Reinforced concrete underground heat exchanger prefabricated module and installation method thereof

Abstract

The present application relates to the technical field of ground source heat exchange, and discloses a prefabricated module of a reinforced concrete underground heat exchanger and a mounting method thereof, which comprises a heat exchanger body, a heat exchange channel is defined in the heat exchanger body, the heat exchange channel is communicated with an air inlet pipe and an air outlet pipe respectively, and helical ribs are arranged in a helical shape on the inner surface of the heat exchange channel. The heat exchange channel is separated from a shallow stratum by the heat exchanger body, the heat exchanger body made of reinforced concrete is used as a heat exchange structure, has the ability of resisting water vapor erosion and extrusion deformation, and prolongs the service life. Meanwhile, the helical ribs are arranged in the heat exchange channel, and the air entering the heat exchange channel forms a cyclone, so that an air boundary layer is avoided to be formed on the inner wall of the channel, and the heat exchange efficiency is improved. Heat exchange grooves are arranged on the front and back sides of the heat exchanger body, the heat exchange area of the heat exchanger body and the shallow stratum is increased, a plurality of heat exchange channels are arranged in a meandering manner in the heat exchanger body, the pipeline arrangement length is increased, and the excavation amount of the trench is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of ground source heat exchange technology, and in particular to a prefabricated module of reinforced concrete underground heat exchanger and its installation method. Background Technology

[0002] Shallow ground layers possess natural temperature stability. In summer, the temperature of shallow ground layers is lower than the outdoor temperature; while in winter, the temperature of shallow ground layers is higher than the outdoor temperature. Ground source heat exchange technology is a highly efficient and energy-saving technology that utilizes shallow ground layers as a constant heat source and cold source for building heating and cooling.

[0003] In ground source heat exchange systems, underground ventilation ducts are typically made of materials such as PVC, concrete, and cast iron, which present the following technical drawbacks in practical applications:

[0004] 1. Studies have shown that the burial depth of underground ventilation ducts should be 4 to 6 meters and the length of the ducts often exceeds 30 meters. Therefore, during the construction of ground source heat exchange systems, a large amount of shallow strata need to be excavated, resulting in high engineering construction costs.

[0005] 2. Underground ventilation ducts mostly use circular or square cross-sections, so the heat exchange area between the duct and the shallow ground is relatively small, resulting in low heat exchange efficiency;

[0006] 3. The inner wall of underground ventilation ducts is mostly smooth. When air flows, due to the viscosity of the fluid, the air velocity close to the duct wall will decrease, thus forming an air boundary layer on the duct wall. The presence of the air boundary layer will hinder the heat exchange between the air in the middle of the duct and the duct, thereby further reducing the heat exchange efficiency.

[0007] 4. When underground ventilation ducts are buried in shallow soil, the soil will squeeze the ducts from all sides and cause water vapor erosion, resulting in a generally shorter service life for underground ventilation ducts.

[0008] In view of this, how to overcome all or part of the above-mentioned technical defects is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to provide a prefabricated module for a reinforced concrete underground heat exchanger and its installation method, so as to solve the problems existing in the prior art.

[0010] To achieve the above objectives, the present invention provides a prefabricated module for a reinforced concrete underground heat exchanger, comprising:

[0011] The heat exchanger body is buried in a shallow stratum and has internally defined heat exchange channels. The heat exchange channels are respectively connected to the air inlet pipe and the air outlet pipe. The air inlet pipe is connected to the outside atmosphere, and the air outlet pipe is connected to the indoor exhaust system.

[0012] Spiral ribs are arranged in a spiral shape on the inner surface of the heat exchange channel. After the air enters the heat exchange channel, it forms a swirling flow through the spiral ribs.

[0013] Furthermore, there are multiple heat exchange channels arranged at intervals from top to bottom, and the two ends of each heat exchange channel extend to the left and right end faces of the heat exchanger body, respectively; adjacent heat exchange channels are connected by bends.

[0014] Furthermore, one end of the uppermost heat exchange channel is an air inlet, and the other end is connected to the adjacent heat exchange channel below via a bend. One end of the lowermost heat exchange channel is an air outlet, and the other end is connected to the adjacent heat exchange channel above via a bend. The air inlet pipe is connected to the air inlet, and the air outlet pipe is connected to the air outlet.

[0015] Furthermore, the area between two adjacent heat exchange channels of the heat exchanger body is the first connection area, and the front and rear sides of the heat exchanger body are recessed inward to form multiple heat exchange grooves, and the positions of the multiple heat exchange grooves correspond to the first connection area.

