Air conditioner and control method thereof

Abstract

The application provides an air conditioner and a control method thereof. The control method of the air conditioner comprises the following steps: obtaining a surface temperature Tr of an evaporator of the air conditioner; starting a first anti-freezing mode if the surface temperature Tr meets a first anti-freezing mode starting condition; and starting a second anti-freezing mode after the first anti-freezing mode reaches a regulation target. The application alleviates the temperature fluctuation problem caused by the running of the freezing protection mechanism of the air conditioner.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air conditioning technology, in particular to an air conditioner and a control method thereof. BACKGROUND

[0002] When the air conditioner is in a cooling operation, the surface temperature of the evaporator is often too low due to low inlet air temperature, insufficient refrigerant circulation, and other factors, which is called evaporator freezing. Evaporator freezing will lead to water leakage, water blowing, ice blowing and other adverse consequences.

[0003] To solve the problem of evaporator freezing, the air conditioner usually reduces the frequency of the compressor until it stops running during the cooling operation. However, the frequency reduction, shutdown, startup, and frequency increase operations during the operation of the air conditioner will cause large temperature fluctuations, affecting the user's cooling and heating experience. SUMMARY

[0004] The present application aims to at least solve one of the above-mentioned defects in the prior art.

[0005] The present application aims to alleviate the temperature fluctuation problem caused by the running freezing protection mechanism of the air conditioner.

[0006] In one aspect, the present application provides a control method of an air conditioner, comprising:

[0007] obtaining the surface temperature Tr of the evaporator of the air conditioner;

[0008] if the surface temperature Tr meets the first anti-freezing mode starting condition, starting the first anti-freezing mode;

[0009] starting the second anti-freezing mode after the first anti-freezing mode reaches the adjustment target.

[0010] Optionally, the adjustment items of the first anti-freezing mode include one of increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the indoor fan speed of the air conditioner, and increasing the opening degree of the expansion valve of the air conditioner.

[0011] Optionally, the adjustment target is that the surface temperature Tr no longer meets the first anti-freezing mode starting condition, or the adjustment parameter of the adjustment item has been adjusted to the limit value.

[0012] Optionally, the adjustment strategy of at least one adjustment item is to adjust the corresponding adjustment parameter step by step until the adjustment target is reached.

[0013] Optionally, the adjustment items of the first anti-freezing mode include multiple items of increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the indoor fan speed of the air conditioner, and increasing the opening degree of the expansion valve of the air conditioner.

[0014] Optionally, in the first anti-freezing mode, each of the control items is executed in a preset order; and

[0015] If the surface temperature Tr no longer satisfies the first anti-freezing mode starting condition before the control parameter of the control item in the front of the order is adjusted to the limit value, it is determined that the adjustment target is achieved, otherwise the next control item is entered;

[0016] The control item in the last of the order makes the surface temperature Tr no longer satisfy the first anti-freezing mode starting condition, or the control parameter is adjusted to the limit value, and it is determined that the adjustment target is achieved.

[0017] Optionally, in the first anti-freezing mode, each of the control items is executed simultaneously.

[0018] When the surface temperature Tr no longer satisfies the first anti-freezing mode starting condition, or the control parameter of each of the control items is adjusted to the limit value, it is determined that the adjustment target is achieved.

[0019] Optionally, the surface temperature Tr satisfying the first anti-freezing mode starting condition comprises Tr≤T1, T1 being a preset freezing protection temperature.

[0020] Optionally, the second anti-freezing mode comprises controlling the compressor of the air conditioner to reduce frequency until stopping.

[0021] In another aspect, the present application also provides an air conditioner comprising a controller, the controller comprising a processor and a memory, the memory storing a computer program, the computer program being executed by the processor to implement the control method according to any one of the above.

