Refrigeration device, refrigeration system thereof, control method, control apparatus, storage medium

Abstract

The present application relates to the field of refrigeration technology, and specifically provides a refrigeration device, a refrigeration system thereof, a control method, a control device and a storage medium, aiming at solving the problem of high cost and influence on stable operation of the existing defrosting scheme of the refrigeration system. The refrigeration system provided by the present application comprises a first heat exchanger and a first gas-liquid separator. The first heat exchanger comprises a first heat exchange part, and the first gas-liquid separator is arranged on a pipeline connected with the outlet of the first heat exchange part. The gas outlet of the first gas-liquid separator is communicated with the inlet of a second heat exchanger or a main pipeline communicated with the inlet through a first branch pipeline. A first electromagnetic valve is arranged on the first branch pipeline, and the first electromagnetic valve is used at least for controlling the opening and closing of the first branch pipeline, so that the gaseous refrigerant separated by the first gas-liquid separator is used for defrosting the second heat exchanger. The refrigeration system provided by the present application can defrost in a low-cost manner, and can ensure that the unit does not stop due to too low suction pressure, thereby improving the stability of the operation of the refrigeration system.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, specifically providing a refrigeration device and its refrigeration system, control method, control device, and storage medium. Background Technology

[0002] Refrigeration systems are used to regulate indoor air temperature. There are various types of refrigeration equipment equipped with refrigeration systems, such as chiller units and household air conditioners. Taking chiller units as an example, because chiller units operate continuously for cooling, severe frost buildup on the indoor unit can reduce its heat exchange capacity. This prevents the refrigerant in the evaporator from undergoing sufficient phase change, leading to excessively low compressor suction pressure. In severe cases, this can even cause the compressor to shut down, seriously affecting the stable operation of the refrigeration system.

[0003] The main methods for solving the frosting problem in existing technologies are as follows: 1. Using compressor hot gas bypass technology, which involves sending the high-temperature and high-pressure gaseous refrigerant discharged from the compressor directly to the indoor unit through a bypass branch, using the heat of the gaseous refrigerant to melt the frost layer; 2. Configuring electric heating, which releases heat to melt the frost layer; 3. Refrigerant reverse circulation, which involves changing the refrigerant flow direction by setting a four-way valve, turning the heat exchanger, which was originally used to release cold energy, into one that releases heat, so as to achieve the purpose of defrosting itself.

[0004] However, each of the above technical solutions has its own shortcomings. When using compressor hot gas bypass technology, the evaporation temperature will be too high, which will affect the normal operation of the compressor. When using electric heating defrosting, a large amount of electricity is required, which will significantly increase the system's energy consumption. When using refrigerant reverse circulation, the refrigerant reverse circulation will interrupt the cooling process, which will seriously affect the indoor temperature and cause greater fluctuations in the indoor temperature. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problems of high cost and impact on stable operation of existing defrosting solutions for refrigeration systems.

[0006] In a first aspect, the present invention provides a refrigeration system comprising a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger sequentially connected via a main pipeline to form a refrigerant circulation loop. The first heat exchanger includes a first heat exchange section. The refrigeration system further includes a first gas-liquid separator disposed on a pipeline connected to the outlet of the first heat exchange section. The first gas-liquid separator has a gas outlet, which is connected via a first branch pipeline to the inlet of the second heat exchanger or a main pipeline connected to the inlet. A first solenoid valve is disposed on the first branch pipeline. The first solenoid valve is used at least to control the on / off state of the first branch pipeline so that the first branch pipeline can be connected in the event of frost formation on the second heat exchanger, and the gaseous refrigerant separated by the first gas-liquid separator is used to defrost the second heat exchanger.

[0007] The refrigeration system provided by this invention, by installing a first gas-liquid separator on the main pipeline connected to the outlet of the first heat exchange section, connects the outlet of the first gas-liquid separator to the inlet of the second heat exchanger or the main pipeline connected to the inlet through a first branch pipeline, and installs a first solenoid valve on the first branch pipeline, so that when the second heat exchanger is detected to be severely frosted and needs to be defrosted, by connecting the first branch pipeline, the medium-temperature and medium-pressure gaseous refrigerant separated from the first gas-liquid separator is mixed with the low-temperature and low-pressure liquid refrigerant in the main pipeline, thereby increasing the temperature of the refrigerant entering the second heat exchanger, thus raising the evaporation temperature and meeting the defrosting requirements of the second heat exchanger. At the same time, compared with the compressor hot gas bypass solution, it can reduce the change in the outlet air temperature of the second heat exchanger, improve the stability of the refrigeration system, and reduce the fluctuation of indoor temperature.

