The heating steam turbine PT-80/100-130/13 with industrial and heating steam extraction is designed to directly drive the TVF-120-2 electric generator with a rotation speed of 50 rps and release heat for production and heating needs.
The nominal values of the main parameters of the turbine are given below.
Power, MW
nominal 80
maximum 100
Steam ratings
pressure, MPa 12.8
temperature, 0 C 555
Consumption of extracted steam for production needs, t/h
nominal 185
maximum 300
Limits of change in steam pressure in regulated heating outlet, MPa
upper 0.049-0.245
lower 0.029-0.098
Production selection pressure 1.28
Water temperature, 0 C
nutritious 249
cooling 20
Cooling water consumption, t/h 8000
The turbine has the following adjustable steam extractions:
production with absolute pressure (1.275 0.29) MPa and two heating extractions - upper with absolute pressure in the range of 0.049-0.245 MPa and lower with pressure in the range of 0.029-0.098 MPa. The heating bleed pressure is regulated using one control diaphragm installed in the upper heating bleed chamber. The 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 on. Network water must be passed through the network heaters of the lower and upper heating stages sequentially and in equal quantities. The flow of water passing through network heaters must be controlled.
The turbine is a single-shaft two-cylinder unit. The flow part of the HPC has a single-coil control stage and 16 pressure levels.
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 levels,
second (between heating extractions) two pressure stages,
the third - a regulating stage and two pressure stages.
Rotor high pressure solid forged. First ten rotor discs low pressure forged integrally with the shaft, the remaining three disks are mounted.
The turbine steam distribution is nozzle. At the exit from the HPC, part of the steam goes to the controlled production extraction, the rest is sent to the LPC. Heating extractions are carried out from the corresponding LPC chambers.
To reduce warm-up time and improve start-up conditions, steam heating of flanges and studs and supply of live steam to front seal CVP.
The turbine is equipped with a shaft turning device that rotates the shaft line of the turbine unit at a frequency of 3.4 rpm.
The turbine blade apparatus is designed to operate at a network frequency of 50 Hz, which corresponds to a turbine unit rotor speed of 50 rpm (3000 rpm). Long-term operation of the turbine is allowed with a network frequency deviation of 49.0-50.5 Hz.
3.3.4 Steam turbine unit PT-80/100-130/13
The heating steam turbine PT-80/100-130/13 with industrial and heating steam extraction is designed to directly drive the TVF-120-2 electric generator with a rotation speed of 50 rps and release heat for production and heating needs.
Power, MW
nominal 80
maximum 100
Steam ratings
pressure, MPa 12.8
temperature, 0 C 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
nutritious 249
cooling 20
Cooling water consumption, t/h 8000
The turbine has the following adjustable steam extractions:
production with absolute pressure (1.275 ± 0.29) MPa and two heating extractions - upper with absolute pressure in the range of 0.049-0.245 MPa and lower with pressure in the range of 0.029-0.098 MPa. The heating bleed pressure is regulated using one control diaphragm installed in the upper heating bleed chamber. The 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 on. Network water must be passed through the network heaters of the lower and upper heating stages sequentially and in equal quantities. The flow of water passing through network heaters must be controlled.
The turbine is a single-shaft two-cylinder unit. The flow part of the HPC has a single-coil control stage and 16 pressure levels.
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 levels,
second (between heating extractions) two pressure stages,
the third - a regulating stage and two pressure stages.
High pressure rotor is solid forged. The first ten disks of the low-pressure rotor are forged integrally with the shaft, the remaining three disks are mounted.
The turbine steam distribution is nozzle. At the exit from the HPC, part of the steam goes to the controlled production extraction, the rest is sent to the LPC. Heating extractions are carried out from the corresponding LPC chambers.
To reduce warm-up time and improve start-up conditions, steam heating of flanges and studs and live steam supply to the front seal of the HPC are provided.
The turbine is equipped with a shaft turning device that rotates the shaft line of the turbine unit at a frequency of 3.4 rpm.
The turbine blade apparatus is designed to operate at a network frequency of 50 Hz, which corresponds to a turbine unit rotor speed of 50 rpm (3000 rpm). Long-term operation of the turbine is allowed with a network frequency deviation of 49.0-50.5 Hz.
3.3.5 Steam turbine unit R-50/60-130/13-2
The steam turbine with back pressure R-50/60-130/13-2 is designed to drive the TVF-63-2 electric generator with a rotation speed of 50 s -1 and release steam for production needs.
The nominal values of the main parameters of the turbine are given below:
Power, MW
Nominal 52.7
Maximum 60
Initial steam parameters
Pressure, MPa 12.8
Temperature, о С 555
Pressure in the exhaust pipe, MPa 1.3
The turbine has two unregulated steam extractions designed to heat 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 disks are forged integrally with the shaft. Turbine steam distribution with bypass. Fresh steam is supplied to a free-standing steam box containing an automatic shut-off valve, from where the steam is supplied 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 when the frequency deviation in the network is 49.0-50.5 Hz
The turbine unit is equipped protective devices to simultaneously turn off the high pressure pump while simultaneously turning on the bypass line by sending a signal. Atmospheric diaphragm valves installed on the exhaust pipes and opening when the pressure in the pipes increases to 0.12 MPa.
3.3.6 Steam turbine unit T-110/120-130/13
The heating steam turbine T-110/120-130/13 with heating steam extraction is designed to directly drive the TVF-120-2 electric generator with a rotation speed of 50 r/s and release heat for heating needs.
The nominal values of the main parameters of the turbine are given below.
Power, MW
nominal 110
maximum 120
Steam ratings
pressure, MPa 12.8
temperature, 0 C 555
nominal 732
maximum 770
Limits of change in steam pressure in regulated heating outlet, MPa
upper 0.059-0.245
lower 0.049-0.196
Water temperature, 0 C
nutritious 232
cooling 20
Cooling water consumption, t/h 16000
Steam pressure in the condenser, kPa 5.6
The turbine has two heating outlets - lower and upper, designed for stepwise heating of network water. When heating the network water in stages with steam from two heating outlets, the control maintains the set temperature of the network water behind the upper network heater. When heating the network water with one lower heating outlet, the temperature of the network water is maintained behind the lower network heater.
The pressure in adjustable heating outlets can vary within the following limits:
in the upper 0.059 - 0.245 MPa with two heating extractions turned on,
in the lower 0.049 - 0.196 MPa with the upper heating supply turned off.
The T-110/120-130/13 turbine is a single-shaft unit consisting of three cylinders: HPC, CSD, LPC.
The HPC is single-flow, has a two-coil control stage and 8 pressure levels. The high pressure rotor is solid forged.
The CSD is also single-flow and has 14 pressure levels. 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 CSD is installed in the housing, the remaining diaphragms are installed in cages.
The LPC is dual-flow, has two stages in each flow of left and right rotation (one control and one pressure stage). The length of the last stage working blade 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 front seal of the HPC is increased by mixing hot steam from the control valve rods or from the main steam line. From the last compartments of the seals, the steam-air mixture is sucked off by a seal suction ejector.
To reduce the heating time and improve the turbine start-up conditions, steam heating of the HPC flanges and studs is provided.
The turbine blade apparatus is designed to operate at a network frequency of 50 Hz, which corresponds to a turbine unit rotor speed of 50 rpm (3000 rpm).
Long-term operation of the turbine is allowed with a network frequency deviation 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 Almaty CHPP-2 by changing the water-chemical regime of the make-up water preparation system in order to increase the temperature of the network water to 140–145 C”
Specific heat consumption for two-stage heating of network water.
