A two-working-fluid throttling cryocooler with shortened start-up time and a control method thereof

Abstract

The application provides a double-working substance throttling refrigerator and a control method for shortening the starting time, the double-working substance throttling refrigerator comprises a first gas working substance source, a second gas working substance source and a throttling refrigeration assembly, the throttling refrigeration assembly comprises a precooling stage refrigeration assembly and a refrigeration stage refrigeration assembly, the gas inlet end of the precooling stage refrigeration assembly is connected with the first gas working substance source through a pipeline, and the gas inlet end of the refrigeration stage refrigeration assembly is connected with the first gas working substance source and the second gas working substance source through a pipeline. The application connects two gas working substance sources with different refrigeration capacities at the gas inlet end of the refrigeration stage refrigeration assembly, controls the gas inlet mode of the refrigeration stage, uses the first gas working substance with a larger refrigeration capacity in the initial stage of the refrigeration stage, and then uses the second gas working substance in the later stage, so that the refrigeration rate of the front temperature zone of the refrigeration stage is improved, and the overall starting time of the refrigerator is effectively shortened.

Description

Technical Field

[0001] This invention belongs to the field of throttling refrigerator technology, specifically relating to a dual-working-fluid throttling refrigerator and its control method for shortening start-up time. Background Technology

[0002] Throttling-cooled detectors are widely used in air-to-air and air defense missiles due to their small size, short cooling time, and low electromagnetic interference. The development direction of the next generation of infrared focal plane detectors is Swap3 (small size, low weight, high performance, low power consumption and low cost integrated into one). Detector chips are often limited by temperature, so it is necessary to develop throttling coolers for lower temperature ranges.

[0003] A dual-fluid throttling refrigerator mainly consists of a high-pressure gas cylinder, heat exchange tubes, a mandrel, a throttling orifice, and connecting pipes. The heat exchange tubes are fixed to the mandrel by spiral winding. Generally, the working fluid in the high-pressure gas cylinder flows through the heat exchange tubes and experiences a temperature drop at the throttling orifice. The throttled, low-temperature return working fluid flows through the external fins of the heat exchange tubes, exchanges heat with the incoming working fluid inside the tubes, and is then discharged into the environment. In this way, the high-temperature incoming working fluid is continuously cooled by the low-temperature return working fluid, allowing the working fluid to be throttled at a lower temperature, thus achieving an even lower cooling temperature, until a portion of the working fluid is liquefied, reaching a gas-liquid two-phase equilibrium. Compared to existing single-fluid throttling refrigerators, the dual-fluid throttling refrigerator adopts a two-stage injection structure. The pre-cooling stage uses argon for rapid pre-cooling, and the cooling stage uses nitrogen to achieve a lower cooling temperature. The combination of these two stages enables rapid cooling in the lower temperature range of the throttling refrigerator.

[0004] Existing dual-fluid throttling refrigerators employ two independent and simultaneous inlet pipes. Typically, nitrogen is used as the refrigerant in the cooling stage, while argon is used in the pre-cooling stage. The high cooling capacity of argon allows for rapid cooling of the high-pressure nitrogen in the cooling stage, enabling the cooling stage to quickly reach a lower temperature (compared to 100K). The overall startup time comprises two parts: the time it takes for the refrigerant in the cooling stage to be pre-cooled to a suitable pre-throttling temperature and the time it takes for the refrigerant in the cooling stage to cool the Dewar flare. However, existing inlet-type refrigerators using nitrogen as the refrigerant have a relatively small cooling capacity, resulting in slower cooling of the cooling stage's thermal mass and consequently extending the overall startup time. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-working-refrigerant throttling refrigerator that shortens start-up time, which can at least solve some of the defects existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dual-working-fluid throttling refrigerator for shortening start-up time includes a first working gas source, a second working gas source, and a throttling refrigeration component. The throttling refrigeration component includes a pre-cooling stage refrigeration component and a refrigeration stage refrigeration component. The inlet end of the pre-cooling stage refrigeration component is connected to the first working gas source through a pipe, and the inlet end of the refrigeration stage refrigeration component is connected to the first working gas source and the second working gas source through a pipe.

[0008] Furthermore, the first working gas source is an argon source, and the second working gas source is a nitrogen source.

