Construction technology for improving heat exchange efficiency of ground source heat pump buried pipe

Abstract

The invention relates to the technical field of buried pipe construction, in particular to a construction technology for improving the heat exchange efficiency of a buried pipe of a ground source heat pump. Comprising the following steps: preparing materials; digging a groove; laying buried pipes; filling a backfill material; connecting a heat exchange medium; testing system performance; and covering a protective layer. According to the construction technology for improving the heat exchange efficiency of the buried pipe of the ground source heat pump, the heat exchange efficiency of the buried pipe can be remarkably improved, system energy consumption can be reduced, the service life can be prolonged, and the construction cost can be reduced through the measures of optimizing material selection, standardizing the construction process, improving the connecting and sealing technology, perfecting a system testing and evaluating mechanism, strengthening protection layer arrangement and the like. Therefore, sustainable development of geothermal energy utilization is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of underground pipe construction, and in particular to a construction process for improving the heat exchange efficiency of underground pipes of ground source heat pumps. Background Art

[0002] In today's global energy shortage and the growing demand for environmental protection, geothermal energy, as a clean and renewable energy resource, has received widespread attention for its development and utilization. As one of the core technologies for geothermal energy utilization, the buried pipe heat exchange system achieves heat transfer and storage through heat exchange between buried pipes and soil or groundwater, and is widely used in heating, cooling and hot water supply. However, the heat exchange efficiency of buried pipes is affected by many factors, such as soil characteristics, climate conditions, pipe materials, construction technology, etc. Among them, the optimization of construction technology is of great significance to improving heat exchange efficiency, reducing system energy consumption and extending service life.

[0003] The underground pipe heat exchange system mainly uses closed pipes (i.e. underground pipes) buried underground, soil or groundwater as heat source or cold source, and circulating medium (such as water, ethylene glycol solution, etc.) flows in the pipe to absorb or release heat. Its working principle is based on three heat transfer methods: heat conduction, convection and radiation. Among them, heat conduction between soil and underground pipes is the key factor in heat exchange efficiency.

[0004] However, in actual applications, the buried pipe heat exchange system faces many challenges: first, the soil characteristics are complex and changeable. The soil thermal conductivity, humidity, density and other parameters in different regions vary greatly, affecting the heat exchange efficiency; second, the climate conditions are changeable, especially under extreme climate conditions, the soil temperature fluctuates greatly, affecting the stable operation of the system; third, the pipe material and structural design directly affect the heat exchange area and efficiency; fourth, the non-standard construction process may cause problems such as pipe bending, folding, displacement, etc., which in turn affects the heat exchange performance.

[0005] At present, although the construction technology of buried pipe heat exchange system has made certain progress, it still has many limitations, which are mainly manifested in the following aspects: (1) The construction unit selects low-quality materials, which leads to pipeline aging and deformation, affecting efficiency and life. The connection parts and sealing materials are improperly selected, which are prone to leakage. (2) The trench excavation and laying are not standardized, and the depth, width and shape are not accurately designed, resulting in uneven laying and uneven spacing, which affects the heat exchange effect. The soil backfill does not consider the thermal conductivity performance, which increases the thermal resistance. (3) The connection and sealing technology is not up to standard, the sealing is poor, it is easy to leak, the system efficiency is reduced, the torque control is improper, and the sealing materials and connection parts are easily damaged. (4) The system testing and evaluation are not comprehensive, there are hidden dangers, and the later operation effect is affected. (5) The setting of the protective layer is unreasonable, the material selection is improper or the laying method is not standardized, which makes the protective layer easy to be damaged and corroded, and cannot effectively protect the system. Summary of the invention

[0006] The present invention provides a construction process for improving the heat exchange efficiency of the buried pipes of a ground source heat pump. By optimizing material selection, standardizing construction processes, improving connection and sealing technologies, improving system testing and evaluation mechanisms, and strengthening protective layer settings, the heat exchange efficiency of the buried pipes can be significantly improved, system energy consumption can be reduced, and service life can be extended, thereby promoting the sustainable development of geothermal energy utilization.

