Energy storage power generation system for thermal power plants

Abstract

A power generation system for thermal power plants, comprising: a power generation system and a first-stage heat release mechanism. The power generation system comprises: a heating boiler, a high-pressure cylinder of a steam turbine and a generator, wherein the heating boiler comprises: a furnace, a steam drum, a downcomer connecting the steam drum and the bottom of the furnace, and a reheater and a superheater; the first-stage heat release mechanism is used to heat cold reheat steam, wherein the first-stage heat release mechanism replaces part of the heat energy required at the reheater position during peak power consumption to improve the top load capacity of the unit. The above structure can effectively solve the problem of insufficient thermal energy storage efficiency and inability to achieve deep peak regulation in thermal power plants in the prior art during low power consumption periods.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage power generation systems for thermal power plants, and in particular to an energy storage power generation system for thermal power plants and a system thereof. Background Art

[0002] A thermal power plant, also known as a thermal power plant, is a factory that uses combustible materials such as coal as fuel to produce electricity. Its basic production process is: when the fuel is burned, it heats water to generate steam, converting the chemical energy of the fuel into thermal energy. The steam pressure drives the turbine to rotate, converting the thermal energy into mechanical energy. The turbine then drives the generator to rotate, converting the mechanical energy into electrical energy. Thermal power generation is the main force in the development of electricity in modern society, but thermal power generation is prone to energy waste during the low electricity consumption period. How to effectively store the excess heat generated by thermal power plants during the low electricity consumption period, so as to achieve stable operation of thermal power plants during the low electricity consumption period and achieve deep peak regulation, is a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0003] The present invention aims to provide an energy storage power generation system for a thermal power plant and a system thereof, so as to solve the problem that the thermal power plant in the prior art has insufficient thermal energy storage efficiency during the low electricity consumption period and cannot achieve deep peak regulation. To this end, the present invention provides an energy storage power generation system for a thermal power plant, comprising:

[0004] A power generation system comprises: a heating boiler, a high-pressure cylinder of a steam turbine and a generator, wherein the heating boiler comprises: a furnace, a steam drum, a downcomer connecting the steam drum and the bottom of the furnace, a reheater and a superheater; feed water enters the steam drum of the heating boiler, a water working medium descends to the bottom of the furnace along the downcomer, the water working medium absorbs heat energy in the furnace and evaporates into a steam-water mixture, the steam-water mixture rises back to the steam drum, then flows out of the steam drum and enters the superheater to further absorb heat to become high-temperature and high-pressure main steam; the main steam flows into the high-pressure cylinder of the steam turbine to expand, and the cold reheat steam flowing out of the outlet of the high-pressure cylinder of the steam turbine flows back to the reheater of the heating boiler to absorb heat to obtain hot reheat steam, which drives the generator to generate electricity;

[0005] The first-stage heat release mechanism is used to heat the cold reheat steam. The first-stage heat release mechanism replaces part of the heat energy required at the reheater position during the peak period of electricity consumption, thereby improving the top load capacity of the unit.

[0006] Optionally, the power generation system further comprises: a steam turbine intermediate pressure cylinder and a steam turbine low pressure cylinder;

[0007] The hot reheated steam obtained by entering the reheater to absorb heat flows into the intermediate pressure cylinder and the low pressure cylinder of the steam turbine in sequence to expand and do work; the high, intermediate and low pressure cylinders of the steam turbine are coaxially connected.

[0008] Optionally, the first-stage heat release mechanism includes: a packed bed high-temperature heat storage unit and a first-stage heat release heat exchanger;

[0009] The gaseous working medium is driven to enter the packed bed high-temperature heat storage unit, absorbs heat energy to a high-temperature state, and then enters the first passage of the first-stage heat releasing heat exchanger along the pipeline to release heat energy; at the same time, cold reheat steam flows out from the outlet of the high-pressure cylinder of the steam turbine, and the cold reheat steam enters the second passage of the first-stage heat releasing heat exchanger to absorb heat energy to a hot reheat steam state, returns to the hot reheat steam main passage along the pipeline, and flows to the intermediate-pressure cylinder of the steam turbine to perform work.

[0010] Optionally, a first regulating valve for controlling the outflow of the cold reheat steam is provided on the pipeline at the outlet position of the high-pressure cylinder of the steam turbine.

[0011] Optionally, the power generation system further comprises: a high-pressure heater assembly, a deaerator, a water pump small steam turbine and a low-pressure heater assembly;

[0012] Extract steam from the interstages of the high-pressure cylinder of the steam turbine and the intermediate-pressure cylinder of the steam turbine, and provide the steam to the high-pressure heater assembly, the heating steam of the deaerator, and the steam supply to the small steam turbine of the feedwater pump respectively;

[0013] Steam is extracted from the interstage of the low-pressure cylinder of the steam turbine and provided to the low-pressure heater assembly.

[0014] Optionally, the power generation system further comprises: a condenser and a condensate polishing device;

[0015] The condenser condenses the exhaust steam from the low-pressure cylinder 10 of the steam turbine into condensate and collects it in the hot well, and transports the condensate in the hot well to the condensate polishing device; the exhaust steam of the small steam turbine of the feed water pump is introduced into the condenser.

