Frozen soil roadbed heat pipe with radiation refrigeration coupling phase change module

Abstract

The utility model relates to a frozen soil roadbed heat pipe with a radiation refrigeration coupling phase change module, and belongs to the technical field of frozen soil roadbed heat pipes. In order to solve the problem that the existing frozen soil roadbed heat pipe does not work in summer, the utility model provides a frozen soil roadbed heat pipe with a radiation refrigeration coupling phase change module, which comprises a heat pipe and a radiation refrigeration coupling phase change module, the radiation refrigeration coupling phase change module comprises a cold storage and heat exchange device and a daytime radiation refrigeration layer laid on the upper surface of the cold storage and heat exchange device, the cold storage and heat exchange device is fixedly arranged at the top of the heat pipe, and the top of the heat pipe stretches into the cold storage and heat exchange device and makes contact with a phase change cold storage material stored in the cold storage and heat exchange device. The daytime radiation refrigeration material is used for cooling and storing cold for the phase change cold storage material and then exchanges heat with the heat pipe, so that the heat pipe can be efficiently driven to work all year round to maintain thermal stability of a frozen soil foundation, and the problem that the existing heat pipe cannot work in a warm season where refrigeration is most needed due to the fact that the environment temperature is higher than the frozen soil temperature is solved.

Description

Technical Field

[0001] This utility model belongs to the field of heat pipe technology for frozen soil roadbeds, and particularly relates to a heat pipe for frozen soil roadbeds with a radiation cooling coupling phase change module. Background Technology

[0002] Permafrost generally refers to soil containing solid water and frozen for two or more years. In my country, permafrost is mainly distributed in the Qinghai-Tibet Plateau, the Pamir Mountains and western high mountains, and the Greater and Lesser Khingan Mountains in the northeast. In recent years, with global warming and the asphalt paving of roads, the upper limit of permafrost has degraded significantly, causing roadbed defects such as uneven settlement and longitudinal cracks. Furthermore, due to the unique climate and geographical conditions, permafrost pavement defects are numerous and severe. These roadbed and pavement defects seriously affect the types and service life of highway and railway projects.

[0003] Heat pipes for permafrost subgrades are a widely used active protection measure for permafrost. They transfer heat from the permafrost layer beneath the subgrade to the atmosphere through circulation, thereby lowering the temperature of the permafrost layer and maintaining its frozen state. However, heat pipes only transfer heat in one direction. During the warmer seasons when cooling is most needed, the heat pipes cannot activate when the ground temperature is lower than the air temperature, failing to cool the subgrade. Therefore, developing highly reliable, year-round operating heat pipes for permafrost subgrades is a pressing issue that needs to be addressed in this field. Summary of the Invention

[0004] To address the problem of existing heat pipes in frozen soil subgrades not working in summer, this invention provides a heat pipe for frozen soil subgrades with a radiation cooling coupling phase change module.

[0005] The technical solution of this utility model:

[0006] A heat pipe for frozen soil roadbed with a radiation cooling coupled phase change module includes a heat pipe and a radiation cooling coupled phase change module disposed on the top of the heat pipe. The radiation cooling coupled phase change module includes a cold storage heat exchange device and a daytime radiation cooling layer laid on the upper surface of the cold storage heat exchange device. The top of the heat pipe extends into the interior of the cold storage heat exchange device and contacts the phase change cold storage material stored in the cold storage heat exchange device.

[0007] Furthermore, a heat exchange fin assembly is provided on the outer periphery of the top of the heat pipe. The heat exchange fin assembly extends into the interior of the cold storage heat exchange device and comes into contact with the phase change cold storage material stored in the cold storage heat exchange device.

[0008] Furthermore, a heat exchange fin assembly is provided on the outer periphery of the top of the heat pipe. The upper half of the heat exchange fin assembly extends into the interior of the cold storage and heat exchange device and contacts the phase change cold storage material stored in the cold storage and heat exchange device. The lower half of the heat exchange fin assembly is on the outside of the cold storage and heat exchange device and contacts the atmospheric environment.

