Method and device for testing heat transfer performance of heat pipe steel wire bundle anchor rod

Abstract

The invention relates to a method and device for testing heat transfer performance of a heat pipe steel wire bundle anchor rod, and the device is characterized in that the heat pipe steel wire bundle anchor rod is vertically arranged and sequentially comprises a heat dissipation condensation section, a heat insulation section and an evaporation heat absorption section from top to bottom; a cooling water jacket of the cooling system is sleeved outside a heat dissipation condensation section of the heat pipe steel wire bundle anchor rod, and the cooling water jacket is connected with a low-temperature water circulator through a water conveying pipeline to form cooling water circulation. A heating water jacket of the heating system is sleeved outside an evaporation heat absorption section of the heat pipe steel wire bundle anchor rod, and the heating water jacket is connected with a high-temperature water circulator through a water conveying pipeline to form heating water circulation; the thermocouples are evenly arranged on the outer wall of the heat pipe in the heat pipe steel wire bundle anchor rod from top to bottom. According to the testing method, the heat exchange performance of the heat pipe steel wire bundle anchor rod when the heat pipe steel wire bundle anchor rod is used for underground structure heat exchange can be accurately and truly known, and a reliable theoretical basis is provided for structural size design of the heat pipe steel wire bundle anchor rod.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology for anchoring underground structures, specifically to a method and apparatus for testing the heat transfer performance of heat pipe steel wire bundle anchor rods. Background Technology

[0002] Urban underground space is developing rapidly, exhibiting trends of diversified functions, large scale, and increasing depth. Achieving "low-carbon" and "green" development is key to underground space development. Underground space is surrounded by soil and rock layers, which differs significantly from the above-ground building space environment. The enclosing structure of underground space is soil. Due to the soil's own heat storage capacity and the lag and attenuation of ground temperature waves, soil temperature exhibits the characteristics of "warm in winter and cool in summer," which can absorb some of the heat dissipation from the underground space.

[0003] Due to the poor heat transfer performance between air and surrounding rock under natural conditions, improving the heat transfer performance between the two can reduce the load and energy consumption for regulating the thermal and humidity environment of underground spaces. Heat pipe wire bundle anchors are multifunctional anchors that integrate wire bundles and heat pipes within the anchor rod body. They can anchor the underground structure of a building and, under passive conditions, transfer heat from the internal environment of the underground space to the underground retaining structure through the heat pipes. This saves the cost of constructing additional underground heat exchange devices, consumes no extra energy, does not affect the structural load-bearing performance, and avoids occupying additional underground space, thus saving underground space resources.

[0004] However, in practical applications, the heat transfer performance of heat pipe wire bundle anchors is unknown. The heat transfer performance varies greatly depending on different structural parameters, air environment, and surrounding rock temperature. Currently, there is no relevant testing method to test the heat transfer performance of heat pipe wire bundle anchors, which seriously restricts their engineering application. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for testing the heat transfer performance of heat pipe wire bundle anchor bolts, so as to solve the problem that there is currently a lack of relevant testing methods to test the heat transfer performance of heat pipe wire bundle anchor bolts.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A device for testing the heat transfer performance of heat pipe wire bundle anchor bolts is provided. The device includes heat pipe wire bundle anchor bolts, a heating system, a cooling system, and thermocouples.

[0008] The heat pipe steel wire bundle anchor rod is arranged vertically, and from top to bottom it consists of a heat dissipation and condensation section, an insulation section and an evaporation and heat absorption section. It has a heat pipe inside and a steel wire bundle is set outside the heat pipe.

[0009] The cooling system includes a low-temperature water circulator, a water supply pipeline, and a cooling water jacket. The cooling water jacket is fitted over the heat dissipation and condensation section of the heat pipe wire bundle anchor rod. The cooling water jacket is connected to the low-temperature water circulator through the water supply pipeline to form a cooling water circulation.

[0010] The heating system includes a high-temperature water circulator, a water supply pipeline, and a heating water jacket. The heating water jacket is fitted over the evaporation and heat absorption section of the heat pipe wire bundle anchor rod. The heating water jacket is connected to the high-temperature water circulator through the water supply pipeline to form a heating water circulation.