Conditions: G k3-4 = Gin ChSD + 5 t/h; t j - see fig. ; t 1V ≈ 20 °C; W@ 8000 m3/h
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °C; t 1V ≈ 20 °C; W@ 8000 m3/h; Δ i PEN = 7 kcal/kg
|
Rice. 10, A, b, V, G |
AMENDMENTS TO THE COMPLETE ( Q 0) AND SPECIFIC ( qG |
Type |
A) on deviation pressure fresh pair from nominal on ± 0.5 MPa (5 kgf/cm2)
α q t = ± 0,05 %; α G 0 = ± 0,25 %
b) on deviation temperature fresh pair from nominal on ± 5 °C
V) on deviation consumption nutritious water from nominal on ± 10 % G 0
G) on deviation temperature nutritious water from nominal on ± 10 °C
|
Rice. eleven, A, b, V |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO THE COMPLETE ( Q 0) AND SPECIFIC ( q t) HEAT CONSUMPTION AND FRESH STEAM CONSUMPTION ( G 0) IN CONDENSING MODE |
Type |
A) on shutdown groups PVD
b) on deviation pressure spent pair from nominal
V) on deviation pressure spent pair from nominal
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °C; G pit = G 0
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °C
Conditions: G pit = G 0; R 9 = 0.6 MPa (6 kgf/cm2); t pit - see fig. ; t j - 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 j - see fig.
Note. Z= 0 - the control diaphragm is closed. Z= max - the control diaphragm is 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 POWER OF CHSP AND STEAM PRESSURE IN THE UPPER AND LOWER HEATING OUTLETS |
Type |
Conditions: R n = 1.3 MPa (13 kgf/cm2) at Gin ChSD ≤ 221.5 t/h; R n = Gin ChSD/17 - at Gin ChSD > 221.5 t/h; i n = 715 kcal/kg; R 2 = 5 kPa (0.05 kgf/cm2); t j - see fig. , ; τ2 = f(P WTO) - see fig. ; Q t = 0 Gcal/(kW h)
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT INFLUENCE OF HEATING LOAD ON TURBINE POWER WITH SINGLE-STAGE HEATING OF NETWORK WATER |
Type |
Conditions: R 0 = 1.3 (130 kgf/cm2); t 0 = 555 °C; R NTO = 0.06 (0.6 kgf/cm2); R 2 @ 4 kPa (0.04 kgf/cm2)
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT MODE DIAGRAM FOR SINGLE-STAGE HEATING OF NETWORK WATER |
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 = 5 kPa (0.05 kgf/cm2); G pit = G 0.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT DIAGRAM OF MODES FOR TWO-STAGE HEATING OF NETWORK WATER |
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 = 5 kPa (0.05 kgf/cm2); G pit = G 0; τ2 = 52 ° WITH.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT DIAGRAM OF MODES UNDER THE MODE WITH PRODUCTION SELECTION ONLY |
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 ChSD) - see fig. thirty; R 2 = 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 NETWORK WATER |
Type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °C; P n = 1.3 MPa (13 kgf/cm2); R NTO = 0.09 MPa (0.9 kgf/cm2); R 2 = 5 kPa (0.05 kgf/cm2); G pit = G 0; Q t = 0
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SPECIFIC HEAT CONSUMPTION FOR TWO-STAGE HEATING OF NETWORK WATER |
Type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °C; P n = 1.3 MPa (13 kgf/cm2); R WTO = 0.12 MPa (1.2 kgf/cm2); R 2 = 5 kPa (0.05 kgf/cm2); G pit = G 0; τ2 = 52 °C; Q t = 0.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SPECIFIC HEAT CONSUMPTION UNDER MODE WITH PRODUCTION SELECTION ONLY |
Type |
Conditions: R 0 = 13 MPa (130 kgf/cm2); t 0 = 555 °C; P n = 1.3 MPa (13 kgf/cm2); R WTO and R NTO = f(Gin ChSD) - see fig. ; R 2 = 5 kPa (0.05 kgf/cm2); G pit = G 0.
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT MINIMUM POSSIBLE PRESSURE IN THE BOTTOM HEATING OUTLET WITH SINGLE-STAGE HEATING OF NETWORK WATER |
Type |
|
Rice. 41, A, b |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT TWO-STAGE HEATING OF NETWORK WATER (According to DATA from LMZ POTS) |
Type |
A) minimally possible pressure V upper T-selection And calculated temperature reverse network water
b) amendment on temperature reverse network water
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION TO POWER FOR PRESSURE DEVIATION IN THE LOWER HEATING OUTLET FROM NOMINAL WITH SINGLE-STAGE HEATING OF NETWORK WATER (According to DATA from LMZ POTS) |
Type |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION TO POWER FOR PRESSURE DEVIATION IN THE UPPER HEATING SYSTEM FROM NOMINAL WITH TWO-STAGE HEATING OF NETWORK WATER (ACCORDING TO LMZ POTS DATA) |
Type |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION FOR EXHAUST STEAM PRESSURE (ACCORDING TO LMZ POT DATA) |
Type |
1 Based on data from POT LMZ.
On deviation pressure fresh pair from nominal on ±1 MPa (10 kgf/cm2): To complete 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 SELECTIONS1 |
Type |
1 Based on data from POT LMZ.
On deviation temperature fresh pair from nominal on ±10°C:
To complete consumption warmth
To consumption fresh pair
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL HEAT CONSUMPTION ( Q 0) AND FRESH STEAM CONSUMPTION ( G 0) IN MODES WITH ADJUSTABLE SELECTIONS1 |
Type |
1 Based on data from POT LMZ.
On deviation pressure V P-selection from nominal on ± 1 MPa (1 kgf/cm2):
To complete consumption warmth
To consumption fresh pair
|
Rice. 49 A, b, V |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SPECIFIC COOPERATION ELECTRICITY GENERATION |
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 upper And lower district heating 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 district heating 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 SPECIFIC COMBINATION ELECTRICITY GENERATION FOR PRESSURE IN REGULATED SELECTIONS |
Type |
A) on pressure V production selection
b) on pressure V upper heating selection
V) on pressure V lower heating selection
1. CONDITIONS FOR COMPILATION OF ENERGY CHARACTERISTICS
A typical energy characteristic was compiled on the basis of reports on thermal tests of two turbine units: at Chisinau CHPP-2 (work performed by Yuzhtekhenergo) and at CHPP-21 Mosenergo (work performed by MGP PO Soyuztechenergo). The characteristic reflects the average efficiency of a turbine unit that has undergone major renovation and operating according to the thermal circuit shown in Fig. ; under the following parameters and conditions accepted as nominal:
The pressure and temperature of fresh steam in front of the turbine stop valve is 13 (130 kgf/cm2)* and 555 °C;
* In the text and graphs - absolute pressure.
