Dual system refrigerator and defrosting method thereof

Abstract

The application provides a dual-system refrigerator and a defrosting method thereof, wherein the dual-system refrigerator comprises a compressor, a condenser, an evaporator assembly, an exhaust pipe, a return pipe, a reversing device, a first throttling assembly and a second throttling assembly. The reversing device is configured to make one end of the exhaust pipe communicate with an exhaust port of the compressor and simultaneously make one end of the return pipe communicate with an intake port of the compressor, or make one end of the exhaust pipe communicate with the intake port of the compressor and simultaneously make one end of the return pipe communicate with the exhaust port of the compressor. The application can realize the following two defrosting conditions: 1. simultaneous defrosting of two evaporators; 2. defrosting of one evaporator and refrigeration of the other evaporator. In the defrosting process, the application reverses the working roles of the condenser and the evaporator, which is beneficial to the automatic defrosting effect of the heat circulation of the refrigeration system of the air-cooled refrigerator. Compared with other air-cooled refrigerators, the application does not need to use additional defrosting heating wires, achieves the effects of energy saving and reduction of power consumption of the refrigerator, and has high safety.

Description

Technical Field

[0001] This invention relates to the field of refrigerator technology, and in particular to a dual-system refrigerator and its defrosting method. Background Technology

[0002] After running for a period of time, the evaporator of a frost-free refrigerator will frost up. Frost will affect its operating efficiency. Therefore, the evaporator needs to be defrosted after the refrigerator has been cooling for a period of time.

[0003] Existing air-cooled refrigerators use electrically heated evaporators for defrosting. Specifically, the compressor stops, and an electric heating element operates, using the radiant heat generated to defrost the evaporator. The defrosting effect is controlled by adjusting the defrosting time and the defrosting termination temperature. However, electrically heated defrosting has the following problems: 1. Electric heating increases refrigerator energy consumption; 2. The longer defrosting time leads to a significant increase in the internal temperature of the refrigerator; 3. The heating element itself is an electrical component with relatively low safety performance. Summary of the Invention

[0004] The purpose of this invention is to overcome or at least partially solve the above problems by providing a dual-system refrigerator and its defrosting method to improve the defrosting speed and defrosting safety of the evaporator.

[0005] Specifically, the present invention provides a dual-system refrigerator, including a compressor and a condenser. The dual-system refrigerator also includes an evaporator assembly, an exhaust pipe, a return pipe, a reversing device, a first throttling assembly, and a second throttling assembly.

[0006] The reversing device is configured to connect one end of the exhaust pipe to the exhaust port of the compressor and simultaneously connect one end of the return pipe to the intake port of the compressor, or connect one end of the exhaust pipe to the intake port of the compressor and simultaneously connect one end of the return pipe to the exhaust port of the compressor.

[0007] The inlet of the condenser is connected to the other end of the exhaust pipe;

[0008] The evaporator assembly includes two refrigerant inlets, two refrigerant outlets, two evaporators, a third throttling component, and a refrigerant flow path system. The refrigerant flow path system is configured such that the two evaporators are connected in parallel through the two refrigerant inlets and the two refrigerant outlets, or one refrigerant inlet and one refrigerant outlet are shut off, and the two evaporators are connected in series through another refrigerant inlet and another refrigerant outlet, with the third throttling component positioned between the two evaporators connected in series.

[0009] The first throttling component is disposed between the outlet of the condenser and the two refrigerant inlets, configured to throttle the refrigerant flowing out of the condenser, and to allow the refrigerant to simultaneously enter the two refrigerant inlets or selectively enter each of the refrigerant inlets; and the first throttling component is in an off state when one or both of the evaporators are defrosting;

[0010] The other end of the return pipe is connected to the two refrigerant outlets via a first three-way valve;

[0011] The second throttling component is disposed between the outlet of the condenser and the two refrigerant inlets, and is configured to throttle the refrigerant flowing out of the refrigerant inlets and into the condenser when one or both of the evaporators are defrosting.

