A control method and device of an independent variable frequency outdoor unit and an air conditioner

Abstract

The application provides a control method and device of an independent variable frequency outdoor unit and an air conditioner. The control method of the independent variable frequency outdoor unit comprises the following steps: acquiring a connection pipe size and a real-time running frequency of a compressor; simulating an inner disc temperature according to the connection pipe size and the real-time running frequency of the compressor; determining a frequency correction coefficient according to a temperature difference between the inner disc temperature and a target inner disc temperature; and correcting a target frequency according to the frequency correction coefficient. The application solves the problem that the air conditioner unit control is not accurate, comfortable and energy-saving due to the fact that a pressure sensor is added at the gas return end of the compressor, the inner disc temperature data of the indoor unit is simulated through the pressure value, and 24V and 485 communication are taken into account.

Description

Technical Field

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

[0002] Most existing air conditioners use RS-485 communication control, while some international markets use a separate 24V outdoor unit control system. This system uses 24V AC on / off signals to control the outdoor unit's operation, allowing for flexible pairing with different third-party indoor units. However, with 24V communication control, only on / off signals can be transmitted between the indoor and outdoor units. Compared to RS-485 communication control, this method cannot perform inverter control on the outdoor unit. To address this issue, existing 24V communication air conditioners cannot perform inverter control on the outdoor unit. A pressure sensor is added to the compressor's return gas end to simulate indoor unit temperature data using pressure readings, thus balancing both 24V and RS-485 communication.

[0003] However, due to the target low-pressure closed-loop control, the pressure value and the temperature of the indoor unit are greatly affected by other factors, resulting in insufficient accuracy, comfort and energy saving in actual control. In addition, the pressure sensor is expensive, making it uneconomical. Summary of the Invention

[0004] To address the issue of insufficient precision, comfort, and energy efficiency in air conditioning unit control caused by 24V and 485 communication, which requires adding a pressure sensor to the compressor's return gas end to simulate indoor unit temperature data using pressure values, this invention provides a control method for an independent inverter outdoor unit. The control method includes: acquiring the connecting pipe dimensions and the compressor's real-time operating frequency; simulating and calculating the indoor unit temperature based on the connecting pipe dimensions and the compressor's real-time operating frequency; determining a frequency correction coefficient based on the temperature difference between the measured indoor unit temperature and a target indoor unit temperature; and correcting the target frequency based on the frequency correction coefficient.

[0005] Compared to existing technologies, this technical solution achieves the following advantages: By acquiring the connecting pipe dimensions and the compressor's real-time operating frequency, the corresponding inner panel temperature can be simulated and calculated based on these parameters, thus accommodating both 24V and 485 communication and expanding the unit's applicability. Compared to simulating the inner panel temperature data using pressure values, this method offers higher adjustment accuracy, greater comfort, and energy savings. Furthermore, since no pressure sensor is required, it reduces overall unit cost and improves economic efficiency.

[0006] In one embodiment of the present invention, the connecting pipe size includes the connecting pipe length and the connecting pipe diameter; the step of simulating and calculating the inner disk temperature based on the connecting pipe size and the real-time operating frequency of the compressor includes: determining a connecting pipe size correction value based on the connecting pipe length, the standard length of the connecting pipe, and the connecting pipe diameter; determining a compressor real-time operating frequency correction value based on the compressor real-time operating frequency and the compressor minimum operating frequency; and simulating and calculating the inner disk temperature based on the connecting pipe size correction value, the compressor real-time operating frequency correction value, and a reference inner disk temperature value; wherein, T 模拟低压 =T0-T1-T2; T 模拟低压 T1 is the inner plate temperature; T0 is the reference inner plate temperature value; T1 is the connecting pipe size correction value; T2 is the compressor real-time operating frequency correction value.

