Underground heat exchanger for ground source heat pump unit

Abstract

The invention provides an underground heat exchanger for a ground source heat pump unit, which belongs to the technical field of ground source heat pumps and comprises a water inlet module, a water drainage module, a heat exchange module, a circulating pump and a heat source water circulation module. The heat exchange module comprises a shell and a heat exchange mechanism arranged in the shell. The number of the heat exchange mechanisms is at least two, and the at least two heat exchange mechanisms are vertically arranged in the shell. One end of the heat exchange mechanism is connected with the water inlet module, and the other end is connected with the drainage module. The circulating pump is arranged in the water inlet module or the water outlet module; the circulating pump is used for driving underground water to enter the heat exchange mechanism from the water inlet module and be drained from the drainage module. The heat source water circulation module is connected with the shell and used for conveying heat source water into the shell and recycling the heat source water in the shell so that the heat source water can flow between the shell and the heat exchange mechanism, and therefore the heat source water exchanges heat with the heat exchange mechanism.

Description

Technical Field

[0001] The present invention belongs to the technical field of ground source heat pumps, and more specifically, relates to a downhole heat exchanger for a ground source heat pump unit. Background Art

[0002] The downhole heat exchanger used in geothermal heat pump units is a shell-and-tube heat exchanger that exchanges heat between groundwater and heat source water. During the heat exchange process, the groundwater and heat source water are not separated, and heat exchange occurs through metal pipes. The heat exchanger does not pump the groundwater out of the ground; it simply heats the heat source water by circulating it underground. After the heat source water extracts heat through the ground-source heat pump, it is then sent back underground to be heated by the heat exchanger. To ensure heat exchange, the shell-and-tube heat exchanger is typically over 30 meters long and arranged vertically in a 200-meter-deep underground well. Groundwater from -200 meters circulates through the heat exchanger's inner tubes to -160 meters. The heat source water flows through the gap between the inner tubes and the heat exchanger's outer shell to the bottom of the heat exchanger, where it exchanges heat with the inner tube walls, heating the heat source water.

[0003] Existing heat exchangers have the following drawbacks: as groundwater flows upward, it continuously exchanges heat with the heat source water, causing the groundwater's heat to continuously dissipate and its temperature to continuously decrease. As the groundwater flows through the top of the heat exchanger, its temperature is lower, resulting in poor heat transfer efficiency at the top. Summary of the Invention

[0004] The object of the present invention is to provide a downhole heat exchanger for a ground source heat pump unit, aiming to solve the problem of low heat exchange efficiency at the top of the downhole heat exchanger for a ground source heat pump unit in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide a downhole heat exchanger for a ground source heat pump unit, comprising:

[0006] Water inlet module;

[0007] Drainage module;

[0008] A heat exchange module comprising a housing and a heat exchange mechanism disposed inside the housing; at least two heat exchange mechanisms are provided, and at least two heat exchange mechanisms are arranged vertically in the housing; one end of the heat exchange mechanism is connected to the water inlet module, and the other end is connected to the drainage module;

[0009] a circulation pump, provided in the water inlet module or the drainage module; the circulation pump is used to drive groundwater from the water inlet module into the heat exchange mechanism and be discharged from the drainage module; and

[0010] A heat source water circulating module is connected to the shell and used to deliver heat source water into the shell and recover heat source water from the shell, so that the heat source water flows between the shell and the heat exchange mechanism and exchanges heat with the heat exchange mechanism.

[0011] In a possible implementation, the water inlet module is arranged at the bottom of the shell, the water outlet module is arranged at the top of the shell, and the circulating pump is arranged in the water outlet module.

[0012] In a possible implementation, the water inlet module includes a sieve water guide pipe fixedly connected to the outer side of the bottom of the shell, and the bottom of the heat exchange mechanism penetrates through the bottom of the shell and communicates with the sieve water guide pipe.

[0013] In a possible implementation, the water outlet module includes a flower pipe fixedly connected to the top of the shell, and the top of the heat exchange mechanism penetrates through the top of the shell and communicates with the flower pipe.

