Frequency control method of air conditioner and air conditioner

Abstract

The application discloses a frequency control method of an air conditioner and the air conditioner, and the method comprises the following steps: when the air conditioner enters a refrigeration mode operation, monitoring a high-pressure temperature, determining a high-pressure temperature correction value based on the high-pressure temperature; monitoring a current evaporation temperature of an indoor unit, determining a refrigeration target temperature difference based on the current evaporation temperature and the high-pressure temperature correction value; wherein the refrigeration target temperature difference is positively correlated with the high-pressure temperature; determining a frequency correction amplitude of a compressor based on the refrigeration target temperature difference, and the increasing amplitude of a target frequency of the compressor is periodically controlled to be the frequency correction amplitude; wherein when the refrigeration target temperature difference is less than a preset temperature difference threshold, the frequency correction amplitude is a positive value, and when the refrigeration target temperature difference is greater than the preset temperature difference threshold, the frequency correction amplitude is a negative value. The application realizes the joint control of the frequency of the compressor based on the evaporation temperature and the high-pressure temperature, takes into account the control of the refrigeration effect and the high-pressure, improves the operation reliability of the air conditioner, and improves the refrigeration effect of the air conditioner.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically, to a frequency control method for an air conditioner and an air conditioner. Background Technology

[0002] When an air conditioner operates in a high-temperature cooling environment, if the indoor space is small, the high-pressure level may rise rapidly after startup, leading to shutdown. Existing high-pressure control technology typically triggers compressor frequency limiting or reduction operation after detecting a certain high-pressure temperature. However, this frequency limiting or reduction usually only occurs when the high-pressure level reaches a high value, and even after the compressor begins reducing its frequency, it cannot control the rapidly increasing high-pressure level. This results in low reliability of the air conditioner and can negatively impact its cooling performance. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a frequency control method and an air conditioner that achieves compressor frequency control based on a combination of evaporation temperature and high-pressure temperature, balancing cooling effect and high-pressure control, thereby improving the operational reliability and cooling effect of the air conditioner.

[0004] According to an embodiment of the present invention, a frequency control method for an air conditioner is provided, comprising: when the air conditioner enters a cooling mode, monitoring a high-pressure temperature and determining a high-pressure temperature correction value based on the high-pressure temperature; monitoring the current evaporation temperature of the indoor unit and determining a target cooling temperature difference based on the current evaporation temperature and the high-pressure temperature correction value; wherein the target cooling temperature difference is positively correlated with the high-pressure temperature; determining a frequency correction amplitude for the compressor based on the target cooling temperature difference, and periodically controlling the increase of the target frequency of the compressor as the frequency correction amplitude; wherein when the target cooling temperature difference is less than a preset temperature difference threshold, the frequency correction amplitude is positive, and when the target cooling temperature difference is greater than the preset temperature difference threshold, the frequency correction amplitude is negative.

[0005] By adopting the above technical solution, after the air conditioner enters the cooling mode, a high-pressure temperature correction value is determined based on the high-pressure temperature, and a target cooling temperature difference is determined based on the current evaporation temperature and the high-pressure temperature correction value. Then, the compressor frequency correction amplitude is determined based on the target cooling temperature difference. This achieves joint control of the compressor frequency based on the evaporation temperature and the high-pressure temperature, taking into account both the cooling effect and the control of the high-pressure pressure. By setting the frequency correction amplitude to a positive value when the high-pressure temperature is low, the compressor frequency can be increased, improving the cooling effect. By setting the frequency correction amplitude to a negative value when the high-pressure temperature is high, the compressor frequency can be decreased, thereby controlling the high-pressure pressure to decrease rapidly, avoiding affecting the stability of the air conditioner's operation, improving the air conditioner's operational reliability, and enhancing the air conditioner's cooling effect.

[0006] Preferably, the step of determining the high-pressure temperature correction value based on the high-pressure temperature includes: when the high-pressure temperature is less than a first preset high-pressure temperature, determining the high-pressure temperature correction value as -A*(1-fn / fmax); where A is a constant, fn is the current operating frequency of the compressor, and fmax is the maximum frequency of the compressor; when the high-pressure temperature is greater than or equal to the first preset high-pressure temperature and less than a second preset high-pressure temperature, determining the high-pressure temperature correction value as 0; when the high-pressure temperature is greater than or equal to the second preset high-pressure temperature, determining the high-pressure temperature correction value based on the high-pressure temperature and the rate of change of the high-pressure temperature.

