Refrigeration system, cryopreservation box, refrigeration control method and device, storage medium

Abstract

The application discloses a refrigeration system, a low-temperature storage box, a refrigeration control method and device, and a storage medium. The refrigeration system comprises a gas-liquid separator, an inlet of the gas-liquid separator is connected to an outlet of a condenser, a gas outlet of the gas-liquid separator is connected to an inlet of a first heat exchange pipe of a condensing evaporator, a liquid outlet of the gas-liquid separator is connected to an inlet of a second heat exchange pipe of the condensing evaporator through a first throttling element, and an outlet of the second heat exchange pipe is connected to a suction inlet of a compressor. The first heat exchange pipe comprises at least two outlets, each outlet corresponds to a different heat exchange length, each outlet of the first heat exchange pipe is connected to an inlet of an evaporator through a second throttling element, and an outlet of the evaporator is connected to an inlet of the second heat exchange pipe. During system operation, only one outlet of the first heat exchange pipe is in communication with the second throttling element at any moment. The application can preferentially adjust the heat exchange length of the condensing evaporator, then adjust the compressor, reduce the frequency increasing demand of the compressor when the cold output needs to be increased, and avoid the compressor from having too large a frequency decreasing amplitude when the cold output needs to be reduced.

Description

TECHNICAL FIELD

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

[0002] The medical low-temperature storage box is mainly used for storing biological samples such as cells, tissues, viruses, fertilized eggs, and clinical samples which have important values, and the temperature range is between-20℃ and-150℃. The product in the temperature range of-86℃ and below has a wide temperature control range, and the product mainly uses a cascade refrigeration system or a self-cascade refrigeration system.

[0003] At present, when the low-temperature storage box is running, the output cooling capacity is mainly controlled by the compressor. If the current output cooling capacity is insufficient, the compressor frequency is increased to increase the cooling capacity output, which will increase the energy consumption, and even lead to excessive energy consumption. If the current output cooling capacity is too large, the compressor frequency is reduced to reduce the cooling capacity output, and if the compressor frequency reduction is too large, the refrigeration system will run unstably, and even stop. SUMMARY

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

[0005] To solve the above technical problems, the embodiments of the present application provide a refrigeration system, comprising:

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

[0007] The first heat exchange pipe comprises at least two outlets, each outlet corresponding to a different heat exchange length, and each outlet of the first heat exchange pipe 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 pipe;

[0008] During the system running process, only one outlet of the first heat exchange pipe is in communication with the second throttling element at any time.

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

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

[0011] Optionally, a first temperature sensor is arranged at the inlet of the evaporator to detect the evaporator inlet temperature; and a second temperature sensor is arranged at the outlet of the evaporator to detect the evaporator outlet temperature.

[0012] The embodiment of the present application also provides a refrigeration control method applied to the refrigeration system, and the method comprises the following steps:

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

[0014] controlling the heat exchange length of the first heat exchange pipe 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] controlling the rotating speed of the compressor according to the evaporator inlet temperature and the evaporator outlet temperature, so that the temperature difference between the evaporator inlet and outlet is within a second preset range.

[0016] Optionally, the step of controlling the heat exchange length of the first heat exchange pipe according to the set temperature and the evaporator inlet temperature comprises the following steps:

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

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

[0019] if the first difference is within the first preset range, keeping the current heat exchange length of the first heat exchange pipe unchanged;

[0020] if the first difference is less than the lower limit value of the first preset range, increasing the heat exchange length of the first heat exchange pipe, and returning to the step of calculating the difference between the set temperature and the evaporator inlet temperature after a first preset time;

[0021] if the first difference is greater than the upper limit value of the first preset range, decreasing the heat exchange length of the first heat exchange pipe, and returning to the step of calculating the difference between the set temperature and the evaporator inlet temperature after a first preset time.

[0022] Optionally, the step of increasing the heat exchange length of the first heat exchange pipe comprises the following steps: closing the valve corresponding to the current outlet in the connected state of the first heat exchange pipe, 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;

[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, so that the previous outlet is in a connected state, wherein the heat exchange length corresponding to the previous outlet is less than the heat exchange length corresponding to the current outlet.

