A control method, device, storage medium, and air conditioner for an air conditioner

Abstract

This invention provides a control method, device, storage medium, and air conditioner for an air conditioner. The method includes: after the air conditioner is turned on for heating and enters anti-cold air control, determining whether the air conditioner meets the conditions for exiting anti-cold air control and whether it is in the compressor frequency dwell control stage; when it is determined that the air conditioner meets the conditions for exiting anti-cold air control and is in the compressor frequency dwell control stage, determining whether the indoor heat exchanger pipe temperature is less than or equal to a second preset temperature value; if it is determined that the indoor heat exchanger pipe temperature is less than or equal to the second preset temperature value, increasing the opening degree of the air conditioner's throttling element according to the temperature rise rate of the indoor heat exchanger pipe temperature; after increasing the opening degree of the air conditioner's throttling element, determining whether the air conditioner's compressor is undergoing liquid compression according to the compressor phase current; if it is determined that the air conditioner's compressor is undergoing liquid compression, decreasing the opening degree of the air conditioner's throttling element. The solution provided by this invention can improve the reliability of the compressor.

Description

TECHNICAL FIELD

[0001] The present application relates to the control field, and particularly to a control method and device of an air conditioner, a storage medium and the air conditioner. BACKGROUND

[0002] When the heat pump air conditioner is used for heating in winter, the higher the outdoor environment temperature is, the higher the requirements for the air conditioner operation reliability and comfort are. On the one hand, the air conditioner operates at high load in low temperature conditions, and the oil return state of the air conditioner system is poor, which easily leads to oil shortage or oil shortage of the compressor, reduces the air conditioner reliability and service life; on the other hand, the heating temperature rise rate of the air conditioner is slow in low temperature conditions, the air outlet temperature is low when the air conditioner is just started, and there is a risk of cold air blowing, which leads to user discomfort.

[0003] The related technology sets a frequency stay platform in the compressor startup frequency rising process, so that the air conditioner maintains a certain frequency for a certain time before continuing to rise the frequency, to improve the oil return condition of the compressor and improve the air conditioner low temperature operation reliability. At the same time, a cold wind prevention control function is designed, and the indoor fan is started after the indoor temperature of the air conditioner rises to a certain value, so as to ensure that the air outlet temperature of the air conditioner will not be too low, and improve the user comfort.

[0004] However, the above technical solution has the following problems: the compressor oil return reliability control technology and the cold wind prevention control technology lack coupled control, and the method for ensuring the reliability of the air conditioner is single, only relying on the frequency stay control technology in the compressor frequency rising stage, which restricts the air conditioner heating early stage capacity output, and leads to the air conditioner cannot blow hot air quickly. SUMMARY

[0005] The main purpose of the present application is to overcome the defects of the above related technology, and provide a control method and device of an air conditioner, a storage medium and the air conditioner, to solve the problem that the system reliability is reduced in the related technology when the air conditioner is in a large heat output state.

[0006] This invention provides a method for controlling an air conditioner, comprising: after the air conditioner is turned on for heating and enters anti-cold air control, determining whether the air conditioner meets the conditions for exiting anti-cold air control and whether the air conditioner is in a compressor frequency dwell control stage; the compressor frequency dwell control refers to maintaining the compressor at a set frequency for a set time during the frequency ramp-up process after the compressor starts, and then continuing to ramp up the frequency; the set frequency is recorded as the dwell point frequency of the compressor frequency dwell control, and the set time is recorded as the dwell duration of the compressor frequency dwell control; when it is determined that the air conditioner meets the conditions for exiting anti-cold air control, and When the air conditioner is in the compressor frequency dwell control phase, it is determined whether the indoor heat exchanger tube temperature is less than or equal to a second preset temperature value. If the indoor heat exchanger tube temperature is less than or equal to the second preset temperature value, the opening degree of the air conditioner's throttling element is increased according to the temperature rise rate of the indoor heat exchanger tube temperature. After increasing the opening degree of the air conditioner's throttling element, it is determined whether the air conditioner's compressor is undergoing liquid compression according to the compressor phase current. If the air conditioner's compressor is undergoing liquid compression, the opening degree of the air conditioner's throttling element is decreased to increase the compressor's suction superheat.

[0007] Optionally, determining whether the air conditioner meets the conditions for exiting anti-cold air control includes: determining whether the indoor heat exchanger pipe temperature of the air conditioner is greater than or equal to a first preset temperature value; if the indoor heat exchanger pipe temperature is greater than or equal to the first preset temperature value, then the air conditioner is determined to meet the conditions for exiting anti-cold air control; and / or, determining whether the air conditioner is in the compressor frequency dwell control stage, including: if the cumulative compressor runtime of the air conditioner is greater than a preset duration, and less than or equal to the sum of the cumulative compressor runtime when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control, then the air conditioner is determined to be in the compressor frequency dwell control stage; and / or, increasing the opening degree of the throttling element of the air conditioner according to the temperature rise rate of the indoor heat exchanger pipe temperature, including: determining the interval in which the temperature rise rate of the indoor heat exchanger pipe temperature falls within two or more preset temperature rise rate intervals. Wherein, each of the two or more preset temperature rise rate intervals corresponds to an opening increment; the opening increment of the throttling element of the air conditioner is determined according to the opening increment corresponding to the interval in which the temperature rise rate of the indoor heat exchanger tube temperature is located in the two or more preset temperature rise rate intervals; the opening of the throttling element of the air conditioner is increased according to the determined opening increment of the throttling element of the air conditioner; and / or, based on the compressor phase current of the air conditioner, it is determined whether the compressor is undergoing liquid compression, including: obtaining the maximum fluctuation value of the compressor phase current, the maximum fluctuation value of the compressor phase current is equal to the difference between the maximum value of the effective value of the compressor phase current and the minimum value of the effective value of the compressor phase current within a predetermined time; determining whether the compressor is undergoing liquid compression based on the ratio of the obtained maximum fluctuation value of the compressor phase current to the average fluctuation value of the compressor phase current under preset liquid-free compression conditions.

[0008] Optionally, determining whether the compressor is undergoing liquid compression based on the ratio of the maximum fluctuation value of the compressor phase current to the preset average fluctuation value of the compressor phase current under liquid-free compression conditions includes: determining whether the compressor is undergoing liquid compression based on the relationship between the root mean square error of the square of the ratio of the maximum fluctuation value of the compressor phase current to the preset average fluctuation value of the compressor phase current under liquid-free compression conditions and a set threshold.

[0009] Optionally, it further includes: when it is determined that the air conditioner meets the conditions for exiting anti-cold air control, but the air conditioner is not in the compressor frequency dwell control stage, controlling the air conditioner to maintain its current heating operation; wherein, the situation where the air conditioner is not in the compressor frequency dwell control stage includes: the cumulative running time of the air conditioner's compressor is less than or equal to a preset time, and / or the cumulative running time of the air conditioner's compressor is greater than the sum of the cumulative running time of the compressor when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control; and / or, when the air conditioner meets the conditions for exiting compressor frequency dwell control, controlling the air conditioner to resume normal heating operation; the conditions for exiting compressor frequency dwell control include: the cumulative running time of the compressor is greater than the sum of the cumulative running time of the compressor when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control; and / or, if it is determined that the compressor has not undergone liquid compression, then the dwell time of compressor frequency dwell control is corrected according to the current throttling element opening and compressor frequency of the air conditioner.

[0010] Optionally, the dwell time of the compressor frequency dwell control is determined based on the outdoor ambient temperature, including: determining the temperature range in which the outdoor ambient temperature falls within two or more preset temperature ranges; wherein each of the two or more preset temperature ranges corresponds to a duration; determining the dwell time of the air conditioner currently performing compressor frequency dwell control based on the duration corresponding to the temperature range in which the outdoor ambient temperature falls within the two or more preset temperature ranges; and / or, the cumulative compressor running time when entering compressor frequency dwell control is determined based on the compressor's initial start frequency, the duration of the compressor start-up phase, and the compressor's frequency ramp-up rate; wherein, the calculation formula for the cumulative compressor running time s1 when entering compressor frequency dwell control is as follows: s1=(F1-F start ) / v+s other

[0011] Where F1 is the dwell point frequency of the compressor frequency dwell control, F start The initial starting frequency of the compressor is s. other The duration of the compressor start-up phase is given by ν, and the compressor's frequency ramp-up rate is given by ν.

[0012] And / or, based on the current throttling element opening and compressor frequency of the air conditioner, the dwell time of the compressor frequency dwell control is corrected, including: determining the correction time based on the current throttling element opening and compressor frequency of the air conditioner, and correcting the dwell time of the compressor frequency dwell control based on the determined correction time; wherein, the corrected dwell time is equal to the dwell time of the current compressor frequency dwell control of the air conditioner minus the correction time.

[0013] Another aspect of the present invention provides a control device for an air conditioner, comprising: a first judgment unit, configured to, after the air conditioner is turned on for heating and enters anti-cold air control, determine whether the air conditioner meets the conditions for exiting anti-cold air control and whether the air conditioner is in a compressor frequency dwell control stage; the compressor frequency dwell control refers to maintaining the compressor at a set frequency for a set time during the frequency increase process after the compressor starts, and then continuing to increase the frequency; the set frequency is recorded as the dwell point frequency of the compressor frequency dwell control, and the set time is recorded as the dwell duration of the compressor frequency dwell control; a second judgment unit, configured to, when the first judgment unit determines that the air conditioner meets the conditions for exiting anti-cold air control and the air conditioner is in a compressor frequency dwell control stage... During the dwell control phase, it is determined whether the indoor heat exchanger tube temperature of the air conditioner is less than or equal to a second preset temperature value; the control unit is used to increase the opening degree of the air conditioner's throttling element according to the temperature rise rate of the indoor heat exchanger tube temperature if the second determination unit determines that the indoor heat exchanger tube temperature is less than or equal to the second preset temperature value; the third determination unit is used to determine whether the air conditioner's compressor is undergoing liquid compression according to the compressor phase current after the control unit increases the opening degree of the air conditioner's throttling element; the control unit is also used to: if the third determination unit determines that the air conditioner's compressor is undergoing liquid compression, decrease the opening degree of the air conditioner's throttling element to increase the compressor's suction superheat.

