WO2019158048A1

WO2019158048A1 - Defrost control method for air conditioner

Info

Publication number: WO2019158048A1
Application number: PCT/CN2019/074847
Authority: WO
Inventors: 许文明; 王飞; 付裕
Original assignee: 青岛海尔空调器有限总公司
Priority date: 2018-02-14
Filing date: 2019-02-12
Publication date: 2019-08-22
Also published as: CN108444047A

Abstract

The present invention relates to the technical field of air conditioners, and specifically relates to a defrost control method for an air conditioner capable of more accurately determine a timing for defrost. The defrost control method of the present invention comprises: when an air conditioner is performing a heating operation, detecting a real-time current value of a fan in an outdoor unit; comparing the real-time current value of the fan with first standard current values, second standard current values and third standard current values which are selected in advance; and determining, according to a comparison result, whether to cause the air conditioner to enter a defrost mode, wherein the first standard current values are current values of the fan measured at different rotation speeds when the outdoor unit is not affected by frost; the second standard current values are current values of the fan measured at different rotation speeds when the outdoor unit is partially affected by frost, and the third standard current values are current values of the fan measured at different rotation speeds when the outdoor unit is fully affected by frost. The invention enables a defrost timing to be selected more accurately, and can reduce defrost times required for an air conditioner, thereby improving user experience.

Description

Air conditioner defrosting control method

Technical field

The invention belongs to the technical field of air conditioners, and in particular relates to a method for controlling defrosting of an air conditioner.

Background technique

As a device capable of adjusting the indoor ambient temperature, the air conditioner works by reducing or raising the indoor ambient temperature by a high-pressure/low-pressure/gaseous/liquid state transition between the circulating pipes. From the perspective of the indoor unit, the air conditioner is in a cooling or heating condition. When the air conditioner is running in heat, if the temperature of the outdoor coil is too low under certain humidity conditions, it will cause frosting, and the outdoor coil frosting will cause the heat exchange efficiency of the outdoor heat exchanger to decrease, affecting the system of the air conditioner. Thermal effects reduce the comfort of the indoor environment and affect the user experience. Therefore, in the case where the air conditioner is in a heating condition, it is necessary to perform timely and effective defrosting of the outdoor coil of the air conditioner.

The existing technical solutions usually determine the degree of frosting of the outdoor coil by the humidity and the outdoor coil temperature, and then perform the corresponding defrosting operation according to the frost condition of the outdoor coil. However, this way of judging the frosting requires the accuracy of the outdoor coil sensor to be high, and it is accurate when the outdoor heat exchanger is well-split. Once the outdoor heat exchanger is not well-distributed, the outdoor coil sensor is It is impossible to accurately determine the evaporation temperature of each split (the outdoor coil sensor can only judge the evaporation temperature of one split). In this case, it is prone to the following situation: the outdoor coil actually has frost formation, but the temperature of the outdoor coil is high, so that the defrosting cannot be accurately controlled, resulting in frost or defrosting. Not clean. In view of this, it is important to choose the right defrosting timing.

Therefore, the present invention proposes a new defrosting control method.

Summary of the invention

In order to solve the above problems in the prior art, that is, in order to more accurately judge the timing of entering the defrosting, the present invention proposes an air conditioner defrosting control method, the defrosting control method comprising the following steps: heating in the air conditioner In the case of working conditions, detecting the real-time current value of the outdoor fan; comparing the real-time current value of the outdoor fan with the selected first standard current value, the second standard current value, and the third standard current value; determining whether to make the air conditioner according to the comparison result The device enters a defrost mode; wherein the first standard current value is a current value of the outdoor fan measured at different speeds in a state where the outdoor unit is not frosted; and the second standard current value is a portion of the outdoor unit The current value of the outdoor fan measured at different speeds in the state of the frost; the third standard current value is the current value of the outdoor fan measured at different speeds in the state where the outdoor unit is completely frosted.

