Cold storage system and control method, device and storage medium thereof

Abstract

The present application discloses a cold storage system and its control method, device, and storage medium. The system includes: a medium-temperature evaporator; a low-temperature evaporator whose maximum boundary value within its operating temperature range is less than the minimum boundary value within the medium-temperature evaporator's operating temperature range; a condenser; an ejector including an output port, a first input port connected to the output end of the condenser, and a second input port connected to the output end of the low-temperature evaporator, the output port being respectively connected to a throttle valve and the input end of the medium-temperature evaporator; a compressor having one end connected to the output end of the medium-temperature evaporator and the other end connected to the input end of the condenser; a medium-temperature defrost heater; a low-temperature defrost heater, the output end of which is connected to the input end of the medium-temperature defrost heater; and a heat accumulator. The cold storage system is refrigerated by the two evaporators with different operating temperatures working together to achieve a refrigeration cycle. The heat accumulator absorbs waste heat from the compressor to defrost the evaporator, thereby reducing the probability of frost formation on the evaporator and reducing frosting energy consumption.

Description

Technical Field

[0001] The present application relates to, but is not limited to, the field of refrigeration technology, and in particular to a cold storage system and a control method, device, and storage medium thereof. Background Art

[0002] Traditional cold storage systems only have single-stage evaporators. In order to meet the minimum temperature requirement of the temperature zone in the cold storage system, the evaporator must operate at a temperature lower than the minimum required temperature of the temperature zone. In this case, if the air temperature in the current cold storage system is high, the evaporator will easily frost when it comes into contact with the air due to the large temperature difference, which will cause the compressor of the cold storage system to operate at a low evaporating temperature for a long time, resulting in a decrease in the refrigeration effect of the cold storage system, an increase in the energy consumption of the system, and a reduction in system performance. Summary of the Invention

[0003] The embodiments of the present application provide a cold storage system and its control method, device, and storage medium, which can effectively improve the refrigeration efficiency of the cold storage system while reducing system energy consumption and ensuring system performance.

[0004] In a first aspect, an embodiment of the present application provides a cold storage system, comprising:

[0005] Medium temperature evaporator;

[0006] The low-temperature evaporator has a maximum boundary value in the operating temperature range that is smaller than the minimum boundary value in the operating temperature range of the medium-temperature evaporator;

[0007] condenser;

[0008] an ejector, comprising an output port, a first input port connected to the output end of the condenser, and a second input port connected to the output end of the low-temperature evaporator, the output ports being respectively connected to a throttle valve and the input end of the medium-temperature evaporator, and an end of the throttle valve away from the output port being connected to the input end of the low-temperature evaporator;

[0009] a compressor, one end of which is connected to the output end of the medium-temperature evaporator and the other end of which is connected to the input end of the condenser;

[0010] a medium-temperature defrost heater abutting against the medium-temperature evaporator;

[0011] a low-temperature defrost heater, abutting against the low-temperature evaporator, and having an output end connected to an input end of the medium-temperature defrost heater;

[0012] a heat accumulator filled with a phase change material, further comprising a first heat exchange pipeline and a second heat exchange pipeline in contact with the phase change material, wherein the compressor is connected to an input end of the first heat exchange pipeline through a first port and a second port of a three-way reversing valve, an output end of the first heat exchange pipeline is connected to the first input port, an input end of the second heat exchange pipeline is connected to the medium-temperature defrost heater, and an output end of the second heat exchange pipeline is connected to an input end of the low-temperature defrost heater via a solution pump;

[0013] The three-way reversing valve further includes a third port, and the compressor is connected to the input end of the condenser through the first port and the third port.

[0014] In a second aspect, an embodiment of the present application provides a control method for a cold storage system, which is applied to the cold storage system of the first aspect, and the method includes:

[0015] Starting the compressor to compress the low-temperature, low-pressure fluid output from the medium-temperature evaporator into a high-temperature, high-pressure fluid. The high-temperature, high-pressure fluid enters the condenser for heat exchange processing and then flows to the first input port of the ejector.

