Air conditioning system control method, air conditioning system and computer readable storage medium

Abstract

The application discloses an air conditioner system control method, an air conditioner system and a computer readable storage medium. The outdoor heat exchanger of the air conditioner system is divided into multiple outdoor sub-heat exchangers from top to bottom. Each outdoor sub-heat exchanger is provided with an adjusting valve for adjusting refrigerant flow. The control method comprises the following steps: starting the air conditioner system; and adjusting the refrigerant amount entering each outdoor sub-heat exchanger according to the current operation mode and temperature parameter of the air conditioner system to improve the heat exchange efficiency of the system. The application can make the top air-out multi-connected machine run under different loads and working conditions, and the refrigerant amount entering different branches of the outdoor heat exchanger can be maintained in a better running state, thereby obtaining better heat exchanger effect and reliability.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to an air conditioning system control method, an air conditioning system, and a computer-readable storage medium. Background Technology

[0002] Currently, most outdoor unit heat exchangers in multi-split air conditioning systems are designed as a single unit, making it impossible to control the upper and lower heat exchangers separately. Although some heat exchangers adopt a two-tiered design, this only results in two separate branches for liquid or air intake due to the height of the heat exchanger, without achieving independent control.

[0003] However, because large-capacity multi-split air conditioners typically use a top-discharge airflow design, there is a significant difference in airflow between the upper and lower heat exchangers. Therefore, the upper and lower heat exchangers need to be designed differently. Currently, mainstream manufacturers adjust the length of the capillary tubes at the liquid distribution front of the upper and lower heat exchangers. By controlling the capillary tube length, the amount of refrigerant received by the upper heat exchanger is adjusted to be greater than that received by the lower heat exchanger. However, once the capillary tube length is designed, it cannot be adjusted further. Furthermore, multi-split air conditioners have a wide load adjustment range, and the proportion of refrigerant distributed to the heat exchangers varies under different operating conditions. Therefore, this adjustment method cannot ensure that the refrigerant is optimally distributed under all load conditions. Summary of the Invention

[0004] In order to solve the technical problem of uneven refrigerant distribution in outdoor heat exchangers in the prior art, the present invention proposes an air conditioning system control method, an air conditioning system, and a computer-readable storage medium.

[0005] The technical solution adopted in this invention is: This invention proposes a control method for an air conditioning system. The outdoor heat exchanger of the air conditioning system is divided into multiple outdoor sub-heat exchangers from top to bottom. Each outdoor sub-heat exchanger is equipped with a regulating valve to adjust the refrigerant flow. The control method includes the following steps: The air conditioning system is turned on and running; Based on the current operating mode and operating parameters of the air conditioning system, the regulating valves are controlled to adjust the amount of refrigerant entering each of the outdoor heat exchangers, thereby improving the heat exchange efficiency of the system.

[0006] Furthermore, when the current operating mode of the air conditioning system is heating mode, controlling each of the regulating valves to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the system's heat exchange efficiency specifically includes the following steps: Set the initial heating opening degree of the regulating valve of each outdoor heat exchanger; The regulating valve of at least one outdoor sub-heat exchanger located above adjusts its opening degree according to the original control logic of the air conditioner, and the opening degree adjustment of the regulating valves of other outdoor sub-heat exchangers follows the opening degree adjustment of the regulating valve of at least one outdoor sub-heat exchanger located above according to a preset ratio.

[0007] In a specific embodiment, the outdoor heat exchanger of the air conditioning system is divided into two outdoor sub-heat exchangers from top to bottom. The step of controlling each of the regulating valves to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the system's heat exchange efficiency further includes the following steps: Run at the preset time; Get the defrost temperature T1 of the outdoor sub-heat exchanger located above, the defrost temperature T2 of the outdoor sub-heat exchanger located below, the current operating frequency P1 of the compressor, and the maximum operating frequency P2 of the compressor. Calculate the target defrosting temperature difference ΔT, where ΔT = n * P1 / P2, and n is a preset value; Determine whether T1-T2≥ΔT+a or T1-T2≤ΔT+a is true, where a is a preset value; if yes, adjust the opening of the regulating valve K2 of the lower outdoor sub-heat exchanger according to the defrosting temperature and the defrosting temperature difference; if no, return to the steps of adjusting the opening of the regulating valve of at least one upper outdoor sub-heat exchanger according to the original control logic of the air conditioner.

[0008] Furthermore, the adjustment amount K2B of the regulating valve K2 of the outdoor sub-heat exchanger located below, which is set according to the defrost temperature and the defrost temperature difference, is specifically calculated as follows: K2 B = [(T1-T2)-ΔT ] / m*100%, where m is a preset value.

