Low-energy heat pump system based on geothermal water and cross-seasonal energy storage and its operation method

Abstract

This invention discloses a low-energy heat pump system based on geothermal water and interseasonal energy storage, and its operation method. The system sequentially connects the geothermal water extraction well, the primary heat exchange pipeline of the heat exchanger assembly, and the geothermal water reinjection well. The secondary heat exchange pipeline of the heat exchanger assembly is connected to the cooling and heating users. One end of the heat pump unit is connected to the secondary heat exchange pipeline of the heat exchanger assembly, and the other end's cooling and heating ends are both connected to the cooling and heating users. One end of the high-temperature heat pump unit is connected to both the secondary heat exchange pipeline of the heat exchanger assembly and the heating end of the heat pump unit, and the other end is connected to the cooling and heating users through an interseasonal heat storage tank. The interseasonal cold storage tank is connected to the cooling end of the heat pump unit, and the other end is connected to the cooling and heating users. A cooling tower is connected to the interseasonal cold storage tank. This invention enables a combined cooling strategy using the interseasonal cold storage tank and the heat pump unit in summer, and a combined heating strategy using the heat exchanger assembly, the heat pump unit, and the interseasonal heat storage tank in winter.

Description

Technical Field

[0001] This invention belongs to the field of heat pump heating and cooling technology, specifically relating to a low-energy heat pump system based on geothermal water and cross-seasonal energy storage and its operation method. Background Technology

[0002] Currently, my country is actively promoting the implementation of its dual-carbon strategy, with various departments strictly formulating corresponding measures to reduce carbon emissions. In the building sector, HVAC energy consumption accounts for the largest proportion of total building energy consumption; therefore, reducing HVAC energy consumption is a crucial approach to carbon reduction during building operation. With the improvement of people's living standards, the regional demand for heating and cooling in China is constantly expanding. The variety of heating and cooling systems has led to low system operating efficiency and serious waste of HVAC energy, thus necessitating a heating and cooling system to improve energy utilization efficiency. Simultaneously, in recent years, due to severe pollution from winter heating in most parts of northern China, large-scale coal-to-electricity and coal-to-gas conversion plans have been implemented, resulting in a shortage of electricity and natural gas resources, which cannot meet the daily needs of residents and has placed enormous pressure on the electricity and natural gas sectors. Therefore, developing other types of clean energy heating and cooling systems is urgently needed.

[0003] Currently, geothermal water cascade utilization systems are generally used for heating in northern regions and cannot be used for cooling in summer. In addition, geothermal water utilization efficiency is low, and the system relies excessively on ground source heat pump systems to raise the temperature during the heating season, which increases system energy consumption and reduces operating efficiency. For example, the invention patent "Uninterrupted Medium-Deep Geothermal Resource Cascade Utilization Heating System" (CN109931651A) mentions a cascade utilization heating system that absorbs and utilizes high, medium, and low grade portions of geothermal water through heat exchangers, high-temperature heat pumps, and low-temperature heat pumps. However, this system is only suitable for winter heating and cannot provide cooling in summer. In addition, this system does not store the condensation heat of the heat pump unit, and the heat pump unit operates for a long time during the heating season, resulting in increased power consumption. The invention patent "Cross-Seasonal Cold and Heat Storage System" (CN107525180B) mentions a heating and cooling system that uses ice source heat pump units to achieve cross-seasonal cold and heat storage. However, the ice source heat pump units mentioned in this system consume a lot of electricity when running, resulting in high operating costs. Moreover, the system is complex to debug during operation and it is difficult to meet the heating and cooling needs of users. The invention patent "Vertical Geothermal Energy Storage Air Conditioning System" (CN1137352C) mentions a heat exchange and storage system suitable for residential buildings. However, this system has a limited scope of application and is only suitable for small-scale use. The geothermal water is reinjected without being utilized in a cascade manner, resulting in low geothermal water utilization. Furthermore, most of the equipment is located underground, leading to low operability and poor heating and cooling effects. The invention patent "A Seasonal Energy Storage Ground Source Heat Pump System" (CN103277939B) mentions a system that stores industrial waste heat in the base layer of the soil and rock mass for use in winter. Seasonal heating systems, primarily used in industrial applications, require a certain scale of geothermal base layer, resulting in high construction costs and poor heat storage. Furthermore, the discharge of heat to the base layer in summer consumes a significant amount of electricity, contradicting carbon reduction strategies. The invention patent "Integrated Renewable Energy Cooling and Heating System" (CN104864447B) mentions a system that comprehensively utilizes deep geothermal, shallow geothermal, and desalinated seawater thermal energy. However, this system simply connects these units in parallel for heating without considering system efficiency, thus still resulting in wasted thermal energy. The invention patent "Low-Cost Geothermal Heating-Energy Storage Integrated System and Application" (CN113531630A) mentions a system that stores the heat from geothermal water using an energy storage unit for heating. This system can only be used for winter heating, and the heat storage capacity of the energy storage unit is affected by the temperature of the geothermal water, while its peak-shaving capacity is limited. The invention patent "Low-Cost Geothermal Heating-Energy Storage Integrated System and Application" (CN113531630A) also mentions a system that stores the heat generated by intermittent energy sources and combines it with geothermal water for heating. This system requires not only sufficient geothermal water resources but also sufficient intermittent energy sources, making it difficult to balance the heating needs of different regions, thus limiting its application scope. Summary of the Invention

[0004] In view of this, the present invention provides a low-energy heat pump system based on geothermal water and cross-seasonal energy storage and its operation method. It can utilize a strategy of combined cooling with cross-seasonal cold storage tanks and heat pump units in summer, and a strategy of combined heating with primary heat exchangers, secondary heat exchangers, heat pump units and cross-seasonal heat storage tanks in winter, thereby minimizing the start-up time of heat pump units, reducing system energy consumption and improving system operating efficiency.

[0005] This invention is achieved through the following technical solution:

[0006] A low-energy heat pump system based on geothermal water and cross-seasonal energy storage includes a geothermal water extraction well, a geothermal water reinjection well, a heat exchanger assembly, a heat pump unit, a high-temperature heat pump unit, a cross-seasonal heat storage tank, a cooling tower, a cross-seasonal cold storage tank, and users for cooling and heating.

[0007] The geothermal water extraction well, the primary heat exchange pipeline of the heat exchanger assembly, and the geothermal water reinjection well are connected in sequence; the secondary heat exchange pipeline of the heat exchanger assembly is connected to the cooling and heating users for supplying heat to the cooling and heating users.

[0008] One end of the heat pump unit is connected to the secondary heat exchange pipe of the heat exchanger assembly, and the other end is divided into a cooling end and a heating end. Both the cooling end and the heating end are connected to the users who need cooling and heating. The cooling end is used to provide cooling to the users who need cooling and heating, and the heating end is used to provide heating to the users who need cooling and heating.

[0009] One end of the high-temperature heat pump unit is connected to the secondary heat exchange pipe of the heat exchanger assembly and the heating end of the heat pump unit, and the other end is connected to the cooling and heating users through the cross-seasonal heat storage tank. The high-temperature heat pump unit is used to store heat in the cross-seasonal heat storage tank, and the cross-seasonal heat storage tank is used to supply heat to the cooling and heating users.

[0010] The cross-seasonal cold storage tank is connected to the cooling end of the heat pump unit and the other end is connected to the cooling and heating users. The cross-seasonal cold storage tank is used to provide cooling to the cooling and heating users. The cooling tower is connected to the cross-seasonal cold storage tank and is used to store cold in the cross-seasonal cold storage tank.

[0011] Furthermore, the heat pump system also includes a pressure tank and domestic hot water users;

[0012] The pressure tank stores domestic water. The input end of the pressure tank is connected to an external water source, and the output end of the pressure tank is connected to domestic hot water users. The external water source provides domestic hot water to domestic hot water users through the pressure tank.

[0013] The pressure tank exchanges heat with the secondary heat exchange pipes of the heat exchanger assembly, which heats the domestic water in the pressure tank; the pressure tank exchanges heat with the cross-seasonal heat storage tank, which further heats the domestic water in the pressure tank.