[0016] Optionally, the power generation system further comprises: a deaerator and a shaft seal heater; the high-pressure heater assembly is provided with a built-in steam cooling section and a built-in drain cooling section, and the low-pressure heater assembly is provided with a built-in drain cooling section;

[0017] The high-pressure heater of the high-pressure heater assembly is drained by gravity in a step-by-step manner to the deaerator, and the low-pressure heater of the low-pressure heater assembly is drained by gravity in a step-by-step manner, and then merged with the shaft seal heater drain to flow into the condenser hot well of the condenser; the steam source of the shaft seal heater is the shaft seal steam of the turbine.

[0018] Optionally, the condensate in the condenser hot well passes through a condensate pump, a condensate polishing device, a shaft seal heater and the low-pressure heater assembly in sequence before entering the deaerator;

[0019] The deoxygenated water passing through the deaerator enters the steam drum of the heating boiler from the deaerator feed water tank through the pre-pump, the main feed water pump and the high-pressure heater assembly.

[0020] Optionally, the high-voltage heater assembly includes: a first-stage high-voltage heater, a second-stage high-voltage heater and a third-stage high-voltage heater; and / or,

[0021] The low-pressure heater assembly includes: a first-stage low-pressure heater, a second-stage low-pressure heater, a third-stage low-pressure heater and a fourth-stage low-pressure heater.

[0022] Optionally, the energy storage power generation system for thermal power plants also includes:

[0023] The second stage heat release mechanism includes: a feed water heater, a main feed water pump, and a steam generator; the gaseous working fluid flowing out of the first passage of the first stage heat release heat exchanger enters the heating feed water passage and / or the heating deoxygenated water passage through the first three-way valve;

[0024] The gaseous working medium flowing out of the first passage of the first-stage heat-releasing heat exchanger enters the heating feedwater passage, and enters the first passage of the feedwater heater to release heat energy; at the same time, a stream of feedwater is drawn out from behind the main feedwater pump, enters the second passage of the feedwater heater to absorb heat energy, and then merges with the main feedwater passage and enters the steam drum of the heating boiler to reduce the steam extraction amount of the high-pressure cylinder of the steam turbine and the intermediate-pressure cylinder of the steam turbine, and provide a part of the heat energy required by the high-pressure heater assembly; and / or,

[0025] The gaseous medium flowing out of the first passage of the first-stage heat-releasing heat exchanger enters the heated deoxygenated water passage, and enters the first passage of the steam generator to release heat energy; at the same time, a stream of deoxygenated water is drawn out from the outlet position of the deaerator, and is driven to flow into the second passage of the steam generator to absorb heat energy to a superheated steam state. The resulting superheated steam flows to the low-pressure cylinder of the steam turbine, and after mixing with the exhaust steam of the intermediate-pressure cylinder of the steam turbine, enters the low-pressure cylinder of the steam turbine to expand and perform work, so as to increase the work done by the low-pressure cylinder of the steam turbine during peak power consumption.

[0026] Optionally, the energy storage power generation system for thermal power plants also includes:

[0027] The third-stage heat release mechanism includes: a condensate heater and a heating heat exchanger; after the gaseous working medium flowing out of the first passage of the steam generator and the feedwater heater merges, it enters the heating condensate passage and / or the heating passage respectively through the control of the second three-way valve;

[0028] After the first passage of the steam generator and the gaseous working medium flowing out of the feedwater heater merge, the gaseous working medium is passed through the heated condensate passage into the first passage of the condensate heater 31 to release heat energy; at the same time, part of the condensate is drawn out from the condensate polishing device, enters the second passage of the condensate heater to absorb heat energy, and then enters the deaerator along the pipeline to reduce the steam extraction amount of the low-pressure cylinder of the steam turbine and replace part of the heat energy required by the low-pressure heater assembly; and / or,

[0029] After the gaseous working medium flowing out of the first passage of the steam generator and the feed water heater merge, it passes through the heating passage into the first passage of the heat supply heat exchanger to release heat energy; at the same time, the water working medium in the thermal system is driven to enter the second passage of the heat supply heat exchanger to absorb heat energy, and is driven to transfer the heated water working medium to the heat user side.

[0030] Optionally, the amount of water supplied by the main water supply pump is controlled by a second regulating valve 33; and / or the amount of condensate supplied by the condensate polishing device to the second passage of the condensate heater is controlled by a third regulating valve.

[0031] Optionally, the energy storage power generation system for thermal power plants also includes:

[0032] The heat storage subsystem includes: a packed bed high temperature heat storage unit and an induced draft fan;

[0033] During the period of low electricity consumption, the high-temperature flue gas in the furnace chamber of the heating boiler enters the packed bed high-temperature heat storage unit, and the high-temperature flue gas exchanges heat with the solid heat storage material in the packed bed high-temperature heat storage unit to store thermal energy in the solid heat storage material. The gas that has released the thermal energy is transferred back to the heating boiler by the induced draft fan and merges with the flue gas in the heating boiler before entering the dust collector for dust removal.

