Control method and control device of air conditioning system, air conditioning system and storage medium

Abstract

The application discloses a control method and device of an air conditioning system, the air conditioning system and a computer readable storage medium. The control method comprises the following steps: acquiring an outdoor environment temperature and an indoor load parameter; when the air conditioning system is in a heating mode, the outdoor environment temperature is less than or equal to a first preset temperature, the indoor load parameter is less than or equal to a first preset load value, and only one outdoor unit is in an operating state, determining that the air conditioning system enters a special mode; in the special mode, controlling the outdoor unit in a shutdown state to close corresponding first and second valves, so that the outdoor unit in the shutdown state is isolated from a common refrigerant pipeline; when the air conditioning system satisfies an exit condition, controlling the outdoor unit in the shutdown state to open the corresponding first and second valves, so that the outdoor unit in the shutdown state is communicated with the common refrigerant pipeline. In the control method, the heating effect of the air conditioning system can be improved.

Description

Technical Field

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

[0002] In related technologies, multi-split air conditioning systems typically employ a structure where multiple outdoor units are connected in parallel and share a common refrigerant pipeline. Heating capacity is adjusted by starting and stopping different outdoor units. Under low-temperature heating and low-load conditions, only one outdoor unit may be operating, while the others remain off. However, under this operating condition, the heating capacity of the air conditioning system is significantly reduced, resulting in poor indoor heating performance. Summary of the Invention

[0003] The present invention provides a control method, control device, air conditioning system, and computer-readable storage medium for an air conditioning system to solve at least one of the aforementioned technical problems.

[0004] This invention provides a control method for an air conditioning system, the air conditioning system including an indoor unit and multiple outdoor units connected in parallel, the multiple outdoor units being connected to a common refrigerant pipeline through a first valve and a second valve, the common refrigerant pipeline being connected to the indoor unit; The control method includes: Obtain outdoor ambient temperature and indoor load parameters; When the air conditioning system is in heating mode, the outdoor ambient temperature is less than or equal to the first preset temperature, the indoor load parameter is less than or equal to the first preset load value, and only one outdoor unit is in operation, the air conditioning system is determined to enter a dedicated mode. In the dedicated mode, the outdoor unit in the shutdown state is controlled to close the corresponding first valve and second valve, so as to isolate the outdoor unit in the shutdown state from the common refrigerant pipeline; When the air conditioning system meets the exit conditions, the outdoor unit in the shutdown state is controlled to open the corresponding first valve and second valve, so that the outdoor unit in the shutdown state is connected to the common refrigerant pipeline.

[0005] In the above control method, in the dedicated mode, the outdoor unit in the shutdown state is controlled to close the corresponding first valve and second valve, so that the outdoor unit in the shutdown state is isolated from the common refrigerant pipeline. This can reduce the impact of the ineffective refrigerant volume formed by the outdoor unit in the shutdown state on the outdoor unit in the operating state, thereby improving the heating effect of the air conditioning system.

[0006] In some embodiments, the outdoor unit includes a compressor, the main inlet of which is connected to the common refrigerant line via the first valve, and the outlet of the compressor is connected to the common refrigerant line via the second valve. The control method further includes: In the dedicated mode, the operating frequency of the compressor of the outdoor unit in operation is controlled within a set dedicated frequency range; When the air conditioning system meets the exit condition, the operating frequency of the compressor of the outdoor unit in operation is controlled to be within a set normal frequency range. The upper limit of the set normal frequency range is greater than the upper limit of the set dedicated frequency range, and the lower limit of the set normal frequency range is less than the lower limit of the set dedicated frequency range.

[0007] In some embodiments, the outdoor unit includes a compressor, the secondary inlet of which is connected to the common refrigerant line via a third valve, and the control method further includes: In the dedicated mode, the outdoor unit in operation is controlled to open the corresponding third valve; When the air conditioning system meets the exit condition, the outdoor unit in operation is controlled to close the corresponding third valve.

[0008] In some embodiments, the outdoor unit includes an outdoor heat exchanger, and a fourth valve is provided between the outdoor heat exchanger and the second valve. The fourth valve is used to throttle and reduce the pressure of the refrigerant from the second valve, so as to facilitate the evaporation and heat absorption of the refrigerant in the outdoor heat exchanger. The control method further includes: In the dedicated mode, the opening degree of the fourth valve is adjusted according to the set dedicated intake superheat range; When the air conditioning system meets the exit condition, the opening of the fourth valve is adjusted according to the set conventional intake superheat range, wherein the set special intake superheat range is smaller than the set conventional intake superheat range.

[0009] In some embodiments, the first preset temperature is 0°C to 3°C.

[0010] In some implementations, the first preset load ratio is 10% to 18%.

[0011] In some implementations, the exit condition includes at least one of the following: The outdoor ambient temperature is greater than or equal to the second preset temperature; The indoor load parameter is greater than or equal to the second preset load value; The air conditioning system requires the activation of a second or more outdoor units.

[0012] An embodiment of the present invention provides a control device, including a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the control method described in any of the above embodiments.

