Heat exchanger, air conditioner outdoor unit and air conditioner

Abstract

The utility model relates to the technical field of air conditioning, and discloses a heat exchanger which comprises a plurality of heat exchange units connected in parallel, each heat exchange unit comprises a plurality of heat exchange channels and can switch the series-parallel connection state of the heat exchange channels, the heat exchange units are connected with a throttling device in series, and the throttling device can switch a conduction mode and a throttling mode. When the throttling device is in the conduction mode, a refrigerant enters the heat exchange unit through the throttling device to defrost the heat exchange unit, and when the throttling device is in the throttling mode, the refrigerant is throttled and depressurized when passing through the throttling device. The utility model further discloses an air conditioner outdoor unit and an air conditioner.

Description

Technical Field

[0001] This application relates to the technical field of air conditioning, for example, to a heat exchanger, an outdoor unit of an air conditioner, and an air conditioner. Background Art

[0002] When the air conditioner operates in the heating mode, the outdoor heat exchanger serves as an evaporator. The temperature of the outdoor heat exchanger is relatively low, and water vapor in the air easily forms a frost layer attached to the outdoor heat exchanger. After the outdoor heat exchanger is frosted, its heat exchange capacity decreases. If defrosting is not carried out, the heating of the air conditioner cannot continue. Some air conditioners perform defrosting by reversing the four-way valve, but after the four-way valve is reversed, the heating of the air conditioner will be interrupted, affecting the comfort of the indoor environment.

[0003] In order to enable the air conditioner to still operate in the heating mode during defrosting, a segmented defrosting air conditioner is disclosed in the related art. The air conditioner includes an outdoor unit and an indoor unit. The outdoor unit includes a compressor, an outdoor heat exchanger, and a total throttling device. The indoor unit includes an indoor heat exchanger. The outdoor heat exchanger is divided into several segments, and a throttling device is provided between each segment of the outdoor heat exchanger and the total throttling device. Through segmented defrosting of the outdoor heat exchanger in the related art, uninterrupted heating and defrosting can be achieved, so that the room temperature does not decrease significantly during the defrosting process.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0005] The multiple segments of the outdoor heat exchanger are connected in parallel. When the outdoor heat exchanger serves as a condenser, the gaseous refrigerant is divided into multiple paths and flows through multiple segments in the outdoor heat exchanger. The travel of the gaseous refrigerant is relatively short, and it is difficult to obtain sufficient subcooling degree. The refrigeration effect of the air conditioner needs to be further improved.

[0006] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0007] To have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. The summary is not a general review, nor is it intended to identify key / important constituent elements or delineate the protection scope of these embodiments, but rather serves as a preface to the subsequent detailed description.

[0008] The embodiments of the present disclosure provide a heat exchanger, an outdoor unit of an air conditioner, and an air conditioner, so that the air conditioner can perform segmented defrosting and improve the refrigeration effect of the air conditioner.

[0009] In some embodiments, the heat exchanger includes a plurality of heat exchange units connected in parallel. Each heat exchange unit includes a plurality of heat exchange passages, and the series-parallel state of the plurality of heat exchange passages can be switched. A throttling device is connected in series with the heat exchange unit. The throttling device can switch between a conduction mode and a throttling mode. When the throttling device is in the conduction mode, the refrigerant passes through the throttling device and enters the heat exchange unit to defrost the heat exchange unit. When the throttling device is in the throttling mode, the refrigerant is throttled and depressurized when passing through the throttling device.

[0010] In some embodiments, the throttling device is an electronic expansion valve, and the opening degree of the electronic expansion valve can be continuously adjusted.

[0011] In some embodiments, the plurality of heat exchange units include a first heat exchange unit and a second heat exchange unit, and the second heat exchange unit is located below the first heat exchange unit.

[0012] In some embodiments, the heat exchanger includes a gas collecting pipe, a liquid collecting pipe, a first throttling device, and a second throttling device. Among them, the gas collecting pipe is provided with a first inlet and outlet, and the first interfaces of the first heat exchange unit and the second heat exchange unit are connected to the gas collecting pipe; the liquid collecting pipe is provided with a second inlet and outlet, and the second interfaces of the first heat exchange unit and the second heat exchange unit are connected to the liquid collecting pipe; the first throttling device is arranged between the second interface of the first heat exchange unit and the liquid collecting pipe; the second throttling device is arranged between the second interface of the second heat exchange unit and the liquid collecting pipe.

[0013] In some embodiments, the heat exchanger further includes a first temperature sensor, a second temperature sensor, and a control unit. Among them, the first temperature sensor is used to obtain the temperature of the first heat exchange unit; the second temperature sensor is used to obtain the temperature of the second heat exchange unit. The control unit is configured to control the first throttling device to close when the temperature of the first heat exchange unit is lower than a preset temperature, and / or the control unit is configured to control the second throttling device to close when the temperature of the second heat exchange unit is lower than a preset temperature.

[0014] In some embodiments, the heat exchanger further includes a total throttling device, and the total throttling device is connected to the second inlet and outlet of the liquid collecting pipe. When the heat exchanger is used as an evaporator, the refrigerant flows through the total throttling device and the liquid collecting pipe in sequence.

[0015] In some embodiments, the heat exchange unit of the heat exchanger further includes a on-off control component, and the on-off control component is connected in series with the heat exchange unit. The on-off control component and the throttling device are respectively located at both ends of the heat exchange unit.

