CN110500148B - High-back-pressure heat supply and monitoring method and system for large steam turbine generator unit - Google Patents

High-back-pressure heat supply and monitoring method and system for large steam turbine generator unit Download PDF

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Publication number
CN110500148B
CN110500148B CN201910782957.9A CN201910782957A CN110500148B CN 110500148 B CN110500148 B CN 110500148B CN 201910782957 A CN201910782957 A CN 201910782957A CN 110500148 B CN110500148 B CN 110500148B
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heat exchanger
water
steam
valve
heat
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CN110500148A (en
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文立斌
吴健旭
卢广陵
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Electric Power Research Institute of Guangxi Power Grid Co Ltd
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Electric Power Research Institute of Guangxi Power Grid Co Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D15/00—Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby
    • F01D15/10—Adaptations for driving, or combinations with, electric generators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K11/00—Plants characterised by the engines being structurally combined with boilers or condensers
    • F01K11/02—Plants characterised by the engines being structurally combined with boilers or condensers the engines being turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K13/00—General layout or general methods of operation of complete plants
    • F01K13/003—Arrangements for measuring or testing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K13/00—General layout or general methods of operation of complete plants
    • F01K13/02—Controlling, e.g. stopping or starting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K17/00—Using steam or condensate extracted or exhausted from steam engine plant
    • F01K17/02—Using steam or condensate extracted or exhausted from steam engine plant for heating purposes, e.g. industrial, domestic

Abstract

The invention belongs to the high back pressure heat supply monitoring and controlling technology, in particular to a high back pressure heat supply and monitoring method and a system of a large turbo generator set, wherein the system comprises a communicating pipe butterfly valve, a vacuum pump, a high back pressure heat exchanger, a heat user heat exchanger, a water replenishing tank, a variable frequency water pump, a condensate pump, a heat user heat exchanger, a monitoring system, a high back pressure heat exchanger steam side pressure measuring device, a high back pressure heat exchanger water side inlet temperature measuring device, a heat user heat exchanger water side outlet temperature measuring device, a low pressure cylinder 1 exhaust steam temperature measuring device, a low pressure cylinder 2 exhaust steam temperature measuring device, a pipeline and a valve.

Description

High-back-pressure heat supply and monitoring method and system for large steam turbine generator unit
Technical Field
The invention belongs to a high back pressure heat supply monitoring and controlling technology, and particularly relates to a high back pressure heat supply and monitoring method and system for a large steam turbine generator unit.
Background
Because the small boiler has low heating and heat supply efficiency and causes serious air pollution, the national development and improvement committee, the energy agency and the like jointly issue the requirement of central heating of a cogeneration management method, and a large number of coal-fired generating sets carry out cogeneration transformation or newly establish cogeneration sets. However, the widely adopted steam extraction heat supply type large-scale steam turbine generator unit releases latent heat of vaporization through condenser condensation after steam works, and the problem of large amount of cold source loss exists.
Disclosure of Invention
In order to solve the problems, the invention provides a high back pressure heat supply and monitoring method and a system for a large steam turbine generator unit, and the specific technical scheme is as follows:
a high back pressure heat supply and monitoring method for a large steam turbine generator unit comprises the following steps:
s1: checking before heat supply:
the generator set is in a shutdown state, whether the action of each valve on a pipeline connected with the high back pressure heat exchanger, the heat consumer heat exchanger, the water replenishing tank and the variable frequency water pump is normal is checked and confirmed, each valve is in a closed state, and the communicating pipe butterfly valve is fully opened;
s2: water injection operation and inspection of a hot water supply system:
the generator set is in a shutdown state, a tenth stop valve and a ninth stop valve in front and at the back of a heat exchanger of a heat consumer are fully opened, an eighth stop valve on a water pipeline of a supplementary water tank is fully opened, a fifth stop valve, a sixth stop valve and a seventh stop valve in front and at the back of a variable frequency water pump are fully opened, a third regulating valve is gradually opened, water is injected into the heat consumer system, the variable frequency water pump is started after full water injection, the rotating speed of the variable frequency water pump is gradually increased, and the leakage conditions of the pipeline and each valve are checked;
s3: high back pressure vacuum start-up:
after the vacuum pump is started and operates normally, the steam side vacuum of the high back pressure heat exchanger reaches the starting operation condition of the generator set;
s4: initial starting;
when the water outlet temperature of the heat user heat exchanger cannot be increased only by adjusting the opening of the first adjusting valve, the monitoring system gradually closes the communicating pipe butterfly valve to increase the water outlet temperature of the heat user heat exchanger;
s5: monitoring the operation condition of the generator set:
the monitoring system monitors the operation condition of the generator set according to the measurement data of the steam side pressure measuring device of the high back pressure heat exchanger, the water side inlet temperature measuring device of the heat consumer heat exchanger and the water side outlet temperature measuring device of the heat consumer heat exchanger;
s6: stopping the heat supply system:
gradually closing the first regulating valve until the first regulating valve is completely closed; after the first regulating valve is withdrawn, the first stop valve, the second stop valve and the third stop valve are closed; stopping the generator set and the variable frequency water pump; gradually closing the third regulating valve until the third regulating valve is completely closed; and closing the eighth stop valve, the seventh stop valve and the sixth stop valve.
