Refrigerating system, low-temperature storage box, refrigerating control method and device and storage medium

Abstract

The invention discloses a refrigeration system, a low-temperature preservation box, a refrigeration control method and device and a storage medium. The refrigerating system comprises a gas-liquid separator with an inlet connected to an outlet of a condenser, an air outlet connected to an inlet of a first heat exchange pipe of a condensation evaporator, a liquid outlet connected to an inlet of a second heat exchange pipe of the condensation evaporator through a first throttling element, and an outlet of the second heat exchange pipe connected to an air suction port of a compressor; the first heat exchange tube comprises at least two outlets, the outlets correspond to different heat exchange lengths, each outlet of the first heat exchange tube is connected to an inlet of the evaporator through a second throttling element, and an outlet of the evaporator is connected to an inlet of the second heat exchange tube; in the running process of the system, only one outlet of the first heat exchange pipe communicates with the second throttling element at any moment. The heat exchange length of the condensation evaporator can be adjusted preferentially, then the compressor is adjusted, the frequency increasing requirement of the compressor is reduced when cooling capacity output needs to be increased, and the frequency reducing amplitude of the compressor is prevented from being too large when cooling capacity output needs to be reduced.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration technology, and in particular to a refrigeration system, a low-temperature preservation box, a refrigeration control method and device, and a storage medium. Background Art

[0002] Medical cryogenic storage boxes are mainly used to store valuable biological samples such as cells, tissues, viruses, fertilized eggs, and clinical samples. The temperature range is between -20℃ and -150℃. Products in the temperature range of -86℃ and below have a wider temperature control range, and the products mainly use cascade refrigeration systems or self-cascade refrigeration systems.

[0003] At present, when the low-temperature preservation box is in refrigeration operation, the output of cooling capacity is mainly controlled by the compressor. If the current output cooling capacity is insufficient, increasing the compressor frequency to increase the cooling capacity output will increase energy consumption, or even lead to excessive energy consumption. If the current output cooling capacity is too large, reducing the compressor frequency to reduce the cooling capacity output. If the compressor frequency reduction is too large, the refrigeration system will be unstable or even shut down. Summary of the invention

[0004] The embodiments of the present invention provide a refrigeration system, a low-temperature preservation box, a refrigeration control method and device, and a storage medium, so as to at least solve the problem that the existing refrigeration control scheme increases energy consumption and reduces system operation stability.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a refrigeration system, comprising:

[0006] A gas-liquid separator, wherein the inlet thereof is connected to the outlet of the condenser, the gas outlet thereof is connected to the inlet of the first heat exchange tube of the condenser evaporator, the liquid outlet thereof is connected to the inlet of the second heat exchange tube of the condenser evaporator through the first throttling element, and the outlet of the second heat exchange tube is connected to the suction port of the compressor;

[0007] The first heat exchange tube comprises at least two outlets, each outlet corresponds to a different heat exchange length, each outlet of the first heat exchange tube is connected to the inlet of the evaporator through a second throttling element, and the outlet of the evaporator is connected to the inlet of the second heat exchange tube;

[0008] During the operation of the system, at any time, only one outlet of the first heat exchange tube is connected to the second throttling element.

[0009] Optionally, a respective valve is provided on the pipeline connected to each outlet of the first heat exchange tube.

[0010] Optionally, the first heat exchange tube and the second heat exchange tube are a tube-in-tube structure, the first heat exchange tube is an outer tube, and the second heat exchange tube is an inner tube.

[0011] Optionally, a first temperature sensor is provided at the inlet of the evaporator for detecting the inlet temperature of the evaporator; and a second temperature sensor is provided at the outlet of the evaporator for detecting the outlet temperature of the evaporator.

[0012] The embodiment of the present invention further provides a refrigeration control method, which is applied to the refrigeration system described in the embodiment of the present invention, and the method includes:

[0013] Detect the evaporator inlet temperature and evaporator outlet temperature;

[0014] Controlling the heat exchange length of the first heat exchange tube according to the set temperature and the evaporator inlet temperature so that the difference between the set temperature and the evaporator inlet temperature is within a first preset range;

[0015] The compressor speed is controlled according to the evaporator inlet temperature and the evaporator outlet temperature so that the evaporator inlet and outlet temperature difference is within a second preset range.

[0016] Optionally, controlling the heat exchange length of the first heat exchange tube according to the set temperature and the evaporator inlet temperature includes:

[0017] Calculating the difference between the set temperature and the evaporator inlet temperature, and recording it as a first difference;

[0018] Determining whether the first difference is within the first preset range;

[0019] If the first difference is within the first preset range, the current heat exchange length of the first heat exchange tube is kept unchanged;

[0020] If the first difference is less than the lower limit of the first preset range, the heat exchange length of the first heat exchange tube is increased, and after a first preset time, the step of calculating the difference between the set temperature and the evaporator inlet temperature is returned to be executed;

[0021] If the first difference is greater than the upper limit of the first preset range, the heat exchange length of the first heat exchange tube is reduced, and after a first preset time, the step of calculating the difference between the set temperature and the evaporator inlet temperature is returned to be executed.

