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

Abstract

The present application discloses a cold storage refrigeration system and its defrost control method, device, and storage medium. The system includes: a medium-temperature heat accumulator filled with a first phase change material; a low-temperature heat accumulator connected to the medium-temperature heat accumulator and filled with a second phase change material having a phase change temperature lower than the first phase change material; an air cooler; an evaporator connected to the air cooler and the low-temperature heat accumulator via a throttle valve; a defrost heater abutting the evaporator surface and connected to the medium-temperature heat accumulator and the low-temperature heat accumulator; a compressor having one end connected to the heat exchange pipe of the medium-temperature heat accumulator and the air cooler via a three-way reversing valve, and the other end connected to the evaporator. The low-temperature heat accumulator, the medium-temperature heat accumulator, the solution pump, and the defrost heater sequentially form a loop. The present application utilizes two heat accumulators with phase change materials having different phase change temperatures to absorb exhaust waste heat from the compressor over a wide temperature range while simultaneously performing staged defrosting of the evaporator via the two-stage heat accumulator, thereby reducing system 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 refrigeration system and its defrosting control method, refrigeration method, device, and medium. Background Art

[0002] When traditional mobile cold storage refrigeration systems operate under low-temperature conditions, the evaporator is prone to frost, affecting the system's cooling efficiency. Therefore, the evaporator needs to be defrosted in a timely manner. The existing method is to install an electric heating device directly near the evaporator to defrost the evaporator through heat conduction. However, this method results in high system energy consumption and shortens the service life of the cold storage refrigeration system. Summary of the Invention

[0003] The embodiments of the present application provide a cold storage refrigeration system and a defrost control method, device, and storage medium thereof, which can effectively reduce the system energy consumption during operation of the cold storage refrigeration system when defrosting the evaporator and increase the service life of the system.

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

[0005] a medium-temperature heat accumulator filled with a first phase change material;

[0006] a low-temperature heat accumulator connected to the medium-temperature heat accumulator, wherein the low-temperature heat accumulator is filled with a second phase change material, and a first phase change temperature of the first phase change material is greater than a second phase change temperature of the second phase change material;

[0007] air cooler;

[0008] an evaporator, connected to the air cooler and the low-temperature heat accumulator respectively through a throttle valve;

[0009] a defrost heater abutting against a surface of the evaporator, the defrost heater being connected to the medium-temperature heat accumulator via a solution pump, and the defrost heater being connected to the low-temperature heat accumulator;

[0010] A compressor, one end of which is connected to the medium-temperature heat accumulator and the air cooler respectively through a three-way reversing valve, and the other end of which is connected to the evaporator;

[0011] The interior of the medium-temperature heat accumulator also includes a first heat exchange pipeline and a second heat exchange pipeline whose outer walls contact the first phase change material, and the low-temperature heat accumulator also includes a third heat exchange pipeline and a fourth heat exchange pipeline whose outer walls contact the second phase change material, wherein one end of the first heat exchange pipeline is connected to the three-way reversing valve, and the other end is connected to the third heat exchange pipeline, one end of the second heat exchange pipeline is connected to the defrost heater through the solution pump, and the other end is connected to the fourth heat exchange pipeline, the end of the third heat exchange pipeline away from the medium-temperature heat accumulator is connected to the evaporator through a throttle valve, and the end of the fourth heat exchange pipeline away from the medium-temperature heat accumulator is connected to the defrost heater.

[0012] In some embodiments, a first stop valve is connected between the air cooler and the throttle valve, and a second stop valve is connected between the low-temperature heat accumulator and the throttle valve.