[0014] In a possible implementation, the heat exchange mechanism includes:

[0015] A heat exchange pipe is arranged inside the shell and has a reserved gap inside the shell; when the underground water passes through the heat exchange pipe, the underground water exchanges heat with the heat source water in the shell; the heat exchange pipe penetrates through the bottom of the shell downward and communicates with the sieve water guide pipe, or penetrates through the top of the shell upward and communicates with the flower pipe; and

[0016] A main pipe is arranged inside the shell; the main pipe penetrates through the top of the shell upward and communicates with the flower pipe, or penetrates through the bottom of the shell downward and communicates with the sieve water guide pipe; one end of the heat exchange pipe is connected to the main pipe and communicates with the main pipe.

[0017] In a possible implementation, the main pipe includes:

[0018] A horizontal pipe is fixedly connected to the shell; the horizontal pipe is connected to and communicates with the heat exchange pipe; and

[0019] A vertical pipe has one end connected to the horizontal pipe and the other end penetrating through the bottom of the shell and communicating with the sieve water guide pipe or penetrating through the top of the shell and communicating with the flower pipe.

[0020] In a possible implementation, the heat exchange mechanism further includes a support fixedly connected to the inside of the shell, and the support is used to fix the heat exchange pipe and the vertical pipe.

[0021] In a possible implementation, the heat source water circulating module includes:

[0022] An inlet pipe, one end of which is connected to the top of the shell, and the other end of which is connected to the heat exchange station; the inlet pipe is used to input heat source water into the shell;

[0023] A drain pipe, one end of which is connected to the bottom of the shell, and the other end of which is connected to the heat exchange station; the drain pipe is used to drain the heat source water in the shell.

[0024] In a possible implementation, the shell is internally provided with a partition plate, which is arranged between adjacent heat exchange mechanisms, and divides the shell into non-communicating spaces;

[0025] The heat source water circulation module further comprises a connecting pipe, which is arranged inside the shell, and passes through the partition plate, and is used to communicate the spaces on both sides of the partition plate, so that the heat source water can exchange heat with all the heat exchange mechanisms.

[0026] In a possible implementation, the shell is internally provided with a partition plate, which is arranged between adjacent heat exchange mechanisms, and divides the shell into non-communicating spaces;

[0027] The heat source water circulation module further comprises a connecting pipe for communicating the spaces on both sides of the partition plate, which is arranged outside the shell, and both ends of the connecting pipe are located above and below the partition plate respectively, and both ends of the connecting pipe are connected to the shell and communicate with the inside of the shell.

[0028] The underground heat exchanger for a ground source heat pump unit provided by the present application has the following beneficial effects compared with the prior art: when the underground heat exchanger for a ground source heat pump unit works, the circulating pump sends the underground water from the inlet module into each heat exchange mechanism respectively, exchanges heat with the heat source water respectively, and sends the underground water to the drain module for re-discharge to the underground. The underground water used in each heat exchange mechanism is directly sent from the inlet module into the heat exchange mechanism, and then directly sent to the drain module for discharge, so that there is a roughly same and large temperature difference between the underground water and the heat source water in each heat exchanger, thereby making each heat exchange mechanism maintain a high heat exchange efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0030] Figure 1 A structure diagram of an underground heat exchanger for a ground source heat pump unit provided by the present application;

[0031] Figure 2 Another structure diagram of the downhole heat exchanger for the ground source heat pump unit provided by the embodiment of the present application is provided.

[0032] Mark explanation:

[0033] 1, water inlet module; 2, drainage module; 3, heat exchange module; 31, shell; 32, heat exchange mechanism; 321, heat exchange pipe; 322, main pipe; 3221, horizontal pipe; 3222, vertical pipe; 33, support; 4, circulating pump; 5, heat source water circulation module; 51, water inlet pipe; 52, drainage pipe; 53, connecting pipe; 6, partition. DETAILED DESCRIPTION

[0034] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0035] Reference Figure 1 And Figure 2 Now the downhole heat exchanger for the ground source heat pump unit provided by the present application is described. The downhole heat exchanger for the ground source heat pump unit comprises a water inlet module 1, a drainage module 2, a heat exchange module 3, a circulating pump 4 and a heat source water circulation module 5.

