CN113124544B - Air-conditioning unit and its defrosting control method - Google Patents

Abstract

The invention belongs to the technical field of air conditioning, and in particular relates to an air conditioning unit and a defrosting control method thereof. The invention aims to solve the problem that it is difficult to accurately judge the best timing for the air-conditioning unit to enter the defrosting mode in the defrosting control method of the existing air-conditioning unit. For this reason, the defrosting control method of the present invention includes: when the current outdoor temperature is less than or equal to the preset outdoor temperature, obtaining the temperature of the outdoor coil; if the temperature of the outdoor coil is less than or equal to the duration of the preset outdoor coil temperature When the first preset duration is reached, the current of the outdoor fan is further obtained; according to the obtained current of the outdoor fan, the outlet air temperature of the outdoor unit is selectively obtained; according to the current outdoor temperature and the outlet air temperature of the outdoor unit, selectively Make the air conditioning unit run in the defrosting mode, so that the air conditioning unit can enter the defrosting mode at the most appropriate time, so as to effectively ensure the heating effect of the air conditioning unit.

Description

Air-conditioning unit and its defrosting control method

technical field

The invention belongs to the technical field of air conditioning, and in particular relates to an air conditioning unit and a defrosting control method thereof.

Background technique

The air conditioning unit includes an indoor unit, an outdoor unit, and a refrigerant circulation circuit connected between the indoor unit and the outdoor unit. The refrigerant continuously exchanges heat between the outdoor unit and the indoor unit through the refrigerant circulation circuit. Take the heating condition of the air conditioner as an example, since the coil of the outdoor unit is always in a low temperature state, and the outdoor temperature is also low; at this time, if the outdoor environment still has high humidity, the coil of the outdoor unit will The tubes are prone to frosting, and as the frosting continues, the heat exchange efficiency of the outdoor unit will drop sharply, and the wind resistance will increase, which will lead to the continuous attenuation of the heating capacity of the entire air conditioning unit. Therefore, when the air conditioner unit is running in heating mode, it is necessary to constantly monitor whether the coil of the outdoor unit has frosted, and it is also necessary to select an appropriate time to enter the defrosting mode, so as to avoid unnecessary energy loss.

When judging the defrosting timing, the existing air-conditioning units do not differentiate the judging methods according to the different conditions of the outdoor ambient temperature, which easily leads to the problem of inaccurate judging results. Specifically, when the air-conditioning unit is heating in an ultra-low temperature environment, the outdoor ambient temperature and humidity are often very low, and its evaporation temperature is also very low, which makes it difficult to accurately determine the frosting situation based on the coil temperature. In other words, when the outdoor ambient temperature is very low and the humidity is very low, the air conditioning unit is prone to misjudgment, which will cause the air conditioning unit to enter unnecessary false defrosting, which will frequently affect the heating performance of the air conditioning unit, seriously Affect the heat exchange efficiency of the air conditioning unit and the comfort of the user.

Correspondingly, there is a need in the art for a new air-conditioning unit and its defrosting control method to solve the above problems.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, that is, in order to solve the problem that the defrosting control method of the existing air-conditioning unit is difficult to accurately judge the best time for the air-conditioning unit to enter the defrosting mode, the present invention provides a defrosting control method for the air-conditioning unit , the air conditioner unit includes an outdoor unit, the outdoor unit includes an outdoor coil and an outdoor fan, and the defrosting control method includes: when the current outdoor temperature is less than or equal to a preset outdoor temperature, acquiring the temperature of the outdoor coil temperature; if the temperature of the outdoor coil is less than or equal to the preset outdoor coil temperature and the duration reaches the first preset duration, then further obtain the current of the outdoor fan; according to the obtained current of the outdoor fan, select selectively acquire the outlet air temperature of the outdoor unit; and selectively enable the air conditioner unit to operate in a defrosting mode according to the current outdoor temperature and the outlet air temperature of the outdoor unit.