[0034] The technical solution of the present invention has the following advantages:

[0035] 1. The energy storage power generation system for a thermal power plant provided by the present invention comprises:

[0036] A power generation system comprises: a heating boiler, a high-pressure cylinder of a steam turbine and a generator, wherein the heating boiler comprises: a furnace, a steam drum, a downcomer connecting the steam drum and the bottom of the furnace, and a reheater and a superheater; feed water enters the steam drum of the heating boiler, a water working medium descends to the bottom of the furnace along the downcomer, the water working medium absorbs heat energy in the furnace and evaporates into a steam-water mixture, the steam-water mixture rises back to the steam drum, then flows out of the steam drum and enters the superheater to further absorb heat to become high-temperature and high-pressure main steam; the main steam flows into the high-pressure cylinder of the steam turbine to expand, and the cold reheat steam flowing out of the outlet of the high-pressure cylinder of the steam turbine flows back to the reheater of the heating boiler to absorb heat to obtain hot reheat steam, and then enters the intermediate-pressure cylinder and the low-pressure cylinder in turn to perform work, thereby driving the generator to generate electricity;

[0037] The first-stage heat release mechanism is used to heat the cold reheat steam. The first-stage heat release mechanism replaces part of the heat energy required at the reheater position during the peak period of electricity consumption, thereby improving the top load capacity of the unit.

[0038] In the present invention, the power generation system generates high-temperature and high-pressure main steam by heating the boiler, and generates electricity through the generator to effectively realize the power generation function of the thermal power plant. In addition, in order to improve the thermal energy storage efficiency of the thermal power plant during the low electricity consumption period and realize deep peak regulation. The first-level heat release mechanism in the present invention stores the heat energy released by the thermal power plant during the low electricity consumption period through the packed bed high-temperature heat storage unit, and replaces part of the heat energy required at the reheater position during the peak electricity consumption period of the thermal power plant, heats the cold reheat steam, and then improves the top load capacity of the unit.

[0039] 2. The energy storage power generation system for a thermal power plant provided by the present invention further comprises: a steam turbine intermediate pressure cylinder and a steam turbine low pressure cylinder; the hot reheated steam obtained by entering the reheater to absorb heat flows into the steam turbine intermediate pressure cylinder and the steam turbine low pressure cylinder in turn to expand and perform work; the high, intermediate and low pressure cylinders of the steam turbine are coaxially connected.

[0040] In the present invention, the energy conversion efficiency of the thermal power plant can be effectively improved by allowing the hot reheated steam obtained by entering the reheater to absorb heat to flow into the intermediate pressure cylinder of the steam turbine and the low pressure cylinder of the steam turbine in sequence to expand and perform work.

[0041] 3. The energy storage power generation system for a thermal power plant provided by the present invention further comprises: a high-pressure heater assembly, a deaerator, a water pump small steam turbine and a low-pressure heater assembly; steam is extracted from the interstages of the high-pressure cylinder of the steam turbine and the intermediate-pressure cylinder of the steam turbine, and provided to the high-pressure heater assembly, the heating steam of the deaerator, and the steam supply to the water pump small steam turbine respectively; steam is extracted from the interstages of the low-pressure cylinder of the steam turbine and provided to the low-pressure heater assembly.

[0042] The high-pressure heater assembly, deaerator and feedwater pump small steam turbine in the present invention can provide hot steam through the high-pressure cylinder of the steam turbine and the medium-pressure cylinder of the steam turbine; the low-pressure heater assembly in the present invention can provide hot steam through the low-pressure cylinder of the steam turbine. The above arrangement can effectively realize the self-circulation of the energy storage power generation system and improve the energy utilization efficiency.

[0043] 4. The energy storage power generation system for thermal power plants provided by the present invention further comprises: a condenser and a condensate polishing device; the condenser condenses the exhaust steam from the low-pressure cylinder 10 of the steam turbine into condensate and collects it in the hot well, and transports the condensate in the hot well to the condensate polishing device; the exhaust steam of the small steam turbine of the feed water pump is introduced into the condenser. The condensate in the hot well of the condenser passes through the condensate pump, the condensate polishing device, the shaft seal heater and the low-pressure heater assembly in sequence, and then enters the deaerator; the deoxygenated water passing through the deaerator enters the steam drum of the heating boiler from the deaerator feed water tank through the pre-pump, the main feed water pump and the high-pressure heater assembly.

[0044] In the present invention, condensed water can be effectively obtained through the above-mentioned condenser and condensed water polishing device, so that the condensed water can participate in the heat cycle of the energy storage power generation system in the present invention.

[0045] 5. The energy storage and power generation system for a thermal power plant provided by the present invention, wherein the high-pressure heater assembly includes: a first-stage high-pressure heater, a second-stage high-pressure heater and a third-stage high-pressure heater; and / or, the low-pressure heater assembly includes: a first-stage low-pressure heater, a second-stage low-pressure heater, a third-stage low-pressure heater and a fourth-stage low-pressure heater.

