Air conditioner

Abstract

The application discloses an air conditioner, which comprises a refrigerant circulation loop, an indoor fan, an outdoor fan, an indoor air blower, an outdoor air blower, an outdoor return air temperature sensor, an indoor return air temperature sensor, an indoor outlet air temperature sensor, and a controller configured to: in response to an instruction of air conditioner refrigeration operation, preliminarily judge whether the air conditioner has refrigerant leakage according to the indoor outlet air temperature; when it is preliminarily judged that the air conditioner has refrigerant leakage, control the compressor to stop operation, and after a first preset time, control the compressor to start again, and after the air conditioner operates according to preset parameters for a second preset time, calculate the current refrigeration capacity of the air conditioner according to the current first indoor outlet air temperature and the current first indoor return air temperature, determine the refrigerant leakage degree of the air conditioner according to the current refrigeration capacity, and improve the accuracy of judging refrigerant leakage and the safety of air conditioner operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to an air conditioner. BACKGROUND

[0002] In the production, transportation, installation and use of air conditioners, there may be a phenomenon of refrigerant leakage. When a large amount of refrigerant leaks, if the compressor continues to operate, the temperature of the compressor winding will rise sharply, causing the lubricating oil to vaporize at high temperature, at which time there is a risk of explosion when encountering an electric spark. In the prior art, the leakage protection of refrigerant is basically based on the difference between the return air temperature and the coil temperature, or the exhaust gas superheat or the current load. Although the above measures can predict refrigerant leakage, there will be misjudgments to varying degrees, for example, when the outdoor environment temperature changes, the exhaust gas temperature rises too fast, the compressor frequency changes too fast, and the coil temperature changes too fast, which will all affect the discrimination of refrigerant leakage. Therefore, how to accurately determine whether the air conditioning system has refrigerant leakage and to alarm when the air conditioning system has refrigerant leakage is a problem to be solved. SUMMARY

[0003] The present application aims to at least solve one of the problems in the prior art. To this end, the object of the present application is to propose an air conditioner.

[0004] The air conditioner provided by the application comprises: a refrigerant circulation loop, which enables refrigerant to perform refrigeration circulation in a loop composed of a compressor, a condenser, an expansion valve and an evaporator, one of the condenser and the evaporator being an outdoor heat exchanger and the other being an indoor heat exchanger; an indoor fan, which is used to drive indoor air to pass through the indoor heat exchanger so that the refrigerant exchanges heat with the indoor air; an outdoor fan, which is used to drive outdoor air to pass through the outdoor heat exchanger so that the refrigerant exchanges heat with the outdoor air; an indoor fan motor, which is used to drive the indoor fan to rotate; an outdoor fan motor, which is used to drive the outdoor fan to rotate; an outdoor return air temperature sensor, which is used to detect the outdoor return air temperature of the air conditioner; an indoor return air temperature sensor, which is used to detect the indoor return air temperature of the air conditioner; an indoor outlet air temperature sensor, which is used to detect the indoor outlet air temperature of the air conditioner; and a controller, which is configured to: in response to an instruction for the air conditioner to perform refrigeration, control the compressor to start so that the air conditioner performs refrigeration; preliminarily determine whether the air conditioner leaks refrigerant according to the indoor outlet air temperature; when it is preliminarily determined that the air conditioner leaks refrigerant, control the compressor to stop running, and after a first preset time, control the compressor to start again, and control the operating frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan to run according to preset parameters for a second preset time, then acquire a current first indoor outlet air temperature and a current first indoor return air temperature, calculate the current refrigeration capacity of the air conditioner according to the current first indoor outlet air temperature and the current first indoor return air temperature, determine the refrigerant leakage degree of the air conditioner according to the current refrigeration capacity, and control the compressor to continue running or stop running according to the refrigerant leakage degree.

[0005] In addition, the air conditioner according to the embodiment of the application can further have the following additional technical features.

[0006] Further, when preliminarily determining whether the air conditioner leaks refrigerant according to the indoor outlet air temperature, the controller is specifically configured to: when the operating time of the compressor reaches a third preset time, acquire a current second indoor outlet air temperature; and when the operating time of the compressor reaches a fourth preset time, acquire a current third indoor outlet air temperature; preliminarily determine whether the air conditioner leaks refrigerant according to the second indoor outlet air temperature and the third indoor outlet air temperature; and the third preset time is less than the fourth preset time.

[0007] Further, when the controller preliminarily determines that the air conditioner has refrigerant leakage according to the second indoor air outlet temperature and the third indoor air outlet temperature, the controller is specifically configured to: preliminarily determine that the air conditioner has refrigerant leakage when an absolute value of a difference between the second indoor air outlet temperature and the third indoor air outlet temperature is less than a preset difference; and preliminarily determine that the air conditioner does not have refrigerant leakage when the absolute value of the difference between the second indoor air outlet temperature and the third indoor air outlet temperature is not less than the preset difference.

[0008] Further, after preliminarily determining that the air conditioner has refrigerant leakage, the controller is further configured to: return to performing the step of preliminarily determining whether the air conditioner has refrigerant leakage according to the indoor air outlet temperature again.

[0009] Further, when the controller controls the operating frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan to operate according to preset parameters, the controller is specifically configured to: obtain a current fourth indoor return air temperature and a current outdoor return air temperature; determine a first operating frequency of the compressor, a first opening degree of the expansion valve, a first rotating speed of the outdoor fan and a second rotating speed of the indoor fan according to the current fourth indoor return air temperature and the current outdoor return air temperature; control the compressor to operate at the first operating frequency, control the opening degree of the expansion valve to reach a first preset opening degree, control the outdoor fan to operate at the first rotating speed, and control the indoor fan to operate at the second rotating speed.

[0010] Further, when the controller determines the first operating frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan and the second rotating speed of the indoor fan according to the current fourth indoor return air temperature and the current outdoor return air temperature, the controller is specifically configured to: determine the first operating frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan and the second rotating speed of the indoor fan according to the current fourth indoor return air temperature and the current outdoor return air temperature by table lookup.

