Air conditioning system and control method thereof

Abstract

The application provides an air conditioning system and a control method thereof. The air conditioning system comprises an indoor fan. The control method comprises a refrigerant concentration detection step. Before the refrigerant concentration detection step is performed, the following steps are performed: detecting an indoor environment temperature, a voltage and a current of the indoor fan; calculating a temperature influence coefficient a according to the indoor environment temperature and a voltage influence coefficient b according to the voltage; judging whether the air conditioning system is in a running state; if the result of the judgment is yes, calculating a conversion current Ix under a set temperature and a set voltage of the indoor environment according to the current, the temperature influence coefficient and the voltage influence coefficient; and comparing the conversion current Ix with a preset current value, judging whether the indoor fan is stalled according to the comparison result of the conversion current Ix and the preset current value; and if the result of the judgment is no, the steps of conversion, comparison and judgment are not performed. The application improves the accuracy of the judgment of whether the indoor fan is stalled and the reliability of the air conditioning system.

Description

Technical Field

[0001] This invention relates to the field of air conditioning, specifically to an air conditioning system and its control method. Background Technology

[0002] In response to the full-scale switch to R454B refrigerant in North America, and considering the flammability of R454B, it is necessary to test the R454B refrigerant according to the UL60335 safety standard to prevent refrigerant leakage and potential safety issues.

[0003] In the event of a refrigerant leak, the proper functioning of the indoor fan is crucial for ensuring the refrigerant can be diluted to a safe concentration. Therefore, it is essential to ensure the indoor fan operates normally and that its minimum airflow exceeds the minimum airflow required by safety regulations. However, the operation of the indoor fan is affected by various parameters, and it is possible that the airflow may be less than the minimum requirement, which may go undetected. This can lead to refrigerant concentrations exceeding the standard in some areas, ultimately causing safety malfunctions. Summary of the Invention

[0004] To address the above problems, this invention provides an air conditioning system and its control method. Before detecting the refrigerant concentration, the converted current of the indoor fan is determined based on the temperature influence coefficient, voltage influence coefficient, and current current. The comparison between the converted current and the preset current value is used to determine whether the indoor fan is stalling, thereby improving the accuracy of determining whether the indoor fan is stalling normally and the reliability of the air conditioning system.

[0005] This invention provides a control method for an air conditioning system, the air conditioning system including an indoor fan, the control method including: a refrigerant concentration detection step, and the control method further including: performing the following steps before performing the refrigerant concentration detection step:

[0006] Testing steps: Test the indoor ambient temperature, the voltage and current of the indoor fan;

[0007] Data processing steps: Calculate the temperature influence coefficient a based on the indoor ambient temperature; calculate the voltage influence coefficient b based on the voltage.

[0008] Judgment steps: Determine whether the air conditioning system is running;

[0009] If the judgment result of the judgment step is yes, then the conversion, comparison, and judgment steps are executed; if the judgment result of the judgment step is no, then the conversion, comparison, and judgment steps are not executed; wherein,

[0010] The conversion, comparison, and judgment steps include: calculating the converted current Ix under the indoor environment set temperature T0 and set voltage conditions based on the current, temperature influence coefficient, and voltage influence coefficient; comparing the converted current Ix with the preset current value; and judging whether the indoor fan has stalled based on the comparison result of the converted current Ix and the preset current value.

[0011] According to this technical solution, when the air conditioning system is in operation, the converted current under the set indoor temperature and voltage is calculated by combining the influence coefficients of current, temperature, and voltage. This overcomes the influence of indoor temperature and voltage on the current, improving the accuracy of the current data. The comparison between the converted current and the preset current value determines whether the indoor fan is stalling, improving the accuracy of the indoor fan condition assessment. When the air conditioning system is in operation, this application determines whether the indoor fan is stalling by comparing the converted current with the preset current value, eliminating the need to consider the influence of static pressure on the indoor fan's airflow, thus saving the use of a static pressure detector and reducing costs. By accurately judging the indoor fan's operating condition, faults can be detected and addressed promptly, ensuring that the indoor fan can still output air normally in the event of refrigerant leakage, diluting the refrigerant concentration and improving the reliability of the air conditioning system.

[0012] In an optional technical solution of the present invention, the converted current Ix = I / (a*b), where I is the current in the detection step.

[0013] According to this technical solution, the converted current is calculated by combining the actual current, voltage influence coefficient and temperature influence coefficient, which overcomes the influence of voltage and indoor ambient temperature on the current, improves the accuracy of the converted current and the accuracy of judging whether the indoor fan is stalling, and helps to ensure the reliability of the air conditioning system.