[0022] In the control method of the present application, the anti-freezing program comprises a first anti-freezing mode and a second anti-freezing mode, the control items of the first anti-freezing mode comprising increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the rotation speed of the indoor fan of the air conditioner, and increasing the opening degree of the expansion valve of the air conditioner, and the second anti-freezing mode comprising controlling the compressor of the air conditioner to reduce frequency until stopping. The first anti-freezing mode is executed first, and when the adjustment target of the first anti-freezing mode is achieved, the second anti-freezing mode is started. Through the two adjustments, the anti-freezing target is gradually achieved, and the time of reducing frequency and stopping is shorter, avoiding large fluctuations in indoor temperature caused by directly reducing the frequency of the compressor or stopping the compressor.

[0023] Further, the control method of the present application, the first anti-freezing mode is designed with multiple control items, in the specific control, the preset order runs each control item. If the control parameter of the control item in the order is adjusted to the limit value before the surface temperature Tr no longer meets the first anti-freezing mode opening condition, it is judged that the adjustment target is achieved (subsequently entering the second anti-freezing mode), otherwise the next control item is entered; The control item in the last order makes the surface temperature Tr no longer meet the first anti-freezing mode opening condition, or the control parameter is adjusted to the limit value, and it is judged that the adjustment target is achieved (subsequently entering the second anti-freezing mode). In this way, the number of control items enabled can be minimized, and large temperature fluctuations can be avoided as much as possible.

[0024] The above and other objects, advantages and features of the present application will become more apparent from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] Some specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. The same reference numbers in different drawings denote the same or similar components or parts. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

[0026] Figure 1 is a schematic diagram of a circulating system of an air conditioner according to an embodiment of the present application;

[0027] Figure 2 is a schematic block diagram of an air conditioner according to an embodiment of the present application;

[0028] Figure 3 is a schematic diagram of an indoor unit structure of an air conditioner according to an embodiment of the present application;

[0029] Figure 4 is a schematic diagram of a control method of an air conditioner according to an embodiment of the present application;

[0030] Figure 5 is a flowchart of a control method of an air conditioner according to an embodiment of the present application;

[0031] Figure 6 is a flowchart of a control method of an air conditioner according to another embodiment of the present application. DETAILED DESCRIPTION

[0032] The air conditioner and the control method thereof according to the embodiments of the present application will be described below with reference to Figures 1 to 6

[0033] ​The computer program product of the present application can be a storage medium or a record medium such as a floppy disk, a CD-ROM, a DVD, a Blu-ray Disc™, a USB, a memory card, or a hard disk for example. The computer program element preferably enables a computer to execute the method of the application.

[0034] The flowcharts of the embodiments provided herein are not intended to indicate a special order of executing the operations of the methods, and not all of the operations of the methods are included in each embodiment. In addition, the methods can include additional operations. Additional changes can be made to the above-described methods within the scope of the technical ideas of the embodiments provided herein.

[0035] It should be noted that the logic and / or the steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, and can be specifically embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus or device, such as a computer-based system, a system including a processor, or other system that can fetch the instructions from the instruction execution system, apparatus or device and execute the instructions, or in conjunction with these instructions.

[0036] In one aspect, the embodiments of the present application provide an air conditioner. The air conditioner is used for adjusting indoor air, including adjusting temperature, humidity, air quality, humidifying, dehumidifying, introducing fresh air, etc. The air conditioner of the embodiments of the present application can be a household air conditioner or a central air conditioner. Specifically, the specific form of the air conditioner can be a split wall-mounted type, a split vertical type, an integrated type, a ceiling type, etc. The embodiments of the present application do not have any limitation on the specific form of the air conditioner.

[0037] Figure 1 is a schematic diagram of a circulating system of an air conditioner according to an embodiment of the present application; Figure 2 is a schematic block diagram of an air conditioner according to an embodiment of the present application; Figure 3 is a schematic diagram of an indoor unit structure of an air conditioner according to an embodiment of the present application.

[0038] As Figure 1As shown, the air conditioner of this embodiment of the invention consists of an evaporator 72, a condenser 74, a compressor 71, an expansion valve 73, and other necessary components forming a vapor compression refrigeration cycle system, which outputs cold / hot air through the indoor fan 30 to achieve cooling and heating of the indoor environment.

