A method and system for combined cooling and heating based on nuclear energy combined with heat pumps

Abstract

The application discloses a cold and heat combined supply method based on nuclear energy combined with a heat pump, which comprises the following steps: in the electricity low valley period of the heating season, high-temperature heating medium is prepared by heat exchange using steam extraction of a steam turbine in a nuclear power plant to perform heating; and in the electricity low valley period of the cooling season, low-temperature cooling medium is prepared by a heat pump unit using nuclear power valley electricity to perform cooling. The application further discloses a cold and heat combined supply system based on nuclear energy combined with a heat pump. The application can fully utilize nuclear energy, realizes heating and cooling, and improves energy utilization efficiency.

Description

Technical Field

[0001] This invention relates to the field of comprehensive utilization of nuclear energy, specifically to a method and system for combined cooling and heating based on nuclear energy combined with a heat pump. Background Technology

[0002] Nuclear energy, as a clean energy source that can replace fossil fuels on a large scale, is mainly used for power generation. In recent years, with the maturity of nuclear power technology, nuclear energy has also been used for heating, industrial steam supply, seawater desalination, hydrogen production, and other fields.

[0003] Currently, nuclear heating mainly utilizes steam extracted from nuclear power plant turbines to heat nearby buildings during winter. However, due to high electricity loads during peak hours (such as daytime working hours), using steam extracted from nuclear power plant turbines for heating during the day reduces power generation, leading to insufficient power generation or insufficient heating. Furthermore, during the summer daytime, public buildings have a greater demand for cooling, while the demand is relatively lower during off-peak hours (such as nighttime), resulting in significant electricity waste at night. In addition, because the temperature of thermal wastewater from nuclear power plants is higher than that of seawater, direct discharge into the ocean can negatively impact the surrounding marine ecosystem. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for combined heating and cooling based on nuclear energy and heat pump, which can make full use of nuclear energy to achieve heating and cooling, improve energy utilization efficiency, save energy, and achieve comprehensive utilization of nuclear energy.

[0005] According to one aspect of the present invention, a method for combined cooling and heating based on nuclear energy and a heat pump is provided, the technical solution of which is as follows:

[0006] A combined heating and cooling method based on nuclear energy and heat pumps includes: during the off-peak electricity consumption period of the heating season, steam is extracted from the turbines of the nuclear power plant and heat is exchanged to produce a high-temperature heating medium for heating; during the off-peak electricity consumption period of the cooling season, off-peak electricity from the nuclear power plant is used to produce a low-temperature cooling medium through a heat pump unit for cooling.

[0007] Preferably, the method further includes:

[0008] During the off-peak electricity demand period of the heating season, steam is extracted from the turbines of nuclear power plants to produce a high-temperature circulating medium through heat exchange. This medium is then further heated by phase change heat storage materials. During the peak electricity demand period of the heating season, phase change heat storage materials are used to produce a high-temperature heating medium for heating.

[0009] Preferably, the phase change temperature of the phase change thermal storage material matches the temperature of the high-temperature circulating medium.

[0010] Preferably, the method further includes:

[0011] During the heating season, the wastewater from nuclear power plants is used as a heat source, and high-temperature heating medium is produced by heat pump units for supplementary heating.

[0012] Preferably, the method further includes:

[0013] During the off-peak electricity demand period of the cooling season, the low-temperature cooling medium produced by phase change cold storage materials and heat pump units is further heat-exchanged for cold storage. During the peak electricity demand period of the cooling season, the low-temperature cooling medium produced by phase change cold storage materials is used for cooling, thereby achieving peak shaving and valley filling.

[0014] Preferably, the phase change temperature of the phase change cold storage material described in this method matches the temperature of the low-temperature cooling medium.

[0015] According to another aspect of the present invention, a combined cooling and heating system based on nuclear energy and a heat pump is provided, the technical solution of which is as follows:

[0016] A combined heating and cooling system based on nuclear energy and a heat pump includes a first heat exchanger, a second heat exchanger, a heat pump unit, and heating and cooling pipelines, wherein:

[0017] The first heat exchanger is connected to the steam turbine in the nuclear power plant, the second heat exchanger is connected to the first heat exchanger through a circulation pipeline, the heating pipeline is connected to the second heat exchanger, a circulation medium flows in the circulation pipeline, and a heating medium flows in the heating pipeline. The first heat exchanger is used to introduce steam extracted from the steam turbine and exchange heat with the circulation medium, so that the circulation medium absorbs the heat from the steam extracted from the steam turbine and rises in temperature to obtain a high-temperature circulation medium. The second heat exchanger is used to introduce the high-temperature circulation medium and exchange heat with the heating medium in the heating pipeline to heat the heating medium and achieve heating.

[0018] The heat pump unit is connected to the warm wastewater system and power supply system of the nuclear power plant, as well as the cooling pipeline. The cooling pipeline contains a cooling medium. The heat pump unit is used to utilize off-peak electricity from the nuclear power plant to cool the cooling medium in the cooling pipeline using the warm wastewater as a cold source, so as to obtain a low-temperature cooling medium and achieve cooling.

