Heat pipe structure based on solar thermochemical adsorption refrigeration and frozen soil protection method

Abstract

The invention provides a heat pipe structure based on solar thermochemical adsorption refrigeration and a frozen soil protection method, the heat pipe structure comprises a heat pipe, the heat pipe is of an internally sealed U-shaped hollow structure, and a refrigeration working medium is arranged in the heat pipe; the heat pipe comprises a high-temperature adsorption bed, a condensation section, an evaporation section and a low-temperature adsorption bed which are communicated in sequence; the high-temperature adsorption bed is filled with a high-temperature adsorbent and is used for desorbing the refrigerant under the heating action of solar energy to obtain a high-temperature refrigerant; the condensation section is vertically arranged and is used for condensing the high-temperature refrigeration working medium to obtain a condensed refrigeration working medium and enabling the condensed refrigeration working medium to enter the evaporation section under the action of gravity; the evaporation section is transversely arranged and is used for evaporating the condensed refrigerant under the heating action of the frozen soil temperature and the adsorption action of the low-temperature adsorbent to obtain the evaporated refrigerant; and the low-temperature adsorption bed is filled with a low-temperature adsorbent for adsorbing the evaporated refrigerant. According to the scheme, the cooling effect of the heat pipe on frozen soil and the heat stability of the heat pipe are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of frozen soil engineering, and in particular to a heat pipe structure based on solar thermal chemical adsorption refrigeration and a frozen soil protection method. Background Art

[0002] In the western mountainous areas, which are located in high-altitude cold areas, the temperature field of the roadbed changes due to seasonal changes and temperature changes, causing soil erosion and water phase changes inside the soil body, resulting in the formation of frozen soil freeze-thaw cycles in winter and summer, with frost heave and melting sinking, which changes the material parameters of the roadbed soil layer and protective structure layer, directly affecting the safety of road use, reducing the service life of the road, and increasing driving safety hazards. Therefore, the stability of the frozen soil roadbed is one of the biggest problems facing the construction of the Qinghai-Tibet Railway.

[0003] In response to the frozen soil problem, scientists from the Chinese Academy of Sciences proposed an engineering design idea of ​​"actively cooling the roadbed and actively protecting the frozen soil". At present, there are two basic methods: increasing the thermal resistance of the roadbed and actively cooling the soil. The methods of increasing the thermal resistance of the roadbed include adding insulation boards and filling the roadbed. However, in the context of global warming, especially in high-temperature and high-ice content areas, the engineering measures of simply increasing the thermal resistance of the roadbed to protect the frozen soil will be difficult to ensure the long-term stability of the roadbed in permafrost areas; while the active cooling methods include installing heat pipes, laying stone layers and laying ventilation pipes to isolate heat, and using the cold climate conditions of the plateau to continuously input "cold" into the ground to keep the frozen soil frozen. The heat pipe is a one-way heat transfer element. It uses the excellent heat transfer efficiency of the two-phase closed thermosyphon to actively control the temperature of the frozen soil roadbed, effectively raising the upper limit of the frozen soil. It has been widely used in the construction of permafrost areas such as the Qinghai-Tibet Highway, the Qinghai-Tibet Railway, power transmission projects and oil pipelines, and has played a positive role in maintaining the stability of the foundation.

[0004] Although heat pipes have a good cooling effect in permafrost areas and play a positive role in maintaining the thermal stability of frozen roadbeds, they do not work in warm seasons. They only work in cold seasons when the outside temperature is lower than the roadbed temperature and reaches the starting temperature difference of the heat pipes. The effective working time throughout the year is limited. In addition, as the construction of highways in permafrost areas gradually advances, due to the limitation of the effective radius of heat pipes, it is difficult to meet the control requirements in the middle of the road far away from the heat pipes when heat pipes are used alone on large-scale and wide roadbeds. In addition, the thermal stability of heat pipes is poor. After working for a long time, the ground temperature drop will decrease, and the working power and refrigeration performance will decay. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a heat pipe structure and a frozen soil protection method based on solar thermal chemical adsorption refrigeration. The heat pipe structure adopts a new heat pipe technology of adsorption refrigeration cycle with ammonia as refrigerant and halide as adsorbent to solve the problem of seasonal operation and small effective cooling radius of traditional heat pipes. The heat pipe structure designed by the present invention can give full play to the advantages of adsorption refrigeration cycle, make full use of the latent heat of vaporization of ammonia, significantly improve the cooling effect of heat pipes on frozen soil and the thermal stability of heat pipes, and help the development of railways in plateau areas.