[0011] Further, when the controller calculates the current refrigerating capacity of the air conditioner according to the current first indoor air outlet temperature and the current first indoor return air temperature, the controller is specifically configured to calculate the current refrigerating capacity by the following formula:

[0012] Q1=v0*k*(Tc-Th),

[0013] wherein Q1 is the current refrigerating capacity, k is an air volume conversion coefficient, Tc is the current first indoor air outlet temperature, and Th is the current first indoor return air temperature.

[0014] Further, the controller is configured to determine the refrigerant leakage degree of the air conditioner according to the current refrigeration capacity, and control the compressor to continue running or stop running according to the refrigerant leakage degree, by: obtaining a preset refrigeration capacity corresponding to the preset parameter; determining a refrigerant leakage amount according to the current refrigeration capacity and the preset refrigeration capacity; determining the refrigerant leakage degree of the air conditioner according to the refrigerant leakage amount, and controlling the compressor to continue running or stop running according to the refrigerant leakage degree.

[0015] Further, when determining the refrigerant leakage amount according to the current refrigeration capacity and the preset refrigeration capacity, the controller is specifically configured to calculate the refrigerant leakage amount by the following formula:

[0016] J = Q1 / Qi * b * 100%,

[0017] wherein J is the refrigerant leakage amount, Q1 is the current refrigeration capacity, Qi is the preset refrigeration capacity, and b is a refrigerant leakage coefficient.

[0018] Further, when determining the refrigerant leakage degree of the air conditioner according to the refrigerant leakage amount, and controlling the compressor to continue running or stop running according to the refrigerant leakage degree, the controller is specifically configured to: when the refrigerant leakage amount is greater than a first preset value, determine that the air conditioner has no refrigerant leakage, and control the compressor to continue running; when the refrigerant leakage amount is greater than a second preset value and not greater than the first preset value, determine that the air conditioner has partial refrigerant leakage, control the compressor to continue running, and issue an alarm information; when the refrigerant leakage amount is greater than a third preset value and not greater than the second preset value, determine that the air conditioner has serious refrigerant leakage, control the compressor to stop running, and issue an alarm information; when the refrigerant leakage amount is less than the third preset value, determine that the air conditioner has complete refrigerant leakage, control the compressor to stop running, and issue an alarm information; wherein the first preset value is greater than the second preset value, and the second preset value is greater than the third preset value.

[0019] According to the air conditioner of the embodiment of the present application, in response to the instruction of the refrigeration operation of the air conditioner, the compressor is controlled to start, whether the air conditioner has refrigerant leakage is preliminarily judged according to the indoor outlet air temperature; when it is preliminarily judged that the air conditioner has refrigerant leakage, the compressor is controlled to stop running, and after the first preset time, the compressor is controlled to start again, and the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan are controlled to run according to the preset parameters for the second preset time, then the current first indoor outlet air temperature and the current first indoor return air temperature are obtained, the current refrigeration capacity of the air conditioner is calculated according to the current first indoor outlet air temperature and the current first indoor return air temperature, the refrigerant leakage degree of the air conditioner is determined according to the current refrigeration capacity, and the compressor is controlled to continue running or stop running according to the refrigerant leakage degree, which can improve the accuracy of judging whether the refrigerant has leakage and the safety of the operation of the air conditioner. Further, after it is preliminarily determined that the air conditioner has refrigerant leakage, the step of preliminarily judging whether the air conditioner has refrigerant leakage according to the indoor outlet air temperature is executed again, which can further improve the accuracy of judging whether the refrigerant has leakage.

[0020] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood by considering the following detailed description, from which the above-mentioned aspects and advantages of the present application will become apparent, and in part will be realized.

[0022] Figure 1 is a structural schematic diagram of an air conditioner according to an embodiment of the present application;

[0023] Figure 2 is a flow chart of preliminarily judging whether the air conditioner has refrigerant leakage according to the indoor outlet air temperature according to an embodiment of the present application;

[0024] Figure 3 is a flow chart of preliminarily judging whether the air conditioner has refrigerant leakage according to the second indoor outlet air temperature and the third indoor outlet air temperature according to an embodiment of the present application;

[0025] Figure 4 is a flow chart of controlling the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan to run according to the preset parameters according to an embodiment of the present application;

[0026] Figure 5 is a flow chart of determining the refrigerant leakage degree of the air conditioner according to the current refrigeration capacity according to an embodiment of the present application;

[0027] Figure 6is a flowchart of determining a refrigerant leakage degree of an air conditioner according to a refrigerant leakage amount and controlling a compressor to continue operation or stop operation according to the refrigerant leakage degree according to an embodiment of the present application;

[0028] Figure 7 is a flowchart of a control method of an air conditioner according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0030] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0031] The terms "first", "second" are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0032] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] In the present application, the air conditioner performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, an expansion valve and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation, and supplies refrigerant to the air that has been adjusted and heat exchanged.

[0034] The compressor compresses a refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the ambient environment through the condensation process.

[0035] The expansion valve expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant 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 exchanging heat with a material to be cooled using latent heat of evaporation of the refrigerant. Throughout the cycle, the air conditioner can adjust the temperature of an indoor space.

[0036] The outdoor unit of the air conditioner refers to a portion of the refrigeration cycle including the compressor and the outdoor heat exchanger, the indoor unit of the air conditioner includes the indoor heat exchanger, and the expansion valve can be provided in the indoor unit or the outdoor unit.

[0037] The indoor heat exchanger and the outdoor heat exchanger serve as a condenser or an evaporator. When the indoor heat exchanger serves as a condenser, the air conditioner serves as a heater in a heating mode, and when the indoor heat exchanger serves as an evaporator, the air conditioner serves as a cooler in a cooling mode.

[0038] Hereinafter, a description will be given of an air conditioner according to an embodiment of the present application with reference to the accompanying drawings. Figures 1-7 An air conditioner according to an embodiment of the present application is described.