Preferably, the step S5 is as follows:
when the monitoring system monitors that the steam side pressure P of the high back pressure heat exchanger is higher than a set value P according to the measurement data of the steam side pressure measuring device of the high back pressure heat exchangerSetting upWhen the temperature is higher than the set temperature, the monitoring system increases the water flow rate of the heat supply system by increasing the rotating speed of the variable frequency water pump so that the steam side pressure of the high back pressure heat exchanger meets the requirement;
if the detected steam side pressure P of the high back pressure heat exchanger is lower than the set value PSetting upWhen the temperature is higher than the set temperature, the monitoring system reduces the rotating speed of the variable frequency water pump to increase the water flow rate of the heat supply system so that the steam side pressure of the high back pressure heat exchanger meets the requirement;
when the monitoring system monitors the outlet water temperature T of the heat exchanger of the heat consumer according to the measurement data of the outlet temperature measuring device at the water side of the heat exchanger of the heat consumerGo outIs lower than a set value TGo out of settingWhen the first regulating valve is fully opened, the outlet water temperature of the heat user heat exchanger can not meet the requirement, and the monitoring system gradually reduces the opening degree of the communicating pipe butterfly valve;
when the outlet water temperature T of the heat exchanger of the heat user is monitoredGo outHigher than a set value TGo out of settingWhen the temperature of the outlet water of the heat user heat exchanger reaches the requirement, the monitoring system reduces the input energy of the heat user heat exchanger by reducing the opening of the first regulating valve;
when the monitoring system monitors that the measured temperature of the low-pressure cylinder 1 exhaust steam temperature measuring device or the low-pressure cylinder 2 exhaust steam temperature measuring device exceeds a threshold value TLow rowAnd when the temperature is lowered, the monitoring system opens the regulating valve to spray water.
A high back pressure heat supply and monitoring system of a large-scale steam turbine generator unit comprises a boiler reheater, a high pressure cylinder, an intermediate pressure cylinder and a low pressure cylinder; the low-pressure cylinder comprises a low-pressure cylinder 1, a low-pressure cylinder 2 and a generator; the system also comprises a communicating pipe butterfly valve, a vacuum pump, a high back pressure heat exchanger, a heat user heat exchanger, a supplementary water tank, a variable frequency water pump, a condensate pump, the heat user heat exchanger, a monitoring system, a high back pressure heat exchanger steam side pressure measuring device, a high back pressure heat exchanger water side inlet temperature measuring device, a heat user heat exchanger water side outlet temperature measuring device, a low pressure cylinder 1 exhaust steam temperature measuring device, a low pressure cylinder 2 exhaust steam temperature measuring device, a pipeline and a valve;
the communicating pipe butterfly valve is arranged on the communicating pipe between the intermediate pressure cylinder and the low pressure cylinder and used for adjusting steam supply pressure on the steam side of the heat exchanger for the heat consumer and adjusting the outlet water temperature of the heat exchanger for the heat consumer by adjusting the steam supply pressure;
the steam inlet of the high back pressure heat exchanger is connected with the steam exhaust pipe of the low pressure cylinder, and the water outlet of the high back pressure heat exchanger is connected with the condensate pump through a pipeline; the condensate pump is used for conveying water condensed in the steam chamber of the high-back-pressure heat exchanger to the boiler reheater, and recycling working media of the thermodynamic system of the generator set is kept;
the steam inlet of the heat consumer heat exchanger is connected with a communicating pipe between the intermediate pressure cylinder and the low pressure cylinder in front of the communicating pipe butterfly valve sequentially through a second stop valve, a first regulating valve, a first check valve and a first stop valve, and the steam outlet of the heat consumer heat exchanger is connected with the steam chamber of the high back pressure heat exchanger through a third stop valve;
the water side inlet of the heat user heat exchanger is connected with the water side outlet of the high back pressure heat exchanger through a tenth stop valve; the water side outlet of the heat user heat exchanger is connected with the water inlet of the heat user heat exchanger through a ninth stop valve; the water outlet of the heat user heat exchanger is connected with the variable frequency water pump sequentially through a seventh stop valve, a third check valve and a sixth stop valve; the variable frequency water pump is connected with a water side inlet of the high back pressure heat exchanger through a second check valve and a fifth stop valve in sequence;
the supplementary water tank is connected with the variable frequency water pump sequentially through an eighth stop valve, a fourth check valve, a third regulating valve and a sixth stop valve;
