the evaporator refrigeration machine, for example, in a chiller. Supply and return pipelines are laid between the XU evaporator and the SCR air cooler to circulate the coolant through them. Pipelines must be thermally insulated. The insulation prevents condensation from forming on cold pipe surfaces. The refrigerant pipes and their insulation complicate the installation work.
So, the SCR refrigeration systems under consideration are designed to generate cold, transfer it directly to air through the XY evaporator or transfer cold to the coolant, transfer the coolant to the air conditioner air cooler, transfer cold from the coolant to the cooled air and return the heated coolant to the evaporator of the refrigeration machine to repeat the refrigeration cycle.
There are many varieties of refrigeration units used in SCR. Figure 1 shows the schematic diagrams of air cooling systems.
Fig.1. Air cooling systems determining the conditions for the use of refrigerants of various pipes
They present:
Direct expansion system in which the cooled air is in direct contact with the XU evaporator;
Indirect refrigeration systems with refrigerant in which the XU evaporator cools the intermediate refrigerant, which is then transferred to the air conditioner air conditioner in contact with the cooled air.
In indirect cooling systems with intermediate coolant, five types of execution are distinguished:
open system with intermediate coolant and closed evaporator;
Open system with an intermediate coolant and an evaporator placed in a tank communicating with open air;
closed system with an intermediate refrigerant and a closed evaporator, in which the evaporator is in a closed volume, cools the intermediate refrigerant circulating in this volume, which, in turn, is supplied to a closed secondary heat exchanger to cool the conditioned air;
Closed system with intermediate refrigerant and open evaporator, the evaporator is placed in a tank, cools the circulating intermediate refrigerant, which in turn is fed into a closed secondary heat exchanger to cool the conditioned air;
Double-circuit or multi-circuit refrigerant systems, which can be performed similarly to one of the listed refrigerant systems, except that they have two or more intermediate heat exchangers, and in the last circuit the intermediate refrigerant can be in direct contact with the cooling medium in a spray device or similar devices or similar systems.
Figure 2 shows a diagram of a typical refrigeration unit with an air cooler 1 and air cooled condenser 6 for SLE. The refrigeration plant for SCR usually consists of two separate units: compressor-condenser unit and air cooler unit.
Fig.2. Typical scheme refrigeration unit with one air cooler and air condenser for SCR:
1 - air cooler; 2 - filter cleaner; 3 - vibration isolator; 4 And 5 - low and high pressure switch; 6 - air condenser; 7 - receiver; 8 - filter dryer; 9 - compressor; 10 - crankcase heater; 11 - sight glass; 12 - shut-off valve; 13 And 27 - pressure and condensation control relay; 14 , 15 - solenoid valve housing with coil; 16, 17 - thermostatic valve; 18 - condensation pressure regulator; 19 - differential check valve; 20 - C1C system; 21 - sight glass; 22 - filter; 23 - cold start protection thermostat; 24 - liquid separator; 25 - check valve; 26 - oil separator
Compressor 9 refrigeration compressor sucks refrigerant vapor from the evaporator-air cooler 1, installed in a room where the required temperature is maintained, compresses to a condensation pressure and is fed into an air condenser 6 . In the condenser, the vaporized refrigerant condenses, heating the air blown through it, and the refrigerant passes into liquid state. From the condenser liquid refrigerant enters the receiver 7 . From the receiver enters the filter-drier 8 , where the removal of residual moisture, impurities and contaminants, then, passing through a sight glass with a moisture indicator 11 , is throttled in the expansion valve to the boiling pressure 16, 17 and fed into the evaporator. In the evaporator, the refrigerant boils, removing heat from the cooling object (the air surrounding the evaporator).
Refrigerant vapor from the evaporator through the liquid separator 24 and filter on the suction side 2 enters the compressor. Then the cycle of operation of the refrigeration machine is repeated.
2. ORGANIZATION AND TECHNOLOGY OF WORK PERFORMANCE
Features of installation of refrigeration subsystems of air conditioning systems (ACS)
Mounting refrigeration equipment are carried out according to the project (according to a standard or individual project) or scheme, which is attached to the supplied equipment and is described in the factory installation, operation and maintenance instructions.
When drawing up the wiring diagram and the equipment layout plan, it is necessary to minimize the length of the pipelines to be laid.
The sequence of installation and commissioning of refrigeration systems can be as follows:
Installation of refrigeration equipment;
Installation of pipelines and automation devices;
Installation of electrical systems;
System pressure test for tightness;
Vacuum system;
Filling the system with refrigerant;
System start;
Adjustment of automation devices;
Control, registration and output to operating parameters.
Installation of refrigeration equipment does not fundamentally differ from the installation of equipment for ventilation systems (SV) and SLE. The specific features of the installation are set out in the technical documentation that arrives at the facility together with the equipment and instruments of the instrumentation.
Refrigeration equipment for SCR systems is supplied mainly aggregated - in blocks, after the installation of refrigeration equipment, the installation of connecting pipelines is carried out: pipelines for refrigerants and pipelines for hydraulic systems. The condition for the long-term performance of the refrigeration system is the absence of foreign particles, moisture and contaminants in the refrigeration circuit. To fulfill this condition, the refrigerant lines must be thoroughly cleaned before assembly. Installation must be carried out by professionals experienced in the installation of refrigeration systems. For execution installation work installers use a special set of tools.
Installation of pipelines for refrigerants
As a rule, freon pipelines are made from two main types of special copper pipelines designed for refrigeration installations.
1. Tubing up to 7/8 in. (2.2 cm) in annealed copper, supplied in coils of various lengths, which bend well with spring mandrels or tube benders. They are well flared, which allows the use of pipe fittings. As a rule, sets of double flexible copper pipes in thermal insulation are used.
2. Pipes with a diameter of more than 7/8 inches from ordinary copper, supplied in lengths not exceeding 4 m. Such pipes are difficult to bend, so the joints of the segments and bends of pipelines are made with special elements (fittings) and connected by soldering with various solders.
For soldering, silver or copper-phosphorus solder is usually used. They have high tensile strength and vibration resistance. Solders are produced in the form of rods 3.2x3.2x500 mm and rods with a diameter of 1.6 mm. Various solders contain from 40 to 56% silver. Oxygen-containing fluxes are used to obtain an ideal tube connection.
Pipes are laid along the route in accordance with the project or installation scheme and are mainly located horizontally or vertically. The exception is the horizontal sections of the suction and discharge pipelines, which are performed with a slope of at least (5%) towards the compressor or condenser to facilitate oil return.
Fig.3. Scheme of installation of oil lifting loops on ascending sections of pipelines with a length of more than 7.5 m:
but- discharge pipeline; b- suction pipeline
In the lower parts of the ascending vertical sections of the suction and discharge lines with a height of more than 3 m, it is necessary to install oil lifting loops. Figure 3 shows the schemes for installing oil lifting loops on ascending sections of pipelines longer than 7.5 m, and Figure 4 shows a possible design of the oil lifting loop and its recommended dimensions.
Thermal insulation works
Calculation, design and installation of thermal insulation is carried out in accordance with SNiP 41-03-2003 (introduced to replace SNiP 2.04.14-88 * "Thermal insulation of equipment and pipelines") and SP 41-103-2000 (calculation method), taking into account the requirements fire safety, sanitary and hygienic standards and design standards adopted in certain industries.
In 2003 NTP "Pipeline" ( software) and OJSC "Teploproekt" (calculation methods and information base) have developed a computer program for automated design of thermal insulation of equipment and pipelines "Izolyatsia". When insulating process pipelines, various types of insulation are used depending on the technical requirements. Progressive types of insulation can be considered insulation based on foamed rubber or polyethylene. Each type has its pros and cons. The positive properties of insulation can be reduced to zero with poor-quality installation. Leading manufacturers of foam insulation made of foamed polyethylene ("Thermaflex International Holding BV", "Mirel Trading", "Energo-flex") and synthetic rubber ("Lisolante K-Flex") "Armacell Europe Gmbh", "Wihlem Kaimann GmbH & Co" Aeroflex International Co, Ltd, YSOLIS.
When installing insulation, the following rules must be observed:
1. Always carry out the isolation operation on cold equipment and pipelines.
2. When cutting and fitting insulating pipes, use only high-quality auxiliary tools, using a professional set of insulators, consisting of:
wooden fixture for cutting and a long sharp knife;
templates;
A set of circular stainless steel knives.
3. Glue the joints of the seams with a special glue based on polychloroprene at a temperature of at least 10 °C.
Figures 5 and 6 show the tools listed above.
Fig.5. Templates
Fig.6. Circular knives
Errors associated with improper installation of insulation can lead to intractable problems, which include:
Arbitrary replacement of insulation marking;
Incorrect selection of accessories for installation;
Transition to a smaller thickness of thermal insulation;
Violation of the temperature range of operation;
Improper preparation of the system and its surface;
Wrong work with glue;
Application of foam insulation for outdoor use without additional protection.
Mounting steel pipes wires hydraulic refrigeration systems SCR
Installation of SCR hydraulic refrigeration systems can be carried out by all industrial methods that ensure the quality of the connections, in accordance with the current regulations. There are three main connection methods: welding, threaded connection and gluing steel pipelines. Welded connections steel pipelines can be performed by welders if they have documents on passing tests in accordance with the "Rules for the certification of welders" approved by Gosgortekhnadzor. Welding is carried out in accordance with GOST 16037-80 "Welded joints of steel pipelines".
Another connection method is threaded connections using fittings (fittings). The universal kit for the installer is shown in Fig.7.
Fig.7. Universal kit for plumbing SANY KIT in a plastic case
The set consists of the following tools:
Pipe cutter for cutting pipes up to 1 1/4" in diameter;
Device for cutting threads up to 1" in diameter;
Plumbing pliers;
Universal angle wrench SUPER S1.
Adhesive joints are used when installing pipelines made of carbon and low-alloy steels (including those with corrosion-resistant coatings - galvanized, enameled, illuminated, etc.) up to 100 mm, operating at overpressure up to 1.0 MPa, operating temperature from -60 to 90 °C and intended for transportation of various substances, to which, under the specified parameters, epoxy adhesives or epoxy-based fiberglass are chemically resistant.
Installation of plastic (polymer) pipelines of hydraulic refrigeration systems of SCR
Currently, polypropylene pipes and fittings are widely used for the installation of SCR refrigeration systems. Advantages of plastic pipes:
No corrosion;
Long service life;
When freezing, the pipes do not collapse, but increase in diameter and, after thawing, acquire the same size;
Good absorption of hydraulic noise;
Low pressure losses in pipes and fittings;
Low thermal conductivity.
For the installation of plastic pipelines, various connecting and fasteners are used. The main methods of connecting pipeline sections:
Contact welding into the socket;
Threaded connection with a metal pipeline;
Connection on loose flanges;
Connection with union nut.