[0007] By adopting the above technical solution, when the high pressure is low, the high pressure temperature correction value is set to a negative value, which can enable the compressor to operate at a higher frequency. When the high pressure rises to between the first preset high pressure temperature and the second preset high pressure temperature, the high pressure temperature correction value is set to 0, which can avoid affecting the stable operation of the air conditioner. When the high pressure is high, the high pressure temperature correction value is determined based on the high pressure temperature and the rate of change of the high pressure temperature, so that the frequency can be reduced in time when the high pressure temperature rises rapidly.

[0008] Preferably, when the high-pressure temperature is greater than or equal to the second preset high-pressure temperature, the high-pressure temperature correction value is positively correlated with both the high-pressure temperature and the rate of change of the high-pressure temperature, and the rate of change of the high-pressure temperature is the difference between the high-pressure temperature detected in the current cycle and the high-pressure temperature detected in the previous cycle.

[0009] By adopting the above technical solution, the high-pressure temperature correction value is positively correlated with both the high-pressure temperature and the rate of change of the high-pressure temperature. When the high-pressure temperature or the rate of change of the high-pressure temperature is large, the frequency correction amplitude can be increased in time, so that the compressor runs at a reduced frequency before the frequency limit is triggered, thereby quickly reducing the high-pressure pressure or reducing the rate of increase of the high-pressure pressure, thus improving the stability of the air conditioner operation.

[0010] Preferably, the target temperature difference for cooling is equal to the target evaporation temperature minus the current evaporation temperature plus the high-pressure temperature correction value.

[0011] By adopting the above technical solution, the target temperature difference of the evaporation temperature is corrected based on the high-pressure temperature correction value. When adjusting the compressor frequency, both the evaporation temperature and the high-pressure temperature can be taken into account, thereby balancing the cooling effect and the high-pressure control effect of the air conditioner.

[0012] Preferably, the frequency correction amplitude is inversely correlated with the target temperature difference for cooling.

[0013] By adopting the above technical solution, the frequency correction amplitude is inversely correlated with the target temperature difference for cooling. This allows for a gradual reduction in the compressor's frequency increase rate as the compressor frequency rises when the high pressure is low, ensuring the cooling effect. Conversely, it allows for a gradual increase in the compressor's frequency decrease rate as the high pressure temperature rises when the high pressure is high, thus reducing the high pressure temperature in a timely manner and ensuring the stable operation of the air conditioner.

[0014] Preferably, the corrected target frequency of the compressor is = Fn(1+ΔF); where Fn is the current target frequency of the compressor and ΔF is the frequency correction magnitude.

[0015] Preferably, the frequency control method further includes: determining the period duration of the modified target frequency based on the high-pressure temperature.

[0016] By adopting the above technical solution, the period of the target frequency correction can be determined based on the high pressure and temperature conditions. The period of the target frequency correction can be adaptively adjusted to avoid the frequency adjustment being too fast or too slow, which would affect the stable operation of the air conditioner.

[0017] Preferably, the step of determining the period duration of the target frequency correction based on the high-pressure temperature includes: when the high-pressure temperature is less than a first preset high-pressure temperature, determining the period duration as a first preset duration; when the high-pressure temperature is greater than or equal to the first preset high-pressure temperature and less than a second preset high-pressure temperature, determining the period duration to be equal to the period duration of the previous cycle; when the high-pressure temperature is greater than or equal to the second preset high-pressure temperature, determining the initial period duration as the first preset duration, and determining the period duration of the current cycle based on the high-pressure temperature and the period duration of the previous cycle; wherein the period duration of the current cycle is less than the period duration of the previous cycle.

[0018] By adopting the above technical solution, when the high pressure is low, the cycle duration of the target frequency correction is controlled to a fixed value to ensure the stable operation of the air conditioner. When the high pressure is high, the cycle duration of the target frequency correction is controlled to become shorter and shorter, which can quickly adjust the compressor frequency and thus reduce the high pressure rapidly.

[0019] Preferably, the period duration t of the current period n =t n-1 -(T 高压n -Second preset high pressure temperature) / T 高压n *α; where t n-1 T represents the duration of the previous cycle. 高压n α represents the high-pressure temperature of the current cycle, and α is the corrected time constant.

[0020] According to an embodiment of the present invention, another aspect provides an air conditioner including a computer-readable storage medium storing a computer program and a processor, the computer program being read and executed by the processor to implement the method as described in any of the first aspects.

