Heat pipe structure based on solar-thermal chemical adsorption refrigeration and permafrost protection method

Abstract

The application provides a heat pipe structure based on solar heat chemical adsorption refrigeration and a permafrost protection method, and the heat pipe structure comprises a heat pipe, the heat pipe is in a U-shaped hollow structure sealed internally, 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 sequentially connected; the high-temperature adsorption bed is internally filled with a high-temperature adsorbent and is used for desorbing the refrigeration working medium under the heating action of solar energy to obtain high-temperature refrigeration working medium; the condensation section is vertically arranged and is used for condensing the high-temperature refrigeration working medium to obtain 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 horizontally arranged and is used for evaporating the condensed refrigeration working medium under the heating action of permafrost temperature and the adsorption action of the low-temperature adsorbent to obtain evaporated refrigeration working medium; and the low-temperature adsorption bed is internally filled with a low-temperature adsorbent and is used for adsorbing the evaporated refrigeration working medium. The scheme improves the permafrost temperature-lowering effect of the heat pipe and the thermal stability of the heat pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of frozen soil engineering. Specifically, it relates to a heat pipe structure based on solar heat chemical adsorption refrigeration and a frozen soil protection method. BACKGROUND

[0002] In the western mountainous area, the temperature field of the roadbed changes due to seasonal changes and temperature changes, causing water and soil loss and water phase changes in the soil body, thereby causing the frozen soil area to form a frost heaving uplift and a thawing subsidence frozen soil freeze-thaw cycle phenomenon in winter and summer, which changes the material parameters in the roadbed soil layer and the protective structure layer, directly affecting the safety of road use, reducing the service life of the road, and increasing the driving safety hazards. Therefore, the stability of the frozen soil roadbed is one of the biggest problems faced by the Qinghai-Tibet Railway engineering construction.

[0003] In view of the frozen soil problem, scientists of the Chinese Academy of Sciences have proposed an engineering design idea of "actively cooling the roadbed and actively protecting the frozen soil". Currently, there are two basic ways of increasing the thermal resistance of the roadbed and actively cooling. The method of increasing the thermal resistance of the roadbed includes adding a heat insulation plate and roadbed filling, but in the context of global warming, especially in high-temperature and high-ice-content areas, simply using the method of 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 the permafrost area; and the method of actively cooling includes installing heat pipes, laying stone layers and laying ventilation pipes to insulate heat, and using the cold climate conditions of the plateau to continuously input "cold" into the ground to maintain the frozen state of the frozen soil. The heat pipe is a one-way heat transfer element that uses the excellent heat transfer efficiency of a two-phase closed heat siphon to actively regulate and control the ground temperature of the frozen soil roadbed, effectively raising the upper limit of the frozen soil, and 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 the heat pipe has good cooling effect in the permafrost area and plays a positive role in maintaining the thermal stability of the frozen soil roadbed, the heat pipe does not work in the warm season and only works when the outside temperature is lower than the roadbed body temperature and the heat pipe starts to work. The effective working time is limited throughout the year. In addition, with the gradual advancement of the construction of the permafrost area highway, due to the limitation of the effective radius of the heat pipe, the heat pipe alone is difficult to achieve the regulation and control requirements in the road position far from the heat pipe on a large-scale wide roadbed; and the thermal stability of the heat pipe is poor, and the ground temperature decreases, the working power and refrigeration performance decay after a long time of work. SUMMARY

[0005] In view of the deficiencies in the prior art, the application provides a heat pipe structure based on solar heat chemical adsorption refrigeration and a permafrost protection method, which adopts a new heat pipe technology of an adsorption refrigeration cycle with ammonia as a refrigeration working medium and halide as an adsorbent to solve the problems of seasonal operation and small effective cooling radius of a traditional heat pipe.The heat pipe structure designed in the application can take advantage of the adsorption refrigeration cycle, fully utilize the latent heat of ammonia vaporization, and significantly improve the cooling effect of the heat pipe on permafrost and the thermal stability of the heat pipe, thereby assisting the development of railways in plateau regions.

[0006] The application provides a heat pipe structure based on solar heat chemical adsorption refrigeration, which comprises a heat pipe.

[0007] The heat pipe comprises a high-temperature adsorption bed, a condensation section, an evaporation section and a low-temperature adsorption bed which are sequentially connected.