[0007] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: Calculations based on thermodynamic theory show that the refrigerant friction resistance h... f =λ*(l / d)*(v 2 / 2g); where λ is the friction coefficient). Therefore, the main factors affecting suction pressure, i.e., the inner disk temperature, are refrigerant velocity v, connecting pipe length l, and connecting pipe diameter d. The compressor operating frequency directly affects the refrigerant velocity, so the main factors affecting suction pressure, i.e., the inner disk temperature decay, are compressor operating frequency f, connecting pipe length l, and connecting pipe diameter d. Therefore, the simulated inner disk temperature T can be obtained by determining a baseline inner disk temperature value, then simulating and calculating the connecting pipe size correction value based on the connecting pipe length, standard connecting pipe length, and connecting pipe diameter; simulating and calculating the compressor real-time operating frequency correction value based on the compressor's real-time operating frequency and minimum operating frequency; and finally correcting the baseline inner disk temperature value based on the simulated connecting pipe size correction value and the compressor's real-time operating frequency correction value. 模拟低压 This refers to the internal temperature corresponding to the target low pressure under cooling conditions, which makes the temperature control accuracy of the air conditioning unit more precise and detailed, thus improving comfort.

[0008] In one embodiment of the present invention, the connecting pipe size correction value is positively correlated with the connecting pipe length; the connecting pipe size correction value is negatively correlated with the connecting pipe diameter.

[0009] Compared with existing technologies, the technical effects achieved by this solution are as follows: the longer the connecting pipe, the greater the friction resistance, and therefore the larger the correction value for the connecting pipe size, resulting in a higher simulated inner disc temperature T. 模拟低压 The smaller the diameter of the connecting pipe, the smaller the friction resistance; therefore, the smaller the correction value for the connecting pipe size, and the smaller the simulated inner disk temperature T. 模拟低压 The larger it is.

[0010] In one embodiment of the present invention, the step of determining the connecting pipe size correction value based on the connecting pipe length, the standard length of the connecting pipe, and the connecting pipe diameter includes: T1 = a*(l-l0) / d; where a is the connecting pipe size correction coefficient; l is the connecting pipe length; l0 is the standard length of the connecting pipe; and d is the connecting pipe diameter.

[0011] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: when the length l of the connecting pipe is the standard length l0, the length and diameter of the connecting pipe have a significant impact on T. 模拟低压 The impact is relatively small and requires no correction. When the connecting pipe length l is greater than the standard connecting pipe length l0, the longer the connecting pipe length l, the greater the friction resistance, and therefore the larger the connecting pipe size correction value; the larger the connecting pipe diameter, the smaller the friction resistance, and therefore the smaller the connecting pipe size correction value. Since the connecting pipe length has a greater impact on the connecting pipe size correction value T1 than the connecting pipe diameter, we set l-l0 as the numerator and d as the denominator, defining a*(l-l0) / d to simulate the effect of the connecting pipe size on T1. 模拟低压 The impact.

[0012] In one embodiment of the present invention, the diameter of the connecting pipe is calculated as d = d1 + d2; where d is the diameter of the connecting pipe; d1 is the diameter of the connecting pipe at both ends of the high-pressure shut-off valve; and d2 is the diameter of the connecting pipe at both ends of the low-pressure shut-off valve.

[0013] Compared with existing technologies, the technical effects achieved by adopting this technical solution are as follows: As can be seen from the schematic diagram of the air conditioning unit, the two ends of the high-pressure shut-off valve are connected to the first connecting pipe, and the two ends of the low-pressure shut-off valve are connected to the second connecting pipe. Therefore, the pipe diameter d of the air conditioning unit is calculated as the sum of the pipe diameter d1 of the connecting pipe at both ends of the high-pressure shut-off valve and the pipe diameter d2 of the connecting pipe at both ends of the low-pressure shut-off valve.

[0014] In one embodiment of the present invention, the real-time operating frequency correction value of the compressor is positively correlated with the real-time operating frequency of the compressor.

[0015] Compared with existing technologies, the technical effects achieved by this solution are as follows: the higher the real-time operating frequency of the compressor, the greater the refrigerant friction resistance, the larger the real-time operating frequency correction value of the compressor, and the higher the simulated internal disk temperature T. 模拟低压 The smaller it is.