[0011] The thermocouples are evenly arranged from top to bottom on the outer wall of the heat pipe inside the heat pipe wire bundle anchor rod, and are used to measure the temperature at different locations of the heat pipe.

[0012] Furthermore, the device also includes a flow meter installed on the water supply pipelines of the cooling water circulation and the heating water circulation to monitor the circulation water flow rate and thereby calculate the heat released by the cooling water circulation and the heat absorbed by the heating water circulation.

[0013] Furthermore, the device also includes a pressure sensor disposed at the top of the heat pipe for monitoring the vapor pressure of the heat pipe.

[0014] Furthermore, the data collected by the thermocouple, the flow meter, and the pressure sensor are all transmitted to the data acquisition instrument.

[0015] Furthermore, the device also includes a rotating platform, the bottom of which is supported on the top of the rotating platform. The bottom of the rotating platform has a rotating support that rotates in a vertical plane, thereby allowing the heat pipe wire bundle anchor rod to tilt left and right.

[0016] Furthermore, the heat pipe wire bundle anchor rod, the cooling water jacket, and the heating water jacket are covered with an insulation jacket, and the insulation jacket is wrapped with aluminum foil.

[0017] On the other hand, a test method is provided for the heat transfer performance testing device for heat pipe wire bundle anchor bolts as described above, the method comprising:

[0018] Build the device;

[0019] Start the low-temperature water circulator, adjust the cooling water flow rate and set the cooling water temperature;

[0020] Start the high-temperature water circulator, adjust the heating water flow rate and set the heating water temperature;

[0021] After the temperatures of the cooling water and heating water stabilize, record the flow data collected by the flow meter.

[0022] Record and observe the temperature data collected by the thermocouple, and wait for the heat pipe to reach a steady-state operating condition;

[0023] After the heat pipe has been running in steady state for a specified time, the data collection is stopped, and the average heat transfer coefficient of the evaporation and heat absorption section, the average heat transfer coefficient of the heat dissipation and condensation section, and the overall thermal resistance of the heat pipe are calculated.

[0024] Furthermore, the calculation process for the average heat transfer coefficient of the evaporation heat absorption section is as follows:

[0025]

[0026] in:

[0027] The average heat transfer coefficient of the evaporation heat absorption section;

[0028] Q e The heat absorbed by the evaporation heat absorption section;

[0029] D is the diameter of the heat pipe;

[0030] L e This refers to the length of the evaporation and heat absorption section;

[0031] This represents the average temperature of the evaporative heat absorption section.

[0032] T v This is the saturated vapor temperature inside the heat pipe;

[0033] This represents the average temperature of the heat dissipation and condensation section.

[0034] The flow rate of the heated water;

[0035] c p This is the specific heat capacity of water;

[0036] T out,e This refers to the cooling water outlet temperature.

[0037] T in,e This refers to the inlet temperature of the cooling water.

[0038] Furthermore, the calculation process for the average heat transfer coefficient of the heat dissipation and condensation section is as follows:

[0039]

[0040]

[0041] in:

[0042] The average heat transfer coefficient of the heat dissipation and condensation section;

[0043] Q cThe heat dissipation and condensation section releases heat;

[0044] L c This refers to the length of the heat dissipation and condensation section;

[0045] This represents the average temperature of the adiabatic section.

[0046] This refers to the flow rate of the cooling water.

[0047] T out,c This refers to the cooling water outlet temperature.

[0048] T in,c This refers to the inlet temperature of the cooling water.

[0049] Furthermore, the calculation process for the overall thermal resistance of the heat pipe is as follows:

[0050]

[0051] in:

[0052] R is the overall thermal resistance of the heat pipe.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] This invention provides a method and apparatus for testing the heat transfer performance of heat pipe wire bundle anchors, which can accurately and realistically understand the heat transfer performance of heat pipe wire bundle anchors when used for heat exchange in underground structures, provide a reliable theoretical basis for the structural dimension design of heat pipe wire bundle anchors, and provide direct technical guidance for practical design and engineering applications. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0056] Figure 1 This is a diagram showing the composition of the heat transfer performance testing device for heat pipe steel wire bundle anchor bolts provided in an embodiment of the present invention.

