Refrigerant circulation system, defrosting method, refrigerator and air conditioner

Abstract

The present disclosure relates to a refrigerant circulation system, a defrosting method, a refrigerator and an air conditioner. The refrigerant circulation system comprises: a compressor (10); a first heat exchanger (20), which is connected to the discharge port of the compressor (10) through a refrigerant flow path; a second heat exchanger (30), whose two ends are respectively connected to the first heat exchanger (20) and the suction port of the compressor (10) through the refrigerant flow path; and a first control valve (40), which is arranged between the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30), and is configured to make the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30) in a throttling state under a cooling condition or a heating condition, and to make the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30) in a straight-through state under a defrosting condition. The embodiment of the present disclosure can reduce the power input during the defrosting process.

Description

Technical Field

[0001] The present disclosure relates to the field of refrigeration, and in particular to a refrigerant circulation system, a defrosting method, a refrigerator and an air conditioner. Background Art

[0002] For air-cooled refrigerators, the evaporator of the freezer needs to be defrosted after frost. In some related technologies, electric heating is used for defrosting, which requires large power input and energy consumption. In addition, the temperature of the freezer rises significantly during defrosting, exceeding 3°C, and can exceed 10°C in severe cases, resulting in uneven temperature and affecting food storage. Summary of the invention

[0003] In view of this, the embodiments of the present disclosure provide a refrigerant circulation system, a defrosting method, a refrigerator and an air conditioner, which can reduce the power input during the defrosting process.

[0004] In one aspect of the present disclosure, a refrigerant circulation system is provided, comprising: a compressor; a first heat exchanger connected to a discharge port of the compressor through a refrigerant flow path; a second heat exchanger, both ends of which are connected to the first heat exchanger and a suction port of the compressor through refrigerant flow paths, respectively; and a first control valve, arranged between the refrigerant flow path between the first heat exchanger and the second heat exchanger, and configured to make the refrigerant flow path between the first heat exchanger and the second heat exchanger in a throttling state under a cooling condition or a heating condition, and to make the refrigerant flow path between the first heat exchanger and the second heat exchanger in a straight-through state under a defrosting condition.

[0005] In some embodiments, the first control valve includes: an electronic expansion valve connected in series on the refrigerant flow path between the first heat exchanger and the second heat exchanger, the opening of the electronic expansion valve is set to the maximum opening in the defrosting condition, and is set to a non-maximum opening in the refrigeration condition or the heating condition.

[0006] In some embodiments, the first control valve includes: a throttle valve and a switching valve connected in parallel, and the switching valve is configured to conduct the refrigerant flow path where the switching valve is located under the defrosting condition, and disconnect the refrigerant flow path where the switching valve is located under the cooling condition or the heating condition.

[0007] In some embodiments, the refrigerant circulation system also includes: a heat exchange device, arranged on the refrigerant flow path between the second heat exchanger and the suction port of the compressor; and a second control valve, arranged on the refrigerant flow path between the second heat exchanger and the heat exchange device, and configured to make the refrigerant flow path between the second heat exchanger and the heat exchange device in a straight-through state under the refrigeration condition or the heating condition, and to make the refrigerant flow path between the second heat exchanger and the heat exchange device in a throttling state when the defrosting effect of the second heat exchanger does not meet the preset conditions under the defrosting condition.

[0008] In some embodiments, the heat exchange device includes: a heat exchange medium container, which is filled with liquid heat exchange medium for exchanging heat with the environment; and a heat exchange sleeve, which is connected in series in the refrigerant flow path between the second heat exchanger and the suction port of the compressor, and is arranged in the heat exchange medium container, for exchanging heat between the refrigerant circulating in the heat exchange sleeve and the liquid heat exchange medium.

[0009] In some embodiments, the heat exchange medium container is a water immersion box, and the liquid heat exchange medium is water.

[0010] In some embodiments, the heat exchange sleeve has a size smaller than that of the second heat exchanger.

[0011] In some embodiments, the first heat exchanger is also disposed in the heat exchange medium container, and is used to allow the refrigerant circulating in the first heat exchanger to exchange heat with the liquid heat exchange medium.

[0012] In some embodiments, the refrigerant circulation system also includes: a temperature sensing bag, which is arranged at the lowest temperature position of the second heat exchanger and is configured to detect the current lowest temperature of the second heat exchanger; wherein the preset condition is that the current lowest temperature of the second heat exchanger exceeds the first preset temperature within a first preset time period.

[0013] In some embodiments, the refrigerant circulation system further includes: an anti-condensation pipe connected in series on the refrigerant flow path between the first control valve and the first heat exchanger; and / or a filter connected in series on the refrigerant flow path between the first heat exchanger and the first control valve.

[0014] In some embodiments, the refrigerant circulation system also includes: a controller, which is signal-connected to the first control valve and the second control valve, and is configured to switch the operating conditions of the refrigerant circulation system, and send control instructions to the first control valve and the second control valve according to the operating conditions of the refrigerant circulation system.