[0013] In a second aspect, an embodiment of the present application provides a defrost control method, which is applied to the cold storage refrigeration system of the first aspect, wherein the three-way reversing valve includes a first port, a second port, and a third port, wherein the first port faces the compressor, the second port faces the medium-temperature heat accumulator, and the third port faces the air cooler, and the method includes:

[0014] When no defrost control signal is received, the solution pump is turned off, the compressor is started, and the third port is closed. The compressor compresses the low-temperature, low-pressure fluid output from the evaporator into a high-temperature, high-pressure gas, and the gas is sequentially flowed through the first port and the second port of the three-way reversing valve to the medium-temperature heat accumulator and the low-temperature heat accumulator for heat exchange processing;

[0015] After the medium-temperature heat accumulator and the low-temperature heat accumulator complete the heat storage operation, the second port is closed and the third port is connected, so that the remaining gas output by the compressor flows to the air cooler through the first port and the third port of the three-way reversing valve, so that the gas output by the air cooler flows to the evaporator through the throttle valve to absorb heat and cool;

[0016] When a defrost control signal is received, the compressor is turned off, the solution pump is started, and the low-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a first solution;

[0017] The medium-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a second solution, wherein the temperature of the second solution is higher than the temperature of the first solution;

[0018] The second solution and the first solution flow to the evaporator in sequence through the solution pump to defrost the evaporator.

[0019] In some embodiments, after the second solution and the first solution flow sequentially through the solution pump to the evaporator to defrost the evaporator, the method further includes:

[0020] obtaining the surface temperature of the evaporator in real time;

[0021] When the surface temperature reaches a first temperature threshold, the solution pump is turned off and the compressor is restarted.

[0022] In some embodiments, the gas is passed through the first port and the second port of the three-way reversing valve and flows sequentially to the medium-temperature heat accumulator and the low-temperature heat accumulator for heat exchange treatment, including:

[0023] When the gas flows into the first heat exchange pipeline, the heat of the gas is transferred to the first phase change material through the pipe wall of the first heat exchange pipeline, and the current first reference temperature of the first phase change material is detected in real time;

[0024] When the gas flows into the third heat exchange pipeline, the heat of the gas is transferred to the second phase change material through the wall of the third heat exchange pipeline, and the current second reference temperature of the second phase change material is detected in real time;

[0025] When the first reference temperature reaches the first phase change temperature and the second reference temperature reaches the second phase change temperature, it is determined that the medium-temperature heat accumulator and the low-temperature heat accumulator complete the heat storage operation, and the second port is closed.

[0026] In some embodiments, the low-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a first solution, comprising:

[0027] The solution absorbs heat transferred by the second phase change material through the fourth heat exchange pipeline in the fourth heat exchange pipeline to obtain the first solution;

[0028] The medium-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a second solution, including:

[0029] The solution absorbs heat transferred by the first phase change material through the second heat exchange pipeline in the second heat exchange pipeline to obtain the second solution.

[0030] 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 defrost control method as described in the second aspect.

[0031] In a fourth aspect, an embodiment of the present application further provides a cold storage refrigeration system, comprising the control device of the third aspect.

[0032] 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 defrost control method as described in the second aspect.

[0033] The embodiment of the present application provides a cold storage refrigeration system and its defrost control method, device, and storage medium, the system comprising: a medium-temperature heat accumulator, the interior of which is filled with a first phase change material; a low-temperature heat accumulator, connected to the medium-temperature heat accumulator, the interior of the low-temperature heat accumulator is filled with a second phase change material, the first phase change temperature of the first phase change material is greater than the second phase change temperature of the second phase change material; an air cooler; an evaporator, connected to the air cooler and the low-temperature heat accumulator respectively through a throttle valve; a defrost heater, abutting against the surface of the evaporator, the defrost heater is connected to the medium-temperature heat accumulator through a solution pump, and the defrost heater is connected to the low-temperature heat accumulator; a compressor, one end of which is connected to the medium-temperature heat accumulator and the air cooler respectively through a three-way reversing valve The medium-temperature heat accumulator further comprises a first heat exchange pipe and a second heat exchange pipe whose outer wall contacts the first phase change material, and the low-temperature heat accumulator further comprises a third heat exchange pipe and a fourth heat exchange pipe whose outer wall contacts the second phase change material, wherein one end of the first heat exchange pipe is connected to the three-way reversing valve, and the other end is connected to the third heat exchange pipe, one end of the second heat exchange pipe is connected to the defrost heater through the solution pump, and the other end is connected to the fourth heat exchange pipe, the end of the third heat exchange pipe away from the medium-temperature heat accumulator is connected to the evaporator through a throttle valve, and the end of the fourth heat exchange pipe away from the medium-temperature heat accumulator is connected to the defrost heater. According to the solution provided in the embodiment of the present application, by using two heat accumulators with phase change materials of different phase change temperatures to absorb the exhaust waste heat of the compressor in a wide temperature range, the two-stage heat accumulator is used to realize the release of stepped heat energy, and the evaporator is defrosted in stages, which can effectively reduce the energy consumption of the system while improving the defrosting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a module diagram of a cold storage refrigeration system provided by an embodiment of the present application;

