CN103423911B - Refrigerator - Google Patents

Abstract

A refrigerator based on microchannel heat recovery and heat exchange technology and coke soup effect processed by atomic diffusion fusion welding technology includes: inlet and outlet parts, heat recovery and heat exchange parts, throttling parts, and evaporation chamber. Among them, the entrance and exit part has an inlet and an outlet; the heat recovery part is composed of at least one high-temperature layer and at least one low-temperature layer adjacent to each other, and each layer has at least one channel, after the relatively high-temperature and high-pressure gas enters the channel of the high-temperature layer Enter the throttling part to complete a throttling and cooling, and then flow to the evaporation chamber with a large space to throttling and cooling again. Due to the throttling and cooling, part of the gas is condensed into liquid, and the rest is low-temperature and low-pressure gas. The two are mixed together to form a low-temperature and low-pressure gas. Vapor-liquid mixture; the low-temperature and low-pressure vapor-liquid mixture keeps the evaporation chamber at a low temperature and cools the high-temperature devices connected to it, and the gas in the evaporation chamber flows back into the channel of the low-temperature layer to exchange heat with the relatively high-temperature and high-pressure gas in the channel of the adjacent high-temperature layer. Exit discharge.

Description

Cooler

technical field

A heat transfer technology based on microchannel heat transfer technology and processed by atomic diffusion fusion welding technology, which is used in the detection and guidance of satellites, weapons, radars, etc., low-temperature electron microscopy, low-temperature medicine, and heat dissipation of electronic components. Cooler with burnt soup effect.

Background technique:

In gas liquefaction and low-temperature refrigeration technology, the Joule-Thomson throttling refrigeration effect (hereinafter referred to as JT effect) of actual gas is the most commonly used method, and as early as 1895, a JT effect throttling refrigeration cycle was developed. For industrial gas liquefaction ^[1] . The development of miniature JT effect refrigerators began in the 1950s, and it usually consists of a counterflow recuperator, a throttling element and an evaporation chamber. Generally, a stainless steel tube with a small diameter (about φ0.5-φ1mm) is used. The ribs are wound around the tube and then a spiral tube is wound on the mandrel. One end of the stainless steel tube is equipped with a throttling element (fixed or adjustable small hole) , capillary or porous material), then insert the Dewar. The throttled gas-liquid mixture is evaporated and refrigerated at the bottom of the Dewar tube (called the head evaporation chamber). The annular gap between the inner wall of the Dewar tube and the mandrel is the channel for the backflow gas, and the backflow low-pressure gas is used for precooling. High-pressure hot gas flow before throttling ^[1] .

Figure 1 is a single-stage JT effect refrigerator with a counter-flow recuperator. As shown in Figure 1, most of the currently used JT effect refrigerators still maintain a structure similar to that of the refrigerator in Figure 1. In such a structure, the mandrel in the middle only plays a supporting role but takes up a lot of space; due to the large difference in length between the incoming flow in the finned spiral tube and the return flow outside the tube, and the gap between the annular gaps is difficult to control, the heat transfer is not good. Sufficient; there is only one or two air intake channels, and the cooling capacity is relatively small. These problems make the cooling capacity of the JT effect small, the compactness is not high, and the application field is relatively limited. The survey found that, as a cooling solution for mid-to-high-end electronic equipment, the JT effect cooler will be more and more used if the cooling capacity can be appropriately enlarged ^[2-9] .

From the analysis of domestic and foreign research literature, it can be seen that with the breakthrough of some key technologies, the development of J-T effect refrigerators has new developments. At present, the research and development status of the J-T effect refrigerator at home and abroad related to the present invention is as follows:

In 2006, Wang Tiangang ^[10,11] put forward two design schemes based on the existing design parameters and related data. Scheme 1 is to arrange all the heat exchanger, throttling element and evaporator on one base material, and use different sizes The fine channel replaces the corresponding heat exchanger, throttling capillary and other components. Option 2 is to use small and parallel thin copper coils as heat exchangers, use welding to make the air inlet and outlet pipelines tightly combined, replace the throttle capillary with closed spiral fine channels, and connect the heat exchanger and throttle elements Connect with the evaporator with pipes to realize throttling expansion refrigeration. The prototype was made by excimer laser micromachining, laser welding and other technologies, and the experimental research was carried out.