[0014] In the optional technical solution of the present invention, the temperature influence coefficient a = 1 + m * (T1 - T0), where T1 is the indoor ambient temperature in the detection step, T0 is the indoor ambient set temperature, m > 0, and m is the dependent variable of T0.

[0015] According to this technical solution, the temperature influence coefficient is determined by combining the difference between the indoor ambient temperature and the indoor ambient set temperature, and the converted current is determined by combining the temperature influence coefficient. This overcomes the current variation caused by the indoor ambient temperature factor and improves the accuracy of the current data. For different indoor ambient set temperatures, the m value changes accordingly, so that there are corresponding temperature influence coefficients under different indoor ambient set temperatures. This improves the accuracy of the converted current under different indoor ambient set temperatures and the accuracy of judging whether the indoor fan is stalling.

[0016] In the optional technical solution of the present invention, the voltage influence coefficient b = 1 - n * (U1 - U0), where U1 is the voltage in the detection step, U0 is the set voltage, n > 0, and n is the dependent variable of U0.

[0017] According to this technical solution, the voltage influence coefficient is determined by combining the difference between the actual voltage and the set voltage, and the converted current is determined by combining the voltage influence coefficient. This overcomes the current variation caused by voltage factors and improves the accuracy of current data. For different set voltages, the value of m changes accordingly, so that there are corresponding voltage influence coefficients under different room set voltages. This improves the accuracy of converted current under different room set voltages and the accuracy of judging whether the indoor fan is stalling.

[0018] In the optional technical solution of the present invention, it further includes: a preset step: preset the initial current data set of the indoor fan at different fan speeds, set static pressures, different set voltages, and different indoor ambient set temperatures; in the conversion, comparison, and judgment steps, the preset current value is associated with the initial current of the indoor fan at the corresponding fan speed.

[0019] According to this technical solution, the preset current value is correlated with the initial current. By pre-setting the initial current dataset of the indoor fan under different fan speeds, set static pressures, different set voltages, and different indoor ambient temperatures, the accuracy of the preset current value under different operating conditions can be improved. Furthermore, since the static pressure is a preset value, the use of a static pressure detector can be reduced, eliminating the influence of static pressure on the current and lowering costs while ensuring accuracy. By pre-setting different fan speeds, corresponding initial currents and preset current values ​​are provided for each speed, improving the accuracy of determining whether the indoor fan is stalling by comparing the converted current with the preset current value.

[0020] In the optional technical solution of the present invention, determining whether the internal fan is stalling based on the comparison result of the converted current Ix and the preset current value includes:

[0021] Determine whether the converted current Ix is not less than k1*I0, where I0 is the initial current of the corresponding windshield under the set static pressure, and 0 < k1 < 1.

[0022] If the converted current Ix is not less than k1*I0, then the output internal fan is normal and has not stalled; and determine whether there is a static pressure fault.

[0023] If the converted current Ix is less than k1*I0, determine whether the air conditioning system has an indoor fan stall or abnormal fault.

[0024] According to this technical solution, if the converted current Ix is not less than k1*I0, it indicates that the air volume is normal, the indoor fan is normal and not stalled, and further judgment is needed to determine whether there is a static pressure fault. This can promptly detect the problem of mismatch between the fan speed and the current, ensuring the reliability of the air conditioning system. If the converted current Ix is less than k1*I0, it indicates that the air volume is insufficient, and the indoor fan may be stalled or malfunctioning. Therefore, further judgment is needed to determine whether the indoor fan is stalled or malfunctioning.

[0025] In the optional technical solutions of the present invention, whether the air conditioning system has an indoor fan stall or abnormal malfunction includes:

[0026] Determine if the air conditioning system is in anti-cold air mode;

[0027] If the air conditioning system is in anti-cold air mode, then proceed with the judgment steps;

[0028] If the air conditioning system is not in anti-cold air mode, the output indoor fan will stall or malfunction; and it will be determined whether the converted current Ix is not less than the current threshold.

[0029] If the converted current Ix is not less than the current threshold, then the refrigerant concentration detection step is performed;

[0030] If the converted current Ix is less than the current threshold, then determine whether the number of times the internal fan stalls or has an abnormal fault meets the number threshold.

[0031] If the number of times the internal fan stalls or malfunctions meets the threshold, the air conditioning system will be shut down.

[0032] If the number of times the internal fan stalls or malfunctions does not meet the threshold, then the refrigerant concentration detection step will be performed.

