A control method and device of a parallel unit air conditioner, an air conditioner and a medium

Abstract

The application provides a control method and device of a parallel unit air conditioner, an air conditioner and a medium. The control method of the parallel unit air conditioner comprises the following steps: acquiring working parameters of each outdoor unit module of the parallel unit air conditioner; judging whether each outdoor unit module is a liquid return bias flow module according to the working parameters; correcting a target superheat degree of the outdoor unit module in the case that the outdoor unit module is the liquid return bias flow module; judging again whether the outdoor unit module exists liquid return after the outdoor unit module is corrected in the target superheat degree; and adjusting the operating parameters of the outdoor unit module in the case that the outdoor unit module exists liquid return. The application solves the technical problem that the refrigerant of the parallel unit air conditioner is not uniform when flowing to each outdoor unit module, which leads to bias flow and abrasion of the outdoor unit module.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to a control method of a parallel unit air conditioner, a control device of a parallel unit air conditioner, an air conditioner and a readable storage medium. BACKGROUND

[0002] When the parallel unit air conditioner is running in the heating defrosting mode, the heating reversing oil return mode and the refrigeration oil return mode, the refrigerant backflow to each outdoor unit module in the parallel unit air conditioner is uneven, which can cause flow deviation, and a large amount of refrigerant can flow to one of the outdoor unit modules, resulting in excessive refrigerant backflow to the outdoor unit module, wearing out the compressor of the outdoor unit module and affecting the normal operation of the parallel unit air conditioner.

[0003] At present, the parallel unit air conditioner of the related technology has not solved the problem of uneven refrigerant backflow to each outdoor unit module, resulting in flow deviation and wearing out the outdoor unit module. SUMMARY

[0004] The present application solves the technical problem of uneven refrigerant backflow to each outdoor unit module in the parallel unit air conditioner of the prior art, resulting in flow deviation and wearing out the outdoor unit module.

[0005] To solve the above problems, the present application provides a control method of a parallel unit air conditioner, which comprises: obtaining the working parameters of each outdoor unit module of the parallel unit air conditioner; determining whether each outdoor unit module is a backflow deviation module according to the working parameters; correcting the target superheat of the outdoor unit module in the case that the outdoor unit module is a backflow deviation module; determining whether the outdoor unit module has backflow again after the target superheat of the outdoor unit module is corrected; and adjusting the operating parameters of the outdoor unit module in the case that the outdoor unit module has backflow.

[0006] Compared with existing technologies, the technical effects achieved by this solution are as follows: By pre-determining the operating parameters of each outdoor unit module in the target operating mode, it is possible to identify whether there is refrigerant backflow deviation. Outdoor unit modules exhibiting refrigerant backflow deviation are marked as such, facilitating subsequent monitoring and target superheat correction to further prevent refrigerant backflow during operation. Target superheat correction also prevents excessive refrigerant backflow into the compressor of the outdoor unit module during operation, thus reducing compressor damage and mitigating the uneven distribution of refrigerant in parallel air conditioning units during the target operating mode, ensuring operational reliability. After target superheat correction, the presence of refrigerant backflow is assessed again. To determine if the refrigerant backflow problem has been resolved through target superheat correction, if refrigerant backflow still exists in some outdoor unit modules in the parallel air conditioning unit after correction, further adjustments to the operating parameters of the outdoor unit modules are needed to mitigate the damage caused by refrigerant backflow.

[0007] In one embodiment of the present invention, target superheat correction of the outdoor unit module includes: obtaining a first exhaust superheat value and a first intake superheat value of the outdoor unit module; and performing target superheat correction on the outdoor unit module based on the first exhaust superheat value and the first intake superheat value; wherein the first exhaust superheat value is the value of the compressor exhaust superheat before the outdoor unit module is running; and the first intake superheat value is the value of the gas separator intake superheat before the outdoor unit module is running.

[0008] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the first exhaust superheat value can be used to determine whether the compressor exhaust temperature of the outdoor unit module is too low, and the first intake superheat value can be used to determine whether there is liquid return in the gas separator of the outdoor unit module.

[0009] In one embodiment of the present invention, the target overheat correction of the outdoor unit module is performed based on the first exhaust superheat value and the first intake superheat value, including: comparing the first exhaust superheat value with the first exhaust superheat threshold, and the first intake superheat value with the first intake superheat threshold, to obtain a comparison result; performing target overheat correction on the outdoor unit module based on the comparison result; when the first exhaust superheat value is less than or equal to the first exhaust superheat threshold and the first intake superheat value is greater than the first intake superheat threshold, performing target overheat correction on the outdoor unit module based on the first overheat correction coefficient; and / or when the first exhaust superheat value is less than or equal to the first exhaust superheat threshold and the first intake superheat value is less than or equal to the first intake superheat threshold, performing target overheat correction on the outdoor unit module based on the second overheat correction coefficient.