[0016] The ejector causes the fluid inside to flow out through the output port, passes through the throttle valve in sequence for throttling and cooling, flows to the low-temperature evaporator for evaporation and heat absorption, and then flows back to the second input port;

[0017] The ejector causes the refluxed fluid to flow again through the output port to the medium-temperature evaporator for evaporation and heat absorption, and the low-temperature and low-pressure fluid flowing out of the medium-temperature evaporator flows back to the compressor.

[0018] In some embodiments, the cold storage system further includes a heat accumulator, and before the high-temperature and high-pressure fluid enters the condenser for heat exchange and flows to the first input port of the ejector, the method further includes:

[0019] The solution pump is turned off, the third port is closed, and the compressor flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage;

[0020] After the heat accumulator completes the heat storage operation, the second port is closed and the third port is connected, so that the high-temperature and high-pressure fluid can flow to the condenser through the first port and the third port of the three-way reversing valve.

[0021] In some embodiments, the heat accumulator is filled with a phase change material, an outer wall of the first heat exchange pipeline is in contact with the phase change material, and after the compressor flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage processing, the method further includes:

[0022] detecting the third surface temperature of the heat accumulator in real time;

[0023] When the third surface temperature reaches the phase change temperature of the phase change material, it is determined that the heat storage operation of the heat accumulator is completed.

[0024] In some embodiments, the cold storage system further includes a medium-temperature defrost heater. After the compressor flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage, the method further includes:

[0025] When receiving a defrost control signal, shutting down the compressor;

[0026] After the solution inside the second heat exchange pipeline is heat exchanged with the phase change material, a high-temperature solution is obtained;

[0027] Starting the solution pump to pump the high-temperature solution into the low-temperature defrost heater;

[0028] The solution outputted from the low-temperature defrost heater passes through the medium-temperature defrost heater and flows back to the second heat exchange pipeline to perform cyclic defrosting on the low-temperature evaporator and the medium-temperature evaporator in sequence.

[0029] In some embodiments, after the solution outputted from the low-temperature defrost heater passes through the medium-temperature defrost heater and flows back to the second heat exchange pipeline to sequentially circulate and defrost the low-temperature evaporator and the medium-temperature evaporator, the method further includes:

[0030] detecting in real time a first surface temperature of the medium-temperature evaporator and a second surface temperature of the low-temperature evaporator;

[0031] When the first surface temperature reaches a first temperature threshold and the second surface temperature reaches a second temperature threshold, the solution pump is turned off and the compressor is turned on again.

[0032] In a third aspect, an embodiment of the present application provides a control device comprising at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the control method of the cold storage system as described in the first aspect.

[0033] In a fourth aspect, an embodiment of the present application further provides a cold storage system, comprising the control device of the second aspect.

[0034] In a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the control method of the cold storage system as described in the first aspect.

[0035] The embodiment of the present application provides a cold storage system and its control method, device, and storage medium, the system comprising: a medium-temperature evaporator; a low-temperature evaporator, wherein the maximum boundary value in the operating temperature range is less than the minimum boundary value in the operating temperature range of the medium-temperature evaporator; a condenser; an ejector, comprising an output port, a first input port connected to the output end of the condenser, and a second input port connected to the output end of the low-temperature evaporator, wherein the output port is respectively connected to a throttle valve and an input end of the medium-temperature evaporator, and an end of the throttle valve away from the output port is connected to the input end of the low-temperature evaporator; a compressor, one end of which is connected to the output end of the medium-temperature evaporator and the other end is connected to the input end of the condenser; a medium-temperature defrost heater, which abuts against the The medium-temperature evaporator; a low-temperature defrost heater, which is abutted against the low-temperature evaporator and has its output connected to the input of the medium-temperature defrost heater; a heat accumulator filled with a phase change material, and further comprising a first heat exchange pipeline and a second heat exchange pipeline in contact with the phase change material, wherein the compressor is connected to the input of the first heat exchange pipeline through the first port and the second port of a three-way reversing valve, the output of the first heat exchange pipeline is connected to the first input port, the input of the second heat exchange pipeline is connected to the medium-temperature defrost heater, and the output of the second heat exchange pipeline is connected to the input of the low-temperature defrost heater through a solution pump; wherein the three-way reversing valve further comprises a third port, and the compressor is connected to the input of the condenser through the first port and the third port. According to the solution provided in the embodiment of the present application, the refrigeration cycle of the cold storage system is realized by cooperating with two evaporators with different operating temperatures, and the heat accumulator is used to absorb the waste heat of the compressor to defrost the evaporator, effectively increasing the average evaporation temperature, reducing the probability of frost formation on the evaporator and the energy consumption of the system, and performing a defrost operation on the evaporator when defrosting is required, thereby reducing the consumption of additional energy during the system defrosting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a module diagram of a cold storage system provided by an embodiment of the present application;