[0015] In one aspect of the present disclosure, a refrigerator is provided, comprising: the aforementioned refrigerant circulation system.

[0016] In some embodiments, the refrigerator includes: a freezer compartment, wherein the second heat exchanger in the refrigerant circulation system acts as an evaporator under refrigeration conditions to control the temperature of the freezer compartment.

[0017] In one aspect of the present disclosure, an air conditioner is provided, comprising: the aforementioned refrigerant circulation system.

[0018] In some embodiments, the air conditioner further includes: an outdoor unit, wherein the second heat exchanger in the refrigerant circulation system is arranged in the outdoor unit and absorbs heat outdoors as an evaporator under heating conditions.

[0019] In one aspect of the present disclosure, a defrosting method for the aforementioned refrigerant circulation system is provided, comprising: when the operating condition of the refrigerant circulation system is switched from a cooling condition or a heating condition to a defrosting condition, a control instruction is sent to the first control valve so that the first control valve switches the refrigerant flow path between the first heat exchanger and the second heat exchanger from a throttling state to a straight-through state.

[0020] In some embodiments, the refrigerant circulation system also includes a heat exchange device and a second control valve, the heat exchange device is arranged on the refrigerant flow path between the second heat exchanger and the suction port of the compressor, and the second control valve is arranged on the refrigerant flow path between the second heat exchanger and the heat exchange device; wherein, the defrosting method also includes: if under the defrosting condition, the defrosting effect of the second heat exchanger does not meet the preset conditions, a control instruction is sent to the second control valve so that the second control valve switches the refrigerant flow path between the second heat exchanger and the heat exchange device from a straight-through state to a throttling state.

[0021] In some embodiments, the preset condition is that the current lowest temperature of the second heat exchanger exceeds a first preset temperature within a first preset time period.

[0022] In some embodiments, the defrosting method also includes: when the operating condition of the refrigerant circulation system is in the refrigeration condition or the heating condition, when it is determined that the current minimum temperature of the second heat exchanger is lower than a second preset temperature within a second preset time period, the operating condition of the refrigerant circulation system is switched from the refrigeration condition or the heating condition to the defrosting condition.

[0023] In some embodiments, the defrosting method further includes: determining the moisture content of an object whose temperature is controlled by the second heat exchanger as an evaporator; and adjusting the second preset time according to the moisture content of the object and the defrosting time.

[0024] Therefore, according to the embodiment of the present disclosure, a first control valve is provided between the first heat exchanger and the second heat exchanger, and the first control valve is placed in a throttling state in the refrigerant flow path in the refrigeration condition or the heating condition, and in a straight-through state in the refrigerant flow path in the defrosting condition. In this way, the first control valve acts as a throttling unit between the condenser and the evaporator in the refrigeration condition or the heating condition, and no longer throttles in the defrosting condition, so that the high-temperature and high-pressure refrigerant in the condenser flows directly into the evaporator, and the evaporator is defrosted by hot gas. Since the hot gas defrosting and defrosting is carried out inside the evaporator, it is mainly conduction heat exchange. Compared with the defrosting method of heating the air with the evaporator by convection or directly radiating the evaporator to defrost in the related art, no additional power is required, thereby reducing the power invested in the defrosting process, and compared with the electric heating method, the defrosting effect is faster and the defrosting temperature rise is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0026] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0027] Figure 1-Figure 5 They are schematic diagrams of structures of some embodiments of the refrigerant circulation system according to the present disclosure;

[0028] Figure 6 is a schematic diagram comparing temperature rises when defrosting according to some embodiments of the refrigerant circulation system disclosed herein and related technologies using an electric heater;

[0029] Figure 7 is a schematic diagram of the process of some embodiments of the defrosting method disclosed in the present invention;

[0030] Figure 8 is a schematic flow chart of other embodiments of the defrosting method disclosed herein;

[0031] Fig. 9 It is a schematic diagram comparing the temperature rise during multiple defrosting according to some embodiments of the refrigerant circulation system disclosed herein and during defrosting using related technologies using an electric heater.

[0032] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0033] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0034] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other device without an intermediate device, or may not be directly connected to the other device but have an intermediate device.

[0036] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0037] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0038] Figure 1-Figure 5 They are schematic diagrams of the structures of some embodiments of the refrigerant circulation system according to the present disclosure. Figure 1-Figure 5In some embodiments, the refrigerant circulation system includes: a compressor 10, a first heat exchanger 20, a second heat exchanger 30 and a first control valve 40. The first heat exchanger 20 is connected to the discharge port of the compressor 10 through a refrigerant flow path. Both ends of the second heat exchanger 30 are respectively connected to the first heat exchanger 20 and the suction port of the compressor 10 through the refrigerant flow path. The first control valve 40 is arranged between the refrigerant flow path between the first heat exchanger 20 and the second heat exchanger 30, and is configured to make the refrigerant flow path between the first heat exchanger 20 and the second heat exchanger 30 in a throttling state under a cooling condition or a heating condition, and to make the refrigerant flow path between the first heat exchanger 20 and the second heat exchanger 30 in a straight-through state under a defrosting condition.

