A nuclear-storage power generation system with peak regulation through high-pressure steam extraction throttling and its working method

Abstract

The present invention discloses a nuclear-storage power generation system and its operating method for peak load regulation through high-pressure steam extraction throttling. The system consists of a nuclear power subsystem and a heat storage subsystem. The heat storage subsystem includes an oil-water heat exchanger, a cold oil tank, and a hot oil tank. Both the cold and hot oil tanks are insulated, and the hot oil tank is equipped with an electric heater. The nuclear power subsystem includes a reactor, a steam generator, a steam turbine, a deaerator, high- and low-pressure heaters, etc. During actual system operation, the core power remains essentially unchanged. When the grid load command decreases, the nuclear power subsystem converts excess power into thermal energy stored in the thermal oil tank via the electric heater, allowing the unit to participate in peak load regulation. When the grid load command increases, the thermal oil in the hot oil tank converts its own thermal energy into feedwater heat via the oil-water heat exchanger, thereby reducing steam extraction from the high-pressure heater, increasing turbine work, and enabling the unit to participate in valley load regulation. This invention can improve the peak load regulation capability of nuclear power while maintaining a substantially unchanged core power.

Description

Technical Field

[0001] The present invention belongs to the technical field of power generation, and in particular relates to a nuclear-storage power generation system for peak regulation through high-pressure steam extraction throttling and a working method thereof. Background Art

[0002] Electricity, led by clean energy sources like wind, solar, and nuclear power, is gradually replacing thermal power as the dominant force in my country's power mix. However, due to the intermittent and volatile nature of renewable energy, the increased on-grid power generation is bound to impact the safe and stable operation of the power grid. At the same time, evolving industrial and social electricity consumption patterns are further widening the peak-to-valley range of the power grid, necessitating increased flexibility and the need for more generators to participate in "peak shaving and valley filling."

[0003] As an important clean energy source, nuclear power is the only one capable of meeting large-scale power supply needs. It boasts high power density, mature power generation technology, and stable output. With rising coal prices, the cost of peak and frequency regulation for thermal power generation has increased significantly, and the inclusion of nuclear power plants in peak load regulation is becoming increasingly common. However, given the technical limitations and safety risks associated with frequently and rapidly changing reactor power, most nuclear power plants operate solely as baseload power, making it difficult for them to participate in grid peak load regulation. Summary of the Invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a nuclear-storage power generation system and its working method for peak regulation through high-pressure steam extraction throttling. By coupling energy storage and pressurized water reactor nuclear power units, the system can improve the peak regulation capability of the nuclear power units while keeping the core power basically unchanged, providing a reference for solving the problem of nuclear power participating in power grid peak regulation in the future.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A nuclear-storage power generation system for peak regulation by high-pressure steam extraction throttling, consisting of a nuclear energy subsystem and a heat storage subsystem, wherein the nuclear energy subsystem includes a reactor 1, a steam generator 2, a steam turbine high-pressure cylinder 3, a steam turbine low-pressure cylinder 4, a generator 5, a condenser 6, a low-pressure heater 7, a deaerator 8, a feedwater pump 9, a second-stage high-pressure heater 10, and a first-stage high-pressure heater 11; the heat storage subsystem includes an oil-water heat exchanger 12, a cold oil tank 13, a hot oil tank 14, and an oil pump 15; wherein the reactor 1 serves as the heat source of the steam generator 2; the outlet of the steam generator 2 is connected to the inlet of the steam turbine high-pressure cylinder 3, and the outlet of the steam turbine high-pressure cylinder 3 is connected to the steam The inlet of the turbine low-pressure cylinder 4, the turbine high-pressure cylinder 3, the turbine low-pressure cylinder 4 and the generator 5 are coaxially connected, the outlet of the turbine low-pressure cylinder 4 is connected to the inlet of the condenser 6, the outlet of the condenser 6 is connected to the water side inlet of the low-pressure heater 7, the water side outlet of the low-pressure heater 7 is connected to the water side inlet of the deaerator 8, the water side outlet of the deaerator 8 is connected to the inlet of the feed water pump 9, the outlet of the feed water pump 9 is connected to the water side inlet of the second-stage high-pressure heater 10, the water side inlet of the second-stage high-pressure heater 10 is provided with a third valve V3, the water side outlet of the second-stage high-pressure heater 10 is connected to the water side inlet of the first-stage high-pressure heater 11, the first-stage high-pressure heater The water side inlet of the heat exchanger 11 is provided with a fifth valve V5, and the water side outlet of the first stage high pressure heater 11 is connected to the inlet of the steam generator 2; the outlet of the cold oil tank 13 is connected to the inlet of the hot oil tank 14, the outlet of the hot oil tank 14 is connected to the hot side inlet of the oil-water heat exchanger 12 through the oil pump 15, and the hot side outlet of the oil-water heat exchanger 12 is connected to the inlet of the cold oil tank 13 through the seventh valve V7; the cold side inlet of the oil-water heat exchanger 12 is connected to the water side inlet main pipe of the second stage high pressure heater 10 and the first stage high pressure heater 11 through the fourth valve V4 and the sixth valve V6 respectively, and the cold side outlet of the oil-water heat exchanger 12 is connected to the first stage high pressure heater On the water side outlet main pipe of the steam turbine 11; the first-stage high-pressure heater 11, the second-stage high-pressure heater 10, the deaerator 8 and the low-pressure heater 7 all use extraction steam as the heat source. The specific connection relationship is: the first-stage interstage extraction steam of the steam turbine high-pressure cylinder 3 serves as the heat source of the first-stage high-pressure heater 11, and a first valve V1 is provided on the first section of the interstage extraction steam pipeline; the second-stage interstage extraction steam of the steam turbine high-pressure cylinder 3 serves as the heat source of the second-stage high-pressure heater 10, and a first valve V2 is provided on the second section of the interstage extraction steam pipeline; the exhaust steam of the steam turbine high-pressure cylinder 3 serves as the heat source of the deaerator 8, and the interstage extraction steam of the steam turbine low-pressure cylinder 4 serves as the heat source of the low-pressure heater 7.