[0037] Figure 2 is a flowchart of the steps of a control method for a cold storage system provided by another embodiment of the present application;

[0038] Figure 3 This is a structural diagram of a control device provided in another embodiment of the present application.

[0039] Reference numerals:

[0040] Compressor 1; three-way reversing valve 2; first port a; second port b; third port c; condenser 3; first stop valve 4; heat accumulator 5; first heat exchange pipeline 501; second heat exchange pipeline 502; second stop valve 6; ejector 7; medium-temperature defrost heater 8; medium-temperature evaporator 9; throttle valve 10; low-temperature defrost heater 11; low-temperature evaporator 12; solution pump 13; temperature transmitter 14. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0042] It is understood that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and the like in the specification, claims, or accompanying drawings are used to distinguish similar items and are not necessarily used to describe a specific sequence or precedence.

[0043] Traditional cold storage systems only have single-stage evaporators. In order to meet the minimum temperature requirement of the temperature zone in the cold storage system, the evaporator must operate at a temperature lower than the minimum required temperature of the temperature zone. In this case, if the current air temperature is high, the evaporator will easily frost when it comes into contact with the air due to the large temperature difference, which will cause the compressor of the cold storage system to operate at a low evaporating temperature for a long time, resulting in a decrease in the refrigeration effect of the cold storage system, an increase in the energy consumption of the system, and a reduction in system performance.

[0044] In order to solve the above-mentioned problems, the embodiment of the present application provides a cold storage system and its control method, device, and storage medium, the system comprising: a medium-temperature evaporator; a low-temperature evaporator, the maximum boundary value in the operating temperature range of which is less than the minimum boundary value in the operating temperature range of the medium-temperature evaporator; a condenser; an ejector, comprising an output port, a first input port connected to the output end of the condenser, and a second input port connected to the output end of the low-temperature evaporator, the output ports being respectively connected to a throttle valve and the input end of the medium-temperature evaporator, the throttle valve having an end away from the output port being connected to the input end of the low-temperature evaporator; a compressor, one end of which is connected to the output end of the medium-temperature evaporator and the other end of which is connected to the input end of the condenser; a medium-temperature defrosting heater a heat accumulator, which is in contact with the medium-temperature evaporator; a low-temperature defrost heater, which is in contact with the low-temperature evaporator, and its output end is connected to the input end of the medium-temperature defrost heater; a heat accumulator, which is filled with phase change material, and also includes a first heat exchange pipeline and a second heat exchange pipeline in contact with the phase change material, the compressor is connected to the input end of the first heat exchange pipeline through the first port and the second port of the three-way reversing valve, the output end of the first heat exchange pipeline is connected to the first input port, the input end of the second heat exchange pipeline is connected to the medium-temperature defrost heater, and the output end of the second heat exchange pipeline is connected to the input end of the low-temperature defrost heater through a solution pump; wherein, the three-way reversing valve also includes a third port, and the compressor is connected to the input end of the condenser through the first port and the third port. According to the solution provided in the embodiment of the present application, the refrigeration cycle of the cold storage system is realized by cooperating with two evaporators with different working temperatures, and the evaporator is defrosted by absorbing the waste heat of the compressor by the heat accumulator, thereby effectively increasing the average evaporation temperature, reducing the frosting probability of the evaporator and the energy consumption of the system, and at the same time, defrosting the evaporator when there is a defrosting demand, reducing the consumption of additional energy during the system defrosting process.