[0039] In this embodiment, a first control valve is arranged between the first heat exchanger and the second heat exchanger, and the first control valve is placed in a throttling state in the refrigerant flow path under the refrigeration or heating conditions, and in a straight-through state in the refrigerant flow path under the defrosting condition. In this way, the first control valve acts as a throttling unit between the condenser and the evaporator under the refrigeration or heating conditions, forming a refrigeration / heating refrigerant circulation loop including a compressor, a first heat exchanger (as a condenser), a first control valve (as a throttling unit) and a second heat exchanger (as an evaporator).

[0040] The first control valve switches to a straight-through state under the defrosting condition and no longer throttles the refrigerant, which allows the high-temperature and high-pressure refrigerant in the condenser to flow directly into the evaporator through the first control valve, and performs hot gas defrosting and defrosting on the evaporator. Since hot gas defrosting and defrosting are performed inside the evaporator, mainly by conduction heat exchange, compared with the defrosting method of heating the air with the evaporator by convection or directly defrosting the evaporator by radiation heating in the related art, no additional power is required, thereby reducing the power invested in the defrosting process. Moreover, compared with the electric heating method, the hot gas defrosting and defrosting method adopted in this embodiment has a faster defrosting speed and a smaller defrosting temperature increase. In addition, eliminating the electric heater is also better for electrical safety.

[0041] The refrigerant circulation system of this embodiment can be applied to various types of equipment that require defrosting of the evaporator, such as refrigerators or air conditioners. Taking a refrigerator including the refrigerant circulation system of this embodiment as an example, the refrigerator includes a freezer in addition to the refrigerant circulation system. The refrigerator can also include a cold storage room, a variable temperature room, etc. The second heat exchanger in the refrigerant circulation system can be used as an evaporator under refrigeration conditions to control the temperature of the freezer. When the first control valve puts the refrigerant flow path in which it is located in a throttling state under refrigeration conditions or heating conditions, the refrigerant circulation system can form a refrigeration cycle loop, the temperature of the first heat exchanger is around 42°C, and the heat is dissipated to the outside, and the second heat exchanger can reach below -26°C, cooling the freezer compartment of the refrigerator so that the temperature of the freezer compartment can reach -18°C.

[0042] For air-cooled refrigerators, the air duct system allows the cooled airflow to enter the freezer, temperature-changing room and refrigeration room to realize the normal refrigeration function of the refrigerator. Due to the presence of water vapor, after a certain number of door openings and closings, the second heat exchanger will frost. The related technology uses an electric heater to radiate or air convection heat transfer on the second heat exchanger outside the second heat exchanger to achieve defrosting. The heated air will also enter the freezer, etc. through the air duct system, resulting in a significant temperature rise in the freezer, etc., affecting the storage conditions.

[0043] For the refrigerator of this embodiment, when defrosting is required, the working mode of the refrigerator is switched from the refrigeration mode to the defrosting mode. In the defrosting mode, the first control valve is switched to the straight-through state, and the refrigerant is no longer throttled. The high-temperature and high-pressure refrigerant in the first heat exchanger can directly flow into the second heat exchanger through the first control valve, so as to achieve the defrosting of the frost on the second heat exchanger by the high-temperature gaseous refrigerant. This method can save the electric heater, thereby saving the cost of components and the energy consumed by the electric heater defrosting. In addition, in terms of the defrosting effect, the hot gas defrosting is achieved by direct conduction heating of the second heat exchanger by the high-temperature gaseous refrigerant flowing into the inside of the second heat exchanger, with small heat loss, and does not directly heat the air around the second heat exchanger, so that the temperature rise of the freezer compartment is less, thereby minimizing the impact on the storage conditions of the refrigerator.

[0044] Figure 6 Schematic diagram comparing the temperature rise during defrosting according to some embodiments of the refrigerant circulation system disclosed herein and related technologies using electric heaters. Figure 6 Curve A is the temperature rise curve of the refrigerator freezer room using an electric heater for defrosting, and curve B is the temperature rise curve of the refrigerator freezer room including the refrigerant circulation system of this embodiment. The temperature peak T of curve A A The temperature peak T above the B curve B , and T B Compared with the temperature difference before and after defrosting, the temperature difference in the freezer is smaller, so it has less impact on the storage conditions in the freezer.

[0045] In some other embodiments of the present application, an electric heater may be further included as a backup so that any defrosting method can be selected according to the situation, or both hot air defrosting and electric heating defrosting methods can be used simultaneously to increase the defrosting speed.

