Countercurrent defrosting refrigerator and control method thereof

Abstract

The invention discloses a countercurrent defrosting refrigerator and a control method thereof, relates to the technical field of refrigerators, and aims to solve the problem that lubricating oil in a compressor flows into an evaporator or a condenser in the running process of the countercurrent defrosting refrigerator. The countercurrent defrosting refrigerator comprises a condenser, a pressure reducer, an evaporator and an oil adjusting loop, the condenser is configured to release heat under the refrigeration working condition and absorb heat under the defrosting working condition, and one end of the evaporator is connected with one end of the condenser through the pressure reducer. The end, close to the evaporator, of the condenser is further connected with the end, close to the condenser, of the evaporator through an oil adjusting loop in the flowing direction of refrigerants. And the oil adjusting loop is in a normally closed state and is configured to be conducted for a second preset duration after a first preset duration when the countercurrent defrosting refrigerator is switched to a refrigeration working condition and / or a defrosting working condition. The counter-flow defrosting refrigerator is used for improving the lubricating effect of the compressor and prolonging the service life of the compressor.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigerators, and particularly to a countercurrent defrosting refrigerator and a control method thereof. Background Art

[0002] A refrigerator is a common electrical appliance in people's daily life. It can refrigerate through structures such as a compressor or a semiconductor refrigeration component to maintain a low-temperature environment in the storage cavity, thereby extending the shelf life of preset items such as foodstuffs placed in the storage cavity.

[0003] For example, the freezing chamber, refrigerating chamber, and variable-temperature chamber of the refrigerator are cooled by refrigerant compressed by a compressor and driven to circulate. Among them, during the mechanical movement of the compressor for compressing the refrigerant, lubricating oil is required to lubricate its own components to prevent mechanical failures caused by long-term wear, thereby increasing the service life of the compressor.

[0004] However, during the process of the compressor compressing the refrigerant, the lubricating oil in the compressor enters the condenser (or evaporator) along with the refrigerant and stays in the condenser (or evaporator), resulting in a reduction in the lubricating oil in the compressor. While affecting the service life of the compressor, the lubricating oil adhering to the inner wall surface of the condenser (or evaporator) will also reduce the heat exchange efficiency of the refrigerant. Summary of the Invention

[0005] The present invention provides a countercurrent defrosting refrigerator and a control method thereof, aiming to solve the problem that the lubricating oil in the compressor of the countercurrent defrosting refrigerator will flow into the evaporator or condenser during operation.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] On the one hand, the present application provides a countercurrent defrosting refrigerator, including a condenser, a pressure reducer, an evaporator, and an oil regulation circuit. The condenser is configured to release heat under refrigeration conditions and absorb heat under defrosting conditions. One end of the evaporator is connected to one end of the condenser through a pressure reducer. Along the flow direction of the refrigerant, the end of the condenser close to the evaporator is also connected to the end of the evaporator close to the condenser through the oil regulation circuit. The oil regulation circuit is in a normally closed state and is configured to: when the countercurrent defrosting refrigerator switches to refrigeration conditions and / or switches to defrosting conditions, the oil regulation circuit is conducted for a second preset duration after a first preset duration.

[0008] Thus, by providing an oil adjustment circuit between the condenser and the evaporator, and making the oil adjustment circuit conduct for a second preset duration after a first preset duration when the refrigerator switches to the refrigeration mode and the defrosting mode. During the first preset duration before the oil adjustment circuit conducts, the compressor can be started to enable the pressure reducer to accumulate a relatively high refrigerant pressure in the upstream circuit in the refrigerant flow direction. When the oil adjustment circuit conducts, the high-pressure refrigerant accumulated in the upstream circuit rapidly flows through the oil adjustment circuit and flushes the inner wall of the downstream evaporator (or condenser), flushing the lubricating oil inside back into the compressor, so that the operating compressor has sufficient lubricating oil for lubrication, thereby avoiding wear failures of the compressor caused by lack of lubricating oil and being beneficial to improving the heat exchange efficiency of the refrigerant in the evaporator (or condenser).

[0009] In some embodiments, the counter-flow defrost refrigerator includes a condenser, a pressure reducer, an evaporator, and a switching valve. The condenser is configured to release heat in the refrigeration mode and absorb heat in the defrosting mode. One end of the evaporator is connected to one end of the condenser through the pressure reducer. The switching valve is at least partially arranged in parallel with the pressure reducer to form an oil adjustment circuit in parallel with the pressure reducer, and the switching valve is configured to: at least when the counter-flow defrost refrigerator switches to the refrigeration mode, adjust the switching valve to make the oil adjustment circuit conduct for a second preset duration after a first preset duration. The oil adjustment circuit is in a normally closed state. By arranging the switching valve at least partially in parallel with the pressure reducer, the oil adjustment circuit can be formed, and the structure of the existing refrigerator can be directly improved, which has a wide application range.

[0010] In some embodiments, the switching valve is a two-position two-way electrically controlled valve. Along the refrigerant flow direction, one end of the switching valve is connected to the end of the pressure reducer close to the evaporator, and the other end of the switching valve is connected to the end of the pressure reducer close to the condenser, with a simple structure.

[0011] In some embodiments, the switching valve is a two-position three-way electrically controlled valve. Along the refrigerant flow direction, the condenser is serially arranged with the evaporator through the first end and the second end of the switching valve in sequence, and the third end of the switching valve is connected to the first end or the second end of the switching valve through the pressure reducer, so that the pressure reducer is arranged in parallel with the first end or the second end of the switching valve. Through the configuration of the two-position three-way electrically controlled valve, the influence of the pressure reducer on the conducting oil adjustment circuit can be avoided.

[0012] In some embodiments, the counter-flow defrost refrigerator further includes a compressor and a controller. The controller is electrically connected to the compressor and the switching valve, and is configured to: when the counter-flow defrost refrigerator switches from the defrosting mode to the refrigeration mode and the compressor starts, the controller controls the switching valve to conduct the oil adjustment circuit for a second preset duration after a first preset duration, so as to facilitate the compressor to recover the lubricating oil flowing out in the defrosting mode through the automatic control of the oil adjustment circuit.

[0013] In some embodiments, the controller is configured such that when the counter-flow defrost refrigerator switches from the refrigeration mode to the defrost mode and the compressor starts, after a first preset duration, the controller controls the switching valve to conduct the oil regulation circuit for a second preset duration, so as to facilitate the compressor to recover the lubricating oil flowing out during the refrigeration mode through the automatic control of the oil regulation circuit.

[0014] In some embodiments, the controller is configured such that after the oil regulation circuit is first conducted for the second preset duration, the controller controls the switching valve to repeatedly conduct the oil regulation circuit for the second preset duration every first preset duration, and the oil regulation circuit is repeatedly conducted a preset number of times. By repeatedly conducting the oil regulation circuit, the recovery effect of the lubricating oil in the evaporator (or condenser) is improved.