[0010] Compared with existing technologies, the technical effects achieved by this solution are as follows: When the first exhaust superheat value is less than or equal to the first exhaust superheat threshold and the first intake superheat value is greater than the first intake superheat threshold, it indicates that there is no liquid in the gas separator, but there is a risk of liquid return to the outdoor unit module. At this time, the target superheat of the outdoor unit module is corrected by k1, and the target superheat correction is increased by k1 until the first exhaust superheat value is greater than the first exhaust superheat threshold or after continuous correction for a first duration, the target operating mode is entered. When the first exhaust superheat value is less than or equal to the first exhaust superheat threshold and the first intake superheat value is less than or equal to the first intake superheat threshold, it indicates that there is liquid in the gas separator and there is a risk of liquid return to the outdoor unit module. At this time, the target superheat of the outdoor unit module is corrected by k2, and the target superheat correction is increased by k2 until the first exhaust superheat value is greater than the first exhaust superheat threshold or after continuous correction for a second duration, the target operating mode is entered.

[0011] In one embodiment of the present invention, determining whether liquid return exists in the outdoor unit module again includes: obtaining the second exhaust superheat value of the outdoor unit module; comparing the second exhaust superheat value with the second exhaust superheat threshold; determining that liquid return exists in the outdoor unit module when the second exhaust superheat value is less than the second exhaust superheat threshold; wherein, the second exhaust superheat value is the value of the compressor exhaust superheat after the outdoor unit module has been running.

[0012] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: After the outdoor unit module is corrected for the target superheat, the outdoor unit module can enter the target operating mode normally. After entering the target operating mode, it is necessary to determine whether there is liquid return in the outdoor unit module again. By obtaining the second exhaust superheat value of the outdoor unit module and comparing the size of the second exhaust superheat value and the second exhaust superheat threshold, it is determined whether there is liquid return in the outdoor unit module.

[0013] In one embodiment of the present invention, adjusting the operating parameters of the outdoor unit module includes: obtaining the low-pressure of the compressor in the outdoor unit module; correcting the compressor frequency based on the low-pressure and a low-pressure threshold; correcting the compressor frequency based on a first frequency correction coefficient when the low-pressure is less than the low-pressure threshold; and / or not correcting the compressor frequency when the low-pressure is greater than or equal to the low-pressure threshold.

[0014] Compared with existing technologies, the technical effects achieved by this solution are as follows: it can identify which outdoor unit module has liquid return. If an outdoor unit module has liquid return, the superheat of the compressor discharge of that module will decrease, even below the second discharge superheat threshold. In the case of liquid return, high-frequency operation causes greater damage to the compressor, and the low pressure is lower during high-frequency operation, making it easier for the gas-liquid refrigerant to evaporate and boil, resulting in the compressor drawing in more wet vapor. Therefore, controlling the compressor frequency is an effective way to reduce compressor damage.

[0015] In one embodiment of the present invention, obtaining the operating parameters of each outdoor unit module of the parallel air conditioning unit and determining whether each outdoor unit module is a liquid return deflection module based on the operating parameters includes: when the parallel air conditioning unit is running in the target operating mode, obtaining the exhaust superheat value before operation and the exhaust superheat value after operation of each outdoor unit module; and determining whether each outdoor unit module is a liquid return deflection module based on the exhaust superheat value before operation and the exhaust superheat value after operation.

[0016] Compared with existing technologies, the technical effect achieved by this technical solution is as follows: when liquid refrigerant returns to the outdoor unit module, the liquid refrigerant will reduce the exhaust temperature of the compressor in the outdoor unit module. Therefore, the superheat of the compressor exhaust of the outdoor unit module can be used to determine whether there is liquid refrigerant flow deviation in the corresponding outdoor unit module.

[0017] In one embodiment of the present invention, determining whether each outdoor unit module is a liquid return deflection module based on the exhaust superheat value before operation and the exhaust superheat value after operation includes: calculating the average exhaust superheat value of the parallel unit air conditioner after operation based on the exhaust superheat value of each outdoor unit module after operation; obtaining the lowest exhaust superheat value of the outdoor unit module based on the exhaust superheat value before operation and the exhaust superheat value after operation of each outdoor unit module; determining whether the outdoor unit module meets the deflection condition based on the exhaust superheat value after operation, the average exhaust superheat value after operation, and the lowest exhaust superheat value; if the outdoor unit module meets the deflection condition, determining that the outdoor unit module is a liquid return deflection module; wherein, the deflection condition is that the absolute value of the difference between the exhaust superheat value after operation and the average exhaust superheat value after operation is greater than or equal to a first difference threshold, and the lowest exhaust superheat value is less than or equal to a lowest exhaust superheat threshold.

