Thermoelectric decoupling system of secondary reheating unit and operation method of thermoelectric decoupling system

Abstract

The invention relates to the technical field of thermal power generation, and provides a secondary reheating unit thermoelectric decoupling system and an operation method thereof.The operation method comprises the steps that steam exhausted by an intermediate-pressure cylinder of a secondary reheating power generation system is fed into a heat supply network heater through steam extraction to heat primary network return water; in the electric power trough period, the compression type heat pump system recovers dead steam waste heat of the secondary reheating power generation system and heats heat supply network return water, the electric boiler consumes surplus electric power generated by the secondary reheating power generation system to heat primary network return water, and the heat storage tank discharges high-temperature water which enters a heat supply network for water supply. In the peak period of electric power, the compression type heat pump system, the heat storage tank and the electric boiler do not work, and the heat supply load requirement is met through steam extraction; and in the electric power flat section, dead steam waste heat of the secondary reheating power generation system is recycled, heat supply network return water is heated, and high-temperature water is stored in the heat storage tank. The energy utilization efficiency can be greatly improved, and deep peak regulation is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal power generation, in particular to a once-through reheat unit thermal-electric decoupling system and a method for operating the same. BACKGROUND

[0002] The statements in this section merely provide background technology related to the present application and do not necessarily constitute the prior art.

[0003] Under the background of continuous adjustment and optimization of global energy structure, the power industry is facing the dual challenges of energy efficient utilization and energy saving and emission reduction, and needs to actively explore and adopt cleaner and more efficient power generation technologies. Due to the strong randomness and volatility of clean energy, higher requirements are put forward for the flexibility of the power system, and the unit needs to have the ability to quickly respond to load changes and deep peak shaving. However, due to the fact that the heat supply demand cannot be flexibly adjusted to generate power, and in recent years the heat supply demand has been continuously growing with the development of cities, the unit is forced to operate at high load during a certain period of time, and cannot effectively respond to the peak shaving demand of the power grid, which greatly reduces the operating economy of the unit. Therefore, it is necessary to carry out deep peak shaving and thermal-electric decoupling transformation on the traditional thermal power unit. SUMMARY

[0004] In order to solve the problems in the prior art, the present application provides a once-through reheat unit thermal-electric decoupling system and a method for operating the same. The once-through reheat system, the compression heat pump system, the heat storage tank and the electric boiler are coupled in a multi-system collaborative manner. The compression heat pump system recovers low-grade waste heat from the exhaust steam. The heat storage tank realizes time-shifting control of thermal energy. The electric boiler consumes low-price surplus electricity, which can greatly improve the energy utilization efficiency and realize deep peak shaving.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: The present application provides a once-through reheat unit thermal-electric decoupling system in the first aspect.

[0006] The once-through reheat unit thermal-electric decoupling system comprises a once-through reheat power generation system, a compression heat pump system, a heat storage tank, an electric boiler and a heat network heater. The once-through reheat power generation system is connected with the heat network heater. Steam discharged from the intermediate pressure cylinder of the once-through reheat power generation system is sent to the heat network heater to heat the primary network return water. The secondary reheat power generation system is connected to a compression heat pump system. The return water of the heating network is connected to the compression heat pump system and the heat storage tank. The compression heat pump system is also connected to the heating network heater. The heating network supply water is connected to the heat storage tank and the electric boiler. During periods of low electricity demand, the compression heat pump system recovers the waste heat from the secondary reheat power generation system to heat the return water of the heating network. The electric boiler consumes surplus electricity generated by the secondary reheat power generation system to heat the return water of the primary network. The heat storage tank releases high-temperature water, which enters the heating network supply water. During periods of high electricity demand, the compression heat pump system, the heat storage tank, and the electric boiler are not in operation. The heating load demand is met by extracting steam. During periods of flat electricity demand, the waste heat from the secondary reheat power generation system is recovered to heat the return water of the heating network and high-temperature water is stored in the heat storage tank.