[0046] Take the air conditioner including the refrigerant circulation system of the present embodiment as an example. In addition to the refrigerant circulation system, the air conditioner also includes an outdoor unit. The second heat exchanger in the refrigerant circulation system is arranged in the outdoor unit and absorbs heat outdoors as an evaporator under heating conditions. When the air conditioner is heating in winter, the heat exchanger in the outdoor unit may be frosted and needs to be defrosted. Under the heating condition of the air conditioner, the refrigerant discharged from the compressor first enters the first heat exchanger in the indoor unit, and then enters the second heat exchanger in the outdoor unit after the throttling effect of the first control valve. When the second heat exchanger needs to be defrosted, the air conditioner is switched to the defrost mode.

[0047] In the defrost mode, the first control valve switches to a straight-through state and no longer throttles the refrigerant. The high-temperature and high-pressure refrigerant in the first heat exchanger can flow directly into the second heat exchanger through the first control valve, thereby achieving defrosting of the frost on the second heat exchanger by the high-temperature gaseous refrigerant. Compared with the method of using another unit to assist in defrosting in the related art, this embodiment does not require another heating unit to assist in defrosting, so it can save costs and improve adaptability. For refrigeration and air conditioning, when the external ambient temperature is too low and causes frost on the outdoor heat exchanger, the embodiment of the present application can also be used to achieve hot gas defrosting.

[0048] refer to Figure 2 In some embodiments, the first control valve 40 includes: an electronic expansion valve 41 connected in series on the refrigerant flow path between the first heat exchanger 20 and the second heat exchanger 30, the opening of the electronic expansion valve 41 is set to the maximum opening in the defrosting condition, and is set to a non-maximum opening in the cooling condition or the heating condition. The electronic expansion valve 41 can achieve direct flow of the refrigerant flow path between the first heat exchanger 20 and the second heat exchanger 30 in the maximum opening state, so that the high-temperature gaseous refrigerant in the first heat exchanger 20 can directly enter the second heat exchanger 30 through the electronic expansion valve 41 to achieve hot gas defrosting. The electronic expansion valve 41 can adjust the opening according to the actual situation of the cooling condition or the heating condition in the non-maximum opening to meet the cooling or heating requirements.

[0049] In some embodiments, the refrigerant circulation system further includes a controller. The controller is connected to the first control valve 40 by signal, and is configured to switch the working condition of the refrigerant circulation system, and send a control instruction to the first control valve 40 according to the working condition of the refrigerant circulation system. For example, the controller is connected to the electronic expansion valve 41 by signal, and the electronic expansion valve 41 can adjust its opening according to the control instruction sent by the controller.

[0050] refer to Figure 3In some embodiments, the first control valve 40 includes: a throttle valve 42 and a switching valve 43 connected in parallel. The switching valve 43 is configured to conduct the refrigerant flow path where the switching valve 43 is located under the defrosting condition, and disconnect the refrigerant flow path where the switching valve 43 is located under the cooling condition or the heating condition. The throttle valve 42 can use a throttling element such as a capillary tube. The controller can be connected to the switching valve 43 by signal, and the switching valve 43 can conduct or disconnect the refrigerant flow path where it is located according to the control command issued by the controller.

[0051] When the switching valve 43 cuts off the refrigerant flow path where it is located, the throttle valve 42 is equivalent to a throttling element of the refrigerant circulation circuit. When the switching valve 43 is turned on, the pressure drop of the refrigerant flow path where it is located is less than the pressure drop of the refrigerant flow path where the throttle valve 42 is located, so that the high-temperature refrigerant of the first heat exchanger 20 mainly flows into the second heat exchanger 30 through the switching valve 43 to achieve hot gas defrosting.

[0052] Considering that the heat accumulated when the first heat exchanger 20 acts as a condenser under cooling or heating conditions may not be sufficient to achieve defrosting of the second heat exchanger 30, refer to Figure 4 and Figure 5 In some embodiments, the refrigerant circulation system further includes: a heat exchange device 50 and a second control valve 60. The heat exchange device 50 is disposed on the refrigerant flow path between the second heat exchanger 30 and the suction port of the compressor 10. The second control valve 60 is disposed on the refrigerant flow path between the second heat exchanger 30 and the heat exchange device 50.

[0053] In the cooling condition or the heating condition, the second control valve 60 makes the refrigerant flow path between the second heat exchanger 30 and the heat exchange device 50 in a straight-through state. In the defrosting condition, the second control valve 60 still keeps the refrigerant flow path between the second heat exchanger 30 and the heat exchange device 50 in a straight-through state. If the defrosting effect of the second heat exchanger 30 can meet the preset conditions, there is no need to switch the second control valve 60. When the defrosting effect of the second heat exchanger 30 does not meet the preset conditions, the second control valve 60 makes the refrigerant flow path between the second heat exchanger 30 and the heat exchange device 50 in a throttling state.