In 2007, Lerou ^[12] used etching processing technology to produce a micro-JT effect cooler on a glass wafer. The glass wafer has three layers, and rectangular channels are etched between the layers. There are 8 different designs of heat exchangers14 samples, the groove depth is from 2mm to 4mm, the length is from 15mm to 35mm, and nitrogen is used as the working fluid. The target cooling capacity is 10mW, and the top temperature is 96K. The measurement can reach a maximum cooling capacity of 20mW and a top temperature of 100K.

In 2008, Jianlin YU ^[13] added a suction injection device behind the evaporation chamber to form a new coke soup closed refrigeration cycle. The experimental results showed that the refrigeration efficiency was significantly improved.

In 2010, M HLin ^[14] of the University of Colorado in the United States used six hollow glass fiber tubes in capillary glass tubes to build a miniature scorched soup refrigerator. The glass fiber tubes are high-pressure incoming flow, and the small tube and large tube are low-pressure backflow. , the top is a flat plate type, and the throttling element is a JT expansion valve. Using a mixed working fluid composed of 5 components, the extreme refrigeration temperature in the experiment can reach 77K.

It is generally considered that the hydraulic diameter of the channel is less than 1 mm as a microchannel. Many literatures show that the heat transfer capacity of the microchannel is significantly enhanced compared with the conventional channel. The compactness of the microchannel heat exchanger can reach more than ^1500m2 / ^m3 , and the liquid-liquid heat exchange The volume heat transfer coefficient reaches 7000W/(m ³ K) ^[15] , but due to the surface roughness effect, inlet section effect and other factors, the effect is different from the conventional scale, and the resistance coefficient is relatively large. Because the channel is small, if the working fluid is not clean enough, it is easy to cause blockage. In addition, the influence of axial heat conduction is more significant in some cases.

Atomic diffusion fusion welding technology is a relatively new micro-processing technology at home and abroad. It is different from the micro-channel J-T effect refrigerator processing method proposed by other researchers at home and abroad. A whole with a similar microstructure can achieve: 1) The joint part has no contact thermal resistance, and the manufactured refrigerator has good sealing performance, high pressure resistance, and can withstand a large pressure ratio to ensure throttling cooling effect. 2) The heat exchange on the hot and cold sides of the heat exchanger can realize a multi-layer micro-channel structure, the number of channels can be hundreds or thousands, and the layout and size can be adjusted according to needs. Other microfabrication techniques currently in the literature on microchannel J-T effect refrigerators cannot achieve such a structure.

Invention content:

In view of the above problems, the present invention adopts atomic diffusion fusion welding technology, combines the J-T effect refrigerator and the multilayer microchannel structure together, and finds that the multilayer microchannel structure replaces the conventional spiral fin tube type around the mandrel of the JT effect refrigerator After the heat exchanger (Hampson type heat exchanger), the two can make use of their strengths and circumvent their weaknesses, thereby drawing the refrigerator of the present invention.

The refrigerator of the present invention comprises: an inlet and outlet part, a heat recovery heat exchange part, a throttling part, and an evaporation chamber.

The entrance and exit part has an inlet and an outlet. The inlet can make the relatively high-temperature and high-pressure gas enter the refrigerator and distribute the airflow formed by the relatively high-temperature and high-pressure gas to the heat recovery heat exchange part connected to it. device.

The heat recovery heat exchange part is composed of at least one high-temperature layer with multiple high-temperature and high-pressure channels and at least one low-temperature layer with at least one low-temperature and low-pressure channel. The low-temperature and low-pressure gas in the multiple high-temperature and high-pressure channels of the high-temperature layer of the upper layer exchanges heat with the low-temperature and low-pressure gas in the multiple low-temperature and low-pressure channels of the adjacent low-temperature layer to become a lower-temperature gas and enter the throttling part.

