A heat extraction - heat compensation switching device for a shell - and - tube heat exchanger

Abstract

A heat extraction - heat compensation switching device for a double - pipe heat exchanger, which relates to a heat exchanger control switching device. The outer pipe of the heat exchanger extends deep into the heat source well. The inner pipe of the heat exchanger is inside the outer pipe of the heat exchanger. A movable one - way valve forms a thin - wall section of the inner pipe in the middle of the inner pipe of the heat exchanger. Heat circulation holes are opened in the upper half of the thin - wall section of the inner pipe. A movable valve core is movably arranged inside the thin - wall section of the inner pipe and is provided with a one - way gate. The connecting pipe between the reversing valve and the unit inlet and the connecting pipe between the reversing valve and the unit outlet are connected to the condenser side of the refrigeration unit or the evaporator side of the heat pump unit. The connecting pipe between the inner pipe and the reversing valve is communicated with the inner pipe of the heat exchanger. The connecting pipe between the outer pipe and the reversing valve is communicated with the outer pipe of the heat exchanger. The reversing valve is connected between the four connecting pipes and can switch the fluid flow direction. The circulation pump drives the fluid to circulate. Through the reversing valve and the movable one - way valve, the switching of different flow directions and flow paths under the heat extraction and heat compensation conditions is realized, promoting the geothermal heat recovery and improving the long - term operation energy efficiency, system reliability and economy.

Description

Technical Field

[0001] The present invention relates to a heat exchanger control switching device, in particular to a heat extraction - heat replenishment switching device for a double - pipe heat exchanger, and belongs to the technical field of medium - deep geothermal heat pump heating. Background Art

[0002] As a clean, efficient, and low - carbon green heating method, medium - deep geothermal heat pumps have become an important option for heating transformation. This technology extracts underground heat energy through a double - pipe heat exchanger at a depth of 1500 - 3500 m. The heat source is stable, and the bottom - hole temperature can reach 80°C. The double - pipe heat exchanger is placed in a borehole. In the heat extraction mode, the fluid enters from the outer - pipe annulus and flows out from the inner pipe, extracting heat energy through a closed - loop cycle of heat extraction without water extraction, which can effectively protect groundwater.

[0003] However, with the increase in the operation years, the geotechnical body will show a heat decay phenomenon, that is, the heat stored in the geotechnical body around the heat source well decreases year by year, and the geotechnical temperature drops, resulting in a decrease in the average inlet and outlet temperature of the double - pipe heat exchanger or a decrease in the heat extraction amount, reducing the long - term operation energy efficiency of the system. Most existing projects do not take heat replenishment measures, resulting in the risk of energy efficiency decline or even failure during the long - term operation of the system. Therefore, in order to maintain the temperature of the underground geotechnical body, it is necessary to replenish heat during the non - heating period to promote the heat recovery of the geotechnical body.

[0004] The system can use the waste heat on the condenser side of the summer refrigeration unit as the heat replenishment heat source to achieve waste heat utilization and energy conservation. The flow directions of the heat replenishment and heat extraction modes are usually opposite: in the heat extraction mode, the fluid of the double - pipe heat exchanger is from the outside in and out from the inside, while in the heat replenishment mode, it is from the inside in and out from the outside. The outlet water temperature on the condenser side of the refrigeration unit is mostly higher than 35°C, and the deep geotechnical temperature is generally higher than 35°C. Therefore, heat can only be released into the geotechnical body in the upper part of the buried - pipe heat exchanger. At present, the switching of the fluid flow direction and path is usually achieved by setting multiple valves and pipelines, resulting in a very complex pipeline system, cumbersome regulation, high cost, and low reliability. Therefore, it is urgent to study a new heat extraction - heat replenishment switching method to find a simple, reliable, economical, and feasible way to improve the long - term operation efficiency of the medium - deep geothermal heat pump system. Summary of the Invention