[0057] Figure 2 This is a structural diagram of a heat pipe wire bundle anchor provided in an embodiment of the present invention.

[0058] Figure 3 This is a schematic diagram of the construction of heat pipe wire bundle anchor bolts provided in an embodiment of the present invention.

[0059] Figure 4 This is a schematic diagram of the heat pipe structure provided in an embodiment of the present invention.

[0060] Figure 5 This is a temperature change curve of the measuring point provided in an embodiment of the present invention.

[0061] The diagram is labeled as follows:

[0062] 1-Computer, 2-Data acquisition instrument, 3-Low temperature water circulator, 4-High temperature water circulator, 5-Flow meter, 6-Pressure sensor, 7-Aluminum foil, 8-Insulation jacket, 9-Cooling water jacket, 10-Thermocouple, 11-Heat pipe steel wire bundle anchor, 12-Heating water jacket, 13-Rotating table;

[0063] 1101-Wire bundle, 1102-Isolation ring, 1103-Clamping ring, 1104-Heat pipe, 1105-Anchor block, 1106-Nut, 1107-Anchor rod body, 1108-Underground space, 1109-Rib plate, 1110-Anchor joint end;

[0064] A-Evaporation and heat absorption section, B-Heat dissipation and condensation section, C-Outer shell, D-Liquid suction core, E-Vacuum chamber, F-Insulation section. Detailed Implementation

[0065] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0066] In the description of this invention, it should be understood that the terms "upper", "lower", "in", "out", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0067] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0068] It should also be noted that although the order of steps is mentioned in the method description, in some cases, steps may be performed in a different order than that described here, and this should not be interpreted as a restriction on the order of steps.

[0069] The heat pipe wire bundle anchor bolt 11 is a new type of anchor bolt that not only anchors underground structures but also transfers underground heat through the excellent thermal conductivity of the heat pipe, thus playing a role in heat conduction. Figure 2-4 The heat pipe wire bundle anchor 11 includes an anchor rod body 1107, a wire bundle 1101, a heat pipe 1104, and an anchor block 1105.

[0070] Specifically, the heat pipe 1104 is axially positioned within the anchor rod body 1107, located on the central axis of the anchor rod body 1107, and extends continuously along the length of the anchor rod body. The outer shell C of the heat pipe 1104 is made of metal, and its interior contains a liquid wick D and a vacuum chamber E, divided into an evaporation and heat absorption section A, an insulation section F, and a heat dissipation and condensation section B. The steel wire bundle 1101 is composed of multiple strands of steel wire twisted together, axially positioned within the anchor rod body 1107, and consists of multiple strands evenly distributed around the outer periphery of the heat pipe 1104. The ends of the steel wire bundle 1101 protrude from the ends of the anchor rod body 1107 and are anchored by anchor blocks 1105.

[0071] In addition, multiple isolation rings 1102 are provided inside the anchor rod body 1107. Each isolation ring 1102 is a metal circular plate, perpendicular to the axial direction and evenly arranged along the axial direction, with a central hole and an outer peripheral hole. A heat pipe 1104 is inserted into the central hole of the isolation ring 1102, and a steel wire bundle 1101 is inserted into the outer peripheral hole of the isolation ring 1102. The diameter of the isolation ring 1102 is equal to the inner diameter of the anchor rod body 1107. The outer periphery of the isolation ring 1102 is close to the inner wall of the anchor rod body 1107, and is confined within the anchor rod body 1107 by friction, or it can be directly fixed to the inner wall of the anchor rod body 1107. Multiple clamping rings 1103 are also provided inside the anchor rod body 1107. Each clamping ring 1103 is a metal circular plate, perpendicular to the axial direction and evenly arranged along the axial direction, with a central hole and an outer peripheral hole. The central hole of the clamping ring 1103 corresponds axially to the central hole of the isolation ring 1102. A heat pipe 1104 is inserted into the center hole of a clamping ring 1103, and a wire bundle 1101 is inserted into the outer peripheral hole of the clamping ring 1103. The diameter of the clamping ring 1103 is smaller than the inner diameter of the anchor rod body 1107. Isolation rings 1102 and clamping rings 1103 are arranged alternately. The wire bundle 1101 passes through the outer peripheral hole of the isolation ring 1102, and its two ends pass through the outer peripheral holes of the two clamping rings 1103 respectively and are tied together.