[0033] According to this technical solution, if the air conditioner is in anti-cold air mode, the current is 0, making it impossible to determine whether the indoor fan is stalling or malfunctioning. Therefore, the system returns to the judgment step to re-evaluate whether the air conditioning system is operating. If the air conditioner is not in anti-cold air mode, and the converted current Ix < k1*I0, it indicates that the indoor fan's airflow is insufficient. Further judgment is made regarding the relationship between the converted current Ix and the current threshold, which is based on the UL60335 standard and corresponds to the current value at the minimum airflow. If the converted current Ix is not less than the current threshold, it indicates that the airflow is acceptable, and the refrigerant detection step is executed. If the converted current Ix is less than the current threshold, it indicates insufficient airflow, and the indoor fan is stalling or malfunctioning. Further, it is determined whether the number of times the indoor fan has stalled or malfunctioned exceeds a threshold. If it exceeds the threshold but the air conditioning system is still operating normally, it indicates no refrigerant leakage. In this case, the system is stopped and inspected to eliminate potential safety hazards. If the number of times does not exceed the threshold, the refrigerant concentration detection step is executed.

[0034] In an optional technical solution of the present invention, determining whether a static pressure fault exists includes:

[0035] Determine whether the converted current Ix is not less than k2*I0, where k2>k1;

[0036] If the converted current Ix is not less than k2*I0, then there is a static pressure fault in the output. It is recommended to switch the fan speed and perform the refrigerant concentration detection procedure.

[0037] If the converted current Ix is less than k2*I0, then the refrigerant concentration detection step is executed.

[0038] According to this technical solution, when the converted current Ix is not less than k2*I0, it indicates a mismatch between the current and the fan speed, and the static pressure of the indoor fan is outside its maximum operating range, resulting in an output static pressure fault. It is recommended to switch the fan speed, allowing the system to operate without shutting down, thus improving the reliability of the air conditioning system. Specifically, switching the fan speed refers to adjusting the fan speed according to the actual situation. 。 If the fan speed is at its lowest setting, it is recommended to increase it. If the fan speed is at its highest setting, maintain that setting. If the converted current Ix is less than k2*I0, it indicates that the airflow is low. In this case, perform a refrigerant concentration test. Based on the test results, the airflow of the indoor fan can be adjusted promptly to ensure user safety.

[0039] The optional technical solutions of the present invention also include:

[0040] Check whether the indoor and outdoor units of the air conditioning system are in communication mode;

[0041] If the indoor unit and the outdoor unit are in communication mode, control the indoor fan to the highest speed and turn off the outdoor unit;

[0042] If the indoor unit and outdoor unit are not in communication mode, then control and adjust the indoor fan to the highest fan speed.

[0043] According to this technical solution, the indoor and outdoor units communicate in different ways and adopt different control schemes, which improves the control flexibility of the air conditioning system.

[0044] In another aspect, the present invention provides an air conditioning system and a control method for operating the air conditioning system described above. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the outdoor unit structure of the air conditioning system in an embodiment of the present invention.

[0046] Figure 2 This is a schematic diagram of the indoor unit structure of the air conditioning system in an embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram of the control method of the air conditioning system in an embodiment of the present invention.

[0048] Figure 4 This is a schematic diagram of the specific control method of the air conditioning system in an embodiment of the present invention.

[0049] Figure label:

[0050] Outdoor unit 1; compressor 11; four-way valve 12; outdoor heat exchanger 13; throttle valve 14; gas-liquid separator 15; first shut-off valve 16; second shut-off valve 17; indoor unit 2; indoor heat exchanger 21; indoor fan 22; indoor electrical control board 23; refrigerant sensor 24; indoor temperature sensor 25. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0052] like Figure 1 , Figure 2 As shown, this embodiment provides a control method for an air conditioning system. The air conditioning system includes an outdoor unit and an indoor unit. The outdoor unit 1 includes a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, a throttle valve 14, a gas-liquid separator 15, a first shut-off valve 16, and a second shut-off valve 17. The indoor unit 2 includes an indoor heat exchanger 21, an indoor fan 22, and an indoor electronic control board 23. The compressor 11, the four-way valve 12, the outdoor heat exchanger 13 or the indoor heat exchanger 21, the throttle valve 14, the indoor heat exchanger 21 or the outdoor heat exchanger 13, and the gas-liquid separator 15 are connected sequentially through pipelines to form a refrigerant circulation. The first shut-off valve 16 is located between the throttle valve and the indoor heat exchanger 21, and the second shut-off valve 17 is located between the indoor heat exchanger and the gas-liquid separator 15. The four-way valve 12 is used to change the flow direction of the refrigerant, so that the refrigerant at the outlet of the compressor 11 is connected to the indoor heat exchanger 21 or the outdoor heat exchanger 13. Furthermore, the indoor unit also includes a refrigerant sensor 24 and an indoor temperature sensor 25, which are used to detect the refrigerant concentration and the indoor ambient temperature, respectively.