[0005] To solve the deficiencies in the background art, the present invention provides a heat extraction - heat replenishment switching device for a double - pipe heat exchanger. Through the setting of a reversing valve and a movable one - way valve, it can realize the switching of different flow directions and flow paths in the heat extraction and heat replenishment modes, promote the heat recovery of the geotechnical body, improve the long - term operation energy efficiency, enhance the system reliability, and improve the economy.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A heat extraction - heat compensation switching device for a shell - and - tube heat exchanger, comprising a reversing valve, an inner - tube and reversing - valve connecting pipe, a movable one - way valve, an inner tube of the heat exchanger, an outer tube of the heat exchanger, an outer - tube and reversing - valve connecting pipe, a reversing - valve and unit - inlet connecting pipe, a reversing - valve and unit - outlet connecting pipe, and a circulation pump. Both the upper and lower ends of the outer tube of the heat exchanger are hermetically arranged and extend deep into the heat source well. The inner tube of the heat exchanger is coaxially arranged inside the outer tube of the heat exchanger, its upper end extends out of the outer tube of the heat exchanger, and there is a gap between its lower end and the outer tube of the heat exchanger. The movable one - way valve includes a heat - circulation hole, a thin - wall section of the inner tube, a movable valve core, a valve shaft, a one - way gate plate, and a limiting ring. The outer diameter of the middle position of the inner tube of the heat exchanger remains unchanged while the inner diameter increases, causing its wall thickness to decrease to form the thin - wall section of the inner tube. The number of openings of the heat - circulation hole is several and they are vertically spaced and opened in the upper half of the thin - wall section of the inner tube. The movable valve core is a circular - tube structure that can move up and down and is fitted inside the thin - wall section of the inner tube to control whether the heat - circulation hole is closed. The valve shaft is horizontally arranged inside the movable valve core. The one - way gate plate is composed of two semi - circular plates hinged on both sides of the valve shaft. The limiting ring is arranged on the inner wall of the movable valve core and is located at the bottom of the one - way gate plate to limit its downward flipping. The reversing - valve and unit - inlet connecting pipe and the reversing - valve and unit - outlet connecting pipe are connected to the condenser side of the refrigeration unit or the evaporator side of the heat pump unit. The inner - tube and reversing - valve connecting pipe is communicated with the upper end of the inner tube of the heat exchanger. The outer - tube and reversing - valve connecting pipe is communicated with the pipe wall of the outer tube of the heat exchanger outside the heat source well. The reversing valve is connected between the inner - tube and reversing - valve connecting pipe, the outer - tube and reversing - valve connecting pipe, the reversing - valve and unit - inlet connecting pipe, and the reversing - valve and unit - outlet connecting pipe to be able to switch the flow direction of the fluid between the inner tube and the outer tube of the heat exchanger. The circulation pump is arranged in the middle section of the reversing - valve and unit - outlet connecting pipe to drive the fluid circulation.

[0007] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0008] 1. Convenient and reliable: The switching of different flow directions and flow paths in the heat extraction and heat compensation working conditions is realized through the device of the present invention. Compared with the traditional switching using multiple groups of valves and pipes, the system is more concise, the control and adjustment are more convenient, and the system reliability is higher.

[0009] 2. High energy efficiency: By injecting the waste heat on the condenser side of the refrigeration unit into the shell - and - tube heat exchanger through the device of the present invention, the waste heat can be effectively utilized, and the heat recovery of the rock and soil body can be promoted. The system has higher energy efficiency and can extend the service life of the system.

[0010] 3. Economy: The use of the device of the present invention can significantly improve the economy of the medium - deep geothermal heat pump system. Description of the Drawings

[0011] Figure 1It is the schematic diagram of the heat compensation working condition of the heat extraction-compensation switching device of the tube-in-tube heat exchanger of the present invention;

[0012] Figure 2 It is the schematic diagram of the heat extraction working condition of the heat extraction-compensation switching device of the tube-in-tube heat exchanger of the present invention;

[0013] Figure 3 It is the structural schematic diagram of the reversing valve of the present invention;

[0014] Figure 4 It is the A-A sectional view of the movable one-way valve of the present invention in Figure 1 ;

[0015] Figure 5 It is the B-B sectional view of the movable one-way valve of the present invention in Figure 2 ;

[0016] In the figure: 1 reversing valve, 1.1 valve body shell, 1.2 switching gate plate, 1.3 valve rod, 1.4 handle, 2 connecting pipe between the inner pipe and the reversing valve, 3 movable one-way valve, 3.1 heat circulation hole, 3.2 thin-walled section of the inner pipe, 3.3 movable valve core, 3.4 valve shaft, 3.5 one-way gate plate, 3.6 limit ring, 4 inner pipe of the heat exchanger, 5 outer sleeve of the heat exchanger, 6 connecting pipe between the outer sleeve and the reversing valve, 7 connecting pipe between the reversing valve and the unit inlet, 8 connecting pipe between the reversing valve and the unit outlet, 9 circulation pump. Specific embodiments