[0016] Furthermore, the heat exchange channel near the top or bottom of the heat exchanger body is the edge heat exchange channel, and the area between the edge heat exchange channel and the top or bottom of the heat exchanger body is the second connection area. The front and rear sides of the heat exchanger body are recessed inward to form multiple heat exchange grooves corresponding to the second connection area.

[0017] Furthermore, the multiple heat exchange grooves are arranged in the longitudinal and transverse directions, with vertical ribs formed on both sides of the same row of heat exchange grooves, and horizontal ribs formed between adjacent rows of heat exchange grooves. The tops of the multiple vertical ribs are connected by an upper connecting plate, and the bottoms of the multiple vertical ribs are connected by a lower connecting plate.

[0018] Furthermore, the heat exchange groove corresponding to the second connection area extends to the front and rear sides of the upper or lower connection plate.

[0019] Furthermore, the heat exchanger body is formed by concrete pouring, the vertical ribs are provided with stirrups, and the second connecting area and the transverse ribs are provided with longitudinal bars, which are tied to the stirrups.

[0020] Furthermore, bolt connection holes are provided on the ribs on the left and right sides of the heat exchanger body, and adjacent heat exchanger bodies are connected by bolts, and the heat exchange channels of adjacent heat exchanger bodies are sealed and connected.

[0021] This invention also provides an installation method for a prefabricated module of a reinforced concrete underground heat exchanger, which includes the following steps:

[0022] S1: Trench is formed by excavation in shallow strata;

[0023] S2: Place a preset number of heat exchanger bodies in the trench, align the bolt connection holes of adjacent heat exchanger bodies and connect them with bolts to seal and connect the heat exchange channels of adjacent heat exchanger bodies.

[0024] S3: The uppermost heat exchange channel has an air inlet at one end and is connected to the adjacent heat exchange channel below it via a bend at the other end. The lowermost heat exchange channel has an air outlet at one end and is connected to the adjacent heat exchange channel above it via a bend at the other end. The remaining heat exchange pipes are connected sequentially from top to bottom via bends. Connect the air inlet pipe to the air inlet and the air outlet pipe to the air outlet.

[0025] S4: Lead the air inlet duct above the ground and install an air purifier. Connect the air inlet duct to the air purifier. Lead the air outlet duct indoors and connect it to the indoor exhaust system.

[0026] S5: Backfill trench.

[0027] The present invention discloses the following technical effects:

[0028] 1. This invention abandons the traditional underground ventilation duct and defines a heat exchange channel within the heat exchanger body. The heat exchange channel can be separated from the shallow strata by the heat exchanger body. The heat exchanger body, made of reinforced concrete, serves as the heat exchange structure, which has the ability to resist water vapor erosion and extrusion deformation, thus extending its service life. At the same time, spiral ribs are set in the heat exchange channel, and the air forms a swirling flow after entering the heat exchange channel, which can avoid the formation of an air boundary layer on the inner wall of the channel, thereby improving the heat exchange efficiency and heat exchange effect.

[0029] 2. Multiple heat exchange channels are arranged meanderingly within the heat exchanger body, which can increase the pipeline length per unit length, significantly reduce the amount of trench excavation, thereby reducing the trench excavation area and lowering the project construction cost.

[0030] 3. Heat exchange grooves are provided on the front and rear sides of the heat exchanger body, forming vertical and horizontal ribs, which can increase the heat exchange area between the heat exchanger body and the shallow formation and greatly improve the heat exchange efficiency. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the heat exchanger body structure;

[0033] Figure 2 This is a lateral layout diagram of the heat exchange channels;

[0034] Figure 3 This is a diagram showing the arrangement of stirrups and longitudinal reinforcement.

[0035] Figure 4 This is a schematic diagram of the side panel structure;

[0036] Figure 5 This is a schematic diagram of the base plate and vertical plate structure;

[0037] Figure 6 This is a schematic diagram of the screw structure;

[0038] Figure 7 This is a schematic diagram of the installation of the present invention;

[0039] The components include: 1. Heat exchanger body; 101. Heat exchange channel; 102. First connection area; 103. Heat exchange groove; 104. Second connection area; 105. Vertical rib; 106. Horizontal rib; 107. Upper connecting plate; 108. Lower connecting plate; 2. Air inlet pipe; 3. Air outlet pipe; 4. Indoor exhaust system; 5. Spiral rib; 6. Bend; 7. Stirrup; 8. Longitudinal rib; 9. Bolt connection hole; 10. Side plate; 11. Punch; 12. Base plate; 13. Vertical plate; 14. Screw; 15. Side plate connection hole; 16. Positioning hole; 17. Threaded hole; 18. Air purifier. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Example 1

[0043] like Figures 1 to 7 As shown, the present invention provides a prefabricated module for a reinforced concrete underground heat exchanger, comprising:

[0044] The heat exchanger body 1 is buried in a shallow stratum and has a heat exchange channel 101 defined inside. The heat exchange channel 101 is connected to the air inlet pipe 2 and the air outlet pipe 3 respectively. The air inlet pipe 2 is connected to the outside atmosphere and the air outlet pipe 3 is connected to the indoor exhaust system 4.

