Ground source heat pump unit

Abstract

The invention relates to the technical field of ground source heat pumps, and discloses a ground source heat pump unit which comprises an underground water circulating pump, a heat pump circulating water supply pipe, a heat pump circulating water return pipe and a shell-and-tube heat exchanger, the shell-and-tube heat exchanger is buried underground, a seepage groove is formed in the top of the shell-and-tube heat exchanger, and the underground water circulating pump is erected above the seepage groove; the heat pump circulating water supply is communicated with the shell pass of the shell-and-tube heat exchanger. The underground water circulating pump is communicated with the shell pass of the shell-and-tube heat exchanger. Compared with the prior art, the device has the advantages that the heat exchange area of the shell-and-tube heat exchanger is large, the heat exchange efficiency is high, the occupied area of the shell-and-tube heat exchanger is small when the shell-and-tube heat exchanger is vertically buried underground, the underground water circulating pump is provided for achieving underground water circulating heat exchange, soil with a larger area and underground water with a larger flow participate in heat exchange, and high heat redundancy is guaranteed; and the system can be allowed to have small-amplitude heat exchange imbalance.

Description

Technical Field

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

[0002] At present, the underground heat exchange system uses buried tube heat exchangers, and the buried tube forms include horizontal buried tubes and vertical buried tubes.

[0003] Horizontal buried tubes are usually buried shallowly, with low requirements for excavation technology and lower initial investment than vertical buried tubes. However, they cover a large area and have a large excavation workload. The vertical buried tube ground source heat pump system covers a small area, is minimally affected by the outside world, has a good constant temperature effect, requires very little maintenance cost after construction, has low power consumption, and the operating cost is greatly reduced.

[0004] The existing underground heat exchange system mainly relies on a water pump to drive the heat / cooling medium water of the ground source heat pump to flow in the buried tubes for heat exchange. For the buried tubes, there is no power to drive the external heat exchange medium (soil and groundwater) to flow, which limits the heat exchange efficiency of the buried tube heat exchanger. Moreover, only the soil and groundwater in some areas participate in the heat exchange in this way. If the heat exchange amount of the heat exchange system is unbalanced, it is easy to cause the soil temperature to be too high or too low. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the existing underground heat exchange system has a large floor area, low heat exchange efficiency, and small heat redundancy, and it is easy to have an unbalanced heat exchange amount. The present invention provides a ground source heat pump unit.

[0006] To solve the above technical problem, the technical solution provided by the present invention is: a ground source heat pump unit, which includes a groundwater circulation pump, a heat pump circulation water supply pipe, a heat pump circulation water return pipe, and a shell-and-tube heat exchanger. The shell-and-tube heat exchanger is buried underground. A seepage groove is provided at the top of the shell-and-tube heat exchanger. The groundwater circulation pump is installed above the seepage groove. The heat pump circulation water supply pipe is connected to the side surface at the top of the shell-and-tube heat exchanger, and the heat pump circulation water return pipe is connected to the side surface at the bottom of the shell-and-tube heat exchanger.

[0007] A confluence groove is provided at the bottom of the shell-and-tube heat exchanger. An opening partition is provided at the top of the confluence groove. A gravel filling layer is filled between the opening partition and the seepage groove. The center of the confluence groove is sunken downward, and an overflow pipe is provided inside it. A jet pump is fixedly sleeved inside the overflow pipe. The outlet of the jet pump is connected to the bottom of the shell-and-tube heat exchanger. The top of the shell-and-tube heat exchanger is connected to the inlet of the groundwater circulation pump, and the outlet of the groundwater circulation pump is connected to the seepage groove.

[0008] Further, an overflow groove is provided in the seepage groove, and the outlet of the groundwater circulation pump is discharged into the overflow groove.

[0009] Further, a plurality of overflow holes are provided around the top of the overflow pipe, and the bottom is sealed.

[0010] Furthermore, a plurality of heat exchange tubes are provided inside the shell-and-tube heat exchanger, and the heat exchange tubes connect the upper and lower ends of the shell-and-tube heat exchanger.

[0011] Furthermore, an auxiliary heat exchanger is provided inside the gravel pack layer. The auxiliary heat exchanger is hollow inside, and a plurality of fins are provided on its circumference. The outer sides of the fins are in contact with the gravel pack layer.