[0018] Compared with existing technologies, the technical effect achieved by this solution is as follows: the flow deviation condition is that the absolute value of the difference between the exhaust superheat value and the average exhaust superheat value after operation is greater than or equal to a first difference threshold, and the minimum exhaust superheat value is less than or equal to a minimum exhaust superheat threshold. In other words, when the absolute value of the difference between the exhaust superheat value and the average exhaust superheat value after operation is greater than or equal to the first difference threshold, and the minimum exhaust superheat value is less than or equal to the minimum exhaust superheat threshold, i.e., when TH... n -TH ’ n ≥a, and When this occurs, it indicates that there is a flow deviation in the nth outdoor unit module of the parallel air conditioning unit. This outdoor unit module is a liquid return flow deviation module.

[0019] On the other hand, embodiments of the present invention also provide a control device for a parallel air conditioning unit, the control device comprising: an acquisition module for acquiring the operating parameters of each outdoor unit module of the parallel air conditioning unit; a first judgment module for judging whether each outdoor unit module is a liquid return bias module based on the operating parameters; a first correction module for correcting the target superheat of the outdoor unit module when it is a liquid return bias module; a second judgment module for judging whether liquid return exists in the outdoor unit module again after the target superheat correction is performed; and a control module for adjusting the operating parameters of the outdoor unit module when liquid return exists in the outdoor unit module.

[0020] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: The control device of the parallel unit air conditioner in this embodiment is used to implement the control method of the parallel unit air conditioner as in any embodiment of the present invention, and therefore it has all the beneficial effects of the control method of the parallel unit air conditioner as in any embodiment of the present invention, which will not be repeated here.

[0021] In another aspect, embodiments of the present invention also provide a parallel unit air conditioner, which includes: a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When the program or instructions are executed by the processor, they implement the steps of the control method of the parallel unit air conditioner as described in any of the above embodiments.

[0022] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the parallel unit air conditioner in this embodiment operates as the control method of the parallel unit air conditioner in any embodiment of the present invention, and therefore has all the beneficial effects of the control method of the parallel unit air conditioner in any embodiment of the present invention, which will not be repeated here.

[0023] In another aspect, embodiments of the present invention also provide a readable storage medium storing a program or instructions, which, when executed by a processor, implement the steps of the control method for a parallel unit air conditioner as described in any of the above embodiments.

[0024] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: The readable storage medium in this embodiment is used to store the control method of the parallel unit air conditioner as in any embodiment of the present invention, and therefore it has all the beneficial effects of the control method of the parallel unit air conditioner as in any embodiment of the present invention, which will not be repeated here.

[0025] By adopting the technical solution of the present invention, the following technical effects can be achieved:

[0026] (1) Correct the target superheat of the return liquid deviation module to avoid excessive refrigerant return to the compressor of the outdoor unit module during operation, which would damage the compressor, reduce the disadvantage of uneven distribution of the parallel air conditioner when it is running in the target operating mode, and ensure the reliability of operation.

[0027] (2) After the outdoor unit module is corrected for the target superheat, it is determined again whether there is liquid return in the outdoor unit module. In order to determine whether the liquid return problem of the liquid return deflection module has been solved by the target superheat correction, if there is still liquid return in the outdoor unit module in the parallel air conditioner after the target superheat correction, it is necessary to further adjust the operating parameters of the outdoor unit module to alleviate the damage caused by liquid return to the outdoor unit module.

[0028] (3) When liquid return occurs in the outdoor unit module, the liquid refrigerant will reduce the exhaust temperature of the compressor in the outdoor unit module. Therefore, the superheat of the compressor exhaust of the outdoor unit module can be used to determine whether there is liquid return deviation in the corresponding outdoor unit module. Attached Figure Description

[0029] Figure 1 This is a flowchart of a control method for a parallel unit air conditioner provided in Embodiment 1 of the present invention.

[0030] Figure 2 This is a system schematic diagram of a parallel unit air conditioner provided in Embodiment 1 of the present invention.

[0031] Figure 3 This is a schematic block diagram of the structure of a control device for a parallel unit air conditioner provided in the second embodiment of the present invention.

[0032] Figure 4 This is a block diagram of a parallel unit air conditioner provided in the third embodiment of the present invention.

