Method and device for controlling defrosting of air conditioner outdoor unit, air conditioner, storage medium

Abstract

The application relates to the technical field of smart homes, and discloses a method for controlling defrosting of an air conditioner outdoor unit, a defrosting branch is arranged between an outlet end of an outdoor heat exchanger of the air conditioner and a four-way valve; the outdoor heat exchanger comprises a first outdoor heat exchanger and a second outdoor heat exchanger connected in series, and a second electronic expansion valve is arranged on a series pipeline; the method comprises the following steps: responding to an outdoor defrosting instruction of the air conditioner; controlling a first electronic expansion valve between the outdoor heat exchanger and an indoor heat exchanger to be closed, and controlling the defrosting branch to be conducted; determining a control strategy of the second electronic expansion valve according to an exhaust pressure of a compressor or an outdoor unit coil temperature, and controlling the second electronic expansion valve to be executed. The method makes the refrigerant not flow through the indoor heat exchanger during defrosting, reduces energy consumption, and helps to improve the defrosting efficiency. Meanwhile, the defrosting effect is ensured by controlling the opening degree of the second electronic expansion valve. The application further discloses a device for controlling defrosting of an air conditioner outdoor unit, an air conditioner and a storage medium.

Description

Technical Field

[0001] This application relates to the field of smart home appliance technology, such as a method and apparatus for controlling the defrosting of an outdoor unit of an air conditioner, an air conditioner, and a storage medium. Background Technology

[0002] When an air conditioner is running in heating mode, the outdoor unit is prone to frost buildup. Normally, switching the air conditioner to cooling mode defrosts the outdoor unit. However, during defrosting, the indoor heat exchanger absorbs heat, causing significant fluctuations in the indoor temperature. Especially in colder environments, these temperature fluctuations can affect the user's heating comfort.

[0003] Related technologies disclose an air conditioning system including an indoor unit and an outdoor unit. The indoor unit contains an outdoor heat exchanger. The outdoor unit includes a first outdoor heat exchanger, a second outdoor heat exchanger, a compressor, a four-way solenoid valve, a first three-way solenoid valve, a second three-way solenoid valve, a solenoid shut-off valve, a first three-way valve, a second three-way valve, a third three-way valve, a fourth three-way valve, a first throttling element, and a second throttling element, all connected by pipes. During defrosting, the four-way solenoid valve, the first three-way solenoid valve, and the second three-way solenoid valve control the second outdoor heat exchanger to replace the indoor heat exchanger when the first outdoor heat exchanger is defrosting. Conversely, when the second outdoor heat exchanger is defrosting, the first outdoor heat exchanger replaces the indoor heat exchanger.

[0004] In the process of implementing the embodiments of this disclosure, at least the following problems were found in the related art:

[0005] In related technologies, during defrosting, the two outdoor heat exchangers alternately function as evaporators and condensers to achieve defrosting. This increases the defrosting time and reduces the heating experience for indoor users. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0007] This disclosure provides a method and apparatus for controlling the defrosting of an outdoor unit of an air conditioner, an air conditioner, and a storage medium, to improve defrosting efficiency without affecting indoor temperature comfort.

[0008] In some embodiments, the air conditioner includes a refrigerant circulation loop; a defrost branch is provided between the outlet end of the outdoor heat exchanger and the four-way valve; the outdoor heat exchanger includes a first outdoor heat exchanger and a second outdoor heat exchanger connected in series, and a second electronic expansion valve is provided on the series pipeline; the method includes: responding to an outdoor defrost command from the air conditioner; controlling the first electronic expansion valve between the outdoor heat exchanger and the indoor heat exchanger to close, and controlling the defrost branch to open; determining a control strategy for the air conditioner based on the compressor's discharge pressure or the outdoor unit coil temperature, and controlling its execution.

[0009] In some embodiments, the apparatus includes a processor and a memory storing program instructions, the processor being configured to, when executing the program instructions, perform the aforementioned method for controlling the defrosting of an outdoor unit of an air conditioner.

