Construction method of composite energy underground continuous wall

Abstract

The application discloses a composite energy underground continuous wall and a construction method thereof. The composite energy underground continuous wall comprises heat exchange pipes and a steel reinforcement cage arranged in the continuous wall. The continuous wall comprises the steel reinforcement cage, a heat exchange layer attached to an underground soil layer, and a heat insulation layer facing an underground space. A separation layer is arranged between the heat exchange layer and the heat insulation layer, and the separation layer is located in the middle of the steel reinforcement cage. The heat exchange pipes are fixedly bound with the steel reinforcement cage. The heat exchange layer exchanges temperature with the underground soil layer, so that energy recycling is realized. The heat exchange layer and the underground space are separated by the heat insulation layer, so that energy exchange between the underground space and the heat exchange layer is reduced, energy loss is reduced, the continuous wall has heat insulation and heat storage performance, energy utilization is improved, and the use value of the continuous wall is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of buried pipes of a ground source heat pump system, in particular to a composite energy underground continuous wall and a construction method thereof. Background Art

[0002] Under the background of the "dual carbon" goal, achieving sustainable energy utilization and developing and utilizing clean energy are the current development directions of my country. Shallow geothermal energy has the characteristics of large reserves, wide distribution, clean and renewable.

[0003] By combining the composite energy underground continuous wall with the ground source heat pump buried pipe to form an energy composite energy underground continuous wall, it can play the dual role of underground shallow geothermal extraction and anti-seepage retaining soil. At the same time, it can avoid the high drilling cost and large space occupation of the buried pipe heat exchanger, and has good economic benefits.

[0004] Existing technologies combining hybrid energy underground continuous walls with heat exchange tubes typically arrange the heat exchange tubes along the depth of the composite energy underground continuous wall. When one side of the composite energy underground continuous wall is an underground space, convection heat exchange between the continuous wall and the air within the underground space significantly reduces the heat exchange efficiency of the heat exchange tubes and accelerates heat dissipation from the surrounding soil. Therefore, it is crucial to develop a hybrid energy underground continuous wall that can balance heat exchange and insulation. Summary of the Invention

[0005] The present invention is to address the above-mentioned deficiencies in the prior art and provide a composite energy underground continuous wall and its construction method. The heat exchange layer exchanges temperature with the underground soil layer to achieve energy recovery and utilization. The heat exchange layer is separated from the underground space by the heat insulation layer, reducing the energy exchange between the underground space and the heat exchange layer, thereby reducing energy loss. As a result, the continuous wall has the performance of heat insulation and heat storage, improving energy utilization and enhancing the use value of the continuous wall.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A composite energy underground continuous wall includes a heat exchange tube and a steel cage placed inside the continuous wall. The continuous wall includes the steel cage, a heat exchange layer in contact with the underground soil layer, and a heat insulation layer facing the underground space. A separation layer is provided between the heat exchange layer and the heat insulation layer. The separation layer is located in the middle of the steel bar hole. The heat exchange tube is tied and fixed to the steel cage.

[0008] Preferably, the separation layer includes a mesh cloth and a steel mesh, the steel mesh is fixed in the middle of the steel cage, the mesh cloth is laid on one side of the steel mesh, and the steel mesh and the mesh cloth are tied and fixed to the steel cage.

[0009] Preferably, the heat exchange tube is fixed to the steel cage by tying wire.

[0010] Preferably, the heat exchange tube is a HDPE heat exchange tube, which is tied inside the steel cage, and the inlet section and the outlet section of the heat exchange tube extend out of the steel cage.

[0011] Preferably, the outer diameter of the heat exchange tube is 19mm-38mm, the wall thickness is 2mm-2.5mm, the distance between the heat exchange tubes is 200mm-500mm, and the inlet and outlet sections of the heat exchange tube extend 200mm-500mm out of the steel cage.

[0012] Preferably, the heat exchange layer is heat storage concrete mixed with concrete and low melting point paraffin wax, and the heat insulation layer is heat insulation concrete using ceramsite as concrete aggregate, and the particle size of the ceramsite is 5mm to 20mm.

[0013] Preferably, the low melting point paraffin wax is selected from No. 20 to No. 40, with a melting point of 17.5° C. to 42.5° C., and the addition amount is 2% to 5% of the mass of the concrete.