[0021] This invention has the following beneficial effects: After the air conditioner enters cooling mode, a high-pressure temperature correction value is determined based on the high-pressure temperature, and a target cooling temperature difference is determined based on the current evaporation temperature and the high-pressure temperature correction value. Then, the compressor frequency correction amplitude is determined based on the target cooling temperature difference. This achieves joint control of the compressor frequency based on the evaporation temperature and the high-pressure temperature, taking into account both the cooling effect and the control of the high-pressure pressure. By setting the frequency correction amplitude to a positive value when the high-pressure temperature is low, the compressor frequency can be increased, improving the cooling effect. By setting the frequency correction amplitude to a negative value when the high-pressure temperature is high, the compressor frequency can be decreased, thereby controlling the high-pressure pressure to decrease rapidly, avoiding affecting the stability of the air conditioner's operation, improving the air conditioner's operational reliability, and enhancing the air conditioner's cooling effect. Attached Figure Description

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0023] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0024] Figure 1 A flowchart of a frequency control method for an air conditioner provided by the present invention;

[0025] Figure 2 This is a structural schematic diagram of an air conditioner provided by the present invention. Detailed Implementation

[0026] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] This embodiment provides a frequency control method for an air conditioner, which can be applied to air conditioners, see below. Figure 1 The flowchart of the frequency control method for the air conditioner shown mainly includes the following steps S102 to S106:

[0029] Step S102: When the air conditioner enters the cooling mode, monitor the high-pressure temperature and determine the high-pressure temperature correction value based on the high-pressure temperature.

[0030] See also Figure 2 The diagram shows the structure of an air conditioner, which includes an indoor heat exchanger 21, an outdoor heat exchanger 22, a four-way valve 23, and a compressor 24. A first temperature sensor 25 is installed on the exhaust pipe of the compressor. The first temperature sensor 25 is used to monitor the high-pressure temperature of the air conditioner. A second temperature sensor 26 is installed in the middle of the coil of the indoor heat exchanger 21. The second temperature sensor 26 is used to monitor the evaporation temperature of the indoor unit.

[0031] When the outdoor ambient temperature is higher than a certain value and the air conditioner is running in cooling mode, the high-pressure temperature is detected in real time by the first temperature sensor installed on the exhaust pipe, and the corresponding high-pressure temperature correction value is determined based on the high-pressure temperature. This high-pressure temperature correction value is used to correct the cooling target temperature difference. When the high-pressure temperature is high, the high-pressure temperature correction value is positively correlated with the high-pressure temperature, so that the compressor frequency can be quickly adjusted when the high pressure is high.

[0032] Step S104: Monitor the current evaporation temperature of the indoor unit, and determine the target cooling temperature difference based on the current evaporation temperature and the high-pressure temperature correction value;

[0033] The target cooling temperature difference is positively correlated with the high-pressure temperature. Based on the temperature sensor installed on the indoor unit's coil, the current evaporation temperature of the indoor unit is monitored in real time. The target temperature difference is calculated based on the current evaporation temperature and the target evaporation temperature, and then corrected using a high-pressure temperature correction value to obtain the final target cooling temperature difference. This target cooling temperature difference is positively correlated with the high-pressure temperature; that is, the higher the high-pressure temperature, the larger the target cooling temperature difference.

[0034] Step S106: Determine the frequency correction range of the compressor based on the target temperature difference for refrigeration, and periodically control the increase of the target frequency of the compressor as the frequency correction range;

[0035] When the target temperature difference is less than the preset temperature difference threshold, the frequency correction amplitude is positive; when the target temperature difference is greater than the preset temperature difference threshold, the frequency correction amplitude is negative.

[0036] Since the target temperature difference for cooling is positively correlated with the high-pressure temperature, when the high-pressure temperature is at a high level, the target temperature difference for cooling will exceed the preset temperature difference threshold, resulting in a negative value for the calculated frequency correction amplitude. This can reduce the target frequency of the compressor and thus quickly reduce the high-pressure pressure. When the high-pressure pressure is at a low level, there is room for the high-pressure pressure to rise, and the target temperature difference for cooling is lower than the preset temperature difference threshold, resulting in a positive value for the calculated frequency correction amplitude. This can increase the target frequency of the compressor and thus improve the cooling effect.

