Refrigerant diagnosis method and device, multi-split air conditioner and storage medium

Abstract

The application discloses a refrigerant diagnosis method and device, a multi-split air conditioner and a storage medium, and belongs to the technical field of air conditioners. The application acquires the outdoor environment temperature of the outdoor unit when the multi-split air conditioner meets the refrigerant diagnosis condition; determines the operation mode of the multi-split air conditioner according to the outdoor environment temperature, calculates the refrigerant judgment parameter and the temperature difference parameter according to the operation mode; and judges the refrigerant amount based on the refrigerant judgment parameter and the temperature difference parameter. In this way, the refrigerant amount is judged based on the temperature parameters of the outdoor unit and the indoor unit and the refrigerant judgment parameter when the multi-split air conditioner meets the refrigerant diagnosis condition, so that the judgment of the refrigerant amount is more accurate, the installation and after-sales personnel can handle the situation in time when the refrigerant amount is insufficient, and the influence of too much or too little refrigerant on the reliability and comfort of the system is avoided.

Description

Technical Field

[0001] This invention relates to the field of air conditioner technology, and in particular to a refrigerant diagnostic method, device, multi-split air conditioner, and storage medium. Background Technology

[0002] Multi-split air conditioning systems have numerous indoor units, complex and long piping connections, and require a large amount of refrigerant to charge. Due to the complexity of the piping and the number of indoor units, human error in calculations can lead to excessive or insufficient refrigerant levels. Furthermore, multi-split systems typically have many welds, and installation quality varies considerably. If the system pressure-holding time is insufficient before refrigerant charging, it may result in minor leaks upon startup or refrigerant leakage through the high-pressure system after a period of operation, leading to insufficient refrigerant. Excessive refrigerant can, in severe cases, cause liquid return, resulting in liquid compression, or excessively high system pressure triggering high-pressure protection shutdown. Conversely, insufficient refrigerant may cause indoor units to lack refrigerant, resulting in insufficient capacity to meet user cooling and heating needs. It may also lead to excessive superheating, potentially triggering exhaust high-temperature protection or low-pressure protection. Therefore, accurately determining the refrigerant level is crucial in practical engineering. In related technologies, the amount of refrigerant in the system is mainly determined by the compressor's exhaust, the compressor's exhaust superheat, the system's high and low pressures, and the compressor's return gas superheat. However, in complex operating environments, misjudgments can sometimes occur.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The main objective of this invention is to provide a refrigerant diagnostic method, device, multi-split air conditioner, and storage medium, aiming to solve the technical problem that the refrigerant quantity diagnosis of existing multi-split air conditioners is inaccurate and prone to misjudgment in complex environments.

[0005] To achieve the above objectives, the present invention provides a refrigerant diagnostic method, which is applied to a multi-split air conditioner, the multi-split air conditioner including an outdoor unit and multiple indoor units, and the refrigerant diagnostic method for the air conditioner includes: When the multi-split air conditioner meets the refrigerant diagnostic conditions, the outdoor ambient temperature of the outdoor unit is obtained; The operating mode of the multi-split air conditioner is determined based on the outdoor ambient temperature, and refrigerant judgment parameters and temperature difference parameters are calculated based on the operating mode. The refrigerant quantity is determined based on the refrigerant judgment parameters and the temperature difference parameters.

[0006] Optionally, when the multi-split air conditioner meets the refrigerant diagnostic conditions, obtaining the outdoor ambient temperature of the outdoor unit includes: When the multi-split air conditioner enters the refrigerant diagnostic function, the outdoor unit fan is controlled to run at the target fan speed for an initial stable duration. The target indoor unit is determined from among the indoor units, and the target indoor unit is the indoor unit that participates in the refrigerant diagnosis; Calculate the sum of the rated capacity of each target indoor unit and the rated capacity of the outdoor unit; When the ratio of the total rated capacity of the indoor units to the rated capacity of the outdoor units is a preset ratio, the multi-split air conditioner is determined to meet the refrigerant diagnostic conditions, and the outdoor ambient temperature of the outdoor unit is obtained.

[0007] Optionally, determining the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and calculating refrigerant judgment parameters and temperature difference parameters based on the operating mode, includes: When the outdoor ambient temperature meets the preset temperature range, the operating mode of the multi-split air conditioner is determined to be cooling mode; The expansion valve opening degree, high pressure saturation temperature, and condenser outlet temperature of the outdoor unit are obtained for each indoor unit that is turned on within a first preset time period. The refrigerant determination parameters are determined based on the opening degree of the expansion valve. The temperature difference parameter is calculated based on the high-pressure saturation temperature and the condenser outlet temperature. The temperature difference parameter is the difference between the average value of the high-pressure saturation temperature and the average value of the condenser outlet temperature.

[0008] Optionally, after determining that the operating mode of the multi-split air conditioner is cooling mode when the outdoor ambient temperature meets the preset temperature range, the method further includes: Obtain the expansion valve opening of the indoor unit that is turned on, the condenser outlet temperature of the outdoor unit, and the return air temperature of the outdoor unit; The refrigerant determination parameters are determined based on the opening degree of the expansion valve. The temperature difference parameter is calculated based on the outdoor unit return air temperature and the condenser outlet temperature. The temperature difference parameter is the difference between the average value of the outdoor unit return air temperature and the average value of the condenser outlet temperature.