[0019] Preferably, the system further includes a phase change heat storage tank, which is connected to the first heat exchanger through the circulation pipeline. The phase change heat storage tank is equipped with phase change heat storage material. The phase change heat storage tank is used to receive the high-temperature circulating medium obtained by heat exchange in the first heat exchanger, and to further exchange heat with the high-temperature circulating medium using the phase change heat storage material to achieve heat storage.

[0020] The phase change heat storage tank is also connected to the heating pipeline and is used to heat the heating medium in the heating pipeline using the phase change heat storage material during peak electricity consumption periods to produce a high-temperature heating medium, thereby achieving peak shaving and valley filling.

[0021] Preferably, the heat pump unit includes a compressor, a first evaporator / condenser, a throttling valve, and a second evaporator / condenser. The compressor, the first evaporator / condenser, the throttling valve, and the second evaporator / condenser are connected in sequence via pipes to form a closed-loop circuit. Refrigerant flows through the closed-loop circuit. The first evaporator / condenser is connected to the drain pipe, and the second evaporator / condenser is connected to both the heating pipeline and the heating pipe. A four-way reversing valve is installed on the pipe between the compressor and the first and second evaporators / condensers. The four-way reversing valve is used to control the compressor outlet to switch to... The heat pump unit is connected to the first evaporator / condenser and controls the compressor inlet to switch to the second evaporator / condenser to switch the heat pump unit to the cooling mode to obtain a low-temperature cooling medium for cooling. It is also used to control the compressor inlet to switch to the first evaporator / condenser and control the compressor outlet to switch to the second evaporator / condenser. The heat pump unit is also used to heat the refrigerant in the first evaporator / condenser using warm water as a heat source, and then compress the heated refrigerant through the compressor before passing it into the second evaporator / condenser for heat exchange to heat the heating medium in the heating pipeline to obtain a high-temperature heating medium for supplementary heating.

[0022] Preferably, the system also includes a phase change cold storage tank, which is connected to the second evaporator / condenser. The phase change cold storage tank is equipped with phase change cold storage material. The phase change cold storage tank is used to receive the low-temperature cooling medium produced by the heat pump unit and to further exchange heat with the low-temperature freezing medium using the phase change cold storage material to achieve cold storage.

[0023] The phase change cold storage tank is also connected to the cooling pipeline and is used to exchange heat between the phase change cold storage material and the cooling medium in the cooling pipeline to produce a low-temperature cooling medium. During peak electricity consumption periods, the low-temperature cooling medium produced by the cold energy stored in the phase change cold storage material is used to supply all or part of the cooling load, thereby achieving peak shaving and valley filling.

[0024] Preferably, the system also includes a monitoring and control device, which is connected to the compressor and the four-way reversing valve in the heat pump unit, respectively, to monitor the ambient temperature and control the four-way reversing valve to switch the heat pump unit to the cooling mode to produce a low-temperature cooling medium for cooling or to the heating mode to produce a high-temperature heating medium for supplemental heating.

[0025] The combined cooling and heating method and system based on nuclear energy and heat pumps of the present invention have the following beneficial effects:

[0026] (1) Nuclear energy can be fully utilized for heating and cooling, realizing combined heating and cooling, improving energy efficiency, saving energy, and achieving comprehensive utilization of nuclear energy. For heating, it can alleviate the smog and environmental pollution caused by using fossil fuels for heating. For cooling, it can reduce the impact of direct discharge of wastewater into the sea on the ecology. It is low-carbon, clean, and environmentally friendly.

[0027] (2) It can also extract steam from the turbine for heating and heat storage during the low electricity consumption period in the heating season (winter). The stored heat can be used for heating during the peak electricity consumption period. This can make full use of nuclear energy and alleviate the problem of insufficient energy supply when nuclear power plants supply both electricity and heating during the peak electricity consumption period. This can achieve peak shaving and valley filling in winter, save energy, and achieve comprehensive utilization of nuclear energy.

[0028] (3) It can also monitor the ambient temperature in real time and determine the heat load / cooling load demand. When the heat storage / cooling storage is insufficient during the off-peak electricity hours in cold / hot weather, the heat pump unit can be turned on to supplement the heating / cooling by running the heating mode / cooling mode.

[0029] (4) During the off-peak hours of the cooling season (summer), the cooling mode of the heat pump unit can be turned on to use the off-peak electricity of the nuclear power plant for cooling and to store the cold energy for use during the peak hours of electricity consumption. This reduces the peak electricity load and achieves peak shaving and valley filling in summer, avoiding problems such as insufficient power generation or heating during peak hours and power waste during off-peak hours, thus achieving the goal of comprehensive utilization of nuclear energy and energy conservation. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a combined cooling and heating system based on nuclear energy and a heat pump, as described in an embodiment of the present invention.