[0036] The heat exchange module 3 comprises a shell 31 and a heat exchange mechanism 32 arranged inside the shell 31; the heat exchange mechanism 32 is at least two, and at least two heat exchange mechanisms 32 are arranged vertically in the shell 31; one end of the heat exchange mechanism 32 is connected with the water inlet module 1, and the other end is connected with the drainage module 2. The circulating pump 4 is arranged in the water inlet module 1 or the drainage module 2; the circulating pump 4 is used to drive the underground water to enter the heat exchange mechanism 32 from the water inlet module 1 and to be discharged from the drainage module 2. The heat source water circulation module 5 is connected with the shell 31, which is used to transport heat source water to the shell 31 and recover heat source water in the shell 31, so that the heat source water flows between the shell 31 and the heat exchange mechanism 32, thereby the heat source water exchanges heat with the heat exchange mechanism 32.

[0037] When heat exchange is performed, the circulating pump 4 works to send the underground water with higher temperature in the heat exchange well into each heat exchange mechanism 32 from the drainage module 2. Meanwhile, the heat exchange station sends the heat source water into the shell 31 through the heat circulating water module, and the heat source water is circulated to the heat exchange station after heat exchange with each heat exchange mechanism 32. After the underground water exchanges heat with the heat source water in the heat exchange mechanism 32, the underground water is discharged into the heat exchange well through the drainage module 2. The underground water enters different heat exchange mechanisms 32 and exchanges heat with the heat source water in each heat exchange mechanism 32. The underground water basically does not exchange heat with the heat source water before entering the heat exchange mechanism, so the temperature of the underground water in each heat exchange mechanism 32 is not much different, and there is a large temperature difference between the underground water and the heat source water. Therefore, the heat exchange efficiency of the heat exchange mechanism 32 at the top of the heat exchange mechanism 32 with the heat source water is higher.

[0038] In a possible implementation, the water inlet module 1 is arranged at the bottom of the shell 31, the drainage module 2 is arranged at the top of the shell 31, and the circulating pump 4 is arranged in the drainage module 2.

[0039] The circulating pump 4 drives the underground water to enter each heat exchange mechanism 32 from below the heat exchange module 3 and is finally discharged into the heat exchange well from the top of the heat exchange module 3. The underground water is filled in each heat exchange mechanism 32 by being driven to enter each heat exchange mechanism 32 upward, so that the underground water exchanges heat with the heat source water.

[0040] In the ground source heat pump system, the circulating pump is like the heart of blood circulation, which drives the heat transfer medium to continuously flow between the soil heat exchanger and the building terminal. From the structural composition, the circulating pump adopts a vertical multi-stage centrifugal design, mainly including three modules of a motor section, a mechanical seal section and a pump body section. The motor section usually selects an IE4 energy efficiency grade permanent magnet synchronous motor, which cooperates with a frequency converter to realize 30-100% stepless speed regulation; the mechanical seal section adopts a double-end face packaged seal, the inner layer is a silicon carbide sealing ring to prevent underground water from seeping in, and the outer layer is equipped with a leakage sensor; the flow passage of the pump body section is optimized through a hydraulic model, the impeller is made of stainless steel precision casting, and the inlet and outlet flanges meet the DIN standard to facilitate pipeline connection. The additional shock-absorbing base can effectively control the operating noise below 65 decibels.

[0041] The outstanding feature of such a pump is environmental adaptability. The flow part is made of 316L stainless steel or titanium alloy material, which can withstand a corrosion environment with a chlorine ion concentration of 500 mg / L in underground water. The built-in temperature sensor can monitor the medium state in real time, and automatically start the anti-freezing protection program when detecting fluid below 0℃. The unique axial force balance structure makes the bearing life break through 30,000 hours, and the maintenance period is prolonged by 50% compared with ordinary water pumps. The intelligent control system can also automatically match the best flow according to the outdoor temperature, so that the system COP value is always maintained above 4.5.