[0007] The technical solution adopted by the present invention is: a construction process for improving the heat exchange efficiency of the buried pipe of a ground source heat pump, comprising the following steps: Step 1: Prepare materials: Prepare the materials required for the buried pipe heat exchange system, including buried pipes, heat exchange media, connectors, and necessary construction tools and testing equipment; Step 2: Digging trenches: According to the design drawings, dig trenches of appropriate depth and width at the designated location to ensure that the buried pipes can be laid smoothly and meet the heat exchange requirements; Step 3: Laying underground pipes: Lay the underground pipes flat in the trench according to the design requirements, keep the pipes flat and evenly spaced, and avoid bending and folding; Step 4: Filling backfill material: After the underground pipe is laid, fill the trench with backfill material to ensure that the underground pipe is completely covered and that the backfill material has good thermal conductivity; Step 5: Connect the heat exchange medium: Connect the buried pipe to the inlet and outlet of the heat exchange medium, and ensure that the connection is well sealed and leak-free to ensure heat exchange efficiency; Step 6: Test system performance: After completing the connection, start the heat exchange system for testing, check the heat exchange efficiency of the buried pipe and the operation of the entire system, and ensure that the buried pipe heat exchange system meets the design requirements; Step 7: Cover with a protective layer: After the test is correct, cover the buried pipe heat exchange system to prevent external factors from damaging the system and extend the service life of the buried pipe heat exchange system.

[0008] As a further improvement of the present invention, the buried pipe is made of polyethylene material, the diameter of the buried pipe is 30-50 mm, and the structure of the buried pipe is a serpentine, U-shaped or spiral design to increase the heat exchange area and improve the heat exchange efficiency.

[0009] As a further improvement of the present invention, in step 2, the depth of the trench is adjusted according to local climatic conditions and soil characteristics. The depth of the trench ensures that the buried pipe is located below the permafrost layer to avoid affecting the heat exchange efficiency due to soil freezing. At the same time, the width of the trench is greater than the width of the buried pipe to facilitate laying and backfilling operations.

[0010] As a further improvement of the present invention, in the step three, when laying the buried pipes, fixing clamps and binding belts are used to fix the buried pipes at preset positions at the bottom of the trench at certain intervals to prevent displacement due to soil settlement and external forces; at the same time, the spacing between the buried pipes is maintained at 30-50 cm to ensure a good heat exchange space between the soil and the pipe wall.

[0011] As a further improvement of the present invention, in step four, the backfill material uses a material with good thermal conductivity and stability, including fine sand, gravel and backfill soil; during the filling process, a layered filling method is adopted to ensure that the backfill material is evenly covered on the buried pipe to avoid gaps and bubbles, so as to reduce thermal resistance and improve heat conduction efficiency.

[0012] As a further improvement of the present invention, in step five, when connecting the heat exchange medium, first use a special cleaning agent to thoroughly clean the connection part to remove any possible oil, dust and other impurities, then apply an appropriate amount of sealant and use a sealing gasket to ensure the sealing of the connection part. At the same time, during the connection process, use appropriate torque to avoid over-tightening or over-loosening to prevent damage to the sealing material and deformation of the connection part.

[0013] As a further improvement of the present invention, in step six, when testing the system performance, an automated testing device is used to conduct a comprehensive performance evaluation of the buried pipe heat exchange system.

[0014] As a further improvement of the present invention, the method for the detection equipment to perform a comprehensive performance evaluation on the buried pipe heat exchange system comprises the following steps: S1: First, check the tightness of the system through pressure testing to ensure there are no leaks; S2: Next, a flow test is performed to verify whether the heat exchange medium flows smoothly in the buried pipe heat exchange system and whether the flow meets the design requirements; S3: Then, the heat exchange efficiency is evaluated through temperature testing, and the inlet and outlet temperature differences under different working conditions are recorded to ensure that the heat exchange effect meets expectations; S4: Finally, use computer software to analyze the test data and generate a detailed performance report to provide a basis for subsequent system optimization and maintenance.

