Electronic expansion valve control method, electronic device, and medium

Abstract

The present application belongs to the technical field of multiple outdoor units in parallel, and specifically provides an electronic expansion valve control method, an electronic device and a medium, aiming to solve the problem that the opening degree control method of the existing electronic expansion valve easily leads to uneven distribution of refrigerant of the outdoor unit and insufficient heat exchange. To this end, the present application obtains the actual superheat degree △T_t and the initial target superheat degree △T_ct of each outdoor unit; obtains the uneven distribution correction value △T_xt and / or the exhaust temperature correction value △T_dt of each outdoor unit; corrects the initial target superheat degree △T_ct of each outdoor unit based on the obtained uneven distribution correction value △T_xt and / or the exhaust temperature correction value △T_dt of each outdoor unit, to obtain the corrected target superheat degree △TO of each outdoor unit; and controls the opening degree of the electronic expansion valve based on the actual superheat degree T_t and the corrected target superheat degree △TO of each outdoor unit. Such a setting can comprehensively adjust the opening degree of the electronic expansion valve from the aspects of sufficient heat exchange, balanced distribution and reliability.

Description

Technical Field

[0001] This invention belongs to the field of parallel connection technology of multiple outdoor units, and specifically provides an electronic expansion valve control method, electronic equipment, and readable storage medium. Background Technology

[0002] The application scenarios of multiple outdoor units in parallel are quite complex. The installation height and distance between the outdoor and indoor units differ significantly, making it crucial to achieve balanced liquid supply to the evaporator during cooling or heating operation.

[0003] Currently, in parallel systems with multiple outdoor units operating in heating mode, the opening of the electronic expansion valve of each outdoor unit is controlled by the target superheat of the outdoor heat exchanger. All outdoor units share the same target superheat. When the actual superheat of an outdoor unit exceeds the target superheat, the opening of the electronic expansion valve is increased, increasing the refrigerant supply to the outdoor heat exchanger; conversely, when the actual superheat is less than the target superheat, the opening of the electronic expansion valve is decreased, reducing the refrigerant supply to the outdoor heat exchanger. However, this control method is slow in adjusting refrigerant distribution balance, and in certain situations, the system may remain in a state of refrigerant distribution imbalance for extended periods.

[0004] Furthermore, in a system with multiple outdoor units connected in parallel, the varying distances between the outdoor and indoor units result in different refrigerant supplies. Outdoor units closer to the indoor units receive more refrigerant, while those farther away receive less. By controlling the target superheat of the outdoor units, the actual superheat of the units closer to the indoor units reaches the target value, and the opening of their electronic expansion valves stabilizes. However, the electronic expansion valves of the units farther from the indoor units reach their maximum opening, but the actual superheat still exceeds the target superheat. This situation leads to prolonged periods of uneven heat distribution in the outdoor units, resulting in insufficient heat exchange in the outdoor heat exchangers and reduced system capacity and energy efficiency.

[0005] Accordingly, there is a need in the field for a new electronic expansion valve control method to solve the above problems. Summary of the Invention

[0006] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem that the existing electronic expansion valve opening control method easily leads to uneven refrigerant distribution in the outdoor unit and insufficient heat exchange in the heat exchanger.

[0007] To achieve the above objectives, in a first aspect, the present invention provides an electronic expansion valve control method applied to a system of multiple outdoor units connected in parallel, the method comprising the following steps:

[0008] Obtain the actual superheat ΔT_t and the initial target superheat ΔT_ct for each outdoor unit;

[0009] Obtain the shunt imbalance correction value △T_xt and / or exhaust temperature correction value △T_dt for each outdoor unit;

[0010] The initial target superheat △T_ct of each outdoor unit is corrected based on the obtained shunt imbalance correction value △T_xt and / or exhaust temperature correction value △T_dt of each outdoor unit, so as to obtain the corrected target superheat △TO of each outdoor unit.

[0011] The opening degree of the electronic expansion valve is controlled based on the actual superheat ΔT_t of each outdoor unit and the corrected target superheat ΔTO.

[0012] In the optional technical solution of the above electronic expansion valve control method, obtaining the shunt imbalance correction value △T_xt of each outdoor unit includes:

[0013] Obtain the average superheat ΔT_tad of the multi-outdoor unit parallel system;

[0014] The correction value △T_xt for the unbalanced distribution of each outdoor unit is determined based on the actual superheat △T_t of each outdoor unit and the average superheat △T_tad of the parallel system of multiple outdoor units.

