Steam turbine operation. Steam Turbine Operating Instructions Diagram of Condenser Turbine Fri 80
| Assignment for a course project | 3 |
|
| 1. | Initial reference data | 4 |
| 2. | Calculation of the boiler plant | 6 |
| 3. | Construction of the steam expansion process in the turbine | 8 |
| 4. | Steam and feed water balance | 9 |
| 5. | Determination of parameters of steam, feed water and condensate by PTS elements | 11 |
| 6. | Compilation and solution of heat balance equations for sections and elements of PTS | 15 |
| 7. | Energy power equation and its solution | 23 |
| 8. | Calculation check | 24 |
| 9. | Definition of energy indicators | 25 |
| 10. | Choice auxiliary equipment | 26 |
| Bibliography | 27 |
|
Assignment for a course project
Student: Onuchin D.M..
Project theme: Calculation of the thermal scheme of PTU PT-80/100-130/13
Project Data
P 0 \u003d 130 kg / cm 2;
;
;
Q t \u003d 220 MW;
;
.
Pressure in unregulated withdrawals - from reference data.
Training additional water- from the atmospheric deaerator "D-1.2".
The volume of the settlement part
Design calculation of PTU in the SI system for rated power.
Determination of energy indicators of the work of vocational schools.
The choice of auxiliary equipment for vocational schools.
1. Initial reference data
The main indicators of the turbine PT-80/100-130.
Table 1.
| Parameter | Value | Dimension |
| Rated power | 80 | MW |
| Max power | 100 | MW |
| Initial pressure | 23,5 | MPa |
| Initial temperature | 540 | WITH |
| Pressure at the outlet of the HPC | 4,07 | MPa |
| The temperature at the outlet of the HPC | 300 | WITH |
| Superheated steam temperature | 540 | WITH |
| Cooling water consumption | 28000 | m 3 / h |
| Cooling water temperature | 20 | WITH |
| Condenser pressure | 0,0044 | MPa |
The turbine has 8 unregulated steam extractions designed to heat the feed water in the heaters low pressure, deaerator, in heaters high pressure and to power the drive turbine of the main feed pump. The exhaust steam from the turbo drive is returned to the turbine.
Table 2.
| Selection | Pressure, MPa | Temperature, 0 С |
|
| I | LDPE №7 | 4,41 | 420 |
| II | PVD №6 | 2,55 | 348 |
| III | PND №5 | 1,27 | 265 |
| Deaerator | 1,27 | 265 |
|
| IV | PND №4 | 0,39 | 160 |
| V | PND №3 | 0,0981 | - |
| VI | PND №2 | 0,033 | - |
| VII | PND №1 | 0,003 | - |
The turbine has two heating steam extractions, upper and lower, designed for one and two-stage heating of network water. Heating extractions have the following pressure regulation limits:
Upper 0.5-2.5 kg / cm 2;
Lower 0.3-1 kg/cm 2 .
2. Calculation of the boiler plant
WB - upper boiler;
NB - lower boiler;
Obr - reverse network water.
D WB, D NB - steam flow to the upper and lower boilers, respectively.
Temperature graph: t pr / t o br \u003d 130 / 70 C;
T pr \u003d 130 0 C (403 K);
T arr \u003d 70 0 C (343 K).
Determination of steam parameters in heating extractions
We accept uniform heating on the VSP and NSP;
We accept the value of underheating in network heaters 
.
We accept pressure losses in pipelines 
.
The pressure of the upper and lower extractions from the turbine for VSP and LSP:
bar; 
bar.
h WB =418.77 kJ/kg
h NB \u003d 355.82 kJ / kg
D WB (h 5 - h WB /) \u003d K W SV (h WB - h NB) →
→ D WB =1.01∙870.18(418.77-355.82)/(2552.5-448.76)=26.3 kg/s
D NB h 6 + D WB h WB / + K W SV h OBR \u003d KW SV h NB + (D WB +D NB) h NB / →
→ D NB \u003d / (2492-384.88) \u003d 25.34 kg / s
D WB + D NB \u003d D B \u003d 26.3 + 25.34 \u003d 51.64 kg / s
3. Construction of the steam expansion process in the turbine
Let us take the pressure loss in the steam distribution devices of the cylinders:
;
;
;
In this case, the pressure at the inlet to the cylinders (behind the control valves) will be:
The process in the h,s-diagram is shown in fig. 2.
4. Balance of steam and feed water.
We assume that the end seals (D KU) and the steam ejectors (D EP) receive steam of higher potential.
The spent steam from the end seals and from the ejectors is directed to the stuffing box heater. We accept heating of condensate in it:
The spent steam in the ejector coolers is directed to the ejector heater (EP). Heating in it:
We accept the steam flow to the turbine (D) as a known value.
Intra-station losses of the working fluid: D UT =0.02D.
Steam consumption for end seals will be 0.5%: D KU = 0.005D.
Steam consumption for the main ejectors will be 0.3%: D EJ = 0.003D.
Then:
Steam consumption from the boiler will be:
Because drum boiler, it is necessary to take into account the blowdown of the boiler.
D prod \u003d 0.015D \u003d 1.03D K \u003d 0.0154D.
The amount of feed water supplied to the boiler:
Amount of additional water:
Condensate losses for production:
(1-K pr) D pr \u003d (1-0.6) ∙ 75 \u003d 30 kg / s.
The pressure in the boiler drum is approximately 20% higher than the fresh steam pressure at the turbine (due to hydraulic losses), i.e.
P q.v. =1.2P 0 =1.2∙12.8=15.36 MPa → 
kJ/kg.
The pressure in the continuous blowdown expander (CRP) is about 10% higher than in the deaerator (D-6), i.e.
P RNP \u003d 1.1P d \u003d 1.1 ∙ 5.88 \u003d 6.5 bar →
→
kJ/kg;
kJ/kg;
kJ/kg;
D P.R. \u003d β ∙ D prod \u003d 0.438 0.0154D \u003d 0.0067D;
D V.R. \u003d (1-β) D prod \u003d (1-0.438) 0.0154D \u003d 0.00865D.
D ext \u003d D ut + (1-K pr) D pr + D v.r. =0.02D+30+0.00865D=0.02865D+30.
We determine the consumption of network water through network heaters:
We accept leaks in the heat supply system of 1% of the amount of circulating water.
Thus, the required performance of chem. water treatment:
5. Determination of parameters of steam, feed water and condensate by PTS elements.
We accept the pressure loss in the steam pipelines from the turbine to the heaters of the regenerative system in the amount of:
| I selection | PVD-7 | 4% |
| II selection | PVD-6 | 5% |
| III selection | PVD-5 | 6% |
| IV selection | PVD-4 | 7% |
| V selection | PND-3 | 8% |
| VI selection | PND-2 | 9% |
| VII selection | PND-1 | 10% |
The determination of the parameters depends on the design of the heaters ( see fig. 3). In the calculated scheme, all HDPE and LDPE are surface.
In the course of the main condensate and feed water from the condenser to the boiler, we determine the parameters we need.
5.1. We neglect the increase in enthalpy in the condensate pump. Then the parameters of the condensate before the EP:
0.04 bar 
29°С, 
121.41 kJ/kg.
5.2. We take the heating of the main condensate in the ejector heater equal to 5°C.
34 °С; kJ/kg.
5.3. The water heating in the stuffing box heater (SH) is assumed to be 5°С.
39 °С, 
kJ/kg.
5.4. PND-1 - disabled.
It feeds on steam from the VI selection.