[0009] Furthermore, the outer periphery of the sidewalls and bottom of the cold storage and heat exchange device is also provided with a heat insulation layer, which is made of phenolic foam material, expanded vitrified microspheres, rubber and plastic insulation material or glass wool.

[0010] Furthermore, the daytime radiation cooling layer is a daytime radiation cooling coating, a daytime radiation cooling film, a daytime radiation cooling paint, or a daytime radiation cooling fabric.

[0011] Furthermore, the phase change cold storage material stored in the cold storage and heat exchange device is composed of a polymer gel matrix, a phase change material, and water. The polymer gel matrix is ​​one or a combination of hydroxypropyl methylcellulose, methylcellulose, or carboxymethylcellulose. The phase change material is one or a combination of barium chloride-water system, glycine-glycerol complex, n-tetane, or water-mixed potassium sorbate.

[0012] Furthermore, the heat pipe contains, from bottom to top, a liquid cooling section, an evaporation section, a transition section, and a heat dissipation section.

[0013] Furthermore, the liquid refrigeration section is used to store liquid refrigerant and circulate heat in the heat pipe. After absorbing heat from the frozen soil, the liquid refrigerant absorbs heat, vaporizes, and rises from the evaporation section, carrying away heat. Upon reaching the transition section, it transforms from liquid refrigerant into gaseous refrigerant. The gaseous refrigerant exchanges heat with the phase change cold storage material in the cold storage and heat exchange device in the heat dissipation section, or exchanges heat with the phase change cold storage material in the heat storage tank or the atmospheric environment through the heat exchange fin assembly, and then recondenses from gaseous to liquid.

[0014] The beneficial effects of this utility model are:

[0015] Daytime radiative cooling technology utilizes strong reflection of the solar spectrum (0.3-2.5μm) and through an "atmospheric window" (8-13μm) to cool the environment in a vacuum (3K outer space) without consuming any energy. Under vacuum conditions, it can achieve temperatures 40°C lower than ambient temperatures, even reaching -20°C in high-altitude areas during summer. Phase change energy storage technology utilizes the characteristic of phase change energy storage materials to maintain a near-constant temperature by absorbing or releasing large amounts of energy during phase change, thus controlling the surrounding ambient temperature. This solves the problem of energy supply and demand mismatch in time and space and improves energy utilization efficiency. This invention couples daytime radiative cooling technology with phase change energy storage materials. The daytime radiative cooling material cools and stores the phase change energy storage material, which then exchanges heat with a heat pipe. This efficiently drives the heat pipe to operate year-round, maintaining the thermal stability of the permafrost foundation. It solves the problem that existing heat pipes cannot operate during the warmest season when cooling is most needed, due to ambient temperatures exceeding permafrost temperatures. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the structure of the heat pipe for frozen soil roadbed with radiation cooling coupling phase change module as described in Example 1;

[0017] Figure 2 This is a schematic diagram of the structure of the heat pipe for frozen soil roadbed with a radiation cooling coupling phase change module as described in Example 2;

[0018] Figure 3 This is a schematic diagram of the structure of the heat pipe for frozen soil roadbed with a radiation cooling coupling phase change module as described in Example 3;

[0019] In the diagram, 1 is a heat pipe; 101 is a heat exchange fin assembly; 2 is a radiation cooling coupled phase change module; 201 is a cold storage heat exchange device; 202 is a daytime radiation cooling layer; and 203 is an insulation layer. Detailed Implementation

[0020] The technical solution of this utility model will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of this utility model that do not depart from the spirit and scope of this utility model should be covered within the protection scope of this utility model. In the following embodiments, the process equipment or devices not specifically specified are all conventional equipment or devices in the art. Unless otherwise specified, the raw materials used in the embodiments of this utility model are all commercially available. Unless otherwise specified, the technical means used in the embodiments of this utility model are all conventional means well known to those skilled in the art.