In a preferred embodiment of the air conditioner defrosting control method, the selected first standard current value, the second standard current value, and the third standard current value are respectively different frosting of the outdoor fan at the current speed. Standard current value in the state.

In a preferred embodiment of the above air conditioner defrosting control method, the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes: if the real-time current value of the outdoor fan is greater than or equal to the selected first standard The current value causes the air conditioner to maintain the current heating condition without entering the defrost mode.

In a preferred embodiment of the above air conditioner defrosting control method, the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes: if the real-time current value of the outdoor fan is smaller than the selected first standard current The value, and greater than or equal to the second standard current value, causes the air conditioner to maintain the current heating condition while increasing the throttle opening of the air conditioner without entering the defrost mode.

In a preferred embodiment of the above air conditioner defrosting control method, the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes: if the real-time current value of the outdoor fan is smaller than the selected second standard current The value, and greater than or equal to the selected third standard current value, causes the air conditioner to maintain the current heating condition, and reduces the frequency of the compressor based on the increase in the throttle opening of the air conditioner, Enter the defrost mode.

In a preferred embodiment of the above air conditioner defrosting control method, the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes: if the real-time current value of the outdoor fan is smaller than the selected third standard current The value causes the air conditioner to enter the defrost mode.

In a preferred embodiment of the above air conditioner defrosting control method, the "increasing the throttle opening degree of the air conditioner" is specifically: increasing the throttle opening degree by the set number of steps.

In a preferred embodiment of the above air conditioner defrosting control method, the "reducing the frequency of the compressor" is specifically: reducing the compression frequency to a set percentage of the original frequency.

In a preferred embodiment of the above air conditioner defrosting control method, the defrosting control method further includes a step of determining whether to exit the defrosting mode, the step comprising: comparing the outdoor fan after the air conditioner enters the defrosting mode The real-time current value and the selected first standard current value; determining whether to cause the air conditioner to exit the defrost mode according to the comparison result.

In a preferred embodiment of the above air conditioner defrosting control method, the step of "determining whether to cause the air conditioner to exit the defrosting mode according to the comparison result" includes: if the real-time current value of the outdoor fan is greater than or equal to the selected first standard current The value exits the defrost mode.

In the technical solution of the present invention, the degree of frosting of the outdoor coil is determined according to the law that the current of the outdoor fan changes with the change in the degree of frosting of the outdoor coil. Specifically, the present invention compares the real-time current value of the outdoor fan with the selected first standard current value, the selected second standard current value, and the selected third standard current value, respectively, according to the comparison result. Judging the current frosting state of the outdoor coil, and then performing corresponding operations according to the frosting state of the outdoor coil, for example, increasing the throttle opening degree, reducing the compressor operating frequency, etc. until the real-time current value of the outdoor fan is lower than When the third standard current value is selected, the degree of frosting of the outdoor coil is large, and the air conditioner is put into the defrost mode. It can be seen that the present invention can more accurately select the defrosting timing, and effectively eliminate the limitation in the prior art that the outdoor coil temperature is used to judge the degree of frosting, reduce the number of defrosting of the air conditioner, and improve the user experience.

DRAWINGS

1 is a main flow chart of a defrosting control method for an air conditioner according to the present invention;

2 is a detailed flow chart of the defrosting control method of the air conditioner of the present invention;

Fig. 3 is a schematic block diagram of an air conditioner of the present invention.

Detailed ways

The embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings, which are obvious, but not all Example. 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 scope of the present invention. For example, although the various steps of the method of the present invention are described in a particular order in the present application, these sequences are not limiting, and those skilled in the art can follow different orders without departing from the basic principles of the present invention. Perform the steps.

The prior art mainly judges the degree of frosting of the outdoor coil by the outdoor coil temperature, but as described in the background art, this method is easily affected by factors such as shunting and sensor accuracy, so that the outdoor coil temperature is used to judge There are certain limitations in the degree of frosting. The air conditioner defrosting control method proposed by the present invention aims to eliminate the limitation in judging the degree of frosting by using the outdoor coil temperature, and to more accurately judge the timing of entering the defrosting.