[0033] Figure 5 This is a schematic diagram of the structure of a readable storage medium provided in the fourth embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1-Gas separator; 2-Compressor; 3-Ambient temperature sensor; 4-Oil temperature sensor; 5-Filter; 6-Exhaust temperature sensor; 7-Oil separator; 8-High pressure sensor; 9-Outdoor heat exchanger; 10-Low pressure sensor; 11-Four-way valve; 12-Indoor unit heat exchanger; 13-Gas pipe shut-off valve; 14-Outdoor electronic expansion valve; 15-Liquid pipe shut-off valve; 16-Indoor unit electronic expansion valve; 17-Indoor unit gas pipe temperature sensor; 18-Indoor unit liquid pipe temperature sensor; 100-Control device for parallel air conditioning units; 101-Acquisition module; 102-First judgment module; 103-First correction module; 104-Second judgment module; 105-Control module; 200-Parallel air conditioning units; 210-Memory; 211-Computer program; 220-Processor; 300-Readable storage medium; 310-Computer-executable instructions. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of the present invention more apparent and understandable, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] See Figure 1 The flowchart illustrates a control method for a parallel air conditioning unit according to the first embodiment of the present invention. The control method for the parallel air conditioning unit includes:

[0039] S100: Obtain the operating parameters of each outdoor unit module of the parallel air conditioning unit;

[0040] S200: Determines whether each outdoor unit module is a liquid return deflection module based on the operating parameters.

[0041] Specifically, the operating parameters of the outdoor unit modules include the exhaust superheat value before and after operation for each module. These parameters are used to pre-determine whether any outdoor unit modules exhibit liquid return deviation during target operation. Modules exhibiting liquid return deviation are marked as such for subsequent monitoring and target superheat correction, further preventing liquid return during operation. The number of outdoor unit modules is at least two; the number of liquid return deviation modules can be 0, 1, ..., n, depending on the actual determination.

[0042] S300: When the outdoor unit module is a liquid return deflection module, the target superheat correction is performed on the outdoor unit module.

[0043] Specifically, the target superheat correction is performed on the refrigerant return deflection module to prevent excessive refrigerant return to the compressor of the outdoor unit module during operation, which could damage the compressor. This also reduces the uneven distribution of refrigerant in parallel air conditioning units during target operating modes, ensuring operational reliability. The target superheat correction methods include: correcting the discharge superheat of the refrigerant return deflection module by adjusting the opening of the electronic expansion valve; and pre-emptively evacuating the refrigerant return deflection module to reserve sufficient liquid level for storing refrigerant returned due to deflection.

[0044] In one specific embodiment, see Figure 2 The present invention provides a system schematic diagram of a parallel unit air conditioner according to Embodiment 1. Each outdoor unit module includes a compressor 2, a gas separator 1, an oil separator 7, a four-way valve 11, an outdoor electronic expansion valve 14, a high-pressure sensor 8, a low-pressure sensor 10, an exhaust temperature sensor 6, etc.; the indoor unit module includes an indoor unit electronic expansion valve 16, an indoor unit gas pipe temperature sensor 17, an indoor unit liquid pipe temperature sensor 18, etc.

[0045] S400: After the outdoor unit module has been corrected for the target overheat, check again whether there is liquid return in the outdoor unit module;

[0046] S500: Adjust the operating parameters of the outdoor unit module when liquid return occurs in the outdoor unit module.

[0047] Specifically, after the outdoor unit module is corrected for the target superheat, it is checked again to see if liquid return exists in the outdoor unit module. This is to determine whether the liquid return problem of the liquid return deviation module has been resolved through the target superheat correction. If liquid return still exists in the outdoor unit module of the parallel air conditioning unit after the target superheat correction, it is necessary to further adjust the operating parameters of the outdoor unit module to mitigate the damage caused by liquid return to the outdoor unit module.

[0048] Furthermore, target overheat correction is performed on the outdoor unit module, including:

[0049] S310: Obtain the first exhaust superheat value and the first intake superheat value of the outdoor unit module;

[0050] S320: Based on the first exhaust superheat value and the first intake superheat value, the outdoor unit module is corrected for the target superheat.

[0051] The first exhaust superheat value is the value of the compressor exhaust superheat before the outdoor unit module is running; the first intake superheat value is the value of the gas intake superheat before the outdoor unit module is running.

[0052] Specifically, a temperature sensor can be installed at the exhaust port of the compressor in each outdoor unit module to obtain the exhaust superheat value of each outdoor unit module; a temperature sensor can be installed at the intake port of the gas separator in each outdoor unit module to obtain the intake superheat value of each outdoor unit module. The first exhaust superheat value can be used to determine whether the compressor exhaust temperature of the outdoor unit module is too low, and the first intake superheat value can be used to determine whether there is liquid return in the gas separator of the outdoor unit module.

