Heat exchange device for geothermal well

Abstract

The utility model provides a heat exchange device for a geothermal well, which comprises a heat exchange component arranged in the geothermal well and comprising a first inner pipe and a second inner pipe, the heat exchange tube set is arranged in the first inner tube and provided with at least one heat exchange tube, the first inner tube and a shell pass outside the heat exchange tube set form a heat exchange side of the heat exchange assembly so as to communicate with an external geothermal environment, and a tube pass in the heat exchange tube forms a circulation side of the heat exchange assembly so as to communicate with an external water environment; the partition plate extends in the axial direction of the first inner pipe, and a water passing opening is formed in the upper portion of the partition plate so that the heat exchange side can be divided into a first part and a second part, the heat preservation assembly is arranged below the heat exchange assembly and communicates with the heat exchange side; and the submersible pump is arranged in the heat preservation assembly and is configured to pump geothermal water in the geothermal environment to the heat exchange side.

Description

TECHNICAL FIELD

[0001] The utility model relates to geothermal energy heat extraction technical field especially relates to a heat exchange device for geothermal well. BACKGROUND

[0002] Geothermal energy is widely used in heating, power generation, hot spring and agricultural greenhouse fields, and at present, the exploitation of geothermal energy is mainly through geothermal well. The geothermal well includes extraction well and recharge well, wherein the extraction well is suitable for extracting geothermal water, and after the geothermal water exchanges heat with the external water environment, it is re-injected into the ground through the recharge well.

[0003] In order to prevent the problem of ground subsidence caused by excessive extraction of underground water, and to realize the recycling of geothermal energy, the existing relevant standards and regulations stipulate that the proportion of geothermal tail water recharge in the same layer should be greater than or equal to 95%.

[0004] Therefore, how to provide a heat exchange device that can effectively improve the geothermal tail water recharge in the same layer has become a technical problem to be solved. SUMMARY

[0005] In order to solve the above and other technical problems in the prior art, the utility model provides a heat exchange device for geothermal well, which is suitable for improving the geothermal tail water recharge in the same layer.

[0006] The utility model provides a heat exchange device for geothermal well, comprising: a heat exchange assembly arranged in a geothermal well, comprising: a first inner tube; a heat exchange tube group arranged in the first inner tube and having at least one heat exchange tube, the first inner tube and the shell side outside the heat exchange tube group form the heat exchange side of the heat exchange assembly to communicate with the external geothermal environment, and the tube side in the heat exchange tube forms the circulation side of the heat exchange assembly to communicate with the external water environment; a partition plate extending along the axial direction of the first inner tube and forming a water passage at the upper part to separate the heat exchange side into a first part and a second part connected in series at the upper part; a heat preservation assembly arranged below the heat exchange assembly and communicating with the heat exchange side; and a submersible pump arranged in the heat preservation assembly and configured to extract geothermal water in the geothermal environment to the heat exchange side.

[0007] In an illustrative embodiment, the heat preservation assembly comprises: a heat preservation tube sleeved on the outside of the submersible pump; an upper water inlet pipe arranged between the first flange at the upper end of the heat preservation tube and the first inner tube; and a lower water inlet pipe arranged at the second flange at the lower end of the heat preservation tube and extending into the geothermal environment.

[0008] In an illustrative embodiment, the heat preservation tube comprises a second inner tube and a second outer tube, and the second inner tube and the second outer tube are filled with a heat preservation layer.

[0009] In an illustrative embodiment, the heat exchange device further comprises a first connector disposed at an upper portion of the first inner tube, having a first water inlet and a first water outlet, the first water inlet and the first water outlet being located on two sides of the partition; a second connector disposed at a lower portion of the first inner tube, having a second water inlet in communication with the first portion and a second water outlet in communication with the second portion; wherein the upper water inlet pipe is in communication with the second water inlet.

[0010] In an illustrative embodiment, the heat exchange device further comprises a joint plate; the heat exchange pipe is configured as a U-shaped pipe, both ends of the heat exchange pipe being connected to the joint plate and being located at the first portion and the second portion, respectively.

[0011] In an illustrative embodiment, an axis of the second water inlet coincides with an axis of the second connector, and the second water outlet is offset from the axis of the second connector.

[0012] In an illustrative embodiment, the heat exchange device comprises a plurality of second water outlets, the plurality of second water outlets being arranged at intervals around the axis of the second connector.