[0021] Example 1

[0022] This embodiment provides a heat pipe for frozen soil roadbed with a radiative cooling coupled phase change module. It consists of a heat pipe 1 and a radiative cooling coupled phase change module 2 fixedly mounted on top of the heat pipe. The radiative cooling coupled phase change module 2 includes a cold storage heat exchange device 201 and a daytime radiative cooling layer 202 laid on the upper surface of the cold storage heat exchange device 201. The daytime radiative cooling layer 202 is used to generate cooling capacity. An insulation layer 203 is provided on the outer periphery of the side walls and bottom of the cold storage heat exchange device 201. The insulation layer is made of a low thermal conductivity insulation material and is used to store the cooling capacity of the low-temperature phase change cold storage material. In this embodiment, the insulation layer is made of phenolic foam material. The cold storage heat exchange device 201 is fixedly mounted on top of the heat pipe 1, with the top of the heat pipe 1 extending into the interior of the cold storage heat exchange device 201 and contacting the phase change cold storage material stored in the cold storage heat exchange device 201.

[0023] In this embodiment, the daytime radiation cooling layer is a daytime radiation cooling coating, composed of functional fillers and a matrix; the specific preparation method is as follows, and the amount of each raw material added is in parts by mass:

[0024] Step 1: Mix 30 parts of TiO2 particles with a particle size distribution of 0.2-1μm, 10 parts of SiO2 particles with a particle size distribution of 2-10μm, 10 parts of deionized water as solvent, 2 parts of sodium polycarboxylate as dispersant, 2 parts of acrylate homopolymer as leveling agent, and 1.5 parts of propylene glycol phenyl ether as film-forming aid. Stir the mixture in a mixer at 100r / min for 30min to prepare a color paste.

[0025] Step 2: Add 40 parts of water-based acrylic resin and 1 part of carboxymethyl cellulose thickener to the color paste prepared in Step 1, and stir in a mixer at 500 r / min for 30 min until uniform to obtain radiation cooling coating.

[0026] Step 3: Apply the coating obtained in Step 2 to the surface of the aluminum sheet using a flow coating method, and after drying, obtain a radiation cooling coating with a thickness of 200μm.

[0027] In this embodiment, the phase change cold storage material stored in the cold storage and heat exchange device is composed of a polymer gel matrix, a phase change material, and water. The preparation method of the phase change cold storage material is as follows, and the amount of each raw material added is in parts by mass:

[0028] Two parts of hydroxypropyl methylcellulose polymeric gel matrix, 20 parts of barium chloride-water phase change material, and 80 parts of water were stirred at 500 r / min for 30 min at room temperature and then loaded into a cold storage and heat exchange device 201 to obtain a phase change cold storage material with a thickness of 10 cm.

[0029] The daytime radiation cooling coating is placed on top of the cold storage heat exchange device 201 with an opening at the top, so that the phase change cold storage material inside the cold storage heat exchange device 201 can directly contact the aluminum plate at the bottom of the daytime radiation cooling coating, thereby achieving the cooling of the phase change cold storage material by the daytime radiation cooling coating.

[0030] The working principle and method of the heat pipe for frozen soil roadbed in this embodiment are as follows:

[0031] According to the requirements, a permafrost roadbed heat pipe system with a radiation cooling coupling phase change module is inserted into the permafrost foundation. The heat pipe 1 contains a liquid cooling section, an evaporation section, a transition section and a heat dissipation section from bottom to top. When inserting the heat pipe system into the permafrost foundation, the liquid cooling section and the evaporation section are inserted into the permafrost foundation.

[0032] The liquid cooling section of the heat pipe stores liquid refrigerant and circulates heat within the pipe. After absorbing heat from the frozen soil subgrade, the liquid refrigerant vaporizes in the evaporation section, rises, and carries away the heat. Upon reaching the transition section, it transforms from a liquid refrigerant into a gaseous refrigerant. In the heat dissipation section at the top of the heat pipe, the gaseous refrigerant exchanges heat with the phase change cold storage material in the cold storage heat exchange device, and condenses back into a liquid state.