Installation of PPRC systems requires minimal cost time and effort. Socket welding technology allows you to quickly ensure the durability of a sealed connection. The reliability of welded joints is the highest in comparison with other methods and approaches the strength of the pipes themselves, but requires higher qualifications from the installation personnel. After installation of pipelines of the freon circuit and testing for leaks with leak detectors different kind the system is evacuated and the system is charged with refrigerant using a filling station or a gauge manifold. Depending on the refrigerant used (single-component or multi-component), charging can be done with both gaseous and liquid refrigerants. Always follow the refrigerant charge recommendations in the air conditioner installation and operation manual supplied with the equipment. The optimal amount of charged freon can be determined by suction and discharge pressure or by superheat in the evaporator.
Features of installation of split systems, fan coil units and chillers
Features of installation of split system air conditioners
In practice, the installation of small refrigeration units is divided into standard and non-standard. Under standard this implies installation with a refrigerant line length of up to 5 m, a suction line diameter of up to 16 mm, a connection and control panel located at a distance of up to two meters from the unit, with one air cooler, without a remote condenser and oil lifting loops, and the presence of power supply of the required power.
Standard installation includes:
Delivery of equipment;
Installation of units on the wall on specially prepared brackets;
Punching of one hole for connecting communications;
Laying a route up to 5 m long without oil lifting loops;
Electrical connections and piping connections of the system;
Checking the system for tightness (for pressure and vacuum);
Refueling with freon;
Commissioning works.
Under non-standard installation means installation taking into account the additional requirements of the customer. For example, installing a remote condenser, having two or more air coolers in the room, increasing overall length pipelines over 5 m, laying pipelines through several walls (partitions), laying pipelines in decorative boxes, etc.
The split system consists of two separate units, which can be installed at a considerable distance from each other. indoor unit installed in an air-conditioned room, and outdoor unit- on the outside building. In this type of installation, axial fans are used to ensure that the unit works properly, there must be no obstruction to the air flow, and the minimum clearances specified in the instructions for the unit must be observed. The prevailing air direction should not be directed towards the installation. In apartments and small offices use wall-mounted split systems. With greater cooling capacity in rooms of complex shape - cassette or canal, in rooms with glass partitions - ceiling, in the halls of restaurants and large halls - columnar. If the number of indoor units becomes more than six, and the maximum distance between the units reaches 100 m, such systems are called multizone (zonal-modular) or VRF systems.
Install the indoor unit as close as possible to a window or wall facing the street to shorten the refrigerant piping route. The maximum distance should not exceed 15 m. High furnishings should not be placed in the path of the air flow supplied to the working area, and the covering jet of the cooled flow should cover the maximum area of the room. Since the air supply to cassette modules occur in four directions, it should not be mounted close to the wall, and all communications are located behind the false ceiling, as with channel systems; free space must be at least 350 mm. indoor units channel systems should be mounted close to the outer wall, as they allow up to (10-20%) fresh air to be mixed in. Because floor and ceiling And cassette modules completed drainage pump, we must try to locate them near the sewer pipelines for drainage.
Outdoor unit mounted on the outside of the building on a ready-made mounting bracket near the window, so that it is possible to carry out service work without a climber. The unit should be installed so that it is well ventilated by outside air and protected from direct sunlight.
Mounting of the outdoor unit must be carried out on a sufficiently strong wall on a ready-made bracket, designed for a weight of 80 kg. The distance of the unit from the system must be at least 10 cm.
When choosing a place to install the indoor unit, consider the following requirements:
Do not place the unit near sources of heat and humidity;
Do not install the unit near a doorway;
There must be no obstruction to the air blown out of the indoor unit;
A reliable condensate drain (drainage) must be organized at the installation site of the unit;
The installation site of the unit must be chosen in such a way that there is no direct (direct) supply of cooled air to people;
The distances from the indoor unit to the walls, ceiling and floor must be at least certain values (Fig. 8).
Fig.8. Mounting position of the indoor unit of the split system
The wall-mounted or floor-to-ceiling type indoor unit is mounted using the mounting plate and brackets included in the delivery. The mounting plate is attached to the wall with screws strictly in level. In this case, the normal removal of condensate formed during the operation of the air conditioner is ensured.
To drain the condensate, a special drainage pipeline is installed, usually made of a soft corrugated tube. Sometimes a rigid smooth tube is used, for example, when laying a drainage pipeline in suspended ceilings with small slopes.
Drainage is made into the sewer to the street, and sometimes into a special container, usually by gravity. If for some reason it is not possible to organize the draining of condensate by gravity, then it is necessary to use drainage pumps. When draining through the wall to the street, it is necessary to drill a hole with an inclination (the outer edge is lower than the inner one).
When pulling the copper pipes, control cable and drain tube through the hole, it is necessary to ensure that there are no kinks, breaks, or jams on the drain tube. It is unacceptable to touch the drain tube when it is bare, i.e. unprotected thermal insulation of the gas line, especially for modules with a heat pump. When the air conditioner is in heating mode, the temperature of the gas line may reach a temperature sufficient to melt the material from which the drain pipe is made, which may lead to blockage drainage system.
The drain tube must have the necessary throughput and be laid with a slope of at least 1% so that there are no rises and sags along the pipe.
It is recommended to drain the condensate into the sewerage inside the room. Before the place where condensate is collected into the sewer, a siphon must be installed on the line to prevent penetration unpleasant odors into the room.
When the air conditioner operates in cooling mode in winter, there is a danger of moisture freezing at the outlet of the drain pipe. Special electric heaters or heating cables of appropriate capacity can be used to protect the outlet section of the drainage pipeline from freezing. Their power supply must be independent of the rest of the electrical circuit and must be supplied continuously, except during the maintenance of air conditioners.
When installing the indoor unit under the ceiling, make sure that the filter can be removed for cleaning.
Column-type air conditioners are installed on the floor and, if possible, attached to the wall to give rigidity to the structure.
The indoor and outdoor units are interconnected with copper pipes in thermal insulation.
Features of installation of fan coils
A local air conditioning unit used to cool or heat the air, with a built-in fan, filter, electric heater and control panel is called a fan coil unit. Fancoils are available in various designs:
For vertical installation below a window in the enclosure;
For hidden vertical installation under a window without casing;
For horizontal ceiling mounting in an enclosure;
For concealed horizontal installation in false ceilings;
Cassette type for installation in false ceiling;
Wall mounted, by analogy with the internal blocks of split systems;
Cabinet type.
Fancoils are installed in groups, serving several rooms or floors. The piping schemes of the heat and cold supply system can be two-pipe, three-pipe and four-pipe, depending on the tasks that need to be solved. Placement and installation are carried out according to the installation and maintenance instructions supplied with the fan coil unit. Mounting feature is correct setting hydraulic system using balancing valves to ensure the required distribution of liquid to all fan coil units.
Chiller installation features
chiller is a complete refrigeration machine designed for liquid cooling (water, antifreeze liquids). System chiller-fan coil differs from all other air conditioning systems in that it is not freon that circulates between the outdoor and indoor units, but water, an aqueous solution of propylene glycol, ethylene glycol or other antifreezes. Installation is carried out in accordance with the Chiller Installation Manual supplied with the manufacturer. When placing the chiller, pay attention to:
On the uniformity of the distribution of gravity created by the unit; to prevent the transmission of vibration to building structures, created by the unit when the units are placed in technical rooms and on the roof, by installing the units on vibration isolators;
Around the chiller, it is necessary to provide free space for air to flow to the condensers, for the possibility and convenience of carrying out service work, maintenance and repair of the compressor and heat exchange equipment.
Hydraulic connection of the chiller to pumping station should be made with flexible connections, passages through ceilings and walls should be made in sleeves, without connecting pipes rigidly with structures.
When using water as a coolant and placing the chiller in an unheated room, it should be possible to drain the water during the cold season.
3. REQUIREMENTS FOR THE QUALITY OF WORK PERFORMANCE
Testing of ventilation and air conditioning systems and their acceptance into operation
1. Pre-start tests of ventilation and air conditioning systems are carried out by the working commission according to the program approved by the customer.
2. Completely assembled ventilation and air conditioning systems together with automation systems and remote control, passed tests and adjustment in the scope of approved programs:
For performance in terms of air, heat and acoustic measurements and temperature and humidity conditions;
On the sanitary and hygienic effect (for experimental and head samples);
For sealing locking devices and structures, as well as adjusting the system of collective anti-chemical protection.
3. By the time of testing, the following documents must be submitted:
Technical descriptions of systems;
Working drawings and change sheets;
Presentation note of the installation organization;
Certificates for the acceptance of equipment and premises for installation;
Route passports for installation and commissioning;
Equipment audit certificates;
Acts of testing units and elements of systems for tightness;
Program of individual tests.
4. The pre-launch tests include:
Checking the quality of work performed;
Checking the completeness of equipment;
Testing and verification of all units in order to determine the technological parameters;
Testing and verification of automation systems.
5. When conducting pre-launch tests, there must be:
Fan performance determined;
The compliance with the project of the volumes of air passing through the air distributing, air inlet, air outlet and other devices was checked;
Identified leaks in the ventilation system;
The uniformity of heating of the heaters and the operation of the injectors were checked.
6. Deviations in fan performance, air flow or air volume in the entire system or passing through various devices must not exceed ±10%. The amount of suction or air leakage due to leaks for general ventilation should not exceed 10-15%. For special ventilation systems, this value is set by the relevant technical conditions.
7. Ventilation and air conditioning systems in the individual test project are tested together with remote and automatic control systems. The test results are considered satisfactory if during the test there were no failures in the operation of automation devices and equipment, and the deviations of the actual parameters of the operating mode did not exceed the permissible limits. Upon completion of individual tests, an act is drawn up, and the working commission decides on the admission of the ventilation and air conditioning system to complex tests or commissioning. The purpose of complex tests is to check the readiness of the ventilation and air conditioning system for the operation of the entire complex or the calculated technological load. Ventilation and air conditioning systems are considered to have passed comprehensive tests if during the tests fluctuations in temperature, relative humidity and concentration of harmful substances were within the established norms. At the time of acceptance, the following must be specified:
Deviations from the project made during the construction and installation works (agreed with the design organization and the customer);
Characteristics of air ducts, fans, heaters, electric motors, electrical appliances, hermetic valves, filters, their serviceability during operation and compliance with design data;
The results of testing, adjustment and adjustment of ventilation systems performed by the installation and commissioning organizations;
Quality of construction and installation works performed;
Multiplicity of air exchange in each room of buildings for all modes and programs; actual overpressure or rarefaction of air in the premises.
The act is accompanied by a set of working drawings and acts of hidden works.
4. MATERIAL AND TECHNICAL RESOURCES
Tools and fixtures for installation and service of refrigeration equipment
For installation, maintenance and repair of refrigeration equipment, the following set of tools, instruments and fixtures is recommended:
Tool for mounting copper, brass and steel pipes;
Device for soldering and welding pipes;
Devices for vacuuming and filling the refrigeration system;
Devices for determining the place of leaks in the refrigeration system;
Devices for the installation of electrical circuits and automation circuits.
When using copper, brass, steel and plastic pipes for installation, various tools are used for high-quality installation work:
Tools for mounting copper and brass pipes;
Tools for mounting steel pipes;
Mounting tools polymer pipes.
Pipe cutter (Fig. 9) allows a very clean cut copper pipeline of the required length, and when using a hacksaw, it is necessary to process the ends of the pipeline (both the inner and outer surfaces) with a device (Fig. 10) for deburring.
