Ultra-miniature throttling refrigerator

Abstract

The present application relates to throttling refrigerator technical field, specifically, it relates to a kind of super micro throttling refrigerator, including plate structure, the plate structure includes sequentially bonded multiple substrates from top to bottom, the inside of the plate structure is provided with sequentially communicated high-pressure flow channel, throttling element, expansion cavity and low-pressure flow channel, the throttling element and the expansion cavity are arranged in layers, and the throttling hole of the throttling element is just for the top of the expansion cavity.This application improves the uniformity of super micro throttling refrigerator cold end temperature, avoids the crack of throttling refrigerator and chip due to temperature non-uniformity;Expansion cavity multi-point heat transfer, can reduce the time of expansion cavity temperature to reach stable, conducive to later detector imaging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of throttling refrigerators, in particular to an ultra-micro throttling refrigerator. BACKGROUND

[0002] Throttling refrigeration detectors are widely used in air-to-air and air defense missiles due to their small size, short refrigeration time, and small electromagnetic interference, such as the TN-2 project of the applicant. The development direction of the new generation of infrared focal plane detectors is Swap3 (small size, low weight, high performance, low power consumption and low cost), and the detector is often limited by space, and a smaller cryogenic refrigerator needs to be developed. Compared with the existing rapid cooling throttling refrigerator, the ultra-micro throttling refrigerator uses MEMS technology to prepare a micro high-low pressure fluid channel to replace the mechanically wound capillary tube, which has the characteristics of small size, light weight, good batch production, and low cost, and is conducive to the realization of low-cost miniaturization of infrared assemblies.

[0003] At present, most of the ultra-micro throttling refrigerators are bonded by three glass substrates. Before bonding, high-pressure gas microchannels, low-pressure gas microchannels, throttling elements, expansion cavities and other components are etched and processed on two of the glass substrates. After the high-pressure gas passes through the high-pressure gas microchannel, the throttling element generates a throttling effect, and the throttled low-temperature gas flows out to the atmosphere through the low-pressure gas microchannel, and in this process, the backflow of low-temperature gas exchanges heat with the high-pressure gas through the glass substrate, continuously reducing the temperature of the high-pressure gas before throttling, and finally the refrigeration temperature of the refrigerator is reduced to the two-phase region of the working medium and reaches equilibrium.

[0004] At present, the expansion cavity and the throttling element of this type of ultra-micro throttling refrigerator are arranged on the same side, and the gas working medium flowing out of the throttling element will continue to expand and absorb heat at the outlet of the throttling element, which means that if the throttling element is only arranged on one side of the expansion cavity, the temperature difference at different positions in the expansion cavity during the cooling process will be large, which will bring two negative effects: first, the large temperature difference at different positions in the expansion cavity will cause a large temperature difference at different positions of the chip (the chip is completely attached to the expansion cavity), thereby increasing the thermal stress on the surface of the chip and causing the chip to crack; second, the large temperature difference at different positions in the expansion cavity will increase the time for the chip temperature to reach a stable equilibrium, thereby increasing the imaging time of the detector. Therefore, in order to reduce the risk of chip cracking and reduce the imaging time of the detector, it is necessary to reduce the temperature difference at different positions in the expansion cavity of the refrigerator during the cooling process, and therefore the relative position of the throttling element and the expansion cavity of the refrigerator needs to be redesigned. SUMMARY

[0005] The present application aims to provide an ultra-micro throttling refrigerator that can improve the uniformity of the cold end temperature of the ultra-micro throttling refrigerator and avoid cracking of the throttling refrigerator and the chip (completely attached to the expansion cavity) caused by uneven temperature.

[0006] The technical solution of this invention is implemented as follows:

[0007] An ultra-miniature throttling cooler includes a plate structure comprising multiple substrates bonded sequentially from top to bottom. The plate structure has a high-pressure flow channel, a throttling element, an expansion cavity, and a low-pressure flow channel arranged sequentially inside. The throttling element and the expansion cavity are arranged in layers, with the throttling orifice of the throttling element facing directly above the expansion cavity.