[0014] Furthermore, the heat pump system also includes a valve assembly, which includes: valve one, valve two, valve three, valve four, valve five, valve six, valve seven, valve eight, valve nine, valve ten, valve eleven and valve twelve;

[0015] The heat exchanger assembly includes a primary heat exchanger and a secondary heat exchanger;

[0016] The cooling end of the heat pump unit is an evaporator, and the heating end is a condenser;

[0017] The geothermal water extraction well is connected to the input end of the primary heat exchange pipe of the first-stage heat exchanger via a pipeline. The output end of the primary heat exchange pipe of the first-stage heat exchanger is connected to the input end of the primary heat exchange pipe of the second-stage heat exchanger via a pipeline. The output end of the primary heat exchange pipe of the second-stage heat exchanger is connected to the geothermal water reinjection well via a pipeline.

[0018] The output end of the cooling and heating user is connected to the input end of the secondary heat exchange channel of the primary heat exchanger through pipe c, and the output end of the secondary heat exchange channel of the primary heat exchanger is connected to the input end of the cooling and heating user through pipe b.

[0019] The output end of the secondary heat exchange pipe of the secondary heat exchanger is connected to pipe b through pipe e, and the intersection of pipe e and pipe b is point G; the input end of the secondary heat exchange pipe of the secondary heat exchanger is connected to pipe c through pipe f, and the intersection of pipe c and pipe f is point H.

[0020] The first input terminal of the evaporator of the heat pump unit is connected to pipe e through pipe a, and the intersection of pipe a and pipe e is point I. The first output terminal of the evaporator is connected to pipe f. The second input terminal of the evaporator is connected to pipe c through pipe g, and the intersection of pipe g and pipe c is point K. The second output terminal of the evaporator is connected to pipe b through pipe d, and the intersection of pipe d and pipe b is point J.

[0021] The output end of the condenser of the heat pump unit is connected to the pipe b through pipe h, and the intersection of pipe h and pipe b is point L. The input end of the condenser is connected to the pipe c through pipe i, and the intersection of pipe i and pipe c is point M.

[0022] The heating outlet of the interseasonal thermal storage tank is connected to pipe b through pipe k, and the intersection of pipe k and pipe b is point A; the heating return outlet of the interseasonal thermal storage tank is connected to pipe c through pipe l, and the intersection of pipe l and pipe c is point P.

[0023] The heat storage outlet of the interseasonal heat storage tank is connected to the first input end of the high-temperature heat pump unit; the first output end of the high-temperature heat pump unit is connected to pipe c through pipe m, and the intersection of pipe m and pipe c is point Q; the second input end of the high-temperature heat pump unit is connected to pipe b through pipe j, and the intersection of pipe j and pipe b is point N; the second output end of the high-temperature heat pump unit is connected to the heat storage inlet of the interseasonal heat storage tank.

[0024] The cooling outlet of the interseasonal cold storage tank is connected to pipe b through pipe s, and the intersection of pipe s and pipe b is point U. The cooling return outlet of the interseasonal cold storage tank is connected to pipe c through pipe r, and the intersection of pipe r and pipe c is point T.

[0025] The cold storage outlet of the interseasonal cold storage tank is connected to pipe g via pipe q, and the cold storage inlet of the interseasonal cold storage tank is connected to pipe d via pipe p, with point S being the intersection of pipe p and pipe d; at the same time, pipe q is connected to pipe h via branch n, with point R being the intersection of branch n and pipe h, and point X being the intersection of branch n and pipe q; pipe p is connected to pipe i via branch o, with point B being the intersection of branch o and pipe p.

[0026] The cooling tower is connected to branch n and branch o via pipe w, that is, one end of pipe w is connected to branch o and the other end of pipe w is connected to branch n, and the intersection of pipe w and branch n is point Y; the middle part of pipe w flows through the cooling tower, and the cooling tower cools the hot water in pipe w.

[0027] Pipeline j and pipeline n are connected through branch t, ​​and the intersection of pipeline n and branch t is point V, while the intersection of pipeline j and branch t is point W; pipeline m and pipeline o are connected through branch u.

[0028] Valve 1 is installed on pipeline b, between points N and J; Valve 2 is located on pipeline j, between points N and W; Valve 3 is located on pipeline e, between points G and I; Valve 4 is located on pipeline a; Valve 5 is located on pipeline d, between points S and J; Valve 6 is located on pipeline h, between points R and L; Valves 7, 9, and 10 are all located on pipeline n, with Valve 7 between points R and V, Valve 9 between points V and Y, and Valve 10 between points Y and X; Valve 8 is located on pipeline p, between points S and B; Valve 11 is located on pipeline k, between points Z and A; and Valve 12 is located on pipeline s.

[0029] Furthermore, the valve assembly also includes valve thirteen; the heat exchanger assembly also includes a three-stage heat exchanger;

[0030] The primary heat exchange pipe of the tertiary heat exchanger is connected in series between the primary heat exchange pipe of the secondary heat exchanger and the geothermal water reinjection well. That is, the output end of the primary heat exchange pipe of the secondary heat exchanger is connected to the input end of the primary heat exchange pipe of the tertiary heat exchanger through a pipeline, and the output end of the primary heat exchange pipe of the tertiary heat exchanger is connected to the geothermal water reinjection well through a pipeline.

[0031] The output end of the secondary heat exchange pipe of the three-stage heat exchanger is connected to the input end of the secondary heat exchange pipe of the three-stage heat exchanger through pipe z, and pipe z flows through the pressure tank. The water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger heats the domestic water in the pressure tank through pipe z.

[0032] Pipeline k and pipeline l exchange heat with the pressure tank through pipeline y. One end of pipeline y is connected to pipeline k, and the intersection of pipeline y and pipeline k is point Z. The other end of pipeline y is connected to pipeline l. Pipeline y flows through the pressure tank, and the hot water flowing out from the cross-seasonal heat storage tank further heats the domestic water in the pressure tank through pipeline y. Valve thirteen is located on pipeline y.

[0033] Furthermore, the heat exchanger assembly adopts a fixed tube sheet heat exchanger or a U-shaped tube sheet heat exchanger.

[0034] An operation method for a low-energy heat pump system based on geothermal water and cross-seasonal energy storage. Based on the aforementioned low-energy heat pump system, the operation method includes two operation modes: a summer operation mode and a winter operation mode. The switching between the summer operation mode and the winter operation mode can be achieved by switching the opening and closing of the valves in the valve group.

[0035] Furthermore, in the summer operation mode, heat storage and cooling are carried out. At the beginning of cooling, all valves are closed. First, valve twelve is opened, and the cooling circulation loop consisting of the pipe section from the cooling outlet to the cooling return port in the cross-seasonal cold storage tank, the pipe section from point U on pipe s, pipe r, and pipe b to the cooling and heating users, and the pipe section from point T on pipe c to the cooling and heating users is connected. The cold energy in the cross-seasonal cold storage tank is used to provide cooling to the cooling and heating users.

[0036] When the cooling capacity in the cross-seasonal cold storage tank cannot meet the cooling demand, valve twelve is closed, the heat pump unit is turned on and valve five is opened. The second cooling circulation loop, consisting of the pipe sections at the second input and second output ends of the evaporator in the heat pump unit, the pipe section from point J on pipe d, pipe g, and pipe b to the cooling and heating users, and the pipe section from point K on pipe c to the cooling and heating users, is connected, and the cooling capacity generated by the evaporator of the heat pump unit is used to provide cooling to the cooling and heating users.

[0037] During summer heat storage, in addition to using heat pump units for cooling, the high-temperature heat pump unit, valves two, seven, and nine are opened. Hot water flowing from the condenser of the heat pump unit is mixed with hot water flowing from the secondary heat exchange pipes of the primary heat exchanger within the high-temperature heat pump unit. The mixture is then heated by the high-temperature heat pump unit and connected to the inter-seasonal heat storage tank for heat storage. This method simultaneously recovers heat from the condenser of the heat pump unit and extracts some heat from the geothermal water from the well. When the inter-seasonal heat storage tank reaches its heat storage limit, the excess heat generated by the condenser in the heat pump unit is discharged through a cooling tower.

[0038] During the entire process of summer heat storage and cooling, geothermal water flows out from the geothermal water extraction well, passes through the primary heat exchanger, the secondary heat exchanger, and the tertiary heat exchanger in sequence to exchange heat and cool down before flowing into the geothermal water reinjection well.

