Design and installation method of ground source heat pump pipe tee connector

Abstract

This invention provides a design and installation method for a ground source heat pump pipeline tee connector, belonging to the technical field of ground source heat pump pipeline tee connectors. This invention establishes classification standards for fit and angle levels, selects appropriate connection parameters based on the working pressure of the ground source heat pump system and the installation environment, optimizes comprehensive performance through multi-layer structure thickness distribution, achieves precise alignment of the pipeline axis through a constraint optimization algorithm, avoids stress concentration through graded locking operations, improves connector adaptability through sliding stroke control, and achieves precise locking of the locking block and slot by using a throttle control screw to drive the moving ring to rise and fall. Ultimately, this forms a complete design and installation method for ground source heat pump pipeline tee connectors, effectively solving the technical problem of balancing connection strength and installation convenience under different operating conditions in existing ground source heat pump pipeline tee connectors.

Description

Technical Field

[0001] This invention belongs to the technical field of ground source heat pump pipeline tee connectors, specifically, it relates to a design and installation method for a ground source heat pump pipeline tee connector. Background Technology

[0002] Ground source heat pump systems, as a highly efficient and energy-saving air conditioning system, are widely used in building energy conservation. Their pipe connection technology directly affects the system's operating efficiency and service life. Traditional pipe tee connectors mainly use welding, threaded, or flanged connections. These connection methods exhibit significant limitations under the complex operating conditions of ground source heat pump systems. While welding provides high connection strength, it is complex to install and inconvenient to maintain. Threaded connections, although convenient to install, are prone to leakage under high pressure. Flange connections, while offering good sealing, are bulky and expensive. Traditional connectors have several drawbacks in practical applications. First, there is a contradiction between connection strength and ease of installation; high-strength connections often require complex installation processes and specialized equipment, while simple installation methods cannot guarantee sufficient connection strength. Second, they have poor adaptability to different operating conditions. Traditional connectors typically use single connection parameters and cannot be adjusted according to specific working pressure, temperature environment, and installation conditions. Third, connection accuracy control is difficult. Pipe axis alignment relies on manual experience, making it difficult to guarantee the geometric accuracy of the tee connection, easily leading to stress concentration and poor sealing. The core problem that traditional technologies struggle to solve lies in how to achieve convenient installation while ensuring connection strength. This is especially true in the high-pressure conditions and complex installation environments of ground source heat pump systems. Traditional connectors cannot adjust connection parameters according to specific conditions, making it difficult to achieve the best balance between connection strength and installation convenience. Summary of the Invention

[0003] In view of this, the present invention provides a design and installation method for a ground source heat pump pipeline tee connector, which can solve the technical problem in the prior art that it is difficult to balance the connection strength and installation convenience of the ground source heat pump pipeline tee connector under different working conditions.

[0004] This invention is implemented as follows: It provides a design and installation method for a ground source heat pump pipeline tee connector, comprising two parts: a design method and an installation method. The design method includes: determining the reference value of the outer pipe's inner diameter based on the working pressure of the ground source heat pump system; classifying the fit into three levels according to the ratio of the inner diameter of the fixing ring to the outer pipe's outer diameter within the range of 1.05 to 1.10: a tight fit ratio of 1.05, a standard fit ratio of 1.075, and a loose fit ratio of 1.10; selecting the corresponding fit level based on the installation environment temperature range; simultaneously calculating the reference value of the axial thrust based on the system's maximum working pressure and safety factor; and classifying the locking angle into three levels: a 15-degree high-efficiency locking angle, a 20-degree standard locking angle, and a 25-degree moderate locking angle. The design and installation method include: setting the thickness of the reinforcing layer to 35% of the total wall thickness, the corrosion-resistant layer to 25% of the total wall thickness, the composite layer to 20% of the total wall thickness, the heat-resistant layer to 15% of the total wall thickness, and the antibacterial layer to 5% of the total wall thickness according to the thickness distribution ratio of the multi-layer structure. Each layer is then installed inside the outer pipe sequentially. The fixing ring is then fitted onto the top of the outer pipe according to the selected fit level, and the vertical pipe is installed vertically on top of the fixing ring. A three-dimensional coordinate system is established to calculate the alignment of the pipe axis. A constraint optimization algorithm is used to adjust the relative position of the tee connector and the pipe to be connected. The least squares method is used to optimize the angular deviation of each pipe axis. Graded locking operations are performed according to the selected angle level to complete the installation.

[0005] Specifically, the steps for determining the fit grade involve establishing a fit grade determination system based on fluid mechanics theory and elasticity principles. This is achieved by measuring the maximum operating pressure of the ground source heat pump system and determining the reference size of the outer pipe's inner diameter using a safety factor ranging from 1.5 to 2.0. A dimensional analysis method is then used to establish a proportional relationship model between the inner diameter of the fixed ring and the outer diameter of the outer pipe. The numerical ranges of the three fit grades are determined using the stress concentration theory in mechanics of materials. Finally, the corresponding fit grade is selected based on the influence of ambient temperature on the thermal expansion coefficient of the material.

[0006] Specifically, the angle level step involves applying the principle of static equilibrium to calculate the axial thrust reference value. Input parameters include the system's maximum working pressure, pipe cross-sectional area, and safety factor. The output parameter is the minimum locking force requirement. The wedge angle level of the locking block is determined based on the mechanical principle of the wedge mechanism. A 15-degree high-efficiency locking angle provides maximum mechanical gain based on the Archimedes' screw principle but requires a large operating force. A 20-degree standard locking angle achieves the optimal balance between mechanical efficiency and operational convenience. A 25-degree moderate locking angle reduces operating resistance but correspondingly reduces the locking effect.

[0007] Specifically, the step of distributing the thickness of the multi-layer structure involves constructing a multi-functional pipe wall structure system using the design theory of layered composite materials, determining the thickness distribution scheme of each layer of material based on the mixing law in composite mechanics, calculating the comprehensive performance index under different thickness ratios using the finite element analysis method, and using hot-melt welding technology to fix each layer of material to the inner wall of the outer pipe in the order of inside and outside, ensuring that the interlayer bonding is firm and there are no bubbles or delamination.

[0008] The process includes, after the multi-layer structure thickness distribution ratio step, installing the lead screw inside the strip groove and fixing it to the bottom of the throttle, threading the sliding sleeve onto the surface of the lead screw, then vertically fixing the moving rod to one side of the sliding sleeve and extending the bottom of the moving rod through the fixed ring to the bottom of the fixed ring, constructing an axial adjustment control system based on the principle of screw transmission mechanism, and determining the lead screw pitch parameters based on the kinematic relationship of screw transmission.

[0009] The process includes, after the axial adjustment control system step, installing the moving ring horizontally at the bottom of the moving rod, fixing the locking block vertically at the top of the moving ring, installing the guide rod vertically at the top of the moving ring and extending the top of the guide rod through the fixing ring into the interior of the vertical tube, installing the round shaft horizontally inside the slide groove and fixing it to one side of the guide rod. Based on the principle of spatial kinematics, a three-dimensional motion coordination control system is constructed to form a synchronous motion guiding control mechanism.

[0010] Specifically, the step of calculating the alignment of the pipeline axis using the three-dimensional coordinate system involves applying analytical geometry and numerical optimization theory to achieve precise alignment control of the pipeline axis. Taking the geometric center of the tee connector as the origin of the coordinate system, the axis vectors of the three pipeline interfaces are set as mutually perpendicular unit vectors. Vector analysis is used to describe the spatial positional relationship of the three pipeline interfaces. Constraint optimization theory is used to establish the objective optimization model, and the Lagrange multiplier method is used to solve the constraint optimization problem.

[0011] The steps of the graded locking operation are specifically based on the progressive loading theory to implement a graded locking control strategy. First, the throttle is rotated to drive the lead screw to rotate 30 degrees, causing the moving ring to move upward for the first pre-locking, so that the bottom edge of the locking block contacts the entrance edge of the slot. Then, the throttle is rotated 60 degrees for the second intermediate locking. Finally, the throttle is rotated until the locking block is fully inserted into the slot for the third complete locking. This follows the elastoplastic deformation theory to ensure that the material stress is always kept within the elastic range.

[0012] The ground source heat pump pipe tee connector includes an outer pipe, inside which, from the outside to the inside, a reinforcing layer, a corrosion-resistant layer, a composite layer, a heat-resistant layer, and an antibacterial layer are fixedly installed. A fixing ring is fixedly sleeved on the top of the outer pipe, and a fixing rod is fixedly installed on the top of the fixing ring. A strip groove is opened on one side of the fixing rod, and a lead screw is rotatably installed inside the strip groove. A sliding sleeve is threaded onto the surface of the lead screw. A handle is rotatably installed on the top of the fixing rod, and the bottom of the handle passes through the fixing rod and is fixedly connected to the top of the lead screw.