[0033] Example 2

[0034] This embodiment provides a heat pipe for frozen soil roadbed with a radiation cooling coupled phase change module, including a heat pipe 1 and a radiation cooling coupled phase change module 2 fixedly installed on the top of the heat pipe. The radiation cooling coupled phase change module 2 includes a cold storage heat exchange device 201 and a daytime radiation cooling layer 202 laid on the upper surface of the cold storage heat exchange device 201. The daytime radiation cooling layer 202 is used to generate cold energy. The outer periphery of the side wall and bottom of the cold storage heat exchange device 201 is provided with a heat insulation layer 203. The heat insulation layer is made of a low thermal conductivity heat insulation material and is used to store the cold energy of the low temperature phase change material. In this embodiment, the heat insulation layer is made of phenolic foam material.

[0035] The cold storage heat exchange device 201 is fixedly installed on the top of the heat pipe 1. A heat exchange fin assembly 101 is also provided on the outer periphery of the top of the heat pipe 1. The heat exchange fin assembly is used to increase the heat exchange area. The heat exchange fin assembly 101 extends into the interior of the cold storage heat exchange device 201 and comes into contact with the phase change cold storage material stored in the cold storage heat exchange device 201.

[0036] In this embodiment, the daytime radiation cooling layer is a daytime radiation cooling coating, composed of functional fillers and a matrix; the specific preparation method is as follows, and the amount of each raw material added is in parts by mass:

[0037] Step 1: Mix 30 parts of TiO2 particles with a particle size distribution of 0.2-1μm, 10 parts of SiO2 particles with a particle size distribution of 2-10μm, 10 parts of deionized water as solvent, 2 parts of sodium polycarboxylate as dispersant, 2 parts of acrylate homopolymer as leveling agent, and 1.5 parts of propylene glycol phenyl ether as film-forming aid. Stir the mixture in a mixer at 100r / min for 30min to prepare a color paste.

[0038] Step 2: Add 40 parts of water-based acrylic resin and 1 part of carboxymethyl cellulose thickener to the color paste prepared in Step 1, and stir in a mixer at 500 r / min for 30 min until uniform to obtain radiation cooling coating.

[0039] Step 3: Apply the coating obtained in Step 2 to the surface of the aluminum sheet using a flow coating method, and after drying, obtain a radiation cooling coating with a thickness of 200μm.

[0040] In this embodiment, the phase change cold storage material stored in the cold storage and heat exchange device is composed of a polymer gel matrix, a phase change material, and water. The preparation method of the phase change cold storage material is as follows, and the amount of each raw material added is in parts by mass:

[0041] Two parts of hydroxypropyl methylcellulose polymeric gel matrix, 20 parts of barium chloride-water phase change material, and 80 parts of water were stirred at 500 r / min for 30 min at room temperature and then loaded into a cold storage and heat exchange device 201 to obtain a phase change cold storage material with a thickness of 10 cm.

[0042] The daytime radiation cooling coating is placed on top of the cold storage heat exchange device 201 with an opening at the top, so that the phase change cold storage material inside the cold storage heat exchange device 201 can directly contact the aluminum plate at the bottom of the daytime radiation cooling coating, thereby achieving the cooling of the phase change cold storage material by the daytime radiation cooling coating.

[0043] The working principle and method of the heat pipe for frozen soil roadbed in this embodiment are as follows:

[0044] According to the requirements, a permafrost roadbed heat pipe system with a radiation cooling coupling phase change module is inserted into the permafrost foundation. The heat pipe 1 contains a liquid cooling section, an evaporation section, a transition section and a heat dissipation section from bottom to top. When inserting the heat pipe system into the permafrost foundation, the liquid cooling section and the evaporation section are inserted into the permafrost foundation.