[0014] Preferably, the mesh cloth is made of glass fiber mesh cloth with a mesh size of 3mm*3mm~5mm*5mm, a mesh width of 1000mm~2000mm, a mesh length of 10m~100m, and a thickness of 0.2mm~0.4mm; the steel wire mesh is made of galvanized steel wire mesh with a mesh size of 10mm*10mm~20mm*20mm and a wire diameter of 0.9mm~1.6mm; the binding wire is made of galvanized steel wire or flame-burned iron wire with a diameter of 0.3mm~0.5mm.

[0015] A construction method for a composite energy underground continuous wall comprises the following steps:

[0016] 1) Lay out infrastructure, construct guide walls and excavate trench sections. The top surface of the guide walls must be higher than the construction ground and at least 1.5m above the groundwater level.

[0017] 2) Fabricate a steel cage according to the size of the trough section, secure a wire mesh to the middle of the cage, and lay a mesh cloth on the wire mesh. Tie the wire mesh and mesh cloth to the cage using wire ties to form a separation layer. Arrange heat exchange tubes in a straight line on the side of the separation layer facing the underground soil layer, and secure the heat exchange tubes to the inner side of the cage using wire ties.

[0018] 3) Hoist the steel cage into the trough section;

[0019] 4) Lower the concrete pouring conduit to 0.5m from the bottom of the trench section and pour concrete. Pour concrete on both sides of the separation layer at the same time. Pour heat storage concrete on the side facing the underground soil layer and pour insulation concrete on the side facing the underground space to complete the construction of the composite energy underground continuous wall trench section.

[0020] Preferably, in step 4), the concrete is poured in layers, and vibrated in time after the layer-by-layer pouring is completed.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention realizes energy recycling and utilization by exchanging temperature between the heat exchange layer and the underground soil layer, and separates the heat exchange layer from the underground space through the insulation layer, thereby reducing the energy exchange between the underground space and the heat exchange layer, thereby reducing energy loss, so that the composite energy underground continuous wall has the performance of heat insulation and heat storage, improves the energy utilization rate, and enhances the use value of the composite energy underground continuous wall; in addition, compared with the existing technology, the composite energy underground continuous wall of the present application has a larger contact area with the ground, a stronger support effect, and an improved structural strength.

[0023] 2. When the energy composite underground continuous wall and energy pile are operated in conjunction with the present invention, the influence of groundwater seepage on the heat exchange performance of the energy pile can be effectively reduced, thereby reducing the influence on its bearing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A longitudinal sectional view of the present invention;

[0025] Figure 2 It is a transverse partial cross-sectional view of the present invention;

[0026] Figure 3 Schematic diagram of the separation layer structure.

[0027] In the figure: 1-underground soil layer; 2-heat exchange layer; 3-heat exchange tube; 4-partition layer; 5-insulation layer; 6-underground space; 7-rebar cage; 8-mesh cloth; 9-wire mesh; 10-binding wire. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] like Figure 1-2 As shown, a composite energy underground continuous wall includes a heat exchange tube 3 and a steel cage 7 placed in the continuous wall. The continuous wall includes the steel cage 7, a heat exchange layer 2 adhered to the underground soil layer 1 and an insulation layer 5 facing the underground space 6. A separation layer 4 is provided between the heat exchange layer 2 and the insulation layer 5. The separation layer 4 is located in the middle of the steel hole, and the heat exchange tube 3 and the steel cage 7 are tied and fixed.

[0030] The separation layer 4 includes a mesh cloth 8 and a steel mesh 9. The steel mesh 9 is fixed in the middle of the steel cage 7. The mesh cloth 8 is laid on one side of the steel mesh 9. The steel mesh 9 and the mesh cloth 8 are tied and fixed to the steel cage 7.

[0031] The heat exchange tube 3 is fixed to the steel cage 7 by tying wire 10 .

[0032] The heat exchange tube 3 is a HDPE heat exchange tube 3 with high thermal conductivity and good isothermal performance. The heat exchange tube 3 is tied inside the steel cage 7, and the inlet and outlet sections of the heat exchange tube 3 extend out of the steel cage 7.

[0033] The outer diameter of the heat exchange tube 3 is 19mm-38mm, the wall thickness is 2mm-2.5mm, the spacing between the heat exchange tubes 3 is 200mm-500mm, and the inlet and outlet sections of the heat exchange tube 3 extend 7200mm-500mm out of the steel cage.