69.12 °С, 
289.31 kJ / kg \u003d h d2 (drainage from HDPE-2).
°С, 
4.19∙64.12=268.66kJ/kg
It feeds on steam from the V selection.
Heating steam pressure in the heater body:
96.7 °С, 
405.21 kJ/kg;
Water parameters behind the heater:
°С, 
4.19∙91.7=384.22 kJ/kg.
We preliminarily set the temperature increase due to the mixing of flows in front of LPH-3 by 
, i.e. we have:
It feeds on steam from the IV selection.
Heating steam pressure in the heater body:
140.12°С, 
589.4 kJ/kg;
Water parameters behind the heater:
°С, 
4.19∙135.12=516.15 kJ/kg.
Parameters of the heating medium in the drain cooler:
5.8. Feed water deaerator.
Feed water deaerator operates at constant steam pressure in the casing
R D-6 \u003d 5.88 bar → t D-6 H \u003d 158 ˚C, h ’D-6 \u003d 667 kJ / kg, h ”D-6 \u003d 2755.54 kJ / kg,
5.9. Feed pump.
Let's take the pump efficiency 
0,72.
Discharge pressure: MPa. °C, and the parameters of the heating medium in the drain cooler:
Steam parameters in the steam cooler:
°C; 
2833.36 kJ/kg.
We set the heating in OP-7 equal to 17.5 ° С. Then the temperature of the water behind the HPH-7 is equal to °С, and the parameters of the heating medium in the drain cooler are:
°C; 
1032.9 kJ/kg.
Feed water pressure after HPH-7 is:
Water parameters behind the heater itself.
3.3.4 Steam turbine plant PT-80/100-130/13
Heating steam turbine PT-80/100-130/13 with industrial and heating steam extraction is designed for direct drive electric generator TVF-120-2 with a rotation speed of 50 rpm and heat supply for the needs of production and heating.
Power, MW
nominal 80
maximum 100
Rated steam parameters
pressure, MPa 12.8
temperature, 0 С 555
Consumption of extracted steam for production needs, t/h
nominal 185
maximum 300
upper 0.049-0.245
lower 0.029-0.098
Production selection pressure 1.28
Water temperature, 0 C
nutritional 249
cooling 20
Cooling water consumption, t/h 8000
The turbine has the following adjustable steam extractions:
production with an absolute pressure (1.275 ± 0.29) MPa and two heating selections - the upper one with an absolute pressure in the range of 0.049-0.245 MPa and the lower one with a pressure in the range of 0.029-0.098 MPa. The heating extraction pressure is regulated by means of one control diaphragm installed in the upper heating extraction chamber. Regulated pressure in the heating outlets is maintained: in the upper outlet - when both heating outlets are turned on, in the lower outlet - when one lower heating outlet is turned on. Network water through the network heaters of the lower and upper stages of heating must be passed sequentially and in equal quantities. The flow of water passing through the network heaters must be controlled.
The turbine is a single-shaft two-cylinder unit. The HPC flow path has a single-row control stage and 16 pressure stages.
The flow part of the LPC consists of three parts:
the first (up to the upper heating outlet) has a control stage and 7 pressure stages,
the second (between the heating taps) two pressure stages,
the third - the control stage and two pressure stages.
The high pressure rotor is one-piece forged. The first ten disks of the low-pressure rotor are forged integrally with the shaft, the remaining three disks are mounted.
The steam distribution of the turbine is nozzle. At the exit from the HPC, part of the steam goes to controlled production extraction, the rest goes to the LPC. Heating extractions are carried out from the corresponding LPC chambers.
To reduce the warm-up time and improve start-up conditions, steam heating of flanges and studs and live steam supply to the HPC front seal are provided.
The turbine is equipped with a barring device that rotates the shafting of the turbine unit at a frequency of 3.4 rpm.
The turbine blade apparatus is designed to operate at a mains frequency of 50 Hz, which corresponds to a turbine rotor speed of 50 rpm (3000 rpm). Allowed long work turbines with a frequency deviation in the network of 49.0-50.5 Hz.
3.3.5 Steam turbine plant Р-50/60-130/13-2
The R-50/60-130/13-2 counterpressure steam turbine is designed to drive the TVF-63-2 electric generator with a rotation speed of 50 s -1 and to release steam for production needs.
The nominal values of the main parameters of the turbine are given below:
Power, MW
Rated 52.7
Maximum 60
Initial steam parameters
Pressure, MPa 12.8
Temperature, o C 555
Pressure in the exhaust pipe, MPa 1.3
The turbine has two unregulated steam extractions intended for heating feed water in high pressure heaters.
Turbine design:
The turbine is a single-cylinder unit with a single-crown control stage and 16 pressure stages. All rotor discs are forged integrally with the shaft. Steam distribution of the turbine with bypass. Fresh steam is supplied to a free-standing steam box in which an automatic shutter valve is located, from where the steam passes through bypass pipes to four control valves.
The turbine blade apparatus is designed to operate at a frequency of 3000 rpm. Long-term operation of the turbine is allowed with a frequency deviation in the network of 49.0-50.5 Hz
The turbo unit is equipped protective devices for joint shutdown of the HPH with simultaneous activation of the bypass line by giving a signal. Atmospheric diaphragm valves installed on the exhaust pipes and opening when the pressure in the pipes rises to 0.12 MPa.
3.3.6 Steam turbine plant T-110/120-130/13
Heating steam turbine T-110/120-130/13 with heating steam extraction is designed for direct drive of electric generator TVF-120-2 with a rotation speed of 50 rpm and heat supply for heating needs.
The nominal values of the main parameters of the turbine are given below.
Power, MW
nominal 110
maximum 120
Rated steam parameters
pressure, MPa 12.8
temperature, 0 С 555
nominal 732
maximum 770
Limits of steam pressure change in controlled heating extraction, MPa
upper 0.059-0.245
lower 0.049-0.196
Water temperature, 0 C
nutritional 232
cooling 20
Cooling water consumption, t/h 16000
Vapor pressure in the condenser, kPa 5.6
The turbine has two heating extractions - lower and upper, designed for stepwise heating of network water. In case of stepwise heating of network water with steam from two heating extractions, the control maintains the set temperature of network water downstream of the upper network heater. When heating network water with one lower heating extraction, the temperature of network water is maintained behind the lower network heater.
Pressure in adjustable heating extractions can vary within the following limits:
in the upper 0.059 - 0.245 MPa with two heating extractions turned on,
at the bottom 0.049 - 0.196 MPa with the top heating off.
Turbine T-110/120-130/13 is a single-shaft unit consisting of three cylinders: high pressure cylinder, low pressure cylinder, low pressure cylinder.
The HPC is single-flow, has a two-row control stage and 8 pressure stages. The high-pressure rotor is one-piece forged.
TsSD - also single-flow, has 14 steps of pressure. The first 8 disks of the medium pressure rotor are forged integrally with the shaft, the remaining 6 are mounted. The guide vane of the first stage of the TsSD is installed in the housing, the remaining diaphragms are installed in holders.
LPC - double-flow, has two stages in each stream of left and right rotation (one control and one pressure stage). The length of the working blade of the last stage is 550 mm, the average diameter of the impeller of this stage is 1915 mm. The low pressure rotor has 4 mounted discs.
In order to facilitate the start-up of the turbine from a hot state and increase its maneuverability during operation under load, the temperature of the steam supplied to the penultimate chamber of the HPC front seal is increased by mixing hot steam from the control valve stems or from the main steam pipeline. From the last compartments of the seals, the vapor-air mixture is sucked off by the suction ejector from the seals.