[0015] In some embodiments, the counter-flow defrost refrigerator further includes a four-way valve, a first switch member, a second switch member, a third switch member, and a cycle time control module. The first switch member is electrically connected to the four-way valve and is used to control the four-way valve to switch and adjust between the refrigeration mode and the defrost mode. The third switch member is electrically connected to the switching valve through the cycle time control module and the second switch member in sequence, and the third switch member is arranged in parallel with the first switch member. And the cycle time control module is configured such that when the first switch member controls the four-way valve to switch from the defrost mode to the refrigeration mode, the third switch member starts the cycle time control module in the first state, so that the cycle time control module controls the second switch member to close the oil regulation circuit. The cycle time control module in the first state switches to the second state after the first preset duration, so that the cycle time control module controls the switching valve to conduct the oil regulation circuit through the second switch member, and the duration of the second state is the second preset duration. So that the switching valve and the oil regulation circuit can operate automatically.

[0016] In some embodiments, the cycle time control module is configured such that the cycle time control module in the second state switches to the first state after the second preset duration, so that the first state and the second state are repeatedly cycled a preset number of times. The repeatedly conducted oil regulation circuit can improve the flushing effect on the lubricating oil in the evaporator or condenser.

[0017] In some embodiments, the first preset duration is 1 min to 2 min or 2 min to 3 min.

[0018] In some embodiments, the second preset duration is 5 s to 10 s or 10 s to 15 s.

[0019] In some embodiments, the preset number of times is 5 to 10 times.

[0020] In some embodiments, the pressure reducer is a capillary tube structure or an electronic expansion valve structure, and the structure is simple.

[0021] In some embodiments, the countercurrent defrosting refrigerator further includes a compressor and a four-way valve. The compressor has a suction end and a discharge end. The four-way valve has a first port, a second port, a third port, and a fourth port. The first port is connected to the suction end, the second port is connected to the discharge end, the third port is connected to one end of the condenser away from the pressure reducer along the flow direction of the refrigerant, and the fourth port is connected to one end of the evaporator away from the pressure reducer along the flow direction of the refrigerant. The first port and the fourth port are in communication, and the second port and the third port are in communication, so that the countercurrent defrosting refrigerator enters the refrigeration mode. The first port and the third port are in communication, and the second port and the fourth port are in communication, so that the countercurrent defrosting refrigerator enters the defrosting mode.

[0022] In some embodiments, the pressure reducer is an electronic expansion valve structure, and the pressure reducer is configured as follows: when the electronic expansion valve is at the maximum opening, the pressure reducer is an oil regulating circuit in a conducting state. When the electronic expansion valve is at the minimum opening, the pressure reducer is an oil regulating circuit in a closed state. By adjusting the pressure reducer, the effect of the oil regulating circuit can be achieved, and the structure is simple.

[0023] On the other hand, the present application also provides a control method for a countercurrent defrosting refrigerator. When the countercurrent defrosting refrigerator switches from the defrosting mode to the refrigeration mode, the oil regulating circuit is controlled to be conducted for a second preset duration after a first preset duration. And / or, when the countercurrent defrosting refrigerator switches from the refrigeration mode to the defrosting mode, the oil regulating circuit is controlled to be conducted for a second preset duration after a first preset duration.

[0024] The control method for the countercurrent defrosting refrigerator provided by the embodiments of the present application is used to control the countercurrent defrosting refrigerator in the above aspect, so it can solve the same technical problems and achieve the same technical effects, which will not be elaborated here.

[0025] In some embodiments, when the countercurrent defrosting refrigerator switches to the refrigeration mode or the defrosting mode, after the compressor starts, the oil regulating circuit is controlled to be conducted for a second preset duration after a first preset duration.

[0026] In some embodiments, after the oil regulating circuit is first conducted for the second preset duration, the oil regulating circuit is controlled to be conducted for the second preset duration every time after the first preset duration, so that the oil regulating circuit is repeatedly conducted for a preset number of times. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a schematic perspective view of a refrigerator provided by an embodiment of the present application;

[0029] Figure 2 is Figure 1 a sectional view of the box shown in;

[0030] Figure 3 is a schematic connection diagram of the first refrigerator provided by the embodiment of the present application under the refrigeration condition;

[0031] Figure 4 is Figure 3 a schematic connection diagram of the first refrigerator shown in under the defrosting condition;

[0032] Figure 5 is a schematic connection diagram of the second refrigerator provided by the embodiment of the present application under the refrigeration condition;

[0033] Figure 6 is Figure 5 a schematic connection diagram of the first refrigerator shown in under the defrosting condition;

[0034] Figure 7 is Figure 6 a schematic connection diagram of the refrigerator shown in for conducting the oil regulation circuit under the defrosting condition;

[0035] Figure 8 is Figure 5 a schematic connection diagram of the refrigerator shown in for conducting the oil regulation circuit under the refrigeration condition;

[0036] Figure 9 is a schematic connection diagram of the third refrigerator provided by the embodiment of the present application with an oil regulation circuit;

[0037] Figure 10 is a schematic connection diagram of the fourth refrigerator provided by the embodiment of the present application under the refrigeration condition;

[0038] Figure 11 is Figure 10 a schematic connection diagram of the refrigerator shown in for conducting the oil regulation circuit under the refrigeration condition;

[0039] Figure 12 is a schematic connection diagram of the fifth refrigerator provided by the embodiment of the present application under the defrosting condition;

[0040] Figure 13 is Figure 5 a schematic control connection diagram of the four-way valve and the switching valve shown in;

[0041] Figure 14 is Figure 5 a schematic control connection diagram of the compressor, four-way valve and switching valve shown in.

[0042] Reference numerals:

[0043] 100 - refrigerator;

[0044] 1 - Cabinet; 11 - Storage cavity; 12 - Outer shell; 13 - Inner liner; 14 - Thermal insulation layer;

[0045] 2 - Door body;

[0046] 31 - Compressor; 32 - Four - way valve; 33 - Condenser; 34 - Pressure reducer; 35 - Evaporator; 36 - Switching valve;

[0047] 4 - Oil - regulating circuit;

[0048] 51 - First switch component; 52 - Second switch component; 53 - Third switch component;

[0049] 61 - Circulation time - control module;

[0050] 7 - Controller. Detailed implementation manners

[0051] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "rear", "inner", "outer", etc. are based on the orientation or relative positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. Without special instructions, in the case of satisfying the relative positional relationships shown in the accompanying drawings, the above - mentioned orientation descriptions can be flexibly set during the actual application process.

[0053] The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0054] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", and "communicated" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two components or the electrical connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In the embodiments of the present invention, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the presence of additional identical elements in the process, article or device including that element.

[0056] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. In any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present invention, it should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0057] On the one hand, as Figure 1 shown, Figure 1 FIG. is a schematic perspective view of a countercurrent defrosting refrigerator (hereinafter referred to as refrigerator 100) provided by an embodiment of the present application. The refrigerator 100 may include a box body 1 and a door body 2. The box body 1 may be a box-shaped structure approximately in the shape of a cuboid, or the box body 1 may also be a box-shaped structure of other shapes. A storage cavity 11 is formed inside the box body 1 for freezing or refrigerating preset items. The door body 2 is connected to the box body 1 so that the door body 2 can open or close the storage cavity 11.