[0008] The high-temperature adsorption bed is internally filled with a high-temperature adsorbent for desorbing the refrigeration working medium under the heating action of solar energy to obtain high-temperature refrigeration working medium.

[0009] The condensation section is vertically arranged for condensing the high-temperature refrigeration working medium to obtain condensed refrigeration working medium and enabling the condensed refrigeration working medium to enter the evaporation section under the action of gravity.

[0010] The evaporation section is horizontally arranged for evaporating the condensed refrigeration working medium under the heating action of permafrost temperature and the adsorption action of a low-temperature adsorbent to obtain evaporated refrigeration working medium.

[0011] The low-temperature adsorption bed is internally filled with the low-temperature adsorbent for adsorbing the evaporated refrigeration working medium.

[0012] Further, the high-temperature adsorption bed and the low-temperature adsorption bed are both horizontally arranged, the part of the heat pipe inserted into the permafrost layer is in a U-shaped structure, and the two parts exposed from the permafrost layer are both in an inverted L-shaped structure.

[0013] Further, the refrigeration working medium is ammonia.

[0014] Further, the high-temperature adsorbent and the low-temperature adsorbent both adopt halide adsorbents.

[0015] Further, a solar energy collector is arranged on the outside of the high-temperature adsorption bed for absorbing solar radiation energy, so that the high-temperature adsorbent in the high-temperature adsorption bed is heated to desorb refrigeration working medium ammonia to obtain ammonia gas.

[0016] Further, a nozzle section is arranged between the condensation section and the evaporation section for controlling the fluid pressure and speed of the condensed refrigeration working medium.

[0017] Further, the nozzle section is provided with a nozzle in the form of a converging-diverging nozzle.

[0018] Further, an adiabatic section is further included, which is located between the nozzle section and the evaporation section.

[0019] Further, a liquid seal section is further included, one end of which is in communication with the adiabatic section and the other end of which is located in the evaporation section, the liquid seal section being provided with a liquid seal device for ensuring the flow direction and state of the refrigerant in the heat pipe.

[0020] The application further provides a permafrost protection method based on solar heat chemical adsorption refrigeration, which is realized by using the heat pipe structure based on solar heat chemical adsorption refrigeration according to any one of the above.

[0021] Under the heating action of the solar energy, the high-temperature adsorbent in the high-temperature adsorption bed desorbs the refrigerant to obtain the high-temperature refrigerant.

[0022] The high-temperature refrigerant enters the condensation section to be condensed to obtain the condensed refrigerant.

[0023] The condensed refrigerant enters the evaporation section under the action of gravity.

[0024] The condensed refrigerant evaporates under the heating action of the permafrost temperature and the adsorption action of the low-temperature adsorbent to obtain the evaporated refrigerant.

[0025] The evaporated refrigerant is adsorbed by the low-temperature adsorbent in the low-temperature adsorption bed and releases adsorption heat.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] (1) The new heat pipe technology of the adsorption refrigeration cycle using ammonia as the refrigerant and halide as the adsorbent is used to solve the problems of seasonal operation and small effective cooling radius of the traditional heat pipe.

[0028] (2) The advantages of the adsorption refrigeration cycle can be taken, the latent heat of ammonia vaporization can be fully utilized, the cooling effect of the heat pipe on the permafrost and the thermal stability of the heat pipe can be significantly improved, and the development of the railway in the plateau area can be promoted.

[0029] (3) The adsorption and desorption of the high-temperature adsorbent and the low-temperature adsorbent on the refrigerant ammonia are fully utilized to promote the evaporation and condensation process of the refrigerant ammonia in the heat pipe.

[0030] (4) In summer, the high temperature adsorbent in the high temperature adsorption bed is heated by the solar collector, and the refrigerant ammonia is desorbed, and the ammonia enters the condensing section and is condensed, and the speed is increased by the nozzle, and then enters the evaporation section, and is evaporated under the adsorption of the low temperature adsorbent, so as to realize the cooling of the permafrost and solve the problem that the current highland permafrost heat pipe does not work in summer.

[0031] (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.