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0018] As Figures 1 to 5 shown, a heat extraction-compensation switching device for a tube-in-tube heat exchanger includes a reversing valve 1, a connecting pipe 2 between the inner pipe and the reversing valve, a movable one-way valve 3, an inner pipe 4 of the heat exchanger, an outer sleeve 5 of the heat exchanger, a connecting pipe 6 between the outer sleeve and the reversing valve, a connecting pipe 7 between the reversing valve and the unit inlet, a connecting pipe 8 between the reversing valve and the unit outlet, and a circulation pump 9.

[0019] Combined with Figures 1 to 3As shown in the figure, the reversing valve 1 includes a valve body housing 1.1, a switching gate plate 1.2, a valve stem 1.3 and a handle 1.4. The interior of the valve body housing 1.1 is a cylindrical cavity. Four pipe orifices are evenly arranged circumferentially on its outer side wall and are respectively connected to the inner pipe and the reversing valve connecting pipe 2, the outer sleeve pipe and the reversing valve connecting pipe 6, the reversing valve and the unit inlet connecting pipe 7, and the reversing valve and the unit outlet connecting pipe 8 through flanges. The valve body housing 1.1 is made of stainless steel, and its size is determined according to the flow rate and pressure. The diameters of the four pipe orifices are consistent with the corresponding connecting pipes. The switching gate plate 1.2 is a rectangular plate and is arranged at the central position inside the valve body housing 1.1. The switching gate plate 1.2 is also made of stainless steel. Its length is equal to the inner diameter of the valve body housing 1.1, its width is equal to the inner height of the valve body housing 1.1, and its thickness is determined according to the fluid pressure, ensuring that the switching gate plate 1.2 can divide the cylindrical cavity of the valve body housing 1.1 into two airtight and non - communicating parts. The valve stem 1.3 is coaxially and rotationally sealed to the top of the valve body housing 1.1 and is fixedly connected to the switching gate plate 1.2. The switching gate plate 1.2 can rotate around the valve stem 1.3. By controlling the rotation of the switching gate plate 1.2 through the valve stem 1.3, the flow direction of the fluid between the inner pipe 4 of the heat exchanger and the outer sleeve pipe 5 of the heat exchanger can be switched. The handle 1.4 is fixed at the end of the valve stem 1.3 and can control the rotation of the switching gate plate 1.2 through manual rotation. Of course, an electric control mechanism can also be used to replace the handle 1.4 to control the rotation of the switching gate plate 1.2 through electric rotation, so as to realize angle adjustment and flow direction switching;

[0020] Combined with Figures 1 to 2 As shown in the figure, one end of the inner pipe and the reversing valve connecting pipe 2 is communicated with the upper end of the inner pipe 4 of the heat exchanger, and the other end of the inner pipe and the reversing valve connecting pipe 2 is connected to the corresponding pipe orifice of the reversing valve 1 through a flange;

