Air conditioner and control method thereof

Abstract

The invention discloses an air conditioner and a control method thereof. The air conditioner comprises a refrigerant circulation loop, an exhaust temperature sensor and a controller. The controller is configured to obtain the exhaust temperature, judge whether the air conditioner has a frequency reduction protection phenomenon or not according to the exhaust temperature, and control the air conditioner when judging that the air conditioner has the frequency reduction protection phenomenon. And the target operation frequency or the frequency reduction speed of the compressor is adjusted according to the frequency of the frequency reduction protection phenomenon of the air conditioner and the operation state of the air conditioner entering the frequency reduction protection process last time, so that repeated frequency increasing and decreasing of the air conditioner are avoided, the service life of the compressor is prolonged, and user experience is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and more particularly to an air conditioner and a control method thereof. Background Art

[0002] An air conditioner is an electrical product widely used in people's lives. The air conditioner plays an important role in regulating the indoor temperature, can provide a healthy and comfortable indoor environment for users, and meet the normal work, life and learning needs.

[0003] In order to make the air conditioner have optimal performance and cost advantages, the manufacturer designs the exhaust temperature of the compressor to be relatively high, and its temperature change is also more obvious. In this case, if the exhaust protection frequency reduction speed of the compressor is set too slow, after the compressor runs to the preset frequency, due to the high exhaust temperature, the exhaust temperature frequency reduction protection will be triggered. However, due to the slow frequency reduction speed, the exhaust temperature will continue to rise until the shutdown protection is triggered, causing the compressor to stop; if the exhaust protection frequency reduction speed of the compressor is set too fast, due to the certain hysteresis between the exhaust temperature and the adjustment of the compressor frequency, after the compressor has exited the exhaust temperature frequency reduction protection, the exhaust temperature will continue to drop, resulting in the system determining that the exhaust temperature is lower than the set temperature and then increasing the frequency. After increasing the frequency to the preset frequency, the frequency reduction action is triggered, and so on, resulting in the indoor air output being alternately cold and hot, greatly affecting the comfort of users. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the object of the present invention is to provide an air conditioner and a control method thereof.

[0005] An air conditioner provided by the present invention includes: a refrigerant circulation circuit that enables the refrigerant to perform a refrigeration cycle in a circuit composed of a compressor, a condenser, an expansion valve, and an evaporator, where one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; an exhaust temperature sensor for detecting the exhaust temperature of the compressor; and a controller configured to: obtain the exhaust temperature, determine whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature, and when it is determined that the air conditioner has a frequency reduction protection phenomenon, adjust the target operating frequency or the frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last enters the frequency reduction protection process, so as to prevent the air conditioner from repeatedly increasing and decreasing the frequency.

[0006] In addition, the air conditioner according to the embodiment of the present invention may further have the following additional technical features:

[0007] Further, when determining whether the air conditioner has a frequency reduction protection phenomenon based on the exhaust temperature, the controller is specifically configured to: when the exhaust temperature reaches a preset exhaust protection frequency reduction temperature, determine that the air conditioner has a frequency reduction protection phenomenon; when the exhaust temperature does not reach the preset exhaust protection frequency reduction temperature, determine that the air conditioner does not have a frequency reduction protection phenomenon.

[0008] Further, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner during the last frequency reduction protection process, the controller is specifically configured to: when the number of times the air conditioner has a frequency reduction protection phenomenon is greater than a preset number, adjust the target operating frequency or the frequency reduction speed of the compressor according to the operating state of the air conditioner during the last frequency reduction protection process; when the number of times the air conditioner has a frequency reduction protection phenomenon is not greater than the preset number, do not adjust the target operating frequency or the frequency reduction speed of the compressor.

[0009] Further, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the operating state of the air conditioner during the last frequency reduction protection process, the controller is specifically configured to: obtain the highest exhaust temperature during the last frequency reduction protection process of the air conditioner, and the first operating frequency of the compressor corresponding to the air conditioner during the last frequency reduction protection process; adjust the target operating frequency or the frequency reduction speed of the compressor according to the highest exhaust temperature and the first operating frequency.

[0010] Further, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the highest exhaust temperature and the first operating frequency, the controller is specifically configured to: calculate a first difference between a preset exhaust protection shutdown temperature and the highest exhaust temperature; adjust the target operating frequency or the frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature, and the first operating frequency.