[0034] The heat exchange layer 2 is heat storage concrete mixed with concrete and low melting point paraffin wax, and the heat insulation layer 5 is made of ceramsite instead of stone as the aggregate of concrete, with a particle size of 5mm to 20mm and the same mixing amount as sand.

[0035] Low melting point paraffin wax is selected from No. 20 to No. 40, with a melting point of 17.5℃ to 42.5℃, and the addition amount is 2% to 5% of the concrete mass.

[0036] The mesh cloth 8 is selected from glass fiber mesh cloth 8 with a mesh size of 3mm*3mm~5mm*5mm, a mesh width of 1000mm~2000mm, a mesh length of 10m~100m, and a thickness of 0.2mm~0.4mm; the steel wire mesh 9 is selected from galvanized steel wire mesh 9 with a mesh size of 10mm*10mm~20mm*20mm and a wire diameter of 0.9mm~1.6mm; the binding wire 10 is selected from galvanized steel wire or flame-burned iron wire with a diameter of 0.3mm~0.5mm.

[0037] like Figure 1-3 As shown, a construction method of a composite energy underground continuous wall includes the following steps:

[0038] 1) Investigate and analyze the geological conditions of the slope, conduct engineering geological exploration and design, and analyze the distribution of soil layers, groundwater levels and their changes, as well as the structure, lithology, weathering degree and layer thickness of the bedrock;

[0039] Level and compact the construction site in accordance with the design data requirements, and lay out infrastructure such as water supply, drainage, power supply, roads, and temporary buildings that meet construction requirements;

[0040] Construct the guide wall according to the construction design requirements. The top surface of the guide wall should be slightly higher than the construction ground and should be at least 1.5m higher than the groundwater level.

[0041] Excavate trench sections according to construction design requirements, and select trenching machinery based on the engineering geology and hydrogeology of the trenching site, construction environment, etc.

[0042] 2) Fabricate a steel cage 7 according to the size of the trough section, secure a wire mesh 9 to the middle of the steel cage 7, and lay a mesh cloth 8 on the wire mesh 9. Tie the wire mesh 9 and the mesh cloth 8 to the steel cage 7 using ties 10 to form a separation layer 4. Arrange heat exchange tubes 3 in a straight line on the side of the separation layer 4 facing the underground soil layer 1, and secure the heat exchange tubes 3 to the inner side of the steel cage 7 using ties 10.

[0043] 3) After the trough is cleaned and the slurry is replaced, the steel cage 7 is hoisted into the trough section;

[0044] 4) Lower the concrete pouring conduit to a position 0.5m from the bottom of the trench section and pour concrete. Pour concrete on both sides of the partition layer 4 at the same time. Pour heat storage concrete on the side facing the underground soil layer 1, and pour insulation concrete on the side facing the underground space 6. Use a layered concrete pouring method. After the layered pouring is completed, vibrate in time to complete the construction of the composite energy underground continuous wall trench section.

[0045] The following are two specific construction methods provided in this application:

[0046] Example 1:

[0047] A construction method of a composite energy composite energy underground continuous wall comprises the following steps:

[0048] 1) Investigate and analyze the geological conditions of the slope, conduct engineering geological exploration and design, analyze the distribution of soil layers, groundwater levels and changes, and the structure, lithology, weathering degree and layer thickness of the bedrock.

[0049] 2) In accordance with the requirements of the design data, the construction site shall be leveled and compacted, and infrastructure such as water supply, drainage, power supply, roads and temporary buildings that meet the construction requirements shall be laid out.

[0050] 3) Construct the guide wall according to the construction design requirements. The top surface of the guide wall should be slightly higher than the construction ground and should be more than 1.5m higher than the groundwater level.

[0051] 4) Excavate the trench section according to the construction design requirements, and select trenching machinery based on the engineering geology and hydrogeology conditions of the trenching site, the construction environment, etc.

[0052] 5) According to the size of the construction trench section, a steel cage 7 is made; the trench section is 6m long, 0.6m thick, and buried to a depth of 15m.

[0053] like Figure 3As shown, a steel mesh 9 is fixed to the center of the reinforcement cage 7, and a mesh cloth 8 is laid on the steel mesh 9. The steel mesh 9 and the mesh cloth 8 are then tied to the reinforcement cage 7 with tying wires 10 to form a separation layer 4. The steel mesh 9 is a galvanized steel mesh 9 with a mesh size of 10 mm * 10 mm and a wire diameter of 1.2 mm. The mesh cloth 85 is a glass fiber mesh 8 with a mesh size of 3 mm * 3 mm, a mesh width of 2 m, a mesh length of 15 m, and a thickness of 0.4 mm.