[0008] In some feasible embodiments of the above-described refrigeration system, the first heat exchanger further includes a second heat exchange section, which is connected to the downstream side of the first heat exchange section, and the liquid outlet of the first gas-liquid separator is connected to the inlet of the second heat exchange section.

[0009] In some feasible embodiments of the above-mentioned refrigeration system, the refrigeration system further includes a second branch pipe, one end of which is connected to the outlet of the first gas-liquid separator or to the first branch pipe, and the other end of which is connected to a pipe connected to the outlet of the second heat exchange section. A second solenoid valve is provided on the second branch pipe, and the second solenoid valve is used to control the opening and closing of the second branch pipe.

[0010] By setting up a second heat exchange section and a second branch pipe, the overall structure of the first heat exchanger is divided into two relatively independent heat exchange areas: a first heat exchange section and a second heat exchange section. The second heat exchange section is located downstream of the first heat exchange section, and the two are connected in series on the main pipeline. A second solenoid valve is installed on the second branch pipe. During operation, when the refrigeration system is running under low load conditions (low outdoor temperature), by connecting the second branch pipe, the liquid refrigerant separated from the first gas-liquid separator can bypass the second heat exchange section and directly enter the main pipeline. This reduces the effective heat exchange area of ​​the first heat exchanger and avoids the problem of insufficient cooling in local flow paths of the first heat exchanger. In other words, by adjusting the heat exchange area, the heat exchange capacity of the first heat exchanger is fully utilized. When the refrigeration system is running normally, the second solenoid valve is controlled to close or disconnect the second branch pipe.

[0011] In some feasible implementations of the above-described refrigeration system, the heat exchange area of ​​the first heat exchange section is larger than the heat exchange area of ​​the second heat exchange section.

[0012] Since the first heat exchanger section undertakes the main heat exchange function, the heat exchange area of ​​the first heat exchanger section is set to be larger than that of the second heat exchanger section.

[0013] During operation, the total heat exchange area of ​​the first heat exchange section and the second heat exchange section is configured according to the compressor capacity of the refrigeration system, and the ratio of the heat exchange area of ​​the first heat exchange section and the second heat exchange section is determined according to the subcooling capacity that the second heat exchange section needs to bear.

[0014] In a second aspect, the present invention also provides a control method for a refrigeration system, the refrigeration system comprising a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger sequentially connected via a main pipeline to form a refrigerant circulation loop. The first heat exchanger includes a first heat exchange section. The refrigeration system further includes a first gas-liquid separator disposed on a pipeline connected to the outlet of the first heat exchange section. The first gas-liquid separator has a gas outlet, the gas outlet being connected to the inlet of the second heat exchanger via a first branch pipeline. A first solenoid valve is disposed on the first branch pipeline, the first solenoid valve being used at least to control the on / off state of the first branch pipeline.

[0015] The control method includes: when the frosting degree of the second heat exchanger reaches the defrosting condition, controlling the first solenoid valve to open so that the gaseous refrigerant obtained by the first gas-liquid separator can be used to defrost the second heat exchanger.

[0016] In some feasible implementations of the above-mentioned refrigeration system control method, the step of determining whether the degree of frosting on the second heat exchanger meets the defrosting conditions includes:

[0017] Obtain the compressor's suction pressure and the coil temperature of the second heat exchanger; compare the suction pressure with a preset suction pressure threshold and compare the coil temperature of the second heat exchanger with a preset coil temperature threshold; if the suction pressure is less than or equal to the preset suction pressure threshold and the coil temperature is less than or equal to the preset coil temperature threshold and this continues for a set time, then it is determined that the defrosting condition has been met.