The pressure in the regulated production outlet is 13 (13 kgf/cm2) with a natural increase at flow rates at the entrance to the ChSD of more than 221.5 t/h;
The pressure in the upper district heating extraction is 0.12 (1.2 kgf/cm2) with a two-stage scheme for heating network water;
The pressure in the lower heating outlet is 0.09 (0.9 kgf/cm2) with a single-stage scheme for heating network water;
Pressure in the regulated production extraction, upper and lower heating extractions in condensation mode with pressure regulators turned off - fig. And ;
Exhaust steam pressure:
a) to characterize the condensation mode and work with selections for single-stage and two-stage heating of network water at constant pressure- 5 kPa (0.05 kgf/cm2);
b) to characterize the condensation mode at constant flow rate and temperature of cooling water - in accordance with the thermal characteristics of the condenser at t 1V= 20 °C and W= 8000 m3/h;
The high and low pressure regeneration system is fully turned on, the deaerator 0.6 (6 kgf/cm2) is powered by production steam;
Feed water consumption is equal to fresh steam consumption, 100% of production condensate is returned at t= 100 °C carried out in a deaerator 0.6 (6 kgf/cm2);
The temperature of the feed water and the main condensate behind the heaters corresponds to the dependencies shown in Fig. , , , , ;
The increase in enthalpy of feed water in the feed pump is 7 kcal/kg;
The electromechanical efficiency of the turbine unit was adopted based on testing of a similar turbine unit carried out by Dontekhenergo;
Limits of pressure regulation in selections:
a) production - 1.3 ± 0.3 (13 ± 3 kgf/cm2);
b) upper district heating with a two-stage heating scheme for heating water - 0.05 - 0.25 (0.5 - 2.5 kgf/cm2);
a) lower district heating with a single-stage heating scheme for heating water - 0.03 - 0.10 (0.3 - 1.0 kgf/cm2).
Heating of network water in a district heating plant with a two-stage scheme for heating network water, determined by factory calculated dependencies τ2р = f(P VTO) 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 forming the basis of this Standard Energy Characteristic was processed using the “Tables of Thermophysical Properties of Water and Water Steam” (M.: Standards Publishing House, 1969). According to the conditions of the LMZ POT, the return condensate of the production selection is introduced at a temperature of 100 ° C into the main condensate line after HDPE No. 2. When compiling the Typical Energy Characteristics, it is accepted that it is introduced at the same temperature directly into the deaerator 0.6 (6 kgf/cm2) . According to the conditions of the LMZ POT, with two-stage heating of network water and modes with a steam flow rate at the entrance to the CSD of more than 240 t/h (maximum electrical load with low production output), HDPE No. 4 is completely switched off. When compiling the Standard Energy Characteristics, it was accepted that when the flow rate at the entrance to the CSD is over 190 t/h, part of the condensate is directed to the HDPE bypass No. 4 in such a way 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
Along with the turbine, the turbine unit includes the following equipment:
Generator TVF-120-2 from the Elektrosila plant with hydrogen cooling;
Two-pass capacitor 80 KTSS-1 with a total surface of 3000 m2, of which 765 m2 is the share of 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 flow 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 into the condenser);
Two main three-stage ejectors EP-3-701 and one starting ejector 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 area of 1300 m2 each, designed to pass 2300 m3/h of network water;
Four condensate pumps of KN-KS 80/155 network water heaters driven by electric motors with a power of 75 kW each (two pumps for each PSG);
One network pump of the first lift SE-5000-70-6 with a 500 kW electric motor;
One network pump II lift SE-5000-160 with a 1600 kW electric motor.
3. CONDENSATION MODE
In condensation mode with pressure regulators turned off, the total gross heat consumption and fresh steam consumption, depending on the power at the generator terminals, are expressed by the equations:
At constant condenser pressure
P 2 = 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 range from 40 to 80 MW.
The consumption of heat and fresh steam during condensation mode for a given power is determined from the given dependencies with the subsequent introduction of the necessary corrections according to the corresponding graphs. These amendments take into account the difference between operating conditions and nominal ones (for which the Typical Characteristics were compiled) and serve to recalculate the characteristics data to operating conditions. During reverse recalculation, the signs of the amendments are reversed.
The amendments adjust the consumption of heat and fresh steam at a constant power. When several parameters deviate from the nominal values, the corrections are algebraically summed up.
4. MODE WITH ADJUSTABLE SELECTIONS
When the controlled extractions are turned on, the turbine unit can operate with single-stage and two-stage heating schemes for heating water. It is also possible to work without heating extraction with one production unit. The corresponding typical diagrams of modes for steam consumption and the dependence of specific heat consumption on power and production output are given in Fig. - , and specific electricity generation per heat consumption in Fig. - .
The mode diagrams are calculated according to the scheme used by POT LMZ and are shown in two fields. The upper field is a diagram of the modes (Gcal/h) of a turbine with one production extraction at Q t = 0.
When the heating load is turned on and other unchanged conditions, either only stages 28 - 30 are unloaded (with one lower mains heater turned on), or stages 26 - 30 (with two mains heaters turned on) and the turbine power is reduced.
The power reduction value depends on the heating load and is determined
Δ N Qt = KQ T,
Where K- specific change in turbine power Δ determined during testing 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 fresh steam consumption at a given power N t and two (production and heating) selections will be according to top margin correspond to some fictitious power N ft and one production selection
N ft = N t + Δ N Qt.
The inclined straight lines in the lower field of the diagram allow you to determine graphically the value of the given turbine power and heating load N ft, and according to it and production selection, fresh steam consumption.
The values of specific heat consumption and specific electricity generation for thermal consumption are calculated based on data taken from the calculation of regime diagrams.
The graphs of the dependence of specific heat consumption on power and production output are based on the same considerations as the basis for the LMZ POT mode diagram.
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 a charting system q t = f(N T, Q t) at different Q n = const, since it is more convenient to use. For unprincipled reasons, the graphs of specific heat consumption are made without a lower field; the methodology for using them is explained with examples.
The typical characteristic does not contain data characterizing the mode for three-stage heating of network water, since this mode was not mastered anywhere in installations of this type during the testing period.
The influence of deviations of parameters from those accepted when calculating the Typical Characteristics as nominal is taken into account in two ways:
a) parameters that do not affect heat consumption in the boiler and heat supply to the consumer at constant mass flow rates G 0, G n and G t, - by introducing amendments 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) corrections for P 0, t 0 and P n are added to those found after making the above amendments to the fresh steam flow rate and the total heat flow rate, after which the fresh steam flow rate and heat flow rate (total and specific) are calculated for the given conditions.
Data for live steam pressure correction curves are calculated using test results; all other correction curves are based on LMZ POT data.
5. EXAMPLES OF DETERMINING SPECIFIC HEAT CONSUMPTION, FRESH STEAM CONSUMPTION AND SPECIFIC HEATING WORKS
Example 1. Condensation mode with disconnected pressure regulators in the selections.
Given: N t = 70 MW; P 0 = 12.5 (125 kgf/cm2); t 0 = 550 °C; R 2 = 8 kPa (0.08 kgf/cm2); G pit = 0.93 G 0; Δ t pit = t pete - t npit = -7 °C.
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 |
Determination method |
Received value |
Fresh steam consumption at nominal conditions, t/h |
Fresh steam temperatures |
Feed water consumption |
Total correction to specific heat consumption, % |
Specific heat consumption under given conditions, kcal/(kW h) |
|
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, %: |
Live steam pressure |
Fresh steam temperatures |
Exhaust steam pressure |
Feed water consumption |
Feed water temperatures |
Total correction to fresh steam consumption, % |
Fresh steam consumption under given conditions, t/h |
|
Table P2
* When adjusting power for pressure in the upper heating output 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 noticeable difference G CHSDvkh" from G CHSDin all values in pp. 4 - 11 should be checked according to the specified G CHSDin. The calculation of specific heating workings is carried out similarly to that given in the example. Development of heating output and correction to it for actual pressure R WTO is determined according to Fig. , b And , b. Example 4. Mode without heating extraction. Given: N t = 80 MW; Q n = 120 Gcal/h; Q t = 0; R 0 = 12.8 (128 kgf/cm2); t 0 = 550 °C; R 7.65 |
Pressure in the upper heating extraction, (kgf/cm2)* |
R WTO |
Rice. By G CHSDin" |
Pressure in the lower heating outlet, (kgf/cm2)* |
R NTO |
Rice. By G CHSDin" |
* Pressures in the ChSND selections and condensate temperature in the HDPE can be determined from condensation regime graphs depending on G ChSDin, with the ratio G CHSDin/ G 0 = 0,83.