[0039] When domestic hot water needs to be provided to users, the water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger heats the domestic water in the pressure tank through pipe z. When the temperature of the domestic water in the pressure tank reaches the set temperature, it is output to the domestic hot water users to provide domestic hot water at the set temperature. When the three-stage heat exchanger alone cannot heat the domestic water in the pressure tank to the set temperature, valve thirteen is opened. The domestic water in the pressure tank mixes with the hot water discharged from the heating outlet of the inter-seasonal heat storage tank to further raise the temperature before being output to the domestic hot water users to provide domestic hot water at the set temperature.

[0040] Furthermore, when using a heat pump unit for cooling, valve eight is opened during off-peak electricity consumption periods, connecting the cold storage circuit consisting of the pipe sections at the second input and second output ends of the evaporator in the heat pump unit, pipe p, pipe q, and the pipe section between the cold storage inlet and outlet in the interseasonal cold storage tank; the cooling capacity generated by the evaporator of the heat pump unit is used to store cold in the interseasonal cold storage tank; during peak electricity consumption periods, the heat pump unit is shut down, valve twelve is opened, and cooling is provided solely by the interseasonal cold storage tank.

[0041] Furthermore, in winter operation mode, cold storage and heating are implemented. During winter heating, user loads are divided into several levels: Level 1 load at the beginning of heating; Level 2 load when outdoor temperature decreases and heating load increases; Level 3 load when outdoor temperature decreases further and heating load increases again; and Level 4 load when heating load reaches its peak. The specific operating procedure for heating is as follows:

[0042] At the beginning of the heating season, all valves are closed. Under primary load, valve one is opened to directly supply heating using the primary heat exchanger. This means that the heating circulation loop consisting of the secondary heat exchange pipes, pipes b and c of the primary heat exchanger and the users of heating and cooling is connected. The primary heat exchanger achieves direct heating to the users of heating and cooling by exchanging heat with the geothermal water flowing from the geothermal well. At the same time, the high-temperature heat pump unit and valve two are opened to use geothermal water to store heat in the interseasonal heat storage tank.

[0043] At level 2 load, valve 3 is opened, and a combined heating method using the primary and secondary heat exchangers is adopted. That is, the first heating loop, consisting of the secondary heat exchange pipes of the primary heat exchanger, pipe b, pipe c, and the heating / cooling users, is connected. The second heating loop, consisting of the secondary heat exchange pipes of the secondary heat exchanger, pipe e, pipe f, the section from point G on pipe b to the heating / cooling users, and the section from point H on pipe c to the heating / cooling users, is connected. The primary and secondary heat exchangers achieve combined heating for the heating / cooling users by exchanging heat with the geothermal water flowing out of the geothermal water extraction well.

[0044] At level 3 load, valve 11 is opened and valve 2 is closed. The combined heating mode of geothermal water and cross-seasonal heat storage tank is adopted. That is, the first heating loop is connected, which consists of the secondary heat exchange pipes of the primary heat exchanger, pipe b, pipe c and the heating and cooling users. The second heating loop is connected, which consists of the secondary heat exchange pipes of the secondary heat exchanger, pipe e, pipe f, the section from point G on pipe b to the heating and cooling users, and the section from point H on pipe c to the heating and cooling users. The third heating loop is connected, which consists of the section between the heating outlet and the heating return in the cross-seasonal heat storage tank, pipe k, pipe l, the section from point A on pipe b to the heating and cooling users, and the section from point P on pipe c to the heating and cooling users. The primary heat exchanger and the secondary heat exchanger achieve combined heating for the heating and cooling users through heat exchange with the geothermal water flowing out of the geothermal water extraction well and the heat provided by the cross-seasonal heat storage tank.

[0045] At level four load, valves four and six are opened, at which point the heat pump unit starts operating, utilizing a combined heating mode of direct geothermal water supply + inter-seasonal thermal storage tank + heat pump unit. Specifically, heating loop one, consisting of the secondary heat exchange pipes of the primary heat exchanger, pipes b and c, and the section between the supplying and receiving users, is connected. Heating loop two, consisting of the secondary heat exchange pipes of the secondary heat exchanger, pipes e and f, the section from point G on pipe b to the supplying and receiving users, and the section from point H on pipe c to the supplying and receiving users, is also connected. The section of pipe k between the heating outlet and the heating return outlet in the inter-seasonal thermal storage tank is also connected. The heating circulation loop consisting of point A on pipe l and pipe b to the cooling and heating users, and point P on pipe c to the cooling and heating users, is connected in three stages. The heating circulation loop consisting of the condenser of the heat pump unit, pipe i, pipe h, point L on pipe b to the cooling and heating users, and point M on pipe c to the cooling and heating users, is connected in four stages. The primary heat exchanger and the secondary heat exchanger achieve combined heating for the cooling and heating users by exchanging heat with the geothermal water flowing out of the geothermal water extraction well, the heat provided by the cross-seasonal heat storage tank, and the heat provided by the condenser of the heat pump unit.

[0046] During winter cold storage, valve 10 is opened to connect the cooling tower to the interseasonal cold storage tank, and antifreeze is added to the circulating medium in the loop formed by the cooling tower and the interseasonal cold storage tank. The cooling tower collects the cold energy from the outside air and transfers it to the interseasonal cold storage tank for cold storage, which is then used for cooling in the summer.

[0047] During the entire process of winter cold storage and heating, geothermal water flows out from the geothermal water extraction well, and after passing through the primary heat exchanger, the secondary heat exchanger, and the tertiary heat exchanger for heat exchange and cooling, it flows into the geothermal water reinjection well.

[0048] When domestic hot water needs to be provided to users, the water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger heats the domestic water in the pressure tank through pipe z. When the temperature of the domestic water in the pressure tank reaches the set temperature, it is output to the domestic hot water users to provide domestic hot water at the set temperature. When the three-stage heat exchanger alone cannot heat the domestic water in the pressure tank to the set temperature, valve thirteen is opened. The domestic water in the pressure tank mixes with the hot water discharged from the heating outlet of the inter-seasonal heat storage tank to further raise the temperature before being output to the domestic hot water users to provide domestic hot water at the set temperature.

[0049] Furthermore, when using a heat pump unit for heating, valve seven is opened during off-peak electricity consumption periods to connect the condenser of the heat pump unit to the inter-seasonal heat storage tank. The heat generated by the condenser of the heat pump unit stores heat in the inter-seasonal heat storage tank.

[0050] Beneficial effects:

[0051] (1) The heat pump system of the present invention can make full use of geothermal water, cross-seasonal energy storage tanks and heat pump units for heating or cooling. That is, in summer, it uses a strategy of combining cross-seasonal cold storage tanks and heat pump units for cooling, and in winter, it adopts a strategy of combining primary heat exchanger, secondary heat exchanger, heat pump unit and cross-seasonal heat storage tank for heating. This minimizes the start-up time of heat pump units, reduces system energy consumption and improves system operating efficiency. At the same time, it achieves the purpose of making full use of clean energy for heating and cooling. Moreover, the present invention is easy to use, easy to operate, has good stability, wide applicability and high reliability.

[0052] (2) This invention can not only provide cooling and heating to users, but also provide domestic hot water to domestic hot water users and heat the domestic water to improve the convenience and comfort of using domestic water.

[0053] (3) The primary heat exchanger, secondary heat exchanger and tertiary heat exchanger in the heat exchanger assembly of the present invention all adopt fixed tube sheet heat exchanger or U-shaped tube sheet heat exchanger, which improves the heat exchange effect between geothermal water and other components.

[0054] (4) This invention proposes an operating strategy for the system under different loads during winter and summer heating and cooling operations. By switching the valves in the valve group, the summer operation mode and the winter operation mode can be switched, which greatly reduces the system's energy consumption and improves the system's operating efficiency.

[0055] (5) This invention combines geothermal water, geothermal water cascade heat exchange channels, heat pump units and cross-seasonal energy storage tanks to achieve both heating and cooling functions. The system adopts a time-sharing joint heating and cooling mode among its various equipment, which greatly reduces the start-up time of the heat pump units during winter heating and summer cooling, effectively improves the system's operating efficiency, greatly reduces the consumption of high-grade energy such as electricity and natural gas, complies with the clean energy heating policy, and powerfully promotes the implementation of the dual-carbon strategy.