[0022] Optionally, increasing the heat exchange length of the first heat exchange tube comprises: closing a valve corresponding to a current outlet in a connected state on the first heat exchange tube, and opening a valve corresponding to a next outlet of the current outlet, so that the next outlet is in a connected state, wherein the heat exchange length corresponding to the next outlet is greater than the heat exchange length corresponding to the current outlet;

[0023] Reducing the heat exchange length of the first heat exchange tube includes: closing the valve corresponding to the current outlet of the first heat exchange tube that is in a connected state, and opening the valve corresponding to the previous outlet of the current outlet to make the previous outlet in a connected state, wherein the heat exchange length corresponding to the previous outlet is smaller than the heat exchange length corresponding to the current outlet.

[0024] Optionally, controlling the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature includes:

[0025] Calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature, and recording it as a second difference;

[0026] Determining whether the second difference is within the second preset range;

[0027] If the second difference is within the second preset range, keeping the current speed of the compressor unchanged;

[0028] If the second difference is less than the lower limit of the second preset range, the compressor speed is increased, and after a second preset time, the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature is returned to be executed;

[0029] If the second difference is greater than the upper limit of the second preset range, the compressor speed is reduced, and after a second preset time, the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature is returned to be executed.

[0030] The embodiment of the present invention further provides a refrigeration control device, which is applied to the refrigeration system described in the embodiment of the present invention, and the device includes:

[0031] A detection module, used for detecting the evaporator inlet temperature and the evaporator outlet temperature;

[0032] a first control module, configured to control the heat exchange length of the first heat exchange tube according to a set temperature and the evaporator inlet temperature, so that the difference between the set temperature and the evaporator inlet temperature is within a first preset range;

[0033] The second control module is used to control the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature so that the evaporator inlet and outlet temperature difference is within a second preset range.

[0034] The embodiment of the present invention further provides a low-temperature preservation box, comprising: the refrigeration system described in the embodiment of the present invention.

[0035] The embodiment of the present invention further provides a non-volatile computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the refrigeration control method described in the embodiment of the present invention is implemented.

[0036] By applying the technical solution of the present invention, at least two outlets are set at different length sections of the first heat exchange tube of the condenser evaporator. By changing the connection state of each outlet, the heat exchange length of the condenser evaporator can be adjusted, thereby changing its heat exchange capacity. During refrigeration control, the heat exchange length of the condenser evaporator is adjusted first, and then the compressor speed is adjusted. When the cooling output needs to be increased, the heat exchange length of the condenser evaporator is adjusted first to increase the heat exchange, thereby reducing the frequency increase demand of the compressor, thereby reducing energy consumption; when the cooling output needs to be reduced, the heat exchange length of the condenser evaporator is adjusted first to reduce the heat exchange, thereby avoiding excessive frequency reduction of the compressor, ensuring the stability of system operation, and meeting the actual cooling demand while solving the problem that the existing refrigeration control scheme will increase energy consumption and reduce the stability of system operation, which is more conducive to the long-term stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of a refrigeration system provided by an embodiment of the present invention;

[0038] Figure 2 is a flow chart of a refrigeration control method provided by an embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of a refrigeration control flow provided by an embodiment of the present invention;

[0040] Figure 4 This is a refrigeration flow chart of the low-temperature storage box provided by the embodiment of the present invention when it is just turned on;

[0041] Figure 5 is a structural block diagram of a refrigeration control device provided by an embodiment of the present invention;

[0042] Figure 6 is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present invention;

[0043] Description of reference numerals:

[0044] Compressor 1, condenser 2, gas-liquid separator 3, condenser evaporator 4, first throttling element 5, second throttling element 6, evaporator 7, first valve 8, second valve 9, third valve 10, first temperature sensor 11, second temperature sensor 12, drying filter 13. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification, claims and drawings of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0048] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0049] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0050] Example 1

[0051] This embodiment provides a refrigeration system, which may be a self-cascade refrigeration system and may be used in a low-temperature storage box.

[0052] Figure 1 Schematic diagram of a refrigeration system provided by an embodiment of the present invention. Figure 1 As shown, the refrigeration system includes: a compressor 1, a condenser 2, a gas-liquid separator 3, a condenser evaporator 4, a first throttling element 5, a second throttling element 6 and an evaporator 7.

[0053] The condenser evaporator 4 includes a first heat exchange tube and a second heat exchange tube, and the medium flowing in the first heat exchange tube exchanges heat with the medium flowing in the second heat exchange tube.