[0016] In one embodiment of the present invention, determining the compressor real-time operating frequency correction value based on the compressor real-time operating frequency and the compressor minimum operating frequency includes: T2 = b*(ff) min ) / f min Where T2 is the real-time operating frequency correction value of the compressor; b is the compressor frequency correction coefficient; f is the real-time operating frequency of the compressor; f minThe minimum operating frequency of the compressor; f ≥ f min .

[0017] Compared with existing technologies, the technical effects achieved by adopting this technical solution are: by defining (ff) min ) / f min The ratio of the compressor's current operating frequency to its minimum operating frequency is used to simulate the effect of the compressor's operating frequency on T. 模拟低压 The influence relationship is multiple, thus enabling b*(ff) min ) / f min The real-time operating frequency correction value T2 of the compressor was calculated through simulation.

[0018] In one embodiment of the present invention, when the length of the connecting pipe is the standard length of the connecting pipe, and the diameters of the connecting pipes at both ends of the high-pressure shut-off valve and the low-pressure shut-off valve are the standard diameters of the connecting pipes, when the air conditioning unit is running under rated cooling conditions and the compressor is operating at its minimum frequency, the corresponding actual inner wall temperature value of the air conditioning unit is taken as the reference inner wall temperature value.

[0019] Compared with existing technologies, the technical effects achieved by this solution are as follows: When the length of the connecting pipe is the standard length, and the diameters of the connecting pipes at both ends of the high-pressure shut-off valve and the low-pressure shut-off valve are the standard diameters, the air conditioning unit, under rated cooling conditions and running at the compressor's minimum frequency, is essentially at its minimum cooling capacity output, with the highest outlet air temperature and the highest inner wall temperature. Therefore, based on this, the actual inner wall temperature value of the air conditioning unit at this time is taken as the benchmark inner wall temperature value. Increasing the connecting pipe length l, decreasing the connecting pipe diameter d, and increasing the compressor frequency f all affect T. 模拟低压 Perform negative correction.

[0020] This invention provides a control device for an independent variable frequency outdoor unit. The control device implements any of the control methods described above. The control device includes: an acquisition module for acquiring the connecting pipe size and the real-time operating frequency of the compressor; a simulation calculation module for simulating and calculating the inner disk temperature based on the connecting pipe size and the real-time operating frequency of the compressor; a determination module for determining a frequency correction coefficient based on the temperature difference between the inner disk temperature and the target inner disk temperature; and a correction module for correcting the target frequency based on the frequency correction coefficient.

[0021] This invention provides an air conditioner, including a controller, which executes an executable program to implement any of the control methods for an independent inverter outdoor unit as described above.

[0022] By adopting the technical solution of the present invention, the following technical effects can be achieved:

[0023] (1) By acquiring the connecting pipe size and the compressor's real-time operating frequency, the corresponding inner plate temperature can be simulated and calculated based on the connecting pipe size and the compressor's real-time operating frequency, thus accommodating both 24V and 485 communication and expanding the unit's applicability. Compared to simulating the inner plate temperature data of the indoor unit through pressure values, the adjustment accuracy is higher, resulting in greater comfort and energy savings; furthermore, since no pressure sensor is required, the overall cost and economy are reduced.

[0024] (2) According to thermodynamic calculations, the frictional resistance h of the refrigerant is... f =λ*(l / d)*(v 2 / 2g); where λ is the friction coefficient). Therefore, the main factors affecting suction pressure, i.e., the inner disk temperature, are refrigerant velocity v, connecting pipe length l, and connecting pipe diameter d. The compressor operating frequency directly affects the refrigerant velocity, so the main factors affecting suction pressure, i.e., the inner disk temperature decay, are compressor operating frequency f, connecting pipe length l, and connecting pipe diameter d. Therefore, the simulated inner disk temperature T can be obtained by determining a baseline inner disk temperature value, then simulating and calculating the connecting pipe size correction value based on the connecting pipe length, standard connecting pipe length, and connecting pipe diameter; simulating and calculating the compressor real-time operating frequency correction value based on the compressor's real-time operating frequency and minimum operating frequency; and finally correcting the baseline inner disk temperature value based on the simulated connecting pipe size correction value and the compressor's real-time operating frequency correction value. 模拟低压 This refers to the internal temperature corresponding to the target low pressure under cooling conditions, which makes the temperature control accuracy of the air conditioning unit more precise and detailed, thus improving comfort.