[0056] (6) In summer cooling, the heat pump unit is turned on during off-peak electricity consumption, and the cold energy generated by the evaporator of the heat pump unit is used to store cold energy in the cross-seasonal cold storage tank; in winter heating, the heat pump unit is turned on during off-peak electricity consumption, and the heat generated by the condenser of the heat pump unit is used to store heat energy in the cross-seasonal heat storage tank; this invention realizes the recovery and storage of waste cold and heat from the system during heating and cooling, and its cross-seasonal use, thereby reducing HVAC energy consumption and lowering the overall heating and cooling operating costs of the system; on the one hand, in summer, the cross-seasonal heat storage tank recovers waste heat from the condenser side of the heat pump unit and absorbs heat from geothermal water; on the other hand, in winter, the cold energy is stored using natural cold sources for summer cooling, which can effectively reduce the cooling start-up time of the heat pump unit and reduce system energy consumption; During summer cooling, the stored cold energy from winter (which does not consume electricity) is used first. When the cold storage tank is insufficient, the heat pump unit is then turned on for cooling. This saves electricity during summer cooling. At the same time, the heat pump unit inevitably generates heat (40-50℃) during cooling, which is higher than the summer temperature. This heat is stored for winter heating. Geothermal water can also be stored in summer. The interseasonal heat storage tank is filled and used for winter use, reducing winter heating energy consumption. During winter heating, geothermal water is used first. When the load increases, primary and secondary plate heat exchangers are used for heating. When the load increases again, geothermal water and heat storage tanks are used for heating. When the load reaches its peak, the heat pump unit is turned on for heating, minimizing the heat pump unit's operating time. At the same time, the natural cold source stored in winter is used to reduce summer cooling energy consumption.

[0057] In summary, the geothermal extraction well of this invention is sequentially connected to a primary heat exchanger, a secondary heat exchanger, and a tertiary heat exchanger, and finally the geothermal water is reinjected into the geothermal reinjection well. The secondary heat exchange pipes of the primary heat exchanger are connected to the heating and cooling users. During non-heating and low-load periods, the water can be mixed with the condenser side of the heat pump unit and then connected to the high-temperature heat pump unit for heat storage, achieving a recovery and heat storage function. The secondary heat exchange pipes of the secondary heat exchanger are connected to the heat pump unit, providing a heat source for winter heating. During low heating loads, the primary and secondary heat exchangers can be used together for heating, reducing system power consumption. The cooling tower is connected to the inter-seasonal cold storage tank in winter for inter-seasonal cold storage. The tertiary heat exchanger and the inter-seasonal cold storage tank are mixed through a pressure tank to produce 50-60°C domestic hot water. The evaporator side of the heat pump unit is connected to the users for summer cooling. When the load is low, it can be connected to the inter-seasonal cold storage tank for peak-shaving cold storage; the condenser side of the heat pump unit is connected to the high-temperature heat pump unit in summer for inter-seasonal heat storage. When the heat storage tank reaches its maximum capacity, the condenser side of the heat pump unit is connected to the cooling tower to discharge heat to the outside; this invention utilizes geothermal water coupled with the inter-seasonal energy storage tank to realize the inter-seasonal use of heat and cold, enabling the traditional geothermal water cascade utilization system to achieve simultaneous supply of heat and cold, while utilizing off-peak electricity storage to stabilize the grid load; it fully recovers the heat from the condenser side of the heat pump unit and the natural cold energy outdoors in winter, greatly reducing the power consumption of the heat pump unit, greatly improving the utilization rate of geothermal water and the operating efficiency of the entire system; therefore, compared with the prior art, the system described in this invention has a wide range of applications. This system can simultaneously meet the cooling, heating and domestic hot water needs of different types of users while consuming less electricity. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the structural composition of the present invention;

[0059] Figure 2 This is a schematic diagram showing the geothermal water outlet temperature of the present invention at 55°C;

[0060] Figure 3 This is a schematic diagram of the summer operating conditions of the present invention;

[0061] Figure 4 This is a schematic diagram of the winter operating conditions of the present invention.

[0062] Among them, 1-geothermal water extraction well, 2-geothermal water reinjection well, 3-primary heat exchanger, 4-secondary heat exchanger, 5-tertiary heat exchanger, 6-heat pump unit, 7-high temperature heat pump unit, 8-inter-seasonal heat storage tank, 9-cooling tower, 10-inter-seasonal cold storage tank, 11-pressure tank, 12-cooling and heating user, 13-domestic hot water user, 14-valve one, 15-valve two, 16-valve three, 17-valve four, 18-valve five, 19-valve six, 20-valve seven, 21-valve eight, 22-valve nine, 23-valve ten, 24-valve eleven, 25-valve twelve, 26-valve thirteen. Detailed Implementation

[0063] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0064] Example 1:

[0065] This embodiment provides a low-energy heat pump system based on geothermal water and cross-seasonal energy storage. See Appendix. Figure 1-2 It includes a geothermal extraction well 1, a geothermal reinjection well 2, a primary heat exchanger 3, a secondary heat exchanger 4, a tertiary heat exchanger 5, a heat pump unit 6, a high-temperature heat pump unit 7, a cross-seasonal thermal storage tank 8, a cooling tower 9, a cross-seasonal cold storage tank 10, a pressure tank 11, a cooling and heating user 12, a domestic hot water user 13, and a valve assembly; among them, the cross-seasonal thermal storage tank 8 and the cross-seasonal cold storage tank 10 are collectively referred to as cross-seasonal energy storage tanks;

[0066] The valve group includes: valve 14, valve 25, valve 36, valve 47, valve 518, valve 619, valve 720, valve 821, valve 922, valve 1023, valve 112, valve 1225, and valve 1326.

[0067] Each of the primary heat exchanger 3, the secondary heat exchanger 4, and the tertiary heat exchanger 5 is provided with two heat exchange pipes, namely a primary side heat exchange pipe and a secondary side heat exchange pipe.

[0068] The heat pump unit 6 consists of an evaporator and a condenser;

[0069] The overall connection relationship of the heat pump system is as follows:

[0070] The geothermal water extraction well 1 is connected to the input end of the primary heat exchange pipe of the first-stage heat exchanger 3 through a pipeline. The output end of the primary heat exchange pipe of the first-stage heat exchanger 3 is connected to the input end of the primary heat exchange pipe of the second-stage heat exchanger 4 through a pipeline. The output end of the primary heat exchange pipe of the second-stage heat exchanger 4 is connected to the input end of the primary heat exchange pipe of the third-stage heat exchanger 5 through a pipeline. The output end of the primary heat exchange pipe of the third-stage heat exchanger 5 is connected to the geothermal water reinjection well 2 through a pipeline. The geothermal water extraction well 1, the first-stage heat exchanger 3, the second-stage heat exchanger 4, the third-stage heat exchanger 5, the geothermal water reinjection well 2 and the pipelines connecting them form a geothermal water cascade heat exchange channel.

[0071] The pressure tank 11 stores domestic water. The input end of the pressure tank 11 is connected to an external water source through a pipeline, and the output end of the pressure tank 11 is connected to the domestic hot water user 13 through a pipeline. The external water source provides domestic water to the domestic hot water user 13 through the pressure tank 11.

[0072] The output end of the secondary heat exchange pipe of the three-stage heat exchanger 5 is connected to the input end of the secondary heat exchange pipe of the three-stage heat exchanger 5 through pipe z, and pipe z flows through the pressure tank 11. The water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger 5 heats the domestic water in the pressure tank 11 through pipe z.

[0073] The output end of the cooling and heating user 12 is connected to the input end of the secondary heat exchange channel of the primary heat exchanger 3 through pipe c, and the output end of the secondary heat exchange channel of the primary heat exchanger 3 is connected to the input end of the cooling and heating user 12 through pipe b.

[0074] The output end of the secondary heat exchange pipe of the secondary heat exchanger 4 is connected to pipe b through pipe e, and the intersection of pipe e and pipe b is point G; the input end of the secondary heat exchange pipe of the secondary heat exchanger 4 is connected to pipe c through pipe f, and the intersection of pipe c and pipe f is point H.

[0075] The first input end of the evaporator of the heat pump unit 6 is connected to the pipe e through pipe a, and the intersection of pipe a and pipe e is point I. The first output end of the evaporator is connected to the pipe f. The second input end of the evaporator is connected to the pipe c through pipe g, and the intersection of pipe g and pipe c is point K. The second output end of the evaporator is connected to the pipe b through pipe d, and the intersection of pipe d and pipe b is point J.

[0076] The output end of the condenser of the heat pump unit 6 is connected to the pipe b through pipe h, and the intersection of pipe h and pipe b is point L. The input end of the condenser is connected to the pipe c through pipe i, and the intersection of pipe i and pipe c is point M.