[0058] Exemplarily, the door body 2 may be rotatably connected to one side of the box body 1 so that the door body 2 can open or close the storage cavity 11 by rotating. Alternatively, the door body 2 may be connected to the box body 1 through a hinge or a guide rail, both of which can satisfy the opening or closing of the storage cavity 11 through the door body 2.

[0059] In some embodiments, as Figure 2As shown, the box body 1 may include an outer shell 12, an inner container 13, and a heat insulation layer 14. A storage cavity 11 is formed inside the inner container 13, and the storage cavity 11 is used for refrigerating or freezing preset items. The inner container 13 is located inside the outer shell 12 to enhance the structural strength of the box body 1 through the outer shell 12. The heat insulation layer is filled between the inner container 13 and the outer shell 12 to reduce the heat exchange between the storage cavity 11 and the external environment, thereby increasing the low-temperature preservation period of the preset items in the storage cavity 11 and facilitating the reduction of refrigeration power consumption.

[0060] To maintain a stable freezing and / or refrigerating temperature inside the storage cavity 11, as Figure 3 shown, the refrigerator 100 includes a compressor 31, a four-way valve 32, a condenser 33, a pressure reducer 34, and an evaporator 35. The compressor 31 has a suction end and a discharge end, and the four-way valve 32 has a first port A, a second port B, a third port C, and a fourth port D. The first port A is connected to the suction end, the second port B is connected to the discharge end, one end of the condenser 33 can be connected to the third port C, one end of the evaporator 35 can be connected to the other end of the condenser 33 through the pressure reducer 34, and the other end of the evaporator 35 can be connected to the fourth port D.

[0061] When the first port A is in communication with the fourth port D as Figure 3 shown, and the second port B is in communication with the third port C, so that the refrigerator 100 is in the refrigeration mode, the refrigerant flowing out of the discharge end of the compressor 31 can circulate successively along the second port B, the third port C, the condenser 33, the pressure reducer 34, the evaporator 35, the fourth port D, the first port A, and the suction end of the compressor 31.

[0062] In this way, the gaseous refrigerant flowing out of the compressor 31 can be liquefied at the condenser 33 and release heat. After the liquefied refrigerant flows through the pressure reducer 34 with a capillary tube or an electronic throttling valve structure, it will vaporize in the evaporator 35 and absorb heat through the evaporator 35, thereby cooling the surroundings of the evaporator 35, and the vaporized refrigerant is sucked into the compressor 31 and compressed. The air in the storage cavity 11 can be circulated through the evaporator 35 by setting a duct structure and a fan to maintain the refrigerating temperature and freezing temperature in the storage cavity 11 (such as a freezing chamber, a refrigerating chamber, and a variable temperature chamber). Since the refrigeration of the compressor 31 has a high power consumption ratio, it is beneficial to improve the energy-saving effect of the refrigerator 100 in the refrigeration mode, that is, the refrigerator 100 consumes less electricity and is environmentally friendly.

[0063] In addition, when the first port A is as Figure 4When the shown part is conducted with the third port C and the second port B is conducted with the fourth port D to make the refrigerator 100 in the defrosting condition, the refrigerant flowing out from the exhaust end of the compressor 31 can circulate successively along the second port B, the fourth port D, the evaporator 35, the pressure reducer 34, the condenser 33, the third port C, the first port A and the suction end of the compressor 31, that is, compared with the refrigeration condition, the refrigerant flows reversely among the condenser 33, the pressure reducer 34 and the evaporator 35.

[0064] In this way, the gaseous refrigerant flowing out from the compressor 31 can be liquefied and release heat at the evaporator 35. After flowing through the pressure reducer 34, the liquefied refrigerant will vaporize in the condenser 33 and absorb heat through the condenser 33, so as to cool the surrounding of the evaporator 35. And the vaporized refrigerant is sucked into the compressor 31 and compressed. If frosting occurs on the surface of the evaporator 35 during the refrigeration condition, the refrigerator 100 can be adjusted to the defrosting condition to melt the frost on the surface of the evaporator 35 through the liquefaction heat release of the refrigerant, thereby improving the heat exchange efficiency between the evaporator 35 and the flowing air.

[0065] Between the compressor 31, the condenser 33 and the evaporator 35, the four-way valve 32 in the above embodiment can be used to switch the refrigeration condition and the heating condition of the refrigerator 100. In addition, a switching circuit of the refrigeration condition and the heating condition can also be formed by connecting the solenoid valve and the flow pipeline.

[0066] For example, the exhaust end of the compressor 31, the condenser 33, the pressure reducer 34, the evaporator 35 and the suction end of the compressor 31 are connected in sequence. A two-position three-way valve is connected between the evaporator 35 and the suction end of the compressor 31, and another two-position three-way valve is connected between the condenser 33 and the exhaust end of the compressor 31. The last port of the former two-position three-way valve is connected to the exhaust end of the compressor 31 through a pipeline, and the last port of the latter two-position three-way valve is connected to the suction end of the compressor 31 through a pipeline. That is, by controlling the conduction states of the two two-position three-way valves, the refrigerator 100 can also be switched and adjusted between the refrigeration condition and the defrosting condition.

[0067] Heating and defrosting the evaporator 35 through the reverse flow of the refrigerant can improve the defrosting speed and melting efficiency of the surface of the evaporator 35, and has a high energy consumption ratio.

[0068] Since the compressor 31 needs lubricating oil to lubricate its own components during the mechanical operation of compressing the refrigerant, so as to prevent mechanical failures caused by long-term wear and thus improve the service life of the compressor 31. However, during the process of the compressor 31 compressing the refrigerant, the lubricating oil in the compressor 31 enters the condenser 33 (or the evaporator 35) along with the refrigerant and stays in the condenser 33 (or the evaporator 35), resulting in a reduction in the lubricating oil in the compressor 31. While affecting the service life of the compressor 31, the lubricating oil adhering to the inner wall surface of the condenser 33 (or the evaporator 35) will also reduce the heat exchange efficiency of the refrigerant.

[0069] To solve the above problems, as Figure 5 shown, along the flow direction of the refrigerant, one end of the evaporator 35 is connected to one end of the condenser 33 through a pressure reducer 34. On this basis, the refrigerator 100 further includes an oil regulating circuit 4. Along the flow direction of the refrigerant, one end of the condenser 33 close to the evaporator 35 is also connected to one end of the evaporator 35 close to the condenser 33 through the oil regulating circuit 4, and the oil regulating circuit 4 is in a normally closed state.

[0070] Among them, the oil regulating circuit 4 is configured to: when the refrigerator 100 switches to the refrigeration working condition, the oil regulating circuit 4 is conducted for a second preset duration after a first preset duration. It is also possible to set that when the refrigerator 100 switches to the defrosting working condition, the oil regulating circuit 4 is conducted for a second preset duration after a first preset duration.