[0014] Optionally, the first determining unit determines whether the air conditioner meets the conditions for exiting anti-cold air control, including: determining whether the indoor heat exchanger pipe temperature of the air conditioner is greater than or equal to a first preset temperature value; if the indoor heat exchanger pipe temperature is greater than or equal to the first preset temperature value, then the air conditioner is determined to meet the conditions for exiting anti-cold air control; and / or, the first determining unit determines whether the air conditioner is in the compressor frequency dwell control stage, including: if the cumulative compressor runtime of the air conditioner is greater than a preset duration, and less than or equal to the sum of the cumulative compressor runtime when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control, then the air conditioner is determined to be in the compressor frequency dwell control stage; and / or,

[0015] The control unit increases the opening degree of the air conditioner's throttling element based on the temperature rise rate of the indoor heat exchanger tubes, including: determining the interval where the temperature rise rate of the indoor heat exchanger tubes falls within two or more preset temperature rise rate intervals, wherein each of the two or more preset temperature rise rate intervals corresponds to an opening degree increment; determining the opening degree increment of the air conditioner's throttling element based on the opening degree increment corresponding to the interval where the temperature rise rate of the indoor heat exchanger tubes falls within the two or more preset temperature rise rate intervals; increasing the opening degree of the air conditioner's throttling element based on the determined opening degree increment; and / or, the third judgment unit determines whether the compressor is undergoing liquid compression based on the compressor phase current of the air conditioner, including: acquiring the maximum fluctuation value of the compressor phase current, the maximum fluctuation value of the compressor phase current being equal to the difference between the maximum value and the minimum value of the effective value of the compressor phase current within a predetermined time; determining whether liquid compression exists in the compressor based on the ratio of the acquired maximum fluctuation value of the compressor phase current to the average fluctuation value of the compressor phase current under a preset liquid-free compression condition.

[0016] Optionally, the third judgment unit determines whether the compressor has liquid compression based on the ratio of the maximum fluctuation value of the compressor phase current to the preset average fluctuation value of the compressor phase current under liquid-free compression conditions. This includes determining whether the compressor has liquid compression based on the relationship between the root mean square error of the square of the ratio of the maximum fluctuation value of the compressor phase current to the preset average fluctuation value of the compressor phase current under liquid-free compression conditions and a set threshold.

[0017] Optionally, the control unit is further configured to: when the first judgment unit determines that the air conditioner meets the conditions for exiting anti-cold air control, but the air conditioner is not in the compressor frequency dwell control stage, control the air conditioner to maintain its current heating operation; wherein, the situation where the air conditioner is not in the compressor frequency dwell control stage includes: the cumulative running time of the air conditioner's compressor is less than or equal to a preset time, and / or the cumulative running time of the air conditioner's compressor is greater than the sum of the cumulative running time of the compressor when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control; and / or, the control unit is further configured to: when the air conditioner meets the conditions for exiting compressor frequency dwell control, control the air conditioner to resume normal heating operation; the conditions for exiting compressor frequency dwell control include: the cumulative running time of the compressor is greater than the sum of the cumulative running time of the compressor when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control; and / or, the control device further includes, a correction unit, configured to, if the third judgment unit determines that the compressor has not undergone liquid compression, correct the dwell time of the compressor frequency dwell control according to the current throttling element opening and compressor frequency of the air conditioner.

[0018] Optionally, the control device further includes: a first determining unit, configured to determine the dwell time of the compressor frequency dwell control, wherein the dwell time of the compressor frequency dwell control is determined based on the outdoor ambient temperature, including: determining the temperature range in which the outdoor ambient temperature falls within two or more preset temperature ranges; wherein each of the two or more preset temperature ranges corresponds to a duration; determining the dwell time of the air conditioner currently performing compressor frequency dwell control based on the duration corresponding to the temperature range in which the outdoor ambient temperature falls within the two or more preset temperature ranges; and / or, the control device further includes: a second determining unit, configured to determine the cumulative running time of the compressor when entering compressor frequency dwell control based on the compressor initial start frequency, the duration of the compressor start-up phase, and the compressor frequency ramp-up rate;

[0019] The formula for calculating the cumulative compressor runtime s1 when entering compressor frequency dwell control is as follows: s1=(F1-F start ) / v+s other

[0020] Where F1 is the dwell point frequency of the compressor frequency dwell control, F start The initial starting frequency of the compressor is s. other The duration of the compressor start-up phase is given by ν, and the compressor's frequency ramp-up rate is given by ν.

[0021] And / or, the correction unit, based on the current throttling element opening and compressor frequency of the air conditioner, corrects the dwell time of the compressor frequency dwell control, including: determining the correction time based on the current throttling element opening and compressor frequency of the air conditioner, and correcting the dwell time of the compressor frequency dwell control based on the determined correction time; wherein, the corrected dwell time is equal to the dwell time of the current compressor frequency dwell control of the air conditioner minus the correction time.

[0022] In another aspect, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0023] In another aspect, the present invention provides an air conditioner, including a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of any of the methods described above.

[0024] In another aspect, the present invention provides an air conditioner including any of the control devices described above.

[0025] According to the technical solution of the present invention, when the heating operation exits the anti-cold air and is in the frequency dwell control stage, the opening degree of the throttling element is adjusted by monitoring the change of the inner pipe temperature and the rate of change of the inner pipe temperature to increase the air conditioning capacity output, improve the system oil return, increase the air conditioning outlet temperature, and shorten the dwell time of constant frequency operation. At the same time, liquid compression identification and control are performed by monitoring the compressor phase current fluctuation to avoid liquid compression of the compressor, thus improving both user heating comfort and compressor operation reliability.

[0026] While ensuring that the air conditioner can quickly blow hot air, this paper addresses the problem of reduced reliability of existing air conditioning systems under high heat output conditions, achieving comfortable and reliable operation of the air conditioner and improving the user experience.

[0027] According to the technical solution of the present invention, by using multiple parameters to comprehensively control the system reliability, the problem of poor heating comfort caused by the single reliability control method of the current compressor can be solved. While ensuring the air conditioner's high capacity output and rapid heating operation, reliability problems such as compressor oil shortage, oil-air shortage, or liquid compression are avoided, thereby maximizing user heating comfort and compressor lifespan. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a schematic diagram of an embodiment of the air conditioner control method provided by the present invention;

[0030] Figure 2 A flowchart illustrating the steps of one specific implementation method is shown;

[0031] Figure 3 This is a schematic diagram of another embodiment of the air conditioner control method provided by the present invention;

[0032] Figure 4 This is a schematic diagram of another embodiment of the air conditioner control method provided by the present invention;

[0033] Figure 5 This is the air conditioning operation control logic according to the present invention;

[0034] Figure 6 This is the compressor reliability control logic according to the present invention;

[0035] Figure 7 This is a structural block diagram of an embodiment of the air conditioner control device provided by the present invention;

[0036] Figure 8This is a structural block diagram of another embodiment of the air conditioner control device provided by the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] The relevant technology incorporates a frequency pause platform during the compressor's start-up and frequency ramp-up process. This allows the air conditioner to maintain a certain frequency for a specific period before continuing to ramp up, improving oil return in the compressor and enhancing the reliability of low-temperature operation. Simultaneously, a heating anti-cold air control function is designed, ensuring that the indoor fan only activates after the compressor starts and the internal pipe temperature reaches a certain value, thus preventing the air conditioner's outlet temperature from becoming too low and improving user comfort.

[0040] However, the above technical solutions have the following problems: the compressor oil return reliability control technology and the anti-cold air control technology lack coupled control, and the method to ensure the reliability of the air conditioner is singular, relying solely on the compressor frequency standby control technology during the frequency boosting phase. This restricts the air conditioner's output capacity in the early heating stage, causing the air conditioner to fail to quickly blow hot air. Furthermore, when the compressor frequency standby control occurs after the anti-cold air control is disengaged, there is still a risk of blowing cold air, affecting the user experience. This is because during the low-temperature heating start-up frequency boosting phase of the air conditioner, the initial room temperature is low, while the air conditioner's heat output is low and the internal pipe temperature rises slowly. Directly turning on the internal fan at this time will cause the outlet air temperature to drop rapidly. Therefore, the internal pipe temperature needs to be higher than the target pipe temperature (e.g., 40℃) to restore normal operating fan speed. However, when the internal pipe temperature is just above the target pipe temperature, but the compressor is in the frequency dwell phase, the air conditioner's heat output does not increase in real time, while the internal fan speed increases rapidly. This causes the internal pipe temperature and the outlet air temperature to drop continuously, resulting in poor anti-cold air effect. For example, in the heating operation under the condition of 0℃ internal temperature and -5℃ external temperature, the relevant technical solution enters frequency dwell control after the compressor has accumulated 160 seconds of operation, and exits the air conditioner's anti-cold air function at 190 seconds. At this time, the internal pipe temperature drops rapidly from 40℃ to 28℃, and the outlet air temperature drops to 18℃~20℃, resulting in a low outlet air temperature.

[0041] This invention provides a method for controlling an air conditioner.

[0042] Figure 1 This is a schematic diagram of an embodiment of the air conditioner control method provided by the present invention.

[0043] like Figure 1 As shown, according to an embodiment of the present invention, the control method includes at least steps S110, S120, S130, S140 and S150.

[0044] Step S110: After the air conditioner is turned on for heating and enters the anti-cold air control, determine whether the air conditioner meets the conditions for exiting the anti-cold air control and whether the air conditioner is in the compressor frequency dwell control stage.

[0045] The compressor frequency dwell control refers to maintaining the compressor at a set frequency for a set time during the frequency increase process after the compressor starts, and then continuing to increase the frequency; the set frequency is recorded as the dwell point frequency of the compressor frequency dwell control, and the set time is recorded as the dwell duration of the compressor frequency dwell control.

