A heat rejection device for a heat engine

Abstract

A kind of refrigerator hot end and its heat dissipation method, two-phase heat exchange structure based on capillary structure will be coupled with refrigerator hot end, form the light and efficient heat transfer refrigerator hot end;Adopt gas-liquid two-phase heat transfer working medium under the driving of capillary force realizes the long-distance high-efficiency dissipation of the heat of refrigerator hot end, can ensure the long-distance dissipation of the large power heat generated by refrigerator hot end under the condition of reducing the weight, size and heat transfer temperature difference of traditional refrigerator hot end, can be applied to space cryogenic refrigerator hot end high-efficiency heat dissipation.

Description

Technical Field

[0001] This invention relates to the field of space thermal control, and in particular to a heat dissipation device for the hot end of a refrigerator. Background Technology

[0002] Refrigeration units (such as pulse tube refrigerators and Stirling refrigerators) are widely used in tasks such as infrared remote sensing, deep space exploration, and space science exploration. They can operate normally under input electrical power and achieve cooling at the cold end, providing cooling capacity to the payload and thus maintaining the low-temperature environment required for the payload to operate.

[0003] Normally, a refrigeration unit operates at a low temperature at its cold end and a high temperature at its hot end. To maintain long-term stable operation, heat dissipation is typically required at the hot end of the refrigeration unit, as shown in the attached diagram. Figure 5 As shown in the attached diagram. In space missions, heat pipe technology is commonly used to dissipate heat from the hot end of the refrigerator. The typical approach is to design a heat dissipation surface at the hot end of the refrigerator, attach the evaporator section of the heat pipe to this surface, and attach the condenser section of the heat pipe to a radiant heat sink. This allows the heat generated at the hot end of the refrigerator to be transferred to the radiator and dissipated outwards via heat pipes. Figure 6 As shown.

[0004] When using heat pipes for heat transfer, two characteristics need to be considered:

[0005] (1) Heat transfer capacity

[0006] Based on the characteristics of heat pipes, for a completed heat pipe design, the product of its maximum heat transfer power and its length is a relatively fixed value. Therefore, its maximum heat transfer power is lower when the transmission distance is long, and lower when the heat transfer power is high.

[0007] (2) Heat flux density

[0008] Due to the characteristics of heat pipes, the connection between the evaporator section and the heat source requires a certain heat flux density (the ratio of heat transfer power to contact area) to ensure normal heat transfer. Therefore, to ensure that the heat flux density meets the requirements for heat pipe operation, the contact area between the heat pipe and the heat source must be proportional to the heat transfer power.

[0009] In summary, for low-power refrigerators, the heat generated at the hot end is relatively small (generally less than 50W), and heat pipes can be used to connect the hot end to meet the heat transfer requirements. However, due to the longer heat transfer path, the temperature difference is still relatively large. For high-power refrigerators (heat generated at the hot end of 50W to 300W, or even higher), the size of the heat-generating part at the hot end is not significantly larger than that of low-power refrigerators, typically within... Within this range, in order to effectively dissipate the heat generated, if a conventional heat pipe solution is adopted, the hot end of the refrigerator needs to be designed as a large structure so that the coupling between the hot end of the refrigerator and the heat pipe can achieve normal heat transfer. However, the large size of the hot end structure of the refrigerator itself will have a large heat transfer temperature difference and will significantly increase the weight of the hot end of the refrigerator, which is not conducive to the strict weight requirements of the space mission.

[0010] Therefore, reducing the heat transfer temperature difference during the heat dissipation process at the hot end of the refrigerator while simultaneously reducing the weight of the refrigerator is an urgent requirement for space missions. Summary of the Invention

[0011] In view of this, the present invention provides a heat dissipation device for the hot end of a refrigerator, which can achieve efficient heat dissipation at the hot end of the refrigerator and significantly reduce the weight of traditional refrigerators, thus helping to meet the strict weight requirements of space missions.

