CN109869786B

CN109869786B - Steam extraction and heat supply integrated system for power peak regulation of combined cycle unit and operation method of steam extraction and heat supply integrated system

Info

Publication number: CN109869786B
Application number: CN201910108083.9A
Authority: CN
Inventors: 郑立军; 常浩; 高新勇; 徐海鹏; 何晓红; 李成磊; 俞聪; 李国司; 王伟; 洪纯珩; 吴畅; 夏明�
Original assignee: Huadian Electric Power Research Institute Co Ltd
Current assignee: Huadian Electric Power Research Institute Co Ltd
Priority date: 2019-02-02
Filing date: 2019-02-02
Publication date: 2023-07-18
Anticipated expiration: 2039-02-02
Also published as: CN109869786A

Abstract

The invention relates to a steam extraction and heat supply integrated system for power peak shaving of a combined cycle unit and an operation method thereof, wherein the steam extraction and heat supply integrated system comprises a gas turbine unit and a steam turbine unit, and is based on an energy cascade utilization principle, the integrated design of different steam extraction modes is carried out, so that the operation capacity of a thermal electrolytic coupler of the combined cycle unit is effectively improved, and the heating requirements of residents are ensured; in addition, the hot water heat storage system is simultaneously coupled in the heat supply system and the boiler water supply system, so that the cooperative matching of the power peak regulation and heat supply of the combined cycle unit is realized, and the power peak regulation capacity of the combined cycle unit in the operation of the pure condensation working condition is increased. After the invention is applied, the working capacity loss in the heat supply process is effectively reduced while the heat supply capacity of the combined cycle unit is deeply excavated. And particularly, the deep peak shaving capability of the thermal power unit is realized according to the current severe power peak shaving policy requirements, the requirements of a power grid on unit peak shaving are practically met, and the method has higher practical application value.

Description

Steam extraction and heat supply integrated system for power peak regulation of combined cycle unit and operation method of steam extraction and heat supply integrated system

Technical Field

The invention belongs to the technical field of cogeneration, and particularly relates to a steam extraction and heat supply integrated system for power peak regulation of a combined cycle unit and an operation method thereof.

Background

At present, the policy in China gradually pays attention to popularization of new energy sources, reduces the proportion of the thermal power generating unit, and makes the development of the thermal power generating unit face serious tests. Currently, in order to improve the comprehensive energy utilization efficiency of the thermal power generating unit and strive for more power generation utilization hours, the heat supply capacity of the thermal power generating unit is deeply excavated, and the thermal power generating unit is more and more valued in various communities. The gas heat and power cogeneration is an energy utilization mode for simultaneously producing heat energy and electric energy, and uses high-grade heat energy for power generation and low-grade heat energy for heat supply, thereby improving the utilization efficiency of energy, reducing environmental pollution and having great application value in the aspects of energy conservation, consumption reduction and pollution emission reduction.

At present, the gas-heat-electricity cogeneration central heating system mainly has the problems that the heat-electricity ratio is low, the heat-electricity ratio generated by the conventional gas-heat-electricity cogeneration combination is limited to a certain extent, the more advanced the unit with high conversion efficiency is, the smaller the heat-electricity ratio is, taking a 10 ten thousand kW unit as an example, and the heat-electricity ratio is about 0.7. Especially, under the severe situation of current thermal power depth peak regulation, the unit is often operated under a low-load working condition, and the external heat supply capacity of the unit is lower at the moment, so that the heat supply safety is seriously influenced. However, in the prior art, for example, a combined cycle cogeneration system (patent No. 201310401252.0) is to utilize high-emission steam extraction to reduce temperature and pressure and then supply heat to the outside, and the technical defect is that: (1) The cascade utilization of energy is not considered, and the loss of the working capacity of direct temperature and pressure reduction is larger; (2) The thermal power depth peak regulation needs are not considered, so that the unit needs to operate at high load to meet the external heat supply, and the peak regulation capability of the unit is poor.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the steam extraction and heat supply integrated system for the power peak regulation of the combined cycle unit, which is reasonable in design and reliable in performance, and the operation method thereof.

The invention solves the problems by adopting the following technical scheme: a steam extraction and heat supply integrated system for combined cycle unit power peak shaving, comprising: a gas turbine unit and a steam turbine unit;

the gas turbine unit comprises a gas turbine compressor, a gas turbine combustion chamber, a gas turbine and a first generator, wherein an exhaust port of the gas turbine compressor is connected with an air inlet of the gas turbine combustion chamber, an exhaust port of the gas turbine combustion chamber is connected with an air inlet of the gas turbine, an exhaust port of the gas turbine is connected with a flue gas inlet of the waste heat boiler through a flue gas discharge pipe, the gas turbine drives the first generator to generate power, and the gas turbine is coaxially connected with the gas turbine compressor;

the steam turbine unit comprises a waste heat boiler, a steam turbine high-pressure cylinder, a steam turbine medium-pressure cylinder, a steam turbine low-pressure cylinder, a second generator, a condenser, a condensate pump, a hot water heat exchanger, a shaft seal heater, a deaerator, a first temperature and pressure reducing device, a second temperature and pressure reducing device, a third temperature and pressure reducing device, working equipment, power equipment, a heat supply network heater, a hydrophobic heat exchanger, a heat supply network circulating pump, a first circulating pump, a hot water heat accumulator, a second circulating pump and a radiator, the steam turbine high-pressure cylinder, the steam turbine medium-pressure cylinder and the steam turbine low-pressure cylinder are coaxially connected and drive a second generator to generate electricity, the waste heat boiler comprises a flue gas preheater, a low-pressure steam drum, a low-pressure superheater, a high-pressure steam drum, a reheater and a high-pressure superheater, a water outlet of the flue gas preheater is simultaneously connected with a water inlet of the low-pressure steam drum and a water inlet of the high-pressure steam drum, the steam outlet of the low pressure steam drum is connected with the steam inlet of the low pressure superheater, the steam outlet of the high pressure steam drum is connected with the steam inlet of the high pressure superheater, the steam inlet of the steam turbine high pressure cylinder is connected with the steam outlet of the high pressure superheater through a high pressure steam pipe, a valve I is arranged at the steam inlet of the steam turbine high pressure cylinder, the steam outlet of the steam turbine high pressure cylinder is connected with the steam inlet of the reheater through a cold steam pipe, a valve IV is arranged at the steam inlet of the reheater, the steam outlet of the reheater is connected with the steam inlet of the steam turbine medium pressure cylinder through a hot steam pipe, a valve VI is arranged at the steam inlet of the steam turbine medium pressure cylinder, the steam outlet of the steam turbine medium pressure cylinder is connected with the steam inlet of the steam turbine low pressure cylinder through a communicating pipe, a hydraulic pressure communicating pipe is arranged at the steam inlet of the steam turbine low pressure cylinder, the valve I is connected with one end of the low pressure steam pipe, the fourteen valve is installed at one end of the low pressure steam pipe, the steam outlet of the low pressure superheater is connected with the other end of the low pressure steam pipe, the fifteen valve is installed at the other end of the low pressure steam pipe, the steam outlet of the low pressure cylinder of the steam turbine is connected with the condenser, the water inlet end of the boiler water supply pipe is connected with the condenser, the water outlet end of the boiler water supply pipe is connected with the water inlet of the flue gas preheater, the condensate pump, the hot water heat exchanger, the shaft seal heater and the deaerator are sequentially installed on the boiler water supply pipe along the water flowing direction, the steam inlet end of the high pressure steam bypass is connected with the high pressure steam pipe, the steam outlet end of the high pressure steam bypass is connected with the steam inlet end of the first medium pressure steam branch pipe, the second valve, the first temperature and pressure reducing device and the third valve are sequentially installed on the high pressure steam bypass along the steam flowing direction, the steam outlet end of the first medium pressure steam branch pipe is connected with the steam inlet of the third temperature and pressure reducing device, a valve No. nine is arranged on the first medium pressure steam branch pipe, the steam inlet end of the cold re-steam bypass is connected with the cold re-steam pipe, the steam outlet end of the cold re-steam bypass is connected with the steam inlet end of the first medium pressure steam branch pipe, a valve No. five is arranged on the cold re-steam bypass, the steam inlet end of the hot re-steam bypass is connected with the hot re-steam pipe, the steam outlet end of the hot re-steam bypass is connected with the steam inlet end of the first medium pressure steam branch pipe, a valve No. seven, a valve No. two are sequentially arranged on the hot re-steam bypass along the steam flow direction, the steam inlet end of the low pressure steam bypass is connected with the low pressure steam pipe, the steam outlet end of the low pressure steam bypass is connected with the steam inlet end of the heating pipe, and a valve No. thirteen is arranged on the low pressure steam bypass, the steam outlet of the heating steam extraction pipe is connected with the steam inlet of the heating network heater, a seventeen valve is arranged on the heating steam extraction pipe, the steam outlet of the third temperature and pressure reduction device is connected with the steam inlet of the heating steam extraction pipe, a ten valve is arranged on the steam outlet of the third temperature and pressure reduction device, the steam inlet of the second medium-pressure steam branch pipe is connected with the steam inlet of the first medium-pressure steam branch pipe, an eleven valve is arranged on the second medium-pressure steam branch pipe, the steam outlet of the second medium-pressure steam branch pipe is connected with the steam inlet of the working equipment, the steam outlet of the working equipment is connected with the steam inlet of the heating steam extraction pipe, a twelve valve is arranged on the steam outlet of the working equipment, the water drainage outlet of the heating network heater is connected with the high-temperature water drainage inlet of the water drainage heat exchanger, the low-temperature water drainage outlet of the water drainage heat exchanger is connected with the water inlet of the condensation water pump through the water drainage pipe, an eighteen valve is arranged on a hydrophobic pipe, a heat supply network water return pipe is connected with a low-temperature water side inlet of a hydrophobic heat exchanger, a thirty-four valve is arranged at a low-temperature water side inlet of the hydrophobic heat exchanger, a nineteenth valve and a heat supply network circulating pump are arranged on the heat supply network water return pipe, a low-temperature water side outlet of the hydrophobic heat exchanger is connected with a water side inlet of a heat supply network heater, a water side outlet of the heat supply network heater is connected with a heat supply network water supply pipe, a thirty-five valve and a twenty-number valve are respectively arranged on a water side outlet of the heat supply network heater and the heat supply network water supply pipe, one end of a hot water heat accumulator is simultaneously connected with one end of a heat accumulating low-temperature water pipe and one end of a first heat accumulating low-temperature branch pipe, the other end of the hot water accumulator is connected with one end of the heat accumulating high-temperature water pipe, the other end of the heat accumulating low-temperature water pipe is connected with the low-temperature water side inlet of the hydrophobic heat exchanger, and install first circulating pump on heat accumulation low temperature water pipe, first circulating pump is provided with heat accumulation low temperature bypass, and installs twenty-third valve, twenty-second valve and twenty-first valve respectively on the import, export and the heat accumulation low temperature bypass of first circulating pump, the other end and the high temperature water side exit linkage of hot water heat exchanger of first heat accumulation low temperature branch pipe, and install twenty-seventh valve on first heat accumulation low temperature branch pipe, the other end and the heat supply pipe of heat accumulation high temperature water pipe are connected, and install the second circulating pump on heat accumulation high temperature water pipe, the second circulating pump is provided with the heat accumulation high temperature bypass, and installs twenty-fourth valve, twenty-fifth valve and twenty-sixth valve respectively on import, export and the heat accumulation high temperature bypass of second circulating pump, the export of second circulating pump still is connected with the one end of first heat accumulation high Wen Zhiguan, and the other end and the high temperature water side entrance linkage of hot water heat exchanger of first heat accumulation high Wen Zhiguan, and install twenty-eighth valve on first heat accumulation high temperature branch pipe.