[0031] In the diagram: 1-Reactor; 2-Steam generator; 3-Steam turbine; 4-Generator; 5-Condenser; 6-First heat exchanger; 7-Second heat exchanger; 8-Phase change heat storage tank; 9-Compressor; 10-Four-way reversing valve; 11-First evaporator / condenser; 12-Throttle valve; 13-Second evaporator / condenser; 14-Phase change cold storage tank; 15-First control valve; 16-Second control valve; 17-Fifth control valve; 18-Fourth control valve; 19-Third control valve; 20-Monitoring and control device; 21-Indoor heat exchanger; 22-Extraction steam pipeline. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0033] In the description of this invention, it should be noted that the terms "above" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience and simplification of the description and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "setting," "installation," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Example 1

[0037] like Figure 1 As shown, this embodiment discloses a combined cooling and heating method based on nuclear energy combined with a heat pump, which includes:

[0038] During the off-peak electricity demand period of the heating season, steam is extracted from the turbines in nuclear power plants and heat is exchanged to produce a high-temperature heating medium for heating.

[0039] During off-peak electricity demand periods in the cooling season, the off-peak electricity from the nuclear power plant is used to produce a low-temperature cooling medium through heat pump units for cooling.

[0040] Specifically, the heating and cooling in this embodiment mainly refer to heating and cooling for buildings such as schools, commercial buildings, and residences near the nuclear power plant. Since the electricity load is high during the day and low at night, heating is achieved by using steam extracted from the nuclear power plant turbine to produce a high-temperature heating medium during off-peak hours (such as nighttime) in the heating season, thus fully utilizing nuclear energy. Similarly, cooling is achieved by using off-peak electricity from the nuclear power plant to produce a cooling medium during off-peak hours in the cooling season, avoiding electricity waste during off-peak hours and improving energy efficiency.

[0041] It should be noted that the method in this embodiment also includes: during the cooling season, using the warm wastewater from the nuclear power plant as a cold source to directly exchange heat with the cooling medium to obtain a low-temperature cooling medium for cooling, or using the warm wastewater from the nuclear power plant as a cold source and indirectly exchanging heat with the cooling medium through a heat pump unit to obtain a low-temperature cooling medium for cooling. This cooling method is more suitable for situations where the cooling demand is not very high.

[0042] In some embodiments, the method further includes:

[0043] During the off-peak electricity demand period of the heating season, steam is extracted from the turbines of nuclear power plants to produce a high-temperature circulating medium through heat exchange. This medium is then further heated by phase change heat storage materials. During the peak electricity demand period of the heating season, phase change heat storage materials are used to produce a high-temperature heating medium for heating.

[0044] In this embodiment, the high-temperature circulating medium can be water, more specifically, high-temperature water from a nuclear power plant. The phase change temperature of the phase change thermal storage material matches the temperature of the high-temperature circulating medium, and can specifically be paraffin wax, hexadecanoic acid, tetradecanoic acid, etc.

[0045] Phase change thermal storage tanks can store some of the heat extracted from steam turbines in nuclear power plants during off-peak hours for use in heating during peak hours.

[0046] In some embodiments, the method further includes:

[0047] During the heating season, based on real-time monitoring of the building's heat load demand and ambient temperature, the wastewater from the nuclear power plant is used as a heat source, and a high-temperature heating medium is produced by a heat pump unit for supplementary heating.

[0048] Specifically, when insufficient heat load demand is detected and / or the ambient temperature is lower than the preset temperature threshold, the heat pump unit is started to use warm wastewater as a low-temperature heat source to produce a high-temperature heating medium for supplementary heating; otherwise, the heat pump unit is shut down.

[0049] In some embodiments, the method further includes:

[0050] During the off-peak electricity demand period of the cooling season, the low-temperature cooling medium produced by phase change cold storage materials and heat pump units is further heat-exchanged for cold storage. During the peak electricity demand period of the cooling season, the low-temperature cooling medium produced by phase change cold storage materials is used for cooling.

[0051] The phase change temperature of the phase change cold storage material is matched with the temperature of the low-temperature cooling medium, which can be a saline hydrate, water, etc.

[0052] Phase change cold storage tanks can store the cold energy of low-temperature cooling media generated from off-peak electricity at nuclear power plants during off-peak hours, and use it for cooling during peak hours, thus achieving the effect of peak shaving and valley filling.

[0053] The beneficial effects of the combined cooling and heating method based on nuclear energy and heat pumps in this embodiment are as follows:

[0054] (1) Nuclear energy can be fully utilized for heating and cooling, realizing combined heating and cooling, improving energy efficiency, saving energy, and achieving comprehensive utilization of nuclear energy. For heating, it can alleviate the smog and environmental pollution caused by using fossil fuels for heating. For cooling, it can reduce the impact of direct discharge of wastewater into the sea on the ecology. It is low-carbon, clean, and environmentally friendly.

[0055] (2) It can also extract steam from the turbine for heating and heat storage during the off-peak hours of the heating season (such as winter). The stored heat can be used for heating during the peak hours of electricity consumption. This can make full use of nuclear energy and alleviate the problem of insufficient energy supply when nuclear power plants supply both electricity and heating during peak hours. This can achieve peak shaving and valley filling in winter, save energy, and achieve comprehensive utilization of nuclear energy.

[0056] (3) It can also monitor the ambient temperature in real time and determine the heat load / cooling load demand. When the heat storage / cooling storage is insufficient during the off-peak electricity hours in cold / hot weather, the heat pump unit can be turned on to supplement the heating / cooling by running the heating mode / cooling mode.