[0011] Further, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature, and the first operating frequency, the controller is specifically configured to: when the first difference is less than a first preset temperature, adjust the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency; when the first difference is not less than the first preset temperature, reduce the frequency reduction speed of the compressor.

[0012] Further, when reducing the frequency reduction speed of the compressor, the controller is specifically configured to: extend the time required to reduce the operating frequency of the compressor by a preset frequency.

[0013] Further, when adjusting the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency, the controller is specifically configured to: calculate a second difference between the highest exhaust temperature and the preset exhaust protection frequency reduction temperature; and adjust the target operating frequency of the compressor according to the second difference and the first operating frequency.

[0014] Further, when adjusting the target operating frequency of the compressor according to the second difference and the first operating frequency, the controller is specifically configured to: when the second difference is less than a second preset temperature, use the difference between the first operating frequency and a first preset frequency as the target operating frequency; when the second difference is not less than the second preset temperature, use the difference between the first operating frequency and a second preset frequency as the target operating frequency; wherein, the first preset frequency is less than the second preset frequency.

[0015] According to the air conditioner of the embodiment of the present invention, by obtaining the exhaust temperature, judging whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature, and when judging that the air conditioner has a frequency reduction protection phenomenon, adjusting the target operating frequency or the frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last enters the frequency reduction protection process, so that the air conditioner not only has a faster exhaust protection frequency reduction speed, avoiding compressor shutdown caused by slow frequency reduction speed, but also can avoid the phenomenon of repeated frequency increase and decrease of the air conditioner, thereby prolonging the service life of the compressor and improving the user experience.

[0016] In view of the above problems, the present invention also provides a control method for an air conditioner, which is used for the air conditioner described in any of the above embodiments. The method includes the following steps: obtaining the exhaust temperature of the air conditioner, and judging whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature; when judging that the air conditioner has a frequency reduction protection phenomenon, adjusting the target operating frequency or the frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last enters the frequency reduction protection process, so as to avoid repeated frequency increase and decrease of the air conditioner.

[0017] According to the control method of the air conditioner of the embodiment of the present invention, by obtaining the exhaust temperature, judging whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature, and when judging that the air conditioner has a frequency reduction protection phenomenon, adjusting the target operating frequency or the frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last enters the frequency reduction protection process, so that the air conditioner not only has a faster exhaust protection frequency reduction speed, avoiding compressor shutdown caused by slow frequency reduction speed, but also can avoid the phenomenon of repeated frequency increase and decrease of the air conditioner, thereby prolonging the service life of the compressor and improving the user experience.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned by practice of the present invention. Description of the Drawings

[0019] The above and additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 is a schematic diagram of a refrigeration cycle system of an air conditioner according to an embodiment of the present invention;

[0021] Figure 2 is a schematic structural diagram of a controller according to an embodiment of the present invention;

[0022] Figure 3 is a schematic structural diagram of an air conditioner according to an embodiment of the present invention;

[0023] Figure 4 is a flowchart for judging whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature according to an embodiment of the present invention;

[0024] Figure 5 is a flowchart for adjusting the target operating frequency or frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it enters the frequency reduction protection process for the last time according to an embodiment of the present invention;

[0025] Figure 6 is a flowchart for adjusting the target operating frequency or frequency reduction speed of the compressor according to the operating state of the air conditioner when it enters the frequency reduction protection process for the last time according to an embodiment of the present invention;

[0026] Figure 7 is a flowchart for adjusting the target operating frequency or frequency reduction speed of the compressor according to the highest exhaust temperature and the first operating frequency according to an embodiment of the present invention;

[0027] Figure 8 is a flowchart for adjusting the target operating frequency or frequency reduction speed of the compressor according to the first difference value, the highest exhaust temperature and the first operating frequency according to an embodiment of the present invention;

[0028] Figure 9 is a flowchart for adjusting the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency according to an embodiment of the present invention;

[0029] Figure 10 is a flowchart for adjusting the target operating frequency of the compressor according to the second difference value and the first operating frequency according to an embodiment of the present invention;

[0030] Figure 11It is a flowchart of a control method for an air conditioner according to an embodiment of the present invention. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0033] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0034] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0035] As Figure 1 shown, one of the indoor heat exchanger and the outdoor heat exchanger is a condenser, and the other is an evaporator. In the present invention, the air conditioner performs a refrigeration cycle by using a compressor, a condenser, an expansion valve, an evaporator, and a four-way valve. The refrigeration cycle includes a series of processes, involving compression, condensation, expansion, and evaporation, and supplying refrigerant to the air that has been conditioned and heat-exchanged.