[0008] Furthermore, the throttling element and the expansion cavity are respectively disposed on the upper and lower sides of the same substrate.

[0009] Furthermore, the throttling element includes a plurality of throttling orifices, which are uniformly arranged above the expansion cavity.

[0010] Furthermore, the throttling element includes a plurality of throttling tubes communicating with the outlet of the high-pressure flow channel, and each throttling tube is provided with at least one throttling orifice.

[0011] Furthermore, the plate structure includes a cover plate, a high-pressure side plate, and a low-pressure side plate bonded sequentially from top to bottom. The high-pressure flow channel and the throttling element are formed on the upper side of the high-pressure side plate, the expansion cavity is at least partially formed on the lower side of the high-pressure side plate, and the low-pressure flow channel is formed on the upper side of the low-pressure side plate.

[0012] Furthermore, the expansion cavity includes a first expansion cavity formed on the lower side of the high-pressure side plate and a second expansion cavity formed on the upper side of the low-pressure side plate, and the first expansion cavity and the second expansion cavity are connected.

[0013] Furthermore, the cover plate is provided with a high-pressure air inlet, which is connected to the high-pressure flow channel.

[0014] Furthermore, the plate structure is provided with a low-pressure vent hole, which is connected to the low-pressure flow channel. The low-pressure vent hole includes an outlet of the low-pressure flow channel, a through hole on the high-pressure side plate, and a vent hole on the cover plate.

[0015] Furthermore, both the high-pressure flow channel and the low-pressure flow channel are spirally arranged.

[0016] Furthermore, the high-pressure flow channel, the low-pressure flow channel, and the throttling element are all fabricated on the substrate by laser etching and / or wet etching.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] Compared to existing ultra-miniature throttling coolers where the throttling element and expansion cavity are positioned on the same side of the substrate and the throttling orifice is directly opposite the side of the expansion cavity, this invention changes the relative positions of the throttling element and expansion cavity. It arranges the throttling element and expansion cavity in upper and lower layers, with the throttling orifice directly above the expansion cavity. This increases the flexibility of the throttling element arrangement, resulting in a greater number of cold sources cooling the expansion cavity and a more uniform spatial distribution. Therefore, the main advantages of this structure are as follows:

[0019] 1. Improved the temperature uniformity of the cold end of the ultra-miniature throttling cooler, avoiding chip cracking caused by uneven temperature in the throttling cooler and the chip (which is completely in contact with the expansion chamber);

[0020] 2. Multi-point heat transfer in the expansion cavity can reduce the time it takes for the expansion cavity temperature to stabilize, which is beneficial for subsequent detector imaging. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Fig. 1 This is a schematic diagram of the structure of the ultra-miniature throttling cooler after bonding according to the present invention;

[0023] Fig. 2 This is a schematic diagram of the exploded structure of the ultra-miniature throttling refrigerator of the present invention;

[0024] Fig. 3 This is a schematic diagram of the internal flow channel structure of the ultra-miniature throttling cooler of the present invention.

[0025] In the picture:

[0026] 1-Low-pressure side plate; 101-Low-pressure flow channel; 2-High-pressure side plate; 201-High-pressure flow channel;

[0027] 3-Cover plate; 4-High-pressure air inlet; 5-Air outlet; 6-Through hole;

[0028] 7-Throttle element; 8-Expansion chamber; 9-Throttle orifice; 11-Outlet. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0034] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] The following is in conjunction with the appendixFigs. 1-3 The following describes some embodiments of the present invention in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0036] Example 1