[0057] (4) During the off-peak hours of the cooling season (such as summer), the cooling mode of the heat pump unit can be turned on to use the off-peak electricity of the nuclear power plant for cooling and to store the cold energy for use during the peak hours of electricity consumption. This reduces the peak electricity load and achieves peak shaving and valley filling in summer, avoiding problems such as insufficient power generation or heating during peak hours and power waste during off-peak hours, thus achieving the goal of comprehensive utilization of nuclear energy and energy conservation.

[0058] Example 2

[0059] like Figure 1 As shown, this embodiment discloses a combined heating and cooling system based on nuclear energy and a heat pump, used in the method described in Embodiment 1. It includes a first heat exchanger 6, a second heat exchanger 7, a heat pump unit, and heating and cooling pipelines, wherein:

[0060] The first heat exchanger 6 is connected to the steam extraction port of the steam turbine 3 in the nuclear power plant through the steam extraction pipeline 22. The second heat exchanger 7 is connected to the first heat exchanger 6 through a circulation pipeline. The heating pipeline is connected to the second heat exchanger 7 through a first pipeline. The circulation pipeline contains a circulating medium, and the heating pipeline contains a heating medium. The first heat exchanger 6 is used to introduce steam extracted from the steam turbine and exchange heat with the circulating medium, so that the circulating medium absorbs the heat from the steam extracted from the steam turbine and rises in temperature to obtain a high-temperature circulating medium. The second heat exchanger 7 is used to introduce the high-temperature circulating medium and exchange heat with the heating medium in the heating pipeline to heat the heating medium. The heated heating medium is then transported to schools, commercial buildings, residences and other buildings through the heating pipeline for heat exchange to achieve heating.

[0061] The heat pump unit is connected to the warm wastewater system, power supply system, and cooling pipelines in the nuclear power plant. Cooling medium flows in the cooling pipelines. The heat pump unit is used to cool the cooling medium in the cooling pipelines by using off-peak electricity from the nuclear power plant through the power supply system and warm wastewater as a cold source, thereby achieving cooling.

[0062] Specifically, such as Figure 1 As shown, in a nuclear power plant, steam generator 2 absorbs the heat generated by reactor 1, and the generated steam enters turbine 3 to do work, which powers generator 4 to generate electricity. The steam discharged after doing work is called turbine exhaust steam. The warm wastewater system includes condenser 5, inlet pipe, and drain pipe. Condenser 5 is connected to turbine 3, inlet pipe, and drain pipe respectively, and is used to introduce turbine exhaust steam and exchange heat with water (such as seawater) introduced through the inlet pipe to produce warm wastewater. The drain pipe is connected to a heat pump unit, and the warm wastewater is introduced through the drain pipe into the heat pump unit to cool the cooling medium in the cooling pipeline. The steam turbine 3 is equipped with an extraction port, preferably located on the intermediate stage of the turbine. The steam extracted from the extraction port is the turbine extraction steam. The first heat exchanger 6 directly receives the turbine extraction steam from the turbine 3 through the extraction steam pipeline to produce a high-temperature circulating medium. After heat exchange, the turbine extraction steam condenses into water. The first heat exchanger 6 is also connected to the steam generator 2 to return the condensed water to the steam generator 2 for recycling. The circulating medium can specifically be water, more precisely, high-temperature water from a nuclear power plant. Both the heating and cooling pipelines are connected to the indoor heat exchanger 21. The heat from the heating medium in the heating pipeline is transferred to the building through the indoor heat exchanger 21 to provide heating, and the cold energy from the cooling medium in the cooling pipeline is transferred to the building through the indoor heat exchanger 21 to provide cooling.

[0063] In some embodiments, the system further includes a phase change heat storage tank 8, which is connected to the first heat exchanger 6 via the circulation pipeline. The phase change heat storage tank 8 contains phase change heat storage material and is used to receive the high-temperature circulating medium obtained from heat exchange in the first heat exchanger. It further exchanges heat with the high-temperature circulating medium using the phase change heat storage material to achieve heat storage. The phase change heat storage tank 8 is also connected to the heating pipeline via a second pipeline and is used to heat the heating medium in the heating pipeline using the phase change heat storage material to obtain a high-temperature heating medium, thereby achieving peak shaving and valley filling in winter.

[0064] Specifically, a second control valve 16 is installed on the second pipeline, and a first control valve 15 is installed on the first pipeline. During off-peak electricity consumption periods in the heating season, the second control valve 16 is closed, and the first control valve 15 is opened. Steam is extracted from the turbine 3 through the extraction steam pipeline 22 and enters the first heat exchanger 6 to produce a high-temperature circulating medium. Part of the high-temperature circulating medium flows into the second heat exchanger 7 to produce a high-temperature heating medium, which is then sent to various buildings for heating. At the same time, another part of the high-temperature circulating medium flows into the phase change heat storage tank 8 to exchange heat with the phase change heat storage material. The phase change heat storage material absorbs heat and changes from a solid to a liquid state, thereby storing the heat. The circulating medium after heat exchange returns to the first heat exchanger 6 for another heat exchange and temperature increase to produce a high-temperature circulating medium, thus achieving circulation. During peak electricity consumption periods in the heating season, steam is no longer extracted from turbine 3. The nuclear power plant only performs power generation cycle, and the second control valve 16 is opened and the first control valve 15 is closed, so that the heating medium flows through the phase change heat storage tank 8 and exchanges heat with the phase change heat storage material to obtain a high-temperature heating medium. That is, the building heating heat during peak electricity consumption periods is provided by the heat stored in the phase change heat storage tank 8 during off-peak electricity consumption periods.

