Thermal on-off component, liquid gap type thermal switch and switching method of liquid gap type thermal switch

Abstract

The invention discloses a thermal breaking component, a liquid gap type thermal switch and a switching method thereof, and relates to the technical field of thermal switchs.The thermal breaking component comprises a hot end body, a cold end body and a supporting cylinder, a heat conduction cavity is defined by the hot end body, the cold end body and the supporting cylinder, and the heat conduction cavity can be filled with a heat conduction medium; a hot end extension cylinder is fixed to the face, close to the cold end body, of the hot end body, a cold end extension column is fixed to the face, close to the hot end body, of the cold end body, a heat conduction gap is formed between the hot end extension cylinder and the cold end extension column, and the heat conduction media comprise liquid heat conduction media. The hot end body and the cold end body can conduct heat. The liquid gap type thermal switch comprises a thermal on-off component and an adsorption pump, and the adsorption pump is communicated with the heat conduction cavity through a communicating pipe. The liquid heat-conducting medium with better heat conductivity is filled in the heat-conducting gap to realize the opening of the hot open end part, and the switch ratio is better.

Description

Technical Field

[0001] The invention relates to the technical field of thermal switches, and in particular to a thermal breaking component, a liquid gap type thermal switch and a switching method thereof. Background Art

[0002] With the development of space science, disciplines such as microgravity basic physics, space astronomy, space environment and space physics, new space application technologies and deep space exploration have an increasingly broad demand for extremely low temperatures, and thus the research on extremely low temperature refrigeration technology has also been increasingly valued by the scientific community. The universe is an extremely low temperature environment (about 3K). To observe deep space, improve the sensitivity of the detector and the thermal stability of the entire system, the temperature of the equipment has an extremely low requirement. Extremely low temperature refrigeration is also a key technology for related research such as space station condensed matter physics and microgravity physics. For example, the International Space Station studies the triple critical exponent problem of 3He-4He, which requires an extremely low temperature environment of 0.9 K.

[0003] Adsorption refrigeration technology, which emerged in the late 1980s, has the advantages of long life, no moving parts, no vibration, high reliability, and no electromagnetic interference. Different working fluids can be used to achieve a refrigeration temperature ranging from a few hundred mK to room temperature, and the adsorption bed can be far away from the cold end for easy layout. Therefore, adsorption refrigerators are increasingly favored by space and aerospace technology applications.

[0004] The heat switch is a key component of the adsorption refrigerator. It can realize the heat transfer between the control body (evaporator or adsorption bed) and the heat sink. By switching the heat switch, the heat transfer can be turned on or off. Foreign research on space heat switches began with the space heat switches used in the Apollo program in the United States in the 1960s. It has developed with the development of aerospace technology. Various types of heat switches have been developed. According to the principle of thermal resistance, they can be divided into contact type, air gap type, field effect type and heat pipe type.

[0005] The air gap type heat switch, which is widely used at present, changes the heat exchange capacity of the heat switch by adding or extracting gaseous working medium between the heat conducting plates, thereby realizing the opening and closing of the heat switch. Specifically, as shown in the existing patent CN110108060B, "an adsorption pump and an air gap type heat switch", which includes a hot end, a cold end, a support and an adsorption pump. When the hot end of the adsorption pump is heated, the adsorption capacity of the activated carbon inside it decreases as the temperature increases, thereby realizing the degassing process. When there is a certain pressure of helium in the gap, its thermal resistance is small, so as to form a substantial thermal conduction. When the heating of the hot end of the adsorption pump is stopped, the adsorption capacity of the activated carbon in the adsorption pump is enhanced, and then the air is pumped out, so that the inside of the heat switch is close to a vacuum, the thermal resistance value of the cold end and the hot end is increased, and the substantial thermal disconnection is realized.

[0006] However, the existing air-gap thermal switch has a relatively complex structure and requires an adsorption pump to extract the gas of the thermal switch. Moreover, for the same substance, the thermal conductivity of the liquid is better than that of the gas, so the air-gap thermal switch has the disadvantage of a small switching ratio.