[0072] The anchor bolt body 1107 has an anchoring joint 1110 at its end, which is formed by twisting together multiple strands of steel wire 1101 and threading them. The anchoring joint 1110 passes through an anchor block 1105 with an opening, and a nut 1106 is screwed into the anchoring joint 1110 and tightened to achieve the anchoring effect. In addition, the various isolation rings 1102 and clamping rings 1103 are connected as a whole by cross-arranged ribs 1109.

[0073] During use, the anchoring section end 10 is welded and threaded to facilitate the installation of the nut 6. Then, before tightening the nut 6, a tensile test is performed on the anchor rod to observe whether the wire bundle is loose, ensuring the stability of the anchor rod. After that, the nut 6 is tightened to the maximum extent, and the anchoring stability of the entire anchoring device is tested. Finally, the exposed part of the anchoring section end 10 is covered with cement grout or a protective cover is applied to protect the anchoring end.

[0074] Specifically, bottom-hole grouting is used to ensure the grout in the rock strata is full. The anchor grouting pump is adjusted to ensure it is securely connected and operating normally, meeting the required grouting pressure. The grouting pipe of the anchor grouting pump is inserted into the pre-set bottom of the hole, and the pump is turned on. Note that the grouting pipe needs to be slowly pulled out while grouting. The tail of the anchor rod is inserted into the grouted hole with the bottom facing out. The head of the anchor rod is fixed to one side of the underground structure using anchor block 1105 and nut 1106 for stability. After the grout has solidified, the grouting pipe is pulled out.

[0075] After the underground space 1108 is completed and put into use, the structure of this invention can play a heat exchange role: When the indoor temperature is high, the liquid at the bottom of the heat pipe in the anchor rod at the top of the underground space building is heated, causing it to evaporate. The steam reaches the condensation section at the top of the heat pipe, where a condensation and heat dissipation process occurs, transferring heat to the rock layer. The condensed liquid, under gravity, automatically flows back to the evaporation section at the bottom of the heat pipe, where it is heated and evaporates again, continuously circulating to transfer heat from the underground space to the surrounding rock, achieving the purpose of heat dissipation for the underground space building. When the indoor temperature is low, due to the high temperature of the underground rock layer, the cooling liquid at the bottom of the heat pipe in the anchor rod on both sides of the underground space is heated and evaporates, carrying heat into the underground space building. When the steam reaches the top, it is condensed back into cooling liquid and flows back to the bottom along the heat pipe wall, continuously circulating to carry heat from the rock layer into the underground space building, thus achieving the effect of heating the underground space building.

[0076] This invention provides a device for testing the heat transfer performance of the aforementioned heat pipe wire bundle anchor 11. This device can accurately, effectively, and quickly obtain the heat transfer performance data of the heat pipe wire bundle anchor 11, thereby providing a basis for the structural dimension design of the heat pipe wire bundle anchor 11. Figure 1 Specifically, the device includes a heat pipe wire bundle anchor 11, a heating system, a cooling system, and a thermocouple 10. The heat pipe wire bundle anchor 11 is arranged vertically, and from top to bottom, it consists of a heat dissipation and condensation section B, an insulation section F, and an evaporation and heat absorption section A.

[0077] The cooling system includes a cryogenic water circulator 3, water supply pipelines, and a cooling water jacket 9. The cooling water jacket 9 is fitted over the heat dissipation and condensation section 8 of the heat pipe wire bundle anchor rod 11. The cooling water jacket 9 is connected to the cryogenic water circulator 3 through the water supply pipelines to form a cooling water circulation system. To improve heat exchange efficiency and the uniformity of vertical temperature distribution in the water jacket, the cooling water jacket 9 is supplied with water from the top and returned from the bottom, and the water supply pipelines need to be insulated.