[0015] In the optional technical solutions of the above-mentioned electronic expansion valve control method, determining the shunt imbalance correction value △T_xt of each outdoor unit based on the actual superheat T_t of each outdoor unit and the average superheat △T_tad of the parallel system of multiple outdoor units includes:

[0016] The absolute value of the difference between the actual superheat ΔT_t and the average superheat ΔT_tad of each outdoor unit is obtained respectively. The absolute value of the difference is compared with the difference threshold, and the correction value ΔT_xt for the unbalanced distribution of each outdoor unit is determined based on the comparison result.

[0017] In the optional technical solutions of the above electronic expansion valve control method, obtaining the actual superheat T_t of each outdoor unit includes:

[0018] Obtain the heat exchanger outlet temperature Toci and suction pressure Ps of each outdoor unit;

[0019] Based on the obtained intake pressure Ps of each outdoor unit, the corresponding saturation temperature Ps_t is obtained.

[0020] The actual superheat ΔT_t of each outdoor unit is obtained according to the formula ΔT_t=Toci-Ps_t;

[0021] And / or, obtaining the average superheat ΔT_tad of the multiple outdoor units in parallel system includes:

[0022] According to the formula Obtain the average superheat ΔT_tad, where N is the total number of outdoor units, and Q... i For the capacity of each outdoor unit.

[0023] In the optional technical solution of the above electronic expansion valve control method, the step of determining the shunt imbalance correction value △T_xt of each outdoor unit based on the comparison result includes:

[0024] When the absolute value of the difference is less than or equal to the difference threshold, the preset first correction value is used as the outdoor unit's unbalanced distribution correction value △T_xt;

[0025] When the absolute value of the difference is greater than the difference threshold, according to the formula Obtain the corresponding outdoor unit's unbalanced distribution correction value △T_xt.

[0026] In the optional technical solutions of the above-mentioned electronic expansion valve control method, obtaining the exhaust temperature correction value △T_dt of each outdoor unit includes:

[0027] Obtain the exhaust temperature Td of each outdoor unit;

[0028] The exhaust temperature Td of each outdoor unit is compared with the first preset temperature, and the exhaust temperature correction value △T_dt of each outdoor unit is determined based on the comparison result. The exhaust temperature correction value △T_dt is greater than or equal to the first preset maximum exhaust temperature correction value.

[0029] Alternatively, obtain the exhaust temperature Td and exhaust pressure Pd of each outdoor unit;

[0030] The exhaust pressure Pd of each outdoor unit is used to obtain the saturation temperature Pd_t corresponding to the exhaust pressure.

[0031] The exhaust temperature superheat ΔTd of each outdoor unit is obtained according to the formula ΔTd=Td-Pd_t;

[0032] The exhaust temperature superheat △Td of each outdoor unit is compared with the second preset temperature, and the exhaust temperature correction value △T_dt of each outdoor unit is determined based on the comparison result. The exhaust temperature correction value △T_dt is less than or equal to the second preset maximum exhaust temperature correction value.

[0033] In the optional technical solution of the above electronic expansion valve control method, comparing the exhaust temperature Td of each outdoor unit with a first preset temperature, and determining the exhaust temperature correction value △T_dt of each outdoor unit based on the comparison result includes:

[0034] The number of times the exhaust temperature Td of the outdoor unit is greater than the first preset temperature is obtained. As the number of times increases, the exhaust temperature correction value △T_dt of each outdoor unit determined based on the comparison results decreases within the range of being greater than or equal to the first preset maximum exhaust temperature correction value.

[0035] Alternatively, the step of comparing the exhaust temperature superheat ΔTd of each outdoor unit with a second preset temperature and determining the exhaust temperature correction value ΔT_dt of the outdoor unit based on the comparison results includes: obtaining the number of times the exhaust temperature superheat ΔTd of the outdoor unit is less than the second preset temperature, and as the number of times increases, the exhaust temperature correction value ΔT_dt of the outdoor unit determined based on the comparison results increases within the range of less than or equal to the second preset maximum exhaust temperature correction value.

[0036] In the optional technical solution of the above electronic expansion valve control method, controlling the opening degree of the electronic expansion valve based on the actual superheat ΔT_t and the corrected target superheat ΔTO of each outdoor unit includes:

[0037] When the actual superheat △T_t is greater than the corrected target superheat △TO, the electronic expansion valve of the corresponding outdoor unit is controlled to increase its opening based on the existing opening.