[0046] The number of heaters in the high-pressure heater assembly and the low-pressure heater assembly of the present invention is not specifically limited, but considering energy efficiency and economy, the high-pressure heater assembly and the low-pressure heater assembly of the present invention are respectively provided with three heaters.

[0047] 6. The energy storage power generation system for a thermal power plant provided by the present invention further comprises:

[0048] The second stage heat release mechanism includes: a feed water heater, a main feed water pump, and a steam generator; the gaseous working fluid flowing out of the first passage of the first stage heat release heat exchanger enters the heating feed water passage and / or the heating deoxygenated water passage through the first three-way valve;

[0049] The gaseous working medium flowing out of the first passage of the first-stage heat-releasing heat exchanger enters the heating feedwater passage, and enters the first passage of the feedwater heater to release heat energy; at the same time, a stream of feedwater is drawn out from behind the main feedwater pump, enters the second passage of the feedwater heater to absorb heat energy, and then merges with the main feedwater passage and enters the steam drum of the heating boiler to reduce the steam extraction amount of the high-pressure cylinder of the steam turbine and the intermediate-pressure cylinder of the steam turbine, and provide a part of the heat energy required by the high-pressure heater assembly; and / or,

[0050] The gaseous working medium flowing out of the first passage of the first-stage heat-releasing heat exchanger enters the heated deoxygenated water passage, and enters the first passage of the steam generator to release heat energy; at the same time, a stream of deoxygenated water is drawn out from the outlet position of the deaerator, and is driven to flow into the second passage of the steam generator to absorb heat energy to a superheated steam state. The resulting superheated steam flows to the low-pressure cylinder of the steam turbine, and after mixing with the exhaust steam of the intermediate-pressure cylinder of the steam turbine, enters the low-pressure cylinder of the steam turbine to expand and perform work, so as to increase the work done by the low-pressure cylinder of the steam turbine during peak power consumption.

[0051] In the present invention, by providing a second-stage heat release mechanism connected to the first-stage heat release heat exchanger, one of the gaseous working fluids of the second-stage heat release mechanism can enter the first passage of the feedwater heater to release heat energy, thereby improving the utilization rate of heat energy. Another gaseous working fluid of the second-stage heat release mechanism can enter the first passage of the steam generator to release heat energy, thereby improving the utilization rate of heat energy. The above arrangement realizes the second-stage heat release of the heat release system and effectively utilizes the energy of the thermal power plant.

[0052] 7. The energy storage power generation system for a thermal power plant provided by the present invention further comprises:

[0053] The third-stage heat release mechanism includes: a condensate heater and a heating heat exchanger; after the gaseous working medium flowing out of the first passage of the steam generator and the feedwater heater merges, it enters the heating condensate passage and / or the heating passage respectively through the control of the second three-way valve;

[0054] After the gaseous working medium flowing out of the first passage of the steam generator and the feedwater heater merge, it is passed through the heating condensate passage into the first passage of the condensate heater 31 to release heat energy; at the same time, part of the condensate is drawn out from the condensate polishing device, enters the second passage of the condensate heater to absorb heat energy, and then enters the deaerator along the pipeline to reduce the steam extraction amount of the low-pressure cylinder of the steam turbine and replace part of the heat energy required by the low-pressure heater assembly; and / or,

[0055] After the gaseous working medium flowing out of the first passage of the steam generator and the feed water heater merge, it passes through the heating passage into the first passage of the heat supply heat exchanger to release heat energy; at the same time, the water working medium in the thermal system is driven to enter the second passage of the heat supply heat exchanger to absorb heat energy, and is driven to transfer the heated water working medium to the heat user side.

[0056] In the present invention, after the first passage of the steam generator and the gas working medium flowing out of the feedwater heater merge, they are driven to enter the third-stage heat release mechanism. One stream of the gas working medium of the third-stage heat release mechanism passes through the heating condensate passage into the first passage of the condensate heater 31 to release heat energy; another stream of the gas working medium of the third-stage heat release mechanism passes through the heating passage into the first passage of the heating heat exchanger to release heat energy. The above arrangement realizes multi-stage heat release of the heat release system, effectively utilizes the energy of the thermal power plant, and improves energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 A schematic diagram of the structure of an energy storage power generation system for a thermal power plant provided by the present invention;

[0059] Figure 2 A schematic diagram of the furnace structure in the energy storage power generation system provided by the present invention.

[0060] Description of reference numerals:

[0061] 1-heating boiler; 2-high-pressure cylinder of steam turbine; 3-generator; 4-steam drum; 5-downcomer; 6-reheater; 7-superheater; 8-packed bed high-temperature heat storage unit; 9-intermediate-pressure cylinder of steam turbine; 10-low-pressure cylinder of steam turbine; 11-first-stage heat release heat exchanger; 12-first regulating valve; 13-deaerator; 14-feedwater pump small steam turbine; 15-condenser; 16-shaft seal heater; 17-condensate pump; 18-condensate polishing device; 19-pre-pump; 20-main feedwater pump; 21-first-stage high-pressure heater; 22- Second-stage high-pressure heater; 23-third-stage high-pressure heater; 24-first-stage low-pressure heater; 25-second-stage low-pressure heater; 26-third-stage low-pressure heater; 27-fourth-stage low-pressure heater; 28-feedwater heater; 29-steam generator; 30-first three-way valve; 31-condensate heater; 32-heating heat exchanger; 33-second regulating valve; 34-third regulating valve; 35-induced draft fan; 36-dust collector; 37-circulating fan; 38-boosting water pump; 39-hot water supply pump; 40-second three-way valve. DETAILED DESCRIPTION