[0039] Figure 1 FIG. 1 is a structural schematic view of an air conditioner according to an embodiment of the present application. As shown in FIG. 1, the air conditioner includes a compressor 1, a condenser 2, an expansion valve 3, and an evaporator 4. Figure 1As shown, an air conditioner comprises: an indoor fan 10, a refrigerant circulation loop 20, an outdoor fan 30, an outdoor heat exchanger 40, an indoor heat exchanger 50, an indoor fan 60, an outdoor fan 70, an outdoor return air temperature sensor 80, an indoor return air temperature sensor 90, an indoor outlet air temperature sensor 100 and a controller 110. Wherein the refrigerant circulation loop 20 makes the refrigerant in the compressor, the condenser, the expansion valve and the evaporator to carry out the refrigeration cycle, one of the condenser and the evaporator is the outdoor heat exchanger 40, and the other is the indoor heat exchanger 50; the indoor fan 10 is used to drive the indoor air to pass through the indoor heat exchanger 50, so that the refrigerant exchanges heat with the indoor air; the outdoor fan 30 is used to drive the outdoor air to pass through the outdoor heat exchanger 40, so that the refrigerant exchanges heat with the outdoor air; the indoor fan is used to drive the indoor fan 10 to rotate; the outdoor fan 70 is used to drive the outdoor fan 30 to rotate; the outdoor return air temperature sensor 80 is used to detect the outdoor return air temperature of the air conditioner; the indoor return air temperature sensor 90 is used to detect the indoor return air temperature of the air conditioner; the indoor outlet air temperature sensor 100 is used to detect the indoor outlet air temperature of the air conditioner; the controller 110 is configured to: in response to the instruction of the refrigeration operation of the air conditioner, control the compressor to start, so that the air conditioner refrigeration runs; according to the indoor outlet air temperature, preliminarily judge whether the air conditioner occurs refrigerant leakage; when preliminarily judging that the air conditioner occurs refrigerant leakage, control the compressor to stop running, and after a first preset time, control the compressor to start again, and control the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan 70 and the rotating speed of the indoor fan 60 to run according to the preset parameters for a second preset time, then obtain the current first indoor outlet air temperature and the current first indoor return air temperature, calculate the current refrigeration capacity of the air conditioner according to the current first indoor outlet air temperature and the current first indoor return air temperature, determine the refrigerant leakage degree of the air conditioner according to the current refrigeration capacity, so as to control the compressor to continue running or stop running according to the refrigerant leakage degree.

[0040] Specifically, when the air conditioner is running in the refrigeration state, if the refrigerant amount in the air conditioner is sufficient, with the accumulation of the running time of the compressor, the indoor ambient temperature gradually decreases, and the air supply temperature passing through the indoor heat exchanger 50 also gradually decreases. When the indoor and outdoor ambient temperatures are stable, the indoor return air temperature and the indoor outlet air temperature of the air conditioner also remain within a certain range. In specific embodiments, when the air conditioner is running in the refrigeration mode, from the start of the compressor to when the air conditioner system tends to be stable, the indoor outlet air temperature of the air conditioner presents a process of first rapidly decreasing to slowly decreasing, and then gradually stabilizing. Therefore, according to the change of the indoor outlet air temperature of the air conditioner in the refrigeration process, it can be preliminarily judged whether the air conditioner has refrigerant leakage. When the air conditioner has refrigerant leakage, according to the different degrees of refrigerant leakage of the air conditioner, the refrigeration effect, i.e. the refrigeration capacity, of the air conditioner is also different. Therefore, after preliminarily judging whether the air conditioner has refrigerant leakage, by calculating the real-time refrigeration capacity of the air conditioner and comparing it with the preset refrigeration capacity, according to the comparison result, it can be determined whether the air conditioner has refrigerant leakage and the degree of refrigerant leakage of the air conditioner, which can improve the accuracy of judging whether the refrigerant has leaked and the safety of the air conditioner operation.

[0041] In an embodiment of the present application, as shown in Figure 2 When preliminarily judging whether the air conditioner has refrigerant leakage according to the indoor outlet air temperature, the controller 110 is specifically configured to: obtain the current second indoor outlet air temperature when the running time of the compressor reaches a third preset time; and obtain the current third indoor outlet air temperature when the running time of the compressor reaches a fourth preset time; preliminarily judge whether the air conditioner has refrigerant leakage according to the second indoor outlet air temperature and the third indoor outlet air temperature; and the third preset time is less than the fourth preset time.

[0042] Specifically, when the air conditioner is running in the refrigeration mode, from the start of the compressor to when the air conditioner system tends to be stable, the indoor outlet air temperature presents a process of first rapidly decreasing to slowly decreasing, and then gradually stabilizing. In specific embodiments, when the cumulative running time of the compressor reaches a third preset time such as t3, the second indoor outlet air temperature such as T2 of the air conditioner is obtained through the indoor outlet air temperature sensor 100, and when the compressor continues to run to a fourth running time such as t4, the third indoor outlet air temperature such as T3 of the air conditioner is obtained through the indoor outlet air temperature sensor 100. Then, according to the second indoor outlet air temperature T2 and the third indoor outlet air temperature T3, it can be preliminarily judged whether the air conditioner has refrigerant leakage, so that after preliminarily judging whether the air conditioner has refrigerant leakage, the degree of refrigerant leakage of the air conditioner is determined according to the refrigeration capacity, the compressor is controlled to continue to run or stop running according to the degree of refrigerant leakage, the accuracy of judging whether the refrigerant has leaked is improved, and the safety of the air conditioner operation is improved.

[0043] In an embodiment of the present application, as shown in Figure 3As shown, when preliminarily judging whether the air conditioner has refrigerant leakage according to the second indoor air outlet temperature and the third indoor air outlet temperature, the controller 110 is specifically configured to preliminarily determine that the air conditioner has refrigerant leakage when the absolute value of the difference between the second indoor air outlet temperature and the third indoor air outlet temperature is less than a preset difference value, and preliminarily determine that the air conditioner does not have refrigerant leakage when the absolute value of the difference between the second indoor air outlet temperature and the third indoor air outlet temperature is not less than the preset difference value.

[0044] Specifically, when the air conditioner does not have refrigerant leakage, the third indoor air outlet temperature, for example, Tc1, is much lower than the second indoor air outlet temperature, for example, Tc0, within a period of time, for example, 10 minutes, after the compressor starts refrigeration, and thus the air conditioner is preliminarily determined to have refrigerant leakage according to the absolute value of the difference between the second indoor air outlet temperature Tc0 and the third indoor air outlet temperature Tc1. Specifically, when the absolute value of the difference between the second indoor air outlet temperature Tc0 and the third indoor air outlet temperature Tc1 is less than a preset difference value, for example, n, i.e., |Tc1-Tc0|<n, it is preliminarily determined that the air conditioner has refrigerant leakage; and when the absolute value of the difference between the second indoor air outlet temperature Tc0 and the third indoor air outlet temperature Tc1 is not less than the preset difference value n, it is preliminarily determined that the air conditioner does not have refrigerant leakage. Preferably, n is 0-5.