[0006] The present invention provides a heat pipe structure based on solar thermal chemical adsorption refrigeration, comprising a heat pipe, wherein the heat pipe is an internally sealed U-shaped hollow structure, and a refrigerant is arranged in the heat pipe; The heat pipe comprises a high temperature adsorption bed, a condensation section, an evaporation section and a low temperature adsorption bed which are connected in sequence; The high-temperature adsorption bed is filled with a high-temperature adsorbent for desorbing the refrigerant under the heating effect of solar energy to obtain a high-temperature refrigerant; The condensing section is arranged vertically, and is used to condense the high-temperature refrigerant to obtain condensed refrigerant, and allows the condensed refrigerant to enter the evaporating section under the action of gravity; The evaporation section is arranged transversely, and is used to evaporate the condensed refrigerant under the heating effect of the frozen soil temperature and the adsorption effect of the low-temperature adsorbent to obtain evaporated refrigerant; The low-temperature adsorption bed is filled with the low-temperature adsorbent for adsorbing the evaporated refrigerant.

[0007] Furthermore, the high-temperature adsorption bed and the low-temperature adsorption bed are both arranged horizontally, the portion of the heat pipe inserted into the frozen soil layer is in a U-shaped structure, and the two portions exposed from the frozen soil layer are in an inverted L-shaped structure.

[0008] Furthermore, the refrigerant is ammonia.

[0009] Furthermore, the high-temperature adsorbent and the low-temperature adsorbent are both halide adsorbents.

[0010] Furthermore, a solar collector is arranged outside the high-temperature adsorption bed for absorbing solar radiation energy so that the high-temperature adsorbent in the high-temperature adsorption bed is heated and then desorbs the refrigerant ammonia to obtain the ammonia gas.

[0011] Furthermore, it also includes a nozzle section, which is located between the condensation section and the evaporation section and is used to control the fluid pressure and speed of the condensed refrigerant.

[0012] Furthermore, the nozzle section is provided with a nozzle, and the nozzle is a gradually converging and expanding tube.

[0013] Furthermore, it also includes an insulation section, which is located between the nozzle section and the evaporation section.

[0014] Furthermore, it also includes a liquid sealing section, one end of which is connected to the insulation section and the other end is located in the evaporation section. The liquid sealing section is provided with a liquid sealing device for ensuring the flow direction and state of the refrigerant in the heat pipe.

[0015] The present invention also provides a method for protecting frozen soil based on solar thermal chemical adsorption refrigeration, which is implemented by using any one of the heat pipe structures based on solar thermal chemical adsorption refrigeration described above, comprising: Under the heating effect of the solar energy, the high-temperature adsorbent in the high-temperature adsorption bed desorbs the refrigerant to obtain the high-temperature refrigerant; The high-temperature refrigerant enters the condensation section to be condensed to obtain the condensed refrigerant; The condensed refrigerant enters the evaporation section under the action of gravity; The condensed refrigerant evaporates under the heating effect of the frozen soil temperature and the adsorption effect of the low-temperature adsorbent to obtain the evaporated refrigerant; The evaporated refrigerant is adsorbed by the low-temperature adsorbent in the low-temperature adsorption bed and releases adsorption heat.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) A new heat pipe technology with an adsorption refrigeration cycle using ammonia as the refrigerant and halides as the adsorbent is used to solve the problems of seasonal operation and small effective cooling radius of traditional heat pipes.

[0017] (2) It can give full play to the advantages of the adsorption refrigeration cycle, make full use of the latent heat of vaporization of ammonia, significantly improve the cooling effect of the heat pipe on the frozen soil and the thermal stability of the heat pipe, and promote the development of railways in plateau areas.