[0025] (3) When the length of the connecting pipe is the standard length, and the diameters of the connecting pipes at both ends of the high-pressure shut-off valve and the low-pressure shut-off valve are the standard diameters, the air conditioning unit, under rated cooling conditions, operates at its minimum compressor frequency during testing. At this point, the air conditioning unit is essentially at its minimum cooling capacity output, with the highest outlet air temperature and the highest internal wall temperature. Therefore, based on this, the actual internal wall temperature value of the air conditioning unit at this time is taken as the benchmark internal wall temperature value. Increasing the connecting pipe length l, decreasing the connecting pipe diameter d, and increasing the compressor frequency f all affect T. 模拟低压 Perform negative correction. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating a control method for an independent variable frequency outdoor unit provided by the present invention.

[0027] Figure 2 This is a schematic diagram of the air conditioning unit.

[0028] Figure 3This is a schematic diagram of the control device for an independent variable frequency outdoor unit.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100. Air conditioning unit; 1. Evaporator; 2. Centrifugal fan; 3. Low-pressure shut-off valve; 4. High-pressure shut-off valve; 5. Gas separator; 6. Electronic expansion valve; 7. Variable frequency compressor; 8. High-pressure switch; 9. Condenser; 11. Inner panel temperature sensor; 12. Indoor temperature sensor; 13. Return gas temperature sensor; 14. Outdoor temperature sensor; 15. Condenser tube temperature sensor; 16. Exhaust temperature sensor; 17. Outer panel temperature sensor; 21. Low-pressure shut-off valve connecting pipe; 22. High-pressure shut-off valve connecting pipe. Detailed Implementation

[0031] 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.

[0032] See Figure 1 This is a flowchart illustrating a control method for an independent variable frequency outdoor unit provided by the present invention. The control method for the independent variable frequency outdoor unit includes, for example, the following steps: S10: obtaining the connecting pipe size and the real-time operating frequency of the compressor; S20: simulating and calculating the inner plate temperature based on the connecting pipe size and the real-time operating frequency of the compressor; S30: determining a frequency correction coefficient based on the temperature difference between the inner plate temperature and the target inner plate temperature; S40: correcting the target frequency based on the frequency correction coefficient.

[0033] Understandably, by obtaining the connecting pipe dimensions and the compressor's real-time operating frequency, the corresponding inner panel temperature can be simulated and calculated based on these parameters. This allows for both 24V and 485 communication, expanding the unit's applicability. Compared to simulating the inner panel temperature data using pressure values, this method offers higher adjustment accuracy, greater comfort, and energy savings. Furthermore, since no pressure sensor is required, it reduces overall unit cost and improves economic efficiency.

[0034] In one specific embodiment, ΔT evaporation temperature difference = T target low pressure for cooling - T simulated low pressure; where T simulated low pressure is a variable experimental simulation value, equivalent to the corresponding inner plate temperature of the evaporator; T target low pressure for cooling is the target inner plate temperature, the preferred value of which is 7℃-10℃. The frequency correction method for the temperature difference ΔT evaporation temperature difference is shown in the following table:

[0035]

[0036] The target frequency is calculated as follows: target frequency = previous target frequency + current target frequency × ΔF (target correction frequency). Specifically, the frequency correction cycle Δt = [30, 90] s, with a preferred value of 30 s. The target frequency is calculated by rounding off the top air outlet controller.