[0009] In a specific embodiment, the outdoor heat exchanger of the air conditioning system is divided into two outdoor sub-heat exchangers from top to bottom. When the current operating mode of the air conditioning system is heating mode, controlling each of the regulating valves to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system specifically includes the following steps: Set the initial heating opening degree of the regulating valve of each outdoor heat exchanger; Run at the preset time; Obtain the defrosting temperature T1 of the upper outdoor sub-heat exchanger and the defrosting temperature T2 of the lower outdoor sub-heat exchanger. Determine whether T1-T2≥a or T1-T2≤-a is true. If yes, adjust the opening of the regulating valve K2 of the lower outdoor sub-heat exchanger according to the defrosting temperature and the defrosting temperature difference, and then return to the step of running for the preset time. If no, return to the step of running for the preset time.

[0010] Furthermore, the opening adjustment amount K2B of the regulating valve K2 of the outdoor sub-heat exchanger located below, which is set according to the defrosting temperature and the defrosting temperature difference, is specifically calculated as follows: K2B=(T1-T2) / m*100%, where m is a preset value.

[0011] In a specific embodiment, the outdoor heat exchanger of the air conditioning system is divided into two outdoor sub-heat exchangers from top to bottom. When the current operating mode of the air conditioning system is cooling mode, the outdoor ambient temperature, inlet pipe temperature TJ, outlet pipe temperature Tc, system high pressure PH, and system low pressure PL are detected. When the outdoor ambient temperature is lower than the preset ambient temperature, the first low-temperature cooling control is activated. The first low-temperature refrigeration control system adjusts the amount of refrigerant entering each of the outdoor heat exchangers based on the system pressure, inlet pipe temperature TJ, and outlet pipe temperature Tc, thereby improving the system's heat exchange efficiency.

[0012] Furthermore, the first cryogenic refrigeration control specifically includes: Set the initial opening degree of the regulating valve for low-temperature cooling of each outdoor heat exchanger; Determine if the system high pressure PH is greater than the preset high pressure; if so, increase the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below by the first preset degree and maintain it for the second preset time, then return to the step of determining the system high pressure PH; if not, determine whether to reduce the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below or switch to the second low temperature refrigeration control based on the pipe temperature and the system low pressure.

[0013] Furthermore, the step of determining whether to reduce the opening degree K2 of the regulating valve of the lower outdoor sub-heat exchanger or switch to the second low-temperature refrigeration control based on the pipe temperature and system low pressure specifically includes: Determine whether the following conditions are met: the inlet pipe temperature TJ is less than the preset inlet pipe temperature, the outlet pipe temperature Tc is less than the preset outlet pipe temperature, and the system low pressure PL is less than the preset system low pressure. If so, then determine whether the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below is greater than 0; if it is greater than 0, reduce the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below to the second preset opening degree, and maintain the operation for the second preset time, and then return to the step of determining the system high pressure PH; if it is less than or equal to 0, switch to the second low temperature refrigeration control. If not, return to the step of determining the system's high-pressure pH.

[0014] Furthermore, the second cryogenic refrigeration control specifically includes the following steps: Set the second low-temperature refrigeration initial opening degree of the regulating valve of each outdoor sub-heat exchanger; Determine if the system high pressure PH is greater than the preset high pressure; if so, increase the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above by the first preset degree and maintain it for the second preset time, then return to the step of determining the system high pressure PH; if not, determine whether to close the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above based on the pipe temperature and the system low pressure.

[0015] Furthermore, the step of determining whether to reduce the opening degree K1 of the regulating valve of the upper outdoor sub-heat exchanger based on the pipe temperature and system low pressure specifically includes the following steps: Determine whether the following conditions are met: the inlet pipe temperature TJ is less than the preset inlet pipe temperature, the outlet pipe temperature Tc is less than the preset outlet pipe temperature, and the system low pressure PL is less than the preset system low pressure. If yes, then determine whether the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above is greater than 0; if it is greater than 0, reduce the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above to a second preset degree and maintain it for a second preset time, then return to the step of determining the system high pressure PH; if it is less than or equal to 0, return to the step of determining the system high pressure PH. If not, return to the step of determining the system's high-pressure pH.

[0016] The present invention also proposes an air conditioning system, characterized in that the above-mentioned air conditioning system control method is used to control and adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system.

[0017] The present invention also proposes a computer-readable storage medium for storing a computer program, which executes the above-described air conditioning system control method when the computer program is run.

