A nuclear power unit warm drainage waste heat utilization system

Abstract

The present invention relates to the technical field of nuclear power waste heat utilization, and specifically discloses a nuclear power unit warm drainage waste heat utilization system. The circulating water outlet and the circulating water inlet of the condenser are connected by pipeline A, and pipeline A passes through the primary heat pump to achieve heat exchange; the primary heat pump and the secondary heat pump are connected by pipeline B to form a loop, and the primary heat pump acts as a heat source to exchange heat with the secondary heat pump; the secondary heat pump and the low-pressure evaporator are connected by pipeline D to form a loop, and the secondary heat pump acts as a heat source to exchange heat with the low-pressure evaporator; the demineralized water device is connected to the low-pressure evaporator through pipeline E; the low-pressure evaporator is connected to the steam superheater through pipeline F, and the steam superheater is connected to the steam compressor through pipeline G. The system of the present invention uses heat pump technology to collect the waste heat of warm drainage and generate steam, which can greatly improve the nuclear energy utilization efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear power waste heat utilization, and particularly relates to a nuclear power unit warm drainage waste heat utilization system. Background Art

[0002] At present, pressurized water reactor nuclear power plants are the mainstream nuclear power plants worldwide and are also the main nuclear power plants in the second and third generations of nuclear power in China. The pressurized water reactor nuclear power unit uses the primary coolant to carry the heat generated by nuclear fission in the reactor core out of the reactor core, and uses a steam generator to generate steam to drive a steam turbine generator set to generate electricity. Since the steam parameters of pressurized water reactor nuclear power units are low, the thermoelectric conversion efficiency is lower than that of thermal power units and other types of units. A large amount of heat is discharged in the form of warm drainage, and the nuclear energy utilization efficiency is not high, resulting in huge waste. Therefore, it is necessary to explore technologies for utilizing the waste heat of warm drainage from pressurized water reactor nuclear power units to improve the nuclear energy utilization efficiency of the units without affecting the safe and stable operation of the units.

[0003] Searching for relevant publicly disclosed patents of nuclear power units found that: in terms of nuclear energy steam supply, there is a technology for converting secondary loop steam into industrial steam using steam conversion technology, such as "Thermoelectric combined system and production process applicable to large pressurized water reactor nuclear power units" (CN 114033512 A), but this patented technology does not utilize the waste heat of warm drainage to generate industrial steam, and at the same time, extracting secondary loop steam will reduce the steam used by the steam turbine and reduce the power generation of the unit; in terms of nuclear energy waste heat energy storage, there is energy storage of waste heat from spent fuel pools, residual heat removal systems, main steam bypass systems, etc., such as "A nuclear power plant waste heat energy storage and distribution and reuse system" (CN 216487339U), but this patented technology also does not involve the relevant content of collecting and utilizing the waste heat of warm drainage; in terms of warm drainage waste heat utilization, there is a technology for producing high-temperature water for heating using heat pump technology, such as "Nuclear power plant waste heat utilization system and nuclear power plant waste heat utilization method" (CN 112489843 A), but this patented technology fails to utilize the waste heat of warm drainage to produce industrial steam and is only applicable to areas with heating requirements, having certain limitations.

[0004] Therefore, there is an urgent need to design a nuclear power unit warm drainage waste heat utilization system to solve the above problems and improve the nuclear energy utilization efficiency of the unit. Summary of the Invention

[0005] The purpose of the present invention is to provide a nuclear power unit warm drainage waste heat utilization system to realize the collection and utilization of the waste heat of warm drainage from nuclear power units and solve the problem of low nuclear energy utilization efficiency of pressurized water reactor nuclear power units.

[0006] The technical solution of the present invention is as follows:

[0007] A nuclear power unit warm drainage waste heat utilization system, the circulating water outlet and the circulating water inlet of the condenser are connected by pipeline A, and pipeline A passes through the primary heat pump to achieve heat exchange;

[0008] The primary heat pump and the final heat pump are connected by pipeline B to form a loop, and the primary heat pump acts as a heat source to exchange heat with the final heat pump;

[0009] The final heat pump and the low-pressure evaporator are connected by pipeline D to form a loop, and the final heat pump acts as a heat source to exchange heat with the low-pressure evaporator;

[0010] The demineralized water device is connected to the low-pressure evaporator through pipeline E;

[0011] The low-pressure evaporator is connected to the steam superheater through pipeline F, and the steam superheater is connected to the steam compressor through pipeline G.

[0012] The said pipeline E passes through the primary heat pump to achieve preheating.

[0013] On pipeline A at the circulating water outlet and the circulating water inlet of the condenser, discharge valves are respectively installed.