[0018] In some feasible embodiments of the control method for the above-described refrigeration system, the first heat exchanger further includes a second heat exchange section connected to the downstream side of the first heat exchange section. The liquid outlet of the first gas-liquid separator is connected to the inlet of the second heat exchange section. The refrigeration system further includes a second branch pipe, one end of which is connected to the gas outlet of the first gas-liquid separator or to the first branch pipe, and the other end of which is connected to a pipe connected to the outlet of the second heat exchange section. A second solenoid valve is installed on the second branch pipe to control the on / off state of the second branch pipe.

[0019] The control method further includes: controlling the second solenoid valve to open when the outdoor temperature is lower than a preset temperature threshold.

[0020] In a third aspect, the present invention also provides a refrigeration device, the refrigeration device including a memory and a processor, the memory being adapted to store a plurality of program codes, the program codes being adapted to be loaded and run by the processor to execute the control method of the refrigeration system described in any of the foregoing technical solutions.

[0021] In a fourth aspect, the present invention also provides a computer-readable storage medium adapted to store a plurality of program codes, the program codes being adapted to be loaded and run by a processor to perform the control method of the refrigeration system described in any of the foregoing technical solutions.

[0022] In a fifth aspect, the present invention also provides a control device for a refrigeration device, the control device comprising a control module, the control module being used to execute the control method of the refrigeration system described in any of the foregoing technical solutions.

[0023] Those skilled in the art will understand that, since the aforementioned refrigeration equipment, control device, and computer-readable storage medium are equipped with related software and hardware capable of executing the aforementioned refrigeration system control method, they possess all the technical effects that the aforementioned control method can achieve, and will not be elaborated further here. Attached Figure Description

[0024] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0025] Figure 1This is a schematic diagram of the refrigeration system of the refrigeration unit provided in an embodiment of the present invention;

[0026] Figure 2 A flowchart illustrating the control method for a refrigeration unit provided in an embodiment of the present invention;

[0027] List of reference numerals in the attached diagram:

[0028] 1. Compressor; 2. Oil separator; 3. First heat exchanger; 4. First gas-liquid separator; 5. Liquid receiver; 6. Dryer filter; 7. Sight glass; 8. Expansion valve; 9. Second heat exchanger; 10. Second gas-liquid separator; 11. First branch line; 12. First solenoid valve; 13. Second branch line; 14. Second solenoid valve; 15. Check valve; 16. High pressure sensor; 17. Liquid line shut-off valve; 18. Gas line shut-off valve; 19. Capillary tube; 20. Third solenoid valve; 21. Low pressure sensor; 22. Oil return capillary tube; 23. Outdoor bypass solenoid valve; 24. Indoor solenoid valve; 25. High pressure switch. Detailed Implementation

[0029] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0030] To better illustrate the invention, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that the invention can be practiced without certain specific details.

[0031] In the description of this invention, terms such as "upper," "lower," "inner," and "outer," which indicate direction or positional relationships, are based on actual application and are used merely for ease of description. They do not indicate or imply that the device to be protected must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. Furthermore, ordinal numbers such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] Figure 1This is a schematic diagram of the refrigeration system of the refrigeration unit provided in an embodiment of the present invention.

[0034] like Figure 1 As shown, a refrigeration unit consists of an outdoor unit (which is typically installed outdoors) and an indoor unit (which is typically installed indoors or in a room), i.e., a single-unit system. Alternatively, the outdoor unit of a refrigeration unit can be equipped with multiple indoor units connected in parallel, i.e., a multi-unit system. Figure 1 Only one indoor unit is shown. When multiple indoor units are configured, the configurations of the multiple indoor units can be the same or different, depending on the actual needs.