[0046] In one specific implementation, determining whether the air conditioner meets the conditions for exiting anti-cold air control includes: determining the indoor heat exchanger tube temperature T of the air conditioner. s If the temperature is greater than or equal to the first preset temperature value T1, then the indoor heat exchanger tube temperature T is determined. sIf the temperature is greater than or equal to the first preset temperature value T1, then the air conditioner is determined to meet the conditions for exiting the anti-cold air control.

[0047] Specifically, the temperature of the indoor heat exchanger tubes (referred to as the inner tube temperature) T is detected and recorded in real time. s Determine the temperature T of the indoor heat exchanger tubes in the air conditioner. s The relationship with the preset temperature value T1 is that the first preset temperature value T1 is the target internal pipe temperature of the indoor heat exchanger when the anti-cold air control is lifted. If T s If the temperature is less than T1, meaning the indoor heat exchanger pipe temperature is low and the air outlet temperature is low, then the indoor fan should remain off or running at low speed to prevent direct cold airflow; if T... s If the temperature is greater than or equal to T1, meaning the temperature of the indoor heat exchanger tube is high enough to meet the conditions for exiting the anti-cold air control, then the anti-cold air control will be exited and the indoor fan will switch to the set fan speed.

[0048] In one specific implementation, determining whether the air conditioner is in the compressor frequency dwell control stage includes: if the cumulative running time s of the air conditioner's compressor is greater than the preset time s0, and less than or equal to the sum of the cumulative running time s1 of the compressor when entering the compressor frequency dwell control and the dwell time t of the compressor frequency dwell control, then the air conditioner is determined to be in the compressor frequency dwell control stage.

[0049] When the air conditioner is turned on for heating, it enters anti-cold air control mode, the indoor fan is turned off or runs at the set low speed, and the outdoor ambient temperature T is detected and recorded. w Indoor ambient temperature T n Calculate the temperature difference between indoor and outdoor environments (referred to as indoor-outdoor temperature difference): ΔT = T n -T w According to the outdoor ambient temperature T w The temperature difference ΔT between indoor and outdoor ambient temperatures determines the dwell point frequency F1 of the compressor frequency dwell control, based on the outdoor ambient temperature T. w Determine the dwell time t for compressor frequency dwell control. This dwell time is the duration during which the compressor frequency is maintained at the frequency dwell point when performing compressor frequency dwell control; the dwell point frequency F1 = c1T. w +c2ΔT+c3, where c1, c2, and c3 are fitting coefficients, obtained by designing orthogonal verification experiments to fit the data.

[0050] The dwell time t of the compressor frequency dwell control is based on the outdoor ambient temperature T. w To determine, determine the outdoor ambient temperature T. w The temperature range is located within one or more preset temperature ranges, where each of the preset temperature ranges corresponds to a duration, i.e., based on the outdoor ambient temperature T. wThe dwell time t of the air conditioner when performing compressor frequency dwell control is determined by the duration corresponding to the temperature range in one or more preset temperature ranges.

[0051] For example, ① when T w When A < T, the corresponding stay duration is t1; ② When A ≤ T w When ≤ B, the corresponding dwell time is t2; ③ When T w When A = -7℃ and B = 18℃, the corresponding dwell time is t3; for example, when A = -7℃ and B = 18℃, t1, t2, and t3 are 120s, 30s, and 0s, respectively.

[0052] When the outdoor ambient temperature T w When the temperature is lower and the indoor-outdoor temperature difference ΔT is larger, the system oil return condition is poor. Therefore, the compressor residence point frequency F1 is lower and the residence time t is longer, which makes the compressor oil discharge rate lower and the oil return time longer, thus improving the system oil return.

[0053] Preferably, the dwell frequency F1 of the compressor frequency dwell control is determined to be different from the preset minimum value of the compressor dwell frequency F. min The relationship when F1 < F min Then F1 takes F min This avoids a decrease in air conditioner reliability due to a slow compressor oil return rate. When the outdoor ambient temperature Tw is higher and the indoor-outdoor temperature difference ΔT is smaller, the system's oil return condition is better, resulting in a higher compressor dwell time frequency F1 and a shorter dwell time t, leading to greater heating output and a faster indoor temperature rise rate. The relationship between F1 and the maximum dwell time frequency F of the compressor frequency dwell control is determined. max The relationship when F1 > F max Then F1 takes F max This prevents the compressor from over-discharged oil, which could lead to oil shortage or oil depletion in the system, thus ensuring the reliability of the air conditioner's operation.

[0054] The cumulative running time s1 of the compressor when entering the compressor frequency dwell control is determined based on the initial compressor start-up frequency, the duration of the compressor start-up phase, and the compressor frequency ramp-up rate.

[0055] In one specific implementation, the formula for calculating the cumulative compressor runtime s1 when entering compressor frequency dwell control is as follows:

[0056] s1=(F1-F start ) / v+s other

[0057] Where F1 is the dwell point frequency of the compressor frequency dwell control, F start The initial starting frequency (Hz) of the compressor, s otherThe duration of the compressor start-up phase can include, for example, compressor standby time (i.e., compressor standby start-up time), compressor start-up protection control time, compressor AC current or module current or overload protection frequency limiting time; v is the compressor frequency ramp-up rate, which is a fixed parameter value.

[0058] When the air conditioner meets the conditions for exiting the anti-cold air control, the current cumulative compressor running time s is detected, and the relationship between the cumulative compressor running time s and the preset time s0 and the cumulative running time s1 at the compressor frequency dwell point is determined. If the cumulative compressor running time s of the air conditioner is greater than the preset time s0, and less than or equal to the sum of the cumulative compressor running time s1 when entering the compressor frequency dwell control and the dwell time t of the compressor frequency dwell control, that is, s is greater than s0 and less than or equal to (s1+t), that is, when the air conditioner reaches the target indoor pipe temperature condition for exiting the anti-cold air control, it just enters or is in the compressor frequency dwell control stage. At this time, exiting the anti-cold air control will cause the indoor heat exchanger pipe temperature and the outlet air temperature to drop rapidly, so the compressor reliability control is entered to improve the heat output of the air conditioner.

[0059] When it is determined that the air conditioner meets the conditions for exiting anti-cold air control, but the air conditioner is not in the compressor frequency dwell control stage, the air conditioner is controlled to maintain its current heating operation. The situation where the air conditioner is not in the compressor frequency dwell control stage includes: the cumulative running time of the air conditioner's compressor is less than or equal to a preset duration, and / or the cumulative running time of the air conditioner's compressor is greater than the sum of the cumulative running time of the compressor when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control.

[0060] That is, if the cumulative running time s of the air conditioner compressor is less than or equal to the preset time s0, it indicates that the current room temperature is high, the load is low, and the temperature rise rate is fast, making it difficult to blow cold air. Therefore, the air conditioner will maintain normal heating operation. Before the compressor starts, the indoor heat exchanger tube temperature is similar to the room temperature. During the start-up phase, if the indoor heat exchanger tube temperature rise rate is faster than a certain value, meaning the time to reach the exit condition is less than the preset time s0, it indicates that the room temperature is high and it is difficult to blow cold air. The preset time s0 can be measured experimentally or obtained based on the required indoor tube temperature rise rate. If the cumulative running time s of the air conditioner compressor is greater than the sum of the cumulative running time s1 of the compressor when entering compressor frequency dwell control and the dwell time t of compressor frequency dwell control, i.e., s is greater than (s1+t), the compressor has exited frequency dwell control, and the air conditioner is in the compressor frequency increase phase, with the heating capacity continuously increasing. Therefore, the air conditioner will maintain normal heating operation.

[0061] Step S120: When it is determined that the air conditioner meets the conditions for exiting the anti-cold air control and the air conditioner is in the compressor frequency dwell control stage, it is determined whether the indoor heat exchanger tube temperature of the air conditioner is less than or equal to the second preset temperature value.

[0062] Specifically, when it is determined that the air conditioner meets the conditions for exiting anti-cold air control, and the air conditioner is in the compressor frequency dwell control stage, it enters compressor reliability control. After entering compressor reliability control, the indoor heat exchanger tube temperature T is detected. s Determine the indoor heat exchanger tube temperature T s The relationship between T and the second preset temperature value T2. If T s If the temperature is greater than T2, meaning the internal pipe temperature drops slowly after resuming normal fan speed and the outlet air temperature remains high, then continue operating in the current state; if T... s If the temperature is less than or equal to T2, the internal pipe temperature and the outlet air temperature will drop rapidly after the fan speed is restored to normal, posing a risk of blowing cold air.

[0063] Step S130: If it is determined that the indoor heat exchanger tube temperature is less than or equal to the second preset temperature value, then the opening degree of the throttling element of the air conditioner is increased according to the temperature rise rate of the indoor heat exchanger tube.

[0064] The throttling element can specifically be a throttling element between the indoor and outdoor heat exchangers of an air conditioner. By acquiring the temperature change value of the indoor heat exchanger tube temperature every n seconds, the temperature rise rate of the indoor heat exchanger tube temperature can be calculated.

[0065] Figure 2 A flowchart illustrating the steps of one specific implementation is shown. Figure 2 As shown, in one specific embodiment, step S130 includes steps S131, S132 and S133.

[0066] Step S131: Determine the temperature rise rate of the indoor heat exchanger tube within one of two or more preset temperature rise rate ranges.

[0067] Step S132: Determine the opening increment of the throttling element of the air conditioner based on the opening increment corresponding to the interval in which the temperature rise rate of the indoor heat exchanger tube is located in the two or more preset temperature rise rate intervals.

[0068] Step S133: Increase the opening degree of the throttling element of the air conditioner according to the determined opening degree increment of the throttling element of the air conditioner.

[0069] Wherein, each of the two or more preset temperature rise rate intervals corresponds to an opening increment; that is, the opening increment corresponding to the interval in which the temperature rise rate of the indoor heat exchanger tube is located in the two or more preset temperature rise rate intervals is determined as the opening increment of the throttling element of the air conditioner.