[0010] In some embodiments, the air conditioner includes: a refrigerant circulation loop comprising a compressor, a four-way valve, an outdoor heat exchanger, a first electronic expansion valve, and an indoor heat exchanger connected in sequence; a defrost branch disposed between the outlet end of the outdoor heat exchanger and the four-way valve, and connected in parallel with the refrigerant circulation loop between the outlet end of the outdoor heat exchanger, the first electronic expansion valve, the indoor heat exchanger, and the four-way valve; wherein the outdoor heat exchanger comprises a first outdoor heat exchanger and a second outdoor heat exchanger connected in series, and a second electronic expansion valve is provided on the pipeline between the two; and, as described above, a device for controlling the defrosting of the outdoor unit of the air conditioner.

[0011] In some embodiments, the storage medium stores program instructions that, when executed, perform the aforementioned method for controlling the defrosting of an outdoor air conditioning unit.

[0012] The method, apparatus, air conditioner, and storage medium for controlling the defrosting of an outdoor unit of an air conditioner provided in this disclosure can achieve the following technical effects:

[0013] In this embodiment, the outdoor heat exchanger includes two heat exchangers connected in series. During defrosting, the first electronic expansion valve in the refrigerant circulation loop is closed, while the defrost branch is open. This prevents the low-temperature refrigerant after defrosting from flowing into the indoor heat exchanger and affecting the indoor ambient temperature. Furthermore, the refrigerant used for defrosting the outdoor heat exchanger flows into the compressor via the defrost branch, reducing energy consumption and improving defrosting efficiency. During defrosting, the second electronic expansion valve between the two outdoor heat exchangers is controlled based on the compressor's discharge pressure or the outdoor unit's coil temperature to ensure effective defrosting.

[0014] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0015] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0016] Figure 1 This is a schematic diagram of the structure of an air conditioner provided in an embodiment of this disclosure;

[0017] Figure 2 This is a schematic diagram of a method for controlling the defrosting of an outdoor unit of an air conditioner, provided in an embodiment of this disclosure;

[0018] Figure 3 This is a schematic diagram of another method for controlling the defrosting of an outdoor unit of an air conditioner, provided in an embodiment of this disclosure;

[0019] Figure 4 This is a schematic diagram of another method for controlling the defrosting of an outdoor unit of an air conditioner, provided in an embodiment of this disclosure;

[0020] Figure 5 This is a schematic diagram of another method for controlling the defrosting of an outdoor unit of an air conditioner, provided in an embodiment of this disclosure;

[0021] Figure 6 This is a schematic diagram of a device for controlling the defrosting of an outdoor unit of an air conditioner, provided in an embodiment of this disclosure.

[0022] Figure label:

[0023] 10: Compressor; 20: Four-way valve; 30: Outdoor heat exchanger; 31: First outdoor heat exchanger; 32: Second outdoor heat exchanger; 40: Indoor heat exchanger; 51: First electronic expansion valve; 52: Second electronic expansion valve; 60: Defrosting branch; 61: On / off valve; 70: Gas-liquid separator. Detailed Implementation

[0024] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0025] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0026] Unless otherwise stated, the term "multiple" means two or more.

[0027] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0028] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0029] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0030] Combination Figure 1 As shown, the air conditioner includes a refrigerant circulation loop, which comprises a compressor 10, a four-way valve 20, an outdoor heat exchanger 30, a first electronic expansion valve 51, and an indoor heat exchanger 40 connected sequentially by pipes. A defrost branch 60 is provided between the outlet end of the outdoor heat exchanger 30 and the four-way valve 20. The outlet end of the outdoor heat exchanger 30 refers to the outlet end of the outdoor heat exchanger 30 in the direction of refrigerant flow when the air conditioner is operating in cooling mode. When the air conditioner is defrosting the outdoor unit (i.e., operating in cooling mode), the first electronic expansion valve 51 is closed, and the defrost branch 60 is open. The high-temperature refrigerant discharged from the compressor 10 flows into the outdoor heat exchanger 30 through the four-way valve 20, and after heat exchange and defrosting in the outdoor heat exchanger 30, it flows back to the compressor through the defrost branch 60 and the four-way valve 20. After the first electronic expansion valve 51 is closed, the refrigerant flowing out of the outdoor heat exchanger 30 no longer flows through the indoor heat exchanger 40. In this way, when the air conditioner switches from heating mode to defrost mode, the low-temperature refrigerant does not flow through the indoor unit. This ensures that the temperature comfort of indoor users is not affected, while also reducing the system's energy consumption and improving defrost efficiency during defrost. Furthermore, it eliminates the noise generated by the refrigerant flow in the indoor unit during defrost.