[0045] Spiral ribs 5 are arranged in a spiral shape on the inner surface of the heat exchange channel 101. After the air enters the heat exchange channel 101, it forms a swirling flow through the spiral ribs 5.

[0046] In this embodiment, the shallow strata refer to the strata 10 to 25 meters below the surface. The shallow strata are "constant temperature layers" with a temperature that remains basically unchanged throughout the year. Taking the North China Plain as an example, the temperature is about 17 to 20°C, which can be used for cooling in summer and heating in winter.

[0047] In this embodiment, the specific dimensions and pitch of the spiral rib 5 can be flexibly adjusted according to the actual application scenario, and are not limited here.

[0048] In this embodiment, there are multiple heat exchange channels 101 arranged at uniform intervals from top to bottom, and the arrangement direction is horizontal. The two ends of the heat exchange channels 101 extend to the left and right end faces of the heat exchanger body 1, respectively. Adjacent heat exchange channels 101 are connected by bends 6.

[0049] In this embodiment, one end of the uppermost heat exchange channel 101 is an air inlet, and the other end is connected to the adjacent heat exchange channel 101 below via a bend 6. One end of the lowermost heat exchange channel 101 is an air outlet, and the other end is connected to the adjacent heat exchange channel 101 above via a bend 6. The air inlet pipe 2 is connected to the air inlet, and the air outlet pipe 3 is connected to the air outlet.

[0050] In this embodiment, the area between two adjacent heat exchange channels 101 of the heat exchanger body 1 is the first connection area 102. The front and rear sides of the heat exchanger body 1 are recessed inward to form a plurality of heat exchange grooves 103, and the positions of the plurality of heat exchange grooves 103 correspond to the positions of the first connection area 102.

[0051] In this embodiment, the heat exchange channel 101 near the top or bottom of the heat exchanger body 1 is the edge heat exchange channel 101, and the area between the edge heat exchange channel 101 and the top or bottom of the heat exchanger body 1 is the second connection area 104. The front and rear sides of the heat exchanger body 1 are recessed inward to form a plurality of heat exchange grooves 103 corresponding to the second connection area 104.

[0052] In this embodiment, multiple heat exchange grooves 103 are arranged in the longitudinal and transverse directions. Vertical ribs 105 are formed on both sides of the same row of heat exchange grooves 103, and horizontal ribs 106 are formed between two adjacent rows of heat exchange grooves 103. The tops of the multiple vertical ribs 105 are connected by an upper connecting plate 107, and the bottoms of the multiple vertical ribs 105 are connected by a lower connecting plate 108.

[0053] In this embodiment, the heat exchange groove 103 corresponding to the second connection area 104 extends to the front and rear sides of the upper connection plate 107 or the lower connection plate 108.

[0054] In this embodiment, the heat exchange groove 103 corresponding to the first connection area 102 is trapezoidal, and the heat exchange groove 103 corresponding to the second connection area 104 is roughly half of a trapezoid.

[0055] In this embodiment, the heat exchanger body 1 is formed by concrete pouring, and stirrups 7 are provided in the vertical ribs 105. Longitudinal bars 8 are provided in the second connecting area 104 and the transverse ribs 106. The longitudinal bars 8 are tied to the stirrups 7.

[0056] In this embodiment, bolt connection holes 9 are provided on the ribs on the left and right sides of the heat exchanger body 1. The bolt connection holes 9 are arranged at intervals with the heat exchange channels 101. Adjacent heat exchanger bodies 1 are connected by bolts, and the heat exchange channels 101 of adjacent heat exchanger bodies 1 are sealed and connected.

[0057] In this embodiment, sealing rings can be provided at both ends of the heat exchange channel 101 to improve the connection sealing between the heat exchange channel 101 and the bend 6, as well as the connection sealing between the heat exchange channel 101 and another heat exchange channel 101.