[0016] In some embodiments, the heat exchange unit includes a plurality of refrigerant pipes, a first manifold assembly, a second manifold assembly, and a valve assembly. Among them, the plurality of refrigerant pipes form the plurality of heat exchange passages; the first manifold assembly is provided with a first interface, and the first end of each heat exchange passage is connected to the first manifold assembly; the second manifold assembly is provided with a second interface, and the second end of each heat exchange passage is connected to the second manifold assembly; the valve assembly is disposed between the first manifold assembly and the second manifold assembly, and the valve assembly is used to switch the series-parallel states of the plurality of heat exchange passages.

[0017] In some embodiments, the outdoor unit of the air conditioner includes the above-mentioned heat exchanger and a plurality of fans, and the plurality of fans are arranged corresponding to the plurality of heat exchange units.

[0018] In some embodiments, the air conditioner includes the above-mentioned heat exchanger, and the heat exchanger is installed in the indoor unit and / or the outdoor unit of the air conditioner.

[0019] In some embodiments, the air conditioner includes the above-mentioned outdoor heat exchanger.

[0020] The heat exchanger, the outdoor unit of the air conditioner, and the air conditioner provided by the embodiments of the present disclosure can achieve the following technical effects:

[0021] The heat exchanger can achieve segmented defrosting so that the heating for the room can be continuous, improving the comfort experience of heating; the heat exchange unit of the heat exchanger can switch the series-parallel states of the plurality of heat exchange passages. When the heat exchanger is used as a condenser, the evaporation branches are fewer, and when it is used as an evaporator, the evaporation branches are more, improving the refrigeration and heating energy efficiency of the air conditioner.

[0022] The above general description and the following description are only exemplary and explanatory, and are not used to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent elements shown to be similar. The drawings do not constitute a scale limitation, and among them:

[0024] Figure 1 is a schematic structural diagram of a heat exchanger provided by an embodiment of the present disclosure;

[0025] Figure 2 is a schematic structural diagram of a heat exchange unit of a heat exchanger provided by an embodiment of the present disclosure;

[0026] Figure 3 is a schematic structural diagram of a heat exchange unit of another heat exchanger provided by an embodiment of the present disclosure;

[0027] Figure 4It is a schematic diagram of a heat exchanger provided by an embodiment of the present disclosure when used as an evaporator;

[0028] Figure 5 It is a schematic diagram of a heat exchanger provided by an embodiment of the present disclosure when used as a condenser;

[0029] Figure 6 It is a schematic diagram of the heat exchange unit of the heat exchanger provided by an embodiment of the present disclosure when storing liquid;

[0030] Figure 7 It is a schematic diagram of the structure of an air conditioner provided by an embodiment of the present disclosure.

[0031] Reference numerals:

[0032] 100: Heat exchange unit; 101: First heat exchange unit; 102: Second heat exchange unit; 110: Heat exchange passage; 111: First heat exchange passage; 112: Second heat exchange passage; 113: Third heat exchange passage; 120: Throttling device; 121: First throttling device; 122: Second throttling device; 131: First confluence component; 132: Second confluence component; 133: Valve component; 134: First valve member; 135: Second valve member; 136: First interface; 137: Second interface; 210: Gas collecting pipe; 211: First inlet and outlet; 220: Liquid collecting pipe; 221: Second inlet and outlet; 231: First temperature sensor; 232: Second temperature sensor; 410: On-off control component; 51: Compressor; 52: Total throttling device; 53: Indoor heat exchanger; 54: First fan; 55: Second fan. Detailed implementation manners

[0033] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are only for reference and illustration purposes and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of explanation, multiple details are provided to fully understand the disclosed embodiments. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be shown in a simplified manner.

[0034] The terms "first", "second", etc. in the description and claims of the embodiments of the present disclosure and the above-mentioned accompanying drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0035] In the embodiments of the present disclosure, the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "middle", "outer", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the embodiments of the present disclosure and their examples, and are not used to limit that the indicated devices, elements, or components must have a specific orientation, or be constructed and operated in a specific orientation. Moreover, in addition to being used to represent an orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0036] In addition, the terms "arrangement", "connection", and "fixation" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there can be internal communication between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0037] Unless otherwise specified, the term "plurality" means two or more.

[0038] In the embodiments of the present disclosure, the character " / " indicates that the objects before and after are in an "or" relationship. For example, A / B means: A or B.

[0039] The term "and / or" is a description of the associated relationship of an object, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B these three relationships.

[0040] It should be noted that, without conflict, the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0041] When the air conditioner operates in the heating mode, the outdoor heat exchanger serves as an evaporator. The temperature of the outdoor heat exchanger is relatively low, and water vapor in the air easily forms a frost layer adhering to the outdoor heat exchanger. After the outdoor heat exchanger is frosted, its heat exchange capacity decreases. If defrosting is not carried out, the heating of the air conditioner cannot continue. Some air conditioners defrost by reversing the four-way valve, but after the four-way valve is reversed, the heating of the air conditioner will be interrupted, affecting the comfort of the indoor environment. In order to enable the air conditioner to still operate in the heating mode during defrosting, a segmented defrosting air conditioner is disclosed in the related art. The air conditioner includes an outdoor unit and an indoor unit. The outdoor unit includes a compressor, an outdoor heat exchanger, and a total throttling device. The indoor unit includes an indoor heat exchanger. The outdoor heat exchanger is divided into several segments, and a throttling device is provided between each segment of the outdoor heat exchanger and the total throttling device. The related art can achieve uninterrupted heating and defrosting by segmentally defrosting the outdoor heat exchanger, so that the room temperature does not decrease significantly during the defrosting process.