[0012] Optionally, the refrigerant flow path system includes two second three-way valves, a third three-way valve, and a fourth three-way valve;

[0013] The outlets of the two evaporators are respectively connected to the two refrigerant outlets;

[0014] One port of each second three-way valve is connected to one of the refrigerant inlets, and the other port of each second three-way valve is connected to one of the inlets of the evaporator;

[0015] The two ports of the third three-way valve are respectively connected to the third ports of the two second three-way valves;

[0016] The third throttling component is disposed between the third connection port of the third three-way valve and one connection port of the fourth three-way valve;

[0017] The other two ports of the fourth three-way valve are respectively connected between the outlets of the two evaporators and the corresponding refrigerant outlets.

[0018] Optionally, the third throttling component is a third capillary.

[0019] Optionally, the second throttling component includes:

[0020] Second capillary;

[0021] A first pipe section is disposed between the outlet of the condenser and one of the refrigerant inlets, and a second capillary tube is disposed on the first pipe section;

[0022] The second pipe section is located between another refrigerant inlet and the end of the first pipe section furthest from the condenser.

[0023] Optionally, the first throttling component includes:

[0024] The first throttling main circuit has its inlet connected to the outlet of the condenser;

[0025] Two throttling branches, the inlet of each throttling branch is connected to the outlet of the first throttling main branch, and the outlet of each throttling branch is connected to the two refrigerant inlets respectively;

[0026] A first valve is disposed on the first throttling bus and configured to open or close the first throttling bus;

[0027] A throttling element is disposed on the first throttling bus.

[0028] Optionally, the throttling element is a solenoid valve.

[0029] Optionally, the first throttling assembly further includes a drying filter disposed on the first throttling bus.

[0030] Optionally, each of the throttling branches is provided with a first capillary tube and a second valve for opening or closing the first throttling branch.

[0031] Optionally, the reversing device is a four-way reversing valve.

[0032] The present invention also provides a defrosting method for a dual-system refrigerator, comprising the following steps:

[0033] The first step is to determine whether the evaporator needs defrosting;

[0034] The second step involves controlling the reversing device when one of the evaporators needs defrosting, connecting the compressor's exhaust port to one end of the return pipe and connecting the compressor's intake port to one end of the exhaust pipe; closing the first throttling assembly; controlling the first three-way valve to connect the other end of the return pipe to the refrigerant outlet corresponding to the evaporator that needs defrosting; and controlling the refrigerant flow path system to connect the evaporator that needs defrosting, the third throttling assembly, and another evaporator in series.

[0035] When the two evaporators need to defrost, control the reversing device to connect the compressor's exhaust port to one end of the return pipe and the compressor's intake port to one end of the exhaust pipe; close the first throttling assembly; control the first three-way valve to connect the other end of the return pipe to the refrigerant outlets corresponding to the two evaporators; control the refrigerant flow path system to connect the two evaporators in parallel.

[0036] This invention enables two defrosting scenarios: 1. Simultaneous defrosting of both evaporators; 2. Defrosting one evaporator while simultaneously cooling the other. During the defrosting process, this invention reverses the roles of the condenser and evaporator, facilitating the thermal circulation of the refrigerator's own cooling system to achieve automatic defrosting. Compared to other air-cooled refrigerators, this invention eliminates the need for additional defrosting heating wires, resulting in energy savings, reduced power consumption, and high safety.

[0037] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0038] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0039] Figure 1 This is a schematic diagram of a dual-system refrigerator according to an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of a dual-system refrigerator according to another embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of a dual-system refrigerator according to another embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of a dual-system refrigerator according to another embodiment of the present invention. Detailed Implementation

[0043] The following reference Figures 1 to 4 This invention describes a dual-system refrigerator according to an embodiment of the present invention. The terms "front," "rear," "upper," "lower," "top," "bottom," "inner," "outer," and "lateral," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the purpose of facilitating and simplifying the description of the invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0044] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," etc., may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically stated, this indicates that other features are not excluded and may be further included.

