Cold storage system for nuclear power plant

Abstract

The utility model discloses a cold storage system for a nuclear power plant, the cold storage system comprises a refrigeration cycle, a cold storage cycle and a freezing cycle, the refrigeration cycle provides a cold energy source for a terminal user and the cold storage system; the cold storage cycle is used for storing and using cold energy provided by the refrigeration cycle; the refrigeration cycle obtains cooling capacity from the refrigeration cycle or the cold storage cycle, and appropriate plant temperature and operation conditions of a process system are provided for the nuclear power plant; and the refrigeration cycle and / or the cold storage cycle provide a cold source for the freezing cycle. The corresponding cold storage system is designed according to the normal working condition and the accident working condition of the nuclear power plant, the problem that a cold source in an existing chilled water system is single can be solved, and the load requirement of a user is met; under the accident working condition, the cold storage device is adopted to replace an air-cooled anti-seismic unit for cooling, the installed capacity and manufacturing cost of a chilled water system can be reduced through the design, and meanwhile the capacity of an SBO diesel engine can be reduced.

Description

Technical Field

[0001] The present application relates to the field of cold storage technology, and in particular to a cold storage system for a nuclear power plant. Background Art

[0002] The chilled water system is an important auxiliary system of a nuclear power plant. Under normal operating conditions of a nuclear power plant, it provides chilled water to various chilled water users to meet the temperature requirements of various functional rooms in the nuclear power plant and the operating requirements of the process system. At the same time, under the condition of loss of heat sink (H1 condition) or power outage of the whole plant (SBO condition), the chilled water system still needs to provide chilled water for important ventilation systems and injection pump motor coolers to ensure the habitability of the main control room and the normal operation of the instrumentation and control DCS (Distributed Control System) cabinets and electrical cabinets, thereby ensuring the safe operation of the nuclear power plant. When the nuclear power plant is in normal operating conditions, the chilled water system generally starts a water-cooled chiller to provide chilled water. The water-cooled chiller relies on the equipment cooling water to take away the heat of the condenser to maintain the normal operation of the chiller, and the equipment cooling water transfers the heat of the condenser to the final heat sink - seawater through the plate heat exchanger and the important plant water system. However, when the nuclear power plant is in H1 condition, important plant water systems and equipment cooling water systems fail, and the water-cooled chillers that have lost cooling water cannot continue to work. In order to ensure the normal operation of the power plant, it is necessary to start the air-cooled chillers to ensure the cooling needs of important users; when the nuclear power plant is in SBO condition, the equipment fails due to power outage. At this time, it is necessary to load the SBO diesel engine to power some modules of the air-cooled chiller to ensure the cooling needs of important users.

[0003] However, there are several problems with the use of air-cooled chillers in the prior art: 1) Since air-cooled chillers are only used under accident conditions and the frequency of use is extremely low, the overall installed capacity of the chilled water system is invisibly increased; 2) Since some modules of the air-cooled chiller need to be used under SBO conditions, the capacity of the SBO diesel engine also increases accordingly; 3) Since the air-cooled chiller needs to be used under accident conditions, there are special earthquake resistance requirements and the unit is expensive.

[0004] The existing patent CN205783485U discloses a dual-cooling-source multi-condition water-cooled energy storage system. The energy storage system includes a refrigeration main unit, which is equipped with a cooling tower. The refrigeration main unit and the cooling tower are set up as a main unit refrigeration cycle loop, and a cooling pump is provided on the main unit refrigeration cycle loop; the refrigeration main unit is connected to the terminal load and set up as a main unit independent cooling cycle loop with the terminal load, and a chilled water pump is provided on the main unit independent cooling cycle loop; the terminal load is also provided with a chilled water storage tank and set up as a cycle loop with the chilled water storage tank, and the chilled water storage tank is respectively set up as a cycle loop with the refrigeration main unit and the cooling tower. The chilled water storage tank is provided with a chilled water storage pump, and the refrigeration main unit, the terminal load and the chilled water storage tank are arranged in parallel. This patent can realize multi-mode cooling and cold storage, and the cold storage cost is relatively low. However, the working mode of this chilled water storage system is more suitable for the air-conditioning system field.