[0031] Furthermore, the outdoor heat exchanger 30 includes a first outdoor heat exchanger 31 and a second outdoor heat exchanger 32 connected in series, and a second electronic expansion valve 52 is provided on the series pipeline. During defrosting, the opening degree of the second electronic expansion valve 52 can be adjusted to control defrosting. In related technologies, especially in the later stages of defrosting, the discharge pressure and return pressure of the compressor 10 will rapidly increase as the frost layer gradually disappears. If the discharge pressure or return pressure reaches a safety protection value, the compressor 10 will execute protection control logic and end defrosting. This can lead to incomplete defrosting, with the frost layer not being completely removed. Furthermore, if the compressor 10 fails to protect itself in time, it can damage the air conditioning unit. Therefore, the second electronic expansion valve 52 and two outdoor heat exchangers are provided here. By adjusting the opening degree of the second electronic expansion valve 52, the compressor return pressure and discharge pressure can be controlled in the middle and later stages of defrosting. This avoids excessive compressor pressure causing over-protection and interruption of defrosting, thereby ensuring the defrosting effect. In some embodiments, the air conditioner also includes a gas-liquid separator 70. When the air conditioner is defrosting the outdoor unit, the high-temperature refrigerant discharged by the compressor 10 flows into the outdoor heat exchanger 30 through the four-way valve 20. After defrosting in the outdoor heat exchanger 30, it flows back to the compressor through the defrost branch 60, the four-way valve 20, and the gas-liquid separator 70.

[0032] Optionally, a shut-off valve 61 is provided on the defrost branch 60. The shut-off valve 61 can be a solenoid valve or an electronic expansion valve, etc. During normal operation of the air conditioner, the shut-off valve 61 is in the closed state to block the defrost branch. During defrosting, the shut-off valve 61 is in the open state, and the first electronic expansion valve 51 closes simultaneously. This allows the defrost branch 60 to be open, and during defrosting, the refrigerant flows through the defrost branch 60 instead of flowing into the indoor unit.

[0033] In some embodiments, during normal operation of the air conditioner, the opening degree of the on-off valve 61 can be controlled according to the air conditioner's operating status and heating demand. Specifically, in the air conditioner's heating mode, if the compressor 10's operating parameters are relatively low and the heating demand is also relatively low, the on-off valve 61 can be opened to a certain degree. This can increase the refrigerant pressure and temperature flowing into the outdoor heat exchanger 30, thereby helping to slow down the frosting rate of the outdoor heat exchanger 30, and even preventing frosting in some operating conditions. When the heating demand is relatively high, the defrosting branch 60 will affect indoor heating, making it difficult to meet user needs. When the air conditioner compressor's operating frequency, exhaust temperature, and other parameters are high, the outdoor heat exchanger temperature is high. This will cause the refrigerant temperature flowing back to the compressor to be too high (i.e., the return gas temperature is too high), which is detrimental to the compressor's operation.

[0034] Combination Figure 2 As shown in the embodiments of this disclosure, a method for controlling the defrosting of an outdoor unit of an air conditioner is provided, comprising:

[0035] S101, the processor responds to the outdoor defrost command of the air conditioner.

[0036] S102, the processor controls the first electronic expansion valve between the outdoor heat exchanger and the indoor heat exchanger to close, and controls the defrost branch to be turned on.

[0037] S103, the processor determines the control strategy of the second electronic expansion valve based on the compressor's discharge pressure or the outdoor unit's coil temperature, and controls its execution.

[0038] This section addresses defrosting in heating mode. Specifically, in heating mode, it responds to the outdoor unit's defrosting command. This means controlling the four-way valve to switch to cooling mode. Simultaneously, it closes the first electronic expansion valve between the outdoor and indoor heat exchangers, preventing refrigerant from flowing into the indoor unit. The defrosting branch then opens, allowing the high-temperature, high-pressure refrigerant to exchange heat in the outdoor heat exchanger, melting the frost layer. The cooled, low-pressure refrigerant then flows back to the compressor via the defrosting branch.