[0035] Figure 2 is a flowchart of the steps of a defrost control method provided by another embodiment of the present application;

[0036] Figure 3 This is a structural diagram of a control device provided in another embodiment of the present application.

[0037] Reference numerals:

[0038] Compressor 1; three-way reversing valve 2; first port a; second port b; third port c; air cooler 3; first stop valve 4; medium-temperature heat accumulator 5; first heat exchange pipeline 501; second heat exchange pipeline 502; low-temperature heat accumulator 6; third heat exchange pipeline 601; fourth heat exchange pipeline 602; second stop valve 7; throttle valve 8; evaporator 9; defrost heater 10; solution pump 11; temperature transmitter 12. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] When traditional mobile cold storage refrigeration systems operate under low-temperature conditions, the evaporator is prone to frost, affecting the system's cooling efficiency. Therefore, the evaporator needs to be defrosted in a timely manner. The existing method is to install an electric heating device directly near the evaporator to defrost the evaporator through heat conduction. However, this method results in high system energy consumption and shortens the service life of the cold storage refrigeration system.

[0042] In order to solve the above-mentioned problems, the embodiment of the present application provides a cold storage refrigeration system and its defrost control method, device, and storage medium. The system includes: a medium-temperature heat accumulator, which is filled with a first phase change material; a low-temperature heat accumulator, which is connected to the medium-temperature heat accumulator, and the low-temperature heat accumulator is filled with a second phase change material, and the first phase change temperature of the first phase change material is greater than the second phase change temperature of the second phase change material; an air cooler; an evaporator, which is respectively connected to the air cooler and the low-temperature heat accumulator through a throttle valve; a defrost heater, which abuts against the surface of the evaporator, and the defrost heater is connected to the medium-temperature heat accumulator through a solution pump, and the defrost heater is connected to the low-temperature heat accumulator; a compressor, one end of which is respectively connected to the medium-temperature heat accumulator through a three-way reversing valve and the air cooler, and the other end is connected to the evaporator; the medium-temperature heat accumulator also includes a first heat exchange pipeline and a second heat exchange pipeline whose outer walls contact the first phase change material, and the low-temperature heat accumulator also includes a third heat exchange pipeline and a fourth heat exchange pipeline whose outer walls contact the second phase change material, wherein one end of the first heat exchange pipeline is connected to the three-way reversing valve, and the other end is connected to the third heat exchange pipeline, one end of the second heat exchange pipeline is connected to the defrost heater through the solution pump, and the other end is connected to the fourth heat exchange pipeline, the end of the third heat exchange pipeline away from the medium-temperature heat accumulator is connected to the evaporator through a throttle valve, and the end of the fourth heat exchange pipeline away from the medium-temperature heat accumulator is connected to the defrost heater. According to the solution provided in the embodiment of the present application, two heat accumulators with phase change materials having different phase change temperatures are used to absorb the exhaust waste heat of the compressor in a wide temperature range, while the two-stage heat accumulator is used to release stepped heat energy and perform staged defrosting on the evaporator, which can effectively reduce the system energy consumption while improving the defrosting effect.

