Control method of air conditioning system, air conditioning system and vehicle

Abstract

The invention provides a control method of an air conditioning system, the air conditioning system and a vehicle. The control method comprises: detecting a pressure value of a heat exchanger outlet; determining whether the pressure value is within a target pressure range; when the pressure value is not within the target pressure range, determining a difference value between the pressure value and the target pressure range; adjusting the opening degree of the expansion valve and the pulse period of the expansion valve according to the difference value to enable the pressure value at the outlet of the heat exchanger to be within the target pressure range. The pressure value can change along with the change of the thermal load at the outlet of the heat exchanger, the change of the pressure value can cause the fluctuation of the superheat degree of the outlet of the heat exchanger, and the opening degree and the pulse period of the expansion valve are adjusted according to the pressure value to enable the pressure value to be within the target pressure range, so that the fluctuation of the superheat degree of the outlet of the heat exchanger is small; and the expansion valve can have a larger refrigerant flow adjusting range, the temperature adjusting and controlling capacity of the expansion valve to the heat exchanger is improved, and the temperature uniformity of the heat exchanger is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a control method of an air conditioning system, an air conditioning system and a vehicle. BACKGROUND

[0002] With the development of technology, the demand and application of vehicles have gradually increased, and the cooling of the battery in the vehicle has also become a problem that needs to be concerned and optimized. In the prior art, the superheat at the outlet of the heat exchanger is adjusted by adjusting the opening degree of the expansion valve. However, this way has limited temperature regulation ability of the heat exchanger, and the temperature uniformity of the heat exchanger is poor. SUMMARY

[0003] The embodiments of the present application provide a control method of an air conditioning system, an air conditioning system and a vehicle, which can at least partially solve the above technical problems.

[0004] In a first aspect, the present application provides a control method of an air conditioning system, the air conditioning system comprising an expansion valve and a heat exchanger, the heat exchanger comprising a heat exchanger inlet and a heat exchanger outlet, the expansion valve being arranged at the heat exchanger inlet. The control method comprises:

[0005] detecting a pressure value of the heat exchanger outlet;

[0006] determining whether the pressure value is within a target pressure range;

[0007] when the pressure value is not within the target pressure range, determining a difference between the pressure value and the target pressure range;

[0008] adjusting the opening degree of the expansion valve and adjusting the pulse period of the expansion valve according to the difference, so that the pressure value at the heat exchanger outlet is within the target pressure range.

[0009] In a second aspect, the present application provides an air conditioning system applied to a vehicle, comprising:

[0010] a heat exchanger, the heat exchanger comprising a heat exchanger inlet and a heat exchanger outlet;

[0011] a sensor arranged at the heat exchanger outlet, for detecting a pressure value of the heat exchanger outlet;

[0012] an expansion valve arranged at the heat exchanger inlet;

[0013] a controller for determining whether the pressure value is within a target pressure range;

[0014] when the pressure value is not within the target pressure range, determining a difference between the pressure value and the target pressure range;

[0015] adjusting an opening degree of the expansion valve and adjusting a pulse period of the expansion valve according to the difference value, so that the pressure value at the outlet of the heat exchanger is within the target pressure range.

[0016] In a third aspect, the present application provides a vehicle, comprising:

[0017] The air conditioning system described above.

[0018] In a fourth aspect, the present application provides a controller, comprising a processor and a memory, the memory being connected with the processor, the memory storing a computer program, and the processor executing the computer program to perform the steps of the control method of the air conditioning system described above.

[0019] In a fifth aspect, the present application provides a computer readable storage medium, the computer readable storage medium storing a computer program, and the computer program being used by a processor to perform the steps of the control method of the air conditioning system described above.