[0071] The above two conditions can be satisfied simultaneously or can be set alternatively, and no limitation is made thereto. Among them, in the embodiment of the present application, the oil regulating circuit 4 that is conducted after delaying the first preset duration is to enable the compressor 31 to operate for a period of time so that the refrigerant pressure in the refrigerant circuit upstream of the pressure reducer 34 is large enough, so that when the oil regulating circuit 4 is conducted, the refrigerant can quickly relieve pressure through the oil regulating circuit 4 and flush the corresponding condenser 33 (or the evaporator 35).

[0072] Based on this, it is also possible to set that the oil regulating circuit 4 is conducted for a second preset duration after delaying the first preset duration compared with the starting time of the compressor 31. In this way, the interference duration during the delayed start of the compressor 31 compared with the switching adjustment of the four-way valve 32 can be excluded. When the delayed start duration of the compressor 31 compared with the switching adjustment of the four-way valve 32 is between 0 and 10 s or does not affect the conduction effect of the oil regulating circuit 4, the delayed conduction time of the oil regulating circuit 4 can be based on the working condition switching time of the refrigerator 100 or the starting time of the compressor 31 after switching, and no limitation is made thereto.

[0073] Exemplarily, when the refrigerator 100 is in Figure 5 the shown refrigeration working condition, along the flow direction of the refrigerant, the four-way valve 32 (such as Figure 3The third port C (as shown) is connected to one end of the condenser 33 away from the pressure reducer 34, and the fourth port D is connected to one end of the evaporator 35 away from the pressure reducer 34. In this way, the refrigerant flows through the condenser 33, the pressure reducer 34, the evaporator 35, and the fourth port D in sequence from the third port C and is then sucked into the suction end of the compressor 31. The refrigerant liquefies and releases heat at the condenser 33, and the refrigerant vaporizes and absorbs heat at the evaporator 35 to efficiently cool the storage cavity 11 (such as Figure 1 as shown).

[0074] When the refrigerator 100 switches from the refrigeration mode to Figure 6 the defrosting mode as shown, the refrigerant flows through the evaporator 35, the pressure reducer 34, and the condenser 33 in sequence and is then sucked into the suction end of the compressor 31 through the four-way valve 32. In the above process, the refrigerant liquefies and releases heat at the evaporator 35 to melt the frost on the surface of the evaporator 35, and the liquid refrigerant vaporizes and absorbs heat at the condenser 33 to improve the heating efficiency at the evaporator 35.

[0075] In the refrigeration mode, since the lubricating oil in the compressor 31 is mixed with the gaseous refrigerant and flows into the condenser 33, when the refrigerator 100 switches to Figure 6 and Figure 7 the defrosting mode as shown, after the compressor 31 operates for the first preset duration, the refrigerant pressure in the circuit between the evaporator 35 and the pressure reducer 34 is relatively high. At this time, by conducting the oil regulating circuit 4 for the second preset duration, the gaseous refrigerant in the high-pressure state can flow into the condenser 33 quickly through the oil regulating circuit 4, so that the high-pressure refrigerant flushes the inner wall of the condenser 33 at a high speed and flushes the lubricating oil flowing into the condenser 33 in the refrigeration mode back into the compressor 31.

[0076] In addition, when the refrigerator 100 switches from the defrosting mode to Figure 5 and Figure 8 the refrigeration mode as shown, since part of the lubricating oil of the compressor 31 in the defrosting mode will flow into the evaporator 35, at this time, the oil regulating circuit 4 is conducted for the second preset duration after the first preset duration. By setting the compressor 31 in the refrigeration mode to operate for the first preset duration, the refrigerant in the circuit between the condenser 33 and the pressure reducer 34 in the refrigeration mode can have a relatively high pressure, so that the high-pressure refrigerant after conducting the oil regulating circuit 4 can flush the inner wall of the evaporator 35 at a high speed through the oil regulating circuit 4 and flush the lubricating oil flowing into the evaporator 35 in the defrosting mode back into the compressor 31.

[0077] Thus, by arranging an oil regulating circuit 4 between a condenser 33 and an evaporator 35, and making the oil regulating circuit 4 conduct for a second preset duration after a first preset duration when the refrigerator 100 switches to a refrigeration condition and a defrosting condition, in the first preset duration before the oil regulating circuit 4 conducts, the compressor 31 can be started to enable the pressure reducer 34 to accumulate a relatively high refrigerant pressure in the upstream circuit in the refrigerant flow direction. When the oil regulating circuit 4 conducts, the high-pressure refrigerant accumulated in the upstream circuit rapidly flows through the oil regulating circuit 4 and flushes the inner wall of the downstream evaporator 35 (or condenser 33), flushing the lubricating oil inside back into the compressor 31, so that there is sufficient lubricating oil in the operating compressor 31 for lubrication, thereby avoiding wear failures of the compressor 31 caused by lack of lubricating oil and being beneficial to improving the heat exchange efficiency of the refrigerant in the evaporator 35 (or condenser 33).

[0078] It should be noted that since the evaporator 35 and the condenser 33 are connected by the pressure reducer 34, and the conduction amount of the pressure reducer 34 is relatively small under normal conditions, so that there is a relatively high air pressure in the upstream circuit of the pressure reducer 34 and a relatively low air pressure in the downstream circuit of the pressure reducer 34. By connecting and arranging the oil regulating circuit 4 between the condenser 33 and the evaporator 35, and the flow rate of the conducting oil regulating circuit 4 is much larger than the flow rate of the pressure reducer 34 under normal conditions, so that a large amount of refrigerant will flow rapidly between the condenser 33 and the evaporator 35 through the oil regulating circuit 4 when the oil regulating circuit 4 is in a conducting state.

[0079] Exemplarily, the pressure reducer 34 can be a capillary tube structure or an electronic expansion valve structure. For example, the minimum inner diameter of the oil regulating circuit 4 in a conducting state is equivalent to the inner diameter of a pipeline above 5 mm.

[0080] Taking the pressure reducer 34 as a capillary tube as an example, the inner diameter of the capillary tube applicable to the refrigerator 100 is between 0.15 mm and 1.5 mm, which is much smaller than the inner diameter of the refrigerant circuit (such as the oil regulating circuit 4). Taking the example that the oil regulating circuit 4 is arranged in parallel with the pressure reducer 34, when the oil regulating circuit 4 is in a conducting state, since the inner diameter of the conducting oil regulating circuit 4 is much larger than the inner diameter of the capillary tube of the pressure reducer 34, that is, most of the refrigerant will flow rapidly between the condenser 33 and the evaporator 35 through the oil regulating circuit 4, and at this time, it can be regarded that the capillary tube is in a closed state.

[0081] Taking the pressure reducer 34 as an electronic expansion valve as an example, the oil regulating circuit 4 can be arranged in parallel with the electronic expansion valve, so that the refrigerant can flow at a high speed in the conducting oil regulating circuit 4.