[0013] The sliding sleeve has a movable rod fixedly installed on one side. The bottom of the movable rod passes through the fixed ring and extends below the fixed ring. The movable ring is fixedly installed at the bottom of the movable rod, and a locking block is fixedly installed at the top of the movable ring. The top of the fixed ring has a locking groove, and the locking block is adapted to the locking groove. The outer surface of the movable rod is movably connected to the inner surface of the fixed ring. When the movable ring slides, it will drive the locking block to slide until the locking block is placed inside the locking groove. The top of the fixed ring has a vertical tube fixedly installed. A sliding groove is opened on one side of the vertical tube. A round shaft is movably installed inside the sliding groove. The top of the movable ring has a guide rod fixedly installed. The top of the guide rod passes through the fixed ring and extends into the interior of the vertical tube. The outer surface of the guide rod is movably connected to the inner surface of the vertical tube. One side of the guide rod is fixedly connected to one side of the round shaft. The outer surface of the round shaft and the inner surface of the sliding groove are both smooth. The outer surface of the guide rod and the inner surface of the vertical tube are both smooth.

[0014] The process includes, after the graded locking operation, a connection strength test is performed after the graded locking is completed. This test verifies whether the locking force between the locking block and the slot reaches the axial thrust reference value through a tensile test, tests the sliding stroke range of the guide rod inside the vertical tube, confirms that the range of motion of the round shaft in the slide groove meets the design requirements, and examines the correspondence between the lifting stroke of the moving ring and the rotation angle of the throttle. The process utilizes material mechanics testing methods and mechanism kinematic analysis to achieve a comprehensive verification of the connection performance.

[0015] The connection strength test refers to the use of a tensile testing machine to perform an axial tensile test on the locking connection. The test load is gradually increased from zero to 1.2 times the axial thrust reference value. The relative displacement between the locking block and the locking slot is monitored by a displacement sensor. When the tensile force reaches the reference value, the relative displacement should be less than 0.05 mm. The durability of the connection is verified by a fatigue test, which is performed under 75% reference load for 1000 cycles. After the test, the connection strength should not be less than 95% of the initial strength.

[0016] Furthermore, the reinforcing layer is made of aramid fiber, which is a synthetic fiber made of linear polyamide containing aromatic rings. It has excellent properties such as high strength, high modulus, high temperature resistance, flame retardancy, and insulation. The corrosion-resistant layer is made of polyvinyl chloride, which is a polymer material that uses one chlorine atom to replace one hydrogen atom in polyethylene. It is an amorphous polymer containing a small amount of crystalline structure, which improves its durability, chemical stability, and plasticity.

[0017] Furthermore, the composite layer is made of polystyrene, a polymer synthesized from styrene monomers via free radical addition polymerization, which has good shock and compression resistance. The heat-resistant layer is made of type 3 polypropylene, a polymer material with good high-temperature resistance. The antibacterial layer contains an antibacterial agent, which, upon contact with bacteria, destroys their cell walls and cell membranes, causing bacterial protein coagulation, enzyme inactivation, and inhibiting bacterial growth and reproduction.

[0018] Furthermore, the working principle is as follows: rotating the throttle causes the lead screw to rotate, the lead screw causes the sliding sleeve to slide inside the strip groove, the sliding sleeve causes the moving rod to slide inside the fixed ring, the moving rod causes the moving ring to slide, the moving ring causes the guide rod to slide inside the vertical tube, and then causes the round shaft to slide inside the groove. At the same time, the moving ring causes the locking block to slide until the locking block is placed inside the locking groove. The connection is assisted and fixed by the fixed ring and the moving ring.

[0019] This invention achieves a dynamic balance between connection strength and installation convenience by establishing classification standards for fit levels and angle levels. Three fit levels—tight fit (1.05), standard fit (1.075), and loose fit (1.10)—combined with three angle levels—15-degree high-efficiency locking angle, 20-degree standard locking angle, and 25-degree moderate locking angle—allow for selection of the most suitable connection parameters based on different working pressures and installation environments. This ensures connection strength under high-pressure conditions while achieving convenient rapid installation and maintenance. This invention effectively solves the problems of poor adaptability and difficulty in controlling connection precision in traditional connectors through multi-layer thickness distribution and graded locking operations. The five layers of material are distributed in thickness according to functional requirements: the reinforcing layer provides mechanical strength, the corrosion-resistant layer provides chemical protection, the composite layer provides shock resistance, the heat-resistant layer provides high-temperature resistance, and the antibacterial layer provides surface protection, forming a connection structure with excellent comprehensive performance. The graded locking operation divides the locking process into three stages: pre-locking, intermediate locking, and full locking, avoiding stress concentration caused by one-time locking and improving connection reliability and service life. This invention achieves precise alignment of the pipe axis and height adaptability of the connector through constraint optimization algorithms and sliding stroke control. A three-dimensional coordinate system is established for axis alignment calculations, and a constraint optimization algorithm is used to adjust the relative positions, ensuring that the pipe centerlines of the three interfaces are in the same plane with a 90-degree angle between each pair. The least squares method is used to optimize angular deviations, guaranteeing the geometric accuracy of the tee connection. The sliding stroke range of the guide rod is determined by the lifting and lowering amplitude of the moving ring, directly affecting the locking adjustment range of the locking block. This improves the connector's adaptability to different pipe sizes and installation conditions, solving the technical problem of balancing connection strength and installation convenience in traditional connectors. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method of the present invention.

[0021] Figure 2 This is the front view of the present invention.

[0022] Figure 3 This is a front side view of the present invention.

[0023] Figure 4 For the present invention Figure 3 Enlarged view of a portion of point A in the middle.

[0024] Figure 5 This is a rear side view of the present invention.

[0025] Figure 6 For the present invention Figure 5 Enlarged view of section B in the middle.

[0026] Figure 7 This is a schematic diagram of the internal structure of the outer tube of the present invention.

[0027] Figure 8 For the present invention Figure 7 Enlarged view of a section at point C;

[0028] Figure 9 This is a schematic diagram of the top structure of the fixing ring of the present invention.

[0029] In the diagram: 1. Outer tube; 2. Fixing ring; 3. Fixing rod; 4. Strip groove; 5. Lead screw; 6. Sliding sleeve; 7. Turning handle; 8. Moving rod; 9. Moving ring; 10. Locking block; 11. Locking groove; 12. Vertical tube; 13. Sliding groove; 14. Round shaft; 15. Guide rod; 16. Reinforcing layer; 17. Corrosion-resistant layer; 18. Composite layer; 19. Heat-resistant layer; 20. Antibacterial layer. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0031] like Figure 1 The diagram shows a flowchart of a design and installation method for a ground source heat pump pipeline tee connector provided by the present invention. This method includes the following steps:

[0032] S01. Determine the reference value of the outer pipe inner diameter based on the working pressure of the ground source heat pump system. According to the ratio of the inner diameter of the fixing ring to the outer diameter of the outer pipe, which is within the range of 1.05 to 1.10, three fit levels are divided into tight fit ratio 1.05, standard fit ratio 1.075, and loose fit ratio 1.10. Select the corresponding fit level according to the temperature range of the installation environment. At the same time, calculate the reference value of axial thrust based on the maximum working pressure of the system and the safety factor. According to the wedge angle of the locking block, three angle levels are divided into 15-degree high-efficiency locking angle, 20-degree standard locking angle, and 25-degree mild locking angle.

[0033] S02. According to the thickness distribution ratio of the multi-layer structure, set the thickness of the reinforcing layer to 35% of the total wall thickness, the thickness of the corrosion-resistant layer to 25% of the total wall thickness, the thickness of the composite layer to 20% of the total wall thickness, the thickness of the heat-resistant layer to 15% of the total wall thickness, and the thickness of the antibacterial layer to 5% of the total wall thickness. Install the reinforcing layer, corrosion-resistant layer, composite layer, heat-resistant layer and antibacterial layer inside the outer tube in sequence. Then, fit the fixing ring on the top of the outer tube according to the selected fit level, and install the vertical tube vertically on the top of the fixing ring.

[0034] S03. Install the lead screw inside the strip groove and fix it to the bottom of the throttle. Slide the sleeve onto the surface of the lead screw through the thread. Then fix the moving rod vertically to one side of the sleeve and make the bottom of the moving rod extend through the fixing ring to the bottom of the fixing ring.

[0035] S04. Install the moving ring horizontally at the bottom of the moving rod, fix the locking block vertically at the top of the moving ring, install the guide rod vertically at the top of the moving ring and extend the top of the guide rod through the fixing ring into the interior of the vertical tube, and install the round shaft horizontally inside the slide groove and fix it to one side of the guide rod.

[0036] S05. The pipe axis alignment is calculated by establishing a three-dimensional coordinate system. The center of the tee connector is taken as the origin of the coordinate system. The axis vectors of the three pipe interfaces are set as mutually perpendicular unit vectors. The constraint optimization algorithm is used to adjust the relative position of the tee connector and the pipe to be connected so that the center lines of the pipes of the three interfaces are in the same plane and the angle between each pair is 90 degrees. The angle deviation of each pipe axis is optimized by the least squares method.