6. LEGEND
|
Name |
Designation |
Power, MW: |
electrical at the generator terminals |
N T, N tf |
high pressure internal parts |
N iCHVD |
medium and low pressure internal parts |
N iCHSND |
total losses of the turbine unit |
Σ∆ N sweat |
electromechanical efficiency |
High pressure cylinder (or part) |
Low (or medium and low) pressure cylinder |
TsSD (ChSND) |
Steam consumption, t/h: |
to the turbine |
for production |
for district heating |
for regeneration |
G PVD, G HDPE, G d |
through the last stage of CVP |
G ChVDskv |
at the entrance to the ChSD |
G CHSDinh |
at the entrance to the ChND |
G CHNDin |
to the capacitor |
Feed water consumption, t/h |
Consumption of returned production condensate, t/h |
Cooling water flow through the condenser, m3/h |
Heat consumption per turbine unit, Gcal/h |
Heat consumption for production, Gcal/h |
Absolute pressure, (kgf/cm2): |
before the stop valve |
behind control and overload valves |
P.I.-IV cl, P lane |
in the control stage chamber |
P r.st. |
in unregulated sampling chambers |
P.I.-VII P |
in the production selection chamber |
in the upper heating chamber |
in the lower heating chamber |
in the capacitor, kPa (kgf/cm2) |
Temperature (°C), 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 from production extraction |
feed water behind the PVD |
t pit5, t pit6, t pit7 |
feed water behind the plant |
t Pete, i Pete |
network water at the entrance to and exit from the installation |
cooling water entering and leaving the condenser |
t 1c, t 2v |
Increasing the enthalpy of feed water in the pump |
∆i PEN |
Specific gross heat consumption for electricity generation, kcal/(kW h) |
q T, q tf |
Specific cogeneration electricity generation, kWh/Gcal: |
production steam |
district heating 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
80 MW POWER
Steam condensing turbine PT-80/100-130/13 (Fig. 1) with controlled steam extraction (production and two-stage heating) with a nominal power of 80 MW, with a rotation speed of 3000 rpm, is intended for direct drive of an alternating current generator with a power of 120 MW 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 stepwise heating of network water and must work in conjunction with a condensing unit (Fig. 2).
The turbine is designed to operate with the following basic parameters, which are presented in Table 1.
The turbine has adjustable steam extraction: production with a pressure of 13±3 kgf/cm 2 abs.; two district 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 using one control diaphragm installed in the lower heating chamber.
The regulated pressure in the district heating extractions is maintained: in the upper extraction when two heating extractions are switched on, in the lower – when one lower heating extraction is switched on.
Heating of feed water is carried out sequentially in the HDPE, deaerator and HPH, which are fed with steam from turbine extractions (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 |
Parameters of steam in the sampling chamber |
Quantity selected steam, t/h |
|
|
Pressure, kgf/cm 2 abs. |
Temperature, С |
||
|
PVD No. 6 |
|||
|
Deaerator |
|||
|
HDPE No. 2 |
|||
|
HDPE No. 1 |
|||
The feed water entering the regenerative system of the turbine unit from the deaerator has a temperature of 158° C.
At nominal parameters of fresh steam, cooling water flow rate of 8000 m3 h, cooling water temperature of 20 ° C, regeneration fully turned on, the amount of water heated in the HPH equal to 100% steam flow rate, when the turbine unit is operating according to the scheme with a deaerator 6 kgf/ cm 2 abs. with stepwise heating of network water, with full use of the turbine throughput and minimal steam passage 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 extraction 1 kgf/cm 2 abs. and in the lower selection 0.35 kgf/cm 2 abs.; the maximum value of production extraction at a pressure in the extraction 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 nominal power of 80 MW and the absence of heating extraction, the maximum production extraction will be about 245 t/h; the maximum total value of district heating extraction is 200 t/h; with this amount of withdrawal and the absence of production withdrawal, the capacity will be about 76 MW; with a rated power of 80 MW and no production extraction, the maximum heating extraction will be 150 t/h. In addition, a rated power of 80 MW can be achieved with a maximum heating output of 200 t/h and a production output of 40 t/h.
Long-term operation of the turbine is allowed with the following deviations of the main parameters from the nominal ones: fresh steam pressure 125-135 kgf/cm 2 abs.; fresh steam temperature 545-560° C; increasing the temperature of the cooling water at the condenser inlet to 33 ° C and the cooling water flow rate of 8000 m 3 h; simultaneous reduction in the amount of production and heating steam extraction to zero.
When the fresh steam pressure increases to 140 kgf/cm 2 abs. and temperatures up to 565° C, turbine operation is allowed for no more than 30 minutes, and total duration Turbine operation at these parameters should not exceed 200 hours per year.
Long-term operation of a turbine with a maximum power of 100 MW with certain combinations of production and heating extractions depends on the magnitude of extractions and is determined by the regime diagram.
Turbine operation is not allowed: when the steam pressure in the production sampling chamber is above 16 kgf/cm 2 abs. and in the heating extraction chamber above 2.5 kgf/cm 2 abs.; when the steam pressure in the overload valve chamber (behind the 4th stage) is above 83 kgf/cm 2 abs.; when the steam pressure in the chamber of the LPC control wheel (behind the 18th stage) is above 13.5 kgf/cm 2 abs.; when the pressure regulators are turned on and the pressure in the production sampling chamber is below 10 kgf/cm 2 abs., and in the lower heating sampling chamber below 0.3 kgf/cm 2 abs.; for exhaust into the atmosphere; turbine exhaust temperature above 70° C; according to a temporary unfinished installation scheme; with the upper heating extraction switched on and the lower heating extraction switched off.
The turbine is equipped with a shaft turning device that rotates the turbine rotor.
The turbine blade unit is designed to operate at a network frequency of 50 Hz (3000 rpm).
Long-term operation of the turbine is allowed with deviations in the network frequency within the range of 49-50.5 Hz, short-term operation at a minimum frequency of 48.5 Hz, and startup of the turbine on sliding steam parameters from cold and hot states.
The approximate duration of turbine starts from various thermal states (from shock to rated 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.
It is allowed to operate the turbine at idle speed after load shedding for no more than 15 minutes, provided that the condenser is cooled with circulating water and the rotary diaphragm is fully open.
Guaranteed heat costs. In table Table 3 shows the guaranteed specific heat consumption. Specific steam consumption is guaranteed with a tolerance of 1% over the test accuracy tolerance.
Table 3
|
Power at generator terminals, MW |
Production selection |
Heat extraction |
Temperature of network water at the inlet to the network heater, PSG 1, °C |
Generator efficiency, % |
Feedwater heating temperature, °C |
Specific heat consumption, kcal/kWh |
||
|
Pressure, kgf/cm 2 abs. |
Pressure, kgf/cm 2 abs. |
Amount of steam taken, t/h |
||||||
* Pressure regulators in the selections are turned off.
Turbine design. The turbine is a single-shaft two-cylinder unit. The flow part of the HPC has a single-coil control stage and 16 pressure levels.