[0037] Furthermore, the connecting pipe dimensions include the connecting pipe length and the connecting pipe diameter; the step of simulating and calculating the inner disk temperature based on the connecting pipe dimensions and the compressor's real-time operating frequency includes: determining a connecting pipe dimension correction value based on the connecting pipe length, the standard connecting pipe length, and the connecting pipe diameter; determining a compressor real-time operating frequency correction value based on the compressor's real-time operating frequency and the compressor's minimum operating frequency; and simulating and calculating the inner disk temperature based on the connecting pipe dimension correction value, the compressor real-time operating frequency correction value, and the reference inner disk temperature value; wherein, T 模拟低压 =T0-T1-T2; T 模拟低压 T1 is the inner plate temperature; T0 is the reference inner plate temperature value; T1 is the connecting pipe size correction value; T2 is the compressor real-time operating frequency correction value.

[0038] For example, an air conditioning unit 100 may include: an evaporator 1, a centrifugal fan 2, a low-pressure shut-off valve 3, a high-pressure shut-off valve 4, a gas separator 5, an electronic expansion valve 6, a variable frequency compressor 7, a high-pressure switch 8, and a condenser 9; an inner wall temperature sensor 11, an indoor temperature sensor 12, a return air temperature sensor 13, an outdoor temperature sensor 14, a condenser middle pipe temperature sensor 15, an exhaust temperature sensor 16, and an outer wall temperature sensor 17. A low-pressure shut-off valve connecting pipe 21 is provided at the low-pressure shut-off valve 3, and a high-pressure shut-off valve connecting pipe 22 is provided at the high-pressure shut-off valve 4. The dimensions of these connecting pipes refer to the dimensions of the low-pressure shut-off valve connecting pipe 21 and the high-pressure shut-off valve connecting pipe 22.

[0039] It is understandable that, according to thermodynamic calculations, the frictional resistance h of the refrigerant is... f =λ*(l / d)*(v 2 / 2g); where λ is the friction coefficient). Therefore, the main factors affecting suction pressure, i.e., the inner disk temperature, are refrigerant velocity v, connecting pipe length l, and connecting pipe diameter d. The compressor operating frequency directly affects the refrigerant velocity, so the main factors affecting suction pressure, i.e., the inner disk temperature decay, are compressor operating frequency f, connecting pipe length l, and connecting pipe diameter d. Therefore, the simulated inner disk temperature T can be obtained by determining a baseline inner disk temperature value, then simulating and calculating the connecting pipe size correction value based on the connecting pipe length, standard connecting pipe length, and connecting pipe diameter; simulating and calculating the compressor real-time operating frequency correction value based on the compressor's real-time operating frequency and minimum operating frequency; and finally correcting the baseline inner disk temperature value based on the simulated connecting pipe size correction value and the compressor's real-time operating frequency correction value. 模拟低压 This refers to the internal temperature corresponding to the target low pressure under cooling conditions, which makes the temperature control accuracy of the air conditioning unit more precise and detailed, thus improving comfort.

[0040] Furthermore, the correction value for the connecting pipe size is positively correlated with the length of the connecting pipe; the correction value for the connecting pipe size is negatively correlated with the diameter of the connecting pipe.

[0041] It is understandable that the longer the connecting pipe, the greater the friction resistance, and therefore the larger the correction value for the connecting pipe size. This affects the simulated inner disc temperature T. 模拟低压 The smaller the diameter of the connecting pipe, the smaller the friction resistance; therefore, the smaller the correction value for the connecting pipe size, and the smaller the simulated inner disk temperature T. 模拟低压 The larger it is.

[0042] Furthermore, determining the connecting pipe size correction value based on the connecting pipe length, the standard connecting pipe length, and the connecting pipe diameter includes: T1 = a*(l-l0) / d; where a is the connecting pipe size correction coefficient; l is the connecting pipe length; l0 is the standard connecting pipe length; and d is the connecting pipe diameter. The standard connecting pipe length l0 is 5m; the connecting pipe size correction coefficient a ranges from 2.0 to 4.0; the preferred value of the connecting pipe size correction coefficient a is 3; and the connecting pipe length l ranges from 5m to 50m.