[0037] The frequency control method for the air conditioner provided in this embodiment determines a high-pressure temperature correction value based on the high-pressure temperature after the air conditioner enters cooling mode, determines the target cooling temperature difference based on the current evaporation temperature and the high-pressure temperature correction value, and then determines the compressor frequency correction amplitude based on the target cooling temperature difference. This achieves joint control of the compressor frequency based on the evaporation temperature and the high-pressure temperature, taking into account both the cooling effect and the control of the high-pressure pressure. By setting the frequency correction amplitude to a positive value when the high-pressure temperature is low, the compressor frequency can be increased, improving the cooling effect. By setting the frequency correction amplitude to a negative value when the high-pressure temperature is high, the compressor frequency can be decreased, thereby controlling the high-pressure pressure to decrease rapidly, avoiding affecting the stability of the air conditioner's operation, improving the air conditioner's operational reliability, and enhancing the air conditioner's cooling effect.

[0038] In one embodiment, this embodiment provides a method for calculating the target temperature difference for cooling:

[0039] Target temperature difference for cooling = target evaporation temperature - current evaporation temperature + high pressure temperature correction value.

[0040] By correcting the target temperature difference of the evaporation temperature based on the high-pressure temperature correction value, both the evaporation temperature and the high-pressure temperature can be taken into account when adjusting the compressor frequency, thereby balancing the cooling effect and the high-pressure control effect of the air conditioner.

[0041] In one embodiment, the frequency correction magnitude is inversely correlated with the target temperature difference. The larger the target temperature difference, the smaller the value of the frequency correction magnitude.

[0042] When the target temperature difference is less than the preset temperature difference threshold, the frequency correction amplitude is positive; when the target temperature difference is greater than the preset temperature difference threshold, the frequency correction amplitude is negative. That is, when the target temperature difference is less than the preset temperature difference threshold, the larger the target temperature difference, the smaller the frequency correction amplitude, meaning the compressor's frequency increase rate is lower; conversely, when the target temperature difference is greater than the preset temperature difference threshold, the larger the target temperature difference, the smaller the frequency correction amplitude, meaning the compressor's frequency decrease rate is greater. By controlling the frequency correction amplitude to be inversely correlated with the target temperature difference, it is possible to gradually reduce the compressor's frequency increase rate as the compressor frequency rises when the high pressure is low, ensuring cooling performance; and to gradually increase the compressor's frequency decrease rate as the high pressure temperature rises when the high pressure is high, timely reducing the high pressure temperature and ensuring stable operation of the air conditioner.

[0043] In one embodiment, the corrected target frequency of the compressor is Fn(1+ΔF); where Fn is the current target frequency of the compressor and ΔF is the frequency correction magnitude.

[0044] Please refer to Table 1 below for the corresponding values ​​of the target cooling temperature difference and the frequency correction amplitude. Table 1 shows the frequency correction amplitude values ​​corresponding to different ranges of the target cooling temperature difference ΔT:

[0045] Table 1: Corresponding Values ​​of Target Temperature Difference for Cooling and Frequency Correction Amplitude

[0046]

[0047] The value of T0 can be in the range of 3-5℃.

[0048] In one embodiment, this embodiment provides an implementation method for determining a high-pressure temperature correction value based on the high-pressure temperature, which can be performed by referring to the following steps:

[0049] Step (1): When the high pressure temperature is lower than the first preset high pressure temperature, determine the high pressure temperature correction value as -A*(1-fn / fmax);

[0050] Where A is a constant, A is greater than or equal to 2, fn is the current operating frequency of the compressor, and fmax is the maximum frequency of the compressor; the first preset high-pressure temperature can be determined according to the type of refrigerant in the air conditioner. When the refrigerant is R32, the range of the first preset high-pressure temperature can be 45-50℃; when the refrigerant is R290, the range of the first preset high-pressure temperature can be 70-75℃.

[0051] When the high-pressure temperature is low, the high-pressure temperature correction value is -A*(1-fn / fmax), where fn / fmax is the ratio of the compressor's current operating frequency to its maximum frequency. This ratio is always less than or equal to 1. The lower the compressor's current operating frequency, the smaller the value of fn / fmax, and the larger (1-fn / fmax) becomes, and the smaller -A*(1-fn / fmax) becomes. Furthermore, when the high-pressure temperature is lower than the first preset high-pressure temperature, the high-pressure temperature correction value is always less than or equal to 0.

[0052] The aforementioned target temperature difference for cooling is positively correlated with the high-pressure temperature correction value. The smaller the high-pressure temperature correction value, the smaller the target temperature difference for cooling. When the target temperature difference for cooling is lower than the preset temperature difference threshold, the frequency correction amplitude is positive, enabling the compressor frequency to increase.