[0062] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0064] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0066] Example 1

[0067] A thermal power plant energy storage power generation system is recorded, such as Figure 1 As shown, it includes: a power generation system, a heat storage system and a heat release system;

[0068] The power generation system includes: a heating boiler 1, a turbine high-pressure cylinder 2, a turbine medium-pressure cylinder 9, a turbine low-pressure cylinder 10, a generator 3, three high-pressure heaters: a first-stage high-pressure heater 21, a second-stage high-pressure heater 22, and a third-stage high-pressure heater 23, a main feed water pump 20, a pre-pump 19, a deaerator 13, a feed water pump small turbine 14, four low-pressure heaters: a first-stage low-pressure heater 24, a second-stage low-pressure heater 25, a third-stage low-pressure heater 26, and a fourth-stage low-pressure heater 27, a shaft seal heater 16, a condensate polishing device 18, a condensate pump 17, and a condenser 15.

[0069] The operation process of the above power generation system is as follows:

[0070] Step 1, feed water enters the drum 4 of the heating boiler 1, and the water working medium descends to the bottom of the furnace along the downcomer 5. The water working medium absorbs the heat energy in the furnace and evaporates into a steam-water mixture. The steam-water mixture rises back to the drum 4, and then flows out of the drum 4 into the superheater 7 to further absorb heat to become high-temperature and high-pressure main steam.

[0071] Step 2, the main steam flows into the high-pressure cylinder 2 of the steam turbine to expand, and the cold reheated steam flowing out of the outlet of the high-pressure cylinder 2 of the steam turbine returns to the reheater 6 of the heating boiler 1 to absorb heat to obtain hot reheated steam, and then flows into the intermediate-pressure cylinder 9 of the steam turbine and the low-pressure cylinder 10 of the steam turbine to expand and do work. The above-mentioned high-pressure cylinder 2 of the steam turbine, the intermediate-pressure cylinder 9 of the steam turbine and the low-pressure cylinder 10 of the steam turbine are coaxially connected to drive the generator 3 to generate electricity.

[0072] Step 3, extract steam from the high-pressure cylinder 2 and the intermediate-pressure cylinder 9 of the steam turbine, and provide them to the first-stage high-pressure heater 21, the second-stage high-pressure heater 22, the third-stage high-pressure heater 23, the heating steam of the deaerator 13 and the steam supply of the feedwater pump small turbine 14 respectively; extract steam from the low-pressure cylinder 10 of the steam turbine, and provide heating steam to the first-stage low-pressure heater 24, the second-stage low-pressure heater 25, the third-stage low-pressure heater 26 and the fourth-stage low-pressure heater 27 in the present invention respectively.

[0073] Step 4: The condenser 15 condenses the exhaust steam from the low-pressure cylinder 10 of the steam turbine into condensate and collects it in the hot well, which is then sent to the condensate polishing device 18 by the condensate pump 17. The exhaust steam of the feedwater pump small steam turbine 14 is introduced into the condenser 15, and the feed water is replenished by the condenser 15.

[0074] Step 5, the first-stage high-pressure heater 21, the second-stage high-pressure heater 22 and the third-stage high-pressure heater 23 are respectively provided with a built-in steam cooling section and a built-in drain cooling section; the first-stage low-pressure heater 24, the second-stage low-pressure heater 25, the third-stage low-pressure heater 26 and the fourth-stage low-pressure heater 27 are only provided with a built-in drain cooling section. The high-pressure heater drain flows by gravity to the deaerator 13 in a step-by-step manner, and the low-pressure heater drain flows by gravity step by step, and then flows into the hot well of the condenser 15 after merging with the shaft seal heater 16 drain. In addition, the steam source of the shaft seal heater 16 is the steam from the steam turbine shaft seal.

[0075] The condensate in the condenser hot well enters the condensate pump 17 in sequence, passes through the condensate polishing device 18, the shaft seal heater 16 and the low-pressure heater assembly, and then enters the deaerator 13. The deoxygenated water enters the steam drum 4 of the heating boiler 1 from the deaerator feed water tank through the pre-pump 19, the main feed water pump 20 and the high-pressure heater assembly.

[0076] The heat storage system includes: a packed bed high temperature heat storage unit 8 and an induced draft fan 35 .

[0077] The operation process of the above heat storage system is as follows:

[0078] During the low electricity consumption period, high-temperature flue gas is extracted from the furnace chamber of the heating boiler 1, and the high-temperature flue gas enters the packed bed high-temperature heat storage unit 8 from the top thereof, and exchanges heat with the solid heat storage material inside the packed bed high-temperature heat storage unit 8 to store heat energy therein. The gas that has released the heat energy is returned to the heating boiler 1 along the pipeline by the induced draft fan 35, and after merging with the flue gas in the heating boiler 1, it enters the dust collector 36 for dust removal. In the present invention, the excess heat energy generated by the thermal power plant during the low electricity consumption period is stored through the above-mentioned heat storage method. While the thermal power plant operates smoothly during the low electricity consumption period, the deep peak-shaving capacity is improved.