[0005] The existing patent CN102967018A discloses a ground-source heat pump coupled with water-cooled energy storage based on independent temperature and humidity control, which includes a temperature control system and a humidity control system. The humidity control system uses an independent solution dehumidification type fresh air handling unit to process outdoor fresh air and send the processed fresh air into the room; the temperature control system includes an air-conditioning cold and heat source and an air-conditioning terminal; the air-conditioning cold and heat source adopts a sensible heat cold and heat source combination body composed of ground-source heat pump air-conditioning technology and large temperature difference water-cooled energy storage technology. The sensible heat cold and heat source combination body includes an outdoor heat exchange system, a high-temperature centrifugal chiller, a dual-condition heat pump unit, a chilled water storage fire pool, a chilled water storage / discharge heat exchanger system, pipeline valves and equipment, and a control system; the air-conditioning chilled water or hot water prepared by the sensible heat cold and heat source combination body is distributed to the air-conditioning terminal through a water distributor and a water collector; the air-conditioning terminal adopts an air handling unit, and an electric valve is set on the pipeline. The cold storage design in this patent is mainly used to achieve the purposes of energy conservation and emission reduction, power saving and operation cost saving.

[0006] None of the above existing patents solve the problems of large installed capacity, increased capacity of the SBO diesel engine, and high unit cost caused by the use of air-cooled chillers in the chilled water system of nuclear power plants to cope with accident conditions. Summary of the Invention

[0007] Based on the above technical problems, the present application proposes a chilled water storage system for nuclear power plants, which solves the problems of large installed capacity, increased capacity of the SBO diesel engine, and high unit cost caused by the use of air-cooled chillers in the prior art to cope with accident conditions.

[0008] To achieve the above object, the present application proposes a chilled water storage system for nuclear power plants, and the chilled water storage system includes:

[0009] A refrigeration cycle, which provides a cold source for the terminal user and the chilled water storage system;

[0010] A chilled water storage cycle, which stores and uses the cold provided by the refrigeration cycle;

[0011] The refrigeration cycle obtains cooling capacity from the refrigeration cycle or the chilled water storage cycle, providing suitable plant temperature and operating conditions for the process systems of the nuclear power plant.

[0012] The refrigeration cycle and / or the chilled water storage cycle provides a cold source for the refrigeration cycle.

[0013] Furthermore, the refrigeration cycle, the chilled water storage cycle, and the refrigeration cycle all flow through the plate heat exchanger, and the refrigeration cycle and / or the chilled water storage cycle exchanges heat with the refrigeration cycle through the plate heat exchanger.

[0014] Furthermore, the refrigeration cycle includes a refrigeration unit, a chilled water discharge pump, and a chilled water storage pump. The refrigeration unit produces the first chilled water, which is pumped to the plate heat exchanger through the chilled water discharge pump for heat exchange, and then pumped back to the refrigeration unit by the chilled water storage pump to complete the refrigeration cycle.

[0015] Furthermore, the chilled water storage cycle includes a chilled water storage device and a chilled water storage pump. The excess first chilled water produced by the refrigeration unit flows into the chilled water storage device, and then is pumped back to the refrigeration unit by the chilled water storage pump as a supplement.

[0016] Furthermore, the refrigeration cycle includes a refrigeration unit, a user end, and a chilled water pump. The refrigeration unit produces the first chilled water and sends it to the user end, and then it is pumped back to the refrigeration unit by the chilled water pump to complete the refrigeration cycle.

[0017] Furthermore, the chilled water storage cycle includes a chilled water storage device and a chilled water discharge pump. The first chilled water in the chilled water storage device is pumped to the plate heat exchanger through the chilled water discharge pump for heat exchange, and then flows back to the chilled water storage device to complete the chilled water storage cycle.

[0018] Furthermore, the refrigeration cycle and the chilled water storage cycle are in parallel.

[0019] Furthermore, the refrigeration cycle is in a stopped working state.

[0020] Furthermore, the chilled water storage cycle includes a chilled water storage device and a chilled water discharge pump. The first chilled water in the chilled water storage device is pumped to the plate heat exchanger through the chilled water discharge pump for heat exchange, and then flows back to the chilled water storage device to complete the chilled water storage cycle.