[0045] The liquid cooling section of the heat pipe stores liquid refrigerant and circulates heat within the pipe. After absorbing heat from the frozen soil subgrade, the liquid refrigerant vaporizes in the evaporation section, rises, and carries away the heat. Upon reaching the transition section, it transforms from a liquid to a gaseous refrigerant. In the heat dissipation section at the top of the heat pipe, the gaseous refrigerant achieves efficient heat exchange with the phase change storage material in the cold storage heat exchange device through internal heat exchange fins, and then recondenses from a gaseous state back into a liquid state.

[0046] Example 3

[0047] This embodiment provides a heat pipe for frozen soil roadbed with a radiation cooling coupled phase change module, including a heat pipe 1 and a radiation cooling coupled phase change module 2 fixedly installed on the top of the heat pipe. The radiation cooling coupled phase change module 2 includes a cold storage heat exchange device 201 and a daytime radiation cooling layer 202 laid on the upper surface of the cold storage heat exchange device 201. The daytime radiation cooling layer 202 is used to generate cold energy. The outer periphery of the side wall and bottom of the cold storage heat exchange device 201 is provided with a heat insulation layer 203. The heat insulation layer is made of a low thermal conductivity heat insulation material and is used to store the cold energy of the low temperature phase change material. In this embodiment, the heat insulation layer is made of phenolic foam material.

[0048] The cold storage heat exchange device 201 is fixedly installed on the top of the heat pipe 1. A heat exchange fin assembly 101 is also provided on the outer periphery of the top of the heat pipe 1. The heat exchange fin assembly is used to increase the heat exchange area. The upper half of the heat exchange fin assembly 101 extends into the interior of the cold storage heat exchange device 201 and contacts the phase change cold storage material stored in the cold storage heat exchange device 201. The lower half of the heat exchange fin assembly 101 is on the outside of the cold storage heat exchange device 201 and contacts the atmospheric environment.

[0049] In this embodiment, the daytime radiation cooling layer is a daytime radiation cooling coating, composed of functional fillers and a matrix; the specific preparation method is as follows, and the amount of each raw material added is in parts by mass:

[0050] Step 1: Mix 30 parts of TiO2 particles with a particle size distribution of 0.2-1μm, 10 parts of SiO2 particles with a particle size distribution of 2-10μm, 10 parts of deionized water as solvent, 2 parts of sodium polycarboxylate as dispersant, 2 parts of acrylate homopolymer as leveling agent, and 1.5 parts of propylene glycol phenyl ether as film-forming aid. Stir the mixture in a mixer at 100r / min for 30min to prepare a color paste.

[0051] Step 2: Add 40 parts of water-based acrylic resin and 1 part of carboxymethyl cellulose thickener to the color paste prepared in Step 1, and stir in a mixer at 500 r / min for 30 min until uniform to obtain radiation cooling coating.

[0052] Step 3: Apply the coating obtained in Step 2 to the surface of the aluminum sheet using a flow coating method, and after drying, obtain a radiation cooling coating with a thickness of 200μm.

[0053] In this embodiment, the phase change cold storage material stored in the cold storage and heat exchange device is composed of a polymer gel matrix, a phase change material, and water. The preparation method of the phase change cold storage material is as follows, and the amount of each raw material added is in parts by mass:

[0054] Two parts of hydroxypropyl methylcellulose polymeric gel matrix, 20 parts of barium chloride-water phase change material, and 80 parts of water were stirred at 500 r / min for 30 min at room temperature and then loaded into a cold storage and heat exchange device 201 to obtain a phase change cold storage material with a thickness of 10 cm.

[0055] The daytime radiation cooling coating is placed on top of the cold storage heat exchange device 201 with an opening at the top, so that the phase change cold storage material inside the cold storage heat exchange device 201 can directly contact the aluminum plate at the bottom of the daytime radiation cooling coating, thereby achieving the cooling of the phase change cold storage material by the daytime radiation cooling coating.

[0056] The working principle and method of the heat pipe for frozen soil roadbed in this embodiment are as follows:

[0057] According to the requirements, a permafrost roadbed heat pipe system with a radiation cooling coupling phase change module is inserted into the permafrost foundation. The heat pipe 1 contains a liquid cooling section, an evaporation section, a transition section and a heat dissipation section from bottom to top. When inserting the heat pipe system into the permafrost foundation, the liquid cooling section and the evaporation section are inserted into the permafrost foundation.