[0036] The compressor compresses the refrigerant gas in a high-temperature and high-pressure state that enters from the suction pipe and discharges the compressed refrigerant gas through the discharge pipe. The discharged refrigerant gas flows into the condenser through the condenser inlet pipe. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0037] The indoor heat exchanger and the outdoor heat exchanger are used as condensers or evaporators. When the indoor heat exchanger is used as a condenser, the air conditioner functions as a heater in the heating mode, and when the indoor heat exchanger is used as an evaporator, the air conditioner functions as a cooler in the cooling mode.

[0038] The expansion valve expands the high-temperature and high-pressure liquid-phase refrigerant that has been condensed in the condenser and discharged through the condenser outlet pipe into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant that has expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by using the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. During the entire cycle, the air conditioner can adjust the temperature of the indoor space.

[0039] In the embodiment shown in the present application, the air conditioner further includes a controller 71, and the controller 71 refers to a device that can generate an operation control signal according to the instruction operation code and the timing signal to instruct the air conditioner to execute the control instruction. For example, in response to the received power-on or power-off instruction issued by the user, the controller 71 can perform operations related to the object selected by the power-on or power-off instruction.

[0040] The embodiment of the present application also provides a schematic diagram of the hardware structure of a controller 71, as Figure 2 shown, the controller 71 includes a processor 83, and optionally, a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, the memory 82, and the communication interface 84 are connected through a bus 81.

[0041] The processor 83 may be a central processing unit (CPU), a general-purpose processor 83, a network processor 83 (NP), a digital signal processor 83 (DSP), a microprocessor 83, a microcontroller 83, a programmable logic device (PLD), or any combination thereof. The processor 83 may also be any other device with processing capabilities, such as a circuit, a device, or a software module. The processor 83 may also include multiple CPUs, and the processor 83 may be a single-core (single CPU) processor 83 or a multi-core (multi CPU) processor 83. The processor 83 herein may refer to one or more devices, circuits, or processing cores for processing data (such as computer program instructions).

[0042] The memory 82 may be a read-only memory 82 (ROM) or other types of static storage devices that can store static information and instructions, a random access memory 82 (RAM), or other types of dynamic storage devices that can store information and instructions. It may also be an electrically erasable programmable read-only memory 82 (EEPROM), a compact disc read-only memory (CD ROM), or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer. The embodiments of the present application do not impose any restrictions on this. The memory 82 may exist independently or be integrated with the processor 83. Among them, the memory 82 may contain computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby implementing the control method of the air conditioner provided by the embodiments of the present application.

[0043] The communication interface 84 may be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.). The communication interface 84 may be a module, a circuit, a transceiver, or any device capable of implementing communication.

[0044] The bus 81 may be a peripheral component interconnect (PCI) bus 81 or an extended industry standard architecture (EISA) bus 81, etc. The bus 81 may be divided into an address bus 81, a data bus 81, a control bus 81, etc.

[0045] Combine the following Figures 3 - 11 An air conditioner and a control method thereof according to an embodiment of the present invention are described.

[0046] Figure 3 FIG. 1 is a schematic diagram of the structure of an air conditioner according to an embodiment of the present invention. Figure 3 As shown, an air conditioner includes: a refrigerant circulation loop 11, an exhaust temperature sensor 12 and a controller 71. The refrigerant circulation loop 11 allows the refrigerant to perform a refrigeration cycle in a loop composed of a compressor, a condenser, an expansion valve and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; the exhaust temperature sensor 12 is used to detect the exhaust temperature of the compressor; the controller 71 is configured to: obtain the exhaust temperature, determine whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature, and when it is determined that the air conditioner has a frequency reduction protection phenomenon, adjust the target operating frequency or frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last entered the frequency reduction protection process, so as to avoid repeated frequency increase and decrease of the air conditioner.