[0078] The heating system includes a high-temperature water circulator 4, a water supply pipeline, and a heating water jacket 12. The heating water jacket 12 is fitted over the evaporation and heat absorption section A of the heat pipe wire bundle anchor rod 11. The heating water jacket 12 is connected to the high-temperature water circulator 4 through the water supply pipeline to form a heating water circulation system. To improve heat exchange efficiency and the uniformity of vertical temperature distribution in the water jacket, the heating water jacket 12 is supplied from the bottom and returned from the top, and the water supply pipeline needs to be insulated.

[0079] Both the cooling water jacket 9 and the heating water jacket 12 are cylindrical water jackets, which are fitted over the corresponding parts of the heat pipe wire bundle anchor rod 11, affecting their temperature. The low-temperature water circulator 3 and the high-temperature water circulator 4 can ensure that the water inlet temperature of the water jacket is constant. By controlling the outlet water temperature of the high and low temperature water circulators, the temperature of the heating water jacket 12 and the cooling water jacket 9 can be controlled, so as to achieve the purpose of adjusting the temperature of the evaporation heat absorption section and the heat dissipation condensation section as needed.

[0080] Thermocouples 10 are evenly arranged from top to bottom on the outer wall of heat pipe 1104 within the heat pipe wire bundle anchor rod 11, used to measure the temperature at different locations on heat pipe 1104. Thermocouples 10 are type K, with a temperature range of -40 to 300℃, a measurement accuracy of Class A, and a maximum permissible error of ±0.5℃. Non-standard customized threaded Pt100 resistance thermometers are used to measure the inlet and outlet water temperatures of the heating water jacket 12 and cooling water jacket 9. Their probes are placed in the water flow in the inlet and outlet pipes to measure the inlet and outlet water temperatures. The resistance thermometer has a temperature range of -50 to 300℃, and a measurement error of ±(0.15±0.002|t|).

[0081] The device also includes a flow meter 5, which is installed on the water supply pipelines for the cooling water circulation and heating water circulation. The flow meter 5 is used to monitor the circulating water flow rate and thus calculate the heat released by the cooling water circulation and the heat absorbed by the heating water circulation. The flow meter 5 can be a rotor flow meter with a measurement range of 50–150 L / h.

[0082] The device also includes a pressure sensor 6, which is located at the top of the heat pipe 1104 and is used to monitor the vapor pressure of the heat pipe 1104 to prevent leakage. The pressure sensor has a measurement range of 0 to 0.1 MPa and a measurement accuracy of 0.5.

[0083] Data collected by thermocouple 10, flow meter 5, and pressure sensor 6 are transmitted to data acquisition unit 2, and then sent to computer 1 for data storage and calculation. The acquisition frequency of the data acquisition unit 2 (such as Agilent 34980A) can be set to 1 second / time. In addition, before the experiment officially begins, all thermocouples and RTDs used in the experiment need to be calibrated using the temperature of the constant temperature water bath as a reference standard.

[0084] In addition, the device also includes a rotating platform 13, the bottom of the heat pipe wire bundle anchor rod 11 is supported on the top of the rotating platform 13, the bottom of the rotating platform 13 has a rotating support, the rotating support rotates in the vertical plane, so that the heat pipe wire bundle anchor rod 11 can tilt left and right, and the heat pipe heat transfer performance test can be realized at different tilt angles.

[0085] To reduce heat loss from the external environment and improve testing accuracy, each section of the heat pipe 1104 needs to be wrapped with insulation material. The heat pipe wire bundle anchor rod 11, cooling water jacket 9, and heating water jacket 12 are covered with insulation sleeves 8, and the insulation sleeves 8 are wrapped with aluminum foil 7. Among them, the evaporation heat absorption section needs to use high-temperature resistant insulation material, preferably silica aerogel pads; the cooling water jacket of the heat dissipation and condensation section and the insulation section are preferably insulated with rubber tubes; the outermost layer of the entire heat pipe is wrapped with aluminum foil to reduce heat loss caused by radiative heat transfer.