[0035] The outdoor unit mainly includes a compressor 1, a first heat exchanger 3 (i.e., the outdoor heat exchanger), a liquid receiver 5, and a second gas-liquid separator 10. The indoor unit mainly includes a second heat exchanger 9 (i.e., the indoor heat exchanger), an expansion valve 8, and an indoor solenoid valve 24. The compressor 1 has an exhaust port and an intake port. The exhaust port of the compressor 1 is connected to the inlet of the first heat exchanger 3 via an exhaust pipe; the outlet of the first heat exchanger 3 is connected sequentially to the liquid receiver 5, the expansion valve 8 of the indoor unit, and the inlet of the second heat exchanger 9 via a pipeline (i.e., the liquid pipe in the main pipeline); the outlet of the second heat exchanger 9 is connected to the intake port of the second gas-liquid separator 10 via a pipeline (i.e., the gas pipe in the main pipeline), and the outlet of the second gas-liquid separator 10 is connected to the intake port of the compressor 1 via an intake pipe, thus interconnecting to form a loop that allows refrigerant to circulate. The compressor 1 may include one or more compressors connected in parallel. These compressors may all be variable frequency compressors or some may be variable frequency compressors.

[0036] In this embodiment, a high-pressure switch 25 is installed on the exhaust pipe near the exhaust port of compressor 1 to provide shutdown protection when the exhaust pressure of compressor 1 is too high. An oil separator 2 is installed on the exhaust pipe, wherein the gas input end of the oil separator 2 is connected to the exhaust port of compressor 1, and the gas output end of the oil separator 2 is connected to the inlet of the first heat exchanger 3 through the exhaust pipe; the oil return discharge end of the oil separator 2 is connected to the oil return capillary 22, and the oil return capillary 22 is connected to the suction port of compressor 1 through a pipeline to return the lubricating oil to compressor 1 in a timely manner.

[0037] In one or more embodiments, a compressor heating strip (not shown) is provided at the bottom of the compressor 1 to preheat the compressor 1 when needed. In one or more embodiments, a one-way valve 15 to prevent refrigerant backflow and a high-pressure sensor 16 for detecting the discharge pressure of the compressor 1 are also provided on the discharge pipe. Both the one-way valve 15 and the high-pressure sensor 16 are located downstream of the gas output end of the oil separator 2.

[0038] The receiver 5 receives the liquid refrigerant condensed by the first heat exchanger 3 to regulate the refrigerant flow rate in the circulation loop. In one or more embodiments, a receiver heating strip (not shown) is provided on the receiver 5 to preheat the liquid refrigerant and ensure accurate refrigerant flow supply. Downstream of the receiver 5, a dryer filter 6, a sight glass 7, and a liquid pipe shut-off valve 17 are sequentially arranged on the liquid pipe. The dryer filter 6 dries the moisture in the liquid refrigerant, the sight glass 7 is used to observe the flow of the liquid refrigerant, and the liquid pipe shut-off valve 17 controls the opening and closing of the liquid pipe to cooperate with the gas pipe shut-off valve 18 on the gas pipe to temporarily retain the refrigerant in the refrigeration circulation loop on the outdoor side for disassembly, repair, and maintenance of the refrigeration unit. An indoor solenoid valve 24 is also provided upstream of the expansion valve 8 on the liquid pipe to control the flow of liquid refrigerant into the indoor unit. The expansion valve 8 is a thermostatic expansion valve, an electronic expansion valve, or other types of expansion valve.

[0039] In one or more embodiments, a low-pressure sensor 21 is provided on the suction pipe to detect the suction pressure of the compressor 1.

[0040] In this embodiment, an outdoor balance bypass pipeline is connected in parallel along the refrigerant flow path from the suction pipe to the discharge pipe, and an outdoor bypass solenoid valve 23 is installed on the outdoor balance bypass pipeline. Specifically, one end of the outdoor balance bypass pipeline is connected to the pipeline downstream of the one-way valve 15 of the discharge pipe, and the other end of the outdoor balance bypass pipeline is connected to the suction pipe. By controlling the opening and closing of the outdoor bypass solenoid valve 23, the pressure of the discharge pipe of the compressor 1 can be reduced and the pressure of the suction pipe can be increased, so as to achieve rapid pressure adjustment when the pressure difference between the high-pressure side and the low-pressure side is too large.