[0032] (6) The adsorption type refrigeration or heat storage technology adopted is a high efficiency energy saving technology driven by solar energy or industrial waste heat and the like, and ammonia is often used as the circulating working medium, and the environment friendly refrigeration and heat storage mode does not produce greenhouse effect and ozone hole, and is concerned. Compared with the vapor compression type system, the adsorption type refrigeration or heat storage system has the advantages of simple structure, distributed installation, no noise, long service life, low investment and operation cost.

[0033] In summary, compared with the prior art, the application can effectively solve the problems of seasonal operation and small effective cooling radius of the traditional heat pipe, and for the first time, the heat chemical adsorption refrigeration cycle is combined with the permafrost heat pipe, and the adsorption and desorption of the high temperature and low temperature adsorbent on the refrigerant ammonia can realize the working of the heat pipe in summer, maintain the stability of the working of the heat pipe, and increase the effective cooling radius of the heat pipe underground. And compared with the compression type refrigeration system, the adsorption type refrigeration system has the advantages of simple structure, distributed installation, no noise, long service life, low investment and operation cost, so the application has innovation and high efficiency, and can provide a new idea for the application of the permafrost heat pipe of the highland railway. BRIEF DESCRIPTION OF DRAWINGS

[0034] Other features, objects and advantages of the application will become more apparent through reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0035] Fig. 1 is a semi-sectional schematic view of a heat pipe structure based on solar heat chemical adsorption refrigeration provided by the embodiment of the application;

[0036] Fig. 2 is a sectional schematic view of a high temperature adsorption bed and a solar collector of a heat pipe structure provided by the embodiment of the application.

[0037] In the figure: 101-high temperature adsorption bed; 102-condensing section; 103-nozzle section; 104-adiabatic 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

[0038] The present application will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application. These are within the scope of the present application.

[0039] In the description of the novel heat pipe of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "vertical", "horizontal", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product is used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In addition, the terms "horizontal", "vertical", "vertical", "vertical" and the like do not mean that the components must be absolutely horizontal or suspended, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0041] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "set", "mount", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] Example 1:

[0043] Please refer to Figs. 1-2 The present application provides a heat pipe structure based on solar heat chemical adsorption refrigeration, comprising a heat pipe 203, the heat pipe 203 is a U-shaped hollow structure with an internal seal, and a refrigerant is arranged in the heat pipe 203;

[0044] 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 connected in sequence;

[0045] The high-temperature adsorbent 202 is filled in the high-temperature adsorption bed 101, which is used to desorb the refrigerant under the heating action of solar energy to obtain high-temperature refrigerant, and the high-temperature refrigerant enters the condensation section 102;

[0046] The condensing section 102 is vertically arranged to condense the high-temperature refrigerant to obtain condensed refrigerant while releasing heat, and to allow the condensed refrigerant to enter the evaporation section 106 under the action of gravity;

[0047] The evaporation section 106 is horizontally arranged to evaporate the condensed refrigerant under the heating action of permafrost and the adsorption action of the low-temperature adsorbent 205 to obtain evaporated refrigerant, thereby cooling the permafrost;

[0048] The low-temperature adsorption bed 107 is internally filled with the low-temperature adsorbent 205 to adsorb the condensed refrigerant under the action of the ambient refrigerant, so that the condensed refrigerant is evaporated in the evaporation section 106 to obtain evaporated refrigerant and enters the low-temperature adsorption bed 107 for adsorption while releasing adsorption heat.

[0049] In a specific embodiment, the refrigerant is ammonia, and the high-temperature adsorbent 202 and the low-temperature adsorbent 205 are both halide adsorbents;

[0050] In detail, compared with the technical solution of using methanol as the refrigerant and activated carbon as the adsorbent, using ammonia as the refrigerant and halide adsorbents as the high-temperature adsorbent 202 and the low-temperature adsorbent 205 has obvious advantages in environmental protection (ammonia is an environmentally friendly natural refrigerant and 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, and strict measures must be taken to prevent leakage), safety (at high temperatures, methanol can react with activated carbon to generate non-condensable gases such as dimethyl ether, which can damage the system vacuum and affect the heat and mass transfer performance; ammonia and halide usually do not generate toxic or corrosive substances when combined, making the system safer to operate), system performance (the composite adsorbent formed by halide and ammonia not only increases the adsorption capacity of ammonia but also enhances the heat and mass transfer capacity, making the system have better overall performance), adaptability (ammonia is a wide working temperature range refrigerant and is suitable for efficient refrigeration and heat storage in extreme climate conditions), economy, equipment requirements (the system composed of ammonia and halide can operate at slightly higher than normal pressure, the engineering characteristics are easy to guarantee, the requirements for equipment materials are not high, and the equipment cost is relatively low; in contrast, the activated carbon-methanol system may require more stringent sealing measures and higher-grade materials to prevent methanol leakage and corrosion), and the like.