[0021] Furthermore, the refrigeration cycle includes a chilled water pump and a user end. The second chilled water in the user end is pumped to the plate heat exchanger through the chilled water pump for heat exchange, and the first chilled water after heat exchange flows back to the user end to complete the refrigeration cycle.

[0022] Furthermore, the chilled water discharge pump and the chilled water pump use an SBO diesel engine as a backup power source.

[0023] Furthermore, the chilled water storage system further includes a first temperature sensor located on the return pipe of the user end to monitor the temperature of the chilled water return.

[0024] Further, the cold storage system further includes a second temperature sensor, a third temperature sensor, and a calorimeter. The second temperature sensor and the third temperature sensor are arranged in the cold storage device, and the calorimeter is located near the cold storage device.

[0025] Further, the cold storage device is provided with a low value alarm.

[0026] Further, the cold storage device is a fire fighting water tank.

[0027] Further, the cold storage device, the chilled water pump, the plate heat exchanger, and the chilled water freezer are all earthquake-resistant devices.

[0028] Based on the above technical solutions, the present application has at least the following beneficial effects:

[0029] 1. The present application designs a corresponding cold storage system for normal operating conditions and accident conditions of a nuclear power plant. When the user demand is low under normal operating conditions, the refrigeration cycle provides cooling capacity, and the remaining cooling capacity is stored in the cold storage device; when the user load demand is high, the refrigeration cycle and the cold storage cycle provide cooling capacity for the user, overcoming the problem of a single cold source in the existing chilled water system and meeting the user's load demand; under accident conditions (H1 condition or SBO condition), the cold storage device is used to replace the air-cooled earthquake-resistant unit for cooling. Through this design, the installed capacity and cost of the chilled water system can be reduced, and at the same time, it is beneficial to reduce the capacity of the SBO diesel engine.

[0030] 2. The cold storage device adopted in the present application can be effectively utilized under both normal operating conditions and accident conditions. Compared with the air-cooled chiller, it has a higher usage frequency and a lower cost. When a fire fighting water tank is used as the cold storage device, it can avoid the additional land occupation of the nuclear power plant caused by adding an extra cold storage water tank. The natural stratified water storage method for the fire fighting water tank can reduce the consumption of cooling capacity and improve the reliability of cooling for the user end.

[0031] 3. By setting temperature sensors and calorimeters, the present application can realize real-time monitoring of the cooling capacity demand of the user end and the stored cooling capacity in the cold storage device, so as to ensure that the stored cooling capacity in the cold storage device can cope with accident conditions under various circumstances and improve the safety and reliability of the cold storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The schematic diagrams of the specification attached to this application, which form a part of this application, are used to provide a further understanding of this application. The schematic embodiments and descriptions of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0033] Figure 1 is a schematic diagram of a cold storage system for a nuclear power plant according to an embodiment of this application;

[0034] Figure 2 is a schematic diagram of a cold storage system for a nuclear power plant according to another embodiment of this application;

[0035] Figure 3 A schematic diagram of a cold storage system for a nuclear power plant according to another embodiment of the present application;

[0036] Figure 4 This is a schematic diagram of a cold storage system for a nuclear power plant according to a specific embodiment of the present application.

[0037] The above drawings include the following reference numerals:

[0038] 1. Refrigeration unit; 2. First valve; 3. Second valve; 4. Chilled water pump; 5. Third valve; 6. Fourth valve; 7. Sixth valve; 8. Cold storage device; 9. Cold storage water pump; 10. Fifth valve; 11. Cooling water pump; 12. Plate heat exchanger; 13. User end; 14. First temperature sensor; 15. Second temperature sensor; 16. Third temperature sensor; 17. Calorimeter. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0041] Example

[0042] In order to solve the problems existing in the prior art, the present application proposes a cold storage system for a nuclear power plant. The cold storage system can operate under normal conditions and perform safety-related functions under accident conditions. The design of the air-cooled chilled water anti-seismic unit can be eliminated to reduce the overall installed capacity of the chilled water system, reduce the loading capacity of the SBO diesel engine and the cost of the chilled water unit.