the vacuum pump is communicated with the steam chamber of the high back pressure heat exchanger through a pipeline and is used for sucking air in the steam chamber of the high back pressure heat exchanger and keeping the vacuum of the air;
the high back pressure heat exchanger steam side pressure measuring device is connected with the steam chamber of the high back pressure heat exchanger and is used for measuring the pressure in the steam chamber of the high back pressure heat exchanger;
the high back pressure heat exchanger water side inlet temperature measuring device is arranged at a water side inlet of the high back pressure heat exchanger and is used for measuring the temperature of inlet water at the water side inlet of the high back pressure heat exchanger;
the temperature measuring device of the water side inlet of the heat user heat exchanger is arranged at the water side inlet of the heat user heat exchanger and is used for measuring the temperature of inlet water at the water side inlet of the heat user heat exchanger;
the device for measuring the temperature of the water side outlet of the heat user heat exchanger is arranged at the water side outlet of the heat user heat exchanger and is used for measuring the temperature of outlet water at the water side outlet of the heat user heat exchanger;
the exhaust steam temperature measuring device of the low pressure cylinder 1 is used for measuring the exhaust steam temperature of the low pressure cylinder 1;
the exhaust steam temperature measuring device of the low pressure cylinder 2 is used for measuring the exhaust steam temperature of the low pressure cylinder 2;
the monitoring system is used for acquiring measurement signals of a steam side pressure measurement device of the high-back-pressure heat exchanger, a water side inlet temperature measurement device of the heat consumer heat exchanger, a water side outlet temperature measurement device of the heat consumer heat exchanger, a low-pressure cylinder 1 steam exhaust temperature measurement device and a low-pressure cylinder 2 steam exhaust temperature measurement device, and controlling a communicated pipe butterfly valve, a first regulating valve, a vacuum pump, a second regulating valve, a variable-frequency water pump and a third regulating valve according to the measurement signals;
the monitoring system is respectively connected with a high-back-pressure heat exchanger steam side pressure measuring device, a high-back-pressure heat exchanger water side inlet temperature measuring device, a hot user heat exchanger water side outlet temperature measuring device, a low-pressure cylinder 1 steam exhaust temperature measuring device, a low-pressure cylinder 2 steam exhaust temperature measuring device, a communicated pipe butterfly valve, a first regulating valve, a vacuum pump, a second regulating valve, a variable-frequency water pump and a third regulating valve.
Preferably, the system further comprises a second regulating valve and a fourth stop valve, and the output end of the condensate pump is connected with the low-pressure cylinder sequentially through the second regulating valve and the fourth stop valve.
The invention has the beneficial effects that: the invention provides a high-back-pressure heat supply and monitoring method and a high-back-pressure heat supply and monitoring system for a large-scale steam turbine generator unit.
The invention connects the air inlet of the heat exchanger of the heat consumer with the communicating pipe between the middle pressure cylinder and the low pressure cylinder in front of the butterfly valve of the communicating pipe, connects the air outlet of the heat exchanger of the heat consumer with the steam chamber of the high back pressure heat exchanger, and connects the air outlet of the low pressure cylinder with the high back pressure heat exchanger, thus fully utilizing the latent heat of vaporization released by the condensation after the steam works, realizing the heating of the outward centralized heating and improving the comprehensive utilization level of energy.
Drawings
FIG. 1 is a schematic structural diagram of a high back pressure heating and monitoring system of a large steam turbine generator unit according to the present invention;
wherein: 1-communicated pipe butterfly valve, 2-first stop valve, 3-first check valve, 4-first regulating valve, 5-second stop valve, 6-third stop valve, 7 vacuum pump, 8-fourth stop valve, 9-second regulating valve, 10-condensate pump, 11-high back pressure heat exchanger, 12-high back pressure heat exchanger steam side pressure measuring device, 13-high back pressure heat exchanger water side inlet temperature measuring device, 14-fifth stop valve, 15-second stop valve, 16-variable frequency water pump, 17-sixth stop valve, 18-third stop valve, 19-seventh stop valve, 20-heat user heat exchanger, 21-third regulating valve, 22-fourth stop valve, 23-eighth stop valve, 24-supplementary water tank, 25-outlet temperature measuring device of water side of heat exchanger for heat consumer, 26-ninth cut-off valve, 27-heat exchanger for heat consumer, 28-tenth cut-off valve, 29-inlet temperature measuring device of water side of heat exchanger for heat consumer, 30-exhaust temperature measuring device of low pressure cylinder 2, 31-exhaust temperature measuring device of low pressure cylinder 1, 32-monitoring system.