[0013] An air conditioning system provided by an embodiment of the present invention includes an indoor unit, a plurality of outdoor units connected in parallel, and a control device as described in the above embodiment. The plurality of outdoor units are all connected to a common refrigerant pipeline through a first valve and a second valve. The common refrigerant pipeline is connected to the indoor unit. The control device is electrically connected to the outdoor unit, the indoor unit, the first valve, and the second valve, respectively.

[0014] The present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the control method described in any of the above embodiments.

[0015] Additional aspects and advantages of the invention will be set forth in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein: Figure 1 This is a flowchart illustrating the control method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the air conditioning system in heating mode according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the air conditioning system in cooling mode according to an embodiment of the present invention; Figure 4 This is a schematic diagram of another module of the air conditioning system according to an embodiment of the present invention.

[0017] Explanation of key component reference numerals: Air conditioning system 100, indoor unit 10, outdoor unit 20, first valve 30, second valve 40, common refrigerant pipeline 50, control device 60, indoor heat exchanger 101, fifth valve 102, compressor 201, third valve 202, outdoor heat exchanger 203, fourth valve 204, plate heat exchanger 205, four-way valve 206, one-way valve 207, first temperature sensor 208, first pressure sensor 209, second temperature sensor 210, second pressure sensor 211, gas-liquid separator 212, third temperature sensor 213, processor 601, memory 602. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of the present invention, and should not be construed as limiting the embodiments of the present invention.

[0019] Please see Figures 1 to 3 The present invention provides a control method for an air conditioning system 100, the air conditioning system 100 including an indoor unit 10 and a plurality of outdoor units 20 connected in parallel, the plurality of outdoor units 20 being connected to a common refrigerant pipeline 50 through a first valve 30 and a second valve 40, the common refrigerant pipeline 50 being connected to the indoor unit 10; Control methods include: Step S01: Obtain outdoor ambient temperature and indoor load parameters; Step S03: When the air conditioning system 100 is in heating mode, the outdoor ambient temperature is less than or equal to the first preset temperature, the indoor load parameter is less than or equal to the first preset load value, and only one outdoor unit 20 is in operation, the air conditioning system 100 is determined to enter the special mode. Step S05a: In dedicated mode, control the outdoor unit 20 in the shutdown state to close the corresponding first valve 30 and second valve 40 so as to isolate the outdoor unit 20 in the shutdown state from the common refrigerant pipeline 50. Step S07a: When the air conditioning system 100 meets the exit conditions, the outdoor unit 20 in the shutdown state is controlled to open the corresponding first valve 30 and second valve 40 so that the outdoor unit 20 in the shutdown state is connected to the common refrigerant pipeline 50.

[0020] In the above control method, in the dedicated mode, the outdoor unit 20 in the shutdown state is controlled to close the corresponding first valve 30 and second valve 40, so that the outdoor unit 20 in the shutdown state is isolated from the common refrigerant pipeline 50. This can reduce the impact of the ineffective refrigerant volume formed by the outdoor unit 20 in the shutdown state on the outdoor unit 20 in the operating state, thereby improving the heating effect of the air conditioning system 100.

[0021] Specifically, the air conditioning system 100 includes, but is not limited to, a multi-split air conditioning system 100 and a multi-split heat pump system. The air conditioning system 100 includes an indoor unit 10 and multiple outdoor units 20 connected in parallel. All outdoor units 20 are connected to the indoor unit 10 via a common refrigerant pipeline 50. Each outdoor unit 20 is equipped with a first valve 30 and a second valve 40, which control the connection between the corresponding outdoor unit 20 and the common refrigerant pipeline 50. Through the coordinated operation of multiple outdoor units 20 and the indoor unit 10, the indoor ambient temperature can be regulated. Optionally, the number of indoor units 10 and outdoor units 20 can be determined according to actual needs; this invention does not impose a specific limitation on this. Figure 2 In the middle, the air conditioning system 100 includes 2 outdoor units 20 and 4 indoor units 10.

[0022] Optionally, the outdoor unit 20 includes a compressor 201, a four-way valve 206, an outdoor heat exchanger 203, a third valve 202, a plate heat exchanger 205, a fourth valve 204, a gas-liquid separator 212, and a one-way valve 207.

[0023] The compressor 201 provides power for the refrigerant cycle, compresses the inhaled low-temperature, low-pressure gaseous refrigerant, and outputs high-temperature, high-pressure gaseous refrigerant. The compressor 201 includes a main inlet, an outlet, and a secondary inlet. The main inlet draws in the low-temperature, low-pressure gaseous refrigerant from the main refrigerant circuit; the secondary inlet draws in the medium-pressure gaseous refrigerant supplied by the jet branch; and the outlet discharges the compressed high-temperature, high-pressure gaseous refrigerant.

[0024] The four-way valve 206 is used to switch the direction of refrigerant flow in order to switch between heating and cooling modes of the air conditioning system 100.