[0045] The embodiments of the present application are further described below with reference to the accompanying drawings.

[0046] refer to Figure 1 , Figure 1 This is a module diagram of a cold storage system provided by an embodiment of the present application.

[0047] Medium temperature evaporator 9;

[0048] The maximum boundary value of the operating temperature range of the low-temperature evaporator 12 is smaller than the minimum boundary value of the operating temperature range of the medium-temperature evaporator 9;

[0049] Condenser 3;

[0050] The ejector 7 includes an output port, a first input port connected to the output end of the condenser 3, and a second input port connected to the output end of the low-temperature evaporator 12. The output port is respectively connected to the throttle valve 10 and the input end of the medium-temperature evaporator 9. The end of the throttle valve 10 away from the output port is connected to the input end of the low-temperature evaporator 12.

[0051] One end of the compressor 1 is connected to the output end of the medium-temperature evaporator 9 , and the other end is connected to the input end of the condenser 3 .

[0052] Specifically, refer to Figure 1 In this embodiment, the medium-temperature evaporator 9 is located above the low-temperature evaporator 12.

[0053] Specifically, this embodiment does not limit the suction pressure range and exhaust pressure range of the compressor 1. The suction pressure range can be 0.6 MPa to 1.2 MPa, and the exhaust pressure range can be 2 MPa to 2.5 MPa. Those skilled in the art can adjust it according to actual conditions.

[0054] Specifically, this embodiment does not limit the operating temperature range of the heat accumulator 5, which can be 15°C to 40°C. The operating temperature range corresponding to the combination of the two evaporators is -30°C to 10°C.

[0055] Understandably, the reference Figure 1Since the first input port of the ejector 7 of this embodiment is connected to the output end of the condenser 3, the second input port is connected to the output end of the low-temperature evaporator 12, and the output port is respectively connected to the input end of the throttle valve 10 and the medium-temperature evaporator 9, and the end of the throttle valve 10 away from the output port is connected to the input end of the low-temperature evaporator 12, the ejector 7 can be used to guide the fluid from the condenser 3 along the movement path A8->A9->A10, first passing through the throttle valve 10 for throttling and cooling, then flowing to the low-temperature evaporator 12 for evaporation and heat absorption, and then returning to the second input port of the ejector 7. The returned fluid passes through the output port again, and flows along the flow direction A8->A1 to the inlet of the medium-temperature evaporator 9 for evaporation and heat absorption. The output low-temperature and low-pressure fluid returns to the input end of the compressor 1, that is, the ejector 7 realizes a two-stage evaporation refrigeration cycle. In addition, the direction of air movement in a conventional cold storage system is from top to bottom. The air flow from top to bottom will form temperature stratification. In addition, the air density of the cold air naturally sinks. Therefore, the upper temperature of the cold storage system is higher and the lower temperature is lower. The medium-temperature evaporator 9 of this embodiment is located above the low-temperature evaporator 12, which can realize the above-mentioned two-stage evaporation refrigeration cycle mechanism, that is, the upper medium-temperature evaporator 9 processes the higher-temperature air, and the lower low-temperature evaporator 12 processes the lower-temperature air. It can effectively avoid the risk of frost caused by the large temperature difference between the evaporator and the contacted air, that is, it can better match the air flowing from top to bottom, effectively increase the average evaporation temperature, reduce power consumption, and ensure the refrigeration effect of the cold storage system.