Detailed Description
For a better understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings in which:
as shown in fig. 1, a high back pressure heat supply and monitoring system for a large steam turbine generator unit includes a boiler reheater, a high pressure cylinder, an intermediate pressure cylinder, and a low pressure cylinder; the low-pressure cylinder comprises a low-pressure cylinder 1, a low-pressure cylinder 2 and a generator; the system also comprises a communicating pipe butterfly valve 1, a vacuum pump 7, a high back pressure heat exchanger 11, a heat user heat exchanger 27, a supplementary water tank 24, a variable frequency water pump 16, a condensate pump 10, a heat user heat exchanger 20, a monitoring system 32, a high back pressure heat exchanger steam side pressure measuring device 12, a high back pressure heat exchanger water side inlet temperature measuring device 13, a heat user heat exchanger water side inlet temperature measuring device 29, a heat user heat exchanger water side outlet temperature measuring device 25, a low pressure cylinder 1 exhaust steam temperature measuring device 31, a low pressure cylinder 2 exhaust steam temperature measuring device 30, a pipeline and a valve;
the communicating pipe butterfly valve 1 is arranged on the communicating pipe between the intermediate pressure cylinder and the low pressure cylinder and is used for adjusting steam supply pressure at the steam side of the heat user heat exchanger 27 and adjusting the outlet water temperature of the heat user heat exchanger 27 by adjusting the steam supply pressure;
the steam inlet of the high back pressure heat exchanger 11 is connected with the steam exhaust pipe of the low pressure cylinder, and the water outlet of the high back pressure heat exchanger 11 is connected with the condensate pump 10 through a pipeline; the condensate pump 10 is used for conveying water condensed in a steam chamber of the high back pressure heat exchanger 11 to a boiler reheater, and recycling working media of a thermodynamic system of the generator set is kept; the output end of the condensate pump 10 is connected with the low-pressure cylinder through a second regulating valve 9 and a fourth stop valve 8 in sequence;
the steam inlet of the heat user heat exchanger 27 is connected with a communicating pipe between a middle pressure cylinder and a low pressure cylinder in front of the communicating pipe butterfly valve 1 sequentially through a second stop valve 5, a first regulating valve 4, a first check valve 3 and a first stop valve 2, and the steam outlet of the heat user heat exchanger 27 is connected with a steam chamber of the high back pressure heat exchanger 11 through a third stop valve 6;
the water side inlet of the hot user heat exchanger 27 is connected to the water side outlet of the high back pressure heat exchanger 11 through a tenth shut-off valve 28; the water side outlet of the heat user heat exchanger 27 is connected with the water inlet of the heat user heat exchanger 20 through a ninth stop valve 26; the water outlet of the heat user heat exchanger 20 is connected with the variable frequency water pump 16 through a seventh stop valve 19, a third check valve 18 and a sixth stop valve 17 in sequence; the variable frequency water pump 16 is connected with the water side inlet of the high back pressure heat exchanger 11 through the second check valve 15 and the fifth stop valve 14 in sequence;
the supplementary water tank 24 is connected with the variable frequency water pump 16 sequentially through an eighth stop valve 23, a fourth check valve 22, a third regulating valve 21 and a sixth stop valve 17;
the vacuum pump 7 is communicated with the steam chamber of the high back pressure heat exchanger 11 through a pipeline and is used for sucking air in the steam chamber of the high back pressure heat exchanger 11 and keeping the vacuum of the air;
the high back pressure heat exchanger steam side pressure measuring device 12 is connected with the steam chamber of the high back pressure heat exchanger 11 and is used for measuring the pressure in the steam chamber of the high back pressure heat exchanger 11;
the high back pressure heat exchanger water side inlet temperature measuring device 13 is arranged at the water side inlet of the high back pressure heat exchanger 11 and is used for measuring the temperature of inlet water at the water side inlet of the high back pressure heat exchanger 11;
a hot user heat exchanger water side inlet temperature measuring device 29 is installed at the water side inlet of the hot user heat exchanger 27 and is used for measuring the temperature of the inlet water at the water side inlet of the hot user heat exchanger 27;
the hot user heat exchanger water side outlet temperature measuring device 25 is installed at the water side outlet of the hot user heat exchanger 27 and is used for measuring the temperature of the outlet water at the water side outlet of the hot user heat exchanger 27;
the exhaust steam temperature measuring device 31 of the low pressure cylinder 1 is used for measuring the exhaust steam temperature of the low pressure cylinder 1;
the exhaust steam temperature measuring device 30 of the low pressure cylinder 2 is used for measuring the exhaust steam temperature of the low pressure cylinder 2;
the monitoring system 32 is used for acquiring measurement signals of a high-back-pressure heat exchanger steam side pressure measuring device 12, a high-back-pressure heat exchanger water side inlet temperature measuring device 13, a hot user heat exchanger water side inlet temperature measuring device 29, a hot user heat exchanger water side outlet temperature measuring device 25, a low-pressure cylinder 1 steam exhaust temperature measuring device 31 and a low-pressure cylinder 2 steam exhaust temperature measuring device 30, and controlling the communicated pipe butterfly valve 1, the first regulating valve 4, the vacuum pump 7, the second regulating valve 9, the variable-frequency water pump 16 and the third regulating valve 21 according to the measurement signals;
the monitoring system 32 is respectively connected with a high back pressure heat exchanger steam side pressure measuring device 12, a high back pressure heat exchanger water side inlet temperature measuring device 13, a hot user heat exchanger water side inlet temperature measuring device 29, a hot user heat exchanger water side outlet temperature measuring device 25, a low pressure cylinder 1 steam exhaust temperature measuring device 31, a low pressure cylinder 2 steam exhaust temperature measuring device 30, a communicating pipe butterfly valve 1, a first regulating valve 4, a vacuum pump 7, a second regulating valve 9, a variable frequency water pump 16 and a third regulating valve 21.