[0020] The present application provides a control method of an air conditioning system, an air conditioning system and a vehicle. The air conditioning system comprises an expansion valve and a heat exchanger, the heat exchanger comprising a heat exchanger inlet and a heat exchanger outlet, and the expansion valve being arranged at the heat exchanger inlet. The control method comprises detecting a pressure value at the heat exchanger outlet; determining whether the pressure value is within a target pressure range; when the pressure value is not within the target pressure range, determining a difference value between the pressure value and the target pressure range; and adjusting an opening degree of the expansion valve and adjusting a pulse period of the expansion valve according to the difference value, so that the pressure value at the outlet of the heat exchanger is within the target pressure range. The air conditioning system of the present application, as the heat load at the outlet of the heat exchanger changes, the pressure value at the outlet of the heat exchanger will change, and the change of the pressure value will cause the superheat at the outlet of the heat exchanger to fluctuate. Therefore, adjusting the opening degree and the pulse period of the expansion valve according to the pressure value can reduce the fluctuation of the superheat at the outlet of the heat exchanger, thereby ensuring the uniformity of the refrigeration of the heat exchanger. Compared with adjusting only the opening degree of the expansion valve, adjusting the opening degree and the pulse period of the expansion valve can make the expansion valve have a larger flow regulation range of the refrigerant, so that when the pressure value at the outlet of the heat exchanger fluctuates in a larger range, the pressure value at the outlet of the heat exchanger can still be kept within the target pressure range after adjustment, thereby increasing the temperature regulation ability of the expansion valve to the heat exchanger and ensuring the uniformity of the heat exchanger. BRIEF DESCRIPTION OF DRAWINGS

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic block diagram of a vehicle in one embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the structure of an air conditioning system according to one embodiment of this application.

[0024] Figure 3 This is a schematic diagram of the air conditioning system in another embodiment of this application.

[0025] Figure 4 This is a schematic diagram of the air conditioning system in another embodiment of this application.

[0026] Figure 5 This is a flowchart of a control method for an air conditioning system according to an embodiment of this application.

[0027] Figure 6 As shown in one embodiment of this application Figure 5 A further sub-flowchart for step S13.

[0028] Figure 7 In another embodiment of this application Figure 5 A further sub-flowchart for step S13.

[0029] Figure 8 This is a flowchart of a control method for an air conditioning system according to another embodiment of this application.

[0030] Figure 9 This is a flowchart of a control method for an air conditioning system in another embodiment of this application.

[0031] Figure 10 This is a flowchart of a control method for an air conditioning system in another embodiment of this application.

[0032] Figure 11 In yet another embodiment of this application Figure 9 A further sub-flowchart for step S41.

[0033] Figure 12 In yet another embodiment of this application Figure 11 A further sub-flowchart for step S411.

[0034] Figure 13 In yet another embodiment of this application Figure 11A further sub-flowchart for step S412.

[0035] Figure 14 This is a flowchart of a control method for an air conditioning system according to another embodiment of this application.

[0036] Figure 15 This is a pressure-enthalpy diagram of the air conditioning system in one embodiment of this application.

[0037] Figure 16 This is a schematic block diagram of the controller in an embodiment of this application.

[0038] Icon labels:

[0039] Vehicles -100;

[0040] Air conditioning system-1; Sensor-200; Heat exchanger-300; Heat exchanger inlet-301; Heat exchanger outlet-302; Expansion valve-400;

[0041] Compressor-11; Compressor inlet-111; Compressor outlet-112; Compressor inlet sensor-113; Compressor outlet sensor-114; Direct cooling plate-12; Direct cooling plate inlet-121; Direct cooling plate outlet-122; Condenser-13; Orifice-14; First sensor-15; First expansion valve-16; Second expansion valve-17; Evaporator-18; Evaporator inlet-181; Evaporator outlet-182; Evaporator outlet sensor-19; Controller-20; Processor-201; Memory-202. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0043] In the description of the embodiments of this application, it should be understood that the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. The term "connection" in this application, unless otherwise specified, primarily refers to a physical structural connection; however, if specified, it may also include direct or indirect connections. The terms "first" and "second" in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

[0044] Please see Figure 1 ,Figure 1 This is a schematic block diagram of a vehicle 100 according to an embodiment of this application. The vehicle 100 includes an air conditioning system 1. The air conditioning system 1 regulates the temperature inside the vehicle 100 and the temperature of the battery inside the vehicle 100 to improve user comfort and battery safety.