[0079] The heat release system includes: a packed bed high-temperature heat storage unit 8, a circulating fan 37, a first-stage heat release heat exchanger 11, a first three-way valve 30, a feed water heater 28, a steam generator 29, a second three-way valve 40, a condensate heater 31, a heating heat exchanger 32, a first regulating valve 12, a second regulating valve 33, a booster water pump 38, a third regulating valve 34, and a hot water supply pump 39.

[0080] The above heat release system has three levels of heat release mechanisms, and the structures and operation processes of each heat release mechanism are as follows:

[0081] The first stage heat release mechanism is used to heat the cold reheat steam, replace part of the heat energy required at the reheater 6 position during the peak period of electricity consumption, and improve the top load capacity of the unit.

[0082] The gaseous working medium is driven by the circulating fan 37, enters the packed bed high temperature heat storage unit 8 to absorb heat energy to a high temperature state, and then enters the first passage of the first stage heat release heat exchanger 11 along the pipeline to release heat energy.

[0083] At the same time, a stream of cold reheat steam is extracted from the outlet of the high-pressure cylinder 2 of the steam turbine, enters the second passage of the first-stage heat release heat exchanger 11 to absorb heat energy to the hot reheat steam state, returns to the hot reheat steam main line along the pipeline, and flows to the intermediate-pressure cylinder 9 of the steam turbine to perform work.

[0084] The amount of cold reheat steam extracted is controlled by the first regulating valve 12 .

[0085] The second stage heat release mechanism includes two branches: a heating water supply channel and a heating deoxygenated water channel. The gaseous working medium flowing out of the first channel of the first stage heat release heat exchanger 11 is divided into two streams through the first three-way valve 30.

[0086] A stream of gaseous working fluid enters the first passage of the feedwater heater 28 along the pipeline to release heat energy. At the same time, a stream of feedwater is drawn out from the main feedwater pump 20, enters the second passage of the feedwater heater 28 to absorb heat energy, and then merges with the main feedwater passage and enters the steam drum 4. The amount of feedwater drawn out is controlled by the second regulating valve 33. The second-stage heat release mechanism can replace part of the heat energy required by the high-pressure heater assembly, thereby reducing the amount of steam extraction from the high-pressure cylinder 2 of the steam turbine and the intermediate-pressure cylinder 9 of the steam turbine. During the peak period of electricity consumption, the work capacity of the high-pressure cylinder 2 of the steam turbine and the intermediate-pressure cylinder 9 of the steam turbine is improved, thereby improving the top load capacity of the unit.

[0087] Another gas in the gaseous working medium enters the first passage of the steam generator 29 along the pipeline to release heat energy. At the same time, a stream of deoxygenated water is drawn out from the outlet of the deaerator 13, pumped into the second passage of the steam generator 29 by the booster water pump 38 to absorb heat energy to the superheated steam state, and flows along the pipeline to the inlet of the low-pressure cylinder 10 of the steam turbine, and then mixes with the exhaust steam of the intermediate-pressure cylinder 9 of the steam turbine and enters the low-pressure cylinder 10 of the steam turbine to expand and do work. The above process increases the work done by the low-pressure cylinder 10 of the steam turbine during the peak period of electricity consumption, thereby increasing the output power of the generator set.

[0088] The third stage heat release mechanism includes two branches: a condensate heating channel and a heating channel. The gaseous working medium flowing out of the first channel of the feedwater heater 28 and the steam generator 29 is combined and then divided into two streams by the second three-way valve 40.

[0089] One of the gaseous working fluids enters the first passage of the condensate heater 31 along the pipeline to release heat energy. At the same time, a stream of condensate is drawn out from the outlet of the condensate polishing device 18, enters the second passage of the condensate heater 31 to absorb heat energy, and then enters the deaerator 13 along the pipeline. The amount of condensate is controlled by the third regulating valve 34. The above process can replace part of the heat energy required by the low-pressure heater assembly, thereby reducing the amount of steam extraction from the low-pressure cylinder and improving the working capacity of the low-pressure cylinder 10 of the steam turbine.

[0090] Another stream of the gas medium passes through the first and third passages of the second three-way valve 40 and flows along the pipeline into the first passage of the heat exchanger 32 to release heat energy. At the same time, the hot water pump 39 drives the water medium into the second passage of the heat exchanger 32 to absorb heat energy and deliver the heat energy to the heat user side. The above process can provide a part of the heat supply during the peak period of heat use.

[0091] Of course, this embodiment does not specifically limit the heat storage structure and principle of the heat storage system. In other embodiments, the heat storage system can also use other heat storage methods such as phase change heat storage materials to achieve heat storage.