To reduce the heating time and improve the conditions for starting the turbine, steam heating of the HPC flanges and studs is provided.
The turbine blade apparatus is designed to operate at a mains frequency of 50 Hz, which corresponds to a turbine rotor speed of 50 rpm (3000 rpm).
Long-term operation of the turbine is allowed with a frequency deviation in the network of 49.0-50.5 Hz. In emergency situations for the system, short-term operation of the turbine is allowed at a network frequency below 49 Hz, but not below 46.5 Hz (the time is specified in the technical specifications).
Information about the work "Modernization of the Almaty CHP-2 by changing the water-chemical regime of the make-up water treatment system in order to increase the temperature of the network water to 140-145 C"
Cogeneration steam turbine PT-80 / 100-130 / 13 of the production association for turbine construction "Leningrad Metal Works" (NOG LMZ) with industrial and heating steam extraction with a rated power of 80 MW, a maximum of 100 MW with an initial steam pressure of 12.8 MPa is designed for direct drive electric generator TVF-120-2 with a rotation frequency of 50 Hz and heat supply for the needs of production and heating.
When ordering a turbine, as well as in other documentation, where it should be designated "Steam turbine 1GG-80/100-130/13 TU 108-948-80".
Turbine PT-80/100-130/13 complies with the requirements of GOST 3618-85, GOST 24278-85 and GOST 26948-86.
The turbine has the following adjustable steam extractions: a production one with an absolute pressure of (1.275 ± 0.29) MPa and two heating extractions: an upper one with an absolute pressure in the range of 0.049-0.245 MPa and a lower one with a pressure in the range of 0.029-0.098 MPa.
The heating extraction pressure is regulated by means of one control diaphragm installed in the upper heating extraction chamber. Regulated pressure in the heating extractions is maintained: in the upper extraction - when both heating extractions are switched on, in the lower extraction - when one lower heating extraction is switched on. Network water through the network heaters of the lower and upper stages of heating is passed sequentially and in the same amount. The flow of water passing through the network heaters is controlled.
Nominal values of the main parameters of the turbine PT-80/100-130/13
| Parameter | PT-8O/100-130/13 |
| 1. Power, MW | |
| nominal | 80 |
| maximum | 100 |
| 2. Initial steam parameters: | |
| pressure, MPa | 12.8 |
| temperature. °C | 555 | 284 (78.88) |
| 4. Consumption of selected steam for production. needs, t/h | |
| nominal | 185 |
| maximum | 300 |
| 5. Production selection pressure, MPa | 1.28 |
| 6. Maximum consumption of live steam, t/h | 470 |
| 7. Limits of steam pressure change in adjustable heating steam extractions, MPa | |
| at the top | 0.049-0.245 |
| in the bottom | 0.029-0.098 |
| 8. Water temperature, °С | |
| nutritional | 249 |
| cooling | 20 |
| 9. Cooling water consumption, t/h | 8000 |
| 10. Steam pressure in the condenser, kPa | 2.84 |
With nominal fresh steam parameters, cooling water flow rate of 8000 m3/h, cooling water temperature of 20 °C, fully activated regeneration, amount of condensate heated in HPH equal to 100% of steam flow rate through the turbine, when the turbine unit is operating with a deaerator of 0.59 MPa, with stepped heating of network water, at full use bandwidth turbine and the minimum passage of steam into the condenser, the following extraction values can be taken:
— nominal values of regulated extractions at a power of 80 MW;
- production selection - 185 t / h at an absolute pressure of 1.275 MPa;
- total heating extraction - 285 GJ / h (132 t / h) at absolute pressures: in the upper extraction - 0.088 MPa and in the lower extraction - 0.034 MPa;
- the maximum value of production selection at an absolute pressure in the selection chamber of 1.275 MPa is 300 t / h. With this value of production extraction and the absence of heating extractions, the turbine power is -70 MW. With a rated power of 80 MW and no heating extraction, the maximum production extraction will be -250 t/h;
— the maximum total value of heating extractions is 420 GJ/h (200 t/h); with this value of heating extractions and the absence of industrial extraction, the turbine power is about 75 MW; with a rated power of 80 MW and no industrial extraction, the maximum heating extraction will be about 250 GJ/h (-120 t/h).
— the maximum power of the turbine with the production and heating extraction off, with a cooling water flow rate of 8000 m3/h at a temperature of 20 °C, with fully switched on regeneration, will be 80 MW. The maximum power of the turbine is 100 MW. obtained with certain combinations of production and heating extractions, depends on the magnitude of the extractions and is determined by the mode aperture.
It is possible to operate the turbine plant with the passage of make-up and network water through the built-in bundle
When the condenser is cooled by network water, the turbine can operate according to the heat schedule. Maximum thermal power of the built-in beam is -130 GJ/h while maintaining the temperature in the exhaust part no higher than 80 °C.
Long-term operation of the turbine with rated power is allowed with the following deviations of the main parameters from the nominal:
- with a simultaneous change in any combination of the initial parameters of live steam - pressure from 12.25 to 13.23 MPa and temperature from 545 to 560 ° C; at the same time, the temperature of the cooling water should not exceed 20 °C;
- when the temperature of the cooling water at the condenser inlet rises to 33 °C and the flow rate of the cooling water is 8000 m3/h, if the initial parameters of the live steam are not lower than the nominal ones;
- while reducing the values of industrial and heating steam extractions to zero.
- with an increase in the pressure of live steam to 13.72 MPa and a temperature of up to 565 ° C, the operation of the turbine is allowed for no more than half an hour, and the total duration of the turbine operation at these parameters should not exceed 200 h / year.
For this turbine unit PT-80/100-130/13, a high-pressure heater No. 7 (PVD-475-230-50-1) is used. PVD-7 operates at steam parameters before entering the heater: pressure 4.41 MPa, temperature 420 °C and steam flow rate 7.22 kg/s. Feed water parameters in this case: pressure 15.93 MPa, temperature 233 °C and flow rate 130 kg/s.
Specific consumption heat at two-stage heating of network water.
Conditions: G k3-4 = Gin NPV + 5 t/h; t to - see fig. ; t 1v ≈ 20 °С; W@ 8000 m3/h
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °С; t 1v ≈ 20 °С; W@ 8000 m3/h; Δ i PEN = 7 kcal/kg
|
Rice. 10, a, b, v, G |
AMENDMENTS TO THE FULL ( Q 0) AND SPECIFIC ( qG |
A type |
a) on the deviation pressure fresh pair from nominal on the ± 0.5 MPa (5 kgf/cm2)
α q t = ± 0,05 %; α G 0 = ± 0,25 %
b) on the deviation temperature fresh pair from nominal on the ± 5 °C
v) on the deviation expense nutritional water from nominal on the ± 10 % G 0
G) on the deviation temperature nutritional water from nominal on the ± 10 °C
|
Rice. eleven, a, b, v |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO THE FULL ( Q 0) AND SPECIFIC ( q r) HEAT CONSUMPTION AND FRESH STEAM CONSUMPTION ( G 0) IN CONDENSATION MODE |
A type |
a) on the shutdown groups LDPE
b) on the deviation pressure spent pair from nominal
v) on the deviation pressure spent pair from nominal
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °С; G pit = G 0
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °С
Conditions: G pit = G 0; R 9 = 0.6 MPa (6 kgf/cm2); t pit - see fig. ; t to - see fig.
Conditions: G pit = G 0; t pit - see fig. ; R 9 = 0.6 MPa (6 kgf/cm2)
Conditions: R n = 1.3 MPa (13 kgf/cm2); i n = 715 kcal/kg; t to - see fig.