[0012] Furthermore, the top of the auxiliary heat exchanger is connected to the outlet of the groundwater circulation pump.

[0013] Furthermore, an annular suction port is provided around the bottom of the jet pump. A jet nozzle is provided inside the annular suction port. The annular suction port extends to the bottom of the overflow pipe. The bottom of the auxiliary heat exchanger is connected to the jet nozzle.

[0014] Furthermore, a groundwater circulation return main pipe is connected to the outlet of the groundwater circulation pump. The groundwater circulation return main pipe is respectively connected to a first groundwater return pipe and a second groundwater return pipe. A first flow regulating valve is provided on the groundwater circulation return main pipe, and a second flow regulating valve is provided on the second groundwater return pipe.

[0015] Furthermore, the end of the first groundwater return pipe extends above the overflow tank. The second groundwater return pipe is connected to the top of the auxiliary heat exchanger. A groundwater supply pipe is provided at the top of the shell-and-tube heat exchanger and is connected to the inlet of the groundwater circulation pump. A jet pump water supply pipe is provided at the bottom of the auxiliary heat exchanger and is connected to the jet nozzle.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The shell-and-tube heat exchanger has a large heat exchange area and an efficient heat exchange structure, and can achieve rapid and efficient heat exchange.

[0018] The shell-and-tube heat exchanger has a compact structure and a small floor area, and is suitable for use in an underground environment with limited space.

[0019] The groundwater circulation pump is used to drive the closed circulation of groundwater. Without increasing the space occupied by the device, a larger area of soil and a larger flow of groundwater can participate in the heat exchange, further improving the heat exchange efficiency, and ensuring a relatively high heat redundancy, which can allow for a small degree of heat exchange imbalance in the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the present invention.

[0021] Figure 2 is a schematic structural diagram inside the gravel pack layer of the present invention.

[0022] Figure 3 is a schematic structural diagram of the shell-and-tube heat exchanger of the present invention.

[0023] Figure 4 It is a schematic structural view of the manifold groove of the present invention.

[0024] Figure 5 It is a schematic structural view of the jet pump of the present invention.

[0025] Figure 6 It is Figure 5 a schematic view at position a in

[0026] Figure 7 It is Figure 5 a schematic view at position b in

[0027] Figure 8 It is a schematic structural view of the auxiliary heat exchanger of the present invention.

[0028] Figure 9 It is a schematic view of the heat exchange fluid circulation of the present invention.

[0029] As shown in the figure: 1. Groundwater circulation pump, 2. Heat pump circulation water supply pipe, 3. Heat pump circulation water return pipe, 4. Groundwater circulation return main pipe, 5. First groundwater return pipe, 6. Second groundwater return pipe, 7. Percolation trough support plate, 8. Percolation trough, 9. Gravel filling layer, 10. Overflow trough, 11. Groundwater supply pipe, 12. Shell-and-tube heat exchanger, 13. Jet pump, 14. Auxiliary heat exchanger, 15. Jet pump water supply pipe, 16. Overflow pipe, 17. Heat exchange pipe, 18. Manifold groove, 19. Open-hole partition plate, 20. Overflow hole, 21. Annular suction port, 22. Jet nozzle, 23. Fins, 24. First flow regulating valve, 25. Second flow regulating valve. Detailed implementation manners

[0030] The present invention will be further described in detail below with reference to the accompanying drawings.

[0031] Combined with the attached Figure 1 、 attached Figure 2 、 attached Figure 3 、 attached Figure 5 and attached Figure 7 , a ground source heat pump unit, which includes a groundwater circulation pump 1, a heat pump circulation water supply pipe 2, a heat pump circulation water return pipe 3 and a shell-and-tube heat exchanger 12. The shell-and-tube heat exchanger 12 is buried underground. A percolation trough 8 is provided at the top of the shell-and-tube heat exchanger 12. A percolation trough support plate 7 is provided above the percolation trough 8. The groundwater circulation pump 1 is installed above the percolation trough support plate 7. The heat pump circulation water supply pipe 2 is communicated with the side surface at the top of the shell-and-tube heat exchanger 12. The heat pump circulation water return pipe 3 is communicated with the side surface at the bottom of the shell-and-tube heat exchanger 12. A plurality of heat exchange pipes 17 are provided inside the shell-and-tube heat exchanger 12, and the heat exchange pipes 17 connect the upper and lower ends of the shell-and-tube heat exchanger 12.