[0086] The test method of the above-mentioned heat pipe wire bundle anchor rod heat transfer performance test device mainly tests the heat transfer performance parameters of the heat pipe wire bundle anchor rod, including the average heat transfer coefficient of the evaporation section, the average heat transfer coefficient of the condensation section, and the overall thermal resistance of the heat pipe. Specifically, it includes the following steps:

[0087] Step 1: Set up the device, turn on the main power, turn on the computer and data acquisition instrument, and create a new folder on the computer to save the temperature and pressure data;

[0088] Step 2: Start the low-temperature water circulator 3, adjust the cooling water flow rate and set the cooling water temperature;

[0089] Step 3: Start the high-temperature water circulator 4, adjust the heating water flow rate and set the heating water temperature;

[0090] Step 4: After the cooling water and heating water temperatures stabilize, record the flow data collected by flow meter 5; stabilization means that the temperature of the outer wall of the heat pipe and the top vapor pressure remain stable, with temperature fluctuations within 0.5℃;

[0091] Step 5: Record and observe the temperature data collected by thermocouple 10, and wait for heat pipe 1104 to reach steady-state operation.

[0092] Step 6: After the heat pipe 1104 has been running in a steady state for half an hour, stop recording and collecting data, and then shut down the high-temperature water circulator and the low-temperature water circulator in turn.

[0093] Multiple cyclic tests were conducted to complete experiments under different heating power conditions. Based on the experimental data, the average heat transfer coefficient of the evaporation and heat absorption section, the average heat transfer coefficient of the heat dissipation and condensation section, and the overall thermal resistance of the heat pipe were calculated.

[0094] The average heat transfer coefficient of the evaporation section of a heat pipe refers to the convective heat transfer coefficient between the working fluid inside the heat pipe and the outer wall of the evaporation section. Considering that the shell material is generally a metal with high thermal conductivity and the pipe wall thickness is very thin, typically only 1 mm, the thermal resistance of the pipe wall is ignored. The calculation process for the average heat transfer coefficient of the evaporation absorption section is as follows:

[0095]

[0096] The heat absorption of the evaporation section is the heat exchange between the heat pipe and the circulating water in the external heating water jacket during the operation phase, which can be calculated by the flow rate of hot water and the temperature difference between the inlet and outlet of cooling water.

[0097]

[0098] in:

[0099] The average heat transfer coefficient of the evaporation heat absorption section;

[0100] Q e The heat absorbed by the evaporation heat absorption section;

[0101] D is the diameter of the heat pipe;

[0102] L e This refers to the length of the evaporation and heat absorption section;

[0103] This represents the average temperature of the evaporative heat absorption section.

[0104] T v This is the saturated vapor temperature inside the heat pipe;

[0105] This represents the average temperature of the heat dissipation and condensation section.

[0106] The flow rate of the heated water;

[0107] c p This is the specific heat capacity of water;

[0108] T out,e This refers to the cooling water outlet temperature.

[0109] T in,e This refers to the inlet temperature of the cooling water.

[0110] The average heat transfer coefficient of the condenser section of a heat pipe refers to the convective heat transfer coefficient between the working fluid inside the heat pipe and the outer wall of the condenser section. Its calculation method is similar to that of the average heat transfer coefficient of the evaporator section. The calculation process for the average heat transfer coefficient of the heat dissipation condenser section is as follows:

[0111]

[0112] The heat released in the condensation section is the heat exchange between the heat pipe and the circulating water in the cooling water jacket outside the pipe during operation, which can be calculated by the flow rate of the cooling water and the temperature difference between the inlet and outlet of the cooling water.

[0113]

[0114] in:

[0115] The average heat transfer coefficient of the heat dissipation and condensation section;

[0116] Q c The heat dissipation and condensation section releases heat;

[0117] L c This refers to the length of the heat dissipation and condensation section;

[0118] This represents the average temperature of the adiabatic section.