[0012] The heat dissipation device for the hot end of the refrigeration unit disclosed herein includes: a hot end heat dissipation evaporation device, a steam pipeline, a liquid pipeline, and a radiative heat dissipation device, wherein:

[0013] The hot end includes a hot end airflow channel, a hot end heat transfer fin, and a hot end shell;

[0014] The hot-end heat dissipation evaporation device is coupled to the hot end of the refrigerator through the shell of the hot end to achieve heat transfer; it is connected to the radiative heat dissipation device through two parallel pipelines, a steam pipeline and a liquid pipeline.

[0015] The hot-end heat dissipation evaporation device contains a gas-liquid two-phase heat transfer medium. After receiving heat from the hot-end shell of the refrigerator in a liquid state, the medium vaporizes and travels through a steam pipe to the radiative heat dissipation device. After dissipating heat, it returns to a liquefied state and travels back to the hot-end heat dissipation evaporation device through a liquid pipe.

[0016] Furthermore, the hot-end heat dissipation evaporation device includes a liquid storage chamber, a transmission core, an evaporation core, and a steam tank; wherein:

[0017] The liquid storage chamber is a hollow structure used to store liquid heat transfer fluid;

[0018] The transport core and the evaporation core are porous media structures. One end of the transport core is inserted into the liquid storage chamber, adhering to the inner wall of the liquid storage chamber and contacting the liquid therein. At the same time, the part outside the liquid storage chamber is adhering to the evaporation core, so that the liquid working fluid in the liquid storage chamber can enter the evaporation core through the transport core under the drive of capillary force.

[0019] The evaporation core is in contact with the hot end shell to enable heat transfer from the hot end shell to the working fluid inside the evaporation core, allowing the liquid working fluid to evaporate upon heating.

[0020] One end of the evaporator core is connected to the steam tank to contain the vaporized working fluid;

[0021] The steam tank is connected to the steam pipeline. When the gas pressure in the tank reaches a certain value, the vaporized substance is driven into the steam pipeline.

[0022] Furthermore, the transmission core is a porous medium with a large hydraulic diameter and high permeability; the evaporation core is a porous medium with a small hydraulic diameter.

[0023] Furthermore, the hot end of the refrigeration unit is a porous hot end structure or a slit fin hot end structure, with multiple steam channels distributed longitudinally along the circumference on its outer surface, and the evaporation core is arranged inside the channels.

[0024] Furthermore, both the steam pipeline and the liquid pipeline are slender metal pipes.

[0025] The heat dissipation device for the hot end of the refrigerator disclosed herein adopts a scheme based on two-phase heat transfer technology and coupling with the hot end of the refrigerator, which can realize the efficient transfer and dissipation of heat generated at the hot end of the refrigerator. While reducing the heat transfer temperature difference, it can significantly reduce the weight and size of the refrigerator.

[0026] Compared with the prior art, the beneficial effects of this disclosure are:

[0027] (1) The heat transfer at the hot end of the refrigerator is achieved through the coupling between the hot end shell and the hot end heat dissipation evaporator. The heat transfer path is short and the heat transfer temperature difference is small.

[0028] (2) The heat transfer is achieved by a two-phase heat exchange method inside the hot end heat dissipation evaporator. It has high heat transfer efficiency and can adapt to a large heat flux density. It can significantly reduce the area required for hot end heat dissipation, so that the size and weight of the hot end heat dissipation evaporator required for the heat dissipation of the refrigeration machine are smaller.

[0029] (3) The internal transmission core of the hot end heat dissipation evaporator is a porous medium with a large hydraulic diameter and high permeability, which is conducive to reducing the flow resistance of the liquid inside it; the evaporation core is a porous medium with a small hydraulic diameter, which is conducive to generating a large capillary force at the gas-liquid interface, thereby enabling long-distance transmission of the working fluid, so that the refrigerator can meet the high-power heat dissipation requirements when the distance between the condenser (radiation heat dissipation surface) and the hot end of the refrigerator is far.

[0030] (4) The steam pipeline and liquid pipeline are slender metal pipes, which introduce less weight in the process of meeting the requirements of long-distance transmission, and can greatly reduce the weight resource requirements of long-distance transmission. Attached Figure Description

[0031] The above and other objects, features and advantages of this disclosure will become more apparent from the more detailed description of exemplary embodiments of this disclosure taken in conjunction with the accompanying drawings, in which the same reference numerals generally represent the same components.