[0054] The gas-liquid separator 3 includes: an inlet, an air outlet and a liquid outlet. The inlet of the gas-liquid separator 3 is connected to the outlet of the condenser 2, the air outlet of the gas-liquid separator 3 is connected to the inlet of the first heat exchange tube of the condenser evaporator 4, the liquid outlet of the gas-liquid separator 3 is connected to the inlet of the second heat exchange tube of the condenser evaporator 4 through the first throttling element 5, and the outlet of the second heat exchange tube is connected to the suction port of the compressor 1.

[0055] The first heat exchange tube includes at least two outlets, each of which corresponds to a different heat exchange length. The heat exchange length refers to the length of the first heat exchange tube that actually participates in the heat exchange. Under the same medium flow rate, the longer the heat exchange length, the greater the heat exchange amount. Each outlet of the first heat exchange tube is located at a different position of the first heat exchange tube. Each outlet of the first heat exchange tube is connected to the inlet of the evaporator 7 through the second throttling element 6, and the outlet of the evaporator 7 is connected to the inlet of the second heat exchange tube. During the operation of the refrigeration system, at any time, only one outlet of the first heat exchange tube is connected to the second throttling element 6. In other words, the heat exchange length of the first heat exchange tube of the condensing evaporator 4 can be adjusted according to actual needs, thereby changing the heat exchange amount.

[0056] In this embodiment, at least two outlets are arranged at different length sections of the first heat exchange tube of the condenser evaporator. By changing the connection state of each outlet, the heat exchange length of the condenser evaporator can be adjusted, thereby changing its heat exchange amount. During refrigeration control, the heat exchange length of the condenser evaporator is adjusted first, and then the compressor speed is adjusted. When the cooling output needs to be increased, the heat exchange length of the condenser evaporator is adjusted first to increase the heat exchange amount, thereby reducing the frequency increase demand of the compressor, thereby reducing energy consumption; when the cooling output needs to be reduced, the heat exchange length of the condenser evaporator is adjusted first to reduce the heat exchange amount, thereby avoiding excessive frequency reduction of the compressor, ensuring the stability of system operation, and meeting the actual cooling demand while solving the problem that the existing refrigeration control scheme will increase energy consumption and reduce the stability of system operation, which is more conducive to the long-term stable operation of the system.

[0057] Each outlet of the first heat exchange tube is connected to a pipeline provided with a respective valve. By controlling the on-off of the valve, it is possible to control whether the corresponding outlet is connected, thereby changing the heat exchange length of the condenser evaporator.

[0058] Figure 1For example, the first heat exchange tube includes three outlets, which are respectively recorded as port A, port B, and port C. The heat exchange length corresponding to port A is greater than the heat exchange length corresponding to port B and greater than the heat exchange length corresponding to port C. Port A corresponds to the maximum heat exchange length of the first heat exchange tube, and port C corresponds to the minimum heat exchange length of the first heat exchange tube. Exemplarily, taking the inlet of the first heat exchange tube as the starting point, port C is set at 1 / 3 of the overall length of the first heat exchange tube, port B is set at 2 / 3 of the overall length of the first heat exchange tube, and port A is set at the end of the first heat exchange tube. Port A corresponds to the first valve 8. When the first valve 8 is opened, port A is connected. Port B corresponds to the second valve 9. When the second valve 9 is opened, port B is connected. Port C corresponds to the third valve 10. When the third valve 10 is opened, port C is connected.

[0059] The first throttling element 5 and the second throttling element 6 can be elements with throttling function such as capillaries and electronic expansion valves.

[0060] This embodiment does not limit the specific structure of the condenser evaporator 4. For example, the first heat exchange tube and the second heat exchange tube can be a sleeve structure, the first heat exchange tube is an outer tube, and the second heat exchange tube is an inner tube, so as to adjust the heat exchange length of the first heat exchange tube.

[0061] A first temperature sensor 11 is provided at the inlet of the evaporator to detect the inlet temperature of the evaporator. A second temperature sensor 12 is provided at the outlet of the evaporator to detect the outlet temperature of the evaporator. The inlet temperature of the evaporator and the outlet temperature of the evaporator can be used as a control basis for the operation of the refrigeration system.

[0062] refer to Figure 1 , the high-temperature and high-pressure refrigerant discharged from the compressor 1 is condensed by the condenser 2, and then enters the gas-liquid separator 3 through the drying filter 13 to be separated into: liquid refrigerant rich in high-boiling-point working medium (i.e., high-temperature refrigerant) and gaseous refrigerant rich in low-boiling-point working medium (i.e., low-temperature refrigerant). The low-temperature refrigerant enters the first heat exchange tube of the condenser evaporator 4, and the high-temperature refrigerant enters the second heat exchange tube of the condenser evaporator 4 after being throttled by the first throttling element 5 (e.g., high-temperature capillary tube) to exchange heat with the low-temperature gaseous refrigerant in the first heat exchange tube, so that the low-temperature refrigerant is further condensed. The condensed low-temperature refrigerant enters the evaporator 7 after being throttled by the second throttling element 6 (e.g., low-temperature capillary tube) for refrigeration. After refrigeration, the refrigerant at the evaporator outlet and the high-temperature throttled refrigerant enter the condenser evaporator 4 together to provide cooling capacity for the condensation of the gaseous low-temperature refrigerant. By controlling the on and off of the first valve 8, the second valve 9, and the third valve 10, the heat exchange length of the first heat exchange tube can be changed, thereby changing the heat exchange amount of the low-temperature refrigerant.

