High efficiency jacketed geothermal heat exchanger

Abstract

The present application relates to the technical field of ground source heat pump, particularly relates to a high-efficiency casing pipe type ground buried pipe heat exchanger for accelerating groundwater seepage. The ground buried pipe heat exchanger comprises a reinforced outer pipe and a composite inner pipe located in the outer pipe, a flow inlet channel is formed between the inner wall of the outer pipe and the outer wall of the inner pipe, and a flow outlet channel is formed in the inner wall of the inner pipe. According to the stratification of geology, a disturbing device is added in the rock-soil layer where groundwater seepage exists, the heat exchange efficiency of the casing pipe type ground buried pipe is improved by accelerating the flow of groundwater, and meanwhile, a hole type protective sleeve is added outside the disturbing device to effectively prevent the impact of soil blocks and stones on the heat exchanger; the inner pipe of the casing pipe heat exchanger adopts a composite heat preservation pipe, which comprises a heat preservation layer and a reinforcing pipe layer, so that the heat loss between the inner pipe and the outer pipe is reduced to the maximum extent, and meanwhile, it is ensured that the heat preservation cotton will not fall off and block the pipeline.

Description

Technical Field

[0001] This invention relates to the field of ground source heat pump technology, and in particular to a high-efficiency shell-and-tube buried pipe heat exchanger that accelerates groundwater seepage. Background Technology

[0002] Ground source heat pumps are highly efficient, energy-saving, and environmentally friendly air conditioning systems that utilize shallow geothermal resources for both heating and cooling. However, the high initial investment and low utilization rate of ground source heat pump systems hinder their promotion and development. Among these factors, the poor heat exchange efficiency of buried pipes is a major contributor. The heat exchange performance of buried pipe heat exchangers is affected by many factors. Under specific geothermal conditions, the thermal conductivity of the buried pipe material and the design of the buried pipe heat exchanger have a significant impact on the heat exchange efficiency of the ground source heat pump system. Accurate and reasonable design is crucial for the efficient operation of the entire ground source heat pump system.

[0003] Currently, commonly used shell-and-tube heat exchangers have low thermal efficiency, and the time required for the circulating working fluid to heat up through geothermal energy within the shell is too long, which cannot meet the application requirements. Existing shell-and-tube heat exchangers typically use PVC or PE plastic materials for their inner and outer tubes, resulting in severe thermal short-circuiting between them. This thermal short-circuiting reduces the temperature difference between the circulating water in the inner and outer tubes, causing heat accumulation inside the tubes and ultimately reducing the heat exchanger's efficiency.

[0004] Groundwater seepage has a significant impact on the heat transfer performance of buried pipes. Increasing the groundwater seepage velocity and decreasing the seepage temperature can enhance the heat exchange capacity of buried pipes. A well-designed heat exchanger for buried pipes can ensure the efficient operation of the system. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the background technology by proposing a high-efficiency shell-and-tube buried pipe heat exchanger that accelerates groundwater seepage. By accelerating groundwater seepage, the heat exchange efficiency is improved, thermal short-circuiting between the circulating fluid in the inner and outer pipes is reduced, the heat exchange effect between the heat exchanger and the soil is enhanced, and the heat exchange performance of the heat exchanger is further improved.

[0006] The technical solution of the present invention is a high-efficiency shell-and-tube buried pipe heat exchanger for accelerating groundwater seepage, comprising a reinforced outer tube and an insulated inner tube vertically installed inside the reinforced outer tube. An annular space between the inner wall of the reinforced outer tube and the outer wall of the insulated inner tube forms an inlet channel, and a fluid inlet is provided at the end of the inlet channel; an outlet channel is formed in the middle of the reinforced outer tube, and a fluid outlet is provided at the end of the outlet channel.

[0007] The circulating working fluid enters from the fluid inlet and then exchanges heat with the soil through the reinforced outer pipe in the inflow channel; the circulating working fluid flows out from the outflow channel through the fluid outlet.

[0008] Preferably, the circulating working fluid is water.

[0009] Preferably, based on the geological stratification, a disturbance device is installed on the outer wall of the reinforced outer pipe in the soil and rock layer where groundwater seepage exists, and the disturbance device is evenly distributed along the outer wall of the reinforced outer pipe.