[0037] The ultra-miniature throttling refrigerator mainly includes a high-pressure gas cylinder, a cover plate 3, a high-pressure side plate 2, a low-pressure side plate 1, and connecting pipes. The throttling element 7 and the hot and cold fluid channels are etched and machined on the high and low-pressure side plates. Finally, the three machined substrates are bonded and sealed to form the ultra-miniature throttling refrigerator. Generally, the working fluid in the high-pressure gas cylinder flows through the high-pressure channel on the high-pressure side plate 2 and is throttled by the throttling element 7. It then expands in the expansion chamber, causing a temperature drop. The throttled, low-temperature return gas working fluid enters the low-pressure channel on the low-pressure side plate 1 and exchanges heat with the high-pressure incoming gas working fluid in the high-pressure channel on the high-pressure side plate 2 before being discharged to the atmosphere. In this way, the high-temperature incoming gas working fluid is continuously cooled by the low-temperature return gas working fluid, allowing the gas working fluid to be throttled at a lower temperature, thus achieving a lower cooling temperature, until a portion of the gas working fluid is liquefied, reaching a gas-liquid two-phase equilibrium state. With the rapid development of micro-low temperature electronic devices and low temperature nanotechnology, this type of ultra-miniature throttling cooler is gradually being applied to important fields such as national defense, space technology, and biomedicine, for example, ultra-miniature infrared detectors, low-noise amplifiers, and superconducting quantum interference devices.

[0038] This invention optimizes and improves the relative positions of the throttling element 7 and the expansion cavity 8 in existing ultra-miniature throttling coolers, proposing an arrangement method that can improve the cold-end temperature uniformity of ultra-miniature throttling coolers. Compared with existing arrangements of the throttling element 7 and expansion cavity 8 in ultra-miniature throttling coolers, this arrangement method, while maintaining the total cross-sectional area of ​​the throttling element 7, divides the throttling element 7 into multiple equal parts and arranges them in a uniform array, changing the previous same-side air intake throttling to opposite-side air intake throttling. This arrangement method, without changing the cooler structure, improves the cold-end temperature uniformity of the cooler by changing the relative positions of the throttling element 7 and the expansion cavity 8, which is beneficial for rapid temperature stabilization of the chip in the later stages and reduces the detector imaging time.

[0039] Reference Figs. 1-3 This embodiment provides a technical solution, as shown below:

[0040] An ultra-miniature throttling refrigerator includes a plate structure, such as Fig. 3As shown, the board structure includes multiple substrates bonded sequentially from top to bottom. The board structure contains a high-pressure flow channel 201, a throttling element 7, an expansion cavity 8, and a low-pressure flow channel 101 connected sequentially. The throttling element 7 and the expansion cavity 8 are arranged in upper and lower layers, with the throttling orifice 9 of the throttling element 7 facing directly above the expansion cavity 8. This embodiment arranges the throttling element and expansion cavity in upper and lower layers, with the throttling orifice facing directly above the expansion cavity. Compared to the conventional approach of placing the throttling element on one side of the expansion cavity and the throttling orifice facing the side of the expansion cavity, this increases the flexibility of the throttling element arrangement. The throttling element can be arranged in a wider range and with more diverse arrangement forms. The throttling orifice can be located in the center of the expansion cavity or evenly distributed above the expansion cavity, improving the temperature uniformity of the cold end of the ultra-miniature throttling cooler. This avoids chip cracking caused by uneven temperature in the throttling cooler and the chip (which is completely attached to the expansion cavity). Furthermore, by setting a larger number of throttling orifices, the expansion cavity can transfer heat at multiple points, reducing the time it takes for the expansion cavity temperature to stabilize, which is beneficial for subsequent detector imaging.

[0041] In this embodiment, the throttling element 7 and the expansion cavity 8 are respectively disposed on the upper and lower sides of the same substrate.

[0042] In this embodiment, the throttling element 7 includes a plurality of throttling orifices 9, which are uniformly arranged above the expansion cavity 8.

[0043] Furthermore, the throttling element includes multiple throttling tubes connected to the outlet of the high-pressure flow channel 201, and each throttling tube is provided with at least one throttling orifice 9. In this preferred embodiment, there are three throttling tubes, and each throttling tube is provided with three throttling orifices 9, that is, the number of throttling orifices 9 in the throttling element 7 is nine, and the nine throttling orifices 9 are arranged in a 3×3 evenly distributed array.

[0044] In this embodiment, the plate structure includes a cover plate 3, a high-pressure side plate 2, and a low-pressure side plate 1, which are bonded together sequentially from top to bottom. It should be noted that the cover plate 3, the high-pressure side plate 2, and the low-pressure side plate 1 can not only be bonded together sequentially from top to bottom; this is merely a preferred embodiment for clarity and ease of understanding. They can also be bonded together sequentially from bottom to top, from left to right, or from right to left, as long as they are bonded sequentially.

