A waste heat recovery system for spent fuel pools in nuclear power plants

Abstract

This invention relates to the field of nuclear power waste heat utilization technology, specifically a waste heat utilization system for spent fuel pools in nuclear power plants. It includes: a nuclear power turbine thermal system, which provides steam, which is condensed in a condenser to form condensate, which exchanges heat with the spent fuel pool waste heat exchange system; the spent fuel pool waste heat exchange system utilizes the condensate flowing through the spent fuel pool waste heat exchanger to exchange heat with the heat generated by the decay of spent fuel in the spent fuel pool, transferring heat to the condensate and increasing its temperature; a spent fuel pool cooling system transfers the waste heat from the spent fuel pool to the equipment cooling water via a heat exchanger; and the equipment cooling water loop system transfers the heat absorbed during equipment cooling to seawater. Its advantages are: using condensate as the main cooling water source for the spent fuel pool, realizing the utilization of spent fuel decay waste heat, increasing condensate temperature, and reducing the heat consumption rate of the turbine thermal system.

Description

Technical Field

[0001] This invention relates to the field of nuclear power waste heat utilization technology, specifically a waste heat utilization system for spent fuel pools in nuclear power plants. Background Technology

[0002] Currently, spent fuel pools at nuclear power plants serve as storage locations for spent fuel. The decay of spent fuel generates heat, which is cooled by equipment cooling water. This cooling water absorbs the decay heat from the spent fuel through a heat exchanger within the pool, and then exchanges heat with seawater through another heat exchanger. Ultimately, the heat from the decaying spent fuel is transferred to the seawater, which is then discharged into the ocean. Therefore, the residual heat from the decaying spent fuel in the spent fuel pools is not effectively utilized, resulting in heat loss. Summary of the Invention

[0003] The present invention addresses the problems existing in the prior art. The purpose of the present invention is to provide a waste heat utilization system for spent fuel pools in nuclear power plants. It can effectively utilize the waste heat after the decay of spent fuel in the spent fuel pool, while increasing the safety of the spent fuel pool.

[0004] The technical solution of this invention is as follows: A waste heat utilization system for spent fuel pools in nuclear power plants, comprising: a nuclear power turbine thermal system, a spent fuel pool waste heat exchange system, a spent fuel pool cooling system, and an equipment cooling water loop system, wherein: the nuclear power turbine thermal system provides steam, which is condensed by a condenser to form condensate, which exchanges heat with the spent fuel pool waste heat exchange system; the spent fuel pool waste heat exchange system utilizes the condensate flowing through the spent fuel pool waste heat exchanger to exchange heat with the heat generated by the decay of spent fuel in the spent fuel pool, and the heat is transferred to the condensate, increasing the condensate temperature; the spent fuel pool cooling system transfers the waste heat from the spent fuel pool to the equipment cooling water via a heat exchanger; the equipment cooling water loop system transfers the heat absorbed during equipment cooling to seawater.

[0005] The nuclear power turbine thermal system includes a turbine unit, condenser, condensate pump, low-pressure heater, deaerator, main feedwater pump set, high-pressure heater, steam generator, and generator. The turbine converts the thermal energy of the steam generated by the steam generator into the kinetic energy of the turbine unit. The condenser condenses the exhaust steam from the turbine unit into condensate. The condensate pump provides kinetic energy to the condensate in the nuclear power turbine thermal system and the spent fuel pool waste heat exchange system. The low-pressure heater is used for... The deaerator heats the condensate flowing through it, and is used to thoroughly mix the condensate with heating steam through atomization or spraying, while removing undissolved oxygen or other non-condensable gases from the condensate. The main feedwater pump set provides kinetic energy to the circulation in the nuclear power turbine thermal system. The high-pressure heater heats the feedwater flowing through it. The steam generator serves to both exchange heat and block radioactive heat transfer agents. The generator converts the rotational kinetic energy of the turbine unit into electrical energy.

[0006] The spent fuel pool waste heat exchange system pressurizes the condensate provided by the nuclear power turbine thermal system via a condensate pump and then introduces it into the spent fuel pool waste heat exchanger. The condensate exchanges heat with the water in the spent fuel pool. After passing through an electric isolation valve after the spent fuel pool waste heat exchanger, the condensate mixes with the condensate diverted by the electric flow regulating valve of the spent fuel pool waste heat exchanger and returns to the nuclear power turbine thermal system. Electric isolation valves are installed at the inlet and outlet of the spent fuel pool waste heat exchanger.

[0007] Radioactive material monitoring instruments are installed at the inlet and outlet of the waste heat exchanger in the spent fuel water tank.