[0009] Optionally, determining the refrigerant judgment parameters based on the expansion valve opening includes: Calculate the average opening value based on the expansion valve opening degree; Read the minimum cooling opening degree of the expansion valve of each indoor unit that is turned on, and calculate the average value of the minimum cooling opening degree; The refrigerant judgment parameter is calculated based on the average opening value and the average minimum opening value, wherein the refrigerant judgment parameter is the ratio of the average opening value to the average minimum opening value.

[0010] Optionally, determining the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and calculating refrigerant judgment parameters and temperature difference parameters based on the operating mode, includes: When the outdoor ambient temperature does not meet the preset temperature range, the operating mode of the multi-split air conditioner is determined to be the heating mode; The heat exchanger inlet temperature, high-pressure saturation temperature, and main expansion valve opening of the outdoor unit are obtained for each indoor unit that is turned on within a second preset time period. Calculate the average inlet temperature of each heat exchanger, the average opening of the main expansion valve, and the average saturation temperature of the high-pressure saturation temperature. The refrigerant determination parameters are determined based on the average inlet temperature. The temperature difference parameter is determined based on the average opening value of the main expansion valve and the average saturation temperature.

[0011] Optionally, determining the refrigerant quantity based on the refrigerant judgment parameter and the temperature difference parameter includes: Select the opening degree comparison threshold range based on the refrigerant judgment parameters; Select the temperature comparison threshold range based on the temperature difference parameter; The refrigerant judgment parameter is compared with the opening degree comparison threshold range to obtain the opening degree comparison result, and the temperature difference parameter is compared with the temperature comparison threshold range to obtain the temperature comparison result; The refrigerant quantity of the multi-split air conditioner is determined based on the opening degree comparison result and the temperature comparison result.

[0012] Furthermore, to achieve the above objectives, the present invention also proposes a refrigerant diagnostic device, the refrigerant diagnostic device comprising: The temperature acquisition module is used to acquire the outdoor ambient temperature of the outdoor unit when the multi-split air conditioner meets the refrigerant diagnostic conditions. The parameter calculation module is used to determine the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and to calculate refrigerant judgment parameters and temperature difference parameters based on the operating mode. The refrigerant diagnostic module is used to determine the amount of refrigerant based on the refrigerant judgment parameters and the temperature difference parameters.

[0013] Furthermore, to achieve the above objectives, the present invention also proposes a multi-split air conditioner, the multi-split air conditioner comprising: a memory, a processor, and a refrigerant diagnostic program stored in the memory and running on the processor, the refrigerant diagnostic program being configured to implement the refrigerant diagnostic method as described above.

[0014] In addition, to achieve the above objectives, the present invention also proposes a storage medium storing a refrigerant diagnostic program, which, when executed by a processor, implements the refrigerant diagnostic method as described above.

[0015] This invention acquires the outdoor ambient temperature of the outdoor unit when the multi-split air conditioner meets the refrigerant diagnostic conditions; determines the operating mode of the multi-split air conditioner based on the outdoor ambient temperature; calculates refrigerant judgment parameters and temperature difference parameters based on the operating mode; and determines the refrigerant quantity based on the refrigerant judgment parameters and the temperature difference parameters. In this way, it achieves refrigerant quantity determination based on the temperature parameters of the outdoor and indoor units and the refrigerant judgment parameters when the multi-split air conditioner meets the refrigerant diagnostic conditions. This makes the refrigerant quantity determination more accurate, facilitates timely handling by installation and after-sales personnel when the refrigerant quantity is insufficient, and avoids the impact of too much or too little refrigerant on the reliability and comfort of the system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a multi-split air conditioner in the hardware operating environment involved in the embodiments of the present invention; Figure 2 This is a flowchart illustrating the first embodiment of the refrigerant diagnostic method of the present invention; Figure 3 This is a flowchart illustrating the second embodiment of the refrigerant diagnostic method of the present invention; Figure 4 This is a flowchart illustrating the third embodiment of the refrigerant diagnostic method of the present invention; Figure 5 This is a schematic diagram of the complete implementation process of one embodiment of the refrigerant diagnosis method of the present invention. Figure 6 This is a structural block diagram of the first embodiment of the refrigerant diagnostic device of the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] Reference Figure 1 , Figure 1This is a schematic diagram of the structure of a multi-split air conditioner in the hardware operating environment involved in the embodiments of the present invention.

[0020] like Figure 1 As shown, the multi-split air conditioner may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen and an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk drive. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0021] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on multi-split air conditioners and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0022] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a refrigerant diagnostic program.

[0023] exist Figure 1 In the multi-split air conditioner shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the multi-split air conditioner of the present invention can be set in the multi-split air conditioner, and the multi-split air conditioner calls the refrigerant diagnostic program stored in the memory 1005 through the processor 1001 and executes the refrigerant diagnostic method provided in the embodiment of the present invention.

[0024] This invention provides a refrigerant diagnostic method, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of a refrigerant diagnostic method according to the present invention.

[0025] In this embodiment, the refrigerant diagnostic method includes the following steps: Step S10: When the multi-split air conditioner meets the refrigerant diagnostic conditions, obtain the outdoor ambient temperature of the outdoor unit.