[0038] When the actual superheat △T_t is less than the corrected target superheat △TO, the electronic expansion valve of the corresponding outdoor unit is controlled to reduce its opening based on the existing opening.

[0039] In a second aspect, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the electronic expansion valve control method as described in any of the preceding claims.

[0040] In a third aspect, the present invention provides a readable storage medium storing a plurality of program codes adapted to be loaded and run by a processor to perform the electronic expansion valve control method described in any one of the preceding descriptions.

[0041] Those skilled in the art will understand that, in the technical solution of this invention, the actual superheat ΔT_t and the initial target superheat ΔT_ct of each outdoor unit are obtained; the flow imbalance correction value ΔT_xt and / or exhaust temperature correction value ΔT_dt of each outdoor unit are obtained; the initial target superheat ΔT_ct of each outdoor unit is corrected based on the obtained flow imbalance correction value ΔT_xt and / or exhaust temperature correction value ΔT_dt, to obtain the corrected target superheat ΔTO of each outdoor unit; and the opening of the electronic expansion valve is controlled based on the actual superheat T_t and the corrected target superheat ΔTO of each outdoor unit. This setup allows for the correction of the initial target superheat of each outdoor unit using the flow imbalance correction value and the exhaust temperature correction value, thereby enabling the setting of different target superheat values ​​according to the actual operating conditions of the outdoor units, achieving comprehensive adjustment of the electronic expansion valve opening from the aspects of sufficient heat exchange, flow balance, and reliability.

[0042] Furthermore, obtaining the imbalance correction value △T_xt for each outdoor unit includes: according to the formula Obtain the average superheat ΔT_tad, where N is the total number of outdoor units, and Q... i To determine the capacity of each outdoor unit, the absolute value of the difference between the actual superheat ΔT_t and the average superheat ΔT_tad of each outdoor unit is obtained. This absolute value is then compared to a threshold value, and based on the comparison, a correction value ΔT_xt for the shunt imbalance of each outdoor unit is determined. This method of correcting the target superheat through shunt imbalance not only accelerates the adjustment speed of shunt balancing but also solves the shunt imbalance problem under specific circumstances, improving system capacity and ensuring stable and efficient system operation. Attached Figure Description

[0043] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Wherein:

[0044] Figure 1 This is a flowchart of the main steps of the electronic expansion valve control method according to the present invention;

[0045] Figure 2 This is a flowchart of the main steps for obtaining the shunt imbalance correction value △T_xt of each outdoor unit according to the present invention;

[0046] Figure 3 This is a flowchart of the main steps for obtaining the exhaust temperature correction value △T_dt of each outdoor unit according to the present invention;

[0047] Figure 4 This is a main structural block diagram of an electronic device used to perform the electronic expansion valve control method of the present invention. Detailed Implementation

[0048] Some embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] In the description of this invention, ordinal numbers such as "first" and "second" are used only to describe different technical features of the same type, and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature specified with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions or means of the various embodiments of this application can be combined with each other, as long as those skilled in the art can implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0050] In the description of this invention, "module" and "processor" can include hardware, software, or a combination of both. A module may include hardware circuitry, various suitable sensors, communication ports, and memory, and may also include software components, such as program code, or a combination of software and hardware. A processor may be a central processing unit, a microprocessor, a digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor may be implemented in software, in hardware, or a combination of both. Non-transitory computer-readable storage media include any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The singular terms "a" and "this" may also include plural forms.

[0051] As described in the background section, in view of the problem that the existing electronic expansion valve opening control method easily leads to uneven refrigerant distribution in the outdoor unit and insufficient heat exchange in the heat exchanger, the present invention provides an electronic expansion valve control method.

[0052] See appendix Figure 1 , Figure 1 This is a flowchart illustrating the main steps of the electronic expansion valve control method according to the present invention. Figure 1 As shown, the electronic expansion valve control method of the present invention is applied to a system of multiple outdoor units connected in parallel. The method includes the following steps:

[0053] Step S101: Obtain the actual superheat ΔT_t and the initial target superheat ΔT_ct for each outdoor unit.

[0054] In some embodiments, the initial target superheat ΔT_ct is a fixed temperature value, for example, the initial target superheat can be 5°C. The values ​​of the initial target superheat described above are only for illustrative purposes and can be selected according to actual needs in practical applications.