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

[0025] Calculate the difference between the evaporator inlet temperature and the evaporator outlet temperature, and record it as the second difference;

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

[0027] If the second difference is within the second preset range, then the current speed of the compressor remains 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 process returns to the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

[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 process returns to the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

[0030] This invention also provides a refrigeration control device, applied to the refrigeration system described in this invention, the device comprising:

[0031] The detection module is used to detect the evaporator inlet temperature and the evaporator outlet temperature;

[0032] The first control module is used to control 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.

[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 temperature difference between the evaporator inlet and outlet is within a second preset range.

[0034] This invention also provides a low-temperature storage box, including the refrigeration system described in this invention.

[0035] This invention also provides a non-volatile computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the cooling control method described in this invention.

[0036] By applying the technical solution of this invention, at least two outlets are provided at different lengths 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 it is necessary to increase the cooling output, the heat exchange capacity is increased by adjusting the heat exchange length of the condenser-evaporator, thereby reducing the compressor's frequency increase requirement and thus reducing energy consumption. When it is necessary to reduce the cooling output, the heat exchange capacity is reduced by adjusting the heat exchange length of the condenser-evaporator, thereby avoiding excessive compressor frequency reduction and ensuring system operational stability. This solution meets the actual cooling demand while solving the problems of increased energy consumption and reduced system operational stability in existing refrigeration control schemes, and is more conducive to long-term stable system operation. Attached Figure Description

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

[0038] Figure 2 This is a flowchart of the refrigeration control method provided in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the refrigeration control process provided in an embodiment of the present invention;

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

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

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

[0043] Explanation of reference numerals in the attached figures:

[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, dryer filter 13. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] It should be noted that the terms "first," "second," etc., used in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

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

[0048] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0049] The optional embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0050] Example 1

[0051] This embodiment provides a refrigeration system, specifically a self-cascading refrigeration system, which can be used in a low-temperature storage box.

[0052] Figure 1 This is a schematic diagram of the refrigeration system provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the refrigeration system includes: compressor 1, condenser 2, gas-liquid separator 3, condenser-evaporator 4, first throttling element 5, second throttling element 6, and 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 outlet, and a liquid outlet. The inlet of the gas-liquid separator 3 is connected to the outlet of the condenser 2. The 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. 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 corresponding to a different heat exchange length. The heat exchange length refers to the actual length of the first heat exchange tube involved in heat exchange; under the same medium flow rate, a longer heat exchange length results in a greater heat exchange capacity. Each outlet of the first heat exchange tube is located at a different position within the tube. Each outlet of the first heat exchange tube is connected to the inlet of the evaporator 7 via a 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 given 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 in the condenser-evaporator 4 can be adjusted according to actual needs, thereby changing the heat exchange capacity.

[0056] This embodiment sets at least two outlets at different lengths 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 it is necessary to increase the cooling output, the heat exchange capacity is increased by adjusting the heat exchange length of the condenser-evaporator, thereby reducing the compressor's frequency increase requirement and thus reducing energy consumption. When it is necessary to reduce the cooling output, the heat exchange capacity is reduced by adjusting the heat exchange length of the condenser-evaporator, thereby avoiding excessive compressor frequency reduction and ensuring system operational stability. While meeting the actual cooling demand, this embodiment solves the problems of increased energy consumption and reduced system operational stability in existing refrigeration control schemes, and 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 separate valve on its own pipe. By controlling the opening and closing of the valve, the connection of the corresponding outlet can be controlled, thereby changing the heat exchange length of the condenser-evaporator.

[0058] Figure 1Taking a first heat exchange tube with three outlets as an example, denoted as outlet A, outlet B, and outlet C, the heat exchange length corresponding to outlet A > the heat exchange length corresponding to outlet B > the heat exchange length corresponding to outlet C. Outlet A corresponds to the maximum heat exchange length of the first heat exchange tube, and outlet C corresponds to the minimum heat exchange length of the first heat exchange tube. For example, taking the inlet of the first heat exchange tube as the starting point, outlet C is located at 1 / 3 of the total length of the first heat exchange tube, outlet B is located at 2 / 3 of the total length of the first heat exchange tube, and outlet A is located at the end of the first heat exchange tube. Outlet A corresponds to the first valve 8; opening the first valve 8 connects outlet A. Outlet B corresponds to the second valve 9; opening the second valve 9 connects outlet B. Outlet C corresponds to the third valve 10; opening the third valve 10 connects outlet C.