[0045] In an embodiment of the present application, after preliminarily determining that the air conditioner has refrigerant leakage, the controller 110 is further configured to return to the step of preliminarily judging whether the air conditioner has refrigerant leakage according to the indoor air outlet temperature.

[0046] Specifically, if the fourth preset time is small, i.e., the third indoor air outlet temperature is obtained before the indoor air outlet temperature rapidly decreases, the preliminary judgment of whether the air conditioner has refrigerant leakage according to the absolute value of the difference between the second indoor air outlet temperature and the third indoor air outlet temperature may be wrong. In order to further improve the accuracy of the judgment of whether the refrigerant has leakage, after preliminarily determining that the air conditioner has refrigerant leakage, the compressor is stopped for a period of time and then restarted, and the step of preliminarily judging whether the air conditioner has refrigerant leakage according to the indoor air outlet temperature is returned to. If the absolute value of the difference between the second indoor air outlet temperature and the third indoor air outlet temperature is still less than the preset difference value, it is preliminarily determined that the air conditioner has refrigerant leakage, and thus the refrigerant leakage degree of the air conditioner is determined according to the refrigeration capacity, the compressor is controlled to continue running or stop running according to the refrigerant leakage degree, and the accuracy of the judgment of whether the refrigerant has leakage and the safety of the operation of the air conditioner are improved.

[0047] In an embodiment of the present application, as shown in FIG. 2, the controller 110 is specifically configured to preliminarily determine whether the air conditioner has refrigerant leakage according to the indoor air outlet temperature. Figure 4As shown, when the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan 70 and the rotating speed of the indoor fan 60 are controlled to run according to the preset parameters, the controller 110 is specifically configured to: acquire the current fourth indoor return air temperature and the current outdoor return air temperature; determine the first running frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan 70 and the second rotating speed of the indoor fan 60 according to the current fourth indoor return air temperature and the current outdoor return air temperature; control the compressor to run at the first running frequency, control the opening degree of the expansion valve to reach the first preset opening degree, control the outdoor fan 70 to run at the first rotating speed, and control the indoor fan 60 to run at the second rotating speed.

[0048] Specifically, after it is preliminarily determined that the air conditioner has refrigerant leakage, the compressor is controlled to stop running for a period of time and then start again, so that the air conditioner runs according to the preset refrigerant leakage judgment running program, thereby calculating the real-time refrigerating capacity of the air conditioner and comparing it with the preset refrigerating capacity, and determining whether the air conditioner has refrigerant leakage and the degree of refrigerant leakage of the air conditioner according to the comparison result. That is, when the compressor is controlled to start again, the current fourth indoor return air temperature T4 and the current outdoor return air temperature T5 are acquired, the first running frequency f of the compressor, the first opening degree p of the expansion valve, the first rotating speed V1 of the outdoor fan and the second rotating speed V2 of the indoor fan are determined according to the fourth indoor return air temperature T4 and the current outdoor return air temperature T5, and the compressor is controlled to run at the first running frequency f, the opening degree of the expansion valve is controlled to reach the first preset opening degree p, the outdoor fan is controlled to run at the first rotating speed V1, and the indoor fan is controlled to run at the second rotating speed V2.

[0049] In an embodiment of the present application, when the first running frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan 70 and the second rotating speed of the indoor fan 60 are determined according to the current fourth indoor return air temperature and the current outdoor return air temperature, the controller 110 is specifically configured to: determine the first running frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan 70 and the second rotating speed of the indoor fan 60 according to the current fourth indoor return air temperature and the current outdoor return air temperature by table lookup.

[0050] In specific embodiments, different fourth indoor return air temperature and different outdoor return air temperature combinations correspond to different first operating frequencies of the compressor, different first opening degrees of the expansion valve, different first rotating speeds of the outdoor fan 70 and different second rotating speeds of the indoor fan 60, so that after obtaining the fourth indoor return air temperature and the outdoor return air temperature, the first operating frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan 70 and the second rotating speed of the indoor fan 60 can be obtained by looking up the table. It should be noted that the corresponding relationship between different fourth indoor return air temperatures and different outdoor return air temperatures and the first operating frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan 70 and the second rotating speed of the indoor fan 60 can be preset according to experiments, which will not be described here.

[0051] In an embodiment of the present application, when calculating the current refrigerating capacity of the air conditioner according to the current first indoor outlet air temperature and the current first indoor return air temperature, the controller 110 is specifically configured to calculate the current refrigerating capacity by the following formula:

[0052] Q1 = v0 * k * (Tc - Th),

[0053] Wherein, Q1 is the current refrigerating capacity, k is the air volume conversion coefficient, Tc is the current first indoor outlet air temperature, and Th is the current first indoor return air temperature.

[0054] Specifically, after initially determining that the air conditioner has refrigerant leakage, the compressor is controlled to stop running for a period of time and then start again. At this time, the air conditioner is operated according to the pre-set refrigerant leakage judgment operation program, that is, the operating frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan 70 and the rotating speed of the indoor fan 60 are operated according to the pre-set parameters for a second pre-set time, then the current first indoor outlet air temperature and the current first indoor return air temperature are obtained, and the current refrigerating capacity is calculated. The refrigerating capacity is compared with the pre-set refrigerating capacity to determine whether the air conditioner has refrigerant leakage and the degree of refrigerant leakage of the air conditioner. It should be noted that the air volume conversion coefficient is a coefficient related to the actual rotating speed of the indoor fan, which can be determined according to experiments.

[0055] In an embodiment of the present application, as shown in Figure 5 When determining the degree of refrigerant leakage of the air conditioner according to the current refrigerating capacity to control the compressor to continue running or stop running, the controller 110 is configured to: obtain a pre-set refrigerating capacity corresponding to the pre-set parameters; determine the refrigerant leakage amount according to the current refrigerating capacity and the pre-set refrigerating capacity; determine the degree of refrigerant leakage of the air conditioner according to the refrigerant leakage amount, and control the compressor to continue running or stop running according to the degree of refrigerant leakage.