[0053] like Figure 3 As shown, the control methods for the air conditioning system include:

[0054] The refrigerant concentration detection procedure involves detecting the refrigerant concentration M1 in the indoor environment.

[0055] The system controls the operation of the air conditioning system by comparing the refrigerant concentration M1 with the concentration threshold M0. If the refrigerant concentration M1 is less than the concentration threshold M0, it indicates no refrigerant leakage, and the air conditioning system operates normally. If the refrigerant concentration M1 is not less than the concentration threshold M0, it indicates a refrigerant leak. By controlling the fan speed of the indoor fan 22 to the highest setting, the airflow can be increased, quickly diluting the refrigerant to a safe concentration. Furthermore, if the indoor and outdoor units can communicate, in addition to increasing the fan speed of the indoor fan 22, the outdoor unit can also be shut down to prevent the refrigerant from continuing to flow and exacerbating the leak, thus preventing the refrigerant concentration in the indoor environment from continuing to increase. If the indoor and outdoor units cannot communicate, the refrigerant can be diluted by adjusting the fan speed of the indoor fan 22.

[0056] Furthermore, to ensure that the indoor fan 22 can operate normally to dilute the refrigerant concentration in the event of a refrigerant leak, it is necessary to monitor the operating status of the indoor fan 22 to ensure its normal operation. In this embodiment, before performing the refrigerant concentration detection step, the control method of the air conditioning system further includes:

[0057] Testing steps: Detect the indoor ambient temperature T1, the voltage U1 and current I of the indoor fan 22, i.e., the actual indoor ambient temperature, actual voltage and actual current;

[0058] Data processing steps: Calculate the temperature influence coefficient a based on the indoor ambient temperature T1, and calculate the voltage influence coefficient b based on the voltage U1;

[0059] Judgment steps: Determine whether the air conditioning system meets the requirements for being in operation;

[0060] If the judgment result of the judgment step is yes, then the conversion, comparison, and judgment steps are executed; if the judgment result of the judgment step is no, then the conversion, comparison, and judgment steps are not executed; wherein,

[0061] The conversion, comparison, and judgment steps include: calculating the converted current Ix under the conditions of set indoor temperature T0 and set voltage U0 based on current I, temperature influence coefficient a, and voltage influence coefficient b; comparing the converted current Ix with the preset current value; and judging whether the indoor fan 22 is stalled based on the comparison result of the converted current Ix and the preset current value.

[0062] In this embodiment, by combining current I, temperature influence coefficient a, and voltage influence coefficient b to calculate the converted current Ix under the indoor ambient set temperature T0 and set voltage U0, the influence of actual indoor ambient temperature and voltage on the current can be overcome, improving the accuracy of the current data under the indoor ambient set temperature T0 and set voltage U0 conditions. The comparison between the converted current Ix and the preset current value determines whether the indoor fan 22 is stalling, improving the accuracy of the indoor fan 22 operating condition assessment. This application determines whether the indoor fan 22 is stalling by comparing the converted current Ix with the preset current, eliminating the need to consider the influence of static pressure on the airflow of the indoor fan 22, saving the use of a static pressure detector and thus saving costs. By accurately judging the operating condition of the indoor fan 22, a fault in the indoor fan 22 can be detected and addressed promptly, ensuring that the indoor fan 22 can still output air normally in the event of refrigerant leakage, diluting the refrigerant concentration, reducing safety hazards, and improving the reliability of the air conditioning system. It should be noted that in the above detection and data processing steps, this embodiment does not limit the order of obtaining and processing the current, voltage, and indoor ambient temperature parameters, as long as it does not affect the retrieval of data in subsequent processes.

[0063] In a preferred embodiment of the present invention, the converted current Ix = I / (a*b), where I is the current in the detection step. Further, the temperature influence coefficient a = 1 + m*(T1 - T0), and the voltage influence coefficient b = 1 - n*(U1 - U0), where n > 0 and n is the dependent variable of U0, and m > 0 and m is the dependent variable of T0.