Referring to Fig. 1, there is shown a main flow chart of a method for controlling defrosting of an air conditioner according to the present invention. As shown in FIG. 1 , the defrosting control method of the present invention comprises the following steps: S110, detecting a real-time current value of an outdoor fan when the air conditioner is in a heating condition; S120, comparing a real-time current value of the outdoor fan and selecting The first standard current value, the second standard current value and the third standard current value are determined; S130, determining whether to make the air conditioner enter the defrosting mode according to the comparison result. Wherein, the first standard current value is a current value of the outdoor fan measured at different speeds in a state where the outdoor unit is not frosted; and the second standard current value is an outdoor fan measured in a state where the outdoor unit is frosted. The current value at the speed; the third standard current value is the current value of the outdoor fan measured at different speeds in the state where the outdoor unit is completely frosted. It should be noted that the "complete frosting" of the present invention is not to say 100% frosting, and the specific ratio can be set by a person skilled in the art as needed, and preferably, the degree of frosting between 80% and 90% is completely complete. frost.

As the degree of frosting of the outdoor coil becomes larger and larger, the wind resistance gradually increases, and the air volume entering the outdoor fan is correspondingly reduced. When the wind resistance increases, the load of the outdoor fan increases correspondingly, and the current of the outdoor fan follows The decrease. In other words, the load of the outdoor fan at a certain speed is determined. If the load of the motor increases at the same speed and the current decreases, the air intake of the outdoor fan decreases, and the degree of frosting of the outdoor coil increases. It can be seen that the current of the outdoor fan will change correspondingly with the degree of frosting of the outdoor coil, that is to say, the current value of different outdoor fans corresponds to different degrees of frosting of the outdoor coil. Therefore, according to the comparison between the real-time current value of the outdoor fan and the standard current value under different degrees of frosting, the degree of frosting of the outdoor coil can be judged, and the outdoor coil temperature/indoor coil temperature can be effectively eliminated in the prior art. To determine the limitations of the degree of frosting. Thereby, the timing of the air conditioner entering the defrosting is more accurately judged. The above steps are further described in detail below.

In the above step S110, the real-time current value of the outdoor fan can be detected by any known means, and will not be described in detail herein.

In the above step S120, the selected first standard current value is the first standard current value of the outdoor fan at the current speed; the selected second standard current value is the second standard current value of the outdoor fan at the current speed; The selected third standard current value is the third standard current value of the outdoor fan at the current speed. Specifically, since the first/second/third standard current values are respectively current values of the outdoor fan measured at different speeds in the state where the outdoor unit is not frosted/partially frosted/completely frosted, the standard current values are The control program of the air conditioner has been written in advance, so after detecting the real-time current value of the outdoor fan, the detected real-time current value can be directly compared with the first/second/third standard current value at the current speed. Comparison. It should be noted that one way of selecting the standard current value may be: by detecting the rotational speed of the outdoor fan, and then selecting the same standard current value as the current rotational speed among the pre-stored standard current values according to the current rotational speed. In addition to this, the standard current value can be selected in other reasonable ways.

In the above step S130, the step of determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result specifically includes: if the real-time current value of the outdoor fan is greater than or equal to the selected first standard current value, maintaining the current system of the air conditioner Thermal conditions do not enter the defrost mode. If the real-time current value of the outdoor fan is less than the selected first standard current value and greater than or equal to the selected second standard current value, the air conditioner maintains the current heating condition and increases the throttle opening of the air conditioner. Degree (increase the throttle opening to the set number of steps, for example, 50 steps), does not enter the defrost mode. If the real-time current value of the outdoor fan is less than the selected second standard current value and is greater than or equal to the selected third standard current value, the air conditioner maintains the current heating condition and the throttle opening of the air conditioner On the basis of the increase, the frequency of the compressor is lowered (as an example, the operating frequency of the compressor can be reduced to 80%), and the defrost mode is not entered. If the real-time current value of the outdoor fan is less than the selected third standard current value, the air conditioner enters the defrost mode.