[0032] Figure 1 This is a schematic diagram of the heat dissipation cycle process of the hot end of the refrigeration unit disclosed herein, wherein: 1-hot end, 2-hot end heat dissipation evaporation device, 3-steam pipeline, 4-liquid pipeline, 5-radiator heat dissipation device;

[0033] Figure 2 This is a schematic diagram of an exemplary heat dissipation device for the hot end of a refrigerator according to the present disclosure, wherein: 1-hot end, 2-hot end airflow channel, 3-hot end shell, 4-liquid pipeline, 5-liquid receiver, 6-transfer core, 7-evaporation core, 8-steam tank, 9-hot end heat dissipation evaporator, 10-steam pipeline, 11-condenser.

[0034] Figure 3 This is a schematic diagram of a porous hot end structure, where: 1-heat exchange fins, 2-steam channels, 3-airflow channels, and 4-hot end shell;

[0035] Figure 4 This is a schematic diagram of a slit-fin hot-end structure, where: 1-steam channel, 2-hot-end shell, 3-gas passage, 4-heat exchange fins;

[0036] Figure 5 This is a 3D diagram of the cold end structure of a traditional refrigeration unit, where: 1-connecting pipe, 2-cold mass, 3-cold end, 4-hot end heat spreader plate, 5-hot end;

[0037] Figure 6 This is a schematic diagram of the hot end structure of a traditional refrigeration unit and its heat dissipation method, where: 1-hot end of the refrigeration unit, 2-heat expansion plate of the hot end of the refrigeration unit, 3-heat pipe, 4-radiant radiator. Detailed Implementation

[0038] Preferred embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0039] This disclosure provides a heat dissipation device for the hot end of a refrigerator, comprising a hot-end heat dissipation evaporator, a steam pipeline, a liquid pipeline, and a radiative heat dissipation device. The hot-end heat dissipation evaporator is coupled to the hot end of the refrigerator via the refrigerator's hot-end shell to achieve heat transfer; and is connected to the radiative heat dissipation device via two parallel pipelines, the steam pipeline and the liquid pipeline. A simplified schematic diagram of its heat dissipation process is attached. Figure 1 As shown: The liquid heat transfer medium of the hot end heat dissipation evaporation device, after receiving heat from the hot spot shell, reaches the radiation heat dissipation device in a vaporized state through the steam pipeline, dissipates heat, returns to the liquefied state, and returns to the hot end heat dissipation evaporation device through the liquid pipeline.

[0040] Appendix Figure 2 An exemplary embodiment of the heat dissipation device for the hot end of a refrigerator according to this disclosure is provided, including: a hot end of the refrigerator 1, a hot end heat dissipation evaporator 9, a liquid pipeline 4, a steam pipeline 10, and a condenser 11 as a radiative heat dissipation device. Wherein:

[0041] Hot end 1 includes: hot end airflow channel 2, hot end shell 3, and hot end heat transfer fins;

[0042] The hot-end heat dissipation evaporator 9 is coupled to the hot end via the hot-end shell 3, and heat is transferred between the two through the hot-end shell. Simultaneously, the hot-end heat dissipation evaporator is connected to the condenser via steam and liquid pipelines.

[0043] The hot-end heat dissipation evaporator 9 includes a liquid reservoir 5, a transmission core 6, an evaporation core 7, a steam tank 8, and a heat transfer medium.

[0044] The liquid reservoir is a cavity, and the transfer core and evaporation core are porous media structures. One end of the transfer core is inserted into the liquid reservoir and contacts its inner wall and the liquid in the liquid reservoir. The part outside the liquid reservoir cavity is in close contact with the evaporation core, so that the liquid in the liquid reservoir enters the transfer core under the action of capillary force and further enters the evaporation core. The evaporation core contacts the hot end shell, realizing the thermal connection between the hot end shell and the working medium inside the evaporation core, so that the working medium inside the evaporation core can be heated and evaporated into steam.

[0045] One end of the evaporator core is connected to the steam tank. The generated steam enters the steam tank. Due to the continuous generation of heat, the amount of steam in the steam tank continues to increase, and then enters the steam pipeline under the drive of gas pressure.