[0042] The typical application scenarios include three system configurations. In the ground-coupled pipe side circulation system, a large-flow low-lift pump set is equipped to cope with the underground pipe loop resistance of more than 200 meters; in the user side secondary circulation system, a high-lift pump is selected to overcome the static pressure of the building vertical pipe; for the radiant heating system with large temperature difference requirement, it is recommended to use a double-pump parallel design to realize 50-70℃ high-temperature water delivery. In the renovation project, a pressure-independent regulating valve is often added to form a hydraulic balance module with the variable frequency pump.

[0043] In a possible implementation, the water inlet module 1 includes a sieve water guide pipe fixedly connected to the outer side of the bottom of the shell 31, and the bottom of the heat exchange mechanism 32 penetrates through the bottom of the shell 31 and communicates with the sieve water guide pipe.

[0044] The sieve water guide pipe is provided with fine filter holes, but when the circulating pump 4 is working, the underground water in the heat exchange well enters the heat exchange mechanism 32 through the sieve water guide pipe, so as to avoid the sundries in the heat exchange well from entering the heat exchange mechanism 32 and reduce the heat exchange efficiency of the heat exchange mechanism 32 and the occurrence of the clogging of the heat exchange mechanism 32. After the underground water enters the sieve water guide pipe, it directly enters the heat exchange mechanism 32 through the bottom of the heat exchange mechanism 32.

[0045] In a possible implementation, the water outlet module 2 includes a flower pipe fixedly connected to the top of the shell 31, and the top of the heat exchange mechanism 32 penetrates through the top of the shell 31 and communicates with the flower pipe.

[0046] After the circulating pump 4 drives the underground water to enter the heat exchange mechanism 32, the underground water finally flows to the flower pipe at the top of the shell 31 through the top of the heat exchange mechanism 32, reenters the heat exchange well through the flower pipe, and thus maintains the underground water level near the heat exchange well.

[0047] In a possible implementation, the heat exchange mechanism 32 includes a heat exchange pipe 321 and a main stem pipe 322.

[0048] The heat exchange pipe 321 is arranged inside the shell 31 and is provided with a reserved gap inside the shell 31; when the underground water passes through the heat exchange pipe 321, the underground water exchanges heat with the heat source water in the shell 31; the heat exchange pipe 321 penetrates through the bottom of the shell 31 downward and communicates with the sieve water guide pipe, or penetrates through the top of the shell 31 upward and communicates with the flower pipe. The heat exchange pipe 321 is vertically arranged and is provided with a plurality of heat exchange pipes 321, so as to increase the contact area of the heat exchange pipe 321 and the heat source water in the shell 31 and improve the heat exchange efficiency. The main stem pipe 322 is arranged inside the shell 31; the main stem pipe 322 penetrates through the top of the shell 31 upward and communicates with the flower pipe, or penetrates through the bottom of the shell 31 downward and communicates with the sieve water guide pipe; one end of the heat exchange pipe 321 is connected to and communicates with the main stem pipe 322.

[0049] In one possible implementation, the main pipe 322 includes a horizontal pipe 3221 and a vertical pipe 3222. The horizontal pipe 3221 is fixedly connected to the shell 31, and the horizontal pipe 3221 is connected to the heat exchange pipe 321. The vertical pipe 3222 is connected to the horizontal pipe 3221 at one end, and is connected to the water screen guide pipe at the bottom of the shell 31 or is connected to the flower pipe at the top of the shell 31.