[0007] Furthermore, in the secondary reheat power generation system, the secondary reheat boiler, ultra-high pressure cylinder, high pressure cylinder, intermediate pressure cylinder, low pressure cylinder, condenser, condensate pump, low pressure heater, feedwater pump, deaerator and high pressure heater are connected in series to form a loop.

[0008] Furthermore, a low-pressure cylinder connecting valve and a cooling steam valve are connected in parallel between the intermediate-pressure cylinder exhaust and the low-pressure cylinder inlet.

[0009] Furthermore, the intermediate-pressure cylinder, high-pressure heater, and low-pressure heater are all connected to the water supply pump.

[0010] Furthermore, the ultra-high pressure cylinder, high pressure cylinder, and medium pressure cylinder are all connected to the high pressure heater; the medium pressure cylinder and low pressure cylinder are all connected to the low pressure heater.

[0011] Furthermore, in the compression heat pump system, the evaporator, regenerator, compressor and condenser are connected in sequence, and one end of the compressor is connected to the electric motor, which is driven by the electrical energy generated by the secondary reheat power generation system.

[0012] Furthermore, the evaporator is used to exchange heat between the circulating cooling water of the secondary reheat power generation system and the circulating working fluid at the outlet of the regenerator.

[0013] Furthermore, the regenerator is used to exchange heat between two streams of hot and cold working fluid from the evaporator outlet and the condenser outlet.

[0014] Furthermore, the condenser is used to exchange heat between the return water from the heating network and the circulating working fluid discharged from the compressor.

[0015] The second aspect of the present invention provides an operation method for a thermoelectric decoupling system of a reheat unit.

[0016] An operation method for a thermoelectric decoupling system of a double reheat unit as described in the first aspect includes the following steps: The steam discharged from the intermediate-pressure cylinder of the secondary reheat power generation system is sent to the heating network heater through steam extraction to heat the primary network return water; In the power valley period, the compression heat pump system recovers the waste heat of the exhaust steam of the secondary reheating power generation system, heats the heat network return water, the electric boiler consumes the surplus power generated by the secondary reheating power generation system to heat the primary network return water, and the heat storage tank releases high-temperature water into the heat network supply water. In the power peak period, the compression heat pump system, the heat storage tank and the electric boiler do not work, and the extraction steam is used to meet the heating load demand. In the power flat section, the waste heat of the exhaust steam of the secondary reheating power generation system is recovered to heat the heat network return water, and high-temperature water is stored in the heat storage tank.

[0017] The secondary reheating unit heat and electricity decoupling system provided by the application realizes multi-system collaborative coupling of the secondary reheating system, the compression heat pump system, the heat storage tank and the electric boiler, the compression heat pump system recovers low-grade waste heat, the heat storage tank realizes time-crossing heat regulation and control, and the electric boiler consumes low-price surplus power, so that the energy utilization efficiency can be greatly improved, and deep peak regulation can be realized.

[0018] The secondary reheating unit heat and electricity decoupling system provided by the application consumes the surplus power generated by the generator through the heat pump system and the electric boiler in the power valley period, releases heat through the heat storage tank, reduces the extraction steam for heating, thereby reducing the boiler load, in the power peak period, the exhaust steam of the medium-pressure cylinder is used for heating, the low-pressure cylinder does not work, only a small amount of cooling steam enters the low-pressure cylinder, the low-pressure rotor is operated with zero output, and thus the heating capacity and the deep peak regulation capacity of the unit are improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings accompanying the specification of the application form part of the application and are used to provide further understanding of the application, and the illustrative embodiments and descriptions used to explain the application do not constitute improper limitations on the application.

[0020] Figure 1 A structure diagram of the secondary reheating unit heat and electricity decoupling system provided by the application is provided. DETAILED DESCRIPTION

[0021] The application will be further described below in combination with the drawings and embodiments.