[0042] The problem of the related art is that multiple segments of the outdoor heat exchanger are connected in parallel. When the outdoor heat exchanger serves as a condenser, the gaseous refrigerant is divided into multiple paths and flows through multiple segments in the outdoor heat exchanger. The travel of the gaseous refrigerant is short, and it is difficult to obtain sufficient subcooling degree. The refrigeration effect of the air conditioner needs to be further improved.

[0043] In order to enable the air conditioner to defrost in segments and improve the refrigeration effect of the air conditioner, in combination with Figure 1-7 As shown, an embodiment of the present disclosure provides a heat exchanger. The heat exchanger includes a plurality of heat exchange units 100 connected in parallel. Each heat exchange unit includes a plurality of heat exchange paths 110 and can switch the series-parallel state of the plurality of heat exchange paths. A throttling device 120 is connected in series with the heat exchange unit 100. The throttling device 120 can switch between a conduction mode and a throttling mode. When the throttling device 120 is in the conduction mode, the refrigerant enters the heat exchange unit through the throttling device to defrost the heat exchange unit. When the throttling device 120 is in the throttling mode, the refrigerant is throttled and depressurized when passing through the throttling device, and then enters the heat exchange unit 100 and evaporates and absorbs heat in the heat exchange unit.

[0044] In the embodiment of the present disclosure, the heat exchange unit 100 is an independent heat exchange structure. The independence of the heat exchange unit is reflected in the first interface 136 and the second interface 137 it has. The flow direction of the refrigerant in the heat exchange unit is from the first interface 136 to the second interface 137, or from the second interface 137 to the first interface 136.

[0045] A plurality of heat exchange units 100 are connected in parallel, and the refrigerant flowing through the evaporator is distributed among the plurality of heat exchange units.

[0046] The heat exchange unit 100 of the heat exchanger is a heat exchange unit with variable flow paths. Specifically, each heat exchange unit 100 includes a plurality of heat exchange paths 110, and the plurality of heat exchange paths 110 can be controlled to switch the series-parallel state.

[0047] Taking one usage mode as an example: when the heat exchanger is used as an evaporator, multiple heat exchange passages 110 of the heat exchange unit 100 are switched to a parallel connection state, and the liquid refrigerant flows from the second interface 137 to the first interface 136. Since the multiple heat exchange passages of the heat exchange unit are in a parallel connection state, this can reduce the pressure drop of the liquid refrigerant in the heat exchange unit. The flow resistance of the liquid refrigerant in the heat exchange unit is small, and the liquid refrigerant can quickly evaporate and absorb heat in the heat exchange unit.

[0048] Taking another usage mode as an example: when the heat exchanger is used as a condenser, multiple heat exchange passages 110 of the heat exchange unit 100 are connected in series, and the gaseous refrigerant flows from the first interface 136 to the second interface 137. Since the multiple heat exchange passages of the heat exchange unit are in a series connection state, the travel of the gaseous refrigerant in the heat exchange unit is longer. The longer travel of the gaseous refrigerant is beneficial to the full heat release and condensation of the gaseous refrigerant, and can make the condensed refrigerant obtain a certain degree of subcooling.

[0049] In a usage scenario, the above heat exchanger is installed in the outdoor unit of the air conditioner and acts as a condenser when the air conditioner cools and as an evaporator when the air conditioner heats.

[0050] When the air conditioner operates in the heating mode, the above heat exchanger acts as an evaporator, and a frost layer gradually appears after operating for a period of time.

[0051] When the heat exchange unit does not need defrosting, the throttling device connected in series with the heat exchange unit is switched to the throttling mode. The refrigerant flowing out of the indoor unit is throttled and depressurized by the throttling device and then enters the heat exchange unit, and evaporates and absorbs heat in the heat exchange unit to enrich the low-grade heat outdoors.

[0052] When the heat exchange unit needs defrosting, the throttling device connected in series with the heat exchange unit is switched to the conduction mode. The refrigerant flowing out of the indoor unit still has a certain temperature, does not depressurize after passing through the throttling device, and then exchanges heat with the frost layer through the heat exchange tube in the heat exchange unit, thereby melting the frost layer of the heat exchange unit.

[0053] Since the multiple heat exchange units are in a series connection state, the heat exchange units that do not need defrosting play an evaporation role, and the heat exchange units that need defrosting are defrosted, and there will be no interference between them. When defrosting one heat exchange unit of the outdoor heat exchanger, the heating indoors will not be interrupted.

[0054] The throttling device can be switched between the conduction mode and the throttling mode by adjusting the opening degree of the throttling device. Exemplarily, when the opening degree of the throttling device is less than or equal to the preset opening degree, the throttling device is switched to the throttling mode, and when the opening degree of the throttling device is greater than the preset opening degree, the throttling device is switched to the conduction mode.