[0050] In one preferred embodiment, two heat exchange mechanisms 32 are provided, and the main pipe 322 in each of the two heat exchange mechanisms 32 is arranged on the opposite side of the shell 31. The two heat exchange mechanisms 32 are arranged one above the other inside the shell 31. The main pipe 322 in the upper heat exchange mechanism 32 is arranged below the heat exchange pipe 321, the horizontal pipe 3221 in the main pipe 322 is arranged above the vertical pipe 3222, the top of the vertical pipe 3222 is connected to and communicates with the horizontal pipe 3221, and the bottom of the vertical pipe 3222 penetrates the bottom of the shell 31 and communicates with the water screen guide pipe. The bottom of the heat exchange pipe 321 is connected to and communicates with the horizontal pipe 3221, and the top of the heat exchange pipe 321 penetrates the top of the shell 31 and communicates with the flower pipe. When the circulating pump 4 is working, the underground water in the heat exchange well enters the vertical pipe 3222 in the upper heat exchange mechanism 32 through the water screen guide pipe, then enters the horizontal pipe 3221 through the vertical pipe 3222, enters the heat exchange pipe 321 through the horizontal pipe 3221, and after completing heat exchange in the heat exchange pipe 321, continues to enter the flower pipe upward, and finally returns to the heat exchange well.

[0051] The main pipe 322 in the lower heat exchange mechanism 32 is arranged above the heat exchange pipe 321, the horizontal pipe 3221 in the main pipe 322 is arranged below the vertical pipe 3222, and the horizontal pipe 3221 is arranged at the top of the heat exchange pipe 321. The top of the vertical pipe 3222 penetrates the top of the shell 31 and communicates with the flower pipe, and the bottom of the vertical pipe 3222 is connected to and communicates with the horizontal pipe 3221. The top of the heat exchange pipe 321 is connected to and communicates with the horizontal pipe 3221, and the bottom of the heat exchange pipe 321 penetrates the bottom of the shell 31 and communicates with the water screen guide pipe. When the circulating pump 4 is working, the underground water in the heat exchange well directly enters the heat exchange pipe 321 through the water screen guide pipe, the underground water completes heat exchange in the heat exchange pipe 321, is collected in the horizontal pipe 3221, enters the vertical pipe 3222 through the horizontal pipe 3221, and finally enters the flower pipe through the vertical pipe 3222, and is sent back to the heat exchange well.

[0052] When the heat exchange module 3 is in operation, after the underground water in the heat exchange well enters the screen water guide pipe, part of the underground water directly enters the lower heat exchange pipe 321, and the other part enters the horizontal pipe 3221 through the vertical pipe 3222 and enters the upper heat exchange pipe 321. The underground water entering the two heat exchange pipes 321 is two parts of underground water independent of each other, which are independent of each other and simultaneously exchange heat with the heat source water in the shell 31. Therefore, the underground water temperatures in the upper and lower heat exchangers are basically the same, and a large and stable temperature difference is maintained with the heat source water, so that the heat exchange efficiency of the two heat exchangers is high.

[0053] In a preferred embodiment, the number of heat exchange mechanisms 32 is three, and the heat exchange mechanism 32 at the lowermost and the heat exchange mechanism 32 at the uppermost are the same as the heat exchange mechanism 32 in the above embodiment. The middle heat exchange mechanism 32 includes a group of heat exchange pipes 321 and two groups of main pipes 322. One group of main pipes 322 is arranged below the heat exchange pipes 321, and the other group of main pipes 322 is arranged above the heat exchange pipes 321. The underground water enters the heat exchange pipes 321 through the main pipes 322 below the heat exchange pipes 321, and finally enters the horizontal pipe through the main pipes 322 above the heat exchange pipes 321.

[0054] In a preferred embodiment, the number of heat exchange mechanisms 32 is four, and the arrangement of the heat exchange mechanisms 32 is the same as that in the embodiment of three heat exchange mechanisms 32.

[0055] In a preferred embodiment, the material of the heat exchange pipe 321 is stainless steel. Stainless steel is the first choice in the chemical industry due to its excellent corrosion resistance. The passivation film formed by chromium elements can resist the corrosion of acid and alkali media, and is particularly suitable for condensers in pharmaceutical factories and sterilization equipment in food processing plants. This type of material can still maintain strength in high temperature environment, but the thermal conductivity coefficient is relatively low, and the heat transfer efficiency is often compensated by increasing the surface area.