Note. Z= 0 - control diaphragm is closed. Z= max - control diaphragm fully open.
Conditions: R wto = 0.12 MPa (1.2 kgf/cm2); R 2 = 5 kPa (0.05 kgf/cm2)
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT INTERNAL CAPACITY OF CHSND AND STEAM PRESSURE IN THE UPPER AND LOWER HEATING OUTPUTS |
A type |
Conditions: R n \u003d 1.3 MPa (13 kgf / cm2) at Gin NPV ≤ 221.5 t/h; R n = Gin HR/17 - at Gin NPV > 221.5 t/h; i n = 715 kcal/kg; R 2 \u003d 5 kPa (0.05 kgf / cm2); t to - see fig. , ; τ2 = f(P WTO) - see fig. ; Q t = 0 Gcal/(kW h)
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT INFLUENCE OF THE HEATING LOAD ON THE POWER OF THE TURBINE WITH SINGLE-STAGE HEATING OF THE NETWORK WATER |
A type |
Conditions: R 0 \u003d 1.3 (130 kgf / cm2); t 0 = 555 °С; R NTO = 0.06 (0.6 kgf/cm2); R 2 @ 4 kPa (0.04 kgf/cm2)
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT DIAGRAM OF MODES WITH SINGLE-STAGE HEATING OF MAINS WATER |
A type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 ° WITH; P n = 1.3 MPa (13 kgf/cm2); R NTO = 0.09 MPa (0.9 kgf / cm2); R 2 \u003d 5 kPa (0.05 kgf / cm2); G pit = G 0.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT DIAGRAM OF MODES WITH TWO-STAGE HEATING OF MAINS WATER |
A type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 ° WITH; P n = 1.3 MPa (13 kgf/cm2); R WTO = 0.12 MPa (1.2 kgf / cm2); R 2 \u003d 5 kPa (0.05 kgf / cm2); G pit = G 0; τ2 = 52 ° WITH.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT OPERATING DIAGRAM IN MODE ONLY WITH INDUSTRIAL SELECTION |
A type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 ° WITH; P n = 1.3 MPa (13 kgf/cm2); R WTO and R NTO = f(Gin HR) - see fig. thirty; R 2 \u003d 5 kPa (0.05 kgf / cm2); G pit = G 0
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SPECIFIC HEAT CONSUMPTION FOR SINGLE-STAGE HEATING OF MAINS WATER |
A type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °С; P n = 1.3 MPa (13 kgf/cm2); R NTO = 0.09 MPa (0.9 kgf / cm2); R 2 \u003d 5 kPa (0.05 kgf / cm2); G pit = G 0; Q t = 0
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SPECIFIC HEAT CONSUMPTION DURING TWO-STAGE HEATING OF MAINS WATER |
A type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °С; P n = 1.3 MPa (13 kgf/cm2); R WTO = 0.12 MPa (1.2 kgf / cm2); R 2 \u003d 5 kPa (0.05 kgf / cm2); G pit = G 0; τ2 = 52 °С; Q t = 0.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SPECIFIC HEAT CONSUMPTION UNDER THE MODE ONLY WITH PRODUCTION SELECTION |
A type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °С; P n = 1.3 MPa (13 kgf/cm2); R WTO and R NTO = f(Gin HR) - see fig. ; R 2 \u003d 5 kPa (0.05 kgf / cm2); G pit = G 0.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT MINIMUM POSSIBLE PRESSURE IN THE LOWER HEAT EXHAUST WITH SINGLE-STAGE MAINS WATER HEATING |
A type |
|
Rice. 41, a, b |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT TWO-STAGE HEATING OF NETWORK WATER (ACCORDING TO LMZ Sweat) |
A type |
a) minimum possible pressure v upper T-selection and estimated temperature reverse network water
b) amendment on the temperature reverse network water
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION TO THE POWER FOR THE DEVIATION OF THE PRESSURE IN THE LOWER HEAT EXHAUST FROM THE RATED AT SINGLE-STAGE HEATING OF THE MAINS WATER (ACCORDING TO THE DATA OF THE LMZ) |
A type |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION TO THE POWER FOR THE DEVIATION OF THE PRESSURE IN THE UPPER HEAT EXHAUST FROM THE RATED AT TWO-STAGE HEATING OF THE MAINS WATER (ACCORDING TO THE DATA FROM LMZ) |
A type |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION FOR EXHAUST STEAM PRESSURE (ACCORDING TO LMZ FET) |
A type |
1 Based on POT LMZ data.
On the deviation pressure fresh pair from nominal on the ±1 MPa (10 kgf/cm2): To full consumption warmth
To consumption fresh pair
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT Q 0) AND FRESH STEAM CONSUMPTION ( G 0) IN MODES WITH ADJUSTABLE bleeds1 |
A type |
1 Based on POT LMZ data.
On the deviation temperature fresh pair from nominal on the ±10 °С:
To full consumption warmth
To consumption fresh pair
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTIONS TO TOTAL HEAT CONSUMPTION ( Q 0) AND FRESH STEAM CONSUMPTION ( G 0) IN MODES WITH ADJUSTABLE bleeds1 |
A type |
1 Based on POT LMZ data.
On the deviation pressure v P-selection from nominal on the ± 1 MPa (1 kgf/cm2):
To full consumption warmth
To consumption fresh pair
|
Rice. 49 a, b, v |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SPECIFIC HEAT GENERATIONS OF ELECTRICITY |
A type |
a) ferry production selection
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 ° C; P n = 1.3 MPa (13 kgf/cm2); ηem = 0.975.
b) ferry top and lower cogeneration selections
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °C; R WTO = 0.12 MPa (1.2 kgf / cm2); ηem = 0.975
v) ferry lower cogeneration selection
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 ° C; R NTO = 0.09 MPa (0.9 kgf / cm2); ηem = 0.975
|
Rice. 50 a, b, v |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO THE SPECIFIC THERMAL POWER GENERATIONS FOR THE PRESSURE IN THE REGULATED OUTPUTS |
A type |
a) on the pressure v production selection
b) on the pressure v upper cogeneration selection
v) on the pressure v lower cogeneration selection
Appendix
1. CONDITIONS FOR COMPILING THE ENERGY CHARACTERISTICS
The typical energy characteristic was compiled on the basis of reports on thermal tests of two turbine units: at Chisinau CHPP-2 (work performed by Yuzhtechenergo) and at CHPP-21 Mosenergo (work performed by MGP PO Soyuztechenergo). The characteristic reflects the average efficiency of a turbine unit that has passed overhaul and operating according to the thermal scheme shown in Fig. ; under the following parameters and conditions taken as nominal:
Pressure and temperature of fresh steam in front of the turbine stop valve - 13 (130 kgf/cm2)* and 555 °С;
* In text and graphs - absolute pressure.