[0058] The precast modules of reinforced concrete underground heat exchangers are formed by casting using molds. The specific manufacturing method is as follows:

[0059] First, a mold adapted to the shape of the heat exchanger body 1 is made. The front and rear sides of the mold are side plates 10, and a punch 11 is provided corresponding to the heat exchange groove 103. The bottom of the mold is a base plate 12, and the left and right sides are vertical plates 13. Threaded holes 17 are opened on the left and right surfaces of the vertical plates 13 corresponding to the heat exchange channel 101. A screw 14 adapted to the threaded rib is made, and the two ends of the screw 14 are threaded to the threaded holes 17 on the two vertical plates 13 respectively, for forming the heat exchange channel 101 during casting. The vertical plates 13, base plate 12 and side plates 10 are welded to form a U-shaped mold. The front and rear sides of the vertical plates 13 and the side plates 10 are provided with preliminary connection holes 15. Bolts can be inserted into the side plate connection holes 15 to initially connect the side plates 10 and the vertical plates 13 (mainly for positioning, but not to the structural strength required for subsequent casting) before welding. Positioning holes 16 are provided on the left and right sides of the vertical plate 13 corresponding to the threaded connection holes, for subsequent machining of threaded connection holes on the left and right sides of the heat exchanger body 1.

[0060] Inside the U-shaped mold, stirrups 7 are arranged corresponding to the vertical ribs 105, and longitudinal ribs 8 are arranged corresponding to the upper connecting plate 107, lower connecting plate 108, and horizontal ribs 106. The longitudinal ribs 8 are then connected and fixed to the stirrups 7. Concrete is poured into the U-shaped mold, and after the concrete has initially set, threaded connection holes are machined. The screw 14 is rotated and removed to form a heat exchange channel 101 with spiral ribs 5. After the concrete reaches the design strength, the mold is removed to obtain the heat exchanger body 1.

[0061] This invention also provides an installation method for a prefabricated module of a reinforced concrete underground heat exchanger, which includes the following steps:

[0062] S1: Trench is formed by excavation in shallow strata;

[0063] S2: Place a preset number of heat exchanger bodies 1 in the trench, align the bolt connection holes 9 of adjacent heat exchanger bodies 1 with each other and connect them with bolts to seal and connect the heat exchange channels 101 of adjacent heat exchanger bodies 1.

[0064] S3: One end of the uppermost heat exchange channel 101 is an air inlet, and the other end is connected to the adjacent heat exchange channel 101 below via a bend 6. One end of the lowermost heat exchange channel 101 is an air outlet, and the other end is connected to the adjacent heat exchange channel 101 above via a bend 6. The remaining heat exchange pipes are connected sequentially from top to bottom via bends 6. Connect the air inlet pipe 2 to the air inlet and the air outlet pipe 3 to the air outlet.

[0065] S4: Lead the air inlet pipe 2 to the ground and install the air purifier 18. Connect the air inlet pipe 2 to the air purifier 18. Lead the air outlet pipe 3 to the room and connect it to the indoor exhaust system 4.

[0066] S5: Backfill trench.

[0067] The specific heat exchange process is as follows:

[0068] In summer, outside air is filtered by air purifier 18 and enters air inlet duct 2, and then enters heat exchange channel 101 along air inlet duct 2. The temperature of heat exchanger body 1 is maintained at 17-20℃ in shallow strata, so the air can be cooled down quickly after entering heat exchange channel 101 to form cool air. The cool air enters air outlet duct 3 along heat exchange channel 101 and is finally supplied to the cooling area by indoor exhaust system.

[0069] In winter, outside air is filtered by air purifier 18 and enters air inlet duct 2, and then enters heat exchange channel 101 along air inlet duct 2. The temperature of heat exchanger body 1 is maintained at 17-20℃ in shallow strata, so the air can be heated up quickly after entering heat exchange channel 101 to form heating air. The heating air enters air outlet duct 3 along heat exchange channel 101 and is finally supplied to the cooling area by indoor exhaust system.

[0070] To maintain the air temperature after heat exchange, an insulation layer can be installed on the outside of the air outlet duct 3 to prevent air temperature loss during transportation.

[0071] Example 2

[0072] The difference between this embodiment and Embodiment 1 is that the length of the heat exchanger body 1 is extended, so that the heat exchange channels 101 are integrated into the same heat exchanger body 1, eliminating the need to assemble multiple heat exchanger bodies 1 and further simplifying the installation process. However, this extended heat exchanger body 1 requires a larger mold during manufacturing, and its overall length cannot be adjusted by increasing or decreasing the number of components. Therefore, in practical applications, the choice between the heat exchanger body 1 disclosed in Embodiment 1 and the heat exchanger body 1 disclosed in Embodiment 2 needs to be comprehensively considered.