[0014] The exhaust steam of the steam turbine unit is discharged to the condenser and cooled into condensate water. The heat released by the condensation of the exhaust steam is absorbed by the cooling circulating water in the condenser to form warm drainage; the warm drainage discharged from the circulating water outlet of the condenser is heat-exchanged through the primary heat pump, and the cooled cooling water returns to the circulating water inlet of the condenser;

[0015] The high-temperature outlet water of the primary heat pump serves as the heat source of the final heat pump, and after heat exchange, it forms the low-temperature return water of the primary heat pump and returns to the primary heat pump;

[0016] The high-temperature outlet water of the final heat pump serves as the heat source of the low-pressure evaporator, and after heat exchange, it forms the low-temperature return water of the final heat pump and returns to the final heat pump;

[0017] The demineralized water device is used to produce low-temperature demineralized water. The low-temperature demineralized water is heated by the primary heat pump to form preheated demineralized water, and then saturated steam is generated by the low-pressure evaporator;

[0018] The saturated steam is heated by the steam superheater to form superheated steam;

[0019] The superheated steam is boosted by the steam compressor to form industrial steam to meet industrial use.

[0020] The temperature of the cooling water is between 20 and 25 °C.

[0021] The temperature of the high-temperature outlet water of the final heat pump is between 90 and 120 °C.

[0022] The temperature of the preheated demineralized water is between 40 and 90 °C.

[0023] The temperature of the saturated steam ranges from 90 to 120 °C, and the pressure ranges from 0.05 to 0.2 Mpa.

[0024] The temperature of the industrial steam ranges from 150 to 400 °C, and the pressure ranges from 0.5 to 8 Mpa.

[0025] The remarkable effects of the present invention are as follows:

[0026] (1) The system of the present invention uses heat pump technology to collect the waste heat of warm discharged water and generate steam, which can greatly improve the nuclear energy utilization efficiency.

[0027] (2) The system of the present invention adopts waste heat recovery, low-pressure evaporation, and steam superheat recompression technologies, which can avoid or reduce the impact of the existing nuclear energy steam supply technical solutions on the power generation capacity of the unit.

[0028] (3) The system of the present invention realizes the recycling of the cooling water in the three loops, which can greatly reduce the warm discharged water area of the unit and reduce the impact of the warm discharged water on the environment.

[0029] (4) The system of the present invention can carry out technical transformation on the operating units, with little impact on the existing systems and equipment, which is beneficial to the safe and stable operation of nuclear power units.

[0030] (5) The temperature of the low-temperature demineralized water is about 20 °C. After preheating it by the present invention, the temperature is raised to the corresponding temperature of the saturated steam, which can improve the efficiency of generating saturated steam in the evaporator. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the warm discharged water waste heat utilization system.

[0032] In the figure: 1 - condenser, 2 - warm discharged water, 3 - cooling water, 4 - primary heat pump, 5 - final heat pump, 6 - high-temperature outlet water of the primary heat pump, 7 - low-temperature return water of the primary heat pump, 8 - high-temperature outlet water of the final heat pump, 9 - low-temperature return water of the final heat pump, 10 - demineralized water device, 11 - low-temperature demineralized water, 12 - preheated demineralized water, 13 - low-pressure evaporator, 14 - saturated steam, 15 - steam superheater, 16 - superheated steam, 17 - steam compressor, 18 - compressed steam. Detailed Embodiments

[0033] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0034] As Figure 1A kind of nuclear power unit warm drainage waste heat utilization system is shown. The circulating water outlet and the circulating water inlet of the condenser 1 are connected by a pipeline A, and the pipeline A passes through the primary heat pump 4 to realize heat exchange. The primary heat pump 4 and the final heat pump 5 are connected by a pipeline B to form a loop, and the primary heat pump 4 is used as a heat source to exchange heat with the final heat pump 5; Multiple intermediate heat pumps can also be added between the primary heat pump 4 and the final heat pump 5, and adjacent heat pumps are connected by pipelines to form a loop to realize multi-stage heat exchange. The final heat pump 5 and the low-pressure evaporator 13 are connected by a pipeline D to form a loop, and the final heat pump 5 is used as a heat source to exchange heat with the low-pressure evaporator 13. The demineralized water device 10 is connected to the low-pressure evaporator 13 through a pipeline E, and the pipeline E passes through the primary heat pump 4 or the intermediate heat pump to realize preheating. The low-pressure evaporator 13 is connected to the steam superheater 15 through a pipeline F, and the steam superheater 15 is connected to the steam compressor 17 through a pipeline G.

[0035] On the pipeline A at the circulating water outlet and the circulating water inlet of the condenser 1, discharge valves are respectively installed.

[0036] The exhaust steam of the steam turbine unit is discharged to the condenser 1 and cooled into condensed water. The heat released by the condensation of the exhaust steam is absorbed by the cooling circulating water in the condenser 1 to form warm drainage 2; The warm drainage 2 discharged from the circulating water outlet of the condenser 1 exchanges heat through the primary heat pump 4, and the cooled water 3 returns to the circulating water inlet of the condenser 1 to circularly obtain the heat released by the condensation of the exhaust steam. The temperature of the cooled water 3 is between 20 and 25 °C.