[0082] Or, it can also be set that the opening degree of the electronic expansion valve can be rapidly adjusted between the maximum opening degree and the pressure reducing opening degree (a capillary tube with an equivalent inner diameter of 0.15 mm to 1.5 mm), and at this time, the pressure reducer 34 with an electronic expansion valve structure can also be used as Figure 9The shown oil blending circuit 4, that is, there is no need to additionally set a parallel oil blending circuit, has a simple structure. Based on this, by setting the maximum opening degree of the electronic expansion valve to be equivalent to an inner diameter of a pipeline of more than 5 mm, when the electronic expansion valve is in a pressure reduction opening degree (i.e., a pressure reduction state or a minimum opening degree), it is considered that the oil blending circuit 4 is in a closed state and the pressure reducer 34 is in a conducting state. When the electronic expansion valve is in the maximum opening degree (i.e., an oil blending state), it is considered that the oil blending circuit 4 is in a conducting state and the pressure reducer 34 is in an approximately closed state, so that the refrigerant flowing at a high speed through the oil blending circuit 4 can quickly wash the lubricating oil in the condenser 33 (or the evaporator 35) and make it flow into the compressor 31.

[0083] In some embodiments, as Figure 5 and Figure 10 shown, the refrigerator 100 may further include a switching valve 36. The switching valve 36 is at least partially arranged in parallel with the pressure reducer 34 to form an oil blending circuit 4 in parallel with the pressure reducer 34. By adjusting the state of the switching valve 36, the oil blending circuit 4 can be in a conducting or closed state. For example, by setting the oil blending circuit 4 to be normally closed through the switching valve 36, at least when the refrigerator 100 switches to the refrigeration working condition, by adjusting the switching valve 36, the oil blending circuit 4 is made to conduct for a second preset time after delaying for a first preset time, so as to backflush the lubricating oil flowing into the evaporator 35 during the defrosting working condition back into the compressor 31.

[0084] In this way, only by additionally installing a switching valve 36 that is at least partially arranged in parallel with the pressure reducer 34 on the basis of the original structure of the refrigerator 100 can the oil blending circuit 4 be formed. The structure is simple. While avoiding the lubricating oil of the compressor 31 staying in the evaporator 35 (or the condenser 33) for a long time, it is also beneficial to improve the refrigeration efficiency of the refrigerator 100.

[0085] It should be noted that in the embodiments of the present application, the refrigerator 100 switching to the refrigeration working condition means that the refrigerator 100 switches from the defrosting working condition to the refrigeration working condition, and the refrigerator 100 switching to the defrosting working condition means that the refrigerator 100 switches from the refrigeration working condition to the defrosting working condition.

[0086] Exemplarily, the switching valve 36 can also be configured to: at least when the refrigerator 100 switches to the refrigeration working condition, adjust the switching valve 36 so that the oil blending circuit 4 conducts for a second preset time after delaying for a first preset time compared with the starting time of the compressor 31.

[0087] Exemplarily, the first preset time can be 1 min to 2 min or 2 min to 3 min, that is, the first preset time satisfies: 1 min ≤ t1 < 2 min or 2 min ≤ t1 ≤ 3 min. For example, the first preset time can be 60 s, 90 s, 120 s, 150 s or 180 s. It is beneficial to improve the service life of the compressor 31 and the refrigeration efficiency of the refrigerator 100. For example, the first preset time can be 2 min.

[0088] If the first preset duration is greater than 3 minutes, that is, a longer delay start time will increase the running time of the compressor 31 without lubricating oil, thus affecting the service life of the compressor 31. If the first preset duration is less than 1 minute, it will result in a shorter running time of the compressor 31, that is, the refrigerant pressure in the upstream circuit of the pressure reducer 34 is relatively small, which is not sufficient to blow the lubricating oil in the downstream evaporator 35 (or condenser 33) back into the compressor 31.

[0089] Correspondingly, the second preset duration can be 5 s to 10 s or 10 s to 15 s, that is, the second preset duration satisfies: 5 s ≤ t2 < 10 s or 10 s ≤ t2 ≤ 15 s. For example, the second preset duration can be 5 s, 7 s, 10 s, 13 s or 15 s. While blowing the lubricating oil back to the compressor 31 more fully, it can also avoid the longer second preset duration from affecting the refrigeration condition or defrosting condition of the refrigerator 100. For example, the second preset duration can be 10 s.

[0090] If the second preset duration is greater than 15 s, that is, a longer conduction time of the oil adjustment circuit will cause significant pressure relief in the upstream of the pressure reducer 34, thus affecting the running time and running effect of the corresponding refrigeration condition (or defrosting condition). If the second preset duration is less than 5 s, that is, a shorter conduction time of the oil adjustment circuit is difficult to blow the lubricating oil fully into the compressor 31.

[0091] In some embodiments, such as Figure 5 and Figure 6 shown, the switching valve 36 can be a two-position two-way electrically controlled valve, that is, a common valve with two ports that can control the conduction and closure between the two ports. Along the flowing direction of the refrigerant, one end of the switching valve 36 is connected to the end of the pressure reducer 34 close to the evaporator 35, and the other end of the switching valve 36 is connected to the end of the pressure reducer 34 close to the condenser 33, so that the switching valve 36 is arranged in parallel with the pressure reducer 34.

[0092] Such as Figure 5 and Figure 6 shown, when the switching valve 36 is in the closed state (i.e., the pressure reducing state) to block the oil adjustment circuit 4, the refrigerator 100 in the refrigeration condition and defrosting condition can operate normally. When the switching valve 36 is adjusted to the Figure 7 and Figure 8 shown conduction state to conduct the oil adjustment circuit 4, the refrigerator 100 in the defrosting condition can blow the lubricating oil in the condenser 33 back into the compressor 31, and the refrigerator 100 in the refrigeration condition can blow the lubricating oil in the evaporator 35 back into the compressor 31.

[0093] In some other embodiments, such as Figure 10 and Figure 11As shown, the switching valve 36 can also be a two-position three-way electrically controlled valve, and the two-position three-way electrically controlled valve has three ports. Along the flow direction of the refrigerant, the condenser 33 is serially arranged with the evaporator 35 through the first end and the second end of the switching valve 36 in sequence, and the third end of the switching valve 36 is connected to the first end or the second end of the switching valve 36 through the pressure reducer 34, so that the pressure reducer 34 is arranged in parallel with the first end or the second end of the switching valve 36.

[0094] Exemplarily, along the flow direction of the refrigerant, taking the end of the switching valve 36 connected to the condenser 33 as the first end of the switching valve 36 and the end of the switching valve 36 connected to the evaporator 35 as the second end of the switching valve 36 as an example. When the third end of the switching valve 36 is connected to the second end of the switching valve 36 through the pressure reducer 34, or the third end of the switching valve 36 is connected to the end of the evaporator 35 close to the switching valve 36 along the flow direction of the refrigerant through the pressure reducer 34, the switching valve 36 is configured to have a pressure reducing state and an oil regulating state.

[0095] When the switching valve 36 is in Figure 10 the pressure reducing state shown, the first end and the third end of the switching valve 36 are conducted, and the second end of the switching valve 36 is in a closed state between the first end and the third end, so that the oil regulating circuit 4 is closed and the refrigerant flows between the evaporator 35 and the condenser 33 through the pressure reducer 34.