[0047] Specifically, when the air conditioner is running at high load, when the exhaust temperature of the compressor reaches the preset exhaust protection frequency reduction temperature, the compressor will be frequency-reduced to reduce the exhaust temperature to avoid burning the compressor, that is, the air conditioner will have frequency reduction protection. During the frequency reduction protection process, since there is a certain lag in the adjustment of the exhaust temperature and frequency of the compressor, if the compressor frequency reduction speed is too fast, the exhaust temperature will continue to drop after the compressor exits the frequency reduction protection. When the exhaust temperature is lower than the prohibited frequency increase temperature, the compressor will increase the frequency. After the frequency is increased to the target operating frequency, the frequency reduction action is triggered, causing the frequency reduction control to frequently enter and release, resulting in large fluctuations in the outlet temperature, system pressure and current power, affecting the user's comfort and the service life of the compressor. Therefore, the embodiment of the present invention obtains the exhaust temperature, determines whether the air conditioner has a frequency reduction protection phenomenon based on the exhaust temperature, and adjusts the target operating frequency or frequency reduction speed of the compressor based on the number of times the air conditioner has a frequency reduction protection phenomenon and the operating status of the air conditioner when it last entered the frequency reduction protection process, so that the air conditioner has a faster exhaust protection frequency reduction speed and avoids compressor shutdown caused by slow frequency reduction speed, and at the same time avoids the air conditioner from repeatedly increasing and decreasing the frequency, thereby extending the service life of the compressor and improving user experience.

[0048] In an embodiment of the present invention, as Figure 4 shown, when determining whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature, the controller 71 is specifically configured to: when the exhaust temperature reaches the preset exhaust protection frequency reduction temperature, determine that the air conditioner has a frequency reduction protection phenomenon; when the exhaust temperature does not reach the preset exhaust protection frequency reduction temperature, determine that the air conditioner does not have a frequency reduction protection phenomenon.

[0049] Specifically, as described above, when the exhaust temperature of the compressor reaches the preset exhaust protection frequency reduction temperature, it is determined that the air conditioner has a frequency reduction protection phenomenon; otherwise, it is determined that the air conditioner does not have a frequency reduction protection phenomenon. In a specific embodiment, the preset exhaust protection frequency reduction temperature can be set according to the actual situation and stored in the controller 71 in advance. Exemplarily, the preset exhaust protection frequency reduction temperature is 43°C.

[0050] In an embodiment of the present invention, as Figure 5 shown, when adjusting the target operating frequency or frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner during the last entry into the frequency reduction protection process, the controller 71 is specifically configured to: when the number of times the air conditioner has a frequency reduction protection phenomenon is greater than the preset number, adjust the target operating frequency or frequency reduction speed of the compressor according to the operating state of the air conditioner during the last entry into the frequency reduction protection process; when the number of times the air conditioner has a frequency reduction protection phenomenon is not greater than the preset number, do not adjust the target operating frequency or frequency reduction speed of the compressor.

[0051] Specifically, when adjusting the target operating frequency or frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner during the last entry into the frequency reduction protection process, if the number of times the air conditioner has a frequency reduction protection phenomenon is greater than the preset number, it is considered that the air conditioner has a frequency reduction protection phenomenon, and repeated frequency increase and decrease will cause the air conditioner to blow cold and hot air alternately, affecting the user experience. At this time, adjust the target operating frequency or frequency reduction speed of the compressor according to the operating state of the air conditioner during the last entry into the frequency reduction protection process to avoid the air conditioner having a frequency reduction protection and repeated frequency increase and decrease phenomena; if the number of times the air conditioner has a frequency reduction protection phenomenon is not greater than the preset number, it is considered that the air conditioner does not have a frequency reduction protection phenomenon, or the air conditioner can operate normally after having a frequency reduction protection and will not have a repeated frequency reduction protection situation. At this time, do not adjust the target operating frequency or frequency reduction speed of the compressor, that is, the air conditioner can operate normally without any treatment.

[0052] In a specific embodiment, the preset number of times can be set according to the actual situation and stored in the controller 71 in advance. Exemplarily, when the preset number of times is 2, if the number of times the air conditioner exhibits frequency reduction protection exceeds 2, the target operating frequency or the frequency reduction speed of the compressor is adjusted according to the operating state of the air conditioner during the last frequency reduction protection process; if the number of times the air conditioner exhibits frequency reduction protection is not greater than 2, the target operating frequency or the frequency reduction speed of the compressor is not adjusted.