[0010] Preferably, a protective sleeve is provided on the outside of the disturbance device, and multiple holes are provided on the protective sleeve at equal intervals.

[0011] Preferably, the outer reinforcing tube is made of galvanized steel pipe.

[0012] Preferably, the inner insulation pipe is a composite multi-layer insulation pipe.

[0013] Preferably, an insulation layer is provided on the outer side of the inner wall of the insulation inner tube, and a thickened layer is provided on the outside of the insulation layer.

[0014] Preferably, the insulation layer of the inner insulated tube is made of polyurethane; the thickened layer is made of PVC; and the inner wall is made of PPR.

[0015] Preferably, a backfill material is poured between the outer wall of the reinforced outer pipe and the rock and soil layer of the well, and the backfill material is bentonite or fine sand.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects:

[0017] This invention obtains the actual geological stratification through geological exploration, adds a disturbance device to the soil and rock layers where groundwater seepage exists, and improves the heat exchange efficiency of the casing-type buried pipe by accelerating the flow of groundwater. At the same time, a perforated protective sleeve is added outside the disturbance device to effectively prevent soil and stones from impacting the heat exchanger. The inner pipe adopts a composite insulation pipe, including an insulation layer and a reinforcing pipe layer, to minimize heat loss between the inner and outer pipes, while ensuring that the insulation cotton will not fall off and block the pipe. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a cross-sectional layout diagram of the composite insulation pipe in a shell-and-tube buried heat exchanger.

[0020] Figure 3 This is a schematic diagram of the disturbance device and protective sleeve for a shell-and-tube buried pipe heat exchanger.

[0021] Reference numerals in the attached diagram: 1. Insulated inner pipe; 2. Reinforced outer pipe; 3. Fluid outlet; 4. Fluid inlet; 5. Geological stratification; 6. Groundwater seepage; 7. Disturbance device; 8. Protective sleeve; 9. Backfill material; 10. Inflow channel; 11. Outflow channel; 1-1. Thickened layer; 1-2. Insulation layer; 1-3. Inner wall; 8-1. Hole. Detailed Implementation

[0022] Example 1

[0023] This invention proposes a high-efficiency shell-and-tube buried pipe heat exchanger for accelerating groundwater seepage. The device includes a reinforced outer pipe 2 and an insulated inner pipe 1 vertically installed inside the outer pipe. An annular space between the inner wall 1-3 of the reinforced outer pipe 2 and the outer wall of the insulated inner pipe 1 forms an inflow channel 10, and an outflow channel 11 is formed in the insulated inner pipe 1. Based on geological stratification, this invention adds a disturbance device 7 to the rock and soil layer where groundwater seepage exists, thereby accelerating the flow of groundwater and improving the heat exchange efficiency of the shell-and-tube buried pipe. At the same time, a perforated protective sleeve 8 is added outside the disturbance device 7 to effectively prevent soil and stones from impacting the heat exchanger. The inner pipe of the shell-and-tube heat exchanger of this invention adopts a composite insulation pipe, including an insulation layer 1-2 and a thickened layer 1-1, which minimizes heat loss between the inner and outer pipes and ensures that the polyurethane material will not fall off and block the pipe.

[0024] like Figure 1 As shown, the circulating working medium enters from the fluid inlet 4, and then exchanges heat with the soil through the reinforcing outer pipe 2 in the inlet channel 10; the circulating working medium flows out from the outlet channel 11 through the fluid outlet 3, wherein the circulating working medium is water.

[0025] like Figure 3 As shown, a disturbance device 7 is installed on the outer wall of the reinforced outer pipe 2, and the disturbance device 7 is evenly distributed along the outer wall of the reinforced outer pipe 2. A protective sleeve 8 is installed on the outside of the disturbance device 7, and multiple holes 8-1 are provided at equal intervals on the protective sleeve 8; the disturbance device 7 is designed with a protruding structure with sharp corners, and it is arranged in a ring array on the outer periphery of the reinforced outer pipe 2, and multiple sets are arranged at equal intervals from top to bottom. When the groundwater flows over the disturbance device 7, it will contact the device and increase the flow velocity.