[0054] Heat exchange tubes 3 are arranged in a straight line inside the steel cage 7 and tied to the cage with tie wires 10. These heat exchange tubes are HDPE with an outer diameter of 25 mm, a wall thickness of 2.3 mm, a spacing of 200 mm, a bend radius of 100 mm, and a height of 400 mm from the bottom. The inlet and outlet sections extend 200 mm beyond the cage. Tie wires 107 are galvanized steel wire with a diameter of 0.3 mm.

[0055] 6) The steel cage 7 is hoisted into the trench after the trench is cleaned and the slurry is replaced.

[0056] 7) Lower the conduit to 0.5m from the bottom of the trench section and pour concrete. Pour the inner and outer layers of the partition layer 4 simultaneously, and adopt a layered concrete pouring method. After pouring, vibrate the layers promptly. Pour insulation concrete toward the side of the underground space 6, and pour heat storage concrete toward the side of the underground soil layer 1, thus completing the construction of the composite energy underground continuous wall trench section. Among them, the heat storage concrete uses No. 30 low-melting point paraffin wax with a melting point of 30°C and a content of 3% of the concrete mass. The insulation concrete uses ceramsite instead of stone as the aggregate of the concrete. The particle size is 10mm and the content is the same as that of sand. The ceramsite needs to be pre-wetted before mixing for at least 24 hours. The pre-wetting needs to be stopped in advance before production to allow the surface of the ceramsite to reach a dry state.

[0057] Example 2

[0058] A construction method of a composite energy composite energy underground continuous wall comprises the following steps:

[0059] 1) Investigate and analyze the geological conditions of the slope, conduct engineering geological exploration and design, analyze the distribution of soil layers, groundwater levels and changes, and the structure, lithology, weathering degree and layer thickness of the bedrock.

[0060] 2) In accordance with the requirements of the design data, the construction site shall be leveled and compacted, and infrastructure such as water supply, drainage, power supply, roads and temporary buildings that meet the construction requirements shall be laid out.

[0061] 3) Construct the guide wall according to the construction design requirements. The top surface of the guide wall should be slightly higher than the construction ground and should be more than 1.5m higher than the groundwater level.

[0062] 4) According to the construction design requirements, excavate the groove section, and select the groove excavating machine according to the engineering geology and hydrogeology conditions of the groove forming site, construction environment and the like.

[0063] 5) According to the size of the construction groove section, make the steel reinforcement cage 7; the groove section length is 8 m, the thickness is 1 m, and the soil entering depth is 25 m.

[0064] Fix the steel wire mesh 9 in the middle of the steel reinforcement cage 7, lay the glass fiber mesh 8 on the steel wire mesh 9, and then bind the steel wire mesh 9 and the glass fiber mesh 8 on the steel reinforcement cage 7 by the binding wire 10 to form the separation layer 4. The steel wire mesh 9 is selected as a galvanized steel wire mesh 9, the mesh size is 10 mm*10 mm, and the wire diameter is 1.2 mm. The glass fiber mesh 8 is selected as a glass fiber mesh 8, the mesh size is 4 mm*4 mm, the mesh width is 2 m, the mesh length is 25 m, and the thickness is 0.4 mm.

[0065] Arrange the heat exchange pipe 3 in a straight line type on the inner side of the steel reinforcement cage 7 and bind it with the steel reinforcement cage 7 by the binding wire 10. The heat exchange pipe 3 is an HDPE heat exchange pipe 3, the outer diameter of the heat exchange pipe 3 is 25 mm, the wall thickness is 2.3 mm, the spacing is 400 mm, the bending radius is 400 mm, the distance from the bottom surface is 500 mm, and the inlet section and the outlet section extend out of the steel reinforcement cage 7 by 300 mm. The binding wire 10 is selected as a galvanized steel wire, and the diameter is 0.3 mm.

[0066] 6) After the steel reinforcement cage 7 is cleaned and the mortar is qualified, hoist and install it into the groove.

[0067] 7) Pour the concrete to the groove section bottom 0.5 m, pour the concrete to the inner and outer two layers of the separation layer 4 at the same time, and adopt the layered pouring concrete mode, and vibrate in time after the layered pouring concrete is completed, pour the heat insulation concrete to the inner layer, and pour the heat storage concrete to the outer layer, and complete the composite energy underground continuous wall groove section construction.