[0043] The embodiments of the present application are further described below with reference to the accompanying drawings.

[0044] refer to Figure 1 , Figure 1 This is a module diagram of a cold storage refrigeration system provided by an embodiment of the present application. The cold storage refrigeration system includes:

[0045] The medium-temperature heat accumulator 5 is filled with a first phase change material;

[0046] The low-temperature heat accumulator 6 is connected to the medium-temperature heat accumulator 5. The low-temperature heat accumulator 6 is filled with a second phase change material, wherein the first phase change temperature of the first phase change material is greater than the second phase change temperature of the second phase change material;

[0047] Air cooler 3;

[0048] The evaporator 9 is connected to the air cooler 3 and the low-temperature heat accumulator 6 through the throttle valve 8;

[0049] The defrost heater 10 is in contact with the surface of the evaporator 9. The defrost heater 10 is connected to the medium-temperature heat accumulator 5 through the solution pump 11. The defrost heater 10 is connected to the low-temperature heat accumulator;

[0050] The compressor 1 has one end connected to the medium-temperature heat accumulator 5 and the air cooler 3 respectively through a three-way reversing valve, and the other end connected to the evaporator 9.

[0051] Specifically, this embodiment does not limit the suction pressure range and exhaust pressure range of the compressor 1. The suction pressure range can be 2.5 MPa to 3.5 MPa, and the exhaust pressure range can be 8 MPa to 10 MPa. Those skilled in the art can adjust it according to actual conditions.

[0052] Specifically, this embodiment does not limit the operating temperature range of the air cooler 3, the medium-temperature heat accumulator 5, the low-temperature heat accumulator 6 and the evaporator 9. The operating temperature range of the air cooler 3 in this embodiment is 30°C to 100°C, the operating temperature range of the medium-temperature heat accumulator 5 is 25°C to 45°C, the operating temperature range of the low-temperature heat accumulator 6 is 10°C to 30°C, and the operating temperature range of the evaporator 9 is -30°C to 10°C.

[0053] It should be noted that the cold storage refrigeration system of this embodiment can be a whole movable type or a fixed type, and no further restrictions are imposed here.

[0054] It is understandable that when a traditional cold storage refrigeration system operates under low-temperature conditions, the evaporator 9 is prone to frost. Conventional electric heating defrosting methods consume high energy and experience severe temperature fluctuations, resulting in a shortened equipment life and reduced operational stability. Based on this, the embodiment of the present application, by providing a two-stage heat accumulator (i.e., a medium-temperature heat accumulator 5 and a low-temperature heat accumulator 6) in the system, can recover the waste heat of the compressor 1 when the compressor 1 is operating. Moreover, due to the presence of two stages of heat accumulators, the temperature range of the recovered heat is relatively wide. Considering that the defrosting of the evaporator 9 requires heat at multiple temperature stages, higher temperature heat (e.g., above 20°C) is initially required for rapid defrosting, while lower temperature heat (e.g., 5 to 15°C) is later required to remove residual frost. In this way, the two-stage heat accumulator of this embodiment can achieve the storage and release of cascaded heat energy, performing defrosting operations at two different temperature stages on the evaporator 9 that requires defrosting, thereby improving the defrosting effect. If only a single heat accumulator is used to recover the waste heat of compressor 1 and release heat for defrosting, it cannot meet the two-stage defrosting requirements of the evaporator 9. For example, the phase change material in the single heat accumulator (such as paraffin, with a corresponding phase change temperature of 50°C) has a narrow temperature range for storing heat, which is much higher than the required defrosting temperature of the evaporator 9. Instead, it will cause overheating waste and may damage the evaporator 9 material. If the phase change temperature of the phase change material is lower than the actual requirement (such as a salt phase change material with a phase change temperature of 0°C), it will not be able to effectively defrost.