[0056] Specifically, the preset refrigerating capacity is a refrigerating capacity of the air conditioner when the refrigerant leakage does not occur, and the air conditioner operates according to preset parameters, that is, the compressor operates at the first operating frequency, the expansion valve is opened at the first opening degree, the outdoor fan 70 operates at the first rotating speed, and the indoor fan 60 operates at the second rotating speed for a second preset time. In specific embodiments, the refrigerating capacities corresponding to different preset parameters can be pre-stored in the memory in the form of a table. In specific embodiments, after the current refrigerating capacity is calculated, the pre-stored preset refrigerating capacity is obtained from the memory, so as to determine the refrigerant leakage amount according to the current refrigerating capacity and the preset refrigerating capacity; the refrigerant leakage degree of the air conditioner is determined according to the refrigerant leakage amount, and the compressor is controlled to continue operating or stop operating according to the refrigerant leakage degree, so as to reduce the safety hazard caused by the refrigerant leakage and improve the safety of the air conditioner operation.

[0057] In an embodiment of the present application, when the refrigerant leakage amount is determined according to the current refrigerating capacity and the preset refrigerating capacity, the controller 110 is specifically configured to calculate the refrigerant leakage amount by the following formula:

[0058] J = Q1 / Qi * b * 100%,

[0059] wherein J is the refrigerant leakage amount, Q1 is the current refrigerating capacity, Qi is the preset refrigerating capacity, and b is the refrigerant leakage coefficient.

[0060] In specific embodiments, b is a coefficient related to the actual rotating speed of the indoor fan 60, and is a first-order function of the rotating speed of the indoor fan 60.

[0061] In an embodiment of the present application, as shown in Figure 6 when the refrigerant leakage degree of the air conditioner is determined according to the refrigerant leakage amount, and the compressor is controlled to continue operating or stop operating according to the refrigerant leakage degree, the controller 110 is specifically configured to: when the refrigerant leakage amount is greater than a first preset value, it is determined that the air conditioner has no refrigerant leakage, and the compressor is controlled to continue operating; when the refrigerant leakage amount is greater than a second preset value and not greater than the first preset value, it is determined that the air conditioner has partial refrigerant leakage, the compressor is controlled to continue operating, and an alarm information is sent; when the refrigerant leakage amount is greater than a third preset value and not greater than the second preset value, it is determined that the air conditioner has serious refrigerant leakage, the compressor is controlled to stop operating, and an alarm information is sent; when the refrigerant leakage amount is less than the third preset value, it is determined that the air conditioner has complete refrigerant leakage, the compressor is controlled to stop operating, and an alarm information is sent; wherein the first preset value is greater than the second preset value, and the second preset value is greater than the third preset value.

[0062] Specifically, according to the size of the refrigerant leakage amount, it is determined whether the refrigerant leaks or not, and the degree of refrigerant leakage is determined, the compressor is controlled to continue running or stop running according to the degree of refrigerant leakage, and the safety of the air conditioner running is improved. In a specific embodiment, the first preset value is 90%, the second preset value is 70%, and the third preset value is 20%. When the refrigerant leakage amount is greater than 90%, it is determined that the refrigerant does not leak, and the air conditioner continues to run. When the refrigerant leakage amount is greater than 70% and not greater than 90%, it is determined that the refrigerant leaks partially, the air conditioner continues to run, and an alarm information is sent. When the refrigerant leakage amount is greater than 20% and not greater than 70%, it is determined that the refrigerant of the air conditioner leaks seriously, the compressor is controlled to stop running, and an alarm information is sent. When the refrigerant leakage amount is less than 20%, it is determined that the refrigerant of the air conditioner leaks completely, the compressor is controlled to stop running, and an alarm information is sent. It can be understood that a sound alarm such as a buzzer or a light alarm indicator light can be used for alarm.

[0063] According to the air conditioner of the embodiment of the present application, in response to the instruction of the air conditioner refrigeration operation, the compressor is controlled to start, whether the air conditioner leaks refrigerant is preliminarily determined according to the indoor outlet air temperature; when it is preliminarily determined that the air conditioner leaks refrigerant, the compressor is controlled to stop running, and after a first preset time, the compressor is controlled to start again, and the running frequency of the compressor, the opening degree of the expansion valve, the speed of the outdoor fan 70 and the speed of the indoor fan 60 are controlled to run according to the preset parameters for a second preset time, then the current first indoor outlet air temperature and the current first indoor return air temperature are obtained, the current refrigeration capacity of the air conditioner is calculated according to the current first indoor outlet air temperature and the current first indoor return air temperature, the degree of refrigerant leakage of the air conditioner is determined according to the current refrigeration capacity, and the compressor is controlled to continue running or stop running according to the degree of refrigerant leakage, which can improve the accuracy of determining whether the refrigerant leaks or not and the safety of the air conditioner running. Further, after it is preliminarily determined that the air conditioner leaks refrigerant, the step of preliminarily determining whether the air conditioner leaks refrigerant according to the indoor outlet air temperature is executed again, which can further improve the accuracy of determining whether the refrigerant leaks or not.

[0064] A further embodiment of the present application also discloses a control method of an air conditioner, which is used for the air conditioner as described in any of the above embodiments, as shown in the accompanying drawings, the method comprises the following steps: Figure 7

[0065] Step S1: in response to the instruction of the air conditioner refrigeration operation, the compressor is controlled to start, so that the air conditioner refrigeration operation is performed.

[0066] Step S2: whether the air conditioner leaks refrigerant is preliminarily determined according to the indoor outlet air temperature.

[0067] ​Step S3: when it is preliminarily judged that the air conditioner has refrigerant leakage, the compressor is controlled to stop running, and after a first preset time, the compressor is controlled to start running again, and the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan are controlled to run according to preset parameters for a second preset time, then the current first indoor outlet air temperature and the current first indoor return air temperature are obtained, the current refrigerating capacity of the air conditioner is calculated according to the current first indoor outlet air temperature and the current first indoor return air temperature, the refrigerant leakage degree of the air conditioner is determined according to the current refrigerating capacity, and the compressor is controlled to continue running or stop running according to the refrigerant leakage degree.