[0092] Of course, this embodiment does not specifically limit the shape or internal structure of the packed bed high temperature heat storage unit 8. In other embodiments, the packed bed high temperature heat storage unit 8 can be cylindrical, spherical or rectangular, and is composed of a pressurized heat-insulating packed bed, positively arranged or staggered cell channels and a heat storage medium.

[0093] Of course, this embodiment does not specifically limit the heat transfer medium used by the packed bed high temperature heat storage unit 8. In other embodiments, flue gas or air is used as the heat transfer medium of the packed bed high temperature heat storage unit 8.

[0094] Of course, this embodiment does not specifically limit the heat storage medium used in the packed bed high temperature heat storage unit 8. In other embodiments, the packed bed high temperature heat storage unit 8 uses solid materials as the heat storage medium. The solid heat storage medium is granular or porous, and is one or a mixture of at least two of rocks, ore, slag, concrete, refractory bricks, ceramic balls, metals, encapsulated phase change materials, etc.

[0095] Of course, this embodiment does not specifically limit the heat storage medium used in the packed bed high temperature heat storage unit 8. In other embodiments, the packed bed high temperature heat storage unit 8 can be arranged in series, in parallel, or in a combination of series and parallel.

[0096] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. An energy storage power generation system for a thermal power plant, characterized in that: include: A power generation system comprises: a heating boiler (1), a high-pressure cylinder of a steam turbine (2) and a generator (3); the heating boiler (1) comprises: a furnace, a steam drum (4), a downcomer (5) connecting the steam drum (4) and the bottom of the furnace, and a reheater (6) and a superheater (7); feed water enters the steam drum (4) of the heating boiler (1), a water working medium descends to the bottom of the furnace along the downcomer (5), the water working medium absorbs heat energy in the furnace and evaporates into a steam-water mixture, and the steam-water mixture rises back to the furnace. The steam drum (4) is then discharged from the steam drum (4) and enters the superheater (7) to further absorb heat to become high-temperature and high-pressure main steam; the main steam flows into the high-pressure cylinder (2) of the steam turbine to expand, and the cold reheat steam flowing out of the outlet of the high-pressure cylinder (2) of the steam turbine returns to the reheater (6) of the heating boiler (1) to absorb heat to obtain hot reheat steam, which drives the generator (3) to generate electricity; the power generation system also includes: a steam turbine intermediate-pressure cylinder (9) and a steam turbine low-pressure cylinder (10); the main steam enters the reheater (6) The hot reheated steam obtained by absorbing heat flows into the intermediate pressure cylinder (9) and the low pressure cylinder (10) of the steam turbine in sequence to expand and perform work; the high, intermediate and low pressure cylinders of the steam turbine are coaxially connected; the power generation system also includes: a high pressure heater assembly, a deaerator (13), a feed water pump small turbine (14) and a low pressure heater assembly; steam is extracted from the interstage of the high pressure cylinder (2) and the intermediate pressure cylinder (9) of the steam turbine and provided to the high pressure heater assembly, the heating steam of the deaerator (13), and the heating steam of the feed water pump (14). The water pump small steam turbine (14) supplies steam; steam is extracted from the interstage of the low-pressure cylinder (10) of the steam turbine and supplied to the low-pressure heater assembly; the power generation system further comprises: a condenser (15) and a condensate polishing device (18); the condenser (15) condenses the exhaust steam from the low-pressure cylinder (10) of the steam turbine into condensate and collects it in a hot well, and transports the condensate in the hot well to the condensate polishing device (18); the exhaust steam of the water pump small steam turbine (14) is introduced into the condenser (15); The first-stage heat release mechanism is used to heat the cold reheat steam. The first-stage heat release mechanism replaces part of the heat energy required by the reheater (6) during the peak period of electricity consumption, thereby improving the top load capacity of the unit. The first-stage heat release mechanism comprises: a packed bed high-temperature heat storage unit (8) and a first-stage heat release heat exchanger (11). The gaseous working medium is driven to enter the packed bed high-temperature heat storage unit (8), absorbs heat energy to a high-temperature state, and then enters the first passage of the first-stage heat release heat exchanger (11) along the pipeline to release heat energy. At the same time, the outlet of the high-pressure cylinder (2) of the steam turbine flows out the cold reheat steam, and the cold reheat steam enters the second passage of the first-stage heat release heat exchanger (11) to absorb heat energy to a hot reheat steam state, returns to the hot reheat steam main passage along the pipeline, and flows to the intermediate-pressure cylinder (9) of the steam turbine to perform work. The energy storage power generation system further comprises: a second-stage heat release mechanism, comprising: a feedwater heater (28), a main feedwater pump (20), and a steam generator (29); the gaseous working fluid flowing out of the first passage of the first-stage heat release heat exchanger (11) enters the heating feedwater passage and / or the heating deoxygenated water passage through the first three-way valve (30); The gaseous working fluid flowing out of the first passage of the first-stage heat-releasing heat exchanger (11) enters the heating feedwater passage and enters the first passage of the feedwater heater (28) to release heat energy; at the same time, a stream of feedwater is drawn out from behind the main feedwater pump (20), enters the second passage of the feedwater heater (28) to absorb heat energy, then merges with the main feedwater passage and enters the steam drum (4) of the heating boiler (1), so as to reduce the steam extraction amount of the turbine high-pressure cylinder (2) and the turbine intermediate-pressure cylinder (9), and provide a part of the heat energy required by the high-pressure heater assembly; and / or, The gaseous working medium flowing out of the first passage of the first-stage heat-releasing heat exchanger (11) enters the heating deoxygenated water passage and enters the first passage of the steam generator (29) to release heat energy; at the same time, a stream of deoxygenated water is drawn out from the outlet of the deoxygenator (13) and driven to flow into the second passage of the steam generator (29) to absorb heat energy to a superheated steam state; the obtained superheated steam flows to the low-pressure cylinder (10) of the steam turbine and is mixed with the exhaust steam of the intermediate-pressure cylinder (9) of the steam turbine and then enters the low-pressure cylinder (10) of the steam turbine to expand and perform work, so as to increase the work done by the low-pressure cylinder (10) of the steam turbine during peak power consumption; The energy storage power generation system further comprises: a third-level heat release mechanism, comprising: a condensate heater (31) and a heating heat exchanger (32); after the gaseous working fluid flowing out of the first passage of the steam generator (29) and the feedwater heater (28) are combined, they enter the heating condensate passage and / or the heating passage respectively through the control of the second three-way valve (40); After the gaseous working medium flowing out of the first passage of the steam generator (29) and the feed water heater (28) merge, it is passed through the heating condensate passage into the first passage of the condensate heater (31) to release heat energy; at the same time, part of the condensate is drawn out from the condensate polishing device (18) and enters the second passage of the condensate heater (31) to absorb heat energy, and then enters the deaerator (13) along the pipeline to reduce the steam extraction amount of the low-pressure cylinder (10) of the steam turbine and replace part of the heat energy required by the low-pressure heater component; and / or, After the gaseous working medium flowing out of the first passage of the steam generator (29) and the feed water heater (28) merge, it is passed through the heating passage into the first passage of the heating heat exchanger (32) to release heat energy; at the same time, the water working medium in the thermal system is driven to enter the second passage of the heating heat exchanger (32) to absorb heat energy, and is driven to transfer the heated water working medium to the heat user side.