[0043] In one specific embodiment, the standard piping length is designed to be 5m. Customers can choose the appropriate length based on their actual installation distance. After installation, installers can set the value of l by adjusting the DIP switch parameters after powering on the machine. Selecting an extended piping length results in a larger l, which increases the friction loss along the pipe. 模拟低压The smaller the value, the more likely it is to cause problems such as excessive performance degradation and poor oil return due to excessively long piping. The recommended upper limit values ​​are as follows based on the cooling capacity level: 12K unit: upper limit = 20m; 18K unit, 24K unit, 30K unit, 36K unit, 42K unit: upper limit = 30m; 48K unit, 60K unit: upper limit = 50m.

[0044] It is understandable that when the length l of the connecting pipe is the standard length l0 of the connecting pipe, the length and diameter of the connecting pipe have a certain relationship with T. 模拟低压 The impact is relatively small and requires no correction. When the connecting pipe length l is greater than the standard connecting pipe length l0, the longer the connecting pipe length l, the greater the friction resistance, and therefore the larger the connecting pipe size correction value; the larger the connecting pipe diameter, the smaller the friction resistance, and therefore the smaller the connecting pipe size correction value. Since the connecting pipe length has a greater impact on the connecting pipe size correction value T1 than the connecting pipe diameter, we set l-l0 as the numerator and d as the denominator, defining a*(l-l0) / d to simulate the effect of the connecting pipe size on T1. 模拟低压 The impact.

[0045] Furthermore, the diameter of the connecting pipe is calculated as d = d1 + d2; where d is the diameter of the connecting pipe; d1 is the diameter of the connecting pipe at both ends of the high-pressure shut-off valve; and d2 is the diameter of the connecting pipe at both ends of the low-pressure shut-off valve.

[0046] The pipe diameter d1 of the connecting pipes at both ends of the high-pressure shut-off valve is a fixed value, and the pipe diameter d2 of the connecting pipes at both ends of the low-pressure shut-off valve is a fixed value. These values ​​are related to the cooling capacity rating of the air conditioning unit. After installation, the installer can set the values ​​of d1 and d2 by adjusting the DIP switch parameters after powering on the unit. Recommended values ​​are as follows: 12K unit: d1 = 6mm, d2 = 12mm; 18K, 24K, 30K, 36K, and 42K units: d1 = 9.52mm, d2 = 16mm; 48K and 60K units: d1 = 9.52mm, d2 = 19mm.

[0047] As can be understood from the schematic diagram of the air conditioning unit, the high-pressure shut-off valve is connected to the first connecting pipe at both ends, and the low-pressure shut-off valve is connected to the second connecting pipe at both ends. Therefore, the pipe diameter d of the air conditioning unit is calculated as the sum of the pipe diameter d1 of the connecting pipe at both ends of the high-pressure shut-off valve and the pipe diameter d2 of the connecting pipe at both ends of the low-pressure shut-off valve.

[0048] Furthermore, the real-time operating frequency correction value of the compressor is positively correlated with the real-time operating frequency of the compressor.

[0049] It is understandable that the higher the real-time operating frequency of the compressor, the greater the refrigerant friction resistance, the larger the real-time operating frequency correction value of the compressor, and the higher the simulated internal disk temperature T. 模拟低压 The smaller it is.

[0050] Furthermore, the step of determining the compressor real-time operating frequency correction value based on the compressor's real-time operating frequency and the compressor's minimum operating frequency includes: T2 = b*(ff) min ) / f min Where T2 is the real-time operating frequency correction value of the compressor; b is the compressor frequency correction coefficient; f is the real-time operating frequency of the compressor; f min The minimum operating frequency of the compressor; f ≥ f min .

[0051] Among them, the minimum operating frequency f of the compressor min The factory default settings are stored in the outdoor unit's EE unit, specifically the compressor's minimum operating frequency f. min The value range is 20Hz-30Hz, and the minimum operating frequency f of the compressor is... min The preferred value is 25Hz.