[0013] In an illustrative embodiment, the heat exchange device further comprises a temperature acquisition device configured to acquire an inlet water temperature and an outlet water temperature of the geothermal water, and a flow acquisition device configured to acquire an inlet water flow and an outlet water flow of the geothermal water; wherein the temperature acquisition device and the flow acquisition device are configured to be communicatively connected to the submersible pump.

[0014] In an illustrative embodiment, a radial side of the first connector is provided with a first groove configured to accommodate at least one of a first cable connected to the temperature acquisition device, a second cable connected to the flow acquisition device, and a third cable connected to the submersible pump.

[0015] In an illustrative embodiment, a radial side of the second connector is provided with a second groove, a projection of the second groove at least partially coinciding with a projection of the first groove in a projection along an axial direction of the first inner tube; wherein the second groove is configured to accommodate the third cable connected to the submersible pump.

[0016] The heat exchange device for geothermal well according to the illustrative embodiment of the present application is provided, and the heat exchange assembly is arranged in the geothermal well, and the geothermal water extracted from the geothermal well exchanges heat with the circulating water in the water environment in the geothermal well, so that the geothermal water can be regarded as being recharged in equal amount. In addition, the heat exchange device for geothermal well further has the heat preservation assembly arranged outside the submersible pump below the heat exchange assembly, so that the heat loss caused by the heat exchange between the geothermal water and the environment in the well before the geothermal water is extracted to the heat exchange assembly can be effectively reduced, and the geothermal water before entering the heat exchange assembly can be kept at a high temperature. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic view of the heat exchange device for geothermal well according to the illustrative embodiment of the present application;

[0018] Figure 2 is Figure 1 a perspective view of the heat exchange assembly part of the illustrative embodiment shown in the figure;

[0019] Figure 3 is Figure 2 a perspective view of the heat exchange assembly omitting the first outer pipe part of the illustrative embodiment shown in the figure;

[0020] Figure 4 is Figure 2 a perspective view of the heat exchanger omitting the first connecting piece of the illustrative embodiment shown in the figure;

[0021] Figure 5 is Figure 4 a perspective view of the heat exchanger omitting the joint plate of the illustrative embodiment shown in the figure;

[0022] Figure 6 is Figure 1 a perspective view of the upper water inlet pipe and the connecting part of the second connecting piece of the illustrative embodiment shown in the figure.

[0023] In the drawings, the meanings of the reference signs are as follows:

[0024] 1, heat exchange assembly;

[0025] 101, first connecting piece;

[0026] 1011, first water inlet;

[0027] 1012, first water return port;

[0028] 1013, first groove;

[0029] 102, joint plate;

[0030] 103, first outer pipe;

[0031] 104, communication pipe;

[0032] 105、first inner tube;

[0033] 106、rib plate;

[0034] 107、partition plate;

[0035] 108、heat exchange pipe group;

[0036] 109、second connecting piece;

[0037] 1091、second water inlet;

[0038] 1092、second water outlet;

[0039] 110、baffle plate;

[0040] 2、temperature collecting device;

[0041] 3、flow collecting device; and

[0042] 4、heat preservation assembly;

[0043] 41、upper water inlet pipe;

[0044] 411、first end;

[0045] 412、second end;

[0046] 42、second inner tube;

[0047] 43、second outer tube;

[0048] 44、first flange;

[0049] 45、second flange;

[0050] 46、lower water inlet pipe; and

[0051] 5、submersible pump. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the utility model more clearly understood, the following will combine with specific embodiments, and refer to the drawings, make the utility model further detailed description.

[0053] The terms used herein are merely for describing specific embodiments, and are not intended to limit the utility model. The terms "include", "contain" and the like used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0054] All terms used herein, including technical and scientific terms, have the meanings commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be further borne in mind that the

[0055] In the case of using expressions such as "at least one of A, B, and C", it generally means to include at least one of A, at least one of B, at least one of C, a combination of at least one of A and at least one of B, a combination of at least one of A and at least one of C, a combination of at least one of B and at least one of C, and a combination of at least one of A, at least one of B and at least one of C, unless otherwise defined. In the case of using expressions such as "at least one of A, B, or C", it generally means to include at least one of A, at least one of B, at least one of C, a combination of at least one of A and at least one of B, a combination of at least one of A and at least one of C, a combination of at least one of B and at least one of C, and a combination of at least one of A, at least one of B and at least one of C, unless otherwise defined.

