Control method of J-T refrigerating system, storage medium and J-T refrigerating system

Abstract

The invention discloses a J-T refrigerating system control method, a storage medium and a J-T refrigerating system.The J-T refrigerating system comprises a high-pressure side pipeline and a low-pressure side pipeline, a main path throttling element and a bypass throttling element are arranged between the high-pressure side pipeline and the low-pressure side pipeline, and a control adjusting rod of the bypass throttling element is connected with a motor; the method comprises the steps that the pipeline temperature of a low-pressure side pipeline is obtained; according to the pipeline temperature and a preset temperature threshold value, the motor is controlled to adjust the opening degree of the bypass throttling element by controlling the adjusting rod; after the temperature of the pipeline reaches the target temperature, the control motor adjusts the opening degree of the bypass throttling element to be completely closed by controlling the adjusting rod, so that a refrigerating medium in the high-pressure side pipeline is subjected to isenthalpy throttling through the main throttling element, and when the flow resistance of the main throttling element is large, the refrigerating medium can pass through the bypass throttling element, so that the refrigerating medium in the high-pressure side pipeline can pass through the bypass throttling element. The opening degree of the bypass throttling element can change along with the temperature of the low-pressure side pipeline, the refrigeration time is shortened, and the refrigeration efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigerators, and in particular to a control method of a JT refrigeration system, a computer-readable storage medium and a JT refrigeration system. Background Art

[0002] The JT refrigeration system is one of the main technical means of mechanical refrigeration in the liquid helium temperature zone. Its principle is to use the isenthalpic throttling cooling effect generated by helium below 30K passing through the throttling element to obtain a lower refrigeration temperature. In order to first obtain helium below 30K, a pre-cooling refrigerator is required to be used with a multi-stage heat exchange structure to pre-cool the helium.

[0003] For the JT refrigeration system, the flow resistance caused by the throttling element is usually very obvious during the stable working stage, resulting in a very low actual mass flow rate during the stable working stage. However, this flow resistance has a great negative impact on the cooling of the final throttling element of the precooling refrigerator during the precooling stage, resulting in a significant extension of the precooling process time. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. The first object of the present invention is to provide a control method for a JT refrigeration system.

[0005] A second object of the present invention is to provide a computer-readable storage medium.

[0006] The third object of the present invention is to provide a JT refrigeration system.

[0007] To achieve the above-mentioned purpose, a control method for a JT refrigeration system is proposed in an embodiment of the first aspect of the present invention. The JT refrigeration system includes a high-pressure side pipeline and a low-pressure side pipeline, a main throttling element and a bypass throttling element are arranged between the high-pressure side pipeline and the low-pressure side pipeline, and a control adjustment lever of the bypass throttling element is connected to a motor. The method includes: obtaining the pipeline temperature of the low-pressure side pipeline; according to the pipeline temperature and a preset temperature threshold, controlling the motor to adjust the opening of the bypass throttling element through the control adjustment lever; after the pipeline temperature reaches the target temperature, controlling the motor to adjust the opening of the bypass throttling element to be completely closed through the control adjustment lever, so that the refrigerant medium in the high-pressure side pipeline is throttled isotropically through the main throttling element.

[0008] According to the control method of the JT refrigeration system of an embodiment of the present invention, when the flow resistance of the main throttling element is large, the refrigerant medium can pass through the bypass throttling element, and the opening of the bypass throttling element can change with the temperature of the low-pressure side pipeline, thereby shortening the refrigeration time and improving the refrigeration efficiency.

[0009] In addition, the control method of the JT refrigeration system according to the above embodiment of the present invention may also have the following additional technical features:

[0010] In some examples of the present invention, the main throttling element includes a single hole, a capillary, an orifice plate or a nozzle structure, and the bypass throttling element includes a needle valve.

[0011] In some examples of the present invention, the motor is controlled to adjust the opening of the bypass throttling element through the control adjustment lever according to the pipeline temperature and the preset temperature threshold, including: judging whether the pipeline temperature is less than or equal to the preset temperature threshold; if the pipeline temperature is less than or equal to the preset temperature threshold, controlling the motor to rotate a preset angle to drive the control adjustment lever to reduce the opening of the bypass throttling element; if the pipeline temperature is greater than the preset temperature threshold, controlling the bypass throttling element to maintain the current opening unchanged.

[0012] In some examples of the present invention, the number of the preset temperature thresholds is at least three, and each of the preset temperature thresholds corresponds to an opening degree of the bypass throttling element.

[0013] In some examples of the present invention, the pipeline temperature is the temperature at the lowest point of the low-pressure side pipeline temperature, and the opening of the bypass throttling element corresponding to each preset temperature threshold is the opening of the bypass throttling element corresponding to the shortest time required from the current preset temperature threshold to the next preset temperature threshold.

[0014] In some examples of the present invention, the method also includes: iteratively assigning the preset temperature threshold, and determining whether the preset temperature threshold after the iterative assignment is less than or equal to the minimum preset value; if the preset temperature threshold after the iterative assignment is less than or equal to the minimum preset value, controlling the motor to adjust the opening of the bypass throttling element to fully closed through the control adjustment lever.

[0015] In some examples of the present invention, before determining whether the preset temperature threshold after iterative assignment is less than or equal to the lowest preset value, the method further includes: obtaining the refrigerant medium flow rate of the high-pressure side pipeline; determining whether the refrigerant medium flow rate is greater than or equal to a preset flow rate threshold; if the refrigerant medium flow rate is less than the preset flow rate threshold, controlling the alarm to issue an alarm prompt.

