CN110762747A - Defrost control method of air conditioner - Google Patents

Abstract

The invention relates to the technical field of air conditioners, in particular to a defrosting control method of an air conditioner. The present invention aims to solve the problem of false defrosting existing in the existing air conditioners under low temperature outdoor conditions. For this purpose, the defrosting control method of the air conditioners of the present invention includes: collecting outdoor environmental parameters and/or operating parameters of the outdoor unit of the air conditioner; Determine whether the air conditioner meets the basic defrosting conditions according to the outdoor environmental parameters and/or operating parameters; when the basic defrosting conditions are met, compare the current fluctuation rate of the outdoor fan with the first set threshold value; selectively turn on according to the comparison result Defrost mode. The present invention can be realized by utilizing the existing detection elements in the air conditioner or by simply adding simple detection elements, has little impact on the cost, and is suitable for mass production.

Description

Defrost control method of air conditioner

technical field

The invention relates to the technical field of air conditioners, in particular to a defrosting control method of an air conditioner.

Background technique

When the air conditioner is heating, there will generally be frost formation. If the air conditioner is not defrosted in time after the air conditioner is frosted, it will affect the performance of the air conditioner. The heating frost is generally located on the evaporator of the outdoor unit. When the heating mode is turned on, the outdoor unit absorbs heat and the indoor unit dissipates heat. Generally, when the heating mode is used, the outdoor ambient temperature is almost below 10°C, and when the outdoor unit absorbs heat, the temperature of the evaporator coil will drop to a lower temperature than the ambient temperature, causing the moisture in the surrounding air to quickly accumulate in the evaporator coil. Frost on top.

In the prior art, the defrosting determination of the air conditioner is basically completed by the defrosting sensor and the ambient temperature sensor. The ambient temperature sensor detects the ambient temperature, and the defrosting temperature sensor detects the temperature of the evaporator coil. Defrost will be performed after the set defrost temperature condition. However, when the outdoor ambient temperature of the unit is very low, especially below -10 °C, the detection of the temperature sensor generally has a large error. At this time, there is often no frost in the actual operation of the unit, but still defrosting. defrosting" phenomenon. The appearance of this "false defrosting" phenomenon not only consumes a lot of electricity, but also affects the indoor temperature and comfort.

Accordingly, there is a need in the art for a defrosting control method for an air conditioner to solve the above problems.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems in the prior art, namely in order to solve the problem of false defrosting existing in the existing air conditioners under low temperature outdoor conditions, the present invention provides a defrosting control method of the air conditioner, the control method comprising:

Collect outdoor environmental parameters and/or operating parameters of the outdoor unit of the air conditioner;

Judging whether the air conditioner meets basic defrosting conditions according to the outdoor environment parameter and/or the operating parameter;

When the basic defrosting conditions are met, comparing the current fluctuation rate of the outdoor fan with the magnitude of the first set threshold;

The defrost mode is selectively turned on according to the comparison result.

In the preferred technical solution of the above-mentioned defrosting control method for an air conditioner, the step of "collecting outdoor environmental parameters and/or operating parameters of the outdoor unit of the air conditioner" specifically includes: collecting outdoor environmental temperature and outdoor unit coil temperature.

In the preferred technical solution of the above-mentioned defrosting control method for an air conditioner, the step of "compare the current fluctuation rate of the outdoor fan and the magnitude of the first set threshold" includes:

Determine the temperature range in which the outdoor ambient temperature is located;

determining the first set threshold according to the temperature interval;

calculating the current fluctuation rate;

Compare the magnitude of the current fluctuation rate with the first set threshold.

In a preferred technical solution of the above-mentioned defrosting control method for an air conditioner, the first set threshold value decreases as the temperature interval decreases.

In a preferred technical solution of the above-mentioned defrosting control method for an air conditioner, the step of "collecting outdoor environment parameters and/or operating parameters of the outdoor unit of the air conditioner" further includes: acquiring the operating time of the air conditioner after the last defrost.

In the preferred technical solution of the above-mentioned defrosting control method for an air conditioner, the step of "calculating the current fluctuation rate" specifically includes: the current fluctuation rate is calculated according to the following formula:

m=i _t /i _o

_Wherein , the m is the current fluctuation rate; the i _t is the average value of the sampling current of the outdoor fan in the first set time period before this calculation; The average value of the sampling current of the outdoor fan within the set time period.