[0045] In this embodiment, the plate structure is provided with a high-pressure flow channel 201, a throttling element 7, an expansion cavity 8 and a low-pressure flow channel 101 connected in sequence. The high-pressure flow channel 201 and the throttling element 7 are formed on the upper side of the high-pressure side plate 2, the expansion cavity 8 is at least partially formed on the lower side of the high-pressure side plate 2, and the low-pressure flow channel 101 is formed on the upper side of the low-pressure side plate 1.

[0046] In this embodiment, the expansion cavity 8 further includes a first expansion cavity formed on the lower side of the high-pressure side plate 2 and a second expansion cavity formed on the upper side of the low-pressure side plate 1. The first expansion cavity and the second expansion cavity are connected to each other, thereby increasing the volume of the expansion cavity and improving the throttling cooling effect.

[0047] In this embodiment, the outlet of the high-pressure flow channel 201 is connected to the expansion cavity 8 through a plurality of throttling holes 9, and the expansion cavity 8 is connected to the inlet of the low-pressure flow channel 101.

[0048] The multiple throttling orifices 9 on the throttling element 7 are evenly distributed corresponding to the expansion cavity 8. The outlet of the high-pressure flow channel 201 is connected to the expansion cavity 8 through the multiple throttling orifices 9, and the airflow can flow evenly to the expansion cavity 8 through the multiple throttling orifices 9.

[0049] In this embodiment, the plate structure is provided with a low-pressure vent hole, which is connected to the low-pressure flow channel 101, and the expansion chamber 8 is connected to the inlet of the low-pressure flow channel 101.

[0050] The low-pressure vent includes an outlet 11 connected to the low-pressure flow channel 101, a through hole 6 on the high-pressure side plate 2, and an outlet 5 on the cover plate 3. The outlet 11 is provided at the outlet of the low-pressure flow channel 101, and the through hole 6 is provided on the high-pressure side plate 2. The outlet 11 is connected to the outlet 5 through the through hole 6, and the low-pressure vent facilitates the discharge of low-pressure gas.

[0051] In this embodiment, both the high-pressure flow channel 201 and the low-pressure flow channel 101 are spirally arranged. The advantage of the spiral arrangement is that it can increase the total length of the high-pressure flow channel 201 and the low-pressure flow channel 101, making the airflow smoother and more uniform.

[0052] The low-pressure side plate 1, the high-pressure side plate 2, and the cover plate 3 are all square plates with the same dimensions. The four sides of the low-pressure side plate 1, the four sides of the high-pressure side plate 2, and the four sides of the cover plate 3 can be perfectly aligned after bonding.

[0053] Furthermore, such as Fig. 2As shown, both the high-pressure flow channel 201 and the low-pressure flow channel 101 are arranged in a square spiral. This is designed based on the fact that both the low-pressure side plate 1 and the high-pressure side plate 2 are square plates. This design can make the most of the space.

[0054] To ensure that there is no cross-flow between the low-pressure side plate 1, the high-pressure side plate 2 and the cover plate 3, all contact surfaces of the two substrates in contact must be bonded during bonding.

[0055] Both the high-pressure flow channel 201 and the low-pressure flow channel 101 are formed by laser etching and / or wet etching.

[0056] The air outlet 11, the through hole 6, and the air outlet 5 are arranged coaxially.

[0057] The diameters of the air outlet 11, the through hole 6, and the air outlet 5 are the same.

[0058] The low-pressure side plate 1, the high-pressure side plate 2, and the cover plate 3 are all glass substrates.