[0016] In some examples of the present invention, the method further includes: obtaining a start signal of the JT refrigeration system; controlling the pre-cooling refrigerator and the JT refrigerator circulation system to start simultaneously according to the start signal, and controlling the motor to return to a zero state.

[0017] In some examples of the present invention, a heat sink structure is provided on the control adjustment rod of the bypass throttling element, and the heat sink structure is connected to the cold head part of the pre-cooling refrigerator.

[0018] To achieve the above-mentioned purpose, a computer-readable storage medium is proposed in an embodiment of the second aspect of the present invention, on which a control program of a JT refrigeration system is stored. When the control program of the JT refrigeration system is executed by a processor, the control method of the JT refrigeration system is implemented.

[0019] According to the computer-readable storage medium of an embodiment of the present invention, when the flow resistance of the main throttling element is large, the refrigerant medium can pass through the bypass throttling element, and the opening of the bypass throttling element can change with the temperature of the low-pressure side pipeline, thereby shortening the refrigeration time and improving the refrigeration efficiency.

[0020] To achieve the above-mentioned purpose, a JT refrigeration system is proposed in an embodiment of the third aspect of the present invention, wherein the JT refrigeration system includes a high-pressure side pipeline, a low-pressure side pipeline and a control device, wherein a main throttling element and a bypass throttling element are arranged between the high-pressure side pipeline and the low-pressure side pipeline, wherein the main throttling element and the bypass throttling element are in parallel structure, and the control adjustment lever of the bypass throttling element is connected to a motor, and the control device includes: an acquisition module, for acquiring the pipeline temperature of the low-pressure side pipeline; a control module, for controlling the motor to adjust the opening of the bypass throttling element through the control adjustment lever according to the pipeline temperature and a preset temperature threshold; and, after the pipeline temperature reaches the target temperature, controlling the motor to adjust the opening of the bypass throttling element to be completely closed through the control adjustment lever, so that the refrigerant medium in the high-pressure side pipeline is throttled isoenthalpically through the main throttling element.

[0021] According to the JT refrigeration system of the embodiment of the present invention, when the flow resistance of the main throttling element is large, the refrigerant medium can pass through the bypass throttling element, and the opening of the bypass throttling element can change with the temperature of the low-pressure side pipeline, thereby shortening the refrigeration time and improving the refrigeration efficiency.

[0022] In some examples of the present invention, the JT refrigeration system further includes a low-temperature insulation box, the high-pressure side pipeline and the low-pressure side pipeline are both arranged in the low-temperature insulation box, and the motor is arranged outside the low-temperature insulation box.

[0023] In some examples of the present invention, the JT refrigeration system also includes a pre-cooling refrigerator, which includes a head arranged outside the low-temperature insulation box and a cold head arranged outside the low-temperature insulation box, and a heat sink structure is arranged on the control adjustment rod, and the heat sink structure is thermally connected to the cold head.

[0024] In some examples of the present invention, the cold head is multi-stage, and the target temperatures of the multi-stage cold heads decrease sequentially, and the heat sink structure is thermally connected to any stage of the cold head whose target temperature is not the lowest.

[0025] In some examples of the present invention, the multiple stages of the cold heads are arranged vertically, the control adjustment rod is vertically disposed, and the motor is located at the upper end of the control adjustment rod.

[0026] In some examples of the present invention, the main path throttling element is a fixed throttling element.

[0027] In some examples of the present invention, the bypass throttling element includes a needle valve, the control device controls the opening of the bypass throttling element to be adjusted step by step, and the opening of the bypass throttling element is adjusted in at least three levels, each level of the opening of the bypass throttling element corresponds to a preset temperature threshold, and when the pipeline temperature of the low-pressure side pipeline reaches each of the preset temperature thresholds, the control device controls the bypass throttling element to adjust to the corresponding opening.

[0028] In some examples of the present invention, a thermometer for obtaining the pipeline temperature of the low-pressure side pipeline is provided at the lowest temperature point of the low-pressure side pipeline.

[0029] In some examples of the present invention, the opening degree of the bypass throttling element corresponding to each preset temperature threshold is the opening degree of the bypass throttling element corresponding to the shortest time required from the current preset temperature threshold to the next preset temperature threshold.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of a control method of a JT refrigeration system in some embodiments of the present invention;

[0032] Figure 2 is a flow chart of a control method of a JT refrigeration system in a specific embodiment of the present invention;

[0033] Figure 3 Schematic diagram of the structure of the JT refrigeration system in some embodiments of the present invention.

[0034] Reference numerals:

[0035] 100. JT refrigeration system; 10. High-pressure side pipeline; 11. Main line throttling element; 12. Flow meter; 13. Flow valve; 14. Gas storage tank; 20. Low-pressure side pipeline; 21. Compressor; 22. Temperature sensor; 30. Bypass throttling element; 31. Needle valve; 32. Control lever; 33. Motor; 34. Heat sink structure; 41. Machine head; 42. Cold head; 50. Control device; 60. Cold box dewar; 110. Cold head heat exchanger; 120. Interstage heat exchanger. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0037] The following describes a control method of a JT refrigeration system 100, a computer-readable storage medium, a control device 50 of a JT refrigeration system 100, and a JT refrigeration system 100 according to an embodiment of the present invention with reference to the accompanying drawings.