[0063] Example 2

[0064] This embodiment provides a refrigeration control method, which is applied to the refrigeration system described in the above embodiment.

[0065] Figure 2 is a flow chart of a refrigeration control method provided by an embodiment of the present invention. Figure 2 As shown, the method comprises the following steps:

[0066] S201, detecting the evaporator inlet temperature and the evaporator outlet temperature.

[0067] S202, controlling the heat exchange length of the first heat exchange tube according to the set temperature and the evaporator inlet temperature, so that the difference between the set temperature and the evaporator inlet temperature is within a first preset range.

[0068] S203, controlling the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature so that the evaporator inlet and outlet temperature difference is within a second preset range.

[0069] The difference between the set temperature and the evaporator inlet temperature is within the first preset range, indicating that the evaporator inlet temperature is within a reasonable range. The evaporator inlet and outlet temperature difference (i.e., the difference between the evaporator inlet temperature and the evaporator outlet temperature) is within the second preset range, indicating that the evaporator inlet and outlet temperature difference is within the target range. The first preset range and the second preset range can be set according to actual conditions.

[0070] In this embodiment, during refrigeration control, the heat exchange length of the condenser evaporator is adjusted first, and then the compressor speed is adjusted so that the evaporator inlet temperature and the evaporator inlet and outlet temperature difference are both within a reasonable range to meet the refrigeration demand. When the cooling output needs to be increased, the heat exchange length of the condenser evaporator is adjusted first to increase the heat exchange amount, thereby reducing the compressor frequency increase demand, thereby reducing energy consumption; when the cooling output needs to be reduced, the heat exchange length of the condenser evaporator is adjusted first to reduce the heat exchange amount, thereby avoiding excessive compressor frequency reduction, ensuring the stability of system operation, and meeting the actual cooling demand while solving the problem that the existing refrigeration control scheme will increase energy consumption and reduce system operation stability, which is more conducive to the long-term stable operation of the system.

[0071] In one embodiment, controlling the heat exchange length of the first heat exchange tube according to the set temperature and the evaporator inlet temperature includes:

[0072] Calculate the difference between the set temperature and the evaporator inlet temperature, and record it as the first difference;

[0073] Determining whether the first difference is within a first preset range;

[0074] If the first difference is within the first preset range, the current heat exchange length of the first heat exchange tube is kept unchanged;

[0075] If the first difference is less than the lower limit of the first preset range, the heat exchange length of the first heat exchange tube is increased, and after the first preset time, the step of calculating the difference between the set temperature and the evaporator inlet temperature is returned to be executed;

[0076] If the first difference is greater than the upper limit of the first preset range, the heat exchange length of the first heat exchange tube is reduced, and after the first preset time, the process returns to the step of calculating the difference between the set temperature and the evaporator inlet temperature.

[0077] Specifically, during cooling, the set temperature will be higher than the evaporator inlet temperature. If the difference between the set temperature and the evaporator inlet temperature is within the first preset range, it means that the evaporator inlet temperature is within a reasonable range, and there is no need to adjust the heat exchange length of the condenser evaporator to change the evaporator inlet temperature. If the difference between the set temperature and the evaporator inlet temperature is less than the lower limit of the first preset range, it means that the evaporator inlet temperature is too high (i.e., the current cooling output is insufficient and the cooling output needs to be increased). At this time, the heat exchange length of the condenser evaporator can be increased to increase the heat exchange amount, thereby reducing the evaporator inlet temperature. If the difference between the set temperature and the evaporator inlet temperature is greater than the upper limit of the first preset range, it means that the evaporator inlet temperature is too low (i.e., the current cooling output is excessive and the cooling output needs to be reduced). At this time, the heat exchange length of the condenser evaporator can be reduced to reduce the heat exchange amount, thereby increasing the evaporator inlet temperature.

[0078] After the adjustment operation is performed, the parameter data of the refrigeration system will change correspondingly to the adjustment operation after a certain period of time. Therefore, the first preset time is set to ensure that the refrigeration system has enough time to respond. Re-judgment after the first preset time can ensure the reliability of the judgment. The first preset time can be set according to actual conditions.