[0096] When the switching valve 36 is in Figure 11 the oil regulating state shown, the first end and the second end of the switching valve 36 are conducted, and the third end of the switching valve 36 is in a closed state between the first end and the second end, so that the oil regulating circuit 4 is conducted and the high-pressure refrigerant flushes the inner wall of the evaporator 35 at a high speed through the oil regulating circuit 4, and the lubricating oil is flushed back into the compressor 31.

[0097] In some other embodiments, as Figure 12 shown, along the flow direction of the refrigerant, the first end of the switching valve 36 is connected to the condenser 33, and the second end of the switching valve 36 is connected to the evaporator 35. When the third end of the switching valve 36 is connected to the first end of the switching valve 36 through the pressure reducer 34, or the third end of the switching valve 36 is connected to the end of the condenser 33 close to the switching valve 36 along the flow direction of the refrigerant through the pressure reducer, the switching valve 36 is also configured to have a pressure reducing state and an oil regulating state.

[0098] When the switching valve 36 is in Figure 12 the oil regulating state shown, the first end and the second end of the switching valve 36 are conducted, and the third end of the switching valve 36 is in a closed state between the first end and the second end, so that the oil regulating circuit 4 is conducted and the lubricating oil in the condenser 33 is blown back into the compressor 31.

[0099] When the switching valve 36 is in a decompression state, the second end and the third end of the switching valve 36 are connected, and the first end and the third end and the second end of the switching valve 36 are in a closed state, so that the oil adjustment circuit 4 is closed and the refrigerant flows between the evaporator 35 and the condenser 33 through the pressure reducer 34.

[0100] It should be noted that in the refrigerator 100 capable of running the defrosting condition, since the refrigerator 100 is in the refrigeration condition for a long time, an oil filter structure can be installed between the compressor 31 and the condenser 33, or the relative installation height of the compressor 31 and the condenser 33 can be adjusted to prevent the lubricating oil in the refrigeration condition from flowing from the compressor 31 into the condenser 33. However, this method is difficult to prevent the lubricating oil in the defrosting condition from flowing from the compressor 31 into the evaporator 35, that is, the compressor 31 of the refrigerator 100 after running the defrosting condition will lack lubricating oil, and part or most of the lubricating oil will flow into the evaporator 35 in the defrosting condition, that is, the refrigerator 100 can be configured to blow the lubricating oil in the evaporator 35 back to the compressor 31 through the conductive oil regulating circuit 4 when switching to the refrigeration condition.

[0101] Since the refrigerator 100 operates in a refrigeration condition for a long time, the default state of the four-way valve 32 (such as no power is connected or a default signal) can be configured to put the refrigerator 100 in a refrigeration state of the refrigeration condition, and the four-way valve 32 receives an adjustment signal and switches to put the refrigerator 100 in a defrosting state of the defrosting condition.

[0102] Correspondingly, the normal state of the switching valve 36 is the decompression state, that is, the oil regulating circuit 4 is closed. And the switching valve 36 receives the corresponding control signal to switch to the oil regulating state, that is, the oil regulating circuit 4 is connected.

[0103] In some embodiments, Figure 13 As shown, the refrigerator 100 further includes a first switch 51, a second switch 52, a third switch 53 and a cycle time control module 61. The first switch 51 is electrically connected to the four-way valve 32 to control the four-way valve 32 to switch between the refrigeration condition and the defrosting condition. The third switch 53 is arranged in parallel with the first switch 51, and the third switch 53 is electrically connected to the switching valve 36 through the cycle time control module 61 and the second switch 52 in sequence to adjust the decompression state and the oil adjustment state of the switching valve 36, and is configured as follows:

[0104] When the first switch 51 controls the four-way valve 32 to switch from the defrosting mode to the refrigeration mode, the third switch 53 starts the cycle time control module 61 in the first state, so that the cycle time control module 61 controls the second switch 52 to close the oil regulating circuit. For example, the second switch 52 can be in a normally closed state at this time, and the switching valve 36 or the electronic expansion valve for the oil regulating circuit 4 is kept in a decompression state, so that the oil regulating circuit 4 remains in a closed state.

[0105] During the cycle of the first state, the cycle time control module 61 switches to the second state after a first preset duration, so that the cycle time control module 61 conducts the oil adjustment circuit 4 through the second switch 52, and the duration of the second state is a second preset duration. The cycle time control module 61 in the second state can connect the switching valve 36 or the electronic expansion valve for the oil adjustment circuit 4 to power through the second switch 52, so that the above structure switches from the decompression state to the oil adjustment state, and is used to blow the lubricating oil in the downstream evaporator 35 back into the compressor 31 through the conducted oil adjustment circuit 4.

[0106] Exemplarily, the first switch 51 can be of normally closed structure, the third switch 53 can be of normally open structure, the third switch 53 can control whether the cycle time control module 61 is powered on, and the cycle time control module 61 starts synchronously and is in the first state after being powered on.

[0107] When the first switch 51 and the third switch 53 receive the defrosting signal together, the first switch 51 (switches to the open state) controls the four-way valve 32 to be powered on and switch to the defrosting mode under the action of the defrosting signal. The third switch 53 switches to the closed state under the action of the defrosting signal, so that the cycle time control module 61 is powered off, so that the normally closed second switch 52 can control the switching valve 36 to be in the decompression state (that is, the oil adjustment circuit 4 remains in a closed state).

[0108] When the continuous defrosting signal received by the first switch 51 and the third switch 53 disappears, the normally closed first switch 51 controls the four-way valve 32 to switch from the defrosting mode to the refrigeration mode. And the normally open third switch 53 controls the cycle time control module 61 to be powered on from the power-off state. At this time, the cycle time control module 61 starts synchronously and enters the first state (so that the oil adjustment circuit 4 remains in a closed state). The cycle time control module 61 in the first state switches to the second state (so that the oil adjustment circuit 4 is in a conducting state) after a first preset duration (such as 2 min), and the duration of the cycle time control module 61 in the second state is a second preset duration.

[0109] The cycle time control module 61 in the second state can enter the first state after a second preset duration (such as 10 s) and always remains in the first state. At this time, the oil adjustment circuit 4 is delayed by 2 min and conducts for 10 s after switching from the defrosting mode to the refrigeration mode, and is used to flush the lubricating oil in the evaporator 35.

[0110] Alternatively, the cyclic time control module 61 can also be configured such that the cyclic time control module 61 in the second state switches to the first state after a second preset duration, so that the first state and the second state repeat cyclically for a preset number of times. For example, if the preset number of times is zero, the conduction time of the fuel adjustment circuit 4 is the second preset duration (such as 10 s). Correspondingly, if the preset number of times is one, the conduction time of the fuel adjustment circuit 4 is 20 s, and if the preset number of times is two, the conduction time of the fuel adjustment circuit 4 is 30 s, and so on.