Furthermore, the deaerator is connected with the steam outlet end of the low-pressure steam bypass, the steam outlet of the third temperature and pressure reduction device, the steam outlet of the acting equipment and the heating steam extraction pipe through the deaeration steam extraction pipe, and sixteen valves are arranged on the deaeration steam extraction pipe.

Furthermore, the acting device drives the power device to act, the acting device is a back press or a screw expander, and the power device is a generator, a condensate pump, a heat supply network circulating pump, a first circulating pump, a second circulating pump and the like.

Furthermore, the third temperature and pressure reducing device is connected with the acting equipment in parallel, and simultaneously provides needed steam for the deaerator and the heat supply network heater.

Further, the steam inlet end of the second medium-pressure steam branch pipe is connected with the steam outlet end of the high-pressure steam bypass, the steam outlet end of the cold re-steam bypass and the steam outlet end of the hot re-steam bypass.

Furthermore, a water supply pipe bypass is arranged on the low-temperature water side of the hot water heat exchanger, and an twenty-nine valve, a thirty-nine valve and a thirty-one valve are respectively arranged on the low-temperature water side inlet, the low-temperature water side outlet and the water supply pipe bypass of the hot water heat exchanger.

Furthermore, one end of the hot water heat accumulator is also connected with one end of a second heat accumulating low-temperature branch pipe, the other end of the second heat accumulating low-temperature branch pipe is connected with a water outlet of the radiator, and a thirty-third valve is arranged on the second heat accumulating low-temperature branch pipe; the outlet of the second circulating pump is also connected with one end of a second heat storage high-temperature branch pipe, the other end of the second heat storage high-temperature branch pipe is connected with the water inlet of the radiator, and a thirty-two valve is arranged on the second heat storage high-temperature branch pipe.

The operation method of the steam extraction and heat supply integrated system for the electric power peak regulation of the combined cycle unit is as follows:

when the unit is in a pure condensation working condition and no power peak regulation requirement exists, the operation is as follows:

only a valve I, a valve IV, a valve VI, a valve thirteen, a hydraulic butterfly valve, a valve fourteen, a valve fifteen, a valve sixteen and a valve thirty-first are opened, the combined cycle unit does not supply heat to the outside, and the deoxidized steam of the deoxidizer is from the low-pressure steam supplementing of the low-pressure superheater or the steam exhaust of the medium-pressure cylinder of the steam turbine;

when the unit is in a pure condensation working condition and has power peak regulation requirements:

A. when the unit needs to reduce the external output electric load, the steam flow entering the steam turbine for acting is reduced through the steam extraction and heat accumulation, and at the moment, the heat accumulation is carried out through the hot water heat accumulator, so that the operation is as follows:

starting a thirteenth valve and a seventeen valve, and using low-pressure steam supplementing from a low-pressure superheater or steam exhaust of a medium-pressure cylinder of a steam turbine as heating steam required by a heat supply network heater; simultaneously opening a twenty-second valve, a twenty-third valve, a twenty-sixth valve, a thirty-fourth valve and a thirty-fifth valve, sequentially conveying low-temperature water from the hot water heat accumulator to a drainage heat exchanger and a heating network heater through a first circulating pump to be heated, forming high-temperature water, and then entering the hot water heat accumulator for storage;

Or opening a valve No. nine, a valve No. ten and a valve No. seventeen, enabling the medium-pressure steam to enter a third temperature and pressure reduction device to form low-pressure steam after temperature and pressure reduction, and then conveying the low-pressure steam to a heating network heater through a heating steam extraction pipe; simultaneously opening a twenty-second valve, a twenty-third valve, a twenty-sixth valve, a thirty-fourth valve and a thirty-fifth valve, and sequentially heating low-temperature water from a hot water heat accumulator by using a hydrophobic heat exchanger and a heating network heater to form high-temperature water and then storing the high-temperature water in the hot water heat accumulator;

or opening an eleventh valve, a twelfth valve and a seventeen valve, enabling the medium-pressure steam to enter a working device to drive a power device to work so as to form low-pressure steam, and then conveying the low-pressure steam to a heating network heater through a heating steam extraction pipe; simultaneously opening a twenty-second valve, a twenty-third valve, a twenty-sixth valve, a thirty-fourth valve and a thirty-fifth valve, and sequentially heating low-temperature water from a hot water heat accumulator by using a hydrophobic heat exchanger and a heating network heater to form high-temperature water and then storing the high-temperature water in the hot water heat accumulator;

B. when the unit needs to increase the external output electric load, the steam extraction and heat accumulation are not performed at the moment, so that the steam flow entering the steam turbine for doing work is increased, and the hot water heat accumulator is used for releasing heat at the moment, and the operation is as follows:

Starting twenty-fourth, twenty-seventh and twenty-eighth valves, conveying the high-temperature water from the hot water heat accumulator to the hot water heat exchanger through a second circulating pump to release heat, simultaneously starting the twenty-ninth and thirty-eighth valves, closing the thirty-eighth valve, and heating the boiler feed water into the hot water heat exchanger by the high-temperature water from the hot water heat accumulator;

or a twenty-fourth valve, a thirty-second valve and a thirty-third valve are opened, and the high temperature water from the hot water heat accumulator is conveyed to the radiator through the second circulating pump to release heat;

when the unit is in a heating working condition and no power peak regulation is required, the operation is as follows:

only opening a valve I, a valve IV, a valve VI, a valve thirteen, a hydraulic butterfly valve, a valve fourteen, a valve fifteen, a valve sixteen, a valve seventeen, a valve nineteen, a valve twenty, a valve thirty-first, a valve thirty-fourth and a valve thirty-fifth, wherein the combined cycle unit only utilizes the low pressure steam supplementing of the low pressure superheater or the steam exhaust of the middle pressure cylinder of the steam turbine to supply heat to the outside, and the deoxidized steam of the deaerator is from the low pressure steam supplementing of the low pressure superheater or the steam exhaust of the middle pressure cylinder of the steam turbine;

when the unit is in a heating working condition and has power peak regulation requirements:

starting a thirteenth valve and a seventeen valve, and using low-pressure steam supplementing from a low-pressure superheater or steam exhaust of a medium-pressure cylinder of a steam turbine as heating steam required by a heat supply network heater; opening a nineteenth valve, a twenty-fourth valve, a thirty-fourth valve and a thirty-fifth valve, wherein heat supply network water from a heat supply network water return pipe sequentially enters a hydrophobic heat exchanger and a heat supply network heater to be heated, and after forming the heat supply network water, the heat supply network water is externally supplied through a heat supply network water supply pipe; simultaneously opening a twenty-two valve, a twenty-three valve and a twenty-six valve, sequentially conveying low-temperature water from the hot water heat accumulator to the drainage heat exchanger and the heat supply network heater through a first circulating pump to be heated, forming high-temperature water, and then entering the hot water heat accumulator for storage;

or opening a valve No. nine, a valve No. ten and a valve No. seventeen, enabling the medium-pressure steam to enter a third temperature and pressure reduction device to form low-pressure steam after temperature and pressure reduction, and then conveying the low-pressure steam to a heating network heater through a heating steam extraction pipe; opening a nineteenth valve, a twenty-fourth valve, a thirty-fourth valve and a thirty-fifth valve, wherein heat supply network water from a heat supply network water return pipe sequentially enters a hydrophobic heat exchanger and a heat supply network heater to be heated, and after forming the heat supply network water, the heat supply network water is externally supplied through a heat supply network water supply pipe; simultaneously opening a twenty-two valve, a twenty-three valve and a twenty-six valve, and enabling low-temperature water from a hot water heat accumulator to sequentially enter a hydrophobic heat exchanger and a heat supply network heater to be heated, so as to form high-temperature water, and then entering the hot water heat accumulator to be stored;

Or opening an eleventh valve, a twelfth valve and a seventeen valve, enabling the medium-pressure steam to enter a working device to drive a power device to work so as to form low-pressure steam, and then conveying the low-pressure steam to a heating network heater through a heating steam extraction pipe; opening a nineteenth valve, a twenty-fourth valve, a thirty-fourth valve and a thirty-fifth valve, wherein heat supply network water from a heat supply network water return pipe sequentially enters a hydrophobic heat exchanger and a heat supply network heater to be heated, and after forming the heat supply network water, the heat supply network water is externally supplied through a heat supply network water supply pipe; simultaneously opening a twenty-two valve, a twenty-three valve and a twenty-six valve, and enabling low-temperature water from a hot water heat accumulator to sequentially enter a hydrophobic heat exchanger and a heat supply network heater to be heated, so as to form high-temperature water, and then entering the hot water heat accumulator to be stored;

B. when the unit needs to increase the external output electric load, the steam extraction and heat accumulation are not performed at the moment, and the heat release of the hot water heat accumulator is utilized to supply heat to the outside, so that the steam flow entering the steam turbine for doing work is increased, and the operation is as follows:

closing seventeen valves, stopping using the steam extraction of the unit to supply heat to the outside, and opening nineteen valves, twenty-one valves, twenty-four valves and twenty-five valves at the moment, and conveying the high-temperature water from the hot water heat accumulator to a heat supply pipe of a heat supply network to supply heat to the outside through a second circulating pump;

Or a twenty-fourth valve, a twenty-seventh valve and a twenty-eighth valve are opened, high temperature water from the hot water heat accumulator is conveyed to the hot water heat exchanger through the second circulating pump to release heat, meanwhile, a twenty-ninth valve and a thirty-eighth valve are opened, a thirty-eighth valve is closed, and boiler feed water firstly enters the hot water heat exchanger to be heated by the high temperature water from the hot water heat accumulator;

or a twenty-fourth valve, a thirty-second valve and a thirty-third valve are opened, and the high temperature water from the hot water heat accumulator is conveyed to the radiator through the second circulating pump to release heat.

The operation method of the steam extraction and heat supply integrated system for the power peak regulation of the combined cycle unit comprises the following steps:

when the unit has the power peak regulation requirement, the operation steps for providing medium-pressure steam for the third temperature and pressure reduction device and the acting equipment are as follows:

opening a valve No. five, and directly taking exhaust steam from a high-pressure cylinder of the steam turbine as a medium-pressure steam source of a third temperature and pressure reduction device and working equipment;

or opening the valve No. seven and the valve No. eight, and forming steam with lower pressure and temperature after the hot re-steam from the reheater passes through the second temperature and pressure reducing device, wherein the steam is used as a medium-pressure steam source of the third temperature and pressure reducing device and the acting equipment;

Or opening the second valve and the third valve, and forming steam with lower pressure and temperature after the main steam from the high-pressure superheater passes through the first temperature and pressure reducing device, wherein the steam is used as a medium-pressure steam source of the third temperature and pressure reducing device and the acting equipment;

when the unit has no power peak regulation requirement, the heat release selection method of the hot water heat accumulator is as follows:

in the pure condensation working condition, the radiator and the hot water heat exchanger are simultaneously selected to be started, or one of the radiator and the hot water heat exchanger is selected to be started, so that the heat of the hot water heat accumulator is released outwards;

and in the heat supply working condition, the heat supply to the outside through the hot-net water supply pipe, the heat radiator and the hot water heat exchanger are simultaneously selected, or one of the heat supply to the outside through the hot-net water supply pipe, the heat radiator and the hot water heat exchanger is selected to be opened, and the heat accumulator is used for discharging heat to the outside.

when the unit provides heating steam for the heat supply network heater, the low-pressure steam supplementing of the low-pressure superheater or the steam exhaust of the medium-pressure cylinder of the steam turbine is preferentially selected, the steam exhaust of the acting equipment is selected, and the temperature and pressure reduction steam of the third temperature and pressure reduction device is selected;

When the unit provides medium-pressure steam for the third temperature and pressure reduction device and the acting equipment, the high-pressure exhaust steam of the high-pressure cylinder of the steam turbine is preferentially selected and utilized, the hot re-steam of the reheater is selected and utilized, and the main steam of the high-pressure superheater is selected and utilized;

in the pure condensation working condition, the hot water heat exchanger is preferably started for heat release of the hot water heat accumulator outwards, and then the radiator is selected for heat release of the hot water heat accumulator outwards;

and when the heat supply working condition is met, the heat supply pipe is preferably selected to supply heat to the outside through the hot-net water supply pipe for heat release to the outside of the hot-water heat accumulator, then the hot-water heat exchanger is selected to be started for heat release to the outside of the hot-water heat accumulator, and finally the radiator is selected to be started for heat release to the outside of the hot-water heat accumulator.

Compared with the prior art, the invention has the following advantages and effects: the integrated design of different steam extraction modes is carried out based on the energy cascade utilization principle, so that the operation capacity of the thermal-electrolytic coupler of the combined cycle unit is effectively improved, and the heating requirements of residents are ensured; in addition, the hot water heat storage system is simultaneously coupled in the heat supply system and the boiler water supply system, so that the cooperative matching of the power peak regulation and heat supply of the combined cycle unit is realized, and the power peak regulation capacity of the combined cycle unit in the operation of the pure condensation working condition is increased. After the invention is applied, the working capacity loss in the heat supply process is effectively reduced while the heat supply capacity of the combined cycle unit is deeply excavated. And particularly, the deep peak shaving capability of the thermal power unit is realized according to the current severe power peak shaving policy requirements, the requirements of a power grid on unit peak shaving are practically met, and the method has higher practical application value.

Drawings

Fig. 1 is a schematic overall structure of an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and not limited to the following examples.

Examples

Referring to fig. 1, a steam extraction and heat supply integrated system for power peak shaving of a combined cycle unit in this embodiment includes: a gas turbine unit and a steam turbine unit;

the gas turbine unit comprises a gas turbine compressor 1, a gas turbine combustion chamber 2, a gas turbine 3 and a first generator 4, wherein an exhaust port of the gas turbine compressor 1 is connected with an air inlet of the gas turbine combustion chamber 2, an exhaust port of the gas turbine combustion chamber 2 is connected with an air inlet of the gas turbine 3, an exhaust port of the gas turbine 3 is connected with a flue gas inlet of a waste heat boiler 5 through a flue gas discharge pipe 31, the gas turbine 3 drives the first generator 4 to generate power, and the gas turbine 3 is coaxially connected with the gas turbine compressor 1;