[0079] This embodiment can accurately control the heat exchange length of the first heat exchange tube in the condenser evaporator based on the deviation between the evaporator inlet temperature and the set temperature, and adjust the heat exchange amount so that the evaporator inlet temperature is within a reasonable range.

[0080] Furthermore, increasing the heat exchange length of the first heat exchange tube includes: closing the valve corresponding to the current outlet in the connected state on the first heat exchange tube, and opening the valve corresponding to the next outlet of the current outlet, so that the next outlet is in the connected state, wherein the heat exchange length corresponding to the next outlet is greater than the heat exchange length corresponding to the current outlet. If the first heat exchange tube has reached the maximum heat exchange length, it is sufficient to maintain the maximum heat exchange length. This embodiment controls the connected state of the outlet of the first heat exchange tube by a valve, and can simply and quickly increase the heat exchange length to achieve adjustment of the heat exchange length.

[0081] Furthermore, reducing the heat exchange length of the first heat exchange tube includes: closing the valve corresponding to the current outlet in the connected state on the first heat exchange tube, and opening the valve corresponding to the previous outlet of the current outlet, so that the previous outlet is in the connected state, wherein the heat exchange length corresponding to the previous outlet is less than the heat exchange length corresponding to the current outlet. If the first heat exchange tube has been reduced to the minimum heat exchange length, it is sufficient to maintain the minimum heat exchange length. This embodiment controls the connected state of the outlet of the first heat exchange tube by a valve, which can simply and quickly reduce the heat exchange length and achieve adjustment of the heat exchange length.

[0082] In one embodiment, controlling the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature includes:

[0083] Calculate the difference between the evaporator inlet temperature and the evaporator outlet temperature, and record it as the second difference;

[0084] Determining whether the second difference is within a second preset range;

[0085] If the second difference is within the second preset range, the current speed of the compressor is kept unchanged;

[0086] If the second difference is less than the lower limit of the second preset range, the compressor speed is increased, and after the second preset time, the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature is returned to be executed;

[0087] If the second difference is greater than the upper limit of the second preset range, the compressor speed is reduced, and after the second preset time, the process returns to the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

[0088] Specifically, the evaporator inlet temperature is lower than the evaporator outlet temperature, so the second preset range is a negative range. If the evaporator inlet and outlet temperature difference is within the second preset range, it means that the evaporator inlet and outlet temperature difference is within the target range. According to the current operating conditions, the temperature of the target area (such as the temperature in the low-temperature storage box) can be reduced to the set temperature without adjusting the compressor speed. If the evaporator inlet and outlet temperature difference is less than the lower limit of the second preset range, it means that the evaporator inlet and outlet temperature difference is too large (that is, the current cooling output is insufficient and the cooling output needs to be increased). At this time, it is necessary to increase the compressor speed and increase the refrigerant flow through the evaporator to reduce the evaporator inlet and outlet temperature difference; if the compressor has reached the maximum speed, the speed will no longer be increased, and the maximum speed can be maintained. If the evaporator inlet and outlet temperature difference is greater than the upper limit of the second preset range, it means that the evaporator inlet and outlet temperature difference is too small (that is, the current cooling output is excessive and the cooling output needs to be reduced). At this time, the compressor speed can be appropriately reduced to maintain the evaporator inlet and outlet temperature difference within a more reasonable range; if the compressor has dropped to the minimum speed, the speed will no longer be reduced, and the minimum speed can be maintained.

[0089] After the adjustment operation is performed, the parameter data of the refrigeration system will change accordingly to the adjustment operation after a certain period of time. Therefore, a second preset time is set to ensure that the refrigeration system has enough time to respond. Rejudgment is made again after the second preset time to ensure the reliability of the judgment. The second preset time can be set according to actual conditions. Considering that the system response time is different for adjustments to different parameters, the second preset time can be set to be less than the first preset time. Specifically, the compressor speed can be changed according to a certain amplitude or speed.

[0090] Under the premise that the evaporator inlet temperature has been controlled within a reasonable range by adjusting the heat exchange length of the condenser evaporator, this embodiment controls the compressor speed based on the evaporator inlet and outlet temperature difference, which can quickly and accurately control the evaporator inlet and outlet temperature difference within the target range, and when the cooling output needs to be increased, the compressor frequency increase demand can be reduced, thereby reducing energy consumption; when the cooling output needs to be reduced, the compressor frequency reduction range can be avoided to be too large, thereby ensuring the stability of system operation.

[0091] In practical applications, the above refrigeration control process can be executed periodically at certain time intervals to meet the operation requirements of the refrigeration system.

[0092] Combine the following Figure 3 and Figure 4 The above-mentioned refrigeration control method is described. However, it is worth noting that this specific embodiment is only for better illustrating the present application and does not constitute an improper limitation on the present application.

[0093] like Figure 3 As shown, as a specific embodiment, the refrigeration control process includes the following steps:

[0094] S301, during the operation of the refrigeration system, detect the evaporator inlet temperature T in and the evaporator outlet temperature T out .