[0007] When the grid load command increases, thermal oil is used to heat the feed water, thereby reducing the steam extraction of the first-stage high-pressure heater 11 and the second-stage high-pressure heater 10, so that this part of the extracted steam remains in the turbine high-pressure cylinder 3 to perform work, thereby improving the system's valley filling capacity.

[0008] When the grid load instruction decreases, the excess power exceeding the grid demand is introduced into the hot oil tank 15 through the power switch 16 and converted into thermal energy of the thermal oil, thereby improving the peak shaving capability of the system.

[0009] Keeping the power of reactor 1 constant can eliminate shutdown accidents caused by frequent and rapid changes in core power and improve the safety of nuclear power units.

[0010] The cold oil tank 13 and the hot oil tank 14 are both provided with heat preservation measures, and the hot oil tank 14 is provided with an electric heating device.

[0011] The reactor is a pressurized water reactor.

[0012] The cold oil tank 13 and the hot oil tank 14 are arranged at different positions. The low-temperature heat transfer oil in the cold oil tank 13 flows into the hot oil tank 14 under the action of gravity, and only the oil pump 15 is provided at the outlet of the hot oil tank.

[0013] The working method of the nuclear-storage power generation system for peak regulation by high-pressure steam extraction throttling is as follows:

[0014] Mode 1, design condition (100% THA) operation:

[0015] The system operates under the design operating conditions, the first valve V1, the second valve V2, the third valve V3 and the fifth valve V5 are fully opened, the fourth valve V4, the sixth valve V6, the seventh valve V7 and the power switch 16 are fully closed, at this time the heat storage subsystem does not work, the nuclear energy subsystem maintains the design operating conditions (100% THA) of the reactor nuclear power unit, the first section of the interstage extraction steam of the high-pressure cylinder 3 of the steam turbine is used as the heat source of the first stage high-pressure heater 11, the second section of the interstage extraction steam of the high-pressure cylinder 3 of the steam turbine is used as the heat source of the second stage high-pressure heater The heat source of the high-pressure heater 10 is provided by the feed water pump 9; the feed water from the feed water pump 9 passes through the second-stage high-pressure heater 10 and the first-stage high-pressure heater 11 in sequence, then enters the steam generator 2 to absorb heat, becomes saturated steam, flows out from the outlet of the steam generator 2 and enters the high-pressure cylinder 3 and the low-pressure cylinder 4 of the steam turbine in sequence to perform work. The exhaust steam after completing the work is discharged from the turbine outlet, enters the condenser 6 to condense into subcooled water, and then flows through the low-pressure heater 7 and the deaerator 8 in sequence before reaching the feed water pump 9, completing the water (steam) Rankine cycle;

[0016] Mode 2: When the grid load instruction decreases:

[0017] When the grid load instruction decreases, the first valve V1, the second valve V2, the third valve V3, and the fifth valve V5 are kept fully open, the fourth valve V4, the sixth valve V6, and the seventh valve V7 are fully closed, and the power switch 16 is turned on. The nuclear energy subsystem converts the electricity exceeding the grid demand into thermal energy of the thermal oil in the heat storage subsystem through the electric heater in the hot oil tank 14 and stores it to reduce the amount of electricity connected to the grid. The system participates in peak shaving of the grid. The water vapor Rankine cycle is the same as in mode 1.