[0056] At present, the heat exchange device for geothermal well is generally arranged outside the geothermal well. When the geothermal water is taken, the geothermal water is first extracted to the heat exchange device (such as a plate heat exchanger) outside the geothermal well through the extraction well to exchange heat with circulating water, and then the low-temperature geothermal water after heat exchange is recharged to the geothermal environment through the recharge well.

[0057] With the improvement of the awareness of recycling geothermal energy, in order to prevent the problems of geothermal water depletion and ground subsidence caused by excessive collection of geothermal water, the recharge amount after the geothermal water is taken is required, such as the proportion of the same layer recharge amount of geothermal tail water needs to be greater than or equal to 95%.

[0058] Therefore, how to provide a heat exchange device for geothermal well which can effectively improve the recharge amount of geothermal water becomes a technical problem to be solved.

[0059] Figure 1 is a schematic view of the heat exchange device for geothermal well according to the illustrative embodiment of the present application. It should be noted that, in order to illustrate the heat exchange device in detail, the Figure 1 The proportional relationship of each part is modified.

[0060] According to the heat exchange device for geothermal well provided by the present application, the heat exchange device for geothermal well is arranged in the geothermal well, and the heat exchange device for geothermal well is arranged in the geothermal well. Figure 1As shown, the geothermal well heat exchange device comprises a heat exchange assembly 1, a heat preservation assembly 4 and a submersible pump 5. The heat exchange assembly 1 comprises a first inner tube 105, a heat exchange tube group 108 and a partition plate 107. The heat exchange tube group 108 is arranged in the first inner tube 105 and has at least one heat exchange tube. The first inner tube 105 and the outside of the heat exchange tube group 108 form a heat exchange side of the heat exchange assembly 1 to communicate with the external geothermal environment, and the tube inside the heat exchange tube forms a circulation side of the heat exchange assembly 1 to communicate with the external water environment. The partition plate 107 extends along the axial direction of the first inner tube 105 and forms a water passage at the upper portion to divide the heat exchange side into a first part and a second part which are in communication with each other.

[0061] In an exemplary embodiment, referring to Figure 1 As shown, the geothermal well heat exchange device can be applied to various geothermal wells, including any one of a shallow geothermal well (with a depth of about 200-500 meters), a middle geothermal well (with a depth of about 500-1500 meters) and a deep geothermal well (with a depth of about 1500 meters or more). Further, the geothermal well heat exchange device is used in cooperation with a circulation system located outside the geothermal well, and the circulation system is configured with a circulation medium (such as circulating water, etc.). The circulation medium in the circulation system is connected to the circulation side of the heat exchange assembly 1 through a pipeline to make the circulation medium flow to the circulation side of the heat exchange assembly 1 through the heat exchange tube group 108 (i.e. to guide the circulation medium into the geothermal well) and exchange heat with the geothermal water of the heat exchange side.

[0062] In an exemplary embodiment, the water inlet end of the heat exchange side of the heat exchange device (i.e. the second water inlet 1091 described below) is configured to communicate with the heat preservation assembly 4 having a pump chamber (i.e. the heat preservation tube configured with the submersible pump 5 described below) to draw the geothermal water to the heat exchange side of the heat exchange device under the collection of the submersible pump 5. Further, the heat preservation assembly 4 located outside the submersible pump 5 is adapted to insulate at least part of the heat loss of the geothermal water drawn by the submersible pump 5 from the geothermal well environment outside the heat preservation assembly 4.

[0063] In such an embodiment, the heat exchange assembly 1 is arranged in the geothermal well, and the geothermal water drawn from the geothermal well exchanges heat with the circulating water in the water environment in the geothermal well (i.e. can be regarded as taking heat only, not taking water (geothermal water)), and therefore, it can be regarded that the heat exchange device can be equivalent to recharging the geothermal water. In addition, based on the characteristics of the heat exchange assembly 1 exchanging heat in the geothermal well, the volume of the heat exchange assembly 1 is limited due to the limited space in the geothermal well, and therefore, the heat preservation assembly 4 is provided outside the submersible pump 5 arranged below the heat exchange assembly 1. In this way, the heat loss of the geothermal water caused by heat exchange with the well environment before being drawn to the heat exchange assembly 1 can be effectively reduced, so that the geothermal water before entering the heat exchange assembly 1 can be kept at a higher temperature, thereby achieving more sufficient heat exchange.