[0009] Furthermore, the first gaseous working fluid source is connected to the inlet end of the precooling stage refrigeration component through the first inlet pipe, and the second gaseous working fluid source is connected to the inlet end of the refrigeration stage refrigeration component through the second inlet pipe. The first inlet pipe and the second inlet pipe are connected by a connecting pipe, and the connecting pipe and the second inlet pipe are connected by a three-way valve.

[0010] Furthermore, a shut-off valve is provided on the first air inlet pipe, and the shut-off valve is located between the first gas working fluid source and the connecting pipe.

[0011] Furthermore, the precooling stage refrigeration assembly includes a precooling stage heat exchange tube, the inlet end of which is connected to the first inlet pipe, and the outlet end of which is provided with a precooling stage throttling element.

[0012] Furthermore, there are two precooling stage heat exchange tubes, which are arranged in a double spiral side by side. One end of the two precooling stage heat exchange tubes is connected, and the precooling stage throttling element is located at the connection point of the two precooling stage heat exchange tubes.

[0013] Furthermore, the refrigeration stage refrigeration assembly includes a refrigeration stage heat exchange tube, the inlet end of which is connected to the second inlet pipe, the outlet end of which is provided with a refrigeration stage throttling element, and the refrigeration stage heat exchange tube is at least partially located in the refrigeration region of the pre-cooling stage refrigeration assembly.

[0014] Furthermore, the aforementioned dual-refrigerant throttling refrigerator also includes a Dewar, the throttling refrigeration component is placed inside the Dewar, a gas cavity is formed between the throttling refrigeration component and the shell of the Dewar, and the outlet end of the refrigeration stage refrigeration component is connected to the gas cavity.

[0015] In addition, the present invention also provides a control method for the above-mentioned dual-working-refrigerant throttling refrigerator, comprising the following steps:

[0016] In the initial stage of cooling in the dual-working-fluid throttling refrigerator, the first working gas source is turned on and the second working gas source is turned off. The first working gas source supplies the first working gas to the pre-cooling stage refrigeration component and the refrigeration stage refrigeration component respectively. The first working gas generates a throttling effect through the pre-cooling stage refrigeration component and the refrigeration stage refrigeration component and discharges cold gas.

[0017] When the temperature of the cold gas discharged from the refrigeration unit of the refrigeration stage drops to the preset temperature value, the first gas working medium source is turned off to supply the first gas working medium to the refrigeration unit of the refrigeration stage, and at the same time the second gas working medium source is turned on to supply the second gas working medium to the refrigeration unit of the refrigeration stage, until the refrigeration unit of the refrigeration stage discharges cold gas to cool the workpiece to the target temperature.

[0018] Furthermore, the cooling capacity generated by throttling the first working gas is greater than the cooling capacity generated by throttling the second working gas under the same conditions.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] The dual-working-fluid throttling refrigerator provided by this invention connects two gas working fluid sources with different cooling capacities to the air inlet of the refrigeration stage, thereby controlling the air intake mode of the refrigeration stage. This allows the refrigeration stage to use the first gas working fluid with a larger cooling capacity in the initial stage of cooling, and then use the second gas working fluid in the later stage, thereby improving the cooling rate of the front temperature zone of the refrigeration stage and effectively shortening the overall start-up time of the refrigerator.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the dual-working-refrigerant throttling refrigerator of the present invention, which shortens the start-up time.

[0023] Explanation of reference numerals in the attached drawings: 1. First working gas source; 2. Second working gas source; 3. Connecting pipe; 4. Shut-off valve; 5. First inlet pipe; 6. Three-way valve; 7. Second inlet pipe; 8. Pre-cooling stage heat exchanger tube; 9. Pre-cooling stage throttling element; 10. Refrigeration stage heat exchanger tube; 11. Refrigeration stage throttling element; 12. Dewar; 13. Gas chamber. Detailed Implementation