[0026] In this embodiment, the executing entity can be the multi-split air conditioner, which has functions such as data processing, data communication, and program execution. The multi-split air conditioner can be any model containing multiple indoor units. Of course, other devices with similar functions can also be used, and this embodiment does not limit this. For ease of explanation, this embodiment uses a multi-split air conditioner as an example.

[0027] It should be noted that multi-split systems have numerous indoor units, complex and long piping connections, and require a larger amount of refrigerant to charge. Due to the complexity of the piping and the number of indoor units, human error in calculations can lead to excessive or insufficient refrigerant levels. Furthermore, multi-split systems typically have many weld joints, and installation quality varies considerably. If the system pressure-holding time is insufficient before refrigerant charging, it may result in minor leaks upon system startup or refrigerant leakage through the high-pressure system after a period of operation, leading to insufficient refrigerant. Excessive refrigerant can, in severe cases, cause liquid return, resulting in liquid compression, or excessively high system pressure triggering high-pressure protection shutdown. Conversely, insufficient refrigerant may cause indoor units to lack refrigerant, resulting in insufficient indoor unit capacity to meet user cooling and heating needs. It may also lead to excessive superheating, potentially triggering exhaust high-temperature protection or low-pressure protection. Therefore, accurately determining the required refrigerant level is crucial in practical engineering. In related technologies, the refrigerant level in a system is mainly determined by factors such as compressor discharge, compressor discharge superheat, system high and low pressure, and compressor return superheat. However, in complex operating environments, misjudgments can sometimes occur. The solution in this embodiment, when the multi-split air conditioner meets the refrigerant diagnostic conditions, determines the refrigerant level based on the temperature parameters of the outdoor and indoor units, as well as refrigerant judgment parameters. This makes the refrigerant level determination more accurate and facilitates timely handling by installation and after-sales personnel when the refrigerant level is insufficient, preventing excessive or insufficient refrigerant from affecting the system's reliability and comfort.

[0028] It should be understood that before starting the solution, it is necessary to determine whether the multi-split air conditioner meets the starting conditions for the refrigerant diagnostic function. Specifically, to determine whether the refrigerant diagnostic conditions are met, the multi-split air conditioner must first be initialized and run, and then the rated capacity of the indoor units participating in the diagnostic must be determined to meet the conditions.

[0029] Furthermore, in order to determine whether the multi-split air conditioner meets the refrigerant diagnostic conditions, in step S10, it is first determined that the multi-split air conditioner has entered the refrigerant diagnostic function, and then the outdoor unit fan is controlled to run at the target fan speed for an initial stable duration. Specifically, the outdoor unit fan is controlled to run at a high fan speed for a period of time TIME1 to ensure that the outdoor return air temperature sensor T4 detects accurately and that the outdoor return air temperature is the same as the outdoor ambient temperature.

[0030] In practice, after the multi-split air conditioner completes its initial operation, the indoor unit that needs to be diagnosed for refrigerant quantity is determined from among the various indoor units and designated as the target indoor unit. The target indoor unit is preset or selected by the user and can be any number of indoor units. This embodiment does not limit this.

[0031] It should be noted that after the target indoor unit is determined, the rated capacity of each target indoor unit is calculated, and the stability capacity of the outdoor unit in the multi-split air conditioner is obtained.

[0032] It should be understood that the total rated capacity of the target indoor units is required to be R% of the rated capacity of the outdoor units (R is generally taken as 80~120, preferably 100). At this time, it is determined that the multi-split air conditioner meets the refrigerant diagnostic conditions, so the step of obtaining the outdoor ambient temperature of the outdoor unit is initiated.

[0033] This method allows for the determination of whether a multi-split air conditioner meets the preconditions for diagnosis before performing refrigerant quantity diagnosis, thus preventing misdiagnosis.

[0034] Step S20: Determine the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and calculate the refrigerant judgment parameters and temperature difference parameters based on the operating mode.

[0035] In practice, determining the operating mode of a multi-split air conditioner based on the outdoor ambient temperature means determining whether the multi-split air conditioner is in heating or cooling mode based on the specific value of the outdoor ambient temperature, and then calculating different refrigerant judgment parameters and temperature difference parameters according to the different operating modes.

[0036] Step S30: Determine the amount of refrigerant based on the refrigerant judgment parameter and the temperature difference parameter.

[0037] It should be noted that after determining the refrigerant judgment parameters and temperature difference parameters, the refrigerant judgment parameters are compared with the opening degree comparison threshold range, and the temperature difference parameters are compared with the temperature comparison threshold range. The refrigerant quantity is then determined and diagnosed based on the two comparison results.

[0038] Further, in order to accurately determine the refrigerant charge amount, in step S30, an opening comparison threshold range is first selected according to the refrigerant judgment parameter, specifically, different opening comparison threshold ranges and temperature comparison threshold ranges are determined according to the operation mode of the multi-connected air conditioner.

[0039] It should be understood that in the cooling mode, Rp is first determined as the refrigerant judgment parameter, and Rp0 and Rp1 are preset reference thresholds, that is, the opening comparison threshold range.

[0040] Therefore, in the cooling mode, the step of comparing the refrigerant judgment parameter with the opening comparison threshold range includes: Rp is greater than Rp1. If Rp >= Rp0, it prompts that the refrigerant is seriously insufficient, and the process ends; otherwise, the process proceeds to the next step. If Rp >= Rp1, it prompts that the refrigerant is insufficient, and the process ends; otherwise, the process proceeds to the next step.