[0059] The first throttling element 5 and the second throttling element 6 can be capillary tubes, electronic expansion valves, or other elements with throttling functions.

[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 shell-and-tube structure, with the first heat exchange tube being the outer tube and the second heat exchange tube being the inner tube, so as to facilitate the adjustment of the heat exchange length of the first heat exchange tube.

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

[0062] refer to Figure 1 The high-temperature, high-pressure refrigerant discharged from compressor 1 is condensed by condenser 2 and then passes through dryer filter 13 into gas-liquid separator 3, where it is separated into a liquid refrigerant rich in high-boiling-point working fluid (i.e., high-temperature refrigerant) and a gaseous refrigerant rich in low-boiling-point working fluid (i.e., low-temperature refrigerant). The low-temperature refrigerant enters the first heat exchange tube of condenser-evaporator 4, while the high-temperature refrigerant, after being throttled by the first throttling element 5 (e.g., high-temperature capillary tube), enters the second heat exchange tube of condenser-evaporator 4 to exchange heat with the low-temperature gaseous refrigerant in the first heat exchange tube, further condensing the low-temperature refrigerant. The condensed low-temperature refrigerant, after being throttled by the second throttling element 6 (e.g., low-temperature capillary tube), enters evaporator 7 for cooling. The refrigerant at the evaporator outlet, along with the throttled high-temperature refrigerant, enters condenser-evaporator 4 to provide cooling for the condensation of the gaseous low-temperature refrigerant. By controlling the opening and closing 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 capacity of the low-temperature refrigerant.

[0063] Example 2

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

[0065] Figure 2 This is a flowchart of the refrigeration control method provided in an embodiment of the present invention, such as... Figure 2 As shown, the method includes the following steps:

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

[0067] S202, the heat exchange length of the first heat exchange tube is controlled 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 controls the compressor speed based on the evaporator inlet temperature and evaporator outlet temperature to keep the temperature difference between the evaporator inlet and outlet within a second preset range.

[0069] If the difference between the set temperature and the evaporator inlet temperature is within the first preset range, it indicates that the evaporator inlet temperature is within a reasonable range. If the temperature difference between the evaporator inlet and outlet (i.e., the difference between the evaporator inlet temperature and the evaporator outlet temperature) is within the second preset range, it indicates that the temperature difference between the evaporator inlet and outlet is within the target range. The first and second preset ranges 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, followed by the compressor speed, to ensure that the evaporator inlet temperature and the temperature difference between the evaporator inlet and outlet are within a reasonable range, thus meeting the refrigeration requirements. When an increase in cooling capacity output is needed, the heat exchange capacity is increased by adjusting the heat exchange length of the condenser-evaporator, thereby reducing the compressor's frequency increase requirement and reducing energy consumption. Conversely, when a decrease in cooling capacity output is needed, the heat exchange capacity is reduced by adjusting the heat exchange length of the condenser-evaporator, thus preventing excessive compressor frequency reduction and ensuring system operational stability. This approach addresses the issues of increased energy consumption and reduced system operational stability in existing refrigeration control schemes while meeting actual cooling capacity requirements, making it more conducive to long-term stable system operation.

[0071] In one embodiment, controlling the heat exchange length of the first heat exchange tube based on a 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] Determine whether the first difference is within the first preset range;

[0074] If the first difference is within the first preset range, then the current heat exchange length of the first heat exchange tube remains 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. After the first preset time, the process returns to the step of calculating the difference between the set temperature and the evaporator inlet temperature.

[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. 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 indicates 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 indicates that the evaporator inlet temperature is too high (i.e., the current cooling output is insufficient and needs to be increased). In this case, the heat exchange length of the condenser-evaporator can be increased to increase the heat exchange capacity, thereby lowering 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 indicates that the evaporator inlet temperature is too low (i.e., the current cooling output is excessive and needs to be reduced). In this case, the heat exchange length of the condenser-evaporator can be reduced to decrease the heat exchange capacity, thereby increasing the evaporator inlet temperature.