the steam turbine set comprises a waste heat boiler 5, a steam turbine high pressure cylinder 6, a steam turbine medium pressure cylinder 7, a steam turbine low pressure cylinder 8, a second generator 9, a condenser 10, a condensate pump 11, a hot water heat exchanger 12, a shaft seal heater 13, a deaerator 14, a first temperature and pressure reducing device 15, a second temperature and pressure reducing device 16, a third temperature and pressure reducing device 17, a working device 18, a power device 19, a heat supply network heater 20, a drainage heat exchanger 21, a heat supply network circulating pump 22, a first circulating pump 23, a hot water heat accumulator 24, a second circulating pump 25 and a radiator 26, the steam turbine high pressure cylinder 6, the steam turbine medium pressure cylinder 7 and the steam turbine low pressure cylinder 8 are coaxially connected, and the second generator 9 is driven to generate electricity, the waste heat boiler 5 comprises a flue gas preheater 501, a low pressure steam drum 502, a low pressure superheater 503, a high pressure steam drum 504, a reheater 505 and a high pressure superheater 506, the water outlet of the flue gas preheater 501 is connected with the water inlet of the low pressure steam drum 502 and the water inlet of the high pressure steam drum 504 at the same time, the steam outlet of the low pressure steam drum 502 is connected with the steam inlet of the low pressure superheater 503, the steam outlet of the high pressure steam drum 504 is connected with the steam inlet of the high pressure superheater 506, the steam inlet of the turbine high pressure cylinder 6 is connected with the steam outlet of the high pressure superheater 506 through the high pressure steam pipe 33, the first valve 61 is arranged at the steam inlet of the turbine high pressure cylinder 6, the steam outlet of the turbine high pressure cylinder 6 is connected with the steam inlet of the reheater 505 through the cold re-steam pipe 34, the fourth valve 64 is arranged at the steam inlet of the reheater 505, the steam outlet of the reheater 505 is connected with the steam inlet of the turbine medium pressure cylinder 7 through the hot re-steam pipe 35, the sixth valve 66 is arranged at the steam inlet of the turbine medium pressure cylinder 7, the steam outlet of the turbine medium pressure cylinder 7 is connected with the steam inlet of the turbine low pressure cylinder 8 through the communicating pipe 36, the hydraulic butterfly valve 74 is installed at the steam inlet of the low-pressure cylinder 8 of the steam turbine, the communicating pipe 36 is connected with one end of the low-pressure steam pipe 37, the fourteen valve 75 is installed at one end of the low-pressure steam pipe 37, the steam outlet of the low-pressure superheater 503 is connected with the other end of the low-pressure steam pipe 37, the fifteen valve 76 is installed at the other end of the low-pressure steam pipe 37, the steam outlet of the low-pressure cylinder 8 of the steam turbine is connected with the condenser 10, the water inlet end of the boiler water supply pipe 32 is connected with the condenser 10, the water outlet end of the boiler water supply pipe 32 is connected with the water inlet of the flue gas preheater 501, the condensate pump 11, the hot water heat exchanger 12, the shaft seal heater 13 and the deaerator 14 are sequentially installed on the boiler water supply pipe 32 along the water flow direction, the steam inlet end of the high-pressure steam bypass 38 is connected with the high-pressure steam pipe 33, the steam outlet end of the high-pressure steam bypass 38 is connected with the steam inlet end of the first medium-pressure steam branch pipe 42, and a second valve 62, a first temperature and pressure reduction device 15 and a third valve 63 are sequentially installed on the high-pressure steam bypass 38 along the steam flow direction, the steam outlet end of the first medium-pressure steam branch pipe 42 is connected with the steam inlet of the third temperature and pressure reduction device 17, a ninth valve 69 is installed on the first medium-pressure steam branch pipe 42, the steam inlet end of the cold re-steam bypass 39 is connected with the cold re-steam pipe 34, the steam outlet end of the cold re-steam bypass 39 is connected with the steam inlet end of the first medium-pressure steam branch pipe 42, a fifth valve 65 is installed on the cold re-steam bypass 39, the steam inlet end of the hot re-steam bypass 40 is connected with the hot re-steam pipe 35, a seventh valve 67, a second temperature and pressure reduction device 16 and a eighth valve 68 are sequentially installed on the hot re-steam bypass 40 along the steam flow direction, the steam inlet end of the low-pressure steam bypass 41 is connected with the low-pressure steam pipe 37, the steam outlet end of the low-pressure steam bypass 41 is connected with the steam inlet end of the heating steam extraction pipe 45, a thirteen-size valve 73 is arranged on the low-pressure steam bypass 41, the steam outlet end of the heating steam extraction pipe 45 is connected with the steam inlet of the heating network heater 20, a seventeen-size valve 78 is arranged on the heating steam extraction pipe 45, the steam outlet of the third temperature and pressure reducing device 17 is connected with the steam inlet end of the heating steam extraction pipe 45, a ten-size valve 70 is arranged on the steam outlet of the third temperature and pressure reducing device 17, the steam inlet end of the second medium-pressure steam branch pipe 43 is connected with the steam inlet end of the first medium-pressure steam branch pipe 42, an eleven-size valve 71 is arranged on the second medium-pressure steam branch pipe 43, the steam outlet end of the second medium-pressure steam branch pipe 43 is connected with the steam inlet of the working equipment 18, the steam outlet of the working equipment 18 is connected with the steam inlet end of the heating steam extraction pipe 45, a twelve-valve 72 is arranged at the steam outlet of the working equipment 18, the steam outlet of the heat supply network heater 20 is connected with the high-temperature steam outlet of the steam heat exchanger 21, the low-temperature steam outlet of the steam heat exchanger 21 is connected with the water inlet of the condensate pump 11 through a steam outlet pipe 46, an eighteen-valve 79 is arranged on the steam outlet pipe 46, a heat supply network water return pipe 47 is connected with the low-temperature water side inlet of the steam heat exchanger 21, thirty-four-valve 95, nineteenth-valve 80 and heat supply network circulating pump 22 are respectively arranged on the low-temperature water side inlet of the steam heat exchanger 21 and the heat supply network water return pipe 47, the water side outlet of the steam heat exchanger 21 is connected with the water side inlet of the heat supply network heater 20, the water side outlet of the heat supply network heater 20 is connected with a heat supply network water supply pipe 48, thirty-five-valve 96 and twenty-valve 81 are respectively arranged on the water side outlet of the heat supply network heater 20 and the heat supply network water supply pipe 48, one port of the hot water heat accumulator 24 is connected with one end of a heat accumulating low temperature water pipe 49 and one end of a first heat accumulating low temperature branch pipe 53 at the same time, the other port of the hot water heat accumulator 24 is connected with one end of a heat accumulating high temperature water pipe 51, the other end of the heat accumulating low temperature water pipe 49 is connected with a low temperature water side inlet of the hydrophobic heat exchanger 21, a first circulating pump 23 is arranged on the heat accumulating low temperature water pipe 49, the first circulating pump 23 is provided with a heat accumulating low temperature bypass 50, a twenty-third valve 84, a twenty-second valve 83 and a twenty-first valve 82 are respectively arranged on the inlet, the outlet and the heat accumulating low temperature bypass 50 of the first circulating pump 23, the other end of the first heat accumulating low temperature branch pipe 53 is connected with a high temperature water side outlet of the hot water heat exchanger 12, and twenty-seventh valve 88 is installed on the first heat storage low-temperature branch pipe 53, the other end of the heat storage high-temperature water pipe 51 is connected with the heat supply network water supply pipe 48, the second circulating pump 25 is installed on the heat storage high-temperature water pipe 51, the second circulating pump 25 is provided with a heat storage high-temperature bypass 52, twenty-fourth valve 85, twenty-fifth valve 86 and twenty-sixth valve 87 are installed on the inlet, outlet and the heat storage high-temperature bypass 52 of the second circulating pump 25 respectively, the outlet of the second circulating pump 25 is also connected with one end of the first heat storage high Wen Zhiguan 54, the other end of the first heat storage high Wen Zhiguan is connected with the high-temperature water side inlet of the hot water heat exchanger 12, and twenty-eighth valve 89 is installed on the first heat storage high Wen Zhiguan.

The deaerator 14 is connected with the steam outlet end of the low-pressure steam bypass 41, the steam outlet of the third temperature and pressure reduction device 17, the steam outlet of the acting device 18 and the heating steam extraction pipe 45 through the deaeration steam extraction pipe 44, and a sixteen-number valve 77 is arranged on the deaeration steam extraction pipe 44.

The acting device 18 drives the power device 19 to do work, the acting device 18 is a back press or a screw expander, and the power device 19 is a generator, a condensate pump 11, a heat supply network circulating pump 22, a first circulating pump 23 or a second circulating pump 25.

The third temperature and pressure reducing device 17 is connected in parallel with the work device 18 and provides the required steam for the deaerator 14 and the heat supply network heater 20.

The steam inlet end of the second intermediate-pressure steam branch pipe 43 is also connected with the steam outlet end of the high-pressure steam bypass 38, the steam outlet end of the cold re-steam bypass 39 and the steam outlet end of the hot re-steam bypass 40.

The hot water heat exchanger 12 is provided with a water feed pipe bypass 55 on a low temperature water side, and an twenty-ninth valve 90, a thirty-first valve 91, and a thirty-first valve 92 are installed on the hot water heat exchanger 12 low temperature water side inlet, low temperature water side outlet, and water feed pipe bypass 55, respectively.

One end of the hot water heat accumulator 24 is also connected with one end of a second heat accumulation low Wen Zhiguan, the other end of the second heat accumulation low Wen Zhiguan is connected with a water outlet of the radiator 26, and a thirty-third valve 94 is arranged on the second heat accumulation low-temperature branch pipe 57; the outlet of the second circulation pump 25 is also connected with one end of a second heat accumulating high temperature branch pipe 56, the other end of the second heat accumulating high temperature branch pipe 56 is connected with the water inlet of the radiator 26, and a thirty-two valve 93 is installed on the second heat accumulating high temperature branch pipe 56.