[0041] Furthermore, in the refrigeration system provided in this embodiment of the invention, a third branch pipe is connected between the liquid pipe and the gas pipe. One end of the third branch pipe is connected to the liquid pipe upstream of the sight glass 7, and the other end of the third branch pipe is connected to the gas pipe upstream of the second gas-liquid separator 10. A third solenoid valve 20 and a capillary tube 19 are installed on the third branch pipe, so that the third branch pipe is connected in parallel with the second heat exchanger 9. During operation, if the refrigerant charge in the refrigerant circulation loop is too high, too much refrigerant liquid will remain in the evaporator when the system is shut down, which will lead to excessive load during restart, easy wet compression, and difficulty in cooling down. By setting the third branch pipe, the refrigerant flow rate in the refrigerant circulation loop can be adjusted during operation to ensure that the refrigeration system operates under optimal conditions.

[0042] For refrigeration units, their cooling effect deteriorates in high-temperature environments during summer. To address this issue, in this embodiment of the invention, the first heat exchanger 3 is divided into two parts, such as... Figure 1As shown, the first heat exchanger 3 includes a first heat exchange section and a second heat exchange section, which are connected in series in a refrigerant circulation pipeline, with the second heat exchange section located downstream of the first heat exchange section. In one or more embodiments, the first and second heat exchange sections may be, but are not limited to, finned coil heat exchangers or plate heat exchangers, and are equipped with a first heat exchanger fan (not shown). The second heat exchanger 9 includes, but is not limited to, finned coil heat exchangers or plate heat exchangers, and is equipped with a second heat exchanger fan (not shown).

[0043] In this embodiment of the invention, a first gas-liquid separator 4 is connected to the pipeline between the first heat exchange section and the second heat exchange section. The first gas-liquid separator 4 is disposed on the pipeline connected to the outlet of the first heat exchange section. The first gas-liquid separator 4 has a liquid outlet and a gas outlet. The liquid outlet is connected to the inlet of the second heat exchange section, and the gas outlet is connected to the inlet of the second heat exchanger 9 or the main pipeline connected to the inlet through a first branch pipeline 11. A first solenoid valve 12 is disposed on the first branch pipeline 11, and the first solenoid valve 12 is used to control the opening and closing of the first branch pipeline 11. It can be understood that a flow valve can also be disposed on the first branch pipeline 11, forming a valve assembly with the first solenoid valve 12, which can further adjust the flow rate of the first branch pipeline 11 while controlling the opening and closing of the first branch pipeline 11.

[0044] The refrigeration system provided in this embodiment of the invention also includes a second branch pipe 13, such as... Figure 1 As shown, one end of the second branch pipe 13 is connected to the first branch pipe 11, and the other end of the second branch pipe 13 is connected to the pipe between the outlet of the second heat exchange section and the liquid reservoir 5. A second solenoid valve 14 is provided on the second branch pipe 13, and the second solenoid valve 14 is used to control the opening and closing of the second branch pipe 13.

[0045] Based on the structure of the refrigeration system of the refrigeration unit described above, this embodiment of the invention provides a solution to the problem of severe frost buildup in the indoor unit of the refrigeration unit due to continuous refrigeration. This control method can defrost the indoor unit without affecting the normal operation of the refrigeration system, ensuring stable indoor temperature, and has low defrosting cost.

[0046] Specifically, such as Figure 2 As shown, the control method provided in this embodiment of the invention is as follows:

[0047] S10. When the frosting level of the second heat exchanger 9 reaches the defrosting condition, the first solenoid valve 12 is opened so that the gaseous refrigerant obtained by the first gas-liquid separator 4 can be used to defrost the second heat exchanger 9.

[0048] Specifically, after the refrigeration unit has been continuously cooling for a certain period of time, the frost on the second heat exchanger 9 gradually becomes severe, affecting the normal operation of the refrigeration system. The steps to determine whether the degree of frost on the second heat exchanger 9 meets the defrosting conditions include:

[0049] S101, Obtain the suction pressure of compressor 1 and the coil temperature of the second heat exchanger.

[0050] S102. Compare the suction pressure with the preset suction pressure threshold, and compare the coil temperature of the second heat exchanger with the preset coil temperature threshold.

[0051] S103. If the suction pressure is less than or equal to the preset suction pressure threshold and the coil temperature is less than or equal to the preset coil temperature threshold for a set duration, then it is determined that the defrosting condition has been met.

