Geothermal heat pump system

Abstract

A geothermal heat pump system comprises a user side heat exchanger, a refrigerant loop, a first circulation loop, a second circulation loop and a heat exchange pipe buried underground, the refrigerant loop comprises a compressor, a four-way valve, an outdoor heat exchanger and an indoor heat exchanger, and the heat exchange pipe is communicated with the outdoor heat exchanger through the first circulation loop. The indoor heat exchanger is communicated with the user side heat exchanger through a second circulation loop; the refrigerant circuit further comprises a supercooling heat exchanger installed in a pipeline connected between the outdoor heat exchanger and the indoor heat exchanger. By adopting the technical scheme, the problem of low energy collection efficiency of the system is solved, and the heat exchange efficiency of the system is improved.

Description

[Technical field]

[0001] The utility model relates to the technical field of heat pumps, in particular to a geothermal heat pump system. [Background technology]

[0002] As the global energy crisis and environmental problems become increasingly serious, the demand for renewable energy and environmental protection technologies is growing. Geothermal heat pump technology, as an efficient and environmentally friendly heating and cooling method, has received widespread attention and application. Geothermal heat pump systems use the earth's surface soil, groundwater or surface water as heat sources or cold sources, and heat or cool indoor spaces through heat pump cycles, while also providing hot water supply.

[0003] The development and utilization of shallow geothermal energy can be roughly divided into three types: ground source heat pump system, shallow geothermal ventilation pretreatment system and underground heat storage system. The ground source heat pump system has the characteristics of high efficiency and no pollution, among which the vertical buried pipe ground source heat pump system is the most commonly used. The vertical buried pipe ground source heat pump system uses rock and soil as heat source / cold sink, exchanges heat with the rock and soil through underground heat exchangers, and uses heat pump technology to input a small amount of high-level electricity to transport a large amount of cold and heat sources extracted from the underground to indoor buildings for heating / cooling or input into household hot water. Existing ground source heat pump technology generally has problems such as low energy collection efficiency and insufficient energy utilization. [Contents of the utility model]

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a geothermal heat pump system to solve the problem of low energy collection efficiency of the system and improve the heat exchange efficiency of the system.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A geothermal heat pump system, comprising:

[0007] It includes a user-side heat exchanger, a refrigerant circuit, a first circulation circuit, a second circulation circuit and a heat exchange pipe buried under the ground. The refrigerant circuit includes a compressor, a four-way valve, an outdoor heat exchanger and an indoor heat exchanger. The heat exchange pipe is connected to the outdoor heat exchanger through the first circulation circuit, and the indoor heat exchanger is connected to the user-side heat exchanger through the second circulation circuit. The refrigerant circuit also includes a subcooling heat exchanger installed in a pipeline connected between the outdoor heat exchanger and the indoor heat exchanger.

[0008] The utility model is further configured as follows: both the first circulation loop and the second circulation loop are equipped with circulation water pumps.

[0009] The utility model is further configured as follows: the refrigerant circuit also includes a heat exchanger, a third circulation circuit and a water storage tank, the heat exchanger is installed between the compressor and the four-way valve, and the heat exchanger is connected to the water storage tank through the third circulation circuit.

[0010] The utility model is further configured as follows: a throttling device and a cut-off device are installed and connected between the outdoor heat exchanger and the indoor heat exchanger, and the throttling device is installed between the supercooling heat exchanger and the outdoor heat exchanger.

[0011] The utility model is further configured as follows: a temperature sensor is connected to the throttling device, and the temperature sensor is used to monitor the temperature of the circulating fluid.

[0012] The utility model is further configured as follows: the buried depth of the heat exchange tube is 100-180m, the diameter of the drill hole for burying the heat exchange tube is not less than 0.10m and the drilling distance is 4-6m.

[0013] The utility model is further configured as follows: the heat exchange tube comprises a spiral section and a circular tube section connected to each other, the spiral section and the circular tube section together constitute a U-shaped flow path, and the spiral section comprises one or more spiral circular tubes in a spiral shape.

[0014] The utility model is further configured as follows: the diameter of any of the spiral circular tubes is smaller than the diameter of the circular tube section.

[0015] The utility model is further configured as follows: bypass pipes are arranged on both sides of the subcooling heat exchanger, and the subcooling heat exchanger and the bypass pipe are both equipped with solenoid valves for controlling opening and closing.