[0018] Compared with the prior art, the present invention has the following advantages: 1. It can enable top-discharge multi-split units to operate under different loads and conditions, and the amount of refrigerant entering different branches of the outdoor heat exchanger can be maintained at a better operating state, thereby obtaining better heat exchanger performance and reliability.

[0019] 2. When cooling in low outdoor temperatures, it can promptly reduce the outdoor heat exchange area, preventing the indoor unit from having excessively low airflow, or even causing the indoor unit to freeze and frequently start and stop. This improves comfort. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1This is a flowchart of the heating mode in an embodiment of the present invention; Figure 2 This is a flowchart of the cooling mode in an embodiment of the present invention; Figure 3 This is a flowchart of the low-temperature refrigeration mode in an embodiment of the present invention; Figure 4 This is a structural diagram of an embodiment of the present invention; Figure 5 This is a wind direction diagram of the outdoor heat exchanger in an embodiment of the present invention. Detailed Implementation

[0022] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0023] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0024] Because large-capacity multi-split air conditioners typically use a top-discharge airflow design, there is a significant difference in airflow between the upper and lower heat exchangers. Therefore, the upper and lower heat exchangers need to be designed differently. Currently, mainstream manufacturers adjust the length of the capillary tubes at the liquid distribution front of the upper and lower heat exchangers, controlling the refrigerant flow to ensure the upper heat exchanger receives more refrigerant than the lower one. However, once the capillary tube length is designed, it cannot be adjusted further. Furthermore, multi-split air conditioners have a wide load adjustment range, and the proportion of refrigerant distributed to the heat exchangers varies under different operating conditions. Therefore, this adjustment method cannot achieve optimal refrigerant distribution under all load conditions. To address this, this invention proposes an air conditioning system control method that allows direct control of various regulating valves after the air conditioning system is started to adjust the amount of refrigerant entering each outdoor heat exchanger, thereby improving the system's heat exchange efficiency.

[0025] like Figure 1 As shown, this invention proposes a control method for an air conditioning system, wherein the outdoor heat exchanger of the air conditioning system is divided into multiple outdoor sub-heat exchangers arranged from top to bottom. Each outdoor sub-heat exchanger is equipped with a regulating valve for regulating its refrigerant flow rate, and a defrost temperature sensor for detecting its defrost temperature. The control method includes the following steps: The air conditioning system is turned on and running; Based on the current operating mode and parameters of the air conditioning system, each regulating valve is controlled to adjust the amount of refrigerant entering each outdoor heat exchanger, thereby improving the system's heat exchange efficiency.

[0026] This control method allows for intelligent adjustment based on different operating modes and ambient temperatures to optimize the operating efficiency of the outdoor heat exchanger. By dividing the outdoor heat exchanger into multiple sub-heat exchangers and adjusting the refrigerant flow rate of each sub-heat exchanger, more precise refrigerant distribution can be achieved under different load conditions, thereby ensuring that the system achieves optimal heat exchange performance under various operating conditions.

[0027] like Figure 1 As shown, when the air conditioning system is currently operating in heating mode, controlling the various regulating valves to adjust the amount of refrigerant entering each outdoor heat exchanger and improving the system's heat exchange efficiency specifically includes the following steps: Set the initial heating opening degree of the regulating valve of each outdoor heat exchanger; The regulating valve of at least one outdoor heat exchanger located above adjusts its opening according to the original control logic of the air conditioner, such as commonly used PID regulation, step regulation, etc. The opening adjustment amount of the regulating valve of other outdoor sub-heat exchangers is adjusted according to a preset ratio, following the opening adjustment amount of the regulating valve of at least one outdoor sub-heat exchanger located above.

[0028] This control method aims to intelligently adjust the refrigerant quantity of the outdoor sub-heat exchangers in heating mode. First, an initial opening value is set for the regulating valve of each outdoor sub-heat exchanger by setting an initial heating opening. Then, the outdoor sub-heat exchanger at the top adjusts its regulating valve opening according to the air conditioner's original control logic. The opening adjustments of the regulating valves of the remaining outdoor sub-heat exchangers follow the opening adjustment of the regulating valve of at least one of the upper outdoor sub-heat exchangers according to a preset ratio. This preset ratio can be determined based on specific circumstances, for example, a 4:3 or 3:2 ratio. Through this adjustment method, the refrigerant quantity of other outdoor sub-heat exchangers can intelligently adjust according to the state of the upper outdoor sub-heat exchanger to achieve optimal heat exchange performance under different load conditions.