[0053] Step (2): When the high pressure temperature is greater than or equal to the first preset high pressure temperature and less than the second preset high pressure temperature, determine the high pressure temperature correction value to be 0;

[0054] The aforementioned second preset high-pressure temperature = first preset high-pressure temperature + B, where B can range from 8 to 12, with a preferred value of 10. When the high-pressure temperature is between the first and second preset high-pressure temperatures, it indicates that the current high-pressure is relatively stable, and no correction is needed for the target temperature difference; the high-pressure temperature correction value is 0.

[0055] Step (3): When the high pressure temperature is greater than or equal to the second preset high pressure temperature, determine the high pressure temperature correction value based on the high pressure temperature and the rate of change of the high pressure temperature.

[0056] When the high pressure is high, the high pressure temperature correction value is greater than 0. It is necessary to control the compressor frequency reduction in time before triggering frequency limiting. The high pressure temperature correction value is determined based on the high pressure temperature and the rate of change of the high pressure temperature so that the frequency can be reduced in time when the high pressure temperature rises rapidly.

[0057] By setting the high-pressure temperature correction value to a negative value when the high pressure is low, the compressor can operate at a higher frequency. By setting the high-pressure temperature correction value to 0 when the high pressure rises to between the first preset high pressure temperature and the second preset high pressure temperature, the stable operation of the air conditioner can be avoided. By determining the high-pressure temperature correction value based on the high pressure temperature and the rate of change of the high pressure when the high pressure is high, the frequency can be reduced in time when the high pressure temperature rises rapidly.

[0058] In one specific implementation, when the high-pressure temperature is greater than or equal to the second preset high-pressure temperature, the high-pressure temperature correction value is positively correlated with both the high-pressure temperature and the rate of change of the high-pressure temperature. The rate of change of the high-pressure temperature is the difference between the high-pressure temperature detected in the current cycle and the high-pressure temperature detected in the previous cycle.

[0059] The rate of change of high-pressure temperature = the high-pressure temperature detected in the current cycle - the high-pressure temperature detected in the previous cycle. The higher the high-pressure temperature, the larger the high-pressure temperature correction value; similarly, the higher the rate of change of high-pressure temperature, the larger the high-pressure temperature correction value. By making the high-pressure temperature correction value positively correlated with both the high-pressure temperature and its rate of change, the frequency correction amplitude can be increased in a timely manner when the high-pressure temperature or its rate of change is large. This causes the compressor to operate at a reduced frequency before frequency limiting is triggered, thereby quickly reducing the high-pressure pressure or slowing down the rate of increase of the high-pressure pressure, thus improving the stability of the air conditioner's operation.

[0060] In one specific implementation, refer to Table 2 below for the relationship between high-pressure temperature correction values. Table 2 shows the high-pressure temperature correction values ​​under different high-pressure temperatures and rates of change of high-pressure temperature.

[0061] Table 2: Relationship between High Pressure Temperature Correction Values

[0062]

[0063]

[0064] In one embodiment, the method provided in this embodiment further includes: determining the period duration of the target frequency correction based on the high-pressure temperature. During the operation of the air conditioner, if the period duration of the target frequency correction for the compressor is too short, the compressor frequency changes rapidly, which can easily affect the stability of the air conditioner's operation. If the period duration of the target frequency correction for the compressor is too long, the compressor frequency adjustment cannot adapt well to the rapidly changing system environment. By determining the period duration of the target frequency correction based on the high-pressure temperature, the period duration of the target frequency correction can be adaptively adjusted, avoiding the impact of excessively fast or slow frequency adjustment on the stable operation of the air conditioner.

[0065] This embodiment provides an implementation method for determining the period duration of the corrected target frequency based on high pressure temperature. The specific steps are as follows:

[0066] Step 1): When the high-pressure temperature is lower than the first preset high-pressure temperature, the cycle duration is determined to be the first preset duration;

[0067] The value of the first preset duration t1 can be in the range of 20 to 40 seconds, with a preferred value of 30 seconds;

[0068] Step 2): When the high-pressure temperature is greater than or equal to the first preset high-pressure temperature and less than the second preset high-pressure temperature, determine that the cycle duration is equal to the cycle duration of the previous cycle.