[0070] For example, the rate of temperature rise v of the indoor heat exchanger tubes. T When v TWhen the temperature is less than v1, meaning the inner tube temperature drops too quickly, increase the opening of the electronic expansion valve Δk1; when v1 ≤ v T When v ≤ v2, meaning the inner tube temperature drops slowly, increase the opening of the electronic expansion valve Δk2, where Δk1 > Δk2; when v T When the value is greater than v2, that is, the inner tube temperature drops very slowly or the tube temperature rises, the opening increment of the electronic expansion valve is 0.

[0071] In another specific embodiment, based on the indoor heat exchanger tube temperature v T According to a preset formula for calculating the opening increment, the opening increment Δk1 of the air conditioner's throttling element is determined; based on the determined opening increment Δk1, the opening of the air conditioner's throttling element is increased. The formula for calculating the opening increment is: Δk1 = c4v T +c5; where c4 and c5 are fitting coefficients, which can be obtained by designing orthogonal validation experiments to fit the data.

[0072] Step S140: After increasing the opening of the throttling element of the air conditioner, determine whether the compressor of the air conditioner is undergoing liquid compression based on the compressor phase current of the air conditioner.

[0073] When the temperature rise rate of the indoor heat exchanger tubes is negative (indicating a decrease in indoor tube temperature), increasing the expansion valve opening Δk1 can increase the system circulation flow, improve heat output, and enhance the reliability of compressor oil return. The greater the temperature drop rate, the larger Δk1 is, and vice versa. However, it is necessary to avoid excessively low air conditioner exhaust temperature, reduced compressor suction superheat, and excessively low suction dryness, which could lead to compressor liquid compression and affect the reliable operation of the air conditioner. Therefore, the compressor phase current is used to determine whether liquid compression has occurred. Liquid compression refers to the process where, during compressor operation, the unsaturated gas-liquid two-phase refrigerant enters the compressor cylinder through the suction pipe and is compressed; it is also called "wet compression." Liquid compression in the compressor indicates that the suction dryness of the refrigerant at the suction port is <1 (or the suction superheat is less than 0).

[0074] In one specific embodiment, the maximum fluctuation value of the compressor phase current is obtained; based on the ratio of the obtained maximum fluctuation value of the compressor phase current to the preset average fluctuation value of the compressor phase current under liquid-free compression conditions, it is determined whether the compressor is in liquid compression.

[0075] The maximum fluctuation value of the compressor phase current is equal to the difference between the maximum and minimum effective values ​​of the compressor phase current within a predetermined time period. More specifically, the presence of liquid compression in the compressor is determined by the relationship between the root mean square error of the square of the ratio of the maximum fluctuation value of the compressor phase current to the average fluctuation value of the compressor phase current under the preset liquid-free compression condition and a set threshold.

[0076] For example, the effective value I of the compressor phase current is detected and recorded, and the maximum fluctuation value ΔImax of the compressor phase current is calculated every predetermined time period a. The maximum fluctuation value (i.e., the maximum difference) ΔImax of the compressor phase current is equal to the difference between the maximum value Imax and the minimum value Imin of the effective value of the compressor phase current within the detection period; that is, ΔImax = Imax - Imin; where Imax refers to the maximum value of the effective value of the phase current within the predetermined time period a (i.e., period a), and Imin refers to the minimum value of the effective value of the phase current within the predetermined time period a (i.e., period a). The ratio ξ of the maximum fluctuation value ΔImax of the compressor phase current to the average fluctuation value of the compressor phase current under a preset liquid-free compression condition is calculated, and every N times, the relationship between the root mean square error of the square of the ratio ξ of the maximum fluctuation value of the compressor phase current to the average fluctuation value of the compressor phase current under the preset liquid-free compression condition and a set threshold A is determined.

[0077] For example, to facilitate judgment, the root mean square deviation of the square of the ratio ξ of the maximum fluctuation value of the compressor phase current N times to the average fluctuation value of the compressor phase current under the preset liquid-free compression condition is taken. Make a judgment:

[0078] i If the mean squared error If the current in the compressor phase fluctuates greatly, or is equal to or greater than the set threshold A, then liquid compression is present.

[0079] ii. If the mean square error is If the current is less than the set threshold A, the compressor phase current fluctuation is small, and the air conditioner does not perform liquid compression.

[0080] Step S150: If it is determined that the compressor of the air conditioner is undergoing liquid compression, the opening of the throttling element of the air conditioner is reduced to increase the suction superheat of the compressor.

[0081] If the compressor has liquid compression, the opening degree of the throttling element of the air conditioner is reduced by Δk2, and the throttling is increased to improve the suction superheat of the compressor, thereby ensuring the reliability of the compressor.

[0082] Specifically, after each reduction of the preset opening degree (e.g., the throttling element is reduced by 2 steps each time), the compressor of the air conditioner is judged again based on the compressor phase current to determine whether liquid compression is occurring. If liquid compression still exists, the preset opening degree is reduced again until it is determined that there is no liquid compression in the compressor. The cumulative reduction in opening degree is recorded as the second opening degree Δk2.

[0083] Figure 3 This is a schematic diagram of another embodiment of the air conditioner control method provided by the present invention.

[0084] like Figure 3As shown, according to another embodiment of the present invention, based on any of the above embodiments, the air conditioner control method further includes step S160.

[0085] Step S160: If it is determined that the compressor has not undergone liquid compression, then the dwell time t of the compressor frequency dwell control is corrected according to the current throttling element opening degree and compressor frequency of the air conditioner.

[0086] In one specific embodiment, a correction duration is determined based on the current throttling element opening degree and compressor frequency of the air conditioner, and the dwell time of the compressor frequency dwell control is corrected based on the determined correction duration; wherein, the corrected dwell time t of the compressor frequency dwell control is equal to the current dwell time t of the air conditioner's compressor frequency dwell control minus the correction duration Δt, and the correction duration Δt is determined based on the current throttling element opening degree and compressor frequency F of the air conditioner;

[0087] The correction duration Δt = c6Δk + c7k + c8F + c9;

[0088] Where Δk equals the current throttling element opening k minus the initial throttling element opening k0 corresponding to the dwell point frequency, F is the compressor frequency. When the compressor is in the frequency dwell control stage, the compressor frequency is the dwell point frequency of the compressor frequency control. c6, c7, c8, and c9 are fitting coefficients, which can be finally obtained by designing orthogonal verification experiments to fit the data.

[0089] When Δk is larger, that is, the opening of the throttling element is larger, the system circulation flow is higher, and the return of oil and fluid is better, then the correction time Δt is larger and the residence time is shorter; conversely, when Δk is smaller, the return of oil in the system is less, then the correction time Δt is smaller, and the residence time cannot be too short.

[0090] The correction amplitude Δt for the dwell time is also related to the compressor frequency F. The higher the compressor frequency F, the higher the compressor oil discharge rate, requiring a longer oil return time for the compressor to fully return oil, thus resulting in a smaller Δt. Conversely, the lower the compressor frequency F, the lower the compressor oil discharge rate, reducing the risk of oil shortage, thus resulting in a larger Δt, allowing the air conditioner to quickly enter the frequency ramp-up stage for heating.

[0091] Figure 4 This is a schematic diagram of another embodiment of the air conditioner control method provided by the present invention.

[0092] like Figure 4 As shown, according to another embodiment of the present invention, based on any of the above embodiments, the air conditioner control method further includes step S170. Figure 4 Only those based on Figure 3 (The illustrated method diagram of this embodiment is shown)

[0093] Step S170: When the air conditioner meets the conditions for exiting compressor frequency pause control, control the air conditioner to resume normal heating operation.

[0094] The conditions for exiting compressor frequency dwell control include: the cumulative compressor running time s is greater than the sum of the cumulative compressor running time s1 when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control.

[0095] Specifically, if the compressor's cumulative running time s is greater than the sum of the compressor's cumulative running time s1 when entering compressor frequency dwell control and the dwell time t of compressor frequency dwell control (i.e., s is greater than (s1+t), then the compressor has met the time condition to exit frequency dwell control and enter the frequency ramp-up stage. In this case, the compressor reliability control program exits and switches to normal heating operation. If the compressor's cumulative running time s is less than or equal to the sum of the compressor's cumulative running time s1 when entering compressor frequency dwell control and the dwell time t of compressor frequency dwell control (i.e., s is less than or equal to (s1+t), then the compressor is still in the frequency dwell control stage, and the above compressor reliability control program continues to be executed repeatedly.

[0096] To clearly illustrate the technical solution of the present invention, the execution flow of the air conditioner control method provided by the present invention will be described below with reference to a specific embodiment.

[0097] Figure 5 This is the air conditioning operation control logic of the present invention. For example... Figure 5 As shown, when the air conditioner is turned on for heating, it enters the anti-cold air control mode, the indoor fan is turned off or maintains a low speed, and the outdoor ambient temperature T is detected and recorded. w Indoor ambient temperature T n Calculate the temperature difference between indoor and outdoor environments (referred to as indoor-outdoor temperature difference): ΔT = T n -T w According to the outdoor ambient temperature T w The compressor dwell time frequency F1 is determined by the temperature difference ΔT between the indoor and outdoor ambient temperatures, based on the outdoor ambient temperature T. w Determine the dwell time t for compressor frequency dwell control, and the dwell point frequency F1 = c1T w +c2ΔT+c3, where c1, c2, and c3 are fitting coefficients, obtained by designing orthogonal verification experiments to fit the data.

[0098] Based on outdoor ambient temperature T w The dwell time t of the compressor frequency dwell control is determined, the compressor frequency ramp-up rate v is obtained, the cumulative running time s1 of the compressor when it enters the compressor frequency dwell control is calculated, and the indoor heat exchanger tube temperature T is detected and recorded in real time during the heating process. s(referred to as internal pipe temperature), first determine the air conditioner's internal pipe temperature T. s The relationship with the first preset temperature value T1: 1) If T s If the temperature is less than T1, meaning the internal pipe temperature of the air conditioner is low and the air outlet temperature is low, then the internal fan should remain off or running at low speed to prevent direct cold air from blowing out; 2) If T s If the temperature is greater than or equal to T1, meaning the temperature of the air conditioner's internal pipes is high enough to meet the conditions for exiting the anti-cold air control, then the anti-cold air control will be exited and the internal fan will switch to the set fan speed.