[0029] This intelligent refrigerant distribution method can improve the heat exchange efficiency of the air conditioning system in heating mode, enabling the system to cope with different operating conditions more efficiently, thereby improving overall energy efficiency and performance.

[0030] The following are specific examples illustrating the above heating modes: like Figure 1 As shown, when the air conditioning system is in heating mode, assuming there are two outdoor heat exchangers, let's take an example to illustrate the case where the adjustment ratio is 4:3. Setting the initial heating opening: When the system starts up, an initial opening value is set for the regulating valve of each outdoor sub-heat exchanger through a pre-set initial heating opening. For example, let's assume we set the initial opening of the regulating valve of the upper outdoor sub-heat exchanger to 80%, the initial opening of the regulating valve of the lower outdoor sub-heat exchanger to 60%, and the preset value a=0.1.

[0031] The outdoor sub-heat exchanger regulating valve located at the top is controlled according to the original control logic of the air conditioner. Based on the operating requirements and temperature parameters in heating mode, the regulating valve of the outdoor sub-heat exchanger will adjust its opening degree according to the system's control strategy. Assuming the opening degree adjustment is 10%, that is, the regulating valve of the outdoor sub-heat exchanger will be adjusted from the initial opening degree of 80% to 90%.

[0032] Other outdoor sub-heat exchangers are adjusted accordingly: Following a preset ratio of 4:3, the valve opening adjustment of other outdoor sub-heat exchangers follows the valve opening adjustment of the outdoor sub-heat exchanger located above. The valve opening adjustment of this outdoor sub-heat exchanger is 10% × 4 / 3 ≈ 13.3%.

[0033] Through this adjustment method, the refrigerant volume of the two outdoor sub-heat exchangers is intelligently allocated. The regulating valve of the upper outdoor sub-heat exchanger acts as the primary valve, while the regulating valves of the other sub-heat exchangers follow suit according to a preset 4:3 ratio. In heating mode, different outdoor sub-heat exchangers adjust their refrigerant volume based on the status of the upper outdoor sub-heat exchanger to optimize system heat exchange efficiency and meet optimal heat exchange requirements under different load conditions. This intelligent refrigerant allocation method allows the system to more efficiently handle the operating conditions in heating mode, improving overall energy efficiency and performance.

[0034] like Figure 1 As shown, the outdoor heat exchanger of the air conditioning system is divided into two outdoor sub-heat exchangers from top to bottom, with corresponding regulating valve openings of K1 and K2. Controlling each regulating valve to adjust the amount of refrigerant entering each outdoor sub-heat exchanger to improve the system's heat exchange efficiency further includes the following steps: Run at the preset time; Detect the defrost temperature T1 of the outdoor sub-heat exchanger located above, the defrost temperature T2 of the outdoor sub-heat exchanger located below, the current operating frequency P1 of the compressor, and the maximum operating frequency P2 of the compressor. Calculate the target defrosting temperature difference ΔT, ΔT=n*P1 / P2, where n is a preset value. The value of n varies for different heat exchangers, and can be between 0.8 and 1.2, for example, n=1; Determine whether T1-T2≥ΔT+a or T1-T2≤ΔT+a is true, where a is a preset value; if yes, adjust the opening of the regulating valve K2 of the lower outdoor sub-heat exchanger according to the defrosting temperature and the defrosting temperature difference; if no, return to the steps of adjusting the opening of the regulating valve of at least one upper outdoor sub-heat exchanger according to the original control logic of the air conditioner.

[0035] Furthermore, the opening adjustment amount K2B of the regulating valve K2 of the outdoor sub-heat exchanger located below is specifically calculated based on the defrost temperature and the defrost temperature difference: K2 B = [(T1-T2)-ΔT ] / m*100%, where m is a preset value, ranging from 8 to 20, with 10 recommended. This is because a large defrosting temperature difference between the upper and lower layers indicates a higher upper temperature and a lower lower temperature, meaning the lower evaporation temperature is too low. This implies the lower regulating valve is not open enough and needs to be increased to increase the refrigerant flow.

[0036] It should be noted that equating the load rate with the target defrost temperature difference is to maintain a reasonable temperature difference between the upper and lower heat exchangers. The upper part of the outdoor heat exchanger has a large airflow (i.e., the heat exchange effect of the upper outdoor sub-heat exchanger is better), resulting in a higher evaporation temperature and a larger refrigerant volume, meaning a larger opening of the electronic expansion valve on the upper heat exchanger. Conversely, a lower load leads to an overall increase in evaporation temperature, mitigating this phenomenon. ∆T = 1*P1 / P2 calculates a full-load temperature difference of 1℃. By adjusting the regulating valve of the lower outdoor sub-heat exchanger, the actual defrost temperature difference between the upper and lower heat exchangers is kept within the range of the target defrost temperature difference ±a℃. This ensures that the refrigerant volume of both heat exchangers operates within an optimal range.