In the preferred technical solution of the above-mentioned defrosting control method, the step of "selectively obtaining the outlet air temperature of the outdoor unit according to the obtained current of the outdoor fan" specifically includes: calculating the current of the outdoor fan and The ratio of the preset current is recorded as a first ratio; if the first ratio is greater than the first preset ratio, the outlet air temperature of the outdoor unit is obtained.

In the preferred technical solution of the above-mentioned defrosting control method, the preset current is determined in the following manner: within the second preset time period after the last defrosting, the current of the outdoor fan is obtained multiple times; The average value of the currents of the plurality of outdoor fans is the preset current.

In the preferred technical solution of the above-mentioned defrosting control method, the control method further includes: in the case that the first ratio is less than or equal to the first preset ratio, further obtaining the current heating operation of the air conditioning unit duration; if the duration of the heating operation of the air conditioning unit reaches a third preset duration, the air conditioning unit is operated in a defrosting mode.

In the preferred technical solution of the above-mentioned defrosting control method, the step of "selectively enabling the air-conditioning unit to operate in the defrosting mode according to the current outdoor temperature and the outlet air temperature of the outdoor unit" specifically includes: calculating the preset The ratio of the difference to the difference between the current outdoor temperature and the outlet air temperature of the outdoor unit is recorded as a second ratio; the second ratio is compared with a second preset ratio; according to the second ratio As a result of comparison with the second preset ratio, the air conditioner unit is selectively operated in a defrosting mode.

In the preferred technical solution of the above-mentioned defrosting control method, the step of "selectively enabling the air-conditioning unit to operate in the defrosting mode according to the comparison result between the second ratio and the second preset ratio" specifically includes: if If the second ratio is greater than the second preset ratio, the air conditioner unit is operated in a defrosting mode.

In the preferred technical solution of the above-mentioned defrosting control method, the step of "selectively enabling the air-conditioning unit to operate in the defrosting mode according to the comparison result between the second ratio and the second preset ratio" specifically includes: if If the second ratio is less than or equal to the second preset ratio, the duration of the current heating operation of the air conditioning unit is further obtained; if the duration of the current heating operation of the air conditioning unit reaches the fourth preset duration , then make the air conditioning unit operate in the defrosting mode.

In the preferred technical solution of the above-mentioned defrosting control method, the determination method of the preset difference is: within the fifth preset time period after the end of the last defrosting, the outlet air temperature of the outdoor unit and The outdoor temperature is obtained at least once; the difference between the outdoor temperature and the obtained average value of the outlet air temperatures of the plurality of outdoor units is calculated to be the preset difference.

In the preferred technical solution of the above-mentioned defrosting control method, the defrosting control method further includes: when the temperature of the outdoor coil is greater than the preset outdoor coil temperature, or the temperature of the outdoor coil is less than or equal to the preset If the duration of the preset outdoor coil temperature does not reach the first preset duration, further obtain the duration of the current heating operation of the air conditioner; if the duration of the current heating operation of the air conditioner is When the duration reaches the sixth preset duration, the air conditioner unit is operated in the defrosting mode.

The present invention also provides an air-conditioning unit, the air-conditioning unit includes a controller, and the controller can execute the defrosting control method described in any one of the above preferred technical solutions.

Those skilled in the art can understand that, in the technical solution of the present invention, the air conditioner unit of the present invention includes an outdoor unit, and the outdoor unit includes an outdoor coil and an outdoor fan, and the defrosting control method of the present invention includes: If the temperature is less than or equal to the preset outdoor temperature, obtain the temperature of the outdoor coil; The current of the outdoor fan; according to the obtained current of the outdoor fan, selectively obtain the outlet air temperature of the outdoor unit; according to the current outdoor temperature and the outlet air temperature of the outdoor unit, selectively use The air conditioning unit operates in defrost mode. The defrosting control method of the present invention is specially proposed for the situation that the outdoor temperature is low. Using the defrosting control method of the present invention can accurately judge the frosting situation of the outdoor unit in the case of ultra-low temperature heating, so that the air conditioning unit The defrosting mode can be entered at the most appropriate time, thereby effectively ensuring the heating effect of the air-conditioning unit, so as to effectively improve the operating efficiency of the air-conditioning unit and the user's heat exchange experience. In addition, the air-conditioning unit can obtain parameters by relying on the original electronic components, that is, the defrosting control method of the present invention can be performed without adding other electronic components, so as to effectively ensure that the structure of the air-conditioning unit does not need to Any transformation, and its manufacturing cost will not increase, and it is very convenient to apply.