In this embodiment, the specific operation method is as follows:

only opening the valve 61, the valve 64, the valve 66, the valve 73, the hydraulic butterfly valve 74, the valve 75, the valve 76, the valve 77 and the valve 92, wherein the combined cycle unit does not supply heat to the outside, and the deoxidized steam of the deoxidizer 14 is from the low-pressure steam supplementing of the low-pressure superheater 503 or the steam exhausting of the medium-pressure cylinder 7 of the steam turbine;

A. when the unit needs to reduce the load of the external output electricity, the steam flow entering the steam turbine for doing work is reduced through the steam extraction and heat storage, and at the moment, the heat storage is performed through the hot water heat accumulator 24, and the operation is as follows:

opening a thirteenth valve 73 and a seventeen valve 78, and using low-pressure steam supplementing from the low-pressure superheater 503 or steam exhaust from the medium-pressure cylinder 7 of the steam turbine as heating steam required by the heating network heater 20; simultaneously, a twenty-second valve 83, a twenty-third valve 84, a twenty-sixth valve 87, a thirty-fourth valve 95 and a thirty-fifth valve 96 are opened, low-temperature water from the hot-water heat accumulator 24 is sequentially conveyed into the hydrophobic heat exchanger 21 and the heat supply network heater 20 through the first circulating pump 23 to be heated, and the high-temperature water is formed and then enters the hot-water heat accumulator 24 to be stored;

Or opening valve 69, valve 70 and valve 78, wherein the medium-pressure steam enters the third temperature and pressure reduction device 17 to be subjected to temperature and pressure reduction to form low-pressure steam, and then the low-pressure steam is conveyed to the heating network heater 20 through the heating steam extraction pipe 45; simultaneously opening a twenty-second valve 83, a twenty-third valve 84, a twenty-sixth valve 87, a thirty-fourth valve 95 and a thirty-fifth valve 96, and enabling low-temperature water from the hot water heat accumulator 24 to sequentially enter the hydrophobic heat exchanger 21 and the heat network heater 20 to be heated, and enabling the low-temperature water to enter the hot water heat accumulator 24 for storage after being formed;

or opening the eleven valve 71, the twelve valve 72 and the seventeen valve 78, enabling the medium-pressure steam to enter the acting equipment 18 to drive the power equipment 19 to act to form low-pressure steam, and then conveying the low-pressure steam to the heating network heater 20 through the heating steam extraction pipe 45; simultaneously opening a twenty-second valve 83, a twenty-third valve 84, a twenty-sixth valve 87, a thirty-fourth valve 95 and a thirty-fifth valve 96, and enabling low-temperature water from the hot water heat accumulator 24 to sequentially enter the hydrophobic heat exchanger 21 and the heat network heater 20 to be heated, and enabling the low-temperature water to enter the hot water heat accumulator 24 for storage after being formed;

B. when the unit needs to increase the load of the external output electricity, the steam extraction and heat accumulation are not performed at the moment, so that the steam flow entering the steam turbine to do work is increased, and the hot water heat accumulator 24 is used for releasing heat at the moment, and the operation is as follows:

The twenty-fourth valve 85, the twenty-seventh valve 88 and the twenty-eighth valve 89 are opened, high-temperature water from the hot water heat accumulator 24 is conveyed to the hot water heat exchanger 12 through the second circulating pump 25 to release heat, meanwhile, the twenty-ninth valve 90 and the thirty-eighth valve 91 are opened, the thirty-eighth valve 92 is closed, and boiler feed water firstly enters the hot water heat exchanger 12 and is heated by the high-temperature water from the hot water heat accumulator 24;

or the twenty-fourth valve 85, the thirty-second valve 93 and the thirty-third valve 94 are opened, and the high temperature water from the hot water heat accumulator 24 is conveyed to the radiator 26 through the second circulating pump 25 to release heat;

only opening a valve 61, a valve 64, a valve 66, a valve 73, a hydraulic butterfly valve 74, a valve 75, a valve 76, a valve 77, a valve 78, a valve 80, a valve 81, a valve 92, a valve 95 and a valve 96, wherein the combined cycle unit only utilizes the low-pressure steam supplement of the low-pressure superheater 503 or the steam exhaust of the middle pressure cylinder 7 of the steam turbine to supply heat to the outside, and the deoxidized steam of the deoxidizer 14 is from the low-pressure steam supplement of the low-pressure superheater 503 or the steam exhaust of the middle pressure cylinder 7 of the steam turbine;

opening a thirteenth valve 73 and a seventeen valve 78, and using low-pressure steam supplementing from the low-pressure superheater 503 or steam exhaust from the medium-pressure cylinder 7 of the steam turbine as heating steam required by the heating network heater 20; opening the nineteenth valve 80, the twenty-fourth valve 81, the thirty-fourth valve 95 and the thirty-fifth valve 96, and sequentially heating the heat supply network water from the heat supply network water return pipe 47 into the hydrophobic heat exchanger 21 and the heat supply network heater 20 to form high-temperature heat supply network water and then supplying the high-temperature heat supply network water to the outside through the heat supply network water supply pipe 48; simultaneously, a twenty-two valve 83, a twenty-three valve 84 and a twenty-six valve 87 are opened, low-temperature water from the hot water heat accumulator 24 is sequentially conveyed into the hydrophobic heat exchanger 21 and the heat network heater 20 through the first circulating pump 23 to be heated, and the high-temperature water is formed and then enters the hot water heat accumulator 24 to be stored;

or opening valve 69, valve 70 and valve 78, wherein the medium-pressure steam enters the third temperature and pressure reduction device 17 to be subjected to temperature and pressure reduction to form low-pressure steam, and then the low-pressure steam is conveyed to the heating network heater 20 through the heating steam extraction pipe 45; opening the nineteenth valve 80, the twenty-fourth valve 81, the thirty-fourth valve 95 and the thirty-fifth valve 96, and sequentially heating the heat supply network water from the heat supply network water return pipe 47 into the hydrophobic heat exchanger 21 and the heat supply network heater 20 to form high-temperature heat supply network water and then supplying the high-temperature heat supply network water to the outside through the heat supply network water supply pipe 48; simultaneously, a twenty-two valve 83, a twenty-three valve 84 and a twenty-six valve 87 are opened, low-temperature water from the hot water heat accumulator 24 sequentially enters the hydrophobic heat exchanger 21 and the heat supply network heater 20 to be heated, and the high-temperature water is formed and then enters the hot water heat accumulator 24 to be stored;

Or opening the eleven valve 71, the twelve valve 72 and the seventeen valve 78, enabling the medium-pressure steam to enter the acting equipment 18 to drive the power equipment 19 to act to form low-pressure steam, and then conveying the low-pressure steam to the heating network heater 20 through the heating steam extraction pipe 45; opening the nineteenth valve 80, the twenty-fourth valve 81, the thirty-fourth valve 95 and the thirty-fifth valve 96, and sequentially heating the heat supply network water from the heat supply network water return pipe 47 into the hydrophobic heat exchanger 21 and the heat supply network heater 20 to form high-temperature heat supply network water and then supplying the high-temperature heat supply network water to the outside through the heat supply network water supply pipe 48; simultaneously, a twenty-two valve 83, a twenty-three valve 84 and a twenty-six valve 87 are opened, low-temperature water from the hot water heat accumulator 24 sequentially enters the hydrophobic heat exchanger 21 and the heat supply network heater 20 to be heated, and the high-temperature water is formed and then enters the hot water heat accumulator 24 to be stored;

B. when the unit needs to increase the load of outputting electricity to the outside, the steam extraction and heat accumulation are not carried out at the moment, and the heat release of the hot water heat accumulator 24 is utilized to supply heat to the outside, so that the steam flow entering the steam turbine for doing work is increased, and the operation is as follows:

closing or closing the seventeen valves 78, reducing or stopping the external heat supply by using the extraction steam of the unit, and opening the nineteen valves 80, the twenty-first valve 81, the twenty-fourth valve 85 and the twenty-fifth valve 86 at the moment, and conveying the high temperature water from the hot water heat accumulator 24 to the heat supply network water supply pipe 48 for external heat supply through the second circulating pump 25;

Or a twenty-fourth valve 85, a twenty-seventh valve 88 and a twenty-eighth valve 89 are opened, high-temperature water from the hot water heat accumulator 24 is conveyed to the hot water heat exchanger 12 through the second circulating pump 25 to release heat, meanwhile, a twenty-ninth valve 90 and a thirty-eighth valve 91 are opened, a thirty-eighth valve 92 is closed, and boiler feed water firstly enters the hot water heat exchanger 12 and is heated by the high-temperature water from the hot water heat accumulator 24;

or twenty-four valve 85, thirty-two valve 93 and thirty-three valve 94 are opened, and the high temperature water from the hot water heat accumulator 24 is sent to the radiator 26 through the second circulation pump 25 to release heat.