The throttling part, corresponding to the different high-temperature layers of the heat-regenerating heat exchange part, is composed of multiple throttling layers with at least one microchannel. Each high-temperature layer is connected to a throttling layer correspondingly. layer enters the corresponding throttling layer to complete throttling and cooling once, and then flows to the evaporation chamber with a large space to throttling and cooling again. Due to throttling and cooling, part of the gas is condensed into liquid, and the rest is low-temperature and low-pressure gas. Together they form a low-temperature and low-pressure vapor-liquid mixture.

The evaporation chamber gathers the above-mentioned low-temperature and low-pressure vapor-liquid mixture and is always in a low-temperature state. The evaporation chamber is connected with the high-temperature device that needs to be refrigerated, and absorbs the heat of the high-temperature device to achieve the effect of cooling it. The low-temperature and low-pressure vapor-liquid mixture in the evaporation chamber absorbs After heating, the phase changes into low-temperature and low-pressure gas and flows back into the low-temperature and low-pressure channel of the low-temperature layer of the heat exchange part, and realizes heat exchange with relatively high-temperature and high-pressure gas in multiple high-temperature and high-pressure channels of the adjacent high-temperature layer, and finally exits the refrigerator from the outlet .

Further, the refrigerator provided by the present invention may also have such a feature: the throttling part is formed by stacking multiple micro-channels which are finer than each high-temperature and high-pressure channel of the heat-regeneration heat exchange part, and the micro-channels are stacked in layers. The layer where it is located is meandering and spiraling, thereby increasing the length of the throttling process and improving the throttling effect.

Furthermore, the refrigerator provided by the present invention may also have such a feature: the throttling part is composed of a plurality of airflow passages with a porous structure, so as to complete the throttling and refrigeration of the lower-temperature gas.

Further, the refrigerator provided by the present invention may also have the following features: the throttling part is formed by stacking a plurality of micro-channels that are finer than each high-temperature and high-pressure channel of the heat-regeneration part, and the micro-channels adopt Porous structure, the fine channels with porous structure meander and spiral in the layer where it is located, thus increasing the length of the throttling process and improving the throttling effect.

Furthermore, the refrigerator provided by the present invention may also have such a feature: the axially outermost layer of the refrigerator is closed at the inlet and outlet to form a hollow channel, so that the refrigerator can be insulated from heat.

Furthermore, the refrigerator provided by the present invention may also have such a feature: the outer layer of the refrigerator has an insulation layer made of insulation material.

Furthermore, the refrigerator provided by the present invention may also have the following feature: the outer layer of the refrigerator has a shell made of low thermal conductivity material with heat insulation performance.

Further, the refrigerator provided by the present invention may also have such a feature: the hydraulic diameters of all channels in the refrigerator are designed in the range of millimeters and microns.

Further, the refrigerator provided by the present invention may also have such a feature: the multilayer microchannel structure of the refrigerator is made by atomic diffusion fusion welding technology.

In addition, the refrigerator provided by the present invention may also have the following feature: the size and shape of the evaporation chamber depend on the size and shape of the application occasion of the refrigerator.

Invention function and effect

The present invention combines the J-T effect refrigerator with the multi-layer micro-channel structure produced by atomic diffusion fusion welding technology, and finds that the multi-layer micro-channel structure replaces the conventional spiral fin tube heat exchanger around the core of the J-T effect refrigerator (Hampson heat exchanger) The refrigerator of the present invention was derived.