[0064] According to embodiments of the present invention, such as Figure 1 As shown, the insulation component 4 includes an insulation pipe, an upper water inlet pipe 41, and a lower water inlet pipe 46. The insulation pipe is sleeved on the outside of the submersible pump 5. The upper water inlet pipe 41 is located between the first flange 44 at the upper end of the insulation pipe and the first inner pipe 105. The lower water inlet pipe 46 is located at the second flange 45 at the lower end of the insulation pipe and extends into the geothermal environment.

[0065] According to embodiments of the present invention, such as Figure 1 As shown, the insulation pipe includes a second inner pipe 42 and a second outer pipe 43, with an insulation layer filling the space between the second inner pipe 42 and the second outer pipe 43.

[0066] In one illustrative embodiment, the submersible pump 5 is disposed within the pump chamber section formed inside the insulation pipe, and the submersible pump 5 is coaxially arranged with the insulation pipe and the inner pipe of the heat exchange device. Furthermore, flange structures (i.e., a first flange 44 and a second flange 45) are provided at both the upper and lower ends of the insulation pipe, and are respectively connected to the upper inlet pipe 41 and the lower inlet pipe 46 via these flange structures. The portions of the insulation pipe connected to the upper inlet pipe 41 and the lower inlet pipe 46 should be equipped with corresponding sealing elements (including but not limited to annular seals) to prevent water leakage caused by vibrations from the operation of the submersible pump 5.

[0067] In one illustrative embodiment, the second outer pipe 43 of the insulation pipe is coaxially sleeved on the outside of the second inner pipe 42 to prevent the geothermal water from transferring at least a portion of its heat to the external geothermal well as it flows through the insulation pipe. Furthermore, to improve the insulation performance of the insulation pipe, insulation material (such as insulation cotton) can be filled into the second outer pipe 43 and the second inner pipe 42 to provide further insulation.

[0068] In this embodiment, the heat exchange between the environment inside the insulation pipe and the geothermal well (i.e., outside the insulation pipe) can be reduced by the installation of the insulation pipe, thereby increasing the temperature of the geothermal water entering the heat exchange device. This improves the geothermal utilization rate and enhances the heat exchange effect between the geothermal water and the circulating water, even though the volume of the heat exchange device is limited by the geothermal well (further limiting the heat exchange area).

[0069] Figure 2 yes Figure 1 A perspective view of part of the heat exchange component 1 in the schematic embodiment shown. Figure 3 yes Figure 2 The perspective view of the heat exchange assembly 1 in the illustrative embodiment shown omits the first outer tube 103 portion.

[0070] According to embodiments of the present invention, such as Figure 2 and Figure 3As shown, the heat exchange device further comprises a first connecting member 101 and a second connecting member 109. The first connecting member 101 is arranged at the upper portion of the first inner tube 105, and has a first water inlet 1011 and a first water outlet 1012, which are located at the two sides of the partition plate 107. The second connecting member 109 is arranged at the lower portion of the first inner tube 105, and has a second water inlet 1091 and a second water outlet 1092, which are in communication with the first portion and the second portion, respectively. The upper water inlet pipe 41 is in communication with the second water inlet 1091.

[0071] In an illustrative embodiment, as shown in Figure 2 and Figure 3 , the heat exchange assembly 1 comprises a first inner tube 105 and a first outer tube 103 coaxially arranged (i.e., the axes of the first inner tube 105 and the first outer tube 103 coincide). In detail, a plurality of rib plates 106 are arranged on the outer wall of the first inner tube 105, specifically including a first rib plate 106 and a second rib plate 106. The first rib plate 106 is configured in a ring shape, and a plurality of first rib plates 106 are uniformly spaced along the axial direction of the first inner tube 105 (i.e., the left-right direction as shown in Figure 3 ). The second rib plate 106 is configured in a strip shape, and a plurality of second rib plates 106 are uniformly spaced along the circumferential direction of the first inner tube 105 and extend to both ends of the first inner tube 105 along the axial direction. The first rib plate 106 and the second rib plate 106 include but are not limited to being welded to the outer surface of the first inner tube 105. Further, a heat preservation material, such as heat preservation cotton, is filled between the first inner tube 105 and the first outer tube 103 (i.e., in the space formed by the intersecting first rib plate 106 and second rib plate 106), to further insulate the heat exchange assembly 1 from the environment inside the geothermal well (i.e., outside the heat exchange assembly 1). The principle is similar to the above-mentioned heat preservation tube, and thus will not be described in detail.