[0069] When the high-pressure temperature is greater than or equal to the first preset high-pressure temperature and less than the second preset high-pressure temperature, the period duration of the target frequency correction remains unchanged. That is, when the high-pressure temperature rises from less than the first preset high-pressure temperature to greater than or equal to the first preset high-pressure temperature and less than the second preset high-pressure temperature, the period duration remains the first preset duration; when the high-pressure temperature decreases from greater than or equal to the second preset high-pressure temperature to greater than or equal to the first preset high-pressure temperature and less than the second preset high-pressure temperature, the period duration of the target frequency correction is equal to the previous period.

[0070] Step 3): When the high pressure temperature is greater than or equal to the second preset high pressure temperature, the initial cycle duration is determined as the first preset duration, and the cycle duration of the current cycle is determined based on the high pressure temperature and the cycle duration of the previous cycle.

[0071] The duration of the current cycle is shorter than the duration of the previous cycle, but longer than the minimum cycle duration, which can be 5 seconds.

[0072] When the high pressure temperature is greater than or equal to the second preset high pressure temperature, the cycle duration of the current cycle is made shorter than the cycle duration of the previous cycle. When the high pressure is high, the cycle duration of the target frequency can be controlled to become shorter and shorter, which can quickly adjust the compressor frequency and thus reduce the high pressure rapidly.

[0073] In one specific implementation, the period duration t of the current period is... n =t n-1 -(T 高压n -Second preset high pressure temperature) / T 高压n *α; where t n-1 T represents the duration of the previous cycle. 高压n The current high-pressure temperature is α, and the correction time constant is α. This correction time constant can be determined according to the type of refrigerant in the air conditioner. For R32 refrigerant, the correction time constant ranges from 40 to 60; for R290 refrigerant, the correction time constant ranges from 60 to 80. The correction time constant is an integer.

[0074] The aforementioned second preset high-pressure temperature can be T1+10, for example, the initial cycle duration is t1;

[0075] The duration of the second period is t2 = t1 - T 高压2 -T1-10) / T 高压2 *α

[0076] The duration of the third period is t3 = t2 - (T 高压3 -T1-10) / T 高压3 *α

[0077] The duration of the third period is t4 = t3 - (T 高压4-T1-10) / T 高压4 *α

[0078] …

[0079] The duration t of the nth period n =t n-1 -(T 高压n -T1-10) / T 高压n *α

[0080] The frequency control method for the air conditioner provided in this embodiment realizes the coordinated control of the compressor frequency based on the evaporation temperature difference and high pressure, taking into account both the cooling effect and the high pressure control effect. When the high pressure is low, it is determined that the frequency adjustment is too slow, and the compressor frequency is increased by adjusting the high pressure temperature correction value to quickly improve the cooling effect. When the high pressure is high, the frequency is reduced by adjusting the high pressure temperature correction value, which can control the high pressure of the system to decrease and improve the reliability of the high pressure control of the air conditioner.

[0081] Corresponding to the frequency control method for air conditioners provided in the above embodiments, this embodiment of the invention provides an example of applying the frequency control method for air conditioners, which can be specifically performed according to the following steps:

[0082] Step 1: Periodically update the compressor's target frequency;

[0083] A high-pressure temperature sensor is installed on the exhaust pipe of the air conditioner compressor to monitor the high-pressure temperature. The higher the high-pressure temperature, the higher the high-pressure.

[0084] Calculate ΔT target evaporation temperature difference = target evaporation temperature - actual evaporation temperature + high pressure temperature correction value

[0085] Calculate the new target frequency F = Fn(1 + ΔF), where F is the updated target frequency, Fn is the current target frequency, and ΔF is the frequency correction magnitude.

[0086] The frequency correction amplitude ΔF is determined based on the target temperature difference ΔT. The value of the frequency correction amplitude can be found in the table above, which shows the corresponding values ​​of the target temperature difference and the frequency correction amplitude.

[0087] Step 2, calculate the high-pressure temperature correction value.

[0088] Determine the high-pressure temperature correction value based on the monitored high-pressure temperature:

[0089] ① If the high-pressure temperature is less than T1, the system high-pressure is low. The frequency is corrected using the high-pressure temperature correction value so as to quickly increase the frequency and improve the cooling effect.

[0090] The high-pressure temperature correction value is -10*(1-fn / fmax), where fn / fmax is the ratio between the current frequency and the highest frequency. Different air conditioner models typically have different maximum compressor operating frequencies corresponding to stable outer ring temperatures. See Table 3 below for the relationship between outer ring temperature and compressor maximum frequency. Different outer ring temperatures correspond to different maximum frequencies in different environmental ranges: outer ring temperature < 18℃, low cooling demand, fmax = f1; 18℃ ≤ outer ring temperature < 48℃, high cooling demand, fmax = f2; outer ring temperature ≥ 48℃, high system load, fmax = f3. For example, if the current outer ring temperature is 30℃, then fmax = f2.