Description of drawings

Fig. 1 is a flow chart of the main steps of the defrosting control method of the present invention;

Fig. 2 is a flow chart of detailed steps of a preferred embodiment of the defrosting control method of the present invention.

Detailed ways

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention, and are not intended to limit the protection scope of the present invention. Those skilled in the art can make adjustments as needed so as to adapt to specific applications. For example, the air-conditioning unit described in the present invention can be a one-to-one air-conditioning unit, or a one-to-many multi-connected air-conditioning unit. The change of the application object does not deviate from the basic principle of the present invention, and should belong to this protection scope of the invention.

It should be noted that, in the description of this preferred embodiment, terms such as "inner" and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for convenience of description. It is not intended to indicate or imply that the device or element must have a particular orientation, be constructed in a particular orientation, or operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first", "second", "third", "fourth", "fifth", and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

In addition, in the description of the present invention, unless otherwise clearly stipulated and limited, the term "connected" should be understood in a broad sense, for example, it may be directly connected, or indirectly connected through an intermediary, or it may be an internal connection between two components. connected. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific situations. Although the application describes the various steps of the control method of the present invention in a specific order, these orders are not limiting, and those skilled in the art can perform them in different orders without departing from the basic principles of the present invention the steps.

Based on the problem that the defrosting control method of the existing air conditioning unit is difficult to accurately judge the best time for the air conditioning unit to enter the defrosting mode, the present invention provides a new defrosting control method, the defrosting control method The temperature of the outdoor coil can be obtained when the current outdoor temperature is less than or equal to the preset outdoor temperature; if the duration of the temperature of the outdoor coil is less than or equal to the preset outdoor coil temperature reaches the first preset time length, Then further acquire the current of the outdoor fan; selectively acquire the outlet air temperature of the outdoor unit according to the acquired current of the outdoor fan; and according to the current outdoor temperature and the outlet air temperature of the outdoor unit, The air-conditioning unit is selectively operated in a defrosting mode, so that the air-conditioning unit can enter the defrosting mode at the most appropriate time, thereby effectively improving the operating efficiency of the air-conditioning unit.

Specifically, the air conditioning unit of the present invention includes an indoor unit and an outdoor unit, the indoor unit is provided with an indoor coil, the outdoor unit is provided with an outdoor coil and an outdoor fan, and the indoor coil and the outdoor The coils are connected through the refrigerant circulation loop to realize heat exchange, so as to achieve the effect of changing the room temperature; the outdoor fan is arranged near the outdoor coils so as to effectively improve the heat exchange efficiency of the outdoor coils. It should be noted that those skilled in the art can set the specific structure of the air-conditioning unit according to the actual use requirements, for example, the specific number of the indoor units, the specific type and location of the outdoor fan, and so on. Such specific structural changes related to the air-conditioning unit do not deviate from the basic principle of the present invention, and should belong to the protection scope of the present invention.

Further, the air conditioning unit further includes an outdoor temperature sensor, an outdoor coil temperature sensor, and an air outlet temperature sensor, wherein the outdoor temperature sensor can detect the outdoor temperature of the outdoor unit, and the outdoor coil temperature sensor The temperature of the outdoor coil can be detected, and the outlet air temperature sensor can detect the outlet air temperature of the outdoor unit. It should be noted that the present invention does not impose any restrictions on the specific type, specific setting position and specific setting quantity of the above-mentioned temperature sensors, and technicians can set them by themselves according to actual use requirements; this change does not deviate from the basic principle of the present invention, and should be Belong to the protection scope of the present invention.