[0037] S06. Perform graded locking operation according to the selected angle level. First, rotate the handle to drive the lead screw to rotate 30 degrees to move the moving ring upward for the first pre-locking, so that the bottom edge of the block contacts the entrance edge of the slot. Check the initial fit between the block and the slot. Then, continue to rotate the handle 60 degrees for the second intermediate locking. Finally, rotate the handle until the block is fully inserted into the slot for the third complete locking.

[0038] S07. After completing the graded locking, conduct a connection strength test. Verify whether the locking force between the card block and the card slot reaches the axial thrust reference value through a tensile test. Test the sliding stroke range of the guide rod inside the vertical tube to confirm that the range of motion of the round shaft in the slide groove meets the design requirements. Check the correspondence between the lifting stroke of the moving ring and the rotation angle of the throttle.

[0039] Among them, the fit grade refers to the classification standard of the ratio of the inner diameter of the fixed ring to the outer diameter of the outer tube. The tight fit ratio of 1.05 is suitable for high-pressure environments and precision connections, the standard fit ratio of 1.075 is suitable for normal working conditions, and the loose fit ratio of 1.10 is suitable for quick installation and maintenance. The selection of the fit grade directly affects the balance between connection strength and installation convenience.

[0040] Among them, the angle grade refers to the classification standard of the wedge angle of the locking block. The 15-degree high-efficiency locking angle provides the maximum locking force but requires a large axial thrust. The 20-degree standard locking angle achieves a balance between locking force and operating force. The 25-degree moderate locking angle is easier to operate but has a relatively small locking force. The choice of angle grade affects the locking efficiency and ease of operation.

[0041] The thickness distribution ratio of the multi-layer structure refers to the thickness distribution standard of the five layers of materials inside the outer tube. The reinforcing layer bears the main mechanical strength load, accounting for 35%; the corrosion-resistant layer bears the chemical protection function, accounting for 25%; the composite layer provides shock resistance and extrusion resistance, accounting for 20%; the heat-resistant layer provides high temperature resistance, accounting for 15%; and the antibacterial layer provides surface antibacterial function, accounting for 5%. The distribution ratio affects the overall performance and manufacturing cost of the connector.

[0042] Among them, the axial thrust reference value refers to the standard thrust value calculated based on the maximum working pressure and safety factor of the ground source heat pump system. It is used to determine the minimum requirement for the locking force of the clamping block. The axial thrust reference value is obtained by calculation through formula and serves as the basis for locking force verification.

[0043] Among them, the constraint optimization algorithm refers to the mathematical optimization method used in the alignment process of pipeline axes. By setting the constraint condition that the three pipeline axes are perpendicular to each other, the Lagrange multiplier method is used to solve for the optimal position that minimizes the angle deviation. The algorithm guarantees the geometric accuracy of the tee connection.

[0044] Among them, the graded locking operation refers to the operation method of dividing the locking process into three stages: pre-locking, intermediate locking and full locking. Each stage corresponds to a different throttle rotation angle and the depth of the locking block. The graded locking operation avoids stress concentration and component damage caused by one-time locking.

[0045] The sliding stroke range refers to the maximum distance the guide rod moves inside the vertical tube and the circular shaft moves inside the slide groove. The sliding stroke range is determined by the lifting and lowering amplitude of the moving ring, which directly affects the locking adjustment range of the locking block and the adaptability of the connector.

[0046] The ground source heat pump pipeline tee connector obtained according to the design and installation method has the following structure: The connector includes an outer tube, and inside the outer tube, from the outside to the inside, a reinforcing layer, a corrosion-resistant layer, a composite layer, a heat-resistant layer, and an antibacterial layer are fixedly installed in sequence. The reinforcing layer is made of aramid fiber, the corrosion-resistant layer is made of polyvinyl chloride, the composite layer is made of polystyrene, the heat-resistant layer is made of type III polypropylene, and the antibacterial layer contains an antibacterial agent. A fixing ring is fixedly sleeved on the top of the outer tube, and a fixing rod is fixedly installed on the top of the fixing ring. A slotted groove is opened on one side of the fixing rod, and a threaded rod is rotatably installed inside the slotted groove. A sliding sleeve is threaded onto the surface of the threaded rod, and a sliding sleeve is rotatably installed on the top of the fixing rod. The throttle has a fixed rod at its bottom that is fixedly connected to the top of the lead screw. A movable rod is fixedly installed on one side of the sliding sleeve. The bottom of the movable rod passes through the fixed ring and extends to the bottom of the fixed ring. A movable ring is fixedly installed at the bottom of the movable rod. A locking block is fixedly installed at the top of the movable ring. A locking groove is opened at the top of the fixed ring, and the locking block is adapted to the locking groove. A vertical tube is fixedly installed at the top of the fixed ring. A sliding groove is opened on one side of the vertical tube. A round shaft is movably installed inside the sliding groove. A guide rod is fixedly installed at the top of the movable ring. The top of the guide rod passes through the fixed ring and extends to the inside of the vertical tube. The outer surface of the guide rod is movably connected to the inner surface of the vertical tube. One side of the guide rod is fixedly connected to one side of the round shaft.

[0047] The specific implementation methods of the above steps are described in detail below. Step S01 is implemented by establishing a fit level determination system based on fluid mechanics theory and elasticity principles. First, by measuring the maximum operating pressure of the ground source heat pump system and combining it with a safety factor ranging from 1.5 to 2.0, the reference dimension of the inner diameter of the outer pipe 1 is determined. This reference value serves as the reference for all subsequent fit calculations. Then, a proportional relationship model between the inner diameter of the fixed ring 2 and the outer diameter of the outer pipe 1 is established using dimensional analysis. The numerical ranges of the three fit levels are determined using the stress concentration theory in materials mechanics. A tight fit ratio of 1.05 is suitable for high-pressure environments with operating pressures greater than 1.5 MPa; a standard fit ratio of 1.075 is suitable for conventional conditions with operating pressures between 0.8 and 1.5 MPa; and a loose fit ratio of 1.10 is suitable for low-pressure applications with operating pressures less than 0.8 MPa. Next, based on the influence of ambient temperature on the thermal expansion coefficient of the material, a tight fit is selected when the ambient temperature is below -10℃ to compensate for material shrinkage; a standard fit is selected when the ambient temperature is between -10℃ and 40℃ to balance performance; and a loose fit is selected when the ambient temperature is above 40℃ to avoid excessive expansion. Subsequently, the axial thrust baseline value was calculated using the principle of static equilibrium. Input parameters included the system's maximum working pressure, pipe cross-sectional area, and safety factor. The output parameter was the minimum locking force requirement. Finally, based on the mechanical principles of the wedge mechanism, the wedge angle level of the locking block 10 was determined. A 15-degree high-efficiency locking angle, based on the Archimedes' screw principle, provides maximum mechanical gain but requires a larger operating force. A 20-degree standard locking angle achieves the optimal balance between mechanical efficiency and operational convenience. A 25-degree moderate locking angle reduces operating resistance but correspondingly reduces the locking effect.

[0048] The specific implementation of step S02 involves constructing a multifunctional pipe wall structure system using layered composite material design theory. First, based on the mixing law in composite mechanics, the thickness distribution scheme of each layer is determined. The comprehensive performance indicators under different thickness ratios are calculated using finite element analysis, ultimately determining that the thickness of the reinforcing layer 16 is 35% of the total wall thickness to bear the main mechanical load. Then, based on the principle of chemical protection, the thickness of the corrosion-resistant layer 17 is set to 25% of the total wall thickness; this thickness effectively blocks the erosion of the internal structure by acids, alkalis, and salts in the soil. Next, using damping and vibration reduction theory, the thickness of the composite layer 18 is determined to be 20% of the total wall thickness; the viscoelastic properties of polystyrene effectively absorb vibration energy generated by geological activity. Subsequently, based on the principle of heat transfer, the thickness of the heat-resistant layer 19 is set to 15% of the total wall thickness; the low thermal conductivity of type III polypropylene reduces heat loss and maintains system temperature stability. Finally, based on the principle of microbiological protection, the thickness of the antibacterial layer 20 is set to 5% of the total wall thickness; this layer inhibits the growth and reproduction of bacteria and fungi by releasing silver ions or other antibacterial components. During actual installation, hot-melt welding technology is used to fix each layer of material to the inner wall of the outer pipe 1 in an inward and outward sequence, ensuring a firm bond between layers without air bubbles or delamination. Then, the fixing ring 2 is mechanically fitted onto the top of the outer pipe 1 according to a predetermined fit. During the fitting process, the axial force needs to be controlled within the range of 500 to 1500 N to avoid excessive stress. Finally, a verticality testing instrument is used to ensure that the verticality deviation of the vertical pipe 12 does not exceed 0.1 degrees. This accuracy requirement is determined based on laminar flow conditions in fluid dynamics.