[0055] When defrosting the heat exchange unit, if the refrigerant entering the heat exchange unit is mainly in a liquid state, it is preferable to switch the multiple heat exchange passages of the heat exchange unit to a parallel connection state. This can reduce the refrigerant pressure drop, increase the refrigerant flow rate, and thus improve the defrosting speed. If the refrigerant entering the heat exchange unit is mainly in a gaseous state, it is preferable to switch the multiple heat exchange passages of the heat exchange unit to a series state. This can increase the travel distance of the gaseous refrigerant in the heat exchange unit and enhance the heat exchange effect between the gaseous refrigerant and the frost layer.

[0056] Using the heat exchanger provided by the embodiments of the present disclosure, the heat exchanger can achieve segmented defrosting, so that the heating of the room can be continuous, improving the comfort experience of heating; the heat exchange unit of the heat exchanger can switch the series-parallel states of multiple heat exchange passages, and can switch the series-parallel states of multiple heat exchange passages according to the gas-liquid ratio of the refrigerant during defrosting, thereby improving the defrosting efficiency of the air conditioner. When the heat exchanger is used as a condenser, the evaporation branch is less, and when it is used as an evaporator, the evaporation branch is more, improving the refrigeration and heating energy efficiency of the air conditioner.

[0057] Optionally, the throttling device is an electronic expansion valve, and the opening degree of the electronic expansion valve can be continuously adjusted.

[0058] Using an electronic expansion valve as the throttling device can achieve precise control of the refrigerant flow rate, thereby improving the energy efficiency and comfort of the air conditioning system. The opening degree of the electronic expansion valve can be continuously adjusted, and it can accurately adjust the refrigerant flow rate according to the change of the system load to meet different refrigeration or heating requirements.

[0059] Optionally, the multiple heat exchange units include a first heat exchange unit 101 and a second heat exchange unit 102, and the second heat exchange unit 102 is located below the first heat exchange unit 101.

[0060] The heat exchanger includes multiple heat exchange units, and the multiple heat exchange units are arranged vertically. When the outdoor heat exchanger is frosted, since the condensed water will drip from top to bottom, the thickness of the frost layer also gradually increases from top to bottom. The multiple heat exchange units are arranged vertically, and the heat exchanger can be defrosted for different durations and / or with different intensities according to the thickness of the frost layer. In addition, since the heat exchange tubes are arranged horizontally, the vertical arrangement of the heat exchange units can reduce the interference between the heat exchange units for defrosting and the heat exchange units acting as evaporators when the air flows through the heat exchanger compared with the front-back arrangement.

[0061] The multiple heat exchange units include a first heat exchange unit 101 and a second heat exchange unit 102, that is, at least a part of the heat exchange units in the heat exchanger have the characteristic of vertical arrangement, so they have the above technical effects. In this case, "including" means non-exclusive inclusion.

[0062] Optionally, the heat exchanger includes a gas collecting pipe 210, a liquid collecting pipe 220, a first throttling device 121, and a second throttling device 122. Among them, the gas collecting pipe 210 is provided with a first inlet / outlet 211, and the first interfaces 136 of the first heat exchange unit 101 and the first interfaces 136 of the second heat exchange unit 102 are connected to the gas collecting pipe 210; the liquid collecting pipe 220 is provided with a second inlet / outlet 221, and the second interfaces 137 of the first heat exchange unit 101 and the second interfaces 137 of the second heat exchange unit 102 are connected to the liquid collecting pipe 220; the first throttling device 121 is arranged between the second interface 137 of the first heat exchange unit 101 and the liquid collecting pipe 220; the second throttling device 122 is arranged between the second interface 137 of the second heat exchange unit 102 and the liquid collecting pipe 220.

[0063] As a whole, the heat exchange unit has a first interface 136 and a second interface 137 facing outward. The first interfaces 136 of multiple heat exchange units are connected to the gas collecting pipe 210, and the second interfaces 137 of multiple heat exchange units are connected to the liquid collecting pipe 220, so as to realize the parallel connection of multiple heat exchange units. The throttling device is located between the second interface 137 of the heat exchange unit and the liquid collecting pipe 220. Specifically, when the heat exchanger includes a first heat exchange unit 101 and a second heat exchange unit 102, the first throttling device 121 is located between the second interface 137 of the first heat exchange unit 101 and the liquid collecting pipe 220, and the second throttling device 122 is located between the second interface 137 of the second heat exchange unit 102 and the liquid collecting pipe 220.

[0064] When the heat exchanger is used as a condenser, the refrigerant flows from the first inlet / outlet 211 through the heat exchange unit to the second inlet / outlet 221. When the heat exchanger is used as an evaporator, the refrigerant flows from the second inlet / outlet 221 through the heat exchange unit to the first inlet / outlet 211. When the heat exchanger is used as an evaporator and the heat exchange unit is defrosting, the refrigerant flows from the second inlet / outlet 221 through the heat exchange unit to the first inlet / outlet 211.

[0065] With such a setting form, when the heat exchanger is used as an evaporator, the liquid refrigerant first flows through the corresponding throttling device and then enters the heat exchange path of the heat exchange unit, and the refrigerant can flow in a controlled and orderly manner. When a throttling component is separately provided in the refrigerant circulation system, the throttling device is close to the throttling component in the refrigerant circulation system, which is convenient for switching or replacement.