[0053] In one specific embodiment, when the outdoor unit module is a refrigerant return deflection module, to ensure sufficient space in the gas separator of the refrigerant return deflection module for storing the refrigerant returned during the refrigerant return process, the air separator of the refrigerant return deflection module is evacuated before the outdoor unit module operates in the target operating mode. This provides sufficient space for storing the refrigerant that flows into the refrigerant return deflection module during operation. The target superheat correction method includes evacuating the gas separator of the refrigerant return deflection module in advance to reserve sufficient liquid level for storing the refrigerant returned due to the deflection. Therefore, upon receiving the target operating signal, the exhaust superheat of the refrigerant return deflection module is corrected by adjusting the opening of the electronic expansion valve in the module. For example, closing the opening of the electronic expansion valve in the outdoor unit module reduces the refrigerant flow in the module, thereby reducing the refrigerant flow to the compressor during the refrigerant return process and minimizing damage to the compressor.

[0054] Furthermore, based on the first exhaust superheat value and the first intake superheat value, the outdoor unit module is corrected for target superheat, including:

[0055] S321: Compare the first exhaust superheat value with the first exhaust superheat threshold, and the first intake superheat value with the first intake superheat threshold;

[0056] S322: Correct the target overheat of the outdoor unit module based on the comparison results;

[0057] When the first exhaust superheat value is less than or equal to the first exhaust superheat threshold, and the first intake superheat value is greater than the first intake superheat threshold, the outdoor unit module is corrected for target superheat based on the first superheat correction coefficient; and / or

[0058] When the first exhaust superheat value is less than or equal to the first exhaust superheat threshold and the first intake superheat value is less than or equal to the first intake superheat threshold, the outdoor unit module is corrected for target superheat based on the second superheat correction coefficient.

[0059] In one specific embodiment, when the first exhaust superheat value is less than or equal to the first exhaust superheat threshold, and the first intake superheat value is greater than the first intake superheat threshold, i.e., the first exhaust superheat value ≤ t p1 And the first intake superheat value > tx1 When the gas separator is empty, but there is a risk of liquid return to the outdoor unit module, the target superheat correction for the outdoor unit module is applied using k1. The target superheat correction is then increased by k1 until the first exhaust superheat value exceeds t. p1 Alternatively, the system may continuously adjust the first duration before entering the target operating mode; when the first exhaust superheat value is less than or equal to the first exhaust superheat threshold, and the first intake superheat value is less than or equal to the first intake superheat threshold, i.e., the first exhaust superheat value ≤ t p1 And the first intake superheat value ≤ t x1 If this indicates the presence of liquid in the gas separator and a risk of liquid return to the outdoor unit module, then the target superheat correction for the outdoor unit module is applied using k2. The target superheat correction is then increased by k2 until the first exhaust superheat value exceeds t. p1 Alternatively, the target operating mode can be entered after continuously adjusting the second duration; similarly, when the first exhaust superheat value is greater than the first exhaust superheat threshold, i.e., the first exhaust superheat value > t p1 If the outdoor unit module does not have a risk of liquid return, the liquid return deflection module can enter the target operating mode normally.

[0060] Among them, t p1 This represents the first exhaust superheat threshold, which is selected within the range of 20-30; t x1 k1 represents the first intake overheating threshold; k2 represents the first overheating correction coefficient, which is selected from 1 to 3; k3 represents the second overheating correction coefficient, which is selected from 2 to 5.

[0061] Preferably, the preferred value of the first exhaust superheat threshold is 25, the preferred value of the first intake superheat threshold is 0, the preferred value of the first superheat correction coefficient is 1, the preferred value of the second superheat correction coefficient is 3, the preferred value of the first duration is 5 min, and the preferred value of the second duration is 5 min.

[0062] Furthermore, it is necessary to re-check whether there is liquid return in the outdoor unit module, including:

[0063] S410: Obtain the second exhaust superheat value of the outdoor unit module;

[0064] S420: Compare the magnitudes of the second exhaust superheat and the second exhaust superheat threshold;

[0065] S430: When the second exhaust superheat value is less than the second exhaust superheat threshold, it is determined that there is liquid return in the outdoor unit module;

[0066] The second exhaust superheat value is the value of the compressor exhaust superheat after the outdoor unit module is running.

[0067] In one specific embodiment, after the outdoor unit module undergoes target superheat correction, it can then normally enter the target operating mode. Upon entering the target operating mode, it is necessary to determine again whether liquid return exists in the outdoor unit module. This is done by obtaining the second exhaust superheat value of the outdoor unit module and comparing it with the second exhaust superheat threshold. The determination of whether liquid return exists is as follows: if the second exhaust superheat value is less than the second exhaust superheat threshold, i.e., the second exhaust superheat value... <t p2 If liquid return is detected in the outdoor unit module, the operating parameters of the outdoor unit module need to be adjusted to reduce the damage to the compressor caused by the liquid return. When the second exhaust superheat value is greater than or equal to the second exhaust superheat threshold (i.e., the second exhaust superheat value ≥ t),... p2 When this time, it indicates that there is no risk of liquid return to the outdoor unit module. Among them, t p2 This indicates the second exhaust overheat threshold, which is selected within the range of 5-10.