[0018] (3) The adsorption and desorption effects of high-temperature adsorbent and low-temperature adsorbent on refrigerant ammonia are fully utilized to promote the evaporation and condensation process of refrigerant ammonia in the heat pipe.

[0019] (4) In summer, solar collectors are used to heat the high-temperature adsorbent in the high-temperature adsorption bed to desorb the refrigerant ammonia. The ammonia enters the condensation section and is accelerated by the nozzle. It then enters the evaporation section and absorbs heat and evaporates under the adsorption of the low-temperature adsorbent, achieving frozen soil cooling. This solves the current problem of plateau frozen soil heat pipes not working in summer.

[0020] (5) There is a certain horizontal distance in the evaporation section, which can increase the evaporation range of the refrigerant, thereby increasing the effective cooling radius of the heat pipe.

[0021] (6) The adsorption refrigeration or heat storage technology used is a highly efficient and energy-saving technology driven by medium- and low-temperature heat sources such as solar energy or industrial waste heat. It often uses ammonia as a circulating working fluid and is an environmentally friendly refrigeration and heat storage method that does not produce greenhouse effects or ozone holes, and has attracted much attention. Compared with steam compression systems, adsorption refrigeration or heat storage systems have the advantages of simple structure, distributed installation, no noise, long service life, and low investment and operating costs.

[0022] In summary, compared with the prior art, the present invention can effectively solve the problems of seasonal operation and small effective cooling radius of traditional heat pipes. It is the first time to propose the combination of thermochemical adsorption refrigeration cycle and frozen soil heat pipes, and to use the adsorption and desorption of refrigerant ammonia by high-temperature and low-temperature adsorbents, so that the heat pipes can work in summer, maintain the stability of the heat pipes, and increase the effective cooling radius of the heat pipes underground. Compared with the compression refrigeration system, the adsorption refrigeration system has the advantages of simple structure, distributed installation, no noise, long service life, and low investment and operation costs. Therefore, the invention is innovative and efficient, and can provide new ideas for the application of heat pipes in frozen soil of plateau railways. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, objectives and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0024] Figure 1 is a half-section schematic diagram of a heat pipe structure based on solar thermal chemical adsorption refrigeration provided by an embodiment of the present invention; Figure 2 It is a cross-sectional schematic diagram of a high-temperature adsorption bed and a solar collector of a heat pipe structure provided by an embodiment of the present invention.

[0025] In the figure: 101-high temperature adsorption bed; 102-condensation section; 103-nozzle section; 104-insulation section; 105-liquid seal section; 106-evaporation section; 107-low temperature adsorption bed; 201-solar collector; 202-high temperature adsorbent; 203-heat pipe; 204-nozzle; 205-low temperature adsorbent. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0027] In the description of the novel heat pipe of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "vertical", "lateral", "horizontal", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation to the present invention.

[0028] In addition, the terms "lateral", "horizontal", "vertical", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Embodiment 1: Please refer to Figure 1~Figure 2 The present invention provides a heat pipe structure based on solar thermal chemical adsorption refrigeration, including a heat pipe 203, the heat pipe 203 is an internally sealed U-shaped hollow structure, and a refrigerant is arranged in the heat pipe 203; The heat pipe 203 includes a high temperature adsorption bed 101, a condensation section 102, an evaporation section 106 and a low temperature adsorption bed 107 which are connected in sequence; The high-temperature adsorption bed 101 is filled with a high-temperature adsorbent 202, which is used to desorb the refrigerant under the heating effect of solar energy to obtain a high-temperature refrigerant, and allow the high-temperature refrigerant to enter the condensation section 102; The condensation section 102 is arranged vertically, and is used to condense the high-temperature refrigerant to obtain condensed refrigerant, release heat at the same time, and allow the condensed refrigerant to enter the evaporation section 106 under the action of gravity; The evaporation section 106 is arranged horizontally, and is used to make the condensed refrigerant evaporate under the heating effect of the frozen soil temperature and the adsorption effect of the low-temperature adsorbent 205 to obtain evaporated refrigerant, thereby cooling the frozen soil; The low-temperature adsorption bed 107 is filled with a low-temperature adsorbent 205, which is used to low-temperature adsorb the condensed refrigerant under the action of the ambient refrigerant, so that it evaporates in the evaporation section 106 to obtain evaporated refrigerant, and enters the low-temperature adsorption bed 107 for adsorption, while releasing adsorption heat.