[0007] Therefore, there is an urgent need in the art for a thermal breaking component, a liquid gap type thermal switch and a switching method thereof to solve the above-mentioned problems. Summary of the invention

[0008] The object of the present invention is to provide a thermal breaking component, a liquid gap type thermal switch and a switching method thereof, so as to solve the problems existing in the above-mentioned prior art and utilize the good thermal conductivity of liquid to improve the switching ratio of the thermal breaking component.

[0009] To achieve the above object, the present invention provides the following solutions: The present invention discloses a thermal disconnect component, comprising a hot end body, a cold end body and a support tube, wherein the hot end body and the cold end body are respectively fixed at two ends of the support tube, and a heat conduction cavity is surrounded by the hot end body, the cold end body and the support tube, and the heat conduction cavity can be filled with a heat conduction medium, a hot end extension tube is fixed on a surface of the hot end body close to the cold end body, and a cold end extension column is fixed on a surface of the cold end body close to the hot end body, a heat conduction gap is provided between the hot end extension tube and the cold end extension column, and the heat conduction medium comprises a liquid heat conduction medium, and when the liquid heat conduction medium fills the heat conduction gap, the hot end body and the cold end body can conduct heat.

[0010] Preferably, the inner diameter of the hot end extension cylinder is greater than the diameter of the cold end extension column.

[0011] Preferably, the liquid heat-conducting medium is liquid helium.

[0012] Preferably, the hot end body and the hot end extension tube are manufactured and formed as one piece, and the cold end body and the cold end extension column are manufactured and formed as one piece.

[0013] Preferably, the hot end body, the cold end body, the hot end extension tube and the cold end extension column are all made of oxygen-free copper.

[0014] Preferably, the support tube is made of stainless steel.

[0015] The invention discloses a liquid gap type thermal switch, which comprises a thermal breaking component and an adsorption pump. The adsorption pump is connected with the heat conduction cavity through a connecting pipe.

[0016] The present invention discloses a switching method of a liquid gap type thermal switch, comprising the following steps: Opening state: first install the hot start component, so that the hot end body is connected to the heat source, and the cold end body is connected to the cold source. At this time, the heat transfer medium is in liquid state, and the liquid heat transfer medium fills the heat transfer gap, so that the cold end body is connected to the hot end body. The heat of the cold source is finally transferred to the heat source through the cold end body, the cold end extension column, the liquid at the heat transfer gap, the hot end extension column and the hot end body; Disconnected state: When the connection between the hot end body and the cold end body needs to be disconnected, the heat transfer medium in the heat transfer cavity is first extracted using an adsorption pump. At this time, there is no liquid heat transfer medium in the heat transfer gap, so that heat transfer cannot be carried out between the hot end extension tube and the cold end extension column.

[0017] Compared with the prior art, the present invention has achieved the following technical effects: The present invention utilizes liquid with good thermal conductivity as the heat-conducting medium. When the liquid fills the heat-conducting gap, the connection of the thermal breaking components can be realized, and the switch is relatively large. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is a schematic diagram of the structure of the thermal switch component of Example 1; In the figure: 1-hot end body; 2-cold end body; 3-support tube; 4-hot end extension tube; 5-cold end extension column. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The object of the present invention is to provide a thermal breaking component, a liquid gap type thermal switch and a switching method thereof, so as to solve the problems existing in the above-mentioned prior art and utilize the good thermal conductivity of liquid to improve the switching ratio of the thermal breaking component.

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Embodiment 1 like Figure 1 As shown, this embodiment provides a thermal disconnect component, including a hot end body 1, a cold end body 2 and a support tube 3, the hot end body 1 and the cold end body 2 are arranged opposite to each other, and the hot end body 1 and the cold end body 2 are fixed to the upper and lower ends of the support tube 3 respectively. The hot end body 1, the cold end body 2 and the support tube 3 together form a heat conduction cavity, and the heat conduction cavity can be filled with a heat conduction medium. A hot end extension tube 4 is fixed on the side of the hot end body 1 close to the cold end body 2, and the hot end extension tube 4 is a cylindrical structure. A cold end extension column 5 is fixed on the side of the cold end body 2 close to the hot end body 1, and the cold end extension column 5 is a small cylindrical structure, and a heat conduction gap is provided between the hot end extension tube 4 and the cold end extension column 5. The heat conduction medium includes a liquid heat conduction medium. When the liquid heat conduction medium fills the heat conduction gap, the hot end body 1 and the cold end body 2 can conduct heat.