[0016] The utility model is further configured as follows: the subcooling heat exchanger is also connected to the outdoor heat exchanger through the first circulation loop, and the subcooling heat exchanger uses the geothermal water after the heat exchange by the outdoor heat exchanger to perform heat exchange.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] 1. The utility model system optimizes the refrigerant circuit by introducing a subcooling heat exchanger. The subcooling heat exchanger is installed in the pipeline between the throttling device and the indoor heat exchanger, and uses the geothermal water after heat exchange in the outdoor heat exchanger for secondary heat exchange. By throttling the refrigerant in the throttling device and flowing into the subcooling heat exchanger, the geothermal water is used for subcooling, thereby improving the heating performance and operation stability of the system;

[0019] 2. The utility model adds a heat exchanger between the compressor and the four-way valve, and connects it to the water tank through the third circulation loop. This technology not only makes full use of the heat in the refrigerant circuit, provides hot water for the water tank, but also increases the versatility of the system;

[0020] 3. The heat exchange tube of the utility model adopts a U-shaped flow path design combining a spiral section and a circular tube section. The spiral section includes one or more spiral circular tubes in a spiral shape. This design significantly increases the heat exchange area and improves the heat exchange efficiency.

Brief Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the geothermal heat pump system of this embodiment;

[0022] Figure 2 Schematic diagram of the structure of the heat exchange tube of this embodiment.

[0023] Figure numerals: 1. user-side heat exchanger; 21. first circulation loop; 22. second circulation loop; 23. third circulation loop; 31. compressor; 32. four-way valve; 33. outdoor heat exchanger; 34. indoor heat exchanger; 35. subcooling heat exchanger; 36. throttling device; 4. heat exchange tube; 41. spiral section; 42. circular tube section; 51. heat exchanger; 52. water tank. [Specific implementation method]

[0024] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0025] It should be understood that the various steps described in the method implementation of the present utility model can be performed in different orders and / or performed in parallel. In addition, the method implementation may include additional steps and / or omit the steps shown. The scope of the present utility model is not limited in this respect.

[0026] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "connected" may be directly connected or indirectly connected through intermediate components (elements). The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0027] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish between devices, modules or units, and are not used to limit these devices, modules or units to be different devices, modules or units, nor are they used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0028] Geothermal heat pump system, also known as ground source heat pump (GSHP), uses normal temperature soil or surface water (groundwater) as heat source, and realizes seasonal conversion of energy through efficient heat pump technology. The system consists of ground source heat pump unit, geothermal energy exchange system, and building system, and is designed to replace the traditional mode of air conditioning, heating and heat supply of refrigerators and boilers. It is an effective way to improve the urban atmospheric environment and save energy.

[0029] like Figure 1 and Figure 2 As shown, the utility model discloses a geothermal heat pump system, comprising:

[0030] The system includes a user-side heat exchanger 1, a refrigerant circuit, a first circulation circuit 21, a second circulation circuit 22, and a heat exchange pipe 4 buried under the ground. The refrigerant circuit includes a compressor 31, a four-way valve 32, an outdoor heat exchanger 33, and an indoor heat exchanger 34. The heat exchange pipe 4 is connected to the outdoor heat exchanger 33 through the first circulation circuit 21, and the indoor heat exchanger 34 is connected to the user-side heat exchanger 1 through the second circulation circuit 22. The refrigerant circuit also includes a subcooling heat exchanger 35 installed in a pipeline connected between the outdoor heat exchanger 33 and the indoor heat exchanger 34. A throttling device 36 and a cut-off device are installed and connected between the outdoor heat exchanger 33 and the indoor heat exchanger 34, and the throttling device 36 is installed between the subcooling heat exchanger 35 and the outdoor heat exchanger 33. By introducing the subcooling heat exchanger 35, the refrigerant circuit is optimized, and the geothermal water after heat exchange in the outdoor heat exchanger 33 is used for secondary heat exchange, thereby improving the heating performance and operation stability of the system.

[0031] Optionally, the subcooling heat exchanger 35 is also connected to the outdoor heat exchanger 33 through the first circulation loop 21. The subcooling heat exchanger 35 uses the geothermal water after heat exchange in the outdoor heat exchanger 33 for heat exchange, and uses the geothermal water to cool the refrigerant, thereby improving the heat exchange efficiency of the refrigerant in the outdoor heat exchanger 33.