In addition, the air conditioner unit also includes a controller, and the controller can obtain the detection data of each sensor; specifically, the outdoor temperature of the outdoor unit is detected by the outdoor temperature sensor, and the outdoor temperature of the outdoor coil is detected by the outdoor coil. The temperature sensor detects the temperature of the outdoor coil, and the outlet air temperature of the outdoor unit is detected by the outlet air temperature sensor. The controller is also capable of controlling the operating mode of the air conditioning unit, for example, controlling the air conditioning unit to operate in a defrosting mode.

It should be noted that the present invention does not impose any restrictions on the specific operations performed by the air-conditioning unit after entering the defrosting mode, and technicians can set it according to actual use requirements; Realize the defrosting of the outdoor coil; as another example, it is also possible to realize the defrosting of the outdoor coil with the help of an electric heater; and for example, it is also possible to realize different levels of defrosting modes by combining multiple defrosting methods, which are not restrictive.

In addition, those skilled in the art can also understand that the present invention does not impose any restrictions on the specific structure and model of the controller, and the controller can be the original controller of the air conditioning unit, or it can be a In the defrosting control method of the present invention, the controller is provided separately, and technicians can set the structure and model of the controller according to actual use requirements.

Referring first to Fig. 1, this figure is a flow chart of the main steps of the defrosting control method of the present invention. As shown in Figure 1, based on the air-conditioning unit described in the above embodiment, the defrosting control method of the present invention mainly includes the following steps:

S1: Obtain the temperature of the outdoor coil when the current outdoor temperature is less than or equal to the preset outdoor temperature;

S2: if the temperature of the outdoor coil is less than or equal to the preset temperature of the outdoor coil and the duration reaches the first preset duration, further obtain the current of the outdoor fan;

S3: Selectively obtain the outlet air temperature of the outdoor unit according to the obtained current of the outdoor fan;

S4: According to the current outdoor temperature and the outlet air temperature of the outdoor unit, selectively enable the air conditioner to operate in the defrosting mode.

In step S1, if the current outdoor temperature is less than or equal to the preset outdoor temperature, it means that the air conditioner unit is operating in the heating mode in an ultra-low temperature environment. In this case, the controller can pass the The outdoor coil temperature sensor detects the temperature of the outdoor coil. It should be noted that the present invention does not impose any restrictions on the specific value of the preset outdoor temperature, which can be set by technicians according to actual use requirements. Preferably, the preset outdoor temperature can be set according to the local humidity conditions . Further preferably, the preset outdoor temperature is set to -15°C.

In addition, it should be noted that the present invention does not impose any restrictions on the specific method of obtaining the temperature of the outdoor coil, and technicians can set it by themselves according to actual use requirements; preferably, the outdoor coil is provided with multiple The outdoor coil temperature sensor can obtain the temperature of multiple points on the outdoor coil through a plurality of outdoor coil temperature sensors, and based on the obtained multiple coil temperatures, the controller can select the lowest temperature One is used as the temperature of the outdoor coil, so that the temperature of a place on the heat exchange coil where frosting is most likely to occur is taken as the temperature of the outdoor coil.

Based on the obtained result of step S1, in step S2, if the controller determines that the temperature of the outdoor coil is less than or equal to the preset outdoor coil temperature for a duration that reaches the first preset duration, then the The controller further obtains the current of the outdoor fan; it should be noted that the present invention does not impose any restrictions on the specific method of obtaining the current of the outdoor fan by the controller, and technicians can set it by themselves according to actual use requirements.

In addition, it should be noted that the present invention does not impose any restrictions on the specific values of the preset outdoor coil temperature and the first preset duration, which can be set by technicians according to actual use requirements; preferably, the The preset outdoor coil temperature is set to -20°C, and the first preset time length is set to 5 minutes.

Based on the acquisition result of step S2, in step S3, the controller can selectively acquire the outlet air temperature of the outdoor unit according to the acquired current of the outdoor fan; There are no restrictions on the specific judgment conditions used in , and technicians can set them according to actual use needs. As long as it is judged that the outdoor unit has a risk of frosting through the obtained current of the outdoor fan, the above-mentioned The outlet air temperature of the outdoor unit is sufficient.