[0045] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of an air conditioning system 1 according to an embodiment of this application. The air conditioning system 1 is applied to a vehicle 100. The air conditioning system 1 includes a heat exchanger 300, a sensor 200, an expansion valve 400, and a controller 20. The heat exchanger 300 includes a heat exchanger inlet 301 and a heat exchanger outlet 302. The sensor 200 is located at the heat exchanger outlet 302 and is used to detect the pressure value at the heat exchanger outlet 302. The expansion valve 400 is located at the heat exchanger inlet 301. The controller 20 is used to determine whether the pressure value is within a target pressure range. When the pressure value is not within the target pressure range, it determines the difference between the pressure value and the target pressure range, and adjusts the opening degree and pulse period of the expansion valve 400 according to the difference to bring the pressure value at the heat exchanger outlet 302 within the target pressure range. Figure 2 The arrows in the diagram indicate the direction of refrigerant flow within the air conditioning system 1.

[0046] In some embodiments, such as Figure 2 As shown, the air conditioning system 1 further includes a compressor 11 and a condenser 13. The compressor 11 includes a compressor inlet 111 and a compressor outlet 112. The condenser 13 is disposed between the compressor outlet 112 and the heat exchanger inlet 301. The expansion valve 400 is disposed between the condenser 13 and the heat exchanger inlet 301. The compressor 11 is used to compress the refrigerant, causing the refrigerant to heat up and vaporize. The condenser 13 cools the refrigerant gas into a liquid refrigerant. The expansion valve 400 releases the pressure of the liquid refrigerant, thereby lowering the boiling point of the refrigerant. When the refrigerant passes through the heat exchanger 300, it vaporizes and absorbs heat, thereby achieving the purpose of absorbing heat from the air and cooling the system.

[0047] Please see Figure 3 , Figure 3This is a schematic diagram of the air conditioning system 1 according to another embodiment of this application. The heat exchanger 300 includes a direct cooling plate 12 and an evaporator 18. The direct cooling plate 12 and the evaporator 18 are connected in parallel and then connected to the compressor 11. The expansion valve 400 includes a first expansion valve 16 and a second expansion valve 17. The direct cooling plate 12 includes a direct cooling plate inlet 121 and a direct cooling plate outlet 122. The evaporator 18 includes an evaporator inlet 181 and an evaporator outlet 182. The first expansion valve 16 is connected to the branch where the direct cooling plate 12 is located and is located at the direct cooling plate inlet 121 of the direct cooling plate 12. The second expansion valve 17 is connected to the branch where the evaporator 18 is located and is located at the evaporator inlet 181 of the evaporator 18. The direct cooling plate 12 is used to cool the battery in the vehicle 100, and the evaporator 18 is used to cool the vehicle cabin. The air conditioning system 1 also includes a throttling orifice 14, which is located at the direct cooling plate outlet 122 of the direct cooling plate 12.

[0048] Therefore, the throttling orifice 14 can increase the pressure value of the direct cooling plate outlet 122 to reduce the superheat of the direct cooling plate outlet 122, thereby making it easier to adjust the superheat of the direct cooling plate outlet 122 by adjusting the opening of the first expansion valve 16. This allows the superheat of the direct cooling plate outlet 122 to be within the target superheat range, and also improves the temperature uniformity of the direct cooling plate 12 and reduces the temperature difference of the battery during the cooling process. This further controls the temperature of the battery within a suitable temperature range, improves the quality of the battery, extends the capacity and service life of the battery, and prevents the battery from being damaged. In addition, the evaporator 18 and the second expansion valve 17 can cool the vehicle cabin to improve the comfort of the user in the vehicle cabin.

[0049] Specifically, as mentioned above, the throttling orifice 14 increases the pressure at the outlet 122 of the direct cooling plate, thereby increasing the evaporation temperature at the outlet 122 to reduce the superheat of the direct cooling plate 12, further improving the heat exchange efficiency of the direct cooling plate 12. The first expansion valve 16 controls the superheat and pressure at the outlet 122 of the direct cooling plate, reducing the temperature difference between the inlet 121 and the outlet 122 of the direct cooling plate, resulting in better temperature uniformity of the direct cooling plate 12, further improving the temperature uniformity of the battery, and protecting the direct cooling plate 12 and the battery. This ensures that the superheat before the throttling orifice 14 is within the target superheat range, and then the superheat is increased to the optimal superheat through the throttling orifice 14, preventing liquid slugging of the compressor 11, reducing maintenance costs, and saving energy. The outlet 122 of the direct cooling plate is the area before the throttling orifice 14, and the pressure at the outlet 122 is the evaporation pressure.