[0032] Specifically, the heat exchange tube 4 is buried under the ground and exchanges heat with the soil or groundwater as the heat source or cold source of the system. The heat exchange tube 4 adopts a U-shaped tube form, and the heat exchange tube 4 is connected to the outdoor heat exchanger 33 through the first circulation loop 21. As one of the core components of the geothermal heat pump system, the heat exchange tube 4 mainly provides a stable heat source or cold source for the system by exchanging heat with the soil or groundwater. The heat exchange tube 4 is buried under the ground and uses geothermal energy, a renewable natural energy source, to achieve efficient conversion and utilization of energy. When the system is in heating mode, the heat exchange tube 4 absorbs heat from the soil and transfers the heat to the outdoor heat exchanger 33 through the first circulation loop 21. The outdoor heat exchanger 33 transfers the heat in the geothermal water to the refrigerant. The heat energy is circulated through the refrigerant circuit and is finally transported to the user side to achieve heating of the indoor space.

[0033] Specifically, the compressor 31 is used to compress the low-temperature and low-pressure refrigerant gas into the high-temperature and high-pressure refrigerant gas; the four-way valve 32 changes the direction of the refrigerant gas compressed by the compressor 31 through the four-way valve 32 to realize a refrigeration or heating cycle; the indoor heat exchanger 34 is used as an evaporator for cooling operation and a condenser for heating operation; the outdoor heat exchanger 33 is used as a condenser for cooling operation and an evaporator for heating operation.

[0034] For example, in winter, the compressor 31 sucks in refrigerant gas and compresses it into a high-temperature and high-pressure state; after the direction of the four-way valve 32 is switched, the high-temperature and high-pressure refrigerant gas flows to the indoor heat exchanger 34, and the refrigerant gas condenses by heat release in the indoor heat exchanger 34, and transfers heat to the user-side heat exchanger 1 through the second circulation loop 22, and the condensed refrigerant changes from gas to liquid; the liquid refrigerant enters the supercooling heat exchanger 35 to exchange heat with geothermal water, further reducing the temperature of the liquid refrigerant; when the liquid refrigerant passes through the throttling device 36, the pressure and temperature are further reduced; the low-pressure and low-temperature liquid refrigerant enters the outdoor heat exchanger 33, and the refrigerant evaporates by absorbing external heat (such as heat in the soil), changing from liquid to gas, and the circulating liquid in the first circulation loop 21 is cooled and continues to circulate to the heat exchange tube 4; the evaporated refrigerant gas is sucked in by the compressor 31 again to start a new round of circulation.

[0035] Optionally, both the first circulation loop 21 and the second circulation loop 22 are equipped with a circulation water pump, which plays a key role in the circulation loop. By driving the fluid (such as water, geothermal water, etc.) to flow continuously in the circulation loop, heat transfer, recovery or distribution is achieved, ensuring the efficient operation of the system and the comfort and stability of the indoor environment.

[0036] Optionally, the refrigerant circuit further includes a heat exchanger 51 , a third circulation circuit 23 and a water storage tank 52 , the heat exchanger 51 is installed between the compressor 31 and the four-way valve 32 , and the heat exchanger 51 is connected to the water storage tank 52 through the third circulation circuit 23 .

[0037] Specifically, the heat exchanger 51 is installed between the compressor 31 and the four-way valve 32. The refrigerant gas compressed under high temperature and high pressure is always discharged through the heat exchanger 51, and part of the heat is transferred to the water in the water tank 52 through the third circulation loop 23. Therefore, the water tank 52 can always use hot water during cooling or heating, thereby improving the utilization rate of heat.

[0038] Optionally, a temperature sensor is connected to the throttling device 36, and the temperature sensor is used to monitor the temperature of the circulating fluid. By monitoring the temperature of the circulating fluid, the system can adjust the working state in time to ensure that the refrigerant circulates within the optimal temperature range, thereby improving the operating efficiency of the entire system; at the same time, the temperature sensor also provides an important basis for system fault diagnosis. Once an abnormal temperature is detected, the system can respond quickly and in time to avoid potential operating risks.

[0039] Optionally, the buried depth of the heat exchange tube 4 is 100-180m, the diameter of the drill hole for burying the heat exchange tube 4 is not less than 0.10m and the drill hole spacing is 4-6m. The heat exchange tube 4 includes a spiral section 41 and a circular tube section 42 connected to each other, and the spiral section 41 and the circular tube section 42 together constitute a U-shaped flow path, and the spiral section 41 includes one or more spiral circular tubes in a spiral shape, and the diameter of any spiral circular tube is smaller than the diameter of the circular tube section 42. The heat exchange tube 4 adopts a U-shaped flow path design combining a spiral section 41 and a circular tube section 42, and the spiral section 41 includes one or more spiral circular tubes in a spiral shape. This design significantly increases the heat exchange area and improves the heat exchange efficiency.