Further, in step S4, the controller can selectively enable the air conditioning unit to operate in a defrosting mode according to the current outdoor temperature and the outlet air temperature of the outdoor unit. It should be noted that the present invention does not impose any restrictions on the specific judgment conditions used in this step, and technicians can set them by themselves according to actual use requirements. For example, when the current outdoor temperature and the outlet air temperature of the outdoor unit exceed The air-conditioning unit is controlled to operate in the defrosting mode only when a certain range is reached, or the air-conditioning unit is controlled to operate in the defrosting mode only when the current outdoor temperature and the outlet air temperature of the outdoor unit satisfy a certain relational expression. These specific control logic changes do not deviate from the basic principles of the present invention, and should belong to the protection scope of the present invention, as long as the judgment conditions used in this step are judged by the current outdoor temperature and the outlet air temperature of the outdoor unit Whether there is frosting on the outdoor unit, so that the air conditioner unit can selectively run the defrosting mode.

Referring to Fig. 2 below, this figure is a flow chart of detailed steps of a preferred embodiment of the defrosting control method of the present invention. As shown in Figure 2, based on the air conditioning unit described in the above embodiments, a preferred embodiment of the defrosting control method of the present invention specifically includes the following steps:

S101: Obtain the current outdoor temperature when the air conditioner unit is in the heating mode;

S102: Determine whether the current outdoor temperature is less than or equal to the preset outdoor temperature; if not, execute step S103; if yes, execute step S104;

S103: judging whether the air conditioner unit needs to run the defrosting mode through the conventional defrosting judging method;

S104: Obtain the temperature of the outdoor coil;

S105: Determine whether the duration of the temperature of the outdoor coil being less than or equal to the preset temperature of the outdoor coil reaches the first preset duration; if not, execute step S106; if yes, execute step S108;

S106: Obtain the duration of the current heating operation of the air conditioner;

S107: If the duration of the current heating operation of the air conditioner reaches the sixth preset duration, make the air conditioner operate in the defrosting mode;

S108: Obtain the current of the outdoor fan;

S109: Calculate the ratio of the current of the outdoor fan to the preset current, and record it as the first ratio;

S110: Determine whether the first ratio is greater than the first preset ratio; if not, execute step S111; if yes, execute step S113;

S111: Obtain the duration of the current heating operation of the air conditioner;

S112: If the duration of the current heating operation of the air conditioner reaches the third preset duration, make the air conditioner operate in the defrosting mode;

S113: Obtain the outlet air temperature of the outdoor unit;

S114: Calculate the ratio of the preset difference to the difference between the current outdoor temperature and the outlet air temperature of the outdoor unit, and record it as the second ratio;

S115: Determine whether the second ratio is greater than the second preset ratio; if not, execute step S116; if yes, execute step S118;

S116: Obtain the duration of the current heating operation of the air conditioner;

S117: If the duration of the current heating operation of the air-conditioning unit reaches the fourth preset duration, make the air-conditioning unit operate in the defrosting mode;

S118: Make the air conditioner run in the defrosting mode.

In step S101, when the air conditioner unit is in the heating mode, the controller can acquire the current outdoor temperature through the outdoor temperature sensor; it should be noted that this acquisition method is not limiting, technical Personnel can also set their own acquisition methods according to actual usage needs; for example, the current outdoor temperature can also be obtained through networking.

Next, in step S102, the controller can determine whether the current outdoor temperature obtained in step S101 is less than or equal to the preset outdoor temperature, so as to determine whether the outdoor unit is operating in an ultra-low temperature environment. It should be noted that the present invention does not impose any restrictions on the specific value of the preset outdoor temperature, which can be set by technicians according to actual use requirements. Preferably, the preset outdoor temperature can be set according to the local humidity conditions . Further preferably, the preset outdoor temperature is set to -15°C.