[0037] The system determines the current status of the outdoor sub-heat exchanger by acquiring relevant temperature and frequency parameters and calculating the target defrosting temperature difference ΔT after a preset running time. Based on the determination, the opening of the regulating valve on the lower outdoor sub-heat exchanger is adjusted accordingly. If specific conditions are met, the valve opening will be further adjusted according to a certain formula to optimize refrigerant distribution and improve the system's heat exchange efficiency. If the conditions are not met, the original adjustment method will continue according to the preset control logic. The system can more precisely adjust the refrigerant quantity of the outdoor sub-heat exchanger to adapt to the optimal heat exchange requirements under different load conditions, thereby improving the performance and energy efficiency of the air conditioning system in heating mode.

[0038] like Figure 2 As shown, the outdoor heat exchanger of the air conditioning system is divided into two outdoor sub-heat exchangers from top to bottom, with corresponding regulating valve openings of K1 and K2. When the current air conditioning system is in heating mode, the refrigerant flow is adjusted by controlling the regulating valves of each outdoor sub-heat exchanger to improve the system's heat exchange efficiency. The specific steps include: Set the initial heating opening degree of each outdoor heat exchanger. That is, before starting the cooling mode, set the regulating valve of each outdoor heat exchanger to a suitable initial heating opening degree. Specifically, the initial opening degree of K1 is 100%, that is, fully open, and the initial opening degree of K2 is 80%.

[0039] Run for a preset time, allowing it to work normally for a period of time within the preset running time. The defrosting temperature T1 of the upper outdoor sub-heat exchanger and the defrosting temperature T2 of the lower outdoor sub-heat exchanger can be obtained in real time by defrosting temperature sensing bulb or other detection methods. Calculate the temperature difference between T1 and T2, i.e., ΔT = T1 - T2, and compare it with the preset deviation value a. If ΔT ≥ a or ΔT ≤ -a, adjust the opening amount K2 of the regulating valve K2 of the outdoor sub-heat exchanger below according to the defrosting temperature and the defrosting temperature difference. B Based on the actual defrosting temperature and temperature difference, adjust the opening degree K2 of the regulating valve located on the lower outdoor substation heat exchanger to optimize heat exchange efficiency, and then return to the preset running time. The opening degree of the regulating valve can increase or decrease the amount of refrigerant entering. Based on the new regulating valve opening degree K2, continue to run the system for the preset time period to observe and verify the improvement in heat exchange efficiency.

[0040] If the defrosting temperature difference does not meet the set conditions: If the defrosting temperature difference does not meet the preset conditions, it indicates that the current regulating valve opening K2 may be inappropriate or requires further adjustment. In this case, return to the step of running for the preset time, continue to monitor and calculate the defrosting temperature difference, and recalculate and adjust the regulating valve opening K2 based on the new data.

[0041] Specifically, the opening adjustment amount K2 of the regulating valve located on the lower outdoor sub-heat exchanger is set according to the defrost temperature and the defrost temperature difference. B The specific calculation formula is: K2 B = (T1-T2) / m*100%, where m is a preset value, ranging from 8 to 20, with 10 being recommended.

[0042] The above adjustment of K2 opening degree is a percentage of the total opening degree. For example, in an electronic expansion valve with a total of 3000 steps, K2 is calculated. B =1%, meaning the electronic expansion valve opens 30 steps.

[0043] The optimal preset value for 'a' is 0.1. Different units can be set with different values ​​for 'a', and the recommended range for 'a' is 0.1 to 0.5.

[0044] The recommended preset running time after each adjustment is 3 to 5 minutes to ensure normal adjustment and operation of the unit.

[0045] Through the above steps, the air conditioning system can improve its heat exchange efficiency and achieve more efficient cooling operation by dynamically adjusting the refrigerant flow in the outdoor unit heat exchanger during cooling mode. This optimized control can adapt to changing environmental conditions under different operating circumstances, enabling the air conditioning system to operate more intelligently and energy-efficiently.