[0051] The high-temperature adsorption bed 101 and the low-temperature adsorption bed 107 are both horizontally arranged, the part of the heat pipe 203 inserted into the permafrost layer has a U-shaped structure, and the two parts exposed from the permafrost layer both have an inverted L-shaped structure;

[0052] The outer side of the high-temperature adsorption bed 101 is provided with a solar heat collector 201 for absorbing solar radiation energy so that the high-temperature adsorbent 202 in the high-temperature adsorption bed 101 is heated to desorb the refrigerant ammonia to obtain ammonia gas;

[0053] Generally, the condensing section 102 and the evaporating section 106 of the heat pipe 203 present a certain angle, and the specific angle can be adjusted according to actual effects, being 30°-150°.

[0054] In detail, the heat pipe is vacuum sealed, the heat pipe is filled with the refrigerant ammonia, and the internal pressure of the heat pipe is adjusted according to the characteristics of the ammonia.

[0055] According to the desorption and adsorption of the high-temperature adsorbent 202 and the low-temperature adsorbent 205 on the refrigerant ammonia, the circulation in the heat pipe can be discussed separately in summer daytime and nighttime. Taking summer daytime as an example.

[0056] The high-temperature adsorption bed 101 is horizontally arranged, and is filled with the high-temperature adsorbent 202. The specific type can be determined according to the temperature and pressure of the actual application site. Referring to Fig. 2 It is a sectional view of the high-temperature adsorption bed 101, the high-temperature adsorbent 202 is filled in the heat pipe 203, and the high-temperature adsorbent 202 has small holes in the inside for ammonia gas passage.

[0057] The condensing section 102 is vertically arranged, and is connected with the high-temperature adsorption bed 101 and the evaporating section 106. Influenced by the external environment, the temperature of the pipe wall is relatively lower than that of the high-temperature adsorption bed 101. The gaseous ammonia starts to condense at the pipe wall, changes from gaseous state to liquid state, and releases heat. Under the action of gravity, the liquid ammonia continuously flows down along the vertical pipe wall. The outer wall of the condensing section 102 is provided with fins, the fins increase the heat exchange area and strengthen the heat transfer. The specific type and quantity of the fins can be determined according to specific requirements.

[0058] The evaporating section 106 is horizontally arranged, and is connected with the condensing section 102 and the low-temperature adsorption bed 107. Influenced by the soil temperature and the low-temperature adsorbent 205, the liquid ammonia condensed from the condensing section 102 starts to evaporate in the evaporating section 106, changes from liquid state to gaseous state, and absorbs heat, so that the frozen soil is cooled.

[0059] The low-temperature adsorption bed 107 is horizontally arranged, and is filled with the low-temperature adsorbent 205. The specific type can be determined according to the temperature and pressure of the actual application site. Referring to Fig. 2 The 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, and the low-temperature adsorbent 205 has small holes in the inside for ammonia gas passage. Different from the high-temperature adsorption bed 101, no solar heat collector is needed here.

[0060] Working principle: in summer daytime, when the ambient temperature is 10-20℃, the solar collector 201 heats the high-temperature adsorption bed 101, and the solar collector 201 can increase the temperature by 20° or even more during the day, and the specific temperature increase 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 condensing section 102 through the small pore channel; at this time, the condensing section 102 is at ambient temperature, which is relatively low compared to the temperature of the ammonia, and the ammonia is condensed in the condensing section 102, releasing heat, and changing from a gaseous state to a liquid state, flowing down the vertical pipe wall, and entering 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, changes from a liquid state to a gaseous state, and enters the low-temperature adsorption bed 107, and the surrounding permafrost is cooled, and the effective cooling radius can be determined by the horizontal length of the evaporation section 106.

[0061] The heat pipe structure provided by the application promotes the flow and phase change process of the refrigerant ammonia in the heat pipe by introducing 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 in the heat pipe, reduce unstable factors in the phase change process, and thereby improve the reliability and stability of the heat pipe 203.