[0056] In some embodiments, the cold storage system further comprises:

[0057] The medium-temperature defrost heater 8 is in contact with the medium-temperature evaporator 9;

[0058] The low-temperature defrost heater 11 is in contact with the low-temperature evaporator 12, and its output end is connected to the input end of the medium-temperature defrost heater 8;

[0059] Heat accumulator 5 is filled with phase change material and further includes a first heat exchange pipeline 501 and a second heat exchange pipeline 502, both of which are in contact with the phase change material. Compressor 1 is connected to the input end of the first heat exchange pipeline 501 through the first port a and the second port b of the three-way reversing valve 2. The output end of the first heat exchange pipeline 501 is connected to the first input port. The input end of the second heat exchange pipeline 502 is connected to the medium-temperature defrost heater 8. The output end of the second heat exchange pipeline 502 is connected to the input end of the low-temperature defrost heater 11 through the solution pump 13.

[0060] The three-way reversing valve 2 further includes a third port c, and the compressor 1 connects the third port c to the input end of the condenser 3 through the first port a.

[0061] Understandably, the reference Figure 1Since the compressor 1 is connected to the heat accumulator 5 and the condenser 3 respectively through the three-way reversing valve 2, the exhaust waste heat of the compressor 1 can be stored in the heat accumulator 5, thereby improving the mismatch problem between heat supply and demand in the time dimension. The heat accumulator 5 recovers the exhaust heat of the compressor 1 and stores it in the phase change material. When there is a defrosting demand, the evaporator is defrosted, which can reduce the consumption of additional energy during the system defrosting process.

[0062] In some embodiments, a first stop valve 4 is connected between the condenser 3 and the ejector 7 , and a second stop valve 6 is connected between the heat accumulator 5 and the ejector 7 .

[0063] It can be understood that in this embodiment, a first stop valve 4 is set between the condenser 3 and the ejector 7 to cut off the flow of refrigerant and prevent backflow when maintaining or repairing the ejector 7; a second stop valve 6 is set between the heat accumulator 5 and the ejector 7, which can control the on-off control of the heat storage circuit based on the system heat storage demand.

[0064] refer to Figure 2 , Figure 2 This is a flowchart of a method for controlling a cold storage system provided by another embodiment of the present application. This embodiment of the present application provides a method for controlling a cold storage system, which is applied to the cold storage system of the above embodiment. The method includes but is not limited to the following steps:

[0065] Step S10, start the compressor, the compressor compresses the low-temperature, low-pressure fluid output from the medium-temperature evaporator into a high-temperature, high-pressure fluid, and the high-temperature, high-pressure fluid enters the condenser for heat exchange treatment and then flows to the first input port of the ejector.

[0066] It can be understood that, referring to the description of the above embodiment, the high-pressure fluid from the condenser serves as the driving fluid to enter the first input port of the ejector, providing support for the auxiliary cold storage system to implement a two-stage evaporative refrigeration cycle.

[0067] In addition, when executing Figure 2 After the high-temperature and high-pressure fluid in step S10 enters the condenser for heat exchange treatment and flows to the first input port of the ejector, the control method of the cold storage system of this embodiment further includes but is not limited to the following steps:

[0068] Step S11, closing the solution pump and the third port, and the compressor flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage;

[0069] Step S12: After the heat accumulator completes the heat storage operation, the second port is closed and the third port is connected, so that the high-temperature and high-pressure fluid can flow to the condenser through the first port and the third port of the three-way reversing valve.

[0070] It is understood that before the high-temperature, high-pressure fluid enters the condenser for heat exchange and flows to the first input port of the ejector, this embodiment first stores the heat from the compressor's exhaust gas to recover waste heat, allowing the evaporator to be defrosted when defrosting is required. After the heat storage operation is completed, the third port c is closed, allowing the compressor to compress the low-temperature, low-pressure fluid output from the medium-temperature evaporator into high-temperature, high-pressure gas, which is then directed to the condenser through the first port a and second port b of the three-way reversing valve.

[0071] In addition, in some embodiments, after the compressor in step S11 flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage processing, the control method of the cold storage system of this embodiment further includes but is not limited to the following steps:

[0072] Real-time detection of the third surface temperature of the heat accumulator;

[0073] When the third surface temperature reaches the phase change temperature of the phase change material, it is determined that the heat storage operation of the heat storage device is completed.