Fig.9. pipe cutter
Fig.10. Pipe end deburring tool
Figure 11 shows the flaring (unfolding) for the nipple connection and the expander (Figure 12) with a mandrel.
Fig.11. Razbortovka
Fig.12. Mandrel Expander Set
For bending pipelines, a manual pipe bender is used (Fig. 13).
Fig.13. Manual pipe bender
When performing welding work, it is necessary to have a welding or soldering unit. For pipelines of small diameters, soldering with propane torches can be used instead of welding. For pipelines of large diameters, a welding unit with an oxygen-acetylene torch is used (Fig. 14).
Fig.14. Oxy-acetylene welding unit
For evacuation and refrigerant filling system, it is recommended to use a filling station (Fig. 15) or the following kit:
Fig.15. Portable filling station
Manometric manifold with low and high pressure gauges, a vacuum gauge and a set of hoses (Fig. 16);
Two-stage vacuum pump with vacuum gauge (Fig. 15);
Filling cylinder for filling control or filling scales. One of the collector samples and ways to connect it are shown in Fig.16.
Fig.16. Portable Gauge Manifold and Flexible Hose Connection Diagram
Such a manifold has 4 hoses with union nuts and 4 valves.
To purge flexible hoses:
A, C, D- open, IN- closed (flexible hose N 2 under pressure) 1, 3, 4 - connected to the collector as shown in the diagram, but the opposite ends are free; 2 IN- open to start blowing.
To control the pressure in the circuit:
FROM And D- closed BUT And IN- open all the way 1 And 3 - connected as shown in the diagram; H And L- unscrew until it stops, then screw it in 1/3 of a turn. Watch the pressure.
To purge the circuit:
BUT And IN- closed FROM And D- open, 1 And 3 - connected as shown in the diagram, 4 - connected at one end to the collector, as shown in the diagram, the other end is free, H And L BUT- open at the beginning of the external purge (through flexible hose 4).
To charge refrigerant through the suction line:
A, B, D- closed FROM- open, 1, 2, 3 - connected as shown in the diagram, H- unscrew it until it stops, then screw it in 1/2 turn, L- turn halfway IN
To charge oil through the suction line of the circuit:
A, B, D- closed FROM- open, 1 - connected as shown in the diagram, 2 - connected at one end to the collector, as shown in the diagram, and at the other end to the oil reservoir, H- close all the way L- close all the way IN- slowly open, adjusting the oil flow.
To evacuate and charge the circuit:
BUT And IN- closed FROM And D- open, 1 And 3 - connected as shown in the diagram, H And L- unscrew until it stops, then screw it in 1/2 turn. If the pressure gauges show residual pressure, purge the circuit before vacuuming, BUT- open, H And L- half open 2 And 4 - connected as shown in the diagram.
Start the pump and complete the evacuation:
BUT- close, then put the pump, H- unscrew it until it stops, then screw it in 1/2 turn, D- closed, IN- slowly open, adjusting the refrigerant flow.
For refrigerant leak detection regardless of its composition, the method of lathering or using litmus papers (ammonia or R22, R502) can be used. There are also various equipment for detecting leaks. Figure 17 shows a halide lamp, it is used for non-flammable refrigerants with excess pressure in the system.
Fig.17. Halogen lamp
With a special additive to the refrigerant, an ultraviolet lamp (Fig. 18) can be used to detect leaks due to the glow of tracer gas in its rays.
Fig.18. Ultraviolet lamp for detecting leaks due to the glow of tracer gas in its rays
The device, shown in Fig. 19, allows you to detect leaks of both CFC and HCFC refrigerants, as well as absolutely non-polluting HFC refrigerants (R134a).
Fig.19. Electronic leak detector for CFC, HCFC and YPC refrigerants
The device shown in Fig. 20, whose operation is based on the principle of ionization of the gas between two electrodes.
Fig.20. Ionization leak detector for CFC, HCFC and HFC refrigerants
To identify faults in electrical diagrams A refrigeration specialist has current clamps (Fig. 21), which allow you to measure voltage (in volts) and electrical resistance (in ohms).
Fig.21. Clamp meters
Using current clamps in ohmmeter mode allows you to:
Check indirectly the resistance of the windings of the electric motors of the compressor, fan for compliance with specifications;
Detect a short to ground in the motor winding;
Determine whether the motor terminals belong to the starting and running windings by measuring their resistances;
Identify short-circuited windings;
Check relay or contactor contacts.
Using current clamps in voltmeter mode allows you to:
Check the voltage at the motor terminals;
Identify the linear and zero phases, as well as the ground wire;
Check the correct grounding of electrical systems; check fuses;
Detect voltage surges or stray currents. Using current clamps in ammeter mode allows you to:
Check the starting current;
Check electrical systems in ascending order;
Adjust unloading at launches with increasing time;
Check the primary winding in the current transformer;
Distinguish a star connection from a delta connection;
Check phase imbalance;
Check the current of the locked rotor against the data given on the motor housing.
Refrigerants and coolants
Refrigerant (refrigerant) is the working body of the refrigeration machine, changing its state of aggregation in the process of passing through the equipment elements operating both in the direct cycle (cooling mode) and in the reverse cycle (cooling mode). heat pump). Removing heat from the environment, the refrigerant boils, passing from a liquid to a gaseous state. Due to the endothermic nature of the process, cold is produced. The heat taken from the air is removed from the refrigeration machine during the transition of the refrigerant from a gaseous state to a liquid state during an exothermic process in the condenser.
Substances used in refrigeration should have a low boiling point at atmospheric pressure, the boiling vapor volumes should not be too large, and the condensation pressures should not be too high. It must be non-corrosive to construction materials and oils, as least toxic as possible, non-flammable and explosion-proof.
Table 4.1 lists the main refrigerants currently in use and for the future.
Table 4.1
KEY REFRIGERANTS CURRENTLY USED AND FOR THE FUTURE
| Designation | Name | ||
| Trichloromethane | |||
| Dichlorodifluoromethane | |||
| Bromochlorodifluoromethane | |||
| Trifluorochloromethane | |||
| Bromotrifluoromethane | |||
| Difluorochloromstane | |||
| Trifluoromethane | |||
| difluoromethane | |||
| Trichlorotrifluoroethane | |||
| Dichlorotetrafluoroethane | |||
| Chloropentafluoroethane | |||
| Dichlorotrifluoroethane | |||
| Chlortetrafluoroethane | |||
| Pentafluoroethane | |||
| Tetrafluoroethane | |||
| Dichlorofluoroethane | |||
| Chlorodifluoroethane | |||
| Trifluoroethane | |||
| Difluoroethane | |||
| carbon dioxide |
Table 4.2 presents the main physical properties and maximum allowable concentrations of refrigerants currently most commonly used in SCR and recommended for future use.
Table 4.2
GROUPS OF REFRIGERANTS USED IN HU SCR, THEIR PHYSICAL PROPERTIES
| Cooling group | Refrigeration number | chemical name | Chemical formula | body molecule lar mass | Gas constant, J/(kg K) | Boiling point at 101.3 kPa, °C | Freezing point, °С | Critical temperature, °C |
| Fluorotrichloromethane | ||||||||
| Difluorodichloromethane | ||||||||
| Difluorobrommethane | ||||||||
| Trifluorochloromethane | ||||||||
| Trifluorobromomethane | ||||||||
| difluoromethane | ||||||||
| Trifluoromethane | ||||||||
| Trifluorotrichloroethane | ||||||||
| Tetrafluorodichloroethane | ||||||||
| Pentafluorochloroethane | ||||||||
| R12 (73.8%) + R152а (26.2%) | ||||||||
| R22 (48.8%) + R115 (51.2%) | ||||||||
| methylene chloride | ||||||||
| Methyl chloride | ||||||||
| Ethyl chloride | ||||||||
| Methyl formate | ||||||||
| Sulfur dioxide | ||||||||
| dichloroethylene | ||||||||
| Isobutane | ||||||||
| Propylene |
The NF E35-400 standard divides refrigerants into three groups:
Group I - non-toxic and non-flammable refrigerants.
Group II - refrigerants with a certain degree of toxicity.
Group III - refrigerants according to the degree of ignition and the formation of explosive mixtures with air at a lower concentration limit of 3.5% by volume.
The NF E35-400 standard also specifies the conditions for the use of various refrigeration systems, as well as their location and the conditions for laying pipelines for transporting the refrigerant, depending on the group to which this refrigerant belongs, as well as the category of premises.
In connection with environmental problems, the prospects of using ammonia as a working fluid in refrigeration units of air conditioning systems have again been considered. Ammonia is environmentally less harmful, cheap, available and has excellent thermodynamic properties.
Ammonia's main disadvantage is its toxicity, flammability at certain concentrations, and incompatibility with copper.
The use of refrigeration units using ammonia as a refrigerant must be carried out by enterprises and organizations licensed to perform this type of work, and projects must be approved by the Gosgortekhnadzor of Russia. It is forbidden to use refrigeration units with direct cooling (direct boiling of the refrigerant in the air cooler) for comfortable air conditioning in administrative and industrial premises.
Refrigerants, with the exception of refrigerants of groups II and III, are classified as explosion-proof and non-toxic chemical compounds or mixtures, however, on contact with open fire, fluorine- and chlorine-containing refrigerants decompose, releasing chlorine and phosgene compounds (nerve gas).
In the event of a fire in the premises where refrigeration units are located, insulating or filtering gas masks should be used. With an increase in the concentration of freon vapor in the room, the oxygen content drops and suffocation sets in, since the density of most refrigerants is greater than the density of air, and when it leaks, it tries to take lower levels in the rooms. It is not recommended to fill more than 80% of the refrigerant tank by volume.
coolants are an intermediate body through which heat is transferred from the air of the cooled room to the refrigerant. The coolant can be water, aqueous solutions of salts or liquids with a low freezing point - antifreeze, etc. Coolants are used where direct cooling is undesirable or not possible.
Common coolants are sodium chloride (NaCl), calcium chloride salts (CaCl), aqueous solutions of glycols. Due to the high corrosive activity of salt solutions, the cost of repairs during the operation of equipment is significant, therefore, solutions are now increasingly used. polyhydric alcohols such as propylene glycol (PG), ethylene glycol, glycerin, which is typical for systems central air conditioning. When designing and installing systems with glycol coolants, their physical and chemical features should be taken into account. Glycols have a smaller molecular size, which leads to the formation of leaks (especially at low temperatures and high concentrations), if the gasket material is not properly selected in the seals. It is not recommended to use galvanized steel pipes in systems with glycol coolants.
For first aid if a person is affected by a refrigerant, ammonia, valerian drops should be in the first-aid kit, drinking water, Vishnevsky ointment or penicillin ointment, sterile wipes, bandages and cotton wool.
In case of poisoning with freon refrigerants, before the arrival of a doctor, the victim is taken out to Fresh air or in a clean warm room. The victim is allowed to inhale oxygen for 30-40 minutes, warmed with heating pads, allowed to inhale ammonia from a cotton wool and drink strong tea or coffee.
If the mucous membrane is damaged, rinse with a 2% solution of soda or water. In case of contact with eyes, rinse them with plenty of clean water.