[0025] The outdoor heat exchanger 203 is used to exchange heat between the refrigerant and the outdoor air. In heating mode, the outdoor heat exchanger 203 acts as an evaporator to absorb heat from the outdoor environment; in cooling mode, the outdoor heat exchanger 203 acts as a condenser to release heat to the outdoor environment.

[0026] The fourth valve 204 is located between the outdoor heat exchanger 203 and the second valve 40. In heating mode, the fourth valve 204 can throttle and reduce the pressure of the high-pressure liquid refrigerant entering the outdoor heat exchanger 203 and adjust the evaporation flow rate to regulate the heating capacity.

[0027] A plate heat exchanger 205 is located between the second valve 40 and the fourth valve 204 to achieve indirect heat exchange between the refrigerant in the main circuit and the refrigerant in the jet branch. Specifically, a jet branch is provided between the second valve 40 and the secondary inlet of the compressor 201, and a third valve 202 is located on the jet branch. In heating mode, when the third valve 202 is open, part of the high-pressure liquid refrigerant from the second valve 40 directly enters the plate heat exchanger 205 in the main circuit, and then enters the outdoor heat exchanger 203 after being throttled by the fourth valve 204, and then is delivered to the main inlet of the compressor 201; the other part is throttled and depressurized by the third valve 202 and enters the plate heat exchanger 205 in the jet branch. After absorbing heat from the refrigerant in the main circuit in the plate heat exchanger 205, it forms a medium-pressure gaseous refrigerant, which then enters the secondary inlet of the compressor 201 to mix with the refrigerant in the main circuit and is then compressed by the compressor 201.

[0028] The gas-liquid separator 212 is installed before the main inlet of the compressor 201 to separate the liquid refrigerant in the return gas, so that the refrigerant entering the compressor 201 is mainly in gaseous state, thereby reducing the risk of liquid slugging in the compressor 201.

[0029] A one-way valve 207 is located at the outlet of compressor 201 to prevent refrigerant from entering the interior of compressor 201 from the outlet of compressor 201, thereby protecting compressor 201.

[0030] The indoor unit 10 includes an indoor heat exchanger 101 and a fifth valve 102.

[0031] The indoor heat exchanger 101 is used to exchange heat between the refrigerant and the indoor air. In heating mode, the indoor heat exchanger 101 acts as a condenser, releasing heat to the indoor environment; in cooling mode, the indoor heat exchanger 101 acts as an evaporator, absorbing heat from the indoor environment.

[0032] The fifth valve 102 is located between the indoor heat exchanger 101 and the second valve 40. In the cooling mode, the fifth valve 102 can throttle and reduce the pressure of the high-pressure liquid refrigerant entering the indoor heat exchanger 101 and adjust the evaporation flow rate to regulate the cooling capacity.

[0033] During the operation of the air conditioning system 100, when the air conditioning system 100 is in heating mode, such as Figure 2The compressor 201 draws in low-temperature, low-pressure gaseous refrigerant at its main inlet and compresses it to form high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant is diverted via four-way valve 206 to the first valve 30 and then transported to the indoor unit 10 through the common refrigerant pipeline 50. There, it exchanges heat with indoor air in the indoor heat exchanger 101, releasing heat to the indoor environment before condensing to form high-pressure liquid refrigerant. The high-pressure liquid refrigerant returns to the outdoor unit 20 via the common refrigerant pipeline 50 and the second valve 40. After being throttled and depressurized by the fourth valve 204, it enters the outdoor heat exchanger 203, where it absorbs heat from the outdoor environment and evaporates to form low-temperature, low-pressure gaseous refrigerant. This gaseous refrigerant then returns to the main inlet of the compressor 201 via four-way valve 206 and gas-liquid separator 212, thus completing the refrigerant cycle for heating.

[0034] When the third valve 202 is opened, part of the high-pressure liquid refrigerant flowing out from the second valve 40 is throttled and depressurized into medium-pressure gaseous refrigerant through the third valve 202 of the jet branch, and then flows back to the secondary inlet of the compressor 201 after heat exchange in the plate heat exchanger 205.

[0035] When the air conditioning system 100 is in cooling mode, such as Figure 3 The compressor 201 draws in low-temperature, low-pressure gaseous refrigerant at its main inlet and compresses it to form high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant is diverted through the four-way valve 206 into the outdoor heat exchanger 203, where it releases heat to the outdoor environment and condenses to form high-pressure liquid refrigerant. The high-pressure liquid refrigerant then enters the indoor unit 10, which is in operation, through the second valve 40 and the common refrigerant line 50. After being throttled and depressurized by the fifth valve 102, it absorbs heat from the indoor environment in the indoor heat exchanger 101 and evaporates to form low-temperature, low-pressure gaseous refrigerant. Subsequently, it returns to the main inlet of the compressor 201 via the common refrigerant line 50, the first valve 30, the four-way valve 206, and the gas-liquid separator 212, thus completing the refrigerant cycle.