[0052] The judgment principle is based on the following: when the second heat exchanger 9 is severely frosted, it will affect the heat exchange capacity of the second heat exchanger 9, preventing the refrigerant in the second heat exchanger 9 from being fully vaporized into gaseous refrigerant. As a result, the suction pressure of the compressor 1 will decrease and fail to reach the preset suction pressure threshold. In addition, since the suction pressure is also affected by the indoor and outdoor ambient temperature, there is a risk of false defrosting judgment. Therefore, in this embodiment of the invention, the coil temperature of the second heat exchanger is further detected. When the coil temperature is less than or equal to the preset coil temperature threshold and remains so for a set period of time, it is determined that the defrosting condition has been met, indicating that the second heat exchanger 9 needs to be defrosted to enhance its heat exchange capacity.

[0053] Alternatively, one can directly determine whether the second heat exchanger 9 has reached the conditions requiring defrosting by observation.

[0054] When the first solenoid valve 12 is opened to connect the first branch pipe 11, the refrigerant in the main pipe connected to the inlet of the first heat exchange section of the first heat exchanger 3 will not change. Sufficient heat exchange can be carried out in the first heat exchange section. When the gas-liquid mixture of refrigerant discharged from the first heat exchange section enters the first gas-liquid separator 4 for gas-liquid separation, the liquid refrigerant enters the second heat exchange section or directly enters the liquid reservoir 5 via the second branch pipe 13. Then, it is converted into low-temperature and low-pressure liquid refrigerant through the expansion valve 8. The amount of refrigerant flowing in the main pipe between the first heat exchange section and the second heat exchanger 9 is reduced. Meanwhile, the medium-temperature and medium-pressure gaseous refrigerant discharged from the outlet of the first gas-liquid separator 4 merges with the liquid refrigerant in the main pipe before entering the second heat exchanger 9, causing the pressure and temperature of the refrigerant entering the second heat exchanger 9 to increase. When it is higher than the original evaporation pressure / evaporation temperature, some of the heat is used to melt the frost layer on the second heat exchanger 9, thereby achieving the purpose of defrosting.

[0055] The control method provided in this embodiment of the invention introduces the medium-temperature and medium-pressure gaseous refrigerant obtained by the first gas-liquid separator 4 into the pipeline connected to the inlet of the second heat exchanger 9. This mixes the medium-temperature and medium-pressure gaseous refrigerant with the low-temperature and low-pressure liquid refrigerant in the main pipeline before entering the second heat exchanger 9, thereby increasing the overall temperature of the refrigerant in the second heat exchanger 9 and achieving the purpose of defrosting the second heat exchanger 9. Compared with existing solutions that use the hot gas bypass principle of compressor 1, the refrigeration system provided in this embodiment of the invention, during the defrosting process, does not require diverting the high-temperature gaseous refrigerant that should have entered the first heat exchanger 3 for defrosting. Therefore, it can avoid the problem that the traditional defrosting principle can easily lead to low superheat of compressor 1 in the suction gas, which can further lead to liquid slugging of compressor 1, and also avoid the problem that the discharge temperature / discharge pressure is too high due to excessive suction temperature / pressure, which can exceed the alarm value. Although the defrosting efficiency of the refrigeration system and corresponding control method provided in this embodiment of the invention is lower than that of the hot gas bypass solution of compressor 1, it can effectively avoid the risk of liquid slugging during the defrosting process and improve the working stability, safety and reliability of the refrigeration system.

[0056] The control method provided by this invention can also adjust the heat exchange capacity of the system itself according to the changes in the heat load of the refrigeration system, so as to give full play to the heat exchange performance of the heat exchanger.

[0057] Specifically, it includes the following steps:

[0058] S20. When the outdoor temperature is lower than the preset temperature threshold, control the second solenoid valve 14 to open.

[0059] Specifically, under normal refrigeration conditions, the exhaust from compressor 1 passes through oil separator 2 and then sequentially through the first heat exchange section and the first gas-liquid separator 4 before entering the second heat exchange section. In the second heat exchange section, subcooling heat exchange is achieved, so that the heat exchange performance of both the first and second heat exchange sections is fully utilized.