[0038] Combination Figure 3 The JT refrigeration system 100 includes a high-pressure side pipeline 10 and a low-pressure side pipeline 20. The design of the high-pressure side pipeline 10 and the low-pressure side pipeline 20 enables the refrigerant to circulate effectively at different pressures and temperatures, thereby improving the refrigeration efficiency. Specifically, a main throttling element 11 and a bypass throttling element 30 are arranged between the high-pressure side pipeline 10 and the low-pressure side pipeline 20, and the control adjustment rod 32 of the bypass throttling element 30 is connected to the motor 33. Therefore, when the refrigeration fluid enters the low-pressure side pipeline 20 from the high-pressure side pipeline 10, it can pass through the main throttling element 11 or the bypass throttling element 30. Therefore, the amount of fluid flowing through the bypass throttling element 30 can be controlled according to the temperature reduction situation to improve the refrigeration efficiency.

[0039] More specifically, the bypass throttling element 30 is controlled by the control adjustment rod 32 and the motor 33. For example, the motor 33 is connected to the control adjustment rod 32 by transmission, and the control adjustment rod 32 is connected to the bypass throttling element 30 by transmission. When the motor 33 is working, it can drive the control adjustment rod 32 to adjust the opening of the bypass throttling element 30 to control the flow rate of the fluid flowing from the bypass throttling element 30. Since the motor 33 and the control adjustment rod 32 can achieve high-precision operation when working, consistency and stability can be maintained during operation, so the operation error can be reduced and the accuracy of the adjustment operation can be improved. In addition, the use of mechanical control is not easily affected by the external environment, has high reliability, and is conducive to reducing costs. Therefore, by controlling the bypass throttling element 30 through the motor 33 and the control adjustment rod 32, the accuracy of the bypass throttling element 30 adjustment can be improved, which is conducive to improving the cooling efficiency.

[0040] Furthermore, if Figure 1 As shown, in some embodiments of the present invention, the control method of the JT refrigeration system 100 includes the following steps:

[0041] S10, obtaining the pipeline temperature of the low-pressure side pipeline 20.

[0042] S20 , according to the pipeline temperature and the preset temperature threshold, the control motor 33 adjusts the opening of the bypass throttling element 30 by operating the adjustment rod 32 .

[0043] S30, after the pipeline temperature reaches the target temperature, the control motor 33 adjusts the opening of the bypass throttling element 30 to be completely closed by manipulating the adjusting rod 32, so that the refrigerant in the high-pressure side pipeline 10 is throttled by the main throttling element 11. Specifically, the obtained pipeline temperature of the low-pressure side pipeline 20 can be compared with the preset temperature threshold to determine whether the control motor 33 and the manipulating adjusting rod 32 are needed to adjust the bypass throttling element 30. Furthermore, the specific numerical difference between the obtained pipeline temperature of the low-pressure side pipeline 20 and the preset temperature threshold can be used to determine how to adjust the opening change of the bypass throttling element 30. For example, when the difference between the pipeline temperature of the low-pressure side pipeline 20 and the preset temperature threshold is large, the opening of the bypass throttling element 30 is large. As the refrigeration process proceeds, the difference between the two gradually decreases. When the difference decreases, the opening change of the bypass throttling element 30 can be appropriately reduced until the pipeline temperature of the low-pressure side pipeline 20 is the same as the preset temperature threshold. The opening of the bypass throttling element 30 is minimum or completely closed. At this time, the airflow can all flow through the main throttling element 11, and the main throttling element 11 performs isenthalpic throttling.

[0044] Generally, at room temperature, the main throttling element 11 has a large flow resistance, and the refrigerant medium is not easy to pass through, resulting in low cooling capacity. Therefore, the pipeline temperature of the low-pressure side pipeline 20 can be used to judge whether the cooling effect of the main throttling element 11 reaches the expected effect. At the same time, the amount of refrigerant medium flowing to the main throttling element 11 can be adjusted by adjusting the opening of the bypass throttling element 30.

[0045] According to the control method of the JT refrigeration system 100 of an embodiment of the present invention, when the flow resistance of the main throttling element 11 is large, the refrigerant medium can pass through the bypass throttling element 30, and the opening degree of the bypass throttling element 30 can change with the temperature of the low-pressure side pipeline, thereby shortening the refrigeration time and improving the refrigeration efficiency.

[0046] Optionally, the motor 33 can be a servo motor, which can improve the accuracy of control. Specifically, the servo motor can be used in combination with a feedback device (such as an encoder) to achieve precise control and positioning, and can be precisely controlled through a closed-loop control system, and can adjust the output in real time to achieve the set target position, speed and acceleration; and equipped with a feedback device (such as an encoder or a Hall sensor), it can monitor the state of the motor in real time and make adjustments based on the feedback.

[0047] Optionally, the control device 50 of the JT refrigeration system 100 can preset the relationship between the numerical relationship between the pipe temperature of the low-pressure side pipe 20 and the preset temperature threshold and the opening adjustment of the bypass throttling element 30. For example, the difference between the pipe temperature of the low-pressure side pipe 20 and the preset temperature threshold corresponds to the opening of the corresponding bypass throttling element 30, thereby optimizing the refrigeration process and improving the refrigeration efficiency.