[0077] The heating outlet of the interseasonal heat storage tank 8 is connected to pipe b via pipe k, and the intersection of pipe k and pipe b is point A; the heating return port of the interseasonal heat storage tank 8 is connected to pipe c via pipe l, and the intersection of pipe l and pipe c is point P; pipe k and pipe l exchange heat with the pressure tank 11 via pipe y, that is, one end of pipe y is connected to pipe k, the intersection of pipe y and pipe k is point Z, the other end of pipe y is connected to pipe l, and pipe y flows through the pressure tank 11. The hot water flowing out of the interseasonal heat storage tank 8 heats the domestic water in the pressure tank 11 through pipe y;

[0078] The heat storage outlet of the interseasonal heat storage tank 8 is connected to the first input end of the high-temperature heat pump unit 7; the first output end of the high-temperature heat pump unit 7 is connected to the pipe c through the pipe m, and the intersection of the pipe m and the pipe c is point Q; the second input end of the high-temperature heat pump unit 7 is connected to the pipe b through the pipe j, and the intersection of the pipe j and the pipe b is point N; the second output end of the high-temperature heat pump unit 7 is connected to the heat storage inlet of the interseasonal heat storage tank 8.

[0079] The cooling outlet of the cross-seasonal cold storage tank 10 is connected to the pipe b through the pipe s, and the intersection of the pipe s and the pipe b is point U. The cooling return port of the cross-seasonal cold storage tank 10 is connected to the pipe c through the pipe r, and the intersection of the pipe r and the pipe c is point T.

[0080] The cold storage outlet of the interseasonal cold storage tank 10 is connected to the pipe g via pipe q, and the cold storage inlet of the interseasonal cold storage tank 10 is connected to the pipe d via pipe p, with the intersection of pipe p and pipe d being point S; at the same time, pipe q is connected to the pipe h via branch n, with the intersection of branch n and pipe h being point R, and the intersection of branch n and pipe q being point X; pipe p is connected to the pipe i via branch o, with the intersection of branch o and pipe p being point B;

[0081] The cooling tower 9 is connected to branch n and branch o through pipe w, that is, one end of pipe w is connected to branch o and the other end of pipe w is connected to branch n, and the intersection of pipe w and branch n is point Y; the middle part of pipe w flows through the cooling tower 9, and the cooling tower 9 cools the hot water in pipe w.

[0082] Pipeline j and pipeline n are connected by branch t, ​​and the intersection of pipeline n and branch t is point V, and the intersection of pipeline j and branch t is point W; pipeline m and pipeline o are connected by branch u.

[0083] Among them, on pipe b, points G, N, J, L, A and U are set sequentially along the direction from the first-stage heat exchanger 3 to the cooling and heating user 12, and on pipe c, points T, P, M, K, Q and H are set sequentially along the direction from the cooling and heating user 12 to the first-stage heat exchanger 3.

[0084] Valve 14 is installed on pipe b, between points N and J; Valve 15 is located on pipe j, between points N and W; Valve 16 is located on pipe e, between points G and I; Valve 17 is located on pipe a; Valve 18 is located on pipe d, between points S and J; Valve 19 is located on pipe h, between points R and L; Valve 20, 22, and 23 are all located on pipe n, with Valve 20 between points R and V, Valve 22 between points V and Y, and Valve 23 between points Y and X; Valve 21 is located on pipe p, between points S and B; Valve 24 is located on pipe k, between points Z and A; Valve 25 is located on pipe s; Valve 26 is located on pipe y.

[0085] The capacity of the cross-seasonal heat storage tank 8 and cross-seasonal cold storage tank 10 of the heat pump system in this embodiment can be further adjusted according to user needs. The cold and heat storage media include, but are not limited to, water, heat transfer oil, molten salt, paraffin, composite phase change materials, etc.

[0086] In this embodiment, the heat pump system is equipped with heat exchange coils in the interseasonal heat storage tank 8 and the interseasonal cold storage tank 10, and the heat exchange medium in the heat exchange coils is treated water.

[0087] In this embodiment, the outer surfaces of the cross-seasonal cold storage tank 8 and cross-seasonal cold storage tank 10 of the heat pump system are provided with high-efficiency heat insulation material.

[0088] In this embodiment, the internal circulation of the heat pump unit 6 in the heat pump system is a refrigerant circulation;

[0089] In this embodiment, the primary heat exchanger 3, the secondary heat exchanger 4, and the tertiary heat exchanger 5 of the heat pump system are all plate heat exchangers, including but not limited to fixed tube sheet heat exchangers, U-shaped tube sheet heat exchangers, etc.

[0090] In this embodiment, the user 12 of the heat pump system can be a radiator, underfloor heating, or fan coil system, etc.

[0091] Example 2:

[0092] Based on Example 1, this embodiment provides an operation method for a low-energy heat pump system based on geothermal water and cross-seasonal energy storage. This operation method includes two operation modes: a summer operation mode and a winter operation mode. The switching between the summer and winter operation modes can be achieved by changing the opening and closing of valves in the valve group.

[0093] In summer operation mode, heat storage and cooling are provided; see appendix. Figure 3Close valves 1-14, 3-16, 4-17, 6-19, 10-23, and 11-24; do not simultaneously open valves 2-15, 5-18, 7-20, 8-21, 9-22, 12-25, and 13-26.

[0094] At the beginning of the cooling supply, all valves are closed. First, valve 1225 is opened, and the cooling circulation loop consisting of the pipe section from the cooling outlet to the cooling return port in the inter-seasonal cold storage tank 10, the pipe section between point U on pipe s, pipe r, and pipe b and the cooling user 12, and the pipe section between point T on pipe c and the cooling user 12 is connected. The cooling capacity in the inter-seasonal cold storage tank 10 is used to supply cooling to the cooling user 12.

[0095] When the cooling capacity in the interseasonal cold storage tank 10 cannot meet the cooling demand, valve 12 25 is closed, heat pump unit 6 is turned on and valve 5 18 is opened. The second cooling circulation loop formed by the pipe sections of the second input end and the second output end of the evaporator in heat pump unit 6, the pipe section between point J on pipe d, pipe g, and pipe b and the cooling and heating user 12, and the pipe section between point K on pipe c and the cooling and heating user 12 is connected, and the cooling capacity generated by the evaporator of heat pump unit 6 is used to provide cooling to the cooling and heating user 12.

[0096] When heat pump unit 6 is used for cooling, during the peak shaving and valley filling phase of the power grid, that is, during the off-peak electricity consumption period, valve 821 is opened, and the cold storage circuit consisting of the pipe sections of the second input end and the second output end of the evaporator in heat pump unit 6, pipe p, pipe q, and the pipe section between the cold storage inlet and cold storage outlet in the cross-seasonal cold storage tank 10 is connected; the cold energy generated by the evaporator of heat pump unit 6 is used to store cold energy in the cross-seasonal cold storage tank 10; during the peak electricity consumption period, heat pump unit 6 is turned off, valve 1225 is opened, and only the cross-seasonal cold storage tank 10 is used for cooling;

[0097] During summer heat storage, in addition to using heat pump unit 6 for cooling, high-temperature heat pump unit 7, valve 15, valve 20, and valve 22 are activated. The hot water flowing out of the condenser of heat pump unit 6 is mixed with the hot water flowing out of the secondary heat exchange pipe of primary heat exchanger 3 in high-temperature heat pump unit 7. After being heated by high-temperature heat pump unit 7, it is connected to the inter-seasonal heat storage tank 8 to store heat. This method simultaneously recovers the heat from the condenser of heat pump unit 6 and extracts some heat from the geothermal water in geothermal well 1. When the inter-seasonal heat storage tank 8 reaches its heat storage limit, the excess heat generated by the condenser in the heat storage heat pump unit 6 is discharged through cooling tower 9.

[0098] During the entire process of summer heat storage and cooling, geothermal water flows out from geothermal water extraction well 1, and after passing through primary heat exchanger 3, secondary heat exchanger 4, and tertiary heat exchanger 5 for heat exchange and cooling, it flows into geothermal water reinjection well 2.