For the JT effect refrigerator, the two parts of heat transfer and throttling are the key. The heat exchange part is heat exchange between the incoming flow and the return flow air. Compared with the Hampson type heat exchanger, the micro-channel structure does not require mandrel support, the heat exchange capacity is strong, the compactness is high, and the air-gas heat exchange will not cause the micro-channel to be blocked. There is no need to worry about the large pressure drop of the microchannel. The data show that the Bernoulli effect in the flow process can be used to assist in throttling and cooling ^[16-18] . In addition, the micro-channel gas path can be dozens, hundreds or even more, and with a suitable head evaporation chamber, the cooling capacity can be increased many times. The inlet pressure of the JT effect refrigerator is generally tens of megapascals. The atomic diffusion fusion welding technology is used to manufacture the technology, and the channels of the multi-layer microchannel structure support each other, and the pressure bearing performance is excellent. Therefore, the microchannel heat recovery and heat exchange JT effect refrigerator It has the characteristics of high pressure resistance, not only safe and reliable, but more importantly, it can ensure the throttling pressure ratio and achieve better throttling refrigeration effect. The microchannel heat recovery and heat exchange JT effect refrigerator adopts materials with relatively moderate thermal conductivity, such as stainless steel, ceramics, glass, silicon, etc. Reasonable channel design and overall design can handle the axial and radial conductivity of the refrigerator in this embodiment. The contradictory relationship between heat and heat can achieve the optimal heat transfer efficiency of microchannel heat exchangers ^{[19, 20]} . In addition, the evaporation chamber can be easily changed in shape during fabrication to suit different applications. Therefore, compared with the existing technology, the refrigerator with multi-layer microchannel heat recovery and heat exchange effect produced by atomic diffusion fusion welding technology should have good refrigeration performance, high compactness, large relative cooling capacity, safety and reliability, and easy to adapt to different The characteristics of the application.

references

[1] Yang Haiming. Optimal Design and Experimental Research of Throttle Refrigerator. Master Thesis of Hefei University of Technology. 2002

[2] Yang Yi, Li Shimo. Micro J-T restrictor (MMR), Cryogenic Engineering, 1991, 81(5): 41-47

[3] Ren Jing, Luo Jingwei, Sun Zhongzhang. Application and development of cryogenic refrigeration technology in optoelectronic devices. Low temperature and superconductivity, 2000, 36(4): 6-12

[4] Tang Xiaowei. Application research of open throttling refrigeration technology in local environmental temperature control. Vacuum and low temperature, 2010, 16(4): 223-226

[5]Ray Radebaugh.Cryocoolers: the state of the art and recent developments.Journal of Physics Condensed Matter.200921:164219

[6] H.J.M.ter Brake, G.F.M.Wiegerinck.Low-power cryocoolersurvey, Cryogenics, 2002, 42(11):705-718

[7] Jayne Fereday, Tom Bradshaw, Martin Crook, Anna Orlowska, Ravinder Bhatia, Martin Linder, Olivier Pin, Arnaud Scommegna, Sylvain Vey.Cryocooler modeling methodology Cryogenics, 2006, 46(2-3): 183-190

[8] Hiroyuki Sugita, Takao Nakagawa, Hiroshi Murakami, Atsushi Okamoto, Hiroki Nagai, Masahide Murakami, Katsuhiro Narasaki, Masayuki Hirabayashi. Cryogenic infrared mission "JAXA/SPICA" with advanced cryocoolers, Cryogenics 4, 04-2003, 4, 2006, -157

[9] Hiroyuki Sugita, Takao Nakagawa, Hiroshi Murakami, Atsushi Okamoto, Hiroki Nagai, Masahide Murakami, Katsuhiro Narasaki, Masayuki Hirabayashi. Cryogenic system design of the nextgeneration infrared space telescope SPICA. 2010, 56-57

[10] Wang Tiangang, Chen Xuekang, Cao Shengzhu, Wang Rui, Yang Jianping, Wu Gan. Analysis and Research of Micro-throttle Refrigerator MMR. Vacuum and Low Temperature, 2006, 26(3): 149-152