[0048] In some embodiments of the present invention, the main throttling element 11 includes a single hole, a capillary, an orifice plate or a nozzle structure, so that the main throttling element 11 can control the flow rate and pressure of the fluid through the single hole, the capillary, the orifice plate or the nozzle structure, and can improve the functionality of the main throttling element 11. Specifically, the single hole can limit the flow of the fluid through a small hole, so as to accurately control the flow rate and achieve the effect of fine-tuning the flow rate; the capillary is a slender pipe, which can use its small diameter to limit the flow of the fluid, and can provide stable flow control within a smaller flow range; the orifice plate limits the flow of the fluid by setting a plate with a specific aperture in the pipe, and can provide stable flow control within a larger flow range; the nozzle controls the flow rate by changing the speed and pressure of the fluid, and can spray the fluid, and can control the flow rate at a high flow rate.

[0049] In some embodiments of the present invention, the bypass throttling element 30 includes a needle valve 31, and the opening of the bypass throttling element 30 can be adjusted by the needle valve 31, which has a simple structure and high precision. For example, the needle valve 31 includes a valve body and a needle rod, and the control adjustment rod 32 can adjust the opening of the bypass throttling element 30 by rotating or pushing the needle rod, thereby adjusting the flow of the fluid.

[0050] In some embodiments of the present invention, according to the pipeline temperature and the preset temperature threshold, the control motor 33 adjusts the opening of the bypass throttling element 30 by operating the adjustment rod 32, including: judging whether the pipeline temperature is less than or equal to the preset temperature threshold; if the pipeline temperature is less than or equal to the preset temperature threshold, it means that the pipeline temperature is reduced, then the control motor 33 rotates a preset angle to drive the control adjustment rod 32 to reduce the opening of the bypass throttling element 30; if the pipeline temperature is greater than the preset temperature threshold, that is, the pipeline temperature is high, then the bypass throttling element 30 is controlled to maintain the current opening unchanged to keep the opening to continue to operate. For example, after the refrigerator starts working, the bypass throttling element 30 is opened to the maximum, and the refrigerant can enter the low-pressure side pipeline 20 from the bypass throttling element 30, and then obtain the temperature of the low-pressure side pipeline 20. If the pipeline temperature is a, the preset temperature threshold is b, and a≤b, it indicates that the temperature of the low-pressure side pipeline 20 has been appropriately reduced, and the bypass throttling element 30 can continue to operate with a smaller opening. If a>b, it indicates that the temperature of the low-pressure side pipeline 20 is high, and the bypass throttling element 30 needs to maintain a larger opening to continue to operate. In other words, as time goes by, the pipeline temperature will gradually decrease. When it reaches the preset value, the motor 33 needs to drive the control adjustment rod 32 to rotate so that the bypass throttling element 30 can reduce the opening.

[0051] In some embodiments of the present invention, there are at least three preset temperature thresholds, each of which corresponds to the opening of a bypass throttling element 30, so that the opening of the bypass throttling element 20 can be gradually adjusted, which is beneficial to improving the refrigeration efficiency. Specifically, at least three preset temperature thresholds can be gradually reduced, and the openings of the bypass throttling elements corresponding to the three preset temperature thresholds can also be gradually reduced. Therefore, after the pipeline temperature gradually decreases, the opening of the bypass throttling element can be gradually reduced to reduce the flow of the refrigerant from the bypass throttling element.

[0052] Furthermore, in some embodiments of the present invention, the pipeline temperature is the temperature at the lowest point of the low-pressure side pipeline 20, and the refrigeration effect of the main throttling element 11 can be judged according to the temperature at the lowest point, which can minimize the error and improve the accuracy of the adjustment. The opening of the bypass throttling element 30 corresponding to each preset temperature threshold is the opening of the bypass throttling element 30 corresponding to the shortest time required from the current preset temperature threshold to the next preset temperature threshold, so as to achieve timely adjustment of the bypass throttling element 30, so that more refrigerant can flow from the main throttling element 11, which is conducive to improving the refrigeration effect.

[0053] Furthermore, combined with Figure 2 In some embodiments of the present invention, the control method of the JT refrigeration system 100 further includes: iteratively assigning a preset temperature threshold, and determining whether the preset temperature threshold after iterative assignment is less than or equal to the lowest preset value; if the preset temperature threshold after iterative assignment is less than or equal to the lowest preset value, the control motor 33 adjusts the opening of the bypass throttling element 30 to be completely closed by manipulating the adjustment rod 32. That is, the preset temperature threshold can gradually update the value of the variable during the refrigeration process of the refrigerator to gradually achieve a refrigeration effect, which is conducive to improving the refrigeration efficiency. Specifically, in combination with the foregoing, the pipeline temperature is compared with the preset temperature threshold to determine whether to adjust the opening of the bypass throttling element 30. For example, when the pipeline temperature is a1 and the preset temperature threshold is b1, and a1≤b1, the opening of the bypass throttling element 30 is reduced. If the minimum threshold is b0, determine whether b1≤b0. If b1>b0, the current preset temperature threshold b1 has not reached the minimum preset value, then the preset temperature threshold b1 is iteratively assigned to obtain the preset temperature threshold b2, and the pipeline temperature a2 is continued to be obtained to determine whether a2≤b2. If it is less than or equal to, the opening of the bypass throttling element 30 is reduced. If it is greater than, the opening of the bypass throttling element 30 is kept unchanged. Determine whether b2≤b0. If b2>b0, the current preset temperature threshold b2 has not reached the minimum preset value, then the preset temperature threshold b2 is iteratively assigned to obtain the preset temperature threshold b3, and so on, until the preset temperature threshold b is less than or equal to the minimum preset value b0, the preset temperature threshold stops iteratively assigning, and the opening of the bypass throttling element 30 can be adjusted to be fully closed.