[0065] The phase change temperature of the phase change heat storage material is matched with the temperature of the high-temperature circulating medium, and can specifically be paraffin, hexadecanoic acid, tetradecanoic acid, etc.

[0066] Both the first control valve 15 and the second control valve 16 are preferably solenoid valves.

[0067] The phase change heat storage tank 8 can store the heat extracted from the steam turbines in nuclear power plants during off-peak hours and use it for heating during peak hours, thus achieving the effect of peak shaving and valley filling.

[0068] In some embodiments, the heat pump unit includes a compressor 9, a first evaporator / condenser 11, a throttle valve 12, and a second evaporator / condenser 13. The compressor 9, the first evaporator / condenser 11, the throttle valve 12, and the second evaporator / condenser are connected in sequence via pipes to form a closed loop. Refrigerant flows through the closed loop. The first evaporator / condenser 11 is connected to a drain pipe in a warm water drainage system. A third control valve 19 is installed on the drain pipe. When the third control valve 19 is closed, warm water flows into the first evaporator / condenser 11. The second evaporator / condenser 13 is connected to both heating and cooling pipelines for supplying heating or cooling media. A four-way reversing valve is installed on the pipeline between the compressor 9 and the first evaporator / condenser 11 and the second evaporator / condenser 13. 10. The four-way reversing valve 10 is used to control the outlet (exhaust port) of the compressor 9 to be connected to the first evaporator / condenser 11 and to control the inlet (air inlet) of the compressor 9 to be connected to the second evaporator / condenser 13, so that the heat pump unit switches to the cooling mode to obtain a low-temperature cooling medium for cooling. It is also used to control the inlet of the compressor 9 to be connected to the first evaporator / condenser 11 and to control the outlet of the compressor 9 to be connected to the second evaporator / condenser 13, so that the heat pump unit switches to the heating mode. The heat pump unit is also used to heat the refrigerant introduced into the first evaporator / condenser using warm water as a heat source. The heated refrigerant is compressed by the compressor 9 and then introduced into the second evaporator / condenser 13 to heat the heating medium in the heating pipeline, so as to obtain a high-temperature heating medium for supplementary heating.

[0069] Specifically, when the heat pump unit is in heating mode, the four-way reversing valve 10 connects the outlet of the compressor 9 to the second evaporator / condenser 13 and the inlet of the compressor 9 to the first evaporator / condenser 11. The solenoid valve 19 is closed, and warm water flows into the first evaporator / condenser 11. The refrigerant absorbs the heat from the warm water in the first evaporator / condenser 11. After being compressed by the compressor 9, it exchanges heat with the heating medium at the second evaporator / condenser 13. The refrigerant condenses and releases heat, while the heating medium absorbs heat and rises in temperature. The heated heating medium is then sent to the building for heating. After condensation, the refrigerant is depressurized by the throttle valve 12 and re-enters the first evaporator / condenser 11 to absorb heat from the warm water, thus achieving a cycle.

[0070] When the heat pump unit is in cooling mode, the four-way reversing valve 10 connects the inlet of the compressor 9 to the second evaporator / condenser 13 and the outlet of the compressor 9 to the first evaporator / condenser 11. Warm water flows into the first evaporator / condenser 11 as the cold source of the heat pump unit and exchanges heat with the compressed high-temperature and high-pressure refrigerant. The refrigerant releases heat and cools down. Then, it passes through the throttle valve 12 to reduce the pressure and enters the second evaporator / condenser 13 to exchange heat with the cooling medium, absorbing the heat of the heating medium to produce a low-temperature cooling medium. The refrigerant after heat exchange enters the compressor 9 again, is compressed, and then enters the first evaporator / condenser 11 again to exchange heat with the warm water and release heat, thus realizing the cycle.

[0071] It should be noted that cooling and heating pipelines can share the same set of pipelines. In this case, the heating and cooling mediums are the same, and specifically, it can be water. When the heat pump unit is in heating mode, the pipeline is used as a heating pipeline; when the heat pump unit is in cooling mode, the pipeline is used as a cooling pipeline.

[0072] In this embodiment, the third control valve 19 is preferably a solenoid valve.