[0036] Understandably, during the operation of the air conditioning system 100, different numbers of outdoor units 20 can be activated based on the indoor load parameters. When the indoor load parameters are high, it indicates that the current indoor heat / cooling capacity required is large. In this case, multiple outdoor units 20 can be activated simultaneously to improve the operating performance of the air conditioning system 100. When the indoor load parameters are low, it indicates that the current indoor heat / cooling capacity required is small. In this case, only some outdoor units 20 can be activated to reduce the energy consumption of the air conditioning system 100.

[0037] Under certain special operating conditions, when the air conditioning system 100 is in heating mode, the outdoor ambient temperature is low, and the indoor load parameters are small, in order to reduce power consumption, only one outdoor unit 20 of the air conditioning system 100 is in operation, while the other outdoor units 20 are in shutdown mode. However, if the outdoor unit 20 in shutdown mode is still connected to the common refrigerant pipeline 50, the heat exchanger, refrigerant pipeline, and gas-liquid separator 212 and other components inside the outdoor unit 20 in shutdown mode will form a large volume of ineffective refrigerant, thereby occupying some refrigerant and affecting the refrigerant circulation of the outdoor unit 20 in operation mode, which can easily lead to a decrease in the heating effect of the air conditioning system 100.

[0038] Therefore, this embodiment provides a control method for an air conditioning system 100. When the air conditioning system 100 is in heating mode, the outdoor ambient temperature is less than or equal to a first preset temperature, the indoor load parameter is less than or equal to a first preset load value, and only one outdoor unit 20 is in operation, the air conditioning system 100 is determined to enter a dedicated mode. In the dedicated mode, the outdoor unit 20 in the shutdown state is controlled to close the corresponding first valve 30 and second valve 40, which can isolate the outdoor unit 20 in the shutdown state from the common refrigerant pipeline 50. When the air conditioning system 100 meets the exit conditions, the outdoor unit 20 in the shutdown state is controlled to open the corresponding first valve 30 and second valve 40, so that the outdoor unit 20 in the shutdown state is reconnected to the common refrigerant pipeline 50.

[0039] It should be noted that the outdoor ambient temperature can be obtained through a third temperature sensor 213 located around the outdoor heat exchanger 203. The indoor load parameter is used to characterize the current load level of the air conditioning system 100, and can be obtained by the ratio of the total rated heating capacity of the currently operating indoor units 10 to the rated heating capacity of the currently operating outdoor unit 20.

[0040] It is understood that in this embodiment, in the dedicated mode, after the outdoor unit 20 in the shutdown state closes the corresponding first valve 30 and second valve 40, the outdoor unit 20 in the shutdown state can be isolated from the common refrigerant pipeline 50, thereby preventing components such as the heat exchanger, refrigerant pipeline, and gas-liquid separator 212 inside the outdoor unit 20 in the shutdown state from participating in the refrigerant circulation. Since the ineffective refrigerant volume formed by the outdoor unit 20 in the shutdown state is isolated, the refrigerant circulation loop volume corresponding to the outdoor unit 20 in the operating state decreases, and the proportion of refrigerant participating in the effective circulation increases, which is beneficial to improving the heat exchange efficiency of the outdoor unit 20 in the operating state. Especially under low-temperature heating and low-load operation conditions, by reducing the impact of ineffective refrigerant volume on the refrigerant circulation, the heating operation state of the outdoor unit 20 in the operating state can be effectively improved, thereby improving the heating effect and operational stability of the air conditioning system 100.

[0041] Furthermore, after the exit conditions are met, the first valve 30 and the second valve 40 are reopened to reconnect the outdoor unit 20, which was in a shutdown state, to the common refrigerant pipeline 50. This allows the coordinated operation of multiple outdoor units 20 to be restored according to subsequent load demands, balancing the operating performance under low load conditions and the heating capacity under high load conditions. Optionally, after the exit conditions are met, the first valve 30 and the second valve 40 can be slowly opened to gradually bring the internal pressure of the outdoor unit 20 in a shutdown state to match the pressure in the common refrigerant pipeline 50. This reduces the pressure fluctuations caused by the valve opening and helps the air conditioning system 100 smoothly return to the coordinated operation of multiple outdoor units 20.

[0042] Optionally, the first valve 30 and the second valve 40 can be various types of control valves, and the present invention does not specifically limit them. In one embodiment, the first valve 30 and the second valve 40 include solenoid valves for realizing rapid on / off control between the outdoor unit 20 and the common refrigerant pipeline 50.

[0043] Optionally, the third valve 202, the fourth valve 204, and the fifth valve 102 are various types of control valves capable of flow regulation. The present invention does not specifically limit them. In one embodiment, the third valve 202, the fourth valve 204, and the fifth valve 102 include electronic expansion valves.

[0044] In some implementations, please refer to Figure 2 The outdoor unit 20 includes a compressor 201. The main inlet of the compressor 201 is connected to the common refrigerant pipeline 50 through a first valve 30, and the outlet of the compressor 201 is connected to the common refrigerant pipeline 50 through a second valve 40. The control method also includes: In dedicated mode, the operating frequency of the compressor 201 of the outdoor unit 20, which is in operation, is controlled within a set dedicated frequency range. When the air conditioning system 100 meets the exit conditions, the operating frequency of the compressor 201 of the outdoor unit 20, which is in operation, is controlled to be within the set normal frequency range. The upper limit of the set normal frequency range is greater than the upper limit of the set dedicated frequency range, and the lower limit of the set normal frequency range is less than the lower limit of the set dedicated frequency range.