[0021] Combined with Figures 1 to 2 and Figures 4 to 5As shown in the figure, the movable one-way valve 3 includes a heat circulation hole 3.1, a thin-walled section 3.2 of the inner tube, a movable valve core 3.3, a valve shaft 3.4, a one-way shutter 3.5, and a limit ring 3.6. The outer diameter of the middle position of the inner tube 4 of the heat exchanger remains unchanged while the inner diameter increases, reducing the wall thickness to 1 / 2 of the original to form the thin-walled section 3.2 of the inner tube. The upper end of the thin-walled section 3.2 of the inner tube is 1 / 2 of the depth of the heat source well from the wellhead of the heat source well, and the height of the thin-walled section 3.2 of the inner tube is 0.4 - 1.0 m. The number of openings of the heat circulation hole 3.1 is several and they are vertically spaced and opened in the upper half area of the thin-walled section 3.2 of the inner tube. The total opening area of the heat circulation hole 3.1 is equal to the cross-sectional area of the inner tube 4 of the heat exchanger. The movable valve core 3.3 is arranged in a circular tube structure inside the thin-walled section 3.2 of the inner tube. The movable valve core 3.3 is made of PE material. The height of the movable valve core 3.3 is half of the height of the thin-walled section 3.2 of the inner tube. The inner diameter of the movable valve core 3.3 is 2 - 3 mm smaller than the inner diameter of the inner tube 4 of the heat exchanger, and the outer diameter of the movable valve core 3.3 is 0.5 mm smaller than the inner diameter of the thin-walled section 3.2 of the inner tube, ensuring that the movable valve core 3.3 is in contact with the thin-walled section 3.2 of the inner tube and can move up and down. The valve shaft 3.4 is horizontally arranged in the center inside the movable valve core 3.3 for the installation of the one-way shutter 3.5. The one-way shutter 3.5 is composed of two semi-circular plates and is hinged on both sides of the valve shaft 3.4, and can be turned upwards by 90° respectively with the valve shaft 3.4 as the axis. The limit ring 3.6 is arranged on the inner wall of the movable valve core 3.3 and is located at the bottom of the one-way shutter 3.5 to limit the downward turning of the one-way shutter 3.5. The fluid in the inner tube 4 of the heat exchanger flows from bottom to top during the heating period, i.e., the heat extraction working condition. The movable valve core 3.3 of the movable one-way valve 3 moves to the upper end of the thin-walled section 3.2 of the inner tube under the action of fluid pressure and buoyancy. At this time, the one-way shutter 3.5 is opened, and the heat circulation hole 3.1 is closed by the movable valve core 3.3. When the fluid in the inner tube 4 of the heat exchanger flows from top to bottom during the heat recovery period, i.e., the heat replenishment working condition, the movable valve core 3.3 of the movable one-way valve 3 moves to the lower end of the thin-walled section 3.2 of the inner tube under the action of fluid pressure. At this time, the one-way shutter 3.5 is closed, the heat circulation hole 3.1 is not closed by the movable valve core 3.3, and the fluid enters the annular cavity between the inner tube 4 of the heat exchanger and the outer casing 5 of the heat exchanger through the heat circulation hole 3.1;

[0022] Combined with Figures 1 to 2 As shown in the figure, the inner tube 4 of the heat exchanger is coaxially arranged inside the outer casing 5 of the heat exchanger. The upper end of the inner tube 4 of the heat exchanger extends out of the outer casing 5 of the heat exchanger, and there is a gap between the lower end of the inner tube 4 of the heat exchanger and the outer casing 5 of the heat exchanger;

[0023] Combined with Figures 1 to 2 As shown in the figure, the lower end of the outer casing 5 of the heat exchanger is closed and extends deep into the heat source well, and the upper end of the outer casing 5 of the heat exchanger is closed to connect and fix the inner tube 4 of the heat exchanger;

[0024] Combined with Figures 1 to 2As shown, one end of the outer sleeve pipe connecting pipe 6 is communicated with the pipe wall of the heat exchanger outer sleeve pipe 5 outside the heat source well, and the other end of the outer sleeve pipe connecting pipe 6 is flange-connected to the corresponding pipe orifice of the reversing valve 1;

[0025] Combined with Figures 1 to 2 As shown, one end of the connecting pipe 7 between the reversing valve and the unit inlet and one end of the connecting pipe 8 between the reversing valve and the unit outlet are respectively flange-connected to the corresponding pipe orifices of the reversing valve 1. The other ends of the connecting pipe 7 between the reversing valve and the unit inlet and the connecting pipe 8 between the reversing valve and the unit outlet are connected to the condenser side of the refrigeration unit under the heat supplement condition and to the evaporator side of the heat pump unit under the heat extraction condition;

[0026] Combined with Figures 1 to 2 As shown, the circulation pump 9 is arranged in the middle section of the connecting pipe 8 between the reversing valve and the unit outlet to drive the fluid circulation on the heat source side.

[0027] The specific principle of the present invention is as follows:

[0028] By rotating the handle 1.4 on the reversing valve 1, the angle of the switching gate 1.2 can be adjusted, the communication state between the inner pipe and the reversing valve connecting pipe 2, the outer sleeve pipe and the reversing valve connecting pipe 6, the connecting pipe 7 between the reversing valve and the unit inlet, and the connecting pipe 8 between the reversing valve and the unit outlet can be changed, and at the same time, the opening and closing state of the movable check valve 3 can be changed, so as to change the flow path and direction.