[0078] After the adjustment operation is performed, the refrigeration system's parameter data will only change accordingly after a certain period of time. Therefore, setting a first preset time ensures that the refrigeration system has sufficient time to respond. Re-evaluating after the first preset time ensures 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 and adjust the heat exchange capacity based on the deviation between the evaporator inlet temperature and the set temperature, 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 of the first heat exchange tube that is in a connected state, and opening the valve corresponding to the 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. If the first heat exchange tube has already reached its maximum heat exchange length, it can be maintained at the maximum heat exchange length. This embodiment, for the first heat exchange tube, controls the connection state of its outlet through valves, which can easily and quickly increase the heat exchange length and realize the 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 of the first heat exchange tube, which is in a connected state, and opening the valve corresponding to the previous outlet, so that the previous outlet is in a 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 already been reduced to the minimum heat exchange length, then it can be operated at the minimum heat exchange length. This embodiment, for the first heat exchange tube, controls the connection state of its outlet through valves, 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 based on 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] Determine whether the second difference is within the second preset range;

[0085] If the second difference is within the second preset range, the current speed of the compressor remains 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 process returns to the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

[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, therefore the second preset range is a negative range. If the evaporator inlet and outlet temperature difference is within the second preset range, it means the evaporator inlet and outlet temperature difference is within the target range. Under the current operating conditions, the temperature in the target area (e.g., the temperature inside the low-temperature storage box) can drop to the set temperature, and there is no need to adjust the compressor speed. If the evaporator inlet and outlet temperature difference is less than the lower limit of the second preset range, it means the evaporator inlet and outlet temperature difference is too large (i.e., the current cooling output is insufficient, and the cooling output needs to be increased). In this case, the compressor speed needs to be increased to increase the refrigerant flow through the evaporator to reduce the evaporator inlet and outlet temperature difference. If the compressor has already reached its maximum speed, the speed should not be increased further, and the maximum speed should be maintained. If the evaporator inlet and outlet temperature difference is greater than the upper limit of the second preset range, it means the evaporator inlet and outlet temperature difference is too small (i.e., the current cooling output is excessive, and the cooling output needs to be reduced). In this case, the compressor speed can be appropriately reduced to keep the evaporator inlet and outlet temperature difference within a reasonable range. If the compressor has already dropped to its minimum speed, the speed should not be reduced further, and the minimum speed should be maintained.

[0089] After the adjustment operation is performed, the refrigeration system parameters will only change accordingly after a certain period of time. Therefore, a second preset time is set to ensure that the refrigeration system has sufficient time to respond. A re-evaluation is then performed 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 varies for different parameter adjustments, the second preset time can be set to be shorter than the first preset time. Specifically, the compressor speed can be changed by a certain magnitude or speed.

[0090] This embodiment, 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, controls the compressor speed based on the temperature difference between the evaporator inlet and outlet. It can quickly and accurately control the temperature difference between the evaporator inlet and outlet within the target range. Furthermore, when it is necessary to increase the cooling output, it can reduce the compressor's frequency increase requirement, thereby reducing energy consumption; when it is necessary to reduce the cooling output, it can avoid the compressor's frequency reduction too much, ensuring the stability of system operation.

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

[0092] The following is combined with Figure 3 and Figure 4 The above-described refrigeration control method is explained in detail. However, it is worth noting that the specific embodiment is only for better illustration of this application and does not constitute an improper limitation of this application.

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

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

[0095] S302, determine whether T1≤T is satisfied. s -T in If ≤T2, proceed to S303; otherwise, proceed to S308. T s The set temperature is indicated by [T1, T2], which represents the first preset range.

[0096] S303, further determine whether T3≤T is satisfied. in -T out If ≤T4, proceed to S304; otherwise, proceed 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 proceed to S311.

[0098] S305, determine whether T is satisfied. in -T out <T3, if yes, proceed to S306; otherwise, proceed to T. in -T out >T4, enter S307.

[0099] S306: The compressor increases its speed and runs for Y hours before returning to S303. Y represents the second preset time mentioned above. If the compressor has already reached its maximum speed, it will not increase the speed further and will simply maintain the maximum speed.

[0100] S307: The compressor reduces its speed and runs for Y hours before returning to S303. If the compressor has already reached its minimum speed, it will not reduce the speed further and will continue to run at the minimum speed.