[0041] In specific implementation, in the cooling mode, the temperature comparison threshold range is determined to be a threshold range less than A, and A can be any preset temperature threshold. Therefore, the determination method of the temperature comparison result in the cooling mode is: if TCavg-T3avg < A, it prompts that the refrigerant charge amount is in a normal range, and the process ends; otherwise, it prompts that the refrigerant is excessive, and the process ends. Wherein, TCavg is the average value of high-pressure saturation temperature, and T3avg is the average value of the refrigerant outlet temperature of the outdoor unit.

[0042] It should be noted that in the heating mode, Poavg is first determined as the refrigerant judgment parameter, and the opening comparison threshold range at this time is composed of three thresholds P0, P1 and P2, where P0, P1 and P2 are any values that increase sequentially. Therefore, the step of judging the opening comparison result is: if Poavg <= P0, it prompts that the refrigerant is seriously excessive, and the process ends; otherwise, the process proceeds to the next step. If Poavg <= P1, it prompts that the refrigerant is excessive, and the process ends; otherwise, the process proceeds to the next step. If Poavg <= P2, it prompts that the refrigerant charge amount is in a normal range, and the process ends; otherwise, the process proceeds to the next step.

[0043] It should be understood that in the heating mode, the temperature comparison threshold range is determined as a value range less than B, and B can be any preset temperature threshold. Therefore, the determination method of the temperature comparison result in the heating mode is: if TCavg-TAavg < B, it prompts that the refrigerant is seriously insufficient, and the process ends; otherwise, it prompts that the refrigerant is insufficient, and the process ends. Wherein, TCavg is the average value of high-pressure saturation temperature, and TAavg is the average value of the inlet temperature of the heat exchanger.

[0044] In this way, the parameters participating in refrigerant diagnosis can be processed in sub-intervals according to the corresponding outdoor return air temperature T4 (different parameter values can be taken for each T4 interval), so that the refrigerant charge amount can be accurately determined.

[0045] This embodiment enables the determination of refrigerant quantity based on the temperature parameters of the outdoor and indoor units and refrigerant judgment parameters when the refrigerant diagnostic conditions are met in a multi-split air conditioner. This makes the refrigerant quantity determination more accurate and facilitates timely handling by installation and after-sales personnel when the refrigerant quantity is insufficient, thus avoiding the impact of too much or too little refrigerant on the reliability and comfort of the system.

[0046] refer to Figure 3 , Figure 3 This is a flowchart illustrating a second embodiment of a refrigerant diagnostic method according to the present invention.

[0047] Based on the first embodiment described above, the refrigerant diagnostic method of this embodiment includes the following in step S20: Step S201: When the outdoor ambient temperature meets the preset temperature range, determine the operating mode of the multi-split air conditioner as the cooling mode.

[0048] It should be noted that the outdoor ambient temperature is first compared with the preset temperature range to determine whether the multi-split air conditioner is operating in cooling or heating mode. Specifically, if T4 >= TCOOL, the operating mode is determined to be cooling mode. Here, TCOOL is a preset temperature threshold, which can be any value, and this embodiment does not impose any restrictions on it.

[0049] Furthermore, in order to determine the refrigerant quantity in a low-cost multi-split air conditioner without a high-pressure sensor, after step S201, within a first preset time period, the expansion valve openings P1, P2...PN (N is the total number of indoor units in operation), the outdoor unit return air temperature T4, and the outdoor unit condenser outlet temperature T3 of all operating indoor units are obtained.

[0050] It should be understood that the refrigerant judgment parameters are then calculated as the indoor unit opening degrees P1, P2...PN, and the average value Pavg is taken. The ratio Rp of Pavg and Pmin-cool is then calculated. Specifically, the minimum cooling opening degree of the expansion valve of the indoor unit is read when it is turned on, and its average value Pmin-cool is calculated.

[0051] In practice, the temperature difference parameter is T3avg-T4avg, where the average values ​​of T4 and T3 are taken as T4avg and T3avg, respectively.

[0052] In this way, the refrigerant quantity can be accurately determined through parameter calculation even in low-cost multi-split air conditioners that do not have high-pressure sensors installed.

[0053] Step S202: Obtain the expansion valve opening degree, high pressure saturation temperature, and condenser outlet temperature of the indoor unit in operation within the first preset time period.

[0054] It should be understood that when the system is set to run in cooling mode, the multi-split air conditioner is first controlled to start cooling operation and timed, and the parameters during the period from TIME2 minutes to TIME3 minutes are recorded and processed. The first preset time period is the period from TIME2 minutes to TIME3 minutes.

[0055] In practice, the parameters obtained include: the expansion valve openings P1, P2...PN of all indoor units that are turned on (N is the total number of indoor units that are turned on), the return air temperature of the outdoor unit T4, the high-pressure saturation temperature TC (which can be calculated from the high-pressure sensor data), and the condenser outlet temperature of the outdoor unit T3.

[0056] Step S203: Determine the refrigerant judgment parameters based on the opening degree of the expansion valve.

[0057] It should be noted that the refrigerant judgment parameter is calculated based on the opening value of the expansion valve.