[0015] As a further improvement of the present invention, in step seven, a material with strong corrosion resistance and weather resistance is used as the main component of the protective layer, which is composed of a high-density polyethylene film, a glass fiber cloth, and a waterproof coating.

[0016] As a further improvement of the present invention, the method for covering the protective layer comprises the following steps: SS1: First, lay a layer of high-density polyethylene film on the surface of the buried pipe heat exchange system as a basic protective layer; SS2: Lay a layer of glass fiber cloth on the polyethylene film to enhance the overall strength and toughness of the protective layer; SS3: Then use waterproof paint to paint the entire protective layer to improve the corrosion resistance and weather resistance of the protective layer; SS4: Finally, after the laying and painting of the protective layer, the covering operation is carried out.

[0017] Beneficial effects of the present invention: (1) Significantly improve heat exchange efficiency: The present invention adopts optimized buried pipe materials and structures, such as selecting polyethylene materials and designing them into serpentine, U-shaped or spiral shapes, which greatly increases the heat exchange area, making the heat exchange between geothermal energy and the surrounding soil more sufficient. In addition, combined with the selection and laying method of backfill materials, thermal resistance is further reduced, ensuring that heat can be efficiently transferred, thereby significantly improving the overall efficiency of the buried pipe heat exchange system.

[0018] (2) Enhanced system stability and durability: During the construction process, the present invention improves the connection and sealing technology and adopts special cleaning agents, sealants and sealing gaskets to ensure that the connection parts are tight and leak-free, effectively preventing leakage problems caused by poor sealing. At the same time, the position of the buried pipe is stabilized by the use of fixing clamps and binding belts to prevent it from shifting due to soil settlement or external force, further enhancing the stability of the system. In addition, the setting of the protective layer is strengthened and corrosion-resistant and weather-resistant materials are used to effectively resist erosion from the external environment and extend the service life of the system.