In a preferred technical solution of the above defrosting control method for an air conditioner, the sampling method is AD sampling.

In the preferred technical solution of the above-mentioned defrosting control method for an air conditioner, the step of "selectively enabling the defrosting mode according to the comparison result" specifically includes:

When the current fluctuation rate is greater than or equal to the first set threshold, the air conditioner is controlled to start a defrosting mode.

In the preferred technical solution of the above-mentioned defrosting control method of the air conditioner, the step of "selectively enabling the defrosting mode according to the comparison result" further comprises:

When the current fluctuation rate is less than the first set threshold, further determine whether the current fluctuation rate is less than or equal to a second set threshold;

According to the comparison result, the air conditioner is selectively controlled to turn on the defrosting mode.

In the preferred technical solution of the above-mentioned defrosting control method for an air conditioner, the step of “selectively controlling the air conditioner to enable the defrosting mode according to the comparison result” specifically includes: when the current fluctuation rate is less than or equal to the second setting When the threshold is set, the air conditioner is controlled to enter the defrosting mode.

Those skilled in the art can understand that, in a preferred technical solution of the present invention, the control method includes: collecting outdoor environmental parameters and/or operating parameters of the outdoor unit of the air conditioner; determining the air conditioner according to the outdoor environmental parameters and/or the operating parameters Whether the basic defrosting conditions are met; when the basic defrosting conditions are met, compare the current fluctuation rate of the outdoor fan with the magnitude of the first set threshold; and selectively enable the defrosting mode according to the comparison result.

On the basis of the basic defrosting conditions, the present invention adds the condition of judging the current fluctuation rate of the outdoor fan and the magnitude of the first set threshold, and judges whether the air conditioner really needs defrosting by the current fluctuation rate of the outdoor fan, avoiding the need for defrosting. The "false defrost" problems such as no-frost defrosting or frost-free defrosting caused by the basic defrosting conditions avoid the waste of resources and improve the user experience. Specifically, when the current fluctuation rate of the outdoor fan is greater than the first set threshold, it proves that the amount of frost on the outdoor unit increases, the power of the fan increases, and the current value fluctuates greatly. At this time, turning on the defrost mode can effectively ground to defrost the outdoor unit. When the current fluctuation rate of the outdoor unit is less than the first set threshold, it proves that the outdoor unit is not frosted or only slightly frosted, which is not enough to affect the operation of the air conditioner. The frost is likely to be a false defrost. Therefore, the defrost mode is not turned on at this time, which can effectively save energy and improve the user experience. That is to say, the defrosting control method of the air conditioner of the present invention solves the problem of false defrosting existing in the existing air conditioner under the outdoor low temperature condition, and the control steps are simple and effective, using the existing detection elements in the air conditioner or simply adding a simple The present invention can be realized by using only the detection element, which has almost no impact on the cost, and is suitable for mass production.

Description of drawings

The defrosting control method of the air conditioner of the present invention will be described below with reference to the accompanying drawings. In the attached picture:

Fig. 1 is the flow chart of the defrosting control method of the air conditioner of the present invention;

2 is a flow chart of comparing the current fluctuation rate of the outdoor fan and the first set threshold in the method of the present invention;

FIG. 3 is a schematic diagram of the logic of the defrosting control method of the air conditioner of the present invention.

Detailed ways

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention. For example, in addition to being set to 0.95, the second set threshold may also be selected within a range of less than 1 according to the actual situation, for example, may also be 0.96, 0.97, 0.94, and the like.

First, referring to FIG. 1 , the defrosting control method of the air conditioner of the present invention will be introduced. 1 is a schematic flowchart of a defrosting control method for an air conditioner of the present invention.