[0064] In this embodiment, the temperature influence coefficient is determined by combining the difference between the indoor ambient temperature T1 and the indoor ambient set temperature T0, and the converted current Ix is determined by combining the temperature influence coefficient. This overcomes the current variation caused by the indoor ambient temperature T1 and improves the accuracy of the current data. Similarly, the voltage influence coefficient is determined by combining the difference between the actual voltage and the set voltage U0, and the converted current Ix is determined by combining the voltage influence coefficient. This overcomes the current variation caused by the voltage factor and improves the accuracy of the current data. The converted current Ix is calculated by combining the actual current, the voltage influence coefficient, and the temperature influence coefficient. This overcomes the influence of voltage and indoor ambient temperature T1 on the current, improving the accuracy of the converted current Ix and the accuracy of determining whether the indoor fan 22 is stalling, which is beneficial to improving the reliability of the air conditioning system. Furthermore, the value of m changes accordingly for different indoor ambient set temperatures T0, resulting in corresponding temperature influence coefficients for different indoor ambient set temperatures. This improves the accuracy of the converted current Ix and the accuracy of determining whether the indoor fan 22 is stalling under different indoor ambient set temperatures. The value of m changes accordingly for different set voltages U0, resulting in a corresponding voltage influence coefficient under different set voltages. This improves the accuracy of the converted current Ix under different set voltages and the accuracy of judging whether the internal fan 22 is stalling.

[0065] In a preferred embodiment of the present invention, the air conditioning system being in operation means that the air conditioning system is not in a state where the current is 0 within 3 minutes of power-on, or the air conditioning system is not in anti-cold air mode, or the air conditioning system is not in standby mode. That is, excluding any of the following situations: the air conditioning system has a current of 0 within 3 minutes of power-on, is in anti-cold air mode, or is in standby mode, the air conditioning system is considered to be in operation. By determining whether the air conditioning system is in operation, false alarms can be prevented. When the air conditioning system is in normal operation, the converted current Ix is calculated, improving the accuracy of the converted current Ix calculation and the accuracy of determining whether the indoor fan 22 is stalling.

[0066] In a preferred embodiment of the present invention, the control method further includes a preset step: preset the initial current dataset of the indoor fan 22 under different fan speeds, set static pressures, different set voltages U0, and different indoor ambient set temperatures; in the conversion, comparison, and judgment steps, the preset current value is associated with the initial current of the indoor fan 22 at the corresponding fan speed; further, it also includes identifying the fan speed of the indoor fan 22 so as to determine the initial current based on parameters such as the fan speed.

[0067] By linking the preset current value with the initial current in the above manner, and by pre-setting the initial current dataset of the indoor fan 22 under different fan speeds, set static pressures, different set voltages U0, and different indoor ambient temperatures, the accuracy of the preset current value under different operating conditions can be improved. Furthermore, since the static pressure is a set value, the use of a static pressure detector can be reduced, eliminating the influence of static pressure on the current, thus lowering costs while ensuring accuracy. By pre-setting different fan speeds, corresponding initial currents and preset current values ​​are provided for each speed, improving the accuracy of determining whether the indoor fan 22 is stalling by comparing the converted current Ix with the preset current value.

[0068] In a preferred embodiment of the present invention, determining whether the internal fan 22 has stalled based on the comparison between the converted current Ix and the preset current value includes:

[0069] Determine whether the converted current Ix is not less than k1*I0, where I0 is the initial current of the corresponding fan speed at the set static pressure, 0 < k1 < 1, such as K1 = 95%, where 95% is the margin left to account for current fluctuations; it should be noted that I0 is the initial current of the corresponding fan speed, preferably the initial current value taken when the set static pressure, set voltage U0 and indoor ambient set temperature T0 in the current data set are the same as the indoor ambient set temperature, set voltage and set static pressure of the current air conditioning system.

[0070] If the converted current Ix is not less than k1*I0, then the output indoor fan 22 is normal and has not stalled; and determine whether there is a static pressure fault; if the converted current Ix is less than k1*I0, determine whether there is a stall or abnormal fault of the indoor fan 22 in the air conditioning system.

[0071] In this embodiment, if the converted current Ix is not less than k1*I0, it indicates that the air volume is normal, the indoor fan 22 is normal and not stalled, and further judgment is needed to determine whether there is a static pressure fault. This can promptly detect the problem of mismatch between the fan speed and the current, ensuring the reliability of the air conditioning system. If the converted current Ix is less than k1*I0, it indicates that the air volume is insufficient, and the indoor fan 22 may have stalled or malfunctioned. Therefore, further judgment is needed to determine whether the indoor fan 22 has indeed stalled or malfunctioned, improving the accuracy of the judgment on the indoor fan 22.