[0046] like Figure 3 As shown, the outdoor heat exchanger of the air conditioning system is divided into two outdoor sub-heat exchangers from top to bottom, and the corresponding regulating valve openings are K1 and K2. When the current operating mode of the air conditioning system is cooling mode, the outdoor ambient temperature, inlet pipe temperature TJ, outlet pipe temperature Tc, system high pressure PH, and system low pressure PL are detected. When the outdoor ambient temperature is lower than the preset ambient temperature, the first low-temperature cooling control is activated. The first low-temperature refrigeration control system adjusts the amount of refrigerant entering each of the outdoor heat exchangers based on the system pressure, inlet pipe temperature TJ, and outlet pipe temperature Tc, thereby improving the system's heat exchange efficiency.

[0047] The first low-temperature refrigeration control specifically includes: Set the initial opening degree for low-temperature cooling of the regulating valves of each outdoor heat exchanger. Specifically, the initial opening degree of K1 is 100%, i.e., fully open, and the initial opening degree of K2 is 80%. Determine if the system high pressure PH is greater than the preset high pressure; if so, increase the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below by the first preset degree and maintain it for the second preset time, then return to the step of determining the system high pressure PH; if not, determine whether to reduce the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below or switch to the second low temperature refrigeration control based on the pipe temperature and the system low pressure.

[0048] The second low-temperature refrigeration control specifically includes the following steps: Set the second low-temperature refrigeration initial opening degree of the regulating valve of each outdoor sub-heat exchanger; Determine if the system high pressure PH is greater than the preset high pressure; if so, increase the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above by the first preset degree and maintain it for the second preset time, then return to the step of determining the system high pressure PH; if not, determine whether to close the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above based on the pipe temperature and the system low pressure.

[0049] Furthermore, determining whether to reduce the opening degree K1 of the regulating valve located on the upper outdoor sub-heat exchanger based on the pipe temperature and system low pressure includes the following steps: Determine whether the following conditions are met: the inlet pipe temperature TJ is less than the preset inlet pipe temperature, the outlet pipe temperature Tc is less than the preset outlet pipe temperature, and the system low pressure PL is less than the preset system low pressure. If yes, then determine whether the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above is greater than 0; if it is greater than 0, reduce the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above to a second preset degree and maintain it for a second preset time, then return to the step of determining the system high pressure PH; if it is less than or equal to 0, return to the step of determining the system high pressure PH. If not, return to the step of determining the system's high-pressure pH.

[0050] In this embodiment, the preset ambient temperature is recommended to be set to 5~15℃. Under such outdoor conditions, the air outlet temperature of the indoor unit is low or even frozen. The recommended value for the preset high-pressure pH is 45~50℃. Under low-temperature refrigeration, the compressor frequency is relatively low, and the compressor should be kept away from low frequency and high load operation as much as possible to avoid damage to the compressor.

[0051] The recommended rate for opening and closing the aforementioned regulating valve to the maximum extent is 10-15%. The recommended rate for closing to the minimum extent is 20-30%.

[0052] The preset inlet pipe temperature, preset outlet pipe temperature, and preset low pressure are recommended to be set to 3~7℃. At this temperature, the outlet air temperature of the indoor unit is relatively low, which may affect comfort. Different units may have different optimal settings.

[0053] The recommended preset running time after each adjustment is 3 to 5 minutes.

[0054] Through the above steps, the air conditioning system can dynamically adjust the refrigerant flow rate of the outdoor heat exchanger according to actual operating conditions in low-temperature environments, thereby improving the system's heat exchange efficiency and achieving more efficient cooling operation. The first low-temperature cooling control strategy adjusts the system's operating state based on a comparison between the system's high pressure and the preset high pressure, while the second low-temperature cooling control strategy further optimizes the cooling effect based on the inlet and outlet pipe temperatures and the system's low pressure. This intelligent control strategy contributes to the system's energy saving and performance optimization.

[0055] The present invention also proposes an air conditioning system that uses the above-described air conditioning system control method to control and adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system.

[0056] The air conditioning system is a multi-split system, and the outdoor heat exchanger adopts a top-discharge airflow design. Specifically, the outdoor heat exchanger is divided into upper and lower layers.