[0032] The above-mentioned heat pump circulating water pipeline exchanges heat through the shell-side flow of the shell-and-tube heat exchanger 12, and the groundwater circulation pump 1 drives the groundwater to flow through the tube-side of the shell-and-tube heat exchanger 12 for heat exchange. Among them, the groundwater enters at the bottom of the shell-and-tube heat exchanger 12 and discharges at the top, and the heat pump circulating water enters above the shell-and-tube heat exchanger 12 and discharges below.

[0033] When the device is specifically implemented, it needs to cooperate with the ground-source heat pump. The ground-source heat pump belongs to the prior art and will not be further described in this application. In addition to exchanging heat with the groundwater in the shell-and-tube heat exchanger 12, the heat pump circulating water also exchanges heat with the primary side of the ground-source heat pump, so as to achieve stable heat transfer between the primary side of the ground-source heat pump and the groundwater.

[0034] The outlet of the groundwater circulation pump 1 is connected to the groundwater circulation return main pipe 4. The groundwater circulation return main pipe 4 is respectively connected to the first groundwater return pipe 5 and the second groundwater return pipe 6. A first flow regulating valve 24 is provided on the groundwater circulation return main pipe 4, and a second flow regulating valve 25 is provided on the second groundwater return pipe 6.

[0035] An overflow tank 10 is provided in the infiltration tank 8. The end of the first groundwater return pipe 5 extends above the overflow tank 10 and discharges into the overflow tank 10 at the outlet of the groundwater circulation pump 1.

[0036] Combined with the attached Figure 3 、attached Figure 4 、attached Figure 5 and attached Figure 6 ,a confluence tank 18 is provided at the bottom of the shell-and-tube heat exchanger 12. An opening partition 19 is provided at the top of the confluence tank 18. A gravel filling layer 9 is filled between the opening partition 19 and the infiltration tank 8. The center of the confluence tank 18 is sunken downward. An overflow pipe 16 is provided inside it. A plurality of overflow holes 20 are provided around the top of the overflow pipe 16, and the bottom is sealed. A jet pump 13 is fixedly sleeved inside the overflow pipe 16. The outlet of the jet pump 13 is connected to the bottom of the shell-and-tube heat exchanger 12. A ring-shaped suction port 21 is provided around the bottom of the jet pump 13. A jet nozzle 22 is provided inside the ring-shaped suction port 21. The ring-shaped suction port 21 extends to the bottom of the overflow pipe 16. A groundwater supply pipe 11 is provided at the top of the shell-and-tube heat exchanger 12 and is connected to the inlet of the groundwater circulation pump 1.

[0037] The flow direction of the two-phase fluid for heat exchange in the present invention refers to the attached Figure 9 ,wherein the heat / cooling medium water from the external ground-source heat pump enters the shell side of the shell-and-tube heat exchanger 12 through the heat pump circulating water supply pipe 2 and discharges from the heat pump circulating water return pipe 3 and returns to the ground-source heat pump.

[0038] The groundwater in the gravel filling layer 9 flows downward by its own gravity, enters the confluence tank 18 through the opening partition 19 and converges at the sunken part in its center. The small particles carried by the groundwater settle here, and the relatively clear groundwater in the upper layer enters the overflow pipe 16 through the overflow holes 20.

[0039] Since the tube side of the shell-and-tube heat exchanger 12 is connected to the inlet of the groundwater circulation pump 1, when the groundwater circulation pump 1 operates, the negative pressure at the inlet sucks the heat exchange tubes 17, causing the inside of the jet pump 13 connected to the tube side of the shell-and-tube heat exchanger 12 to also be in a negative pressure state. The groundwater in the overflow pipe 16 is sucked through the annular suction port 21. The groundwater enters the tube side of the shell-and-tube heat exchanger 12 through the jet pump 13 and exchanges heat with the hot / cooling medium water of the external ground source heat pump, and finally leaves the shell-and-tube heat exchanger 12 and is discharged into the overflow tank 10 through the groundwater circulation pump 1. When the liquid level in the overflow tank 10 is high enough, it flows into the seepage tank 8, and the groundwater returns to the gravel pack 9 through the micropores on the wall of the seepage tank 8, and exchanges heat with the groundwater and soil inside the gravel pack 9 and then repeats the above cycle.