[0074] It can be understood that the condition for determining whether the heat storage operation is completed in this embodiment is to determine whether the third surface temperature of the heat storage device reaches the phase change temperature of the phase change material. Figure 1 By installing a temperature transmitter 14 on the heat accumulator, the temperature value of the temperature transmitter corresponding to the heat accumulator (i.e., the third surface temperature) is detected in real time. When it is detected that the third surface temperature reaches the phase change temperature of the phase change material inside the heat accumulator, it is determined that the heat storage operation is completed, thereby providing effective heat support for the subsequent defrosting operation.

[0075] In addition, in some embodiments, after executing step S11, the control method of the cold storage system of this embodiment further includes but is not limited to the following steps:

[0076] Step S13, when receiving the defrost control signal, turning off the compressor;

[0077] Step S14, the solution in the second heat exchange pipeline is subjected to heat exchange treatment with the phase change material to obtain a high-temperature solution;

[0078] Step S15, starting the solution pump, which pumps the high-temperature solution into the low-temperature defrost heater;

[0079] In step S16, the solution outputted from the low-temperature defrost heater passes through the medium-temperature defrost heater and flows back to the second heat exchange pipeline to perform cyclic defrosting on the low-temperature evaporator and the medium-temperature evaporator in sequence.

[0080] Specifically, ethylene glycol solution is used in the defrost cycle passage of this embodiment.

[0081] It can be understood that, referring to the description of the above embodiment, after executing step S11, the heat accumulator stores heat to support the defrosting demand. After receiving the defrost control signal, the compressor is turned off, and after the solution inside the second heat exchange pipeline is heat-exchanged with the phase change material, a high-temperature solution is obtained. The solution pump is started, and the high-temperature solution is pumped into the low-temperature defrost heater through the solution pump to first defrost the low-temperature evaporator. Then, the solution output by the low-temperature defrost heater passes through the medium-temperature defrost heater to defrost the medium-temperature evaporator. The solution finally flows back to the second heat exchange pipeline to perform step-by-step cycle defrosting on the low-temperature evaporator and the medium-temperature evaporator in turn. Since the surface temperature of the low-temperature evaporator is lower, the frost speed and thickness are usually much higher than those of the medium-temperature evaporator. More heat is needed to melt the frost layer. The defrosting process of this embodiment is to use the heat of the high-temperature solution in the low-temperature zone (i.e., the low-temperature evaporator) first. After the defrosting of the low-temperature evaporator is completed, even if the solution temperature drops, it will still be higher than the surface temperature of the medium-temperature evaporator, and defrosting can continue to be effective, avoiding energy redundancy caused by the direct use of high-temperature heat in the medium-temperature zone; at the same time, since the defrosting operation requires the evaporator to stop running, the time-sharing defrosting method of this embodiment can avoid the temperature fluctuation of the cold storage system caused by the simultaneous cessation of refrigeration of multiple evaporators, and reduce the drastic fluctuation of the compressor suction pressure, thereby ensuring the operational stability of the cold storage system.

[0082] In some embodiments, after executing step S16, the control method of the cold storage system of this embodiment further includes but is not limited to the following steps:

[0083] Step S161, detecting the first surface temperature of the medium-temperature evaporator and the second surface temperature of the low-temperature evaporator in real time;

[0084] Step S162: When the first surface temperature reaches a first temperature threshold and the second surface temperature reaches a second temperature threshold, the solution pump is turned off and the compressor is turned on again.

[0085] It can be understood that by arranging temperature transmitters on the surfaces of the medium-temperature evaporator and the low-temperature evaporator, the first surface temperature of the medium-temperature evaporator and the second surface temperature of the low-temperature evaporator can be detected in real time. The target condition for completing the defrost operation in this embodiment is that the surface temperature of the two evaporators reaches the preset defrost completion temperature threshold, that is, when the first surface temperature reaches the first temperature threshold and the second surface temperature reaches the second temperature threshold, it is determined that the phase change heat storage defrost cycle is currently completed. At this time, the solution pump is turned off, the compressor is restarted, and the normal refrigeration mode is continued.