[0024] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. 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.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection", and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an abutting connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0028] like Figure 1 As shown, this embodiment provides a dual-working-fluid throttling refrigerator to shorten start-up time, including a first working-fluid source 1, a second working-fluid source 2, and a throttling refrigeration assembly. The throttling refrigeration assembly includes a pre-cooling stage refrigeration assembly and a refrigeration stage refrigeration assembly. The inlet of the pre-cooling stage refrigeration assembly is connected to the first working-fluid source 1 via a pipe, and the inlet of the refrigeration stage refrigeration assembly is connected to the first working-fluid source 1 and the second working-fluid source 2 via pipes. The first working-fluid source 1 is used to supply the first working-fluid, and the second working-fluid source 2 is used to supply the second working-fluid. Under the same conditions, the throttling capacity of the first working-fluid is set to be greater than that of the second working-fluid. For example, argon can be used as the first working-fluid, and nitrogen can be used as the second working-fluid. Under the same conditions, the properties of nitrogen itself determine that its throttling capacity is only one-third that of argon. The specific selection of the first and second working-fluids can be determined according to the cooling temperature range of the workpiece to be cooled.

[0029] When using the dual-working-fluid throttling refrigerator of this embodiment for cooling, in the initial stage of cooling, the first working-fluid source 1 is turned on and the second working-fluid source 2 is turned off. The first working-fluid source 1 supplies the first working-fluid to both the pre-cooling stage refrigeration component and the refrigeration stage refrigeration component. The first working-fluid generates a throttling effect through the pre-cooling stage refrigeration component and the refrigeration stage refrigeration component, and then discharges cold gas. In this initial stage of cooling, both the pre-cooling stage and the refrigeration stage use the first working-fluid with a larger throttling cooling capacity for cooling. However, due to the limitation of the target cooling temperature of the workpiece, the refrigeration stage can only use the second working-fluid. Therefore, when the temperature of the cold gas discharged from the refrigeration stage refrigeration component drops to a certain preset temperature value, the first working-fluid source 1 is turned off from supplying the first working-fluid to the refrigeration stage refrigeration component. The first working-fluid source 1 continues to supply the first working-fluid to the pre-cooling stage refrigeration component, while the second working-fluid source 2 is turned on from the refrigeration stage refrigeration component to supply the second working-fluid until the refrigeration stage refrigeration component discharges cold gas to cool the workpiece to the target temperature.

[0030] In one specific implementation, the first working gas source 1 is connected to the inlet end of the pre-cooling stage refrigeration component via the first inlet pipe 5, and the second working gas source 2 is connected to the inlet end of the refrigeration stage refrigeration component via the second inlet pipe 7. The first inlet pipe 5 and the second inlet pipe 7 are connected by a connecting pipe 3, and the connecting pipe 3 and the second inlet pipe 7 are connected by a three-way valve 6. During operation, both the first working gas source 1 and the second working gas source 2 are initially closed, and the refrigeration unit is not working. Then, the first working gas source 1 and the three-way valve 6 are simultaneously opened. At this time, the first working gas source 1 supplies the first working gas, and the three-way valve 6 connects the connecting pipe 3 to the second inlet pipe 7. The first working gas is divided into two paths: one path enters the pre-cooling stage refrigeration component through the first inlet pipe 5, producing a throttling effect before pre-cooling the refrigeration stage refrigeration component; the other path enters the refrigeration stage refrigeration component through the connecting pipe 3 and the second inlet pipe 7, producing a throttling effect before being discharged. Gas cooling of the workpiece: When the temperature of the cold gas discharged from the refrigeration stage component drops to the preset temperature value, rotate the three-way valve 6 to close the connection between the connecting pipe 3 and the second inlet pipe 7, thereby connecting the second inlet pipe 7 to the second gas working fluid source 2. At the same time, turn on the second gas working fluid source 2. At this time, the first gas working fluid source 1 is still in the open state. The first gas working fluid enters the pre-cooling stage refrigeration stage component only through the first inlet pipe 5. Simultaneously, the second gas working fluid source 2 delivers the second gas working fluid into the refrigeration stage component, generating a throttling effect before discharging the cold gas to cool the workpiece to the target temperature. In this embodiment, the preset temperature value should be greater than the liquefaction temperature of the first gas working fluid to at least ensure that the first gas working fluid will not liquefy.