[0039] like Figure 2 As shown, the wall-mounted air conditioner indoor unit of this embodiment of the invention also includes a controller 800. The controller 800 includes a processor 810 and a memory 820. The memory 820 stores a computer program 821. When the computer program 821 is executed by the processor 810, it is used to implement the air conditioner control method of any of the following embodiments of the invention.

[0040] Figure 3 This illustrates the indoor unit of a split-type wall-mounted air conditioner. For example... Figure 3 As shown, the indoor unit of the air conditioner includes a housing 10, which defines a receiving space for accommodating the main components of the indoor unit, including an evaporator 72, an indoor fan 30, etc. An indoor air outlet 12 is provided at the lower front of the housing 10 to blow out heat exchange airflow. An indoor air inlet 11 is provided at the top of the housing 10 to draw in indoor air. An air duct 15 is defined inside the housing 10, and the outlet of the air duct 15 connects to the indoor air outlet 12. The indoor fan 30 is disposed within the housing 10 and is used to blow the regulated airflow within the housing 10 through the air duct 15 to the indoor air outlet 12 to regulate the indoor air. The regulated airflow may be, for example, heat exchange airflow (cold airflow, hot airflow), purification airflow, humidification airflow, fresh airflow, etc.

[0041] Another aspect of this invention provides a control method for an air conditioner. During air conditioner operation, various factors such as low inlet air temperature and insufficient refrigerant circulation often lead to excessively low surface temperatures of the evaporator 72, eventually resulting in ice formation, a condition known as evaporator freezing. Evaporator freezing can cause adverse consequences such as water leakage, water blowing, and ice buildup. The control method of this invention aims to prevent and eliminate evaporator freezing.

[0042] Figure 4 This is a schematic diagram of an air conditioner control method according to an embodiment of the present invention.

[0043] like Figure 4 As shown, the air conditioner control method of this embodiment generally includes the following steps:

[0044] Step S402: Obtain the surface temperature Tr of the evaporator 72 of the air conditioner. (e.g.) Figure 2 As shown, the air conditioner may include a temperature detection device 80 for detecting the surface temperature Tr of the evaporator 72. The temperature detection device 80 may be a temperature sensor.

[0045] Step S404: If the surface temperature Tr meets the conditions for activating the first antifreeze mode, activate the first antifreeze mode.

[0046] For example, the surface temperature Tr satisfies the conditions for activating the first antifreeze mode as follows: Tr≤T1, where T1 is the preset freezing protection temperature. When Tr≤T1, it is considered that the evaporator 72 has a high risk of freezing or may have already begun to freeze. The critical temperature at which the evaporator 72 is about to freeze can be determined through multiple experiments to reasonably determine the value of T1. For example, T1 can be 0℃, 1℃, 2℃, etc.

[0047] The goal of the first antifreeze mode is to delay the freezing process of the evaporator 72 or eliminate some of the freezing. However, during the operation of the first antifreeze mode, the compressor 71 should not be significantly reduced in frequency or even shut down, so as to avoid large fluctuations in indoor temperature.

[0048] Step S406: After the first anti-freeze mode achieves the adjustment target, the second anti-freeze mode is activated.

[0049] Specifically, the second anti-freeze mode includes controlling the air conditioner compressor 71 to reduce its frequency until it stops, thus stopping the air conditioner from cooling. Because the first anti-freeze mode (equivalent to an anti-freeze pre-process) is added, the second anti-freeze mode (equivalent to the main anti-freeze process) proceeds faster, meaning the time for compressor 71 to reduce its frequency and stop is shorter, resulting in shorter periods of indoor temperature fluctuation.

[0050] The inventors recognized that the main reasons for evaporator freezing are as follows: low air intake temperature of the indoor unit; severe throttling and uneven distribution of refrigerant due to insufficient refrigerant circulation; low indoor fan speed and low indoor air circulation volume; and dirty and clogged indoor filter.

[0051] Based on the above understanding, in some embodiments of the present invention, the aforementioned first antifreeze mode control items include increasing the air outlet area of ​​the indoor air outlet 12 of the air conditioner, increasing the speed of the indoor fan 30 of the air conditioner, and increasing the opening degree of the expansion valve 73 of the air conditioner. The air conditioner can select one of the above three items according to the experimental results, which is called "single item adjustment mode".