Based on the judgment result of step S102, if the current outdoor temperature is greater than the preset outdoor temperature, step S103 is executed, that is, the controller can judge whether the air conditioner unit needs to run the defrosting mode through a conventional defrosting judging method . It should be noted that the present invention does not impose any restrictions on the judgment methods involved in this step, and technicians can set them by themselves according to actual use requirements; for example, judge directly by the temperature of the outdoor coil, or directly by the temperature of the outlet air make judgments etc.

Based on the judgment result of step S102, if the current outdoor temperature is less than or equal to the preset outdoor temperature, step S104 is executed, that is, the controller can detect the temperature of the outdoor coil through the outdoor coil temperature sensor. temperature. It should be noted that the present invention does not impose any restrictions on the specific method of obtaining the temperature of the outdoor coil, and technicians can set it according to actual use requirements; preferably, the outdoor coil is provided with a plurality of outdoor coils The temperature sensor can obtain the temperature of multiple points on the outdoor coil through a plurality of outdoor coil temperature sensors. Based on the obtained multiple coil temperatures, the controller can select the one with the lowest temperature as the The temperature of the outdoor coil is determined so that the temperature of a place on the heat exchange coil where frosting is most likely to occur is taken as the temperature of the outdoor coil.

Next, in step S105, the controller can determine whether the duration of the temperature of the outdoor coil being less than or equal to the preset temperature of the outdoor coil reaches the first preset duration. It should be noted that the present invention does not impose any restrictions on the specific values of the preset outdoor coil temperature and the first preset duration, and technicians can set them by themselves according to actual use requirements; preferably, the preset The temperature of the outdoor coil is set to -20° C., and the first preset time length is set to 5 minutes.

Based on the judgment result of step S105, if the temperature of the outdoor coil is greater than the preset outdoor coil temperature, or the duration of the temperature of the outdoor coil is less than or equal to the preset outdoor coil temperature does not reach the preset If the first preset duration is specified, step S106 is executed, that is, the controller further obtains the duration of the heating operation of the air conditioner unit, so as to avoid false defrosting and effectively avoid all defrosting. Describe the problem that the air conditioning unit did not defrost in time. Based on this, in step S108, if the duration of the current heating operation of the air conditioning unit reaches the sixth preset duration, the air conditioning unit is operated in the defrosting mode; otherwise, the defrosting mode is not operated. It should be noted that the present invention does not impose any limitation on the specific value of the sixth preset duration, which can be set by technicians according to actual usage requirements; preferably, the sixth preset duration is set to 3 hours.

Based on the judgment result of step S105, if the temperature of the outdoor coil is less than or equal to the preset outdoor coil temperature and the duration reaches the first preset duration, step S108 is executed, that is, the controller further obtains The current of the outdoor fan; it should be noted that the present invention does not impose any restrictions on the specific method for the controller to obtain the current of the outdoor fan, and technicians can set it according to actual use requirements.

Further, in step S109, the controller can calculate the ratio of the current of the outdoor fan to the preset current, which is denoted as a first ratio. As a preferred setting method, within the second preset time period after the last defrosting of the air conditioning unit, the controller can obtain the current of the outdoor fan multiple times, and calculate the average value of the multiple currents The value is the preset current; of course, the preset current can also be a set fixed value. Preferably, the second preset time length is set to 3 minutes, that is, within 3 minutes after the last defrosting of the air conditioning unit, the controller can obtain the current of the outdoor fan multiple times, and calculate how many times The average value of currents is the preset current. In addition, technicians can set the specific value of the second preset duration and the number of acquisition times of the current of the outdoor fan according to actual usage requirements, which is not limiting.

Further preferably, the current of the outdoor fan used in this step is also the average value of multiple values within the second preset time range before the current moment, and the second preset time length is set to 3min For example, the current of the outdoor fan is the average value of the current of the outdoor fan within 3 minutes before the current moment. Of course, technicians can set the number of acquisitions when calculating the average value according to actual usage requirements.