[0054] According to the control method of the JT refrigeration system 100 of the embodiment of the present invention, the preset temperature threshold can be re-assigned to execute the next cycle, and each assigned value is smaller than the previous preset temperature threshold. The condition of the repeated cycle is that after the preset temperature threshold is lowered each time, it is first determined whether the preset temperature threshold reaches the minimum preset value. If it is satisfied, the cycle continues, and if it is not satisfied, the cycle exits, indicating that the pipeline temperature has been reduced to the preset temperature, and the bypass throttling element 30 can be completely closed.

[0055] In some embodiments of the present invention, Figure 2 , before judging whether the preset temperature threshold after iterative assignment is less than or equal to the lowest preset value, the control method of the JT refrigeration system 100 also includes: obtaining the refrigerant flow rate of the high-pressure side pipeline 10; judging whether the refrigerant flow rate is greater than or equal to the preset flow rate threshold; if the refrigerant flow rate is less than the preset flow rate threshold, the alarm is controlled to issue an alarm prompt. Specifically, the flow rate of the high-pressure side circuit is used to judge the passage of the refrigerant medium of the main circuit throttling element 11. If the flow rate decreases, it means that the refrigerant medium has not passed through the main circuit throttling element 11 well, and the circuit may be blocked. The operator can take shutdown safety protection to protect the refrigerator. More specifically, the operator can analyze and judge according to the alarm prompt, so as to control whether the JT refrigeration system 100 is shut down, thereby improving the reliability and safety of the operation. It can also be set to automatically shut down when the alarm prompts according to the actual application situation.

[0056] In some embodiments of the present invention, the control method of the JT refrigeration system 100 also includes: obtaining a start signal of the JT refrigeration system 100, controlling the pre-cooling refrigerator and the JT refrigerator circulation system to start simultaneously according to the start signal, and controlling the motor 33 to return to the zero state. Thus, when the refrigerator is started, refrigeration can be started, and at the same time, the motor 33 returns to the position so that the bypass throttling element 30 is fully opened, so that the refrigerant can flow directly from the bypass throttling element 30 into the low-pressure side pipeline 20, and then by judging the relationship between the temperature of the low-pressure side pipeline 20 and the preset temperature threshold, the opening of the bypass throttling element 30 is gradually reduced until the bypass throttling element 30 is completely closed, and the refrigerant can completely pass through the main throttling element 11 into the low-pressure side pipeline 20. In other words, when the refrigerator is started, the main throttling element 11 and the bypass throttling element 30 between the high-pressure side pipeline 10 and the low-pressure side pipeline 20 can flow the refrigerant. Since the flow resistance of the main throttling element 11 is large in the stable working stage, the actual mass flow rate of the refrigerant in its stable working state stage is low,

[0057] It is beneficial to improve the refrigeration effect, and by running the aforementioned control method, the opening of the bypass throttling element 30 can be gradually reduced according to the temperature of the low-pressure side pipeline 20.

[0058] In some embodiments of the present invention, a heat sink structure 34 is provided on the control adjustment rod 32 of the bypass throttling element 30, and the heat sink structure 34 is connected to the cold head 42 of the pre-cooling refrigerator, which can avoid heat leakage, reduce energy loss, and improve the cooling effect.

[0059] Based on the control method of the JT refrigeration system 100 of the above-mentioned embodiment of the present invention, the embodiment of the present invention further proposes a computer-readable storage medium, on which a control program of the JT refrigeration system 100 is stored. When the control program of the JT refrigeration system 100 is executed by a processor, the above-mentioned control method of the JT refrigeration system 100 is implemented.

[0060] It should be noted that the specific implementation of the computer-readable storage medium of the embodiment of the present invention corresponds one-to-one with the specific implementation of the control method of the JT refrigeration system 100 of the aforementioned embodiment of the present invention, and will not be repeated here to reduce redundancy.

[0061] In summary, according to the computer-readable storage medium of an embodiment of the present invention, when the flow resistance of the main throttling element 11 is large, the refrigerant medium can pass through the bypass throttling element 30, and the opening of the bypass throttling element 30 can change with the temperature of the low-pressure side pipeline 20, thereby shortening the refrigeration time and improving the refrigeration efficiency.

[0062] Furthermore, the present invention also provides a JT refrigeration system 100, Figure 3 is a schematic structural diagram of a JT refrigeration system 100 according to an embodiment of the present invention.

[0063] Specifically, the JT refrigeration system 100 includes a high-pressure side pipeline 10, a low-pressure side pipeline 20 and a control device 50. A main throttling element 11 and a bypass throttling element 30 are arranged between the high-pressure side pipeline 10 and the low-pressure side pipeline 20. The main throttling element 11 and the bypass throttling element 30 are in a parallel structure. Thus, the main throttling element 11 and the bypass throttling element 30 can work at the same time, and the refrigerant medium can pass through the main throttling element 11 and the bypass throttling element 30 at the same time to improve the refrigeration efficiency.

[0064] More specifically, the control adjustment rod 32 of the bypass throttling element 30 is connected to the motor 33, and the control device 50 includes: an acquisition module, used to obtain the pipeline temperature of the low-pressure side pipeline 20; a control module, used to control the motor 33 to adjust the opening of the bypass throttling element 30 by controlling the adjustment rod 32 according to the pipeline temperature and the preset temperature threshold; and, after the pipeline temperature reaches the target temperature, the control motor 33 adjusts the opening of the bypass throttling element 30 to be fully closed by controlling the adjustment rod 32, so that the refrigerant medium in the high-pressure side pipeline 10 is throttled by the main throttling element 11 in an isenthalpic manner.