[0054] refer to Figure 4 and Figure 5In some embodiments, the refrigerant circulation system further includes: a temperature sensing package 71, which is arranged at the lowest temperature position of the second heat exchanger 30 (for example, the bottom of the second heat exchanger 30, etc.), and is configured to detect the current lowest temperature of the second heat exchanger 30. Accordingly, the preset condition in the aforementioned embodiment is that the current lowest temperature of the second heat exchanger 30 exceeds the first preset temperature (for example, 10°C, etc.) within a first preset time (for example, 15 minutes, etc.). In other embodiments, the preset condition can also take other forms, such as only judging whether the current lowest temperature exceeds the first preset temperature, etc. The temperature of the second heat exchanger may also not be limited to the lowest temperature, for example, the temperatures of multiple positions on the second heat exchanger are collected and the average is taken, or the temperature of the second heat exchanger is collected or calculated by other means.

[0055] Taking the refrigerator as an example, under the defrosting condition, the first control valve switches to the straight-through state and no longer throttles the refrigerant, while the second control valve remains in the straight-through state and does not throttle the refrigerant. At this time, the high-temperature and high-pressure refrigerant in the first heat exchanger can flow directly into the second heat exchanger through the first control valve, defrost the evaporator with hot gas, and flow back to the compressor through the second control valve and the heat exchange device.

[0056] If the defrosting of the second heat exchanger does not reach the end condition, for example, the current minimum temperature of the second heat exchanger does not reach 10°C, or the time of exceeding 10°C does not exceed 15 minutes, the controller issues an instruction to the second control valve 60 so that the second control valve 60 makes the refrigerant flow path between the second heat exchanger 30 and the heat exchange device 50 in a throttling state. In this way, the second control valve 60 is equivalent to a throttling unit in the refrigerant circulation loop, while the first heat exchanger 20 and the second heat exchanger 30 are equivalent to the condenser in the refrigerant circulation loop, and the heat exchange device 50 is equivalent to the evaporator in the refrigerant circulation loop. The heat absorbed by the heat exchange device 50 is transferred to the second heat exchanger along the refrigerant circulation loop, so that the second heat exchanger continues to heat up and defrost.

[0057] exist Figure 4 and Figure 5 In the embodiment, the heat exchange device 50 includes: a heat exchange medium container 51 and a heat exchange sleeve 52. The heat exchange medium container 51 is filled with a liquid heat exchange medium for exchanging heat with the environment. For example, the heat exchange medium container 51 is a water soaking box, and the liquid heat exchange medium is water. The water in the water soaking box can come from the defrosting water discharged from the water receiving tray, and the water is basically consistent with the external environment temperature under the cooling or heating conditions.

[0058] The heat exchange sleeve 52 is connected in series to the refrigerant flow path between the second heat exchanger 30 and the suction port of the compressor 10, and is disposed in the heat exchange medium container 51, and is used to exchange heat between the refrigerant circulating in the heat exchange sleeve 52 and the liquid heat exchange medium. Compared with the heat exchange with air, the liquid heat exchange medium has a certain heat capacity and can provide more heat to the refrigerant circulation system under the defrosting condition.

[0059] In order to reduce the influence of the heat exchange sleeve 52 on the refrigeration cycle when it functions as an evaporator under normal cooling or heating conditions, in some embodiments, the size of the heat exchange sleeve 52 is smaller than that of the second heat exchanger 30 .

[0060] refer to Figure 5 In some embodiments, the first heat exchanger 20 may also be disposed in the heat exchange medium container 51, so as to exchange heat between the refrigerant circulating in the first heat exchanger 20 and the liquid heat exchange medium. In other words, the first heat exchanger 20 and the heat exchange sleeve 52 may be disposed adjacent to each other and both may be immersed in the liquid heat exchange medium in the heat exchange medium container 51, which may further enhance the heat exchange effect.

[0061] In the refrigeration condition, the first heat exchanger 20 acts as a condenser to release heat to the liquid heat exchange medium, causing the temperature of the liquid heat exchange medium to rise, so that the liquid heat exchange medium begins to store heat, for example, the temperature is consistent with that of the first heat exchanger 20, both of which are 40°C. When switched to the defrosting condition, the heat exchange sleeve 52 is equivalent to an evaporator through the switching of the second control valve, and it can absorb heat from the heat-storing liquid heat exchange medium. The absorbed heat is transferred to the second heat exchanger for defrosting as the refrigerant circulates in the refrigerant circulation loop, thereby enhancing the defrosting effect and reducing the defrosting time.

[0062] In addition, refer to Figure 4 and Figure 5 In some embodiments, the refrigerant circulation system may further include: an anti-condensation pipe 72 and / or a filter 73. The anti-condensation pipe 72 is connected in series to the refrigerant flow path between the first control valve 40 and the first heat exchanger 20, and can be used as a condenser with the first heat exchanger 20 under refrigeration conditions. The filter 73 is connected in series to the refrigerant flow path between the first heat exchanger 20 and the first control valve 40, and can filter the refrigerant before it enters the first control valve, and filter out impurities in the refrigerant.