[0026] The disturbance device 7 improves the heat exchange efficiency of the shell-and-tube heat exchanger by accelerating the flow of groundwater. The disturbance device 7 is evenly distributed on the outer wall of the reinforced outer tube 2. At the same time, a perforated protective sleeve 8 is added outside the disturbance device 7 to effectively prevent soil and stones from hitting the heat exchanger and improve the safety performance of the heat exchanger.

[0027] Example 2

[0028] This invention proposes a high-efficiency casing-type buried pipe heat exchanger for accelerating groundwater seepage. Unlike Embodiment 1, in this embodiment, the reinforcing outer pipe 2 is made of galvanized steel. Galvanized steel ensures good heat exchange performance while being resistant to rust, and its high strength provides excellent support.

[0029] In this embodiment, the inner insulated pipe 1 is a composite multi-layer insulated pipe. An insulation layer 1-2 is provided on the outer side of the inner wall 1-3 of the inner insulated pipe 1, and a thickening layer 1-1 is provided on the outer side of the insulation layer 1-2; the insulation layer 1-2 of the inner insulated pipe 1 is made of polyurethane material; the thickening layer 1-1 is made of PVC material; and the inner wall 1-3 is made of PPR material.

[0030] Polyurethane material is tightly bonded to the inner and outer pipes, ensuring good thermal insulation performance and effectively reducing heat loss of buried pipes; PVC material is tightly bonded to the outside of polyurethane material, has good corrosion resistance and high strength, thus protecting the polyurethane insulation layer and preventing it from falling off; PPR material has good toughness, high strength, and excellent processing performance, making it easy to process when used internally.

[0031] Backfill material 9 is poured between the outer wall of the reinforced outer pipe 2 and the rock and soil layer of the well. Bentonite or fine sand can be used for backfilling. The backfill material helps the buried pipe heat exchanger to exchange heat with the surrounding soil, and at the same time, fixes and protects the buried pipe well.

[0032] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A high efficiency jacketed geothermal heat exchanger for accelerating groundwater seepage, characterized in that, It includes a reinforced outer tube (2) and an insulated inner tube (1) installed vertically inside the reinforced outer tube (2). The annular space between the inner wall of the reinforced outer tube (2) and the outer wall of the insulated inner tube (1) forms an inlet channel (10), and a fluid inlet (4) is provided at the end of the inlet channel (10). An outlet channel (11) is formed in the middle of the insulated inner tube (1), and a fluid outlet (3) is provided at the end of the outlet channel (11). A disturbance device (7) is provided on the outer wall of the reinforcing outer tube (2), and the disturbance device (7) is evenly distributed along the outer wall of the reinforcing outer tube (2); a protective sleeve (8) is provided on the outside of the disturbance device (7), and multiple holes (8-1) are provided at equal intervals on the protective sleeve (8); The circulating working fluid enters from the fluid inlet (4) and exchanges heat with the soil through the reinforced outer pipe (2) in the inlet channel (10); the circulating working fluid flows out from the outlet channel (11) through the fluid outlet (3).

2. The high efficiency jacketed geobore heat exchanger for accelerating groundwater seepage according to claim 1, characterized in that: The circulating working fluid is water.

3. The high efficiency pipe-in-pipe geothermal heat exchanger of claim 1, wherein: (2) The outer pipe is reinforced with galvanized steel pipe material.

4. The high efficiency jacketed geobore heat exchanger of claim 1, wherein: The inner insulated pipe (1) is a composite multi-layer insulated pipe.

5. The high efficiency pipe-in-pipe geothermal heat exchanger of claim 4, wherein: An insulation layer (1-2) is provided on the outside of the inner wall (1-3) of the inner tube (1), and a thickened layer (1-1) is provided on the outside of the insulation layer (1-2).

6. The high efficiency pipe-in-pipe geothermal heat exchanger of claim 5, wherein: The insulation layer (1-2) of the inner insulated tube (1) is made of polyurethane; the thickened layer (1-1) is made of PVC; and the inner wall (1-3) is made of PPR.

7. The high efficiency pipe-in-pipe geothermal heat exchanger of claim 6, wherein: The outer wall of the protective sleeve (8) is filled with backfill material (9) between the well and the rock and soil layer. The backfill material (9) is bentonite or fine sand.

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