[0099] Considering that disabling the anti-cold air function might lead to insufficient heat output from the air conditioner, causing a rapid drop in air outlet temperature after increasing the fan speed, it is necessary to maximize the air conditioner's output capacity to improve comfort. When the air conditioner disables the anti-cold air function, the current cumulative compressor runtime s is detected and recorded. The relationship between the cumulative compressor runtime s and the preset runtime s0 and the cumulative runtime s1 at the dwell point is then determined.

[0100] If the compressor's cumulative running time s is less than or equal to the preset time s0, that is, the current room temperature is high, the load is low, the temperature rise rate is fast, and it is not easy to blow cold air, then maintain the current state of normal heating operation; before the compressor starts, the internal pipe temperature is similar to the room temperature. During the start-up phase, when the internal pipe temperature rise rate is faster than a certain value, that is, the time to reach the exit condition is less than or equal to s0, it indicates that the room temperature is high and it is not easy to blow cold air.

[0101] ii. If s is greater than s0 and less than or equal to (s1+t), that is, when the air conditioner reaches the target internal pipe temperature condition for exiting the anti-cold air control, it just enters or is in the compressor frequency dwell control stage. At this time, exiting the anti-cold air control will cause the internal pipe temperature and the outlet air temperature to drop rapidly, and then enter the compressor reliability control to improve the heat output of the air conditioner.

[0102] iii. If s is greater than (s1+t), that is, the air conditioner is in the compressor frequency increase stage and the heating capacity continues to increase, then the current state of normal heating operation will be maintained.

[0103] Figure 6 This is the compressor reliability control logic according to the present invention. For example... Figure 6 As shown, after the air conditioner enters the compressor reliability control, the indoor heat exchanger tube temperature T is detected and recorded. s The rate of temperature rise v of the inner tube T First, determine the temperature T of the air conditioner's internal pipe. s The relationship with the second preset temperature value T2 (T2 is less than T1)

[0104] 1) If T s If the temperature is greater than T2, meaning that the internal pipe temperature drops slowly after the fan speed is restored and the outlet air temperature remains high, then the current operation will continue.

[0105] 2) If T s If the temperature is less than or equal to T2, meaning the internal pipe temperature and outlet air temperature drop rapidly after the fan speed is restored to normal, posing a risk of cold air blowing out, then the rate of temperature rise v of the air conditioner's internal pipe temperature should be calculated further. T Based on the calculated temperature rise rate v of the inner tube T Determine the opening increment Δk1 of the air conditioning flow control element.

[0106] When the temperature rise rate is negative (indicating a decrease in pipe temperature), the expansion valve opening increases by Δk1, increasing the system circulation flow, heat generation, and compressor oil return reliability. The greater the temperature drop rate, the larger Δk1 is, and vice versa. However, it is necessary to avoid excessively low air conditioner exhaust temperature, reduced compressor suction superheat, and excessively low suction dryness, which could lead to compressor liquid compression and affect the reliable operation of the air conditioner. Therefore, the effective value of the compressor phase current I is continuously monitored and recorded, and the maximum difference ΔI between the compressor phase currents is calculated every 'a' time intervals. max The maximum difference in the compressor phase current is equal to the difference between the maximum and minimum effective values ​​of the compressor phase current within the detection period; ΔI max =I max -I min Among them, I max I refers to the maximum effective value of the phase current within period a. min It refers to the minimum effective value of the phase current within a period a.

[0107] Calculate and record ΔI max The ratio ξ of the average phase current fluctuation value under the preset liquid-free compression condition is used to determine the relationship between the root mean square error of the square of the phase current fluctuation ratio ξ and the preset value A every N times.

[0108] iIf If the current is greater than or equal to A, it means that the compressor phase current fluctuates greatly and liquid compression exists. In this case, reduce the opening degree of the expansion valve Δk2 and increase the throttling to improve the suction superheat and ensure the reliability of the compressor.

[0109] ii If If the value is less than A, it means the compressor phase current fluctuation is small, and the air conditioner has not experienced liquid compression. Continue to judge, detect, and record the current expansion valve opening k. Based on the current compressor frequency F and the throttling element opening k, adjust the dwell time t-Δt of the compressor frequency dwell control, where...

[0110] Δt=c6Δk+c7k+c8F+c9;

[0111] In the formula, Δk is the current valve opening k minus the initial valve opening corresponding to the frequency dwell point. When Δk is larger, that is, the valve opening is larger, the system circulation flow is higher, and the oil and liquid return is better, then Δt is larger and the dwell time is shorter; conversely, when Δk is smaller, the system oil return is less, then Δt is smaller, and the dwell time cannot be too short.

[0112] The variation amplitude Δt of the dwell time is also related to the compressor frequency F. The higher the compressor frequency F, the higher the compressor oil discharge rate, requiring a longer oil return time for the compressor to fully return oil, thus resulting in a smaller Δt. Conversely, the lower the compressor frequency F, the lower the compressor oil discharge rate, reducing the risk of oil shortage, thus resulting in a larger Δt, allowing the air conditioner to quickly enter the frequency ramp-up stage for heating.

[0113] The compressor's cumulative runtime (in seconds) is continuously monitored and recorded during operation.

[0114] a. If s is greater than (s1+t), that is, the compressor reaches the time condition for exiting frequency dwell control and enters the frequency increase stage, then the compressor reliability control program will be exited and normal heating operation will be switched to normal operation.

[0115] b. If s is less than or equal to (s1+t), that is, the compressor is still in the frequency dwell control stage, then the above compressor reliability control program will continue to be executed repeatedly.

[0116] After adopting the above-mentioned air conditioning operation control method, the air conditioner can continue to maintain a high outlet air temperature and a large heat output after the anti-cold air control is turned off, thereby improving the heating temperature rise rate, avoiding the air conditioner blowing cold air when heating, and avoiding problems such as compressor liquid slugging and oil shortage, thus ensuring reliable and comfortable operation of the air conditioner.

[0117] Figure 7 This is a structural block diagram of an embodiment of the air conditioner control device provided by the present invention. Figure 7 As shown, the control device 100 includes: a first judgment unit 110, a second judgment unit 120, a control unit 130, and a third judgment unit 140.

[0118] The first judgment unit 110 is used to determine whether the air conditioner meets the conditions for exiting the anti-cold air control and whether the air conditioner is in the compressor frequency dwell control stage after the air conditioner is turned on for heating and enters the anti-cold air control.

[0119] The compressor frequency dwell control refers to maintaining the compressor at a set frequency for a set time during the frequency increase process after the compressor starts, and then continuing to increase the frequency; the set frequency is recorded as the dwell point frequency of the compressor frequency dwell control, and the set time is recorded as the dwell duration of the compressor frequency dwell control.

[0120] In one specific embodiment, the first determining unit 110 determines whether the air conditioner meets the conditions for exiting anti-cold air control, including: determining the indoor heat exchanger tube temperature T of the air conditioner. s If the temperature is greater than or equal to the first preset temperature value T1, then the indoor heat exchanger tube temperature T is determined. s If the temperature is greater than or equal to the first preset temperature value T1, then the air conditioner is determined to meet the conditions for exiting the anti-cold air control.

[0121] Specifically, the indoor heat exchanger tube temperature T is detected and recorded in real time. s Determine the temperature T of the indoor heat exchanger tubes in the air conditioner. s The relationship with the preset temperature value T1 is that the first preset temperature value T1 is the target internal pipe temperature of the indoor heat exchanger when the anti-cold air control is lifted. If T s If the temperature is less than T1, meaning the indoor heat exchanger pipe temperature is low and the air outlet temperature is low, then the indoor fan should remain off or running at low speed to prevent direct cold airflow; if T... s If the temperature is greater than or equal to T1, meaning the temperature of the indoor heat exchanger tube is high enough to meet the conditions for exiting the anti-cold air control, then the anti-cold air control will be exited and the indoor fan will switch to the set fan speed.

[0122] In one specific implementation, the first determination unit 110 determines whether the air conditioner is in the compressor frequency dwell control stage, including: if the cumulative running time s of the air conditioner's compressor is greater than the preset time s0, and less than or equal to the sum of the cumulative running time s1 of the compressor when entering the compressor frequency dwell control and the dwell time t of the compressor frequency dwell control, then it is determined that the air conditioner is in the compressor frequency dwell control stage.

[0123] When the air conditioner is turned on for heating, it enters anti-cold air control mode, the indoor fan is turned off or runs at the set low speed, and the outdoor ambient temperature T is detected and recorded. w Indoor ambient temperature T n Calculate the temperature difference between indoor and outdoor environments (referred to as indoor-outdoor temperature difference): ΔT = T n -T w According to the outdoor ambient temperature T w The temperature difference ΔT between indoor and outdoor ambient temperatures determines the dwell point frequency F1 for compressor frequency dwell control. The dwell time t for compressor frequency dwell control is determined based on the outdoor ambient temperature Tw. The dwell time is the duration for which the compressor frequency is maintained at the dwell point during compressor frequency dwell control. Dwell point frequency F1 = c1T w +c2ΔT+c3, where c1, c2, and c3 are fitting coefficients, obtained by designing orthogonal verification experiments to fit the data.

[0124] Preferably, the control device 100 further includes: a first determining unit (not shown), used to determine the dwell time t of the compressor frequency dwell control. The dwell time t of the compressor frequency dwell control is based on the outdoor ambient temperature T. w To determine, determine the outdoor ambient temperature T. w The temperature range in which the air conditioner currently performs compressor frequency dwell control is determined based on the duration corresponding to the temperature range in which the outdoor ambient temperature Tw is located within the two or more preset temperature ranges.

[0125] For example, ① when T w When A < T, the corresponding stay duration is t1; ② When A ≤ T w When ≤ B, the corresponding dwell time is t2; ③ When T w When A = -7℃ and B = 18℃, the corresponding dwell time is t3; for example, when A = -7℃ and B = 18℃, t1, t2, and t3 are 120s, 30s, and 0s, respectively.