The high back pressure heat exchanger water side inlet temperature measuring device 13, the heat consumer heat exchanger water side outlet temperature measuring device 25, the heat consumer heat exchanger water side inlet temperature measuring device 29, the low pressure cylinder 2 exhaust steam temperature measuring device 30 and the low pressure cylinder 1 exhaust steam temperature measuring device 31 respectively comprise E-type thermocouples.
The high back pressure heat exchanger vapor side pressure measurement device 12 comprises an EJA series pressure transmitter.
The condensate pump 10 adopts an NLT350-400 x 6 type cylindrical bag type vertical multistage centrifugal pump. The vacuum pump 7 adopts a 2BW 4353-OMK 4-Z type liquid ring vacuum pump. The variable frequency water pump 16 adopts an 1800KLS-23 vertical diagonal flow pump. The monitoring system (32) adopts an OVATION decentralized control system; the regulating valves 4, 9 and 21 adopt electric regulating valves; the stop valves 2, 5, 6, 8, 14, 17, 19, 23, 26 and 28 adopt bellows stop valves; the communicating pipe butterfly valve 1 adopts an electric butterfly valve; the high back pressure heat exchanger 11 and the heat consumer heat exchanger 20 are tube heat exchangers; the check valves 3, 15, 18 and 22 are stainless steel horizontal check valves.
The working principle of the system is as follows:
the working principle of the system is as follows: the heat supply system mainly takes away the heat of the steam exhausted by the low-pressure cylinder of the steam turbine through the circulation of the working medium water of the heat consumer, and the temperature of the water entering the condenser through the circulation of the working medium water of the heat consumer is higher than the ambient temperature, so that the exhaust backpressure of the steam turbine is higher than the backpressure of a pure condenser working condition, the work-done generating capacity of the steam turbine can be reduced, the latent heat of vaporization released by the condensation of the exhaust steam of the steam turbine is fully utilized, and the comprehensive utilization level of energy is improved. After working medium water flow of a heat consumer absorbs heat of exhausted steam of a low-pressure cylinder of the steam turbine through a condenser, the temperature of the working medium water flow cannot meet the temperature requirement of the heat consumer, so that steam is extracted from a communicating pipe between a medium-pressure cylinder and the low-pressure cylinder of the steam turbine for heating, and when the load of a unit is low, the steam extraction amount is adjusted through a communicating pipe butterfly valve 1; when the temperature of the working medium water of the heat user at the inlet of the condenser is higher, the opening degree of the first regulating valve 4 is reduced to reduce the steam extraction amount and reduce the energy input of the steam extraction to the heat supply system; the condenser vacuum is operated according to a design value, the temperature of the working medium water of the heat consumer returned to the condenser inlet is in a design value range by adjusting the steam extraction amount, and the rotating speed of the variable frequency pump 16 is adjusted to change the flow speed of the working medium water of the heat consumer, so that the condenser vacuum is effectively controlled.
Taking the application of a 330MW subcritical, single intermediate reheating and two-cylinder two-exhaust-gas compressor unit to heat supply engineering as an example, the average heat load is 50W/m2Corresponding heating area 900 ten thousand m2The basic parameters of the unit are shown in table 1.
TABLE 1 basic parameters of heat supply unit
Parameter(s) Unit of Numerical value
Rated power MW 330
Main steam pressure (Absolute pressure) MPa 17.75
Temperature of main steam ℃ 540
Reheat steam pressure (Absolute pressure) MPa 3.72
Reheat steam temperature ℃ 540
Exhaust pressure of intermediate pressure cylinder (absolute pressure) MPa 1.02
Exhaust temperature of intermediate pressure cylinder ℃ 352.1
Operating speed r/min 3000
High back pressure heat exchanger vapor side pressure (absolute pressure) kPa 45
Water side inlet temperature of high back pressure heat exchanger ℃ 55
Inlet water temperature of heat exchanger for heat consumer ℃ 75.7
Outlet water temperature of heat exchanger for heat consumer ℃ 97
A high back pressure heat supply and monitoring method for a large steam turbine generator unit comprises the following steps:
s1: checking before heat supply:
the generator set is in a stop state, whether the action of each valve on the pipeline connected with the high back pressure heat exchanger 11, the heat user heat exchanger 27, the supplementary water tank 24 and the variable frequency water pump 16 is normal or not is checked and confirmed, each valve is in a closed state, and the communicating pipe butterfly valve 1 is fully opened.
S2: water injection operation and inspection of a hot water supply system:
the generator set is in a shutdown state, a tenth stop valve 28 and a ninth stop valve 26 before and after a heat user heat exchanger 27 are fully opened, an eighth stop valve 23 on a water conveying pipeline of a supplementary water tank 24 is fully opened, a fifth stop valve 14, a sixth stop valve 17 and a seventh stop valve 19 before and after a variable frequency water pump 16 are fully opened, a third regulating valve 21 is gradually opened, water is injected into a heat user pipeline system, the variable frequency water pump 16 is started after full water injection, the rotating speed of the variable frequency water pump is gradually increased, and the leakage conditions of the pipeline and each valve are checked.