[0063] The various embodiments of the above-mentioned refrigerant circulation system disclosed in the present invention can be applied to various types of refrigeration / heating equipment with defrosting requirements, such as refrigerators, air conditioners, etc. Therefore, the present invention also provides a refrigerator, including the above-mentioned refrigerant circulation system embodiment. The refrigerator may also include: a freezer compartment, wherein the second heat exchanger 30 in the refrigerant circulation system acts as an evaporator under refrigeration conditions to control the temperature of the freezer compartment. In addition, the present invention also provides an air conditioner (such as a household air conditioner), including the above-mentioned refrigerant circulation system. The air conditioner may also include: an outdoor unit, wherein the second heat exchanger 30 in the refrigerant circulation system is arranged in the outdoor unit, and acts as an evaporator under heating conditions to absorb heat outdoors.

[0064] Based on the above-mentioned embodiments of the refrigerant circulation system, the present disclosure also provides corresponding embodiments of the defrosting method. The defrosting method includes: when the working condition of the refrigerant circulation system is switched from the cooling condition or the heating condition to the defrosting condition, a control instruction is sent to the first control valve 40 so that the first control valve 40 switches the refrigerant flow path between the first heat exchanger 20 and the second heat exchanger 30 from the throttling state to the straight-through state. Each step of the defrosting method can be completed by the controller in the refrigerant circulation system calling the program instructions in the memory.

[0065] Figure 7 Schematic diagram of some embodiments of the defrosting method disclosed in the present invention. Figure 7 In some embodiments, the defrosting method may include step 100 and step 200. In step 100, when the working condition of the refrigerant circulation system is switched from the cooling condition or the heating condition to the defrosting condition, a control instruction is sent to the first control valve 40. In step 200, according to the received control instruction, the first control valve 40 switches the refrigerant flow path between the first heat exchanger 20 and the second heat exchanger 30 from the throttling state to the straight-through state.

[0066] In this embodiment, the first control valve acts as a throttling unit between the condenser and the evaporator in the refrigeration condition or the heating condition, and no longer throttles in the defrosting condition, so that the high-temperature and high-pressure refrigerant in the condenser flows directly into the evaporator to perform hot gas defrosting on the evaporator. Since hot gas defrosting and defrosting are performed inside the evaporator, mainly by conduction heat exchange, compared with the defrosting method of heating the air with the evaporator by convection or directly radiating and heating the evaporator in the related art, no additional power is required, thereby reducing the power input during the defrosting process, and compared with the electric heating method, the defrosting effect is faster and the defrosting temperature rise is smaller.

[0067] Figure 8 Schematic diagram of the process flow of other embodiments of the defrosting method disclosed in the present invention. Figure 8In some embodiments, the refrigerant circulation system further includes a heat exchange device 50 and a second control valve 60, wherein the heat exchange device 50 is disposed on the refrigerant flow path between the second heat exchanger 30 and the suction port of the compressor 10, and the second control valve 60 is disposed on the refrigerant flow path between the second heat exchanger 30 and the heat exchange device 50. Accordingly, the defrosting method further includes steps 300 to 500.

[0068] In step 300, it is determined whether the defrosting effect of the second heat exchanger 30 meets the preset condition under the defrosting condition. If the preset condition is met, the process goes to step 500, otherwise, the process goes to step 400. The preset condition here can be that the current minimum temperature of the second heat exchanger 30 exceeds a first preset temperature (e.g., 10° C., etc.) within a first preset time (e.g., 15 minutes, etc.).

[0069] In step 400, a control instruction is sent to the second control valve 60 so that the second control valve 60 switches the refrigerant flow path between the second heat exchanger 30 and the heat exchange device 50 from a straight-through state to a throttling state. In this way, the second control valve 60 is equivalent to a throttling unit in the refrigerant circulation loop, while the first heat exchanger 20 and the second heat exchanger 30 are equivalent to a condenser in the refrigerant circulation loop, and the heat exchange device 50 is equivalent to an evaporator in the refrigerant circulation loop. The heat absorbed by the heat exchange device 50 is transferred to the second heat exchanger along the refrigerant circulation loop, so that the second heat exchanger continues to heat up and defrost.

[0070] In step 500, the refrigerant circulation system is exited from the defrosting state, for example, switched to the cooling state or the heating state.

[0071] For equipment such as refrigerators that need to maintain a low temperature in some of their internal spaces (such as the freezer), the conditions for starting defrosting and the duration of defrosting have an impact on the defrosting effect and the degree of temperature rise in the freezer. In order to reduce the impact of the defrosting process on the freezer, segmented defrosting control can be achieved by controlling the conditions for entering the defrosting state.