[0045] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," and "coupling," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] Figure 1 This is a schematic diagram of a dual-system refrigerator according to an embodiment of the present invention, as shown below. Figure 1 As shown, and refer to Figures 2 to 4 This invention provides a dual-system refrigerator, which includes a compressor 10, a condenser 20, an evaporator assembly 30, an exhaust pipe 40, a return pipe 50, a reversing device 60, a first throttling assembly 70, and a second throttling assembly 80.

[0047] The reversing device 60 is configured to connect one end of the exhaust pipe 40 to the exhaust port of the compressor 10 and simultaneously connect one end of the return pipe 50 to the intake port of the compressor 10, or connect one end of the exhaust pipe 40 to the intake port of the compressor 10 and simultaneously connect one end of the return pipe 50 to the exhaust port of the compressor 10. The inlet of the condenser 20 is connected to the other end of the exhaust pipe 40. The evaporator assembly 30 includes two refrigerant inlets, two refrigerant outlets, two evaporators 31, a third throttling assembly 32, and a refrigerant flow path system 33. The refrigerant flow path system is configured such that the two evaporators 31 are connected in parallel through the two refrigerant inlets and two refrigerant outlets, or one refrigerant inlet and one refrigerant outlet are shut off, and the two evaporators are connected in series through another refrigerant inlet and another refrigerant outlet, with the third throttling assembly 32 positioned between the two evaporators 31 connected in series. The first throttling assembly 70 is disposed between the outlet of the condenser 20 and the two refrigerant inlets, configured to throttle the refrigerant flowing out of the condenser and allow the refrigerant to simultaneously enter both refrigerant inlets or selectively enter each refrigerant inlet; and the first throttling assembly is in the off state when one or both evaporators are defrosting. The other end of the return pipe is connected to the two refrigerant outlets via a first three-way valve 51. The second throttling assembly 80 is disposed between the outlet of the condenser 20 and the two refrigerant inlets, configured to throttle the refrigerant flowing out of the refrigerant inlets and allow it to enter the condenser when one or both evaporators 31 are defrosting.

[0048] The working process of a dual-system refrigerator is as follows:

[0049] When the dual-system refrigerator is continuously cooling, the refrigerant flow path is as follows: it is discharged from the exhaust port of the compressor 10, flows through the reversing device 60, the exhaust pipe 40, the condenser 20, and the first throttling component 70 in sequence, and then enters the two parallel evaporators 31 for cooling through the two refrigerant inlets. Then it flows out through the two refrigerant outlets, and then flows through the first three-way valve 51, the return pipe 50, and the reversing device 60 in sequence, and flows back to the intake port of the compressor 10.

[0050] When one of the evaporators 31 in the dual-system refrigerator needs to defrost, the refrigerant flow path is as follows: it is discharged from the exhaust port of the compressor 10, flows sequentially through the reversing device 60, the return pipe 50, the first three-way valve 51, and the refrigerant outlet corresponding to the evaporator 31 that needs to be defrosted, then flows through the evaporator that needs to be defrosted to defrost it, then flows through the third throttling component 32 to throttle the refrigerant, then flows into the other evaporator to cool it, then enters the second throttling component 80 through the refrigerant inlet corresponding to the other evaporator 31, then flows sequentially through the condenser 20, the exhaust pipe 40, and the reversing device 60, and flows back to the intake port of the compressor 10.

[0051] When one of the evaporators 31 in the dual-system refrigerator needs to defrost, the refrigerant flows as follows: it is discharged from the exhaust port of the compressor 10, flows through the reversing device 60, the return pipe 50, and the first three-way valve 51 in sequence, and then enters the two parallel evaporators 31 through the two refrigerant outlets to defrost them. Then it enters the second throttling assembly 80 through the two refrigerant inlets mentioned above, and then flows through the condenser 20, the exhaust pipe 40, and the reversing device 60 in sequence, and flows back to the intake port of the compressor 10.

[0052] Therefore, this invention can achieve the following two defrosting scenarios: 1. Simultaneous defrosting of both evaporators; 2. Defrosting one evaporator while simultaneously cooling the other. During the defrosting process, this invention reverses the roles of the condenser and evaporator, facilitating the thermal circulation of the refrigerator's own refrigeration system to achieve automatic defrosting. Compared to other air-cooled refrigerators, this invention does not require an additional defrosting heating wire, achieving energy savings, reducing refrigerator power consumption, and ensuring high safety.