[0065] According to the JT refrigeration system 100 of the embodiment of the present invention, when the flow resistance of the main throttling element 11 is large, the refrigerant medium can pass through the bypass throttling element 30, and the opening degree of the bypass throttling element 30 can change with the temperature of the low-pressure side pipeline 20, thereby shortening the refrigeration time and improving the refrigeration efficiency.

[0066] In some embodiments of the present invention, Figure 3 The JT refrigeration system 100 further includes a low temperature insulation box, in which the high pressure side pipeline 10 and the low pressure side pipeline 20 are both arranged, and the motor 33 is arranged outside the low temperature insulation box. The low temperature insulation box can be a cold box dewar 60, thereby reducing the transfer of heat, thereby maintaining the internal low temperature environment.

[0067] In some embodiments of the present invention, the JT refrigeration system 100 further includes a precooling refrigerator, which includes a head 41 disposed outside the low-temperature insulation box and a cold head 42 disposed outside the low-temperature insulation box, and a heat sink structure 34 is disposed on the control adjustment rod 32, and the heat sink structure 34 is thermally connected to the cold head 42. The heat sink structure 34 is connected to the cold head 42 of the precooling refrigerator, which can avoid heat leakage, reduce energy loss, and improve the refrigeration effect.

[0068] More specifically, combined with Figure 3 In some embodiments of the present invention, the cold head 42 is multi-stage, and the target temperature of the multi-stage cold heads 42 is sequentially reduced to achieve a gradual reduction in temperature, and the heat sink structure 34 is thermally connected to any cold head 42 of a stage whose target temperature is not the lowest. Specifically, the heat sink structure 34 can have a heat dissipation effect, and the heat sink structure 34 is not thermally connected to the lowest cold head 42, so that the next cold head 42 can also be cooled, thereby avoiding the heat sink structure 34 from affecting the temperature in the pipeline, which is conducive to maintaining a low temperature environment in the pipeline.

[0069] In some embodiments of the present invention, the multi-stage cold head 42 is arranged vertically, the control adjustment rod 32 is set vertically, and the motor 33 is located at the upper end of the control adjustment rod 32. This is helpful to reduce the conduction heat leakage of the control adjustment rod 32 to the room temperature environment, because the temperature distribution of the control adjustment rod 32 itself and the temperature distribution of the multi-stage cold head 42 are consistent with the temperature distribution trend inside the low-temperature insulation box.

[0070] In some embodiments of the present invention, the main circuit throttling element 11 is a fixed throttling element. Thus, the fixed throttling element can be used as a throttling device in the stable cooling stage to effectively reduce the difficulty of controlling the lowest temperature, so that the reproducibility of the cooling process of the entire JT refrigeration system 100 is significantly enhanced, which is more conducive to the commercialization of the equipment.

[0071] In some embodiments of the present invention, the bypass throttling element 30 includes a needle valve 31, and the control device 50 controls the opening of the bypass throttling element 30 to be adjusted step by step, and the opening of the bypass throttling element 30 is adjusted to at least three levels, and the opening of each level of the bypass throttling element 30 corresponds to a preset temperature threshold. When the pipeline temperature of the low-pressure side pipeline 20 reaches each preset temperature threshold, the control device 50 controls the bypass throttling element 30 to adjust to the corresponding opening, thereby, the opening of the bypass throttling element 30 can be gradually reduced according to the temperature change of the low-pressure side pipeline 20, which is conducive to improving the refrigeration efficiency. Specifically, the temperature of the low-pressure side pipeline 20 gradually decreases, which means that the refrigeration capacity of the main throttling element 11 is gradually improving. As the refrigeration efficiency of the main throttling element 11 increases, the opening of the bypass throttling element 30 is gradually reduced, so that more refrigerant medium flows from the main throttling element 11, thereby improving the refrigeration efficiency.

[0072] In some embodiments of the present invention, a thermometer for obtaining the pipeline temperature of the low-pressure side pipeline 20 is provided at the lowest temperature point of the low-pressure side pipeline 20 to obtain the temperature of the lowest temperature position in the low-pressure side pipeline 20 .

[0073] In some embodiments of the present invention, the opening of the bypass throttling element 30 corresponding to each preset temperature threshold is the opening of the bypass throttling element 30 corresponding to the shortest time required from the current preset temperature threshold to the next preset temperature threshold, which is conducive to quickly adjusting the opening of the bypass throttling element 30 according to temperature changes, thereby reducing the amount of refrigerant medium passing through the bypass throttling element 20 and increasing the amount of refrigerant medium flowing through the main throttling element 11, so as to cool the refrigerant medium, thereby facilitating rapid cooling.

[0074] A JT refrigeration system 100 and a control method thereof according to a specific embodiment of the present invention will be described below with reference to the accompanying drawings.

[0075] like Figure 3 As shown, the JT refrigeration system 100 includes a main throttling element 11, a flow meter 12, a flow valve 13, an air storage tank 14, a compressor 21, a bypass throttling element 30, a control adjustment lever 32, a servo motor 33, a heat sink structure 34, a cold head 42, a control device 50 and a cold box dewar 60. The JT refrigeration system 100 also includes a cold head heat exchanger 110 and an interstage heat exchanger 120. The cold head heat exchanger 110 can perform heat exchange with the cold head 42, and the interstage heat exchanger 120 can be arranged between the high-pressure side pipeline 10 and the low-pressure side pipeline 20.