[0029] The system uses the waste heat on the condenser side of the refrigeration unit as the heat supplement heat source. Since the hot water on the condenser side of the refrigeration unit is mostly higher than 35°C, and the temperature of the deep rock and soil is usually higher than 35°C. If the hot water enters the annular cavity from the bottom end of the inner pipe 4 of the heat exchanger, the heat of the hot water cannot be released to the underground rock and soil. However, in the present invention, a heat circulation hole 3.1 is arranged in the middle of the inner pipe 4 of the heat exchanger, so that the fluid only circulates in the shallow layer, and the heat is released to the shallow rock and soil to realize the heat supplement of the rock and soil mass.

[0030] Under the heat supplement condition, the angle of the switching gate 1.2 is as Figure 1As shown, the fluid flow path is as indicated by the arrows: Driven by the circulating pump 9, the hot water from the condenser side of the refrigeration unit successively passes through the reversing valve and the unit outlet connecting pipe 8, the reversing valve 1, and the inner pipe and reversing valve connecting pipe 2 and is injected into the inner pipe 4 of the heat exchanger. The fluid in the inner pipe 4 of the heat exchanger flows downward. The movable valve core 3.3 of the movable one-way valve 3 moves to the lower end of the thin-walled section 3.2 of the inner pipe under the action of the fluid pressure, and the heat circulation hole 3.1 is opened. The two semi-circular plates of the one-way gate 3.5 rotate and fall to the limit ring 3.6 around the valve shaft 3.4 under the action of gravity and pressure, and the one-way gate 3.5 is in the closed state. The fluid in the inner pipe 4 of the heat exchanger returns to the annular cavity through the heat circulation hole 3.1, releases heat to the surrounding rock and soil during the upward flow, and then successively flows through the outer sleeve and reversing valve connecting pipe 6, the reversing valve 1, and the reversing valve and unit inlet connecting pipe 7 and returns to the condenser side of the cold unit. During this period, the fluid in the lower half of the heat source well does not participate in the circulation. Since the temperature of the deep rock and soil is high, it can be left to recover naturally. In this way, a heat replenishment cycle in the upper half is formed to promote the temperature recovery of the underground rock and soil mass.

[0031] Under the heat extraction condition, by rotating the handle 1.4, the switching gate 1.2 rotates 90°, and the angle of the switching gate 1.2 is as Figure 2 As shown, the fluid flow path is as indicated by the arrows: Driven by the circulating pump 9, the cold fluid from the evaporator side of the heat pump unit successively passes through the reversing valve and the unit outlet connecting pipe 8, the reversing valve 1, and the outer sleeve and reversing valve connecting pipe 6 and is injected into the outer sleeve 5 of the heat exchanger. The fluid in the outer sleeve 5 of the heat exchanger flows downward, extracts the heat of the surrounding rock and soil and the temperature rises, and then enters the inner pipe 4 of the heat exchanger from the bottom. The fluid in the inner pipe 4 of the heat exchanger flows upward from bottom to top. The movable valve core 3.3 of the movable one-way valve 3 moves to the upper end of the thin-walled section 3.2 of the inner pipe under the action of the fluid pressure and buoyancy, the heat circulation hole 3.1 is closed, and the two semi-circular plates of the one-way gate 3.5 turn upward and open around the valve shaft 3.4 under the action of the fluid pressure. The fluid in the inner pipe 4 of the heat exchanger then successively flows through the inner pipe and reversing valve connecting pipe 2, the reversing valve 1, and the reversing valve and unit inlet connecting pipe 7 and returns to the evaporator side of the heat pump unit, thereby forming a heat extraction cycle to extract the underground heat energy during the heating period.

[0032] In summary, only by switching the angle of the switching gate 1.2 in the reversing valve 1 can the fluid flow direction and path be changed, so as to switch between the heat extraction and heat replenishment conditions. It is mainly applied to the switching of the heat extraction - heat replenishment conditions of the rock and soil mass of the medium - deep ground source heat pump. The system is simple, the operation is convenient, and the reliability is higher. At the same time, during the non - heating period, waste heat will be used for heat replenishment, which promotes the heat recovery of the underground rock and soil and ensures the long - term operation energy efficiency of the system.