[0052] The following reference Figure 5 This section will introduce the optimal control process based on the aforementioned "single-item adjustment method".

[0053] Figure 5 This is a flowchart of an air conditioner control method according to an embodiment of the present invention.

[0054] like Figure 5 As shown, the air conditioner control method of one embodiment of the present invention sequentially performs the following steps:

[0055] Step S502: Air conditioning cooling operation.

[0056] Step S504: Obtain the surface temperature Tr of the evaporator 72 of the air conditioner.

[0057] Step S506: Determine whether the surface temperature Tr satisfies the first anti-frost mode starting condition. If yes, execute step S508, otherwise continue to execute step S502, so that the air conditioner continues to run in the cooling mode.

[0058] Step S508: Start the first anti-frost mode. That is, increase the air outlet area of the indoor air outlet 12 of the air conditioner, increase the rotation speed of the indoor fan 30 of the air conditioner, or increase the opening degree of the expansion valve 73 of the air conditioner.

[0059] Step S510: Determine whether the surface temperature Tr no longer satisfies the first anti-frost mode starting condition, or whether the adjustment parameter of the adjustment item has been adjusted to the limit value. If yes, execute step S512, otherwise continue to execute step S508.

[0060] Step S512: Start the second anti-frost mode.

[0061] In the foregoing steps, the adjustment target (hereinafter referred to as "adjustment target") of the first anti-frost mode is that the surface temperature Tr no longer satisfies the first anti-frost mode starting condition, or the adjustment parameter of the adjustment item has been adjusted to the limit value. Of course, it can be understood that if the above adjustment item is already at its limit value without adjustment, it is directly determined that the adjustment target of the first anti-frost mode is achieved.

[0062] For example, if the starting condition is set as Tr≤T1, then "the surface temperature Tr no longer satisfies the first anti-frost mode starting condition" means Tr>T1.

[0063] When the air outlet area of the indoor air outlet 12 is increased, if the air outlet area has been adjusted to the maximum, it indicates that the adjustment parameter has been adjusted to the limit value. When the rotation speed of the indoor fan 30 of the air conditioner is increased, if the rotation speed has been adjusted to the maximum rotation speed and cannot be further increased, it indicates that the adjustment parameter has been adjusted to the limit value. When the opening degree of the expansion valve 73 of the air conditioner is increased, if the opening degree has been adjusted to 100%, it indicates that the adjustment parameter has been adjusted to the limit value.

[0064] As shown in Figure 3 , the indoor unit of the air conditioner can include at least one air deflector 51, 52 for adjusting the air outlet area of the indoor air outlet 12, and also has a function of guiding the upward and downward air outlet angles of the indoor air outlet 12. As shown in Figure 3 , the number of air deflectors is two, which are the air deflector 51 and the air deflector 52 arranged in an up-down manner.

[0065] In the first anti-freezing mode, the regulation strategy of at least one regulation item is: adjusting the corresponding regulation parameter step by step until the regulation target is reached. Preferably, each regulation item is adjusted step by step.

[0066] For example, when the air outlet area of the indoor air outlet 12 is increased, if the air outlet area is already the maximum, it is directly determined that the regulation target is reached. If the air outlet area is not the maximum, the air outlet area is first appropriately increased in the first step, and then Tr is obtained. If "Tr no longer satisfies the first anti-freezing mode opening condition", it is determined that the regulation target is reached and the regulation is stopped. Otherwise, the second step of regulation is started. After the second step of regulation, Tr at this time is obtained. If "Tr no longer satisfies the first anti-freezing mode opening condition", it is determined that the regulation target is reached and the regulation is stopped. Otherwise, the third step of regulation is started. In this way, until "Tr no longer satisfies the first anti-freezing mode opening condition" or the air outlet area has reached the maximum and cannot be further regulated, the regulation is stopped.