[0056] In a preferred embodiment, the material of the heat exchange pipe 321 is copper alloy. Copper alloy is known for its excellent heat conductivity, with a thermal conductivity of more than 400 W / m·K, making it an ideal choice for air conditioning and refrigeration systems. Copper-nickel alloy is widely used in refrigerator evaporators and automobile radiators, which can quickly transfer heat and resist corrosion from chlorine-containing coolants. This material has good processability and can be made into thin-walled pipes to reduce equipment weight, but the cost is relatively high and the mechanical strength is limited, which is not suitable for high-pressure working conditions.

[0057] In a preferred embodiment, the material of the heat exchange pipe 321 is carbon steel. Carbon steel occupies the power plant boiler market due to its economy and high pressure-bearing capacity. The surface can be galvanized or aluminized to delay water vapor oxidation. Coal economizers in thermal power plants and heavy oil heaters in petrochemical enterprises often use this type of material, which has mature welding technology and is easy to maintain. However, ordinary carbon steel is prone to pitting corrosion in acidic environments, and regular chemical cleaning is required to ensure a service life of more than ten years.

[0058] In a possible implementation, the heat exchange mechanism 32 further comprises a support 33 fixedly connected inside the shell 31, and the support 33 is used for fixing the heat exchange pipe 321 and the vertical pipe 3222.

[0059] In a possible implementation, the heat source water circulation module 5 comprises a water inlet pipe 51 and a water outlet pipe 52.

[0060] One end of the water inlet pipe 51 is connected to the top of the shell 31, and the other end is connected to the heat exchange station; the water inlet pipe 51 is used for inputting heat source water into the inside of the shell 31. One end of the water outlet pipe 52 is connected to the bottom of the shell 31, and the other end is connected to the heat exchange station; the water outlet pipe 52 is used for discharging the heat source water in the inside of the shell 31.

[0061] When the heat exchanger works, the circulating pump 4 sends the underground water in the heat exchange well to each heat exchange mechanism 32, and at the same time, the heat exchange station sends the heat source water into the shell 31 through the metal pipe, and finally flows out of the shell 31 through the water outlet pipe 52 and returns to the heat exchange station for circulation. When the heat source water flows in the shell 31, it contacts the heat exchange pipe 321 and exchanges heat, thereby absorbing the heat of the heat exchange pipe 321 and the underground water in the heat exchange pipe 321.

[0062] As the energy scheduling center of the ground source heat pump system, the heat exchange station undertakes the key function of exchanging the cold and heat load of the soil and the building. Its core role is reflected in three aspects: through the underground buried pipe circulating medium, the soil is continuously exchanged all the year round, the shallow geothermal energy is collected and released; the plate heat exchanger is used to isolate the ground coupling side and the user side waterway, and cross contamination of impurities is avoided; the variable frequency water pump and the intelligent control system are used to dynamically adjust the flow, so that the energy efficiency ratio is always maintained above 4.0 under different seasonal conditions.

[0063] The typical heat exchange station adopts a modular steel structure frame, and mainly comprises three functional units. The ground coupling side circulation unit is composed of a corrosion-resistant titanium alloy plate, a sand filter and an expansion tank, and is used for processing underground circulating water containing minerals; the user side unit is provided with a stainless steel centrifugal pump and an electronic descaling instrument, and is used for ensuring the cleanliness of the air conditioning terminal water; the control unit integrates a PLC controller and an Internet of Things sensor, and is used for monitoring more than 20 parameters such as the temperature difference between inlet and outlet water and pipe pressure in real time. All pipes adopt a prefabricated insulation layer design, and the heat loss rate is controlled to be less than 5%.

[0064] This system's technical features are particularly noteworthy for its environmental adaptability. In winter, it extracts heat from 10°C groundwater, raising its temperature through a heat pump and outputting 45°C hot water for heating. In summer, it reverses this process by injecting 30°C waste heat from the building into the 18°C ​​soil for heat dissipation. Its dual-mode operation reduces energy consumption by 40% compared to traditional cooling tower systems, while completely eliminating fan noise and water drift. Its specially designed variable flow system automatically adjusts within a load range of 70%-130%, making it particularly suitable for locations with significant diurnal load fluctuations, such as hotels and hospitals.