[0008] The waste heat exchange system of the spent fuel water tank is equipped with a flow regulation station.

[0009] The waste heat exchange system of the spent fuel water pool is equipped with a bypass for the waste heat exchanger regulating station.

[0010] The equipment cooling water circuit system is connected in parallel with the spent fuel pool waste heat exchange system. It is used as a backup cooling water source for the spent fuel pool in the event of a nuclear power turbine thermal system accident, when the temperature of the spent fuel pool exceeds the limit, or when the operating parameters of the spent fuel pool waste heat exchanger do not meet the requirements.

[0011] The aforementioned equipment cooling water circuit system is used to transfer the heat from spent fuel decay to seawater.

[0012] The beneficial effects of this invention are as follows: The waste heat utilization system of the spent fuel pool in the nuclear power plant of this invention uses condensate as the main cooling water source of the spent fuel pool, realizes the utilization of waste heat from spent fuel decay, increases the temperature of condensate, reduces the heat consumption rate of the turbine thermal system, and improves the thermal economy of the nuclear power plant turbine.

[0013] This invention reduces the emission of decay heat from spent fuel pools into the ocean, thereby reducing thermal pollution effects on the marine environment and minimizing adverse impacts on the local marine ecosystem.

[0014] The cooling water circuit system of this invention serves as a backup cooling system, thereby increasing the diversity of cooling water sources and improving the safety of the spent fuel water pool.

[0015] This invention helps to provide a stable condensate temperature for steam turbines and reduce the impact of external environmental factors on condensate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a waste heat recovery system for spent fuel pools in nuclear power plants, provided by the present invention.

[0017] In the diagram: 1. Nuclear power turbine thermal system; 2. Spent fuel pool waste heat exchange system; 3. Spent fuel pool cooling system; 4. Equipment cooling water circuit system; 101. Steam turbine; 102. Condenser; 103. Condensate pump; 104. Low-pressure heater; 105. Deaerator; 106. Main feedwater pump set; 107. High-pressure heater; 108. Steam generator; 109. Generator; 201. Spent fuel pool waste heat exchanger; 202. Waste heat exchanger regulating station bypass electric isolation valve; 203. Waste heat heat exchanger flow electric regulating valve; 204. Waste heat heat exchanger flow regulating valve upstream manual isolation valve; 205. Waste heat heat exchanger flow regulating valve downstream manual isolation valve; 206. Waste heat heat exchanger upstream electric isolation valve. 207 Electric isolation valve after waste heat heat exchanger; 208 Inlet flow measurement point of waste heat heat exchanger; 209 Inlet temperature measurement point of waste heat heat exchanger; 210 Inlet radioactive material detection measurement point of waste heat heat exchanger; 212 Outlet temperature measurement point of waste heat heat exchanger; 211 Outlet radioactive material detection measurement point of waste heat heat exchanger; 213 Outlet flow measurement point of waste heat heat exchanger; 301 Cooling water pump of spent fuel pool; 302 Electric isolation valve before waste heat heat exchanger on the side of spent fuel pool; 303 Electric isolation valve after waste heat heat exchanger on the side of spent fuel pool; 401 Equipment cooling water heat exchanger; 402 Electric isolation valve before cooling water heat exchanger on the side of equipment; 403 Electric isolation valve after cooling water heat exchanger on the side of equipment. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 As shown, the waste heat utilization system of a spent fuel pool in a nuclear power plant provided by the present invention includes: a nuclear power turbine thermal system 1; a spent fuel pool waste heat exchange system 2; a spent fuel pool cooling system 3; and an equipment cooling water circuit system 4.

[0020] The nuclear power turbine thermal system 1 includes a turbine unit 101, a condenser 102, a condensate pump 103, a low-pressure heater 104, a deaerator 105, a main feedwater pump unit 106, a high-pressure heater 107, a steam generator 108, and a generator 109. The turbine 101 converts the thermal energy of the steam generated by the steam generator 108 into the kinetic energy of the turbine unit 101. The condenser 102 condenses the exhaust steam from the turbine unit 101 after it has completed its work, forming condensate. The condensate pump 103 provides kinetic energy to the condensate in the nuclear power turbine thermal system 1 and the spent fuel pool waste heat exchange system 2. The low-pressure heater 104 heats the condensate flowing through it. The deaerator 105 atomizes or sprays the condensate and mixes it thoroughly with the heating steam, while removing undissolved oxygen or other non-condensable gases from the condensate to achieve the required water quality. The main feedwater pump unit 106 provides kinetic energy to the circulation system 1 of the nuclear power turbine. The high-pressure heater 107 heats the feedwater flowing through it. The steam generator 108 serves to both exchange heat and block radioactive heat transfer agents. The generator 109 converts the kinetic energy generated by the turbine unit 101 into electrical energy.