Pressure in controlled production extraction - 13 (13 kgf/cm2) with a natural increase at flow rates at the inlet to the CSD of more than 221.5 t/h;
Pressure in the upper heat extraction - 0.12 (1.2 kgf / cm2) with a two-stage scheme for heating network water;
Pressure in the lower heating extraction - 0.09 (0.9 kgf / cm2) with a single-stage scheme for heating network water;
Pressure in the controlled production extraction, upper and lower heating extractions in the condensing mode with the pressure regulators turned off - fig. and ;
Exhaust steam pressure:
a) to characterize the condensation mode and work with selections during single-stage and two-stage heating of network water at a constant pressure - 5 kPa (0.05 kgf / cm2);
b) to characterize the condensation mode at a constant flow rate and temperature of the cooling water - in accordance with the thermal characteristic of the condenser at t 1v= 20 °С and W= 8000 m3/h;
The high and low pressure regeneration system is fully turned on, the deaerator 0.6 (6 kgf/cm2) is fed with industrial extraction steam;
The feed water flow rate is equal to the live steam flow rate, return of 100% of the production withdrawal condensate at t= 100 °С carried out in a deaerator 0.6 (6 kgf/cm2);
The temperature of the feed water and the main condensate downstream of the heaters corresponds to the dependencies shown in Fig. , , , , ;
The increase in the enthalpy of feed water in the feed pump - 7 kcal/kg;
The electromechanical efficiency of the turbine unit was adopted according to the test data of the same type of turbine unit, carried out by Dontekhenergo;
Pressure regulation limits in selections:
a) production - 1.3 ± 0.3 (13 ± 3 kgf/cm2);
b) the upper heating plant with a two-stage scheme for heating network water - 0.05 - 0.25 (0.5 - 2.5 kgf / cm2);
a) the lower heating system with a single-stage scheme for heating network water - 0.03 - 0.10 (0.3 - 1.0 kgf / cm2).
Heating of network water in a heating plant with a two-stage scheme for heating network water, determined by the factory design dependencies τ2р = f(P WTO) and τ1 = f(Q T, P WTO) is 44 - 48 °C for maximum heating loads at pressures P WTO = 0.07 ÷ 0.20 (0.7 ÷ 2.0 kgf/cm2).
The test data underlying this Typical Energy Characteristic were processed using the “Tables of Thermophysical Properties of Water and Steam” (Moscow: Publishing House of Standards, 1969). According to the terms of the POT LMZ - the returned condensate of production withdrawal is injected at a temperature of 100 ° C into the main condensate line after LPH No. 2. When compiling the Typical energy characteristic, it is assumed that it is injected at the same temperature directly into the deaerator 0.6 (6 kgf / cm2) . According to the conditions of the POT LMZ, with two-stage heating of network water and modes with a steam flow rate at the inlet to the CSD of more than 240 t/h (maximum electrical load with low production withdrawal), LPH No. 4 is completely turned off. When compiling the Typical energy characteristic, it was assumed that with a flow rate at the inlet to the CSD of more than 190 t/h, part of the condensate is sent to bypass LPH No. 4 so that its temperature in front of the deaerator does not exceed 150 °C. This is required to ensure good deaeration of the condensate.
2. CHARACTERISTICS OF THE EQUIPMENT INCLUDED IN THE TURBO PLANT
The turbine unit, along with the turbine, includes the following equipment:
Hydrogen-cooled TVF-120-2 generator from Elektrosila plant;
Two-way condenser 80 KTsS-1 with a total area of 3000 m2, of which 765 m2 falls on the built-in beam;
Four low pressure heaters: HDPE No. 1 built into the condenser, HDPE No. 2 - PN-130-16-9-11, HDPE No. 3 and 4 - PN-200-16-7-1;
One deaerator 0.6 (6 kgf/cm2);
Three high pressure heaters: PVD No. 5 - PV-425-230-23-1, PVD No. 6 - PV-425-230-35-1, PVD No. 7 - PV-500-230-50;
Two circulation pumps 24NDN with a supply of 5000 m3 / h and a pressure of 26 m of water. Art. with electric motors of 500 kW each;
Three condensate pumps KN 80/155 driven by electric motors with a power of 75 kW each (the number of pumps in operation depends on the steam flow to the condenser);
Two main three-stage ejectors EP-3-701 and one starting EP1-1100-1 (one main ejector is constantly in operation);
Two network water heaters (upper and lower) PSG-1300-3-8-10 with a surface of 1300 m2 each, designed to pass 2300 m3/h of network water;
Four condensate pumps for network water heaters KN-KS 80/155 driven by electric motors with a capacity of 75 kW each (two pumps for each PSG);
One network pump of I lifting SE-5000-70-6 with an electric motor of 500 kW;
One network pump II lifting SE-5000-160 with an electric motor 1600 kW.
3. CONDENSATION MODE
In the condensing mode with the pressure regulators turned off, the total gross heat consumption and fresh steam consumption, depending on the power at the generator outputs, is expressed by the equations:
At constant pressure in the condenser
P 2 \u003d 5 kPa (0.05 kgf / cm2);
Q 0 = 15,6 + 2,04N T;
G 0 = 6,6 + 3,72N t + 0.11( N t - 69.2);
At constant flow ( W= 8000 m3/h) and temperature ( t 1v= 20 °C) cooling water
Q 0 = 13,2 + 2,10N T;
G 0 = 3,6 + 3,80N t + 0.15( N t - 68.4).
The above equations are valid within the power variation from 40 to 80 MW.
The consumption of heat and live steam in the condensing mode for a given power is determined by the given dependencies, followed by the introduction of the necessary amendments according to the corresponding graphs. These corrections take into account the difference in operating conditions from the nominal ones (for which the Type Characteristic is compiled) and serve to convert these characteristics to operating conditions. When recalculating, the signs of the corrections are reversed.
The corrections correct the consumption of heat and live steam at a constant power. When several parameters deviate from the nominal values, the corrections are algebraically summed up.
4. MODE WITH CONTROLLED SELECTIONS
When the regulated extractions are enabled, the turbine unit can operate with one-stage and two-stage schemes for heating network water. It is also possible to work without heat extraction with one production one. The corresponding typical regime diagrams for steam consumption and the dependence of specific heat consumption on power and production selection are given in fig. - , and the specific generation of electricity on heat consumption in fig. - .
The mode diagrams are calculated according to the scheme used by the POT LMZ and are shown in two fields. The upper field is the mode diagram (Gcal/h) of the turbine with one production extraction at Q t = 0.
When the heating load is turned on and other unchanged conditions, either only the 28th - 30th stages are unloaded (with one lower network heater on), or the 26th - 30th stages (with two network heaters on) and the turbine power is reduced.
The value of power reduction depends on the heating load and is determined
Δ N Qt = KQ T,
where K- specific change in turbine power determined during testing Δ N Qt/Δ Q t, equal to 0.160 MW / (Gcal h) with single-stage heating, and 0.183 MW / (Gcal h) with two-stage heating of network water (Fig. 31 and 32).
It follows that the consumption of live steam at a given power N t and two (industrial and heating) extractions will correspond to some fictitious power in the upper field N ft and one production selection
N ft = N t + Δ N Qt.
The inclined straight lines of the lower field of the diagram make it possible to graphically determine the value N ft, and according to it and the production selection, the consumption of fresh steam.
The values of specific heat consumption and specific power generation for heat consumption are calculated according to the data taken from the calculation of regime diagrams.
The graphs of the dependence of the specific heat consumption on the power and production selection are based on the same considerations as in the basis of the diagram of the POT LMZ modes.
A schedule of this type was proposed by the turbine shop of the MGP PO "Soyuztekhenergo" ("Industrial Energy", 1978, No. 2). It is preferable to the charting system q t = f(N T, Q t) at various Q n = const, since it is more convenient to use it. The graphs of the specific heat consumption, for reasons of a non-principled nature, are made without the bottom field; the method of using them is explained by examples.
The typical characteristic does not contain data characterizing the mode with three-stage heating of network water, since such a mode was not mastered anywhere at installations of this type during the testing period.