[0068] Preferably, the second exhaust overheat threshold value is 8.

[0069] Furthermore, adjust the operating parameters of the outdoor unit module, including:

[0070] S510: Obtain the low-pressure reading of the compressor in the outdoor unit module;

[0071] S520: Corrects the compressor frequency based on the low-pressure and low-pressure threshold.

[0072] When the low-pressure is lower than the low-pressure threshold, the compressor frequency is corrected according to the first frequency correction coefficient; and / or

[0073] When the low-pressure is greater than or equal to the low-pressure threshold, the compressor frequency is not corrected.

[0074] In a specific embodiment, S400 can determine which outdoor unit module has liquid return. If an outdoor unit module has liquid return, the superheat of the compressor discharge of that outdoor unit module will decrease, even below the second superheat threshold. In the case of liquid return, high-frequency operation will cause greater damage to the compressor, and the low pressure will be lower during high-frequency operation, making it easier for the gas-liquid refrigerant to evaporate and boil, resulting in the compressor drawing in more wet vapor. Therefore, controlling the compressor frequency is an effective way to reduce compressor damage.

[0075] The specific adjustment method is as follows: when the second exhaust superheat value is less than the second exhaust superheat threshold, and the low-pressure is less than the low-pressure threshold, that is, the second exhaust superheat value... <t p2When the low-pressure pressure < p1, the compressor frequency is corrected according to f1, and at this time, the compressor frequency of the outdoor unit module is corrected - f1; when the second exhaust superheat value is less than the second exhaust superheat threshold and the low-pressure pressure is greater than or equal to the low-pressure threshold, that is, the second exhaust superheat value < t p2 When the low-pressure pressure ≥ p1, the compressor frequency of the outdoor unit module maintains the current frequency at this time; when the second exhaust superheat value is greater than or equal to the second exhaust superheat threshold, that is, the second exhaust superheat value ≥ t p2 It indicates that there is no risk of liquid return in the outdoor unit module, and the compressor of the outdoor unit module outputs control according to the normal capacity. Where, p1 represents the low-pressure threshold, f1 represents the first frequency correction coefficient, and the selection range of the first frequency correction coefficient is 5 - 15.

[0076] Preferably, the preferred value of the first frequency correction coefficient is 5.

[0077] Furthermore, obtain the working parameters of each outdoor unit module of the parallel unit air conditioner, and judge whether each outdoor unit module is a liquid return and flow deviation module according to the working parameters, including:

[0078] S110: When the parallel unit air conditioner operates in the target operation mode, obtain the pre-operation exhaust superheat value and the post-operation exhaust superheat value of each outdoor unit module.

[0079] In a specific embodiment, when operating in the target operation mode, the refrigerant flowing inside the manifold is generally in a gas-liquid mixed state. At this time, how to distribute the refrigerant and control the liquid return is more important. If not handled well, it will lead to flow deviation, and a large amount of refrigerant will flow to the liquid return and flow deviation module, resulting in excessive liquid return of the refrigerant in the liquid return and flow deviation module and wearing the compressor of the liquid return and flow deviation module. Therefore, it is urgent to solve. Preferably, an exhaust temperature sensor can be set at the exhaust port of the compressor in each outdoor unit module to obtain the exhaust superheat value of each outdoor unit module.

[0080] The specific process of obtaining the exhaust superheat value is as follows: Therefore, in the target operation mode, obtain the exhaust superheat values of the compressors in each outdoor unit module before operating in the target operation mode, which are respectively recorded as: TH1, TH2,..., TH n ; obtain the exhaust superheat values of the compressors in each outdoor unit module after operating in the target operation mode, which are respectively recorded as: TH ’ 1, TH ’ 2,..., TH ’ n . Where, n represents the number of outdoor unit modules in the parallel unit air conditioner; TH1 represents the exhaust superheat before operation of the first outdoor unit module in the parallel unit air conditioner, that is, the pre-operation superheat value of the first outdoor unit module in the parallel unit air conditioner; TH ’1 represents the exhaust superheat of the first outdoor unit module in a parallel air conditioning unit after operation; that is, the superheat value of the first outdoor unit module in a parallel air conditioning unit after operation. TH n This represents the exhaust superheat of the nth outdoor unit module in a parallel air conditioning unit before operation; TH is the superheat value of the nth outdoor unit module in a parallel air conditioning unit before operation. ’ n This represents the exhaust superheat of the nth outdoor unit module in a parallel air conditioning unit after it has been running; in other words, it is the superheat value of the nth outdoor unit module in a parallel air conditioning unit after it has been running.

[0081] Specifically, the target operating modes include: heating defrosting mode, heating reversing oil return mode, and cooling oil return mode.