S3: high back pressure vacuum start-up:
after the vacuum pump 7 is started and the operation is normal, the steam side vacuum of the high back pressure heat exchanger 11 is enabled to reach the starting operation condition of the generator set.
S4: initial starting;
after the generator set is started and normally operates, the first stop valve 2, the second stop valve 5 and the third stop valve 6 are fully opened, the monitoring system 32 adjusts the opening degree of the first adjusting valve 4 according to the test data of the outlet temperature measuring device 25 at the water side of the heat exchanger of the heat consumer, so that the outlet water temperature of the heat exchanger 27 of the heat consumer meets the heat supply requirement, and when the outlet water temperature of the heat exchanger 27 of the heat consumer cannot be improved only by adjusting the opening degree of the first adjusting valve 4, the monitoring system 32 gradually closes the communicating pipe butterfly valve 1 to improve the outlet water temperature of the heat exchanger 27 of the heat consumer.
S5: monitoring the operation condition of the generator set:
the monitoring system 32 monitors the operation condition of the generator set according to the measurement data of the steam side pressure measuring device 12, the water side inlet temperature measuring device 13, the water side inlet temperature measuring device 29 and the water side outlet temperature measuring device 25 of the high back pressure heat exchanger; the method comprises the following specific steps:
when the monitoring system 32 monitors that the steam-side pressure P of the high back-pressure heat exchanger 11 is higher than the set value P according to the measurement data of the steam-side pressure measuring device 12 of the high back-pressure heat exchangerSetting upIf the rotating speed of the variable frequency water pump 16 is increased, the monitoring system 32 increases the heating rate by 45 +/-5 kPaThe flow rate of the system water enables the pressure on the steam side of the high back pressure heat exchanger 11 to reach the requirement;
if the detected vapor side pressure P of the high back pressure heat exchanger 11 is lower than the set value PSetting upWhen the pressure of the steam side of the high back pressure heat exchanger 11 reaches the requirement, the monitoring system 32 increases the flow rate of the water of the heating system by reducing the rotation speed of the variable frequency water pump 16;
when the monitoring system 32 monitors the outlet water temperature T of the heat exchanger 27 of the hot user according to the measured data of the outlet temperature measuring device 25 at the water side of the heat exchanger of the hot userGo outIs lower than a set value TGo out of settingWhen the opening degree of the first regulating valve 4 is increased, the monitoring system 32 increases the input energy of the heat consumer heat exchanger 27 to enable the outlet water temperature of the heat consumer heat exchanger 27 to meet the requirement, and when the first regulating valve 4 is fully opened and the outlet water temperature of the heat consumer heat exchanger 27 cannot meet the requirement, the monitoring system 32 gradually reduces the opening degree of the butterfly valve 1 of the communicating pipe;
when the outlet water temperature T of the heat exchanger 27 of the hot user is monitoredGo outHigher than a set value TGo out of settingWhen the temperature is not less than 97 ± 2 ℃, the monitoring system 32 reduces the input energy of the heat consumer heat exchanger 27 by reducing the opening degree of the first regulating valve 4, so that the outlet water temperature of the heat consumer heat exchanger 27 reaches the requirement;
when the monitoring system 32 monitors that the measured temperature of the exhaust steam temperature measuring device 31 of the low pressure cylinder 1 or the exhaust steam temperature measuring device 30 of the low pressure cylinder 2 exceeds the threshold value TLow rowAnd when the temperature is not less than 120 ℃, the monitoring system 32 opens the regulating valve 9 to spray water for cooling.
S6: stopping the heat supply system:
gradually closing the first regulating valve 4 until the valve is completely closed; the first stop valve 2, the second stop valve 5 and the third stop valve 6 are closed after the first regulating valve 4 is withdrawn; stopping the generator set and the variable frequency water pump 16; gradually closing the third regulating valve 21 until the third regulating valve is completely closed; the eighth cut-off valve 23, the seventh cut-off valve 19, and the sixth cut-off valve 17 are closed.