[0095] S302, determine whether T1≤T s -T in ≤T2, if yes, go to S303, if no, go to S308. s represents the set temperature, and [T1, T2] represents the first preset range.

[0096] S303, further determine whether T3≤T in -T out ≤T4, if yes, go to S304, if no, go to S305. [T3, T4] represents the second preset range.

[0097] S304, keep the current heat exchange length of the first heat exchange tube and the current speed of the compressor unchanged, and enter S311.

[0098] S305, determine whether T is satisfied in -T out <T3, if yes, go to S306, if no, then T in -T out >T4, enter S307.

[0099] S306, the compressor increases the speed, and returns to S303 after running for Y hours. Y represents the second preset time. If the compressor has reached the maximum speed, the speed is no longer increased, and the compressor can be kept running at the maximum speed.

[0100] S307, the compressor reduces the speed, and returns to S303 after running for Y hours. If the compressor has already reduced to the minimum speed, the speed is no longer reduced, and the minimum speed is maintained.

[0101] S308, determine whether T is satisfied s -T in <T1, if yes, go to S309, if no, then T s -T in >T2, enter S310.

[0102] S309, increase the heat exchange length of the first heat exchange tube, and return to S302 after running for Z hours. Z represents the first preset time. If the first heat exchange tube has reached the maximum heat exchange length, then the maximum heat exchange length is maintained for operation.

[0103] S310, reduce the heat exchange length of the first heat exchange tube, and return to S302 after running for Z hours. If the first heat exchange tube has been reduced to the minimum heat exchange length, keep running at the minimum heat exchange length.

[0104] S311, after running for Q hours, returns to S301 to perform the next round of judgment and control.

[0105] like Figure 4 As shown, taking the low temperature storage box as an example, based on Figure 1 In the case where the first heat exchange tube includes three outlets, the refrigeration control process after the low-temperature storage box is turned on includes the following steps:

[0106] S401, the low temperature storage box is powered on and operated.

[0107] S402, according to the current working condition and the set temperature Ts, the compressor operates at the target speed Po, and in the initial state, port B is connected, and ports A and C are closed.

[0108] S403, after X minutes, detect the evaporator inlet temperature T inand the evaporator outlet temperature T out After the machine has been running for X minutes and entered a stable operating state, it is allowed to detect T in and T out As the refrigeration system runs, T can be tested at any time according to demand. in and T out .

[0109] S404, determine whether T1≤T s -T in ≤T2, if yes, go to S405, if no, go to S410.

[0110] S405, further determine whether T3≤T in -T out ≤T4, if yes, go to S406, if no, go to S407.

[0111] S406, keep the current B port connected and the current speed Po running. After Q hours, re-check T in and T out , to conduct the next round of judgment and control, please refer to Figure 3 process.

[0112] S407, determine whether T is satisfied in -T out <T3, if yes, go to S408, if no, then T in -T out >T4, enter S409.

[0113] S408, the compressor increases its speed at a rate of ΔP1 / h. After running for Y hours, it can be re-determined whether T3≤T in -T out ≤T4, specific reference Figure 3 process.

[0114] S409, the compressor reduces its speed at a rate of ΔP2 / h. After running for Y hours, it can be re-determined whether T3≤T in -T out ≤T4, specific reference Figure 3 process.

[0115] S410, judging whether T is satisfied s -T in <T1, if yes, go to S411, if no, then T s -T in >T2, enter S412.

[0116] S411, increase the heat exchange length of the first heat exchange tube, that is, switch to: port A is connected, port B and port C are closed. After running for Z hours, it can be re-judged whether T1≤T s -T in ≤T2, specific reference Figure 3 process.

[0117] S412, reduce the heat exchange length of the first heat exchange tube, that is, switch to: port C is connected, port A and port B are closed. After running for Z hours, it can be re-determined whether T1≤T s -T in ≤T2, specific reference Figure 3 process.

[0118] In this embodiment, at least two outlets are arranged at different length sections of the first heat exchange tube of the condenser evaporator, and at least two valves are arranged accordingly to control the on and off of each outlet respectively. The heat exchange length of the condenser evaporator is automatically adjusted according to the cooling demand to change the refrigerant state before throttling by the second throttling element, and the compressor speed is further controlled to realize the control of the refrigerant state of the evaporator inlet and outlet. Therefore, when it is necessary to increase the cooling output, the frequency increase demand of the compressor can be reduced, unnecessary frequency increase of the compressor can be avoided, and energy consumption can be reduced. When it is necessary to reduce the cooling output, excessive frequency reduction of the compressor can be avoided, thereby ensuring the stability of system operation. While meeting the cooling demand under different working conditions, it solves the problem that the existing refrigeration control scheme will increase energy consumption and reduce the stability of system operation, which is more conducive to the long-term stable operation of the system.