[0066] Optionally, the heat exchanger further includes a first temperature sensor 231, a second temperature sensor 232, and a control unit. Among them, the first temperature sensor 231 is used to obtain the temperature of the first heat exchange unit 101; the second temperature sensor 232 is used to obtain the temperature of the second heat exchange unit 102. The control unit is configured to control the first throttling device 121 to close when the temperature of the first heat exchange unit 101 is lower than a preset temperature, and / or the control unit is configured to control the second throttling device 122 to close when the temperature of the second heat exchange unit 102 is lower than a preset temperature.

[0067] When the air conditioner operates in the heating mode, the temperature of the heat exchanger is an important indicator for determining whether defrosting is required. Setting the first temperature sensor 231 corresponding to the first heat exchange unit 101 and the second temperature sensor 232 corresponding to the second heat exchange unit 102 is conducive to the control unit of the air conditioner to determine the frosting state based on the temperature of the heat exchange unit and perform defrosting control.

[0068] Specifically, when the temperature of the first heat exchange unit 101 is lower than the preset temperature, it is considered that the first heat exchange unit 101 needs to be defrosted. At this time, the first throttling device 121 switches to the conduction mode, and the refrigerant flowing out of the condenser enters the first heat exchange unit 101 to melt the frost layer on the first heat exchange unit 101. After the defrosting of the first heat exchange unit 101 is completed, the first throttling device 121 switches to the throttling mode so that the refrigerant continues to evaporate and absorb heat in the first heat exchange unit 101. When the temperature of the second heat exchange unit 102 is lower than the preset temperature, it is considered that the second heat exchange unit 102 needs to be defrosted. At this time, the second throttling device 122 switches to the conduction mode, and the refrigerant flowing out of the condenser enters the second heat exchange unit 102 to melt the frost layer on the second heat exchange unit 102. After the defrosting of the second heat exchange unit 102 is completed, the second throttling device 122 switches to the throttling mode so that the refrigerant continues to evaporate and absorb heat in the second heat exchange unit 102. Since the defrosting of the first heat exchange unit 101 and the second heat exchange unit 102 is carried out alternately, the heating operation of the air conditioner will not be interrupted.

[0069] Exemplarily, the preset temperature is greater than or equal to -5°C and less than or equal to 0°C. Preferably, the preset temperature is -2°C.

[0070] After the temperature of the heat exchange unit reaches 0°C, the frost layer begins to form. When the temperature of the heat exchange unit reaches -2°C, it is prompted that the heat exchange capacity of the heat exchange unit decreases, and the frost layer will gradually increase. At this time, the defrosting of the second heat exchange unit 102 is started. When the heat exchange unit is frosted, as the frost layer increases, the thermal conductivity increases, and the temperature drop rate of the heat exchange unit gradually decreases and gradually approaches the outdoor ambient temperature. If the preset temperature is too low, the start of defrosting will be delayed and the defrosting cannot be carried out in time at the beginning of the frost layer. If the preset temperature is too high, the defrosting will start before the frost layer is significantly formed, and the defrosting is too frequent, which has a certain impact on indoor heating.

[0071] It should be noted that when the air conditioner operates in the cooling mode, the temperature of the condenser is always higher than the preset temperature.

[0072] With such a setting method, the air conditioner can automatically defrost and the defrosting start timing is reasonable.

[0073] Optionally, the heat exchanger further includes a total throttling device 52, which is connected to the second inlet / outlet 221 of the liquid collecting pipe 220. When the heat exchanger serves as an evaporator, the refrigerant flows through the total throttling device 52 and the liquid collecting pipe 220 in sequence.

[0074] The total throttling device 52 serves as a throttling component of the refrigerant circulation system. When the air conditioner operates in heating mode and cooling mode other than the defrosting mode, the refrigerant is throttled and reduced by the total throttling device 52. Adopting such a setting method is beneficial to the uniform distribution of the refrigerant among multiple heat exchange units during the refrigeration and heating of the air conditioner.

[0075] Optionally, the heat exchange unit of the heat exchanger further includes an on-off control component 410, which is arranged between the heat exchange unit and the gas collecting pipe 210.

[0076] The heat exchange unit further includes an on-off control component 410, which can enable the heat exchange unit to switch between the liquid storage function and the heat exchange function.

[0077] Specifically, when the heat exchanger serves as an evaporator and the heat exchange unit functions as a liquid storage, the throttling device is opened. The liquid refrigerant enters the heat exchange unit from the second interface 137. At this time, the on-off control component 410 can be opened or closed. When the on-off control component 410 is opened, the pressure difference between the first interface 136 and the second interface 137 of the heat exchange unit is relatively large, and the refrigerant can quickly fill the heat exchange unit under the action of the pressure difference. When the on-off control component 410 is closed, the pressure inside the heat exchange unit is approximately the same as the pressure at the outlet part of the evaporator, and the temperature of the evaporator is relatively low. In a high-pressure and low-temperature environment, the refrigerant can be relatively stably maintained in a liquid state in the heat exchange unit. When the amount of refrigerant inside the heat exchange unit reaches the liquid storage requirement, the on-off control component 410 and the throttling device are closed, and the refrigerant entering the heat exchange unit is temporarily stored. When releasing the temporarily stored refrigerant, the throttling device is opened, and the pressure at the first interface 136 of the heat exchange unit changes, and the liquid refrigerant absorbs heat and evaporates and is sucked into the suction port of the compressor 51.