[0031] The dual-fluid throttling refrigerator provided in this embodiment connects the first air inlet pipe 5 of the precooling stage and the second air inlet pipe 7 of the refrigeration stage through a connecting pipe 3 and a three-way valve 6. This allows for a change in the air intake method of the refrigeration stage. For the refrigeration stage, two gaseous working fluids are used in a time-segmented air intake mode. In the initial stage of cooling, the refrigeration stage uses the first gaseous working fluid with a larger cooling capacity. In the later stage of cooling, the second gaseous working fluid, which is suitable for the target cooling temperature range of the workpiece, is used. With this improved air intake method, the time it takes for the refrigeration stage to cool the workpiece to a certain temperature using the first gaseous working fluid with a larger cooling capacity is shorter than the time it takes to cool to the same temperature using the second gaseous working fluid. Since the start-up time of the refrigerator includes the time for the refrigeration stage gaseous working fluid to be precooled to a suitable pre-throttling temperature and the time for the refrigeration stage working fluid to cool the workpiece, the dual-fluid throttling refrigerator and air intake method of this embodiment greatly shorten the time for the refrigeration stage gaseous working fluid to be precooled to a suitable pre-throttling temperature, thereby achieving the goal of shortening the overall start-up time.

[0032] In some embodiments, a shut-off valve 4 is provided on the first air inlet pipe 5 to control the opening / closing of the first gas working medium delivery; specifically, the shut-off valve 4 is provided on the first air inlet pipe 5 in the portion between the first gas working medium source 1 and the connecting pipe 3.

[0033] In one specific embodiment, the precooling stage refrigeration assembly includes a precooling stage heat exchange tube 8. The inlet end of the precooling stage heat exchange tube 8 is connected to the first inlet pipe 5, and the outlet end of the precooling stage heat exchange tube 8 is provided with a precooling stage throttling element 9. The first gaseous working fluid enters the precooling stage heat exchange tube 8 through the first inlet pipe 5, and then flows through the precooling stage heat exchange tube 8 to reach the precooling stage throttling element 9. When the high-pressure first gaseous working fluid passes through the precooling stage throttling element 9, the pressure drops suddenly, generating a throttling effect, which causes the temperature of the first gaseous working fluid to drop, and the resulting cold gas is used to cool the refrigeration stage assembly. Similarly, the refrigeration stage refrigeration assembly includes a refrigeration stage heat exchange tube 10. The inlet end of the refrigeration stage heat exchange tube 10 is connected to the second inlet pipe 7. The outlet end of the refrigeration stage heat exchange tube 10 is provided with a refrigeration stage throttling element 11. The refrigeration stage heat exchange tube 10 is at least partially located in the refrigeration region of the pre-cooling stage refrigeration assembly. The gaseous working fluid of the refrigeration stage (i.e., the first gaseous working fluid or the second gaseous working fluid) enters the refrigeration stage heat exchange tube 10 through the second inlet pipe, and then flows through the refrigeration stage heat exchange tube 10 to reach the refrigeration stage throttling element 11. When the high-pressure refrigeration stage gaseous working fluid passes through the refrigeration stage throttling element 11, the pressure drops suddenly, producing a throttling effect, which causes the temperature of the refrigeration stage gaseous working fluid to drop. The resulting cold gas is used to cool the workpiece.

[0034] In some embodiments, both the precooling stage heat exchange tube 8 and the refrigeration stage heat exchange tube 10 adopt a finned tube structure. Specifically, the dual-working-fluid throttling refrigerator also includes a mandrel, and both the precooling stage heat exchange tube 8 and the refrigeration stage heat exchange tube 10 are wound on the mandrel. The precooling stage throttling element 9 can be a throttling orifice opened on the precooling stage heat exchange tube, and the refrigeration stage throttling element 11 can also be a throttling orifice opened on the refrigeration stage heat exchange tube.

[0035] In a preferred embodiment, there are two precooling stage heat exchange tubes 8, which are arranged in a double spiral and wound around a mandrel. One end of the two precooling stage heat exchange tubes 8 is connected, and the precooling stage throttling element 9 is located at the connection point of the two precooling stage heat exchange tubes 8. The other end of one of the two precooling stage heat exchange tubes 8 is connected to the first air inlet pipe 5, serving as the air inlet of the precooling stage refrigeration assembly, while the other end of the other precooling stage heat exchange tube 8 serves as the air outlet of the precooling stage refrigeration assembly.

[0036] Furthermore, the dual-working-refrigerant throttling cooler of this embodiment also includes a Dewar 12, the throttling cooling component is placed inside the Dewar 12, and a gas cavity 13 is formed between the throttling cooling component and the shell of the Dewar 12. The outlet end of the refrigeration stage component is connected to the gas cavity 13. The workpieces such as chips and cold screens to be cooled are placed inside the Dewar 12, and the cold gas generated by the throttling of the refrigeration stage component is used to cool the workpieces.