[0119] This refers to the flow rate of the cooling water.

[0120] T out,c This refers to the cooling water outlet temperature.

[0121] T in,c This refers to the inlet temperature of the cooling water.

[0122] The overall thermal resistance of a heat pipe is the ratio of the average temperature difference between the evaporation section and the average temperature of the condensation section to the amount of heat absorbed by the evaporation section. The calculation process for the overall thermal resistance of a heat pipe is as follows:

[0123]

[0124] in:

[0125] R is the overall thermal resistance of the heat pipe.

[0126] The average temperature of the evaporation section is the arithmetic mean of all temperature measurement points in the evaporation section. The average temperature of the adiabatic section is the arithmetic mean of all temperature measurement points in the adiabatic section. The average temperature of the condensation section is the arithmetic mean of all temperature measurement points in the condensation section. Considering that the shell material is a metal with a high thermal conductivity, and that good insulation measures were taken for the adiabatic section during the experiment, and through extensive experimental verification, the saturated vapor temperature T of the working fluid inside the heat pipe can be considered as... v Approximately equivalent to the average temperature of the adiabatic section

[0127] Example:

[0128] A heat pipe with a diameter of 10 mm, a working fluid of methanol, and a liquid filling rate of 35% was selected. Temperature sensors were installed in the evaporation section, the adiabatic section, and the condensation section, with numbers of 4, 2, and 4 respectively, denoted as T1-T. 10 .

[0129] The experiment was conducted according to the above testing method, with the hot water temperature set at 85℃ and the cooling water temperature at 25℃. The circulation flow rates of both hot water and cooling water were 100L / h. The temperature changes at the measuring points were as follows: Figure 5 After 200 seconds, the heat pipe reaches a stable operating state.

[0130] After testing, the average heat transfer coefficient of the evaporation section, the average heat transfer coefficient of the condensation section, and the overall thermal resistance of the heat pipe were calculated to be 1812.24 W / m. 2 K, 2454.33 W / m 2 ·K, 0.153K / W.

[0131] Based on the above test results, the structural parameters of the anchor bolt can be designed according to the specific application scenario of the heat pipe wire bundle anchor bolt. The main parameters include the length L of the condensation section. c Length of evaporation section L e Obtain the air temperature T at which the heat pipe wire bundle anchor bolt contacts. air With the surrounding rock temperature T s Since the heat pipe is in long-term contact with the surrounding rock, it can be assumed that there is no direct thermal resistance between it and the surrounding rock, and the heat transfer capacity of the heat pipe can be calculated:

[0132]

[0133] Among them, h air The air-side convective heat transfer coefficient can be selected from appropriate engineering empirical formulas, such as the Dittus-Boelter formula, depending on whether it is natural convection or forced convection.

[0134] The length L of the condensation section can then be obtained by solving the following equation. c Length of evaporation section L e Length ratio relationship:

[0135]

[0136] Based on the obtained proportional relationship, the design of the evaporation section length and the condensation section length can be completed.

[0137] The testing method and apparatus provided by this invention can solve the problems of unknown heat exchange performance and lack of theoretical basis for structural size design when heat pipe wire bundle anchors are used in underground structures. The results are reliable and effective, and can provide guidance for practical design and engineering applications.

[0138] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A heat transfer performance testing device for heat pipe steel wire bundle anchor bolts, characterized in that: The device includes a heat pipe wire bundle anchor (11), a heating system, a cooling system, and a thermocouple (10); The heat pipe wire bundle anchor (11) is arranged vertically, and from top to bottom it consists of a heat dissipation and condensation section (B), an insulation section (F) and an evaporation and heat absorption section (A). It has a heat pipe (1104) inside and a wire bundle (1101) is provided outside the heat pipe (1104). The cooling system includes a low-temperature water circulator (3), a water supply pipeline and a cooling water jacket (9). The cooling water jacket (9) is sleeved outside the heat dissipation and condensation section (8) of the heat pipe wire bundle anchor rod (11). The cooling water jacket (9) is connected to the low-temperature water circulator (3) through the water supply pipeline to form a cooling water circulation. The heating system includes a high-temperature water circulator (4), a water supply pipeline, and a heating water jacket (12). The heating water jacket (12) is fitted over the evaporation and heat absorption section (A) of the heat pipe wire bundle anchor rod (11). The heating water jacket (12) is connected to the high-temperature water circulator (4) through the water supply pipeline to form a heating water circulation. The thermocouples (10) are evenly arranged from top to bottom on the outer wall of the heat pipe (1104) inside the heat pipe wire bundle anchor rod (11) to measure the temperature at different positions of the heat pipe (1104).