[0031] In a specific embodiment, the refrigerant is ammonia, and the high-temperature adsorbent 202 and the low-temperature adsorbent 205 are both halide adsorbents; In detail, compared with the technical solution of using methanol as a refrigerant and activated carbon as an adsorbent, using ammonia as a refrigerant and a halide adsorbent as a high-temperature adsorbent 202 and a low-temperature adsorbent 205 is more environmentally friendly (ammonia is an environmentally friendly natural refrigerant that has no destructive effect on the ozone layer and the environment; although methanol performs well in some applications, it is highly toxic and can cause death if inhaled in large quantities, so leakage must be strictly prevented during use), and safe (at high temperatures, methanol will react in the presence of activated carbon to generate non-condensable gases such as dimethyl ether, which will destroy the system vacuum and affect the heat and mass transfer performance; when ammonia is combined with halides, toxic or corrosive gases are usually not generated). Corrosive substances, the system operation is safer), system performance (the composite adsorbent formed by halides and ammonia not only increases the adsorption capacity of ammonia, but also enhances the heat and mass transfer capacity, making the overall performance of the system better), adaptability (ammonia, as a working fluid with a wide operating temperature range, is suitable for efficient refrigeration and heat storage under extreme climatic conditions), economy, equipment requirements (the system composed of ammonia and halides can operate under a positive pressure slightly higher than normal pressure, the engineering characteristics are easy to ensure, the requirements for equipment materials are not high, and the equipment cost is low; in contrast, the activated carbon-methanol system may require more stringent sealing measures and more advanced materials to prevent methanol leakage and corrosion).

[0032] The high temperature adsorption bed 101 and the low temperature adsorption bed 107 are both arranged horizontally, the part of the heat pipe 203 inserted into the frozen soil layer is in a U-shaped structure, and the two parts exposed from the frozen soil layer are in an inverted L-shaped structure; A solar collector 201 is disposed outside the high-temperature adsorption bed 101 to absorb solar radiation energy so that the high-temperature adsorbent 202 in the high-temperature adsorption bed 101 is heated and then desorbs the refrigerant ammonia to obtain ammonia gas; In general, the condensation section 102 and the evaporation section 106 of the heat pipe 203 present a certain angle, and the specific angle can be adjusted according to the actual effect, and is 30°~150°.

[0033] In detail, the heat pipe is vacuum-sealed, filled with refrigerant ammonia, and the internal pressure of the heat pipe is adjusted according to the characteristics of ammonia.

[0034] According to the desorption and adsorption of the refrigerant ammonia by the high temperature adsorbent 202 and the low temperature adsorbent 205, the heat pipe internal circulation can be discussed separately in summer daytime and nighttime. Take summer daytime as an example.

[0035] The high temperature adsorption bed 101 is arranged horizontally and filled with high temperature adsorbent 202. The specific type can be determined according to the temperature and pressure of the actual application location. Figure 2 , which is a cross-sectional view of the high-temperature adsorption bed 101, the high-temperature adsorbent 202 is filled in the heat pipe 203, and small holes are left inside the high-temperature adsorbent 202, which are ammonia channels.

[0036] The condensation section 102 is vertically arranged and connected to the high-temperature adsorption bed 101 and the evaporation section 106. Affected by the external environment, the temperature of the tube wall is relatively low compared to the high-temperature adsorption bed 101. The vaporous working fluid ammonia begins to condense on the tube wall, changing from vapor to liquid, and releasing heat. Under the action of gravity, the liquid ammonia flows continuously downward along the vertical tube wall. The outer wall of the condensation section 102 is equipped with fins, which increase the heat exchange area and enhance heat transfer. The specific model and quantity of the fins can be determined according to specific needs.