[0072] In a preferred embodiment of the present invention, whether the air conditioning system has a stall or abnormal malfunction of the indoor fan 22 includes:

[0073] Determine if the air conditioning system is in anti-cold air mode;

[0074] If the air conditioning system is in anti-cold air mode, then proceed with the judgment steps;

[0075] If the air conditioning system is not in anti-cold air mode, the output indoor fan 22 will stall or malfunction; and it will be determined whether the converted current Ix is not less than the current threshold.

[0076] If the converted current Ix is not less than the current threshold, then the refrigerant concentration detection step is performed;

[0077] If the converted current Ix is less than the current threshold, then determine whether the number of times the internal fan 22 stalls or has an abnormal fault meets the number threshold.

[0078] If the number of times the indoor fan 22 stalls or malfunctions meets the threshold, the air conditioning system will be shut down; if the number of times the indoor fan 22 stalls or malfunctions does not meet the threshold, the refrigerant concentration detection step will be executed.

[0079] In this embodiment, if the air conditioner is in anti-cold air mode, the current is 0, and it is impossible to determine whether the indoor fan 22 is stalled or malfunctioning. Therefore, the system returns to the judgment step to determine whether the air conditioning system is running. If the air conditioner is not in anti-cold air mode and the converted current Ix < k1*I0, it indicates that the airflow of the indoor fan 22 is insufficient. The system further judges the relationship between the converted current Ix and the current threshold. The current threshold is the UL60335 standard, which corresponds to the current value under the minimum airflow. If the converted current Ix is not less than the current threshold, it indicates that the airflow is acceptable, and the refrigerant concentration detection step is executed. If the converted current Ix is less than the current threshold, it indicates that the airflow is insufficient, and the indoor fan 22 is stalled or malfunctioning. Furthermore, it is judged whether the number of times the indoor fan 22 stalls or malfunctions exceeds the number threshold. If it exceeds the number threshold, but the air conditioning system is still running normally, it indicates that there is no refrigerant leakage. At this time, the system is stopped for inspection and cannot be restarted without power failure to eliminate safety hazards. If the number does not exceed the number threshold, the refrigerant concentration detection step is executed.

[0080] In a preferred embodiment of the present invention, determining whether a static pressure fault exists includes:

[0081] Determine whether the converted current Ix is not less than k2*I0, k2>k1. Specifically, K2=150%, which is the ratio of the current value of the maximum static pressure in the static pressure range (0-200pa) under this windshield to the current value under the set static pressure of 0pa, and leaves a fluctuation margin.

[0082] If the converted current Ix is not less than k2*I0, then there is a static pressure fault in the output. It is recommended to switch the fan speed and perform the refrigerant concentration detection procedure.

[0083] If the converted current Ix is less than k2*I0, then the refrigerant concentration detection step is executed.

[0084] Using the above method, if the converted current Ix is not less than k2*I0, it indicates a mismatch between the current and the fan speed, and the indoor fan's static pressure is outside its maximum operating range, resulting in an output static pressure fault. It is recommended to switch the fan speed, allowing the system to operate without shutting down, thus improving the reliability of the air conditioning system. Specifically, switching the fan speed means adjusting the fan speed according to the actual situation. 。 If the fan speed is at its lowest setting, it is recommended to increase the fan speed; if it is at its highest setting, maintain the highest setting. In this embodiment, a static pressure fault can be displayed, suggesting a fan speed switch to remind manual operation and prevent automatic fan speed switching from causing malfunctions, thus improving the reliability of the air conditioner. If the converted current is less than k2*I0, it indicates that the airflow is low. A refrigerant concentration detection step should be performed, and the airflow of the indoor fan 22 can be adjusted promptly based on the concentration detection results to ensure user safety.

[0085] Example

[0086] like Figure 4 As shown, this embodiment provides a control method for an air conditioning system, including:

[0087] Step S1: First, detect the indoor ambient temperature T1, then convert the indoor ambient temperature T1 into a temperature influence coefficient a, where a = 1 + m * (T1 - T0), and m is the unit temperature change coefficient. The meanings of T1 and T0 are the same as above and will not be repeated here. This formula is derived for the same motor, the same fan speed, and the same static pressure, with the only variable being the indoor ambient temperature. For some indoor fans 22, this coefficient m = 0.0025, and T0 = 25℃. It should be noted that the temperature influence coefficient a and the coefficient m will change according to the set indoor ambient temperature T0.