The flow part of the LPC consists of three parts: the first (up to the upper heating extraction) has a control stage and seven pressure levels, the second (between the heating extractions) has two pressure levels and the third has a control stage and two pressure levels.
The high pressure rotor is solid forged. The first ten disks of the low-pressure rotor are forged integrally with the shaft, the remaining three disks are mounted.
The HPC and LPC rotors are rigidly connected to each other using 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 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 the steam flows through bypass pipes to the turbine control valves.
Upon exiting the HPC, part of the steam goes to the controlled production extraction, the rest is sent to the LPC.
Heat extraction is carried out from the corresponding LPC chambers. Upon exiting the last stages of the low pressure turbine turbine, the exhaust steam enters a 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. a temperature of about 140°C from a collector fed by steam from the equalizing line of the deaerator (6 kgf/cm 2 abs.) or the steam space of the tank.
From the outermost compartments of the seals, the steam-air mixture is sucked 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 warm-up time and improve start-up conditions, steam heating of flanges and studs and live steam supply to the front seal of the HPC are provided.
Regulation and protection. The turbine is equipped with a hydraulic control system (Fig. 3);
1- power limiter; 2-block of speed regulator spools; 3-remote control; 4-automatic shutter servomotor; 5-speed regulator; 6-safety regulator; 7-spool safety regulator; 8-remote servomotor position indicator; 9-CVD servomotor; 10-servomotor ChSD; 11-servomotor ChND; 12-electrohydraulic converter (EGC); 13-summing spools; 14-emergency electric pump; 15-reserve electric lubrication pump; 16-start electric pump of the control system (AC);
I-pressure line 20 kgf/cm 2 abs.;II-line to the spool of the HPC servomotor;III-line to the spool of the servomotor Ch"SD; IV-line to the spoolat the servomotor ChND; V-suction line of centrifugal main pump; VI-lubrication line 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.
Rearrangement of the control valves for the fresh steam inlet, the control valves in front of the CSD and the rotary diaphragm of the steam bypass in the CSD is carried out by servomotors, which are controlled by the speed regulator and the extraction pressure regulators.
The regulator is designed to maintain the rotation speed of the turbogenerator with 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 rotation speed of the turbogenerator, and it is possible to synchronize the generator at any emergency frequency in the system; maintaining a given generator load during parallel operation of the generator; maintaining normal frequency during single generator operation; increasing the rotation speed when testing the safety regulator strikers.
The control mechanism can be actuated either manually, directly at the turbine, or remotely, from the control panel.
Bellows pressure regulators are designed for automatic maintenance steam pressure in the controlled extraction chambers with unevenness of about 2 kgf/cm 2 for production extraction and about 0.4 kgf/cm 2 for district heating extraction.
The control system contains an electrohydraulic converter (EGC), the closing and opening of the control valves of which is affected by technological protection and emergency automation of the power system.
To protect against an unacceptable increase in rotation speed, the turbine is equipped with a safety regulator, two centrifugal strikers of which are instantly activated when the rotation speed reaches 11-13% above the nominal, which causes the closure of the automatic fresh steam shutter, control valves and rotary diaphragm. In addition, there is additional protection on the speed control spool block, which is triggered when the frequency increases by 11.5%.
The turbine is equipped with an electromagnetic switch, which, when triggered, closes the automatic shutter, control valves and rotary diaphragm.
The influence 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 permissible; vacuum relay in case of an unacceptable drop in vacuum in the condenser to 470 mm Hg. Art. (when the vacuum decreases to 650 mm Hg, the vacuum relay gives a warning signal); fresh steam temperature potentiometers in case of an unacceptable decrease in fresh 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 signaling of an alarm signal.
The turbine is equipped with a power limiter used in special cases to limit the opening of control valves.
Check valves are designed to prevent acceleration of the turbine by the reverse flow of steam and are installed on pipelines (regulated and unregulated) for steam extraction. The valves are closed by a counterflow of steam and by automation.
The turbine unit is equipped with electronic regulators with actuators to maintain: a given steam pressure in the end seal manifold by influencing the steam supply valve from the equalizing line of the deaerators 6 kgf/cm 2 or from the steam space of the tank; level in the condensate collector of the condenser with a maximum deviation from the set one ±200 mm (the same regulator turns on condensate recirculation at low steam flows 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 the joint shutdown of all HPHs with simultaneous activation of the bypass line and a signal (the device is triggered in the event 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 HPHs to the first limit); atmospheric diaphragm valves, which are installed on the exhaust pipes of the LPC and open when the pressure in the pipes increases to 1.2 kgf/cm 2 abs.
Lubrication system 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 using two injectors connected in series.
To service the turbogenerator during its start-up, a starting oil pump with a rotation speed of 1,500 rpm is provided.
The turbine is equipped with one backup pump with an AC electric motor and one emergency pump with a DC electric motor.
When the lubricant pressure drops to the appropriate values, the backup and emergency pumps are automatically turned on by the lubricant pressure switch (RPS). The RDS is periodically tested during turbine operation.
When the pressure is below the permissible value, the turbine and shaft turning device are disconnected from the RDS signal to the electromagnetic switch.
The working capacity of the welded structure tank is 14 m 3 .
To clean the oil from mechanical impurities, filters are installed in the tank. The design of the tank allows for quick and safe filter changes. There is a fine oil filter to remove mechanical impurities, which ensures constant filtration of part of the oil flow consumed by the 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.
Condensing device intended for servicing the turbine installation, it 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 provides a separate built-in bundle for heating make-up or network water, the heating surface of which is about 20% of the entire surface of the condenser.
An equalizing vessel is supplied with the condenser for connecting an electronic level controller 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 HDPE section No. 1 is installed.
The air removal device consists of two main three-stage ejectors (one backup), designed to suck air and ensure the normal heat exchange process in the condenser and other vacuum devices heat exchange and one starting ejector to quickly raise the vacuum in the condenser to 500-600 mm Hg. Art.
Two condensate pumps (one backup) of a vertical type are installed in the condensation device to pump out condensate and supply 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 purification of cooling water supplied to the oil coolers and gas coolers of the unit, filters with rotating screens are installed for on-the-fly washing.
Start ejector circulation system designed to fill the system with water before starting the turbine unit, as well as to remove air when it accumulates at the upper points of the drain circulation conduits and in the upper water chambers of 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 to heat feed water (turbine condensate) with steam taken from the intermediate stages of the turbine. The installation consists of a surface working steam condenser, a main ejector, surface steam coolers made of labyrinth seals, surface HDPE, after which the turbine condensate is sent to the surface HDPE deaerator to heat the feed water after the deaerator in an amount of about 105% of the maximum turbine steam flow.
HDPE No. 1 is built into the condenser. The remaining HDPEs are installed by a separate group. HPH Nos. 5, 6 and 7 - vertical design with built-in desuperheaters and drainage coolers.
HPHs are equipped with group protection, consisting of automatic outlet and check valves at the water inlet and outlet, an automatic valve with an electromagnet, a pipeline for starting and shutting down the heaters.
Each HDPE and HDPE, except HDPE No. 1, is equipped with a condensate drain control valve controlled by an electronic “regulator”.
Draining heating steam condensate from heaters is cascade. From HDPE No. 2, condensate is pumped out by a drain pump.
Condensate from PVD No. 5 is directly sent to the deaerator 6 kgf/cm 2 abs. or if there is insufficient pressure in the heater at low turbine loads, it automatically switches to draining into the HDPE.
The characteristics of the main equipment of the regenerative installation are given in Table. 4.