[0058] Furthermore, in order to accurately calculate the refrigerant judgment parameters, the average value of the expansion valve opening of all the indoor units that are turned on is first calculated and denoted as Pavg.

[0059] It should be understood that the minimum opening degree of the expansion valve of each indoor unit of the current multi-split air conditioner in cooling mode is then read, so that the average value of the minimum opening degree of cooling of all indoor units can be calculated, denoted as Pmin-cool.

[0060] In practice, the ratio Rp of Pavg and Pmin-cool is calculated and used as a parameter for refrigerant determination.

[0061] Step S204: Calculate the temperature difference parameter based on the high-pressure saturation temperature and the condenser outlet temperature. The temperature difference parameter is the difference between the average value of the high-pressure saturation temperature and the average value of the condenser outlet temperature.

[0062] It should be noted that the temperature difference parameter is defined as TCavg-T3avg, where the average values ​​of TC and T3 are taken as TCavg and T3avg, respectively.

[0063] In this embodiment, the amount of refrigerant is determined by using the ratio Rp of the average indoor unit opening value Pavg to Pmin-cool during cooling operation, combined with the average values ​​TCavg and T3 of the outdoor unit parameters TC and T3.

[0064] refer to Figure 4 , Figure 4 This is a flowchart illustrating a third embodiment of a refrigerant diagnostic method according to the present invention.

[0065] Based on the foregoing first embodiment, in this embodiment, the refrigerant diagnosis method includes the following step S20: Step S21: when the outdoor ambient temperature does not satisfy the preset temperature range, determining that the operation mode of the multi-connected air conditioner is the heating mode.

[0066] It should be noted that when the outdoor ambient temperature T4 < TCOOL, it is determined that the outdoor ambient temperature does not satisfy the preset temperature range, so the operation mode of the multi-connected air conditioner is determined to be the heating mode.

[0067] Step S22: acquiring the heat exchanger inlet temperature of the turned-on indoor units among all indoor units, the high-pressure saturation temperature, and the opening degree of the main expansion valve of the outdoor unit within a second preset time period.

[0068] It should be understood that heating operation is started and timing is performed, and parameters during the period from the TIME4-th minute to the TIME5-th minute of operation are recorded and processed, specifically including the inlet temperatures TA1, TA2...TAN of the heat exchangers of all turned-on indoor units (N is the total number of turned-on indoor units), the outdoor unit return air temperature T4, the outdoor unit main expansion valve opening degree Po, and the high-pressure saturation temperature TC (which can be calculated from data of a high-pressure pressure sensor). The second preset time period refers to the period from the TIME4-th minute to the TIME5-th minute.

[0069] Step S23: calculating an inlet temperature average value of the heat exchanger inlet temperatures, a main expansion valve opening average value of the main expansion valve opening degrees, and a saturation temperature average value of the high-pressure saturation temperatures.

[0070] In specific implementation, the inlet temperatures TA1, TA2...TAN of the indoor unit heat exchangers are calculated to obtain an average value TAavg. Average values Poavg and TCavg of the outdoor unit Po and TC are obtained.

[0071] Step S24: determining a refrigerant judgment parameter according to the inlet temperature average value.

[0072] It should be noted that the refrigerant judgment parameter at this time is Poavg, that is, the average value of the opening degree of the main expansion valve of the outdoor unit of the multi-connected air conditioner.

[0073] Step S25: determining a temperature difference parameter according to the main expansion valve opening average value and the saturation temperature average value.

[0074] It should be understood that the temperature difference parameter in the heating mode is TCavg-TAavg.

[0075] In specific implementation, reference is made to Figure 5 for the complete implementation process of the present solution. Through this method, judgment of the refrigerant charge of the multi-connected air conditioner can be implemented under different operation modes.

[0076] In this embodiment, during heating operation, the average inlet temperature TAavg of the indoor unit heat exchanger is used, combined with the outdoor unit parameters, the main expansion valve opening Po, and the average values ​​Poavg and TCavg of the high-pressure saturation temperature TC, to determine the amount of refrigerant.

[0077] Furthermore, embodiments of the present invention also propose a storage medium storing a refrigerant diagnostic program, wherein the refrigerant diagnostic program, when executed by a processor, implements the steps of the refrigerant diagnostic method described above.

[0078] Since this storage medium adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0079] Reference Figure 6 , Figure 6 This is a structural block diagram of the first embodiment of the refrigerant diagnostic device of the present invention.

[0080] like Figure 6 As shown, the refrigerant diagnostic device proposed in this embodiment of the invention includes: The temperature acquisition module 10 is used to acquire the outdoor ambient temperature of the outdoor unit when the multi-split air conditioner meets the refrigerant diagnostic conditions.

[0081] In this embodiment, the executing entity can be the multi-split air conditioner, which has functions such as data processing, data communication, and program execution. The multi-split air conditioner can be any model containing multiple indoor units. Of course, other devices with similar functions can also be used, and this embodiment does not limit this. For ease of explanation, this embodiment uses a multi-split air conditioner as an example.