[0082] S120: Determine whether each outdoor unit module is a liquid return deflection module based on the exhaust superheat value before and after operation.

[0083] In one specific embodiment, when liquid refrigerant returns to the outdoor unit module, the liquid refrigerant will lower the exhaust temperature of the compressor in the outdoor unit module. Therefore, the superheat of the compressor exhaust of the outdoor unit module can be used to determine whether there is liquid refrigerant flow deviation in the corresponding outdoor unit module.

[0084] The specific judgment process is as follows:

[0085] S121: Calculate the average exhaust superheat value of the parallel air conditioning units after operation based on the exhaust superheat value of each outdoor unit module.

[0086] Specifically, this can be achieved by obtaining the exhaust superheat value of each outdoor unit module after operation, and then calculating the average exhaust superheat value of all outdoor unit modules operating in the target operating mode based on the feedback of the exhaust superheat value of each outdoor unit module after operation. Among them, TH ’ dv This represents the average superheat of the exhaust gas after operation.

[0087] S122: Obtain the minimum exhaust superheat value of each outdoor unit module based on the exhaust superheat value before and after operation of each outdoor unit module.

[0088] Specifically, S110 can obtain the exhaust superheat value before and after operation for each outdoor unit module, and select the minimum value between the two by comparing the exhaust superheat values ​​before and after operation, which is recorded as the minimum exhaust superheat value. in This represents the minimum exhaust superheat value of the nth outdoor unit module in a parallel air conditioning unit.

[0089] S123: Based on the exhaust superheat value after operation, the average exhaust superheat value after operation, and the lowest exhaust superheat value, determine whether the outdoor unit module meets the flow deviation condition;

[0090] S124: If the outdoor unit module meets the deflection condition, determine that the outdoor unit module is a liquid return deflection module;

[0091] The flow deviation condition is that the absolute value of the difference between the exhaust superheat value and the average exhaust superheat value after operation is greater than or equal to the first difference threshold, and the minimum exhaust superheat value is less than or equal to the minimum exhaust superheat threshold.

[0092] In other words, when the absolute value of the difference between the exhaust superheat value and the average exhaust superheat value after operation is greater than or equal to the first difference threshold, and the lowest exhaust superheat value is less than or equal to the lowest exhaust superheat threshold, i.e., when TH... n -TH ’ n ≥a, and When this occurs, it indicates that the nth outdoor unit module in the parallel air conditioning unit has a flow deviation, and this outdoor unit module is a liquid return deviation module. Here, 'a' represents the first difference threshold, which is selected from 8 to 15; TH min This indicates the minimum exhaust superheat threshold.

[0093] Preferably, the first difference threshold is 10, and the minimum exhaust superheat threshold is 0.

[0094]

Example 2

[0095] See Figure 3 This embodiment also provides a control device 100 for a parallel air conditioning unit, including, for example: an acquisition module 101, used to acquire the operating parameters of each outdoor unit module of the parallel air conditioning unit; a first judgment module 102, used to determine whether each outdoor unit module is a liquid return bias module based on the operating parameters; a first correction module 103, used to perform target superheat correction on the outdoor unit module when it is a liquid return bias module; a second judgment module 104, used to determine again whether liquid return exists in the outdoor unit module after the target superheat correction is performed; and a control module 105, used to adjust the operating parameters of the outdoor unit module when liquid return exists in the outdoor unit module.

[0096] In one specific embodiment, the acquisition module 101, the first judgment module 102, the first correction module 103, the second judgment module 104, and the control module 105 of the control device 100 of the parallel unit air conditioner cooperate to implement the control method of the parallel unit air conditioner as described in the first embodiment above, which will not be repeated here.

[0097]

Example 3

[0098] See Figure 4 This embodiment provides a schematic diagram of the structure of a parallel unit air conditioner 200. The parallel unit air conditioner 200 includes, for example, a processor 220 and a memory 210 electrically connected to the processor 220. The memory 210 stores a computer program 211. The processor 220 loads the computer program 211 to implement the control method of the parallel unit air conditioner as in the first embodiment.

[0099]

Example 4

[0100] See Figure 5 This embodiment also provides a readable storage medium 300, which stores computer-executable instructions 310. When the computer-executable instructions 310 are read and run by the processor, the air conditioner where the readable storage medium 300 is located is controlled to implement the control method of the parallel unit air conditioner as in the first embodiment.

[0101] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0102] If the functionality is implemented as a software module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for parallel air conditioning units, characterized in that, The control method includes: Obtain the operating parameters of each outdoor unit module of the parallel air conditioning unit; Based on the operating parameters, determine whether each outdoor unit module is a liquid return deflection module; When the outdoor unit module is the liquid return deflection module, the target superheat correction is performed on the outdoor unit module; After the outdoor unit module is corrected for the target superheat, it is determined again whether there is liquid return in the outdoor unit module; If liquid return occurs in the outdoor unit module, adjust the operating parameters of the outdoor unit module.

