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

Abstract

The present application relates to the technical field of buried pipe construction, especially relates to a construction process for improving the heat exchange efficiency of ground source heat pump buried pipes. The process comprises the following steps: preparing materials; digging a trench; laying buried pipes; filling backfill materials; connecting heat exchange medium; testing system performance; covering a protective layer. The present application provides a construction process for improving the heat exchange efficiency of ground source heat pump buried pipes. By optimizing material selection, standardizing construction procedures, improving connection and sealing technology, perfecting system testing and evaluation mechanisms, and strengthening protective layer settings, the heat exchange efficiency of 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.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ground heat exchanger construction, and particularly relates to a construction process for improving the heat exchange efficiency of a ground heat exchanger of a ground source heat pump. BACKGROUND

[0002] Under the background of global energy shortage and increasing environmental protection demand, geothermal energy as a clean and renewable energy resource has attracted widespread attention. As one of the core technologies for geothermal energy utilization, the ground heat exchanger system realizes heat transfer and storage through heat exchange between the ground heat exchanger and the soil or underground water, and is widely used in heating, refrigeration and hot water supply fields. However, the ground heat exchanger efficiency is affected by many factors, such as soil properties, climate conditions, pipe material quality, construction process, etc., and the optimization of the construction process is of great significance to improve the heat exchange efficiency, reduce the system energy consumption and prolong the service life.

[0003] The ground heat exchanger system mainly uses the closed pipeline (i.e. ground heat exchanger) buried underground to utilize the soil or underground water as a heat source or cold source, and realizes heat absorption or release through the circulation of medium (such as water, glycol solution, etc.) in the pipeline. Its working principle is based on three heat transfer modes of heat conduction, convection and radiation, and the heat conduction between the soil and the ground heat exchanger is the key factor affecting the heat exchange efficiency.

[0004] However, in practical application, the ground heat exchanger system faces many challenges: first, the soil properties are complex and changeable, and the parameters such as soil thermal conductivity, humidity and density in different regions differ greatly, affecting the heat exchange efficiency; second, the climate conditions change greatly, especially in extreme climate conditions, the soil temperature fluctuates greatly, affecting the stable operation of the system; third, the pipe material quality 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 and displacement, which further affect the heat exchange performance.

[0005] At present, although the construction process of the ground heat exchanger system has made certain progress, there are still many limitations, mainly in the following aspects: (1) the construction unit selects low-quality materials, which leads to pipe aging and deformation, affecting the efficiency and service life, and improper selection of connecting parts and sealing materials may cause leakage. (2) The trench excavation and laying are not standardized, and the depth, width and shape are not accurately designed, which leads to uneven laying and uneven spacing, affecting the heat exchange effect, and the soil backfill does not consider the heat conduction performance, which increases the thermal resistance. (3) The connection and sealing technology are not good enough, the sealing performance is poor, and the system efficiency is reduced, the torque control is not proper, and the sealing materials and connecting parts are easily damaged. (4) The system test and evaluation are not comprehensive, and there are hidden dangers, which affect the later operation effect. (5) The protection layer is not reasonably set, the material is not properly selected or the laying method is not standardized, which leads to easy damage and corrosion of the protection layer, and the system cannot be effectively protected. SUMMARY

[0006] The present application provides a construction process for improving the heat exchange efficiency of ground source heat pump buried pipes, which can significantly improve the heat exchange efficiency of buried pipes, reduce system energy consumption, and prolong service life by optimizing material selection, standardizing construction process, improving connection and sealing technology, perfecting system testing and evaluation mechanism, and strengthening protective layer setting, thereby promoting the sustainable development of geothermal energy utilization.