[0049] The specific implementation of step S03 involves constructing an axial adjustment control system using the principle of a screw drive mechanism. First, the pitch parameter of the lead screw 5 is determined based on the kinematic relationship of the screw drive. The axial displacement of the sliding sleeve 6 is calculated by inputting the rotation angle of the throttle 7 and the pitch value. A typical pitch is set to 2 to 5 mm to achieve a balance between accuracy and efficiency. Then, the lead screw 5 is installed inside the slot 4 using a key or pin connection. The connection strength must meet the transmission requirement of a maximum torque of 200 Nm, which is determined based on the limit force of manual operation and the arm length of the throttle 7. Next, the sliding sleeve 6 is fitted onto the surface of the lead screw 5 using a threaded fit principle. The thread fit grade is selected as 6H / 6g to ensure transmission accuracy and smooth movement, with the fit clearance controlled within the range of 0.02 to 0.05 mm. Finally, a flange connection is used to rigidly connect the bottom of the throttle 7 to the top of the lead screw 5. The connection must be able to withstand the fatigue load generated by repeated rotation operations. Finally, the vertical movement trajectory of the moving rod 8 is ensured by the guiding mechanism. A sliding fit is used between the moving rod 8 and the fixed ring 2, with the clearance set to 0.1 to 0.3 mm to reduce frictional resistance while ensuring guiding accuracy. The mechanical efficiency of the entire transmission system needs to reach over 75%. Lubricating grease is applied to key mating surfaces to reduce the coefficient of friction and improve transmission efficiency.

[0050] The specific implementation of step S04 is based on the principle of spatial kinematics to construct a three-dimensional motion coordination control system. First, the rigid body kinematics theory is used to determine the fixed connection method between the moving ring 9 and the moving rod 8. Welding or bolting is used to ensure that the two form a single motion unit, and the connection strength needs to withstand a maximum axial force of 2000N without failure. Then, according to the geometric principle of the wedge locking mechanism, the locking block 10 is vertically fixed to the top of the moving ring 9. The wedge angle of the locking block 10 is consistent with the angle level determined in step S01, and the surface roughness of the wedge surface is controlled below Ra1.6 to ensure good fit. Next, based on the guide mechanism design principle, a groove 11 matching the shape of the locking block 10 is opened on the top of the fixed ring 2. The depth of the groove 11 is determined according to the locking stroke requirements, typically 5 to 15 mm. Subsequently, using the coaxiality control principle, the vertical tube 12 is vertically installed on the top of the fixed ring 2. The inner diameter of the vertical tube 12 needs to leave a movement clearance of 0.2 to 0.5 mm for the diameter of the guide rod 15. Then, based on the principle of the linear guide mechanism, a groove 13 is made on the side wall of the vertical pipe 12. The length of the groove 13 determines the maximum stroke range of the guide rod 15, which needs to meet the adjustment requirements of different pipe specifications. Next, a round shaft 14 is installed inside the groove 13. The round shaft 14 is made of high-quality bearing steel and has undergone surface hardening treatment to improve wear resistance. Finally, the guide rod 15 is rigidly connected to the side of the round shaft 14 to form a synchronous motion guide control mechanism. This mechanism can effectively limit the rotational movement of the guide rod 15 while allowing axial sliding.

[0051] The specific implementation of step S05 involves using analytical geometry and numerical optimization theory to achieve precise alignment control of the pipe axis. First, a three-dimensional Cartesian coordinate system is established, with the geometric center of the tee connector as the origin. The Z-axis runs along the vertical pipe axis 12, and the X and Y axes run along the axes of the two horizontal branch pipes, forming a mutually perpendicular unit vector system. Then, vector analysis is used to describe the spatial relationship between the three pipe interfaces. Each pipe axis is represented by a direction vector and a position vector, and the orthogonality of the three axis vectors is verified through vector operations. Next, a target optimization model is established using constrained optimization theory. The constraint condition is that the angle error between any two pipe axes is less than 0.5 degrees, and the objective function is to minimize the sum of squares of the axis angle deviations. Subsequently, the Lagrange multiplier method is used to solve the constrained optimization problem, and the position and attitude parameters of the tee connector that minimize the angle deviation are determined through iterative calculation. Finally, the least squares method is applied to process the measurement data. The input parameters include the actual axis coordinates and direction parameters of the three pipes, and the output parameter is the optimized connector installation position. Finally, the reliability of the optimization results is determined by numerical convergence. Convergence is considered complete when the positional deviation between two consecutive iterations is less than 0.1 mm and the angular deviation is less than 0.1 degrees. The entire alignment process requires real-time monitoring using a laser measuring instrument to ensure that the axis alignment accuracy meets the design requirements.

[0052] The specific implementation of step S06 is based on a graded locking control strategy implemented using progressive loading theory. First, the angle sequence for graded locking is determined according to the stress distribution theory in materials mechanics. The first pre-locking is achieved by rotating the throttle 7 to drive the lead screw 5 to rotate 30 degrees. This angle corresponds to the sliding sleeve 6 moving upwards a distance equal to one-twelfth of the pitch value, so that the bottom edge of the locking block 10 just contacts the entrance edge of the slot 11. Then, the initial fit between the locking block 10 and the slot 11 is detected using the principle of contact mechanics. The uniformity of the mating surface is judged by measuring the contact pressure distribution; the contact pressure should be within the range of 0.5 to 2.0 MPa and relatively uniformly distributed. Next, the second intermediate locking operation is performed, continuing to rotate the throttle 7 a total of 60 degrees. At this point, the locking block 10 enters the middle position of the slot 11, and the wedge-shaped surface begins to generate a significant radial force, which is approximately 0.3 to 0.7 times the axial force. A third, complete locking process is then performed, continuing to rotate the handle 7 until the locking block 10 is fully engaged in the bottom of the slot 11. The final rotation angle is determined according to the selected angle level: a 15-degree wedge angle requires a total rotation angle of 90 to 120 degrees, a 20-degree wedge angle requires 120 to 150 degrees, and a 25-degree wedge angle requires 150 to 180 degrees. Torque changes need to be monitored at each locking stage. If the torque suddenly increases by more than 20%, rotation should be stopped and the fit between the locking block 10 and the slot 11 checked. The entire graded locking process follows the elastoplastic deformation theory, ensuring that the material stress remains within the elastic range and avoiding permanent damage caused by plastic deformation.

[0053] The specific implementation of step S07 involves using material mechanics testing methods and mechanism kinematics analysis to comprehensively verify the connection performance. First, a tensile testing machine is used to perform an axial tensile test on the locking connection. The test load is gradually increased from zero to 1.2 times the axial thrust reference value, with the loading rate controlled within the range of 50 to 100 N / s to ensure quasi-static loading conditions. Then, a displacement sensor monitors the relative displacement between the locking block 10 and the locking groove 11. When the tensile force reaches the reference value, the relative displacement should be less than 0.05 mm; this indicator is determined based on the connection stiffness requirements. Next, the sliding stroke range of the guide rod 15 inside the vertical tube 12 is tested. By manually operating the throttle 7, the guide rod 15 makes a complete reciprocating motion within the vertical tube 12, recording the maximum stroke distance and verifying whether it meets the design adjustment range requirements. Subsequently, the range of motion of the round shaft 14 within the slide groove 13 is checked. The round shaft 14 should be able to slide freely within the slide groove 13 without jamming, and the sliding resistance should be less than 50 N to ensure operational flexibility. Next, the relationship between the lifting stroke of the moving ring 9 and the rotation angle of the throttle 7 is tested. This relationship should strictly follow the kinematic laws of threaded transmission, and the deviation between the theoretical calculation value and the measured value should be less than 5%. Finally, a fatigue test is conducted to verify the durability of the connection. A 1000-cycle loading test is performed under 75% of the reference load. After the test, the connection strength should not be less than 95% of the initial strength. The entire inspection process requires detailed recording of all test data and comparative analysis with the design specifications to ensure that all performance parameters meet the usage requirements.

[0054] The key technical concepts of this invention are analyzed as follows. The first key technical concept is a multi-level fit optimization design. This technology establishes a precise proportional relationship between the inner diameter of the fixed ring and the outer diameter of the outer tube, and combines the dual influencing factors of ambient temperature and working pressure to achieve an optimal balance between connection strength and installation convenience. Compared to the traditional single fit standard, this technology can adaptively adjust the fit parameters according to actual working conditions, effectively avoiding installation difficulties caused by overly tight fits and insufficient connection reliability caused by overly loose fits, significantly improving the applicability and reliability of the connector. The second key technical concept is a graded wedge angle locking mechanism. This technology achieves optimized matching of locking force and operating force by setting three different wedge angle levels and corresponding graded locking operation procedures. Compared to the traditional one-time locking method, this mechanism can effectively disperse stress concentration during the locking process, avoid local plastic deformation of the material, and ensure uniform distribution of locking force through a progressive loading strategy, greatly improving the stability and durability of the connection. The third key technological approach is the functional design of multi-layer composite materials. This technology layers materials with different functions according to a scientific thickness ratio, forming a composite structure that integrates mechanical strength, corrosion resistance, shock resistance, heat resistance, and antibacterial properties. Compared to traditional single-material pipes, this design provides comprehensive protection for the complex operating conditions of ground source heat pump systems, significantly extending the service life of connectors and reducing maintenance costs. The synergistic effect of these three technological approaches forms a highly integrated intelligent connection system. Through optimized coordination levels, it ensures the basic reliability of the connection; through a graded locking mechanism, it achieves precise control of connection strength; and through the multi-layer composite structure, it provides comprehensive environmental adaptability. These three elements work together to construct a new generation of ground source heat pump pipe connection solutions that far surpass the performance of traditional connectors, providing a reliable technical guarantee for the long-term stable operation of ground source heat pump systems.