[0050] In some embodiments, the direct cooling plate 12 is installed at the location of the power battery of the vehicle 100 to cool the power battery, and the evaporator 18 is installed at the location of the cabin of the vehicle 100 to regulate the temperature inside the vehicle cabin.

[0051] In some embodiments, the suitable temperature range for the battery is 15°C-25°C.

[0052] In some embodiments, the diameter of the throttling orifice 14 is 1.6-2.6 mm; and / or the orifice diameter of the throttling orifice 14 remains unchanged.

[0053] Therefore, by adding a fixed-diameter throttling orifice 14, the modification to the air conditioning system 1 is minimal, while also being very space-friendly and improving practicality.

[0054] Preferably, the diameter of the throttling orifice 14 is set to 2.2 mm.

[0055] As mentioned above, since the pressure value at the heat exchanger outlet 302, i.e. the evaporation pressure, will change under different operating conditions and different loads, and the evaporation pressure cannot be actively adjusted by adjusting the orifice diameter of the throttling orifice 14, the pressure value at the direct cooling plate outlet 122 needs to be adjusted by adjusting the opening of the first expansion valve 16.

[0056] In some embodiments, such as Figure 3 As shown, the air conditioning system 1 further includes a condenser 13, and the compressor 11 includes a compressor inlet 111 and a compressor outlet 112. The condenser 13 is disposed between the compressor outlet 112 and the direct cooling plate inlet 121. The first expansion valve 16 is disposed between the condenser 13 and the direct cooling plate inlet 121, and the throttling orifice 14 is disposed between the direct cooling plate outlet 122 and the compressor inlet 111. The first expansion valve 16 and the second expansion valve 17 release the pressure of the liquid refrigerant to lower the boiling point of the refrigerant. When the refrigerant passes through the direct cooling plate 12 and the evaporator 18, it vaporizes and absorbs heat, thereby achieving the purpose of absorbing heat from the air and cooling down. The orifice 14 has a smaller diameter than the first expansion valve 16, which can increase the refrigerant pressure, thereby increasing the boiling point of the refrigerant gas and preventing the refrigerant from vaporizing and absorbing heat at excessively low temperatures.

[0057] Secondly, the pressure is reduced through the throttling orifice 14 to increase the superheat of the heat-absorbing gas-liquid mixture to the optimal superheat. After the gas-liquid mixture is transformed into a refrigeration gas, the refrigeration gas is output to the compressor 11 to complete the refrigeration cycle.

[0058] In some embodiments, the sensor 200 includes a first sensor 15 and an evaporator outlet sensor 19. The first sensor 15 is disposed at the direct cooling plate outlet 122 and is used to detect the temperature and pressure values ​​of the direct cooling plate outlet 122. The evaporator outlet sensor 19 is disposed between the evaporator outlet 182 and the compressor inlet 111 and is used to detect the temperature and pressure values ​​of the evaporator outlet 182. Both the first sensor 15 and the evaporator outlet sensor 19 are temperature and pressure sensors. The first expansion valve 16 and the second expansion valve 17 are both electronic expansion valves. Based on the parameters detected by the two temperature and pressure sensors, the controller 20 controls the opening degree and / or pulse period of the first expansion valve 16 and the second expansion valve 17, respectively.

[0059] In some embodiments, the air conditioning system 1 further includes a compressor outlet sensor 114 and a compressor inlet sensor 113. The compressor outlet sensor 114 is disposed at the compressor outlet 112, and the compressor inlet sensor 113 is disposed at the compressor inlet 111. The compressor outlet sensor 114 is used to detect the pressure and temperature values ​​at the compressor outlet 112, and the compressor inlet sensor 113 is used to detect the pressure and temperature values ​​at the compressor inlet 111.