[0057] like Figure 4 , 5As shown, the multi-split air conditioner specifically includes: compressor 1, four-way valve 2, outdoor heat exchanger 3, subcooler 4, subcooler electronic expansion valve 41, indoor unit electronic expansion valve 5, indoor heat exchanger 6, and gas-liquid separator 7. The compressor's exhaust pipe is equipped with a high-pressure sensor 11 and a compressor exhaust temperature sensor 12. The high-pressure sensor 11 is used to detect the system's high-pressure pH. The compressor's intake pipe is equipped with a low-pressure sensor 13 and a suction temperature sensor 14, which are used to detect the system's low-pressure PL. The indoor heat exchanger 6 has an outlet pipe temperature sensor 61 and an inlet pipe temperature sensor 62 on both sides, which are used to detect the outlet pipe temperature Tc and the inlet pipe temperature TJ, respectively. The defrost temperature sensor 31 on the upper outdoor sub-heat exchanger is used to detect the defrost temperature T1, and the defrost temperature sensor on the lower outdoor sub-heat exchanger is used to detect the defrost temperature T2. The connecting pipes between the upper outdoor sub-heat exchanger and the lower outdoor sub-heat exchanger (in cooling mode) are equipped with regulating valves 32, specifically electronic expansion valves. The pipe connections between the various components are shown in the figure.

[0058] The present invention also proposes a computer-readable storage medium for storing a computer program, which executes the above-described defrosting control method for air conditioning units when the computer program is run.

[0059] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0060] It should be noted that the terminology used above is for describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0061] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0062] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling an air conditioning system, characterized in that, The outdoor heat exchanger of the air conditioning system is divided into multiple outdoor sub-heat exchangers from top to bottom. Each outdoor sub-heat exchanger is equipped with a regulating valve to adjust the refrigerant flow. The control method includes the following steps: The air conditioning system is turned on and running; Based on the current operating mode and operating parameters of the air conditioning system, the regulating valves are controlled to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system. The outdoor heat exchanger of the air conditioning system is divided from top to bottom into at least one outdoor sub-heat exchanger located at the top and an outdoor sub-heat exchange chamber located at the bottom. When the current operating mode of the air conditioning system is heating mode, the specific steps of controlling each of the regulating valves to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system include: Run at the preset time; Get the defrost temperature T1 of the outdoor sub-heat exchanger located above, the defrost temperature T2 of the outdoor sub-heat exchanger located below, the current operating frequency P1 of the compressor, and the maximum operating frequency P2 of the compressor. Calculate the target defrosting temperature difference ΔT, where ΔT = n * P1 / P2, and n is a preset value; Determine whether T1-T2≥ΔT+a or T1-T2≤ΔT+a is true, where a is a preset value; if yes, adjust the opening of the regulating valve K2 of the lower outdoor sub-heat exchanger according to the defrosting temperature and the defrosting temperature difference; if no, return to the steps of adjusting the opening of the regulating valve of at least one upper outdoor sub-heat exchanger according to the original control logic of the air conditioner.

2. The air conditioning system control method as described in claim 1, characterized in that, Controlling the regulating valves to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the system's heat exchange efficiency further includes the following steps: Set the initial heating opening degree of the regulating valve of each outdoor heat exchanger; The regulating valve of at least one outdoor sub-heat exchanger located above adjusts its opening degree according to the original control logic of the air conditioner, and the opening degree adjustment of the regulating valves of other outdoor sub-heat exchangers follows the opening degree adjustment of the regulating valve of at least one outdoor sub-heat exchanger located above according to a preset ratio.

3. The air conditioning system control method as described in claim 1, characterized in that, The opening adjustment amount K2 of the regulating valve located below the outdoor sub-heat exchanger is set according to the defrost temperature and the defrost temperature difference. B The specific calculation formula is: K2 B =[(T1-T2)-ΔT ] / m*100%, where m is a preset value.

4. A method for controlling an air conditioning system, characterized in that, The outdoor heat exchanger of the air conditioning system is divided into multiple outdoor sub-heat exchangers from top to bottom. Each outdoor sub-heat exchanger is equipped with a regulating valve to adjust the refrigerant flow. The control method includes the following steps: The air conditioning system is turned on and running; Based on the current operating mode and operating parameters of the air conditioning system, the regulating valves are controlled to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system. The outdoor heat exchanger of the air conditioning system is divided from top to bottom into at least one outdoor sub-heat exchanger located at the top and an outdoor sub-heat exchange chamber located at the bottom. When the current operating mode of the air conditioning system is heating mode, controlling each of the regulating valves to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system specifically includes the following steps: Set the initial heating opening degree of the regulating valve of each outdoor heat exchanger; Run at the preset time; Obtain the defrosting temperature T1 of the upper outdoor sub-heat exchanger and the defrosting temperature T2 of the lower outdoor sub-heat exchanger. Determine whether T1-T2≥a or T1-T2≤-a is true. If yes, adjust the opening of the regulating valve K2 of the lower outdoor sub-heat exchanger according to the defrosting temperature and the defrosting temperature difference, and then return to the step of running for the preset time. If no, return to the step of running for the preset time.