[0058] The liquid cooling section of the heat pipe stores liquid refrigerant and circulates heat within it. After absorbing heat from the frozen soil subgrade, the liquid refrigerant vaporizes in the evaporation section, rises, and carries away the heat. Upon reaching the transition section, it transforms from a liquid refrigerant into a gaseous refrigerant. In the heat dissipation section at the top of the heat pipe, the gaseous refrigerant exchanges heat with the phase change cold storage material in the cold storage heat exchange device through the internal heat exchange fin assembly 101. Simultaneously, it can also exchange heat with the external atmospheric environment through the external heat exchange fin assembly 102, further improving the efficiency of heat exchange and cooling, and accelerating the refrigerant's recondensation from a gaseous state back into a liquid state.

Claims

1. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module, characterized in that, It includes a heat pipe (1) and a radiation cooling coupled phase change module (2) disposed on the top of the heat pipe (1). The radiation cooling coupled phase change module (2) includes a cold storage heat exchange device (201) and a daytime radiation cooling layer (202) laid on the upper surface of the cold storage heat exchange device (201). The top of the heat pipe (1) extends into the interior of the cold storage heat exchange device (201) and contacts the phase change cold storage material stored in the cold storage heat exchange device (201).

2. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module according to claim 1, characterized in that, The heat pipe (1) is also provided with a heat exchange fin assembly (101) on the outer periphery of the top. The heat exchange fin assembly (101) extends into the interior of the cold storage heat exchange device (201) and comes into contact with the phase change cold storage material stored in the cold storage heat exchange device (201).

3. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module as described in claim 1, characterized in that, The heat pipe (1) is also provided with a heat exchange fin assembly (101) on the outer periphery of the top. The upper half of the heat exchange fin assembly (101) extends into the interior of the cold storage heat exchange device (201) and contacts the phase change cold storage material stored in the cold storage heat exchange device (201). The lower half of the heat exchange fin assembly (101) is outside the cold storage heat exchange device (201) and contacts the atmospheric environment.

4. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module according to any one of claims 1-3, characterized in that, The sidewalls and bottom periphery of the cold storage and heat exchange device (201) are also provided with a heat insulation layer (203), which is made of phenolic foam material, expanded vitrified microspheres, rubber and plastic heat insulation material or glass wool.

5. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module according to claim 4, characterized in that, The daytime radiation cooling layer (202) is a daytime radiation cooling coating, a daytime radiation cooling film, a daytime radiation cooling paint, or a daytime radiation cooling fabric.

6. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module according to claim 5, characterized in that, The phase change cold storage material stored in the cold storage and heat exchange device (201) is composed of a polymer gel matrix, a phase change material and water. The polymer gel matrix is ​​one or a combination of hydroxypropyl methylcellulose, methylcellulose or carboxymethylcellulose. The phase change material is one or a combination of barium chloride-water system, glycine complex glycerol, n-tetane or water-mixed potassium sorbate.

7. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module according to claim 6, characterized in that, The heat pipe (1) contains, from bottom to top, a liquid cooling section, an evaporation section, a transition section and a heat dissipation section.

8. A heat pipe for frozen soil roadbed with a radiative cooling coupling phase change module according to claim 7, characterized in that, The liquid refrigeration section is used to store liquid refrigerant and circulate heat in the heat pipe. After absorbing heat from the frozen soil, the liquid refrigerant absorbs heat and vaporizes from the evaporation section, rising and carrying away heat. When it reaches the transition section, it is converted from liquid refrigerant to gaseous refrigerant. The gaseous refrigerant exchanges heat with the phase change cold storage material in the cold storage heat exchange device (201) in the heat dissipation section, or exchanges heat with the phase change cold storage material in the cold storage heat exchange device (201) or the atmospheric environment through the heat exchange fin assembly (101), and then recondenses from gaseous to liquid.

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