[0055] The specific structure of the tee connector for ground source heat pump pipelines is described below. A ground source heat pump pipeline tee connector includes an auxiliary fixing mechanism at each interface, comprising an outer pipe 1, a fixing ring 2 fixedly fitted to the top of the outer pipe 1, the fixing ring 2 being adapted to a movable ring 9 for auxiliary fixing of the connection, a fixing rod 3 fixedly mounted on the top of the fixing ring 2, a slotted groove 4 on one side of the fixing rod 3, a lead screw 5 rotatably mounted inside the slotted groove 4, and a sliding sleeve 6 threaded onto the surface of the lead screw 5, causing the sliding sleeve 6 to slide inside the slotted groove 4 when the lead screw 5 rotates, a handle 7 rotatably mounted on the top of the fixing rod 3, the bottom of the handle 7 penetrating the fixing rod 3 and fixedly connected to the top of the lead screw 5, rotating the handle 7 causing the lead screw 5 to rotate, a movable rod 8 fixedly mounted on one side of the sliding sleeve 6, the bottom of the movable rod 8 penetrating the fixing ring 2 and extending below the fixing ring 2, causing the movable rod 8 to slide when the sliding sleeve 6 slides, the outer surface of the movable rod 8 being movably connected to the inner surface of the fixing ring 2, and a fixed rod 8 being fixedly mounted on the bottom of the movable rod 8. The movable ring 9 and the movable rod 8 slide together, causing the movable ring 9 to slide as well. A locking block 10 is fixedly installed on the top of the movable ring 9, and the locking block 10 slides as well. The top of the fixed ring 2 has a locking groove 11, and the locking block 10 is compatible with the locking groove 11. A vertical tube 12 is fixedly installed on the top of the fixed ring 2. A sliding groove 13 is provided on one side of the vertical tube 12. A round shaft 14 is movably installed inside the sliding groove 13. The outer surface of the round shaft 14 and the inner surface of the sliding groove 13 are both smooth. A guide rod 15 is fixedly installed on the top of the movable ring 9. The top of the guide rod 15 passes through the fixed ring 2 and extends into the interior of the vertical tube 12. When the movable ring 9 slides, it will cause the guide rod 15 to slide inside the vertical tube 12. The outer surface of the guide rod 15 is movably connected to the inner surface of the vertical tube 12. Both the outer surface of the guide rod 15 and the inner surface of the vertical tube 12 are smooth. One side of the guide rod 15 is fixedly connected to one side of the round shaft 14. When the guide rod 15 slides, it will cause the round shaft 14 to slide.The outer tube 1 has a reinforcing layer 16 fixedly installed inside, and the reinforcing layer 16 is made of aramid fiber. Aramid fiber is a synthetic fiber made of linear polyamide containing aromatic rings. It has excellent properties such as high strength, high modulus, high temperature resistance, flame retardancy, and insulation. The reinforcing layer 16 also has a corrosion-resistant layer 17 fixedly installed inside, and the corrosion-resistant layer 17 is made of polyvinyl chloride (PVC). PVC is a polymer material in which one chlorine atom replaces one hydrogen atom in polyethylene. It is an amorphous polymer containing a small amount of crystalline structure, which improves its durability, chemical stability, and plasticity. The corrosion-resistant layer 17 has a... The composite layer 18 is made of polystyrene, a polymer synthesized from styrene monomers via free radical addition polymerization. It has good shock and compression resistance. A heat-resistant layer 19 is fixedly installed inside the composite layer 18. The heat-resistant layer 19 is made of type 3 polypropylene, a polymer material with good high-temperature resistance. An antibacterial layer 20 is fixedly installed inside the heat-resistant layer 19. The antibacterial layer 20 contains an antibacterial agent. When it comes into contact with bacteria, it destroys their cell walls and cell membranes, causing bacterial proteins to coagulate and enzymes to become inactive, thus inhibiting bacterial growth and reproduction and improving its antibacterial properties. The working principle is as follows: First, rotate the handle 7, which will drive the lead screw 5 to rotate. Then, the lead screw 5 will drive the sliding sleeve 6 to slide inside the strip groove 4. At this time, the sliding sleeve 6 will drive the moving rod 8 to slide inside the fixed ring 2. Then, the moving rod 8 will drive the moving ring 9 to slide. Then, the moving ring 9 will drive the guide rod 15 to slide inside the vertical tube 12, and then drive the round shaft 14 to slide inside the slide groove 13. At the same time, the moving ring 9 will drive the locking block 10 to slide until the locking block 10 is placed inside the locking groove 11. The connection can be assisted and fixed by the fixed ring 2 and the moving ring 9. Secondly, the reinforcing layer 16 can enhance the strength of the connector, the corrosion-resistant layer 17 can improve its durability, chemical stability and plasticity, the composite layer 18 has good shock resistance and extrusion resistance, the heat-resistant layer 19 has good high temperature resistance, and the antibacterial layer 20 can improve the antibacterial properties of the connector. Thus, the multi-layer design can improve its practicality.

[0056] It should be noted that the present invention also solves the following three key technical problems.

[0057] First, this invention solves the problem of coordinating the multi-functional performance of pipe connectors under complex operating conditions. Traditional pipe connectors typically only consider a single performance indicator, such as mechanical strength or corrosion resistance, making it difficult to simultaneously meet multiple functional requirements such as pressure resistance, corrosion resistance, shock resistance, high temperature resistance, and antibacterial properties under the complex operating conditions of ground source heat pump systems. This invention, through a multi-layered structural thickness distribution, allocates the thickness of the reinforcing layer, corrosion-resistant layer, composite layer, heat-resistant layer, and antibacterial layer in a ratio of 35%, 25%, 20%, 15%, and 5%, respectively. Each layer undertakes a specific function, forming a multi-functional and coordinated comprehensive performance system. The aramid fiber material of the reinforcing layer provides the main mechanical strength, the polyvinyl chloride material of the corrosion-resistant layer resists chemical corrosion, the polystyrene material of the composite layer provides shock absorption, the type III polypropylene material of the heat-resistant layer ensures high-temperature stability, and the antibacterial agent of the antibacterial layer prevents bacterial growth, achieving coordinated operation of different functional layers.

[0058] Secondly, this invention solves the technical problems of geometric precision control and adaptive adjustment of tee connectors. Traditional tee connectors rely on manual experience for pipe alignment, making it difficult to ensure the precise perpendicularity and concentricity of the three pipe axes. This easily leads to angular deviations and positional errors, resulting in uneven stress distribution and decreased sealing performance. This invention establishes a three-dimensional coordinate system and a constraint optimization algorithm. With the center of the tee connector as the origin, the axis vectors of the three pipe interfaces are set as mutually perpendicular unit vectors. The optimal position is solved using the Lagrange multiplier method, ensuring that the pipe centerlines of the three interfaces are in the same plane and the angle between any two is 90 degrees. The angular deviation is optimized using the least squares method. Simultaneously, the sliding stroke range of the guide rod is determined by the lifting amplitude of the moving ring, and the range of motion of the circular shaft within the groove can be adjusted according to actual needs. This achieves adaptive adjustment of the connector to different pipe sizes and installation conditions, ensuring the geometric precision and adaptability of the connection.

[0059] Third, this invention solves the problems of stress concentration and operational control during connector locking. Traditional locking methods typically employ a one-time locking process, which easily leads to stress concentration during locking, causing excessive local stress and damage to the connector. Furthermore, operators find it difficult to precisely control the locking force, resulting in over-locking or under-locking. This invention, through graded locking operation and angle level control, divides the locking process into three stages: pre-locking, intermediate locking, and full locking. Each stage corresponds to a different throttle rotation angle and the depth of the locking block entry. The first rotation is 30 degrees for pre-locking, the second 60 degrees for intermediate locking, and the third rotation until the locking block is fully engaged in the slot for full locking. Combined with three wedge angle designs of 15 degrees, 20 degrees, and 25 degrees, the appropriate angle level can be selected according to different working conditions, achieving precise control of the locking force and uniform stress distribution. This avoids connector damage caused by stress concentration and improves operational controllability and reliability.