[0055] In some embodiments, the medium-temperature heat accumulator 5 also includes a first heat exchange pipeline 501 and a second heat exchange pipeline 502 whose outer walls contact the first phase change material, and the low-temperature heat accumulator 6 also includes a third heat exchange pipeline 601 and a fourth heat exchange pipeline 602 whose outer walls contact the second phase change material. One end of the first heat exchange pipeline 501 is connected to the three-way reversing valve, and the other end is connected to the third heat exchange pipeline 601. One end of the second heat exchange pipeline 502 is connected to the defrost heater 10 through the solution pump 11, and the other end is connected to the fourth heat exchange pipeline 602. The end of the third heat exchange pipeline 601 away from the medium-temperature heat accumulator 5 is connected to the evaporator 9 through the throttle valve 8, and the end of the fourth heat exchange pipeline 602 away from the medium-temperature heat accumulator 5 is connected to the defrost heater 10.

[0056] Understandably, the reference Figure 1 In this embodiment, the medium-temperature heat accumulator 5 and the low-temperature heat accumulator 6 each have two heat exchange pipes. The first heat exchange pipe 501 of the medium-temperature heat accumulator 5 and the third heat exchange pipe 601 of the low-temperature heat accumulator 6 are used to recover waste heat from the compressor 1 when the refrigeration system is operating normally. The second heat exchange pipe 502 of the medium-temperature heat accumulator 5 and the fourth heat exchange pipe 602 of the low-temperature heat accumulator 6 are connected to the defrost heater 10 abutting the evaporator 9. When defrosting is required, the heat recovered from the front of the heat accumulator is exchanged and released in the second heat exchange pipe 502 and the fourth heat exchange pipe 602, and the evaporator 9 is defrosted in two stages through the defrost heater 10. In other words, this embodiment uses the medium-temperature and low-temperature dual heat accumulators to work together to store the exhaust waste heat of the compressor 1 in stages, fully covering the wide temperature range of the refrigeration system's waste heat, reducing heat waste while improving energy utilization efficiency.

[0057] In some embodiments, a first stop valve 4 is connected between the air cooler 3 and the throttle valve 8 , and a second stop valve 7 is connected between the low-temperature heat accumulator 6 and the throttle valve 8 .

[0058] It can be understood that this embodiment provides a first stop valve 4 between the air cooler 3 and the throttle valve 8, which can facilitate the safe isolation of the high-pressure side when the throttle valve 8 is repaired, and provides a second stop valve 7 between the low-temperature heat accumulator 6 and the throttle valve 8, which can control the on-off control of the heat storage circuit based on the system heat storage demand.

[0059] refer to Figure 2 , Figure 2 This is a flowchart of the steps of a defrost control method provided by another embodiment of the present application. The embodiment of the present application provides a defrost control method, which is applied to the cold storage refrigeration system described in the above embodiment. In some embodiments, the three-way reversing valve includes a first port, a second port, and a third port. The first port faces the compressor 1, the second port faces the medium-temperature heat accumulator, and the third port faces the air cooler. The method includes but is not limited to the following steps:

[0060] In step S10, when the defrost control signal is not received, the solution pump is turned off, the compressor 1 is started, and the third port is closed. The compressor 1 compresses the low-temperature and low-pressure fluid output from the evaporator into a high-temperature and high-pressure gas, and the gas is directed to the medium-temperature heat accumulator and the low-temperature heat accumulator in turn through the first port and the second port of the three-way reversing valve for heat exchange treatment.

[0061] It can be understood that when the defrost control signal is not received, the cold storage refrigeration system is in normal operation, the solution pump is turned off, and the compressor 1 is started. At this time, the exhaust heat of the compressor 1 is first stored, and the third port c is closed to allow the compressor 1 to compress the low-temperature and low-pressure fluid output from the evaporator into a high-temperature and high-pressure gas, and the gas is passed through the first port a and the second port b of the three-way reversing valve to flow to the medium-temperature heat accumulator and the low-temperature heat accumulator in turn for heat exchange treatment to store the heat required for subsequent evaporator defrosting.