[0045] The above-described embodiments enable the compressor 201 to adjust to different refrigerant circulation conditions under different operating conditions, thereby avoiding high-speed dry burning of the compressor 201 at low flow rates to a certain extent, and reducing the impact of insufficient power on heating effect due to refrigerant circulation.

[0046] Specifically, in dedicated mode, the refrigerant circulation path is reduced, and the overall refrigerant circulation volume is smaller. When the air conditioning system 100 meets the shutdown conditions, such as when the outdoor ambient temperature rises or the indoor load increases, multiple outdoor units 20 need to operate in coordination. At this time, the refrigerant circulation path increases, and the overall refrigerant circulation volume is larger.

[0047] The operating frequency of compressor 201 directly affects the refrigerant circulation and delivery capacity of the air conditioning system per 100 unit time. Therefore, different operating frequency ranges for compressor 201 are set in dedicated mode and non-dedicated mode, allowing compressor 201 to adjust to different refrigerant circulation conditions under different operating conditions. Specifically, a dedicated frequency range is set in dedicated mode to match the operating frequency adjustment of compressor 201 with the lower refrigerant circulation volume; while a conventional frequency range is set in non-dedicated mode to expand the coverage of compressor 201's operating frequency adjustment, adapting to the larger load changes required when multiple outdoor units 20 are operating simultaneously.

[0048] It should be noted that the set normal frequency range refers to the frequency range in which the operating frequency of the compressor 201 is adjusted under normal operating conditions when the air conditioning system 100 operates with multiple outdoor units 20 working together. It can be determined according to the system design load range and the overall performance matching parameters.

[0049] Optionally, the dedicated frequency range can be determined based on the actual operating characteristics of the single outdoor unit 20 under low-temperature heating and low-load operating conditions and the refrigerant circulation requirements. In one embodiment, the dedicated frequency range is set to 20 rpm to 60 rpm. In some examples, the dedicated frequency is set to 20 rpm, 24 rpm, 28 rpm, 32 rpm, 36 rpm, 40 rpm, 44 rpm, 48 rpm, 52 rpm, 56 rpm, 60 rpm, or other values ​​that are greater than or equal to 20 rpm and less than or equal to 60 rpm.

[0050] In some implementations, please refer to Figure 2 The outdoor unit 20 includes a compressor 201, the secondary inlet of which is connected to the common refrigerant line 50 via a third valve 202. The control method also includes: In dedicated mode, the outdoor unit 20, which is in operation, is controlled to open the corresponding third valve 202; When the air conditioning system 100 meets the exit conditions, the outdoor unit 20, which is in operation, is controlled to close the corresponding third valve 202.

[0051] The above implementation method helps to reduce the exhaust temperature of compressor 201, and to a certain extent avoids compressor 201 from entering protective shutdown due to excessive exhaust temperature, which helps to ensure continuous operation of heating mode.

[0052] Specifically, the secondary inlet of compressor 201 is used to draw in medium-pressure gaseous refrigerant supplied by the jet branch. In heating mode, when the third valve 202 is opened, the high-pressure liquid refrigerant from the second valve 40 can be divided into main refrigerant and auxiliary refrigerant. The main refrigerant flows along the normal heating cycle path to the fourth valve 204, while the auxiliary refrigerant is throttled and depressurized by the third valve 202 through the jet branch to form medium-pressure gaseous refrigerant. It then enters the plate heat exchanger 205 to exchange heat with the main refrigerant, forming low-temperature medium-pressure refrigerant. The low-temperature medium-pressure refrigerant enters the compressor 201 from the secondary inlet to participate in the compression process.

[0053] In this embodiment, when the air conditioning system 100 enters the dedicated mode, the outdoor unit 20, which is in operation, opens the corresponding third valve 202, thus opening the jet branch and allowing low-temperature medium-pressure refrigerant to be introduced into the primary inlet of the compressor 201. Since the introduced medium-pressure refrigerant is relatively low in temperature, it can cool the high-temperature refrigerant being compressed inside the compressor 201, thereby further improving the thermal state of the refrigerant inside the compressor 201. The refrigerant mixture, after being cooled by the supplementary gas, is then compressed a second time before being discharged from the compressor 201, which helps to reduce the discharge temperature of the compressor 201.

[0054] When the air conditioning system 100 meets the exit conditions, the outdoor unit 20, which is in operation, closes the corresponding third valve 202, so that the jet branch stops supplying low-temperature medium-pressure refrigerant to the compressor 201 inlet, and the air conditioning system 100 resumes normal refrigerant circulation mode operation.