The present invention is not limited to the above-described embodiments, which are merely preferred embodiments of the present invention, and the present invention is not limited thereto, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (3)

1. A high back pressure heat supply and monitoring method for a large steam turbine generator unit is characterized in that: the high back pressure heat supply and monitoring system of the large-scale steam turbine generator unit comprises a boiler reheater, a high pressure cylinder, an intermediate pressure cylinder and a low pressure cylinder; the low-pressure cylinder comprises a low-pressure cylinder 1, a low-pressure cylinder 2 and a generator; the system also comprises a communicating pipe butterfly valve (1), a vacuum pump (7), a high-back-pressure heat exchanger (11), a heat user heat exchanger (27), a supplementary water tank (24), a variable-frequency water pump (16), a condensate pump (10), a heat user heat exchanger (20), a monitoring system (32), a high-back-pressure heat exchanger steam side pressure measuring device (12), a high-back-pressure heat exchanger water side inlet temperature measuring device (13), a heat user heat exchanger water side inlet temperature measuring device (29), a heat user heat exchanger water side outlet temperature measuring device (25), a low-pressure cylinder 1 steam exhaust temperature measuring device (31), a low-pressure cylinder 2 steam exhaust temperature measuring device (30), a pipeline and a valve;
the communicating pipe butterfly valve (1) is arranged on the communicating pipe between the intermediate pressure cylinder and the low pressure cylinder and is used for adjusting steam supply pressure on the steam side of the heat exchanger (27) for the heat consumer and adjusting the water outlet temperature of the heat exchanger (27) for the heat consumer by adjusting the steam supply pressure;
the steam inlet of the high back pressure heat exchanger (11) is connected with the steam exhaust pipe of the low pressure cylinder, and the water outlet of the high back pressure heat exchanger (11) is connected with the condensate pump (10) through a pipeline; the condensate pump (10) is used for conveying the water condensed in the steam chamber of the high back pressure heat exchanger (11) to a boiler reheater to keep the recycling of the working medium of the thermodynamic system of the generator set;
the steam inlet of the heat user heat exchanger (27) is connected with a communicating pipe between an intermediate pressure cylinder and a low pressure cylinder in front of a communicating pipe butterfly valve (1) sequentially through a second stop valve (5), a first regulating valve (4), a first check valve (3) and a first stop valve (2), and the steam outlet of the heat user heat exchanger (27) is connected with a steam chamber of a high back pressure heat exchanger (11) through a third stop valve (6);
the water side inlet of the heat user heat exchanger (27) is connected with the water side outlet of the high back pressure heat exchanger (11) through a tenth stop valve (28); the water side outlet of the heat user heat exchanger (27) is connected with the water inlet of the heat user heat exchanger (20) through a ninth stop valve (26); a water outlet of the heat user heat exchanger (20) is connected with the variable-frequency water pump (16) through a seventh stop valve (19), a third stop valve (18) and a sixth stop valve (17) in sequence; the variable-frequency water pump (16) is connected with a water side inlet of the high back pressure heat exchanger (11) through a second check valve (15) and a fifth stop valve (14) in sequence;
the supplementary water tank (24) is connected with the variable frequency water pump (16) sequentially through an eighth stop valve (23), a fourth check valve (22), a third regulating valve (21) and a sixth stop valve (17);
the vacuum pump (7) is communicated with the steam chamber of the high back pressure heat exchanger (11) through a pipeline and is used for sucking air in the steam chamber of the high back pressure heat exchanger (11) and keeping the vacuum of the air;
the high back pressure heat exchanger steam side pressure measuring device (12) is connected with the steam chamber of the high back pressure heat exchanger (11) and is used for measuring the pressure in the steam chamber of the high back pressure heat exchanger (11);
the high back pressure heat exchanger water side inlet temperature measuring device (13) is arranged at the water side inlet of the high back pressure heat exchanger (11) and is used for measuring the temperature of inlet water at the water side inlet of the high back pressure heat exchanger (11);
the hot user heat exchanger water side inlet temperature measuring device (29) is arranged at the water side inlet of the hot user heat exchanger (27) and is used for measuring the temperature of inlet water at the water side inlet of the hot user heat exchanger (27);
the hot user heat exchanger water side outlet temperature measuring device (25) is installed at the water side outlet of the hot user heat exchanger (27) and is used for measuring the temperature of outlet water at the water side outlet of the hot user heat exchanger (27);
the exhaust steam temperature measuring device (31) of the low pressure cylinder 1 is used for measuring the exhaust steam temperature of the low pressure cylinder 1;
the exhaust steam temperature measuring device (30) of the low pressure cylinder 2 is used for measuring the exhaust steam temperature of the low pressure cylinder 2;
the monitoring system (32) is used for acquiring measurement signals of a high-back-pressure heat exchanger steam side pressure measurement device (12), a high-back-pressure heat exchanger water side inlet temperature measurement device (13), a hot user heat exchanger water side inlet temperature measurement device (29), a hot user heat exchanger water side outlet temperature measurement device (25), a low-pressure cylinder 1 steam exhaust temperature measurement device (31) and a low-pressure cylinder 2 steam exhaust temperature measurement device (30), and controlling a communicated pipe butterfly valve (1), a first regulating valve (4), a vacuum pump (7), a second regulating valve (9), a variable frequency water pump (16) and a third regulating valve (21) according to the measurement signals;
the monitoring system (32) is respectively connected with a high-back-pressure heat exchanger steam side pressure measuring device (12), a high-back-pressure heat exchanger water side inlet temperature measuring device (13), a hot user heat exchanger water side inlet temperature measuring device (29), a hot user heat exchanger water side outlet temperature measuring device (25), a low-pressure cylinder 1 steam exhaust temperature measuring device (31), a low-pressure cylinder 2 steam exhaust temperature measuring device (30), a communicated pipe butterfly valve (1), a first regulating valve (4), a vacuum pump (7), a second regulating valve (9), a variable-frequency water pump (16) and a third regulating valve (21);