[0099] When domestic hot water needs to be provided to domestic hot water user 13, the water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger 4 heats the domestic water in the pressure tank 11 through pipe z. When the temperature of the domestic water in the pressure tank 11 reaches the set temperature, it is output to domestic hot water user 13 to provide domestic hot water at the set temperature. When the three-stage heat exchanger 4 alone cannot heat the domestic water in the pressure tank 11 to the set temperature, valve 13 26 is opened. The domestic water in the pressure tank 11 mixes with the hot water discharged from the heating outlet of the inter-seasonal heat storage tank 8 to further raise the temperature, and then it is output to domestic hot water user 13 to provide domestic hot water at the set temperature. The set temperature is 50-60℃.

[0100] In winter operation mode, cold storage and heating are provided; see appendix. Figure 4 Close valves 5.18, 8.21, 9.22 and 12.25; do not open valves 1.14, 2.25, 3.16, 4.17, 6.19, 7.20, 10.23, 11.24 and 13.26 at the same time.

[0101] During winter heating, user load is divided into four load levels: Level 1 at the beginning of heating; Level 2 when outdoor temperature decreases and heating load increases; Level 3 when outdoor temperature decreases further and heating load increases again; and Level 4 when heating load reaches its peak. This embodiment prioritizes the cascade utilization of geothermal water for heating. Specifically, at Level 1 load, only geothermal water is used for heating. As the load level increases, the inter-seasonal heat storage tank 8 is activated. When the load peak is reached, the heat pump unit 6 is activated. The specific operating procedure for heating is as follows:

[0102] At the beginning of the heating season, all valves are closed. In the initial stage of heating (first-level load), valve 14 is opened to directly supply heating through the first-level heat exchanger 3. That is, the heating circulation loop formed by the secondary heat exchange pipes, pipes b and c of the first-level heat exchanger 3 and the heating and cooling users 12 is connected. The first-level heat exchanger 3 achieves direct heating to the heating and cooling users 12 through heat exchange with the geothermal water flowing out of the geothermal water extraction well 1. At the same time, the high-temperature heat pump unit 7 and valve 2 are opened to use geothermal water to store heat in the interseasonal heat storage tank 8.

[0103] When the outdoor temperature drops, the heating load increases (secondary load), valve 316 is opened, and the heating is provided by the combined heating of primary heat exchanger 3 and secondary heat exchanger 4. That is, the first heating loop formed by the secondary heat exchange pipes, pipes b and c of primary heat exchanger 3 and the heating and cooling users 12 is connected, and the second heating loop formed by the secondary heat exchange pipes, pipes e and f of secondary heat exchanger 4, the section from point G on pipe b to the heating and cooling users 12, and the section from point H on pipe c to the heating and cooling users 12 is connected. Primary heat exchanger 3 and secondary heat exchanger 4 respectively achieve combined heating for heating and cooling users 12 by exchanging heat with the geothermal water flowing out of geothermal water extraction well 1.

[0104] When the heating load increases again (level 3 load), valve 11 24 is opened and valve 2 15 is closed. A combined heating mode using geothermal water and the inter-seasonal heat storage tank 8 is adopted. This means that the heating circulation loop consisting of the secondary heat exchange pipes of the primary heat exchanger 3, pipes b and c, and the supply / cooling / heating user 12 is connected. The secondary heat exchange pipes of the secondary heat exchanger 4, pipes e and f, the section from point G on pipe b to the supply / cooling / heating user 12, and the section from point H on pipe c to the supply / cooling / heating user 12 are also connected. The second heating cycle loop is connected, and the third heating cycle loop is connected, consisting of the pipe section between the heating outlet and the heating return in the cross-seasonal heat storage tank 8, the pipe section from point A on pipe k, pipe l, and pipe b to the cooling and heating user 12, and the pipe section from point P on pipe c to the cooling and heating user 12. The first-stage heat exchanger 3 and the second-stage heat exchanger 4 achieve joint heating for the cooling and heating user 12 by exchanging heat with the geothermal water flowing out of the geothermal water extraction well 1 and the heat provided by the cross-seasonal heat storage tank 8.

[0105] When the heating load reaches its peak (Level IV load), valves 17 and 19 are opened, and heat pump unit 6 starts operating. The combined heating mode of direct geothermal water supply, inter-seasonal heat storage tank 8, and heat pump unit 6 is activated. Specifically, the first heating loop, consisting of the secondary heat exchange pipes of primary heat exchanger 3, pipes b and c, and the section between the supply and cooling / heating users 12, is connected. The second heating loop, consisting of the secondary heat exchange pipes of secondary heat exchanger 4, pipes e and f, the section from point G on pipe b to the supply and cooling / heating users 12, and the section from point H on pipe c to the supply and cooling / heating users 12, is also activated. The pipes between the heating outlet and the heating return outlet in the inter-seasonal heat storage tank 8 are also activated. The heating circulation loop consisting of the pipe section from point A on pipe k, pipe l, and pipe b to the cooling and heating user 12, and the pipe section from point P on pipe c to the cooling and heating user 12 is connected in three stages. The heating circulation loop consisting of the condenser of heat pump unit 6, the pipe section from point L on pipe i, pipe h, and pipe b to the cooling and heating user 12, and the pipe section from point M on pipe c to the cooling and heating user 12 is connected in four stages. The primary heat exchanger 3 and the secondary heat exchanger 4 achieve combined heating for the cooling and heating user 12 by exchanging heat with the geothermal water flowing out of the geothermal water extraction well 1, the heat provided by the cross-seasonal heat storage tank 8, and the heat provided by the condenser of heat pump unit 6.

[0106] Meanwhile, when heat pump unit 6 is used for heating, during the peak shaving and valley filling stage of the power grid, that is, during the valley period of electricity consumption, valve 720 is opened to connect the condenser of heat pump unit 6 with the cross-seasonal heat storage tank 8. The heat generated by the condenser of heat pump unit 6 stores heat in the cross-seasonal heat storage tank 8, which achieves the purpose of peak shaving.

[0107] During winter cold storage, valve 23 is opened to connect cooling tower 9 to cross-seasonal cold storage tank 10, and antifreeze is added to the circulating medium in the loop formed by cooling tower 9 and cross-seasonal cold storage tank 10. Cooling tower 9 collects the cold energy of the outside air and transfers it to cross-seasonal cold storage tank 10 for cold storage, which is used for cooling in summer.

[0108] During the entire process of winter cold storage and heating, geothermal water flows out from geothermal water extraction well 1, and after being cooled by heat exchangers 3, 4, and 5, it flows into geothermal water reinjection well 2.

[0109] When domestic hot water needs to be provided to domestic hot water user 13, the water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger 4 heats the domestic water in the pressure tank 11 through pipe z. When the temperature of the domestic water in the pressure tank 11 reaches the set temperature, it is output to domestic hot water user 13 to provide domestic hot water at the set temperature. When the three-stage heat exchanger 4 alone cannot heat the domestic water in the pressure tank 11 to the set temperature, valve 13 26 is opened. The domestic water in the pressure tank 11 mixes with the hot water discharged from the heating outlet of the inter-seasonal heat storage tank 8 to further raise the temperature, and then it is output to domestic hot water user 13 to provide domestic hot water at the set temperature. The set temperature is 50-60℃.

[0110] The combined heating mode of primary heat exchanger 3 and secondary heat exchanger 4 refers to the simultaneous activation of primary heat exchanger 3 and secondary heat exchanger 4 when primary heat exchanger 3 cannot meet the heating demand. The water supplied in the secondary heat exchange pipes of primary heat exchanger 3 and secondary heat exchanger 4 is mixed and then supplied to the cooling and heating users 12. (Experiments show that in specific areas, when the outdoor temperature is below 9℃, the direct supply from primary heat exchanger 3 cannot meet the heating demand. At this time, activating the combined heating mode of primary heat exchanger 3 and secondary heat exchanger 4 can meet the heating demand when the outdoor temperature is between 6-9℃, thereby reducing the start-up time of heat pump unit 6.)

[0111] The heat pump system in this embodiment is suitable for areas where the geothermal water temperature is above 55 degrees Celsius. The higher the geothermal water temperature, the lower the energy consumption and the higher the efficiency of the system.

[0112] The heat pump system in this embodiment is suitable for heating and cooling in public buildings and residential buildings with abundant geothermal resources.