[0062] In actual application, the horizontal length of the high- and low-temperature adsorption bed structure can be determined according to the depth of the permafrost layer and the specific refrigeration requirements.

[0063] In actual application, the heat pipe 203 has a diameter of 80-120 mm, and the length of the evaporation section 106 of the heat pipe 203 can be 5-20 m and the length of the condensing section 102 can be 2-5 m according to the needs of roadbed regulation.

[0064] In actual application, in terms of material, the heat pipe 203 can be made of stainless steel, copper, cast iron or other metals with good thermal conductivity.

[0065] Example 2

[0066] Please refer to Figs. 1-2 Example 2 provides a heat pipe structure based on solar thermochemical adsorption refrigeration, which further includes a nozzle section 103 between the condensing section 102 and the evaporation section 106, for controlling the fluid pressure and speed of the condensed refrigerant.

[0067] In one specific embodiment, the nozzle section 103 is provided with a nozzle 204, which is a Laval nozzle, i.e., a converging-diverging nozzle, the cross section of the heat pipe in the condensing section 102 first decreases to reach the throat, then increases again to connect with the evaporating section 106, and the final cross section is always smaller than the initial cross section, so as to effectively control the pressure and velocity of the fluid and help optimize the performance of the heat pipe system.

[0068] Working principle: The low-temperature and high-pressure liquid ammonia condensed in the condensing section 102 flows through the Laval nozzle, the cross section of the fluid decreases, the flow rate increases, the dynamic pressure increases, and the static pressure decreases, forming low-temperature and low-pressure liquid ammonia, which enters the evaporating section 106, and the low-temperature and low-pressure liquid ammonia is more easily absorbed by the adsorption to evaporate, thereby promoting the cooling of the frozen soil.

[0069] The heat pipe structure of the present application is based on the heat chemical adsorption cycle, and a Laval nozzle is arranged between the condensing section 102 and the evaporating 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 evaporating section 106 on the frozen soil.

[0070] In actual application, the type and size of the nozzle 204 need to be determined according to the specific fluid velocity requirement, fluid flow rate and pressure requirement.

[0071] Embodiment 3:

[0072] Please refer to Figs. 1-2 Embodiment 3 provides a heat pipe structure based on solar energy heat chemical adsorption refrigeration, which further comprises an adiabatic section 104 and a liquid seal section 105 based on the heat pipe structure of embodiment 2; the adiabatic section 104 is located between the nozzle section 103 and the evaporating section 106; one end of the liquid seal section 105 communicates with the adiabatic section 104, and the other end is located in the evaporating section 106; the liquid seal section 105 is provided with a liquid seal device for ensuring the flow direction and state of the refrigeration working medium in the heat pipe 203.

[0073] In detail, the adiabatic section 104 uses a smaller pipe diameter, is connected with the larger pipe diameter of the evaporation section 106, the heat pipe of the adiabatic section 104 is inserted into the evaporation section 106 to a depth of about 1 cm, the adiabatic section 104 and the evaporation section 106 are connected by welding or other effective ways, by setting the adiabatic section 104, the temperature difference can be effectively reduced, thereby reducing the thermal resistance of the heat pipe 203, improving the overall heat transfer performance of the heat pipe 203, and the presence of the adiabatic section 104 can prevent or reduce the reverse transfer of heat, thereby ensuring the one-way heat transfer function of the heat pipe 203, improving the accuracy of controlling the direction of heat flow, at the same time, since the adiabatic 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 isothermality of the heat pipe 203, and the setting of the adiabatic section 104 can also help to 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, to ensure the long-term stable operation of the heat pipe 203 system; the liquid seal device can adopt a liquid seal tank type liquid seal device, a U-shaped pipe type liquid seal device, a Π-shaped pipe type liquid seal device, an automatic liquid discharger type liquid seal device, etc., to effectively control the flow direction and distribution of the fluid, prevent the reverse flow or uneven distribution of gas-liquid two-phase in the pipeline, and help optimize the performance of the heat pipe system.

[0074] In practical application, the specific parameters of the adiabatic section 104 can be reasonably set according to the needs, so as to optimize the performance of the heat pipe 203.