[0068] In an embodiment of the present application, the preliminary judgment of whether the air conditioner has refrigerant leakage according to the indoor outlet air temperature comprises: when the running time of the compressor reaches a third preset time, the current second indoor outlet air temperature is obtained; and when the running time of the compressor reaches a fourth preset time, the current third indoor outlet air temperature is obtained; the preliminary judgment of whether the air conditioner has refrigerant leakage is made according to the second indoor outlet air temperature and the third indoor outlet air temperature; and the third preset time is less than the fourth preset time.

[0069] Specifically, when the air conditioner runs in refrigeration mode, the indoor outlet air temperature presents a process of first rapid decrease to slow decrease, and then gradual stabilization from the start of the compressor to the system of the air conditioner tending to be stable. In a specific embodiment, when the cumulative running time of the compressor reaches a third preset time such as t3, the second indoor outlet air temperature of the air conditioner such as T2 is obtained through the indoor outlet air temperature sensor, when the compressor continues to run to reach a fourth running time such as t4, the third indoor outlet air temperature of the air conditioner such as T3 is obtained through the indoor outlet air temperature sensor, then the preliminary judgment of whether the air conditioner has refrigerant leakage can be made according to the second indoor outlet air temperature T2 and the third indoor outlet air temperature T3, so as to determine the refrigerant leakage degree of the air conditioner according to the refrigerating capacity after preliminarily judging that the air conditioner has refrigerant leakage, and control the compressor to continue running or stop running according to the refrigerant leakage degree, thereby improving the accuracy of judging whether the refrigerant has leakage and the safety of the air conditioner running.

[0070] In an embodiment of the present application, the preliminary judgment of whether the air conditioner has refrigerant leakage according to the second indoor outlet air temperature and the third indoor outlet air temperature comprises: when the absolute value of the difference between the second indoor outlet air temperature and the third indoor outlet air temperature is less than a preset difference value, it is preliminarily determined that the air conditioner has refrigerant leakage; and when the absolute value of the difference between the second indoor outlet air temperature and the third indoor outlet air temperature is not less than the preset difference value, it is preliminarily determined that the air conditioner does not have refrigerant leakage.

[0071] Specifically, when the air conditioner does not leak refrigerant, the third indoor air outlet temperature, for example, Tc1, is much lower than the second indoor air outlet temperature, for example, Tc0, within a period of time, for example, 10 minutes, after the compressor starts to cool. Therefore, the air conditioner is preliminarily determined to leak refrigerant according to the absolute value of the difference between the second indoor air outlet temperature Tc0 and the third indoor air outlet temperature Tc1. Specifically, when the absolute value of the difference between the second indoor air outlet temperature Tc0 and the third indoor air outlet temperature Tc1 is less than a preset difference, for example, n, that is, |Tc1-Tc0|<n, the air conditioner is preliminarily determined to leak refrigerant; when the absolute value of the difference between the second indoor air outlet temperature Tc0 and the third indoor air outlet temperature Tc1 is not less than the preset difference n, the air conditioner is preliminarily determined not to leak refrigerant. Preferably, n is 0-5.

[0072] In an embodiment of the present application, after the air conditioner is determined to leak refrigerant, the method further comprises: returning to perform the step of preliminarily determining whether the air conditioner leaks refrigerant according to the indoor air outlet temperature again.

[0073] Specifically, if the fourth preset time is small, that is, the third indoor air outlet temperature is obtained before the indoor air outlet temperature rapidly decreases, the air conditioner may be misjudged when preliminarily determining whether the air conditioner leaks refrigerant according to the absolute value of the difference between the second indoor air outlet temperature and the third indoor air outlet temperature. In order to further improve the accuracy of determining whether the air conditioner leaks refrigerant, after the air conditioner is preliminarily determined to leak refrigerant, the compressor is controlled to stop running for a period of time and then restart. The step of preliminarily determining whether the air conditioner leaks refrigerant according to the indoor air outlet temperature is performed again. If the absolute value of the difference between the second indoor air outlet temperature and the third indoor air outlet temperature is still less than the preset difference, the air conditioner is preliminarily determined to leak refrigerant. Thus, the refrigerant leakage degree of the air conditioner is determined according to the refrigeration capacity, and the compressor is controlled to continue running or stop running according to the refrigerant leakage degree, thereby improving the accuracy of determining whether the air conditioner leaks refrigerant and the safety of the air conditioner running.

[0074] In an embodiment of the present application, the control of the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan is performed according to preset parameters, comprising: obtaining the current fourth indoor return air temperature and the current outdoor return air temperature; determining the first running frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan and the second rotating speed of the indoor fan according to the current fourth indoor return air temperature and the current outdoor return air temperature; controlling the compressor to run at the first running frequency, controlling the opening degree of the expansion valve to reach the first preset opening degree, controlling the outdoor fan to run at the first rotating speed and controlling the indoor fan to run at the second rotating speed.

[0075] Specifically, after the air conditioner is preliminarily determined to have refrigerant leakage, the compressor is controlled to stop running for a period of time and then start again, so that the air conditioner runs according to the preset refrigerant leakage judgment running program, thereby calculating the real-time refrigerating capacity of the air conditioner and comparing the real-time refrigerating capacity with the preset refrigerating capacity to determine whether the air conditioner has refrigerant leakage and determine the refrigerant leakage degree of the air conditioner. That is, when the compressor is controlled to start again, the current fourth indoor return air temperature, for example, T4, and the current outdoor return air temperature, for example, T5, are obtained, the first running frequency f of the compressor, the first opening degree p of the expansion valve, the first rotating speed V1 of the outdoor fan, and the second rotating speed V2 of the indoor fan are determined according to the fourth indoor return air temperature T4 and the current outdoor return air temperature T5, and the compressor is controlled to run at the first running frequency f, the opening degree of the expansion valve is controlled to reach the first preset opening degree p, the outdoor fan is controlled to run at the first rotating speed V1, and the indoor fan is controlled to run at the second rotating speed V2.

[0076] In an embodiment of the present application, the first running frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan, and the second rotating speed of the indoor fan are determined according to the current fourth indoor return air temperature and the current outdoor return air temperature, comprising: the first running frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan, and the second rotating speed of the indoor fan are determined by table lookup according to the current fourth indoor return air temperature and the current outdoor return air temperature.