[0062] It should be noted that the cold storage refrigeration system in this embodiment is a CO2 refrigeration system, that is, Figure 1 The gas flowing in the circuit A1->A2->A5->A6->A7->A8->A9 is CO2, and Figure 1 The gas flowing in the circuit A1->A2->A3->A4 ->A8->A9 is CO2.

[0063] Specifically, in some embodiments, Figure 2 In step S10, the gas is directed to flow to the medium-temperature heat accumulator and the low-temperature heat accumulator in sequence through the first port and the second port of the three-way reversing valve for heat exchange treatment, including but not limited to the following steps:

[0064] Step S11, when the gas flows into the first heat exchange pipeline, the heat of the gas is transferred to the first phase change material through the tube wall of the first heat exchange pipeline, and the current first reference temperature of the first phase change material is detected in real time;

[0065] Step S12: When the gas flows into the third heat exchange pipeline, the heat of the gas is transferred to the second phase change material through the wall of the third heat exchange pipeline, and the current second reference temperature of the second phase change material is detected in real time;

[0066] Step S13: When the first reference temperature reaches the first phase change temperature and the second reference temperature reaches the second phase change temperature, it is determined that the medium-temperature heat accumulator and the low-temperature heat accumulator complete the heat storage operation, and the second port is closed.

[0067] It is understandable that the system structure described in the above embodiment is combined with Figure 1The heat storage process of the medium-temperature heat accumulator and the low-temperature heat accumulator is as follows: when the gas flows to the first heat exchange pipeline, the heat of the gas is transferred to the first phase change material through the tube wall of the first heat exchange pipeline, and the current first reference temperature of the first phase change material is detected in real time; when the gas flows to the third heat exchange pipeline, the heat of the gas is transferred to the second phase change material through the tube wall of the third heat exchange pipeline, and the current second reference temperature of the second phase change material is detected in real time; when the first reference temperature reaches the first phase change temperature and the second reference temperature reaches the second phase change temperature, it is determined that the medium-temperature heat accumulator and the low-temperature heat accumulator have completed the heat storage operation, which can provide effective heat support for subsequent defrosting.

[0068] It should be noted that, in this embodiment, the first phase transition temperature is 35°C, and the second phase transition temperature is 20°C.

[0069] It should be noted that the medium-temperature heat accumulator and the low-temperature heat accumulator in the embodiment of the present application are respectively provided with a temperature transmitter 12, which enables the cold storage refrigeration system to detect the temperature of the phase change material inside the two heat accumulators in real time, thereby facilitating the control of the progress of the heat storage operation.

[0070] In step S20, after the medium-temperature heat accumulator and the low-temperature heat accumulator complete the heat storage operation, the second port is closed and the third port is connected. The remaining gas output by the compressor 1 flows to the air cooler through the first port and the third port of the three-way reversing valve, so that the gas output by the air cooler flows to the evaporator through the throttle valve for heat absorption and refrigeration.

[0071] It can be understood that, after completing the heat storage operation, the second port b is closed and the third port c is connected in this embodiment. The compressor 1 can continue to flow the high-temperature and high-pressure gas based on the loop A1->A2->A3->A4->A8->A9 through the air cooler to exchange heat with the heat exchange fluid. After throttling and cooling through the throttle valve, the gas flows to the evaporator for evaporation and heat absorption, completing the refrigeration cycle.

[0072] Step S30: When a defrost control signal is received, the compressor 1 is turned off, the solution pump is started, and the low-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a first solution;

[0073] In step S40 , the medium-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a second solution, wherein the temperature of the second solution is higher than the temperature of the first solution.