[0043] The cold storage system includes: refrigeration cycle, cold storage cycle and freezing cycle. Among them, the refrigeration cycle is used to provide a source of cold for end users and cold storage system, the cold storage cycle is used to store and use the cold provided by the refrigeration cycle, and the freezing cycle obtains cold from the refrigeration cycle or cold storage cycle to provide the nuclear power plant with suitable plant temperature and process system operating conditions. Sufficient cold is provided to the user end through different operating modes of the refrigeration cycle, cold storage cycle and freezing cycle under different working conditions.

[0044] The following will introduce in detail the composition and operation mode of the cold storage system under normal conditions and accident conditions. Specifically, the accident condition refers to the loss of heat sink condition (H1 condition) or the whole plant power outage condition (SBO condition).

[0045] Figure 1The figure shows a schematic diagram of a chilled water storage system for a nuclear power plant in an embodiment when the user load demand is low under normal operating conditions. In this case, the first chilled water produced by the refrigeration unit 1 can meet all the load demands of the user, and the excess first chilled water can also be stored in the chilled water storage device 8.

[0046] As Figure 1 shown, under normal operating conditions when the user load demand is low, the third valve 5, the fourth valve 6, the fifth valve 10 and the sixth valve 7 are opened, so that the refrigeration unit 1, the chilled water pump 11 and the chilled water storage pump 9 form a refrigeration cycle, the chilled water storage device 8 and the chilled water storage pump 9 form a chilled water storage cycle, and the chilled water pump 4 and the user terminal 13 form a chilled water cycle. Among them, the refrigeration unit 1 is a water-cooled chiller, and the chilled water storage cycle is in parallel with the refrigeration cycle. In this case, a part of the first chilled water produced by the refrigeration unit 1 transfers the cooling capacity to the user terminal 13 through heat exchange in the refrigeration cycle via the plate heat exchanger 12, and the other part is stored in the chilled water storage device 8 through the chilled water storage cycle.

[0047] In the refrigeration cycle, the first chilled water produced by the refrigeration unit 1 passes through the fourth valve 6, is sent to the plate heat exchanger 12 by the chilled water pump 11 for heat exchange with the second chilled water output from the chilled water cycle, and the chilled water after heat exchange passes through the fifth valve 10 and is sent to the refrigeration unit 1 by the chilled water storage pump 9 for re-refrigeration to complete the refrigeration cycle.

[0048] In the chilled water storage cycle, the excess first chilled water produced by the refrigeration unit 1 flows into the chilled water storage device 8 through the fourth valve 6, and is then sent to the refrigeration unit 1 by the chilled water storage pump 9 as a supplement to complete the chilled water storage cycle.

[0049] In the chilled water cycle, the second chilled water output from the user terminal 13 passes through the sixth valve 7, is sent to the plate heat exchanger 12 by the chilled water pump 4 for heat exchange with the first chilled water in the refrigeration cycle, and the first chilled water after heat exchange flows to the user terminal 13 to complete the chilled water cycle.

[0050] It should be understood that the temperature of the second chilled water after heat exchange by the user terminal in this application is higher than the temperature of the first chilled water produced by the refrigeration unit.

[0051] Based Figure 1 on the composition and operation modes of the refrigeration cycle, the chilled water storage cycle and the chilled water cycle of the chilled water storage system in the shown embodiment, the first chilled water produced by the refrigeration unit in the refrigeration cycle can meet the cooling capacity under normal operating conditions when the user load demand is low, and at the same time, the remaining first chilled water can be stored in the chilled water storage device for standby, providing diversified cold sources for the nuclear power plant.

[0052] Figure 2The figure shows a schematic diagram of a chilled water storage system for a nuclear power plant in an embodiment when the user load demand is high under normal operating conditions. In this case, the first chilled water produced by the refrigeration unit 1 cannot meet all the load demands of the user, and the chilled water storage device 8 is used to assist in cooling.

[0053] As Figure 2 shown, under normal operating conditions when the user load demand is high, the first valve 2, the second valve 3, the fifth valve 10 and the sixth valve 7 are opened, so that the refrigeration unit 1, the user terminal 13, and the chilled water pump 4 form a refrigeration cycle, the chilled water storage device 8 and the chilled water discharge pump 11 form a chilled water storage cycle, and the chilled water pump 4 and the user terminal 13 form a chilled water cycle. Among them, the refrigeration unit 1 is a water-cooled chiller. In this case, all the first chilled water produced by the refrigeration unit 1 flows to the user terminal 13. At the same time, the first chilled water stored in the chilled water storage device 8 transfers its cold quantity to the user terminal 13 after heat exchange with the chilled water cycle through the plate heat exchanger 12.