[0072] In an illustrative embodiment, as shown in Figure 2 and Figure 3 , the first connecting member 101 further comprises a communication pipe 104, one end (i.e., the upper end as shown in Figure 3 and Figure 4 ) of the communication pipe 104 is pierced by the first connecting member 101, and the other end (i.e., the lower end, not shown) of the communication pipe 104 is pierced into the first portion or the second portion, to discharge the air in the heat exchange side and prevent the formation of an air layer in the heat exchange side.

[0073] Figure 4 is a perspective view of the heat exchanger of the illustrative embodiment shown in Figure 2 . Figure 5 is a perspective view of the heat exchanger of the illustrative embodiment shown in Figure 4 , omitting the joint plate 102.

[0074] According to the embodiment of the present application, as shown in Figure 4 and Figure 5 , the heat exchange device further comprises a joint plate 102. The heat exchange pipes are configured as U-shaped pipes, and both ends of the heat exchange pipes are connected to the joint plate 102 and are located in the first part and the second part, respectively.

[0075] According to the embodiment of the present application, as shown in Figure 4 and Figure 5 , the first inner pipe 105 forms a cylindrical chamber inside, and the partition plate 107 is arranged in the middle of the chamber and extends in the radial direction (i.e. the approximate up-down direction as shown in Figure 4 ) to divide the chamber into a first part (i.e. the left part as shown in Figure 4 ) and a second part (i.e. the right part as shown in Figure 4 ). In detail, the partition plate 107 is provided with a water passage, which is configured to be approximately the same diameter as the first inner pipe 105, so that the geothermal water can pass through the water passage and flow through the outside of each heat exchange pipe as much as possible.

[0076] Figure 6 is a perspective view of the upper water inlet pipe 41 and the connection part of the second connecting piece 109 of the schematic embodiment as shown in Figure 1 .

[0077] In a schematic implementation, as shown in 4 to Figure 6 , the heat exchange pipe group 108 comprises a plurality of heat exchange pipes. In detail, the plurality of heat exchange pipes include but are not limited to being configured as approximately U-shaped pipes, which include but are not limited to being made of materials with good thermal conductivity (such as copper and other materials). Further, one end of the plurality of heat exchange pipes is located in the first part, and the other end is located in the second part, and both ends of each heat exchange pipe are arranged upward and connected to the porous joint plate 102.

[0078] In a schematic implementation, as shown in Figure 4 , the ends of the plurality of heat exchange pipes are arranged in an array on the joint plate 102. In detail, it includes but is not limited to being configured as an approximately trapezoidal array as shown in Figure 4 . Among them, the heat exchange pipes arranged at the position close to the partition plate 107 of the joint plate 102 are the most, the heat exchange pipes arranged at the position far from the partition plate 107 are the least, and the heat exchange pipes arranged at the positions between gradually decrease.

[0079] In a schematic embodiment, as shown in Figure 5 and Figure 6As shown, the heat exchange pipes are configured as U-shaped pipes, i.e. the heat exchange pipes extend in a direction parallel to the axial direction of the first inner pipe 105 at both ends of the joint plate 102, and the middle part between the two ends of the heat exchange pipes forms a bent pipe. Further, the axial length of the heat exchange pipes close to the partition plate 107 in the heat exchange pipe group 108 is set to be shorter, and the axial length of the heat exchange pipes away from the partition plate 107 is set to be longer. In this way, more heat exchange pipes can be arranged in the first inner pipe 105 to increase the heat exchange area of the heat exchange device.

[0080] In an exemplary embodiment, as shown in Figure 4 and Figure 6 shown, the water inlet end and the water return end of the circulation side (i.e. the heat exchange pipe group 108) of the heat exchange assembly 1 are arranged on the upper joint plate 102, and the water inlet end and the water return end (i.e. the second water inlet 1091 and the second water return 1092) of the heat exchange side of the first inner pipe 105 are arranged on the second connecting piece 109.