[0086] Specifically, the first temperature threshold and the second temperature threshold of this embodiment are set to 5° C. (the specific values ​​of the temperature thresholds can be adjusted by those skilled in the art according to actual conditions and are not limited here).

[0087] In step S20, the ejector causes the internal fluid to flow out through the output port, passes through the throttle valve in sequence for throttling and cooling, flows to the low-temperature evaporator for evaporation and heat absorption, and then flows back to the second input port.

[0088] In step S30, the ejector directs the refluxed fluid to the medium-temperature evaporator through the output port for evaporation and heat absorption, and the low-temperature and low-pressure fluid flowing out of the medium-temperature evaporator flows back to the compressor.

[0089] It should be noted that this embodiment does not limit the refrigerant circulating in the refrigeration cycle, and it can be R32 refrigerant or CO2.

[0090] It is understandable that, referring to the description of the above embodiment, this embodiment can use an ejector to direct the fluid from the condenser along the movement path A8->A9->A10, first passing through the throttle valve for throttling and cooling, then flowing to the low-temperature evaporator for evaporation and heat absorption, and then returning to the second input port of the ejector. The returned fluid passes through the output port again, following the flow direction A8->A1, and flows to the inlet of the medium-temperature evaporator for evaporation and heat absorption. The output low-temperature, low-pressure fluid then returns to the input end of the compressor, thus realizing a two-stage evaporative refrigeration cycle. This can effectively avoid the risk of frost caused by a large temperature difference between the evaporator and the contact air, that is, better match the air flowing from top to bottom, effectively increase the average evaporation temperature, reduce power consumption, and ensure the cooling effect of the cold storage system.

[0091] like Figure 3 As shown, Figure 3 : is a structural diagram of a control device provided in one embodiment of the present application. The present invention also provides a control device 300, comprising:

[0092] The processor 310 may be implemented as a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is configured to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0093] The memory 320 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 320 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 320 and is called by the processor 310 to execute the control method of the cold storage system in the embodiments of this application.

[0094] Input / output interface 330, used to implement information input and output;

[0095] Communication interface 340, used to implement communication interaction between the apparatus and other devices, which can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, Wi-Fi, Bluetooth, etc.);

[0096] bus 350 , which transmits information between various components of the device (e.g., processor 310 , memory 320 , input / output interface 330 , and communication interface 340 );

[0097] The processor 310 , the memory 320 , the input / output interface 330 and the communication interface 340 are connected to each other in communication within the device via the bus 350 .

[0098] In addition, an embodiment of the present application further provides a cold storage system, including the control device 300 of the above embodiment.

[0099] In addition, an embodiment of the present application further provides a storage medium, which is a computer-readable storage medium and stores a computer program. When the computer program is executed by a processor, the control method of the cold storage system described above is implemented.

[0100] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory optionally includes a memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of the above-mentioned networks include but are not limited to the Internet, an intranet, a local area network, a mobile communication network and a combination thereof. The device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and are located in one place, or may be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0101] Those skilled in the art will appreciate that all or some of the steps and systems disclosed above can be implemented as software, firmware, hardware, or any suitable combination thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is well known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0102] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above implementation. Those skilled in the art can also make various equivalent modifications or substitutions under the shared conditions that do not violate the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A cold storage system, characterized in that: include: Medium temperature evaporator; The low-temperature evaporator has a maximum boundary value in the operating temperature range that is smaller than the minimum boundary value in the operating temperature range of the medium-temperature evaporator; condenser; an ejector, comprising an output port, a first input port connected to the output end of the condenser, and a second input port connected to the output end of the low-temperature evaporator, the output ports being respectively connected to a throttle valve and the input end of the medium-temperature evaporator, and an end of the throttle valve away from the output port being connected to the input end of the low-temperature evaporator; a compressor, one end of which is connected to the output end of the medium-temperature evaporator and the other end of which is connected to the input end of the condenser; a medium-temperature defrost heater abutting against the medium-temperature evaporator; a low-temperature defrost heater, abutting against the low-temperature evaporator, and having an output end connected to an input end of the medium-temperature defrost heater; a heat accumulator filled with a phase change material, further comprising a first heat exchange pipeline and a second heat exchange pipeline in contact with the phase change material, wherein the compressor is connected to an input end of the first heat exchange pipeline through a first port and a second port of a three-way reversing valve, an output end of the first heat exchange pipeline is connected to the first input port, an input end of the second heat exchange pipeline is connected to the medium-temperature defrost heater, and an output end of the second heat exchange pipeline is connected to an input end of the low-temperature defrost heater via a solution pump; The three-way reversing valve further includes a third port, and the compressor is connected to the input end of the condenser through the first port and the third port.