[0024] In actual use, the hot end body 1 is connected to the heat source, and the cold end body 2 is connected to the cold source. When the heat conduction gap is filled with heat conduction medium, the heat will be transmitted to the heat source through the cold source, the cold end body 2, the cold end extension column 5, the liquid heat conduction medium in the heat conduction gap, the hot end extension tube 4 and the hot end body 1 in sequence, thereby cooling the heat source.

[0025] In this embodiment, the inner diameter of the hot end extension tube 4 is larger than the diameter of the cold end extension column 5. Figure 1 As shown, a portion of the cold end extension column 5 is located inside the lower end of the hot end extension tube 4, and a heat conducting gap is formed between the outer wall of the cold end extension column 5 and the inner wall of the hot end extension tube 4.

[0026] In this embodiment, the liquid heat transfer medium is liquid helium. However, in actual use, the temperature in the heat transfer cavity will change. When the temperature in the heat transfer cavity is high, the liquid helium will be converted into helium, and when the temperature is low, the helium will be converted into liquid helium. Of course, not all of them will be converted into one form during the conversion process, so there are generally two states of helium and liquid helium in the heat transfer cavity. For this reason, compared with the existing air gap type heat switch (such as patent CN110108060B), this embodiment has a smaller heat transfer gap and a larger heat transfer cavity, which is used to accommodate a larger volume of helium after vaporization.

[0027] In this embodiment, the hot end body 1 and the hot end extension tube 4 are integrally manufactured, and the cold end body 2 and the cold end extension column 5 are integrally manufactured.

[0028] In this embodiment, the hot end body 1 , the cold end body 2 , the hot end extension tube 4 and the cold end extension column 5 are all made of materials with high thermal conductivity, including but not limited to oxygen-free copper.

[0029] In this embodiment, the support tube 3 can be made of a material with good heat insulation properties, including but not limited to stainless steel.

[0030] Embodiment 2 The present embodiment provides a liquid gap type thermal switch, including the thermal breaking component disclosed in the first embodiment, and also includes an adsorption pump. For the adsorption pump, the adsorption pump in patent CN110108060B can be used, that is, including a cold end, a hot end and a support member, the cold end, the support member and the hot end are connected in sequence to form a sealing structure, the sealing structure is filled with an adsorbent, the adsorbent is activated carbon, and extension members are provided on the cold end and the hot end, the extension member extends into the adsorbent and is isolated from the support member. For more specific structural connection relationships, please refer to the original text of patent CN110108060B, which will not be repeated here. Of course, those skilled in the art can also replace it with an adsorption pump of other structures, not just limited to this one. The adsorption pump is connected to the heat-conducting cavity through a connecting pipe. Specifically, one end of the connecting pipe will pass through the cold end body 2 and extend into the heat-conducting cavity.

[0031] Embodiment 3 This embodiment provides a switching method of a liquid gap type thermal switch, based on the liquid gap type thermal switch disclosed in the second embodiment, comprising the following steps: Open state: first install the hot end components, so that the hot end body 1 is connected to the heat source, the temperature of the heat source is 30K, and the cold end body 2 is connected to the cold source, the temperature of the cold source is 4K. Of course, the specific temperature of the heat source and the cold source is not limited to this one. At this time, due to the low temperature of the cold source, the temperature of the cold end body 2 and the heat conduction cavity is also low, and it is lower than the boiling point of the liquid heat conduction medium, so that it cannot be vaporized. Therefore, the heat conduction medium is in a liquid state (i.e., liquid helium), and because there is more liquid heat conduction medium, it can fill the heat conduction gap. Connect the cold end body 2 with the hot end body 1. Specifically, during the heat transfer process, the heat of the cold source is finally transferred to the heat source through the cold end body 2, the cold end extension column 5, the liquid at the heat conduction gap, the hot end extension column and the hot end body 1, so as to cool the heat source. During this process, the adsorption pump is in a closed state, or the connecting pipe is in a closed state.