[0021] The spent fuel water pool waste heat exchange system 2 includes a spent fuel water pool waste heat exchanger 201, a waste heat exchanger regulating station bypass electric isolation valve 202, a waste heat exchanger flow electric regulating valve 203, a waste heat exchanger flow electric regulating valve front manual isolation valve 204, a waste heat heat exchanger flow electric regulating valve rear manual isolation valve 205, a waste heat heat exchanger flow electric isolation valve 206, and a waste heat heat exchanger rear electric isolation valve 207. It is connected to a condensate pump via pipeline. After the condensate pump 103 pressurizes the condensate, it enters the spent fuel water pool waste heat exchanger 201 through the waste heat heat exchanger front manual isolation valve 206. The condensate and spent fuel water exchange heat through the waste heat exchanger 201. The condensate that has absorbed heat flows out through the waste heat heat exchanger rear manual isolation valve 207, mixes with the condensate flowing through the waste heat heat exchanger flow electric regulating valve 203, and then returns to the nuclear power turbine thermal system 1.

[0022] The waste heat exchange system 2 for the spent fuel water tank monitors the inlet flow rate measurement point 208 and the outlet flow rate measurement point 213 of the waste heat exchanger. If the deviation between 208 and 213 is large, the waste heat exchange system 2 for the spent fuel water tank should be checked immediately to prevent condensate from leaking into the spent fuel water tank.

[0023] In the event of a malfunction in the spent fuel pool waste heat exchanger flow electric regulating valve 203, the waste heat exchanger regulating station bypass electric isolation valve 202 will be opened to prevent the malfunction from affecting the operation of the nuclear power turbine thermal system 1, thereby limiting the nuclear power plant load. Simultaneously, the spent fuel pool waste heat exchanger 201 should be shut down. The electric isolation valve 402 before the equipment cooling water heat exchanger and the electric isolation valve 403 after the equipment cooling water heat exchanger will be opened to switch the spent fuel pool waste heat exchange system 2 to the equipment cooling water loop system 4.

[0024] During the adjustment of the flow rate of the spent fuel water tank waste heat exchanger electric regulating valve 203, the temperature change of the spent fuel water tank is taken into account to avoid the phenomenon of the spent fuel water tank becoming too cold.

[0025] The design of the pipeline for the electric flow regulating valve 203 of the spent fuel water pool waste heat heat exchanger and the electric isolation valve 202 of the waste heat heat exchanger regulating station bypass should meet the condensate flow requirements of the nuclear power turbine thermal system 1 when the spent fuel water pool waste heat heat exchanger 201 is in an isolated state.

[0026] The electric isolation valve 206 before the waste heat heat exchanger and the electric isolation valve 207 after the waste heat heat exchanger are used to isolate the waste heat heat exchanger 201 from the system during maintenance or in case of emergency.

[0027] The spent fuel pool cooling system 3 uses the spent fuel pool cooling water pump 301 to transport the working fluid, which has absorbed the decay heat of spent fuel in the spent fuel pool, to the spent fuel pool waste heat exchanger 201 for heat exchange, using the kinetic energy provided by the pump. The working fluid, after releasing heat, returns to the spent fuel pool. In the event of an accident in the nuclear power turbine thermal system 1, when the spent fuel pool water temperature exceeds the limit, or when the operating parameters of the spent fuel pool waste heat exchanger 201 do not meet the requirements, the spent fuel pool cooling water pump 301 sends the working fluid, which has absorbed the decay heat of spent fuel in the spent fuel pool, to the equipment cooling water loop system 4 for cooling.

[0028] The spent fuel water pool cooling water system 3, the spent fuel water pool waste heat heat exchanger 201 and the equipment cooling water heat exchanger 401 are allowed to be connected in parallel for a short time. If the temperature of the spent fuel water pool is high, the spent fuel water pool waste heat heat exchange system 2 will be switched to the equipment cooling water loop system 4 for operation.

[0029] The spent fuel pool waste heat exchange system 2, the equipment cooling water circuit system 4, and all structures and equipment meet nuclear safety level requirements to prevent the escape of radioactive fission products.

[0030] The condensate pressure of the waste heat exchanger 201 in the spent fuel water pool must be greater than the spent fuel water pressure; the cooling water pressure of the equipment cooling water exchanger must be greater than the spent fuel water pressure.

[0031] A waste heat heat exchanger inlet temperature measuring point 209 is installed on the inlet pipe of the electric isolation valve 206 before the waste heat heat exchanger to monitor the condensate temperature in the waste heat heat exchange system 2 of the spent fuel water pool. A waste heat heat exchanger inlet flow measuring point 208 is used to monitor the condensate flow rate through the waste heat heat exchanger 201 of the spent fuel water pool.