[0073] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0074] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A prefabricated module for a reinforced concrete underground heat exchanger, characterized in that, include: The heat exchanger body (1) is buried in a shallow stratum and is formed by concrete pouring. It defines a heat exchange channel (101) inside. The heat exchange channel (101) is connected to the air inlet pipe (2) and the air outlet pipe (3) respectively. The air inlet pipe (2) is connected to the outside atmosphere, and the air outlet pipe (3) is connected to the indoor exhaust system (4). Spiral ribs (5) are arranged in a spiral shape on the inner surface of the heat exchange channel (101). After the air enters the heat exchange channel (101), it forms a swirling flow through the spiral ribs (5). The heat exchange channels (101) are multiple and arranged at intervals from top to bottom. The two ends of the heat exchange channels (101) extend to the left and right end faces of the heat exchanger body (1), respectively. Adjacent heat exchange channels (101) are connected by bends (6). The uppermost heat exchange channel (101) has an air inlet at one end and is connected to the adjacent lower heat exchange channel (101) via a bend (6) at the other end. The lowermost heat exchange channel (101) has an air outlet at one end and is connected to the adjacent upper heat exchange channel (101) via a bend (6) at the other end. The air inlet pipe (2) is connected to the air inlet, and the air outlet pipe (3) is connected to the air outlet.

2. A prefabricated module for a reinforced concrete underground heat exchanger according to claim 1, characterized in that, The area between two adjacent heat exchange channels (101) of the heat exchanger body (1) is the first connection area (102). The front and rear sides of the heat exchanger body (1) are recessed inward to form a plurality of heat exchange grooves (103), and the positions of the plurality of heat exchange grooves (103) correspond to the positions of the first connection area (102).

3. A prefabricated module for a reinforced concrete underground heat exchanger according to claim 2, characterized in that, The heat exchange channel (101) near the top or bottom of the heat exchanger body (1) is the edge heat exchange channel (101). The area between the edge heat exchange channel (101) and the top or bottom of the heat exchanger body (1) is the second connection area (104). The front and rear sides of the heat exchanger body (1) are recessed inward to form multiple heat exchange grooves (103) corresponding to the second connection area (104).

4. A prefabricated module for a reinforced concrete underground heat exchanger according to claim 3, characterized in that, Multiple heat exchange grooves (103) are arranged in the longitudinal and transverse directions. Vertical ribs (105) are formed on both sides of the same row of heat exchange grooves (103), and horizontal ribs (106) are formed between two adjacent rows of heat exchange grooves (103). The tops of multiple vertical ribs (105) are connected by an upper connecting plate (107), and the bottoms of multiple vertical ribs (105) are connected by a lower connecting plate (108).

5. A prefabricated module for a reinforced concrete underground heat exchanger according to claim 4, characterized in that, The heat exchange groove (103) corresponding to the second connection area (104) extends to the front and rear sides of the upper connection plate (107) or the lower connection plate (108).

6. A prefabricated module for a reinforced concrete underground heat exchanger according to claim 4 or 5, characterized in that, The vertical rib (105) is provided with stirrups (7), and the second connecting area (104) and the transverse rib (106) are provided with longitudinal bars (8), which are tied to the stirrups (7).

7. A prefabricated module for a reinforced concrete underground heat exchanger according to claim 6, characterized in that, Bolt connection holes (9) are provided on the ribs on the left and right sides of the heat exchanger body (1). Adjacent heat exchanger bodies (1) are connected by bolts, and the heat exchange channels (101) of adjacent heat exchanger bodies (1) are sealed and connected.

8. A method for installing a prefabricated module of a reinforced concrete underground heat exchanger, used for installing the prefabricated module of the reinforced concrete underground heat exchanger as described in claim 7, comprising the following steps: S1: Trench is formed by excavation in shallow strata; S2: Place a preset number of heat exchanger bodies (1) in the trench, align the bolt connection holes (9) of adjacent heat exchanger bodies (1) with each other and connect them with bolts to seal and connect the heat exchange channels (101) of adjacent heat exchanger bodies (1). S3: The heat exchange channel (101) at the top has an air inlet at one end and is connected to the heat exchange channel (101) below it via a bend (6) at the other end. The heat exchange channel (101) at the bottom has an air outlet at one end and is connected to the heat exchange channel (101) above it via a bend (6) at the other end. The remaining heat exchange pipes are connected from top to bottom via bends (6). Connect the air inlet pipe (2) to the air inlet and the air outlet pipe (3) to the air outlet. S4: Lead the air inlet pipe (2) above the ground and install the air purifier (18). Connect the air inlet pipe (2) to the air purifier (18). Lead the air outlet pipe (3) to the room and connect it to the indoor exhaust system (4). S5: Backfill trench.

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