[0032] Disconnected state: Due to experimental needs, when the staff needs to heat the heat source connected to the hot end body 1 separately and avoid the influence of the cold end body 2 on it, it is necessary to disconnect the connection between the hot end body 1 and the cold end body 2. First, start the adsorption pump. For example, in patent CN110108060B, it is necessary to start the cold source of the cold end in the adsorption pump to cool the adsorbent inside the adsorption pump, thereby enhancing its adsorption capacity, and use the adsorption pump to extract the heat-conducting medium in the heat-conducting cavity. At this time, there is no liquid heat-conducting medium in the heat-conducting cavity and the heat-conducting gap, and there is almost no helium. It can be said that the heat-conducting cavity is almost vacuum, and even if there is helium, it is a trace amount of helium. The trace amount of helium in the narrow heat-conducting gap does not have heat-conducting ability, so that heat conduction cannot be carried out between the hot end extension tube 4 and the cold end extension column 5.

[0033] Then enter the next cycle, that is, when the hot end body 1 and the cold end body 2 need to be connected again, start the heater at the hot end of the adsorption pump to heat the hot end of the adsorption pump, so that the temperature of the adsorbent in the adsorption pump increases, thereby reducing its adsorption capacity, so that the helium in the adsorption pump is discharged and enters the thermal disconnection component through the connecting pipe. Once it enters the heat conduction cavity, the cold source at the cold end body 2 will cool it down, so that it condenses and liquefies here and fills the heat conduction gap, so as to achieve the reconnection of the hot end body 1 and the cold end body 2. The next step is the disconnection state, and the above working steps can be repeated continuously, so I will not repeat them.

[0034] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A thermal disconnect component, comprising a hot end body, a cold end body and a support tube, wherein the hot end body and the cold end body are respectively fixed to the two ends of the support tube, and a heat conduction cavity is formed between the hot end body, the cold end body and the support tube, and the heat conduction cavity can be filled with a heat conduction medium, characterized in that: A hot end extension tube is fixed on one surface of the hot end body close to the cold end body, and a cold end extension column is fixed on one surface of the cold end body close to the hot end body. A heat conduction gap is provided between the hot end extension tube and the cold end extension column. The heat conduction medium includes a liquid heat conduction medium. When the liquid heat conduction medium fills the heat conduction gap, the hot end body and the cold end body can conduct heat.

2. The thermal breaking component according to claim 1, characterized in that: The inner diameter of the hot end extension cylinder is greater than the diameter of the cold end extension column.

3. The thermal breaking component according to claim 1, characterized in that: The liquid heat conducting medium is liquid helium.

4. The thermal breaking component according to claim 1, characterized in that: The hot end body and the hot end extension tube are integrally manufactured and formed, and the cold end body and the cold end extension column are integrally manufactured and formed.

5. The thermal breaking component according to claim 1, characterized in that: The hot end body, the cold end body, the hot end extension tube and the cold end extension column are all made of oxygen-free copper.

6. The thermal breaking component according to claim 1, characterized in that: The support tube is made of stainless steel.

7. A liquid gap type thermal switch, characterized in that: The thermal breaking component comprises the thermal breaking component according to any one of claims 1 to 6, and further comprises an adsorption pump, wherein the adsorption pump is connected to the heat conducting cavity through a connecting pipe.

8. A method for switching a liquid gap type thermal switch, characterized in that: The liquid gap type thermal switch according to claim 7 comprises the following steps: Opening state: first install the hot start component, so that the hot end body is connected to the heat source, and the cold end body is connected to the cold source. At this time, the heat transfer medium is in liquid state, and the liquid heat transfer medium fills the heat transfer gap, so that the cold end body is connected to the hot end body. The heat of the cold source is finally transferred to the heat source through the cold end body, the cold end extension column, the liquid at the heat transfer gap, the hot end extension column and the hot end body; Disconnected state: When the connection between the hot end body and the cold end body needs to be disconnected, the heat transfer medium in the heat transfer cavity is first extracted using an adsorption pump. At this time, there is no liquid heat transfer medium in the heat transfer gap, so that heat transfer cannot be carried out between the hot end extension tube and the cold end extension column.

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