[0078] When the heat exchanger serves as a condenser and the heat exchange unit functions as a liquid storage unit, the on-off control component is opened, and the gaseous refrigerant enters the heat exchange unit from the first interface 136. At this time, the throttling device can be opened or closed. When the throttling device is open, the gaseous refrigerant has a relatively high flow rate inside the heat exchange unit, exchanges heat with the external environment through the heat exchange tubes, and condenses into a liquid state. When the throttling device is closed, the gaseous refrigerant enters the heat exchange unit at a slower speed, with a better condensation effect, and does not flow out from the first interface 136 after condensing into a liquid state. When the amount of refrigerant inside the heat exchange unit reaches the liquid storage requirement, the on-off control component 410 and the throttling device are closed, and the refrigerant entering the heat exchange unit is temporarily stored. When releasing the temporarily stored refrigerant, the on-off control component 410 and the throttling device are opened. The pressure at the second interface 137 of the heat exchange unit that can be changed is less than the pressure at the first interface 136, and the liquid refrigerant enters the evaporator after throttling and evaporates to absorb heat.

[0079] When the heat exchanger serves as an evaporator and the heat exchange unit functions as a liquid storage unit, the multiple heat exchange paths of the heat exchange unit are preferably switched to a parallel state. After the liquid refrigerant enters the heat exchange unit, the multiple parallel-connected heat exchange paths can increase the speed at which the refrigerant fills the heat exchange unit.

[0080] When the heat exchanger serves as an evaporator and the heat exchange unit functions as a liquid storage unit, the multiple heat exchange paths of the heat exchange unit can also be switched to a series state. The liquid refrigerant flows through the multiple series-connected heat exchange paths, which can discharge the gaseous refrigerant inside the heat exchange unit and increase the amount of refrigerant temporarily stored in the heat exchange unit.

[0081] When the heat exchanger serves as a condenser and the heat exchange unit functions as a liquid storage unit, the multiple heat exchange paths of the heat exchange unit are preferably switched to a series state. After the gaseous refrigerant enters the heat exchange unit, the multiple series-connected heat exchange paths can increase the travel distance of the refrigerant inside the heat exchange unit. With a relatively long travel distance of the gaseous refrigerant, it can fully contact the inner wall of the heat exchange tube for heat exchange, thereby increasing the speed of refrigerant condensation.

[0082] When the heat exchanger serves as a condenser and the heat exchange unit functions as a liquid storage unit, the multiple heat exchange paths of the heat exchange unit can also be switched to a parallel state. The pressure loss of the gaseous refrigerant in the parallel-connected heat exchange paths and the series-connected heat exchange paths differs little. In the case of a relatively long cooling time, the gaseous refrigerant can also be fully condensed into a liquid state.

[0083] The heat exchanger provided by the embodiments of the present disclosure has a heat exchange unit that can switch between a heat exchange function and a liquid storage function, eliminating the need for additional liquid storage components, reducing the volume of the heat exchanger and the cost of the liquid storage device. When the heat exchange unit realizes the liquid storage function, the refrigerant temporarily stored in the heat exchange unit is in a liquid state or a gas-liquid coexistence state, and the heat exchange unit can store a relatively large amount of refrigerant. Through the on-off control of the first on-off control component and the throttling device, the amount of refrigerant stored in the heat exchange unit can be flexibly adjusted, so that the amount of refrigerant participating in the cycle is adapted to the operating conditions of the air conditioner. When the heat exchange unit realizes the heat exchange function, multiple heat exchange paths of the heat exchange unit can achieve "multiple evaporation branches and fewer condensation branches", thereby improving the heat exchange effect of the heat exchanger. Using the heat exchanger provided by the embodiments of the present disclosure can improve the refrigeration and heating efficiency of the air conditioner.

[0084] Optionally, the first interface 136 is higher than the second interface 137.

[0085] When the liquid refrigerant enters the heat exchange unit, it flows from the second interface 137 to the first interface 136. When the heat exchange unit functions as a liquid storage unit and a heat exchange unit, the refrigerant entering the heat exchange unit can cause the gaseous refrigerant to preferentially flow out from the first interface 136 under the action of the density difference between the gaseous and liquid refrigerants. With such a setting, the liquid storage capacity of the heat exchange unit can be improved, and the heat exchange effect of the heat exchange unit can also be improved.

[0086] Optionally, the heat exchange unit includes a plurality of refrigerant pipes, a first confluence component 131, a second confluence component 132, and a valve component 133. Among them, the plurality of refrigerant pipes form a plurality of heat exchange paths; the first confluence component 131 is provided with a first interface 136, and the first end of each heat exchange path is connected to the first confluence component 131; the second confluence component 132 is provided with a second interface 137, and the second end of each heat exchange path is connected to the second confluence component 132; the valve component 133 is disposed between the first confluence component 131 and the second confluence component 132, and the valve component 133 is used to switch the series-parallel states of the plurality of heat exchange paths.

[0087] The heat exchange unit includes a plurality of refrigerant pipes, and the relative positions of the plurality of refrigerant pipes are kept fixed and regarded as a whole. As an alternative embodiment, the heat exchange unit includes a bracket, and the plurality of refrigerant pipes are fixed to the bracket in a substantially parallel form.