[0065] In one possible implementation, a partition 6 is provided within the housing 31. The partition 6 is disposed between adjacent heat exchange mechanisms 32, dividing the interior of the housing 31 into separate, interconnected spaces. The heat source water circulation module 5 further includes a connecting pipe 53 disposed within the housing 31. The connecting pipe 53 passes through the partition 6 and connects the spaces on both sides of the partition 6, allowing heat source water to exchange heat with all of the heat exchange mechanisms 32.

[0066] During operation, heat source water enters the heat exchanger through water inlet pipe 51, first falling on baffle 6 before flowing through connecting pipe 53 into the space below baffle 6. Baffle 6 blocks the flow of heat source water after it enters housing 31, limiting its flow rate. This prolongs the contact time between the heat source water and groundwater, improving the heat exchange efficiency of heat exchange mechanism 32.

[0067] In a possible implementation, a partition 6 is provided inside the shell 31 , and the partition 6 is provided between adjacent heat exchange mechanisms 32 to separate the inside of the shell 31 into non-communicating spaces;

[0068] The heat source water circulation module 5 also includes a connecting pipe 53 for connecting the spaces on both sides of the partition 6. The connecting pipe 53 is arranged outside the shell 31. The two ends of the connecting pipe 53 are respectively located above and below the partition 6. Both ends of the connecting pipe 53 are connected to the shell 31 and communicate with the inside of the shell 31.

[0069] Placing the connecting pipe 53 outside the shell 31 further reduces the flow rate of the heat source water within the shell 31. After entering the area above the partition 6 in the shell 31 through the water inlet pipe 51, the heat source water is drawn out of the shell 31 through the connecting pipe 53, and then is sent back through the connecting pipe 53 to the area below the partition 6 in the shell 31. This process prolongs the distance the heat source water travels from above the partition 6 to below it, increasing the time it takes for the heat source water to exchange heat with the groundwater, and improving the heat exchange efficiency of the heat exchange mechanism 32.

[0070] The downhole heat exchanger for the ground source heat pump unit has the advantages that, compared with the prior art, when working, the circulating pump 4 sends the underground water from the water inlet module 1 into each heat exchange mechanism 32 respectively, exchanges heat with the heat source water respectively, and is sent to the water outlet module 2 to be discharged to the underground again. The underground water used in each heat exchange mechanism 32 is directly sent from the water inlet module 1 into the heat exchange mechanism 32 and then directly sent to the water outlet module 2 for discharge, so that the underground water in each heat exchanger and the heat source water have approximately the same and large temperature difference, thereby making each heat exchange mechanism 32 maintain high heat exchange efficiency.

[0071] The above merely describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A downhole heat exchanger for a ground source heat pump unit, characterized in that: include: Water inlet module (1); Drainage module (2); A heat exchange module (3) comprises a shell (31) and a heat exchange mechanism (32) disposed inside the shell (31); at least two heat exchange mechanisms (32) are provided, and at least two heat exchange mechanisms (32) are arranged vertically in the shell (31); one end of the heat exchange mechanism (32) is connected to the water inlet module (1), and the other end is connected to the drainage module (2); a circulation pump (4), arranged in the water inlet module (1) or the drainage module (2); the circulation pump (4) is used to drive groundwater from the water inlet module (1) into the heat exchange mechanism (32) and to be discharged from the drainage module (2); and A heat source water circulation module (5) is connected to the shell (31) and is used to transport heat source water into the shell (31) and recover the heat source water in the shell (31), so that the heat source water flows between the shell (31) and the heat exchange mechanism (32), thereby allowing the heat source water to exchange heat with the heat exchange mechanism (32).