[0055] Step S102: Obtain the shunt imbalance correction value △T_xt and / or exhaust temperature correction value △T_dt for each outdoor unit.

[0056] Step S103: Based on the obtained shunt imbalance correction value △T_xt and / or exhaust temperature correction value △T_dt of each outdoor unit, correct the initial target superheat △T_ct of each outdoor unit to obtain the corrected target superheat △TO of each outdoor unit.

[0057] In some embodiments, the shunt imbalance correction value △T_xt and the exhaust temperature correction value △T_dt of each outdoor unit are obtained. Based on the obtained shunt imbalance correction value △T_xt and exhaust temperature correction value △T_dt of each outdoor unit and the formula △TO=△T_ct+△T_xt+△T_dt, the corrected target superheat △TO of each outdoor unit is obtained. The method for obtaining the corrected target superheat △TO of each outdoor unit described above is only an illustrative example, and can be selected according to actual needs in practical applications.

[0058] Step S104: Control the opening degree of the electronic expansion valve based on the actual superheat △T_t of each outdoor unit and the corrected target superheat △TO.

[0059] Those skilled in the art will understand that this invention obtains the actual superheat ΔT_t and the initial target superheat ΔT_ct of each outdoor unit; obtains the flow imbalance correction value ΔT_xt and / or exhaust temperature correction value ΔT_dt of each outdoor unit; corrects the initial target superheat ΔT_ct of each outdoor unit based on the obtained flow imbalance correction value ΔT_xt and / or exhaust temperature correction value ΔT_dt, to obtain the corrected target superheat ΔTO of each outdoor unit; and controls the opening of the electronic expansion valve based on the actual superheat T_t and the corrected target superheat ΔTO of each outdoor unit. This setup allows for the correction of the initial target superheat of each outdoor unit using the flow imbalance correction value and exhaust temperature correction value, thereby enabling the setting of different target superheat values ​​according to the actual operating conditions of the outdoor units, achieving comprehensive adjustment of the electronic expansion valve opening from the aspects of sufficient heat exchange, flow balance, and reliability.

[0060] In some embodiments, obtaining the actual superheat T_t of each outdoor unit includes: obtaining the heat exchanger outlet temperature Toci and the suction pressure Ps of each outdoor unit; obtaining the saturation temperature Ps_t corresponding to the suction pressure based on the obtained suction pressure Ps of each outdoor unit; and obtaining the actual superheat △T_t of each outdoor unit according to the formula △T_t=Toci-Ps_t.

[0061] For example, a temperature sensor is installed on the main gas pipe of each outdoor unit's heat exchanger, thereby obtaining the outlet temperature Toci of each outdoor unit's heat exchanger; a low-pressure sensor is installed on the suction pipe of each outdoor unit's compressor, thereby obtaining the suction pressure Ps of each outdoor unit. The obtained suction pressure Ps of each outdoor unit is then substituted into the formula ps_t = -0.7267 * ps 4 +7.8015*ps 3 -32.68*ps 2 From +79.279*ps-46.481, the saturation temperature Ps_t corresponding to the suction pressure Ps can be obtained. The methods described above for obtaining the heat exchanger outlet temperature Toci of each outdoor unit, obtaining the suction pressure Ps of each outdoor unit, obtaining the corresponding saturation temperature Ps_t based on the obtained suction pressure Ps, and the values ​​of the coefficients in the calculation formula for the saturation temperature Ps_t are all merely illustrative examples. In practical applications, selections can be made according to actual needs.

[0062] See appendix Figure 2 , Figure 2 This is a flowchart illustrating the main steps of obtaining the imbalance correction value △T_xt for each outdoor unit according to the present invention. Figure 2 As shown, in some embodiments, obtaining the shunt imbalance correction value △T_xt for each outdoor unit includes the following steps:

[0063] Step S201: Obtain the average superheat ΔT_tad of the multi-outdoor unit parallel system.

[0064] Step S202: Determine the shunting imbalance correction value △T_xt for each outdoor unit based on the actual superheat △T_t of each outdoor unit and the average superheat △T_tad of the parallel system of multiple outdoor units.