[0018] Mode 3: When the grid load command increases:

[0019] When the grid load command increases, the openings of the first valve V1, the second valve V2, the third valve V3, the fourth valve V4 and the fifth valve V5 are adjusted according to the "valley filling" demand, the sixth valve V6 and the seventh valve V7 are kept fully open, and the power switch 16 is turned off. At this time, part of the feed water from the feed water pump 9 passes through the fourth valve V4, the sixth valve V6 and the oil-water heat exchanger 12 and enters the steam generator 2, and the other part passes through the third valve V3, the second-stage high-pressure heater 10, the fifth valve V5 and the first-stage high-temperature heater 11 and enters the steam generator 2; the heat storage subsystem returns the thermal energy of the heat transfer oil to the nuclear energy subsystem through the oil-water heat exchanger 12, converting it into thermal energy of the feed water, thereby reducing the steam extraction amount of the first-stage high-pressure heater 11 and the second-stage high-pressure heater 10, allowing this part to continue to do work in the high-pressure cylinder 3 of the steam turbine, thereby increasing the valley filling capacity of the system.

[0020] Compared with the prior art, the present invention has the following characteristics:

[0021] 1. The oil-water heat exchanger can replace part of the high-pressure heater, reducing the steam extraction from the high-pressure cylinder of the steam turbine, allowing this extracted steam to continue to do work in the high-pressure cylinder of the steam turbine, thereby increasing the load-raising capacity of the nuclear-storage power generation system;

[0022] 2. Through the heat storage subsystem, the nuclear-storage power generation system can transfer its excess electricity into the hot oil tank through the electric heater when the grid load instruction decreases, thereby increasing its ability to absorb valley electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the system configuration of the present invention.

[0024] Among them: 1-reactor, 2-steam generator, 3-turbine high-pressure cylinder, 4-turbine low-pressure cylinder, 5-generator, 6-condenser, 7-low-pressure heater, 8-deaerator, 9-feedwater pump, 10-second-stage high-pressure heater, 11-first-stage high-pressure heater, 12-oil-water heat exchanger, 13-cold oil tank, 14-hot oil tank, 15-oil pump, 16-power switch, V1∽V7–valves. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below with reference to the accompanying drawings.

[0026] See also Figure 1 The present invention provides a nuclear-storage power generation system that uses high-pressure steam extraction throttling to regulate peak flow. The system consists of two parts: a nuclear energy subsystem and a heat storage subsystem. The main equipment of each part is as follows:

[0027] The main equipment of the heat storage subsystem is the cold oil tank 13, the hot oil tank 14, the oil pump 15 and the oil-water heat exchanger 12. Its main function is to convert the electricity required for peak shaving into thermal energy of the thermal oil through the electric heater and store it.

[0028] The main equipment of the nuclear energy subsystem is the reactor 1, steam generator 2, steam turbine high-pressure cylinder 3, steam turbine low-pressure cylinder 4, generator 5, condenser 6, low-pressure heater 7, deaerator 8, feedwater pump 9, second-stage high-pressure heater 10, and first-stage high-pressure heater 11. The thermodynamic cycle used is the water (steam) Rankine cycle. Feedwater from the feedwater pump 9 passes through the second-stage high-pressure heater 10, first-stage high-pressure heater 11, or oil-water heat exchanger 12 before entering the steam generator 2 to absorb heat and transform into saturated steam. The saturated steam then enters the steam turbine high-pressure cylinder 3 and the steam turbine low-pressure cylinder 4 to perform work. Exhaust steam from this work enters the condenser 6, where it condenses into subcooled water. The subcooled water then flows through the low-pressure heater 7 and enters the deaerator 11, where it continues the cycle under the action of the feedwater pump 9. When the system operates under the designed working conditions, all the electricity generated by the generator 5 is input into the power grid; when the system participates in peak regulation, if peak shaving is required, the electricity generated by the generator 5, except for the part that meets the power grid load, the rest of the electricity is introduced into the hot oil tank 14 through the power switch 16; if valley filling is required, the high-temperature thermal oil in the hot oil tank 14 flows out under the action of the oil pump 15, and its own heat energy is converted into feed water heat energy through the oil-water heat exchanger 12, thereby meeting the heat absorption demand of the feed water, reducing the steam extraction of the high-pressure heater, and increasing the power generation power of the system.