In the operation method, the following steps are adopted:

when the unit has the power peak regulation requirement, the operation steps for providing medium-pressure steam for the third temperature and pressure reduction device 17 and the working equipment 18 are as follows:

opening a valve No. 65, and directly using exhaust steam from the high-pressure cylinder 6 of the steam turbine as a medium-pressure steam source of the third temperature and pressure reduction device 17 and the working equipment 18;

or opening a valve 67 and a valve 68, and forming steam with lower pressure and temperature after the hot re-steam from the reheater 505 passes through the second temperature and pressure reducing device 16, wherein the steam is used as a medium-pressure steam source of the third temperature and pressure reducing device 17 and the working equipment 18;

Or opening the valve number two 62 and the valve number three 63, and forming steam with lower pressure and temperature after the main steam from the high-pressure superheater 506 passes through the first temperature and pressure reducing device 15, wherein the steam is used as a medium-pressure steam source of the third temperature and pressure reducing device 17 and the working equipment 18;

when the unit has no power peak shaving requirement, the heat release selection method of the hot water heat accumulator 24 is as follows:

in the pure condensation working condition, the radiator 26 and the hot water heat exchanger 12 are simultaneously selected to be started, or one of the radiator 26 and the hot water heat exchanger 12 is selected to be started for the hot water heat accumulator 24 to release heat outwards;

during the heat supply working condition, the heat supply to the outside through the hot-net water supply pipe 48, the heat radiator 26 and the hot-water heat exchanger 12 are turned on, or one of the heat supply to the outside through the hot-net water supply pipe 48, the heat radiator 26 and the hot-water heat exchanger 12 is turned on, so that the heat of the hot-water heat accumulator 24 is released to the outside.

When the unit provides heating steam for the heat supply network heater 20, the low-pressure steam supplementing of the low-pressure superheater 503 or the steam exhaust of the steam turbine medium pressure cylinder 7 are preferably selected and utilized, the steam exhaust of the acting equipment 18 is selected and utilized, and the temperature and pressure reduction steam of the third temperature and pressure reduction device 17 is selected and utilized;

when the unit provides medium-pressure steam for the third temperature and pressure reduction device 17 and the acting device 18, the high-pressure exhaust steam of the high-pressure cylinder 6 of the steam turbine is preferentially selected and utilized, the hot re-steam of the reheater 505 is selected and utilized, and the main steam of the high-pressure superheater 506 is selected and utilized;

In the pure condensation working condition, the hot water heat exchanger 12 is preferably turned on for the heat release of the hot water heat accumulator 24, and then the radiator 26 is selectively turned on for the heat release of the hot water heat accumulator 24;

during heating conditions, the heat is preferably supplied to the outside through the hot-net water supply pipe 48 for the heat of the hot-water heat accumulator 24 to be released to the outside, the hot-water heat exchanger 12 is then selectively turned on for the heat of the hot-water heat accumulator 24 to be released to the outside, and the radiator 26 is finally selectively turned on for the heat of the hot-water heat accumulator 24 to be released to the outside.

The radiator 26 in this embodiment may be water-cooled or air-cooled.

In the specific operation method of this embodiment, all valves have the function of adjusting the fluid flow of the pipeline; other valves have a shut-off function in addition to the hydraulic butterfly valve 74.

In the specific operation method of the embodiment, the opening adjustment of all valves is completed through the remote operation of the DCS control system of the combined cycle unit when the operation is performed under different working conditions; the heat storage and release capacity and time of the hot water heat accumulator 24 are determined by considering the comprehensive factors such as the electric power peak regulation depth requirement, the external heat supply capacity of the unit, the adjustment capacity of the steam extraction integrated system of the unit and the like.

Although the present invention is described with reference to the above embodiments, it should be understood that the invention is not limited to the embodiments described above, but is capable of modification and variation without departing from the spirit and scope of the present invention.

Claims

1. A steam extraction and heat supply integrated system for combined cycle unit power peak shaving, comprising: a gas turbine unit and a steam turbine unit;

the gas turbine unit comprises a gas turbine compressor (1), a gas turbine combustion chamber (2), a gas turbine (3) and a first generator (4), wherein an exhaust port of the gas turbine compressor (1) is connected with an air inlet of the gas turbine combustion chamber (2), an exhaust port of the gas turbine combustion chamber (2) is connected with an air inlet of the gas turbine (3), an exhaust port of the gas turbine (3) is connected with a flue gas inlet of a waste heat boiler (5) through a flue gas discharge pipe (31), the gas turbine (3) drives the first generator (4) to generate electricity, and the gas turbine (3) is coaxially connected with the gas turbine compressor (1);

the steam turbine unit comprises a waste heat boiler (5), a steam turbine high-pressure cylinder (6), a steam turbine medium-pressure cylinder (7), a steam turbine low-pressure cylinder (8), a second generator (9), a condenser (10), a condensate pump (11), a hot water heat exchanger (12), a shaft seal heater (13), a deaerator (14), a first temperature and pressure reduction device (15), a second temperature and pressure reduction device (16), a third temperature and pressure reduction device (17), a working device (18), a power device (19), a heat supply network heater (20), a hydrophobic heat exchanger (21), a heat supply network circulating pump (22), a first circulating pump (23), a hot water heat accumulator (24), a second circulating pump (25) and a radiator (26), the steam turbine high-pressure cylinder (6), the steam turbine medium-pressure cylinder (7) and the steam turbine low-pressure cylinder (8) are coaxially connected, and the second generator (9) is driven to generate electricity, the waste heat boiler (5) comprises a flue gas preheater (501), a low-pressure drum (502), a low-pressure superheater (503), a high-pressure drum (504), a reheater (505) and a high-pressure drum (506), a water inlet of the low-pressure drum (506) and a water inlet of the steam drum (502) are connected at the same time, the steam outlet of the low-pressure steam drum (502) is connected with the steam inlet of the low-pressure superheater (503), the steam outlet of the high-pressure steam drum (504) is connected with the steam inlet of the high-pressure superheater (506), the steam inlet of the turbine high-pressure cylinder (6) is connected with the steam outlet of the high-pressure superheater (506) through a high-pressure steam pipe (33), a valve (61) is arranged at the steam inlet of the turbine high-pressure cylinder (6), the steam outlet of the turbine high-pressure cylinder (6) is connected with the steam inlet of the reheater (505) through a cold reheat pipe (34), a valve (64) is arranged at the steam inlet of the reheater (505), the steam outlet of the reheater (505) is connected with the steam inlet of the turbine medium-pressure cylinder (7) through a hot reheat pipe (35), a valve (66) is arranged at the steam inlet of the turbine medium-pressure cylinder (7), a valve (36) is arranged at the steam outlet of the turbine medium-pressure cylinder (7), a valve (36) is arranged at the steam inlet of the low-pressure cylinder (7), a communication pipe (37) is arranged at the air inlet of the low-pressure cylinder (37), a communication pipe (37) is arranged at the other end of the low-pressure cylinder (37), a communication pipe (37) is arranged at the steam inlet of the low-pressure cylinder (37), the other end of the low-pressure steam pipe (37) is provided with a fifteen-number valve (76), a steam outlet of the steam turbine low-pressure cylinder (8) is connected with the condenser (10), a water inlet end of the boiler water supply pipe (32) is connected with the condenser (10), a water outlet end of the boiler water supply pipe (32) is connected with a water inlet of the flue gas preheater (501), a condensate pump (11), a hot water heat exchanger (12), a shaft seal heater (13) and a deaerator (14) are sequentially arranged on the boiler water supply pipe (32) along the water flow direction, a steam inlet end of the high-pressure steam bypass (38) is connected with a steam inlet end of a first medium-pressure steam branch pipe (42), a steam outlet end of the high-pressure steam bypass (38) is connected with a steam inlet end of a second valve (62), a first temperature and pressure reduction device (15) and a third valve (63) are sequentially arranged on the high-pressure steam bypass (38), a steam outlet end of the first medium-pressure steam bypass (38) is connected with a steam inlet end of the first branch pipe (39) and a steam inlet end of the third pressure reduction device (17) is connected with a steam inlet end of the first bypass (39), and a valve No. five (65) is installed on the cold re-steam bypass (39), the steam inlet end of the hot re-steam bypass (40) is connected with the hot re-steam pipe (35), the steam outlet end of the hot re-steam bypass (40) is connected with the steam inlet end of the first medium-pressure steam branch pipe (42), a valve No. seven (67), a second temperature and pressure reducing device (16) and a valve No. eight (68) are sequentially installed on the hot re-steam bypass (40) along the steam flow direction, the steam inlet end of the low-pressure steam bypass (41) is connected with the low-pressure steam pipe (37), the steam outlet end of the low-pressure steam bypass (41) is connected with the steam inlet end of the heating steam extraction pipe (45), the steam outlet end of the heating steam extraction pipe (45) is connected with the steam inlet of the heating network heater (20), a valve No. seventeen (78) is installed on the heating steam extraction pipe (45), the steam outlet end of the third pressure reducing device (17) is connected with the steam inlet end of the second medium-pressure branch pipe (43), the steam inlet end of the second pressure reducing device (43) is connected with the steam inlet end of the steam outlet end of the second medium-pressure reducing device (43), the steam outlet of the second medium pressure steam branch pipe (43) is connected with the steam inlet of the working device (18), the steam outlet of the working device (18) is connected with the steam inlet of the heating steam extraction pipe (45), a twelve-number valve (72) is arranged at the steam outlet of the working device (18), the water drain outlet of the heat supply network heater (20) is connected with the high-temperature water drain inlet of the water drain heat exchanger (21), the low-temperature water drain outlet of the water drain heat exchanger (21) is connected with the water inlet of the condensate pump (11) through the water drain pipe (46), an eighteen-number valve (79) is arranged on the water drain pipe (46), the heat supply network water return pipe (47) is connected with the low-temperature water side inlet of the water drain heat exchanger (21), a thirty-four-number valve (95) is arranged at the low-temperature water side inlet of the water drain heat exchanger (21), a nineteenth-number valve (80) and a heat supply network circulating pump (22) are arranged on the heat supply network water return pipe (47), the water drain side outlet of the water drain heat exchanger (21) is connected with the water side of the heat supply network heater (20) through the water drain pipe (46), the water supply network (20) is connected with the water supply network (20) outlet of the water supply network (20) and the water supply network (48) is connected with the water supply network (96) through the water supply network (96) and the water supply network (96) through the water supply network (20) and the water supply network (96) and the water supply network (20) is connected with the water supply network (20), one port of the hot water heat accumulator (24) is connected with one end of a heat accumulating low-temperature water pipe (49) and one end of a first heat accumulating low-temperature water pipe (53) at the same time, the other port of the hot water heat accumulator (24) is connected with one end of a heat accumulating high-temperature water pipe (51), the other end of the heat accumulating low-temperature water pipe (49) is connected with a low-temperature water side inlet of a hydrophobic heat exchanger (21), a first circulating pump (23) is arranged on the heat accumulating low-temperature water pipe (49), the first circulating pump (23) is provided with a heat accumulating low-temperature bypass (50), twenty-third valves (84), twenty-second valves (83) and twenty-first valves (82) are respectively arranged on an inlet, an outlet and a heat accumulating low-temperature bypass (50) of the first circulating pump (23), the other end of the first heat accumulating low-temperature water pipe (24) is connected with a high-temperature water side outlet of the hot water heat exchanger (12), twenty-seventeen valves (88) are arranged on a first heat accumulating low-temperature water side outlet Wen Zhiguan, the other end of the heat accumulating high-temperature water pipe (51) is connected with a heat supply pipe (48), and a second circulating pump (52) is arranged on a second circulating pump (25) and a second high-temperature water pipe (25) is arranged on a second circulating pump (25) and a second circulating pump (52) is arranged on the second high-temperature water pipe (52) respectively The twenty-fifth valve (86) and the twenty-sixth valve (87), the outlet of the second circulating pump (25) is also connected with one end of the first heat accumulation height Wen Zhiguan (54), the other end of the first heat accumulation height Wen Zhiguan (54) is connected with the inlet of the hot water heat exchanger (12) at the high temperature water side, and the twenty-eighth valve (89) is arranged on the first heat accumulation height Wen Zhiguan (54);