To extract steam from the outer compartments of the turbine labyrinth seals, a special vacuum cooler SP is supplied.
Steam is suctioned from the intermediate compartments of the turbine labyrinth seals into a vertical CO cooler. The cooler is included in the regenerative circuit for heating the main condensate after HDPE No. 1.
The design of the cooler is similar to that of low-pressure heaters.
Heating of network water is carried out in an installation consisting of two network heaters No. 1 and 2 (PSG No. 1 and 2), connected in pairs to the lower and upper heating outlets, respectively. Type of network heaters is PSG-1300-3-8-1.
|
Equipment identification |
Heating surface, m 2 |
Options working environment |
Pressure, kgf/cm 2 abs., during hydraulic testing in spaces |
|||
|
Water consumption, m 3 / h |
Resistance, m water. Art. |
|||||
|
Built into the capacitor |
||||||
|
HDPE No. 2 |
PN-130-16-9-II |
|||||
|
HDPE No. 3 |
||||||
|
HDPE No. 4 |
||||||
|
HDPE No. 5 |
PV-425-230-23-1 |
|||||
|
HDPE No. 6 |
PV-425-230-35-1 |
|||||
|
HDPE No. 7 |
||||||
|
Steam cooler from intermediate seal chambers |
PN-130-1-16-9-11 |
|||||
|
Steam cooler from seal end chambers |
||||||
Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.
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annotation
In this course work The basic thermal diagram of a power plant based on a cogeneration steam turbine was calculated
PT-80/100-130/13 at temperature environment, the regenerative heating system and network heaters were calculated, as well as the thermal efficiency indicators of the turbine installation and power unit.
The appendix shows a basic thermal diagram based on the PT-80/100-130/13 turbine unit, a graph of the temperatures of the network water and heating load, an h-s diagram of steam expansion in the turbine, a diagram of the modes of the PT-80/100-130/13 turbine unit, a general view of the heater high pressure PV-350-230-50, specification general view PV-350-230-50, longitudinal section of turbine unit PT-80/100-130/13, general specification auxiliary equipment, included in the TPP scheme.
The work is compiled on 45 sheets and includes 6 tables and 17 illustrations. 5 literary sources were used in the work.
The power unit with an electrical capacity of 80 MW consists of a high-pressure drum boiler E-320/140, a turbine PT-80/100-130/13, a generator and auxiliary equipment.
The power unit has seven extractions. In the turbine unit, it is possible to carry out two-stage heating of network water. There is a main and peak boiler, as well as a PVC, which is turned on if the boiler cannot provide the required heating of the network water.
Fresh steam from the boiler with a pressure of 12.8 MPa and a temperature of 555 0 enters the turbine high pressure chamber and, having worked, is sent to the turbine pressure chamber, and then to the low pressure pump. After exhaust, the steam enters the condenser from the low-pressure unit.
The power unit for regeneration includes three high-pressure heaters (HPH) and four low-pressure heaters (LPH). The numbering of the heaters comes from the tail of the turbine unit. The condensate of the heating steam PVD-7 is cascaded into PVD-6, into PVD-5 and then into the deaerator (6 ata). Condensate drainage from PND4, PND3 and PND2 is also carried out in cascade in PND1. Then, from PND1, the heating steam condensate is sent to SM1 (see PrTS2).
The main condensate and feed water are heated sequentially in PE, SH and PS, in four low-pressure heaters (LPH), in a 0.6 MPa deaerator and in three high-pressure heaters (HPH). Steam is supplied to these heaters from three regulated and four unregulated turbine steam extractions.
On the block for heating water in the heating network there is a boiler installation, consisting of lower (PSG-1) and upper (PSG-2) network heaters, powered by steam from the 6th and 7th extraction, respectively, and the PVC. Condensate from the upper and lower network heaters is supplied by drain pumps to mixers SM1 between LPH1 and LPH2 and SM2 between heaters LPH2 and LPH3.
The feedwater heating temperature lies in the range (235-247) 0 C and depends on the initial pressure of fresh steam and the amount of subheating in the HPH7.
The first steam extraction (from the HPC) goes to heating the feed water in HPH-7, the second extraction (from HPC) - to HPH-6, the third (from HPC) - to HPH-5, D6ata, for production; the fourth (from ChSD) - in PND-4, the fifth (from ChSD) - in PND-3, the sixth (from ChSD) - in PND-2, deaerator (1.2 ata), in PSG2, in PSV; the seventh (from the ChND) - in PND-1 and in PSG1.
To make up for losses, the scheme provides for the intake of raw water. Raw water is heated in a raw water heater (RWH) to a temperature of 35 o C, then, after passing chemical cleaning, enters the deaerator 1.2 ata. To ensure heating and deaeration of additional water, the heat of steam from the sixth extraction is used.
Steam from the seal rods in the amount of D pcs = 0.003D 0 goes to the deaerator (6 ata). Steam from the outer chambers of the seals is directed to the SH, from the middle chambers of the seal - to the PS.
Boiler purging is two-stage. Steam from the 1st stage expander goes to the deaerator (6 ata), from the 2nd stage expander to the deaerator (1.2 ata). Water from the 2nd stage expander is supplied to the network water main to partially replenish network losses.
Figure 1. Schematic thermal diagram of a thermal power plant based on technical specifications PT-80/100-130/13
2. Calculation of the basic thermal diagram of a turbine installationPT-80/100-130/13 at high load mode
The calculation of the basic thermal diagram of a turbine installation is made based on the specified steam flow to the turbine. As a result of the calculation, the following is determined:
? electric power of the turbine unit - W e;
? energy indicators of the turbine unit and the thermal power plant as a whole:
b. efficiency factor of thermal power plants for electricity production;
V. efficiency factor of thermal power plants for the production and supply of heat for heating;
d. specific consumption of equivalent fuel for electricity production;
e. specific consumption of equivalent fuel for the production and supply of thermal energy.
2.1 Initial data for calculation
Live steam pressure -
Fresh steam temperature -
Pressure in the condenser - P to =0.00226 MPa
Parameters of production steam:
steam consumption -
serving - ,
reverse - .
Fresh steam consumption per turbine -
The efficiency values of the thermal circuit elements are given in Table 2.1.
Table 2.1. Efficiency of thermal circuit elements
|
Thermal circuit element |
Efficiency |
||
|
Designation |
Meaning |
||
|
Continuous blowdown expander |
|||
|
Bottom network heater |
|||
|
Upper network heater |
|||
|
Regenerative heating system: |
|||
|
Feed pump |
|||
|
Feed water deaerator |
|||
|
Purge cooler |
|||
|
Purified water heater |
|||
|
Condensation water deaerator |
|||
|
Faucets |
|||
|
Seal heater |
|||
|
Seal ejector |
|||
|
Pipelines |
|||
|
Generator |
|||
2.2 Calculation of pressures in turbine outlets
Thermal load The thermal power plant is determined by the needs of the production steam consumer and the supply of heat to external consumers for heating, ventilation and hot water supply.
To calculate the thermal efficiency characteristics of a thermal power plant with an industrial heating turbine at high load mode (below -5°C), it is necessary to determine the steam pressure in the turbine outlets. This pressure is set based on the requirements of the industrial consumer and the temperature schedule of the supply water.
In this course work, a constant extraction of steam for the technological (production) needs of an external consumer is adopted, which is equal to the pressure, which corresponds to the nominal operating mode of the turbine unit, therefore, the pressure in the unregulated extractions of turbines No. 1 and No. 2 is equal to:
The steam parameters in turbine exhausts at nominal mode are known from its basic technical characteristics.