[0113] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-energy heat pump system based on geothermal water and cross-seasonal energy storage, characterized in that, This includes geothermal water extraction wells, geothermal water reinjection wells, heat exchanger components, heat pump units, high-temperature heat pump units, inter-seasonal thermal storage tanks, cooling towers, inter-seasonal cold storage tanks, and users who supply cooling and heating. The geothermal water extraction well, the primary heat exchange pipeline of the heat exchanger assembly, and the geothermal water reinjection well are connected in sequence; the secondary heat exchange pipeline of the heat exchanger assembly is connected to the cooling and heating users for supplying heat to the cooling and heating users. One end of the heat pump unit is connected to the secondary heat exchange pipe of the heat exchanger assembly, and the other end is divided into a cooling end and a heating end. Both the cooling end and the heating end are connected to the users who need cooling and heating. The cooling end is used to provide cooling to the users who need cooling and heating, and the heating end is used to provide heating to the users who need cooling and heating. One end of the high-temperature heat pump unit is connected to the secondary heat exchange pipe of the heat exchanger assembly and the heating end of the heat pump unit, and the other end is connected to the cooling and heating users through the cross-seasonal heat storage tank. The high-temperature heat pump unit is used to store heat in the cross-seasonal heat storage tank, and the cross-seasonal heat storage tank is used to supply heat to the cooling and heating users. The cross-seasonal cold storage tank is connected to the cooling end of the heat pump unit and the other end is connected to the cooling and heating users. The cross-seasonal cold storage tank is used to provide cooling to the cooling and heating users. The cooling tower is connected to the cross-seasonal cold storage tank and is used to store cold in the cross-seasonal cold storage tank. The heat pump system also includes a pressure tank and domestic hot water users; The pressure tank stores domestic water. The input end of the pressure tank is connected to an external water source, and the output end of the pressure tank is connected to domestic hot water users. The external water source provides domestic hot water to domestic hot water users through the pressure tank. The pressure tank exchanges heat with the secondary heat exchange pipes of the heat exchanger assembly, and the secondary heat exchange pipes of the heat exchanger assembly heat the domestic water in the pressure tank; the pressure tank exchanges heat with the cross-seasonal heat storage tank, and the cross-seasonal heat storage tank further heats the domestic water in the pressure tank. The heat pump system also includes a valve group, which includes: valve one, valve two, valve three, valve four, valve five, valve six, valve seven, valve eight, valve nine, valve ten, valve eleven and valve twelve; The heat exchanger assembly includes a primary heat exchanger and a secondary heat exchanger; The cooling end of the heat pump unit is an evaporator, and the heating end is a condenser; The geothermal water extraction well is connected to the input end of the primary heat exchange pipe of the first-stage heat exchanger via a pipeline. The output end of the primary heat exchange pipe of the first-stage heat exchanger is connected to the input end of the primary heat exchange pipe of the second-stage heat exchanger via a pipeline. The output end of the primary heat exchange pipe of the second-stage heat exchanger is connected to the geothermal water reinjection well via a pipeline. The output end of the cooling and heating user is connected to the input end of the secondary heat exchange channel of the primary heat exchanger through pipe c, and the output end of the secondary heat exchange channel of the primary heat exchanger is connected to the input end of the cooling and heating user through pipe b. The output end of the secondary heat exchange pipe of the secondary heat exchanger is connected to pipe b through pipe e, and the intersection of pipe e and pipe b is point G; the input end of the secondary heat exchange pipe of the secondary heat exchanger is connected to pipe c through pipe f, and the intersection of pipe c and pipe f is point H. The first input terminal of the evaporator of the heat pump unit is connected to pipe e through pipe a, and the intersection of pipe a and pipe e is point I. The first output terminal of the evaporator is connected to pipe f. The second input terminal of the evaporator is connected to pipe c through pipe g, and the intersection of pipe g and pipe c is point K. The second output terminal of the evaporator is connected to pipe b through pipe d, and the intersection of pipe d and pipe b is point J. The output end of the condenser of the heat pump unit is connected to the pipe b through pipe h, and the intersection of pipe h and pipe b is point L. The input end of the condenser is connected to the pipe c through pipe i, and the intersection of pipe i and pipe c is point M. The heating outlet of the interseasonal thermal storage tank is connected to pipe b through pipe k, and the intersection of pipe k and pipe b is point A; the heating return outlet of the interseasonal thermal storage tank is connected to pipe c through pipe l, and the intersection of pipe l and pipe c is point P. The heat storage outlet of the interseasonal heat storage tank is connected to the first input end of the high-temperature heat pump unit; the first output end of the high-temperature heat pump unit is connected to pipe c through pipe m, and the intersection of pipe m and pipe c is point Q; the second input end of the high-temperature heat pump unit is connected to pipe b through pipe j, and the intersection of pipe j and pipe b is point N; the second output end of the high-temperature heat pump unit is connected to the heat storage inlet of the interseasonal heat storage tank. The cooling outlet of the interseasonal cold storage tank is connected to pipe b through pipe s, and the intersection of pipe s and pipe b is point U. The cooling return outlet of the interseasonal cold storage tank is connected to pipe c through pipe r, and the intersection of pipe r and pipe c is point T. The cold storage outlet of the interseasonal cold storage tank is connected to pipe g via pipe q, and the cold storage inlet of the interseasonal cold storage tank is connected to pipe d via pipe p, with point S being the intersection of pipe p and pipe d; at the same time, pipe q is connected to pipe h via branch n, with point R being the intersection of branch n and pipe h, and point X being the intersection of branch n and pipe q; pipe p is connected to pipe i via branch o, with point B being the intersection of branch o and pipe p. The cooling tower is connected to branch n and branch o via pipe w, that is, one end of pipe w is connected to branch o and the other end of pipe w is connected to branch n, and the intersection of pipe w and branch n is point Y; the middle part of pipe w flows through the cooling tower, and the cooling tower cools the hot water in pipe w. Pipeline j and pipeline n are connected through branch t, ​​and the intersection of pipeline n and branch t is point V, while the intersection of pipeline j and branch t is point W; pipeline m and pipeline o are connected through branch u. Valve 1 is installed on pipe b, between points N and J; Valve 2 is located on pipe j, between points N and W; Valve 3 is located on pipe e, between points G and I; Valve 4 is located on pipe a; Valve 5 is located on pipe d, between points S and J; Valve 6 is located on pipe h, between points R and L; Valves 7, 9, and 10 are all located on pipe n, with Valve 7 between points R and V, Valve 9 between points V and Y, and Valve 10 between points Y and X; Valve 8 is located on pipe p, between points S and B; Valve 11 is located on pipe k, between points Z and A; Valve 12 is located on pipe s. The valve group also includes valve thirteen; the heat exchanger assembly also includes a three-stage heat exchanger. The primary heat exchange pipe of the tertiary heat exchanger is connected in series between the primary heat exchange pipe of the secondary heat exchanger and the geothermal water reinjection well. The output end of the primary heat exchange pipe of the secondary heat exchanger is connected to the input end of the primary heat exchange pipe of the tertiary heat exchanger through a pipeline. The output end of the primary heat exchange pipe of the tertiary heat exchanger is connected to the geothermal water reinjection well through a pipeline. The output end of the secondary heat exchange pipe of the three-stage heat exchanger is connected to the input end of the secondary heat exchange pipe of the three-stage heat exchanger through pipe z, and pipe z flows through the pressure tank. The water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger heats the domestic water in the pressure tank through pipe z. Pipeline k and pipeline l exchange heat with the pressure tank through pipeline y. One end of pipeline y is connected to pipeline k, and the intersection of pipeline y and pipeline k is point Z. The other end of pipeline y is connected to pipeline l. Pipeline y flows through the pressure tank, and the hot water flowing out from the cross-seasonal heat storage tank further heats the domestic water in the pressure tank through pipeline y. Valve thirteen is located on pipeline y.

2. The low-energy heat pump system based on geothermal water and cross-seasonal energy storage as described in claim 1, characterized in that, The heat exchanger assembly adopts a fixed tube sheet heat exchanger or a U-shaped tube sheet heat exchanger.

3. An operation method for a low-energy heat pump system based on geothermal water and cross-seasonal energy storage, based on the low-energy heat pump system of any one of claims 1-2, characterized in that, This operating method includes two operating modes: summer operating mode and winter operating mode. The switching between summer and winter operating modes can be achieved by changing the opening and closing of the valves in the valve group.