The influence of deviations of parameters from those accepted in the calculation of the Typical characteristic for the nominal ones is taken into account in two ways:
a) parameters that do not affect the heat consumption in the boiler and the supply of heat to the consumer at constant mass flow rates G 0, G n and G t, - by making corrections to the specified power N T( N t+ KQ T).
According to this corrected power according to fig. - fresh steam consumption, specific heat consumption and total heat consumption are determined;
b) amendments to P 0, t 0 and P n are introduced to those found after making the above corrections to the flow rate of live steam and total heat consumption, after which the consumption of live steam and heat consumption (total and specific) are calculated for the given conditions.
Data for live steam pressure correction curves calculated using test results; all other correction curves are based on LMZ FOT data.
5. EXAMPLES OF DETERMINATION OF SPECIFIC HEAT CONSUMPTION, FRESH STEAM CONSUMPTION AND SPECIFIC HEAT OUTPUTS
Example 1. Condensing mode with disconnected pressure regulators in the selections.
Given: N t = 70 MW; P 0 \u003d 12.5 (125 kgf / cm2); t 0 = 550 °С; R 2 \u003d 8 kPa (0.08 kgf / cm2); G pit = 0.93 G 0; Δ t pit = t pit - t npit \u003d -7 ° С.
It is required to determine the total and specific gross heat consumption and fresh steam consumption under given conditions.
The sequence and results are given in table. .
Table P1
|
Designation |
Definition method |
Received value |
Fresh steam consumption under nominal conditions, t/h |
Live steam temperatures |
Feed water flow |
Total correction to specific heat consumption, % |
Specific heat consumption under given conditions, kcal/(kWh) |
|
Total heat consumption under given conditions, Gcal/h |
Q 0 = q T N t10-3 |
Corrections to steam consumption for deviation of conditions from nominal values, %: |
Live steam pressure |
Live steam temperatures |
Exhaust steam pressure |
Feed water flow |
Feed water temperatures |
Total correction to live steam consumption, % |
Live steam consumption under given conditions, t/h |
|
Table P2
* When correcting the power for pressure in the upper heating extraction R WTO different from 0.12 (1.2 kgf/cm2), the result will correspond to the return water temperature corresponding to the given pressure according to the curve τ2р = f(P WTO) in Fig. , i.e. 60 °C. ** In case of a noticeable difference G CHSDin" from G FRRin all values in paragraphs. 4 - 11 should be checked against the specified G FRRin. The calculation of specific heat generation is carried out similarly to that given in the example. Development of heat extraction and correction to it for the actual pressure R WTO is determined by fig. , b and , b. Example 4. Mode without heat extraction. Given: N t = 80 MW; Q n = 120 Gcal/h; Q t = 0; R 0 \u003d 12.8 (128 kgf / cm2); t 0 = 550 °С; R 7.65 |
Pressure in the upper heating extraction, (kgf/cm2)* |
R WTO |
Rice. on G CHSDin" |
Pressure in the lower heating extraction, (kgf/cm2)* |
R NTO |
Rice. on G CHSDin" |
* The pressure in the selections of the CSND and the temperature of the condensate according to the LPH can be determined from the graphs of the condensation regime, depending on G HRin, at the ratio G HRin/ G 0 = 0,83.
6. SYMBOLS
|
Name |
Designation |
Power, MW: |
electrical at generator terminals |
N T, N tf |
internal high pressure |
N iHVD |
interior medium and low pressure |
N iChSND |
total losses of the turbine unit |
Σ∆ N sweat |
electromechanical efficiency |
High pressure cylinder (or part) |
Low (or part of medium and low) pressure cylinder |
TsSD (CSND) |
Steam consumption, t/h: |
to the turbine |
for production |
for heating |
for regeneration |
G PVD, G HDPE, G d |
through the last stage of the CVP |
G ChVDskv |
at the entrance to the CHSD |
G HRin |
at the entrance to the CND |
G CHNDin |
into the capacitor |
Feed water consumption, t/h |
Consumption of the returned condensate of industrial extraction, t/h |
Cooling water consumption through the condenser, m3/h |
Heat consumption for the turbine plant, Gcal/h |
Heat consumption for production, Gcal/h |
Absolute pressure, (kgf/cm2): |
in front of the check valve |
behind control and overload valves |
PI-IV class, P lane |
in control chamber |
P r.st |
in unregulated sampling chambers |
PI-VII P |
in the production selection chamber |
in the upper heating extraction chamber |
in the lower heating extraction chamber |
in the condenser, kPa (kgf/cm2) |
Temperature (°С), enthalpy, kcal/kg: |
fresh steam in front of the stop valve |
t 0, i 0 |
steam in the production selection chamber |
condensate for HDPE |
t To, t k1, t k2, t k3, t k4 |
return condensate production extraction |
feed water for HPH |
t pit5, t pit6, t pit7 |
feed water downstream |
t Pete, i Pete |
network water at the entrance to the installation and exit from it |
cooling water entering and leaving the condenser |
t 1c, t 2v |
Increasing the enthalpy of the feed water in the pump |
∆i PEN |
Specific gross heat consumption for electricity generation, kcal/(kWh) |
q T, q tf |
Specific heat generation of electricity, kWh/Gcal: |
production selection ferry |
steam extraction steam |
Coefficients for conversion to the SI system: |
|
1 t/h - 0.278 kg/s; 1 kgf / cm2 - 0.0981 MPa or 98.1 kPa; 1 kcal/kg - 4.18168 kJ/kg |
STEAM TURBINE PLANT PT-80/100-130/13
POWER 80 MW
Steam condensing turbine PT-80/100-130/13 (Fig. 1) with controlled steam extraction (industrial and two-stage heating) with a rated power of 80 MW, with a rotation speed of 3000 rpm is designed to directly drive an alternating current generator with a power of 120 MW of type TVF-120-2 when working in a block with a boiler unit.
The turbine has a regenerative device for heating feed water, network heaters for staged heating of network water and must work together with a condensing unit (Fig. 2).
The turbine is designed to operate with the following main parameters, which are presented in Table 1.
The turbine has adjustable steam extractions: production with a pressure of 13 ± 3 kgf / cm 2 abs.; two heating extractions (for heating network water): upper with a pressure of 0.5-2.5 kgf / cm 2 abs.; lower - 0.3-1 kgf / cm 2 abs.
Pressure regulation is carried out with the help of one regulating diaphragm installed in the lower heating extraction chamber.
Regulated pressure in the heating extractions is maintained: in the upper extraction when two heating extractions are turned on, in the lower one - when one lower heating extraction is turned on.
The feed water is heated sequentially in the HPH, deaerator and HPH, which are fed with steam from the turbine bleeds (regulated and unregulated).
Data on regenerative selections are given in Table. 2 and correspond to the parameters in all respects.
Table 1 Table 2
|
Heater |
Steam parameters in the selection chamber |
Quantity selected steam, t/h |
|
|
Pressure, kgf / cm 2 abs. |
Temperature, С |
||
|
LDPE No. 6 |
|||
|
Deaerator |
|||
|
PND No. 2 |
|||
|
PND No. 1 |
|||
The feed water coming from the deaerator into the regenerative system of the turbine plant has a temperature of 158°C.