[0022] It should be pointed out that the following detailed description is exemplary and is intended to provide further description of the application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the application belongs.

[0023] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0024] In the present application, the terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is a relationship word determined only for the purpose of describing the structural relationship of the components or elements of the present application, and cannot be understood as a limitation on the present application.

[0025] In the present application, the terms such as "fixedly connected", "connected", "connected" and the like should be understood broadly, which means that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant researchers or technicians in the art, the specific meaning of the above terms in the present application can be determined according to the specific circumstances, and cannot be understood as a limitation on the present application.

[0026] The embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0027] Embodiment 1 The embodiment 1 of the present application provides a heat and electricity decoupling system of a double-reheat unit.

[0028] The double-reheat unit is an advanced representative in the field of thermal power generation. The heat and electricity decoupling modification thereof can realize deep peak shaving, quickly respond to load fluctuations of the power grid, adapt to the peak shaving demand after the access of clean energy power generation, reduce energy waste and operating costs, and improve the comprehensive energy efficiency through waste heat recovery.

[0029] The present embodiment aims to solve the problems of the double-reheat unit that cannot flexibly peak shave due to the rigid constraint of heating demand, poor stability and low comprehensive energy efficiency during low-load operation, as described in the background. Specifically, the technical problems to be solved by the present embodiment include: (1) Solve the problem of insufficient peak shaving capacity in the "heat determines electricity" operation mode: through technical modification, break the forced coupling relationship between the power generation load and the heating output of the traditional double-reheat unit, so that the unit can greatly reduce the power generation power under the premise of guaranteeing the external heating demand, thereby having deep peak shaving capacity and quickly responding to the load fluctuations of the power grid.

[0030] (2) Solve the problems of energy waste and poor economic efficiency under deep peak shaving conditions: recover and utilize the waste heat (such as low-grade waste heat) generated by the unit under low load operation or specific conditions, and improve the overall energy utilization efficiency of the entire system through energy storage and spatiotemporal transfer, reduce operating costs, and avoid sacrificing economic efficiency for the sake of simply pursuing peak shaving.

[0031] This embodiment provides a thermoelectric decoupling system for a reheat unit, which achieves flexible operation of thermoelectric decoupling by modifying the unit by cutting cylinders and adding a heat pump, a heat storage tank and an electric boiler.

[0032] This embodiment provides a thermoelectric decoupling system for a secondary reheat unit, such as... Figure 1 As shown, it includes a secondary reheat power generation system 1, a compression heat pump system 2, a heat storage tank 22, an electric boiler 23, and a heat network heater 24.

[0033] In the secondary reheat power generation system 1, the secondary reheat boiler 3, ultra-high pressure cylinder 4, high pressure cylinder 5, intermediate pressure cylinder 6, low pressure cylinder 7, condenser 13, condensate pump 14, low pressure heater 12, feedwater pump 11, deaerator 10, and high pressure heater 9 are connected in series to form a loop; among them, ultra-high pressure cylinder 4, high pressure cylinder 5, intermediate pressure cylinder 6, and low pressure cylinder 7 are connected in series with generator 8; a low pressure cylinder connecting valve 15 and a cooling steam valve 16 are connected in parallel between the exhaust of the intermediate pressure cylinder and the inlet of the low pressure cylinder.

[0034] In a compression heat pump system, an evaporator 17, a regenerator 18, a compressor 19, and a condenser 20 are connected in sequence. One end of the compressor 19 is connected to a motor 21, which is driven by electrical energy generated by a generator 8. The evaporator 17 is used to exchange heat between the circulating cooling water of the condenser 13 and the circulating working fluid after throttling. The regenerator 18 is used to exchange heat between the low-temperature working fluid from the outlet of the evaporator 17 and the high-temperature working fluid from the outlet of the condenser 20. The condenser 20 is used to exchange heat between the return water of the heating network and the circulating working fluid discharged from the compressor 19. The heat pump system recovers the waste heat of low-grade exhaust steam for heating.