[0126] When the outdoor ambient temperature T w When the temperature is lower and the indoor-outdoor temperature difference ΔT is larger, the system oil return condition is poor. Therefore, the compressor residence point frequency F1 is lower and the residence time t is longer, which makes the compressor oil discharge rate lower and the oil return time longer, thus improving the system oil return.

[0127] Preferably, the compressor dwell time frequency F1 is determined to be different from the preset minimum compressor dwell time frequency F. min The relationship when F1 < F min Then F1 takes F min To avoid a slow compressor oil return rate that could reduce air conditioner reliability. When the outdoor ambient temperature T w The higher the temperature and the smaller the indoor-outdoor temperature difference ΔT, the better the system's oil return condition. This results in a higher compressor dwell time frequency F1, a shorter dwell time t, greater heating output, and a faster indoor temperature rise rate. The comparison between F1 and the preset maximum compressor dwell time frequency F... max The relationship when F1 > F max Then F1 takes F max This prevents the compressor from over-discharged oil, which could lead to oil shortage or oil depletion in the system, thus ensuring the reliability of the air conditioner's operation.

[0128] Preferably, the control device 100 further includes: a first determining unit (not shown), used to determine the cumulative running time s1 of the compressor when entering the compressor frequency dwell control based on the compressor start-up initial frequency, the duration of the compressor start-up phase and the compressor frequency ramp-up rate.

[0129] In one specific implementation, the formula for calculating the cumulative compressor runtime s1 when entering compressor frequency dwell control is as follows:

[0130] s1=(F1-F start ) / v+s other

[0131] Among them, F start The initial starting frequency (Hz) of the compressor, s other The duration of the compressor start-up phase can include, for example, compressor standby time (i.e., compressor standby start-up time), compressor start-up protection control time, compressor AC current or module current or overload protection frequency limiting time; v is the compressor frequency ramp-up rate, which is a fixed parameter value.

[0132] When the air conditioner meets the conditions for exiting the anti-cold air control, the current cumulative compressor running time s is detected, and the relationship between the cumulative compressor running time s and the preset time s0 and the cumulative running time s1 at the compressor frequency dwell point is determined.

[0133] If the cumulative running time s of the air conditioner compressor is less than or equal to the preset time s0, it indicates that the current room temperature is high, the load is low, and the temperature rise rate is fast, making it difficult to blow cold air. Therefore, the air conditioner will maintain its normal heating operation. Before the compressor starts, the indoor heat exchanger tube temperature is similar to the room temperature. During the start-up phase, if the indoor heat exchanger tube temperature rise rate is faster than a certain value, meaning the time to reach the exit condition is less than the preset time s0, it indicates that the room temperature is high and it is difficult to blow cold air. The preset time s0 can be measured experimentally or obtained based on the required indoor tube temperature rise rate.

[0134] ii. If the cumulative running time s of the air conditioner compressor is greater than the preset time s0, and less than or equal to the sum of the cumulative running time s1 of the compressor and the dwell time t of the compressor frequency dwell control when entering the compressor frequency dwell control, that is, s is greater than s0 and less than or equal to (s1+t), that is, when the air conditioner reaches the target indoor pipe temperature condition for exiting the anti-cold air control, it just enters or is in the compressor frequency dwell control stage. At this time, exiting the anti-cold air control will cause the indoor heat exchanger pipe temperature and the outlet air temperature to drop rapidly, and then enter the compressor reliability control to improve the heat output of the air conditioner.

[0135] iii If the cumulative running time s of the air conditioner compressor is greater than the sum of the cumulative running time s1 of the compressor when entering the compressor frequency dwell control and the dwell time t of the compressor frequency dwell control, that is, s is greater than (s1+t), then the compressor has exited the frequency dwell control and the air conditioner is in the compressor frequency increase stage, and the heating capacity continues to increase, then the current state of normal heating operation is maintained.

[0136] The second judgment unit 120 is used to determine whether the indoor heat exchanger tube temperature of the air conditioner is less than or equal to a second preset temperature value when the first judgment unit 110 determines that the air conditioner meets the conditions for exiting the anti-cold air control and the air conditioner is in the compressor frequency dwell control stage.

[0137] Specifically, when it is determined that the air conditioner meets the conditions for exiting anti-cold air control, and the air conditioner is in the compressor frequency dwell control stage, it enters compressor reliability control. After entering compressor reliability control, the indoor heat exchanger tube temperature T is detected. s Determine the indoor heat exchanger tube temperature T s The relationship between T and the second preset temperature value T2. If T s If the temperature is greater than T2, meaning the internal pipe temperature drops slowly after resuming normal fan speed and the outlet air temperature remains high, then continue operating in the current state; if T... s If the temperature is less than or equal to T2, the internal pipe temperature and the outlet air temperature will drop rapidly after the fan speed is restored to normal, posing a risk of blowing cold air.

[0138] The control unit 130 is configured to increase the opening degree of the throttling element of the air conditioner according to the temperature rise rate of the indoor heat exchanger tube if the second judgment unit 120 determines that the indoor heat exchanger tube temperature is less than or equal to a second preset temperature value.

[0139] The throttling element can specifically be a throttling element between the indoor and outdoor heat exchangers of an air conditioner. By acquiring the temperature change value of the indoor heat exchanger tube temperature every n seconds, the temperature rise rate of the indoor heat exchanger tube temperature can be calculated.

[0140] In one specific embodiment, the control unit 130 increases the opening degree of the throttling element of the air conditioner according to the temperature rise rate of the indoor heat exchanger tube temperature, including: determining the interval in which the temperature rise rate of the indoor heat exchanger tube temperature falls within two or more preset temperature rise rate intervals; determining the opening degree increment of the throttling element of the air conditioner according to the opening degree increment corresponding to the interval in which the temperature rise rate of the indoor heat exchanger tube temperature falls within the two or more preset temperature rise rate intervals; and increasing the opening degree of the throttling element of the air conditioner according to the determined opening degree increment of the throttling element of the air conditioner.

[0141] Wherein, each of the two or more preset temperature rise rate intervals corresponds to an opening increment; that is, the opening increment corresponding to the interval in which the temperature rise rate of the indoor heat exchanger tube is located in the two or more preset temperature rise rate intervals is determined as the opening increment of the throttling element of the air conditioner.

[0142] For example, the rate of temperature rise v of the indoor heat exchanger tubes. T When v TWhen the temperature is less than v1, meaning the inner tube temperature drops too quickly, increase the opening of the electronic expansion valve Δk1; when v1 ≤ v T When v ≤ v2, meaning the inner tube temperature drops slowly, increase the opening of the electronic expansion valve Δk2, where Δk1 > Δk2; when v T When the value is greater than v2, that is, the inner tube temperature drops very slowly or the tube temperature rises, the opening increment of the electronic expansion valve is 0.

[0143] In another specific embodiment, based on the indoor heat exchanger tube temperature v T According to a preset formula for calculating the opening increment, the opening increment Δk1 of the air conditioner's throttling element is determined; based on the determined opening increment Δk1, the opening of the air conditioner's throttling element is increased. The formula for calculating the opening increment is: Δk1 = c4v T +c5; where c4 and c5 are fitting coefficients, which can be obtained by designing orthogonal validation experiments to fit the data.

[0144] The control unit 100 is further configured to: when the first judgment unit 110 determines that the air conditioner meets the conditions for exiting the anti-cold air control, but the air conditioner is not in the compressor frequency dwell control stage, control the air conditioner to maintain the current state of heating operation; wherein, the situation where the air conditioner is not in the compressor frequency dwell control stage includes: the cumulative running time of the air conditioner's compressor is less than or equal to a preset time, and / or the cumulative running time of the air conditioner's compressor is greater than the sum of the cumulative running time of the compressor when entering the compressor frequency dwell control and the dwell time of the compressor frequency dwell control.

[0145] If the cumulative running time s of the air conditioner compressor is less than or equal to the preset time s0, it indicates that the current room temperature is high, the load is low, and the temperature rise rate is fast, making it difficult to blow cold air. Therefore, the air conditioner will maintain its normal heating operation. Before the compressor starts, the indoor heat exchanger tube temperature is similar to the room temperature. During the start-up phase, if the indoor heat exchanger tube temperature rise rate is faster than a certain value, meaning the time to reach the exit condition is less than the preset time s0, it indicates that the room temperature is high and it is difficult to blow cold air. The preset time s0 can be measured experimentally or obtained based on the required indoor tube temperature rise rate.

[0146] If the cumulative running time s of the air conditioner compressor is greater than the sum of the cumulative running time s1 of the compressor when entering the compressor frequency dwell control and the dwell time t of the compressor frequency dwell control, that is, s is greater than (s1+t), then the compressor has exited the frequency dwell control and the air conditioner is in the compressor frequency increase stage, and the heating capacity continues to increase, then the current state of normal heating operation is maintained.

[0147] The third judgment unit 140 is used to determine whether the compressor of the air conditioner is undergoing liquid compression based on the compressor phase current of the air conditioner after the control unit 130 increases the opening degree of the throttling element of the air conditioner.

[0148] When the temperature rise rate of the indoor heat exchanger tubes is negative (indicating a decrease in indoor tube temperature), increasing the expansion valve opening Δk1 can increase the system circulation flow, improve heat output, and enhance the reliability of compressor oil return. The greater the temperature drop rate, the larger Δk1 is, and vice versa. However, it is necessary to avoid excessively low air conditioner exhaust temperature, reduced compressor suction superheat, and excessively low suction dryness, which could lead to compressor liquid compression and affect the reliable operation of the air conditioner. Therefore, the compressor phase current is used to determine whether liquid compression has occurred. Liquid compression refers to the process where, during compressor operation, the unsaturated gas-liquid two-phase refrigerant enters the compressor cylinder through the suction pipe and is compressed; it is also called "wet compression." Liquid compression in the compressor indicates that the suction dryness of the refrigerant at the suction port is <1 (or the suction superheat is less than 0).

[0149] In one specific embodiment, the third judgment unit 140 determines whether the compressor is undergoing liquid compression based on the compressor phase current of the air conditioner, including: obtaining the maximum fluctuation value of the compressor phase current; and determining whether the compressor is undergoing liquid compression based on the ratio of the obtained maximum fluctuation value of the compressor phase current to the preset average fluctuation value of the compressor phase current under no-liquid compression conditions.