[0060] Please see Figure 4 , Figure 4 This is a schematic diagram of the air conditioning system 1 in another embodiment of this application. In some embodiments, the second expansion valve 17 is a thermostatic expansion valve, which adjusts its opening degree based on its own superheat. Therefore, the evaporator outlet sensor 19 is not required, saving one sensor, thereby reducing costs and simplifying the control method.

[0061] In some embodiments, the air conditioning system 1 further includes a second sensor, a third sensor, a fourth sensor, a fifth sensor, and a sixth sensor. The second sensor is disposed on the battery and is used to detect the battery temperature, charge level, and charging power. The third sensor is used to detect the ambient temperature of the vehicle 100. The fourth sensor is used to detect the interior temperature of the vehicle 100. The fifth sensor is used to detect the set temperature of the air conditioning system 1. The sixth sensor is used to detect the vehicle speed. The set temperature of the air conditioning system 1 is a preset temperature value for the air conditioning outlet. However, since the evaporator 18 cannot exchange heat with the air completely, the set temperature of the air conditioning system 1 is generally lower than the target interior temperature.

[0062] In some embodiments, the air conditioning system 1 further includes an electric fan located adjacent to the condenser 13. If the speed and compression ratio of the compressor 11 cannot be adjusted, the electric fan is turned on to lower the condensing temperature, allowing the refrigerant in the condenser 13 to dissipate more heat, thereby reducing the condensing pressure. This increases the cooling capacity and reduces the power consumption of the compressor 11, resulting in better performance of the compressor 11.

[0063] Please refer to Figure 5 , Figure 5 This is a flowchart of a control method for an air conditioning system according to an embodiment of this application. It is understood that the air conditioning system 1 can be as described above. Figure 2 , Figure 3 and Figure 4 Any one of the aforementioned air conditioning systems 1 or other types of air conditioning systems 1 is not limited herein. The steps of the control method can be added, removed, or adjusted in sequence according to actual needs, and are not limited herein. The air conditioning system 1 includes an expansion valve 400 and a heat exchanger 300. The heat exchanger 300 includes a heat exchanger inlet 301 and a heat exchanger outlet 302. The expansion valve 400 is disposed at the heat exchanger inlet 301. The control method of the air conditioning system includes:

[0064] S11: Detect the pressure value at the outlet of the heat exchanger;

[0065] S12: Determine whether the pressure value is within the target pressure range; if yes, proceed to S13; otherwise, proceed to S14.

[0066] S13: When the pressure value is within the target pressure range, the opening degree of the expansion valve and the pulse period of the expansion valve are not adjusted;

[0067] S14: When the pressure value is not within the target pressure range, determine the difference between the pressure value and the target pressure range;

[0068] S15: Adjust the opening degree of the expansion valve and the pulse period of the expansion valve according to the difference, so that the pressure value at the outlet of the heat exchanger is within the target pressure range.

[0069] Therefore, by adjusting the opening degree and pulse period of the expansion valve 400 according to the pressure value, the pressure value at the heat exchanger outlet 302 is kept within the target pressure range. This reduces the superheat fluctuation at the heat exchanger outlet 302, thereby ensuring the uniformity of the cooling performance of the heat exchanger 300. Compared to simply adjusting the opening degree of the expansion valve 400, adjusting both the opening degree and pulse period allows the expansion valve 400 to have a wider refrigerant flow regulation range. This ensures that even when the pressure value at the heat exchanger outlet 302 fluctuates within a larger range, the pressure value at the outlet 302 can still be maintained within the target pressure range through adjustment. Therefore, this increases the temperature control capability of the expansion valve 400 over the heat exchanger 300, guaranteeing the uniformity of the heat exchanger 300.

[0070] Specifically, as the heat load changes, the pressure at the heat exchanger outlet 302 will also change, that is, the evaporation pressure will change under different operating conditions and different loads, and thus the evaporation temperature at the heat exchanger outlet 302 will also change, causing the superheat of the heat exchanger 300 to change accordingly. Therefore, the pressure value at the heat exchanger outlet 302 can be adjusted by adjusting the opening degree and pulse period of the expansion valve 400.