[0054] In the refrigeration cycle, the first chilled water produced by the refrigeration unit 1 is directly sent to the user terminal 13 through the second valve 3. The second chilled water output from the user terminal 13 passes through the first valve 2 and is sent to the refrigeration unit 1 by the chilled water pump 4 for re-refrigeration, completing the refrigeration cycle.

[0055] In the chilled water storage cycle, the first chilled water stored in the chilled water storage device 8 is sent to the plate heat exchanger 12 by the chilled water discharge pump 11 for heat exchange with the second chilled water output from the chilled water cycle. The chilled water after heat exchange returns to the chilled water storage device 8 through the fifth valve 10, completing the chilled water storage cycle.

[0056] In the chilled water cycle, the second chilled water output from the user terminal 13 passes through the sixth valve 7 and is sent to the plate heat exchanger 12 by the chilled water pump 4 for heat exchange with the first chilled water in the chilled water storage cycle. The first chilled water after heat exchange flows back to the user terminal 13, completing the chilled water cycle.

[0057] Based on Figure 2 the composition and operation mode of the refrigeration cycle, chilled water storage cycle, and chilled water cycle of the chilled water storage system in the shown embodiment, the first chilled water produced by the refrigeration unit in the refrigeration cycle and the first chilled water stored in the chilled water storage device jointly provide cold quantity for the user terminal, which can overcome the problem of a single cold source in the traditional chilled water storage system, and the chilled water storage cost is relatively low.

[0058] Figure 3 The figure shows a schematic diagram of a chilled water storage system for a nuclear power plant in an embodiment under accident conditions. In this environment, the water-cooled chiller in the refrigeration cycle fails and is in a stopped working state. The air-cooled seismic-resistant unit is cancelled, and the first chilled water stored in the chilled water storage device 8 is used to ensure the cold quantity demand of important users.

[0059] As Figure 3As shown, in the accident condition (H1 condition or SBO condition), the fifth valve 10 and the sixth valve 7 are opened, so that the cold storage device 8 and the chilled water pump 11 form a cold storage cycle, and the chilled water pump 4 and the user end 13 form a chilled water cycle. In this case, the first chilled water stored in the cold storage device 8 transfers the cooling capacity to the user end 13 after heat exchange with the chilled water cycle through the plate heat exchanger 12.

[0060] In the cold storage cycle, the first chilled water in the cold storage device 8 is sent to the plate heat exchanger 12 by the chilled water pump 11 for heat exchange with the second chilled water output from the chilled water cycle, and the chilled water after heat exchange flows back to the cold storage device 8 to complete the cold storage cycle.

[0061] In the chilled water cycle, the second chilled water output from the user end 13 passes through the sixth valve 7 and is sent to the plate heat exchanger 12 by the chilled water pump 4 for heat exchange with the first chilled water in the cold storage cycle, and the first chilled water after heat exchange flows back to the user end 13 to complete the chilled water cycle.

[0062] Based on Figure 3 In the embodiment shown, the composition and operation mode of the cold storage cycle and the chilled water cycle of the cold storage system, the cold storage device 8 is used to replace the air-cooled seismic unit in the prior art, and the first chilled water stored in the cold storage device 8 ensures the cooling capacity demand of important users, which can reduce the installed capacity and cost of the chilled water system and is beneficial to reducing the capacity of the SBO diesel engine.

[0063] The above Figures 1 to 3 The cold storage system shown can not only meet the cooling capacity demand under normal conditions of the nuclear power plant, but also take into account the cooling capacity demand of important users under accident conditions (H1 condition or SBO condition), and can cancel the air-cooled seismic unit set for accident conditions, which is beneficial to improving the overall economy of the nuclear power plant.