[0074] Specifically, in some embodiments, the medium-temperature heat accumulator further includes a second heat exchange pipeline, the outer wall of the second heat exchange pipeline contacts the first phase change material, the low-temperature heat accumulator further includes a fourth heat exchange pipeline, the outer wall of the fourth heat exchange pipeline contacts the second phase change material, one end of the second heat exchange pipeline is connected to the evaporator through a solution pump, the other end of the second heat exchange pipeline is connected to the fourth heat exchange pipeline, and the end of the fourth heat exchange pipeline away from the medium-temperature heat accumulator is connected to the evaporator. Based on the above structure, Figure 2 In step S30, the low-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a first solution, including:

[0075] The solution absorbs the heat transferred by the second phase change material through the fourth heat exchange pipeline in the fourth heat exchange pipeline to obtain a first solution;

[0076] Figure 2 Step S40 includes: the solution absorbs heat transferred by the first phase change material through the second heat exchange pipeline in the second heat exchange pipeline to obtain a second solution.

[0077] It should be noted that the solution flowing through the defrosting circuit (A10->A11->A12->A13) in this embodiment is an ethylene glycol solution.

[0078] It can be understood that the solution absorbs the heat transferred by the second phase change material through the fourth heat exchange pipeline in the fourth heat exchange pipeline to obtain a first solution; the solution absorbs the heat transferred by the first phase change material through the second heat exchange pipeline in the second heat exchange pipeline to obtain a second solution, and the temperature of the first solution is lower than the temperature of the second solution. In this way, the second solution and the first solution are sequentially flowed to the defrost heater through the solution pump, so that the evaporator can be defrosted in stages.

[0079] In step S50 , the second solution and the first solution flow to the defrost heater in sequence through the solution pump to defrost the evaporator.

[0080] Additionally, in some embodiments, when executing Figure 2 After step S50, the defrost control method provided in this embodiment further includes but is not limited to the following steps:

[0081] Step S51, obtaining the surface temperature of the evaporator in real time;

[0082] Step S52: When the surface temperature reaches a first temperature threshold, the solution pump is turned off and the compressor 1 is restarted.

[0083] It should be noted that the reference Figure 1 In this embodiment, a temperature transmitter 12 is provided on the evaporator, and the surface temperature of the evaporator can be obtained in real time through the temperature transmitter 12.

[0084] It can be understood that in this embodiment, the system presets a target condition for defrosting completion, which is that the surface temperature of the evaporator reaches a first temperature threshold (set to 5°C in this embodiment). That is to say, when it is determined that the surface temperature reaches the first temperature threshold, the two-stage phase change heat storage defrost cycle is completed, the defrost operation is completed, the solution pump is turned off, and then the control is to restart the compressor 1 to continue the normal refrigeration mode.

[0085] like Figure 3As 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:

[0086] 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.

[0087] 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 defrost control method of the embodiments of this application.

[0088] Input / output interface 330, used to implement information input and output;

[0089] 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.);

[0090] 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 );

[0091] 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 .

[0092] In addition, an embodiment of the present application further provides a cold storage refrigeration system, including the control device 300 of the above embodiment.

[0093] 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 above-mentioned defrost control method is implemented.

[0094] 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.

[0095] 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.

[0096] 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 refrigeration system, characterized in that: include: a medium-temperature heat accumulator filled with a first phase change material; a low-temperature heat accumulator connected to the medium-temperature heat accumulator, wherein the low-temperature heat accumulator is filled with a second phase change material, and a first phase change temperature of the first phase change material is greater than a second phase change temperature of the second phase change material; air cooler; an evaporator, connected to the air cooler and the low-temperature heat accumulator respectively through a throttle valve; a defrost heater abutting against a surface of the evaporator, the defrost heater being connected to the medium-temperature heat accumulator via a solution pump, and the defrost heater being connected to the low-temperature heat accumulator; A compressor, one end of which is connected to the medium-temperature heat accumulator and the air cooler respectively through a three-way reversing valve, and the other end of which is connected to the evaporator; The interior of the medium-temperature heat accumulator also includes a first heat exchange pipeline and a second heat exchange pipeline whose outer walls contact the first phase change material, and the low-temperature heat accumulator also includes a third heat exchange pipeline and a fourth heat exchange pipeline whose outer walls contact the second phase change material, wherein one end of the first heat exchange pipeline is connected to the three-way reversing valve, and the other end is connected to the third heat exchange pipeline, one end of the second heat exchange pipeline is connected to the defrost heater through the solution pump, and the other end is connected to the fourth heat exchange pipeline, the end of the third heat exchange pipeline away from the medium-temperature heat accumulator is connected to the evaporator through a throttle valve, and the end of the fourth heat exchange pipeline away from the medium-temperature heat accumulator is connected to the defrost heater.