5. The air conditioning system control method as described in claim 4, characterized in that, The opening adjustment amount K2 of the regulating valve located below the outdoor sub-heat exchanger is set according to the defrost temperature and the defrost temperature difference. B The specific calculation formula is: K2 B = (T1-T2) / m*100%, where m is a preset value.

6. A method for controlling an air conditioning system, characterized in that, The outdoor heat exchanger of the air conditioning system is divided into multiple outdoor sub-heat exchangers from top to bottom. Each outdoor sub-heat exchanger is equipped with a regulating valve to adjust the refrigerant flow. The control method includes the following steps: The air conditioning system is turned on and running; Based on the current operating mode and operating parameters of the air conditioning system, the regulating valves are controlled to adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system. The outdoor heat exchanger of the air conditioning system is divided into at least one outdoor sub-heat exchanger located at the top and an outdoor sub-heat exchange chamber located at the bottom. When the current operating mode of the air conditioning system is cooling mode, the outdoor ambient temperature, inlet pipe temperature TJ, outlet pipe temperature Tc, system high pressure PH, and system low pressure PL are detected. When the outdoor ambient temperature is lower than the preset ambient temperature, the first low-temperature cooling control is activated. The first low-temperature refrigeration control system adjusts the amount of refrigerant entering each of the outdoor heat exchangers based on the system pressure, inlet pipe temperature TJ, and outlet pipe temperature Tc, thereby improving the system's heat exchange efficiency.

7. The air conditioning system control method as described in claim 6, characterized in that, The first low-temperature refrigeration control specifically includes: Set the initial opening degree of the regulating valve for low-temperature cooling of each outdoor heat exchanger; Determine if the system high pressure PH is greater than the preset high pressure; if so, increase the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below by the first preset degree and maintain it for the second preset time, then return to the step of determining the system high pressure PH; if not, determine whether to reduce the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below or switch to the second low temperature refrigeration control based on the pipe temperature and the system low pressure.

8. The air conditioning system control method as described in claim 7, characterized in that, The process of determining whether to reduce the opening degree K2 of the regulating valve of the lower outdoor sub-heat exchanger or switch to the second low-temperature refrigeration control based on the pipe temperature and system low pressure specifically includes: Determine whether the following conditions are met: the inlet pipe temperature TJ is less than the preset inlet pipe temperature, the outlet pipe temperature Tc is less than the preset outlet pipe temperature, and the system low pressure PL is less than the preset system low pressure. If so, then determine whether the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below is greater than 0; if it is greater than 0, reduce the opening degree K2 of the regulating valve of the outdoor sub-heat exchanger located below to the second preset opening degree, and maintain the operation for the second preset time, and then return to the step of determining the system high pressure PH; if it is less than or equal to 0, switch to the second low temperature refrigeration control. If not, return to the step of determining the system's high-pressure pH.

9. The air conditioning system control method as described in claim 7 or 8, characterized in that, The second low-temperature refrigeration control specifically includes the following steps: Set the second low-temperature refrigeration initial opening degree of the regulating valve of each outdoor sub-heat exchanger; Determine if the system high pressure PH is greater than the preset high pressure; if so, increase the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above by the first preset degree, maintain the operation for the second preset time, and then return to the step of determining the system high pressure PH. If not, determine whether to reduce the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above, based on the pipe temperature and system low pressure.

10. The air conditioning system control method as described in claim 8, characterized in that, The specific steps for determining whether to reduce the opening degree K1 of the regulating valve located on the upper outdoor sub-heat exchanger based on pipe temperature and system low pressure include: Determine whether the following conditions are met: the inlet pipe temperature TJ is less than the preset inlet pipe temperature, the outlet pipe temperature Tc is less than the preset outlet pipe temperature, and the system low pressure PL is less than the preset system low pressure. If yes, then determine whether the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above is greater than 0; if it is greater than 0, reduce the opening degree K1 of the regulating valve of the outdoor sub-heat exchanger located above to a second preset degree and maintain it for a second preset time, then return to the step of determining the system high pressure PH; if it is less than or equal to 0, return to the step of determining the system high pressure PH. If not, return to the step of determining the system's high-pressure pH.

11. An air conditioning system, characterized in that, The air conditioning system control method according to any one of claims 1 to 10 is used to control and adjust the amount of refrigerant entering each of the outdoor sub-heat exchangers to improve the heat exchange efficiency of the system.

12. A computer-readable storage medium for storing a computer program, characterized in that, When the computer program is executed, it performs the air conditioning system control method according to any one of claims 1 to 10.

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