In order to more clearly illustrate the defrosting control method of the present invention, the defrosting control method of the present invention will be described in detail below with reference to a specific embodiment.

Referring to Fig. 2, Fig. 2 is a detailed flowchart of the air conditioner defrosting control method of the present invention as an example. As shown in FIG. 2, in the case that the air conditioner is in the heating condition, step S210 is first performed to detect the real-time current value I _{s of the} outdoor fan. Then, the process proceeds to step S220, comparing I _s and I _b1 , wherein I _b1 is the selected first standard current value, that is, the current value of the outdoor fan measured at the current speed measured in the state where the outdoor unit is not frosted. If I _s ≥ I _b1 , it indicates that the outdoor coil is not frosted. At this time, step S221 is performed, and the air conditioner maintains the current heating condition; otherwise, step S230 is performed to compare I _s and I _b2 , wherein I _b2 is selected The second standard current value is determined, that is, the current value of the outdoor fan measured at the current speed measured under the condition that the outdoor unit is frosted by 30%. If I _b2 ≤I _s <I _b1 , it indicates that there is a risk of frosting in the outdoor coil at this time. At this time, step S231 is performed, the air conditioner maintains the current heating condition, and the throttle opening is increased by 50 steps; otherwise Step S240 is performed to compare I _s and I _b3 , wherein I _b3 is the selected third standard current value, that is, the current value of the outdoor fan measured at the current speed measured in a state where the outdoor unit is frosted by 90%. If I _b3 ≤I _s <I _b2 , it means that frost has appeared in the outdoor coil at this time. At this time, step S241 is executed, the air conditioner maintains the current heating condition, and the throttle opening is increased by 50 steps. Then, reduce the operating frequency of the compressor to 80%. If the value of I _s is not in the interval, step S250 is performed to determine whether I _s is less than or equal to I _b3 . If I _s <I _b3 , then sufficient frost has accumulated in the outdoor coil at this time, and step S251 is performed. The air conditioner is put into the defrost mode, that is, the outdoor coil is defrosted.

It should be noted that, in the above steps S231 and S241, those skilled in the art can customize the opening degree of the throttle valve and the adjustment degree of the compressor frequency according to the actual application scenario of the air conditioner, as long as it is within a reasonable range. All fall within the scope of protection of the present invention.

The air conditioner defrosting control method of the present invention further includes the step of exiting the defrosting mode. For example, referring to FIG. 2, after the air conditioner enters the defrosting mode, step S260 is performed to compare the values of I _s and I _b1 . If I _s ≥ I _b1 , the current value of the outdoor fan is greater than the selected one. The first standard current value indicates that the frost on the outdoor coil has been removed. At this time, the process proceeds to step S270, and the air conditioner exits the defrosting mode. Otherwise, it indicates that the frost on the outdoor coil has not been completely removed, so that the air conditioner maintains the current defrost mode. It will be readily understood by those skilled in the art that during the defrosting process, the current value of the outdoor fan will gradually increase, and when the real-time current value of the outdoor fan gradually increases to be equal to the selected first standard current value, the outdoor is indicated. The current of the fan is equal to the current value of the outdoor fan of the same speed in the unfrozen state of the air conditioner, that is, the frost on the outdoor coil has been removed.

Referring to FIG. 3, the present invention also provides an air conditioner 100 including an indoor unit 110 and an outdoor unit 120. The outdoor unit 120 is provided with a fan 121 and a current detecting device 122 therein. The air conditioner 100 further includes a compressor 123, a heat exchanger, and a throttle valve 123 to constitute a heat exchange system. The air conditioner 100 can be controlled by applying the defrosting control method described in any of the above embodiments to more accurately select the defrosting timing.