[0073] In some embodiments, the system further includes a phase change cold storage tank 14, which is connected to a second evaporator / condenser 13. The phase change cold storage tank 14 contains a phase change cold storage material and is used to receive the low-temperature cooling medium produced by the heat pump unit. The phase change cold storage material is used to further exchange heat with the low-temperature heating medium to achieve cold storage. The cooled medium after heat exchange is returned to the second evaporator / condenser 13. The phase change cold storage tank 14 is also connected to the cooling pipeline through a third pipeline and is also used to exchange heat with the cooling medium in the cooling pipeline using the phase change cold storage material to produce a low-temperature cooling medium. During peak electricity consumption periods, the low-temperature cooling medium produced by utilizing the cold energy stored in the phase change cold storage material is used to supply all or part of the cooling load, thereby achieving peak shaving and valley filling in summer.

[0074] Specifically, a fourth control valve 18 is installed on the third pipeline, and a fifth control valve 17 is installed on the heating / heat supply pipeline. When supplemental heating is needed, the fourth control valve is closed and the fifth control valve is opened. During off-peak electricity hours in the cooling season, the fourth control valve 18 and the fifth control valve 17 are opened, and a portion of the low-temperature cooling medium produced in the second evaporator / condenser 13 enters the phase change storage tank 14 through the third pipeline to exchange heat with the phase change storage material. This causes the phase change storage material to change from a liquid to a solid state after releasing heat, storing the cooling capacity. The cooled medium after heat exchange returns to the second evaporator / condenser 13 for heat exchange and cooling again, thus achieving a cycle. During peak electricity hours in the cooling season, the fourth control valve 18 and the fifth control valve 17 are opened, allowing the cooling medium to flow through the phase change storage tank and exchange heat with the phase change storage material to produce a low-temperature cooling medium. That is, the building cooling capacity during peak electricity hours is provided by the cooling capacity stored in the phase change storage tank 13 during off-peak electricity hours.

[0075] The phase change temperature of the phase change cold storage material is matched with the temperature of the low-temperature cooling medium, which can be a saline hydrate, water, etc.

[0076] In this embodiment, both the fourth control valve 18 and the fifth control valve 17 are preferably solenoid valves.

[0077] In some embodiments, the system further includes a monitoring and control device 20, which is connected to the compressor 9 and the four-way reversing valve 10 in the heat pump unit, respectively, for monitoring the ambient temperature and controlling the four-way reversing valve 10 to operate according to the ambient temperature, so that the heat pump unit switches to the cooling mode to produce a low-temperature cooling medium for cooling or switches to the heating mode to produce a high-temperature heating medium for supplemental heating.

[0078] Specifically, the monitoring and control device 20 includes a temperature sensor and an automatic controller. The temperature sensor is connected to the automatic controller to detect the ambient temperature and transmit it to the automatic controller. The automatic controller is connected to the compressor 9 and the four-way reversing valve 10 respectively. The automatic controller has preset hot temperature thresholds and cold temperature thresholds. The controller receives the ambient temperature monitored by the temperature sensor and compares it with the hot temperature thresholds and cold temperature thresholds. Based on the comparison results, it determines whether the operating condition is characterized by a large cooling load demand or a large heating load demand. When the determination result is a condition characterized by a large cooling load demand, it controls the four-way reversing valve to operate and starts the compressor, so that the heat pump unit switches to the cooling mode for cooling. When the determination result is a condition characterized by a large heating load demand, it controls the four-way reversing valve 10 to operate and starts the compressor 9, so that the heat pump unit switches to the heating mode for heating.

[0079] It should be noted that, in addition to controlling the operation of the heat pump unit based on the monitored ambient temperature, the monitoring and control device can also control the operation of the heat pump unit based on the temperature of the returned heating and cooling media (i.e., the heating and cooling media flowing out after heat exchange in the building). The specific control logic is similar to that of controlling the operation of the heat pump unit based on the monitored ambient temperature, and will not be elaborated here.

[0080] The working process of the combined cooling and heating system based on nuclear energy and a heat pump in this embodiment is described in detail below:

[0081] During off-peak electricity consumption periods in the heating season, the first control valve 15 and the third control valve 19 are opened, while the second control valve 16, the fourth control valve 17, and the fifth control valve 18 are closed. Steam is extracted from the turbine 3 through the extraction pipeline 22 to the first heat exchanger 6 to obtain a high-temperature circulating medium. This high-temperature circulating medium exchanges heat with the heating medium in the heating pipeline in the second heat exchanger 7, heating the heating medium to obtain a high-temperature heating medium. Then, a portion of the high-temperature heating medium is transported to the indoor heat exchanger 21 through the heating pipeline to provide heating. At the same time, another portion of the high-temperature circulating medium is introduced into the phase change heat storage tank 8 to exchange heat with the phase change heat storage material and store heat.

[0082] During peak electricity consumption periods in the heating season, the first control valve 15 is closed to stop steam extraction from the turbine 3, preventing insufficient power generation. The second control valve 16 and the third control valve 19 are opened, while the fourth control valve 18 and the fifth control valve 17 are closed, allowing the heating medium in the heating pipeline to flow into the phase change heat storage tank 8 for heat exchange with the phase change heat storage material, thereby producing a high-temperature heating medium for heating. Simultaneously, the ambient temperature is monitored by the monitoring and control device 20. When the ambient temperature is lower than the preset cold temperature threshold, the third control valve 19 is closed, allowing warm water to flow into the first evaporator / condenser 11. The fifth control valve 17 is opened, allowing the heating medium in the heating pipeline to flow into the second steam / condenser 13. The four-way reversing valve 10 is controlled to connect the inlet of the compressor 9 to the first evaporator / condenser 11 and the outlet of the compressor 9 to the second evaporator / condenser 13, starting the compressor 9 and putting the heat pump unit into heating mode. The heat pump unit produces a high-temperature heating medium to supplement the heating.