2. The cold storage refrigeration system according to claim 1, characterized in that: A first stop valve is connected between the air cooler and the throttle valve, and a second stop valve is connected between the low-temperature heat accumulator and the throttle valve.

3. A defrost control method, characterized in that: Applicable to the cold storage refrigeration system according to any one of claims 1 to 2, the three-way reversing valve includes a first port, a second port, and a third port, the first port faces the compressor, the second port faces the medium-temperature heat accumulator, and the third port faces the air cooler, and the method includes: When no defrost control signal is received, the solution pump is turned off, the compressor is started, and the third port is closed. The compressor compresses the low-temperature, low-pressure fluid output from the evaporator into a high-temperature, high-pressure gas, and the gas is sequentially flowed through the first port and the second port of the three-way reversing valve to the medium-temperature heat accumulator and the low-temperature heat accumulator for heat exchange processing; After the medium-temperature heat accumulator and the low-temperature heat accumulator complete the heat storage operation, the second port is closed and the third port is connected, so that the remaining gas output by the compressor flows to the air cooler through the first port and the third port of the three-way reversing valve, so that the gas output by the air cooler flows to the evaporator through the throttle valve to absorb heat and cool; When a defrost control signal is received, the compressor is turned off, the solution pump is started, and the low-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a first solution; The medium-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a second solution, wherein the temperature of the second solution is higher than the temperature of the first solution; The second solution and the first solution flow to the defrost heater in sequence through the solution pump to defrost the evaporator.

4. The defrost control method according to claim 3, wherein: After the second solution and the first solution flow sequentially to the evaporator through the solution pump to defrost the evaporator, the method further includes: obtaining the surface temperature of the evaporator in real time; When the surface temperature reaches a first temperature threshold, the solution pump is turned off and the compressor is restarted.

5. The defrost control method according to claim 3, wherein: The gas is flowed sequentially to the medium-temperature heat accumulator and the low-temperature heat accumulator through the first port and the second port of the three-way reversing valve for heat exchange treatment, comprising: When the gas flows into the first heat exchange pipeline, the heat of the gas is transferred to the first phase change material through the pipe wall of the first heat exchange pipeline, and the current first reference temperature of the first phase change material is detected in real time; When the gas flows into the third heat exchange pipeline, the heat of the gas is transferred to the second phase change material through the wall of the third heat exchange pipeline, and the current second reference temperature of the second phase change material is detected in real time; When the first reference temperature reaches the first phase change temperature and the second reference temperature reaches the second phase change temperature, it is determined that the medium-temperature heat accumulator and the low-temperature heat accumulator complete the heat storage operation, and the second port is closed.

6. The defrost control method according to claim 5, characterized in that: The low-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a first solution, including: The solution absorbs heat transferred by the second phase change material through the fourth heat exchange pipeline in the fourth heat exchange pipeline to obtain the first solution; The medium-temperature heat accumulator performs heat exchange processing on the solution inside to obtain a second solution, including: The solution absorbs heat transferred by the first phase change material through the second heat exchange pipeline in the second heat exchange pipeline to obtain the second solution.

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 to enable the at least one control processor to execute the defrost control method according to any one of claims 3 to 6.

8. A cold storage refrigeration system, 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 defrost control method according to any one of claims 3 to 6.

Images