[0040] Optionally, bypass pipes are provided on both sides of the subcooling heat exchanger 35, and both the subcooling heat exchanger 35 and the bypass pipe are equipped with solenoid valves for controlling opening and closing, so that the refrigerant bypasses the subcooling heat exchanger 35 during operation in summer, and the refrigerant passes directly into the indoor heat exchanger 34 through the bypass pipe.

[0041] For example, in summer, the compressor 31 sucks in refrigerant gas and compresses it into a high-temperature and high-pressure state; then the high-temperature and high-pressure refrigerant gas flows to the outdoor heat exchanger 33, and releases heat into the underground soil or water through the exothermic condensation process. The refrigerant becomes liquid after condensation, and the pressure is reduced through the throttling device 36, which controls the solenoid valve, opens the bypass channel, closes the subcooling heat exchanger 35, and directly enters the indoor heat exchanger 34 through the bypass channel; in the indoor heat exchanger 34, the refrigerant absorbs the heat of the indoor air through the second circulation loop 22, thereby lowering the indoor temperature, and at the same time, it evaporates from liquid to gas, and then circulates back to the compressor 31 again to complete the entire refrigeration cycle.

[0042] Some exemplary embodiments of the utility model are described above, but those skilled in the art will appreciate that changes may be made to these exemplary embodiments without departing from the principles or spirit of the utility model, and the scope of the utility model is defined by the claims and their equivalents.

Claims

1. A geothermal heat pump system, characterized in that: include: The invention comprises a user-side heat exchanger (1), a refrigerant circuit, a first circulation circuit (21), a second circulation circuit (22) and a heat exchange pipe (4) buried underground, wherein the refrigerant circuit comprises a compressor (31), a four-way valve (32), an outdoor heat exchanger (33) and an indoor heat exchanger (34), wherein the heat exchange pipe (4) is connected to the outdoor heat exchanger (33) through the first circulation circuit (21), and the indoor heat exchanger (34) is connected to the user-side heat exchanger (1) through the second circulation circuit (22); the refrigerant circuit also comprises a subcooling heat exchanger (35) installed in a pipeline connected between the outdoor heat exchanger (33) and the indoor heat exchanger (34).

2. The geothermal heat pump system according to claim 1, characterized in that: Both the first circulation loop (21) and the second circulation loop (22) are equipped with circulating water pumps.

3. The geothermal heat pump system according to claim 1, characterized in that: The refrigerant circuit also includes a heat exchanger (51), a third circulation circuit (23) and a water storage tank (52); the heat exchanger (51) is installed between the compressor (31) and the four-way valve (32); the heat exchanger (51) is connected to the water storage tank (52) via the third circulation circuit (23).

4. The geothermal heat pump system according to claim 1, characterized in that: A throttling device (36) and a shut-off device are installed and connected between the outdoor heat exchanger (33) and the indoor heat exchanger (34), and the throttling device (36) is installed between the subcooling heat exchanger (35) and the outdoor heat exchanger (33).

5. The geothermal heat pump system according to claim 4, characterized in that: The throttling device (36) is connected to a temperature sensor, which is used to monitor the temperature of the circulating fluid.

6. The geothermal heat pump system according to claim 1, characterized in that: The buried depth of the heat exchange tube (4) is 100-180 m, the diameter of the drill hole for burying the heat exchange tube (4) is not less than 0.10 m, and the drilling hole spacing is 4-6 m.

7. The geothermal heat pump system according to claim 6, characterized in that: The heat exchange tube (4) comprises a spiral section (41) and a circular tube section (42) which are connected to each other. The spiral section (41) and the circular tube section (42) together form a U-shaped flow path. The spiral section (41) comprises one or more spiral circular tubes in a spiral shape.

8. The geothermal heat pump system according to claim 7, characterized in that: The diameter of any of the spiral circular tubes is smaller than the diameter of the circular tube section (42).

9. The geothermal heat pump system according to claim 1, characterized in that: Bypass pipes are arranged on both sides of the subcooling heat exchanger (35), and both the subcooling heat exchanger (35) and the bypass pipe are installed with solenoid valves for controlling opening and closing.

10. The geothermal heat pump system according to claim 1, characterized in that: The subcooling heat exchanger (35) is also connected to the outdoor heat exchanger (33) via the first circulation loop (21), and the subcooling heat exchanger (35) performs heat exchange using the geothermal water after heat exchange in the outdoor heat exchanger (33).

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