[0033] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent conditions of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0034] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A heat extraction - heat compensation switching device for a double - pipe heat exchanger, characterized in that: It includes a reversing valve (1), an inner pipe and a reversing valve connecting pipe (2), a movable one-way valve (3), an inner pipe of the heat exchanger (4), an outer pipe of the heat exchanger (5), an outer pipe and a reversing valve connecting pipe (6), a reversing valve and a unit inlet connecting pipe (7), a reversing valve and a unit outlet connecting pipe (8), and a circulation pump (9). Both the upper and lower ends of the outer pipe of the heat exchanger (5) are closed and extend into the heat source well. The inner pipe of the heat exchanger (4) is coaxially arranged inside the outer pipe of the heat exchanger (5), with its upper end extending out of the outer pipe of the heat exchanger (5), and there is a gap between its lower end and the outer pipe of the heat exchanger (5). The movable one-way valve (3) includes a heat circulation hole (3.1), a thin-walled section of the inner pipe (3.2), a movable valve core (3.3), a valve shaft (3.4), a one-way gate plate (3.5), and a limit ring (3.6). The outer diameter of the middle position of the inner pipe of the heat exchanger (4) remains unchanged while the inner diameter increases, causing the wall thickness to decrease to form the thin-walled section of the inner pipe (3.2). The heat circulation hole (3.1) has a number of openings and is vertically spaced and opened in the upper half of the thin-walled section of the inner pipe (3.2). The movable valve core (3.3) is a circular tube structure that can move up and down and is fitted inside the thin-walled section of the inner pipe (3.2) to control whether the heat circulation hole (3.1) is closed. The valve shaft (3.4) is horizontally arranged inside the movable valve core (3.3). The one-way gate plate (3.5) is composed of two semi-circular plates hinged on both sides of the valve shaft (3.4). The limit ring (3.6) is arranged on the inner wall of the movable valve core (3.3) and is located at the bottom of the one-way gate plate (3.5) to limit its downward flipping. The reversing valve and the unit inlet connecting pipe (7) and the reversing valve and the unit outlet connecting pipe (8) are connected to the condenser side of the refrigeration unit or the evaporator side of the heat pump unit. The inner pipe and the reversing valve connecting pipe (2) are connected and communicated with the upper end of the inner pipe of the heat exchanger (4). The outer pipe and the reversing valve connecting pipe (6) are connected and communicated with the pipe wall of the outer pipe of the heat exchanger (5) outside the heat source well. The reversing valve (1) is connected between the inner pipe and the reversing valve connecting pipe (2), the outer pipe and the reversing valve connecting pipe (6), the reversing valve and the unit inlet connecting pipe (7), and the reversing valve and the unit outlet connecting pipe (8) to be able to switch the flow direction of the fluid between the inner pipe of the heat exchanger (4) and the outer pipe of the heat exchanger (5). The circulation pump (9) is arranged in the middle section of the reversing valve and the unit outlet connecting pipe (8) to drive the fluid circulation.

2. The heat extraction - heat compensation switching device for a double - pipe heat exchanger according to claim 1, characterized in that: The reversing valve (1) includes a valve body housing (1.1), a switching gate plate (1.2), and a valve rod (1.3). The inside of the valve body housing (1.1) is a cylindrical cavity, and four pipe orifices are evenly arranged circumferentially on its outer side wall and are respectively connected to the inner pipe and the reversing valve connecting pipe (2), the outer pipe and the reversing valve connecting pipe (6), the reversing valve and the unit inlet connecting pipe (7), and the reversing valve and the unit outlet connecting pipe (8) through flanges. The switching gate plate (1.2) is arranged at the central position inside the valve body housing (1.1) and can divide the cylindrical cavity into two airtight and non-connected parts. The valve rod (1.3) is coaxially and rotationally sealedly connected to the top of the valve body housing (1.1) and is fixedly connected to the switching gate plate (1.2).

3. The heat extraction - heat compensation switching device for a double - pipe heat exchanger according to claim 2, characterized in that: The handle (1.4) fixed to the end of the valve stem (1.3) is rotated manually to control the rotation of the switching gate (1.2).

4. The heat extraction - heat compensation switching device for a double - pipe heat exchanger according to claim 2, characterized in that: The end of the valve stem (1.3) is controlled by an electric control mechanism to rotate the switching gate (1.2) through electric rotation.

5. The heat extraction - heat compensation switching device for a double - pipe heat exchanger according to claim 1, characterized in that: The upper end of the thin-walled section (3.2) of the inner pipe is at a distance of 1 / 2 of the depth of the heat source well from the wellhead of the heat source well.

6. The heat extraction - heat compensation switching device for a double - pipe heat exchanger according to claim 1, characterized in that: The total opening area of the heat circulation holes (3.1) is equal to the cross-sectional area of the inner pipe (4) of the heat exchanger.

Images