[0081] In such an embodiment, through the above design, the flow direction of the geothermal water in the heat exchange side is upward first and then downward after passing through the water passage; and the flow direction of the circulating water in the circulation side is downward first and then upward after passing through the bent pipe part, so that the flow direction of the circulating water when passing through the first part and the second part is always opposite to that of the geothermal water. Therefore, the heat exchange pipes arranged as above not only have a longer heat exchange length, but also always perform counter-flow heat exchange with the geothermal water in the complete heat exchange process, thereby greatly improving the heat exchange effect of the heat exchange assembly 1 on the basis of limited heat exchange area (limited by the geothermal well).

[0082] According to an embodiment of the present application, as shown in Figure 6 , the axis of the second water inlet 1091 coincides with the axis of the second connecting piece 109, and the second water return 1092 is offset from the axis of the second connecting piece 109.

[0083] According to an embodiment of the present application, as shown in Figure 6 , the heat exchange device comprises a plurality of second water returns 1092, and the plurality of second water returns 1092 are arranged at intervals around the axis of the second connecting piece 109.

[0084] In an exemplary embodiment, as shown in Figure 6 , the second water inlet 1091 is arranged in the middle part of the second connecting piece 109, and is configured as a substantially circular shape and arranged concentrically with the second connecting piece 109. Further, the first end 411 of the upper water inlet pipe 41 is located in the second water inlet 1091 and extends below the heat exchange pipe group 108. Further, the first end 411 is further provided with a circular baffle 110, and the end of the baffle 110 facing the first part (such as Figure 6 shown in the upper part) is provided with a circular baffle 110, and the end of the baffle 110 facing the first part (such as Figure 6The flow channel is formed between the upper end of the second part (as shown) and the second connecting piece 109, which blocks the geothermal water introduced by the second water inlet 1091 and guides it to flow in the radial direction of the second inner tube 42. Further, the second end 412 of the upper water inlet tube is connected to the first flange 44.

[0085] In an illustrative embodiment, as shown, the circular baffle 110 is integrally connected to the partition 107 at one end of the second part (as shown at the lower end) to form a sealed structure, so that the geothermal water flowing back through the second part (as shown at the lower part) is blocked and slowly discharged through the plurality of second water outlets 1092, so as to reduce the flow rate of the geothermal water on the heat exchange side, thereby achieving more sufficient heat exchange with the heat exchange tube group 108. Figure 6 Figure 6 In an illustrative embodiment, as shown, the circular baffle 110 is integrally connected to the partition 107 at one end of the second part (as shown at the lower end) to form a sealed structure, so that the geothermal water flowing back through the second part (as shown at the lower part) is blocked and slowly discharged through the plurality of second water outlets 1092, so as to reduce the flow rate of the geothermal water on the heat exchange side, thereby achieving more sufficient heat exchange with the heat exchange tube group 108. Figure 6

[0086] In an illustrative embodiment, as shown, the second connecting piece 109 is further provided with a plurality of second water outlets 1092. In detail, the plurality of second water outlets 1092 are arranged in the radial direction of the second connecting piece 109 to form an array of second water outlets 1092. Among them, the plurality of second water outlets 1092 in the same array of second water outlets 1092 have the same spacing from the axis of the second connecting piece 109 and are arranged at intervals in the circumferential direction of the second connecting piece 109; the second water outlets 1092 in different arrays of second water outlets 1092 have different spacings from the axis of the second connecting piece 109. Further, the sum of the areas of the plurality of second water outlets 1092 can be configured to be 90% to 100% of the area of the second water inlet 1091, so that the flow rate of the water inlet end (i.e., the second water inlet 1091) on the heat exchange side is greater than or equal to the flow rate of the water outlet end (i.e., the second water outlet 1092). In this way, it is beneficial to more fully heat exchange the geothermal water with the circulating water in the heat exchange tube group 108. Figure 6

[0087] According to an embodiment of the present disclosure, as shown, the single-well heat extraction system further comprises a temperature acquisition device 2 and a flow acquisition device 3. The temperature acquisition device 2 is configured to acquire the inlet temperature and outlet temperature of the geothermal water. The flow acquisition device 3 is configured to acquire the inlet flow and outlet flow of the geothermal water. The temperature acquisition device 2 and the flow acquisition device 3 are in communication connection with the submersible pump 5. Figure 6 In an illustrative embodiment, as shown, the temperature acquisition device 2 includes but is not limited to two temperature transmitters. In detail, the detection end of one temperature transmitter penetrates into the second part (as shown at the lower part) through the hole (which can be the second water outlet 1092 or other through hole similar to the second water outlet 1092) provided on the second connecting piece 109.