[0088] Connect a part of the refrigerant pipes through a card tube or other similar connecting pipe fittings, and this part of the refrigerant pipes forms a heat exchange path in combination. The heat exchange path has a continuous refrigerant flow channel, and the heat exchange path has an inlet end and an outlet end. In the embodiments of the present disclosure, the term "the first end of the heat exchanger path" refers to one of the inlet end and the outlet end, and "the second end of the heat exchange path" refers to the other of the inlet end and the outlet end. It should be noted that the multiple refrigerant pipes combined into a heat exchange path can be in a series connection form, a parallel connection form, or in some cases, a series-parallel combination form, as long as there is an inlet end and an outlet end for the refrigerant. When the diameter of the refrigerant pipe is relatively large, the refrigerant pipes in the heat exchange path are preferably in a series connection form. When the diameter of the refrigerant pipe is relatively small, the refrigerant pipes in the heat exchange path are preferably in a parallel connection form.

[0089] The first end of the heat exchange path is connected to the first confluence component 131, and the second end of the heat exchange path is connected to the second confluence component 132. The valve component 133 is arranged between the first confluence component 131 and the second confluence component 132, and the series-parallel state of multiple heat exchange paths is controlled by the on-off of the valve component 133.

[0090] Specifically, as an implementation manner, multiple refrigerant pipes form at least three heat exchange paths such as the first heat exchange path 111, the second heat exchange path 112, and the third heat exchange path 113. The first ends of the three heat exchange paths are sequentially connected to the first position, the second position, and the third position of the first confluence component 131, and the second ends of the three heat exchange paths are sequentially connected to the fourth position, the fifth position, and the sixth position of the second confluence component 132. The valve component 133 includes a first valve member 134 and a second valve member 135. Among them, the first valve member 134 is arranged on the first confluence component 131 and is located between the first position and the second position; the second valve member 135 is arranged on the second confluence component 132 and is located between the fifth position and the sixth position. When the refrigerant flows from the first interface 136 to the second interface 137, both the first valve member 134 and the second valve member 135 are cut off to connect the three heat exchange paths in series; when the refrigerant flows from the second interface 137 to the first interface 136, both the first valve member 134 and the second valve member 135 are conducted to connect the three heat exchange paths in parallel.

[0091] With such a setting method, the series-parallel state of three heat exchange paths can be switched through two valve members, which facilitates the air conditioner to change the series-parallel form of the heat exchange unit.

[0092] It should be noted that multiple refrigerant pipes can form three-way, five-way or more heat exchange paths. When the number of heat exchange paths exceeds three, some of the heat exchange paths are connected in parallel with the first heat exchange path 111, the second heat exchange path 112 or the third heat exchange path 113. Exemplarily, multiple refrigerant pipes form a first heat exchange path 111, a second heat exchange path 112, a third heat exchange path 113, a fourth heat exchange path, a fifth heat exchange path and a sixth heat exchange path. Among them, the fourth heat exchange path is connected in parallel with the first heat exchange path 111, the fifth heat exchange path is connected in parallel with the second heat exchange path 112, and the sixth heat exchange path is connected in parallel with the third heat exchange path 113. The cases of these heat exchange paths with more than three paths are still within the scope disclosed in the embodiments of the present disclosure.

[0093] Optionally, the first valve member 134 includes a first check valve, and the conduction direction of the first check valve is from the first check valve to the first interface 136.

[0094] When the variable flow splitting unit functions as an evaporator, the refrigerant flows from the second interface 137 to the first interface 136. When the variable flow splitting unit functions as a condenser, the refrigerant flows from the first interface 136 to the second interface 137.

[0095] The first valve member 134 includes a first check valve, and the first check valve can automatically switch between the conducting and cutoff states when the refrigerant flows bidirectionally. By adopting such a setting method, the working reliability of the heat exchange unit can be improved. In addition, compared with a control valve with a control function, the check valve has a lower cost, a simpler structure, and a lower failure rate.

[0096] Optionally, the second valve member 135 includes a second check valve, and the conduction direction of the second check valve is from the second interface 137 to the second check valve.

[0097] The second valve member 135 includes a second check valve, and the second check valve can automatically switch between the conducting and cutoff states when the refrigerant flows bidirectionally. By adopting such a setting method, the working reliability of the heat exchange unit can be improved. In addition, the second valve member 135 includes a second check valve, which can reduce the cost of the heat exchange unit and improve the working reliability of the heat exchange unit.

[0098] The embodiments of the present disclosure provide an outdoor unit of an air conditioner, and the outdoor unit of the air conditioner includes the above-mentioned heat exchanger and multiple fans, and the multiple fans are arranged corresponding to the multiple heat exchange units.

[0099] Combined with Figure 7As shown, the outdoor unit of the air conditioner includes a first fan 54 and a second fan 55. The first fan 54 is arranged corresponding to the first heat exchange unit 101, and the second fan 55 is arranged corresponding to the second heat exchange unit 102. The air conditioner further includes a compressor 51, an indoor heat exchanger 53 and the outdoor unit of the air conditioner. By using the outdoor unit of the air conditioner provided by the embodiments of the present disclosure, alternate defrosting of the heat exchanger can be realized. When the outdoor unit of the air conditioner includes multiple fans, the multiple fans can correspond to the multiple heat exchange units one by one. When defrosting one of the heat exchange units, the corresponding outdoor fan stops rotating. This improves the defrosting speed of the heat exchange unit. Since the outdoor unit of the air conditioner has multiple fans, when defrosting one of the heat exchange units, the remaining fans can still rotate, so that the remaining heat exchange units can still play an evaporation role, enabling the heating of the air conditioner to proceed continuously.