[11] Wang Tiangang, Sun Shuze, Yan Chunjie, Huo Yingjie, Xu Guotai. Experimental verification and performance analysis of a MMR refrigerator. Cryogenic Engineering, 2011, 183(5): 61-64

[12] P.P.P.M. Lerou, G.C.F. Venhorst, T.T. Veenstra, H.V. Jansen, J.F. Burger, H.J. Holland, H.J.M. Ter Brake, and H. Rogalla. All-micromachined Joule-Thomson cold stage, Cryocoolers 2007, 14: 437-441

[13] Jianl in Yu. Improving the performance of small Joule-Thomson cryocooler. Cryogenics, 2008, 48: 426-431

[14]P.E.Bradley, R.Radebaugh, M.Huber, M.-H.Lin, and Y.C.Lee.Development of a mixed refrigerator Joule-Thomson microcryocooler.Cryocooler, 2009, 15:425-432

[15] Zhong Yi, Yin Jiancheng, Pan Shengmin. Research progress of microchannel heat exchangers. Refrigeration and Air Conditioning, 2009, 9(5): 1-4

[16] Kaiser.G, Reibig L, Thurk M, Seidel P. About a new type of closed-cycle cryocooler operating by use of the Bernoulli effect. Cryogenics, 1998, 38: 937-942

[17]L.Y.Xiong, G.Kaiser.A.Binneberg.Theoretical study on aminiature Joule-Thomson & Bernoulli Cryocooler.Cryogenics.2004.44:801-807

[18] Xiong Lianyou. A miniature scorched soup refrigerator. Proceedings of the Seventh National Conference on Low Temperature and Refrigeration Engineering, November 2005, Kunming

[19] Gan Yunhua, Yang Zeliang. Effect of axial heat conduction on heat transfer characteristics in microchannels. Acta Chemical Industry, 2008, 59(10): 2436-2441

[20] Frederik Rogiers, Martine Baelmans. Towards maximal heat transfer rate densities for small-scale high effectiveness parallel-plate heat exchangers. International Journal of Heat and Mass Transfer, 2010(53): 605-614

Detailed ways:

Fig. 2 is a schematic structural diagram of the refrigerator in this embodiment; Fig. 5 is a partial structural schematic diagram of the refrigerator in the embodiment. As shown in Figure 2, the refrigerator combines a J-T effect refrigerator with a multi-layer microchannel structure made by atomic diffusion fusion welding technology, including: an inlet and outlet part 6, a heat recovery part 5, a throttling part 3, And evaporation chamber 4.

Fig. 3 is a partial structural schematic diagram of the inlet and outlet of the refrigerator in the embodiment. As shown in Figure 3, the inlet and outlet part 6 has an inlet 1 and an outlet 2. The inlet can allow relatively high-temperature and high-pressure gas to enter the refrigerator and distribute the airflow formed by the relatively high-temperature and high-pressure gas to the heat recovery heat exchange part connected thereto. The high-temperature and high-pressure gas is composed of gas that can realize the throttling refrigeration effect, and the outlet leads the airflow out of the refrigerator after the refrigerator completes the refrigeration process.

The regenerative heat exchange part is composed of multiple high-temperature layers with multiple high-temperature and high-pressure channels and multiple low-temperature layers with multiple low-temperature and low-pressure channels. The high-temperature layer is adjacent to the low-temperature layer. The low-temperature and low-pressure gas in the multiple high-temperature and high-pressure channels of the high-temperature layer exchanges heat with the low-temperature and low-pressure gas in the multiple low-temperature and low-pressure channels of the adjacent low-temperature layer so that it becomes a lower-temperature gas and enters the throttling part.

Fig. 4 is a partial structural schematic diagram of the throttling part of the refrigerator in the embodiment. As shown in Figure 4, the throttling part, corresponding to the different high-temperature layers of the heat recovery heat exchange part, is composed of multiple throttling layers with at least one microchannel, and each high-temperature layer is connected to a throttling layer correspondingly, The lower temperature gas enters the corresponding throttling layer from the high temperature and high pressure layer to complete a throttling and cooling, and then flows to the evaporation chamber with a large space to throttling and cooling again. Due to the throttling and cooling, part of the gas is condensed into liquid, and the rest is low temperature and low pressure. Gas, the two are mixed together to form a low-temperature and low-pressure vapor-liquid mixture.