[0052] It is understandable that by defining (ff) min ) / f min The ratio of the compressor's current operating frequency to its minimum operating frequency is used to simulate the effect of the compressor's operating frequency on T. 模拟低压 The influence relationship is multiple, thus enabling b*(ff) min ) / f min The real-time operating frequency correction value T2 of the compressor was calculated using simulation. Where, T... 模拟低压 The correction point is when the frequency changes, but to avoid repeated corrections, T is not performed within f±2Hz. 模拟低压 The larger the value of f, the greater the frictional resistance. 模拟低压 The smaller.

[0053] Furthermore, when the length of the connecting pipe is the standard length of the connecting pipe, and the diameters of the connecting pipes at both ends of the high-pressure shut-off valve and the connecting pipes at both ends of the low-pressure shut-off valve are the standard diameters of the connecting pipes, when the air conditioning unit is running under rated cooling conditions and the compressor is operating at its minimum frequency, the corresponding actual inner wall temperature value of the air conditioning unit is taken as the reference inner wall temperature value.

[0054] It is understandable that when the length of the connecting pipe is the standard length, and the diameters of the connecting pipes at both ends of the high-pressure shut-off valve and the low-pressure shut-off valve are the standard diameters, the air conditioning unit, under rated cooling conditions and running at the compressor's minimum frequency during testing, is essentially at its minimum cooling capacity output, with the highest outlet air temperature and the highest internal wall temperature. Therefore, based on this, the actual internal wall temperature value of the air conditioning unit at this time is taken as the benchmark internal wall temperature value. Increasing the connecting pipe length l, decreasing the connecting pipe diameter d, and increasing the compressor frequency f all affect T. 模拟低压Negative correction is performed. The factory-set reference inner disk temperature value T0 is stored in the EE unit of the outdoor unit.

[0055] In one specific embodiment, for an 18K unit with a 5m connecting pipe, d1 = 9.52mm, d2 = 16mm, and a rated cooling operating minimum frequency fmin = 25Hz, the factory default setting for the actual internal temperature of the air conditioning unit is 10℃.

[0056] For example, for a 12K unit, d1 = 6mm, d2 = 12mm, a = 3.0, b = 1.5, T0 = 18℃, the actual installed piping length l = 10m, and fmin = 20Hz. When f = 20Hz, T 模拟低压 =17.17℃; when f=50Hz, T 模拟低压 =14.92℃; when f=90Hz, T 模拟低压 =11.92℃.

[0057] For example, for a 60K unit, d1 = 9.52mm, d2 = 19mm, a = 3.0, b = 1.5, T0 = 15℃, actual installed piping length l = 25m, fmin = 20Hz. When f = 20Hz, T 模拟低压 =12.90℃; when f=50Hz, T 模拟低压 =10.65℃; when f = 90Hz, T 模拟低压 =7.65℃.

[0058] Furthermore, this invention provides a control device for an independent variable frequency outdoor unit. Combined with... Figure 3 The control device 200 of the independent variable frequency outdoor unit includes, for example: an acquisition module 210 for acquiring the connecting pipe size and the real-time operating frequency of the compressor; a simulation calculation module 220 for simulating and calculating the inner plate temperature based on the connecting pipe size and the real-time operating frequency of the compressor; a determination module 230 for determining a frequency correction coefficient based on the temperature difference between the inner plate temperature and the target inner plate temperature; and a correction module 240 for correcting the target frequency based on the frequency correction coefficient.

[0059] In one specific embodiment, the acquisition module 210, the simulation calculation module 220, the determination module 230, and the correction module 240 cooperate to implement any of the independent variable frequency outdoor unit control methods described above, and can achieve the same effect. To avoid repetition, they will not be described again here.

[0060] Furthermore, this invention provides an air conditioner including a controller, which executes an executable program to implement any of the independent inverter outdoor unit control methods described above.