[0067] When the speed of the indoor fan 30 of the air conditioner is increased, if the speed is already the maximum, it is directly determined that the regulation target is reached. If the speed is not the maximum, the speed is first appropriately increased in the first step, and then Tr is obtained. If "Tr no longer satisfies the first anti-freezing mode opening condition", it is determined that the regulation target is reached and the regulation is stopped. Otherwise, the second step of regulation is started. After the second step of regulation, Tr at this time is obtained. If "Tr no longer satisfies the first anti-freezing mode opening condition", it is determined that the regulation target is reached and the regulation is stopped. Otherwise, the third step of regulation is started. In this way, until "Tr no longer satisfies the first anti-freezing mode opening condition" or the speed has reached the maximum and cannot be further regulated, the regulation is stopped.

[0068] When the opening degree of the expansion valve 73 of the air conditioner is increased, if the opening degree is already the maximum, it is directly determined that the regulation target is reached. If the opening degree is not the maximum, the opening degree is first appropriately increased in the first step, and then Tr is obtained. If "Tr no longer satisfies the first anti-freezing mode opening condition", it is determined that the regulation target is reached and the regulation is stopped. Otherwise, the second step of regulation is started. After the second step of regulation, Tr at this time is obtained. If "Tr no longer satisfies the first anti-freezing mode opening condition", it is determined that the regulation target is reached and the regulation is stopped. Otherwise, the third step of regulation is started. In this way, until "Tr no longer satisfies the first anti-freezing mode opening condition" or the opening degree has reached the maximum and cannot be further regulated, the regulation is stopped.

[0069] In some embodiments, the regulation items of the first anti-freezing mode include multiple of the following: increasing the air outlet area of the indoor air outlet 12 of the air conditioner, increasing the speed of the indoor fan 30 of the air conditioner, and increasing the opening degree of the expansion valve 73 of the air conditioner. For example, any two of them, or all three of them.

[0070] In the first anti-freezing mode, the control items are operated in a preset order. If the surface temperature Tr no longer satisfies the first anti-freezing mode starting condition before the control parameter of the control item at the front of the order is adjusted to the limit value, it is determined that the adjustment target is achieved, otherwise the next control item is entered. The control item at the end of the order makes the surface temperature Tr no longer satisfy the first anti-freezing mode starting condition, or the control parameter is adjusted to the limit value, and it is determined that the adjustment target is achieved.

[0071] For example, all the three control items can be adopted, and the control order is designed as follows: first, increase the air outlet area of the indoor air outlet 12 of the air conditioner, then increase the rotating speed of the indoor fan 30 of the air conditioner, and finally increase the opening degree of the expansion valve 73 of the air conditioner. The following refers to the control scheme of this embodiment. Figure 6 The control scheme of this embodiment is introduced.

[0072] Figure 6 is a flow chart of a control method of an air conditioner according to another embodiment of the present application.

[0073] Step S602: The air conditioner is operated in cooling mode.

[0074] Step S604: The surface temperature Tr of the evaporator 72 of the air conditioner is obtained.

[0075] Step S606: It is determined whether the surface temperature Tr satisfies the first anti-freezing mode starting condition. If yes, step S608 is executed, otherwise step S602 is continuously executed to make the air conditioner continue to operate in cooling mode.

[0076] Step S608: The air outlet area of the indoor air outlet 12 is gradually increased.

[0077] Step S610: It is determined whether "Tr no longer satisfies the first anti-freezing mode starting condition before the air outlet area is adjusted to the maximum value" is true. If yes, step S618 is executed to control the compressor 71 to reduce the frequency until it stops. If no, step S612 is executed.

[0078] Step S612: The rotating speed of the indoor fan 30 is gradually increased.

[0079] Step S614: It is determined whether "Tr no longer satisfies the first anti-freezing mode starting condition before the rotating speed of the indoor fan is adjusted to the maximum value" is true. If yes, step S618 is executed to control the compressor 71 to reduce the frequency until it stops. If no, step S616 is executed.

[0080] Step S616: The opening degree of the expansion valve 73 is increased until Tr no longer satisfies the first anti-freezing mode starting condition, or the opening degree of the expansion valve 73 is adjusted to the maximum value.

[0081] Step S618: The compressor 71 is controlled to reduce the frequency until it stops.