[0060] When the outdoor temperature is detected to be lower than the preset temperature threshold, the second solenoid valve 14 is opened, connecting the second branch pipe 13 and activating the cooling mode under low heat load. Specifically, the compressor 1 exhaust passes through the oil separator 2, then through the first heat exchange section, and then through the first gas-liquid separator 4. The liquid refrigerant separated by the first gas-liquid separator 4 bypasses the second heat exchange section and directly enters the main pipe located downstream of the second heat exchange section, thus directly entering the refrigerant circulation path. In this mode, the problem of insufficient cooling in some parts of the first heat exchanger 3 due to uneven airflow during condensation can be avoided, thereby preventing the full utilization of the heat exchange performance of the entire unit and ensuring the working stability and reliability of the refrigeration system.

[0061] The working principle of the refrigeration unit provided in this embodiment of the invention during normal cooling (no defrosting, normal heat load) is as follows:

[0062] When the refrigeration unit receives a cooling command, compressor 1 starts. The refrigerant, compressed by compressor 1, enters the first heat exchange section as a high-temperature, high-pressure gas through the exhaust pipe. In the first heat exchange section, the high-temperature, high-pressure gaseous refrigerant is condensed into a medium-temperature, medium-pressure liquid refrigerant by transferring heat to the airflow generated by the fan of the first heat exchanger. The medium-temperature, medium-pressure liquid refrigerant flows sequentially through the first gas-liquid separator 4, the second heat exchange section, the liquid receiver 5, the dryer filter 6, the sight glass 7, and the liquid pipe shut-off valve 17 before flowing to the expansion valve 8 of the indoor unit. In the expansion valve 8, the medium-temperature, medium-pressure liquid refrigerant is converted into a low-temperature, low-pressure liquid refrigerant, which is then distributed to the second heat exchanger 9. The low-temperature, low-pressure liquid refrigerant absorbs heat from the indoor air and evaporates into a low-temperature, low-pressure gaseous refrigerant, thus cooling the indoor air. After leaving the second heat exchanger 9, the low-temperature, low-pressure gaseous refrigerant passes through the corresponding gas pipe and gas pipe shut-off valve 18 before entering the second gas-liquid separator 10. The gaseous refrigerant, after gas-liquid separation, enters compressor 1 through the suction pipe. This cycle continues, achieving the purpose of cooling and bringing the indoor space to the target cooling temperature.

[0063] It should be noted that steps S10 and S20 do not necessarily have a sequential execution order; the two steps are relatively independent. That is, defrosting can occur during the refrigeration process, and the heat exchange area of ​​the first heat exchanger can be adjusted during defrosting. Furthermore, this embodiment of the invention also provides a refrigeration system, which includes a memory and a processor. The memory is adapted to store multiple program codes, which are adapted to be loaded and run by the processor to execute the control method of the refrigeration system in the aforementioned embodiment.

[0064] This invention also provides a computer-readable storage medium storing a computer program that is executed by a processor to implement the control method of the refrigeration system in the foregoing embodiments.

[0065] Finally, this embodiment of the invention also provides a control device for a refrigeration system, which includes a control module for executing the control method of the refrigeration system in the foregoing embodiments.

[0066] In the description of this invention, "module" and "processor" can include hardware, software, or a combination of both. A module may include hardware circuitry, various suitable sensors, communication ports, and memory, and may also include software components, such as program code, or a combination of software and hardware. A processor may be a central processing unit, microprocessor, image processor, digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor may be implemented in software, in hardware, or a combination of both. Non-transitory computer-readable storage media include any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc.

[0067] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by hardware related to computer program instructions. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable storage medium can include any entity or device capable of carrying the computer program code, a medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory, a random access memory, an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer-readable storage medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable storage medium does not include electrical carrier signals and telecommunication signals.

[0068] Furthermore, it should be understood that since the control module is only used to illustrate the functional units of the system of the present invention, the physical device corresponding to the control module can be the processor itself, or a part of the processor's software, hardware, or a combination of software and hardware. Therefore, the number of control modules can be configured as needed.

[0069] Those skilled in the art will understand that the control module can be adaptively split. Specific splitting of the control module will not cause the technical solution to deviate from the principles of the present invention; therefore, the technical solutions after splitting will all fall within the protection scope of the present invention.