Skin contact with refrigerant causes frostbite. The affected areas are moistened with warm water, and then the affected surface is dried and an ointment bandage is applied.
5. ENVIRONMENT AND SAFETY REGULATIONS
Measures for labor protection during the installation and operation of systems and equipment for ventilation, air conditioning,
pneumatic transport and aspiration
Work on the installation of ventilation systems is largely carried out at high altitude. Climbing work is considered to be all installation work that is carried out at a height of more than 5 m from the surface of the ground, ceiling or working platform.
Workers not younger than 18 and not older than 60 years old, who have passed a special medical examination, are allowed to perform steeplejack work.
Safe execution of installation work at height requires the use of reliable ladders, scaffolds, scaffolds, towers, cradles, etc.
When using metal ladders, their height should provide the worker with the opportunity to work standing on the step, being at a distance of at least 1 m from the upper end of the ladder; at the same time, the worker is obliged to fasten with a carabiner of the mounting belt to reliable elements of building structures. The lower ends of the ladders must have stops in the form of sharp spikes or rubber tips, the upper ends must be fixed to solid structures.
When installing air ducts from suspended cradles, workers must be attached with safety belts to an insurance steel rope that has an autonomous suspension. Safety belts PVU-2 are designed for a maximum weight of a falling person of 100 kg and a braking distance of 0.75 ... 1.5 m. the length of the brake cable is 10 m. The brake cable is attached to the safety belt with a working carabiner.
During the installation of air ducts, it is forbidden to be under the air duct being installed, to cross trusses and other building structures while working at height, and also to work without securing with a safety belt. In dangerous places for the transition, it is necessary to fasten with a safety belt to a steel safety cable, specially stretched for this.
During installation, the technological sequence of delivery of air ducts and ventilation equipment to the installation sites and their installation in the design position must be strictly observed, without creating cramped conditions at the workplace.
All lifting equipment, inventory and tools must correspond to the nature of the work performed and be in good condition. Before starting the installation, the foreman or foreman is obliged to check the lifting mechanisms, rigging devices and register the results of the check in a special journal.
Places for installation of lifting equipment, as well as fastening of lever winches, hoists and blocks to building structures must be agreed with the general contractor. Without the permission of the management of the construction organization, these works are not allowed.
When installing lifting devices on ceilings, bases should be arranged to distribute the concentrated load over a large area.
Fitters performing rigging work must be trained according to a special program and have a certificate for the right to perform rigging work.
Slinging of ventilation equipment and fastening of winches, hoists and blocks to building structures should be carried out in accordance with standard technological maps.
BIBLIOGRAPHY
GOST 30494-96. Buildings residential and public. The parameters of the microclimate in the premises.
GOST 12.1.003-83. SSBT Noise. General safety requirements.
ABOK standard. Buildings residential and public. Air exchange standards.
SNiP 23-01-99. Building climatology.
SNiP 23-02-03. Thermal protection of buildings.
SNiP 2.04.05-91* (ed. 2003). Heating, ventilation and air conditioning.
SNiP 2.08.01-89*. Residential buildings.
SNiP II-12-77. Noise protection.
SanPiN 2.1.2.1002-00. Sanitary and epidemiological requirements for residential buildings and premises.
CH 2.2.4/2.18.562-96. Noise at workplaces in residential premises, public buildings and in residential areas.
MGSN 3.01-01. Residential buildings.
MGSN 2.04-97. Permissible levels of noise, vibration and sound insulation requirements in residential and public buildings.
Manual for MGSN 2.04-97. Design of sound insulation of enclosing structures of residential and public buildings.
SNiP 12-03-2001 Occupational safety in construction. Part 1. General requirements.
SNiP 12-04-2002. Labor safety in construction. Part 2. Construction production.
GOST 12.2.003-91. SSBT. Production equipment. General safety requirements.
GOST 12.3.009-76. SSBT. Loading and unloading works. General safety requirements.
GOST 24258-88. Scaffolding tools. General specifications.
PPB 01-03. Fire safety rules in Russian Federation.
Technical information SCS "Stroytechnologist".
Documents of the database "Techexpert".
Electronic text of the document
prepared by CJSC "Kodeks" and verified according to materials,
provided by Ph.D. Demyanov A.A. (VITU)
(Document)
n1.doc
TYPICAL TECHNOLOGICAL CHART (TTK)
PRODUCTION OF WORKS ON INSTALLATION OF METAL AIR DUCTS
INTERNAL VENTILATION SYSTEMS
1 AREA OF USE
1.1. A typical flow sheet (hereinafter referred to as TTK) was developed for a set of works on the installation of metal air ducts internal systems ventilation.
1.2. A typical flow chart is intended for use in the development of Work Production Projects (PPR), Construction Organization Projects (POS), other organizational and technological documentation, as well as to familiarize workers and engineering and technical workers with the rules for the production of installation work.
1.3. The purpose of creating the presented TTC is to give a recommended scheme of the technological process for carrying out installation work, to show the composition and content of the TTC, examples of filling in the necessary tables.
1.4. On the basis of the TTK, as part of the WEP (as mandatory components of the Work Execution Project), Working Flow Charts are developed for the performance of certain types of installation work.
When linking a Typical flow chart to a specific facility and construction conditions, production schemes, scopes of work, labor costs, mechanization tools, materials, equipment, etc. are specified.
1.5. All working technological maps are developed according to the working drawings of the project, regulate the means of technological support and the rules for implementation technological processes during the production of installation work.
1.6. Regulatory framework for the development of technological maps are: SNiP, SN, SP, GESN-2001 ENiR, production norms for the consumption of materials, progressive local norms and prices, norms for labor costs, norms for the consumption of material and technical resources.
1.7. Working technological maps are considered and approved as part of the PPR by the head of the General Contracting Construction and Installation Organization, in agreement with the Customer's organization, the Customer's Technical Supervision and the organizations that will be in charge of the operation of this building, structure.
1.8. The use of TTK helps to improve the organization of production, increase labor productivity and its scientific organization, reduce costs, improve quality and reduce the duration of construction, safe performance of work, organization of rhythmic work, rational use labor resources and machines, as well as reducing the time for the development of PPR and the unification of technological solutions.
1.9. The scope of work sequentially performed during the installation of the supply ventilation system includes:
Collection of manufactured ventilation parts;
Installation of the ventilation system according to the design scheme;
Commissioning of the ventilation system.
1.10. Ventilation - controlled air exchange in the premises serves mainly to create air conditions favorable for human health, meeting the requirements of the technological process, preserving the equipment and building structures of the building, storing materials and products.
1.11. A person, depending on the type of activity (energy costs), releases heat (100 kcal / hour or more), water vapor (40-70 g / hour) and carbon dioxide (23-45 l / hour) into the surrounding air; production processes can be accompanied by immeasurably large emissions of heat, water vapor, harmful fumes, gases and dust. As a result, the air in the room loses its hygienic qualities that are favorable for the well-being, health and performance of a person.
Hygienic requirements for ventilation are reduced to maintaining certain meteorological conditions of air (temperature, humidity and mobility) and its purity.
1.12. The essence of ventilation is as follows: the supply air is mixed with the room air and as a result of the heat exchange or mass transfer that occurs in the room, the specified air parameters are created.
1.13. Work should be carried out in accordance with the requirements of the following normative documents:
SNiP 3.01.01-85*. Organization of construction production;
SNiP 3.05.01-85. Internal sanitary systems;
SNiP 3.05.05-84. Technological equipment and technological pipelines;
SNiP 12-03-2001. Labor safety in construction. Part 1. General requirements;
SNiP 12-04-2002. Labor safety in construction. Part 2. Construction production.
2. ORGANIZATION AND TECHNOLOGY OF WORK PERFORMANCE
2.1. In accordance with SNiP 3.01.01-85* "Organization of construction production", before the start of construction and installation (including preparatory) work at the facility, the General Contractor is obliged to obtain permission from the Customer to perform installation work in the prescribed manner. The basis for the start of work can be the Certificate of Examination of Hidden Works to Prepare the Premises for Installation of Ventilation.
2.2. The installation of ventilation systems is carried out in accordance with the requirements of SNiP, the Detailed Design, the Project for the production of works and the instructions of the equipment manufacturers. Replacement of materials and equipment provided for by the project is allowed only upon agreement with the design organization and the customer.
2.3. The requirements for the installation of ventilation systems are reduced to ensuring that the design parameters of the air environment in ventilated rooms are provided. This is achieved by maximum sealing of air duct systems and equipment, the necessary sound insulation, proper conditions for the operation, repair and replacement of equipment.
Reducing the time for performing installation and assembly work, while maintaining their high quality, is achieved with high industrialization of work, which consists in the use of standard sections of ventilation chambers, blocks and air duct assemblies (shaped parts - diffuser, confuser, elbows, tees, crosses; control devices - valves gates, throttling devices; fasteners; hangers; brackets; brackets; flanges) prefabricated or made in workshops with appropriate mechanical equipment. On site, as a rule, only manufactured parts are assembled, using mechanisms for moving workpieces and ventilation equipment.
2.4. Prior to the installation of ventilation systems, the following works must be fully completed and accepted by the customer:
Installation of interfloor ceilings, walls and partitions;
Construction of foundations or platforms for the installation of fans, air conditioners and other ventilation equipment;
Building structures of ventilation chambers of supply systems;
Waterproofing work at the installation sites of air conditioners, supply ventilation chambers, wet filters;
Installation of floors (or appropriate preparation) at the places of installation of fans on spring vibration isolators, as well as "floating" bases for the installation of ventilation equipment;
Arrangement of supports for the installation of roof fans, exhaust shafts and deflectors on the roofs of buildings;
Preparation of openings in walls, partitions, ceilings and coatings necessary for laying air ducts;
Construction of foundations, foundations and platforms for the installation of ventilation equipment;
Drawing on the internal and external walls of all premises of auxiliary marks equal to the design marks of the finished floor plus 500 mm;
Plastering (or cladding) the surfaces of walls and niches in places where air ducts are laid;
Mounting openings in walls and ceilings were prepared for the supply of large-sized equipment and air ducts, and crane beams were installed in the ventilation chambers;
Installed in accordance with working documentation embedded parts in building structures for fixing equipment and air ducts;
It is possible to turn on power tools, as well as electric welding machines at a distance of no more than 50 m from one another;
Glazed window openings in external fences, insulated entrances and openings;
Measures have been taken to ensure the safe production of installation work.
Acceptance of the object for installation must be carried out by employees of the installation organization according to the act.
2.5. When accepting an object for installation, the following must be checked:
compliance with all requirements of SNiP and current technical specifications;
availability and correct execution of acts for hidden work;
geometric dimensions and binding to building structures of foundations for ventilation equipment and air conditioners, supporting structures on the roof of the building for installing roof fans and deflectors, openings for the passage of air ducts, mounting openings;
correct installation of embedded parts;
the device of protections of apertures, floorings and canopies.
2.6. Loading blanks on vehicles at procurement enterprises should be carried out by the enterprise, unloading at the facility - by the assembly site.