[0082] It should be noted that multi-split systems have numerous indoor units, complex and long piping connections, and require a larger amount of refrigerant to charge. Due to the complexity of the piping and the number of indoor units, human error in calculations can lead to excessive or insufficient refrigerant levels. Furthermore, multi-split systems typically have many weld joints, and installation quality varies considerably. If the system pressure-holding time is insufficient before refrigerant charging, it may result in minor leaks upon system startup or refrigerant leakage through the high-pressure system after a period of operation, leading to insufficient refrigerant. Excessive refrigerant can, in severe cases, cause liquid return, resulting in liquid compression, or excessively high system pressure triggering high-pressure protection shutdown. Conversely, insufficient refrigerant may cause indoor units to lack refrigerant, resulting in insufficient indoor unit capacity to meet user cooling and heating needs. It may also lead to excessive superheating, potentially triggering exhaust high-temperature protection or low-pressure protection. Therefore, accurately determining the required refrigerant level is crucial in practical engineering. In related technologies, the refrigerant level in a system is mainly determined by factors such as compressor discharge, compressor discharge superheat, system high and low pressure, and compressor return superheat. However, in complex operating environments, misjudgments can sometimes occur. The solution in this embodiment, when the multi-split air conditioner meets the refrigerant diagnostic conditions, determines the refrigerant level based on the temperature parameters of the outdoor and indoor units, as well as refrigerant judgment parameters. This makes the refrigerant level determination more accurate and facilitates timely handling by installation and after-sales personnel when the refrigerant level is insufficient, preventing excessive or insufficient refrigerant from affecting the system's reliability and comfort.

[0083] It should be understood that before starting the solution, it is necessary to determine whether the multi-split air conditioner meets the starting conditions for the refrigerant diagnostic function. Specifically, to determine whether the refrigerant diagnostic conditions are met, the multi-split air conditioner must first be initialized and run, and then the rated capacity of the indoor units participating in the diagnostic must be determined to meet the conditions.

[0084] Furthermore, in order to determine whether the multi-split air conditioner meets the refrigerant diagnostic conditions, in step S10, it is first determined that the multi-split air conditioner has entered the refrigerant diagnostic function, and then the outdoor unit fan is controlled to run at the target fan speed for an initial stable duration. Specifically, the outdoor unit fan is controlled to run at a high fan speed for a period of time TIME1 to ensure that the outdoor return air temperature sensor T4 detects accurately.

[0085] In practice, after the multi-split air conditioner completes its initial operation, the indoor unit that needs to be diagnosed for refrigerant quantity is determined from among the various indoor units and designated as the target indoor unit. The target indoor unit is preset or selected by the user and can be any number of indoor units. This embodiment does not limit this.

[0086] It should be noted that after the target indoor unit is determined, the rated capacity of each target indoor unit is calculated, and the stability capacity of the outdoor unit in the multi-split air conditioner is obtained.

[0087] It should be understood that the total rated capacity of the target indoor units is required to be R% of the rated capacity of the outdoor units (R is generally taken as 80~120, preferably 100). At this time, it is determined that the multi-split air conditioner meets the refrigerant diagnostic conditions, so the step of obtaining the outdoor ambient temperature of the outdoor unit is initiated.

[0088] This method allows for the determination of whether a multi-split air conditioner meets the preconditions for diagnosis before performing refrigerant quantity diagnosis, thus preventing misdiagnosis.

[0089] The parameter calculation module 20 is used to determine the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and to calculate the refrigerant judgment parameter and temperature difference parameter based on the operating mode.

[0090] In practice, determining the operating mode of a multi-split air conditioner based on the outdoor ambient temperature means determining whether the multi-split air conditioner is in heating or cooling mode based on the specific value of the outdoor ambient temperature, and then calculating different refrigerant judgment parameters and temperature difference parameters according to the different operating modes.

[0091] The refrigerant diagnostic module 30 is used to determine the amount of refrigerant based on the refrigerant judgment parameters and the temperature difference parameters.

[0092] It should be noted that after determining the refrigerant judgment parameters and temperature difference parameters, the refrigerant judgment parameters are compared with the opening degree comparison threshold range, and the temperature difference parameters are compared with the temperature comparison threshold range. The refrigerant quantity is then determined and diagnosed based on the two comparison results.

[0093] Furthermore, in order to accurately determine the refrigerant quantity, in step S30, the opening degree comparison threshold range is first selected based on the refrigerant judgment parameters. Specifically, different opening degree comparison threshold ranges and temperature comparison threshold ranges are determined according to the operating mode of the multi-split air conditioner.

[0094] It should be understood that in cooling mode, Rp is first determined as the refrigerant judgment parameter, and Rp0 and Rp1 are preset reference thresholds, which are the opening degree comparison threshold ranges.

[0095] Therefore, in cooling mode, the steps for comparing the refrigerant distribution judgment parameter with the opening comparison threshold range include: Rp > Rp1. If Rp >= Rp0, it indicates a severe refrigerant shortage, and the process ends; otherwise, proceed to the next step. If Rp >= Rp1, it indicates a refrigerant shortage, and the process ends; otherwise, proceed to the next step.

[0096] In specific implementation, in the cooling mode, the temperature comparison threshold range is determined as a threshold range smaller than A, and A can be any preset temperature threshold. Therefore, the method for determining the temperature comparison result in the cooling mode is: if TCavg-T3avg < A, it indicates that the refrigerant charge is in a normal range, and the process ends; otherwise, it indicates that there is excessive refrigerant, and the process ends. Wherein, TCavg is an average value of high-pressure saturation temperature, and T3avg is an average value of refrigerant outlet temperature of the outdoor unit.