The deaerator (14) is connected with the steam outlet end of the low-pressure steam bypass (41), the steam outlet of the third temperature and pressure reduction device (17), the steam outlet of the acting equipment (18) and the heating steam extraction pipe (45) through a deaeration steam extraction pipe (44), and a sixteen-number valve (77) is arranged on the deaeration steam extraction pipe (44); a water supply pipe bypass (55) is arranged on the low-temperature water side of the hot water heat exchanger (12), and an twenty-ninth valve (90), a thirty-first valve (91) and a thirty-first valve (92) are respectively arranged on the low-temperature water side inlet, the low-temperature water side outlet and the water supply pipe bypass (55) of the hot water heat exchanger (12); one end of the hot water heat accumulator (24) is also connected with one end of a second heat accumulation low Wen Zhiguan (57), the other end of the second heat accumulation low Wen Zhiguan (57) is connected with a water outlet of the radiator (26), and a thirty-third valve (94) is arranged on the second heat accumulation low Wen Zhiguan (57); the outlet of the second circulating pump (25) is also connected with one end of a second heat storage high-temperature branch pipe (56), the other end of the second heat storage high-temperature branch pipe (56) is connected with a water inlet of a radiator (26), and a thirty-two valve (93) is arranged on the second heat storage high-temperature branch pipe (56).

2. The steam extraction and heat supply integrated system for electric power peak regulation of a combined cycle unit according to claim 1, wherein the acting device (18) drives the power device (19) to do work, the acting device (18) is a back pressure machine or a screw expander, and the power device (19) is a generator, a condensate pump (11), a heat supply network circulating pump (22), a first circulating pump (23) or a second circulating pump (25).

3. The integrated system for steam extraction and heat supply for power peak shaving of combined cycle units according to claim 1, wherein the third temperature and pressure reducing device (17) is connected in parallel with the working equipment (18) and provides the required steam for the deaerator (14) and the heat supply network heater (20).

4. The steam extraction and heat supply integrated system for power peak shaving of a combined cycle unit according to claim 1, wherein the steam inlet end of the second medium pressure steam branch pipe (43) is simultaneously connected with the steam outlet end of the high pressure steam bypass (38), the steam outlet end of the cold re-steam bypass (39) and the steam outlet end of the hot re-steam bypass (40).

5. A method of operating a steam extraction and heat supply integrated system for combined cycle unit power peaking as defined in any one of claims 1-4, wherein the method of operating is as follows:

only opening a first valve (61), a fourth valve (64), a sixth valve (66), a thirteenth valve (73), a hydraulic butterfly valve (74), a fourteen valve (75), a fifteen valve (76), a sixteen valve (77) and a thirty-first valve (92), wherein the combined cycle unit does not supply heat to the outside, and deoxygenated steam of the deoxygenator (14) is from low-pressure steam supplementing of the low-pressure superheater (503) or steam exhausting of the middle pressure cylinder (7) of the steam turbine;

A. when the unit needs to reduce the external output electric load, the steam flow entering the steam turbine for acting is reduced through the steam extraction and heat accumulation, and at the moment, the heat accumulation is carried out through the hot water heat accumulator (24), and the operation is as follows:

opening a thirteen valve (73) and a seventeen valve (78), and taking low-pressure steam supplementing from a low-pressure superheater (503) or steam exhaust of a middle pressure cylinder (7) of a steam turbine as heating steam required by a heat supply network heater (20); simultaneously, a twenty-two valve (83), a twenty-three valve (84), a twenty-six valve (87), a thirty-four valve (95) and a thirty-five valve (96) are opened, low-temperature water from the hot water heat accumulator (24) is sequentially conveyed into the hydrophobic heat exchanger (21) and the heat supply network heater (20) through the first circulating pump (23) to be heated, and the high-temperature water is formed and then enters the hot water heat accumulator (24) for storage;

Or opening a valve No. 69, a valve No. 70 and a valve No. seventeen (78), enabling the medium-pressure steam to enter a third temperature and pressure reduction device (17) to be subjected to temperature and pressure reduction to form low-pressure steam, and then conveying the low-pressure steam to a heating network heater (20) through a heating steam extraction pipe (45); simultaneously opening a twenty-second valve (83), a twenty-third valve (84), a twenty-sixth valve (87), a thirty-fourth valve (95) and a thirty-fifth valve (96), and enabling low-temperature water from the hot water heat accumulator (24) to sequentially enter the hydrophobic heat exchanger (21) and the heat supply network heater (20) to be heated, so as to form high-temperature water and then enter the hot water heat accumulator (24) for storage;

or an eleven valve (71), a twelve valve (72) and a seventeen valve (78) are opened, medium-pressure steam enters a working device (18) to drive a power device (19) to work so as to form low-pressure steam, and then the low-pressure steam is conveyed to a heating network heater (20) through a heating steam extraction pipe (45); simultaneously opening a twenty-second valve (83), a twenty-third valve (84), a twenty-sixth valve (87), a thirty-fourth valve (95) and a thirty-fifth valve (96), and enabling low-temperature water from the hot water heat accumulator (24) to sequentially enter the hydrophobic heat exchanger (21) and the heat supply network heater (20) to be heated, so as to form high-temperature water and then enter the hot water heat accumulator (24) for storage;