[0072] Fig. 9 This is a schematic diagram comparing the temperature rise during multiple defrosting according to some embodiments of the refrigerant circulation system disclosed herein and defrosting using related technologies using an electric heater. Fig. 9 Curve A is the temperature rise curve of the refrigerator freezer room using an electric heater for defrosting, and curve B is the temperature rise curve of the refrigerator freezer room including the refrigerant circulation system of this embodiment. Relative to the time when the last defrosting was completed, the time t corresponding to the re-entry into the defrosting condition of curve A A (e.g. 56 hours) later than the time t corresponding to the B curve to re-enter the defrosting condition B (For example, 20 hours), and the time interval between two consecutive entering defrosting conditions of curve B is short, thereby achieving the effect of multiple defrosting.

[0073] In the defrosting process of the two methods, the temperature peak T of curve A A The temperature peak T above the B curve B , and T B Compared with the temperature difference of the freezer before and after defrosting, the difference in the temperature value of the freezer is smaller, so the storage conditions in the freezer are less affected. Since the electric heater defrosting method heats up too quickly, it can usually only reduce the impact by increasing the interval of entering the defrosting condition, but this will easily make the frost layer thicker and affect the working effect of the second heat exchanger. Using short time intervals and multiple hot air defrosting will have less impact on the temperature rise of the freezer, and the frost layer will be thinner and the defrosting time will be shorter.

[0074] Therefore, in some embodiments of the present disclosure, the defrosting method may further include: when the operating condition of the refrigerant circulation system is in the refrigeration condition or the heating condition, when it is determined that the current minimum temperature of the second heat exchanger 30 is lower than a second preset temperature (e.g., -24°C, etc.) within a second preset time period (e.g., 20 hours, etc.), the operating condition of the refrigerant circulation system is switched from the refrigeration condition or the heating condition to the defrosting condition.

[0075] The second preset duration here can be adjusted according to actual conditions. Accordingly, in some embodiments, the defrosting method further includes: determining the moisture content of the object for which the second heat exchanger 30 is used as an evaporator for temperature control; adjusting the second preset duration according to the moisture content and defrosting duration of the object. Taking the object as a refrigerator freezer as an example, when determining the moisture content, the air volume, the humidity and temperature state of the air in the box can be determined according to the actual volume of the refrigerator and the temperature and humidity sensor of the refrigerator, so that the total moisture content can be calculated. In addition, the increase in moisture content can also be determined according to the number and duration of opening and closing the door.

[0076] The initial value of the second preset time can be determined according to the calculated total moisture content. In the actual defrosting process, the second preset time can be adjusted according to the change of moisture content in the freezer and the actual defrosting time. For example, if the previous defrosting time (e.g. 3 minutes) is short, for example, it is about 1 / 5 of the longest defrosting time (e.g. 15 minutes), it means that the frost layer of the second heat exchanger is not thick, and the second preset time before entering the defrosting condition can be extended accordingly, for example, the second preset time can be increased by 5 hours. On the contrary, if the previous defrosting time is long, the second preset time before entering the defrosting condition can be shortened.

[0077] The above duration and temperature parameters can be determined according to different ambient temperatures, different humidity conditions, different refrigerator volumes, different door opening and closing times and durations, whether the refrigerator is empty or fully loaded, etc. For example, tests can be conducted in advance in the laboratory to form a database, and the actual operating parameters can be compared and selected based on the database to intelligently determine the conditions for entering the defrosting state each time.

[0078] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0079] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A refrigerant circulation system, characterized in that: include: Compressor (10); A first heat exchanger (20) is connected to a discharge port of the compressor (10) via a refrigerant flow path; A second heat exchanger (30), both ends of which are connected to the first heat exchanger (20) and the suction port of the compressor (10) through refrigerant flow paths; A first control valve (40) is arranged between the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30), and is configured to make the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30) in a throttling state under a cooling condition or a heating condition, and to make the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30) in a straight-through state under a defrosting condition; a heat exchange device (50) disposed on a refrigerant flow path between the second heat exchanger (30) and a suction port of the compressor (10); and The second control valve (60) is arranged on the refrigerant flow path between the second heat exchanger (30) and the heat exchange device (50), and is configured to make the refrigerant flow path between the second heat exchanger (30) and the heat exchange device (50) in a straight-through state under the cooling condition or the heating condition, and to make the refrigerant flow path between the second heat exchanger (30) and the heat exchange device (50) in a throttling state when the defrosting effect of the second heat exchanger (30) does not meet the preset conditions under the defrosting condition.

2. The refrigerant circulation system according to claim 1, characterized in that: The first control valve (40) comprises: an electronic expansion valve (41) connected in series on the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30), the opening of the electronic expansion valve (41) being set to a maximum opening in the defrosting condition, and being set to a non-maximum opening in the cooling condition or the heating condition.