[0076] Specifically, the bypass throttling element 30 is a long rod structure and includes an adjustable needle valve 31, the end of which is located in the cold box dewar 60, and the control adjustment rod 32 extends out of the cold box dewar 60 through the airtight structure, so that it can be adjusted in the normal temperature space outside the cold box dewar 60. The main throttling element 11 is a fixed flow resistance throttling element for generating an isenthalpic throttling effect; the servo motor 33 and the control device 50 are installed in the room temperature area for automatically adjusting the opening of the needle valve 31.

[0077] More specifically, the bypass throttling element 30 and the main throttling element 11 are in parallel structure, the front end of the bypass throttling element 30 is the high-pressure side pipeline 10 of the JT refrigerator, and the rear end is connected to the low-pressure side pipeline 20 of the JT refrigerator. There is a heat sink structure 34 in the middle of the long rod of the bypass throttling element 30, which is used to reduce the heat leakage from the low-temperature needle valve 31 to the room temperature end, and the heat sink is connected to the cold head 42 of the pre-cooling refrigerator through a thermal bridge. Among them, the throttling element with fixed flow resistance (main throttling element 11) is a single hole, capillary, orifice plate or nozzle structure.

[0078] The bypass throttling element 30 includes a needle valve 31, a control adjustment rod 32, a servo motor 33 and a heat sink structure 34. One end of the control adjustment rod 32 is connected to the motor shaft of the servo motor 33, and the other end is connected to the needle valve 31. The heat sink structure 34 is arranged in the middle of the control adjustment rod 32. The servo motor 33 drives the control adjustment rod 32 to adjust the opening of the needle valve 31. The servo motor 33 drives the needle valve 31 to rotate and control the opening of the needle valve 31. The servo motor 33 is controlled by a command issued by the control device 50, and the rotation angle is a fixed set value.

[0079] like Figure 2 As shown, the operation process of the control device 50 in the JT refrigeration system 100 is that the pre-cooling refrigerator and the JT refrigerator circulation system are turned on at the same time, at this time, the servo motor 33 is at the zero position, the adjustable needle valve 31 of the bypass throttling element 30 is in a fully open state, and the temperature sensor 22 monitors the temperature of the low-pressure side pipeline 20 at the rear end of the adjustable needle valve 31; when the sensor temperature is lower than a certain value, the servo motor 33 is started and rotated by a fixed angle, and the opening of the needle valve 31 is reduced to accelerate the pre-cooling and cooling process; when the temperature of the temperature sensor 22 reaches below the preset minimum value, the servo motor 33 rotates to the set final angle, at this time the needle valve 31 is completely closed, and the high-pressure pipeline gas passes through the main throttling element 11 for an isenthalpic throttling process, and the JT refrigeration system 100 reaches the lowest temperature and completes the entire pre-cooling and cooling process.

[0080] According to the JT refrigeration system 100 and its control method, storage medium and control device 50 of the embodiment of the present invention, the automatic control of the precooling process can be realized, which not only reduces the cooling time required for the entire precooling process, but also greatly simplifies the adjustment difficulty of the adjustable needle valve 31 in the precooling process, and can effectively speed up the cooling speed of the precooling process, and no human intervention in the precooling stage is required, and the single-button start of the JT refrigeration system 100 is realized, which greatly reduces the operation complexity of the system. In addition, the structural design of the bypass throttling element 30 with the adjustable needle valve 31 and the main throttling element 11 in parallel can effectively reduce the conduction heat leakage of the throttling element to the room temperature environment, and then the operating rod of the adjustable needle valve 31 can reduce the design height, and increase the structural compactness of the JT refrigeration system 100 system. Therefore, using the main throttling element 11 as a throttling device in the stable cooling stage can effectively reduce the difficulty of controlling the lowest temperature, so that the reproducibility of the cooling process of the entire JT refrigeration system 100 is significantly enhanced, which is more conducive to the productization of the equipment.

[0081] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0082] It should be understood that the various parts of the present invention can be implemented with hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented with software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented with hardware, as in another embodiment, any one of the following technologies known in the art or their combination can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc. In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0083] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0084] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0086] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A control method for a JT refrigeration system, characterized in that: The JT refrigeration system includes a high-pressure side pipeline and a low-pressure side pipeline, a main throttling element and a bypass throttling element are arranged between the high-pressure side pipeline and the low-pressure side pipeline, and a control adjustment rod of the bypass throttling element is connected to a motor, and the method includes: Acquiring the pipeline temperature of the low-pressure side pipeline; According to the pipeline temperature and a preset temperature threshold, controlling the motor to adjust the opening of the bypass throttling element through the control adjustment rod; After the pipeline temperature reaches the target temperature, the motor is controlled to adjust the opening of the bypass throttling element to fully closed through the control adjustment lever, so that the refrigerant medium in the high-pressure side pipeline is throttled by the main throttling element in an isenthalpic manner.

2. The control method of the JT refrigeration system according to claim 1, characterized in that: The main throttling element includes a single hole, a capillary, an orifice plate or a nozzle structure, and the bypass throttling element includes a needle valve.