[0119] Example 3

[0120] Based on the same inventive concept, this embodiment provides a refrigeration control device, which is applied to the refrigeration system described in the above embodiment and can be used to implement the refrigeration control method described in the above embodiment. The refrigeration control device can be implemented by software and / or hardware, and the refrigeration control device can generally be integrated into a controller of the refrigeration system.

[0121] Figure 5 is a structural block diagram of a refrigeration control device provided by an embodiment of the present invention, such as Figure 5 As shown, the refrigeration control device comprises:

[0122] A detection module 51, used to detect the evaporator inlet temperature and the evaporator outlet temperature;

[0123] A first control module 52, configured to control the heat exchange length of the first heat exchange tube according to a set temperature and the evaporator inlet temperature, so that the difference between the set temperature and the evaporator inlet temperature is within a first preset range;

[0124] The second control module 53 is used to control the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature so that the evaporator inlet and outlet temperature difference is within a second preset range.

[0125] Optionally, the first control module 52 includes:

[0126] a first calculation unit, used for calculating a difference between the set temperature and the evaporator inlet temperature, recorded as a first difference;

[0127] A first judging unit, configured to judge whether the first difference is within the first preset range;

[0128] a first control unit, configured to keep the current heat exchange length of the first heat exchange tube unchanged if the first difference is within the first preset range;

[0129] a second control unit, configured to increase the heat exchange length of the first heat exchange tube if the first difference is less than a lower limit of the first preset range, and return to the first calculation unit to execute the step of calculating the difference between the set temperature and the evaporator inlet temperature after a first preset time;

[0130] The third control unit is used to reduce the heat exchange length of the first heat exchange tube if the first difference is greater than the upper limit of the first preset range, and after a first preset time, return to the first calculation unit to execute the step of calculating the difference between the set temperature and the evaporator inlet temperature.

[0131] Optionally, the second control unit is specifically used to: close the valve corresponding to the current outlet on the first heat exchange tube that is in a connected state, and open the valve corresponding to the next outlet of the current outlet to make the next outlet in a connected state, wherein the heat exchange length corresponding to the next outlet is greater than the heat exchange length corresponding to the current outlet.

[0132] Optionally, the third control unit is specifically used to: close the valve corresponding to the current outlet on the first heat exchange tube that is in a connected state, and open the valve corresponding to the previous outlet of the current outlet to make the previous outlet in a connected state, wherein the heat exchange length corresponding to the previous outlet is smaller than the heat exchange length corresponding to the current outlet.

[0133] Optionally, the second control module 53 includes:

[0134] a second calculation unit, used for calculating a difference between the evaporator inlet temperature and the evaporator outlet temperature, recorded as a second difference;

[0135] A second judging unit, configured to judge whether the second difference is within the second preset range;

[0136] a fourth control unit, configured to keep the current speed of the compressor unchanged if the second difference is within the second preset range;

[0137] a fifth control unit, configured to increase the compressor speed if the second difference is less than the lower limit of the second preset range, and return to the second calculation unit to execute the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature after a second preset time;

[0138] The sixth control unit is used to reduce the compressor speed if the second difference is greater than the upper limit of the second preset range, and after a second preset time, return to the second calculation unit to execute the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

[0139] The above refrigeration control device can execute the refrigeration control method provided in the embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. For technical details not described in detail in this embodiment, please refer to the refrigeration control method provided in the embodiment of the present invention.

[0140] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0141] Example 4

[0142] This embodiment provides a low-temperature preservation box, comprising: the refrigeration system described in the above embodiment, and the refrigeration control device described in the above embodiment.

[0143] Example 5

[0144] This embodiment provides a non-volatile computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the refrigeration control method described in the above embodiment is implemented.

[0145] Example 6

[0146] This embodiment provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the refrigeration control method described in the above embodiment when executing the computer program.

[0147] Figure 6 is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present invention, such as Figure 6 As shown, the electronic device includes:

[0148] One or more processors 610 and memory 620, Figure 6 A processor 610 is taken as an example.

[0149] The electronic device may further include: an input device 630 and an output device 640 .

[0150] The processor 610, the memory 620, the input device 630 and the output device 640 may be connected via a bus or other means. Figure 6 The example of connecting through bus is taken in the following.

[0151] The memory 620 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the refrigeration control method in the embodiment of the present invention. The processor 610 executes various functional applications and data processing by running the non-volatile software programs, instructions and modules stored in the memory 620, that is, implementing the above-mentioned refrigeration control method.

[0152] The memory 620 may include a program storage area and a data storage area, wherein the program storage area may store an application required for operating the device and at least one function; the data storage area may store operating data of the refrigeration system, threshold data, etc. In addition, the memory 620 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0153] The input device 630 can receive input digital or character information and generate key signal input related to user settings and function control of the electronic device. The output device 640 can include a display device such as a display screen.