As shown in FIG. 1, in order to solve the problem of false defrosting existing in the existing air conditioner under the outdoor low temperature condition, the present invention provides a defrosting control method of the air conditioner, the method mainly includes:

S100. Collect outdoor environmental parameters and/or operating parameters of the outdoor unit of the air conditioner, for example, collect outdoor environmental parameters or operating parameters of the outdoor unit according to basic defrosting conditions, or collect outdoor environmental parameters and operating parameters of the outdoor unit at the same time. The environmental parameters of the outdoor unit include the outdoor ambient temperature, and the operating parameters of the outdoor unit include the temperature of the outdoor unit coil and operating time data (such as the duration of the temperature data and/or the operating time after the last defrost). Of course, those skilled in the art Corresponding parameters can also be collected according to other basic defrosting conditions. For example, when the defrosting control method of the difference between evaporation temperature and atmospheric temperature is used, the ambient temperature and evaporation temperature need to be collected. Specifically, the refrigerant pressure at the outlet of the evaporator can be collected. Approximate as the evaporation pressure, so as to calculate or look up the table to obtain the evaporation temperature;

S200. Determine whether the air conditioner meets the basic defrosting conditions according to the outdoor environment parameters and/or the operation parameters of the outdoor unit of the air conditioner. For example, after collecting the above parameters, determine the outdoor ambient temperature, the temperature of the outdoor unit coil and the duration of the temperature data Whether the basic defrosting conditions of the air conditioner are met at the same time;

S300. When the basic defrosting conditions are met, compare the current fluctuation rate of the outdoor fan with the magnitude of the first set threshold; for example, after satisfying the basic defrosting conditions, according to the running time data (running time after the last defrosting) Collect the current value of the outdoor fan in the corresponding time period, calculate the current fluctuation rate, and compare the current fluctuation rate with the first set threshold;

S400. Selectively enable the defrost mode according to the comparison result. For example, when the current fluctuation rate is greater than or equal to the first set threshold, the defrost mode is enabled; when the current fluctuation rate is less than the first set threshold, the defrost mode is not enabled frost mode.

In the above scheme, by first judging whether the air conditioner satisfies the basic defrosting conditions, then judging the relationship between the current fluctuation rate and the first set threshold and the second set threshold, and finally selectively turning on the defrost mode according to the judgment result, The defrosting control method of the air conditioner of the present invention has simple and effective steps, and on the basis of the basic defrosting conditions, a condition of judging whether the current fluctuation rate is greater than the first set threshold is added, so as to avoid the basic defrosting conditions. The "false defrost" problem of no-frost defrosting or frost but no defrosting avoids the waste of resources and improves the user experience.

1 and 2, the defrosting control method of the air conditioner of the present invention will be described in detail. 2 is a flow chart of comparing the current fluctuation rate of the outdoor fan and the magnitude of the first set threshold in the method of the present invention.

As shown in FIG. 1 and FIG. 2 , in a preferred embodiment, step S200 specifically includes:

Determine whether the air conditioner meets the basic defrosting conditions according to the outdoor ambient temperature, the temperature of the outdoor unit coil and the duration of the temperature data. For example, determine whether the above parameters meet the following conditions:

1) When T _ao ≧4℃, T _def ≦-6℃ and lasted for 5 minutes;

2) When -6℃≦T _ao ＜4℃, T _def ≦0.8T _ao -8.5 and last for 5 minutes;

3) When -15℃≦T _ao ＜-6℃, when T _def ≦(5×Tao-72)/7/1.08 and lasts for 5 minutes;

4) When T _ao <-15℃, T _def ≦-20℃ and lasts for 5 minutes;

Among them, T _ao is the outdoor ambient temperature; T _def is the outdoor unit coil temperature.

When any one of the above four conditions is met, it is determined that the outdoor unit meets the basic defrosting conditions.

Of course, the above defrosting conditions are only exemplary, and the defrosting conditions are naturally different for different air conditioners. For example, the outdoor unit coil can also be equipped with two temperature sensors. On the premise that the outdoor ambient temperature satisfies the conditions, when one or both of the two temperatures detected by the two temperature sensors are lower than the corresponding set temperature, it is determined as The basic defrosting conditions are met.