[0035] The heat storage tank 22 is connected to the heating network supply water and the heating network return water. It has an internal temperature stratification structure to achieve natural stratification of hot and cold water and efficient heat energy storage. When the electricity price is low, the heat storage tank 22 releases high-temperature water to reduce the unit load. When the electricity price is high, the heat storage tank 22 does not store or release heat. When the electricity price is in the middle range, the heat storage tank 22 stores heat. The electric boiler 23 is connected to the heating network heater 24 and the heating network supply water. Only when the electricity price is low, the electric boiler 23 consumes the electrical energy generated by the generator 8 to heat the heating network water.

[0036] During periods of high heating demand in winter, the unit operates with cylinder cut-off, with only a small amount of cooling steam entering the low-pressure cylinder 7 through the cooling steam valve 16 to remove the heat from the low-pressure rotor and ensure the safe operation of the unit. The heating extraction steam is drawn out from the intermediate-pressure cylinder and enters the heating network heater 24 to heat the heating network water.

[0037] Steam generated by the secondary reheat boiler 3 in the secondary reheat power generation system 1 enters the ultra-high pressure cylinder 4 for expansion and work. Steam discharged from the ultra-high pressure cylinder 4 returns to the secondary reheat boiler 3 for primary reheat and then enters the high pressure cylinder 5 for expansion and work. Steam discharged from the high pressure cylinder 5 returns to the secondary reheat boiler 3 for secondary reheat and then enters the intermediate pressure cylinder 6 for further expansion and work. Part of the steam discharged from the intermediate pressure cylinder 6 enters the low pressure cylinder 7 for deep expansion through the low pressure cylinder connecting valve 15, driving the generator 8 to generate electricity. Alternatively, during cylinder switching, it enters the low pressure cylinder 7 through the cooling steam valve 16 to remove the blower heat from the low pressure rotor. Part of the steam discharged from the intermediate pressure cylinder 6 is sent to the heat network heater 24 through extraction steam to heat the primary network return water. The exhaust steam discharged from the low pressure cylinder 7 enters the condenser 13 and exchanges heat with the evaporator 17. The condensate is pressurized by the condensate pump 14 and then passes through the low pressure heater 12, deaerator 11, feed water pump 10, and high pressure heater 9 in sequence to raise its temperature before returning to the secondary reheat boiler 3 to complete the steam-water cycle.

[0038] In evaporator 17, the circulating cooling water of condenser 13 serves as a low-temperature heat source, exchanging heat with the low-temperature, low-pressure circulating working fluid after throttling from the outlet of condenser 20. The circulating working fluid absorbs the heat from the circulating cooling water, evaporating from a liquid state into a low-temperature, low-pressure gaseous working fluid. The low-temperature, low-pressure gaseous working fluid from the outlet of evaporator 17 enters regenerator 18, where it exchanges heat with the high-temperature liquid working fluid from the outlet of condenser 20. The low-temperature gaseous working fluid absorbs the heat from the liquid working fluid, further increasing its temperature, while the liquid working fluid is cooled. The gaseous working fluid, heated by regenerator 18, enters compressor 19. Compressor 19 is driven by motor 21 powered by generator 8, which adiabatically compresses the gaseous working fluid, making it a high-temperature, high-pressure gaseous working fluid. The high-temperature, high-pressure gaseous working fluid enters condenser 20, exchanging heat with the heat network return water, completing the process of releasing heat to the heat network return water, thereby realizing the transfer of recovered waste steam heat to the heat network water.

[0039] The compression heat pump system 2 recovers the low-grade exhaust heat of the condenser 13 through the evaporator 17, and then heats the primary network return water after heat exchange and compression processes through the regenerator 18, compressor 19, and condenser 20.

[0040] During different power load phases, waste heat is recovered through the compression heat pump system 2, and the thermal storage tank 22 is used to regulate and coordinate with the electric boiler 23 to improve the unit's thermoelectric decoupling capability.