[0064] In a specific embodiment of the present application, the cold storage device 8 is a fire pool. By making full use of the existing fire pool for cold storage, it is avoided that the additional construction of a cold storage pool causes the shortage of land for the nuclear power plant. In this embodiment, the natural stratification water storage method is adopted for the fire pool, and the excess first chilled water produced by the refrigeration unit 1 is stably introduced into the fire pool. Relying on the natural circulation of the density difference, the water temperature of the chilled water in the fire pool is stratified up and down, with the first chilled water at the lower layer and the second chilled water at the upper layer. The natural stratification water storage method can reduce the consumption of cooling capacity and improve the reliability of supplying cold to the user end.

[0065] Generally speaking, the refrigeration unit 1, the chilled water storage pump 9, the chilled water pump 11, and the chilled water pump 4 in the present application use an emergency diesel engine as a backup power source. In a specific embodiment of the present application, the chilled water pump 11 and the chilled water pump 4 use an SBO diesel engine as a backup power source.

[0066] In another specific embodiment of the present application, asFigure 4 As shown in the figure, the cold storage system further includes a first temperature sensor 14, a second temperature sensor 15, a third temperature sensor 16 and a calorimeter 17.

[0067] Among them, the first temperature sensor 14 is located on the return water pipe of the user end 13 and is used to monitor the return water temperature of the chilled water. When the return water temperature is lower than the set value, it means that the cooling load of the user end 13 is relatively low, and the first chilled water produced only by the refrigeration unit 1 can meet the cooling demand of the user end 13. When the return water temperature is higher than the set value, it means that the cooling load of the user end 13 is relatively high, and the refrigeration unit 1 needs to cooperate with the cold storage device 8 for combined cooling to meet the cooling demand of the user end 13.

[0068] The second temperature sensor 15 and the third temperature sensor 16 are arranged in the cold storage device 8, and the calorimeter 17 is located near the cold storage device 8. Specifically, the second temperature sensor 15 is used to monitor the temperature of the second chilled water in the cold storage device 8, and the third temperature sensor 16 is used to monitor the temperature of the first chilled water in the cold storage device 8. By cooperating the second temperature sensor 15 and the third temperature sensor 16 with the calorimeter 17, the real-time monitoring of the cold storage capacity in the cold storage device can be realized.

[0069] In another specific embodiment of the present application, the cold storage device 8 is provided with a low value alarm. When it is monitored that the cold storage capacity in the cold storage device 8 is about to be lower than the cooling demand of important users under accident conditions, the cold storage device 8 stops supplying cooling. By setting a low value alarm in the cold storage device, it can be ensured that the cold storage capacity of the cold storage device can cope with accident conditions at any time, improving the safety and reliability of the cold storage system.

[0070] Furthermore, the cold storage device 8, the chilled water pump 11, the plate heat exchanger 12 and the chilled water pump 4 are all anti-seismic devices, which can meet the anti-seismic requirements of nuclear power plants and further improve the safety and reliability of the cold storage system.

[0071] In summary, from the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0072] 1. The present application designs a corresponding cold storage system for normal conditions and accident conditions of nuclear power plants. When the user demand is relatively low under normal conditions, the cooling capacity is provided through the refrigeration cycle, and the remaining cooling capacity is stored in the cold storage device; when the user load demand is relatively high, the cooling capacity is provided for the user through the refrigeration cycle and the cold storage cycle, overcoming the problem of single cold source in the existing chilled water system and meeting the load demand of the user; under accident conditions (H1 condition or SBO condition), the cold storage device is used to replace the air-cooled anti-seismic unit for cooling. Through this design, the installed capacity and cost of the chilled water system can be reduced, and at the same time, it is beneficial to reduce the capacity of the SBO diesel engine.

[0073] 2. The cold storage device adopted in this application can be effectively utilized under normal and accident conditions. Compared with air-cooled chillers, it has a higher usage frequency and a lower cost. When using a fire pool as the cold storage device, it can avoid the additional land occupation caused by adding a cold storage water tank in the nuclear power plant. The natural stratification water storage method for the fire pool can reduce the cold energy consumption and improve the reliability of cooling supply to the user side.

[0074] 3. By setting temperature sensors and calorimeters, this application can achieve real-time monitoring of the cold energy demand of the user side and the cold storage capacity in the cold storage device, so as to ensure that the cold storage capacity in the cold storage device can cope with accident conditions at any time and improve the safety and reliability of the cold storage system.