2. The heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 1, characterized in that: The device also includes a flow meter (5), which is installed on the water supply pipeline of the cooling water circulation and the heating water circulation to monitor the circulation water flow rate and then calculate the heat release of the cooling water circulation and the heat absorption of the heating water circulation.

3. The heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 2, characterized in that: The device also includes a pressure sensor (6) disposed on the top of the heat pipe (1104) for monitoring the vapor pressure of the heat pipe (1104).

4. The heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 3, characterized in that: The data collected by the thermocouple (10), the flow meter (5) and the pressure sensor (6) are all transmitted to the data acquisition instrument (2).

5. The heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 4, characterized in that: The device also includes a rotating platform (13), the bottom of the heat pipe wire bundle anchor rod (11) is supported on the top of the rotating platform (13), the bottom of the rotating platform (13) has a rotating support, the rotating support rotates in the vertical plane, thereby allowing the heat pipe wire bundle anchor rod (11) to tilt left and right.

6. The heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 5, characterized in that: The heat pipe wire bundle anchor rod (11), the cooling water jacket (9) and the heating water jacket (12) are covered with a heat insulation jacket (8), and the heat insulation jacket (8) is wrapped with aluminum foil (7).

7. The test method of the heat transfer performance testing device for heat pipe wire bundle anchor bolts as described in claim 6, characterized in that: The method includes: Build the device; Start the low-temperature water circulator (3), adjust the cooling water flow rate and set the cooling water temperature; Start the high-temperature water circulator (4), adjust the heating water flow rate and set the heating water temperature; After the cooling water and heating water temperatures stabilize, record the flow data collected by the flow meter (5); Record and observe the temperature data collected by the thermocouple (10), and wait for the heat pipe (1104) to reach a steady-state operating state; After the heat pipe (1104) has been running in steady state for a specified time, the data collection is stopped, and the average heat transfer coefficient of the evaporation and heat absorption section, the average heat transfer coefficient of the heat dissipation and condensation section, and the overall thermal resistance of the heat pipe are calculated.

8. The test method of the heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 7, characterized in that: The calculation process for the average heat transfer coefficient of the evaporation heat absorption section is as follows: in: The average heat transfer coefficient of the evaporation heat absorption section; Q e The heat absorbed by the evaporation heat absorption section; D is the diameter of the heat pipe; L e This refers to the length of the evaporation and heat absorption section; This represents the average temperature of the evaporative heat absorption section. T v This is the saturated vapor temperature inside the heat pipe; This represents the average temperature of the heat dissipation and condensation section. The flow rate of the heated water; c p This is the specific heat capacity of water; T out,e This refers to the cooling water outlet temperature. T in,e This refers to the inlet temperature of the cooling water.

9. The test method of the heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 8, characterized in that: The calculation process for the average heat transfer coefficient of the heat dissipation and condensation section is as follows: in: The average heat transfer coefficient of the heat dissipation and condensation section; Q c The heat dissipation and condensation section releases heat; L c This refers to the length of the heat dissipation and condensation section; This represents the average temperature of the adiabatic section. This refers to the flow rate of the cooling water. T out,c This refers to the cooling water outlet temperature. T in,c This refers to the inlet temperature of the cooling water.

10. The test method of the heat transfer performance testing device for heat pipe wire bundle anchor bolts according to claim 9, characterized in that: The calculation process for the overall thermal resistance of a heat pipe is as follows: in: R is the overall thermal resistance of the heat pipe.

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