[0065] In some embodiments, obtaining the average superheat ΔT_tad of a system with multiple outdoor units connected in parallel includes: according to the formula Obtain the average superheat ΔT_tad, where N is the total number of outdoor units, and Q... iThis refers to the capacity of each outdoor unit. For example, a multi-outdoor-unit parallel system includes a physical host A and physical sub-units B, C, etc., totaling N outdoor units. Sub-units B, C, etc., transmit the actual superheat value ΔT_t to the physical host A. The physical host A receives the actual superheat values ​​sent by each sub-unit and, based on the formula... To obtain the average superheat ΔT_tad. Capability Q i Most of these parameters are located on the air conditioner's nameplate and refer to its ability to regulate temperature. They also represent a method of measuring the air conditioner's maximum usable production capacity. For example, an air conditioner's cooling capacity might be 3600W, and its heating capacity might be 4200W. The outdoor unit settings, the outdoor unit configuration for obtaining the average superheat ΔT_tad, and the values ​​of the capacity parameters described above are merely illustrative examples. In practical applications, selections can be made based on actual needs.

[0066] In some embodiments, determining the shunt imbalance correction value △T_xt for each outdoor unit based on the actual superheat T_t of each outdoor unit and the average superheat △T_tad of the parallel system of multiple outdoor units includes: obtaining the absolute value of the difference between the actual superheat △T_t and the average superheat △T_tad of each outdoor unit, comparing the absolute value of the difference with a difference threshold, and determining the shunt imbalance correction value △T_xt for each outdoor unit based on the comparison result. For example, the parallel system of multiple outdoor units includes a physical host A and physical sub-units B, C, etc. After the physical host A completes the acquisition of the average superheat △T_tad, it transmits the acquired average superheat △T_tad to the physical sub-units B, C, etc., so that the physical host A and the physical sub-units B, C, etc. can calculate their respective shunt imbalance correction values ​​△T_xt. The difference threshold can be 0.2. By comparing the absolute value of the difference with the difference threshold, it is determined whether the actual superheat of each outdoor unit differs too much from the average superheat. Based on the comparison result, the correction value ΔT_xt for the unbalanced current distribution of each outdoor unit is determined. The outdoor unit settings and difference threshold values ​​described above are only illustrative examples. In practical applications, the appropriate settings can be selected according to actual needs.

[0067] In some embodiments, determining the shunt imbalance correction value ΔT_xt for each outdoor unit based on the comparison results includes: when the absolute value of the difference is less than or equal to a difference threshold, using a preset first correction value as the shunt imbalance correction value ΔT_xt for the outdoor unit; when the absolute value of the difference is greater than the difference threshold, using the formula... Obtain the corresponding outdoor unit's refrigerant imbalance correction value △T_xt. For example, a parallel system of multiple outdoor units includes physical main unit A and physical sub-units B, C, etc., totaling N outdoor units. The difference threshold can be 0.2, and the first correction value can be 0. That is, when the absolute value of the difference between the actual superheat △T_t and the average superheat △T_tad of the outdoor unit is less than or equal to 0.2, it indicates that the actual superheat △T_t and the average superheat △T_tad of the outdoor unit are not significantly different, and the refrigerant distribution is relatively balanced. Therefore, the corresponding outdoor unit's refrigerant imbalance correction value △T_xt is 0, and no further refrigerant imbalance correction is applied to the initial target superheat △T_ct. When the absolute value of the difference between the actual superheat △T_t and the average superheat △T_tad of the outdoor unit is greater than 0.2, it indicates that the actual superheat △T_t and the average superheat △T_tad of the outdoor unit differ significantly, and the refrigerant distribution is somewhat unbalanced. Therefore, according to the formula... This is used to obtain the corresponding outdoor unit's imbalance correction value △T_xt. The outdoor unit settings, difference threshold, and first correction value described above are only illustrative examples and can be selected according to actual needs in practical applications.

[0068] like Figure 3 As shown, Figure 3 This is a flowchart illustrating the main steps for obtaining the exhaust temperature correction value △T_dt for each outdoor unit according to the present invention. Figure 3 As shown, in some embodiments, obtaining the exhaust temperature correction value △T_dt for each outdoor unit includes the following steps:

[0069] S301: Obtain the exhaust temperature Td of each outdoor unit.

[0070] S302: Compare the exhaust temperature Td of each outdoor unit with the first preset temperature, and determine the exhaust temperature correction value △T_dt of each outdoor unit based on the comparison result. The exhaust temperature correction value △T_dt is greater than or equal to the first preset maximum exhaust temperature correction value.