[0053] In an embodiment of the present invention, as Figure 6 shown, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the operating state of the air conditioner during the last frequency reduction protection process, the controller 71 is specifically configured to: obtain the highest exhaust temperature during the last frequency reduction protection process of the air conditioner, and the first operating frequency of the compressor corresponding to the air conditioner during the last frequency reduction protection process; adjust the target operating frequency or the frequency reduction speed of the compressor according to the highest exhaust temperature and the first operating frequency.

[0054] Specifically, the operating state of the air conditioner during the last frequency reduction protection process includes the highest exhaust temperature and the first operating frequency of the compressor corresponding to the air conditioner during the last frequency reduction protection process. In some embodiments, if the highest exhaust temperature is not much different from the preset exhaust protection shutdown temperature, when avoiding the phenomenon of repeated frequency increase and decrease of the air conditioner by reducing the frequency reduction speed of the compressor, it is very likely that the exhaust temperature will exceed the preset exhaust protection shutdown temperature due to the compressor's inability to reduce frequency in time, resulting in compressor shutdown. Therefore, when the highest exhaust temperature is not much different from the preset exhaust protection shutdown temperature, the embodiment of the present invention adjusts the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency, so that the highest exhaust temperature is lower than the preset exhaust protection frequency reduction temperature, avoiding the frequency reduction protection phenomenon of the air conditioner, and thus avoiding the repeated frequency increase and decrease of the air conditioner.

[0055] In other embodiments, if the highest exhaust temperature is significantly different from the preset exhaust protection shutdown temperature, when avoiding the phenomenon of repeated frequency increase and decrease of the air conditioner by reducing the frequency reduction speed of the compressor, even if the compressor fails to reduce frequency in time and the exhaust temperature rises, since the highest exhaust temperature is significantly different from the preset exhaust protection shutdown temperature, the exhaust temperature will not exceed the preset exhaust protection shutdown temperature and will not cause compressor shutdown. Therefore, when the highest exhaust temperature is significantly different from the preset exhaust protection shutdown temperature, the embodiment of the present invention avoids the repeated frequency increase and decrease of the air conditioner by reducing the frequency reduction speed of the compressor.

[0056] In a specific embodiment, the preset exhaust protection shutdown temperature can be set according to the actual situation and stored in the controller 71 in advance. Exemplarily, the preset exhaust protection shutdown temperature is 115°C.

[0057] In one embodiment of the present invention, as Figure 7 shown, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the highest exhaust temperature and the first operating frequency, the controller 71 is specifically configured to: calculate a first difference between a preset exhaust protection shutdown temperature and the highest exhaust temperature; and adjust the target operating frequency or the frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature, and the first operating frequency.

[0058] Specifically, as described above, in the embodiment of the present invention, by comparing the preset exhaust protection shutdown temperature and the highest exhaust temperature, it can be determined whether to adjust the target operating frequency or the frequency reduction speed of the compressor to avoid repeated frequency increase and decrease of the air conditioner. Specifically, calculating the first difference between the preset exhaust protection shutdown temperature and the highest exhaust temperature can determine whether the highest exhaust temperature differs greatly from the preset exhaust protection shutdown temperature according to the first difference, so as to determine whether to adjust the target operating frequency or the frequency reduction speed of the compressor to avoid repeated frequency increase and decrease of the air conditioner, that is, adjust the target operating frequency or the frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature, and the first operating frequency.

[0059] In one embodiment of the present invention, as Figure 8 shown, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature, and the first operating frequency, the controller 71 is specifically configured to: when the first difference is less than a first preset temperature, adjust the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency; when the first difference is not less than the first preset temperature, reduce the frequency reduction speed of the compressor.

[0060] Specifically, when adjusting the target operating frequency or the frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature, and the first operating frequency, if the first difference is less than the first preset temperature, it is considered that the highest exhaust temperature does not differ greatly from the preset exhaust protection shutdown temperature. At this time, adjust the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency; if the first difference is not less than the first preset temperature, it is considered that the highest exhaust temperature differs greatly from the preset exhaust protection shutdown temperature. At this time, reduce the frequency reduction speed of the compressor. In this way, repeated frequency increase and decrease of the air conditioner can be avoided, thereby prolonging the service life of the compressor and improving the user experience.