[0039] Furthermore, during the defrosting process, the second electronic expansion valve is adjusted based on the compressor's discharge pressure or the outdoor unit's coil temperature. Understandably, in the initial stages of defrosting, the two outdoor heat exchangers require a larger heat source. At this time, the opening of the second electronic expansion valve can be relatively large. As the defrosting process continues, the heat source required for defrosting the two outdoor heat exchangers gradually decreases. If the opening of the second electronic expansion valve is still relatively large, the outdoor heat exchanger temperature will reach the set temperature prematurely, resulting in incomplete defrosting. Alternatively, a large opening of the second electronic expansion valve may cause an increase in compressor pressure, triggering the air conditioner's over-protection mechanism and interrupting defrosting. This also results in incomplete defrosting of the outdoor heat exchanger. Therefore, it is necessary to reduce the opening of the second electronic expansion valve to limit the compressor pressure or lower the outdoor unit's coil temperature.

[0040] Furthermore, the refrigerant flows through the first outdoor heat exchanger before the second, which can result in better defrosting of the first outdoor heat exchanger during the defrosting process, while the second outdoor heat exchanger may experience incomplete defrosting or freezing. When there are two outdoor heat exchangers, they are usually arranged one above the other. During defrosting, the defrosting water from the upper outdoor heat exchanger flows to the lower outdoor heat exchanger. When the ambient temperature is low, the lower outdoor heat exchanger is prone to freezing. In this case, it is also necessary to reduce the opening of the second electronic expansion valve to ensure that the second outdoor heat exchanger can defrost sufficiently and guarantee the defrosting effect.

[0041] The method for controlling the defrosting of an outdoor air conditioning unit provided in this disclosure includes two heat exchangers connected in series in the outdoor heat exchanger. During defrosting, the first electronic expansion valve in the refrigerant circulation loop is closed, while the defrosting branch is open. This prevents the low-temperature refrigerant after defrosting from flowing into the indoor heat exchanger and affecting the indoor ambient temperature. Furthermore, the refrigerant used for defrosting the outdoor heat exchanger flows into the compressor via the defrosting branch, reducing energy consumption and improving defrosting efficiency. During defrosting, the second electronic expansion valve between the two outdoor heat exchangers is controlled based on the compressor's discharge pressure or the outdoor unit coil temperature to ensure effective defrosting.

[0042] Optionally, in step S103, the processor determines the control strategy for the second electronic expansion valve based on the compressor's discharge pressure or the outdoor unit's coil temperature, including:

[0043] When the compressor's discharge pressure is less than the first discharge pressure, or the outdoor unit's coil temperature is less than the first coil temperature, or the outdoor unit's coil temperature is greater than or equal to the first coil temperature and the duration is less than the first duration, the processor determines that the second electronic expansion valve is at its maximum opening.

[0044] If the compressor's discharge pressure is greater than or equal to the first discharge pressure, or if the outdoor unit's coil temperature is greater than or equal to the first coil temperature and the duration is greater than or equal to the first duration, the processor determines to reduce the opening of the second electronic expansion valve.

[0045] Here, the control strategy for the second electronic expansion valve is determined based on the compressor's discharge pressure, or the outdoor unit coil temperature and its duration. Specifically, when the compressor's discharge pressure is low, the outdoor unit coil temperature is low, or the outdoor unit coil reaches the set first coil temperature but the duration of that temperature is short, the second electronic expansion valve is controlled at its maximum opening. The compressor's discharge pressure and the outdoor unit coil temperature are inversely proportional to the frosting area. That is, the smaller the frosting area, the higher the compressor's discharge pressure, or the higher the outdoor unit coil temperature. Thus, the defrosting status is judged by the compressor's discharge pressure and the outdoor unit coil temperature. When the compressor's discharge pressure is high, or the outdoor unit coil temperature is high but the duration is less than the first duration, it indicates that the outdoor heat exchanger has initially completed defrosting (i.e., the first stage of defrosting is complete). To further ensure thorough defrosting, the opening of the second electronic expansion valve needs to be reduced to perform the second stage of defrosting control. This involves controlling the flow of high-temperature refrigerant to avoid triggering the air conditioning system's overprotection mechanism, thereby improving the defrosting effect.

[0046] In addition, the first exhaust pressure, the first coil temperature, and the first duration are all set values, which can be set based on the type of air conditioner, or determined through multiple experiments.

[0047] Optionally, in step S103, the processor determines to reduce the opening of the second electronic expansion valve, including:

[0048] The higher the compressor's discharge pressure, or the higher the outdoor unit's coil temperature, the smaller the opening of the second electronic expansion valve.