2.7. When transporting air ducts, depending on their type and dimensions, the following should be provided:
for air ducts of small sections - containerization or packaging;
for air ducts of large sections - telescopic installation;
for semi-finished products - special packaging.
2.8. Loading and unloading and rigging work at the facilities is recommended to be carried out with the maximum use of mechanization tools with the help of workers who are part of the assembly teams.
2.9. Persons at least 18 years of age who have undergone special training in the rigging program and received the appropriate certificate are allowed to work on lifting and moving loads.
2.10. Winches, forklifts, truck cranes, pneumatic wheeled and caterpillar jib cranes, tower and gantry cranes should be used as mechanized lifting equipment at facilities.
2.11. Slinging of air ducts and ventilation equipment is recommended to be carried out with inventory lifting equipment.
Slings should be selected depending on the type, weight of the lifted load and the method of slinging. The most common slings are shown in Fig. 1.
Fig.1. Slings
but- lightweight sling with loops; b- lightweight sling with hooks;
in- four-branch sling
2.12. The load to be lifted should be kept from rotation by guys made of hemp ropes with a diameter of 20-25 mm or guys made of steel ropes with a diameter of 8-12 mm. For horizontal elements of ventilation systems (enlarged air duct assemblies), two braces should be used, for vertical elements (sections of air conditioners, roof fans, air ducts, etc.) - one.
The most common slinging methods are shown in Figure 2-24.
Fig.2. Slinging VPA-40
Fig.3. Slinging of autonomous air conditioner KTR-1-2.0-0.46
Fig.4. Slinging of radial (centrifugal) fans, version N 1
Fig.5. Slinging of fans Ts4-70 N 6-8 version N 1
Fig.6. Slinging of fans Ts4-70 N 6-8 version N 6
Fig.7. Slinging fans Ts4-70 N 10, 12.5
Fig.8. Slinging of the upper part of the fan casing Ts4-76 N 16, 20
Fig.9. Slinging of the lower part of the fan casing Ts4-76 N 16, 20
Fig.10. Slinging of the shaft with the fan frame Ts4-76 N 16, 20
Fig.11. Axial fan slinging
Fig.12. Axial fan slinging
Fig.13. Slinging fan VKR-6,3.30.45.6.01
Fig.14. Slinging air-thermal curtain A6.3 STD 729.00.00.001
Fig.15. Scrubber sling
Fig.16. Slinging cyclone type TsN
Fig.17. Slinging packing of the irrigation chamber OKF
Fig.18. Slinging of the packaging of the ventilation unit drive
Fig.19. Slinging of the wheel packaging and guide vane in the casing
Fig.20. Slinging packaging air filter FR-3
Fig.21. Valve Packing Slinging
Fig.22. Slinging the packaging of KO and VK chambers
Fig.23. Air duct slinging
Fig.24. Slinging of an enlarged unit lifted in a vertical position
2.13. The method of installation of air ducts should be chosen depending on their position (horizontal, vertical), placement relative to structures (inside or outside the building, near the wall, near columns, in the inter-farm space, in the shaft, on the roof of the building) and the nature of the building (single or multi-storey , industrial, public, etc.).
2.14. As shaped parts of a complex geometric shape, as well as for connecting ventilation equipment, air distributors, silencers and other devices located in false ceilings, chambers, etc., flexible air ducts made of fiberglass SPL, metal fabric, aluminum foil, etc. should be used. The use of flexible air ducts as straight links is not allowed.
In order to reduce aerodynamic drag, flexible hose parts must have a minimum compression ratio in the assembled position.
2.15. Installation of metal air ducts should be carried out, as a rule, in enlarged blocks in the following sequence:
marking of places for installation of means of fastening air ducts;
installation of fasteners;
coordination with builders of locations and methods of fastening lifting equipment;
delivery to the place of installation of air duct parts;
checking the completeness and quality of the delivered parts of the air ducts;
assembly of air duct parts into enlarged blocks;
installation of the block in the design position and fixing it;
installation of plugs at the upper ends of vertical air ducts located at a height of up to 1.5 m from the floor.
2.16. The length of the unit is determined by the cross-sectional dimensions and type of air duct connection, installation conditions and the availability of lifting equipment.
The length of enlarged blocks of horizontal air ducts connected on flanges should not exceed 20 m.
2.17. Organization charts working area when installing air ducts are given in Fig.25-28.
Fig.25. Scheme of the organization of the working area during the installation of air ducts according to outer wall building
1
- console with block; 2
- winch; 3
- auto-hydraulic lift; 4
- traverse; 5
- guy; 6
- block
Fig.26. Scheme of the organization of the working area during the installation of horizontal air ducts in the building
1
- winch; 2
- traverse; 3
4
- pendants
Fig.27. Scheme of the organization of the working area during the installation of horizontal air ducts on a flyover
1
- enlarged air duct assembly; 2
- traverse; 3
- truck crane; 4
- auto-hydraulic lift
Fig.28. Scheme of the organization of the working area during the installation of vertical air ducts along the outer wall of the building
1
- enlarged air duct assembly; 2
- semi-automatic sling; 3
- winch;
4 - block; 5 - console; 6 - brackets; 7 - stretching
2.18. During the installation of air ducts, step-by-step control should be carried out in accordance with the Operational Control Card.
Card of operational control of installation of metal air ducts
Table 1
| Technological process | Controlled indicators | Measuring tool | Type of control |
| Delivery of air duct parts to the installation site | Checking the completeness of the ventilation system (presence of control devices, fasteners, etc.) | - | Permanent 100%. Visually. Compliance with the picking list, sketches |
| Marking the places of installation of means of fastening air ducts | Fastening installation step in accordance with SNiP 3.05.01-85 | Roulette 10 m Plumb 200 g | Permanent 100% |
| Drilling holes in building structures | drilling depth | steel meter | Permanent 100% |
| Installation of fasteners | Mounting strength | - | Permanent 100%. Visually |
| Assembly into enlarged units of parts of air ducts, regulating and air distribution Devices on site | Correct assembly in accordance with the project. Tightness of connections | - | Visually. Permanent 100% |
| Rise to the design level and interconnection of enlarged air duct assemblies with preliminary fixing | The position of transverse seams and detachable connections of air ducts relative to building structures. Verticality of risers. Absence of kinks, curvature in straight sections of air ducts | Plumb 200 g | Visually. Permanent 100% |
| Alignment of mounted air ducts and their final fixing | Horizontal installation of air ducts and observance of slopes in the distributing sections of air ducts. Density of coverage of the duct by clamps. Reliability and appearance mounts | Metal meter, tape measure 10 m, level 300 mm | Permanent 100%. Visually |
| Connecting air ducts to ventilation equipment | Correct installation of soft inserts (no sagging) | - | Permanent 100%. Visually |
| Testing the operation of control devices | Smooth operation of control devices | Output 100%. Visually |
2.19. Fans must be installed in the following sequence:
acceptance of ventilation chambers;
delivery of the fan or its individual parts to the place of installation;
installation of lifting equipment;
slinging of the fan or individual parts;
lifting and horizontal movement of the fan to the installation site;
fan installation (fan assembly) on supporting structures (foundation, platform, brackets);
checking the correct installation and assembly of the fan;
fixing the fan to the supporting structures;
fan operation check.
2.20. During the installation of fans, step-by-step control must be carried out in accordance with the Operational Control Cards.
Operational control card for installation of centrifugal fans
table 2
| Technological process | Controlled indicators | Measuring tool | Type of control |
| Delivery of the fan unit to the installation site | Checking the availability and quality of components | - | |
| Installing the frame on stands. Installation of vibration isolators under the frame | Horizontal foundation, frames | Level 300 mm | Permanent 100% |
| Installation of fans on a frame with vibration isolators | Pulley verticality, shaft horizontality | Plumb 200 g | Permanent 100% |
| Assembly of fans on the frame: Installing the fan base Installing the lower part of the fan shroud Turbine installation with its frame fastened to the frame Setting the input branch pipe | Fastening strength. Gap between the edge of the front disc of the impeller and the edge of the inlet pipe. Fastening strength | - Ruler | Visually. Permanent 100% |
| Installation of the upper part of the casing and connection on the flanges of the individual parts of the fan casing | Connection tightness | - | Visually. Permanent 100% |
| Adjustment and final mounting of vibration isolators on the frame | Uniformity of settlement of vibration isolators. Strength of fastening of vibration isolators to the frame | - | Visually. Permanent 100% |
| Turbine balancing before start-up | Correct position of the turbine wheel | - | Permanent 100%. (when scrolling, the risks should not match) |
| Mounting the sled and motor on the sled | Parallelism of the sled. The strength of the fastening of the electric motor to the sled. The strength of the connection between the electric motor and the fan. Parallelism of the axes of the fan and motor shafts. Ease of rotation of the fan and motor shafts | Level 300 mm Cord | Constant one hundred%. Visually |
| Installing the belt drive on the pulleys. Belt guard | The alignment of the grooves for the V-belts of the fan pulleys and the electric motor. Correct belt tension | Cord (cord tension in the plane of the ends of the pulleys), steel meter, testing by hand | Permanent 100% |
| Connection of air ducts to the fan with installation of flexible connectors | Tightness of connections. No sag in flexible connectors | - | Visually. Permanent 100% |
Installation operational control card axial fans
Table 3
| Technological process | Controlled indicators | Measuring tool | Type of control |
| | Quality (lack of mechanical damage), completeness | - | Permanent 100%. Visually, compliance with the passport data of the fan and electric motor |
| Installing the fan unit on metal brackets. Fan mount | Strength of supporting structures. The strength of the fan attachment to the supporting structures. vertical, horizontal | plumb line | Visually. Permanent 100% |
| Checking fan operation | The gap between the ends of the blades and shells. Correct direction and ease of rotation of the impeller | Ruler | Permanent 100%. Visual, hand-tested |
Operational control card for installation of roof fans
Table 4
| Supply of a fan complete with an electric motor to the installation site | Completeness, quality (lack of mechanical damage) | - | Permanent 100%. Visually, compliance with the passport data of the fan and electric motor |
| Checking the levelness of the bowl support flange | Horizontal | Level 300 mm | Permanent 100% |
| Connecting the self-opening damper to the fan | Ease of valve movement | - | Permanent 100%. Visual, hand-tested |
| Installing the fan housing on the glass with its fastening with anchor bolts | The strength of the fan attachment to the supporting structures. shaft verticality. Ease of rotation of the fan and motor shafts. Gap between inlet pipe and impeller | plumb line | Permanent 100%. Visually Testing by hand |
| Checking fan operation | Correct direction of wheel rotation | - | Permanent 100%. Visually (according to the project) |
2.21. After completion of the installation of ventilation and air conditioning systems, pre-start individual and complex tests are carried out, which should be carried out in accordance with the requirements of SNiP 3.05.01-85 and SNiP 3.05.05-84.
Participation of representatives of the ventilation, electrical installation organizations and the customer in individual tests is mandatory and is made out by the corresponding entries in the "Journal of applications for scrolling the electric drive together with the mechanism".
Individual tests of ventilation equipment in idle mode are carried out by the installation organization under the guidance of an engineering and technical worker allocated for this purpose.