[0037] The evaporation section 106 is arranged horizontally and connected to the condensation section 102 and the low-temperature adsorption bed 107. Affected by the soil temperature and the adsorption of the low-temperature adsorbent 205, the liquid ammonia condensed by the condensation section 102 begins to evaporate in the evaporation section 106, changing from liquid to vapor and absorbing heat, so that the frozen soil is cooled.

[0038] The low temperature adsorption bed 107 is arranged horizontally and filled with low temperature adsorbent 205. The specific type can be determined according to the temperature and pressure of the actual application location. Figure 2 The cross-sectional view of the low temperature adsorption bed 107 is similar to that of the high temperature adsorption bed 101. The low temperature adsorbent 205 is filled in the heat pipe 203. There are small holes inside the low temperature adsorbent 205, which are ammonia channels. Unlike the high temperature adsorption bed 101, no solar collector is required here.

[0039] Working principle: During the summer daytime, the ambient temperature is 10℃~20℃, and the solar collector 201 heats the high-temperature adsorption bed 101. The solar collector 201 can raise the temperature by 20° or even more during the day. The specific temperature rise will be affected by the local climate and environmental conditions. The high-temperature adsorbent 202 absorbs heat to desorb ammonia, and the ammonia enters the condensation section 102 through the small hole channel; at this time, the condensation section 102 is at ambient temperature, which is lower than the temperature of ammonia. The ammonia condenses in the condensation section 102, releases heat, and changes from vapor to liquid, and flows down along the vertical pipe wall and enters the horizontal evaporation section 106; at this time, the low-temperature adsorption bed 107 is in a low-pressure state, and the liquid ammonia evaporates in the evaporation section 106 under the adsorption of the low-temperature adsorbent 205, and changes from liquid to vapor, and enters the low-temperature adsorption bed 107, while the frozen soil around the evaporation section 106 is cooled, and its effective cooling radius can be determined by the horizontal length of the evaporation section 106.

[0040] The heat pipe structure provided by the present invention promotes the flow and phase change process of the refrigerant ammonia inside the heat pipe through the introduction of a thermochemical adsorption cycle and the adsorption and desorption of ammonia by high and low temperature adsorbents, thereby improving the refrigeration efficiency and energy utilization rate of the heat pipe 203; the thermochemical adsorption cycle can also improve the stability of the refrigerant ammonia inside the heat pipe and reduce the unstable factors in the phase change process, thereby improving the reliability and stability of the heat pipe 203.

[0041] In practical applications, the horizontal lengths of the high and low temperature adsorption bed structures can be determined according to the depth of the frozen soil layer and the specific refrigeration requirements.

[0042] In practical applications, the diameter of the heat pipe 203 is 80 mm-120 mm. According to the needs of roadbed control, the length of the evaporation section 106 of the heat pipe 203 can reach 5 m-20 m, and the length of the condensation section 102 can reach 2 m-5 m.

[0043] In practical applications, in terms of material, the heat pipe 203 can be made of metals with good thermal conductivity, such as stainless steel, copper, and cast iron.

[0044] Embodiment 2: Please refer to Figure 1~Figure 2 The heat pipe structure based on solar thermal chemical adsorption refrigeration provided in Example 2 is based on Example 1 and further includes a nozzle section 103, which is located between the condensation section 102 and the evaporation section 106 and is used to control the fluid pressure and speed of the condensed refrigerant.

[0045] In a specific embodiment, the nozzle section 103 is provided with a nozzle 204. The nozzle 204 adopts a Laval nozzle, that is, a gradually converging and expanding tube. The cross-section of the heat pipe first becomes smaller from the condensation section 102 and reaches the throat. The cross-section of the heat pipe then becomes larger and is then connected to the evaporation section 106. The final cross-section is always smaller than the initial cross-section, so as to effectively control the pressure and velocity of the fluid, which helps to optimize the performance of the heat pipe system.

[0046] Working principle: The low-temperature and high-pressure liquid ammonia condensed in the condensation section 102 flows through the Laval nozzle, the fluid cross-section decreases, the flow velocity increases, the dynamic pressure increases, and the static pressure decreases, forming low-temperature and low-pressure liquid ammonia, which enters the evaporation section 106. The low-temperature and low-pressure liquid ammonia is more likely to absorb heat and evaporate under adsorption, thereby promoting the cooling of the frozen soil.