[0091] Table 3. Relationship between outer ring temperature and compressor maximum frequency

[0092] Maximum frequency fmax f1 f2 f3

[0093] When the difference between fn and fmax is large, the calculated high-pressure temperature correction value will be lower, indicating that the system cooling effect is poor and the frequency needs to be increased to improve the cooling effect. Since the ratio of fn to fmax is between 0 and 1, it needs to be amplified. Using 10*(1-fn / fmax) can convert this ratio into a temperature value, that is, the high-pressure temperature correction value. The high-pressure temperature correction value participates in the calculation of the frequency correction amplitude, which can increase the frequency correction amplitude and realize the frequency increase.

[0094] When the high pressure temperature is less than T1, the high pressure temperature is low, and the calculated values ​​of the high pressure temperature correction are all negative. When the high pressure temperature correction is negative, the target temperature difference for refrigeration decreases, which can increase the target frequency and make the compressor run at a higher frequency.

[0095] ② If T1≤high pressure temperature<T1+10, the system high pressure is relatively stable and there is no need to correct the cooling target temperature difference. In this case, the high pressure temperature correction value = 0.

[0096] ③ If the high-pressure temperature is ≥ T1+10, the high-pressure temperature correction value is determined based on the high-pressure temperature and the rate of change of the high-pressure temperature. Specifically, refer to the table above for the relationship between the high-pressure temperature correction values. The rate of change of the high-pressure temperature ΔT_high-pressure = the high-pressure temperature detected in the current cycle - the high-pressure temperature detected in the previous cycle.

[0097] Among them, the higher the high-pressure temperature, the more the frequency needs to be reduced, and the higher the high-pressure temperature correction value, the faster the compressor can be controlled to reduce the frequency. The higher the high-pressure temperature change rate ΔT, the faster the high-pressure temperature increases, and the higher the high-pressure temperature correction value.

[0098] Step 3: Calculate the target frequency update cycle duration for the compressor.

[0099] In scenarios involving instantaneous startup, system parameters change rapidly. If the compressor frequency correction interval is too long, the frequency adjustment cannot adapt to the rapidly changing system environment. If the compressor correction interval is too short, the frequency changes quickly, resulting in poor system stability. Therefore, it is necessary to design a reasonable target frequency update cycle length.

[0100] ① If the high pressure temperature is < T1, the system high pressure is low and can be operated according to normal requirements. The target frequency is corrected once every t1. The value of t1 can be 20 to 40 seconds, with 30 seconds being the preferred value.

[0101] ②If T1≤high pressure temperature<T1+10, then the cycle duration is the same as the cycle duration of the previous cycle.

[0102] ③ If the high-pressure temperature is ≥ T1 + 10, the frequency update time will be adjusted as follows:

[0103] The initial cycle length is t1;

[0104] The duration of the second period is t2 = t1 - T 高压2 -T1-10) / T 高压2 *α

[0105] The duration of the third period is t3 = t2 - (T 高压3 -T1-10) / T 高压3 *α

[0106] The duration of the third period is t4 = t3 - (T 高压4 -T1-10) / T 高压4 *α

[0107] …

[0108] The duration t of the nth period n =t n-1 -(T 高压n -T1-10) / T 高压n *α

[0109] Among them, T 高压n Let α be the high-pressure temperature of the nth cycle, and α be the correction time constant. This correction time constant can be determined according to the type of refrigerant in the air conditioner. For R32 refrigerant, the correction time constant ranges from 40 to 60; for R290 refrigerant, the correction time constant ranges from 60 to 80. The correction time constant is an integer. To avoid system instability caused by excessively rapid correction, the cycle duration t is specified for each cycle. n The minimum value is 5 seconds.

[0110] (T 高压n -T1-10) / T 高压nThis represents the percentage by which the current high-pressure temperature exceeds (T1+10). The greater the exceedance, the larger the calculated percentage. The time correction value is obtained by multiplying the percentage by α. Then, t... n-1 Subtracting the time correction value can shorten t more quickly. n The value is [value missing]. If the high-voltage temperature exceeds T1+10 each time it is detected, the frequency update time will be shortened in the next cycle. The greater the high-voltage temperature exceeds (T1+10), the more the frequency update time will be shortened, thus enabling rapid frequency correction when the high-voltage temperature is too high.