In summary, the present invention determines the degree of frosting of the outdoor coil according to the law that the current of the outdoor fan changes as the degree of frosting of the outdoor coil changes. Specifically, the present invention compares the real-time current value of the outdoor fan with the selected first standard current value, the selected second standard current value, and the selected third standard current value, respectively, according to the comparison result. Judging the current frosting state of the outdoor coil, and then performing corresponding operations according to the frosting state of the outdoor coil, for example, increasing the throttle opening degree, reducing the compressor operating frequency, etc. until the real-time current value of the outdoor fan is lower than When the third standard current value is selected, the degree of frosting of the outdoor coil is large, and the air conditioner is put into the defrost mode. It can be seen that the present invention can more accurately select the defrosting timing, and effectively eliminate the limitation in the prior art that the outdoor coil temperature is used to judge the degree of frosting, reduce the number of defrosting of the air conditioner, and improve the user experience.

Heretofore, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings, but it is obvious to those skilled in the art that the scope of the present invention is obviously not limited to the specific embodiments. Those skilled in the art can make equivalent changes or substitutions to the related technical features without departing from the principles of the invention, and the modifications and alternatives will fall within the scope of the present invention.

Claims

An air conditioner defrosting control method, characterized in that the defrosting control method comprises the following steps:

Detecting the real-time current value of the outdoor fan when the air conditioner is in a heating condition;

Comparing the real-time current value of the outdoor fan with the selected first standard current value, the second standard current value, and the third standard current value;

Determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result;

The first standard current value is a current value of the outdoor fan measured at different speeds in a state where the outdoor unit is not frosted; and the second standard current value is measured in a state where the outdoor unit is frosted. The current value of the outdoor fan at different speeds; the third standard current value is the current value of the outdoor fan measured at different speeds in the state where the outdoor unit is completely frosted.
The defrosting control method for an air conditioner according to claim 1, wherein the selected first standard current value, second standard current value, and third standard current value are respectively the current fan speed at the current speed Standard current values under different frosting conditions.
The defrosting control method for an air conditioner according to claim 2, wherein the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes:

If the real-time current value of the outdoor fan is greater than or equal to the selected first standard current value, the air conditioner is maintained in the current heating condition and does not enter the defrost mode.
The defrosting control method for an air conditioner according to claim 3, wherein the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes:

If the real-time current value of the outdoor fan is less than the selected first standard current value and greater than or equal to the second standard current value, the air conditioner is maintained to maintain the current heating condition, and the throttle valve of the air conditioner is increased. Opening degree, do not enter the defrost mode.
The defrosting control method for an air conditioner according to claim 4, wherein the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes:

If the real-time current value of the outdoor fan is less than the selected second standard current value and greater than or equal to the selected third standard current value, the air conditioner is maintained in the current heating condition, and in the section of the air conditioner On the basis of an increase in the opening of the flow valve, the frequency of the compressor is lowered, and the defrost mode is not entered.
The defrosting control method for an air conditioner according to claim 5, wherein the step of "determining whether to cause the air conditioner to enter the defrosting mode according to the comparison result" specifically includes:

If the real-time current value of the outdoor fan is less than the selected third standard current value, the air conditioner is caused to enter the defrost mode.
The defrosting control method for an air conditioner according to claim 6, wherein the "increasing the throttle opening degree of the air conditioner" is specifically: increasing the throttle opening degree by a set number of steps.
The defrosting control method for an air conditioner according to claim 6, wherein the "reducing the frequency of the compressor" is specifically: reducing the compression frequency to a set percentage of the original frequency.
The defrosting control method for an air conditioner according to any one of claims 1 to 8, wherein the defrosting control method further comprises the step of judging whether to exit the defrosting mode, the step comprising:

Comparing the real-time current value of the outdoor fan with the selected first standard current value after the air conditioner enters the defrosting mode;

It is judged based on the comparison result whether or not the air conditioner is caused to exit the defrosting mode.
The defrosting control method for an air conditioner according to claim 9, wherein the step of "determining whether to cause the air conditioner to exit the defrosting mode according to the comparison result" includes:

If the real-time current value of the outdoor fan is greater than or equal to the selected first standard current value, the defrost mode is exited.