2, after judging that the air conditioner meets the basic defrosting conditions, in a possible implementation, step S300 specifically includes:

S310. Determine the temperature interval in which the outdoor ambient temperature is located, for example, determine the set temperature interval in which the temperature is located by using the previously obtained ambient temperature, where the temperature interval can be divided into (-∞, -10), [- 10,-5) and [-5,10) three intervals;

S320, determining a first set threshold according to the temperature interval;

In step S320, with the continuous increase of the frosting amount of the outdoor fan, the power of the outdoor fan is also increasing, so the current value is also gradually increasing. Therefore, when defrosting is required, the value of the current fluctuation rate is greater than 1, and therefore, the first set threshold is at least 1. In addition, as the temperature decreases, the frost will be less, and the change of the current will be smaller, so the first set threshold is also smaller, so different temperature ranges correspond to different first set thresholds. The threshold decreases as the temperature interval decreases. For example, in one possible setup:

When 10℃>T _ao ≧-5℃, the first set threshold is 1.08;

When -5°C>T _ao ≧-10°C, the first set threshold is 1.06;

When T _ao <-10°C, the first set threshold is 1.04;

The above-mentioned values of temperature interval and current fluctuation rate are only exemplary, and those skilled in the art can formulate different temperature ranges and select other current fluctuation rates according to the type and model of air conditioners and differences in geographical environment. For example, in southern winter, the air humidity is relatively high, and the amount of frost on the air conditioner is relatively large, so the size of the first set threshold can be increased. For example, when 10°C>T _ao ≧-5°C, the first set threshold is 1.1.

S330. Calculate the current fluctuation rate;

In a more preferred embodiment, the current fluctuation rate can be calculated according to the following formula (1):

m=i _t /i _o (1)

In formula (1), m is the current fluctuation rate; i _t is the average value of the sampling current of the outdoor fan in the first set time period before this calculation; i _o is the stable operation after the last defrost or the first stable operation after the startup. 2. The average value of the sampling current of the outdoor fan within the set time period. Specifically, the first time period and the second time period are preferably 3 minutes, i _t is the average value of the sampling current of the outdoor fan in the first 3 minutes of this calculation, and i _o can be the outdoor fan within 3 minutes after the defrosting is completed. The average value of the sampling current of the blower operation. Those skilled in the art can select different first time periods and second time periods according to different types and models of air conditioners, for example, the first time period and the second time period are 2 minutes or 4 minutes, respectively. Among them, the sampling method is preferably AD sampling, of course, other sampling methods such as interval sampling can also be used. In addition, when calculating the current average value, the maximum and minimum values in the sampling can also be removed to ensure the calculation accuracy of the current average value.

S340. Compare the magnitude of the current fluctuation rate and the first set threshold, for example, compare the calculated current fluctuation rate with the first set threshold determined in S320.

After comparing the magnitude of the current fluctuation rate and the first set threshold, in a possible implementation, step S400 specifically includes: selectively enabling the defrosting mode according to the comparison result. For example, when 10°C>T _ao ≧-5°C, and m≧1.08, the defrost mode is turned on; when -5°C>T _ao ≧-10°C, when m≧1.06, the defrost mode is turned on; _Tao < At -10℃, when m≧1.04, the defrost mode is turned on.

Further, in a more preferred embodiment, when the current fluctuation rate is less than the first set threshold, the defrosting control method for the air conditioner further includes:

Further determine the magnitude of the current fluctuation rate and the second set threshold, and selectively control the air conditioner to open the defrost mode according to the comparison result. For example, when the current fluctuation rate is greater than the second set threshold, it will not defrost, and when the current fluctuates When the rate is less than or equal to the second set threshold, the defrost mode is turned on. Wherein, the second set threshold is less than 1, preferably 0.95. If the current fluctuation rate shows a decreasing trend, it means that the outdoor fan is malfunctioning and the operation is not smooth. At this time, it is not necessary to use the current fluctuation rate to judge the frost formation of the outdoor unit, and defrost it directly according to the basic initial frost conditions. Wherein, the second set threshold value can also be selected within a range of less than 1 according to the actual situation, for example, it can also be 0.96, 0.97, 0.94 and so on.

In the present invention, the above steps can also be removed, and the present invention can also be implemented in the case of removing the above steps, and the problem of frost-free defrosting existing in the prior art can be solved.