With nominal parameters of fresh steam, cooling water flow rate of 8000 m 3 h, cooling water temperature of 20 ° C, fully switched on regeneration, the amount of water heated in the HPH equal to 100% steam flow rate, when the turbine plant is operating according to the scheme with a deaerator 6 kgf / cm 2 abs. with staged heating of network water, with full use of the throughput of the turbine and a minimum passage of steam into the condenser, the following values of regulated extractions can be taken: nominal values of regulated extractions at a power of 80 MW; production selection 185 t/h at a pressure of 13 kgf/cm 2 abs.; total heating extraction 132 t/h at pressures: in the upper selection 1 kgf/cm 2 abs. and in the lower selection 0.35 kgf/cm 2 abs.; the maximum value of production selection at a pressure in the selection chamber of 13 kgf / cm 2 abs. is 300 t/h; with this value of production extraction and the absence of heating extraction, the turbine power will be 70 MW; with a rated power of 80 MW and no heat extraction, the maximum production extraction will be about 245 t/h; the maximum total value of heat extraction is 200 t/h; with this value of extraction and the absence of production extraction, the capacity will be about 76 MW; with a nominal power of 80 MW and no production extraction, the maximum heat extraction will be 150 t/h. In addition, a nominal power of 80 MW can be achieved with a maximum heat extraction of 200 t/h and a production extraction of 40 t/h.
Long-term operation of the turbine is allowed with the following deviations of the main parameters from the nominal ones: live steam pressure 125-135 kgf/cm 2 abs.; live steam temperature 545-560°C; increasing the temperature of the cooling water at the condenser inlet to 33°C and the flow rate of the cooling water is 8000 m 3 h; simultaneous decrease in the value of industrial and heating steam extractions to zero.
When the pressure of live steam is increased to 140 kgf/cm 2 abs. and temperatures up to 565 ° C, the operation of the turbine is allowed for no more than 30 minutes, and the total duration of the operation of the turbine at these parameters should not exceed 200 hours per year.
The long-term operation of a turbine with a maximum power of 100 MW for certain combinations of production and heat extraction depends on the amount of extraction and is determined by the regime diagram.
The operation of the turbine is not allowed: at a steam pressure in the production selection chamber above 16 kgf / cm 2 abs. and in the chamber of heating selection above 2.5 kgf/cm 2 abs.; at a steam pressure in the overload valve chamber (behind the 4th stage) above 83 kgf/cm 2 abs.; at a steam pressure in the chamber of the LPC control wheel (behind the 18th stage) above 13.5 kgf/cm 2 abs.; when the pressure regulators are turned on and the pressures in the production extraction chamber are below 10 kgf/cm 2 abs., and in the lower heating extraction chamber below 0.3 kgf/cm 2 abs.; for exhaust into the atmosphere; the temperature of the exhaust part of the turbine is above 70 ° C; according to a temporary unfinished installation scheme; with the upper heating extraction switched on with the lower heating extraction switched off.
The turbine is equipped with a barring device that rotates the turbine rotor.
The blade assembly of the turbine is designed to operate at a mains frequency of 50 Hz (3000 rpm).
Long-term operation of the turbine is allowed with network frequency deviations within 49-50.5 Hz, short-term operation at a minimum frequency of 48.5 Hz, turbine start-up at sliding steam parameters from cold and hot states.
Approximate duration of turbine start-ups from various thermal states (from shock to nominal load): from a cold state - 5 hours; after 48 hours of inactivity - 3 hours 40 minutes; after 24 hours of inactivity - 2 hours 30 minutes; after 6-8 hours of inactivity - 1 hour 15 minutes.
The turbine is allowed to operate Idling after load shedding, no more than 15 minutes, provided that the condenser is cooled by circulating water and the rotary diaphragm is fully open.
Guaranteed heat costs. In table. 3 shows the guaranteed specific heat consumption. The specific steam consumption is guaranteed with a tolerance of 1% over the tolerance for test accuracy.
Table 3
|
Power at the generator terminals, MW |
Production selection |
Heating selection |
Temperature of network water at the inlet to the network heater, PSG 1, °С |
Generator efficiency, % |
Feed water heating temperature, °C |
Specific heat consumption, kcal/kWh |
||
|
Pressure, kgf / cm 2 abs. |
Pressure, kgf / cm 2 abs. |
Amount of extracted steam, t/h |
||||||
* Pressure regulators in the selections are turned off.
Turbine design. The turbine is a single-shaft two-cylinder unit. The HPC flow path has a single-row control stage and 16 pressure stages.
The flow part of the LPC consists of three parts: the first (before the upper heating extraction) has a control stage and seven pressure stages, the second (between the heating extractions) has two pressure stages and the third has a control stage and two pressure stages.
The high-pressure rotor is one-piece forged. The first ten disks of the low-pressure rotor are forged integrally with the shaft, the remaining three disks are mounted.
The HP and LPC rotors are connected rigidly with the help of flanges forged integrally with the rotors. The rotors of the LPC and the TVF-120-2 type generator are connected by means of a rigid coupling.
Critical speeds of the turbine and generator shafting per minute: 1,580; 2214; 2470; 4650 correspond to I, II, III and IV tones of transverse vibrations.
The turbine has nozzle steam distribution. Fresh steam is supplied to a free-standing steam box, in which an automatic shutter is located, from where steam flows through bypass pipes to the turbine control valves.
Upon leaving the HPC, part of the steam goes to controlled production extraction, the rest goes to the LPC.
Heating extractions are carried out from the corresponding LPC chambers. Upon exiting the last stages of the low pressure cylinder of the turbine, the exhaust steam enters the surface-type condenser.
The turbine is equipped with steam labyrinth seals. Steam is supplied to the penultimate compartments of the seals at a pressure of 1.03-1.05 kgf/cm 2 abs. at a temperature of about 140°C from a collector fed with steam from the equalizing line of the deaerator (6 kgf/cm 2 abs.) or the vapor space of the tank.
From the extreme compartments of the seals, the vapor-air mixture is sucked off by an ejector into a vacuum cooler.
The turbine fixing point is located on the turbine frame on the generator side, and the unit expands towards the front bearing.
To reduce the warm-up time and improve start-up conditions, steam heating of flanges and studs and live steam supply to the HPC front seal are provided.
regulation and protection. The turbine is equipped with a hydraulic control system (Fig. 3);
1- power limiter; 2-block of spools of the speed controller; 3-remote control; 4-automatic shutter servomotor; 5-speed controller; 6-safety regulator; 7-spools of the safety regulator; 8-distance servo position indicator; 9-servomotor CFD; 10-servomotor CSD; 11-servomotor CND; 12-electrohydraulic converter (EGP); 13-summing spools; 14-emergency electric pump; 15-backup electric lubrication pump; 16-starter electric pump of the control system (alternating current);
I- pressure line 20 kgf/cm 2 abs.;II- line to the HPC servomotor spool;III- line to the spool of the servomotor CH "SD; IV-line to the spoolat the LPC servomotor; V-suction line of the centrifugal main pump; VI-line lubrication to oil coolers; VII-line to automatic shutter; VIII-line from the summing spools to the speed controller; IX line of additional protection; X - other lines.
The working fluid in the system is mineral oil.
The shifting of the live steam inlet control valves, control valves in front of the CSD and the rotary steam bypass diaphragm in the LPR is carried out by servomotors, which are controlled by the rotation speed regulator and the selection pressure regulators.
The regulator is designed to maintain the rotational speed of the turbogenerator with an unevenness of about 4%. It is equipped with a control mechanism that is used to: charge the safety regulator spools and open the automatic fresh steam shutter; changes in the rotational speed of the turbogenerator, and it is possible to synchronize the generator at any emergency frequency in the system; maintaining the specified load of the generator during parallel operation of the generator; maintaining normal frequency during single operation of the generator; increasing the speed when testing the strikers of the safety regulator.
The control mechanism can be actuated both manually - directly at the turbine, and remotely - from the control panel.