[0088] Figure 6 In an illustrative embodiment, as shown, the temperature acquisition device 2 includes but is not limited to two temperature transmitters. In detail, the detection end of one temperature transmitter penetrates into the second part (as shown at the lower part) through the hole (which can be the second water outlet 1092 or other through hole similar to the second water outlet 1092) provided on the second connecting piece 109. Figure 6 ​​​​The detection end of the other temperature transmitter penetrates the upstream of the second water inlet 1091 through the sidewall of the upper water inlet pipe 41 to detect the inlet temperature of the geothermal water before heat exchange.

[0089] In an illustrative embodiment, as shown in Figure 2 The flow acquisition device 3 includes, but is not limited to, two flow transmitters. In detail, the detection end of the two flow transmitters penetrates the upstream of the second water inlet 1091 through the sidewall of the upper water inlet pipe 41 to detect the inlet flow of the geothermal water before heat exchange. Further, the detection end of the two flow transmitters is arranged at different positions upstream of the second water inlet 1091 to respectively detect the flow rate of the geothermal water entering the second water inlet 1091 at the at least two positions.

[0090] In an illustrative embodiment, the main body of the temperature acquisition device 2 and the main body of the flow acquisition device 3 are arranged outside the upper water inlet pipe 41.

[0091] In such an embodiment, arranging the temperature acquisition device 2 and the flow acquisition device 3 outside the upper water inlet pipe 41 can prevent the acquisition devices from blocking the geothermal water flowing through the second water inlet 1091, thereby reducing the heat loss caused by the reduced flow rate of the geothermal water, so that the geothermal water can enter the heat exchange side at a higher temperature.

[0092] In an illustrative embodiment, the signal output end of the temperature acquisition device 2 and the flow acquisition device 3 includes, but is not limited to, a communication connection with an external control device (such as a collection card, a single-chip microcomputer, a PLC, a computer, and other devices with signal acquisition functions, etc.) to acquire the temperature difference of the geothermal water after heat exchange and the inlet flow of the geothermal water. Further, the control device is further configured to be connected with the control end of the submersible pump 5, so as to adjust the operating power of the submersible pump 5.

[0093] In such an embodiment, the temperature acquisition device 2 and the flow acquisition device 3 are respectively used to acquire the temperature difference of the geothermal water after heat exchange and the inlet flow of the geothermal water, so as to calculate the heat exchange amount of the geothermal water flowing through the heat exchange side. On this basis, the submersible pump 5 is adjusted in operating parameters (such as adjusting the operating power) according to the heat exchange amount, so as to further adjust the inlet flow of the geothermal water, thereby enabling the circulating water exchanged with the geothermal water to be maintained at (or adjusted to) a suitable temperature, so as to meet the heat extraction requirements of the external water environment.

[0094] According to an embodiment of the present application, as shown in Figure 6 and Figure 2 A first recess 1013 is arranged on one side of the first connecting piece 101 in the radial direction, and is configured to accommodate at least one of a first cable connected to the temperature acquisition device 2, a second cable connected to the flow acquisition device 3, and a third cable connected to the submersible pump 5.

[0095] According to the embodiment of the present application, as shown in Figure 6 and Figure 2 , a radial side of the second connecting piece 109 is provided with a second groove, and in the projection along the axial direction of the first inner tube 105, the projection of the second groove at least partially coincides with the projection of the first groove 1013. Among them, the second groove is configured to accommodate the third cable connected to the submersible pump 5 to pass through.

[0096] In an illustrative embodiment, as shown in Figure 6 and Figure 2 , a radial side (such as the right side as shown in Figure 6 ) of the first connecting piece 101 forms a first groove 1013. Further, the second connecting piece 109 is provided with a second groove (as shown in ​ ) corresponding to the first groove 1013 in the axial direction of the first inner tube 105. The two grooves (i.e. the first groove 1013 and the second groove) are suitable for arranging the first cable, the second cable and the third cable side by side and passing along the axial direction of the first inner tube 105. Among them, the first cable and the second cable include but are not limited to signal transmission cables for transmitting signals (such as electrical signals) collected by the temperature collection device 2 and the flow collection device 3, and the third cable includes but is not limited to a cable for connecting three-phase electricity with the submersible pump 5.

[0097] In an illustrative embodiment, the portion of the first outer tube 103 between the first groove 1013 and the second groove is further provided with a third groove extending in the axial direction of the first outer tube 103.