[0111] Correspondingly, the preset number of times can be set to 0 to 10 times or 4 to 9 times, that is, the cyclic time control module 61 controls the switching valve 36 to conduct 1 to 11 times or 5 to 11 times in the refrigeration condition, so as to improve the performance when switching to the refrigeration condition. If the preset number of times is greater than 10 times, the refrigerant flowing out of the fuel adjustment circuit 4 will affect the refrigeration efficiency of the refrigerator 100. For example, the preset number of times can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10, and there is no limitation in this regard.

[0112] Exemplarily, as Figure 13 shown, the refrigerator 100 further includes a controller 7, and the controller 7 is electrically connected to the first switch member 51 and the third switch member 53 at the same time. The controller 7 continuously outputs a defrosting signal to cause the refrigerator 100 to switch to and maintain the defrosting condition. After the controller 7 stops outputting the defrosting signal, the refrigerator 100 switches from the defrosting condition to the refrigeration condition and continuously operates in the refrigeration condition.

[0113] Alternatively, the four-way valve 32 can also be set to be in the defrosting condition under normal conditions (energized to switch to the refrigeration condition), so that when the controller 7 continuously outputs a refrigeration signal, the refrigerator 100 switches to and maintains the refrigeration condition. At this time, the cyclic time control module 61 is powered off and the fuel adjustment circuit 4 is in a closed state. After the controller 7 stops outputting the refrigeration signal, the refrigerator 100 switches from the refrigeration condition to the defrosting condition and continuously operates in the defrosting condition. At this time, the third switch member 53 controls the cyclic time control module 61 to be powered on and started, so that the fuel adjustment circuit 4 switches to the conducting state when the cyclic time control module 61 is in the second state.

[0114] It should be noted that in the embodiments of the present application, the first switch member 51 and the third switch member 53 can be a relay structure, a triode, or a MOS (Metal Oxide Semiconductor) transistor, that is, an electronic control switch that can control whether a component is powered on through a current signal or a voltage signal.

[0115] The cyclic time control module 61 and the second switching element 52 can be time control switches, and the part of the time control switch corresponding to the second switching element 52 can be a relay structure, a triode or a MOS transistor, which are common components. The time control switch can first control the component to close (or open) for a first preset duration after startup, and then the time control switch controls the component to open (or close) for a second preset duration, and repeats the cycle for a preset number of times.

[0116] In addition, from the third switching element 53 to the second switching element 52, a delay-on module and a delay-off module can also be connected in sequence, so as to achieve the effect that the oil adjustment circuit 4 is delayed and conducted once in the corresponding working condition, and this is not limited. In the description of this specification, specific features, structures, materials or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0117] It should be noted that when the controller 7 is an integrated circuit structure, the cyclic time control module 61 can also be configured as a part of the functional modules of the controller 7, and the corresponding control of the relay can be realized through a preset function program. The corresponding first switching element 51, second switching element 52 and third switching element 53 can all be regarded as a part of the integrated circuit structure of the controller 7, so that the controller 7 can be directly electrically connected to at least one of the compressor 31, the four-way valve 32 and the switching valve 36, and this is not limited.

[0118] Based on this, as Figure 14 shown, the controller 7 can be electrically connected to the compressor 31 and the switching valve 36 to facilitate controlling different states of the compressor 31 and the switching valve 36. The controller 7 can also be electrically connected to the switching valve 36 or the control valve in the corresponding switching circuit to control the refrigeration working condition and the defrosting working condition of the switching refrigerator 100.

[0119] In this way, the controller 7 can directly control the states of the compressor 31, the four-way valve 32 and the switching valve 36.

[0120] In some embodiments, the controller 7 can be configured to: when the refrigerator 100 switches from the defrosting working condition to the refrigeration working condition and the compressor 31 starts up, the controller 7 controls the switching valve 36 to conduct the oil adjustment circuit 4 for a second preset duration after a first preset duration.

[0121] In this way, by setting the first preset duration after the compressor 31 starts, the oil adjustment circuit 4 is correspondingly turned on, which can avoid the situation of insufficient refrigerant pressure in the upstream circuit of the pressure reducer 34 caused by the delayed start of the compressor 31. That is, by ensuring that the compressor 31 operates for the first preset duration, so that there is refrigerant with a higher pressure in the upstream circuit of the pressure reducer 34, so that during the second preset duration when the oil adjustment circuit 4 is turned on, the gaseous refrigerant with a higher pressure can fully flush the inner wall of the downstream evaporator 35 through the oil adjustment circuit 4, so as to blow back the lubricating oil staying in the evaporator 35 into the compressor 31.

[0122] Correspondingly, the controller 7 can also be configured as: when the refrigerator 100 switches from the refrigeration mode to the defrosting mode and the compressor 31 starts, the controller 7 controls the switching valve 36 to turn on the oil adjustment circuit 4 for the second preset duration after the first preset duration. So that the refrigerator 100 can blow back the lubricating oil flowing out of the compressor 31 during the refrigeration mode into the compressor 31 during the defrosting mode.

[0123] In addition, the controller 7 can also be configured as: after the oil adjustment circuit 4 is first turned on for the second preset duration, the controller 7 controls the switching valve 36 to turn on the oil adjustment circuit 4 for the second preset duration every first preset duration, so that the oil adjustment circuit 4 is turned on repeatedly for a preset number of times. For example, if the preset number of times is four, that is, the oil adjustment circuit 4 is turned on five times in the refrigeration mode or the defrosting mode, so that the lubricating oil in the evaporator (or condenser) is flushed to the compressor 31 more thoroughly.

[0124] It should be noted that the controller 7 can make the oil adjustment circuit 4 in the closed state and the turned-on state by controlling the decompression state (the oil adjustment circuit 4 is closed) and the oil adjustment state (the oil adjustment circuit 4 is turned on) of the switching valve 36. Or, the controller 7 can also be electrically connected to the pressure reducer 34 with the structure of an electronic expansion valve, and can also make the oil adjustment circuit 4 in the corresponding closed state and turned-on state by controlling the decompression state and the oil adjustment state of the pressure reducer 34.

[0125] On the other hand, the embodiment of the present application also provides a control method for a countercurrent defrosting refrigerator, and this control method is used to control the countercurrent defrosting refrigerator in the above aspect. The control method includes:

[0126] When the countercurrent defrosting refrigerator switches from the defrosting mode to the refrigeration mode, control the oil adjustment circuit to be turned on for the second preset duration after the first preset duration. It is used to blow back the lubricating oil flowing into the evaporator during the defrosting mode into the compressor.

[0127] When the countercurrent defrosting refrigerator switches from the refrigeration mode to the defrosting mode, control the oil adjustment circuit to be turned on for the second preset duration after the first preset duration. It is used to blow back the lubricating oil flowing into the condenser during the refrigeration mode into the compressor.

[0128] Among them, the control method of the countercurrent defrosting refrigerator provided by the embodiments of the present application is used to control the countercurrent defrosting refrigerator in the above aspect. Therefore, it can solve the same technical problems and achieve the same technical effects, which will not be elaborated here.