Bellows-type pressure regulators are designed to automatically maintain steam pressure in the controlled extraction chambers with an unevenness of about 2 kgf / cm 2 for production extraction and about 0.4 kgf / cm 2 for heating extraction.
The control system has an electro-hydraulic converter (EHP), the closing and opening of the control valves of which are affected by technological protection and emergency automatics of the power system.
To protect against an unacceptable increase in the speed of rotation, the turbine is equipped with a safety regulator, two centrifugal strikers of which are instantly triggered when the speed reaches 11-13% above the nominal, which causes the closing of the automatic fresh steam shutter, control valves and rotary diaphragm. In addition, there is an additional protection on the block of spools of the speed regulator, which is activated when the frequency rises by 11.5%.
The turbine is equipped with an electromagnetic switch, which, when triggered, closes the automatic shutter, control valves and the rotary diaphragm of the LPR.
The impact on the electromagnetic switch is carried out by: an axial shift relay when the rotor moves in the axial direction by an amount
exceeding the maximum allowable; vacuum relay in case of unacceptable vacuum drop in the condenser up to 470 mm Hg. Art. (when the vacuum drops to 650 mm Hg, the vacuum relay gives a warning signal); live steam temperature potentiometers in case of unacceptable decrease in live steam temperature without time delay; key for remote shutdown of the turbine on the control panel; pressure drop switch in the lubrication system with a time delay of 3 s with simultaneous alarm.
The turbine is equipped with a power limiter used in special cases to limit the opening of the control valves.
Check valves are designed to prevent turbine acceleration by reverse steam flow and are installed on pipelines (regulated and unregulated) for steam extraction. The valves are closed by steam counterflow and by automation.
The turbine unit is equipped with electronic regulators with actuators to maintain: the specified steam pressure in the end seal manifold by acting on the steam supply valve from the equalization line of deaerators 6 kgf/cm 2 or from the vapor space of the tank; level in the condensate collector with a maximum deviation from the specified ± 200 mm, (the same regulator turns on condensate recirculation at low steam flow rates in the condenser); level of heating steam condensate in all heaters of the regeneration system, except for HDPE No. 1.
The turbine unit is equipped with protective devices: for joint shutdown of all HPH with simultaneous activation of the bypass line and signaling (the device is triggered in case of an emergency increase in the level of condensate due to damage or violations of the density of the pipe system in one of the HPH to the first limit); atmospheric valves-diaphragms, which are installed on the exhaust pipes of the LPC and open when the pressure in the pipes rises to 1.2 kgf/cm 2 abs.
Lubrication system is designed to supply oil T-22 GOST 32-74 control systems and bearing lubrication systems.
Oil is supplied to the lubrication system up to the oil coolers by means of two injectors connected in series.
To service the turbogenerator during its start-up, a starting oil electric pump with a rotation speed of 1,500 rpm is provided.
The turbine is equipped with one standby pump with an AC motor and one emergency pump with a DC motor.
When the lubrication pressure drops to the appropriate values, the backup and emergency pumps are automatically switched on from the lubrication pressure switch (RDS). RDS is periodically tested during turbine operation.
At a pressure below the allowable one, the turbine and the turning device are disconnected from the RDS signal to the electromagnetic switch.
The working capacity of the welded construction tank is 14 m 3 .
Filters are installed in the tank to clean the oil from mechanical impurities. The design of the tank allows for quick and safe filter changes. There is a fine oil filter from mechanical impurities, which provides continuous filtration of part of the oil consumption consumed by control and lubrication systems.
To cool the oil, two oil coolers (surface vertical) are provided, designed to operate on fresh cooling water from the circulation system at a temperature not exceeding 33 ° C.
condensation device, intended for servicing the turbine plant, consists of a condenser, main and starting ejectors, condensate and circulation pumps and water filters.
Surface two-pass condenser with a total cooling surface of 3,000 m 2 is designed to operate on fresh cooling water. It has a separate built-in bundle for heating make-up or network water, the heating surface of which is about 20% of the entire condenser surface.
A surge vessel is supplied with the condenser for connecting an electronic level control sensor that acts on the control and recirculation valves installed on the main condensate pipeline. The condenser has a special chamber built into the steam part, in which the HDPE section No. 1 is installed.
The air-removing device consists of two main three-stage ejectors (one reserve), designed to suck air and ensure the normal heat exchange process in the condenser and other vacuum heat exchangers, and one starting ejector to quickly raise the vacuum in the condenser to 500-600 mmHg. Art.
The condensing device is equipped with two condensate pumps (one standby) of vertical type for pumping condensate and supplying it to the deaerator through ejector coolers, seal coolers and HDPE. Cooling water for the condenser and generator gas coolers is supplied by circulation pumps.
For mechanical cleaning of the cooling water supplied to the oil coolers and gas coolers of the unit, filters with rotary screens are installed for flushing on the go.
Starting ejector circulation system is designed to fill the system with water before starting the turbine plant, as well as to remove air when it accumulates in the upper points of the drain circulation conduits and in the upper water chambers of the oil coolers.
To break the vacuum, an electric valve is used on the air suction pipeline from the condenser, installed at the starting ejector.
Regenerative device designed for heating feed water (turbine condensate) with steam taken from the intermediate stages of the turbine. The unit consists of a surface working steam condenser, a main ejector, surface steam coolers made of labyrinth seals, and surface low pressure vapor pressure coolers, after which the turbine condensate is sent to the high pressure high pressure deaerator to heat the feed water after the deaerator in an amount of about 105% of the maximum steam flow rate of the turbine.
HDPE No. 1 is built into the capacitor. The rest of the PND are installed by a separate group. HPH No. 5, 6 and 7 - vertical design with built-in desuperheaters and drain coolers.
HPH are supplied with group protection, consisting of automatic outlet and non-return valves at the inlet and outlet of water, an automatic valve with an electromagnet, a pipeline for starting and turning off the heaters.
HPH and HDPE each, except HDPE No. 1, are equipped with a condensate drain control valve controlled by an electronic "regulator.
Draining of heating steam condensate from heaters - cascade. From HDPE No. 2, condensate is pumped out by a drain pump.
Condensate from HPH No. 5 is directly sent to the deaerator 6 kgf/cm 2 abs. or in case of insufficient pressure in the heater at low turbine loads, it automatically switches to draining into the HDPE.
Characteristics of the main equipment of the regenerative plant are given in Table. 4.
A special vacuum cooler SP is supplied to suck steam from the extreme compartments of the labyrinth seals of the turbine.
Steam suction from the intermediate compartments of the labyrinth seals of the turbine is carried out into the CO vertical cooler. The cooler is included in the regenerative circuit for heating the main condensate after LPH No. 1.
The design of the cooler is similar to that of low pressure heaters.
The network water is heated in an installation consisting of two network heaters No. 1 and 2 (PSG No. 1 and 2), connected by steam, respectively, to the lower and upper heating extractions. Type of network heaters - PSG-1300-3-8-1.
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Equipment identification |
Heating surface, m 2 |
Parameters working environment |
Pressure, kgf/cm 2 abs., at hydraulic test in spaces |
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Water consumption, m 3 / h |
Resistance, m of water. Art. |
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built into the condenser |
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PND №2 |
PN-130-16-9-II |
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PND №3 |
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PND №4 |
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PND №5 |
PV-425-230-23-1 |
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PND №6 |
PV-425-230-35-1 |
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PND №7 |
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Steam cooler from intermediate seal chambers |
PN-130-1-16-9-11 |
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Steam cooler from seal end chambers |
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