[0055] Optionally, the outdoor unit 20 includes a first temperature sensor 208, a first pressure sensor 209, a second temperature sensor 210, and a second pressure sensor 211. The first temperature sensor 208 and the first pressure sensor 209 are located at the outlet of the compressor 201. The first temperature sensor 208 is used to monitor the discharge temperature of the compressor 201 in real time, and the first pressure sensor 209 is used to monitor the discharge pressure of the compressor 201 in real time. The second temperature sensor 210 and the second pressure sensor 211 are located at the main inlet of the compressor 201. The second temperature sensor 210 is used to monitor the suction temperature of the compressor 201 in real time, and the second pressure sensor 211 is used to monitor the suction pressure of the compressor 201 in real time.

[0056] In some implementations, please refer to Figure 2 The outdoor unit 20 includes an outdoor heat exchanger 203. A fourth valve 204 is provided between the outdoor heat exchanger 203 and the second valve 40. The fourth valve 204 is used to throttle and reduce the pressure of the refrigerant from the second valve 40, so that the refrigerant can evaporate and absorb heat in the outdoor heat exchanger 203. The control method also includes: In dedicated mode, the opening of the fourth valve 204 is adjusted according to the set dedicated intake superheat range; When the air conditioning system 100 meets the exit conditions, the opening of the fourth valve 204 is adjusted according to the set normal intake superheat range, and the set special intake superheat range is smaller than the set normal intake superheat range.

[0057] The above implementation method can enhance the refrigerant delivery capacity of the outdoor unit 20 in operation, and to a certain extent avoid dry operation caused by insufficient refrigerant in the special mode.

[0058] Specifically, suction superheat refers to the temperature difference between the actual refrigerant temperature at the main inlet of compressor 201 and the saturated evaporation temperature corresponding to the actual refrigerant pressure. Suction superheat reflects the evaporation state of the refrigerant at the outlet of outdoor heat exchanger 203 and the liquid supply state of the refrigerant at the inlet of outdoor heat exchanger 203. The fourth valve 204 is used to regulate the refrigerant flow rate into outdoor heat exchanger 203. When the opening of the fourth valve 204 increases, the refrigerant flow rate into outdoor heat exchanger 203 increases, and the superheat of the refrigerant at the outlet of outdoor heat exchanger 203 decreases accordingly; when the opening of the fourth valve 204 decreases, the refrigerant flow rate into outdoor heat exchanger 203 decreases, and the superheat of the refrigerant at the outlet of outdoor heat exchanger 203 increases accordingly. Therefore, the suction superheat of compressor 201 can be controlled by adjusting the opening of the fourth valve 204.

[0059] When the air conditioning system 100 enters dedicated mode, the set dedicated suction superheat range is smaller than the set conventional suction superheat range. Therefore, the opening degree of the fourth valve 204 in dedicated mode is correspondingly larger than that in non-dedicated mode, allowing more refrigerant to enter the outdoor heat exchanger 203 and participate in the circulation. The increased refrigerant circulation volume per unit time in the air conditioning system 100 enhances the refrigerant delivery capacity of the outdoor unit 20 during operation, thus avoiding dry operation caused by insufficient refrigerant in dedicated mode to a certain extent.

[0060] When the air conditioning system 100 meets the exit conditions, the air conditioning system 100 adjusts the fourth valve 204 according to the set normal intake superheat range, so that the opening of the fourth valve 204 is restored to the control state that is compatible with the normal operating conditions.

[0061] It should be noted that the set normal suction superheat range refers to the superheat range used by the air conditioning system 100 to control the suction state of the compressor 201 under normal operating conditions. It can be determined based on factors such as the rated heating conditions of the air conditioning system 100, the operating characteristics of the compressor 201, and the performance of the outdoor heat exchanger 203. In one embodiment, the normal suction superheat is set to 5°C.

[0062] Optionally, the dedicated suction superheat range can be determined based on the refrigerant circulation characteristics under low-temperature heating and low-load conditions, the compressor 201 operating characteristics, and the heating demand. In one embodiment, the dedicated suction superheat range is set to 0°C to 2°C. In some examples, the dedicated suction superheat is set to 0°C, 0.2°C, 0.4°C, 0.6°C, 0.8°C, 1°C, 1.2°C, 1.4°C, 1.6°C, 1.8°C, 2°C, or other values ​​greater than or equal to 0°C and less than or equal to 2°C.

[0063] In some implementations, the first preset temperature is 0°C to 3°C.

[0064] The above implementation method can effectively determine whether it is necessary to enter the dedicated mode.

[0065] Specifically, in heating mode, when the outdoor ambient temperature is high, the outdoor heat exchanger 203 can obtain more heat from the environment, and the air conditioning system 100 can operate in non-dedicated mode. As the outdoor ambient temperature gradually decreases, the evaporation temperature of the outdoor heat exchanger 203 decreases accordingly, and the refrigerant circulation characteristics change. When the indoor load parameters are small and only a single outdoor unit 20 is operating, the air conditioning system 100 is more likely to experience insufficient refrigerant circulation. In this embodiment, the first preset temperature is set to 0°C to 3°C. When the outdoor ambient temperature is less than or equal to the first preset temperature, it indicates that the air conditioning system 100 has entered a low-temperature operating condition. At this time, combined with the indoor load parameters and the operating status of the outdoor unit 20, it can be further determined whether to enter dedicated mode.