[0129] When controlling the on-state and off-state of the oil regulating circuit, the on-state and off-state of the oil regulating circuit can be controlled by a corresponding switching valve such as a two-position two-way solenoid valve or a two-position three-way solenoid valve, or the maximum opening and pressure-reducing opening of the electronic expansion valve can be adjusted to make the corresponding oil regulating circuit in the on-state and off-state. Among them, in the countercurrent defrosting refrigerator, the above two control processes can exist independently or can be selected, and this is not limited.

[0130] On this basis, when the countercurrent defrosting refrigerator switches to the refrigeration mode or the defrosting mode, after the compressor starts, control the oil regulating circuit to conduct for a second preset duration after a first preset duration. That is, the delayed start of the oil regulating circuit can be based on the start time of the compressor, so as to avoid the influence of the delayed start of the compressor on the return effect of the lubricating oil in the refrigeration mode and the defrosting mode.

[0131] In some embodiments, after the oil regulating circuit is first conducted for a second preset duration, control the oil regulating circuit to conduct for a second preset duration every time after a first preset duration, so that the oil regulating circuit repeats the conduction for a preset number of times. Thereby improving the cleaning and return effect of the lubricating oil in the evaporator (or condenser).

[0132] In the description of this specification, specific features, structures, materials or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0133] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A countercurrent defrosting refrigerator, characterized in that, Comprising: A condenser configured to release heat under refrigeration conditions and absorb heat under defrosting conditions; A pressure reducer; An evaporator, one end of which is connected to one end of the condenser through the pressure reducer; And a switching valve, at least part of the switching valve is arranged in parallel with the pressure reducer to form an oil regulating circuit in parallel with the pressure reducer, and is configured to: At least when the counter-flow defrost refrigerator switches to the refrigeration condition, adjust the switching valve so that the oil regulating circuit is conducted for a second preset duration after a first preset duration of delay; the oil regulating circuit is in a normally closed state.

2. The countercurrent defrosting refrigerator according to claim 1, characterized in that, The switching valve is a two-position two-way electrically controlled valve; along the flow direction of the refrigerant, one end of the switching valve is connected to the end of the pressure reducer close to the evaporator, and the other end of the switching valve is connected to the end of the pressure reducer close to the condenser; or, The switching valve is a two-position three-way electrically controlled valve; along the flow direction of the refrigerant, the condenser is sequentially connected in series with the evaporator through the first end and the second end of the switching valve, and the third end of the switching valve is connected to the first end or the second end of the switching valve through the pressure reducer, so that the pressure reducer is arranged in parallel with the first end or the second end of the switching valve.

3. The countercurrent defrosting refrigerator according to claim 1 or 2, characterized in that, The counter-flow defrost refrigerator further includes: A compressor; And a controller, the controller is electrically connected to the compressor and the switching valve, and is configured to: When the counter-flow defrost refrigerator switches from the defrosting condition to the refrigeration condition, and after the compressor starts, the controller controls the switching valve to conduct the oil regulating circuit for a second preset duration after a first preset duration.

4. The countercurrent defrosting refrigerator according to claim 3, characterized in that, The controller is configured to: After the oil regulating circuit is first conducted for the second preset duration, the controller controls the switching valve to make the oil regulating circuit repeat to conduct for the second preset duration every time after the first preset duration, and the oil regulating circuit repeats to conduct a preset number of times.

5. The countercurrent defrosting refrigerator according to claim 1 or 2, characterized in that, The counter-flow defrost refrigerator further includes: A four-way valve; A first switch member, the first switch member is electrically connected to the four-way valve and is used to control the four-way valve to switch and adjust between the refrigeration condition and the defrosting condition; A second switch member; A third switch member; And a cycle time control module, the third switch member is electrically connected to the switching valve through the cycle time control module and the second switch member in sequence, the third switch member is arranged in parallel with the first switch member, and is configured to: When the first switch member controls the four-way valve to switch from the defrosting condition to the refrigeration condition, the third switch member starts the cycle time control module in the first state, so that the cycle time control module controls the second switch member to close the oil regulating circuit; The cycle time control module in the first state switches to the second state after a first preset duration, so that the cycle time control module controls the second switch member to conduct the oil regulating circuit through the second switch member, and the duration of the second state is the second preset duration.

6. The countercurrent defrosting refrigerator according to claim 1 or 2, characterized in that, The counter-flow defrost refrigerator further includes: A compressor, the compressor has a suction end and a discharge end; and a four-way valve having a first port, a second port, a third port, and a fourth port, wherein the first port is connected to the suction gas end, the second port is connected to the exhaust gas end, the third port is connected to one end of the condenser away from the pressure reducer along the flow direction of the refrigerant, and the fourth port is connected to one end of the evaporator away from the pressure reducer along the flow direction of the refrigerant; the first port and the fourth port are in communication, and the second port and the third port are in communication, so that the reverse flow defrosting refrigerator enters the refrigeration mode; the first port and the third port are in communication, and the second port and the fourth port are in communication, so that the reverse flow defrosting refrigerator enters the defrosting mode.

7. A countercurrent defrosting refrigerator, characterized in that, Comprising: a condenser configured to release heat in the refrigeration mode and absorb heat in the defrosting mode; a pressure reducer; an evaporator, one end of which is connected to one end of the condenser through the pressure reducer; and an oil regulating circuit, along the flow direction of the refrigerant, one end of the condenser close to the evaporator is further connected to one end of the evaporator close to the condenser through the oil regulating circuit; the oil regulating circuit is in a normally closed state and is configured to: when the reverse flow defrosting refrigerator switches to the refrigeration mode and / or switches to the defrosting mode, the oil regulating circuit is turned on for a second preset duration after a first preset duration.

8. The counter-flow defrosting refrigerator according to claim 7, wherein the pressure reducer is an electronic expansion valve structure, and the pressure reducer is configured to: when the pressure reducer of the electronic expansion valve structure is at the maximum opening, the pressure reducer is the oil regulating circuit in the on state; when the pressure reducer is at the minimum opening, the pressure reducer is the oil regulating circuit in the closed state.

9. A control method for a countercurrent defrosting refrigerator, characterized in that, Comprising: when the reverse flow defrosting refrigerator switches from the defrosting mode to the refrigeration mode, controlling the oil regulating circuit to be turned on for a second preset duration after a first preset duration; and / or, when the reverse flow defrosting refrigerator switches from the refrigeration mode to the defrosting mode, controlling the oil regulating circuit to be turned on for a second preset duration after a first preset duration.

10. The control method of the countercurrent defrosting refrigerator according to claim 9, characterized in that, Comprising: in the case where the reverse flow defrosting refrigerator switches to the refrigeration mode or the defrosting mode, when the compressor starts, controlling the oil regulating circuit to be turned on for the second preset duration after the first preset duration; and / or, after the oil regulating circuit is first turned on for the second preset duration, controlling the oil regulating circuit to be turned on for the second preset duration every time after the first preset duration, so that the oil regulating circuit is turned on repeatedly for a preset number of times.

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