[0037] The high-temperature outlet water 6 of the primary heat pump is used as the heat source of the final heat pump 5, and after heat exchange, it forms the low-temperature return water 7 of the primary heat pump and returns to the primary heat pump 4.

[0038] The high-temperature outlet water 8 of the final heat pump is used as the heat source of the low-pressure evaporator 13. The temperature of the high-temperature outlet water 8 of the final heat pump is between 90 and 120 °C. After heat exchange, it forms the low-temperature return water 9 of the final heat pump and returns to the final heat pump 5.

[0039] The demineralized water device 10 is used to produce low-temperature demineralized water 11. The low-temperature demineralized water 11 is heated by the primary heat pump 4 to form preheated demineralized water 12. The temperature of the preheated demineralized water 12 is between 40 and 90 °C, and then saturated steam 14 is generated by the low-pressure evaporator 13. The temperature of the saturated steam 14 is between 90 and 120 °C and the pressure is between 0.05 and 0.2 Mpa. The saturated steam 14 is heated by the steam superheater 15 to form superheated steam 16; The superheated steam 16 is boosted by the steam compressor 17 to form industrial steam 18. The temperature of the industrial steam 18 is between 150 and 400 °C and the pressure is between 0.5 and 8 Mpa, meeting industrial use.

Claims

1. A nuclear power unit warm drainage waste heat utilization system, characterized in that: The outlet and inlet of the circulating water of the condenser (1) are connected by pipeline A, and pipeline A passes through the primary heat pump (4) to achieve heat exchange; The primary heat pump (4) and the secondary heat pump (5) are connected by pipeline B to form a loop, and the primary heat pump (4) acts as a heat source to exchange heat with the secondary heat pump (5); The secondary heat pump (5) and the low-pressure evaporator (13) are connected by pipeline D to form a loop, and the secondary heat pump (5) acts as a heat source to exchange heat with the low-pressure evaporator (13); The demineralized water device (10) is connected to the low-pressure evaporator (13) through pipeline E; The low-pressure evaporator (13) is connected to the steam superheater (15) through pipeline F, and the steam superheater (15) is connected to the steam compressor (17) through pipeline G; On pipeline A at the outlet and inlet of the circulating water of the condenser (1), discharge valves are respectively installed; The exhaust steam of the steam turbine unit is discharged into the condenser (1) to be cooled into condensate water, and the heat released by the condensation of the exhaust steam is absorbed by the cooling circulating water in the condenser (1) to form warm drainage water (2); the warm drainage water (2) discharged from the outlet of the circulating water of the condenser (1) exchanges heat through the primary heat pump (4), and the cooled cooling water (3) returns to the inlet of the circulating water of the condenser (1); The high-temperature outlet water (6) of the primary heat pump serves as the heat source of the secondary heat pump (5), and after heat exchange, it forms the low-temperature return water (7) of the primary heat pump and returns to the primary heat pump (4); The high-temperature outlet water (8) of the secondary heat pump serves as the heat source of the low-pressure evaporator (13), and after heat exchange, it forms the low-temperature return water (9) of the secondary heat pump and returns to the secondary heat pump (5); The demineralized water device (10) is used to produce low-temperature demineralized water (11), and the low-temperature demineralized water (11) is heated by the primary heat pump (4) to form preheated demineralized water (12), and then saturated steam (14) is generated by the low-pressure evaporator (13); The saturated steam (14) is heated by the steam superheater (15) to form superheated steam (16); The superheated steam (16) is boosted by the steam compressor (17) to form industrial steam (18) for industrial use.

2. The waste heat utilization system for warm drainage of a nuclear power unit according to claim 1, characterized in that: The pipeline E passes through the primary heat pump (4) to achieve preheating.

3. A nuclear power unit warm drainage waste heat utilization system according to claim 2, characterized in that: The temperature of the cooling water (3) is between 20 and 25 °C.

4. A nuclear power unit warm drainage waste heat utilization system according to claim 2, characterized in that: The temperature of the high-temperature outlet water (8) of the secondary heat pump is between 90 and 120 °C.

5. A nuclear power unit warm drainage waste heat utilization system according to claim 2, characterized in that: The temperature of the preheated demineralized water (12) is between 40 and 90 °C.

6. The waste heat utilization system for warm discharged water of a nuclear power unit according to claim 2, wherein: The temperature of the saturated steam (14) is between 90 and 120 °C, and the pressure is between 0.05 and 0.2 Mpa.

7. The waste heat utilization system for warm discharged water of a nuclear power unit according to claim 2, characterized in that: The temperature of the industrial steam (18) is between 150 and 400 °C, and the pressure is between 0.5 and 8 Mpa.

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