the method comprises the following steps:
s1: checking before heat supply:
the generator set is in a shutdown state, whether the action of each valve on a pipeline connected with the high back pressure heat exchanger (11), the heat user heat exchanger (27), the supplementary water tank (24) and the variable frequency water pump (16) is normal is checked and confirmed, each valve is in a closed state, and the communicating pipe butterfly valve (1) is fully opened;
s2: water injection operation and inspection of a hot water supply system:
the generator set is in a shutdown state, a tenth stop valve (28) and a ninth stop valve (26) in front and at the back of a heat exchanger (27) of a heat consumer are fully opened, an eighth stop valve (23) on a water pipeline of a supplementary water tank (24) is fully opened, a fifth stop valve (14), a sixth stop valve (17) and a seventh stop valve (19) in front and at the back of a variable frequency water pump (16) are fully opened, a third regulating valve (21) is gradually opened, water is injected into a heat consumer system, the variable frequency water pump (16) is started after full water injection, the rotating speed of the variable frequency water pump is gradually increased, and the leakage conditions of the pipeline and each valve are checked;
s3: high back pressure vacuum start-up:
after the vacuum pump (7) is started and operates normally, the steam side vacuum of the high back pressure heat exchanger (11) reaches the starting operation condition of the generator set;
s4: initial starting;
after the generator set is started and normally operates, the first stop valve (2), the second stop valve (5) and the third stop valve (6) are fully opened, the monitoring system (32) adjusts the opening degree of the first adjusting valve (4) according to the test data of the outlet temperature measuring device (25) at the water side of the heat exchanger of the heat consumer, so that the outlet water temperature of the heat exchanger of the heat consumer (27) meets the heat supply requirement, and when the outlet water temperature of the heat exchanger of the heat consumer (27) cannot be increased only by adjusting the opening degree of the first adjusting valve (4), the monitoring system (32) gradually closes the communicating pipe butterfly valve (1) to increase the outlet water temperature of the heat exchanger of the heat consumer (27);
s5: monitoring the operation condition of the generator set:
the monitoring system (32) monitors the operation condition of the generator set according to the measurement data of the steam side pressure measurement device (12) of the high back pressure heat exchanger, the water side inlet temperature measurement device (13) of the high back pressure heat exchanger, the water side inlet temperature measurement device (29) of the heat consumer heat exchanger and the water side outlet temperature measurement device (25) of the heat consumer heat exchanger;
s6: stopping the heat supply system:
gradually closing the first regulating valve (4) until the first regulating valve is completely closed; the first stop valve (2), the second stop valve (5) and the third stop valve (6) are closed after the first regulating valve (4) is withdrawn; the generator set stops running, and the variable frequency water pump (16) stops running; gradually closing the third regulating valve (21) until the third regulating valve is completely closed; and closing the eighth stop valve (23), the seventh stop valve (19) and the sixth stop valve (17).
2. The high back pressure heat supply and monitoring method of the large-scale steam turbine generator unit according to claim 1, characterized in that: the step S5 is specifically as follows:
when the monitoring system (32) monitors that the steam side pressure P of the high back pressure heat exchanger (11) is higher than a set value P according to the measurement data of the steam side pressure measuring device (12) of the high back pressure heat exchangerSetting upWhen the temperature is high, the monitoring system (32) increases the water flow rate of the heat supply system by increasing the rotating speed of the variable frequency water pump (16) so that the steam side pressure of the high back pressure heat exchanger (11) meets the requirement;
if the detected vapor side pressure P of the high back pressure heat exchanger (11) is lower than the set value PSetting upWhen the temperature is high, the monitoring system (32) increases the water flow rate of the heat supply system by reducing the rotating speed of the variable frequency water pump (16) so that the steam side pressure of the high back pressure heat exchanger (11) meets the requirement;
when the monitoring system (32) monitors the outlet water temperature T of the heat exchanger (27) of the heat consumer according to the measurement data of the outlet temperature measuring device (25) at the water side of the heat exchanger of the heat consumerGo outIs lower than a set value TGo out of settingWhen the temperature of the outlet water of the heat user heat exchanger (27) can not meet the requirement when the first regulating valve (4) is fully opened, the monitoring system (32) gradually reduces the opening degree of the communicating pipe butterfly valve (1);
when the outlet water temperature T of the heat exchanger (27) of the heat consumer is monitoredGo outHigher than a set value TGo out of settingWhen the temperature of the water is higher than the set temperature, the monitoring system (32) reduces the input energy of the heat user heat exchanger (27) by reducing the opening degree of the first regulating valve (4) so that the outlet water temperature of the heat user heat exchanger (27) meets the requirement;
when the monitoring system (32) monitors that the measured temperature of the exhaust steam temperature measuring device (31) of the low pressure cylinder 1 or the exhaust steam temperature measuring device (30) of the low pressure cylinder 2 exceeds TLow rowAnd when the temperature is lowered, the monitoring system (32) opens the second regulating valve (9) to spray water for cooling.
3. The high back pressure heat supply and monitoring method of the large-scale steam turbine generator unit according to claim 1, characterized in that: the low-pressure water pump is characterized by further comprising a second regulating valve (9) and a fourth stop valve (8), wherein the output end of the condensate pump (10) is connected with the low-pressure cylinder sequentially through the second regulating valve (9) and the fourth stop valve (8).
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