[0007] The technical scheme adopted by the present application is: a construction process for improving the heat exchange efficiency of ground source heat pump buried pipes, comprising the following steps:

[0008] Step one, prepare materials: prepare the materials needed for the buried pipe heat exchange system, including buried pipes, heat exchange medium, connecting parts, and necessary construction tools and detection equipment;

[0009] Step two, dig a trench: according to the design drawing, dig a trench of appropriate depth and width at the designated location to ensure that the buried pipe can be smoothly laid and meet the heat exchange requirements;

[0010] Step three, lay the buried pipe: lay the buried pipe in the trench according to the design requirements, keep the pipe flat and the spacing uniform, and avoid bending and folding;

[0011] Step four, fill backfill material: after the buried pipe is laid, fill the trench with backfill material to ensure that the buried pipe is completely covered, and at the same time ensure that the backfill material has good heat conduction performance;

[0012] Step five, connect the heat exchange medium: connect the inlet and outlet of the buried pipe with the heat exchange medium to ensure that the connection is sealed well and there is no leakage to ensure the heat exchange efficiency;

[0013] Step six, test system performance: after the connection is completed, start the heat exchange system for testing, check the heat exchange efficiency of the buried pipe and the operation of the entire system to ensure that the buried pipe heat exchange system meets the design requirements;

[0014] Step seven, cover the protective layer: after testing, cover the buried pipe heat exchange system to prevent external factors from damaging the system and prolong the service life of the buried pipe heat exchange system.

[0015] As a further improvement of the present application, the buried pipe is made of polyethylene material, the pipe diameter of the buried pipe is 30-50 mm, and the structure of the buried pipe is designed in a serpentine, U-shaped or spiral shape to increase the heat exchange area and improve the heat exchange efficiency.

[0016] As a further improvement of the present application, in step two, the depth of the trench is adjusted according to local climate conditions and soil characteristics, and the trench depth ensures that the buried pipe is below the frozen soil 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 the laying and backfilling operation.

[0017] As a further improvement of the present application, in step three, when laying the buried pipe, fixed clamps and binding tapes are used to fix the buried pipe at predetermined positions on the bottom of the trench at certain intervals to prevent displacement under the action of soil settlement and external forces; at the same time, the spacing between the buried pipes is kept at 30-50 cm to ensure good heat exchange space between the soil and the pipe wall.

[0018] As a further improvement of the present application, in step four, the backfilling material uses materials with good thermal conductivity and stability, including fine sand, gravel and backfilling soil; during the filling process, a layered filling method is used to ensure that the backfilling material covers the buried pipe uniformly, avoiding gaps and air bubbles to reduce thermal resistance and improve heat conduction efficiency.

[0019] As a further improvement of the present application, in step five, when connecting the heat exchange medium, first use a special cleaner to thoroughly clean the connection site to remove any possible oil, dust and other impurities, then apply an appropriate amount of sealant, use a sealing gasket to ensure the sealing of the connection site, and at the same time, during the connection process, use appropriate torque to avoid overtightening and overtightening to prevent damage to the sealing material and deformation of the connection site.

[0020] As a further improvement of the present application, in step six, when testing the system performance, use automated detection equipment to comprehensively evaluate the performance of the buried pipe heat exchange system.

[0021] As a further improvement of the present application, the method for the detection equipment to comprehensively evaluate the performance of the buried pipe heat exchange system includes the following steps:

[0022] S1: First, check the system's sealing by pressure test to ensure there are no leaks;

[0023] S2: Next, perform 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;

[0024] S3: Then, evaluate the heat exchange efficiency by temperature test, record the inlet and outlet temperature difference under different working conditions to ensure that the heat exchange effect meets the expectations;

[0025] 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.

[0026] As a further improvement of the application, in step seven, the material with corrosion resistance and weather resistance is used as the main component of the protective layer, which is composed of high-density polyethylene film, glass fiber cloth and waterproof paint.