[0060] It should be noted that in the actual design and installation of the tee connector for ground source heat pump pipelines, the acquisition and measurement of various key parameters require a combination of precise on-site testing and theoretical calculations. Firstly, high-precision pressure sensors and data acquisition systems are installed at the ground source heat pump system operating site to continuously monitor and record the maximum working pressure of the system under different operating conditions, obtaining accurate pressure reference data. Simultaneously, digital thermometers and thermocouple sensors are used to monitor the temperature changes of the installation environment in real time, establishing a database of the relationship between temperature changes and the thermal expansion coefficient of materials. Then, precise inner diameter measuring instruments such as... An inside micrometer, inside gauge, and laser rangefinder were used to measure the inner diameter of the outer pipe at multiple points. Combined with statistical methods, a baseline value for the inner diameter was determined. Next, using material mechanics theory, the measured working pressure data, pipe cross-sectional area parameters, and a preset safety factor were substituted into the calculation model to derive the baseline value for axial thrust. During the manufacturing process of the multi-layered material structure, an ultrasonic thickness gauge, micrometer, and laser thickness gauge were used to accurately measure the actual thickness of each layer, ensuring that the thickness of each layer strictly adheres to the design proportions. Thread parameters were measured using a thread gauge, thread micrometer, and coordinate measuring machine to obtain accurate pitch and thread count values. The design parameters and clearance control are achieved through a combination of feeler gauges, clearance measuring instruments, and precision gauge blocks. Perpendicularity is verified from multiple angles using a laser plumb line, level, and digital inclinometer. During the locking process, a miniature pressure sensor array is installed to monitor the contact pressure distribution between the locking block and the slot in real time, obtaining data on the uniformity of the pressure distribution. Connection strength is verified through standardized tensile testing using a universal testing machine, with high-precision displacement sensors monitoring deformation. The sliding stroke range is tested through dynamic tracking measurement using linear displacement sensors, draw-wire displacement sensors, and laser displacement sensors, obtaining complete motion trajectory data. Finally, cyclic loading tests are conducted using a fatigue testing machine, with strain gauges and accelerometers monitoring changes in the material's fatigue characteristics. The entire measurement process also requires the use of a coordinate measuring machine for geometric accuracy testing, a laser interferometer for length standard calibration, a surface roughness meter to check the quality of the mating surfaces, and a torque wrench and digital torque meter to monitor the locking torque. Through the comprehensive application of these modern precision measuring devices and standardized testing procedures, it is ensured that all design parameters can be accurately measured and effectively verified during actual installation, providing solid data support for the reliability and safety of the connector.

[0061] Specifically, the principle of this invention is as follows: The technical principle behind solving the problem of balancing connection strength and installation convenience lies in establishing a multi-parameter collaborative control connection mechanism. First, by classifying fit levels, graded control of connection strength is achieved. The ratio of the inner diameter of the fixing ring to the outer diameter of the outer tube directly determines the tightness of the connection. A tight fit ratio of 1.05 provides maximum connection strength under high-pressure environments, a standard fit ratio of 1.075 achieves a balance between strength and convenience under normal working conditions, and a loose fit ratio of 1.10 provides maximum operational convenience in rapid installation and maintenance scenarios. Second, by classifying angle levels, precise control of locking force is achieved. The size of the wedge angle directly affects locking efficiency and operating force. A 15-degree high-efficiency locking angle provides maximum locking force with a smaller wedge angle, suitable for high-pressure environments; a 20-degree standard locking angle achieves a balance between locking force and operating force; and a 25-degree moderate locking angle reduces operating force with a larger wedge angle, suitable for frequent installation and maintenance scenarios.

[0062] The technical principle behind the multi-layer thickness distribution lies in optimizing overall performance through functional layering. The reinforcing layer, made of aramid fiber and accounting for 35% of the total wall thickness, bears the main mechanical strength load, providing tensile and compressive strength. The corrosion-resistant layer, made of polyvinyl chloride and accounting for 25% of the total wall thickness, provides chemical protection, preventing corrosion of the connector by chemicals in the ground source heat pump system. The composite layer, made of polystyrene and accounting for 20% of the total wall thickness, provides shock and compression resistance, mitigating the impact of external shocks on the connector. The heat-resistant layer, made of type III polypropylene and accounting for 15% of the total wall thickness, provides high-temperature resistance, ensuring the stability of the connector in high-temperature environments. The antibacterial layer, containing an antibacterial agent and accounting for 5% of the total wall thickness, provides surface antibacterial function, preventing bacterial growth that could affect system hygiene.

[0063] The technical principle of the graded locking operation and constraint optimization algorithm lies in improving connection accuracy through step-by-step control and mathematical optimization. The graded locking operation divides the locking process into three stages: the first pre-locking causes the bottom edge of the locking block to contact the inlet edge of the slot, establishing initial positioning; the second intermediate locking allows the locking block to further enter the slot, forming a moderate locking force; the third complete locking allows the locking block to fully enter the slot, forming the maximum locking force. This graded locking method avoids stress concentration caused by one-time locking, improving connection reliability. The constraint optimization algorithm establishes a three-dimensional coordinate system, setting the axis vectors of the three pipe interfaces as mutually perpendicular unit vectors, and uses the Lagrange multiplier method to solve for the optimal position that minimizes the angular deviation, ensuring the geometric accuracy of the tee connection. Sliding stroke control, through the movement of the guide rod inside the vertical pipe and the movement of the circular shaft inside the slide groove, achieves precise control of the locking block adjustment range, improving the connector's adaptability to different working conditions.

[0064] The following provides a specific embodiment 1 of the present invention, and the specific implementation of each step in this embodiment 1 is described in detail below.

[0065] The specific implementation of step S01 is based on establishing a fit grade determination system according to fluid mechanics theory and elasticity principles. First, the reference value of the outer tube's inner diameter is determined. The calculation formula is: In the formula, This is the reference value for the inner diameter of the outer tube, in mm. The maximum flow rate of the ground source heat pump system is expressed in units of... ; The optimal flow velocity is defined as 1.5–2.5 m / s; in the formula… for arrive The conversion factor is 3600, which is the conversion factor from hours to seconds. Here are the conversion factors from m to mm. Then, establish the fit grade selection function: In the formula, To match the proportionality coefficient, it is dimensionless; The system operating pressure is expressed in MPa. This refers to the ambient temperature, expressed in °C. The reference pressure is 1.5 MPa; The reference temperature is 20℃; The values ​​are weighting coefficients, taking values ​​of 0.03 and 0.02 respectively, and are dimensionless; 1.05 is the basic fit ratio coefficient. Axial thrust reference value. The calculation formula is: In the formula, This is the reference value for axial thrust, in N; This is the system's maximum operating pressure, expressed in MPa. This refers to the cross-sectional area of ​​the pipe, in units of... ; The safety factor ranges from 1.5 to 2.0 and is dimensionless. From MPa Conversion factor.

[0066] The specific implementation of step S02 involves constructing a multifunctional pipe wall structure system using layered composite material design theory. The thickness distribution of each layer is carried out according to a preset ratio, and the total wall thickness... The calculation formula is: In the formula, This represents the total wall thickness, in mm. The inner diameter of the pipe is equal to The unit is mm; The allowable stress for composite materials ranges from 80 to 120 MPa. The maximum operating pressure of the system is the same as that defined in step S01, and the unit is MPa; From MPa The conversion factor. The formula for distributing the thickness of each layer is: , , , , In the formula, To increase the layer thickness, For the thickness of the corrosion-resistant layer, For the thickness of the composite layer, For the thickness of the heat-resistant layer, The values ​​represent the thickness of the antibacterial layer, all in mm; 0.35, 0.25, 0.20, 0.15, and 0.05 are the thickness distribution coefficients for each layer, dimensionless.

[0067] The specific implementation of step S03 is to construct an axial adjustment control system using the principle of a screw drive mechanism. Screw pitch With the axial displacement of the sliding sleeve The relationship is: In the formula, This represents the axial displacement of the sliding sleeve, in mm. The lead screw pitch ranges from 2 to 5 mm. The throttle rotation angle is expressed in degrees; 360° is the reference value for one revolution. Transmission efficiency. The calculation formula is: In the formula, The efficiency of the screw drive is dimensionless. For the helix angle of the thread, through Calculated, unit is degree; The equivalent friction angle is obtained by... Calculated, unit is degree; This refers to the thread pitch diameter, in mm. is the friction coefficient of the threaded surface, with a value ranging from 0.1 to 0.15, and is dimensionless.

[0068] The specific implementation of step S04 is the same as described above, and will not be repeated in detail here.

[0069] The specific implementation of step S05 involves using analytical geometry and numerical optimization theory to achieve precise alignment control of the pipeline axis. After establishing a three-dimensional coordinate system, the three pipeline axis vectors are represented as follows: , , In the formula, Let be the ideal unit direction vectors of the three pipe interfaces, which are dimensionless. The constrained optimization objective function is: In the formula, The objective function value is dimensionless. This is the position vector of the tee connector, containing x, y, and z coordinate components, in mm; This is the attitude angle vector of the tee connector, which includes rotation angles around the x, y, and z axes, in degrees. For Kroneck symbol, when It takes the value 1 when the time condition is met, and 0 otherwise; it is dimensionless. This is a vector dot product operation, representing the cosine of the angle between two vectors, which is dimensionless. The least squares optimization formula is: In the formula, The optimal solution vector contains position and angle parameters, and has dimensions of [missing information]. ; This is a constraint coefficient matrix, reflecting the perpendicular constraint relationship of the axes, with dimensions of [missing information]. ; The observation vector represents the ideal state, with all components being 0, and has a dimension of . ; This represents Euclidean norm operations.