[0111] Corresponding to the frequency control method of the air conditioner provided in the above embodiments, this embodiment provides an air conditioner, which includes a computer-readable storage medium storing a computer program and a processor. The computer program is read and executed by the processor to implement the frequency control method of the air conditioner provided in the above embodiments.

[0112] This embodiment also provides a computer-readable storage medium storing a computer program. When executed by a processor, this computer program implements the various processes of the frequency control method embodiment for the air conditioner described above, and achieves the same technical effect. To avoid repetition, it will not be described again here. The computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0113] Of course, those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by computer-controlled devices. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. The storage medium can be a memory, a disk, an optical disk, etc.

[0114] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0115] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0116] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the air conditioner disclosed in the embodiments, since it corresponds to the frequency control method of the air conditioner disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0117] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0118] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A frequency control method for an air conditioner, characterized in that, include: When the air conditioner enters cooling mode, the high-pressure temperature is monitored, and a high-pressure temperature correction value is determined based on the high-pressure temperature. The current evaporation temperature of the indoor unit is monitored, and the target cooling temperature difference is determined based on the current evaporation temperature and the high-pressure temperature correction value; wherein, the target cooling temperature difference is positively correlated with the high-pressure temperature; The frequency correction amplitude of the compressor is determined based on the target temperature difference for cooling, and the increase in the target frequency of the compressor is periodically controlled as the frequency correction amplitude; wherein, when the target temperature difference for cooling is less than a preset temperature difference threshold, the frequency correction amplitude is positive, and when the target temperature difference for cooling is greater than the preset temperature difference threshold, the frequency correction amplitude is negative. The step of determining the high-pressure temperature correction value based on the high-pressure temperature includes: When the high-pressure temperature is lower than the first preset high-pressure temperature, the high-pressure temperature correction value is determined to be -A*(1-fn / fmax); where A is a constant, A is greater than or equal to 2, fn is the current operating frequency of the compressor, and fmax is the maximum frequency of the compressor; When the high-pressure temperature is greater than or equal to the first preset high-pressure temperature and less than the second preset high-pressure temperature, the high-pressure temperature correction value is determined to be 0. When the high-pressure temperature is greater than or equal to the second preset high-pressure temperature, the high-pressure temperature correction value is determined based on the high-pressure temperature and the rate of change of the high-pressure temperature. When the high-pressure temperature is greater than or equal to the second preset high-pressure temperature, the high-pressure temperature correction value is positively correlated with both the high-pressure temperature and the rate of change of the high-pressure temperature. The rate of change of the high-pressure temperature is the difference between the high-pressure temperature detected in the current cycle and the high-pressure temperature detected in the previous cycle. The target temperature difference for cooling = target evaporation temperature - current evaporation temperature + high pressure temperature correction value; The frequency correction amplitude is inversely correlated with the target temperature difference for cooling.

2. The frequency control method as described in claim 1, characterized in that, The corrected target frequency of the compressor is = Fn(1+ΔF); where Fn is the current target frequency of the compressor and ΔF is the frequency correction magnitude.

3. The frequency control method as described in claim 1, characterized in that, Also includes: The period duration for correcting the target frequency is determined based on the high-pressure temperature.

4. The frequency control method as described in claim 3, characterized in that, The step of determining the period duration of the corrected target frequency based on the high-pressure temperature includes: When the high-pressure temperature is lower than the first preset high-pressure temperature, the cycle duration is determined to be the first preset duration; When the high-pressure temperature is greater than or equal to the first preset high-pressure temperature and less than the second preset high-pressure temperature, the cycle duration is determined to be equal to the cycle duration of the previous cycle. When the high-pressure temperature is greater than or equal to the second preset high-pressure temperature, the initial cycle duration is determined to be the first preset duration, and the cycle duration of the current cycle is determined based on the high-pressure temperature and the cycle duration of the previous cycle; wherein the cycle duration of the current cycle is less than the cycle duration of the previous cycle.

5. The frequency control method as described in claim 4, characterized in that, The period duration t of the current period n =t n-1 -(T 高压n -Second preset high pressure temperature) / T 高压n *α; where t n-1 T represents the duration of the previous cycle. 高压n α represents the high-pressure temperature of the current cycle, and α is the corrected time constant.

6. An air conditioner, characterized in that, The method includes a computer-readable storage medium storing a computer program, which is read and executed by the processor to implement the method as described in any one of claims 1-5.

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