[0027] As a further improvement of the application, the method of covering the protective layer comprises the following steps:

[0028] SS1: First, lay a layer of high-density polyethylene film as the base protective layer on the surface of the buried pipe heat exchange system;

[0029] SS2: Then lay a layer of glass fiber cloth on the polyethylene film to strengthen the overall strength and toughness of the protective layer;

[0030] SS3: Then use waterproof paint to brush the entire protective layer to improve the corrosion resistance and weather resistance of the protective layer;

[0031] SS4: Finally, after the laying and brushing of the protective layer are completed, the earthwork is carried out.

[0032] The beneficial effects of the application are: (1) significantly improve the heat exchange efficiency: the application adopts the optimized buried pipe material and structure, such as polyethylene material and design into serpentine, U-shaped or spiral shape, which greatly increases the heat exchange area, makes the heat exchange of geothermal energy and surrounding soil more sufficient, in addition, combined with the selection and laying method of backfill material, further reduces the thermal resistance, ensures the efficient transmission of heat, thereby significantly improves the overall efficiency of the buried pipe heat exchange system.

[0033] (2) Enhance system stability and durability: in the construction process, through the improvement of connection and sealing technology, the use of special cleaning agent, sealant and sealing ring, etc. Measures to ensure the tightness of the connection part, effectively prevent the leakage problem caused by poor sealing, at the same time, through the use of fixed clamp and binding belt, the position of the buried pipe is stabilized, which prevents displacement under the action of soil settlement or external force, further enhances the stability of the system, in addition, the setting of the protective layer, the use of corrosion-resistant and weather-resistant materials effectively resist the erosion of the external environment, prolong the service life of the system.

[0034] (3) Optimize the construction process and system test: the application optimizes the construction process comprehensively, from preparing materials to covering the protective layer, every step has developed detailed operation specification to ensure the construction quality, at the same time, perfects the system test and evaluation mechanism, uses automatic detection equipment to carry out 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 the construction efficiency, but also reduces the risk of later operation, provides strong guarantee for the long-term stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a flowchart of a construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the embodiments described herein are only used to explain this application and are not intended to limit this application.

[0037] 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:

[0038] 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;

[0039] Step 2: Trench digging: According to the design drawings, dig a trench of appropriate depth and width at the designated location to ensure that the buried pipe can be laid smoothly and meet the heat exchange requirements. The depth of the trench is adjusted according to local climate conditions and soil characteristics. The trench depth ensures that the buried pipe is below the permafrost layer to avoid the impact of soil freezing on heat exchange efficiency. At the same time, the width of the trench is larger than the width of the buried pipe to facilitate laying and backfilling operations.

[0040] Step 3: Laying underground pipes: Lay the underground pipes flat in the trench according to the design requirements, keeping the pipes flat and evenly spaced to avoid bending and folding. When laying the underground pipes, use fixing clamps and binding tape to fix the underground pipes at predetermined intervals at the bottom of the trench to prevent displacement due to soil settlement and external forces. At the same time, the spacing between the underground pipes is kept at 30-50 cm to ensure good heat exchange space between the soil and the pipe wall.

[0041] Step 4: Filling with backfill material: After the buried pipe is laid, fill the trench with backfill material to ensure that the buried pipe is completely covered and that the backfill material has good thermal conductivity. Backfill materials with good thermal conductivity and stability are used, 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 buried pipe to avoid gaps and bubbles, thereby reducing thermal resistance and improving heat conduction efficiency.

[0042] Step five, connect the heat exchange medium: connect the buried pipe with the inlet and outlet of the heat exchange medium, ensure that the connection is sealed well and there is no leakage phenomenon 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 oil stains, dust and other impurities that may exist, then apply an appropriate amount of sealant, use a sealing gasket to ensure the sealing of the connection part, and at the same time, during the connection process, use appropriate torque to avoid over-tightening and over-loosening to prevent damage to the sealing material and deformation of the connection part;