[0077] In an embodiment of the present application, the current refrigerating capacity of the air conditioner is calculated according to the current first indoor outlet air temperature and the current first indoor return air temperature, comprising:

[0078] Q1 = v0 * k * (Tc - Th),

[0079] wherein Q1 is the current refrigerating capacity, k is the air volume conversion coefficient, Tc is the current first indoor outlet air temperature, and Th is the current first indoor return air temperature.

[0080] Specifically, after the air conditioner is preliminarily determined to have refrigerant leakage, the compressor is controlled to stop running for a period of time and then start again, at this time the air conditioner runs according to the preset refrigerant leakage judgment running program, that is, the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan, and the rotating speed of the indoor fan run according to the preset parameters for a second preset time, then the current first indoor outlet air temperature and the current first indoor return air temperature are obtained, and the current refrigerating capacity is calculated, which is compared with the preset refrigerating capacity to determine whether the air conditioner has refrigerant leakage and determine the refrigerant leakage degree of the air conditioner. It should be noted that the air volume conversion coefficient is a coefficient related to the actual rotating speed of the indoor fan, which can be determined according to experiments.

[0081] In one embodiment of the present application, the refrigerant leakage degree of the air conditioner is determined according to the current refrigeration capacity, so as to control the compressor to continue running or stop running according to the refrigerant leakage degree, comprising: obtaining a preset refrigeration capacity corresponding to preset parameters; determining the refrigerant leakage amount according to the current refrigeration capacity and the preset refrigeration capacity; determining the refrigerant leakage degree of the air conditioner according to the refrigerant leakage amount, and controlling the compressor to continue running or stop running according to the refrigerant leakage degree.

[0082] Specifically, the preset refrigeration capacity is the refrigeration capacity of the air conditioner when no refrigerant leakage occurs and the air conditioner runs according to the preset parameters, i.e., the compressor runs at the first running frequency, the expansion valve is opened at the first opening degree, the outdoor fan runs at the first rotating speed, and the indoor fan runs at the second rotating speed for the second preset time. In specific embodiments, the refrigeration capacities corresponding to different preset parameters can be pre-stored in the memory in the form of a table. In specific embodiments, after the current refrigeration capacity is calculated, the pre-stored preset refrigeration capacity is obtained from the memory, so as to determine the refrigerant leakage amount according to the current refrigeration capacity and the preset refrigeration capacity; determine the refrigerant leakage degree of the air conditioner according to the refrigerant leakage amount, and control the compressor to continue running or stop running according to the refrigerant leakage degree, thereby reducing the safety hazards caused by refrigerant leakage and improving the safety of the air conditioner running.

[0083] In one embodiment of the present application, the refrigerant leakage amount is determined according to the current refrigeration capacity and the preset refrigeration capacity, comprising:

[0084] J=Q1 / Qi*b*100%,

[0085] wherein J is the refrigerant leakage amount, Q1 is the current refrigeration capacity, Qi is the preset refrigeration capacity, and b is the refrigerant leakage coefficient.

[0086] In one embodiment of the present application, the refrigerant leakage degree of the air conditioner is determined according to the refrigerant leakage amount, and the compressor is controlled to continue running or stop running according to the refrigerant leakage degree, comprising: when the refrigerant leakage amount is greater than a first preset value, it is determined that the air conditioner has no refrigerant leakage, and the air conditioner is controlled to continue running; when the refrigerant leakage amount is greater than a second preset value and not greater than the first preset value, it is determined that the air conditioner has partial refrigerant leakage, the air conditioner is controlled to continue running, and an alarm information is sent; when the refrigerant leakage amount is greater than a third preset value and not greater than the second preset value, it is determined that the air conditioner has serious refrigerant leakage, the air conditioner is controlled to stop running, and an alarm information is sent; when the refrigerant leakage amount is less than the third preset value, it is determined that the air conditioner has complete refrigerant leakage, the air conditioner is controlled to stop running, and an alarm information is sent; wherein the first preset value is greater than the second preset value, and the second preset value is greater than the third preset value.

[0087] Specifically, according to the size of the refrigerant leakage amount, it is determined whether the refrigerant leaks or not, and the degree of refrigerant leakage is determined, the compressor is controlled to continue running or stop running according to the degree of refrigerant leakage, and the safety of the air conditioner running is improved. In a specific embodiment, the first preset value is 90%, the second preset value is 70%, and the third preset value is 20%. When the refrigerant leakage amount is greater than 90%, it is determined that the refrigerant does not leak, and the air conditioner continues to run. When the refrigerant leakage amount is greater than 70% and not greater than 90%, it is determined that the refrigerant partially leaks, the air conditioner continues to run, and an alarm information is sent. When the refrigerant leakage amount is greater than 20% and not greater than 70%, it is determined that the refrigerant of the air conditioner seriously leaks, the compressor is controlled to stop running, and an alarm information is sent. When the refrigerant leakage amount is less than 20%, it is determined that the refrigerant of the air conditioner completely leaks, the compressor is controlled to stop running, and an alarm information is sent. It can be understood that a sound alarm such as a buzzer or a light alarm indicator light can be used for alarm.

[0088] According to the control method of the air conditioner, in response to the instruction of the air conditioner refrigeration operation, the compressor is controlled to start, whether the refrigerant of the air conditioner leaks is preliminarily determined according to the indoor outlet air temperature, when it is preliminarily determined that the refrigerant of the air conditioner leaks, the compressor is controlled to stop running, and after the first preset time, the compressor is controlled to start again, and the running frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan are controlled to run according to the preset parameters for the second preset time, the current first indoor outlet air temperature and the current first indoor return air temperature are obtained, the current refrigeration capacity of the air conditioner is calculated according to the current first indoor outlet air temperature and the current first indoor return air temperature, the degree of refrigerant leakage of the air conditioner is determined according to the current refrigeration capacity, and the compressor is controlled to continue running or stop running according to the degree of refrigerant leakage, which can improve the accuracy of determining whether the refrigerant leaks or not and the safety of the air conditioner running. Further, after it is preliminarily determined that the refrigerant of the air conditioner leaks, the step of preliminarily determining whether the refrigerant of the air conditioner leaks according to the indoor outlet air temperature is executed again, which can further improve the accuracy of determining whether the refrigerant leaks or not.