[0049] Here, the opening degree of the second electronic expansion valve is determined by the compressor's discharge pressure or the outdoor unit's coil temperature. The opening degree of the second electronic expansion valve is negatively correlated with these two parameters. Specifically, taking the compressor's discharge pressure as an example, the difference between the compressor's discharge temperature and the first discharge pressure can be obtained; the larger the difference, the smaller the opening degree of the second electronic expansion valve. Alternatively, the rate of change of the compressor's discharge temperature can be obtained; the faster the rate of change, the smaller the opening degree of the second electronic expansion valve.

[0050] Combination Figure 3 As shown in the embodiments of this disclosure, another method for controlling the defrosting of an outdoor unit of an air conditioner is provided, including:

[0051] S101, the processor responds to the outdoor defrost command of the air conditioner.

[0052] S102, the processor controls the first electronic expansion valve between the outdoor heat exchanger and the indoor heat exchanger to close, and controls the defrost branch to be turned on.

[0053] S131, when the compressor's discharge pressure is less than the first discharge pressure, or the outdoor unit's coil temperature is less than the first coil temperature, or the outdoor unit's coil temperature is greater than or equal to the first coil temperature and the duration is less than the first duration, the processor determines the second electronic expansion valve to be at its maximum opening and controls its execution.

[0054] S132, when the compressor's discharge pressure is greater than or equal to the first discharge pressure, or the outdoor unit's coil temperature is greater than or equal to the first coil temperature and the duration is greater than or equal to the first duration, the processor determines to reduce the opening of the second electronic expansion valve and controls the execution.

[0055] S204, the processor obtains the defrosting time after adjusting the second electronic expansion valve, the compressor's discharge pressure, and the outdoor unit's coil temperature.

[0056] S205: When the defrosting time reaches the second duration, or the exhaust pressure reaches the second exhaust pressure, or the outdoor unit coil temperature reaches the second coil temperature, the processor controls the air conditioner to stop defrosting.

[0057] Here, after adjusting the opening of the second electronic expansion valve, the second stage of defrosting begins. This defrosting process is constrained by time, as well as by the compressor's discharge pressure and the outdoor unit's coil temperature. The time constraint is to ensure both effective defrosting and the normal operating time of the air conditioner. Specifically, it involves controlling the ratio of defrosting time to overall air conditioner operating time to prevent excessively long defrosting times from affecting overall air conditioner operation. However, the duration of the first defrosting stage is uncontrollable; therefore, the overall defrosting time can be controlled by managing the duration of the second defrosting stage.

[0058] Furthermore, during the second defrosting stage, the defrosting duration, compressor discharge pressure, and outdoor unit coil temperature are monitored. If any one of these three parameters meets the constraints, the air conditioner is controlled to end the defrosting process.

[0059] Optionally, in step S205, the processor controls the air conditioner to stop defrosting, including:

[0060] The processor controls the defrost branch to close and controls the first electronic expansion valve to open; and controls the air conditioner to return to the operating mode before defrosting.

[0061] Here, controlling the air conditioner to stop defrosting includes shutting off the defrost branch and opening the refrigerant circuit in the indoor unit. Simultaneously, it controls the four-way valve to reverse, restoring the air conditioner to its pre-defrost operating mode. Furthermore, the opening of the second electronic expansion valve can be adjusted according to the air conditioner's operating parameters.

[0062] Combination Figure 4 As shown in the embodiments of this disclosure, another method for controlling the defrosting of an outdoor unit of an air conditioner is provided, including:

[0063] S101, the processor responds to the outdoor defrost command of the air conditioner.

[0064] S102, the processor controls the first electronic expansion valve between the outdoor heat exchanger and the indoor heat exchanger to close, and controls the defrost branch to be turned on.

[0065] S304, the processor adjusts the compressor's operating frequency according to the air conditioner's operating parameters; wherein, the air conditioner's operating parameters include one or more of the compressor's exhaust parameters and return parameters.

[0066] S103, the processor determines the control strategy of the second electronic expansion valve based on the compressor's discharge pressure or the outdoor unit's coil temperature, and controls its execution.