2. The downhole heat exchanger for a ground source heat pump unit according to claim 1, characterized in that: The water inlet module (1) is arranged at the bottom of the housing (31), the drainage module (2) is arranged at the top of the housing (31), and the circulation pump (4) is arranged in the drainage module (2).

3. The downhole heat exchanger for a ground source heat pump unit according to claim 2, characterized in that: The water inlet module (1) comprises a water screening guide pipe fixedly connected to the outer surface of the bottom of the shell (31), and the bottom of the heat exchange mechanism (32) passes through the bottom of the shell (31) and communicates with the water screening guide pipe.

4. The downhole heat exchanger for a ground source heat pump unit according to claim 3, characterized in that: The drainage module (2) comprises a flower tube fixedly connected to the top of the shell (31); the top of the heat exchange mechanism (32) passes through the top of the shell (31) and communicates with the flower tube.

5. The downhole heat exchanger for a ground source heat pump unit according to claim 4, characterized in that: The heat exchange mechanism (32) comprises: A heat exchange pipe (321) is arranged inside the shell (31) and a gap is reserved with the inside of the shell (31); when groundwater passes through the heat exchange pipe (321), heat exchange is performed with the heat source water in the shell (31); the heat exchange pipe (321) passes downward through the bottom of the shell (31) and communicates with the screen water guide pipe, or passes upward through the top of the shell (31) and communicates with the flower pipe; and A main pipe (322) is arranged inside the shell (31); the main pipe (322) passes through the top of the shell (31) upwards and communicates with the flower pipe, or passes through the bottom of the shell (31) downwards and communicates with the water screening guide pipe; one end of the heat exchange tube (321) is connected to and communicates with the main pipe (322).

6. The downhole heat exchanger for a ground source heat pump unit according to claim 5, characterized in that: The main pipe (322) includes: A transverse tube (3221) is fixedly connected to the shell (31); the transverse tube (3221) is connected and communicated with the heat exchange tube (321); and One end of the vertical pipe (3222) is connected to the horizontal pipe (3221), and the other end passes through the bottom of the shell (31) and communicates with the water screening diversion pipe, or passes through the top of the shell (31) and communicates with the flower pipe.

7. The downhole heat exchanger for a ground source heat pump unit according to claim 6, characterized in that: The heat exchange mechanism (32) further includes a bracket (33) fixedly connected to the interior of the shell (31), and the bracket (33) is used to fix the heat exchange tube (321) and the vertical tube (3222).

8. The downhole heat exchanger for a ground source heat pump unit according to claim 1, characterized in that: The heat source water circulation module (5) includes: A water inlet pipe (51), one end of which is connected to the top of the shell (31) and the other end of which is connected to the heat exchange station; the water inlet pipe (51) is used to input heat source water into the interior of the shell (31); and A drain pipe (52) has one end connected to the bottom of the shell (31) and the other end connected to the heat exchange station; the drain pipe (52) is used to discharge the heat source water inside the shell (31).

9. The downhole heat exchanger for a ground source heat pump unit according to claim 8, characterized in that: A partition (6) is provided inside the shell (31), and the partition (6) is arranged between adjacent heat exchange mechanisms (32) to separate the inside of the shell (31) into non-communicating spaces; The heat source water circulation module (5) further comprises a connecting pipe (53), wherein the connecting pipe (53) is arranged inside the shell (31), and the connecting pipe (53) passes through the partition (6) and is used to connect the spaces on both sides of the partition (6) so that the heat source water can exchange heat with all the heat exchange mechanisms (32).

10. The downhole heat exchanger for a ground source heat pump unit according to claim 8, characterized in that: A partition (6) is provided inside the shell (31), and the partition (6) is arranged between adjacent heat exchange mechanisms (32) to separate the inside of the shell (31) into non-communicating spaces; The heat source water circulation module (5) further comprises a connecting pipe (53) for communicating with the spaces on both sides of the partition (6); the connecting pipe (53) is arranged outside the shell (31); the two ends of the connecting pipe (53) are respectively located above and below the partition (6); and both ends of the connecting pipe (53) are connected to the shell (31) and communicate with the interior of the shell (31).

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