[0082] The anti-freezing procedure of the embodiment of the present application comprises a first anti-freezing mode and a second anti-freezing mode. The first anti-freezing mode comprises increasing the air outlet area of the indoor air outlet 12, increasing the rotating speed of the indoor fan 30, and increasing the opening degree of the expansion valve 73. The second anti-freezing mode comprises reducing the rotating speed of the compressor 71 until the compressor 71 stops. The first anti-freezing mode is run first, and then the second anti-freezing mode is started when the adjustment target of the first anti-freezing mode is reached. Through the double adjustment, the anti-freezing target is gradually reached, and the large fluctuation of the indoor temperature caused by directly reducing the rotating speed of the compressor 71 or stopping the compressor 71 is avoided.

[0083] In the specific control, each adjustment item is run in the preset order. If the adjustment parameter of the adjustment item in the front of the order is adjusted to the limit value before the surface temperature Tr no longer satisfies the starting condition of the first anti-freezing mode, it is determined that the adjustment target is reached (and then the second anti-freezing mode is entered), otherwise the next adjustment item is entered. The adjustment item in the end of the order makes the surface temperature Tr no longer satisfy the starting condition of the first anti-freezing mode, or the adjustment parameter is adjusted to the limit value, and it is determined that the adjustment target is reached (and then the second anti-freezing mode is entered). In this way, the adjustment items can be reduced as much as possible, and the large fluctuation of the temperature can be avoided as much as possible.

[0084] In other embodiments, each adjustment item is simultaneously executed in the first anti-freezing mode. When the surface temperature Tr no longer satisfies the starting condition of the first anti-freezing mode, or the adjustment parameter of each adjustment item is adjusted to the limit value, it is determined that the adjustment target is reached.

[0085] At this point, those skilled in the art should recognize that although the multiple exemplary embodiments of the present application have been shown and described in detail herein, many other variations or modifications can be determined or deduced directly from the disclosure of the present application according to the principles of the present application without departing from the spirit and scope of the present application. Therefore, the scope of the present application should be understood and recognized as covering all these other variations or modifications.

Claims

1.A control method of an air conditioner, comprising: obtaining a surface temperature Tr of an evaporator of the air conditioner; starting a first anti-freezing mode if the surface temperature Tr meets a first anti-freezing mode starting condition; starting a second anti-freezing mode after the first anti-freezing mode achieves a regulation target; in the first anti-freezing mode, sequentially operating in an order of increasing an air outlet area of an indoor air outlet of the air conditioner, increasing a rotation speed of an indoor fan of the air conditioner, and increasing an opening degree of an expansion valve of the air conditioner, and if a regulation parameter of a regulation item in the front of the order is regulated to a limit value before the surface temperature Tr no longer meets the first anti-freezing mode starting condition, determining that the regulation target is achieved, otherwise, entering a next regulation item; if the regulation parameter of the regulation item at the end of the order is regulated to the limit value or the surface temperature Tr no longer meets the first anti-freezing mode starting condition, determining that the regulation target is achieved; the second anti-freezing mode comprises: controlling a compressor of the air conditioner to reduce frequency until stopping. 2.The control method of claim 1, wherein the regulation item of the first anti-freezing mode comprises one of increasing the air outlet area of the indoor air outlet of the air conditioner, increasing the rotation speed of the indoor fan of the air conditioner, and increasing the opening degree of the expansion valve of the air conditioner. 3.The control method of claim 2, wherein the regulation target is that the surface temperature Tr no longer meets the first anti-freezing mode starting condition or the regulation parameter of the regulation item is regulated to the limit value. 4.The control method of claim 3, wherein a regulation strategy of at least one of the regulation items is: adjusting the corresponding regulation parameter step by step until the regulation target is achieved. 5.The control method of claim 1, wherein The surface temperature Tr satisfies a first anti-freezing mode starting condition, which includes: Tr≤T1, T1 is a preset freezing protection temperature. 6.An air conditioner comprising a controller, the controller comprising a processor and a memory, the memory storing a computer program, the computer program being executed by the processor to implement the control method according to any one of claims 1 to 5.

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