[0097] It should be noted that in the heating mode, Poavg is first determined as the refrigerant judgment parameter, and the opening comparison threshold range is formed by three thresholds P0, P1 and P2, wherein P0, P1 and P2 are any values that increase sequentially. Therefore, the judgment steps for the opening comparison result are: if Poavg ≤ P0, it indicates serious excess refrigerant, and the process ends; otherwise, the process proceeds to the next step. If Poavg ≤ P1, it indicates excess refrigerant, and the process ends; otherwise, the process proceeds to the next step. If Poavg ≤ P2, it indicates that the refrigerant charge is in a normal range, and the process ends; otherwise, the process proceeds to the next step.

[0098] It should be understood that in the heating mode, the temperature comparison threshold range is determined as a value range smaller than B, and B can be any preset temperature threshold. Therefore, the method for determining the temperature comparison result in the heating mode is: if TCavg-TAavg < B, it indicates serious insufficient refrigerant, and the process ends; otherwise, it indicates insufficient refrigerant, and the process ends. Wherein, TCavg is an average value of high-pressure saturation temperature, and TAavg is an average value of heat exchanger inlet temperature.

[0099] Through this method, the parameters participating in refrigerant diagnosis can be processed in intervals according to the corresponding outdoor return air temperature T4 (different parameter values can be adopted for each T4 interval), so that the refrigerant charge can be accurately determined.

[0100] In this embodiment, when the multi-connected air conditioner meets the refrigerant diagnosis condition, the refrigerant charge is determined based on the temperature parameters of the outdoor unit and the indoor unit and the refrigerant judgment parameter, so that the judgment of the refrigerant charge is more accurate, which facilitates timely treatment by installation and after-sales personnel when the refrigerant charge is insufficient, and avoids the influence of excessive or insufficient refrigerant on the reliability and comfort of the system.

[0101] It should be understood that the above description is only an example, and does not constitute any limitation to the technical solution of the present invention. In specific applications, those skilled in the art can make settings as required, and the present invention does not impose any limitation thereon.

[0102] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0103] In addition, for technical details not described in detail in this embodiment, please refer to the refrigerant diagnosis method provided in any embodiment of the present invention, which will not be repeated here.

[0104] Furthermore, it should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system 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 system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0105] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0106] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory (ROM) / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0107] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A refrigerant diagnostic method, characterized in that, The refrigerant diagnostic method is applied to a multi-split air conditioner, which includes an outdoor unit and multiple indoor units. The refrigerant diagnostic method for the air conditioner includes: When the multi-split air conditioner meets the refrigerant diagnostic conditions, the outdoor ambient temperature of the outdoor unit is obtained. Specifically, this includes: when the multi-split air conditioner enters the refrigerant diagnostic function, controlling the outdoor unit fan to run for an initial stable duration according to the target fan speed, determining the target indoor unit from among the indoor units, wherein the target indoor unit is the indoor unit participating in the refrigerant diagnostic, calculating the sum of the rated capacity of the indoor units of each target indoor unit and the rated capacity of the outdoor unit, and when the ratio of the sum of the rated capacity of the indoor units to the rated capacity of the outdoor unit is a preset ratio, determining that the multi-split air conditioner meets the refrigerant diagnostic conditions, and obtaining the outdoor ambient temperature of the outdoor unit. The operating mode of the multi-split air conditioner is determined based on the outdoor ambient temperature. Refrigerant judgment parameters and temperature difference parameters are calculated based on the operating mode. Specifically, when the operating mode is cooling mode, the difference between the average high-pressure saturation temperature of the indoor units and the average condenser outlet temperature of the outdoor unit within a first preset time period is used as the temperature difference parameter. The ratio of the average opening degree of the indoor unit's expansion valve to the average minimum opening degree of the indoor unit's expansion valve is used as the refrigerant judgment parameter. When the operating mode is heating mode, the difference between the average high-pressure saturation temperature of the indoor units and the average heat exchanger inlet temperature within a second preset time period is used as the temperature difference parameter. The average opening degree of the outdoor unit's main expansion valve is used as the refrigerant judgment parameter. The refrigerant quantity is determined based on the refrigerant judgment parameter and the temperature difference parameter, specifically including: selecting an opening degree comparison threshold range according to the refrigerant judgment parameter, selecting a temperature comparison threshold range according to the temperature difference parameter, comparing the refrigerant judgment parameter with the opening degree comparison threshold range to obtain an opening degree comparison result, comparing the temperature difference parameter with the temperature comparison threshold range to obtain a temperature comparison result, and determining the refrigerant quantity of the multi-split air conditioner based on the opening degree comparison result and the temperature comparison result. The result of the refrigerant quantity determination is any one of normal refrigerant, low refrigerant, severely low refrigerant, high refrigerant, and severely high refrigerant.