[0061] 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 control method for an independent variable frequency outdoor unit, characterized in that, The control method for the independent variable frequency outdoor unit includes: Obtain the connecting pipe dimensions and the compressor's real-time operating frequency; the connecting pipe dimensions include the connecting pipe length and the connecting pipe diameter; determine the connecting pipe dimension correction value based on the connecting pipe length, the standard connecting pipe length, and the connecting pipe diameter; determine the compressor's real-time operating frequency correction value based on the compressor's real-time operating frequency and the compressor's minimum operating frequency; The inner disk temperature is simulated and calculated based on the connecting pipe size and the real-time operating frequency of the compressor; wherein, the inner disk temperature is simulated and calculated based on the connecting pipe size correction value, the real-time operating frequency correction value of the compressor, and the reference inner disk temperature value; Among them, T 模拟低压 = T0 - T1 - T2; T 模拟低压 T0 is the reference inner disk temperature; T1 is the connecting pipe size correction value; T2 is the compressor real-time operating frequency correction value. The frequency correction coefficient is determined based on the temperature difference between the inner disk temperature and the target inner disk temperature. The target frequency is corrected according to the frequency correction factor.

2. The control method for an independent variable frequency outdoor unit according to claim 1, characterized in that, The correction value for the connecting pipe size is positively correlated with the length of the connecting pipe; the correction value for the connecting pipe size is negatively correlated with the diameter of the connecting pipe.

3. The control method for an independent variable frequency outdoor unit according to claim 1, characterized in that, The step of determining the connecting pipe size correction value based on the connecting pipe length, the standard length of the connecting pipe, and the connecting pipe diameter includes: T1=a (l-l0) / d; Where a is the correction factor for the size of the connecting pipe; l is the length of the connecting pipe; l0 is the standard length of the connecting pipe; and d is the diameter of the connecting pipe.

4. The control method for an independent variable frequency outdoor unit according to claim 3, characterized in that, The method for calculating the diameter of the connecting pipe is as follows: d = d1 + d2; Where d is the diameter of the connecting pipe; d1 is the diameter of the connecting pipe at both ends of the high-pressure shut-off valve; and d2 is the diameter of the connecting pipe at both ends of the low-pressure shut-off valve.

5. The control method for an independent variable frequency outdoor unit according to claim 4, characterized in that, The real-time operating frequency correction value of the compressor is positively correlated with the real-time operating frequency of the compressor.

6. The control method for an independent variable frequency outdoor unit according to claim 4, characterized in that, The step of determining the compressor real-time operating frequency correction value based on the compressor real-time operating frequency and the compressor minimum operating frequency includes: T2=b (f-f min ) / f min ; Where T2 is the compressor real-time operating frequency correction value; b is the compressor frequency correction coefficient; f is the compressor real-time operating frequency; f min The minimum operating frequency of the compressor; f ≥ f min .

7. The control method for an independent variable frequency outdoor unit according to claim 6, characterized in that, When the length of the connecting pipe is the standard length of the connecting pipe, and the diameters of the connecting pipes at both ends of the high-pressure shut-off valve and the connecting pipes at both ends of the low-pressure shut-off valve are the standard diameters of the connecting pipes, the actual inner wall temperature value of the air conditioning unit under rated cooling conditions, when tested at the minimum operating frequency of the compressor, is taken as the reference inner wall temperature value.

8. A control device for an independent variable frequency outdoor unit, characterized in that, The control device for the independent variable frequency outdoor unit implements the control method for the independent variable frequency outdoor unit according to any one of claims 1-7, wherein the control device for the independent variable frequency outdoor unit comprises: The acquisition module is used to obtain the connecting pipe size and the real-time operating frequency of the compressor; The simulation calculation module is used to simulate and calculate the inner disk temperature based on the size of the connecting pipe and the real-time operating frequency of the compressor. The determination module is used to determine the frequency correction coefficient based on the temperature difference between the inner disk temperature and the target inner disk temperature; The correction module is used to correct the target frequency according to the frequency correction coefficient.

9. An air conditioner, characterized in that, The system includes a controller for executing an executable program to implement the control method for an independent variable frequency outdoor unit as described in any one of claims 1-7.

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