3. The refrigerant circulation system according to claim 1, characterized in that: The first control valve (40) comprises: a throttle valve (42) and a switching valve (43) connected in parallel with each other, wherein the switching valve (43) is configured to conduct the refrigerant flow path where the switching valve (43) is located under the defrosting condition, and to disconnect the refrigerant flow path where the switching valve (43) is located under the cooling condition or the heating condition.

4. The refrigerant circulation system according to claim 1, characterized in that: The heat exchange device (50) comprises: a heat exchange medium container (51), filled with a liquid heat exchange medium for exchanging heat with the environment; and The heat exchange sleeve (52) is connected in series on the refrigerant flow path between the second heat exchanger (30) and the suction port of the compressor (10), and is arranged in the heat exchange medium container (51) to enable the refrigerant circulating in the heat exchange sleeve (52) to exchange heat with the liquid heat exchange medium.

5. The refrigerant circulation system according to claim 4, characterized in that: The heat exchange medium container (51) is a water soaking box, and the liquid heat exchange medium is water.

6. The refrigerant circulation system according to claim 4, characterized in that: The size of the heat exchange sleeve (52) is smaller than the size of the second heat exchanger (30).

7. The refrigerant circulation system according to claim 4, characterized in that: The first heat exchanger (20) is also arranged in the heat exchange medium container (51) and is used to allow the refrigerant circulating in the first heat exchanger (20) to exchange heat with the liquid heat exchange medium.

8. The refrigerant circulation system according to claim 1, characterized in that: Also includes: A temperature sensing package (71), arranged at the lowest temperature position of the second heat exchanger (30), and configured to detect the current lowest temperature of the second heat exchanger (30); The preset condition is that the current minimum temperature of the second heat exchanger (30) exceeds a first preset temperature within a first preset time period.

9. The refrigerant circulation system according to claim 1, characterized in that: Also includes: an anti-condensation pipe (72) connected in series to a refrigerant flow path between the first control valve (40) and the first heat exchanger (20); and / or The filter (73) is connected in series in the refrigerant flow path between the first heat exchanger (20) and the first control valve (40).

10. The refrigerant circulation system according to claim 1, characterized in that: Also includes: A controller is signal-connected to the first control valve (40) and the second control valve (60), and is configured to switch the operating conditions of the refrigerant circulation system and send control instructions to the first control valve (40) and the second control valve (60) according to the operating conditions of the refrigerant circulation system.

11. A refrigerator, characterized in that: include: A refrigerant circulation system according to any one of claims 1 to 10.

12. The refrigerator according to claim 11, characterized in that: Also includes: A freezer compartment, wherein the second heat exchanger (30) in the refrigerant circulation system acts as an evaporator under refrigeration conditions to control the temperature of the freezer compartment.

13. An air conditioner, characterized in that: include: A refrigerant circulation system according to any one of claims 1 to 10.

14. The air conditioner according to claim 13, characterized in that: Also includes: An outdoor unit, wherein the second heat exchanger (30) in the refrigerant circulation system is arranged in the outdoor unit and serves as an evaporator in a heating condition to absorb heat outdoors.

15. A defrosting method for a refrigerant circulation system according to any one of claims 1 to 10, characterized in that: include: When the operating condition of the refrigerant circulation system is switched from a cooling condition or a heating condition to a defrosting condition, a control instruction is sent to the first control valve (40) so that the first control valve (40) switches the refrigerant flow path between the first heat exchanger (20) and the second heat exchanger (30) from a throttling state to a straight-through state.

16. The defrosting method according to claim 15, characterized in that: The refrigerant circulation system further comprises a heat exchange device (50) and a second control valve (60), wherein the heat exchange device (50) is arranged on the refrigerant flow path between the second heat exchanger (30) and the suction port of the compressor (10), and the second control valve (60) is arranged on the refrigerant flow path between the second heat exchanger (30) and the heat exchange device (50); wherein the defrosting method further comprises: If, under the defrosting condition, the defrosting effect of the second heat exchanger (30) does not meet the preset conditions, a control instruction is sent to the second control valve (60) so that the second control valve (60) switches the refrigerant flow path between the second heat exchanger (30) and the heat exchange device (50) from a straight-through state to a throttling state.

17. The defrosting method according to claim 16, characterized in that: The preset condition is that the current minimum temperature of the second heat exchanger (30) exceeds a first preset temperature within a first preset time period.

18. The defrosting method according to claim 15, characterized in that: Also includes: When the operating condition of the refrigerant circulation system is in the cooling condition or the heating condition, when it is determined that the current minimum temperature of the second heat exchanger (30) is lower than the second preset temperature within a second preset time period, the operating condition of the refrigerant circulation system is switched from the cooling condition or the heating condition to the defrosting condition.

19. The defrosting method according to claim 18, characterized in that: Also includes: determining a moisture content of an object for which the second heat exchanger (30) is temperature-controlled as an evaporator; The second preset time period is adjusted according to the moisture content of the object and the defrosting time period.

Images