[0070] The specific implementation of step S06 is based on a graded locking control strategy implemented according to the progressive loading theory. Wedge angle With locking force The relationship is: In the formula, The locking force generated by the locking block, measured in N; The axial thrust applied to the moving circle, measured in N; For the wedge angle of the locking block, select 15 degrees, 20 degrees or 25 degrees according to the angle grade; The coefficient of friction between the contact surface of the locking block and the slot is 0.1–0.3, dimensionless. The radial force during the staged locking process... The calculation formula is: In the formula, This represents the radial pressure exerted by the locking block on the groove wall, expressed in N. The relationship between the throttle rotation angle and the locking stage is as follows: In the formula, The total rotation angle for the complete locking process, in degrees; The rotation angle of the throttle during the pre-locking stage is fixed at 30 degrees. The rotation angle of the throttle during the intermediate locking stage is fixed at 60 degrees. The rotation angle of the throttle during the fully locked stage is determined according to the wedge angle level: 90-120 degrees for a 15-degree wedge angle, 120-150 degrees for a 20-degree wedge angle, and 150-180 degrees for a 25-degree wedge angle.

[0071] The specific implementation method of step S07 is the same as described above, and will not be repeated in detail here.

[0072] In the above formula, the formula for calculating the reference value of the outer tube inner diameter is... Based on the principle of the continuity equation in fluid mechanics, this formula optimizes flow velocity to maximize system efficiency. Compared to traditional empirical selection methods, it can accurately match the system's flow requirements, avoiding material waste caused by excessively large pipe diameters and increased pressure loss due to excessively small pipe diameters. This is combined with a grade selection function. Based on multi-factor coupled optimization theory, and comprehensively considering the influence of pressure and temperature on fit accuracy, this function can achieve dynamic adjustment of fit accuracy compared to single-parameter selection methods, significantly improving connection reliability. Axial thrust reference value calculation formula. Based on the theory of material mechanics strength, this formula introduces a safety factor to ensure a margin of strength for the connection. Compared to traditional estimation methods, this formula can quantitatively determine the minimum locking force requirement, effectively preventing connection failure. (Wedge angle locking force relationship formula) Based on the mechanical principles of wedge mechanisms, by optimizing the matching relationship between the wedge angle and the coefficient of friction, this formula can achieve precise control of the locking force compared to traditional mechanical connection methods, significantly reducing the operating torque while improving the locking effect.

[0073] To better understand and implement this invention, a specific application scenario is provided below as Example 2: The technical team received a task to design a tee connector for a ground source heat pump system in a building. The system is designed to operate at a pressure of 1.25 MPa, with an ambient temperature range of -8°C to 42°C, requiring the connector to possess high reliability and long-term stability. The technical team designed the system according to the design method of this invention.

[0074] First, step S01 is executed. Based on the system's maximum working pressure of 1.25 MPa and a safety factor of 1.8, the baseline value for the outer pipe's inner diameter is calculated to be 110 mm. Due to the large range of ambient temperature variations (temperature difference of 50℃), and considering the coefficient of thermal expansion of type III polypropylene... The technical team selected a standard fit ratio of 1.075 to ensure that thermal expansion and contraction of materials during temperature changes would not affect the reliability of the connection. Based on the axial thrust calculation formula F=P×A×K (where P is the working pressure, A is the pipe cross-sectional area, and K is the safety factor), the baseline value for axial thrust was determined to be 2180N. Considering a balance between ease of operation and locking effect, a standard locking angle of 20 degrees was chosen.

[0075] Next, step S02 is performed to configure the materials according to the thickness distribution ratio of the multi-layer structure. The total wall thickness of the outer tube is set to 20mm, as shown in Table 1:

[0076] Table 1 Thickness Distribution Table for Multi-Layer Structures

[0077]

[0078] The aramid fiber reinforcement layer uses a density of 1.44 g / L. The material, with a strength 5-6 times that of steel wire, can effectively bear the main mechanical loads. The density of the PVC corrosion-resistant layer is 1.4 g / L. It exhibits excellent acid and alkali resistance. The density of the polystyrene composite layer is 1.05 g / L. It can effectively absorb vibration energy. The type III polypropylene heat-resistant layer has a service temperature range of -30 to 140℃, meeting the operating requirements of ground source heat pump systems. The antibacterial layer releases... Ions disrupt bacterial cell walls and inhibit microbial growth.

[0079] In step S03, the lead screw uses a precision thread with a pitch of 3mm. A 30-degree rotation of the throttle corresponds to an axial displacement of 0.25mm in the sliding sleeve, achieving precise position control. The clearance between the moving rod and the fixed ring is controlled at 0.15mm, ensuring both smooth movement and guiding accuracy.

[0080] In step S04, finite element analysis was used to determine that the optimal mating angle between the wedge-shaped surface of the card block and the card slot was 20 degrees, and the contact area was 15. The contact stress under the design load is 145 MPa, which meets the material strength requirements. The sliding stroke range of the guide rod within the vertical pipe is 12 mm, which can meet the adjustment requirements for different installation errors.

[0081] Step S05 uses a three-dimensional coordinate system to calculate the axis alignment. A coordinate system is established with the connector center as the origin, and the axis vectors of the three pipes are (1,0,0), (0,1,0), and (0,0,1), respectively. Through a constraint optimization algorithm, the angular deviation of the three interfaces is controlled within 0.3 degrees to meet the system's fluid dynamics requirements.

[0082] The graded locking operation in step S06 is divided into three stages: the pre-locking stage involves rotating the handle 30 degrees, causing the locking block to contact the slot inlet with a contact pressure of 0.8 MPa; the intermediate locking stage involves rotating the handle 60 degrees further, causing the locking block to enter the middle of the slot with a contact pressure of 1.5 MPa; and the fully locking stage involves rotating the handle to a total angle of 135 degrees, causing the locking block to fully enter the bottom of the slot with a final contact pressure of 2.2 MPa.

[0083] Finally, step S07 was performed for performance verification. The tensile test results showed that when the axial tensile force reached 2400N (1.1 times the baseline value), the relative displacement was only 0.03mm, meeting the connection stiffness requirements. The guide rod sliding stroke test range was 12.5mm, the resistance of the round shaft within the groove was 35N, and the operating torque was 8.5Nm, all meeting design requirements.

[0084] Example 3: The technical team used the tee connector of this invention for actual installation at the ground source heat pump system installation site of a project. The project included 36 connection points, with pipe specifications of DN100, working pressure of 1.0MPa, and ambient temperature range of -5℃ to 35℃.

[0085] Before installation, the technical team used a coordinate measuring machine to perform accuracy testing on the prefabricated pipes, with a measurement accuracy of 0.05 mm. The test results are shown in Table 2:

[0086] Table 2 Pipe Dimension Inspection Results

[0087]

[0088] During installation, the technical team used a laser plumb line to ensure that the verticality deviation of the erected pipe was controlled within 0.08 degrees. Through temperature compensation calculations, when the ambient temperature changes from the standard temperature of 20℃ to the actual temperature of 12℃, the material shrinkage is... A tight fit ratio of 1.05 was selected to compensate for material shrinkage.

[0089] A torque wrench was used for tiered tightening operations: the first pre-tightening torque was 6.5 Nm, the second intermediate tightening torque was 13.2 Nm, and the third full tightening torque was 19.8 Nm. A miniature pressure sensor array monitored the contact pressure distribution during the tightening process, with a pressure distribution uniformity deviation of less than 8%.

[0090] After installation, performance verification tests were conducted. Tensile tests were performed using a universal testing machine. Under a load of 1200N (1.2 times the baseline value), the connector displacement was only 0.04mm, and the connection stiffness was [missing value]. N / m. The fatigue test was conducted under 75% of the reference load for 1000 cycles, and the connection strength remained at 97% of the initial strength, meeting the requirements for long-term use.

[0091] The airtightness test used a helium leak detector, holding the pressure at 1.5 times the working pressure for 30 minutes. The leakage rate was less than [percentage missing]. Pa· / s, far exceeding industry standard requirements. Pa· / s.

[0092] Antibacterial performance test results showed that the antibacterial layer achieved an inhibition rate of 99.2% against Escherichia coli and 98.7% against Staphylococcus aureus, meeting hygiene protection requirements. After 6 months of on-site monitoring, all 36 connection points operated normally without leakage or malfunction.

[0093] Traditional methods for solving the core technical problem of this invention mainly include threaded connections, flange connections, and compression fittings. Threaded connections rely on threaded mating to achieve a seal, but suffer from high precision requirements, difficulty in controlling installation torque, and a tendency to cause stress concentration, resulting in low connection reliability. Flange connections achieve a seal by tightening gaskets with bolts; while offering high connection strength, they are structurally complex, heavy, require ample installation space, and the flange seal is susceptible to failure due to temperature variations. Compression fittings achieve a connection by compressing the pipe with a compression fitting; operation is relatively simple, but the fitting material is prone to aging and loosening over time, and they require high-quality pipe surfaces.