[0047] The heat pipe structure of the present invention is based on a thermochemical adsorption cycle, and a Laval nozzle is arranged between the condensation section 102 and the evaporation section 106, which can improve the heat transfer efficiency and fluid dynamics performance of the heat pipe system, optimize the operation of the heat pipe system, and improve the cooling effect of the evaporation section 106 on frozen soil.

[0048] In practical applications, the type and size of the nozzle 204 also need to be determined based on specific fluid velocity requirements, fluid flow rate, and pressure requirements.

[0049] Embodiment 3: Please refer to Figure 1~Figure 2 A heat pipe structure based on solar thermal chemical adsorption refrigeration provided in Example 3 is based on Example 2 and further includes an insulating section 104 and a liquid sealing section 105; the insulating section 104 is located between the nozzle section 103 and the evaporation section 106; one end of the liquid sealing section 105 is connected to the insulating section 104, and the other end is located in the evaporation section 106, and the liquid sealing section 105 is provided with a liquid sealing device for ensuring the flow direction and state of the refrigerant in the heat pipe 203.

[0050] In detail, the insulating section 104 uses a smaller tube diameter and is connected to the larger tube diameter of the evaporation section 106. The heat pipe of the insulating section 104 is inserted into the bottom of the evaporation section 106 to a depth of about 1 cm. The insulating section 104 and the evaporation section 106 are connected by welding or other effective methods. By providing the insulating section 104, the temperature difference can be effectively reduced, thereby reducing the thermal resistance of the heat pipe 203 and improving the overall heat transfer performance of the heat pipe 203. The presence of the insulating section 104 can prevent or reduce the reverse transfer of heat, thereby ensuring the unidirectional heat transfer function of the heat pipe 203 and improving the accuracy of controlling the direction of heat flow. At the same time, since the insulating section 104 does not participate in heat exchange, it can help maintain the temperature difference between the condensation section 102 and the evaporation section 106, thereby enhancing the heat pipe 203 is isothermal, and the setting of the insulation section 104 can also help isolate the direct thermal contact between the condensation section 102 and the evaporation section 106, thereby reducing the risk of system instability caused by temperature fluctuations or pressure changes, so as to ensure the long-term stable operation of the heat pipe 203 system; the liquid sealing device can adopt a liquid sealing tank type liquid sealing device, a U-shaped tube type liquid sealing device, a Π-shaped tube type liquid sealing device, an automatic drainer type liquid sealing device, etc., to effectively control the flow direction and distribution of the fluid, prevent the refrigerant from backflowing in the pipeline or uneven distribution of the gas-liquid two phases, and help optimize the performance of the heat pipe system.

[0051] In practical applications, the specific parameters of the insulation section 104 can be reasonably set according to requirements, so as to optimize the performance of the heat pipe 203.

[0052] The heat pipe structure provided by the present invention is based on the thermochemical adsorption cycle, and a liquid sealing device is set between the insulation section 104 and the evaporation section 106. It is also a pipeline system installed between the condensation section 102 and the evaporation section 106 to ensure the flow direction and state of the refrigerant in the pipeline, maintain the pressure difference between the high-temperature adsorption bed 101 and the low-temperature adsorption bed 107, and help maintain the efficient operation of the thermochemical adsorption cycle system, maintain the refrigeration effect, reduce energy waste, prevent unnecessary damage or failure, and extend the service life of the system.

[0053] Embodiment 4: The present invention also provides a method for protecting frozen soil based on solar thermal chemical adsorption refrigeration, which is implemented by using the heat pipe structure based on solar thermal chemical adsorption refrigeration described in Example 1, Example 2 or Example 3, and includes: Under the heating effect of solar energy, the high-temperature adsorbent 202 in the high-temperature adsorption bed 101 desorbs the refrigerant to obtain a high-temperature refrigerant; The high-temperature refrigerant enters the condensation section 102 to condense, thereby obtaining condensed refrigerant. The condensed refrigerant enters the evaporation section 106 under the action of gravity; The condensed refrigerant evaporates under the heating effect of the frozen soil temperature and the adsorption effect of the low-temperature adsorbent 205 to obtain evaporated refrigerant; The evaporated refrigerant is adsorbed by the cryogenic adsorbent 205 in the cryogenic adsorption bed 107 and releases adsorption heat.