[0059] The throttling orifice 7 and the expansion cavity 8 are arranged on both sides of the high-pressure side plate 2. This arrangement ensures that during the cooling process, the wall of the expansion cavity 8 is simultaneously cooled by nine evenly distributed cold sources. Compared to the previous single-sided throttling channel structure of the refrigerator, the present invention has a larger number of evenly distributed cold sources, resulting in a shorter heat transfer path. From cooling to reaching a stable temperature, the temperature distribution in the expansion cavity 8 is more uniform, and the time to reach a stable temperature is correspondingly reduced. Therefore, this arrangement of the throttling element and the expansion cavity 8 can effectively improve the uniformity of the cold-end temperature of the ultra-miniature throttling refrigerator.

[0060] The beneficial effects of this invention include at least the following:

[0061] Compared to existing ultra-miniature throttling refrigerators where the throttling element and expansion cavity 8 are on the same side, this invention changes the relative positions of the throttling element and expansion cavity 8 to opposite sides, increasing the flexibility of the throttling element arrangement and resulting in a greater number of cold sources cooling the expansion cavity 8 with a more uniform spatial distribution. Therefore, the main advantages of this structure are as follows:

[0062] 1. Improved the temperature uniformity of the cold end of the ultra-miniature throttling cooler, avoiding chip cracking caused by uneven temperature due to the throttling cooler and chip not being fully in contact with the expansion chamber 8;

[0063] 2. The expansion cavity 8 has multiple heat transfer points, which can reduce the time for the temperature of the expansion cavity 8 to reach a stable state, which is beneficial for subsequent detector imaging.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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. An ultra-miniature throttling cooler, comprising a plate structure, said plate structure comprising multiple substrates bonded sequentially from top to bottom, characterized in that, The plate structure is provided with a high-pressure flow channel (201), a throttling element (7), an expansion cavity (8) and a low-pressure flow channel (101) connected in sequence. The throttling element (7) and the expansion cavity (8) are arranged in layers, and the throttling hole (9) of the throttling element (7) is directly above the expansion cavity (8).

2. The ultra-miniature throttling cooler according to claim 1, characterized in that, The throttling element (7) and the expansion cavity (8) are respectively disposed on the upper and lower sides of the same substrate.

3. The ultra-miniature throttling cooler according to claim 1, characterized in that, The throttling element (7) includes a plurality of throttling orifices (9), which are uniformly arranged above the expansion cavity (8).

4. The ultra-miniature throttling refrigerator according to claim 1 or 3, characterized in that, The throttling element includes a plurality of throttling tubes connected to the outlet of the high-pressure flow channel (201), and each throttling tube is provided with at least one throttling orifice (9).

5. The ultra-miniature throttling cooler according to claim 1, characterized in that, The plate structure includes a cover plate (3), a high-pressure side plate (2), and a low-pressure side plate (1) bonded sequentially from top to bottom. The high-pressure flow channel (201) and the throttling element (7) are formed on the upper side of the high-pressure side plate (2), the expansion cavity (8) is at least partially formed on the lower side of the high-pressure side plate (2), and the low-pressure flow channel (101) is formed on the upper side of the low-pressure side plate (1).

6. The ultra-miniature throttling refrigerator according to claim 5, characterized in that, The expansion cavity (8) includes a first expansion cavity formed on the lower side of the high-pressure side plate (2) and a second expansion cavity formed on the upper side of the low-pressure side plate (1), and the first expansion cavity and the second expansion cavity are connected.

7. The ultra-miniature throttling refrigerator according to claim 5, characterized in that, The cover plate (3) is provided with a high-pressure air inlet (4), which is connected to the high-pressure flow channel (201).

8. The ultra-miniature throttling refrigerator according to claim 5, characterized in that, The plate structure is provided with a low-pressure vent hole, which is connected to the low-pressure flow channel (101). The low-pressure vent hole includes the vent (11) of the low-pressure flow channel (101), the through hole (6) on the high-pressure side plate (2), and the vent (5) on the cover plate (3).

9. The ultra-miniature throttling refrigerator according to claim 1, characterized in that, Both the high-pressure flow channel (201) and the low-pressure flow channel (101) are spirally arranged.

10. The ultra-miniature throttling cooler according to claim 1, characterized in that, The high-pressure flow channel (201), the low-pressure flow channel (101), and the throttling element (7) are all formed on the substrate by laser etching and / or wet etching.

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