[0040] Since there is a large vertical distance between the inlet of the groundwater circulation pump 1 and the overflow pipe 16, the groundwater circulation pump 1 needs to have a strong self-priming ability, and the liquid it transports is groundwater, which may carry some soil sand particles. Therefore, in specific implementation, a twin-screw pump is selected for the groundwater circulation pump 1.

[0041] Generally, when the groundwater circulation pump 1 operates, the negative pressure at its inlet is likely to cause the water to be locally vaporized to form bubbles under negative pressure conditions, and the common pump cavitation is caused thereby. For the present invention, the strong self-priming ability of the groundwater circulation pump 1 will make the negative pressure at its inlet relatively strong. The space inside the heat exchange tube 17 is connected to the inlet of the groundwater circulation pump 1, so that the heat exchange tube 17 is also in a negative pressure state when the device operates, and the groundwater in the heat exchange tube 17 will also be locally vaporized. When the water vaporizes due to the pressure reduction, it will absorb heat from the outside. When the heat pump unit is in the cooling condition, the local vaporization of the groundwater in the heat exchange tube 17 can increase the heat absorbed by the groundwater from the hot / cooling medium water, thereby improving the heat exchange efficiency under the cooling condition.

[0042] On the contrary, when the heat pump unit is in the heating condition, the heat exchange efficiency of the device will be reduced due to the local vaporization of the groundwater in the heat exchange tube 17. Therefore, it is necessary to compensate the pressure of the heat exchange tube 17 when the heat pump unit is in the heating condition.

[0043] Combined with Att Figure 5 、Att Figure 6 、Att Figure 7 and Att Figure 8 In the gravel pack 9, an auxiliary heat exchanger 14 is provided. The auxiliary heat exchanger 14 is hollow inside, and a plurality of fins 23 are provided on its circumference. The outside of the fins 23 is in contact with the gravel pack 9. The top of the auxiliary heat exchanger 14 is connected to the outlet of the groundwater circulation pump 1, and the bottom is connected to the jet nozzle 22. The second groundwater return pipe 6 is connected to the top of the auxiliary heat exchanger 14. A jet pump water supply pipe 15 is provided at the bottom of the auxiliary heat exchanger 14 and is connected to the jet nozzle 22.

[0044] When the heat pump unit is in the heating mode, control and open the second flow regulating valve 25 so that the groundwater discharged by the groundwater circulation pump 1 passes through the auxiliary heat exchanger 14 and enters the jet pump 13. The groundwater forms a water jet through the jet nozzle 22, and relies on the viscosity of the water itself to drive the groundwater near the annular suction port 21 to move in the same direction and enter the heat exchange tube 17. Since the jet pump 13 works to provide an additional groundwater flow rate, the pressure in the heat exchange tube 17 is increased, avoiding local gasification. When the heat pump unit is in the cooling mode, close the second flow regulating valve 25 to stop the jet pump 13 from working, and the groundwater can also enter its internal passage through the annular suction port 21 and reach the heat exchange tube 17.

[0045] In order to ensure that the groundwater discharged by the groundwater circulation pump 1 still has sufficient kinetic energy to make the jet pump 13 work properly when it reaches the jet nozzle 22, this part of the groundwater does not pass through the gravel pack 9 but comes to the jet nozzle 22 through the pipeline formed by the second groundwater return pipe 6, the auxiliary heat exchanger 14 and the jet pump water supply pipe 15. However, when the heat pump unit is in the heating mode, since this part of the groundwater does not fully exchange heat in the gravel pack 9, its mixture with the fully heat-exchanged groundwater in the jet pump 13 will reduce the temperature of the groundwater entering the heat exchange tube 17, thereby reducing the temperature difference between the two sides of the fluid in the heat exchange tube 17 and making the heat exchange effect unsatisfactory. Therefore, fins 23 are provided on the auxiliary heat exchanger 14 to contact the gravel pack 9 for heat exchange, improve the water jet temperature of the jet nozzle 22, and maintain a sufficient temperature difference between the two sides of the fluid in the heat exchange tube 17. In addition, the kinetic energy of the water jet of the jet nozzle 22 comes from the residual kinetic energy of the groundwater discharged by the groundwater circulation pump 1. Therefore, while increasing the groundwater circulation flow rate, the jet pump 13 can improve the energy efficiency of the groundwater circulation pump 1, and can reduce the power consumption of the groundwater circulation pump 1 to a certain extent when the heat pump unit is in the heating mode.