[0098] In such an embodiment, the first groove 1013, the second groove and the third groove of the heat exchange assembly 1 form a continuous recess on the outside of the heat exchange assembly 1. In this way, the cables for connecting the temperature collection device 2, the flow collection device 3 and the submersible pump 5 can be arranged (and / or limited) on the inside of the recess to avoid scratching the cable with the well wall of the geothermal well during hoisting the heat exchange assembly 1.

[0099] It should be further noted that the direction terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", etc., are only with reference to the drawings, and are not intended to limit the scope of protection of the present application. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion in understanding the present application, conventional structures or configurations will be omitted.

[0100] The embodiments of the present application are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present application. Although each embodiment is described above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present application is defined by the appended claims and their equivalents. Without departing from the scope of the present application, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present application.

Claims

1. A heat exchange device for geothermal wells, characterized in that, include: Heat exchange assembly (1), installed inside the geothermal well, includes: First inner tube (105); A heat exchange tube assembly (108) is disposed inside the first inner tube (105) and has at least one heat exchange tube. The shell side of the first inner tube (105) and the heat exchange tube assembly (108) forms the heat exchange side of the heat exchange component (1) to be connected to the external geothermal environment. The tube side inside the heat exchange tube forms the circulation side of the heat exchange component (1) to be connected to the external water environment. A partition (107) extends axially along the first inner tube (105) and forms a water outlet at the top to divide the heat exchange side into a first part and a second part that are connected at the top. A heat insulation component (4) is disposed below the heat exchange component (1) and is connected to the heat exchange side; and A submersible pump (5) is disposed within the insulation component (4) and is configured to extract geothermal water from the geothermal environment to the heat exchange side.

2. The heat exchange device according to claim 1, characterized in that, The thermal insulation component (4) includes: An insulation pipe is fitted over the outside of the submersible pump (5); An upper water inlet pipe (41) is disposed between the first flange (44) at the upper end of the insulation pipe and the first inner pipe (105); and The lower water inlet pipe (46) is provided at the lower end of the insulation pipe via a second flange (45) and extends into the geothermal environment.

3. The heat exchange device according to claim 2, characterized in that, The insulation pipe includes a second inner pipe (42) and a second outer pipe (43), with an insulation layer filling the space between the second inner pipe (42) and the second outer pipe (43).

4. The heat exchange device according to claim 2, characterized in that, The heat exchange device further includes: The first connector (101) is disposed on the upper part of the first inner tube (105) and has a first inlet (1011) and a first outlet (1012). The first inlet (1011) and the first outlet (1012) are located on both sides of the partition (107). The second connector (109) is disposed at the lower part of the first inner tube (105) and has a second inlet (1091) connected to the first part and a second outlet (1092) connected to the second part. The upper water inlet pipe (41) and the second water inlet (1091) are connected.

5. The heat exchange device according to claim 4, characterized in that, The heat exchange device also includes a joint plate (102). The heat exchange tube is configured as a U-shaped tube, with both ends of the heat exchange tube connected to the joint plate (102) and located in the first part and the second part, respectively.

6. The heat exchange device according to claim 4, characterized in that, The axis of the second inlet (1091) coincides with the axis of the second connector (109), and the second outlet (1092) is offset from the axis of the second connector (109).

7. The heat exchange device according to claim 6, characterized in that, It includes multiple second return water inlets (1092), which are arranged at intervals around the axis of the second connector (109).

8. The heat exchange device according to claim 5, characterized in that, Also includes: Temperature acquisition device (2) is configured to acquire the inlet and return water temperatures of the geothermal water; as well as The flow acquisition device (3) is configured to acquire the inflow and return flow of the geothermal water; The temperature acquisition device (2) and the flow acquisition device (3) are configured to communicate with the submersible pump (5).

9. The heat exchange device according to claim 8, characterized in that, The first connector (101) has a first groove (1013) on one radial side, which is configured to accommodate at least one of the first cable connected to the temperature acquisition device (2), the second cable connected to the flow acquisition device (3), and the third cable connected to the submersible pump (5) through which it passes.

10. The heat exchange device according to claim 9, characterized in that, The second connector (109) has a second groove on one radial side. In the projection along the axial direction of the first inner tube (105), the projection of the second groove at least partially overlaps with the projection of the first groove (1013). The second groove is configured to accommodate a third cable connected to the submersible pump (5) through which it passes.

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