[0075] The heat pipe structure provided by the application sets a liquid seal device between the adiabatic section 104 and the evaporation section 106, which is also installed in the pipeline system between the condensation section 102 and the evaporation section 106, ensures the flow direction and state of the refrigerant in the pipeline, maintains the pressure difference between the high-temperature adsorption bed 101 and the low-temperature adsorption bed 107, helps to maintain the efficient operation of the thermochemical adsorption cycle system, maintains the refrigeration effect, reduces energy waste, prevents unnecessary damage or failure, and prolongs the service life of the system.

[0076] Example 4:

[0077] The application also provides a permafrost protection method based on solar thermochemical adsorption refrigeration, which is realized by using the heat pipe structure based on solar thermochemical adsorption refrigeration in the embodiments 1, 2 or 3, comprising:

[0078] Under the heating action of solar energy, the high-temperature adsorbent 202 in the high-temperature adsorption bed 101 desorbs the refrigerant to obtain high-temperature refrigerant;

[0079] The high-temperature refrigerant enters the condensation section 102 to condense and obtain condensed refrigerant;

[0080] The condensed refrigeration medium enters the evaporation section 106 under the action of gravity;

[0081] The condensed refrigeration medium is evaporated under the heating of the frozen earth temperature and the adsorption of the low-temperature adsorbent 205, and the evaporated refrigeration medium is obtained.

[0082] The evaporated refrigeration medium is adsorbed by the low-temperature adsorbent 205 in the low-temperature adsorption bed 107, and releases the adsorption heat.

[0083] The above describes the technical solutions provided by the present application in detail. The principles and implementation manners of the present application are described by applying specific examples, and the above examples are only used to help understand the method of the present application and its core idea. It should be pointed out that, for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A heat pipe structure based on solar thermochemical adsorption refrigeration, characterized in that, It includes a heat pipe (203), which has an internally sealed U-shaped hollow structure and is provided with a refrigerant inside 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) 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 to condense the high-temperature refrigerant to obtain condensed refrigerant, and to allow the condensed refrigerant to enter the evaporation section (106) under the action of gravity. The evaporation section (106) is arranged laterally to allow the condensed refrigerant to evaporate under the heating effect of the frozen soil temperature and the adsorption effect of the low-temperature adsorbent (205) to obtain the evaporated refrigerant. The low-temperature adsorption bed (107) is filled with the low-temperature adsorbent (205) for adsorbing the evaporated refrigerant; Both the high-temperature adsorption bed (101) and the low-temperature adsorption bed (107) are arranged horizontally. The part of the heat pipe (203) inserted into the frozen soil layer has a U-shaped structure, and the two parts exposed in the frozen soil layer have an inverted L-shaped structure.

2. The heat pipe structure based on solar thermochemical adsorption refrigeration as described in claim 1, characterized in that, The refrigerant used is ammonia.

3. The heat pipe structure based on solar thermochemical adsorption refrigeration as described in claim 2, characterized in that, Both the high-temperature adsorbent (202) and the low-temperature adsorbent (205) are halide adsorbents.

4. The heat pipe structure based on solar thermochemical adsorption refrigeration as described in claim 3, characterized in that, A solar collector (201) is provided on the outside of 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) desorbs the refrigerant ammonia after heating to obtain ammonia gas.

5. The heat pipe structure based on solar thermochemical adsorption refrigeration as described in any one of claims 1 to 4, 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 velocity of the condensing refrigerant.

6. The heat pipe structure based on solar thermochemical adsorption refrigeration as described in claim 5, characterized in that, The nozzle section (103) is provided with a nozzle (204), and the nozzle (204) is a tapered and diffuser.

7. The heat pipe structure based on solar thermochemical adsorption refrigeration as described in claim 5, characterized in that, It also includes an insulation section (104) located between the nozzle section (103) and the evaporation section (106).

8. The heat pipe structure based on solar thermochemical adsorption refrigeration as described in claim 7, characterized in that, It also includes a liquid seal section (105), one end of which is connected to the insulation section (104) and the other end is located in the evaporation section (106). The liquid seal section (105) is provided with a liquid seal device to ensure the flow direction and state of the refrigerant in the heat pipe (203).

9. A method for permafrost protection based on solar thermochemical adsorption refrigeration, implemented using a heat pipe structure based on solar thermochemical adsorption refrigeration as described in any one of claims 1 to 8, 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) and condenses to obtain 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) to obtain 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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