The cavity at the top of the refrigerator is the evaporation chamber of the refrigerator in this embodiment. The above-mentioned low-temperature and low-pressure vapor-liquid mixture is kept in a low-temperature state. The cooling effect is that the low-temperature and low-pressure gas-liquid mixture in the evaporation chamber absorbs heat and then phase changes into a low-temperature and low-pressure gas that flows back into the low-temperature and low-pressure channel of the low-temperature layer of the heat-regenerating heat exchange part and is connected with multiple high-temperature channels of the adjacent high-temperature layer. The relatively high-temperature and high-pressure gas in the high-pressure channel realizes heat exchange and finally exits the refrigerator from the outlet.

The relatively high-temperature and high-pressure gas passes through the heat exchange part of the heat exchange part, and the lower temperature gas enters the throttling part to start throttling. Three methods can be used to realize the throttling structure:

1) The throttling part is formed by stacking multiple micro-channels that are finer than each high-temperature and high-pressure channel in the heat-regenerating heat exchange part. The micro-channels meander and circle in the layer where they are located, thereby increasing throttling The length of the process improves the throttling effect.

2) The throttling part is composed of a plurality of airflow passages with a porous structure so as to complete the throttling and cooling of the lower temperature gas.

3) The throttling part is formed by stacking multiple micro-channels that are finer than each high-temperature and high-pressure channel in the heat-regenerating heat exchange part. The micro-channels adopt a porous structure, and the micro-channels with a porous structure are in the position where they are located. The layers are meandering and circling so as to increase the length of the throttling process and improve the throttling effect.

The fluid flowing out from the throttling part enters the relatively large evaporation chamber to complete the throttling refrigeration effect and make the evaporation chamber a low temperature state. The structure of the evaporation chamber is a cavity structure, and the shape can be changed according to the application occasion, such as square, conical, cylindrical, etc. When using a coke soup refrigerator, the device with a higher external temperature is connected to the evaporation chamber, and the low-temperature environment in the evaporation chamber can absorb the heat of the external device, so that the temperature of the external device can be maintained at its limited operating temperature level.

The arrangement of high-temperature layers and low-temperature layers can be in various forms, for example: high-temperature layers and low-temperature layers are alternately distributed, two low-temperature layers are located between two high-temperature layers, and so on.

In the refrigerator in this embodiment, the outermost layer or layers of passages along the axial direction can be closed at the entrance and exit to form hollow passages to prevent the internal fluid from exchanging heat with the outside, play a certain role in heat preservation, and also It may not be closed, and the outer layer may be wrapped with a thermal insulation layer made of thermal insulation material, or it may be a shell made of low thermal conductivity material.

The material of the refrigerator in this embodiment is stainless steel, and the refrigerator can also be made of one of glass, ceramics, silicon, or two kinds of metals, or welded metal and non-metal.

Reasonable channel design and overall design can properly handle the contradictory relationship between the axial and radial heat conduction of the refrigerator in this embodiment, and achieve the optimal heat exchange efficiency of the microchannel heat exchanger.

The design range of the hydraulic diameters of all channels in the refrigerator in this embodiment is millimeter-level and micron-level.

Function and effect of embodiment

The refrigerator according to the embodiment has the characteristics of good refrigeration performance, high compactness, large relative refrigeration capacity, safety and reliability, and easy to be suitable for different applications.