[0019] (3) Comprehensive optimization of construction process and system testing: The present invention has comprehensively optimized the construction process. From preparing materials to covering the protective layer, detailed operating specifications have been formulated for each step to ensure construction quality. At the same time, the system testing and evaluation mechanism has been improved, and automated testing equipment has been used to conduct a comprehensive and detailed performance evaluation, including sealing, flow, temperature and other aspects, to ensure that the system performance meets the design requirements. This improvement not only improves construction efficiency, but also reduces the risk of later operation, providing a strong guarantee for the long-term stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The invention is a flowchart of a construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0022] The present invention provides a construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe, comprising the following steps: Step 1: Prepare materials: Prepare the materials required for the buried pipe heat exchange system, including buried pipes, heat exchange media, connectors, and necessary construction tools and testing equipment; Step 2: Digging trenches: According to the design drawings, trenches of appropriate depth and width are dug at designated locations to ensure that the buried pipes can be laid smoothly and meet the heat exchange requirements. The depth of the trenches is adjusted according to local climate conditions and soil characteristics. The depth of the trenches ensures that the buried pipes are located below the permafrost layer to avoid affecting the heat exchange efficiency due to soil freezing. At the same time, the width of the trenches is greater than the width of the buried pipes to facilitate laying and backfilling operations. Step 3: Laying underground pipes: Lay the underground pipes flat in the trench according to the design requirements, keep the pipes flat and evenly spaced, and avoid bending and folding. When laying underground pipes, use fixing clamps and binding tapes to fix the underground pipes at preset positions at the bottom of the trench at certain intervals to prevent displacement under soil settlement and external forces; at the same time, the spacing between underground pipes is kept at 30-50 cm to ensure good heat exchange space between the soil and the pipe wall; Step 4: Filling with backfill material: After the underground pipe is laid, fill the trench with backfill material to ensure that the underground pipe is completely covered and that the backfill material has good thermal conductivity. The backfill material is made of materials with good thermal conductivity and stability, including fine sand, gravel and special backfill soil. During the filling process, a layered filling method is used to ensure that the backfill material is evenly covered on the underground pipe to avoid gaps and bubbles, so as to reduce thermal resistance and improve thermal conduction efficiency. Step 5, connect the heat exchange medium: connect the buried pipe to the inlet and outlet of the heat exchange medium, ensure that the connection is well sealed and leak-free to ensure the heat exchange efficiency. When connecting the heat exchange medium, first use a special cleaner to thoroughly clean the connection part to remove any possible oil, dust and other impurities, then apply an appropriate amount of sealant and use a sealing gasket to ensure the sealing of the connection part. At the same time, during the connection process, use appropriate torque to avoid over-tightening or over-loosening to prevent damage to the sealing material and deformation of the connection part; Step 6, test system performance: after completing the connection, start the heat exchange system for testing, check the heat exchange efficiency of the buried pipe and the operation of the entire system, ensure that the buried pipe heat exchange system meets the design requirements, and use automated testing equipment to conduct a comprehensive performance evaluation of the buried pipe heat exchange system when testing the system performance. The method includes the following steps: first, check the sealing of the system through a pressure test to ensure that there are no leaks; then, conduct a flow test to verify whether the heat exchange medium flows smoothly in the buried pipe heat exchange system and whether the flow meets the design requirements; then, evaluate the heat exchange efficiency through a temperature test, record the inlet and outlet temperature difference under different working conditions, and ensure that the heat exchange effect meets expectations; finally, use computer software to analyze the test data and generate a detailed performance report to provide a basis for subsequent system optimization and maintenance; Step seven, covering with protective layer: after the test is correct, the underground pipe heat exchange system is covered and protected to prevent external factors from damaging the system and extend the service life of the underground pipe heat exchange system. Corrosion-resistant and weather-resistant materials are used as the main components of the protective layer, which is composed of high-density polyethylene film, glass fiber cloth, and waterproof coating. The method of covering the protective layer includes the following steps: first, laying a layer of high-density polyethylene film as a basic protective layer on the surface of the underground pipe heat exchange system; then laying a layer of glass fiber cloth on the polyethylene film to enhance the overall strength and toughness of the protective layer; then using waterproof coating to paint the entire protective layer to improve the corrosion resistance and weather resistance of the protective layer; finally, after completing the laying and painting of the protective layer, covering with soil is carried out.

[0023] The buried pipe in the present invention is made of polyethylene material, the diameter of the buried pipe is 30-50 mm, and the structure of the buried pipe is a serpentine, U-shaped, or spiral design to increase the heat exchange area and improve the heat exchange efficiency.

[0024] Example: This embodiment provides an embodiment of a construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe, and the specific steps are as follows.

[0025] 1. Material preparation and inspection: Before the formal construction, detailed material preparation and inspection work was first carried out. In addition to the buried pipes, heat exchange media, connectors, construction tools and testing equipment, the quality and specifications of other materials selected met the design requirements. For the buried pipes, in addition to checking their material, pipe diameter and design shape, pressure tests were carried out to ensure that they can withstand the expected working pressure without leakage; for the heat exchange media, their purity, fluidity and thermal conductivity were inspected to ensure that heat can be effectively transferred during the circulation process; for the connectors, their material, size and sealing performance were checked to ensure that the connection is firm and the sealing is reliable. In addition, all construction tools and equipment were debugged and inspected in advance to ensure that they can operate normally during the construction process and avoid affecting the construction progress and quality due to tool failure. At the same time, a detailed material management plan was formulated, including the procurement, storage, collection and recycling of materials, to ensure the effective use of materials and cost control.

[0026] (II) Trench excavation and pretreatment: When excavating the trench, the positioning and measurement are strictly carried out according to the design drawings to ensure that the direction, depth and width of the trench meet the design requirements. At the same time, considering the influence of soil characteristics and climatic conditions on heat exchange efficiency, necessary pretreatment is carried out on the bottom of the trench. Among them, the soil moisture in this area is relatively high, and drainage measures are adopted to reduce the soil moisture content; the soil in this area is relatively soft, and the method of compaction and laying gravel layers is adopted to improve the stability of the soil. In addition, the surrounding environment and facilities are protected to avoid damage to the surrounding environment caused by construction.