To sum up, the advantages of the above preferred embodiment are: the outdoor ambient temperature is divided into multiple ranges, and different first set thresholds are set for different ranges, fully considering that the current change trend of the outdoor fan will change with the temperature The difference is that the accuracy of the current fluctuation rate judgment condition is guaranteed, and the defrosting accuracy of the control method is improved. Comparing the current fluctuation rate with two set thresholds refines the fluctuation range of the current fluctuation rate, improves the accuracy of the current fluctuation rate judgment, and avoids the inaccurate judgment caused by comparing with a set threshold value. question. In addition, in this control method, the present invention can be realized by using the existing detection elements in the air conditioner or by simply adding simple detection elements, which has little impact on the cost and is suitable for mass production.

3 , the working flow of the defrosting control method of the air conditioner of the present invention will be briefly described. 3 is a logic diagram of the defrosting control method of the air conditioner of the present invention.

As shown in Figure 3, in one possible control logic, collect the outdoor ambient temperature and the temperature of the outdoor unit coil → judge whether the basic defrosting conditions are met, and then proceed to the next step, otherwise return to re-collection → AD sampling current value , and calculate the current fluctuation rate m → judge whether m>1.08 is established, if so, start the defrost mode, otherwise go to the next step → judge whether m<0.95 is established, if it is established, start the defrost mode, otherwise collect again.

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

Claims (10)

1. A defrosting control method of an air conditioner, characterized in that the control method comprises:

collecting outdoor environment parameters and/or operating parameters of an air conditioner outdoor unit;

judging whether the air conditioner meets basic defrosting conditions or not according to the outdoor environment parameters and/or the operation parameters;

when the basic defrosting condition is met, comparing the current fluctuation rate of the outdoor fan with a first set threshold value;

and selectively starting the defrosting mode according to the comparison result.

2. The defrosting control method of an air conditioner according to claim 1, wherein the step of collecting the outdoor environment parameters and/or the operation parameters of the outdoor unit of the air conditioner specifically comprises:

the outdoor ambient temperature and the outdoor unit coil temperature are collected.

3. The defrosting control method of an air conditioner according to claim 2, wherein the step of comparing the magnitude of the first set threshold with the current fluctuation rate of the outdoor fan comprises:

judging the temperature interval of the outdoor environment temperature;

determining the first set threshold according to the temperature interval;

calculating the current fluctuation rate;

and comparing the current fluctuation rate with a first set threshold value.

4. The defrosting control method of an air conditioner according to claim 3, wherein the first set threshold is decreased as the temperature section is decreased.

5. The defrosting control method of an air conditioner according to claim 3, wherein the step of collecting the outdoor environment parameter and/or the operation parameter of the outdoor unit of the air conditioner further comprises:

and acquiring the running time of the air conditioner after the last defrosting.

6. The defrosting control method of an air conditioner according to claim 5, wherein the step of "calculating the current fluctuation rate" specifically includes:

the current fluctuation ratio is calculated according to the following formula:

m＝i_t/i_o

wherein m is the current fluctuation rate; i is described_tThe average value of the sampling current of the outdoor fan in the first set time period before the calculation is obtained; i is described_oThe average value of the sampling current of the outdoor fan in the second set time period after the last defrosting or the stable operation of the starting is obtained.

7. The defrost control method of an air conditioner according to claim 6, wherein the sampling method is AD sampling.

8. The defrosting control method of an air conditioner according to any one of claims 1 to 7, wherein the step of selectively turning on the defrosting mode according to the comparison result specifically includes:

and when the current fluctuation rate is greater than or equal to the first set threshold value, controlling the air conditioner to start a defrosting mode.

9. The defrost control method of an air conditioner according to any one of claim 8, wherein the step of selectively turning on the defrost mode according to the comparison result further comprises:

when the current fluctuation rate is smaller than the first set threshold, further judging whether the current fluctuation rate is smaller than or equal to a second set threshold;

and selectively controlling the air conditioner to start the defrosting mode according to the comparison result.

10. The defrosting control method of an air conditioner according to claim 9, wherein the step of selectively controlling the air conditioner to turn on the defrosting mode according to the comparison result specifically includes:

and when the current fluctuation rate is less than or equal to the second set threshold value, controlling the air conditioner to enter a defrosting mode.

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