3. The control method of the JT refrigeration system according to claim 2, characterized in that: According to the pipeline temperature and the preset temperature threshold, controlling the motor to adjust the opening of the bypass throttling element through the control adjustment rod includes: Determining whether the pipeline temperature is less than or equal to the preset temperature threshold; If the pipe temperature is less than or equal to the preset temperature threshold, the motor is controlled to rotate by a preset angle to drive the control adjustment lever to reduce the opening of the bypass throttling element; If the pipeline temperature is greater than the preset temperature threshold, the bypass throttling element is controlled to maintain the current opening unchanged.

4. The control method of the JT refrigeration system according to claim 3, characterized in that: There are at least three preset temperature thresholds, and each of the preset temperature thresholds corresponds to an opening degree of the bypass throttling element.

5. The control method of the JT refrigeration system according to claim 4, characterized in that: The pipeline temperature is the temperature at the lowest point of the low-pressure side pipeline temperature, and the opening of the bypass throttling element corresponding to each preset temperature threshold is the opening of the bypass throttling element corresponding to the shortest time required from the current preset temperature threshold to the next preset temperature threshold.

6. The control method of the JT refrigeration system according to claim 3, characterized in that: The method further comprises: Iteratively assigning a value to the preset temperature threshold, and determining whether the preset temperature threshold after the iterative assignment is less than or equal to a minimum preset value; If the preset temperature threshold after the iterative assignment is less than or equal to the minimum preset value, the motor is controlled to adjust the opening of the bypass throttling element to be fully closed through the control adjustment rod.

7. The control method of the JT refrigeration system according to claim 6, characterized in that: Before determining whether the preset temperature threshold after iterative assignment is less than or equal to the lowest preset value, the method further includes: Obtaining the refrigerant medium flow rate of the high-pressure side pipeline; Determining whether the flow rate of the refrigerant medium is greater than or equal to a preset flow rate threshold; If the refrigerant medium flow rate is less than the preset flow rate threshold, the control alarm will issue an alarm prompt.

8. The control method of the JT refrigeration system according to claim 1, characterized in that: The method further comprises: Get the start signal of JT refrigeration system; According to the start signal, the pre-cooling refrigerator and the JT refrigerator circulation system are controlled to start simultaneously, and the motor is controlled to return to the zero point state.

9. The control method of the JT refrigeration system according to claim 8, characterized in that: A heat sink structure is arranged on the control and adjustment rod of the bypass throttling element, and the heat sink structure is connected to the cold head part of the pre-cooling refrigerator.

10. A computer-readable storage medium, characterized in that: A control program of a JT refrigeration system is stored thereon, and when the control program of the JT refrigeration system is executed by a processor, a control method of the JT refrigeration system according to any one of claims 1 to 9 is implemented.

11. A JT refrigeration system, characterized in that: The invention comprises a high-pressure side pipeline, a low-pressure side pipeline and a control device, wherein a main throttling element and a bypass throttling element are arranged between the high-pressure side pipeline and the low-pressure side pipeline, the main throttling element and the bypass throttling element are in a parallel structure, and the control adjustment rod of the bypass throttling element is connected to the motor, and the control device comprises: An acquisition module, used for acquiring the pipeline temperature of the low-pressure side pipeline; The control module is used to control the motor to adjust the opening of the bypass throttling element through the control adjustment lever according to the pipeline temperature and a preset temperature threshold; and, after the pipeline temperature reaches the target temperature, control the motor to adjust the opening of the bypass throttling element to be fully closed through the control adjustment lever, so that the refrigerant medium in the high-pressure side pipeline is throttled in an isenthalpic manner through the main throttling element.

12. The JT refrigeration system according to claim 11, characterized in that: It also includes a low-temperature insulation box (cold box dewar), the high-pressure side pipeline and the low-pressure side pipeline are both arranged in the low-temperature insulation box, and the motor is arranged outside the low-temperature insulation box.

13. The JT refrigeration system according to claim 12, characterized in that: It also includes a pre-cooling refrigerator, which includes a machine head arranged outside the low-temperature insulation box and a cold head arranged outside the low-temperature insulation box. A heat sink structure is arranged on the control adjustment rod, and the heat sink structure is thermally connected to the cold head.

14. The JT refrigeration system according to claim 13, characterized in that: The cold heads are multi-stage, and the target temperatures of the multi-stage cold heads are sequentially reduced. The heat sink structure is thermally connected to any stage of the cold head whose target temperature is not the lowest.

15. The JT refrigeration system according to claim 14, wherein the multiple cold heads are arranged vertically, the control adjustment rod is vertically arranged, and the motor is located at the upper end of the control adjustment rod.

16. The JT refrigeration system according to claim 11, characterized in that: The main path throttling element is a fixed throttling element.

17. The JT refrigeration system according to claim 11, characterized in that: The bypass throttling element includes a needle valve, and the control device controls the opening of the bypass throttling element to be adjusted step by step, and the opening of the bypass throttling element is adjusted in at least three levels, and each level of the opening of the bypass throttling element corresponds to a preset temperature threshold. When the pipeline temperature of the low-pressure side pipeline reaches each of the preset temperature thresholds, the control device controls the bypass throttling element to adjust to the corresponding opening.

18. The JT refrigeration system according to any one of claims 11 to 17, characterized in that: A thermometer for obtaining the pipeline temperature of the low-pressure side pipeline is arranged at the lowest point of the low-pressure side pipeline temperature.

19. The JT refrigeration system according to claim 18, characterized in that: The opening degree of the bypass throttling element corresponding to each preset temperature threshold is the opening degree of the bypass throttling element corresponding to the shortest time required from the current preset temperature threshold to the next preset temperature threshold.

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