[0094] The advancements of this invention compared to traditional methods are mainly reflected in the following aspects: Regarding connection reliability, the sealing failure rate of traditional threaded connections is approximately 2.8%, flange connections approximately 1.9%, and ferrule connections approximately 3.5%, while the wedge-shaped graded locking mechanism of this invention reduces the sealing failure rate to 0.6%, improving reliability by approximately 65%–83%. Regarding installation efficiency, the average installation time for a single connector using traditional connection methods is 25–35 minutes, while the quick-locking mechanism of this invention shortens the installation time to 18 minutes, improving efficiency by approximately 28%–49%. Regarding maintenance costs, the average annual maintenance cost of traditional connection methods is approximately 8%–12% of the initial cost, while this invention, through a multi-layered protective structure and antibacterial design, reduces the average annual maintenance cost to 6% of the initial cost, a reduction of approximately 17%–33%. Regarding service life, the average service life of traditional connectors is 15–20 years, while this invention, through optimized material configuration and stress distribution, extends the designed service life to 25 years, improving lifespan by approximately 25%–67%. In terms of environmental adaptability, traditional connection methods are prone to loosening or leakage under the influence of temperature changes and geological activities. This invention significantly improves the environmental adaptability and long-term stability of the system by combining grade selection and composite damping structure.

[0095] It should be noted that the variables involved in this invention are explained in detail in Table 3 below.

[0096] Table 3. Variable Explanation Table

[0097]

[0098] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A design and installation method for a tee connector for a ground source heat pump pipeline, characterized in that, The system comprises two parts: design methodology and installation methodology. The design methodology includes: determining the baseline value of the outer pipe's inner diameter based on the working pressure of the ground source heat pump system; classifying the fit into three levels according to the ratio of the inner diameter of the fixing ring to the outer pipe's outer diameter, ranging from 1.05 to 1.10: tight fit (1.05), standard fit (1.075), and loose fit (1.10); selecting the appropriate fit level based on the ambient temperature range; calculating the baseline value of the axial thrust based on the system's maximum working pressure and safety factor; and classifying the locking angle into three levels: a 15-degree high-efficiency locking angle, a 20-degree standard locking angle, and a 25-degree moderate locking angle. The design is completed using three angle levels. The installation method includes: setting the thickness of the reinforcing layer to 35% of the total wall thickness, the corrosion-resistant layer to 25%, the composite layer to 20%, the heat-resistant layer to 15%, and the antibacterial layer to 5% of the total wall thickness according to the multi-layer structure thickness distribution ratio. Each layer is then installed inside the outer pipe sequentially. The fixing ring is then fitted onto the top of the outer pipe according to the selected fit level, and the vertical pipe is installed vertically on top of the fixing ring. Pipeline axis alignment is calculated using a three-dimensional coordinate system, and the tee connection is adjusted using a constraint optimization algorithm. The relative position of the device and the pipe to be connected is optimized using the least squares method to remove angular deviations in the pipe axes. A graded locking operation is then performed according to the selected angle level to complete the installation. The step of classifying the angle levels involves applying the principle of static equilibrium to calculate the axial thrust reference value. Input parameters include the system's maximum working pressure, pipe cross-sectional area, and safety factor. The output parameter is the minimum locking force requirement. The wedge angle level of the locking block is determined based on the mechanical principles of the wedge mechanism. A 15-degree high-efficiency locking angle, based on the Archimedes' screw principle, provides maximum mechanical gain but requires a larger operating force. A 20-degree standard locking angle offers higher mechanical efficiency. To achieve the optimal balance between ease of operation and stability, a 25-degree gradual locking angle reduces operational resistance but correspondingly reduces the locking effect. The steps of the graded locking operation are specifically based on the progressive loading theory to implement a graded locking control strategy. First, rotating the throttle causes the lead screw to rotate 30 degrees, moving the moving ring upwards for the first pre-locking, so that the bottom edge of the locking block contacts the entrance edge of the slot. Then, rotating the throttle 60 degrees further performs the second intermediate locking. Finally, rotating the throttle until the locking block is fully inserted into the slot performs the third complete locking. Following the elastoplastic deformation theory, this ensures that the material stress is always kept within the elastic range.

2. The design and installation method of the ground source heat pump pipeline tee connector according to claim 1, characterized in that, The steps for determining the fit grade are as follows: a fit grade determination system is established based on fluid mechanics theory and elasticity principles. The maximum working pressure of the ground source heat pump system is measured, and the reference size of the outer pipe inner diameter is determined by combining a safety factor of 1.5 to 2.

0. A proportional relationship model between the inner diameter of the fixed ring and the outer diameter of the outer pipe is established using dimensional analysis. The numerical range of the three fit grades is determined by stress concentration theory in mechanics of materials. The corresponding fit grade is selected based on the influence of ambient temperature on the thermal expansion coefficient of the material.

3. The design and installation method of the ground source heat pump pipeline tee connector according to claim 2, characterized in that, The steps for the thickness distribution ratio of the multi-layer structure are as follows: a multi-functional pipe wall structure system is constructed using the layered composite material design theory; the thickness distribution scheme of each layer of material is determined based on the mixing law in composite material mechanics; the comprehensive performance index under different thickness ratios is calculated using the finite element analysis method; and the materials of each layer are fixed to the inner wall of the outer pipe in the order of inside and outside using hot melt welding technology to ensure that the interlayer bonding is firm and there are no bubbles or delamination.

4. The design and installation method of the ground source heat pump pipeline tee connector according to claim 3, characterized in that, After the multi-layer structure thickness distribution ratio step, the process also includes installing the lead screw inside the strip groove and fixing it to the bottom of the throttle, threading the sliding sleeve onto the surface of the lead screw, then vertically fixing the moving rod to one side of the sliding sleeve and extending the bottom of the moving rod through the fixed ring to the bottom of the fixed ring, constructing an axial adjustment control system using the principle of screw transmission mechanism, and determining the lead screw pitch parameters based on the kinematic relationship of screw transmission.

5. The design and installation method of the ground source heat pump pipeline tee connector according to claim 4, characterized in that, Following the axial adjustment control system step, the process also includes horizontally installing the moving ring at the bottom of the moving rod, vertically fixing the locking block at the top of the moving ring, vertically installing the guide rod at the top of the moving ring with the top of the guide rod extending through the fixing ring into the interior of the vertical tube, horizontally installing the round shaft inside the slide groove and fixing it to one side of the guide rod. Based on the principle of spatial kinematics, a three-dimensional motion coordination control system is constructed to form a synchronous motion guiding control mechanism.

6. The design and installation method of the ground source heat pump pipeline tee connector according to claim 5, characterized in that, The steps for calculating the alignment of the pipeline axis in the three-dimensional coordinate system are as follows: using analytical geometry and numerical optimization theory to achieve precise alignment control of the pipeline axis, taking the geometric center of the tee connector as the origin of the coordinate system, setting the axis vectors of the three pipeline interfaces as mutually perpendicular unit vectors, using vector analysis to describe the spatial positional relationship of the three pipeline interfaces, using constrained optimization theory to establish an objective optimization model, and using the Lagrange multiplier method to solve the constrained optimization problem.

7. The design and installation method of the ground source heat pump pipeline tee connector according to claim 6, characterized in that, The ground source heat pump pipeline tee connector includes an outer pipe. The inner side of the outer pipe is fixedly installed with a reinforcing layer, a corrosion-resistant layer, a composite layer, a heat-resistant layer, and an antibacterial layer from the outside to the inside. A fixing ring is fixedly sleeved on the top of the outer pipe. A fixing rod is fixedly installed on the top of the fixing ring. A strip groove is opened on one side of the fixing rod. A lead screw is rotatably installed inside the strip groove. A sliding sleeve is threaded onto the surface of the lead screw. A handle is rotatably installed on the top of the fixing rod. The bottom of the handle passes through the fixing rod and is fixedly connected to the top of the lead screw.

8. The design and installation method of the ground source heat pump pipeline tee connector according to claim 7, characterized in that, A movable rod is fixedly installed on one side of the sliding sleeve. The bottom of the movable rod passes through the fixed ring and extends below the fixed ring. The movable ring is fixedly installed at the bottom of the movable rod, and a locking block is fixedly installed at the top of the movable ring. A locking groove is opened at the top of the fixed ring, and the locking block is adapted to the locking groove. The outer surface of the movable rod is movably connected to the inner surface of the fixed ring. When the movable ring slides, it will drive the locking block to slide until the locking block is placed inside the locking groove. A vertical tube is fixedly installed at the top of the fixed ring. A sliding groove is opened on one side of the vertical tube. A round shaft is movably installed inside the sliding groove. A guide rod is fixedly installed at the top of the movable ring. The top of the guide rod passes through the fixed ring and extends into the interior of the vertical tube. The outer surface of the guide rod is movably connected to the inner surface of the vertical tube. One side of the guide rod is fixedly connected to one side of the round shaft. The outer surface of the round shaft and the inner surface of the sliding groove are both smooth. The outer surface of the guide rod and the inner surface of the vertical tube are both smooth.

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