[0037] In summary, the dual-working-fluid throttling refrigerator provided by this invention connects two gaseous working fluid sources with different cooling capacities to the air inlet of the refrigeration stage, thereby controlling the air intake mode of the refrigeration stage. This allows the refrigeration stage to use the first gaseous working fluid with a larger cooling capacity in the initial stage of cooling, and then use the second gaseous working fluid in the later stage, thereby improving the cooling rate of the front temperature zone of the refrigeration stage and effectively shortening the overall start-up time of the refrigerator.

[0038] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A dual-working-refrigerant throttling refrigerator with shortened start-up time, characterized in that: The system includes a first working gas source, a second working gas source, and a throttling refrigeration component. The throttling refrigeration component includes a pre-cooling stage refrigeration component and a refrigeration stage refrigeration component. The inlet of the pre-cooling stage refrigeration component is connected to the first working gas source via a pipe, and the inlet of the refrigeration stage refrigeration component is connected to both the first and second working gas sources via pipes. The first working gas source is connected to the inlet of the pre-cooling stage refrigeration component via a first inlet pipe, and the second working gas source is connected to the inlet of the refrigeration stage refrigeration component via a second inlet pipe. The first inlet pipe and the second inlet pipe are connected by a connecting pipe, and the connecting pipe and the second inlet pipe are connected by a three-way valve. The refrigeration stage refrigeration assembly includes a refrigeration stage heat exchange tube, the inlet end of which is connected to the second inlet pipe, the outlet end of which is provided with a refrigeration stage throttling element, and the refrigeration stage heat exchange tube is at least partially located in the refrigeration region of the pre-cooling stage refrigeration assembly. It also includes a Dewar, the throttling refrigeration component is placed inside the Dewar, a gas cavity is formed between the throttling refrigeration component and the shell of the Dewar, and the outlet end of the refrigeration stage refrigeration component is connected to the gas cavity.

2. The dual-working-fluid throttling refrigerator with shortened start-up time as described in claim 1, characterized in that: The first working gas source is an argon source, and the second working gas source is a nitrogen source.

3. The dual-fluid throttling refrigerator with shortened start-up time as described in claim 1, characterized in that: The first air inlet pipe is equipped with a shut-off valve, and the shut-off valve is located between the first gas working fluid source and the connecting pipe.

4. The dual-working-fluid throttling refrigerator with shortened start-up time as described in claim 1, characterized in that: The precooling stage refrigeration assembly includes a precooling stage heat exchange tube, the inlet end of which is connected to the first inlet pipe, and the outlet end of which is provided with a precooling stage throttling element.

5. The dual-refrigerant throttling refrigerator with shortened start-up time as described in claim 4, characterized in that: The precooling stage heat exchange tube has two tubes, which are arranged in a double spiral side by side. One end of the two tubes is connected, and the precooling stage throttling element is located at the connection point of the two tubes.

6. A control method for a dual-working-refrigerant throttling refrigerator according to any one of claims 1-5, characterized in that: Includes the following steps: In the initial stage of cooling in the dual-working-fluid throttling refrigerator, the first working gas source is turned on and the second working gas source is turned off. The first working gas source supplies the first working gas to the pre-cooling stage refrigeration component and the refrigeration stage refrigeration component respectively. The first working gas generates a throttling effect through the pre-cooling stage refrigeration component and the refrigeration stage refrigeration component and discharges cold gas. When the temperature of the cold gas discharged from the refrigeration unit of the refrigeration stage drops to the preset temperature value, the first gas working medium source is turned off to supply the first gas working medium to the refrigeration unit of the refrigeration stage, and at the same time the second gas working medium source is turned on to supply the second gas working medium to the refrigeration unit of the refrigeration stage, until the refrigeration unit of the refrigeration stage discharges cold gas to cool the workpiece to the target temperature.

7. The control method for a dual-working-refrigerant throttling refrigerator as described in claim 6, characterized in that: The cooling capacity generated by throttling the first working gas is greater than the cooling capacity generated by throttling the second working gas under the same conditions.

Images