For individual testing of ventilation equipment, the customer appoints a responsible person authorized to give orders for the supply and removal of voltage from electrical installations. The start of electric motors when testing ventilation and air conditioning systems is carried out by a representative of the electrical installation organization.
Comprehensive testing of equipment is carried out by the customer with the participation of representatives of design and construction contractors. Mounting specialized organizations, together with the operating personnel, provide round-the-clock duty to monitor the operation and proper operation of the equipment.
Individual tests of ventilation and air conditioning systems are allowed only after complete assembly and installation of ventilation equipment, installation of guards for moving parts, checking the condition of the electrical wiring, grounding and correct connection of the power supply.
Before starting a comprehensive test and adjustment of the ventilation and air conditioning system, it is necessary to make sure that there are no people in the air conditioners and supply chambers, and also to remove all foreign objects and tools from air ducts, filters, cyclones.
If during the production of pre-start tests of ventilation and air conditioning systems, extraneous noise or equipment vibration exceeding the permissible level is detected, the tests should be stopped immediately.
After disconnecting the ventilation equipment from the power supply, it is impossible to climb and go inside the air ducts, bunkers and shelters until the equipment stops completely.
After completion of pre-start tests and adjustment, as well as during breaks (completion of work, lunch), the ventilation equipment must be disconnected from the power supply.
A typical technological map for the installation of ventilation is compiled for forced ventilation systems, which include a network of air ducts. Its main purpose is to familiarize workers and engineers with how installation work should proceed. ventilation ducts, assistance in the location of equipment inside the premises, the correct distribution of technological processes that will continue to take place in production, and so on.
How to properly install ventilation ducts
Most of the work in the installation of air conditioning and ventilation systems is the installation of ventilation ducts.
Industrial ventilation
And this is not strange, because they are located inside the entire building, if the room is used for industrial purposes, then this is also a large size, plus often it is necessary to carry out installation at a high height, and this greatly complicates the matter. As a result, it is necessary to resort to the help of special machines and equipment. Most often, these are self-propelled cranes, mobile assembly platforms, auto-hydraulic lifts, and so on.
The complexity of installation is influenced by many factors:
- The complexity of the designed system;
- Features of the building design;
- environmental conditions, etc.
To simplify the technological process of installing air ducts, units consisting of straight sections are prefabricated ventilation pipes and shaped parts. After installing each node, you need to check the data that the technological map for the installation of ventilation carries.
Stages of installation of horizontal metal ventilation ducts
To qualitatively establish a network of ventilation ducts, you need to adhere to a certain algorithm of actions.
Fastening
The fasteners are installed first. This is done by welding them to embedded parts or using a special mounting gun. The places where lifting mechanisms will be located are outlined, scaffolding, towers and so on are being prepared. On inventory stands, small parts are assembled into knots, knots are made on the floor from large ventilation ducts. Clamps and other fasteners are installed.
When the intermediate preparation is over, the knots are trailed, guy ropes are tied at the ends of the knots.
The preparatory work is over, you can begin installation. With the help of special lifting mechanisms, the nodes are brought to the previously marked places and suspended from the mounts. It remains, using the flange, to attach part of the system to the previously mounted node.
There are other options for installing air ducts. The method is selected depending on their position in space, the characteristics of the industrial facility, environmental conditions, the location of the air ducts (inside or outside the building), and so on.
If the ventilation system includes air conditioning and air heating, then it should be designed in accordance with all paragraphs of SNiP 2.04.05-91, while foreseeing the possibility of breakdown and repair, and regulatory requirements.
Basic mounting positions
It is important to correctly position the ventilation ducts in relation to building structures. For this, special recommendations have been developed to properly fix round and rectangular air ducts. The main recommendations and dimensions are given below.
The axes of the ventilation pipes are placed parallel to the planes next to which they are mounted. It is necessary to correctly select the distance (accepted in millimeters) from the plane of the wall (ceiling, floor) to the axis of the pipe. If circular ducts are used: L=0.51Dmax+50, where Dmax is the largest diameter of the duct, including the insulator.
ventilation ducts
In the case of using channels with a rectangular cross section, the formula looks like this: L=0.5bmax+x, where bmax is the maximum width of the channel; x - the distance between the outer surface of the pipe and the wall must be at least 5 cm.
It is accepted that for pipes with a width of 10 to 40 cm x = 10 cm, 40 ... 80 cm x = 20 cm, 80 ... 150 cm x = 40 cm. The distance from the axis of the channel to the electrical wire is also important. Round air ducts: L=0.5Dmax+300. Rectangular section: L=0.5bmax+300.
If two ventilation branches run in parallel, then the following minimum distance between their axes is observed. Round section: L=0.5(Dmax+D’max)+250. Rectangular section: L=0.5(bmax+b’max)+x.
In the case when the ventilation pipes are mounted under the ceiling, you must also observe the minimum distance to it. Round section: L=0.5Dmax+100. Rectangular: L=0.5bmax+x. If air ducts pass through building structures, then a distance of 10 centimeters should be observed.
Connecting air ducts
The network of ventilation ducts consists of separate small parts, which are interconnected using bandages, rails, slats, bell-shaped and other connections.
Air line details
To properly fix the ventilation pipes, use the working documentation and the relevant requirements. If flangeless connections are used in the process of fixing, then the following distances between them are adhered to:
- When using pipes with a diameter of less than 400 mm, the distance should be no more than 4 meters;
- If the diameter is 400 mm or more, then the distance becomes up to 3 meters.
When installing air ducts in a horizontal position with a circular section with a diameter of up to 2000 mm or a rectangular one with a side of up to 2000 mm, the distance between the fasteners is assumed to be no more than 6 meters.
If the pipes are installed in a vertical position, then the distance between the fasteners is up to 4 meters.
Installation design
Before installing the ventilation line, it is necessary to correctly make the installation design. It consists of several main steps.
Axonometric diagram
At the first stage, an axonometric diagram of the system is drawn, then the network of air channels is divided into individual parts. Next, you should choose a method for connecting small components to each other and to larger nodes. The places where the fasteners will be located in the future are determined. Sketches of non-standard parts are also made, where all the necessary dimensions for their manufacture are indicated. And at the end, documents for installation design are drawn up:
- Drawings of non-standard parts;
- Axonometric diagram;
- Packing lists.
Depending on the region where the installation of the ventilation system takes place, the kit will also depend required documents. But those three that were listed above will always be present.
Installation of air ducts at an industrial facility
ROUTING
INSTALLATION OF INTERNAL VENTILATION SYSTEMS
1 AREA OF USE
1 AREA OF USE
1.1. The technological map was developed for a set of works on the installation of metal air ducts for internal ventilation systems in public premises.
On the basis of this technological map, technological maps can be developed for the installation of metal air ducts for internal ventilation systems in office premises, offices with various design solutions in relation to specific planning conditions. The technological map under consideration can be tied to a specific object and take into account the accepted design dimensions. At the same time, production schemes, scopes of work, labor costs, mechanization means, materials, equipment, etc. are specified. All technological maps are developed according to the working drawings of the project and regulate the means of technological support, the rules for the implementation of technological processes during the construction, reconstruction of buildings and structures, and the installation of engineering networks.
1.2. For binding or when developing technological maps, the following documents are required as initial data:
- working drawings of the ventilation system;
- architectural and construction drawings and floor plans of buildings;
- building codes and regulations (SNiP, VSN, SP);
- instructions, standards, factory instructions and specifications (TS) for the main materials used (wires, cables, ventilation ducts, air ducts, fittings, etc.);
- unified norms and prices for the installation of ventilation in premises (ENiR, GESN-2001);
- production norms for the consumption of materials (NPRM);
- progressive norms and prices, maps of the organization of labor and labor processes used in the installation of ventilation systems for buildings and structures.
2. GENERAL PROVISIONS
2.1. The normative base for the development of technological maps for ventilation are: SNiP, SN, SP, GESN-2001 ENiR, production norms for the consumption of materials, progressive local norms and prices, norms for labor costs, norms for the consumption of material and technical resources.
2.2. The scope of work sequentially performed during the installation of the supply ventilation system includes:
- collection of manufactured ventilation parts;
- installation of the ventilation system according to the design scheme;
- commissioning of the ventilation system.
2.3. Ventilation - controlled air exchange in the premises serves mainly to create air conditions favorable for human health, meeting the requirements of the technological process, preserving the equipment and building structures of the building, storing materials and products.
A person, depending on the type of activity (energy costs), releases heat (100 kcal / hour or more), water vapor (40-70 g / hour) and carbon dioxide (23-45 l / hour) into the surrounding air; production processes can be accompanied by immeasurably large emissions of heat, water vapor, harmful fumes, gases and dust. As a result, the air in the room loses its hygienic qualities that are favorable for the well-being, health and performance of a person.
Hygienic requirements for ventilation are reduced to maintaining certain meteorological conditions of air (temperature, humidity and mobility) and its purity.
The essence of ventilation is as follows: the supply air is mixed with the room air and as a result of the heat exchange or mass transfer that occurs in the room, the specified air parameters are created.
Work on the installation of ventilation should be carried out, guided by the requirements of the following regulatory documents:
SNiP 3.01.01-85* "Organization of construction production";
________________
* SNiP 3.01.01-85 is not valid. SNiP 12-01-2004 "Organization of construction" is valid hereinafter. - Database manufacturer's note.
SNiP 3.05.01-85* "Internal sanitary systems";
________________
* SNiP 3.05.01-85 is not valid. SP 73.13330.2012 "Internal sanitary systems of buildings. Updated version of SNiP 3.05.01-85" is in force hereinafter. - Database manufacturer's note.
SNiP 3.05.05-84 "Technological equipment and technological pipelines";
SNiP 12-03-2001 "Labor safety in construction. Part 1. General requirements";
SNiP 12-04-2002 "Labor safety in construction. Part 2. Construction production";
SNiP 41-01-2003 "Heating, ventilation, air conditioning";
SP 7.13130.2009 "Heating, ventilation and air conditioning. Fire requirements";
________________
* SP 7.13130.2009 was declared invalid from February 25, 2013 with the entry into force of SP 7.13130.2013 (Order of the EMERCOM of Russia dated February 21, 2013 N 116
SP 60.13330.2012 "Heating, ventilation and air conditioning";
SP 73.13330.2012 "Internal sanitary systems of buildings";
SP 131.13330.2012 "Construction climatology";
GOST 12.1.005-88 SSBT. "General sanitary and hygienic requirements for the air of the working area".
3. ORGANIZATION AND TECHNOLOGY OF WORK PERFORMANCE
3.1. In accordance with SNiP 3.01.01-85* "Organization of construction production", before the start of construction and installation (including preparatory) work at the facility, the General Contractor is obliged to obtain permission from the Customer to perform installation work in the prescribed manner. The basis for the start of work can be the Certificate of Examination of Hidden Works to Prepare the Premises for Installation of Ventilation.
3.2. The installation of ventilation systems is carried out in accordance with the requirements of SNiP, the Detailed Design, the Project for the production of works and the instructions of the equipment manufacturers. Replacement of materials and equipment provided for by the project is allowed only upon agreement with the design organization and the customer.