[0154] The one or more modules are stored in the memory 620, and when executed by the one or more processors 610, the refrigeration control method in any of the above method embodiments is executed.

[0155] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A refrigeration system, characterized in that: include: A gas-liquid separator, wherein the inlet thereof is connected to the outlet of the condenser, the gas outlet thereof is connected to the inlet of the first heat exchange tube of the condenser evaporator, the liquid outlet thereof is connected to the inlet of the second heat exchange tube of the condenser evaporator through the first throttling element, and the outlet of the second heat exchange tube is connected to the suction port of the compressor; The first heat exchange tube comprises at least two outlets, each outlet corresponds to a different heat exchange length, each outlet of the first heat exchange tube is connected to the inlet of the evaporator through a second throttling element, and the outlet of the evaporator is connected to the inlet of the second heat exchange tube; During the operation of the system, at any time, only one outlet of the first heat exchange tube is connected to the second throttling element.

2. The refrigeration system according to claim 1, characterized in that: A respective valve is arranged on the pipeline connected to each outlet of the first heat exchange tube.

3. The refrigeration system according to claim 1, characterized in that: The first heat exchange tube and the second heat exchange tube are in a sleeve structure, the first heat exchange tube is an outer tube, and the second heat exchange tube is an inner tube.

4. The refrigeration system according to any one of claims 1 to 3, characterized in that: A first temperature sensor is arranged at the inlet of the evaporator for detecting the inlet temperature of the evaporator; a second temperature sensor is arranged at the outlet of the evaporator for detecting the outlet temperature of the evaporator.

5. A refrigeration control method, characterized in that: Applied to the refrigeration system according to any one of claims 1 to 4, the method comprising: Detect the evaporator inlet temperature and evaporator outlet temperature; Controlling the heat exchange length of the first heat exchange tube according to the set temperature and the evaporator inlet temperature so that the difference between the set temperature and the evaporator inlet temperature is within a first preset range; The compressor speed is controlled according to the evaporator inlet temperature and the evaporator outlet temperature so that the evaporator inlet and outlet temperature difference is within a second preset range.

6. The method according to claim 5, characterized in that Controlling the heat exchange length of the first heat exchange tube according to the set temperature and the evaporator inlet temperature includes: Calculating the difference between the set temperature and the evaporator inlet temperature, and recording it as a first difference; Determining whether the first difference is within the first preset range; If the first difference is within the first preset range, the current heat exchange length of the first heat exchange tube is kept unchanged; If the first difference is less than the lower limit of the first preset range, the heat exchange length of the first heat exchange tube is increased, and after a first preset time, the step of calculating the difference between the set temperature and the evaporator inlet temperature is returned to be executed; If the first difference is greater than the upper limit of the first preset range, the heat exchange length of the first heat exchange tube is reduced, and after a first preset time, the step of calculating the difference between the set temperature and the evaporator inlet temperature is returned to be executed.

7. The method according to claim 6, characterized in that Increasing the heat exchange length of the first heat exchange tube, comprising: closing a valve corresponding to a current outlet of the first heat exchange tube that is in a connected state, and opening a valve corresponding to a next outlet of the current outlet, so that the next outlet is in a connected state, wherein the heat exchange length corresponding to the next outlet is greater than the heat exchange length corresponding to the current outlet; Reducing the heat exchange length of the first heat exchange tube includes: closing the valve corresponding to the current outlet of the first heat exchange tube that is in a connected state, and opening the valve corresponding to the previous outlet of the current outlet to make the previous outlet in a connected state, wherein the heat exchange length corresponding to the previous outlet is smaller than the heat exchange length corresponding to the current outlet.

8. The method according to claim 5, characterized in that Controlling the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature includes: Calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature, and recording it as a second difference; Determining whether the second difference is within the second preset range; If the second difference is within the second preset range, keeping the current speed of the compressor unchanged; If the second difference is less than the lower limit of the second preset range, the compressor speed is increased, and after a second preset time, the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature is returned to be executed; If the second difference is greater than the upper limit of the second preset range, the compressor speed is reduced, and after a second preset time, the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature is returned to be executed.

9. A refrigeration control device, characterized in that: Applicable to a refrigeration system according to any one of claims 1 to 4, the device comprising: A detection module, used for detecting the evaporator inlet temperature and the evaporator outlet temperature; a first control module, configured to control the heat exchange length of the first heat exchange tube according to a set temperature and the evaporator inlet temperature, so that the difference between the set temperature and the evaporator inlet temperature is within a first preset range; The second control module is used to control the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature so that the evaporator inlet and outlet temperature difference is within a second preset range.

10. A low temperature storage box, characterized in that: include: The refrigeration system according to any one of claims 1 to 4.

11. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the refrigeration control method according to any one of claims 5 to 8 is implemented.

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