It is necessary to determine the actual (i.e., for a given mode) pressure value in the heating extraction. To do this, perform next sequence actions:
1. Based on the given value and the selected (specified) temperature schedule of the heating network, we determine the temperature of the network water behind the network heaters at a given outside air temperature t NAR
t BC = t O.S + b CHP ( t P.S - t O.S)
t BC = 55.6+ 0.6 (106.5 - 55.6) = 86.14 0 C
2. According to the accepted value of water underheating and value t BC we find the saturation temperature in the network heater:
= t Sun + and
86.14 + 4.3 = 90.44 0 C
Then, using the saturation tables for water and water steam, we determine the steam pressure in the network heater R BC =0.07136 MPa.
3. The heat load on the lower network heater reaches 60% of the total load on the boiler room
t NS = t O.S + 0.6 ( t V.S - t O.S)
t NS = 55.6+ 0.6 (86.14 - 55.6) = 73.924 0 C
Using the saturation tables for water and water steam, we determine the steam pressure in the network heater R N C =0.04411 MPa.
4. We determine the steam pressure in the heating (regulated) extractions No. 6, No. 7 of the turbine, taking into account the accepted pressure losses through the pipelines:
where we take losses in pipelines and turbine control systems:; ;
5. According to the value of steam pressure ( R 6 ) in the district heating outlet No. 6 of the turbine, we clarify the steam pressure in the unregulated turbine outlets between the industrial outlet No. 3 and the regulated district heating outlet No. 6 (according to the Flügel-Stodola equation):
Where D 0 , D, R 60 , R 6 - steam flow and pressure in the turbine outlet at the nominal and calculated modes, respectively.
2.3 Calculation of parametersthe process of steam expansion in the turbine compartments inh- Sdiagram
Using the method described below and the values of pressure in the extractions found in the previous paragraph, we will construct a diagram of the process of steam expansion in the flow part of the turbine at t nar=- 15 є WITH.
Intersection point at h, s- an isobar diagram with an isotherm determines the enthalpy of fresh steam (point 0 ).
The fresh steam pressure loss in the stop and control valves and the start-up steam path with the valves fully open is approximately 3%. Therefore, the steam pressure before the first stage of the turbine is equal to:
On h, s- the diagram marks the point of intersection of the isobar with the enthalpy level of fresh steam (point 0 /).
To calculate the steam parameters at the outlet of each turbine compartment, we have the values of the internal relative efficiency of the compartments.
Table 2.2. Internal relative turbine efficiency by compartment
From the resulting point (point 0 /) a line is drawn vertically down (along the isentrope) until it intersects with the pressure isobar in selection No. 3. The enthalpy of the intersection point is equal to.
The enthalpy of steam in the third regenerative selection chamber in the real expansion process is equal to:
Similarly on h,s- the diagram contains points corresponding to the state of steam in the chamber of the sixth and seventh extractions.
After constructing the steam expansion process in h, S- isobars of unregulated extractions to regenerative heaters are plotted on the diagram R 1 , R 2 ,R 4 ,R 5 and the enthalpies of steam in these selections are established.
Built on h,s- in the diagram, the points are connected by a line, which reflects the process of steam expansion in the flow part of the turbine. The graph of the steam expansion process is shown in Fig. A.1. (Appendix A).
According to the built h,s- using the diagram, we determine the temperature of the steam in the corresponding turbine outlet based on the values of its pressure and enthalpy. All parameters are shown in Table 2.3.
2.4 Calculation of thermodynamic parameters in heaters
The pressure in regenerative heaters is less than the pressure in the extraction chambers by the amount of pressure loss due to the hydraulic resistance of the extraction pipelines, safety and shut-off valves.
1. Calculate the pressure of saturated water vapor in regenerative heaters. The pressure loss through the pipeline from the turbine outlet to the corresponding heater is assumed to be equal to:
The pressure of saturated water vapor in feed and condensation water deaerators is known from their technical characteristics and is equal, respectively,
2. Using the table of properties of water and steam in a state of saturation, using the found saturation pressures, we determine the temperature and enthalpy of the heating steam condensate.
3. We accept subheating of water:
In high pressure regenerative heaters - 2єWITH
In low pressure regenerative heaters - 5єWITH,
In deaerators - 0є WITH ,
therefore, the temperature of the water leaving these heaters is:
, є WITH
4. The water pressure behind the corresponding heaters is determined hydraulic resistance path and pump operating mode. The values of these pressures are accepted and shown in Table 2.3.
5. Using the tables for water and superheated steam, we determine the enthalpy of water after the heaters (based on the values of and):
6. Heating of water in the heater is defined as the difference in enthalpies of water at the inlet and outlet of the heater:
, kJ/kg;
kJ/kg;
kJ/kg;
kJ/kg;
kJ/kg
kJ/kg;
kJ/kg;
kJ/kg;
kJ/kg,
where is the enthalpy of the condensate at the outlet of the seal heater. In this work, this value is assumed to be equal.
7. Heat given off by heating steam to water in the heater:
2.5 Parameters of steam and water in a turbine unit
For the convenience of further calculations, the parameters of steam and water in the turbine unit, calculated above, are summarized in Table 2.3.
Data on the parameters of steam and water in drain coolers are given in Table 2.4.
Table 2.3. Parameters of steam and water in a turbine unit
|
p, MPa |
t, 0 WITH |
h, kJ/kg |
p", MPa |
t" H, 0 WITH |
h B H, kJ/kg |
0 WITH |
p B, MPa |
t P, 0 WITH |
h B P, kJ/kg |
kJ/kg |
||
Table 2.4. Parameters of steam and water in drain coolers
2.6 Determination of steam and condensate flow rates in thermal circuit elements
The calculation is performed in the following order:
1. Steam consumption per turbine at design mode.
2. Steam leaks through seals
We accept, then
4. Feed water consumption per boiler (including blowdown)
where is the amount of boiler water going into continuous blowdown
D etc=(b etc/100)·D pg=(1.5/100)·131.15=1.968kg/s
5. Steam exit from the purge expander
where is the proportion of steam released from the purge water in the continuous purge expander
6.Output of purge water from the expander
7.Consumption of additional water from the chemical water treatment plant (CWW)
where is the condensate return coefficient from
industrial consumers, we accept;
The calculation of steam flows into regenerative and network heaters in the deaerator and condenser, as well as condensate flows through heaters and mixers, is based on material and heat balance equations.
Balance equations are compiled sequentially for each element of the thermal circuit.
The first stage of calculating the thermal scheme of a turbine installation is drawing up heat balances of network heaters and determining the steam consumption for each of them based on the given thermal load of the turbine and the temperature schedule. After this, heat balances are compiled for high-pressure regenerative heaters, deaerators and low-pressure heaters.
2.6.1 Network heating installation (boiler room))
Table 2.5. Parameters of steam and water in a network heating installation
|
Index |
Bottom heater |
Upper heater |
|
|
Heating steam Selection pressure P, MPa |
|||
|
Pressure in the heater P?, MPa |
|||
|
Steam temperature t,єС |
|||
|
Heat given off qns, qsu, kJ/kg |
|||
|
Heating steam condensate Saturation temperature tн,єС |
|||
|
Enthalpy at saturation h?, kJ/kg |
|||
|
Network water Underheating in the heater Ins, Ivs, єС |
|||
|
Inlet temperature tос, tнс, єС |
|||
|
Enthalpy at inlet, kJ/kg |
|||
|
Outlet temperature tns,ts, єС |
|||
|
Output enthalpy, kJ/kg |
|||
|
Heating in the heater fns, fvs, kJ/kg |
The installation parameters are determined in the following sequence.