[0070] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A refrigeration system, characterized in that, The refrigeration system includes a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger, which are sequentially connected through a main pipeline to form a refrigerant circulation loop. The first heat exchanger includes a first heat exchange section. The refrigeration system further includes a first gas-liquid separator, which is disposed on a pipeline connected to the outlet of the first heat exchange section. The first gas-liquid separator has a gas outlet, which is connected to the inlet of the second heat exchanger or a main pipeline connected to the inlet via a first branch pipeline. A first solenoid valve is disposed on the first branch pipeline. The first solenoid valve is used to control the opening and closing of the first branch pipeline so that the first branch pipeline can be connected when the second heat exchanger is frosted, and the gaseous refrigerant separated by the first gas-liquid separator is used to defrost the second heat exchanger. The first heat exchanger further includes a second heat exchange section, which is connected to the downstream side of the first heat exchange section, and the liquid outlet of the first gas-liquid separator is connected to the inlet of the second heat exchange section.

2. The refrigeration system according to claim 1, characterized in that, The refrigeration system further includes a second branch pipe, one end of which is connected to the outlet of the first gas-liquid separator or to the first branch pipe, and the other end of which is connected to a pipe connected to the outlet of the second heat exchange section. A second solenoid valve is provided on the second branch pipe, and the second solenoid valve is used to control the opening and closing of the second branch pipe.

3. The refrigeration system according to claim 1, characterized in that, The heat exchange area of ​​the first heat exchange section is larger than that of the second heat exchange section.

4. A control method for a refrigeration system, characterized in that, The refrigeration system includes a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger, which are sequentially connected through a main pipeline to form a refrigerant circulation loop. The first heat exchanger includes a first heat exchange section. The refrigeration system further includes a first gas-liquid separator, which is disposed on a pipeline connected to the outlet of the first heat exchange section. The first gas-liquid separator has a gas outlet, which is connected to the inlet of the second heat exchanger via a first branch pipeline. A first solenoid valve is disposed on the first branch pipeline, and the first solenoid valve is used to control the on / off state of the first branch pipeline. The first heat exchanger further includes a second heat exchange section, which is connected to the downstream side of the first heat exchange section. The liquid outlet of the first gas-liquid separator is connected to the inlet of the second heat exchange section. The control method includes: When the frosting condition of the second heat exchanger reaches the defrosting condition, the first solenoid valve is opened so that the gaseous refrigerant obtained by the first gas-liquid separator can be used to defrost the second heat exchanger.

5. The control method for the refrigeration system according to claim 4, characterized in that, The steps for determining whether the degree of frost on the second heat exchanger meets the defrosting conditions include: Obtain the compressor's suction pressure and the coil temperature of the second heat exchanger; The suction pressure is compared with a preset suction pressure threshold, and the coil temperature of the second heat exchanger is compared with a preset coil temperature threshold. If the suction pressure is less than or equal to the preset suction pressure threshold, and the coil temperature is less than or equal to the preset coil temperature threshold for a set duration, then the defrosting condition is determined to have been met.

6. The control method for the refrigeration system according to claim 4, characterized in that, The first heat exchanger further includes a second heat exchange section connected to the downstream side of the first heat exchange section. The liquid outlet of the first gas-liquid separator is connected to the inlet of the second heat exchange section. The refrigeration system further includes a second branch pipe. One end of the second branch pipe is connected to the gas outlet of the first gas-liquid separator or to the first branch pipe, and the other end of the second branch pipe is connected to a pipe connected to the outlet of the second heat exchange section. A second solenoid valve is installed on the second branch pipe to control the on / off state of the second branch pipe. The control method further includes: When the outdoor temperature is lower than a preset temperature threshold, the second solenoid valve is opened.

7. A refrigeration device, characterized in that, The refrigeration device includes a memory and a processor, the memory being adapted to store multiple program codes, the program codes being adapted to be loaded and run by the processor to perform the control method of the refrigeration system according to any one of claims 4 to 6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium is adapted to store a plurality of program codes, which are adapted to be loaded and run by a processor to perform the control method of the refrigeration system according to any one of claims 4 to 6.

9. A control device for a refrigeration equipment, characterized in that, The control device includes a control module, which is used to execute the control method of the refrigeration system according to any one of claims 4 to 6.

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