[0043] Step six, 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 whole system to ensure that the buried pipe heat exchange system meets the design requirements, when testing the system performance, use automatic detection equipment to comprehensively evaluate the performance of the buried pipe heat exchange system, the method includes the following steps: first, check the sealing of the system through pressure test to ensure that there is no leakage point; then, perform flow test to verify whether the flow of the heat exchange medium in the buried pipe heat exchange system is smooth and whether the flow meets the design requirements; then, evaluate the heat exchange efficiency through temperature test, record the temperature difference between the inlet and outlet under different working conditions to ensure that the heat exchange effect meets the expectation; finally, analyze the test data by using computer software to generate a detailed performance report to provide a basis for subsequent system optimization and maintenance;

[0044] Step seven, cover the protective layer: after testing, cover the buried pipe heat exchange system to prevent external factors from damaging the system and prolong the service life of the buried pipe heat exchange system, use corrosion-resistant and weather-resistant materials as the main components of the protective layer, which is composed of high-density polyethylene film, glass fiber cloth and waterproof paint, the method of covering the protective layer includes the following steps: first, lay a layer of high-density polyethylene film as the basic protective layer on the surface of the buried pipe heat exchange system; then lay a layer of glass fiber cloth on the polyethylene film to strengthen the overall strength and toughness of the protective layer; then use waterproof paint to brush the entire protective layer to improve the corrosion resistance and weather resistance of the protective layer; finally, after completing the laying and brushing of the protective layer, perform the earth covering operation.

[0045] The buried pipe in the application is made of polyethylene material, the pipe diameter of the buried pipe is 30-50 mm, and the structure of the buried pipe is designed in a serpentine, U-shaped or spiral shape to increase the heat exchange area and improve the heat exchange efficiency.

[0046] Embodiment:

[0047] The 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.

[0048] (1) Material preparation and inspection: Before the formal construction, a detailed material preparation and inspection work was first carried out. In addition to the buried pipe, heat exchange medium, connecting parts, construction tools and testing equipment, the quality and specifications of other selected materials meet the design requirements. For the buried pipe, its material, pipe diameter and design shape are checked, and pressure test is carried out to ensure that it can withstand the expected working pressure without leakage; for the heat exchange medium, its purity, fluidity and heat transfer performance are inspected to ensure that it can effectively transfer heat during circulation; for the connecting parts, its material, size and sealing performance are checked to ensure that the connection is firm and reliable. In addition, all construction tools and equipment are also debugged and checked in advance to ensure that they can operate normally during construction, avoiding the influence of tool failure on construction progress and quality. At the same time, a detailed material management plan is formulated, including material procurement, storage, use and recycling, etc., to ensure effective use of materials and cost control.

[0049] (2) Trench excavation and pretreatment: When excavating the trench, strict positioning and measurement are 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 properties and climate conditions on heat exchange efficiency, the bottom of the trench is pretreated as necessary. Among them, the soil humidity in this area is large, and drainage measures are adopted to reduce the soil moisture content; the soil in this area is relatively soft, and ramming and laying gravel layer method is used to improve the stability of the soil. And protect the surrounding environment and facilities to avoid damage to the surrounding environment during construction.

[0050] (3) Buried pipe laying and fixing: During the laying of the buried pipe, professional laying machinery and tools are used to ensure that the buried pipe is laid flat, evenly spaced and meets the design requirements. At the same time, advanced fixing technology is used to firmly fix the buried pipe at the pre-set position on the bottom of the trench. Specifically, special fixing clamps and binding belts are used to fix the buried pipe at regular intervals; a layer of fine sand or gravel is laid on the bottom of the trench as a cushion to improve the stability and heat exchange efficiency of the buried pipe. During the laying process, the buried pipe is also protected from mechanical damage or chemical corrosion.

[0051] (4) Selection and filling of backfilling material: The selection of backfilling material has an important influence on heat exchange efficiency. Therefore, during the backfilling process, materials with good heat conduction performance and stability are selected, including fine sand, gravel or special backfilling soil, etc. At the same time, a layered filling method is used to ensure that the backfilling material is evenly covered on the buried pipe, avoiding air gaps and bubbles. During the filling process, the humidity and density of the backfilling material are also controlled to improve the heat conduction efficiency and stability of the backfilling layer.