[0032] A waste heat heat exchanger outlet temperature measuring point 212 is installed on the pipeline at the outlet of the electric isolation valve 207 after the waste heat heat exchanger. This is used to monitor the temperature rise of the condensate after it flows through the waste heat heat exchanger 201 of the spent fuel water pool and exchanges heat with the spent fuel water pool.

[0033] The radioactive material detection points 210 at the inlet and 211 at the outlet of the waste heat heat exchanger are used to monitor the radiation content in the condensate after heat absorption. If radioactive material is detected, the nuclear power plant's instrumentation and control protection system will quickly close the electric isolation valve 206 before and after the waste heat heat exchanger, thereby shutting down the operation of the spent fuel pool waste heat heat exchanger 201. At the same time, the electric isolation valve 402 before and after the equipment cooling water heat exchanger will be interlocked and opened to switch to the operation of the equipment cooling water circuit system 4.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that these embodiments may be modified to ensure safe operation under nuclear safety conditions without departing from the principles of implementation of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A waste heat recovery system for spent fuel pools in nuclear power plants, characterized in that, include: The system comprises a nuclear power turbine thermal system, a spent fuel pool waste heat exchange system, a spent fuel pool cooling system, and an equipment cooling water loop system. Specifically: the nuclear power turbine thermal system provides steam, which is condensed in a condenser to form condensate, which then exchanges heat with the spent fuel pool waste heat exchange system. The spent fuel pool waste heat exchange system utilizes the condensate flowing through the waste heat exchanger to exchange heat with the heat generated by the decay of spent fuel in the spent fuel pool. This heat is transferred to the condensate, increasing its temperature. The spent fuel pool cooling system transfers the waste heat from the spent fuel pool to the equipment cooling water via a heat exchanger. The equipment cooling water loop system transfers the heat absorbed during equipment cooling to seawater. The nuclear power turbine thermal system includes a turbine unit, condenser, condensate pump, low-pressure heater, deaerator, main feedwater pump set, high-pressure heater, steam generator, and generator. The turbine converts the thermal energy of the steam generated by the steam generator into the kinetic energy of the turbine unit. The condenser condenses the exhaust steam from the turbine unit into condensate. The condensate pump provides kinetic energy to the condensate in the nuclear power turbine thermal system and the spent fuel pool waste heat exchange system. The low-pressure heater is used for... The deaerator heats the condensate flowing through it, and is used to thoroughly mix the condensate with heating steam through atomization or spraying, while removing undissolved oxygen or other non-condensable gases from the condensate. The main feedwater pump set provides kinetic energy to the circulation in the nuclear power turbine thermal system. The high-pressure heater heats the feedwater flowing through it. The steam generator serves to both exchange heat and block radioactive heat transfer agents. The generator converts the rotational kinetic energy of the turbine unit into electrical energy. The spent fuel pool waste heat exchange system pressurizes the condensate provided by the nuclear power turbine thermal system via a condensate pump and then introduces it into the spent fuel pool waste heat exchanger. The condensate exchanges heat with the water in the spent fuel pool. After passing through an electric isolation valve after the spent fuel pool waste heat exchanger, the condensate mixes with the condensate diverted by the electric flow regulating valve of the spent fuel pool waste heat exchanger and returns to the nuclear power turbine thermal system. Electric isolation valves are installed at the inlet and outlet of the spent fuel pool waste heat exchanger.

2. The waste heat recovery system for spent fuel pools in nuclear power plants as described in claim 1, characterized in that: Radioactive material monitoring instruments are installed at the inlet and outlet of the waste heat exchanger in the spent fuel water tank.

3. A waste heat recovery system for spent fuel pools in nuclear power plants as described in claim 1, characterized in that: The waste heat exchange system of the spent fuel water tank is equipped with a flow regulation station.

4. A waste heat recovery system for spent fuel pools in nuclear power plants as described in claim 1, characterized in that: The waste heat exchange system of the spent fuel water pool is equipped with a bypass for the waste heat exchanger regulating station.

5. A waste heat recovery system for spent fuel pools in nuclear power plants as described in claim 1, characterized in that: The equipment cooling water circuit system is connected in parallel with the spent fuel pool waste heat exchange system. It is used as a backup cooling water source for the spent fuel pool in the event of a nuclear power turbine thermal system accident, when the temperature of the spent fuel pool exceeds the limit, or when the operating parameters of the spent fuel pool waste heat exchanger do not meet the requirements.

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