[0071] S303: Alternatively, obtain the exhaust temperature Td and exhaust pressure Pd of each outdoor unit.

[0072] S304: Obtain the saturation temperature Pd_t corresponding to the exhaust pressure based on the exhaust pressure Pd of each outdoor unit.

[0073] S305: Obtain the exhaust temperature superheat △Td of each outdoor unit according to the formula △Td=Td-Pd_t.

[0074] S306: Compare the exhaust temperature superheat △Td of each outdoor unit with the second preset temperature, and determine the exhaust temperature correction value △T_dt of each outdoor unit based on the comparison results. The exhaust temperature correction value △T_dt is less than or equal to the second preset maximum exhaust temperature correction value.

[0075] For example, an exhaust temperature sensor is installed on the compressor exhaust pipe of each outdoor unit to obtain the exhaust temperature Td of each outdoor unit. The first preset temperature can be 95℃, and the first preset maximum exhaust temperature correction value can be -3℃. That is, the exhaust temperature Td of each outdoor unit is compared with 95℃, and the exhaust temperature correction value △T_dt of each outdoor unit is determined based on the comparison result. The exhaust temperature correction value △T_dt is greater than or equal to -3℃. Alternatively, a high-pressure sensor is installed on the compressor exhaust pipe of each outdoor unit to obtain the exhaust pressure Pd of each outdoor unit. The obtained exhaust pressure Pd of each outdoor unit is then substituted into the formula pd_t = -0.7267 * pd. 4 +7.8015*pd 3 -32.68*pd 2 From +79.279*pd-46.481, the saturation temperature Pd_t corresponding to the exhaust pressure Pd can be obtained. The second preset temperature can be 20℃, and the second preset maximum exhaust temperature correction value can be 3℃. That is, the exhaust temperature superheat △Td of each outdoor unit is compared with 20℃, and the exhaust temperature correction value △T_dt of each outdoor unit is determined based on the comparison result. The exhaust temperature correction value △T_dt is less than or equal to 3℃. The above description of the first preset temperature, the first preset maximum exhaust temperature correction value, the second preset temperature and the second preset maximum exhaust temperature correction value, the method of obtaining the exhaust temperature Td, the method of obtaining the exhaust pressure Pd, the method of obtaining the exhaust pressure corresponding to the exhaust pressure Pd based on the obtained exhaust pressure Pd of each outdoor unit, and the value of the coefficient in the calculation formula of the saturation temperature Pd_t are only for illustrative purposes. In actual applications, they can be selected according to actual needs.

[0076] In some embodiments, comparing the exhaust temperature Td of each outdoor unit with a first preset temperature and determining the exhaust temperature correction value △T_dt of each outdoor unit based on the comparison result includes: obtaining the number of times the exhaust temperature Td of the outdoor unit is greater than the first preset temperature, and as the number of times increases, the exhaust temperature correction value △T_dt of the outdoor unit determined based on the comparison result decreases within the range of being greater than or equal to the first preset maximum exhaust temperature correction value; or, comparing the exhaust temperature superheat △Td of each outdoor unit with a second preset temperature respectively, and determining the exhaust temperature correction value △T_dt of each outdoor unit based on the comparison result includes: obtaining the number of times the exhaust temperature superheat △Td of the outdoor unit is less than the second preset temperature, and as the number of times increases, the exhaust temperature correction value △T_dt of the outdoor unit determined based on the comparison result increases within the range of being less than or equal to the second preset maximum exhaust temperature correction value.