Claims (10)

1. A refrigerator, characterized in that, comprising: inlet and outlet; heat recovery and heat exchange; throttling; and evaporation chamber, Wherein, the inlet and outlet part has an inlet and an outlet, the inlet can allow relatively high-temperature and high-pressure gas to enter the refrigerator and distribute the airflow formed by the relatively high-temperature and high-pressure gas to the heat recovery heat exchange part connected thereto, and the outlet will The airflow after the refrigerator completes the refrigeration process is drawn out of the refrigerator; The heat recuperation part is composed of at least one high-temperature layer with multiple high-temperature and high-pressure channels and at least one low-temperature layer with at least one low-temperature and low-pressure channel, the high-temperature layer is adjacent to the low-temperature layer, and the relatively high-temperature and high-pressure The gas enters the multiple high-temperature and high-pressure channels of the high-temperature layer of the heat recovery heat exchange part to exchange heat with the low-temperature and low-pressure gas in the multiple low-temperature and low-pressure channels of the low-temperature layer of the adjacent layer to make it become lower temperature gas and enters said restriction; The throttle part, corresponding to the different high-temperature layers of the heat recovery heat exchange part, is composed of a plurality of throttle layers with at least one microchannel, each of the high-temperature layers corresponds to a throttle layer Connecting, the lower temperature gas enters the corresponding throttling layer from the high temperature layer to complete throttling and cooling once, and then flows to the evaporation chamber with a large space to throttling and cooling again, part of the gas is condensed due to throttling and cooling into a liquid, and the rest are low-temperature and low-pressure gases, and the two are mixed together to form a low-temperature and low-pressure vapor-liquid mixture. The evaporation chamber gathers the above-mentioned low-temperature and low-pressure vapor-liquid mixture and is always in a low-temperature state. The evaporation chamber is connected with high-temperature devices that need to be refrigerated, and absorbs the heat of the high-temperature devices to achieve the effect of cooling them. The low-temperature and low-pressure vapor-liquid in the evaporation chamber The mixture absorbs heat and phase changes into low-temperature and low-pressure gas, which flows back into the low-temperature and low-pressure channel of the low-temperature layer of the heat exchange part, and exchanges heat with relatively high-temperature and high-pressure gas in multiple high-temperature and high-pressure channels of the adjacent high-temperature layer, and finally discharges refrigeration from the outlet device. 2. The refrigerator according to claim 1, characterized in that: The throttling part is formed by stacking a plurality of microscopic channels that are finer than each high-temperature and high-pressure channel in the heat-regenerating heat exchange part. The length of the throttling process is increased, and the throttling effect is improved. 3. The refrigerator according to claim 1, characterized in that: The throttling part is composed of a plurality of gas flow channels with a porous structure so as to accomplish throttling and cooling of the lower temperature gas. 4. The refrigerator according to claim 1, characterized in that: The throttling part is composed of a plurality of micro-channels that are finer than each high-temperature and high-pressure channel of the heat recovery heat exchange part. The micro-channels adopt a porous structure, and the porous structure has a porous structure. The micro channel twists and turns in the layer where it is located, thereby increasing the length of the throttling process and improving the throttling effect. 5. The refrigerator according to claim 1, characterized in that: The size and shape of the evaporation chamber depend on the size and shape of the application of the refrigerator. 6. The refrigerator according to claim 1, characterized in that: The axially outermost layer of the refrigerator is closed at the inlet and outlet to form a hollow passage, so that the refrigerator can be insulated from heat. 7. The refrigerator according to claim 1, characterized in that: The outer layer of the refrigerator has an insulating layer made of insulating material. 8. The refrigerator according to claim 7, characterized in that: The outer layer of the refrigerator is also provided with a shell made of low thermal conductivity material with thermal insulation performance. 9. The refrigerator according to claim 1, characterized in that: The hydraulic diameters of the high-temperature and high-pressure channels, the low-temperature and low-pressure channels and the micro-channels in the refrigerator are designed in the order of millimeters and microns. 10. The refrigerator according to claim 1, characterized in that: The high-temperature and high-pressure channel, the low-temperature and low-pressure channel and the microchannel structure of the refrigerator are fabricated by atomic diffusion fusion welding technology.