[0061] In one embodiment of the present invention, when reducing the frequency reduction speed of the compressor, the controller 71 is specifically configured to: extend the time required to reduce the operating frequency of the compressor by a preset frequency.

[0062] Specifically, the frequency reduction speed of the compressor can be reduced by extending the time required to reduce the operating frequency of the compressor by a preset frequency. In a specific embodiment, the frequency reduction speed of the compressor can be reduced by extending the time for the compressor exhaust frequency reduction protection to reduce by 1 Hz, so as to avoid the air conditioner from repeatedly increasing and decreasing the frequency when the difference between the highest exhaust temperature and the preset exhaust protection shutdown temperature is large.

[0063] In an embodiment of the present invention, as Figure 9 shown, when adjusting the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency, the controller 71 is specifically configured to: calculate a second difference between the highest exhaust temperature and the preset exhaust protection frequency reduction temperature; adjust the target operating frequency of the compressor according to the second difference and the first operating frequency.

[0064] Specifically, when adjusting the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency, the greater the second difference between the highest exhaust temperature and the preset exhaust protection frequency reduction temperature, the more the target operating frequency needs to be reduced, so that after adjusting the target operating frequency of the compressor, the highest exhaust temperature is lower than the preset exhaust protection frequency reduction temperature, avoiding the frequency reduction protection phenomenon of the air conditioner, and thus avoiding the air conditioner from repeatedly increasing and decreasing the frequency.

[0065] In an embodiment of the present invention, as Figure 10 shown, when adjusting the target operating frequency of the compressor according to the second difference and the first operating frequency, the controller 71 is specifically configured to: when the second difference is less than the second preset temperature, use the difference between the first operating frequency and the first preset frequency as the target operating frequency; when the second difference is not less than the second preset temperature, use the difference between the first operating frequency and the second preset frequency as the target operating frequency; wherein, the first preset frequency is less than the second preset frequency.

[0066] Specifically, when adjusting the target operating frequency of the compressor according to the second difference and the first operating frequency, when the second difference is less than the second preset temperature, it is considered that the difference between the highest exhaust temperature and the preset exhaust protection frequency reduction temperature is small, and reducing the target operating frequency of the compressor by a small value can satisfy that the highest exhaust temperature is lower than the preset exhaust protection frequency reduction temperature; when the second difference is not less than the second preset temperature, it is considered that the difference between the highest exhaust temperature and the preset exhaust protection frequency reduction temperature is large, and a larger value needs to be reduced for the target operating frequency of the compressor to satisfy that the highest exhaust temperature is lower than the preset exhaust protection frequency reduction temperature. That is, when the second difference is less than the second preset temperature, the difference between the first operating frequency and the first preset frequency is used as the target operating frequency; when the second difference is not less than the second preset temperature, the difference between the first operating frequency and the second preset frequency is used as the target operating frequency, and the first preset frequency is less than the second preset frequency. In a specific embodiment, the first preset frequency and the second preset frequency can be set according to actual conditions and stored in the controller 71 in advance. Exemplarily, the first preset frequency is 2 Hz and the second preset frequency is 4 Hz.

[0067] According to the air conditioner of the embodiment of the present invention, by obtaining the exhaust temperature, it is judged whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature, and when it is judged that the air conditioner has a frequency reduction protection phenomenon, the target operating frequency or the frequency reduction speed of the compressor is adjusted according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last enters the frequency reduction protection process, so that the air conditioner not only has a fast exhaust protection frequency reduction speed, avoids compressor shutdown caused by slow frequency reduction speed, but also can avoid the phenomenon of repeated frequency increase and decrease of the air conditioner, thereby prolonging the service life of the compressor and improving the user experience.

[0068] A further embodiment of the present invention also discloses a control method for an air conditioner, which is used for the air conditioner described in any of the above embodiments. Figure 11 is a flowchart of a control method for an air conditioner according to an embodiment of the present invention. As Figure 11 shown, the method includes the following steps:

[0069] Step S1: Obtain the exhaust temperature of the air conditioner, and judge whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature.

[0070] Step S2: When it is judged that the air conditioner has a frequency reduction protection phenomenon, adjust the target operating frequency or the frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last enters the frequency reduction protection process, so as to avoid repeated frequency increase and decrease of the air conditioner.