2. The control method according to claim 1, characterized in that, The target overheat correction for the outdoor unit module includes: Obtain the first exhaust superheat value and the first intake superheat value of the outdoor unit module; Based on the first exhaust superheat value and the first intake superheat value, the outdoor unit module is corrected for target superheat. Wherein, the first exhaust superheat value is the value of the compressor exhaust superheat before the outdoor unit module is running; the first intake superheat value is the value of the gas intake superheat before the outdoor unit module is running.

3. The control method according to claim 2, characterized in that, The step of correcting the outdoor unit module for target superheat based on the first exhaust superheat value and the first intake superheat value includes: The comparison results are obtained by comparing the first exhaust superheat value with the first exhaust superheat threshold and the first intake superheat value with the first intake superheat threshold. Based on the comparison results, the outdoor unit module is corrected for target overheating. When the first exhaust superheat value is less than or equal to the first exhaust superheat threshold, and the first intake superheat value is greater than the first intake superheat threshold, the outdoor unit module is corrected for target superheat according to the first superheat correction coefficient; and / or When the first exhaust superheat value is less than or equal to the first exhaust superheat threshold, and the first intake superheat value is less than or equal to the first intake superheat threshold, the outdoor unit module is corrected for target superheat according to the second superheat correction coefficient.

4. The control method according to claim 1, characterized in that, The step of re-determining whether the outdoor unit module has liquid return includes: Obtain the second exhaust superheat value of the outdoor unit module; Compare the magnitudes of the second exhaust superheat and the second exhaust superheat threshold; When the second exhaust superheat value is less than the second exhaust superheat threshold, it is determined that there is liquid return in the outdoor unit module; The second exhaust superheat value is the value of the compressor exhaust superheat after the outdoor unit module is running.

5. The control method according to claim 1, characterized in that, Adjusting the operating parameters of the outdoor unit module includes: Obtain the low-pressure of the compressor in the outdoor unit module; The compressor frequency is corrected based on the low-pressure and low-pressure threshold. When the low-pressure is less than the low-pressure threshold, the compressor frequency is corrected according to the first frequency correction coefficient; and / or When the low pressure is greater than or equal to the low pressure threshold, the compressor frequency is not corrected.

6. The control method according to claim 1, characterized in that, The step of obtaining the operating parameters of each outdoor unit module of the parallel air conditioning unit, and determining whether each outdoor unit module is a liquid return deflection module based on the operating parameters, includes: When the parallel unit air conditioner is running in the target operating mode, the exhaust superheat value before operation and the exhaust superheat value after operation of each outdoor unit module are obtained. Based on the exhaust superheat value before operation and the exhaust superheat value after operation, determine whether each outdoor unit module is the return liquid deflection module.

7. The control method according to claim 6, characterized in that, The step of determining whether each outdoor unit module is a return liquid deflection module based on the exhaust superheat value before operation and the exhaust superheat value after operation includes: The average exhaust superheat value of the parallel unit air conditioner is calculated based on the exhaust superheat value of each outdoor unit module after operation. The minimum exhaust superheat value of each outdoor unit module is obtained based on the exhaust superheat value before operation and the exhaust superheat value after operation of each outdoor unit module. Based on the exhaust superheat value after operation, the average exhaust superheat value after operation, and the lowest exhaust superheat value, determine whether the outdoor unit module meets the flow deviation condition; If the outdoor unit module meets the deflection condition, the outdoor unit module is determined to be the liquid return deflection module; The deflection condition is that the absolute value of the difference between the exhaust superheat value after operation and the average exhaust superheat value after operation is greater than or equal to the first difference threshold, and the minimum exhaust superheat value is less than or equal to the minimum exhaust superheat threshold.

8. A control device for a parallel air conditioning unit, characterized in that, The control device includes: The acquisition module is used to acquire the operating parameters of each outdoor unit module of the parallel air conditioning unit; The first judgment module is used to determine whether each of the outdoor unit modules is a liquid return deflection module based on the operating parameters. The first correction module is used to correct the target superheat of the outdoor unit module when the outdoor unit module is the liquid return deflection module. The second judgment module is used to determine again whether there is liquid return in the outdoor unit module after the target superheat correction is performed on the outdoor unit module; The control module is used to adjust the operating parameters of the outdoor unit module when liquid return occurs.

9. An air conditioner, characterized in that, The air conditioner includes: a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein when the program or instructions are executed by the processor, they implement the steps of the control method for a parallel unit air conditioner as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the control method for a parallel unit air conditioner as described in any one of claims 1 to 7.

Images