[0066] In some examples, the first preset temperature is equal to 0℃, 0.3℃, 0.6℃, 0.9℃, 1.2℃, 1.5℃, 1.8℃, 2.1℃, 2.4℃, 2.7℃, 3℃, or other values ​​that are greater than or equal to 0℃ and less than or equal to 3℃.

[0067] In some implementations, the first preset load ratio is 10% to 18%.

[0068] The above implementation method can effectively determine whether it is necessary to enter the dedicated mode.

[0069] Specifically, in heating mode, when the indoor load parameter is high, it indicates that the current indoor heat demand is large. In this case, the air conditioning system 100 can operate in non-dedicated mode, simultaneously starting multiple outdoor units 20 to improve the operating performance of the air conditioning system 100. As the indoor heat demand decreases, the indoor load parameter decreases. When the outdoor ambient temperature is low and only one outdoor unit 20 is operating, the air conditioning system 100 is more prone to insufficient refrigerant circulation. In this embodiment, the first preset load ratio is set to 10% to 18%. When the indoor load parameter is less than or equal to the first preset load ratio, it indicates that the air conditioning system 100 has entered a low-load operating condition. At this time, combined with the outdoor ambient temperature and the operating status of the outdoor unit 20, it can be further determined whether to enter dedicated mode.

[0070] In some examples, the first preset load ratio is equal to 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, or other values ​​that are greater than or equal to 10% and less than or equal to 18%.

[0071] In some implementations, please refer to Figure 1 and 2 The conditions for withdrawal include at least one of the following: The outdoor ambient temperature is greater than or equal to the second preset temperature; The indoor load parameter is greater than or equal to the second preset load value; The air conditioning system 100 has an operational requirement to start up a second or more outdoor units 20.

[0072] The above implementation method can effectively determine whether it is necessary to exit the dedicated mode.

[0073] Specifically, when the outdoor ambient temperature is greater than or equal to the second preset temperature, it indicates that the outdoor ambient temperature has increased, the outdoor heat exchanger 203 can obtain more heat from the outdoor environment for heating, and the air conditioning system 100 can exit the special mode.

[0074] When the indoor load parameter is greater than or equal to the second preset load value, it indicates that the heating demand on the indoor side has increased, and the air conditioning system 100 has gradually transitioned from a low load condition to a higher load condition. The air conditioning system 100 can exit the special mode.

[0075] When the air conditioning system 100 needs to start the second or more outdoor units 20, it means that the air conditioning system 100 needs to meet the heating demand through the coordinated operation of multiple outdoor units 20, and the air conditioning system 100 can exit the dedicated mode.

[0076] In this embodiment, as long as at least one of the above exit conditions is met, the air conditioning system 100 can be controlled to exit the dedicated mode, thereby improving the adaptability of the air conditioning system 100 under different operating conditions.

[0077] Optionally, a predetermined temperature difference can be set between the second preset temperature and the first preset temperature, and a predetermined difference can also be set between the second preset load value and the first preset load ratio. By setting different entry and exit thresholds, the frequent mode switching caused by fluctuations in outdoor ambient temperature or indoor load parameters around the thresholds can be reduced, thereby improving the stability of the control process.

[0078] In one embodiment, the second preset ambient temperature is 5°C to 8°C, and the second preset load ratio is 20% to 25%. In some examples, the second preset temperature is equal to 5°C, 5.3°C, 5.6°C, 5.9°C, 6.2°C, 6.5°C, 6.8°C, 7.1°C, 7.4°C, 7.7°C, 8°C, or other values ​​greater than or equal to 5°C and less than or equal to 8°C. In some examples, the second preset load ratio is equal to 20%, 20.5%, 21%, 21.5%, 22%, 22.5%, 23%, 24%, 24.5%, 25%, or other values ​​greater than or equal to 20% and less than or equal to 25%.

[0079] Please see Figure 4 The control device 60 provided in this embodiment of the invention includes a processor 601 and a memory 602. The memory 602 stores a computer program. When the computer program is executed by the processor 601, it implements the control method of any of the above embodiments.

[0080] It should be noted that the above explanation of the implementation method and its beneficial effects also applies to the control device 60 in the embodiments of the present invention. To avoid redundancy, it will not be elaborated in detail here.

[0081] Please see Figures 2 to 4 An air conditioning system 100 provided by an embodiment of the present invention includes an indoor unit 10 and a plurality of parallel outdoor units 20, as well as a control device 60 as described above. The plurality of outdoor units 20 are all connected to a common refrigerant pipeline 50 through a first valve 30 and a second valve 40. The common refrigerant pipeline 50 is connected to the indoor unit 10. The control device 60 is electrically connected to the outdoor unit 20, the indoor unit 10, the first valve 30, and the second valve 40, respectively.