[0029] Each device in the system is connected by pipelines, on which valves, fluid machinery, and instruments can be placed according to the system's control needs. Other components of the system include auxiliary equipment, electrical systems, instrumentation and control systems, and facilities to meet safety requirements.

Claims

1. A nuclear-storage power generation system with high-pressure steam extraction throttling and peak regulation, characterized by: The invention is composed of a nuclear energy subsystem and a heat storage subsystem, wherein the nuclear energy subsystem includes a reactor (1), a steam generator (2), a high-pressure cylinder of a steam turbine (3), a low-pressure cylinder of a steam turbine (4), a generator (5), a condenser (6), a low-pressure heater (7), a deaerator (8), a feed water pump (9), and a second-stage high-pressure heater (10). and a first-stage high-pressure heater (11); the heat storage subsystem includes an oil-water heat exchanger (12), a cold oil tank (13), a hot oil tank (14) and an oil pump (15); wherein the reactor (1) serves as a heat source for the steam generator (2); the outlet of the steam generator (2) is connected to the inlet of the high-pressure cylinder (3) of the steam turbine, the outlet of the high-pressure cylinder (3) of the steam turbine is connected to the inlet of the low-pressure cylinder (4) of the steam turbine, the high-pressure cylinder (3) of the steam turbine, the low-pressure cylinder (4) of the steam turbine and the generator (5) are coaxially connected, the outlet of the low-pressure cylinder (4) of the steam turbine is connected to the inlet of the condenser (6), the outlet of the condenser (6) is connected to the water side inlet of the low-pressure heater (7), and the low-pressure heater (7) is connected to the water side inlet of the low-pressure heater (7). The water side outlet of the deaerator (7) is connected to the water side inlet of the deaerator (8), the water side outlet of the deaerator (8) is connected to the inlet of the feed water pump (9), the outlet of the feed water pump (9) is connected to the water side inlet of the second stage high pressure heater (10), the water side inlet of the second stage high pressure heater (10) is provided with a third valve (V3), the water side outlet of the second stage high pressure heater (10) is connected to the water side inlet of the first stage high pressure heater (11), the water side inlet of the first stage high pressure heater (11) is provided with a fifth valve (V5), the water side outlet of the first stage high pressure heater (11) is connected to the inlet of the steam generator (2); the outlet of the cold oil tank (13) is connected to the hot oil tank ( 14), the hot oil tank (14) is connected to the hot end inlet of the oil-water heat exchanger (12) through the oil pump (15), and the hot end outlet of the oil-water heat exchanger (12) is connected to the inlet of the cold oil tank (13) through the seventh valve (V7); the cold end inlet of the oil-water heat exchanger (12) is connected to the water side inlet main pipe of the second stage high pressure heater (10) and the first stage high pressure heater (11) through the fourth valve (V4) and the sixth valve (V6), respectively, and the cold end outlet of the oil-water heat exchanger (12) is connected to the water side outlet main pipe of the first stage high pressure heater (11); the first stage high pressure heater (11), the second stage high pressure heater (10), the deaerator (8) The low-pressure heater (7) has the extraction steam of the high-pressure cylinder (3) and the low-pressure cylinder (4) of the steam turbine as heat sources, and the specific connection relationship is as follows: the first-stage interstage extraction steam of the high-pressure cylinder (3) of the steam turbine serves as the heat source of the first-stage high-pressure heater (11), and a first valve (V1) is provided on the first-stage interstage extraction steam pipeline; the second-stage interstage extraction steam of the high-pressure cylinder (3) of the steam turbine serves as the heat source of the second-stage high-pressure heater (10), and a first valve (V2) is provided on the second-stage interstage extraction steam pipeline; the exhaust steam of the high-pressure cylinder (3) of the steam turbine serves as the heat source of the deaerator (8), and the interstage extraction steam of the low-pressure cylinder (4) of the steam turbine serves as the heat source of the low-pressure heater (7).

2. The nuclear-storage power generation system with high-pressure steam extraction throttling and peak regulation according to claim 1, characterized in that: When the load instruction of the power grid increases, the feed water is heated by heat transfer oil, thereby reducing the extraction steam of the first-stage high-pressure heater (11) and the second-stage high-pressure heater (10), so that this part of the extraction steam continues to do work in the high-pressure cylinder (3) of the steam turbine, thereby improving the valley filling capacity of the system.