[0054] The technical solution provided by the present invention is described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A heat pipe structure based on solar thermal chemical adsorption refrigeration, characterized in that: Comprising a heat pipe (203), the heat pipe (203) being an internally sealed U-shaped hollow structure, and a refrigerant is arranged inside the heat pipe (203); The heat pipe (203) comprises a high-temperature adsorption bed (101), a condensation section (102), an evaporation section (106), and a low-temperature adsorption bed (107) which are connected in sequence; The high-temperature adsorption bed (101) is filled with a high-temperature adsorbent (202) for desorbing the refrigerant under the heating effect of solar energy to obtain a high-temperature refrigerant; The condensation section (102) is arranged vertically, and is used to condense the high-temperature refrigerant to obtain condensed refrigerant, and allows the condensed refrigerant to enter the evaporation section (106) under the action of gravity; The evaporation section (106) is arranged horizontally and is used to evaporate the condensed refrigerant under the heating effect of the frozen soil temperature and the adsorption effect of the low-temperature adsorbent (205) to obtain evaporated refrigerant; The low-temperature adsorption bed (107) is filled with the low-temperature adsorbent (205) for adsorbing the evaporated refrigerant.

2. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to claim 1, characterized in that: The high-temperature adsorption bed (101) and the low-temperature adsorption bed (107) are both arranged transversely; the portion of the heat pipe (203) inserted into the frozen soil layer is in a U-shaped structure, and the two portions exposed from the frozen soil layer are in an inverted L-shaped structure.

3. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to claim 2, characterized in that: The refrigerant is ammonia.

4. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to claim 3, characterized in that: The high-temperature adsorbent (202) and the low-temperature adsorbent (205) are both halide adsorbents.

5. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to claim 4, characterized in that: A solar collector (201) is arranged outside the high-temperature adsorption bed (101) for absorbing solar radiation energy, so that the high-temperature adsorbent (202) in the high-temperature adsorption bed (101) is heated and then desorbs the refrigerant ammonia to obtain the ammonia gas.

6. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to any one of claims 1 to 5, characterized in that: It also includes a nozzle section (103), which is located between the condensation section (102) and the evaporation section (106) and is used to control the fluid pressure and speed of the condensed refrigerant.

7. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to claim 6, characterized in that: The nozzle section (103) is provided with a nozzle (204), and the nozzle (204) is a gradually converging and expanding tube.

8. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to claim 6, characterized in that: It also includes an insulation section (104), wherein the insulation section (104) is located between the nozzle section (103) and the evaporation section (106).

9. The heat pipe structure based on solar thermal chemical adsorption refrigeration according to claim 8, characterized in that: It also comprises a liquid sealing section (105), one end of which is in communication with the insulation section (104), and the other end of which is located in the evaporation section (106), and the liquid sealing section (105) is provided with a liquid sealing device for ensuring the flow direction and state of the refrigerant in the heat pipe (203).

10. A method for permafrost protection based on solar thermal chemical adsorption refrigeration, which is implemented by using the heat pipe structure based on solar thermal chemical adsorption refrigeration as claimed in any one of claims 1 to 9, characterized in that: include: Under the heating effect of the solar energy, the high-temperature adsorbent (202) in the high-temperature adsorption bed (101) desorbs the refrigerant to obtain the high-temperature refrigerant; The high-temperature refrigerant enters the condensation section (102) to condense, thereby obtaining the condensed refrigerant; The condensed refrigerant enters the evaporation section (106) under the action of gravity; The condensed refrigerant evaporates under the heating effect of the frozen soil temperature and the adsorption effect of the low-temperature adsorbent (205), thereby obtaining the evaporated refrigerant; The evaporated refrigerant is adsorbed by the low-temperature adsorbent (205) in the low-temperature adsorption bed (107), and releases adsorption heat.

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