3.3. The requirements for the installation of ventilation systems are reduced to ensuring that the design parameters of the air environment in ventilated rooms are provided. This is achieved by maximum sealing of air duct systems and equipment, the necessary sound insulation, proper conditions for the operation, repair and replacement of equipment.
Reducing the time for performing installation and assembly work, while maintaining their high quality, is achieved with high industrialization of work, which consists in the use of standard sections of ventilation chambers, blocks and air duct assemblies (shaped parts - diffuser, confuser, elbows, tees, crosses; control devices - valves gates, throttling devices; fasteners; hangers; brackets; brackets; flanges) prefabricated or made in workshops with appropriate mechanical equipment. On site, as a rule, only manufactured parts are assembled, using mechanisms for moving workpieces and ventilation equipment.
3.4. Prior to the installation of ventilation systems, the following works must be fully completed and accepted by the customer:
- installation of interfloor ceilings, walls and partitions;
- arrangement of foundations or platforms for the installation of fans, air conditioners and other ventilation equipment;
- building structures of ventilation chambers of supply systems;
- waterproofing works in places of installation of air conditioners, supply ventilation chambers, wet filters;
- arrangement of floors (or appropriate preparation) at the places of installation of fans on spring vibration isolators, as well as "floating" bases for the installation of ventilation equipment;
- arrangement of supports for installation of roof fans, exhaust shafts and deflectors on the roofs of buildings;
- preparation of openings in walls, partitions, ceilings and coatings necessary for laying air ducts;
- arrangement of foundations, foundations and platforms for the installation of ventilation equipment;
- application of auxiliary marks on the internal and external walls of all premises equal to the design marks of the clean floor plus 500 mm;
- plastering (or cladding) of the surfaces of walls and niches in places where air ducts are laid;
- installation openings in walls and ceilings were prepared for the supply of large-sized equipment and air ducts, and crane beams were installed in the ventilation chambers;
- installed in accordance with the working documentation, embedded parts in building structures for fastening equipment and air ducts;
- it is possible to turn on power tools, as well as electric welding machines at a distance of no more than 50 m from one another;
- glazed window openings in external fences, insulated entrances and openings;
- measures have been taken to ensure the safe production of installation work.
Acceptance of the object for installation must be carried out by employees of the installation organization according to the act.
3.5. When accepting an object for installation, the following must be checked:
compliance with all requirements of SNiP and current technical specifications;
availability and correct execution of acts for hidden work;
geometric dimensions and binding to building structures of foundations for ventilation equipment and air conditioners, supporting structures on the roof of the building for installing roof fans and deflectors, openings for the passage of air ducts, mounting openings;
correct installation of embedded parts;
the device of protections of apertures, floorings and canopies.
3.6. Loading blanks on vehicles at procurement enterprises should be carried out by the enterprise, unloading at the facility - by the assembly site.
3.7. When transporting air ducts, depending on their type and dimensions, the following should be provided:
for air ducts of small sections - containerization or packaging;
for air ducts of large sections - telescopic installation;
for semi-finished products - special packaging.
3.8. Loading and unloading and rigging work at the facilities is recommended to be carried out with the maximum use of mechanization tools with the help of workers who are part of the assembly teams.
3.9. Persons at least 18 years of age who have undergone special training in the rigging program and received the appropriate certificate are allowed to work on lifting and moving loads.
3.10. Winches, forklifts, truck cranes, pneumatic wheeled and caterpillar jib cranes, tower and gantry cranes should be used as mechanized lifting equipment at facilities.
3.11. Slinging of air ducts and ventilation equipment is recommended to be carried out with inventory lifting equipment.
Slings should be selected depending on the type, weight of the lifted load and the method of slinging. The most common slings are shown in Fig. 1.
Fig.1. Slings
but- lightweight sling with loops; b- lightweight sling with hooks; in- four-branch sling
3.12. The load to be lifted should be kept from rotation by guys made of hemp ropes with a diameter of 20-25 mm or guys made of steel ropes with a diameter of 8-12 mm. For horizontal elements of ventilation systems (enlarged air duct assemblies), two braces should be used, for vertical elements (sections of air conditioners, roof fans, air ducts, etc.) - one.
The most common slinging methods are shown in Table 1.
Slinging methods
Table 1
|
Name |
||
|
Slinging VPA-40 |
||
|
Slinging of autonomous air conditioner KTR-1-2.0-0.46 |
||
|
Slinging of fans Ts4-70 N 6-8 version N 1 |
||
|
Slinging fans Ts4-70 N 10, 12.5 |
||
|
Slinging of the lower part of the fan casing Ts4-76 N 16, 20 |
||
|
Slinging packing of the irrigation chamber OKF |
||
|
Slinging of the wheel packaging and guide vane in the casing |
||
|
Slinging packaging air filter FR-3 |
||
|
Valve Packing Slinging |
||
|
Slinging the packaging of KO and VK chambers |
||
|
Air duct slinging |
||
|
Slinging of an enlarged unit lifted in a vertical position |
3.13. The method of installation of air ducts should be chosen depending on their position (horizontal, vertical), placement relative to structures (inside or outside the building, near the wall, near columns, in the inter-farm space, in the shaft, on the roof of the building) and the nature of the building (single or multi-storey , industrial, public, etc.).
3.14. As fittings of complex geometric shapes, as well as for connecting ventilation equipment, air distributors, noise suppressors and other devices located in false ceilings, chambers, etc., flexible air ducts made of SPL fiberglass, metal fabric, aluminum foil, etc. should be used. flexible ducts as straight links are not allowed.
In order to reduce aerodynamic drag, flexible hose parts must have a minimum compression ratio in the assembled position.
3.15. Installation of metal air ducts should be carried out, as a rule, in enlarged blocks in the following sequence:
marking of places for installation of means of fastening air ducts;
installation of fasteners;
coordination with builders of locations and methods of fastening lifting equipment;
installation of lifting equipment;
delivery to the place of installation of air duct parts;
checking the completeness and quality of the delivered parts of the air ducts;
assembly of air duct parts into enlarged blocks;
installation of the block in the design position and fixing it;
installation of plugs at the upper ends of vertical air ducts located at a height of up to 1.5 m from the floor.
3.16. The length of the unit is determined by the cross-sectional dimensions and type of air duct connection, installation conditions and the availability of lifting equipment.
The length of enlarged blocks of horizontal air ducts connected on flanges should not exceed 20 m.
3.17. Schemes of the organization of the working area during the installation of air ducts are given in Fig. 2-5.
Fig.2. Scheme of the organization of the working area when installing air ducts along the outer wall of the building
1 - console with block; 2 - winch; 3 - auto-hydraulic lift; 4 - traverse; 5 - guy; 6 - block
Fig.3. Scheme of the organization of the working area during the installation of horizontal air ducts in the building
1 - winch; 2 - traverse; 3 - enlarged air duct assembly; 4 - pendants
Fig.4. Scheme of the organization of the working area during the installation of horizontal air ducts on a flyover
1 - enlarged air duct assembly; 2 - traverse; 3 - truck crane; 4 - auto-hydraulic lift
Fig.5. Scheme of the organization of the working area during the installation of vertical air ducts along the outer wall of the building
1 - enlarged air duct assembly; 2 - semi-automatic sling; 3 - winch; 4 - block; 5 - console; 6 - brackets; 7 - stretching
3.18. During the installation of air ducts, step-by-step control should be carried out in accordance with the Operational Control Card.
3.19. After completion of the installation of ventilation and air conditioning systems, pre-start individual and integrated tests are carried out, which should be carried out in accordance with the requirements of SNiP 3.05.01-85 and SNiP 3.05.05-84.
The participation of representatives of the ventilation, electrical installation organizations and the customer in individual tests is mandatory and is made out by appropriate entries in the "Journal of applications for scrolling the electric drive together with the mechanism".
Individual tests of ventilation equipment in idle mode are carried out by the installation organization under the guidance of an engineering and technical worker allocated for this purpose.
For individual testing of ventilation equipment, the customer appoints a responsible person authorized to give orders for the supply and removal of voltage from electrical installations. The start of electric motors when testing ventilation and air conditioning systems is carried out by a representative of the electrical installation organization.
Comprehensive testing of equipment is carried out by the customer with the participation of representatives of design and construction contractors. Mounting specialized organizations, together with the operating personnel, provide round-the-clock duty to monitor the operation and proper operation of the equipment.
Individual tests of ventilation and air conditioning systems are allowed only after complete assembly and installation of ventilation equipment, installation of guards for moving parts, checking the condition of the electrical wiring, grounding and correct connection of the power supply.
Before starting a comprehensive test and adjustment of the ventilation and air conditioning system, it is necessary to make sure that there are no people in the air conditioners and supply chambers, and also to remove all foreign objects and tools from air ducts, filters, cyclones.
If during the production of pre-start tests of ventilation and air conditioning systems, extraneous noise or equipment vibration exceeding the permissible level is detected, the tests should be stopped immediately.
After disconnecting the ventilation equipment from the power supply, it is impossible to climb and go inside the air ducts, bunkers and shelters until the equipment stops completely.
After completion of pre-start tests and adjustment, as well as during breaks (completion of work, lunch), the ventilation equipment must be disconnected from the power supply.
4. REQUIREMENTS FOR QUALITY AND ACCEPTANCE OF WORKS
4.1. At all stages of work, it is necessary to carry out production quality control of construction and installation works, which includes incoming control of working documentation, structures, products, materials and equipment, operational control of individual construction processes or production operations and acceptance control of intermediate and final work cycles. The composition of controlled indicators, the scope and methods of control must comply with the requirements of SNiP.
4.2. Quality control of construction and installation works should be carried out by specialists or special services equipped with technical means that ensure the necessary reliability and completeness of control. During the input control of working documentation, its completeness and sufficiency of the technical information contained in it for the performance of work should be checked. During the incoming inspection of building structures, products, materials and equipment, their compliance with the requirements of standards or other regulatory documents and working documentation, as well as the presence and content of passports, certificates and other accompanying documents, should be checked by external inspection. The results of the input control are recorded in the Logbook of the results of the input control in the form: GOST 24297-87 *, Appendix 1, to print the original form, see the Logbook of the results of the input control.
________________
* GOST 24297-87 was canceled on the territory of the Russian Federation from 01/01/2014 with the entry into force of GOST 24297-2013 (Order of Rosstandart dated 08/26/2013 N 544-st). - Database manufacturer's note.
4.3. Operational control is carried out in the course of construction processes or production operations in order to ensure the timely detection of defects and the adoption of measures to eliminate and prevent them:
4.3.1. The quality of work performance is ensured by the fulfillment of the requirements of the technical conditions for the production of work, compliance with the necessary technical sequence in the performance of interrelated work, and technical control over the progress of work.
4.3.2. During operational control, it is necessary to check compliance with the technology for performing construction and installation processes specified in the work production projects; compliance of work performed with working drawings, building codes and regulations. Special attention it is necessary to pay attention to the implementation of special measures during construction on subsiding soils, in areas with landslides and karst phenomena, permafrost, as well as in the construction of complex and unique objects.