[0053] In some embodiments of the present invention, the refrigerant flow path system includes two second three-way valves 331, a third three-way valve 332, and a fourth three-way valve 333. The outlets of the two evaporators 31 are respectively connected to two refrigerant outlets; one port of each second three-way valve 331 is a refrigerant inlet, and the other port of each second three-way valve 331 is connected to the inlet of an evaporator 31; the two ports of the third three-way valve 332 are respectively connected to the third ports of the two second three-way valves 331; a third throttling assembly 32 is disposed between the third port of the third three-way valve 332 and one port of the fourth three-way valve 333; the remaining two ports of the fourth three-way valve 333 are respectively connected between the outlets of the two evaporators and the corresponding refrigerant outlets.

[0054] When both evaporators 31 need to be cooled or defrosted simultaneously, closing the third three-way valve 332 and the fourth three-way valve 333 allows the two evaporators 31 to be connected in parallel. When one evaporator 31 needs to be defrosted while the other evaporator 31 needs to be cooled, opening the third three-way valve 332 and the fourth three-way valve 333 allows the evaporator requiring defrosting, the third throttling component, and the other evaporator to be connected in series. The above-described refrigerant flow path system 33 has the advantages of ingenious design and simple structure.

[0055] In some embodiments of the present invention, the third throttling component 32 is a third capillary. In other alternative embodiments, the third throttling component is a solenoid valve.

[0056] In some embodiments of the present invention, such as Figure 1-3As shown, the second throttling assembly 80 includes a second capillary tube 81, a first pipe section 82, and a second pipe section 83. The first pipe section 82 is disposed between the outlet of the condenser and a refrigerant inlet, and the second capillary tube 81 is disposed on the first pipe section 82; the second pipe section 83 is disposed between another refrigerant inlet and the end of the first pipe section 82 away from the condenser 20.

[0057] In this embodiment, the second throttling component 80 is further configured to throttle the refrigerant flowing out of the condenser and allow the refrigerant to simultaneously enter the two refrigerant inlets of the evaporator assembly 30. Specifically, when the dual-system refrigerator is continuously cooling, the refrigerant flowing out of the condenser can enter the two refrigerant inlets of the evaporator assembly 30 through the first throttling component 70 and the second throttling component 80, respectively.

[0058] Furthermore, such as Figure 4 As shown, the second throttling assembly 80 also includes a third valve 84, which is disposed on the first pipe section 82 and located at the inlet of the second capillary tube 81. The third valve 84 is used to control the opening or closing of the first pipe section 82 and the second pipe section 83. When the dual-system refrigerator is continuously cooling, the third valve 84 is closed, and the refrigerant flowing out of the condenser 20 enters the two refrigerant inlets of the evaporator assembly 30 through the first throttling assembly 70. When it is necessary to defrost both evaporators 31 simultaneously or defrost one evaporator 31, the third valve 84 is opened, and the refrigerant flowing out of the refrigerant inlet of the evaporator assembly 30 enters the outlet of the condenser 20 through the second throttling assembly 80.

[0059] In some embodiments of the present invention, the first throttling assembly 70 includes a first throttling main 71, two throttling branch lines 72, a first valve 73, and a throttling element 74.

[0060] The inlet of the first throttling main 71 is connected to the outlet of the condenser 20; the inlet of each throttling branch 72 is connected to the outlet of the first throttling main 71, and the outlet of each throttling branch 72 is connected to two refrigerant inlets respectively; a first valve 73 is installed on the first throttling main 71 and configured to open or close the first throttling main; a throttling element 74 is installed on the first throttling main. Specifically, the first valve 73 is installed at the inlet of the first throttling main 71, and the throttling element 74 is installed at the inlet of the first throttling main 71.

[0061] Preferably, the throttling element is a solenoid valve. In other alternative embodiments, the throttling element is a capillary tube.