2. A control method for a cold storage system, characterized in that: Applied to the cold storage system according to claim 1, the method comprises: Starting the compressor to compress the low-temperature, low-pressure fluid output from the medium-temperature evaporator into a high-temperature, high-pressure fluid. The high-temperature, high-pressure fluid enters the condenser for heat exchange processing and then flows to the first input port of the ejector. The ejector causes the fluid inside to flow out through the output port, passes through the throttle valve in sequence for throttling and cooling, flows to the low-temperature evaporator for evaporation and heat absorption, and then flows back to the second input port; The ejector causes the refluxed fluid to flow again through the output port to the medium-temperature evaporator for evaporation and heat absorption, and the low-temperature and low-pressure fluid flowing out of the medium-temperature evaporator flows back to the compressor.

3. The control method of the cold storage system according to claim 2, characterized in that: Before the high-temperature and high-pressure fluid enters the condenser for heat exchange and flows toward the first input port of the ejector, the method further includes: The solution pump is turned off, the third port is closed, and the compressor flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage; After the heat accumulator completes the heat storage operation, the second port is closed and the third port is connected, so that the high-temperature and high-pressure fluid can flow to the condenser through the first port and the third port of the three-way reversing valve.

4. The control method of the cold storage system according to claim 3, characterized in that: After the compressor flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage processing, the method further includes: detecting the third surface temperature of the heat accumulator in real time; When the third surface temperature reaches the phase change temperature of the phase change material, it is determined that the heat storage operation of the heat accumulator is completed.

5. The control method of the cold storage system according to claim 4, characterized in that: After the compressor flows the high-temperature and high-pressure fluid through the first port and the second port of the three-way reversing valve to the first heat exchange pipeline of the heat accumulator for heat storage, the method further includes: When receiving a defrost control signal, shutting down the compressor; After the solution inside the second heat exchange pipeline is heat exchanged with the phase change material, a high-temperature solution is obtained; Starting the solution pump to pump the high-temperature solution into the low-temperature defrost heater; The solution outputted from the low-temperature defrost heater passes through the medium-temperature defrost heater and flows back to the second heat exchange pipeline to perform cyclic defrosting on the low-temperature evaporator and the medium-temperature evaporator in sequence.

6. The control method of the cold storage system according to claim 5, characterized in that: After the solution outputted from the low-temperature defrost heater passes through the medium-temperature defrost heater and flows back to the second heat exchange pipeline to perform cyclic defrosting on the low-temperature evaporator and the medium-temperature evaporator in sequence, the method further includes: detecting in real time a first surface temperature of the medium-temperature evaporator and a second surface temperature of the low-temperature evaporator; When the first surface temperature reaches a first temperature threshold and the second surface temperature reaches a second temperature threshold, the solution pump is turned off and the compressor is turned on again.

7. A control device, characterized in that: It includes at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the control method of the cold storage system as described in any one of claims 2 to 6.

8. A cold storage system, characterized in that: Comprising the control device according to claim 7.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the control method for the cold storage system according to any one of claims 2 to 6.

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