[0068] The heat storage concrete selects the No. 30 low melting point paraffin, the melting point is 30℃, and the mixing amount is 3% of the mass of the concrete. The heat insulation concrete replaces the stone as the aggregate of the concrete by the ceramsite, the particle size is 15 mm, the mixing amount is the same as the sand, the ceramsite needs to be pre-wetted before mixing, the pre-wetting time is not less than 24 hours, and the production needs to be stopped for pre-wetting in advance to make the surface of the ceramsite reach the dry state.

[0069] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and the equivalent technologies thereof, the present application also intends to include these modifications and variations.

Claims

1. A construction method for a composite energy underground continuous wall, comprising heat exchange tubes and a steel cage placed within the continuous wall, characterized in that: The continuous wall includes a steel cage, a heat exchange layer in contact with the underground soil layer, and a heat insulation layer facing the underground space. A separation layer is provided between the heat exchange layer and the heat insulation layer. The separation layer is located in the middle of the steel bar hole. The heat exchange tubes are tied and fixed to the steel cage. The construction method includes the following steps: 1) Lay out infrastructure, construct guide walls and excavate trench sections. The top surface of the guide walls must be higher than the construction ground and at least 1.5m above the groundwater level. 2) According to the size of the trough section, a steel cage is made. A wire mesh is fixed in the middle of the steel cage. A mesh cloth is laid on the wire mesh. The wire mesh and mesh cloth are tied to the steel cage with wire to form a separation layer. Heat exchange tubes are arranged in a straight line on the side of the separation layer facing the underground soil layer. The heat exchange tubes are fixed to the inner side of the steel cage with wire ties. 3) Hoist the steel cage into the trough section; 4) Lower the concrete pouring conduit to a position 0.5m from the bottom of the trench section and pour concrete. Pour concrete on both sides of the separation layer at the same time. Pour heat storage concrete on the side facing the underground soil layer and pour insulation concrete on the side facing the underground space to complete the construction of the composite energy underground continuous wall trench section.

2. The construction method of a composite energy underground continuous wall according to claim 1, characterized in that: The separation layer includes a mesh cloth and a steel wire mesh. The steel wire mesh is fixed in the middle of the steel cage. The mesh cloth is laid on one side of the steel wire mesh. The steel wire mesh and the mesh cloth are tied and fixed to the steel cage.

3. The construction method of a composite energy underground continuous wall according to claim 1, characterized in that: The heat exchange tube is fixed to the steel cage by tying wire.

4. The construction method of a composite energy underground continuous wall according to claim 1, characterized in that: The heat exchange pipe is a HDPE heat exchange pipe, which is tied inside the steel cage, and the inlet section and outlet section of the heat exchange pipe extend out of the steel cage.

5. The construction method of a composite energy underground continuous wall according to claim 1, characterized in that: The outer diameter of the heat exchange tube is 19mm-38mm, the wall thickness is 2mm-2.5mm, the distance between the heat exchange tubes is 200mm-500mm, and the inlet and outlet sections of the heat exchange tube extend 200mm-500mm out of the steel cage.

6. The construction method of a composite energy underground continuous wall according to claim 1, characterized in that: The heat exchange layer is heat storage concrete mixed with concrete and low melting point paraffin wax, and the heat insulation layer is heat insulation concrete using ceramsite as concrete aggregate, with the particle size of the ceramsite being 5mm to 20mm.

7. The construction method of a composite energy underground continuous wall according to claim 6, characterized in that: The low melting point paraffin wax is selected from No. 20 to No. 40, with a melting point of 17.5°C to 42.5°C, and the addition amount is 2% to 5% of the mass of the concrete.

8. The construction method of a composite energy underground continuous wall according to claim 1, characterized in that: The mesh cloth is made of glass fiber mesh cloth with a mesh size of 3mm*3mm~5mm*5mm, a mesh width of 1000mm~2000mm, a mesh length of 10m~100m, and a thickness of 0.2mm~0.4mm; the steel wire mesh is made of galvanized steel wire mesh with a mesh size of 10mm*10mm~20mm*20mm and a wire diameter of 0.9mm~1.6mm; the binding wire is made of galvanized steel wire or flame-burned iron wire with a diameter of 0.3mm~0.5mm.

9. The construction method of a composite energy underground continuous wall according to claim 1, characterized in that: In the step 4), the concrete is poured in layers, and vibrated promptly after the layers are poured.

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