[0041] During periods of low electricity demand, the compression heat pump system 2 recovers waste heat from exhaust steam to initially heat the return water of the heating network. Furthermore, the return water of the heating network exchanges heat with the extracted steam of the unit in the heating network heater 24. The electric boiler 23 consumes the surplus electricity generated by the generator 8 to heat the primary network return water. The heat storage tank 22 releases high-temperature water, reducing the direct heating load of the unit and further reducing the unit output, thus achieving deep peak shaving.

[0042] During peak electricity demand periods, the compression heat pump system 2, the heat storage tank 22, and the electric boiler 23 are all off. The heating load demand is met by extracting steam, thereby further increasing the amount of electricity fed into the grid.

[0043] In the power grid section, the waste heat of the condenser 13 is recovered by the compression heat pump system 2, the heat storage tank 22 releases unheated low-temperature water and stores high-temperature water heated by the heat exchanger 24, and the electric boiler 23 does not work.

[0044] This embodiment provides a thermoelectric decoupling system for a double reheat unit. By modifying the unit cylinder and recovering waste heat from the heat pump, and coupling the thermal storage tank and the electric boiler, the system's heating and peak-shaving capabilities are enhanced. At the same time, different operating strategies are adopted under different power loads, improving the unit's operational flexibility and economy.

[0045] This embodiment provides a thermoelectric decoupling system for a secondary reheat unit, which improves the peak shaving depth of the unit while meeting the heating load, helps to enhance the operational flexibility of the secondary reheat heating unit, quickly responds to grid load fluctuations, and adapts to the peak shaving needs after the integration of clean energy power generation.

[0046] This embodiment provides a thermoelectric decoupling system for a reheat unit, which coordinates and couples a reheat system, a compression heat pump system, a thermal storage tank, and an electric boiler. The compression heat pump system recovers the waste heat of low-grade exhaust steam, the thermal storage tank realizes cross-time regulation of thermal energy, and the electric boiler consumes low-cost surplus electricity, which can significantly improve energy utilization efficiency and achieve deep peak shaving.

[0047] This embodiment provides a thermoelectric decoupling system for a double reheat unit. Based on the characteristics of the electricity market, it proposes system operation strategies under different electricity loads, realizing multi-path, multi-equipment coordinated decoupled heating and peak-shaving operation, effectively utilizing off-peak electricity resources, and improving system flexibility and peak-shaving capabilities. During off-peak periods, the surplus electricity generated by the generator is consumed through the heat pump system and electric boiler, and heat is released through the thermal storage tank, reducing steam extraction for heating and thus lowering the boiler load. During peak periods, all exhaust steam from the intermediate-pressure cylinder is used for heating, and the low-pressure cylinder does zero work, with only a small amount of cooling steam entering the low-pressure cylinder, achieving "zero" output operation of the low-pressure rotor, thereby improving the unit's heating capacity and deep peak-shaving capability.

[0048] This embodiment provides a thermoelectric decoupling system for a reheat unit, which is simple and easy to implement. It does not require large-scale modifications to the main structure of the unit. Based on different power load requirements, it formulates equipment start-up, shutdown, and operation control strategies, which are easy to implement in actual engineering projects and have good applicability and promotion value.

[0049] Example 2 This embodiment provides an operation method for a thermoelectric decoupling system of a secondary reheat unit as described in Embodiment 1, including the following steps: During periods of high heating demand in winter, the unit operates with cylinder cut-off, with only a small amount of cooling steam entering the low-pressure cylinder 7 through the cooling steam valve 16 to remove the heat from the low-pressure rotor and ensure the safe operation of the unit. The heating extraction steam is drawn out from the intermediate-pressure cylinder and enters the heating network heater 24 to heat the heating network water.