1.Consumption of network water for the calculated mode
2. Heat balance of the lower network heater
Heating steam consumption for the lower network heater
from table 2.1.
3. Heat balance of the upper network heater
Heating steam consumption for the upper network heater
Regenerative high-pressure heaters pressure and feed installation (pump)
PVD 7
Heat balance equation for PVD7
Heating steam consumption at HPH7
PVD 6
Heat balance equation for PVD6
Heating steam consumption at HPH6
heat removed from drain OD2
Feed pump (PN)
Pressure after PN
Pump pressure in PN
Pressure drop
Specific volume of water in PN v PN - determined from tables by value
R Mon.
Feed pump efficiency
Water heating in PN
Enthalpy after PN
Where - from table 2.3;
Heat balance equation for PVD5
Heating steam consumption at HPH5
Table 2.6. Steam consumption by turbine extractions
|
Selection No. |
Designation |
Steam consumption, kg/s |
|
|
D 1 =D P1 |
|||
|
D 2 =D P2 |
|||
|
D 3 =D P3+D D+D P |
|||
|
D 4 =D P4 |
|||
|
D 5 = D NS + D P5 |
|||
|
D 6 =D P6+D Sun++D PSV |
|||
|
D 7 =D P7+D HC |
Total steam flow from turbine extractions
Steam flow into the condenser after the turbine:
Steam and condensate balance error
Since the error in the balance of steam and condensate does not exceed the permissible limit, therefore, all flows of the thermal circuit are taken into account correctly.
As a result of calculating the thermal diagram of a power plant based on a production heating turbine PT-80/100-130/13, operating at high load mode at ambient temperature, the following values of the main parameters characterizing a power plant of this type were obtained:
Steam consumption in turbine extractions
Heating steam consumption for network heaters
Heat supply for heating using a turbine unit
Q T= 72.22 MW;
Heat supply from a turbine unit to industrial consumers
Q P= 141.36 MW;
Total heat consumption for external consumers
Q TP= 231.58 MW;
Generator terminal power
N uh=80.97 MW;
CHP efficiency for electricity production
Efficiency of thermal power plants for the production and supply of heat for heating
Specific fuel consumption for electricity production
b E U= 162.27g/kW/h
Specific fuel consumption for production and supply of thermal energy
b T U= 40.427 kg/GJ
Total efficiency of the CHP plant “gross”
Total efficiency of the CHP plant “net”
Specific consumption of equivalent fuel per station "net"
Bibliography
1. Ryzhkin V.Ya. Thermal power plants: Textbook for universities - 2nd ed., revised. - M.: Energy, 1976.-447 p.
2. Aleksandrov A.A., Grigoriev B.A. Tables of thermophysical properties of water and water vapor: Handbook. - M.: Publishing house. MPEI, 1999. - 168 p.
3. Poleshchuk I.Z. Drawing up and calculation of basic thermal diagrams of thermal power plants. Guidelines for a course project in the discipline “Thermal Power Plants and Nuclear Power Plants”, / Ufa State. aviation technical university - t. - Ufa, 2003.
4. Enterprise standard (STP UGATU 002-98). Requirements for construction, presentation, design. - Ufa.: 1998.
5. Boyko E.A. Steam-tube power plants of thermal power plants: Reference manual - IPC KSTU, 2006. -152s
6. . Thermal and nuclear power plants: Directory/Under the general editorship. Corresponding member RAS A.V. Klimenko and V.M. Zorina. - 3rd ed. - M.: Publishing house MPEI, 2003. - 648 p.: ill. - (Thermal power engineering and heating engineering; Book 3).
7. . Turbines of thermal and nuclear power plants: Textbook for universities / Ed. A.G., Kostyuk, V.V. Frolova. - 2nd ed., revised. and additional - M.: Publishing house MPEI, 2001. - 488 p.
8. Calculation of thermal circuits of steam turbine plants: Educational electronic publication / Poleshchuk I.Z. - State Educational Institution of Higher Professional Education UGATU, 2005.
Symbols of power plants, equipment and their elements (includingtext, pictures, indices)
D - feed water deaerator;
DN - drainage pump;
K - condenser, boiler;
KN - condensate pump;
OE - drainage cooler;
PrTS - basic thermal diagram;
LDPE, HDPE - regenerative heater (high, low pressure);
PVK - peak water heating boiler;
PG - steam generator;
PE - steam superheater (primary);
PN - feed pump;
PS - stuffing box heater;
PSG - horizontal network heater;
PSV - raw water heater;
PT - steam turbine; heating turbine with industrial and heating steam extraction;
PHOV - chemically purified water heater;
PE - ejector cooler;
R - expander;
CHPP - combined heat and power plant;
SM - mixer;
CX - stuffing box refrigerator;
HPC - high pressure cylinder;
LPC - low pressure cylinder;
EG - electric generator;
Calculation of the basic thermal diagram, construction of the steam expansion process in the turbine compartments. Calculation of the regenerative feedwater heating system. Determination of condensate flow, turbine and pump operation. Total blade losses and internal efficiency.
course work, added 03/19/2012
Plotting the steam expansion process in a turbine in an H-S diagram. Determination of parameters and flow rates of steam and water at a power plant. Drawing up basic heat balances for components and devices of the thermal circuit. Preliminary estimate of steam flow per turbine.
course work, added 12/05/2012
Analysis of methods for conducting verification calculations of the thermal circuit of a power plant based on a heating turbine. Description of the design and operation of the capacitor KG-6200-2. Description of the basic thermal diagram of a heating plant based on a T-100-130 type turbine unit.
thesis, added 09/02/2010
Thermal diagram power unit Steam parameters in turbine extractions. Constructing a process in an hs-diagram. Summary table of steam and water parameters. Drawing up basic heat balances for components and devices of the thermal circuit. Calculation of deaerator and network installation.
course work, added 09/17/2012
Construction of the steam expansion process in h-s chart. Calculation of installation of network heaters. Steam expansion process in the feed pump drive turbine. Determination of steam flow per turbine. Calculation of thermal efficiency of thermal power plants and selection of pipelines.
course work, added 06/10/2010
Selection and justification of the basic thermal diagram of the unit. Drawing up a balance of the main flows of steam and water. Main characteristics of the turbine. Construction of the steam expansion process in a turbine on the hs-diagram. Calculation of heating surfaces of a waste heat boiler.
course work, added 12/25/2012
Calculation of a steam turbine, parameters of the main elements schematic diagram steam turbine installation and preliminary construction of the thermal process of steam expansion in the turbine in the h-s diagram. Economic indicators of a steam turbine plant with regeneration.
course work, added 07/16/2013
Drawing up a design thermal diagram of NPP technical specifications. Determination of the parameters of the working fluid, steam flow rates in the exhausts of the turbine unit, internal power and thermal efficiency indicators of the unit as a whole. Power of condensate feed pumps.
course work, added 12/14/2010
The process of steam expansion in a turbine. Determination of consumption of live steam and feed water. Calculation of thermal circuit elements. Solving a matrix using Cramer's method. Program code and output of machine calculation results. Technical and economic indicators of the power unit.
course work, added 03/19/2014
Study of the design of the K-500-240 turbine and thermal calculation of the power plant turbine unit. Selecting the number of turbine cylinder stages and breaking down the differences in steam enthalpy across its stages. Determination of turbine power and calculation of the working blade for bending and tension.