[0067] Here, during the air conditioner defrosting process, it's necessary to adjust the compressor's operating frequency. This involves dynamically adjusting the compressor's operating frequency to ensure proper defrosting. Specifically, the compressor's operating frequency is adjusted based on its discharge and return parameters. Discharge parameters include discharge pressure and temperature; return parameters include return pressure and temperature. Especially in the second stage of defrosting, adjusting the compressor's operating frequency ensures adequate discharge and return pressure. For example, the compression ratio of discharge and return pressures is calculated, and the compressor's operating frequency is adjusted to maintain this ratio within a reasonable range. Furthermore, the compression ratio can be controlled in conjunction with a second electronic expansion valve control strategy. For instance, reducing the opening of the second electronic expansion valve reduces the return pressure, thus providing low-pressure protection.

[0068] Combination Figure 5 As shown in the embodiments of this disclosure, another method for controlling the defrosting of an outdoor unit of an air conditioner is provided, including:

[0069] S101, the processor responds to the outdoor defrost command of the air conditioner.

[0070] S404, the processor controls the indoor unit of the air conditioner to stop running and reduces the operating frequency of the compressor to the preset frequency.

[0071] S102, the processor controls the first electronic expansion valve between the outdoor heat exchanger and the indoor heat exchanger to close, and controls the defrost branch to be turned on.

[0072] S103, the processor determines the control strategy of the second electronic expansion valve based on the compressor's discharge pressure or the outdoor unit's coil temperature, and controls its execution.

[0073] Here, during defrosting, not only does the refrigerant stop flowing through the indoor unit, but the indoor unit also shuts down. Shutting down the indoor unit means the indoor fan stops. Simultaneously, the compressor frequency is reduced. Because the indoor unit stops and the refrigerant no longer flows through it, energy consumption is reduced. Therefore, reducing the compressor frequency during defrosting satisfies defrosting requirements while also helping to reduce energy consumption. Furthermore, the outdoor unit fan also stops during defrosting. This is because in the later stages of defrosting, the outdoor fan accelerates convective heat transfer in the outdoor heat exchanger, causing significant pressure fluctuations in the compressor. This, in turn, affects the air conditioner's lifespan and reliability; therefore, the outdoor fan also stops during defrosting.

[0074] This disclosure provides an apparatus for controlling the defrosting of an outdoor unit of an air conditioner, including a response module, a first control module, and a second control module. The response module is configured to respond to an outdoor defrosting command from the air conditioner. The first control module is configured to close a first electronic expansion valve between the outdoor heat exchanger and the indoor heat exchanger, and to connect the defrosting branch. The second control module is configured to determine a control strategy for a second electronic expansion valve based on the compressor's discharge pressure or the outdoor unit's coil temperature, and to control its execution.

[0075] The device for controlling the defrosting of an outdoor air conditioning unit provided in this embodiment includes two heat exchangers connected in series in the outdoor heat exchanger. During defrosting, the first electronic expansion valve in the refrigerant circulation loop is closed, while the defrosting branch is open. This prevents the low-temperature refrigerant after defrosting from flowing into the indoor heat exchanger and affecting the indoor ambient temperature. Furthermore, the refrigerant used for defrosting the outdoor heat exchanger flows into the compressor via the defrosting branch, reducing energy consumption and improving defrosting efficiency. During defrosting, the second electronic expansion valve between the two outdoor heat exchangers is controlled based on the compressor's discharge pressure or the outdoor unit coil temperature to ensure effective defrosting.

[0076] Combination Figure 6 As shown, this disclosure provides an apparatus for controlling the defrosting of an outdoor unit of an air conditioner, including a processor 100 and a memory 101. Optionally, the apparatus may further include a communication interface 102 and a bus 103. The processor 100, communication interface 102, and memory 101 can communicate with each other via the bus 103. The communication interface 102 can be used for information transmission. The processor 100 can call logical instructions in the memory 101 to execute the method for controlling the defrosting of the outdoor unit of an air conditioner according to the above embodiment.

[0077] Furthermore, the logic instructions in the aforementioned memory 101 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0078] The memory 101, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 100 executes functional applications and data processing by running the program instructions / modules stored in the memory 101, that is, it implements the method for controlling the defrosting of the outdoor unit of the air conditioner in the above embodiments.

[0079] The memory 101 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 101 may include high-speed random access memory and may also include non-volatile memory.