[0082] It should be noted that the above explanation of the implementation method and beneficial effects of the control method also applies to the air conditioning system 100 of the present invention. To avoid redundancy, it will not be elaborated in detail here.

[0083] The present invention provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor 601, implements the control method of any of the above embodiments.

[0084] In some implementations, when the computer program is executed by the processor 601, the control method includes: Step S01: Obtain outdoor ambient temperature and indoor load parameters; Step S03: When the air conditioning system 100 is in heating mode, the outdoor ambient temperature is less than or equal to the first preset temperature, the indoor load parameter is less than or equal to the first preset load value, and only one outdoor unit 20 is in operation, the air conditioning system 100 is determined to enter the special mode. Step S05a: In dedicated mode, control the outdoor unit 20 in the shutdown state to close the corresponding first valve 30 and second valve 40 so as to isolate the outdoor unit 20 in the shutdown state from the common refrigerant pipeline 50. Step S07a: When the air conditioning system 100 meets the exit conditions, the outdoor unit 20 in the shutdown state is controlled to open the corresponding first valve 30 and second valve 40 so that the outdoor unit 20 in the shutdown state is connected to the common refrigerant pipeline 50.

[0085] Computer-readable storage media can be volatile or non-volatile.

[0086] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0087] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or box of code comprising one or more steps for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0088] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, combinations, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A control method for an air conditioning system, characterized in that, The air conditioning system includes an indoor unit and multiple outdoor units connected in parallel. The multiple outdoor units are all connected to a common refrigerant pipeline through a first valve and a second valve. The common refrigerant pipeline is connected to the indoor unit. The control method includes: Obtain outdoor ambient temperature and indoor load parameters; When the air conditioning system is in heating mode, the outdoor ambient temperature is less than or equal to the first preset temperature, the indoor load parameter is less than or equal to the first preset load value, and only one outdoor unit is in operation, the air conditioning system is determined to enter a dedicated mode. In the dedicated mode, the outdoor unit in the shutdown state is controlled to close the corresponding first valve and second valve, so as to isolate the outdoor unit in the shutdown state from the common refrigerant pipeline; When the air conditioning system meets the exit conditions, the outdoor unit in the shutdown state is controlled to open the corresponding first valve and second valve, so that the outdoor unit in the shutdown state is connected to the common refrigerant pipeline.

2. The control method according to claim 1, characterized in that, The outdoor unit includes a compressor, the main inlet of which is connected to the common refrigerant pipeline via the first valve, and the outlet of which is connected to the common refrigerant pipeline via the second valve. The control method further includes: In the dedicated mode, the operating frequency of the compressor of the outdoor unit in operation is controlled within a set dedicated frequency range; When the air conditioning system meets the exit condition, the operating frequency of the compressor of the outdoor unit in operation is controlled to be within a set normal frequency range. The upper limit of the set normal frequency range is greater than the upper limit of the set dedicated frequency range, and the lower limit of the set normal frequency range is less than the lower limit of the set dedicated frequency range.

3. The control method according to claim 1, characterized in that, The outdoor unit includes a compressor, and the secondary inlet of the compressor is connected to the common refrigerant pipeline via a third valve. The control method further includes: In the dedicated mode, the outdoor unit in operation is controlled to open the corresponding third valve; When the air conditioning system meets the exit condition, the outdoor unit in operation is controlled to close the corresponding third valve.

4. The control method according to claim 1, characterized in that, The outdoor unit includes an outdoor heat exchanger, and a fourth valve is provided between the outdoor heat exchanger and the second valve. The fourth valve is used to throttle and reduce the pressure of the refrigerant from the second valve, so that the refrigerant can evaporate and absorb heat in the outdoor heat exchanger. The control method further includes: In the dedicated mode, the opening degree of the fourth valve is adjusted according to the set dedicated intake superheat range; When the air conditioning system meets the exit condition, the opening of the fourth valve is adjusted according to the set conventional intake superheat range, wherein the set special intake superheat range is smaller than the set conventional intake superheat range.

5. The control method according to claim 1, characterized in that, The first preset temperature is 0°C to 3°C.

6. The control method according to claim 1, characterized in that, The first preset load ratio is 10% to 18%.

7. The control method according to any one of claims 1-6, characterized in that, The exit conditions include at least one of the following: The outdoor ambient temperature is greater than or equal to the second preset temperature; The indoor load parameter is greater than or equal to the second preset load value; The air conditioning system requires the activation of a second or more outdoor units.

8. A control device, characterized in that, It includes a processor and a memory, the memory storing a computer program that, when executed by the processor, implements the steps of the control method according to any one of claims 1-7.

9. An air conditioning system, characterized in that, The device includes an indoor unit, multiple outdoor units connected in parallel, and the control device as described in claim 8. The multiple outdoor units are all connected to a common refrigerant pipeline through a first valve and a second valve. The common refrigerant pipeline is connected to the indoor unit. The control device is electrically connected to the outdoor unit, the indoor unit, the first valve, and the second valve, respectively.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the control method according to any one of claims 1-7.

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