[0071] The sensor 200 detects the pressure value at the outlet 302 of the heat exchanger. When the pressure value is not within the target pressure range, the difference between the detected pressure value and the target pressure range is calculated. If the pressure value is lower than the lowest value of the target pressure range, the difference between the pressure value and the highest and lowest values ​​within the target pressure range is negative. If the pressure value is higher than the highest value of the target pressure range, the difference between the pressure value and the highest and lowest values ​​within the target pressure range is positive. At this time, the opening degree and pulse period of the expansion valve 400 are adjusted to stabilize the pressure value within the target pressure range through periodic pulse adjustment of the opening degree of the expansion valve 400, thereby stabilizing the evaporation temperature and superheat within a certain range. This avoids the evaporation temperature from being too high or too low while the pressure value exceeds the target pressure range, ensuring the temperature uniformity of the heat exchanger 300.

[0072] Specifically, as mentioned above, if the pressure value is within the target pressure range, then the pressure value will always be equal to a value within the target pressure range. Therefore, the two differences obtained by subtracting the pressure value from the highest and lowest values ​​within the target pressure range are positive and negative, respectively. Thus, if the pressure value is within the target pressure range, or if the difference between the pressure value and the highest or lowest value within the target pressure range is zero, then the pressure value is also within the target pressure range, and there is no need to control the expansion valve 400.

[0073] Please refer to Figure 6 ,Figure 6 As shown in one embodiment of this application Figure 5 A further sub-flowchart of step S13. Adjusting the opening degree of the expansion valve and the pulse period of the expansion valve based on the difference includes:

[0074] S131: Obtain the opening degree and pulse period according to the difference and correspondence table, wherein the correspondence table records the correspondence between the difference, opening degree and pulse period;

[0075] S132: Adjust the opening degree of the expansion valve and the pulse period of the expansion valve according to the opening degree and the pulse period.

[0076] Therefore, by adjusting the opening degree and pulse cycle of the expansion valve 400 according to the pressure value, the pressure value at the heat exchanger outlet 302 is within the target pressure range, which can reduce the superheat fluctuation at the heat exchanger outlet 302 and thus ensure the uniformity of the cooling of the heat exchanger 300.

[0077] The correspondence table is a data table obtained through a large number of experiments, or the correspondence table can be fitted into a linear regression formula through linear regression.

[0078] Please refer to Figure 7 , Figure 7 In another embodiment of this application Figure 5 A further sub-flowchart of step S13. After adjusting the opening of the expansion valve and the pulse period of the expansion valve according to the difference, so that the pressure value at the heat exchanger outlet is within the target pressure range, the control method includes:

[0079] S21: The expansion valve maintains its current opening and current pulse cycle;

[0080] S22: Detect the real-time pressure value at the outlet of the heat exchanger once every preset periodic time;

[0081] S23: Determine whether the pressure value is within the target pressure range; if yes, proceed to S24; otherwise, proceed to S25.

[0082] S24: If the pressure value at the outlet of the heat exchanger is within the target pressure range, then the opening degree of the expansion valve and the pulse period of the expansion valve shall not be adjusted.

[0083] S25: If the pressure value at the outlet of the heat exchanger is not within the target pressure range, then the difference between the real-time pressure value and the target pressure range is determined again, and the opening degree of the expansion valve and the pulse period of the expansion valve are adjusted according to the difference, so that the pressure value at the outlet of the heat exchanger is within the target pressure range.

[0084] Therefore, the pressure value at the outlet 302 of the heat exchanger is detected in real time, and the opening degree and pulse cycle of the expansion valve 400 are adjusted in a timely manner according to the pressure value, so that the pressure value at the outlet 302 of the heat exchanger is within the target pressure range, thereby ensuring the uniformity of the cooling of the heat exchanger 300.