[0050] Steam generated by the secondary reheat boiler 3 in the secondary reheat power generation system 1 enters the ultra-high pressure cylinder 4 for expansion and work. Steam discharged from the ultra-high pressure cylinder 4 returns to the secondary reheat boiler 3 for primary reheat and then enters the high pressure cylinder 5 for expansion and work. Steam discharged from the high pressure cylinder 5 returns to the secondary reheat boiler 3 for secondary reheat and then enters the intermediate pressure cylinder 6 for further expansion and work. Part of the steam discharged from the intermediate pressure cylinder 6 enters the low pressure cylinder 7 for deep expansion through the low pressure cylinder connecting valve 15, driving the generator 8 to generate electricity. Alternatively, during cylinder switching, it enters the low pressure cylinder 7 through the cooling steam valve 16 to remove the blower heat from the low pressure rotor. Part of the steam discharged from the intermediate pressure cylinder 6 is sent to the heat network heater 24 through extraction steam to heat the primary network return water. The exhaust steam discharged from the low pressure cylinder 7 enters the condenser 13 and exchanges heat with the evaporator 17. The condensate is pressurized by the condensate pump 14 and then passes through the low pressure heater 12, deaerator 11, feed water pump 10, and high pressure heater 9 in sequence to raise its temperature before returning to the secondary reheat boiler 3 to complete the steam-water cycle.

[0051] In evaporator 17, the circulating cooling water of condenser 13 serves as a low-temperature heat source, exchanging heat with the low-temperature, low-pressure circulating working fluid after throttling from the outlet of condenser 20. The circulating working fluid absorbs the heat from the circulating cooling water, evaporating from a liquid state into a low-temperature, low-pressure gaseous working fluid. The low-temperature, low-pressure gaseous working fluid from the outlet of evaporator 17 enters regenerator 18, where it exchanges heat with the high-temperature liquid working fluid from the outlet of condenser 20. The low-temperature gaseous working fluid absorbs the heat from the liquid working fluid, further increasing its temperature, while the liquid working fluid is cooled. The gaseous working fluid, heated by regenerator 18, enters compressor 19. Compressor 19 is driven by motor 21 powered by generator 8, which adiabatically compresses the gaseous working fluid, making it a high-temperature, high-pressure gaseous working fluid. The high-temperature, high-pressure gaseous working fluid enters condenser 20, exchanging heat with the heat network return water, completing the process of releasing heat to the heat network return water, thereby realizing the transfer of recovered waste steam heat to the heat network water.

[0052] The compression heat pump system 2 recovers the low-grade exhaust heat of the condenser 13 through the evaporator 17, and then heats the primary network return water after heat exchange and compression processes through the regenerator 18, compressor 19, and condenser 20.

[0053] During different power load phases, waste heat is recovered through the compression heat pump system 2, and the thermal storage tank 22 is used to regulate and coordinate with the electric boiler 23 to improve the unit's thermoelectric decoupling capability.

[0054] During periods of low electricity demand, the compression heat pump system 2 recovers waste heat from exhaust steam to initially heat the return water of the heating network. Furthermore, the return water of the heating network exchanges heat with the extracted steam of the unit in the heating network heater 24. The electric boiler 23 consumes the surplus electricity generated by the generator 8 to heat the primary network return water. The heat storage tank 22 releases high-temperature water, reducing the direct heating load of the unit and further reducing the unit output, thus achieving deep peak shaving.

[0055] During peak electricity demand periods, the compression heat pump system 2, the heat storage tank 22, and the electric boiler 23 are all off. The heating load demand is met by extracting steam, thereby further increasing the amount of electricity fed into the grid.