[0027] (III) Laying and fixing of buried pipes: During the laying of buried pipes, professional laying machinery and tools are used to ensure that the buried pipes are laid flat, evenly spaced and meet the design requirements. At the same time, advanced fixing technology is used to firmly fix the buried pipes at the preset position at the bottom of the trench. Specifically, special fixing fixtures and binding belts are used to fix the buried pipes at a certain distance; a layer of fine sand or gravel is laid at the bottom of the trench as a cushion to improve the stability and heat exchange efficiency of the buried pipes. During the laying process, the buried pipes are also protected from mechanical damage or chemical corrosion.

[0028] (IV) Selection and filling of backfill materials: The selection of backfill materials has an important impact on the heat exchange efficiency. Therefore, materials with good thermal conductivity and stability should be selected during the backfill process, including fine sand, gravel or special backfill soil. At the same time, a layered filling method is adopted to ensure that the backfill material is evenly covered on the buried pipe to avoid gaps and bubbles. The humidity and density of the backfill material are also controlled during the filling process to improve the thermal conductivity and stability of the backfill layer.

[0029] (V) System connection and debugging: When connecting the heat exchange medium, the operation procedures were strictly followed to ensure that the connection was well sealed and leak-free. At the same time, appropriate torque and sealing materials were used to ensure the firmness and sealing of the connection. After the connection was completed, the system was debugged, including checking the system's sealing, flow rate, temperature and other parameters, and the parameters all met the design requirements. Through this debugging work, problems and hidden dangers in the system can be discovered and solved in a timely manner, ensuring the normal operation and efficient operation of the buried pipe heat exchange system.

[0030] (VI) System testing and evaluation: After the system connection and debugging, the system testing and evaluation work was also carried out. Automated testing equipment was used to conduct a comprehensive performance evaluation of the buried pipe heat exchange system, including pressure testing, flow testing and temperature testing. The test can evaluate the system's performance indicators such as sealing, fluidity and heat exchange efficiency, and the performance indicators all meet the design requirements. At the same time, computer software was used to analyze and process the test data, and detailed performance reports and charts were generated to provide strong data support for subsequent system optimization and maintenance.

[0031] (VII) Covering protection and post-maintenance: After completing the system test and evaluation, the underground heat exchange system was covered to prevent external factors from damaging the system. The use of corrosion-resistant and weather-resistant materials as the main components of the protective layer for laying and painting improved the overall performance and durability of the protective layer. At the same time, a detailed post-maintenance plan was also formulated, including regular inspections, cleaning and maintenance, to ensure the long-term stable operation and efficient operation of the underground heat exchange system.

[0032] It can be seen from the above embodiments that the underground heat exchange system of the present invention performs well in practical applications and has significant energy-saving effects and economic benefits. By optimizing the design and construction process, the system not only improves the heat exchange efficiency, but also extends the service life, reduces maintenance costs, and pays attention to environmental protection and sustainable development. At the same time, it further promotes the underground heat exchange technology, creates greater value for users, and brings more environmental benefits to society.

[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe, characterized in that: The following steps are involved: Step 1: Prepare materials: Prepare the materials required for the buried pipe heat exchange system, including buried pipes, heat exchange media, connectors, and necessary construction tools and testing equipment; Step 2: Digging trenches: According to the design drawings, dig trenches of appropriate depth and width at the designated location to ensure that the buried pipes can be laid smoothly and meet the heat exchange requirements; Step 3: Laying underground pipes: Lay the underground pipes flat in the trench according to the design requirements, keep the pipes flat and evenly spaced, and avoid bending and folding; Step 4: Filling backfill material: After the underground pipe is laid, fill the trench with backfill material to ensure that the underground pipe is completely covered and that the backfill material has good thermal conductivity; Step 5: Connect the heat exchange medium: Connect the buried pipe to the inlet and outlet of the heat exchange medium, and ensure that the connection is well sealed and leak-free to ensure heat exchange efficiency; Step 6: Test system performance: After completing the connection, start the heat exchange system for testing, check the heat exchange efficiency of the buried pipe and the operation of the entire system, and ensure that the buried pipe heat exchange system meets the design requirements; Step 7: Cover with a protective layer: After the test is correct, cover the buried pipe heat exchange system to prevent external factors from damaging the system and extend the service life of the buried pipe heat exchange system.

2. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe according to claim 1, characterized in that: The buried pipe is made of polyethylene material, the diameter of the buried pipe is 30-50 mm, and the structure of the buried pipe is a serpentine, U-shaped or spiral design to increase the heat exchange area and improve the heat exchange efficiency.

3. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe according to claim 1, characterized in that: In step 2, the depth of the trench is adjusted according to local climatic conditions and soil characteristics. The depth of the trench ensures that the buried pipe is located below the permafrost layer to avoid affecting the heat exchange efficiency due to soil freezing. At the same time, the width of the trench is greater than the width of the buried pipe to facilitate laying and backfilling operations.

4. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe according to claim 1, characterized in that: In the step three, when laying the buried pipes, fixing clamps and binding belts are used to fix the buried pipes at preset positions at the bottom of the trench at certain intervals to prevent displacement due to soil settlement and external forces; at the same time, the spacing between the buried pipes is maintained at 30-50 cm to ensure a good heat exchange space between the soil and the pipe wall.

5. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe according to claim 1, characterized in that: In step 4, the backfill material is made of materials with good thermal conductivity and stability, including fine sand, gravel and backfill soil; during the filling process, a layered filling method is adopted to ensure that the backfill material is evenly covered on the buried pipe to avoid gaps and bubbles, so as to reduce thermal resistance and improve thermal conduction efficiency.

6. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe according to claim 1, characterized in that: In step five, when connecting the heat exchange medium, first use a special cleaning agent to thoroughly clean the connection parts to remove any possible oil, dust and other impurities, then apply an appropriate amount of sealant and use sealing gaskets to ensure the sealing of the connection parts. At the same time, during the connection process, use appropriate torque to avoid over-tightening or over-loosening to prevent damage to the sealing material and deformation of the connection parts.

7. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe according to claim 1, characterized in that: In step six, when testing the system performance, an automated testing device is used to conduct a comprehensive performance evaluation of the buried pipe heat exchange system.

8. A construction process for improving the heat exchange efficiency of the buried pipe of a ground source heat pump according to claim 7, characterized in that: The method for the detection equipment to perform a comprehensive performance evaluation on the buried pipe heat exchange system comprises the following steps: S1: First, check the tightness of the system through pressure testing to ensure there are no leaks; S2: Next, a flow test is performed to verify whether the heat exchange medium flows smoothly in the buried pipe heat exchange system and whether the flow meets the design requirements; S3: Then, the heat exchange efficiency is evaluated through temperature testing, and the inlet and outlet temperature differences under different working conditions are recorded to ensure that the heat exchange effect meets expectations; S4: Finally, use computer software to analyze the test data and generate a detailed performance report to provide a basis for subsequent system optimization and maintenance.

9. The construction process for improving the heat exchange efficiency of the buried pipe of a ground source heat pump according to claim 1, characterized in that: In the step seven, corrosion-resistant and weather-resistant materials are used as the main components of the protective layer, which is composed of high-density polyethylene film, glass fiber cloth, and waterproof coating.

10. A construction process for improving the heat exchange efficiency of the buried pipe of a ground source heat pump according to claim 9, characterized in that: The method for covering the protective layer comprises the following steps: SS1: First, lay a layer of high-density polyethylene film on the surface of the buried pipe heat exchange system as a basic protective layer; SS2: Lay a layer of glass fiber cloth on the polyethylene film to enhance the overall strength and toughness of the protective layer; SS3: Then use waterproof paint to paint the entire protective layer to improve the corrosion resistance and weather resistance of the protective layer; SS4: Finally, after the laying and painting of the protective layer, the covering operation is carried out.

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