[0150] The maximum fluctuation value of the compressor phase current is equal to the difference between the maximum and minimum effective values ​​of the compressor phase current within a predetermined time period. More specifically, the presence of liquid compression in the compressor is determined by the relationship between the root mean square error of the square of the ratio of the maximum fluctuation value of the compressor phase current to the average fluctuation value of the compressor phase current under the preset liquid-free compression condition and a set threshold.

[0151] For example, the effective value I of the compressor phase current is detected and recorded, and the maximum fluctuation value ΔImax of the compressor phase current is calculated every predetermined time period a. The maximum fluctuation value (i.e., the maximum difference) ΔImax of the compressor phase current is equal to the difference between the maximum value Imax and the minimum value Imin of the effective value of the compressor phase current within the detection period; that is, ΔImax = Imax - Imin; where Imax refers to the maximum value of the effective value of the phase current within the predetermined time period a (i.e., period a), and Imin refers to the minimum value of the effective value of the phase current within the predetermined time period a (i.e., period a). The ratio ξ of the maximum fluctuation value ΔImax of the compressor phase current to the average fluctuation value of the compressor phase current under a preset liquid-free compression condition is calculated, and every N times, the relationship between the root mean square error of the square of the ratio ξ of the maximum fluctuation value of the compressor phase current to the average fluctuation value of the compressor phase current under the preset liquid-free compression condition and a set threshold A is determined.

[0152] For example, to facilitate judgment, the root mean square deviation of the square of the ratio ξ of the maximum fluctuation value of the compressor phase current N times to the average fluctuation value of the compressor phase current under the preset liquid-free compression condition is taken. Make a judgment:

[0153] i If the mean squared error If the current in the compressor phase fluctuates greatly, or is equal to or greater than the set threshold A, then liquid compression is present.

[0154] ii. If the mean square error is If the current is less than the set threshold A, the compressor phase current fluctuation is small, and the air conditioner does not perform liquid compression.

[0155] The control unit 130 is further configured to: if the third judgment unit 140 determines that the compressor of the air conditioner is undergoing liquid compression, reduce the opening of the throttling element of the air conditioner to increase the suction superheat of the compressor.

[0156] Specifically, if liquid compression occurs in the compressor, the control unit 130 reduces the opening of the throttling element of the air conditioner by Δk2, increasing the throttling to improve the suction superheat of the compressor, thereby ensuring the reliability of the compressor. More specifically, after each reduction of the preset opening (e.g., the throttling element is reduced by 2 steps each time), the control unit again determines whether liquid compression occurs in the air conditioner's compressor based on the compressor phase current. If liquid compression still exists, the preset opening is reduced again until it is determined that there is no liquid compression in the compressor. The cumulative reduction in opening is recorded as the second opening Δk2.

[0157] Figure 8 This is a structural block diagram of another embodiment of the air conditioner control device provided by the present invention. (See diagram below.) Figure 8 As shown, based on any of the above embodiments, the control device 100 further includes a correction unit 160.

[0158] The correction unit 160 is used to correct the dwell time of the compressor frequency dwell control based on the current throttling element opening degree of the air conditioner and the compressor frequency dwell point frequency if the third judgment unit 140 determines that the compressor has not undergone liquid compression.

[0159] In one specific implementation, a correction duration is determined based on the current throttling element opening and compressor frequency of the air conditioner, and the dwell duration of the compressor frequency dwell control is corrected based on the determined correction duration; wherein, the corrected dwell duration is equal to the dwell duration of the current compressor frequency dwell control of the air conditioner minus the correction duration, and the correction duration Δt is determined based on the current throttling element opening and compressor frequency F of the air conditioner;

[0160] The correction duration Δt = c6Δk + c7k + c8F + c9;

[0161] Where Δk equals the current throttling element opening k minus the initial throttling element opening k0 corresponding to the dwell point frequency, F is the compressor frequency, and when the compressor is in the frequency dwell control stage, the compressor frequency is the dwell point frequency of the compressor frequency control. c6, c7, c8, and c9 are fitting coefficients, which can be finally obtained by designing orthogonal verification experiments to fit the data.

[0162] When Δk is larger, that is, the opening of the throttling element is larger, the system circulation flow is higher, and the return of oil and fluid is better, then the correction time Δt is larger and the residence time is shorter; conversely, when Δk is smaller, the return of oil in the system is less, then the correction time Δt is smaller, and the residence time cannot be too short.

[0163] The correction amplitude Δt for the dwell time is also related to the compressor frequency F. The higher the compressor frequency F, the higher the compressor oil discharge rate, requiring a longer oil return time for the compressor to fully return oil, thus resulting in a smaller Δt. Conversely, the lower the compressor frequency F, the lower the compressor oil discharge rate, reducing the risk of oil shortage, thus resulting in a larger Δt, allowing the air conditioner to quickly enter the frequency ramp-up stage for heating.

[0164] According to another embodiment of the present invention, based on the above embodiment, the control unit 130 is further configured to: control the air conditioner to resume normal heating operation when the air conditioner meets the conditions for exiting compressor frequency dwell control.

[0165] The conditions for exiting compressor frequency dwell control include: the cumulative compressor running time s is greater than the sum of the cumulative compressor running time s1 when entering compressor frequency dwell control and the dwell time of compressor frequency dwell control.

[0166] Specifically, if the compressor's cumulative running time s is greater than the sum of the compressor's cumulative running time s1 when entering compressor frequency dwell control and the dwell time t of compressor frequency dwell control (i.e., s is greater than (s1+t), then the compressor has met the time condition to exit frequency dwell control and enter the frequency ramp-up stage. In this case, the compressor reliability control program exits and switches to normal heating operation. If the compressor's cumulative running time s is less than or equal to the sum of the compressor's cumulative running time s1 when entering compressor frequency dwell control and the dwell time t of compressor frequency dwell control (i.e., s is less than or equal to (s1+t), then the compressor is still in the frequency dwell control stage, and the above compressor reliability control program continues to be executed repeatedly.

[0167] The present invention also provides a storage medium corresponding to the control method of the air conditioner, wherein a computer program is stored thereon, and the program, when executed by a processor, implements the steps of any of the aforementioned methods.

[0168] The present invention also provides an air conditioner corresponding to the control method of the air conditioner, comprising a processor, a memory, and a computer program stored in the memory that can run on the processor, wherein the processor executes the program to implement the steps of any of the aforementioned methods.

[0169] The present invention also provides an air conditioner corresponding to the control device of the air conditioner, including the control device of any of the aforementioned air conditioners.

[0170] Accordingly, the solution provided by the present invention, when the heating operation exits the anti-cold air and is in the frequency dwell control stage, monitors the changes in the inner pipe temperature and the rate of change of the inner pipe temperature, adjusts the opening of the throttling element to increase the air conditioning capacity output, improve the system oil return, increase the air conditioning outlet temperature, and shorten the dwell time of constant frequency operation. At the same time, it monitors the compressor phase current fluctuation to identify and control liquid compression, avoids liquid compression of the compressor, and takes into account both improving the user's heating comfort and the compressor's operational reliability.

[0171] While ensuring that the air conditioner can quickly blow hot air, this paper addresses the problem of reduced reliability of existing air conditioning systems under high heat output conditions, achieving comfortable and reliable operation of the air conditioner and improving the user experience.

[0172] According to the technical solution of the present invention, by using multiple parameters to comprehensively control the system reliability, the problem of poor heating comfort caused by the single reliability control method of the current compressor can be solved. While ensuring the air conditioner's high capacity output and rapid heating operation, reliability problems such as compressor oil shortage, oil-air shortage, or liquid compression are avoided, thereby maximizing user heating comfort and compressor lifespan.

[0173] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this invention and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units can be integrated into a single processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit.

[0174] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0175] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0176] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to related technologies, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0177] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method of an air conditioner, characterized by, The method comprises the following steps: After the air conditioner is started and enters the cold-wind prevention control, it is determined whether the air conditioner meets the condition for exiting the cold-wind prevention control and whether the air conditioner is in the compressor frequency staying control stage, comprising: if the accumulated running time of the compressor of the air conditioner is greater than a preset time length and less than or equal to the sum of the accumulated running time of the compressor when entering the compressor frequency staying control and the staying time length of the compressor frequency staying control, it is determined that the air conditioner is in the compressor frequency staying control stage; When it is determined that the air conditioner meets the condition for exiting the cold-wind prevention control and the air conditioner is in the compressor frequency staying control stage, it is determined whether the indoor heat exchanger pipe temperature of the air conditioner is less than or equal to a second preset temperature value; If it is determined that the indoor heat exchanger pipe temperature is less than or equal to the second preset temperature value, the opening degree of the throttling element of the air conditioner is increased according to the temperature rise rate of the indoor heat exchanger pipe temperature; After the opening degree of the throttling element of the air conditioner is increased, it is determined whether the compressor of the air conditioner has liquid compression according to the phase current of the compressor, comprising: the maximum fluctuation value of the phase current of the compressor is obtained, which is equal to the difference between the maximum value and the minimum value of the effective value of the phase current of the compressor within a predetermined time; whether the compressor has liquid compression is determined according to the ratio of the obtained maximum fluctuation value of the phase current of the compressor to the preset average fluctuation value of the phase current of the compressor under the condition of no liquid compression; If it is determined that the compressor of the air conditioner has liquid compression, the opening degree of the throttling element of the air conditioner is reduced to increase the suction superheat of the compressor.

2. The method of claim 1, wherein It is determined whether the air conditioner meets the condition for exiting the cold-wind prevention control, comprising: It is determined whether the indoor heat exchanger pipe temperature of the air conditioner is greater than or equal to a first preset temperature value, and if it is determined that the indoor heat exchanger pipe temperature is greater than or equal to the first preset temperature value, it is determined that the air conditioner meets the condition for exiting the cold-wind prevention control; And / or The opening degree of the throttling element of the air conditioner is increased according to the temperature rise rate of the indoor heat exchanger pipe temperature, comprising: It is determined that the temperature rise rate of the indoor heat exchanger pipe temperature is in a preset interval among two or more temperature rise rate intervals, wherein each interval among the two or more preset temperature rise rate intervals corresponds to an opening degree increment; The opening degree increment of the throttling element of the air conditioner is determined according to the opening degree increment corresponding to the interval among the two or more preset temperature rise rate intervals in which the temperature rise rate of the indoor heat exchanger pipe temperature is located; The opening degree of the throttling element of the air conditioner is increased according to the determined opening degree increment of the throttling element of the air conditioner.