[0101] S308, determine whether T is satisfied. s -T in <T1, if yes, proceed to S309; ​​otherwise, proceed to 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 mentioned above. If the first heat exchange tube has reached its maximum heat exchange length, then maintain the maximum heat exchange length 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 already been reduced to the minimum heat exchange length, then maintain the minimum heat exchange length during operation.

[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 a low-temperature storage box as an example, based on Figure 1 The first heat exchange tube shown has three outlets. The refrigeration control process after the cryogenic storage box is turned on includes the following steps:

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

[0107] S402, based on the current operating conditions and the set temperature Ts, the compressor runs at the target speed Po. Initially, port B is in the connected state, while ports A and C are in the closed state.

[0108] S403, after X minutes, check the evaporator inlet temperature T. inand evaporator outlet temperature T out After running for X minutes since startup, it enters a stable operating state before allowing T detection. in and T out Subsequently, as the refrigeration system operates, T can be monitored at any time as needed. in and T out .

[0109] S404, determine whether T1≤T is satisfied. s -T in If ≤T2, proceed to S405; otherwise, proceed to S410.

[0110] S405, further determine whether T3≤T is satisfied. in -T out If ≤T4, proceed to S406; otherwise, proceed to S407.

[0111] S406, maintain the current B port connection status and the current speed Po. After Q hours, T can be re-detected. in and T out To proceed with the next round of assessment and control, please refer to the following for details. Figure 3 The process.

[0112] S407, determine whether T is satisfied. in -T out <T3, if yes, proceed to S408; otherwise, proceed to 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-evaluated whether T3≤T is satisfied. in -T out ≤T4, see details Figure 3 The process.

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

[0115] S410, determine whether T is satisfied. s -T in <T1, if yes, proceed to S411; otherwise, proceed to T. s -T in >T2, enter S412.

[0116] S411, increase the heat exchange length of the first heat exchange tube, i.e., switch to: port A in the connected state, and ports B and C in the closed state. After running for Z hours, it can be re-evaluated whether T1≤T is satisfied. s -T in ≤T2, see details Figure 3 The process.

[0117] S412, reduce the heat exchange length of the first heat exchange tube, i.e., switch to: port C in the connected state, and ports A and B in the closed state. After running for Z hours, it can be re-evaluated whether T1≤T is satisfied. s -T in ≤T2, see details Figure 3 The process.

[0118] This embodiment sets at least two outlets at different lengths of the first heat exchange tube of the condenser-evaporator, and correspondingly sets at least two valves to control the opening and closing of each outlet. According to the cooling demand, the heat exchange length of the condenser-evaporator is automatically adjusted first to change the refrigerant state before the second throttling element. Then, the compressor speed is further controlled to control the refrigerant state at the inlet and outlet of the evaporator. This reduces the compressor's frequency increase requirement when the cooling output needs to be increased, avoids unnecessary compressor frequency increase, and reduces energy consumption. When the cooling output needs to be reduced, the compressor frequency reduction is avoided to ensure the stability of system operation. While meeting the cooling demand under different operating conditions, it solves the problems of increased energy consumption and reduced system operation stability of existing refrigeration control schemes, 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 applied to the refrigeration system described in the above embodiments, which can be used to implement the refrigeration control method described in the above embodiments. This refrigeration control device can be implemented through software and / or hardware, and is generally integrated into the controller of the refrigeration system.

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

[0122] Detection module 51 is used to detect the evaporator inlet temperature and the evaporator outlet temperature;

[0123] The first control module 52 is used to control 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.

[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 temperature difference between the evaporator inlet and outlet is within a second preset range.

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

[0126] The first calculation unit is used to calculate the difference between the set temperature and the evaporator inlet temperature, and denoted as the first difference.

[0127] The first judgment unit is used to determine whether the first difference is within the first preset range;

[0128] The first control unit is 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] The second control unit is configured to increase the heat exchange length of the first heat exchange tube if the first difference is less than the lower limit of the first preset range, and after a first preset time, return to the first calculation unit to perform the step of calculating the difference between the set temperature and the evaporator inlet temperature.

[0130] The third control unit is configured 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 perform 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, 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.

[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, so that the previous outlet is in a connected state, wherein the heat exchange length corresponding to the previous outlet is less than the heat exchange length corresponding to the current outlet.