[0046] The above describes the present invention and its implementation manners, and this description is not restrictive. The actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar structural modes and embodiments without creative efforts without departing from the spirit of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A ground source heat pump unit, comprising a groundwater circulation pump (1), a heat pump circulation water supply pipe (2), a heat pump circulation water return pipe (3) and a shell and tube heat exchanger (12), wherein the shell and tube heat exchanger (12) is buried underground, a seepage groove (8) is provided on the top of the shell and tube heat exchanger (12), the groundwater circulation pump (1) is erected above the seepage groove (8), the heat pump circulation water supply pipe (2) is connected to the top side of the shell and tube heat exchanger (12), and the heat pump circulation water return pipe (3) is connected to the bottom side of the shell and tube heat exchanger (12), characterized in that: The bottom of the shell and tube heat exchanger (12) is provided with a confluence trough (18), the top of the confluence trough (18) is provided with a perforated baffle (19), a gravel filling layer (9) is provided between the perforated baffle (19) and the seepage trough (8), the center of the confluence trough (18) is concave downward, an overflow pipe (16) is provided inside the confluence trough (18), a jet pump (13) is fixedly sleeved inside the overflow pipe (16), the outlet of the jet pump (13) is connected to the bottom of the shell and tube heat exchanger (12), the top of the shell and tube heat exchanger (12) is connected to the inlet of a groundwater circulation pump (1), and the outlet of the groundwater circulation pump (1) is connected to the seepage trough (8).

2. The ground source heat pump unit according to claim 1, characterized in that: An overflow trough (10) is provided in the seepage trough (8), and the outlet of the groundwater circulation pump (1) discharges into the overflow trough (10).

3. The ground source heat pump unit according to claim 1, characterized in that: The overflow pipe (16) is provided with a plurality of overflow holes (20) around the top and is sealed at the bottom.

4. The ground source heat pump unit according to claim 1, characterized in that: A plurality of heat exchange tubes (17) are provided in the shell and tube heat exchanger (12), and the heat exchange tubes (17) connect the upper and lower ends of the shell and tube heat exchanger (12).

5. The ground source heat pump unit according to claim 1, characterized in that: An auxiliary heat exchanger (14) is arranged inside the gravel filling layer (9). The auxiliary heat exchanger (14) is hollow inside and has a plurality of fins (23) arranged around it. The outer sides of the fins (23) are in contact with the gravel filling layer (9).

6. The ground source heat pump unit according to claim 5, characterized in that: The top of the auxiliary heat exchanger (14) is in communication with the outlet of the water circulation pump (1).

7. The ground source heat pump unit according to claim 6, characterized in that: An annular suction port (21) is provided around the bottom of the jet pump (13), a jet nozzle (22) is provided inside the annular suction port (21), the annular suction port (21) extends to the bottom of the overflow pipe (16), and the bottom of the auxiliary heat exchanger (14) is connected to the jet nozzle (22).

8. The ground source heat pump unit according to claim 1, characterized in that: The outlet of the groundwater circulation pump (1) is connected to a groundwater circulation return main pipe (4), the water circulation return main pipe (4) is respectively connected to a first groundwater return pipe (5) and a second groundwater return pipe (6), a first flow regulating valve (24) is provided on the water circulation return main pipe (4), and a second flow regulating valve (25) is provided on the second groundwater return pipe (6).

9. The ground source heat pump unit according to any one of claims 1 to 8, characterized in that: The end of the first groundwater return pipe (5) extends to above the overflow tank (10), the second groundwater return pipe (6) is connected to the top of the auxiliary heat exchanger (14), a groundwater supply pipe (11) is provided at the top of the shell and tube heat exchanger (12) and is connected to the inlet of the groundwater circulation pump (1), and a jet pump supply pipe (15) is provided at the bottom of the auxiliary heat exchanger (14) and is connected to the jet nozzle (22).

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