[0100] When the heat exchange unit realizes the liquid storage function, if the refrigerant entering the heat exchange unit is a liquid refrigerant, the fan corresponding to the heat exchange unit stops rotating. This can reduce the evaporation of the liquid refrigerant. If the refrigerant entering the heat exchange unit is a gaseous refrigerant, the fan corresponding to the heat exchange unit rotates, which can accelerate the condensation of the liquid refrigerant, thereby increasing the amount of refrigerant stored in the heat exchange unit.

[0101] By adopting such a setting method, the defrosting speed of a single heat exchange unit can be increased, and the liquid storage capacity of the heat exchange unit can be improved.

[0102] The embodiments of the present disclosure provide an air conditioner, which includes the above-mentioned heat exchanger, and the heat exchanger is installed in the indoor unit and / or the outdoor unit of the air conditioner.

[0103] Since the air conditioner provided by the embodiments of the present disclosure includes the heat exchanger described in any one of the above-mentioned embodiments, it has all the beneficial effects of the heat exchanger described in any one of the above-mentioned embodiments, which will not be elaborated here.

[0104] The embodiments of the present disclosure provide an air conditioner, which includes the above-mentioned outdoor heat exchanger.

[0105] Since the air conditioner provided by the embodiments of the present disclosure includes the above-mentioned outdoor unit of the air conditioner, it has all the beneficial effects of the above-mentioned outdoor unit of the air conditioner, which will not be elaborated here.

[0106] The foregoing description and drawings sufficiently illustrate embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural as well as other changes. Embodiments represent merely possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or substituted for portions and features of other embodiments. Embodiments of the present disclosure are not limited to the structures already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A heat exchanger, characterized in that, it includes a plurality of heat exchange units connected in parallel. The heat exchange unit includes a plurality of heat exchange passages and can switch the series-parallel state of the plurality of heat exchange passages. A throttling device is connected in series with the heat exchange unit. The throttling device can switch between a conduction mode and a throttling mode. When the throttling device is in the conduction mode, the refrigerant passes through the throttling device and enters the heat exchange unit to defrost the heat exchange unit. When the throttling device is in the throttling mode, the refrigerant is throttled and depressurized when passing through the throttling device.

2. The heat exchanger according to claim 1, characterized in that, the throttling device is an electronic expansion valve, and the opening degree of the electronic expansion valve can be continuously adjusted.

3. The heat exchanger according to claim 1, characterized in that, The plurality of heat exchange units include: a first heat exchange unit; a second heat exchange unit, located below the first heat exchange unit.

4. The heat exchanger according to claim 3, characterized in that, It includes: a gas collecting pipe, provided with a first inlet and outlet. The first interface of the first heat exchange unit and the first interface of the second heat exchange unit are connected to the gas collecting pipe; a liquid collecting pipe, provided with a second inlet and outlet. The second interface of the first heat exchange unit and the second interface of the second heat exchange unit are connected to the liquid collecting pipe; a first throttling device, arranged between the second interface of the first heat exchange unit and the liquid collecting pipe; a second throttling device, arranged between the second interface of the second heat exchange unit and the liquid collecting pipe.

5. The heat exchanger according to claim 4, wherein It further includes: a first temperature sensor, used to obtain the temperature of the first heat exchange unit; a second temperature sensor, used to obtain the temperature of the second heat exchange unit; a control unit, configured to control the first throttling device to close when the temperature of the first heat exchange unit is lower than a preset temperature, and / or configured to control the second throttling device to close when the temperature of the second heat exchange unit is lower than a preset temperature.

6. The heat exchanger according to claim 4, characterized in that, It further includes: a total throttling device, connected to the second inlet and outlet of the liquid collecting pipe. When the heat exchanger is used as an evaporator, the refrigerant flows through the total throttling device and the liquid collecting pipe in sequence.

7. The heat exchanger according to any one of claims 1 to 6, characterized in that, It further includes: a on-off control component, connected in series with the heat exchange unit. The on-off control component and the throttling device are respectively located at both ends of the heat exchange unit.

8. The heat exchanger according to any one of claims 1 to 6, characterized in that, The heat exchange unit includes: a plurality of refrigerant pipes, forming the plurality of heat exchange passages; a first confluence component, provided with a first interface. The first end of each heat exchange passage is connected to the first confluence component; a second confluence component, provided with a second interface. The second end of each heat exchange passage is connected to the second confluence component; a valve component, arranged between the first confluence component and the second confluence component. The valve component is used to switch the series-parallel state of the plurality of heat exchange passages.

9. An outdoor unit of an air conditioner, characterized in that, it includes the heat exchanger according to any one of claims 1 to 8; and, a plurality of fans, arranged corresponding to the plurality of heat exchange units.

10. An air conditioner, characterized in that, it includes the heat exchanger according to any one of claims 1 to 8, and the heat exchanger is installed in the indoor unit and / or outdoor unit of the air conditioner; or, it includes the outdoor unit of the air conditioner according to claim 9.

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