[0071] In an embodiment of the present invention, determining whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature includes: when the exhaust temperature reaches the preset exhaust protection frequency reduction temperature, determining that the air conditioner has a frequency reduction protection phenomenon; when the exhaust temperature does not reach the preset exhaust protection frequency reduction temperature, determining that the air conditioner does not have a frequency reduction protection phenomenon.

[0072] In an embodiment of the present invention, adjusting the target operating frequency or frequency reduction speed of the compressor according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner during the last frequency reduction protection process includes: when the number of times the air conditioner has a frequency reduction protection phenomenon is greater than the preset number of times, adjusting the target operating frequency or frequency reduction speed of the compressor according to the operating state of the air conditioner during the last frequency reduction protection process; when the number of times the air conditioner has a frequency reduction protection phenomenon is not greater than the preset number of times, not adjusting the target operating frequency or frequency reduction speed of the compressor.

[0073] In an embodiment of the present invention, adjusting the target operating frequency or frequency reduction speed of the compressor according to the operating state of the air conditioner during the last frequency reduction protection process includes: obtaining the highest exhaust temperature during the last frequency reduction protection process of the air conditioner, and the first operating frequency of the compressor corresponding to the last frequency reduction protection process of the air conditioner; adjusting the target operating frequency or frequency reduction speed of the compressor according to the highest exhaust temperature and the first operating frequency.

[0074] In an embodiment of the present invention, adjusting the target operating frequency or frequency reduction speed of the compressor according to the highest exhaust temperature and the first operating frequency includes: calculating a first difference between the preset exhaust protection shutdown temperature and the highest exhaust temperature; adjusting the target operating frequency or frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature and the first operating frequency.

[0075] In an embodiment of the present invention, adjusting the target operating frequency or frequency reduction speed of the compressor according to the first difference, the highest exhaust temperature and the first operating frequency includes: when the first difference is less than the first preset temperature, adjusting the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency; when the first difference is not less than the first preset temperature, reducing the frequency reduction speed of the compressor.

[0076] In an embodiment of the present invention, reducing the frequency reduction speed of the compressor includes: extending the time required to reduce the operating frequency of the compressor by a preset frequency.

[0077] In an embodiment of the present invention, adjusting the target operating frequency of the compressor according to the highest exhaust temperature and the first operating frequency includes: calculating a second difference between the highest exhaust temperature and the preset exhaust protection frequency reduction temperature; adjusting the target operating frequency of the compressor according to the second difference and the first operating frequency.

[0078] In an embodiment of the present invention, adjusting the target operating frequency of the compressor according to the second difference and the first operating frequency includes: when the second difference is less than the second preset temperature, taking the difference between the first operating frequency and the first preset frequency as the target operating frequency; when the second difference is not less than the second preset temperature, taking the difference between the first operating frequency and the second preset frequency as the target operating frequency; wherein, the first preset frequency is less than the second preset frequency.

[0079] According to the control method of the air conditioner in the embodiment of the present invention, by obtaining the exhaust temperature, it is judged whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature, and when it is judged that the air conditioner has a frequency reduction protection phenomenon, the target operating frequency or the frequency reduction speed of the compressor is adjusted according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it enters the frequency reduction protection process for the last time, so that the air conditioner has a relatively fast exhaust protection frequency reduction speed, avoiding compressor shutdown caused by slow frequency reduction speed, and at the same time avoiding the phenomenon of repeated frequency increase and decrease of the air conditioner, thereby prolonging the service life of the compressor and improving the user experience.

[0080] In the description of this specification, the description with reference to terms such as "an embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0081] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An air conditioner, characterized in that: include: A refrigerant circulation loop, wherein the refrigerant performs a refrigeration cycle in a loop consisting of a compressor, a condenser, an expansion valve, and an evaporator, wherein one of the condenser and the evaporator is an outdoor heat exchanger and the other is an indoor heat exchanger; An exhaust temperature sensor, used to detect the exhaust temperature of the compressor; A controller, wherein the controller is configured to: obtain the exhaust temperature, determine whether the air conditioner has a frequency reduction protection phenomenon based on the exhaust temperature, and when determining that the air conditioner has a frequency reduction protection phenomenon, adjust the target operating frequency or frequency reduction speed of the compressor based on the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last entered the frequency reduction protection process.