4.4. Control and assessment of the quality of work during the installation of the ventilation system is carried out in accordance with the requirements of regulatory documents:
SNiP 3.01.01-85*. Organization of construction production;
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TYPICAL TECHNOLOGICAL CARD FOR INSTALLATION OF VENTILATION AND AIR CONDITIONING SYSTEMS
INSTALLATION OF AIR DUCTS
1 AREA OF USE
1 AREA OF USE
A typical technological map (TTK) is drawn up for one of the options for the installation of air ducts for ventilation systems in industrial and public buildings.
The TTK is intended to familiarize workers and engineering and technical workers with the rules for the production of work, as well as for the purpose of using it in the development of work production projects, construction organization projects, and other organizational and technological documentation.
2. GENERAL PROVISIONS
Ventilation systems. Modern methods of installation of air ducts
In the total scope of work on the installation of ventilation, air conditioning, pneumatic transport and aspiration systems at industrial facilities, the most time-consuming is the installation of air ducts.
Most of the duct installation have to be carried out at a height, which complicates the process of assembling ventilation systems, especially if you take into account the significant overall dimensions and weight of parts of ventilation equipment. This necessitates the use of special machines, mechanisms and devices during the installation of ventilation. These include machines such as mobile cranes, auto-hydraulic lifts, self-propelled retractable scaffolds, mobile assembly platforms, etc.
When installing ventilation systems, the method of installing air ducts depends on the design features of ventilation systems, the features of building structures, the conditions for installing ventilation, and the availability of lifting mechanisms.
The most progressive method of air duct installation provides for pre-assembly of air ducts and enlarged units 25-30 m long, made up of straight sections of air ducts and fittings.
Ventilation systems. Installation of horizontal metal air ducts
When installing horizontal metal air ducts, the following sequence of work must be observed:
- install means of fastening by welding to embedded parts or using a construction and assembly gun;
- outline the installation sites for mechanisms for lifting air duct assemblies and prepare inventory scaffolding, scaffolding, towers for work;
- they bring individual parts of air ducts and assemble them into enlarged units on inventory stands, and parts of air ducts of large sections - on the floor;
- install clamps or other means of fastening.
After intermediate assembly of air ducts mounting assembly they trail with inventory slings, and at the ends of the knots they tie guy lines from a hemp rope.
Duct mounting assembly they lift it to the design mark from the inventory scaffolding by a car lift or other mechanisms, then hang it from the previously installed fasteners. At the end of the installation, the air duct is connected by flanges to the previously installed section of the air duct.
In installation practice, there are such options for design solutions for laying metal air ducts, such as laying under the ceiling of a building, on an outer wall, overpass, in an inter-farm space.
When installing air ducts, the following basic requirements of SNiP 3.05.01-85 "Internal sanitary systems" should be observed.
The method of installation of air ducts is chosen depending on their position (vertical, horizontal), the nature of the object, local conditions, location relative to building structures (inside or outside the building, near the wall, near the columns, in the inter-farm space, in the mine, on the roof of buildings), and also from the decisions incorporated in the PPR or standard technological maps.
Air ducts of ventilation, air conditioning and air heating systems should be designed in accordance with the requirements of paragraphs SNiP 2.04.05-91, providing for technical solutions in the projects that ensure the maintainability, explosion and fire safety of systems and regulatory requirements.
Mounting positions, methods of connection and fastening of air ducts
In order to unify the location of air ducts relative to building structures, it is recommended to use the mounting positions of round and rectangular air ducts developed by the Proektpromventilation State Design Institute. These duct mounting positions are determined by the following guidelines and dimensions.
1. Axes of air ducts must be parallel to the planes of building structures.
2. The distance from the duct axis to the surfaces of building structures is calculated using the following formulas:
Where - the maximum diameter of the duct to be laid, including insulation, mm;
Where - the maximum width of the duct to be laid, mm; - distance between the outer surface of the air duct and the wall (at least 50 mm), mm.
With a duct width of 100-400 mm 100 mm, with 400-800 mm 200 mm, with 800-1500 mm 400 mm.
3. The minimum allowable distance from the axis of the duct to the outer surface of the electrical wires is determined by the formulas:
- for round air ducts
For rectangular ducts
4. The minimum allowable distance from the axis of the duct to the outer surface of the pipelines is found by the formulas:
- for round air ducts
For rectangular ducts
5. When laying several air ducts in parallel at the same elevation, the minimum allowable distance between the axes of these air ducts is calculated by the formulas:
- for round air ducts
For rectangular ducts
Where and are the diameters of the air ducts, mm; and - dimensions of the sides of rectangular air ducts, mm.
6. The minimum allowable distance from the axis of the air ducts to the ceiling surface is determined by the formulas:
- for round air ducts
For rectangular ducts
7. When air ducts pass through building structures, flange and other detachable connections of air ducts should be placed at a distance of at least 100 mm from the surface of these structures.
Separate parts of air ducts (straight sections and fittings) are connected to each other in an air duct network using flanged and flangeless connections (bandages, strips, rails, socket and other connections).
Air ducts should be fastened in accordance with the working documentation and the requirements of SNiP 3.05.01-85 *. Fastening of horizontal metal non-insulated air ducts (clamps, hangers, supports, etc.) on a wafer connection should be installed at the following distances:
- no more than 4 m with diameters of a circular duct or dimensions of the larger side of a rectangular duct less than 400 mm;
- no more than 3 m with diameters of a circular duct or dimensions of the larger side of a rectangular duct of 400 mm or more.
Fasteners of horizontal metal non-insulated air ducts on a flange connection of circular cross-section with a diameter of up to 2000 mm or rectangular cross-section with dimensions of its larger side up to 2000 mm inclusive should be installed at a distance of no more than 6 m. round section with a diameter of more than 2000 mm or a rectangular section with the dimensions of its larger side of more than 2000 mm should be assigned as working documentation.
Fasteners of vertical metal air ducts should be installed at a distance of no more than 4 m.
Fastenings of vertical metal air ducts indoors with a floor height of more than 4 m and on the roof of the building should be assigned as a working draft.
The design of the connections of the air duct parts will be discussed in more detail in the special literature.
Development of technical documentation for the manufacture and installation of air ducts
The development of technical documentation for the manufacture and installation of air ducts is reduced to the development of an axonometric wiring diagram of the ventilation (air conditioning) system, picking lists for air duct parts and mass production lists (silencers, dampers, air distributors, umbrellas, deflectors, etc.), as well as drawings (sketches) non-standard parts. The listed technical documentation is called an assembly or assembly and procurement (MZP) project.
The minimum wage is needed to place an order at a procurement enterprise for the manufacture of air duct parts for mounted ventilation and air conditioning systems, to check the completeness of the system blanks, and also to determine the place of each part made at the procurement enterprise in the system during its installation. MZP is developed for each system.
The following initial data are required for the development of MP:
- working drawings of the OB grade of the mounted systems and architectural and construction drawings of the AR grade, plans and sections of the building (structure) at the locations of the mounted systems;
- albums and other materials containing data on unified parts and assemblies of mounted systems;
- overall and connecting dimensions equipment and standard parts;
- recommended mounting positions of assembly units of systems;
- regulatory and methodological materials on the procedure for the implementation and design of MP systems.
Installation design consists of the following steps:
- using RF grade OB, draw an axonometric diagram of the system, divide the routes of the system air ducts into parts, as a rule, unified, contained in albums, norms and other documents;
- choose the types of connection of parts between themselves and with other assembly units of the system;
- establish the places and types of fastenings of the air duct routes of the system;
- develop sketches (drawings) of non-standardized parts with the definition of all the dimensions necessary for their manufacture;
- draw up documents required for MP:
1) axonometric wiring diagram of the system;
2) picking lists;
3) sketches for non-standardized (non-standard, non-standard) parts.
Other documents may be developed. State standard or there are no other uniform standards for the composition of MP documents, and therefore their list may differ in different regions and enterprises. The three items listed above are mandatory documents. However, their structure and content may differ.
Axonometric wiring diagram
is drawn on the basis of the axonometric diagram of the working drawing developed by the design organization before the start of the installation design, i.e. it is available as input. The axonometric wiring diagram may be a copy of the RF circuit in configuration, or it may be depicted arbitrarily on a separate sheet without being drawn to scale. This diagram is marked with fan levels, ceilings, rises, descents of air ducts, as well as the length of horizontal straight sections and all diameters and sections of air ducts. Figure 1 shows for comparison the axonometric diagrams of the same ventilation system and the axonometric diagram from the working drawings and the wiring diagram.
Fig.1. Axonometric diagrams of the ventilation system:
but- scheme of the working drawing; b- wiring diagram; 1...14 - unified parts
The scheme is divided into parts (details). First, standard, typical and unified parts of the system are distinguished, the dimensions of which are known. Then, sketches of non-standard (non-standardized) parts are developed in axonometric projection, and the dimensions necessary for their manufacture are determined. Find the total length of straight sections of the network between standard, typical, shaped parts and other elements. Rectilinear total sections of air ducts are divided into individual sections (parts) of the recommended VSN 353-86 length. In this case, one of the individual sections of each straight duct line may differ from the recommended length. He is called died. The length of the sub-measure is usually specified locally, and therefore it is advisable to make one flange free for movement along the axis of the duct in case of a flange connection. The sections are assigned numbers, they are indicated by numbers in circles, for example (T), which means section number 1. Figure 2 shows a simplified fragment of the axonometric wiring diagram of the ventilation system duct route. The fragment is used to illustrate a simplified picking list (Table 1.1).
Fig.2. Fragment of the wiring diagram of the air ducts:
1 , 2 , 3 - straight sections; 4 - a straight section with an end grid; 5 - a straight section with a grid and an engine; 6 - a straight section with a tie-in; 7 , 8 - taps; 9 - transition
It was noted above that the MP includes the development of picking lists and lists of air duct parts.
For each system, a one or multiple packing lists. The number of statements and their form depend on the requirements of enterprises fulfilling an order for the manufacture of parts. So, for example, the following data can be given in the packing list of the ventilation system: part numbers, their names, part sizes (diameter for circular ducts; dimensions of the sides of rectangular ducts; lengths), quantity (pieces, kg of one piece and the weight of all pieces ), metal thickness. The parts themselves are listed in the statement not in the order in which they are located in the system along the air flow, but according to groupings of the same type:
- straight sections;
- straight sections with tie-ins;
- straight sections with gratings, nets, etc.;
- bends and half-bends;
- transitions;
- boxes.
The composition of groupings and their order in the statement in different regional organizations may differ.
A sample picking list is presented in Table 1.1, which is compiled for a fragment of the system shown in Figure 2. At the end of the picking list, data on the total surface area of the air ducts and the total area by metal thickness, parts (separately for straight sections and fittings, for metal thickness in m and kg) can be given; the number and list of connecting elements (bandages, flanges and connections on the bus - the number for each size); gratings and grids, VEPsh (pressed ejection panel air distributors) and other parts installed on air ducts.
Table 1.1
Picking list of air duct parts
|
N |
the name of detail |
Diameter, mm |
Length, mm |
Quantity, pcs. |
Surface, m |
Note |
|
|
straight section |
Grid with slider 200x200 mm |
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|
Straight section with mesh |
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|
Straight section with grid and slider |
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|
Straight section with inset |
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