[0056] In the power grid section, the waste heat of the condenser 13 is recovered by the compression heat pump system 2, the heat storage tank 22 releases unheated low-temperature water and stores high-temperature water heated by the heat exchanger 24, and the electric boiler 23 does not work.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A thermoelectric decoupling system for a double reheat unit, characterized in that: This includes secondary reheat power generation systems, compression heat pump systems, thermal storage tanks, electric boilers, and heating network heaters; The secondary reheat power generation system is connected to the heating network heater, and the steam discharged from the intermediate pressure cylinder of the secondary reheat power generation system is sent to the heating network heater through steam extraction to heat the primary network return water. The secondary reheat power generation system is connected to a compression heat pump system. The return water of the heating network is connected to the compression heat pump system and the heat storage tank. The compression heat pump system is also connected to the heating network heater. The heating network supply water is connected to the heat storage tank and the electric boiler. During periods of low electricity demand, the compression heat pump system recovers the waste heat from the secondary reheat power generation system to heat the return water of the heating network. The electric boiler consumes surplus electricity generated by the secondary reheat power generation system to heat the return water of the primary network. The heat storage tank releases high-temperature water, which enters the heating network supply water. During periods of high electricity demand, the compression heat pump system, the heat storage tank, and the electric boiler are not in operation. The heating load demand is met by extracting steam. During periods of flat electricity demand, the waste heat from the secondary reheat power generation system is recovered to heat the return water of the heating network and to store high-temperature water in the heat storage tank.

2. The thermoelectric decoupling system for a reheat unit as described in claim 1, characterized in that: In the reheat power generation system, the reheat boiler, ultra-high pressure cylinder, high pressure cylinder, medium pressure cylinder, low pressure cylinder, condenser, condensate pump, low pressure heater, feedwater pump, deaerator and high pressure heater are connected in series to form a loop.

3. The thermoelectric decoupling system for a reheat unit as described in claim 2, characterized in that: A low-pressure cylinder connecting valve and a cooling steam valve are connected in parallel between the medium-pressure cylinder exhaust and the low-pressure cylinder inlet.

4. The thermoelectric decoupling system for a secondary reheat unit as described in claim 2, characterized in that: The medium-pressure cylinder, high-pressure heater, and low-pressure heater are all connected to the water supply pump.

5. The thermoelectric decoupling system for a secondary reheat unit as described in claim 2, characterized in that: The ultra-high pressure cylinder, high pressure cylinder, and medium pressure cylinder are all connected to the high pressure heater; the medium pressure cylinder and low pressure cylinder are all connected to the low pressure heater.

6. The thermoelectric decoupling system for a double reheat unit as described in claim 1, characterized in that: In the compression heat pump system, the evaporator, regenerator, compressor and condenser are connected in sequence, and one end of the compressor is connected to the electric motor, which is driven by the electrical energy generated by the secondary reheat power generation system.

7. The thermoelectric decoupling system for a double reheat unit as described in claim 6, characterized in that: The evaporator is used to exchange heat between the circulating cooling water of the secondary reheat power generation system and the circulating working fluid at the outlet of the regenerator.

8. The thermoelectric decoupling system for a double reheat unit as described in claim 6, characterized in that: The regenerator is used to exchange heat between two streams of hot and cold working fluids, one from the evaporator outlet and the other from the condenser outlet.

9. The thermoelectric decoupling system for a reheat unit as described in claim 6, characterized in that: The condenser is used to exchange heat between the return water from the heating network and the circulating working fluid discharged from the compressor.

10. The operation method of a thermoelectric decoupling system for a double reheat unit as described in any one of claims 1-9, characterized in that: Includes the following steps: The steam discharged from the intermediate-pressure cylinder of the secondary reheat power generation system is sent to the heating network heater through steam extraction to heat the primary network return water; During periods of low electricity demand, the compression heat pump system recovers the waste heat from the secondary reheat power generation system to heat the return water of the heating network. The electric boiler consumes the surplus electricity generated by the secondary reheat power generation system to heat the return water of the primary network. The heat storage tank releases high-temperature water, which then enters the heating network for water supply. During peak electricity demand periods, the compression heat pump system, thermal storage tank and electric boiler are not in operation, and the heating load demand is met by extracting steam. In the power grid section, the waste heat from the secondary reheat power generation system is recovered to heat the return water of the heating network and stored in the heat storage tank.

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