[0075] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

[0076] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0077] It should be noted that in the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

Claims

1. A cold storage system for a nuclear power plant, the cold storage system comprising: A refrigeration cycle that provides a cold source for end-users and the cold storage system; A cold storage cycle that stores and uses the cold energy provided by the refrigeration cycle; A freezing cycle that obtains cold energy from the refrigeration cycle or the cold storage cycle to provide suitable plant temperature and operating conditions for the process systems of the nuclear power plant; characterized in that, The refrigeration cycle and / or the cold storage cycle provides a cold source for the freezing cycle; The refrigeration cycle, the cold storage cycle and the freezing cycle all flow through a plate heat exchanger (12), and the refrigeration cycle and / or the cold storage cycle exchanges heat with the freezing cycle through the plate heat exchanger (12); The refrigeration cycle is in parallel with the cold storage cycle.

2. The cold storage system according to claim 1, wherein The refrigeration cycle includes a refrigeration unit (1), a chilled water pump (11), and a cold storage water pump (9). The refrigeration unit (1) produces first chilled water, which is pumped to the plate heat exchanger (12) through the chilled water pump (11) for heat exchange, and then pumped back to the refrigeration unit (1) through the cold storage water pump (9) to complete the refrigeration cycle.

3. The cold storage system according to claim 2, wherein The cold storage cycle includes a cold storage device (8) and the cold storage water pump (9). The excess first chilled water produced by the refrigeration unit (1) flows into the cold storage device (8), and then is pumped back to the refrigeration unit (1) through the cold storage water pump (9) as a supplement.

4. The cold storage system according to claim 1, characterized in that, The refrigeration cycle includes a refrigeration unit (1), a user end (13), and a chilled water pump (4). The refrigeration unit (1) produces first chilled water and sends it to the user end (13), and then is pumped back to the refrigeration unit (1) through the chilled water pump (4) to complete the refrigeration cycle.

5. The cold storage system according to claim 4, characterized in that, The cold storage cycle includes a cold storage device (8) and a chilled water pump (11). The first chilled water in the cold storage device (8) is pumped to the plate heat exchanger (12) through the chilled water pump (11) for heat exchange, and then flows back to the cold storage device (8) to complete the cold storage cycle.

6. The cold storage system according to claim 1, wherein The refrigeration cycle is in a stopped working state.

7. The cold storage system according to claim 6, characterized in that, The cold storage cycle includes a cold storage device (8) and a chilled water pump (11). The first chilled water in the cold storage device (8) is pumped to the plate heat exchanger (12) through the chilled water pump (11) for heat exchange, and then flows back to the cold storage device (8) to complete the cold storage cycle.

8. The cold storage system according to claim 3, 5 or 7, characterized in that, The freezing cycle includes a chilled water pump (4) and a user end (13). The second chilled water in the user end (13) is pumped to the plate heat exchanger (12) through the chilled water pump (4) for heat exchange, and the first chilled water after heat exchange flows back to the user end (13) to complete the freezing cycle.

9. The cold storage system according to claim 8, characterized in that, The chilled water pump (11) and the chilled water pump (4) use an SBO diesel engine as a backup power source.

10. The cold storage system according to claim 8, characterized in that, The cold storage system further includes a first temperature sensor (14), and the first temperature sensor (14) is located on the return pipe of the user end (13) to monitor the temperature of the chilled water return.

11. The cold storage system according to claim 10, characterized in that, The cold storage system further includes a second temperature sensor (15), a third temperature sensor (16), and a calorimeter (17). The second temperature sensor (15) and the third temperature sensor (16) are arranged in the cold storage device (8), and the calorimeter (17) is located near the cold storage device (8).

12. The system according to claim 8, wherein, The cold storage device (8) is provided with a low-value alarm.

13. The cold storage system according to claim 8, characterized in that, The cold storage device (8) is a fire fighting water tank.

14. The system according to claim 8, wherein The cold storage device (8), the cold water discharge pump (11), the plate heat exchanger (12), and the chilled water pump (4) are all earthquake-resistant devices.

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