3. The method of claim 1, wherein, Whether the compressor has liquid compression is determined according to the ratio of the obtained maximum fluctuation value of the phase current of the compressor to the preset average fluctuation value of the phase current of the compressor under the condition of no liquid compression, comprising: Whether the compressor has liquid compression is determined according to the size relationship between the mean square error of the square of the ratio of the maximum fluctuation value of the phase current of the compressor to the preset average fluctuation value of the phase current of the compressor under the condition of no liquid compression and a set threshold value.

4. The method according to any one of claims 1 to 3, characterized in that, Further comprising: When it is determined that the air conditioner meets the condition for exiting the anti-cold blast control but the air conditioner is not in the compressor frequency dwell control phase, the air conditioner is controlled to maintain the current state of heating operation; The condition that the air conditioner is not in the compressor frequency dwell control phase includes: The accumulated operation time of the compressor of the air conditioner is less than or equal to a preset time length, and / or the accumulated operation time of the compressor of the air conditioner is greater than the sum of the accumulated operation time of the compressor when the compressor frequency dwell control is entered and the dwell time length of the compressor frequency dwell control; And / or, When the air conditioner meets the condition for exiting the compressor frequency dwell control, the air conditioner is controlled to resume normal heating operation; The condition for exiting the compressor frequency dwell control includes that the accumulated operation time of the compressor is greater than the sum of the accumulated operation time of the compressor when the compressor frequency dwell control is entered and the dwell time length of the compressor frequency dwell control; And / or, If it is determined that the compressor does not occur liquid compression, the dwell time length of the compressor frequency dwell control is corrected according to the current throttle element opening degree and the compressor frequency of the air conditioner.

5. The method of claim 4, wherein The dwell time length of the compressor frequency dwell control is determined according to the outdoor environment temperature, including: Determining the temperature interval in which the outdoor environment temperature is located among the preset two or more temperature intervals, wherein each temperature interval in the preset two or more temperature intervals corresponds to a time length; Determining the dwell time length of the compressor frequency dwell control currently performed by the air conditioner according to the time length corresponding to the temperature interval in which the outdoor environment temperature is located among the preset two or more temperature intervals; And / or, The accumulated operation time of the compressor when the compressor frequency dwell control is entered is determined according to the initial frequency of the compressor at startup, the time length of the compressor startup phase, and the frequency increasing rate of the compressor; The formula for calculating the accumulated operation time s1 of the compressor when the compressor frequency dwell control is entered is as follows: s1= (F1-F start ) / v + s other wherein F1 is the hold point frequency of the compressor frequency hold control, F start is the compressor start initial frequency, s other is the compressor start phase duration, v is the compressor ramp rate; And / or, The dwell time length of the compressor frequency dwell control is corrected according to the current throttle element opening degree and the compressor frequency of the air conditioner, including: Determining the correction time length according to the current throttle element opening degree and the compressor frequency of the air conditioner, and correcting the dwell time length of the compressor frequency dwell control according to the determined correction time length; The corrected dwell time length is equal to the dwell time length of the compressor frequency dwell control of the air conditioner at present minus the correction time length.

6. A control device of an air conditioner, characterized by comprising: including: The first determination unit is configured to determine whether the air conditioner meets the condition for exiting the anti-cold blast control and whether the air conditioner is in the compressor frequency dwell control phase after the air conditioner is started and enters the anti-cold blast control, including: if the accumulated operation time of the compressor of the air conditioner is greater than a preset time length and less than or equal to the sum of the accumulated operation time of the compressor when the compressor frequency dwell control is entered and the dwell time length of the compressor frequency dwell control, it is determined that the air conditioner is in the compressor frequency dwell control phase. a second determining unit, configured to determine whether the indoor heat exchanger pipe temperature of the air conditioner is less than or equal to a second preset temperature value when the first determining unit determines that the air conditioner meets the condition for exiting the anti-cold blast control and the air conditioner is in the compressor frequency staying control stage; a control unit, configured to increase the opening degree of the throttling element of the air conditioner according to the temperature rise rate of the indoor heat exchanger pipe temperature if the second determining unit determines that the indoor heat exchanger pipe temperature is less than or equal to the second preset temperature value; a third determining unit, configured to determine whether the compressor of the air conditioner has liquid compression according to the compressor phase current of the air conditioner after the control unit increases the opening degree of the throttling element of the air conditioner, including: obtaining a maximum fluctuation value of the compressor phase current, the maximum fluctuation value of the compressor phase current being equal to a difference between a maximum value of the compressor phase current effective value and a minimum value of the compressor phase current effective value within a predetermined time; and determining whether the compressor has liquid compression according to the obtained maximum fluctuation value of the compressor phase current and a preset compressor phase current average fluctuation value in the case of no liquid compression. The control unit is further configured to decrease the opening degree of the throttling element of the air conditioner to improve the suction superheat of the compressor if the third determining unit determines that the compressor of the air conditioner has liquid compression.

7. The control device according to claim 6, wherein the first determining unit determines whether the air conditioner meets the condition for exiting the anti-cold blast control, including: determining whether the indoor heat exchanger pipe temperature of the air conditioner is greater than or equal to a first preset temperature value, and determining that the air conditioner meets the condition for exiting the anti-cold blast control if the indoor heat exchanger pipe temperature is greater than or equal to the first preset temperature value; and / or the control unit increases the opening degree of the throttling element of the air conditioner according to the temperature rise rate of the indoor heat exchanger pipe temperature, including: determining an interval in which the temperature rise rate of the indoor heat exchanger pipe temperature is located among two or more preset temperature rise rate intervals, wherein each interval among the two or more preset temperature rise rate intervals corresponds to an opening degree increment; determining the opening degree increment of the throttling element of the air conditioner according to the opening degree increment corresponding to the interval in which the temperature rise rate of the indoor heat exchanger pipe temperature is located among the two or more preset temperature rise rate intervals; and increasing the opening degree of the throttling element of the air conditioner according to the determined opening degree increment of the throttling element of the air conditioner. the third determining unit determines whether the compressor has liquid compression according to a ratio of the obtained maximum fluctuation value of the compressor phase current to the preset compressor phase current average fluctuation value in the case of no liquid compression, including:

8. The control device of claim 6, wherein determining whether the compressor has liquid compression according to a size relationship between a mean square error of a square of the ratio of the maximum fluctuation value of the compressor phase current to the preset compressor phase current average fluctuation value in the case of no liquid compression and a set threshold value.

9. The control device according to any one of claims 6-8, wherein the control unit is further configured to ​ When the first judging unit judges that the air conditioner meets the condition for exiting the anti-cold-wind control but the air conditioner is not in the compressor frequency staying control stage, the control unit controls the air conditioner to maintain the current state of heating operation; The condition that the air conditioner is not in the compressor frequency staying control stage includes: The accumulated operation time length of the compressor of the air conditioner is less than or equal to a preset time length, and / or the accumulated operation time length of the compressor of the air conditioner is greater than the sum of the accumulated operation time length of the compressor when the compressor frequency staying control is entered and the staying time length of the compressor frequency staying control; And / or, The control unit is further configured to: When the air conditioner meets the condition for exiting the compressor frequency staying control, the control unit controls the air conditioner to resume normal heating operation; The condition for exiting the compressor frequency staying control includes that the accumulated operation time length of the compressor is greater than the sum of the accumulated operation time length of the compressor when the compressor frequency staying control is entered and the staying time length of the compressor frequency staying control; And / or, The control device further includes a correction unit configured to correct the staying time length of the compressor frequency staying control according to the current throttle element opening degree and the compressor frequency of the air conditioner if the third judging unit judges that the compressor does not generate liquid compression.

10. The control device according to claim 9, wherein The control device further includes a first determining unit configured to determine the staying time length of the compressor frequency staying control, and the staying time length of the compressor frequency staying control is determined according to the outdoor ambient temperature, including: determining the temperature interval in which the outdoor ambient temperature is located among the preset two or more temperature intervals, wherein each temperature interval in the preset two or more temperature intervals corresponds to a time length; determining the staying time length of the compressor frequency staying control currently performed by the air conditioner according to the time length corresponding to the temperature interval in which the outdoor ambient temperature is located among the preset two or more temperature intervals; And / or, The control device further includes a second determining unit configured to determine the accumulated operation time length of the compressor when the compressor frequency staying control is entered according to the initial frequency of the compressor at startup, the time length of the compressor startup stage, and the frequency increasing rate of the compressor; The formula for calculating the accumulated operation time length s1 of the compressor when the compressor frequency staying control is entered is as follows: s1 = (F1 - F start ) / v + s other wherein F1 is the hold point frequency of the compressor frequency hold control, F start is the compressor start initial frequency, s other is the compressor start phase duration, v is the compressor ramp rate; And / or, The correction unit corrects the staying time length of the compressor frequency staying control according to the current throttle element opening degree and the compressor frequency of the air conditioner, including: determining a correction time length according to the current throttle element opening degree and the compressor frequency of the air conditioner, and correcting the staying time length of the compressor frequency staying control according to the determined correction time length; wherein the corrected staying time length is equal to the staying time length of the compressor frequency staying control of the air conditioner at present minus the correction time length.

11. A storage medium, characterized by A computer program is stored thereon, and the program is executed by a processor to implement the steps of the method according to any one of claims 1-5.

12. An air conditioner characterized by comprising: A computer program product comprising a processor, a memory, and a computer program stored on the memory and loadable on the processor, the processor implementing the steps of the method according to any one of claims 1 to 5 when executing the program, or a control device according to any one of claims 6 to 10.

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