2. The refrigerant diagnostic method as described in claim 1, characterized in that, The step of determining the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and calculating refrigerant judgment parameters and temperature difference parameters based on the operating mode, includes: When the outdoor ambient temperature meets the preset temperature range, the operating mode of the multi-split air conditioner is determined to be cooling mode; The expansion valve opening degree, high pressure saturation temperature, and condenser outlet temperature of the outdoor unit are obtained for each indoor unit that is turned on within a first preset time period. The refrigerant determination parameters are determined based on the opening degree of the expansion valve. The temperature difference parameter is calculated based on the high-pressure saturation temperature and the condenser outlet temperature. The temperature difference parameter is the difference between the average value of the high-pressure saturation temperature and the average value of the condenser outlet temperature.

3. The refrigerant diagnostic method as described in claim 2, characterized in that, After determining that the operating mode of the multi-split air conditioner is cooling mode when the outdoor ambient temperature meets the preset temperature range, the method further includes: Obtain the expansion valve opening of the indoor unit that is turned on, the condenser outlet temperature of the outdoor unit, and the return air temperature of the outdoor unit; The refrigerant determination parameters are determined based on the opening degree of the expansion valve. The temperature difference parameter is calculated based on the outdoor unit return air temperature and the condenser outlet temperature. The temperature difference parameter is the difference between the average value of the outdoor unit return air temperature and the average value of the condenser outlet temperature.

4. The refrigerant diagnostic method as described in claim 2, characterized in that, The step of determining the refrigerant judgment parameters based on the expansion valve opening includes: Calculate the average opening value based on the expansion valve opening degree; Read the minimum cooling opening degree of the expansion valve of each indoor unit that is turned on, and calculate the average value of the minimum cooling opening degree; The refrigerant judgment parameter is calculated based on the average opening value and the average minimum opening value, wherein the refrigerant judgment parameter is the ratio of the average opening value to the average minimum opening value.

5. The refrigerant diagnostic method as described in claim 1, characterized in that, The step of determining the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and calculating refrigerant judgment parameters and temperature difference parameters based on the operating mode, includes: When the outdoor ambient temperature does not meet the preset temperature range, the operating mode of the multi-split air conditioner is determined to be the heating mode; The heat exchanger inlet temperature, high-pressure saturation temperature, and main expansion valve opening of the outdoor unit are obtained for each indoor unit that is turned on within a second preset time period. Calculate the average inlet temperature of each heat exchanger, the average opening of the main expansion valve, and the average saturation temperature of the high-pressure saturation temperature. The refrigerant determination parameters are determined based on the average inlet temperature. The temperature difference parameter is determined based on the average opening value of the main expansion valve and the average saturation temperature.

6. A refrigerant diagnostic device, characterized in that, The refrigerant diagnostic device includes: The temperature acquisition module is used to acquire the outdoor ambient temperature of the outdoor unit when the refrigerant diagnostic conditions are met in the multi-split air conditioner. The parameter calculation module is used to determine the operating mode of the multi-split air conditioner based on the outdoor ambient temperature, and to calculate refrigerant judgment parameters and temperature difference parameters based on the operating mode. Specifically, when the operating mode is cooling mode, the difference between the average high-pressure saturation temperature of the indoor units and the average condenser outlet temperature of the outdoor unit within a first preset time period is used as the temperature difference parameter, and the ratio of the average opening degree of the expansion valve of the indoor units to the average minimum opening degree of the expansion valve of the indoor units is used as the refrigerant judgment parameter. When the operating mode is heating mode, the difference between the average high-pressure saturation temperature of the indoor units and the average heat exchanger inlet temperature within a second preset time period is used as the temperature difference parameter, and the average opening degree of the main expansion valve of the outdoor unit is used as the refrigerant judgment parameter. The refrigerant diagnostic module is used to determine the amount of refrigerant based on the refrigerant judgment parameters and the temperature difference parameters; The refrigerant diagnostic module is also used to select an opening comparison threshold range based on the refrigerant judgment parameters; Select the temperature comparison threshold range based on the temperature difference parameter; The refrigerant judgment parameter is compared with the opening degree comparison threshold range to obtain the opening degree comparison result, and the temperature difference parameter is compared with the temperature comparison threshold range to obtain the temperature comparison result; Based on the opening comparison result and the temperature comparison result, the refrigerant quantity of the multi-split air conditioner is determined, and the result of the refrigerant quantity determination is any one of normal refrigerant, low refrigerant, severely low refrigerant, high refrigerant, and severely high refrigerant. The temperature acquisition module is also used to control the outdoor unit fan of the outdoor unit to run at the target windshield for an initial stable duration when the multi-split air conditioner enters the refrigerant diagnostic function. The target indoor unit is determined from among the indoor units, and the target indoor unit is the indoor unit that participates in the refrigerant diagnosis; Calculate the sum of the rated capacity of the indoor units of each target indoor unit and the rated capacity of the outdoor unit; When the ratio of the total rated capacity of the indoor units to the rated capacity of the outdoor units is a preset ratio, the multi-split air conditioner is determined to meet the refrigerant diagnostic conditions, and the outdoor ambient temperature of the outdoor unit is obtained.

7. A multi-split air conditioner, characterized in that, The multi-split air conditioner includes: a memory, a processor, and a refrigerant diagnostic program stored in the memory and running on the processor, the refrigerant diagnostic program being configured to implement the refrigerant diagnostic method as described in any one of claims 1 to 5.

8. A storage medium, characterized in that, The storage medium stores a refrigerant diagnostic program, which, when executed by a processor, implements the refrigerant diagnostic method as described in any one of claims 1 to 5.

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