[0046] After the gaseous heat transfer medium reaches the condenser through the steam pipeline, it condenses and flows into the liquid storage tank through the liquid pipeline under the action of liquid capillary force in the hot end heat dissipation evaporator. This cycle can achieve efficient and continuous transfer of heat generated at the hot end to the condenser.

[0047] In this disclosure, the heat transfer medium is a working medium in a gas-liquid two-phase state within the operating temperature range, which fills the cavities in the liquid pipeline, the liquid reservoir, the transfer core, and the evaporation core during operation.

[0048] In this embodiment, the hot end of the refrigerator can be Figure 3 The porous hot-end structure shown can also be used as Figure 4 The slit-fin hot-end structure shown can have its vapor channels evenly or unevenly distributed around the circumference. Its design aims to minimize the heat transfer resistance of the refrigerant in the airflow channel from the heat exchange fins and hot-end shell to the hot-end evaporator.

[0049] The preferred approach is to arrange the evaporation core and the transfer core in a circumferential direction inside multiple steam channels (one side of the evaporation core has a channel that couples with the hot end shell, and the other side contacts the transfer core). The purpose of this approach is to facilitate process implementation and ensure the contact area between the evaporation core and the hot end shell.

[0050] With based Figure 5 and Figure 6 Compared to the traditional refrigeration unit's hot-end structure and heat dissipation method, the present invention can effectively reduce the temperature difference between the hot-end fins and the radiant heat sink (condenser), significantly reduce weight and size envelope, and enable long-distance heat transfer. The differences between the two are listed in the table below.

[0051] Table 1 Comparison of the present invention with traditional structures and methods

[0052]

[0053] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A heat dissipation device for the hot end of a refrigeration unit, characterized in that, include: The system includes a hot-end heat dissipation evaporation device, steam piping, liquid piping, and a radiant heat dissipation device, among which: The hot-end heat dissipation evaporation device is coupled to the hot end of the refrigerator through the shell of the hot end to achieve heat transfer; it is connected to the radiative heat dissipation device through two parallel pipelines, a steam pipeline and a liquid pipeline. The hot-end heat dissipation evaporation device contains a gas-liquid two-phase heat transfer working fluid. After receiving heat from the hot-end shell of the refrigerator in a liquid state, the working fluid reaches the radiation heat dissipation device through the steam pipeline in a vaporized state, dissipates heat, and returns to the liquefied state, then returns to the hot-end heat dissipation evaporation device through the liquid pipeline. The hot-end heat dissipation evaporation device includes a liquid storage chamber, a transmission core, an evaporation core, and a steam tank; wherein: The liquid storage chamber is a hollow structure used to store liquid heat transfer fluid; The transport core and the evaporation core are porous media structures. One end of the transport core is inserted into the liquid storage chamber, adhering to the inner wall of the liquid storage chamber and contacting the liquid therein. At the same time, the part outside the liquid storage chamber is adhering to the evaporation core, so that the liquid working fluid in the liquid storage chamber can enter the evaporation core through the transport core under the drive of capillary force. The evaporation core is in contact with the hot end shell at the same time, which is used to realize the heat transfer from the hot end shell to the working fluid inside the evaporation core, so that the liquid working fluid can be heated and evaporated. One end of the evaporator core is connected to the steam tank to contain the vaporized working fluid; The steam tank is connected to the steam pipeline. When the gas pressure in the tank reaches a certain value, the vaporized substance is driven into the steam pipeline.

2. The heat dissipation device as described in claim 1, characterized in that, The transmission core is a porous medium with a large hydraulic diameter and high permeability; the evaporation core is a porous medium with a small hydraulic diameter.

3. The heat dissipation device as described in claim 1, characterized in that, The hot end of the refrigeration unit has a porous hot end structure or a slit fin hot end structure, and its outer surface has multiple steam channels distributed longitudinally along the circumference. The evaporation core is arranged inside the channels.

4. The heat dissipation device as described in any one of claims 1-3, characterized in that, Both the steam pipeline and the liquid pipeline are slender metal pipes.

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