[0052] (Five) System connection and debugging: when connecting the heat exchange medium, strictly follow the operating procedures to ensure that the connection is sealed well and there is no leakage. At the same time, appropriate torque and sealing materials are used to ensure the firmness and sealing of the connection part. After the connection is completed, the system is also debugged, including checking the sealing, flow and temperature parameters of the system, and the parameters meet the design requirements. Through this debugging work, problems and hidden dangers in the system can be found and solved in time, ensuring the normal operation and efficient work of the ground heat exchanger system.

[0053] (Six) System testing and evaluation: after completing the system connection and debugging, the system testing and evaluation work is also carried out. Automatic detection equipment is used to comprehensively evaluate the performance of the ground heat exchanger system, including pressure test, flow test and temperature test, etc. Through the test, the sealing, flowability and heat exchange efficiency of the system can be evaluated, and the performance indicators meet the design requirements. At the same time, the test data is analyzed and processed by computer software, and detailed performance report and chart are generated, which provides strong data support for subsequent system optimization and maintenance.

[0054] (Seven) Cover protection and later maintenance: after completing the system testing and evaluation, the ground heat exchanger system is protected to prevent external factors from damaging the system. Corrosion-resistant and weather-resistant materials are used as the main components of the protective layer to improve the overall performance and durability of the protective layer. At the same time, a detailed later maintenance plan is also formulated, including regular inspection, cleaning and repair, etc. to ensure the long-term stable operation and efficient work of the ground heat exchanger system.

[0055] Through the above examples, it can be seen that the ground heat exchanger system of the present application performs well in practical application, has significant energy-saving effect and economic benefit. Through optimization design and construction technology, the system not only improves the heat exchange efficiency, but also prolongs the service life, reduces the maintenance cost, and pays attention to environmental protection and sustainable development. At the same time, the ground heat exchanger technology is further popularized, creating greater value for users and bringing more environmental protection benefits to society.

[0056] The above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A construction process for improving the heat exchange efficiency of a ground source heat pump buried pipe, characterized by: 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: Dig trenches: Dig trenches of appropriate depth and width at designated locations according to the design drawings to ensure that the buried pipes can be laid smoothly and meet heat exchange requirements; Step 3: Lay the 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: Fill with backfill material: After the buried pipe is laid, fill the trench with backfill material to ensure that the buried 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, ensuring 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 to check the heat exchange efficiency of the buried pipes and the operation of the entire system to ensure that the buried pipe heat exchange system meets the design requirements; Step 7: Cover with protective layer: After the test is completed, cover the underground heat exchange system to prevent external factors from damaging the system and extend the service life of the underground heat exchange system; 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; In step 2, the depth of the trench is adjusted according to local climate conditions and soil characteristics. The trench depth 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. In step 3, when laying the underground pipes, fix the underground pipes at predetermined intervals at the bottom of the trench using fixing fixtures and binding tape to prevent displacement due to soil settlement and external forces. At the same time, the spacing between the underground pipes is maintained at 30-50 cm to ensure good heat exchange space between the soil and the pipe wall. 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, thereby reducing thermal resistance and improving heat conduction efficiency. In step 5, when connecting the heat exchange medium, first use a dedicated 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 a sealing gasket 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. In step 6, when testing the system performance, an automated testing device is used to conduct a comprehensive performance evaluation of the buried pipe heat exchange system; The method for comprehensively evaluating the performance of the buried pipe heat exchange system using the detection equipment 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 rate meets the design requirements; S3: Then, evaluate the heat exchange efficiency through temperature testing, record the inlet and outlet temperature differences under different working conditions, and 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; In the step 7, a corrosion-resistant and weather-resistant material is used as the main component of the protective layer, which is composed of a high-density polyethylene film, glass fiber cloth, and a waterproof coating; 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 protective layer is laid and painted, the covering operation is carried out.

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