2. The air conditioner according to claim 1, characterized in that: When judging whether the air conditioner has frequency reduction protection according to the exhaust temperature, the controller is specifically configured as follows: When the exhaust temperature reaches a preset exhaust protection frequency reduction temperature, it is determined that the air conditioner has a frequency reduction protection phenomenon; When the exhaust temperature does not reach the preset exhaust protection frequency reduction temperature, it is determined that the air conditioner does not have a frequency reduction protection phenomenon.

3. The air conditioner according to claim 1, characterized in that: When adjusting the target operating frequency or frequency reduction speed of the compressor according to the number of times the frequency reduction protection phenomenon occurs in the air conditioner and the operating state of the air conditioner entering the frequency reduction protection process for the last time, the controller is specifically configured as follows: When the frequency reduction protection phenomenon of the air conditioner occurs more than a preset number of times, adjusting the target operating frequency or frequency reduction speed of the compressor according to the operating state of the air conditioner when it last entered the frequency reduction protection process; When the frequency reduction protection phenomenon occurs in the air conditioner for a number of times not greater than the preset number of times, the target operating frequency or the frequency reduction speed of the compressor is not adjusted.

4. The air conditioner according to claim 3, characterized in that: When adjusting the target operating frequency or frequency reduction speed of the compressor according to the operating state of the air conditioner entering the frequency reduction protection process for the last time, the controller is specifically configured as follows: Acquire the highest exhaust temperature during the last time the air conditioner enters the frequency reduction protection process, and the first operating frequency corresponding to the compressor during the last time the air conditioner enters the frequency reduction protection process; The target operating frequency or the frequency reduction speed of the compressor is adjusted according to the maximum exhaust temperature and the first operating frequency.

5. The air conditioner according to claim 4, characterized in that: When adjusting the target operating frequency or the frequency reduction speed of the compressor according to the maximum exhaust temperature and the first operating frequency, the controller is specifically configured as follows: Calculating a first difference between a preset exhaust protection shutdown temperature and the maximum exhaust temperature; The target operating frequency or the frequency reduction speed of the compressor is adjusted according to the first difference, the maximum exhaust temperature and the first operating frequency.

6. The air conditioner according to claim 5, characterized in that: When adjusting the target operating frequency or the frequency reduction speed of the compressor according to the first difference, the maximum exhaust temperature and the first operating frequency, the controller is specifically configured as follows: When the first difference is less than a first preset temperature, adjusting the target operating frequency of the compressor according to the maximum exhaust temperature and the first operating frequency; When the first difference is not less than the first preset temperature, the frequency reduction speed of the compressor is reduced.

7. The air conditioner according to claim 6, characterized in that: When reducing the frequency reduction speed of the compressor, the controller is specifically configured as follows: The time required to reduce the operating frequency of the compressor by a preset frequency is prolonged.

8. The air conditioner according to claim 6, characterized in that: When adjusting the target operating frequency of the compressor according to the maximum exhaust temperature and the first operating frequency, the controller is specifically configured as follows: Calculating a second difference between the maximum exhaust temperature and the preset exhaust protection frequency reduction temperature; The target operating frequency of the compressor is adjusted according to the second difference and the first operating frequency.

9. The air conditioner according to claim 8, characterized in that: When adjusting the target operating frequency of the compressor according to the second difference and the first operating frequency, the controller is specifically configured as follows: When the second difference is less than a second preset temperature, taking the difference between the first operating frequency and the first preset frequency as the target operating frequency; When the second difference is not less than the second preset temperature, the difference between the first operating frequency and the second preset frequency is used as the target operating frequency; wherein the first preset frequency is less than the second preset frequency.

10. A method for controlling an air conditioner, characterized in that: For the air conditioner according to any one of claims 1 to 9, the method comprises the following steps: Acquiring the exhaust temperature of the air conditioner, and determining whether the air conditioner has a frequency reduction protection phenomenon according to the exhaust temperature; When determining that the air conditioner has a frequency reduction protection phenomenon, the target operating frequency or frequency reduction speed of the compressor is adjusted according to the number of times the air conditioner has a frequency reduction protection phenomenon and the operating state of the air conditioner when it last entered the frequency reduction protection process.

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