4. The operation method of a low-energy heat pump system based on geothermal water and cross-seasonal energy storage as described in claim 3, characterized in that, In summer operation mode, heat storage and cooling are carried out. At the beginning of cooling, all valves are closed. First, valve twelve is opened, and the cooling circulation loop consisting of the section from the cooling outlet to the cooling return in the cross-seasonal cold storage tank, the section from point U on pipe s, pipe r, and pipe b to the cooling and heating users, and the section from point T on pipe c to the cooling and heating users is connected. The cold energy in the cross-seasonal cold storage tank is used to provide cooling to the cooling and heating users. When the cooling capacity in the cross-seasonal cold storage tank cannot meet the cooling demand, valve twelve is closed, the heat pump unit is turned on and valve five is opened. The second cooling circulation loop, consisting of the pipe sections at the second input and second output ends of the evaporator in the heat pump unit, the pipe section from point J on pipe d, pipe g, and pipe b to the cooling and heating users, and the pipe section from point K on pipe c to the cooling and heating users, is connected, and the cooling capacity generated by the evaporator of the heat pump unit is used to provide cooling to the cooling and heating users. During summer heat storage, in addition to using heat pump units for cooling, the high-temperature heat pump unit, valves two, seven, and nine are opened. Hot water flowing from the condenser of the heat pump unit is mixed with hot water flowing from the secondary heat exchange pipes of the primary heat exchanger within the high-temperature heat pump unit. The mixture is then heated by the high-temperature heat pump unit and connected to the inter-seasonal heat storage tank for heat storage. This method simultaneously recovers heat from the condenser of the heat pump unit and extracts some heat from the geothermal water from the well. When the inter-seasonal heat storage tank reaches its heat storage limit, the excess heat generated by the condenser in the heat pump unit is discharged through a cooling tower. During the entire process of summer heat storage and cooling, geothermal water flows out from the geothermal water extraction well, passes through the primary heat exchanger, the secondary heat exchanger, and the tertiary heat exchanger in sequence to exchange heat and cool down before flowing into the geothermal water reinjection well. When domestic hot water needs to be provided to users, the water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger heats the domestic water in the pressure tank through pipe z. When the temperature of the domestic water in the pressure tank reaches the set temperature, it is output to the domestic hot water users to provide domestic hot water at the set temperature. When the three-stage heat exchanger alone cannot heat the domestic water in the pressure tank to the set temperature, valve thirteen is opened. The domestic water in the pressure tank mixes with the hot water discharged from the heating outlet of the inter-seasonal heat storage tank to further raise the temperature before being output to the domestic hot water users to provide domestic hot water at the set temperature.

5. The operation method of a low-energy heat pump system based on geothermal water and cross-seasonal energy storage as described in claim 4, characterized in that, When a heat pump unit is used for cooling, valve eight is opened during off-peak electricity consumption periods, connecting the cold storage circuit consisting of the pipe sections at the second input and second output ends of the evaporator in the heat pump unit, pipe p, pipe q, and the pipe section between the cold storage inlet and cold storage outlet in the inter-seasonal cold storage tank; the cooling capacity generated by the evaporator of the heat pump unit is used to store cold in the inter-seasonal cold storage tank; during peak electricity consumption periods, the heat pump unit is turned off, valve twelve is opened, and only the inter-seasonal cold storage tank is used for cooling.

6. The operation method of a low-energy heat pump system based on geothermal water and cross-seasonal energy storage as described in claim 3, characterized in that, In winter operation mode, cold storage and heating are implemented. During winter heating, user loads are divided into several levels: Level 1 load at the beginning of heating; Level 2 load as outdoor temperature decreases and heating load increases; Level 3 load as outdoor temperature further decreases and heating load increases again; and Level 4 load when the heating load reaches its peak. The specific operating procedure for heating is as follows: At the beginning of the heating season, all valves are closed. Under primary load, valve one is opened to directly supply heating using the primary heat exchanger. This means that the heating circulation loop consisting of the secondary heat exchange pipes, pipes b and c of the primary heat exchanger and the users of heating and cooling is connected. The primary heat exchanger achieves direct heating to the users of heating and cooling by exchanging heat with the geothermal water flowing from the geothermal well. At the same time, the high-temperature heat pump unit and valve two are opened to use geothermal water to store heat in the interseasonal heat storage tank. At level 2 load, valve 3 is opened, and a combined heating method using the primary and secondary heat exchangers is adopted. That is, the first heating loop, consisting of the secondary heat exchange pipes of the primary heat exchanger, pipe b, pipe c, and the heating / cooling users, is connected. The second heating loop, consisting of the secondary heat exchange pipes of the secondary heat exchanger, pipe e, pipe f, the section from point G on pipe b to the heating / cooling users, and the section from point H on pipe c to the heating / cooling users, is connected. The primary and secondary heat exchangers achieve combined heating for the heating / cooling users by exchanging heat with the geothermal water flowing out of the geothermal water extraction well. At level 3 load, valve 11 is opened and valve 2 is closed. The combined heating mode of geothermal water and cross-seasonal heat storage tank is adopted. That is, the first heating loop is connected, which consists of the secondary heat exchange pipes of the primary heat exchanger, pipe b, pipe c and the heating and cooling users. The second heating loop is connected, which consists of the secondary heat exchange pipes of the secondary heat exchanger, pipe e, pipe f, the section from point G on pipe b to the heating and cooling users, and the section from point H on pipe c to the heating and cooling users. The third heating loop is connected, which consists of the section between the heating outlet and the heating return in the cross-seasonal heat storage tank, pipe k, pipe l, the section from point A on pipe b to the heating and cooling users, and the section from point P on pipe c to the heating and cooling users. The primary heat exchanger and the secondary heat exchanger achieve combined heating for the heating and cooling users through heat exchange with the geothermal water flowing out of the geothermal water extraction well and the heat provided by the cross-seasonal heat storage tank. At level four load, valves four and six are opened, at which point the heat pump unit starts operating, utilizing a combined heating mode of direct geothermal water supply + inter-seasonal thermal storage tank + heat pump unit. Specifically, heating loop one, consisting of the secondary heat exchange pipes of the primary heat exchanger, pipes b and c, and the section between the supplying and receiving users, is connected. Heating loop two, consisting of the secondary heat exchange pipes of the secondary heat exchanger, pipes e and f, the section from point G on pipe b to the supplying and receiving users, and the section from point H on pipe c to the supplying and receiving users, is also connected. The section of pipe k between the heating outlet and the heating return outlet in the inter-seasonal thermal storage tank is also connected. The heating circulation loop consisting of point A on pipe l and pipe b to the cooling and heating users, and point P on pipe c to the cooling and heating users, is connected in three stages. The heating circulation loop consisting of the condenser of the heat pump unit, pipe i, pipe h, point L on pipe b to the cooling and heating users, and point M on pipe c to the cooling and heating users, is connected in four stages. The primary heat exchanger and the secondary heat exchanger achieve combined heating for the cooling and heating users by exchanging heat with the geothermal water flowing out of the geothermal water extraction well, the heat provided by the cross-seasonal heat storage tank, and the heat provided by the condenser of the heat pump unit. During winter cold storage, valve 10 is opened to connect the cooling tower to the interseasonal cold storage tank, and antifreeze is added to the circulating medium in the loop formed by the cooling tower and the interseasonal cold storage tank. The cooling tower collects the cold energy from the outside air and transfers it to the interseasonal cold storage tank for cold storage, which is then used for cooling in the summer. During the entire process of winter cold storage and heating, geothermal water flows out from the geothermal water extraction well, and after passing through the primary heat exchanger, the secondary heat exchanger, and the tertiary heat exchanger for heat exchange and cooling, it flows into the geothermal water reinjection well. When domestic hot water needs to be provided to users, the water flowing out of the secondary heat exchange pipe of the three-stage heat exchanger heats the domestic water in the pressure tank through pipe z. When the temperature of the domestic water in the pressure tank reaches the set temperature, it is output to the domestic hot water users to provide domestic hot water at the set temperature. When the three-stage heat exchanger alone cannot heat the domestic water in the pressure tank to the set temperature, valve thirteen is opened. The domestic water in the pressure tank mixes with the hot water discharged from the heating outlet of the inter-seasonal heat storage tank to further raise the temperature before being output to the domestic hot water users to provide domestic hot water at the set temperature.

7. The operation method of a low-energy heat pump system based on geothermal water and cross-seasonal energy storage as described in claim 6, characterized in that, When using a heat pump unit for heating, valve seven is opened during off-peak electricity hours to connect the condenser of the heat pump unit to the inter-seasonal heat storage tank. The heat generated by the condenser of the heat pump unit stores heat in the inter-seasonal heat storage tank.

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