Next, in step S110, the controller can determine whether the first ratio is greater than the first preset ratio, so as to perform different operations accordingly. It should be noted that the present invention does not impose any restrictions on the value of the first preset ratio; as a preferred setting value, the first preset ratio is set to 1.04 in order to maximize the accuracy of judgment sex.

Based on the judgment result of step S110, if the first ratio is less than or equal to the first preset ratio, step S111 is executed, that is, the controller further acquires the duration of the current heating operation of the air conditioning unit, based on Here, in step S112, if the duration of the current heating operation of the air-conditioning unit reaches the third preset duration, the air-conditioning unit is operated in the defrosting mode; otherwise, the defrosting mode is not operated. It should be noted that the present invention does not impose any restrictions on the specific value of the third preset duration, which can be set by technicians according to actual use requirements; preferably, the third preset duration is shorter than the sixth preset duration. Set duration.

Based on the judgment result of step S110, if the first ratio is greater than the first preset ratio, step S113 is executed, that is, the controller further obtains the outlet air temperature of the outdoor unit.

Further, in step S114, the controller calculates the ratio of the preset difference to the difference between the current outdoor temperature and the outlet air temperature of the outdoor unit, which is recorded as a second ratio. As a preferred setting method, within the fifth preset time period after the last defrosting of the air conditioning unit, the controller can acquire the outlet air temperature of the outdoor unit and the outdoor temperature at least once for multiple times, And calculate the difference between the outdoor temperature and the average value of the outlet air temperatures of the plurality of outdoor units, which is the preset difference. If the outdoor temperature is obtained only once within the fifth preset time period after the last defrosting of the air conditioning unit, then calculate the difference between the outdoor temperature and the average value of the outlet air temperatures of the plurality of outdoor units; if If multiple times of outdoor temperatures are obtained within the fifth preset time period after the last defrosting of the air conditioning unit, the average value of the multiple outdoor temperatures and the average value of the outlet air temperatures of the multiple outdoor units are calculated difference. Preferably, the fifth preset duration is set to 10 minutes, that is, within 10 minutes after the last defrosting of the air conditioning unit, the controller can acquire the outlet air temperature of the outdoor unit multiple times and at least the outdoor temperature once, and calculate the difference between the outdoor temperature and the average value of the outlet air temperatures of the plurality of outdoor units, which is the preset difference. In addition, technicians can set the specific value of the fifth preset duration and the number of acquisition times of the outlet air temperature of the outdoor unit by themselves according to actual usage requirements, which is not limiting.

Further preferably, the outlet air temperature of the outdoor unit used in this step is also the average value of multiple values taken within the preset time range before the current moment, preferably the average value within 3 minutes, that is, the The air outlet temperature of the outdoor unit is the average value of the air outlet temperature of the outdoor unit within 3 minutes before the current moment, first calculate the difference between the current outdoor temperature and the average value of the air outlet temperature, and then calculate the preset The ratio of the difference to the difference is recorded as the second ratio. Of course, technicians can set the number of acquisition times when calculating the average value according to actual usage requirements.

Next, in step S115, the controller can determine whether the second ratio is greater than the second preset ratio, so as to perform different operations accordingly. It should be noted that the present invention does not impose any restrictions on the value of the second preset ratio; as a preferred setting value, the second preset ratio is set to 2 in order to maximize the accuracy of judgment sex.

Based on the judgment result of step S115, if the second ratio is less than or equal to the second preset ratio, step S116 is executed, that is, the controller further obtains the duration of the current heating operation of the air conditioning unit, based on Here, in step S117, if the duration of the current heating operation of the air conditioning unit reaches the fourth preset duration, the air conditioning unit is operated in the defrosting mode; otherwise, the defrosting mode is not operated. It should be noted that the present invention does not impose any restrictions on the specific value of the fourth preset duration, which can be set by technicians according to actual use requirements; preferably, the fourth preset duration is shorter than the third preset duration. Set duration.