[0083] During off-peak electricity demand periods in the cooling season, the first control valve 15, the second control valve 16, and the third control valve 19 are closed, allowing warm water to flow into the first evaporator / condenser 11 and exchange heat with the refrigerant, causing the refrigerant to release heat and cool down. Meanwhile, the fourth control valve 18 and the fifth control valve 17 are opened, allowing the cooling medium in the cooling pipeline to flow into the second evaporator / condenser 13 and exchange heat with the cooled refrigerant, thus cooling the cooling medium and producing a low-temperature cooling medium. Then, a portion of the low-temperature cooling medium is transported to the indoor heat exchanger 21 through the cooling pipeline to achieve cooling; at the same time, another portion of the low-temperature cooling medium is introduced into the phase change cold storage tank 14 to exchange heat with the phase change cold storage material and store cold energy.

[0084] During peak electricity consumption periods in the cooling season, the first control valve 15 and the second control valve 16 are closed, and the third control valve 19 is opened to stop the flow of warm wastewater into the first evaporator / condenser 11. The heat pump unit is shut down, and the fourth control valve 18 and the fifth control valve 17 are opened to allow the cooling medium in the cooling pipeline to flow into the phase change cold storage tank 14 to exchange heat with the phase change cold storage material, thereby producing a low-temperature cooling medium and achieving cooling. At the same time, the ambient temperature is monitored by the monitoring and control device 20. When the ambient temperature is higher than the preset hot temperature threshold, the third control valve 19 is closed, allowing the warm wastewater to flow into the first evaporator / condenser 11. The four-way reversing valve 10 is controlled to connect the inlet of the compressor 9 to the second evaporator / condenser 13 and the outlet of the compressor 9 to the first evaporator / condenser 11, turning on the compressor 9. The heat pump unit enters the cooling mode, and the high-temperature heating medium produced by the heat pump unit supplements the cooling.

[0085] The beneficial effects of the combined cooling and heating system based on nuclear energy and heat pumps in this embodiment are as follows:

[0086] (1) Nuclear energy can be fully utilized for heating and cooling, realizing combined heating and cooling, improving energy efficiency, saving energy, and achieving comprehensive utilization of nuclear energy. For heating, it can alleviate the smog and environmental pollution caused by using fossil fuels for heating. For cooling, it can reduce the impact of direct discharge of wastewater into the sea on the ecology. It is low-carbon, clean, and environmentally friendly.

[0087] (2) It can also extract steam from the turbine for heating and heat storage during the off-peak hours of the heating season (such as winter). The stored heat can be used for heating during the peak hours of electricity consumption. This can make full use of nuclear energy and alleviate the problem of insufficient energy supply when nuclear power plants supply both electricity and heating during peak hours. This can achieve peak shaving and valley filling in winter, save energy, and achieve comprehensive utilization of nuclear energy.

[0088] (3) It can also monitor the ambient temperature in real time and determine the heat load / cooling load demand. When the heat storage / cooling storage is insufficient during the off-peak electricity hours in cold / hot weather, the heat pump unit can be turned on to supplement the heating / cooling by running the heating mode / cooling mode.

[0089] (4) During the off-peak hours of the cooling season (such as summer), the cooling mode of the heat pump unit can be turned on to use the off-peak electricity of the nuclear power plant for cooling and to store the cold energy for use during the peak hours of electricity consumption. This reduces the peak electricity load and achieves peak shaving and valley filling in summer, avoiding problems such as insufficient power generation or heating during peak hours and power waste during off-peak hours, thus achieving the goal of comprehensive utilization of nuclear energy and energy conservation.

[0090] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for combined cooling and heating based on nuclear energy and a heat pump, characterized in that, include: During the off-peak electricity demand period of the heating season, high-temperature heating medium is produced by extracting steam from the turbines of nuclear power plants and exchanging heat for heating. Additionally, high-temperature circulating medium is produced by extracting steam from the turbines of nuclear power plants and exchanging heat for heating, and then further exchanging heat with phase change thermal storage materials for heat storage. During the peak electricity demand period of the heating season, high-temperature heating medium is produced by exchanging heat with phase change thermal storage materials for heating, thus achieving peak shaving and valley filling. During off-peak electricity demand periods in the cooling season, the wastewater from nuclear power plants is used as a cold source. Low-temperature cooling media are produced by heat pump units using off-peak electricity from nuclear power plants for cooling. Additionally, the low-temperature cooling media produced by heat pump units is further heat-exchanged using phase change cold storage materials for cold storage. During peak electricity demand periods in the cooling season, low-temperature cooling media are produced by heat exchange using phase change cold storage materials for cooling, thus achieving peak shaving and valley filling.