[0077] For example, the first preset temperature can be 95℃, and the first preset maximum exhaust temperature correction value can be -3℃. That is, when the exhaust temperature Td of the outdoor unit is detected to be greater than 95℃ for the first time, the corresponding exhaust temperature correction value △T_dt of the outdoor unit is -1℃. When the exhaust temperature Td of the outdoor unit is detected to be greater than 95℃ again, the corresponding exhaust temperature correction value △T_dt of the outdoor unit is -2℃. When the exhaust temperature Td of the outdoor unit is detected to be greater than 95℃ for the third time or more, the corresponding exhaust temperature correction value △T_dt of the outdoor unit is -3℃. This avoids the reduction in compressor volumetric efficiency and the increase in power consumption caused by excessively high exhaust temperature Td, and extends the service life of the compressor. The second preset temperature can be 20℃, and the second preset maximum exhaust temperature correction value can be 3℃. That is, when the exhaust temperature overheat △Td of the outdoor unit is detected to be less than 20℃ for the first time, the corresponding exhaust temperature correction value △T_dt of the outdoor unit is 1℃. When the exhaust temperature overheat △Td of the outdoor unit is detected to be less than 20℃ again, the corresponding exhaust temperature correction value △T_dt of the outdoor unit is 2℃. When the exhaust temperature overheat △Td of the outdoor unit is detected to be less than 20℃ for the third time or more, the corresponding exhaust temperature correction value △T_dt of the outdoor unit is 3℃. This avoids poor oil return and liquid slugging of the compressor caused by excessively low exhaust temperature overheat △Td, and increases the reliability of the compressor operation. The values ​​of the first preset temperature, the first preset maximum exhaust temperature correction value, the second preset temperature, and the second preset maximum exhaust temperature correction value, as well as the setting of the exhaust temperature correction value △T_dt as the number of times the exhaust temperature Td of the outdoor unit is detected to be greater than the first preset temperature, and the setting of the exhaust temperature correction value △T_dt as the number of times the exhaust temperature overheating △Td of the outdoor unit is detected to be less than the second preset temperature, are all just examples. In actual applications, they can be selected according to actual needs.

[0078] In some embodiments, controlling the opening of the electronic expansion valve based on the actual superheat ΔT_t and the corrected target superheat ΔTO of each outdoor unit includes: when the actual superheat ΔT_t is greater than the corrected target superheat ΔTO, controlling the electronic expansion valve of the corresponding outdoor unit to increase its opening based on the existing opening, thereby increasing the refrigerant supply to the corresponding outdoor heat exchanger; when the actual superheat ΔT_t is less than the corrected target superheat ΔTO, controlling the electronic expansion valve of the corresponding outdoor unit to decrease its opening based on the existing opening, thereby decreasing the refrigerant supply to the corresponding outdoor heat exchanger.

[0079] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0080] See appendix Figure 4 , Figure 4 This is a main structural block diagram of an electronic device used to execute the electronic expansion valve control method of the present invention. (Example) Figure 4 As shown, the present invention also provides an electronic device 400 for executing the electronic expansion valve control method of the present invention. The electronic device 400 includes a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, it implements the steps in the various method embodiments described above. Alternatively, when the processor 401 executes the computer program 403, it implements the functions of each module / unit in the device embodiments described above.

[0081] For example, computer program 403 may be divided into one or more modules / units, which are stored in memory 402 and executed by processor 401 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 403 in electronic device 400.

[0082] Electronic device 400 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 400 may include, but is not limited to, processor 401 and memory 402. Those skilled in the art will understand that... Figure 4 This is merely an example of electronic device 400 and does not constitute a limitation on electronic device 400. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device may also include input / output devices, network access devices, buses, etc.

[0083] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0084] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments of the invention herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the invention.

[0085] In the embodiments provided by this invention, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. Multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0086] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0087] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0088] If integrated modules / units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. Computer-readable media may include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in a computer-readable medium may be appropriately added to or subtracted according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media may not include electrical carrier signals and telecommunication signals.

[0089] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. An electronic expansion valve control method, applied to a system of multiple outdoor units in parallel, characterized in that, The method includes the following steps: Obtain the actual superheat ΔT_t and the initial target superheat ΔT_ct for each outdoor unit; Obtain the shunt imbalance correction value △T_xt and / or exhaust temperature correction value △T_dt for each outdoor unit; Based on the obtained shunt imbalance correction value △T_xt and / or exhaust temperature correction value △T_dt of each outdoor unit, the initial target superheat △T_ct of each outdoor unit is corrected to obtain the corrected target superheat △TO of each outdoor unit. The opening degree of the electronic expansion valve is controlled based on the actual superheat △T_t of each outdoor unit and the corrected target superheat △TO. The step of obtaining the shunt imbalance correction value △T_xt for each outdoor unit includes: Obtain the average superheat ΔT_tad of the multi-outdoor unit parallel system; The shunting imbalance correction value △T_xt of each outdoor unit is determined based on the actual superheat △T_t of each outdoor unit and the average superheat △T_tad of the parallel system of multiple outdoor units. The step of obtaining the exhaust temperature correction value △T_dt for each outdoor unit includes: Obtain the exhaust temperature Td of each outdoor unit; The exhaust temperature Td of each outdoor unit is compared with the first preset temperature, and the exhaust temperature correction value △T_dt of each outdoor unit is determined based on the comparison result. The exhaust temperature correction value △T_dt is greater than or equal to the first preset maximum exhaust temperature correction value. Alternatively, obtain the exhaust temperature Td and exhaust pressure Pd of each outdoor unit; The exhaust pressure Pd of each outdoor unit is used to obtain the saturation temperature Pd_t corresponding to the exhaust pressure. The exhaust temperature superheat ΔTd of each outdoor unit is obtained using the formula ΔTd = Td - Pd_t. The exhaust temperature superheat △Td of each outdoor unit is compared with the second preset temperature, and the exhaust temperature correction value △T_dt of each outdoor unit is determined based on the comparison result. The exhaust temperature correction value △T_dt is less than or equal to the second preset maximum exhaust temperature correction value.