[0088] In step S2, the indoor electrical control board 23 detects the voltage U1 of the indoor fan 22 and converts it into a voltage influence coefficient b, where b = 1 - n * (U1 - U0), and n is the unit voltage change coefficient. The meanings of U1 and U0 are the same as above and will not be repeated here. This formula is derived for the same motor, the same fan speed, and the same static pressure, with the only variable being the supply voltage. For some indoor fans 22, this coefficient n is 0.002, and U0 = 230V. It should be noted that the formula b and the coefficient n will change according to the set voltage U0.

[0089] Step S3: Identify the gear position of the internal fan 22.

[0090] During machine development and software parameter setting, input the initial current values ​​I1, I2, I3, I4, and I5 for each fan speed under static pressure c Pa. c represents the set static pressure. If c = 0, the static pressure value can be set according to actual conditions. This implementation example uses a static pressure of 0 Pa. I1 is the current value at fan speed 1, 0 Pa static pressure, 230V rated voltage, and temperature T0. Similarly, I2 is the current value at fan speed 2, 0 Pa static pressure, 230V rated voltage, and temperature T0. I3 is the current value at fan speed 3, 0 Pa static pressure, 230V rated voltage, and temperature T0. I4 is the current value at fan speed 4, 0 Pa static pressure, 230V rated voltage, and temperature T0. I5 is the current value at fan speed 5, 0 Pa static pressure, 230V rated voltage, and temperature T0. For different air conditioning products, the number of fan speeds may vary. If there are more or fewer fan speeds, they can be increased or decreased according to actual conditions; this implementation does not limit this.

[0091] Step S4: Detect the current I of the indoor fan 22. Determine if I = 0, and the current must be within 3 minutes of power-on, or in anti-cold air mode, or in standby mode. If satisfied, proceed to step S8. If not satisfied, convert the current value Ix to the set voltage U0 and set indoor temperature T0 based on the voltage U1 and indoor ambient temperature T1, where Ix = I / (a*b).

[0092] Step S5: Based on the corresponding fan speed setting, determine if Ix ≥ 95% * I0, where I0 is the current value at 0 Pa static pressure under the corresponding fan speed setting. 95% is a margin to account for fluctuations. If Ix ≥ 95% * I0 is satisfied, proceed to step S6, indicating that the internal fan 22 is operating normally and has not stalled. If Ix ≥ 95% * I0 is not satisfied, proceed to step S10.

[0093] Step S6: The internal fan 22 is normal and has not stalled; then determine if Ix ≥ 150% * I0. If Ix ≥ 150% * I0, proceed to step S7. If Ix ≥ 150% * I0 is not satisfied, proceed to step S8.

[0094] Step S7: The indoor electrical control board 23 displays a static pressure abnormality fault. It is recommended to switch to a higher fan speed and proceed to step S8.

[0095] Step S8: Detect the refrigerant concentration M1. Determine if M1 > M0. If so, operate normally and proceed to step S1 to complete one cycle. If not, proceed to step S9.

[0096] Step S9: Check if the indoor unit's DIP switch mode is set to 485. If so, the indoor unit 2 and outdoor unit 1 are in communication mode. In this case, the indoor fan 22 needs to be turned on to its maximum speed, and the outdoor unit should be turned off. If not, the indoor unit 2 and outdoor unit 1 are in 24V non-communication mode. In this case, the indoor control board 23 cannot control the outdoor unit 1 and can only turn the indoor fan 22 to its maximum speed to dilute the R454B refrigerant into the indoor air to prevent it from accumulating and causing an explosion.

[0097] Step S10: Determine if the air conditioning system is in anti-cold air mode. If it is in anti-cold air mode, proceed to step S4. If not, the indoor fan 22 is found to be stalled or malfunctioning. Determine if Ix ≥ Im, where Im is the current value corresponding to the minimum airflow according to UL60335 standard. If this condition is met, proceed to step S8. If not, proceed to step S11.

[0098] Step S11: Determine if the number of times the indoor fan 22 stalls or experiences abnormal malfunctions is greater than or equal to 3. If it does, it proves that the indoor fan 22 does indeed have a problem and needs repair. Since the number of times it has stalled or experienced abnormal malfunctions is 3, logically it proves that the air conditioning system is operating normally and there is no refrigerant leakage. At this point, the system needs to be shut down for repair of the indoor fan 22. It cannot be restored without a power outage to eliminate potential safety hazards.