[0089] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", 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 application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example.

[0090] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and application of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. An air conditioner characterized by comprising: Comprise: A refrigerant circulation loop, which makes refrigerant in a compressor, a condenser, an expansion valve and an evaporator to carry out a refrigeration cycle, one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; An indoor fan for driving indoor air to pass through the indoor heat exchanger to exchange heat between the refrigerant and the indoor air; An outdoor fan for driving outdoor air to pass through the outdoor heat exchanger to exchange heat between the refrigerant and the outdoor air; An indoor fan for driving the indoor fan to rotate; An outdoor fan for driving the outdoor fan to rotate; An outdoor return air temperature sensor for detecting the outdoor return air temperature of the air conditioner; An indoor return air temperature sensor for detecting the indoor return air temperature of the air conditioner; An indoor outlet air temperature sensor for detecting the indoor outlet air temperature of the air conditioner; The controller is configured to: in response to an instruction of the air conditioner to operate in a refrigeration mode, control the compressor to start to operate, so that the air conditioner operates in the refrigeration mode; According to the indoor outlet air temperature, it is preliminarily judged whether the air conditioner leaks refrigerant or not; When it is preliminarily judged that the air conditioner leaks refrigerant, the compressor is controlled to stop operating, and after a first preset time, the compressor is controlled to start operating again, and the operating frequency of the compressor, the opening degree of the expansion valve, the rotating speed of the outdoor fan and the rotating speed of the indoor fan are controlled to operate according to preset parameters for a second preset time, then the current first indoor outlet air temperature and the current first indoor return air temperature are obtained, the current refrigeration capacity of the air conditioner is calculated according to the current first indoor outlet air temperature and the current first indoor return air temperature, the refrigerant leakage degree of the air conditioner is determined according to the current refrigeration capacity, and the compressor is controlled to continue operating or stop operating according to the refrigerant leakage degree; The controller is specifically configured to: when the operating time of the compressor reaches a third preset time, a current second indoor outlet air temperature is obtained; and when the operating time of the compressor reaches a fourth preset time, a current third indoor outlet air temperature is obtained; According to the second indoor outlet air temperature and the third indoor outlet air temperature, it is preliminarily judged whether the air conditioner leaks refrigerant or not; wherein the third preset time is less than the fourth preset time; When it is preliminarily judged according to the second indoor outlet air temperature and the third indoor outlet air temperature whether the air conditioner leaks refrigerant or not, the controller is specifically configured to: When the absolute value of the difference between the second indoor outlet air temperature and the third indoor outlet air temperature is less than a preset difference, it is preliminarily determined that the air conditioner leaks refrigerant; When the absolute value of the difference between the second indoor outlet air temperature and the third indoor outlet air temperature is not less than the preset difference, it is preliminarily determined that the air conditioner does not leak refrigerant; After it is preliminarily determined that the air conditioner leaks refrigerant, the controller is further configured to: Return to execute the step of preliminarily judging whether the air conditioner leaks refrigerant or not according to the indoor outlet air temperature again.

2. The air conditioner of claim 1, wherein The controller is specifically configured to: obtain a current fourth indoor return air temperature and a current outdoor return air temperature; determine a first operating frequency of the compressor, a first opening degree of the expansion valve, a first rotating speed of the outdoor fan and a second rotating speed of the indoor fan according to the current fourth indoor return air temperature and the current outdoor return air temperature; control the compressor to operate at the first operating frequency, control the opening degree of the expansion valve to reach a first preset opening degree, control the outdoor fan to operate at the first rotating speed, and control the indoor fan to operate at the second rotating speed.

3. The air conditioner of claim 2, wherein The controller is specifically configured to: determine the first operating frequency of the compressor, the first opening degree of the expansion valve, the first rotating speed of the outdoor fan and the second rotating speed of the indoor fan according to the current fourth indoor return air temperature and the current outdoor return air temperature by table lookup.

4. The air conditioner of claim 1, wherein The controller is specifically configured to calculate the current refrigeration capacity by the following formula when determining the current refrigeration capacity of the air conditioner according to the current first indoor outlet air temperature and the current first indoor return air temperature: Q1= v0*k*( Tc-Th), wherein Q1 is the current refrigeration capacity, k is an air volume conversion coefficient, Tc is the current first indoor outlet air temperature, and Th is the current first indoor return air temperature.

5. The air conditioner of claim 4, wherein The controller is configured to: obtain a preset refrigeration capacity corresponding to the preset parameters; determine a refrigerant leakage amount according to the current refrigeration capacity and the preset refrigeration capacity; determine the refrigerant leakage degree of the air conditioner according to the refrigerant leakage amount, and control the compressor to continue operating or stop operating according to the refrigerant leakage degree.

6. The air conditioner of claim 5, wherein The controller is specifically configured to calculate the refrigerant leakage amount by the following formula when determining the refrigerant leakage amount according to the current refrigeration capacity and the preset refrigeration capacity: J= Q1 / Qi*b*100%, wherein J is the refrigerant leakage amount, Q1 is the current refrigeration capacity, Qi is the preset refrigeration capacity, and b is a refrigerant leakage coefficient.

7. The air conditioner according to claim 5 or 6, characterized by The controller is specifically configured to: when the refrigerant leakage amount is greater than a first preset value, determine that the air conditioner has no refrigerant leakage, and control the compressor to continue operating; when the refrigerant leakage amount is less than or equal to the first preset value, determine that the air conditioner has refrigerant leakage, and control the compressor to stop operating. When the refrigerant leakage amount is greater than a second preset value and not greater than a first preset value, it is determined that the air conditioner has a refrigerant partial leakage, the compressor continues to run, and an alarm information is sent out; When the refrigerant leakage amount is greater than a third preset value and not greater than the second preset value, it is determined that the air conditioner has a refrigerant serious leakage, the compressor stops running, and an alarm information is sent out; When the refrigerant leakage amount is less than the third preset value, it is determined that the air conditioner has a refrigerant complete leakage, the compressor stops running, and an alarm information is sent out; wherein the first preset value is greater than the second preset value, and the second preset value is greater than the third preset value.

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