3. The nuclear-storage power generation system with high-pressure steam extraction throttling and peak regulation according to claim 1, characterized in that: The power of the nuclear reactor (1) is kept constant.

4. The nuclear-storage power generation system with high-pressure steam extraction throttling and peak regulation according to claim 1, characterized in that: The cold oil tank (13) and the hot oil tank (14) are both provided with heat preservation measures, and the hot oil tank (14) is provided with an electric heater, which is connected to the generator (5) through a power switch (16). When the load instruction of the power grid is reduced, the excess power exceeding the power grid demand is introduced into the hot oil tank (14) through the power switch (16) and converted into heat energy of the heat transfer oil, thereby improving the peak shaving capability of the system.

5. The nuclear-storage power generation system with high-pressure steam extraction throttling and peak regulation according to claim 1, characterized in that: The cold oil tank (13) and the hot oil tank (14) are arranged at different positions. The low-temperature heat-conducting oil in the cold oil tank (13) flows into the hot oil tank (14) under the action of gravity, and only an oil pump (15) is provided at the outlet of the hot oil tank.

6. The method for operating a nuclear-storage power generation system for peak regulation by high-pressure steam extraction throttling according to any one of claims 1 to 5, characterized in that: The following working modes are included: Mode 1, design condition 100% THA operation: The system operates under the design operating conditions, the first valve (V1), the second valve (V2), the third valve (V3) and the fifth valve (V5) are fully opened, the fourth valve (V4), the sixth valve (V6), the seventh valve (V7) and the power switch (16) are fully closed, at this time the heat storage subsystem does not work, the nuclear energy subsystem maintains the design operating conditions of the reactor nuclear power unit 100% THA operation, the first section of the interstage extraction steam of the turbine high pressure cylinder (3) is used as the heat source of the first stage high pressure heater (11), the second section of the interstage extraction steam of the turbine high pressure cylinder (3) is used as the heat source of the second stage high pressure The heat source of the heater (10); the feed water from the feed water pump (9) passes through the second-stage high-pressure heater (10) and the first-stage high-pressure heater (11) in sequence and then enters the steam generator (2) to absorb heat, becomes saturated steam, flows out from the outlet of the steam generator (2) and enters the high-pressure cylinder (3) and low-pressure cylinder (4) of the steam turbine in sequence to perform work, and the exhaust steam after completing the work is discharged from the outlet of the steam turbine and enters the condenser (6) to condense into supercooled water, then flows through the low-pressure heater (7) and the deaerator (8) in sequence and reaches the feed water pump (9), completing the water vapor Rankine cycle; Mode 2: When the grid load instruction decreases: When the grid load instruction decreases, the first valve (V1), the second valve (V2), the third valve V3 and the fifth valve (V5) are kept fully open, the fourth valve (V4), the sixth valve (V6) and the seventh valve (V7) are fully closed, and the power switch (16) is turned on. The nuclear energy subsystem converts the electricity that exceeds the grid demand into the heat energy of the heat transfer oil in the heat storage subsystem through the electric heater in the hot oil tank (14) and stores it to reduce the grid power. The system participates in grid peak shaving. The water vapor Rankine cycle is the same as in mode 1. Mode 3: When the grid load command increases: When the load instruction of the power grid increases, the openings of the first valve (V1), the second valve (V2), the third valve (V3), the fourth valve (V4) and the fifth valve (V5) are adjusted according to the load instruction demand, the sixth valve (V6) and the seventh valve (V7) are kept fully open, and the power switch (16) is turned off. At this time, part of the feed water from the feed water pump (9) passes through the fourth valve (V4), the sixth valve (V6) and the oil-water heat exchanger (12) and enters the steam generator (2), and the other part passes through the third valve (V3), the second-stage high-pressure heater (10), the fifth valve (V5) and the first-stage high-temperature heater (11) and enters the steam generator (2); the heat storage subsystem returns the heat energy of the heat transfer oil to the nuclear energy subsystem through the oil-water heat exchanger (12), and converts it into the heat energy of the feed water, thereby reducing the steam extraction amount of the first-stage high-pressure heater (11) and the second-stage high-pressure heater (10), so that this part continues to do work in the high-pressure cylinder (3) of the steam turbine, thereby increasing the valley filling capacity of the system.

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