B. When the unit needs to increase the external output electric load, the steam extraction and heat accumulation are not performed at the moment, so that the steam flow entering the steam turbine for doing work is increased, and the hot water heat accumulator (24) is used for releasing heat at the moment, and the operation is as follows:

a twenty-fourth valve (85), a twenty-seventh valve (88) and a twenty-eighth valve (89) are opened, high temperature water from the hot water heat accumulator (24) is conveyed to the hot water heat exchanger (12) through the second circulating pump (25) to release heat, meanwhile, a twenty-ninth valve (90) and a thirty-seventh valve (91) are opened, a thirty-eighth valve (92) is closed, and boiler feed water firstly enters the hot water heat exchanger (12) and is heated by the high temperature water from the hot water heat accumulator (24);

or a twenty-fourth valve (85), a thirty-second valve (93) and a thirty-third valve (94) are opened, and the high temperature water from the hot water heat accumulator (24) is conveyed to the radiator (26) through the second circulating pump (25) to release heat;

only opening a valve I (61), a valve IV (64), a valve VI (66), a valve thirteen (73), a hydraulic butterfly valve (74), a valve fourteen (75), a valve fifteen (76), a valve sixteen (77), a valve seventeen (78), a valve nineteen (80), a valve twenty (81), a valve thirty-one (92), a valve thirty-four (95) and a valve thirty-five (96), wherein the combined cycle unit only utilizes the low pressure steam supplementing of the low pressure superheater (503) or the exhaust steam of the steam turbine medium pressure cylinder (7) to supply heat to the outside, and the deoxygenated steam of the deoxygenator (14) comes from the low pressure steam supplementing of the low pressure superheater (503) or the exhaust steam of the steam turbine medium pressure cylinder (7);

opening a thirteen valve (73) and a seventeen valve (78), and taking low-pressure steam supplementing from a low-pressure superheater (503) or steam exhaust of a middle pressure cylinder (7) of a steam turbine as heating steam required by a heat supply network heater (20); opening a nineteenth valve (80), a twenty-first valve (81), a thirty-fourth valve (95) and a thirty-fifth valve (96), and enabling heat supply network water from a heat supply network water return pipe (47) to sequentially enter a hydrophobic heat exchanger (21) and a heat supply network heater (20) to be heated, so that the heat supply network water is outwards supplied through a heat supply network water supply pipe (48) after being formed; simultaneously, a twenty-two valve (83), a twenty-three valve (84) and a twenty-six valve (87) are opened, low-temperature water from the hot-water heat accumulator (24) is sequentially conveyed into the hydrophobic heat exchanger (21) and the heat supply network heater (20) through the first circulating pump (23) to be heated, and the high-temperature water is formed and then enters the hot-water heat accumulator (24) for storage;

Or opening a valve No. 69, a valve No. 70 and a valve No. seventeen (78), enabling the medium-pressure steam to enter a third temperature and pressure reduction device (17) to be subjected to temperature and pressure reduction to form low-pressure steam, and then conveying the low-pressure steam to a heating network heater (20) through a heating steam extraction pipe (45); opening a nineteenth valve (80), a twenty-first valve (81), a thirty-fourth valve (95) and a thirty-fifth valve (96), and enabling heat supply network water from a heat supply network water return pipe (47) to sequentially enter a hydrophobic heat exchanger (21) and a heat supply network heater (20) to be heated, so that the heat supply network water is outwards supplied through a heat supply network water supply pipe (48) after being formed; simultaneously opening a twenty-two valve (83), a twenty-three valve (84) and a twenty-six valve (87), and enabling low-temperature water from the hot water heat accumulator (24) to sequentially enter the hydrophobic heat exchanger (21) and the heat supply network heater (20) to be heated, so as to form high-temperature water and then enter the hot water heat accumulator (24) for storage;

or an eleven valve (71), a twelve valve (72) and a seventeen valve (78) are opened, medium-pressure steam enters a working device (18) to drive a power device (19) to work so as to form low-pressure steam, and then the low-pressure steam is conveyed to a heating network heater (20) through a heating steam extraction pipe (45); opening a nineteenth valve (80), a twenty-first valve (81), a thirty-fourth valve (95) and a thirty-fifth valve (96), and enabling heat supply network water from a heat supply network water return pipe (47) to sequentially enter a hydrophobic heat exchanger (21) and a heat supply network heater (20) to be heated, so that the heat supply network water is outwards supplied through a heat supply network water supply pipe (48) after being formed; simultaneously opening a twenty-two valve (83), a twenty-three valve (84) and a twenty-six valve (87), and enabling low-temperature water from the hot water heat accumulator (24) to sequentially enter the hydrophobic heat exchanger (21) and the heat supply network heater (20) to be heated, so as to form high-temperature water and then enter the hot water heat accumulator (24) for storage;

B. When the unit needs to increase the load of outputting electricity to the outside, the steam extraction and heat accumulation are not carried out at the moment, and the heat release of the hot water heat accumulator (24) is utilized to supply heat to the outside, so that the steam flow entering the steam turbine for doing work is increased, and the operation is as follows:

closing a seventeen valve (78), stopping the external heat supply by utilizing the extraction steam of the unit, and opening a nineteen valve (80), a twenty-first valve (81), a twenty-fourth valve (85) and a twenty-fifth valve (86) at the moment, and conveying the high-temperature water from the hot water heat accumulator (24) to a heat supply pipe (48) of a heat supply network to supply heat to the outside through a second circulating pump (25);

or a twenty-fourth valve (85), a twenty-seventh valve (88) and a twenty-eighth valve (89) are opened, high-temperature water from the hot water heat accumulator (24) is conveyed to the hot water heat exchanger (12) through the second circulating pump (25) to release heat, meanwhile, the twenty-ninth valve (90) and the thirty-seventh valve (91) are opened, the thirty-eighth valve (92) is closed, and boiler feed water firstly enters the hot water heat exchanger (12) and is heated by the high-temperature water from the hot water heat accumulator (24);

or a twenty-fourth valve (85), a thirty-second valve (93) and a thirty-third valve (94) are opened, and the high-temperature water from the hot water heat accumulator (24) is conveyed to the radiator (26) through the second circulating pump (25) to release heat.

6. The method for operating a steam extraction and heat supply integrated system for combined cycle unit power peaking as defined in claim 5, wherein:

when the unit has the power peak regulation requirement, the operation steps for providing medium-pressure steam for the third temperature and pressure reduction device (17) and the acting equipment (18) are as follows:

opening a valve No. 65, and directly taking exhaust steam from a high-pressure cylinder (6) of the steam turbine as a medium-pressure steam source of a third temperature and pressure reducing device (17) and working equipment (18);

or opening a valve No. 67 and a valve No. 68, and forming steam with lower pressure and temperature after the hot re-steam from the reheater 505 passes through the second temperature and pressure reducing device 16, wherein the steam is used as a medium-pressure steam source of the third temperature and pressure reducing device 17 and the working equipment 18;

or opening a second valve (62) and a third valve (63), and forming steam with lower pressure and temperature after the main steam from the high-pressure superheater (506) passes through the first temperature and pressure reducing device (15), wherein the steam is used as a medium-pressure steam source of the third temperature and pressure reducing device (17) and the acting equipment (18);

when the unit has no power peak regulation requirement, the heat release selection method of the hot water heat accumulator (24) is as follows:

In the pure condensation working condition, the radiator (26) and the hot water heat exchanger (12) are simultaneously selected to be started, or one of the radiator (26) and the hot water heat exchanger (12) is selected to be started for the hot water heat accumulator (24) to release heat outwards;

and in the heat supply working condition, the heat supply to the outside through the hot-net water supply pipe (48), the opening of the radiator (26) and the opening of the hot-water heat exchanger (12) are simultaneously selected, or one of the heat supply to the outside through the hot-net water supply pipe (48), the opening of the radiator (26) and the opening of the hot-water heat exchanger (12) is selected, and the heat is released to the outside through the hot-water heat accumulator (24).

7. The method of operating a steam extraction and heat supply integrated system for combined cycle unit power peaking as defined in claim 5 or 6, wherein:

when the unit provides heating steam for the heat supply network heater (20), the low-pressure steam supplementing of the low-pressure superheater (503) or the steam discharging of the middle pressure cylinder (7) of the steam turbine are preferably selected, the steam discharging of the acting equipment (18) is selected, and the temperature and pressure reducing steam of the third temperature and pressure reducing device (17) is selected;

when the unit provides medium-pressure steam for the third temperature and pressure reduction device (17) and the acting equipment (18), the high-pressure steam exhaust of the high-pressure cylinder (6) of the steam turbine is preferentially selected and utilized, the hot re-steam of the reheater (505) is secondarily selected and utilized, and the main steam of the high-pressure superheater (506) is finally selected and utilized;

In the pure condensation working condition, the hot water heat exchanger (12) is preferably selected to be started for the hot water heat accumulator (24) to release heat outwards, and the radiator (26) is then selected to be started for the hot water heat accumulator (24) to release heat outwards;

during the heat supply working condition, the heat supply pipe (48) of the hot network is preferably selected to supply heat to the outside for the heat accumulator (24) to release heat to the outside, the hot water heat exchanger (12) is then selected to be started for the heat accumulator (24) to release heat to the outside, and finally the radiator (26) is selected to be started for the heat accumulator (24) to release heat to the outside.