[0062] Preferably, the first throttling assembly further includes a dryer filter 77, which is disposed on the first throttling main 71. Specifically, the dryer filter 77 is disposed between the outlet of the first valve 73 and the inlet of the throttling element 74. By providing the dryer filter 77, solid impurities and moisture in the refrigerant can be fully absorbed, thereby preventing impurities or moisture in the refrigerant from clogging the first throttling main 71, allowing the refrigerant to work normally and ensuring the cooling effect of the refrigerant.

[0063] Preferably, each throttling branch 72 is equipped with a first capillary tube 75 and a second valve 76. The first capillary tube 75 enhances the cooling effect on the evaporator. The second valve 76 is used to open or close the throttling branch 72. Specifically, when the dual-system refrigerator is continuously cooling, the second valve 76 is opened, thereby opening the throttling branch 72, allowing the refrigerant flowing out of the first throttling main 71 to enter the two refrigerant inlets of the evaporator assembly 30 through the two first capillary tubes 75. When it is necessary to defrost both evaporators 31 simultaneously or only one evaporator 31, the second valve 76 is closed, thereby closing the throttling branch 72.

[0064] In some embodiments of the present invention, the reversing device 60 is a four-way reversing valve. The four-way reversing valve includes a first opening, a second opening, a third opening, and a fourth opening, wherein the first opening is connected to the exhaust port of the compressor; the second opening is connected to one end of the exhaust pipe; the third opening is connected to one end of the return pipe; and the fourth opening is connected to the intake port of the compressor. This reversing device 60 has the advantages of simple structure and low price.

[0065] In some embodiments of the present invention, the dual-system refrigerator is a dual-system air-cooled refrigerator, which further includes a condenser fan 20 and two evaporator fans 34. The condenser fan 20 is located at the condenser 20, and the two evaporator fans 34 are respectively located at the two evaporators 31. When both evaporators 31 are cooling, both the condenser fan 20 and the two evaporator fans 34 are turned on; when both evaporators 31 are defrosting, both evaporator fans 34 are turned off; when one evaporator 31 is defrosting and the other evaporator 31 is cooling, the evaporator fan 34 corresponding to the defrosting is turned off, and the evaporator fan 34 corresponding to the cooling is turned on.

[0066] In some embodiments of the invention, the two evaporators are a refrigerated evaporator and a frozen evaporator, respectively. In other alternative embodiments, the two evaporators are a variable-temperature evaporator and a frozen evaporator, respectively.

[0067] The present invention also provides a defrosting method for a dual-system refrigerator, comprising the following steps:

[0068] The first step is to determine whether evaporator 31 needs defrosting;

[0069] The second step is to control the reversing device 60 when one evaporator 31 needs to defrost, so that the exhaust port of the compressor 10 is connected to one end of the return pipe 50 and the intake port of the compressor 10 is connected to one end of the exhaust pipe 40; close the first throttling assembly 70; control the first three-way valve 51 so that the other end of the return pipe 50 is connected to the refrigerant outlet corresponding to the evaporator 31 that needs to be defrosted; control the refrigerant flow path system 33 so that the evaporator 31 that needs to be defrosted, the third throttling assembly 32 and another evaporator 31 are connected in series.

[0070] When the two evaporators 31 need to defrost, control the reversing device 60 to connect the exhaust port of the compressor 10 with one end of the return pipe 50 and the intake port of the compressor 10 with one end of the exhaust pipe 40; close the first throttling assembly 70; control the first three-way valve 51 to connect the other end of the return pipe 50 with the refrigerant outlets of the two evaporators 31; control the refrigerant flow path system 33 to connect the two evaporators 31 in parallel.