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

[0134] The second calculation unit is used to calculate the difference between the evaporator inlet temperature and the evaporator outlet temperature, which is denoted as the second difference.

[0135] The second judgment unit is used to determine whether the second difference is within the second preset range;

[0136] The fourth control unit is used to maintain the current speed of the compressor unchanged if the second difference is within the second preset range;

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

[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 perform the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

[0139] The above-described refrigeration control device can execute the refrigeration control method provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in the refrigeration control method provided in the embodiments of the present invention.

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

[0141] Example 4

[0142] This embodiment provides a low-temperature storage box, including: 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 storing a computer program thereon, which, when executed by a processor, implements the cooling control method described in the above embodiment.

[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. When the processor executes the computer program, it implements the cooling control method described in the above embodiment.

[0147] Figure 6 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments 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 Take the 610 processor as an example.

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

[0150] The processor 610, memory 620, input device 630, and output device 640 can be connected via a bus or other means. Figure 6 Taking the example of a connection between China and Israel via a bus.

[0151] The memory 620, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the cooling control method in this embodiment of the 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, thereby implementing the aforementioned cooling control method.

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

[0153] Input device 630 can receive input digital or character information, and generate key signal inputs related to user settings and function control of the electronic device. Output device 640 may include display devices 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, they execute the cooling control method in any of the above method embodiments.

[0155] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments 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, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate 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 has its inlet connected to the outlet of a condenser, its gas outlet connected to the inlet of the first heat exchange tube of a condenser-evaporator, its liquid outlet connected to the inlet of the second heat exchange tube of the condenser-evaporator via a first throttling element, and the outlet of the second heat exchange tube connected to the compressor suction port. The first heat exchange tube includes at least two outlets, each outlet corresponding 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 system operation, at any given time, the first heat exchange tube has only one outlet connected to the second throttling element.

2. The refrigeration system according to claim 1, characterized in that, Each outlet of the first heat exchange tube is connected to a pipe with its own valve.

3. The refrigeration system according to claim 1, characterized in that, The first heat exchange tube and the second heat exchange tube are a shell-and-tube structure, with the first heat exchange tube being the outer tube and the second heat exchange tube being the inner tube.

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

5. A refrigeration control method, characterized in that, The method, applied to the refrigeration system according to any one of claims 1 to 4, comprises: Detect the evaporator inlet temperature and evaporator outlet temperature; The heat exchange length of the first heat exchange tube is controlled 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 based on the evaporator inlet temperature and the evaporator outlet temperature to keep the temperature difference between the evaporator inlet and outlet 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: Calculate the difference between the set temperature and the evaporator inlet temperature, and record it as the first difference; Determine whether the first difference is within the first preset range; If the first difference is within the first preset range, then the current heat exchange length of the first heat exchange tube remains 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. After a first preset time, the process returns to the step of calculating the difference between the set temperature and the evaporator inlet temperature. 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. After a first preset time, the process returns to the step of calculating the difference between the set temperature and the evaporator inlet temperature.

7. The method according to claim 6, characterized in that, Increasing 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 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, so that the previous outlet is in a connected state, wherein the heat exchange length corresponding to the previous outlet is less than the heat exchange length corresponding to the current outlet.

8. The method according to claim 5, characterized in that, Controlling the compressor speed based on the evaporator inlet temperature and the evaporator outlet temperature includes: Calculate the difference between the evaporator inlet temperature and the evaporator outlet temperature, and record it as the second difference; Determine whether the second difference is within the second preset range; If the second difference is within the second preset range, then the current speed of the compressor remains 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 process returns to the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature. 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 process returns to the step of calculating the difference between the evaporator inlet temperature and the evaporator outlet temperature.

9. A refrigeration control device, characterized in that, The device is applied to the refrigeration system according to any one of claims 1 to 4, the device comprising: The detection module is used to detect the evaporator inlet temperature and the evaporator outlet temperature; The first control module is used to control 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 second control module is used to control the compressor speed according to the evaporator inlet temperature and the evaporator outlet temperature, so that the temperature difference between the evaporator inlet and outlet 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 the processor, it implements the cooling control method according to any one of claims 5 to 8.

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