[0080] This disclosure provides an air conditioner that includes the aforementioned device for controlling the defrosting of the outdoor unit of the air conditioner.

[0081] This disclosure provides a storage medium storing computer-executable instructions configured to perform the above-described method for controlling the defrosting of an outdoor unit of an air conditioner.

[0082] The aforementioned storage medium can be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0083] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0084] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0085] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0086] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0087] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A method for controlling the defrosting of an outdoor unit of an air conditioner, characterized in that, A defrost branch is provided between the outlet end of the outdoor heat exchanger of the air conditioner and the four-way valve; the outdoor heat exchanger includes a first outdoor heat exchanger and a second outdoor heat exchanger connected in series, and a second electronic expansion valve is provided on the series pipeline; the method includes: Responding to the outdoor defrost command from the air conditioner; The first electronic expansion valve between the outdoor heat exchanger and the indoor heat exchanger is closed, and the defrost branch is opened. The control strategy for the second electronic expansion valve is determined based on the compressor's discharge pressure or the outdoor unit's coil temperature, and its execution is controlled accordingly. Specifically, when the compressor's discharge pressure is less than the first discharge pressure, or the outdoor unit's coil temperature is less than the first coil temperature, or the outdoor unit's coil temperature is greater than or equal to the first coil temperature and the duration is less than the first duration, the second electronic expansion valve is determined to be at its maximum opening; when the compressor's discharge pressure is greater than or equal to the first discharge pressure, or the outdoor unit's coil temperature is greater than or equal to the first coil temperature and the duration is greater than or equal to the first duration, the opening of the second electronic expansion valve is determined to be reduced.

2. The method according to claim 1, characterized in that, The step of determining to reduce the opening of the second electronic expansion valve includes: The higher the discharge pressure of the compressor, or the higher the temperature of the outdoor unit coil, the smaller the opening of the second electronic expansion valve.

3. The method according to claim 1, characterized in that, After determining and controlling the reduction of the opening of the second electronic expansion valve, the process further includes: Obtain the defrosting time, compressor discharge pressure, and outdoor unit coil temperature after adjusting the second electronic expansion valve. If the defrosting time reaches the second duration, or the exhaust pressure reaches the second exhaust pressure, or the outdoor unit coil temperature reaches the second coil temperature, the air conditioner will be controlled to stop defrosting. Among them, the second exhaust pressure is greater than the first exhaust pressure, the second coil temperature is greater than the first coil temperature, and the second duration is less than the first duration.

4. The method according to claim 3, characterized in that, The control of the air conditioner to stop defrosting includes: The defrosting branch is controlled to close, and the first electronic expansion valve is controlled to open; and, Control the air conditioner to restore it to the operating mode before defrosting.

5. The method according to any one of claims 1 to 4, characterized in that, After the defrosting control branch is turned on, it also includes: Adjust the compressor's operating frequency according to the air conditioner's operating parameters; The operating parameters of the air conditioner include the compressor's exhaust parameters and return parameters.

6. The method according to any one of claims 1 to 4, characterized in that, The method, in response to the outdoor defrost command from the air conditioner, further includes: The indoor unit of the air conditioner is controlled to stop running, and... Reduce the compressor's operating frequency to the preset frequency.

7. A device for controlling the defrosting of an outdoor unit of an air conditioner, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to, when executing the program instructions, perform the method for controlling the defrosting of an outdoor unit of an air conditioner as described in any one of claims 1 to 6.

8. An air conditioner, characterized in that, include: The refrigerant circulation loop includes a compressor, a four-way valve, an outdoor heat exchanger, a first electronic expansion valve, and an indoor heat exchanger connected in sequence. A defrosting branch is located between the outlet end of the outdoor heat exchanger and the four-way valve, and is connected in parallel with the refrigerant circulation loop between the outlet end of the outdoor heat exchanger, the first electronic expansion valve, the indoor heat exchanger, and the four-way valve; wherein, the outdoor heat exchanger includes a first outdoor heat exchanger and a second outdoor heat exchanger connected in series, and a second electronic expansion valve is provided on the pipeline between the two; and, The device for controlling the defrosting of an outdoor air conditioning unit as described in claim 7.

9. A storage medium storing program instructions, characterized in that, When the program instructions are executed, they perform the method for controlling the defrosting of an outdoor air conditioning unit as described in any one of claims 1 to 6.

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