2. The electronic expansion valve control method according to claim 1, characterized in that, The correction value △T_xt for the shunting imbalance of each outdoor unit is determined based on the actual superheat T_t of each outdoor unit and the average superheat △T_tad of the parallel system of multiple outdoor units, including: The absolute value of the difference between the actual superheat ΔT_t and the average superheat ΔT_tad of each outdoor unit is obtained respectively. The absolute value of the difference is compared with the difference threshold, and the correction value ΔT_xt for the unbalanced distribution of each outdoor unit is determined based on the comparison result.

3. The electronic expansion valve control method according to claim 2, characterized in that, The process of obtaining the actual superheat T_t of each outdoor unit includes: Obtain the heat exchanger outlet temperature Toci and suction pressure Ps of each outdoor unit; Based on the obtained intake pressure Ps of each outdoor unit, the corresponding saturation temperature Ps_t is obtained. The actual superheat ΔT_t of each outdoor unit is obtained according to the formula ΔT_t=Toci-Ps_t; And / or, obtaining the average superheat ΔT_tad of the multiple outdoor units in parallel system includes: According to the formula Obtain the average superheat ΔT_tad, where N is the total number of outdoor units. For the capacity of each outdoor unit.

4. The electronic expansion valve control method according to claim 3, characterized in that, The determination of the shunt imbalance correction value △T_xt for each outdoor unit based on the comparison results includes: When the absolute value of the difference is less than or equal to the difference threshold, the preset first correction value is used as the outdoor unit's unbalanced distribution correction value △T_xt; When the absolute value of the difference is greater than the difference threshold, according to the formula Obtain the corresponding outdoor unit's unbalanced distribution correction value △T_xt.

5. The electronic expansion valve control method according to claim 1, characterized in that, The exhaust temperature Td of each outdoor unit is compared with a first preset temperature, and the exhaust temperature correction value △T_dt of each outdoor unit is determined based on the comparison result, including: The number of times the exhaust temperature Td of the outdoor unit is greater than the first preset temperature is obtained. As the number of times increases, the exhaust temperature correction value △T_dt of the outdoor unit determined based on the comparison results decreases within the range of being greater than or equal to the first preset maximum exhaust temperature correction value. Alternatively, the step of comparing the exhaust temperature superheat ΔTd of each outdoor unit with the second preset temperature and determining the exhaust temperature correction value ΔT_dt of each outdoor unit based on the comparison results includes: obtaining the number of times the exhaust temperature superheat ΔTd of the outdoor unit is less than the second preset temperature, and as the number of times increases, the exhaust temperature correction value ΔT_dt of the outdoor unit determined based on the comparison results increases within the range of less than or equal to the second preset maximum exhaust temperature correction value.

6. The electronic expansion valve control method according to claim 1, characterized in that, The control of the opening degree of the electronic expansion valve based on the actual superheat ΔT_t and the corrected target superheat ΔTO of each outdoor unit includes: When the actual superheat △T_t is greater than the corrected target superheat △TO, the electronic expansion valve of the corresponding outdoor unit is controlled to increase its opening based on the existing opening. When the actual superheat △T_t is less than the corrected target superheat △TO, the electronic expansion valve of the corresponding outdoor unit is controlled to reduce its opening based on the existing opening.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the electronic expansion valve control method as described in any one of claims 1 to 6.

8. A readable storage medium storing a plurality of program codes, characterized in that, The program code is adapted to be loaded and run by a processor to perform the electronic expansion valve control method according to any one of claims 1 to 6.

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