Based on the judgment result of step S115, if the second ratio is greater than the second preset ratio, step S118 is executed, that is, the controller can make the air-conditioning unit operate in the defrosting mode, so as to avoid false defrosting On the basis of the phenomenon, it can also effectively avoid the problem that the air conditioning unit does not defrost in time

So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings, but those skilled in the art will easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims (8)

1. A defrosting control method for an air-conditioning unit, the air-conditioning unit comprising an outdoor unit, the outdoor unit comprising an outdoor coil and an outdoor fan, characterized in that the defrosting control method comprises: When the current outdoor temperature is less than or equal to the preset outdoor temperature, obtain the temperature of the outdoor coil; If the temperature of the outdoor coil is less than or equal to the preset temperature of the outdoor coil and the duration reaches the first preset duration, then further obtain the current of the outdoor fan; selectively acquiring the outlet air temperature of the outdoor unit according to the acquired current of the outdoor fan; selectively enabling the air conditioner unit to operate in a defrosting mode according to the current outdoor temperature and the outlet air temperature of the outdoor unit; The step of "selectively obtaining the outlet air temperature of the outdoor unit according to the obtained current of the outdoor fan" specifically includes: Calculate the ratio of the current of the outdoor fan to the preset current, and record it as the first ratio; If the first ratio is greater than a first preset ratio, obtain the outlet air temperature of the outdoor unit; The control method also includes: In the case that the first ratio is less than or equal to the first preset ratio, further obtain the duration of the current heating operation of the air conditioning unit; If the duration of the current heating operation of the air conditioning unit reaches a third preset duration, the air conditioning unit is operated in a defrosting mode. 2. The defrosting control method according to claim 1, wherein the method of determining the preset current is: Obtaining the current of the outdoor fan multiple times within a second preset time period after the last defrosting; An average value of the acquired currents of the plurality of outdoor fans is calculated to be the preset current. 3. The defrosting control method according to claim 1 or 2, characterized in that "selectively make the air conditioning unit run in a defrosting mode according to the current outdoor temperature and the outlet air temperature of the outdoor unit" The steps specifically include: Calculate the ratio of the preset difference to the difference between the current outdoor temperature and the outlet air temperature of the outdoor unit, and record it as the second ratio; comparing the second ratio with a second preset ratio; According to the comparison result between the second ratio and the second preset ratio, the air conditioner unit is selectively operated in a defrosting mode. 4. The defrosting control method according to claim 3, characterized in that "according to the comparison result between the second ratio and the second preset ratio, selectively make the air conditioning unit operate in a defrosting mode" The steps specifically include: If the second ratio is greater than the second preset ratio, the air conditioning unit is operated in a defrosting mode. 5. The defrosting control method according to claim 4, characterized in that, "according to the comparison result between the second ratio and the second preset ratio, selectively make the air conditioning unit operate in a defrosting mode" The steps specifically include: If the second ratio is less than or equal to the second preset ratio, further obtain the duration of the current heating operation of the air conditioning unit; If the duration of the current heating operation of the air conditioning unit reaches a fourth preset duration, the air conditioning unit is operated in a defrosting mode. 6. The defrosting control method according to claim 3, wherein the method for determining the preset difference is: within the fifth preset period of time after the last defrosting, obtaining the outlet air temperature of the outdoor unit multiple times and obtaining the outdoor temperature at least once; A difference between the calculated outdoor temperature and the obtained average value of the outlet air temperatures of the plurality of outdoor units is the preset difference. 7. The defrosting control method according to claim 1, characterized in that, the defrosting control method further comprises: When the temperature of the outdoor coil is greater than the preset outdoor coil temperature, or the duration of the outdoor coil temperature is less than or equal to the preset outdoor coil temperature does not reach the first preset duration Next, further obtain the duration of the heating operation of the air-conditioning unit; If the duration of the current heating operation of the air conditioning unit reaches the sixth preset duration, the air conditioning unit is operated in a defrosting mode. 8. An air-conditioning unit, characterized in that the air-conditioning unit comprises a controller capable of executing the defrosting control method according to any one of claims 1-7.

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