[0071] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A dual-system refrigerator, comprising a compressor and a condenser, characterized in that, It also includes an evaporator assembly, an exhaust pipe, a return pipe, a reversing device, a first throttling assembly, and a second throttling assembly; The reversing device is configured to connect one end of the exhaust pipe to the exhaust port of the compressor and simultaneously connect one end of the return pipe to the intake port of the compressor, or connect one end of the exhaust pipe to the intake port of the compressor and simultaneously connect one end of the return pipe to the exhaust port of the compressor. The inlet of the condenser is connected to the other end of the exhaust pipe; The evaporator assembly includes two refrigerant inlets, two refrigerant outlets, two evaporators, a third throttling component, and a refrigerant flow path system. The refrigerant flow path system is configured such that the two evaporators are connected in parallel through the two refrigerant inlets and the two refrigerant outlets, or one refrigerant inlet and one refrigerant outlet are shut off, and the two evaporators are connected in series through another refrigerant inlet and another refrigerant outlet, with the third throttling component positioned between the two evaporators connected in series. The first throttling component is disposed between the outlet of the condenser and the two refrigerant inlets, configured to throttle the refrigerant flowing out of the condenser, and to allow the refrigerant to simultaneously enter the two refrigerant inlets or selectively enter each of the refrigerant inlets; and the first throttling component is in an off state when one or both of the evaporators are defrosting; The other end of the return pipe is connected to the two refrigerant outlets via a first three-way valve; The second throttling component is disposed between the outlet of the condenser and the two refrigerant inlets, and is configured to throttle the refrigerant flowing out of the refrigerant inlets and into the condenser when one or both of the evaporators are defrosting; The refrigerant flow path system includes two second three-way valves, a third three-way valve, and a fourth three-way valve; The outlets of the two evaporators are respectively connected to the two refrigerant outlets; One port of each second three-way valve is connected to one of the refrigerant inlets, and the other port of each second three-way valve is connected to one of the inlets of the evaporator; The two ports of the third three-way valve are respectively connected to the third ports of the two second three-way valves; The third throttling component is disposed between the third connection port of the third three-way valve and one connection port of the fourth three-way valve; The other two ports of the fourth three-way valve are respectively connected between the outlets of the two evaporators and the corresponding refrigerant outlets; The second throttling component includes: Second capillary; A first pipe section is disposed between the outlet of the condenser and one of the refrigerant inlets, and a second capillary tube is disposed on the first pipe section; The second pipe section is located between another refrigerant inlet and the end of the first pipe section furthest from the condenser.

2. The dual-system refrigerator according to claim 1, characterized in that, The third throttling component is a third capillary.

3. The dual-system refrigerator according to claim 1, characterized in that, The first throttling component includes: The first throttling main is connected to the outlet of the condenser; Two throttling branches are provided, with the inlet of each throttling branch connected to the outlet of the first throttling main branch, and the outlet of each throttling branch connected to the two refrigerant inlets respectively. A first valve is disposed on the first throttling bus and configured to open or close the first throttling bus; A throttling element is disposed on the first throttling bus.

4. A dual-system refrigerator according to claim 3, characterized in that, The throttling element is a solenoid valve.

5. The dual-system refrigerator according to claim 3, characterized in that, The first throttling assembly further includes a drying filter, which is disposed on the first throttling bus.

6. The dual-system refrigerator according to claim 3, characterized in that, Each of the throttling branches is provided with a first capillary tube and a second valve for opening or closing the first throttling branch.

7. The dual-system refrigerator according to claim 1, characterized in that, The reversing device is a four-way reversing valve.

8. A defrosting method for a dual-system refrigerator as described in any one of claims 1-7, characterized in that, Includes the following steps: Determine if the evaporator needs defrosting; When one of the evaporators needs defrosting, the reversing device is controlled to connect the compressor's exhaust port to one end of the return pipe and the compressor's intake port to one end of the exhaust pipe; the first throttling assembly is closed; the first three-way valve is controlled to connect the other end of the return pipe to the refrigerant outlet corresponding to the evaporator that needs defrosting; and the refrigerant flow path system is controlled so that the evaporator that needs defrosting, the third throttling assembly, and the other evaporator are connected in series. When the two evaporators need to defrost, control the reversing device to connect the compressor's exhaust port to one end of the return pipe and the compressor's intake port to one end of the exhaust pipe; close the first throttling assembly; control the first three-way valve to connect the other end of the return pipe to the refrigerant outlets corresponding to the two evaporators; control the refrigerant flow path system to connect the two evaporators in parallel.

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