2. The combined cooling and heating method based on nuclear energy combined with a heat pump according to claim 1, characterized in that, The phase change temperature of the phase change thermal storage material is matched with the temperature of the high-temperature circulating medium.

3. The combined cooling and heating method based on nuclear energy combined with a heat pump according to claim 1 or 2, characterized in that, Also includes: During the heating season, the wastewater from nuclear power plants is used as a heat source, and high-temperature heating medium is produced by heat pump units for supplementary heating.

4. The combined cooling and heating method based on nuclear energy combined with a heat pump according to claim 1, characterized in that, The phase change temperature of the phase change cold storage material is matched with the temperature of the low-temperature cooling medium.

5. A combined cooling and heating system based on nuclear energy and a heat pump, characterized in that, This includes a first heat exchanger (6), a second heat exchanger (7), a heat pump unit, a phase change heat storage tank (8), a phase change cold storage tank (14), and heating and cooling pipelines. The first heat exchanger is connected to the steam turbine (3) in the nuclear power plant, the second heat exchanger is connected to the first heat exchanger through a circulation pipeline, and the heating pipeline is connected to the second heat exchanger. The circulation pipeline contains a circulating medium, and the heating pipeline contains a heating medium. The first heat exchanger is used to introduce steam extracted from the steam turbine and exchange heat with the circulating medium. The circulating medium absorbs the heat from the steam extracted from the steam turbine and its temperature rises, thus producing a high-temperature circulating medium. The second heat exchanger is used to introduce a high-temperature circulating medium and exchange heat with the heating medium in the heating pipeline to heat the heating medium and achieve heating. The heat pump unit is connected to the thermal drainage system and power supply system of the nuclear power plant, as well as the cooling pipeline, and a cooling medium flows through the cooling pipeline. Heat pump units are used to utilize off-peak electricity from nuclear power plants to cool the cooling medium in the cooling pipeline by using warm wastewater as a cold source, so as to produce a low-temperature cooling medium and achieve cooling. The phase change heat storage tank is connected to the first heat exchanger through the circulation pipeline. The phase change heat storage tank is equipped with phase change heat storage material. The phase change heat storage tank is used to receive the high-temperature circulating medium obtained by heat exchange in the first heat exchanger, and to further exchange heat with the high-temperature circulating medium using the phase change heat storage material to achieve heat storage. The phase change heat storage tank is also connected to the heating pipeline and is also used to heat the heating medium in the heating pipeline using the phase change heat storage material during peak electricity consumption periods to obtain a high-temperature heating medium, thereby achieving peak shaving and valley filling. The phase change cold storage tank is connected to the heat pump unit. The phase change cold storage tank contains phase change cold storage material. The phase change cold storage tank is used to receive the low-temperature cooling medium produced by the heat pump unit and to further exchange heat between the phase change cold storage material and the low-temperature cooling medium to achieve cold storage. The phase change cold storage tank is also connected to the cooling pipeline and is used to exchange heat between the phase change cold storage material and the cooling medium in the cooling pipeline to produce a low-temperature cooling medium. During peak electricity consumption periods, the low-temperature cooling medium produced by the cold energy stored in the phase change cold storage material is used to supply all or part of the cooling load to achieve peak shaving and valley filling.

6. The combined cooling and heating system based on nuclear energy and a heat pump according to claim 5, characterized in that, The heat pump unit includes a compressor (9), a first evaporator / condenser (11), a throttle valve (12), and a second evaporator / condenser (13). The compressor, the first evaporator / condenser, the expansion valve, and the second evaporator / condenser are connected in sequence via pipes to form a closed-loop circuit. Refrigerant flows through the closed-loop circuit. The first evaporator / condenser is connected to the heated drainage system, and the second evaporator / condenser is connected to both the heating pipeline and the cooling pipeline. Furthermore, a four-way reversing valve (10) is installed on the pipeline between the compressor and the first evaporator / condenser and the second evaporator / condenser. The four-way reversing valve is used to control the compressor outlet to connect to the first evaporator / condenser and to control the compressor inlet to connect to the second evaporator / condenser, so that the heat pump unit switches to cooling mode to obtain a low-temperature cooling medium for cooling. The heat pump unit is used to control the compressor inlet to connect to the first evaporator / condenser and to control the compressor outlet to connect to the second evaporator / condenser. It is also used to heat the refrigerant in the first evaporator / condenser by using warm water as a heat source, and then to compress the heated refrigerant through the compressor and then pass it into the second evaporator / condenser for heat exchange to heat the heating medium in the heating pipeline, so as to obtain a high-temperature heating medium for supplementary heating.

7. The combined cooling and heating system based on nuclear energy and a heat pump according to claim 6, characterized in that, The system also includes a monitoring and control device (20). The monitoring and control device is connected to the compressor and the four-way reversing valve in the heat pump unit, respectively, to monitor the ambient temperature and control the four-way reversing valve to switch the heat pump unit to the cooling mode to produce a low-temperature cooling medium for cooling or to the heating mode to produce a high-temperature heating medium for supplemental heating.

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