[0099] In another aspect, this invention provides an air conditioning system and a control method for operating the aforementioned air conditioning system. The air conditioning system operating the above control method improves the accuracy of the current data of the indoor fan 22 under the conditions of a set indoor temperature T0 and a set voltage U0. By comparing the calculated current Ix with the preset current value, it determines whether the indoor fan 22 is stalling, improving the accuracy of judging the operating condition of the indoor fan 22. This allows for timely detection and handling of indoor fan 22 malfunctions, ensuring that the indoor fan 22 can still output air normally in the event of refrigerant leakage, diluting the refrigerant concentration, reducing safety hazards, and improving the reliability of the air conditioning system. This application determines whether the indoor fan 22 is stalling by comparing the calculated current Ix with the preset current, eliminating the need to consider the influence of static pressure on the airflow of the indoor fan 22, saving the use of a static pressure detector and thus reducing costs.

[0100] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for an air conditioning system, the air conditioning system including an indoor fan, the control method comprising: The refrigerant concentration detection step is characterized in that the control method further includes: performing the following steps before executing the refrigerant concentration detection step: Testing steps: Test the indoor ambient temperature, the voltage and current of the indoor fan; Data processing steps: Calculate the temperature influence coefficient a based on the indoor ambient temperature; calculate the voltage influence coefficient b based on the voltage. Judgment Step: Determine whether the air conditioning system is in operation; If the judgment result of the judgment step is yes, then the conversion, comparison, and judgment steps are executed; if the judgment result of the judgment step is no, then the conversion, comparison, and judgment steps are not executed; wherein, the conversion, comparison, and judgment steps include: Based on the current, the temperature influence coefficient, and the voltage influence coefficient, calculate the converted current Ix under the set indoor temperature and voltage conditions; compare the converted current Ix with the preset current value, and determine whether the indoor fan is stalling based on the comparison result. The control method further includes: Preset steps: Preset the initial current dataset of the indoor fan under different fan speeds, set static pressures, different set voltages, and different indoor ambient temperatures; In the conversion, comparison and judgment steps, the preset current value is related to the initial current of the internal fan at the corresponding fan speed. The step of determining whether the internal fan is stalling based on the comparison result between the converted current Ix and the preset current value includes: Determine if the converted current Ix is not less than k1 I0, where I0 is the initial current of the corresponding windshield under the set static pressure, 0 < k1 < 1; If the converted current Ix is not less than k1 If I0 is detected, the internal fan is normal and not stalled; and it is also determined whether there is a static pressure fault. If the converted current Ix is less than k1 I0, determine whether the air conditioning system has an internal fan stall or abnormal fault; Whether the air conditioning system has an indoor fan stall or abnormal malfunction includes: Determine whether the air conditioning system is in anti-cold air mode; If the air conditioning system is in anti-cold air mode, then the judgment step is executed; If the air conditioning system is not in anti-cold air mode, output the internal fan stall or abnormal fault; and determine whether the converted current Ix is not less than the current threshold. If the converted current Ix is not less than the current threshold, then the refrigerant concentration detection step is performed; If the converted current Ix is less than the current threshold, then determine whether the number of times the internal fan stalls or abnormal faults meets the number threshold. If the number of times the internal fan stalls or malfunctions meets the threshold, the air conditioning system is shut down. If the number of times the internal fan stalls or malfunctions does not meet the threshold, then the refrigerant concentration detection step is executed.

2. The control method for the air conditioning system according to claim 1, characterized in that, The converted current Ix = I / (a b), where I is the current in the detection step.

3. The control method for the air conditioning system according to claim 2, characterized in that, The temperature influence coefficient a = 1 + m (T1 T0), where T1 is the indoor ambient temperature in the detection step, T0 is the indoor ambient set temperature, m>0, and m is the dependent variable of T0.

4. The control method for the air conditioning system according to claim 2, characterized in that, The voltage influence coefficient b = 1 n (U1 U0), where U1 is the voltage in the detection step, U0 is the set voltage, n>0, and n is the dependent variable of U0.

5. The control method for an air conditioning system according to claim 2, characterized in that, The determination of whether a static pressure fault exists includes: Determine whether the converted current Ix is not less than k2. I0, k2 > k1; If the converted current Ix is not less than k2 If I0 is detected, a static pressure fault is output. It is recommended to switch the fan speed and perform the refrigerant concentration detection steps described above. If the converted current Ix is less than k2 If I0, then the refrigerant concentration detection step is executed.

6. The control method for an air conditioning system according to claim 1, characterized in that, Also includes: Check whether the indoor and outdoor units of the air conditioning system are in communication mode; If the indoor unit and the outdoor unit are in communication mode, then the indoor fan is controlled and adjusted to the highest fan speed, and the outdoor unit is turned off; If the indoor unit and the outdoor unit are in non-communication mode, then control and adjust the indoor fan to the highest fan speed.

7. An air conditioning system, characterized in that, A control method for operating an air conditioning system according to any one of claims 1 to 6.

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