2. The energy storage power generation system for a thermal power plant according to claim 1, characterized in that: A first regulating valve (12) for controlling the outflow of the cold reheat steam is arranged on the pipeline at the outlet position of the high-pressure cylinder (2) of the steam turbine.

3. The energy storage power generation system for a thermal power plant according to claim 1, characterized in that: The power generation system further comprises: a deaerator (13) and a shaft seal heater (16); the high-pressure heater assembly is provided with a built-in steam cooling section and a built-in drain cooling section, and the low-pressure heater assembly is provided with a built-in drain cooling section; The high-pressure heater of the high-pressure heater assembly is drained by gravity step by step to the deaerator (13), and the low-pressure heater of the low-pressure heater assembly is drained by gravity step by step, and then flows into the condenser hot well of the condenser (15) after merging with the shaft seal heater (16); the steam source of the shaft seal heater (16) is the shaft seal steam of the steam turbine.

4. The energy storage power generation system for a thermal power plant according to claim 3, characterized in that: The condensate in the condenser hot well passes through a condensate pump (17), a condensate polishing device (18), a shaft seal heater (16) and the low-pressure heater assembly in sequence, and then enters the deaerator (13); The deoxygenated water that has passed through the deaerator (13) enters the steam drum (4) of the heating boiler (1) from the deaerator feed water tank through a pre-pump (19), a main feed water pump (20) and the high-pressure heater assembly.

5. The energy storage power generation system for a thermal power plant according to claim 1, characterized in that: The high-voltage heater assembly comprises: a first-stage high-voltage heater (21), a second-stage high-voltage heater (22) and a third-stage high-voltage heater (23); and / or, The low-pressure heater assembly comprises: a first-stage low-pressure heater (24), a second-stage low-pressure heater (25), a third-stage low-pressure heater (26) and a fourth-stage low-pressure heater (27).

6. The energy storage power generation system for a thermal power plant according to claim 1, characterized in that: The amount of water supplied by the main water supply pump (20) is controlled by a second regulating valve (33); and / or, The amount of condensate flowing from the condensate polishing device (18) into the second passage of the condensate heater (31) is controlled by a third regulating valve (34).

7. The energy storage power generation system for a thermal power plant according to claim 1, characterized in that: Also includes: A heat storage subsystem, comprising: a packed bed high temperature heat storage unit (8) and an induced draft fan (35); During the off-peak period of electricity consumption, the high-temperature flue gas in the furnace chamber of the heating boiler (1) enters the packed bed high-temperature heat storage unit (8), and the high-temperature flue gas exchanges heat with the solid heat storage material in the packed bed high-temperature heat storage unit (8), storing heat energy in the solid heat storage material. The gas that has released the heat energy is transferred back to the heating boiler (1) by the induced draft fan (35) and merges with the flue gas in the heating boiler (1), and then enters the dust collector (36) for dust removal.

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