[0085] Specifically, based on the above, when the pressure value at the heat exchanger outlet 302 is detected, if the pressure value at the heat exchanger outlet 302 is not within the target pressure range, the difference between the real-time pressure value and the target pressure range is determined. An opening value and pulse cycle are obtained based on the difference and a corresponding table. The opening value and pulse cycle of the expansion valve 400 are adjusted according to the opening value and the obtained pulse cycle. For example, if the pulse cycle is 25 seconds, the expansion valve 400 is open at 75% for the first 20 seconds and closed for the last 5 seconds. The sensor 200 detects the pressure value at the heat exchanger outlet 302 every pulse cycle. If the pressure value is still not within the target pressure range, the above steps are repeated to adjust the opening of the expansion valve 400 and the pulse cycle. If the pressure value is within the target pressure range, the expansion valve 400 maintains the same pulse cycle and opening to stabilize the pressure value at the heat exchanger outlet 302.

[0086] When the expansion valve 400 is opened at a fixed opening, the refrigerant enters the heat exchanger 300 through the expansion valve 400. As a large amount of refrigerant continuously enters the heat exchanger 300 to perform heat absorption, the temperature of some heat exchangers 300 may become too low, thus failing to ensure the temperature uniformity of the heat exchanger 300. Therefore, a certain closing time needs to be set within a pulse cycle to give the heat exchanger 300 a certain buffer time to allow it to exchange heat evenly and ensure the temperature uniformity of the heat exchanger 300.

[0087] Please refer to Figure 8 , Figure 8 This is a flowchart of a control method for an air conditioning system according to another embodiment of this application. Before detecting the pressure value at the outlet of the heat exchanger, the control method further includes:

[0088] S31: Detect the temperature and pressure values ​​at the outlet of the heat exchanger;

[0089] S32: Determine the superheat at the heat exchanger outlet based on the temperature and pressure values;

[0090] S33: Adjust the opening of the expansion valve according to the superheat so that the superheat at the heat exchanger outlet is within the target superheat range.

[0091] Therefore, the superheat at the heat exchanger outlet 302 is calculated, and the opening of the expansion valve 400 is adjusted accordingly. By controlling the flow rate of the refrigerant, the superheat is controlled to be within the target superheat range, thereby reducing the temperature difference between the heat exchanger inlet 301 and the heat exchanger outlet 302, making the heat exchange more uniform and protecting the heat exchanger 300.

[0092] Specifically, the sensor 200 detects the temperature and pressure values ​​at the heat exchanger outlet 302, where the pressure value is the evaporation pressure. The evaporation temperature value is matched to the pressure value using a lookup table. The superheat is calculated based on the temperature value at the heat exchanger outlet 302 and the evaporation temperature value. The superheat is compared to the target superheat. If the superheat is not equal to the target superheat, an adjustment opening value is obtained by looking up the difference between the superheat and the target superheat range. The opening of the expansion valve 400 is adjusted according to this adjustment opening value. The temperature and pressure values ​​at the heat exchanger outlet 302 are detected again, and the superheat is calculated. If it still does not meet the requirements, the opening of the expansion valve 400 is adjusted again to ensure that the superheat at the heat exchanger outlet 302 is within the target superheat range. This reduces the temperature difference between the heat exchanger inlet 301 and the heat exchanger outlet 302, thereby improving the temperature uniformity of the heat exchanger 300. When the superheat is equal to the target superheat, there is no need to adjust the opening of the expansion valve 400.

[0093] In some embodiments, an opening value is set. If the difference between the superheat and the target superheat range is not within a preset opening range, the opening value is multiplied by a certain factor to obtain a new opening value. The opening of the expansion valve 400 is adjusted according to this opening value. If the difference between the superheat and the target superheat range is within a preset opening range, the opening of the expansion valve 400 is directly adjusted according to the set opening value.

[0094] In some embodiments, the target superheat is 2K-5K.

[0095] Please refer to Figure 9 , Figure 9 This is a flowchart of a control method for an air conditioning system according to another embodiment of this application. The air conditioning system 1 further includes a compressor 11, and all heat exchangers 300 are connected to the compressor 11. The control method further includes:

[0096] S41: Determine the total cooling capacity of the refrigeration circuit of the air conditioning system;

[0097] S42: Determine the compressor speed based on the total cooling capacity;

[0098] S43: Adjust the compressor speed to the determined speed according to the determined speed.

[0099] Therefore, by determining the total cooling capacity of the air conditioning system 1 and adjusting the speed of the compressor 11 according to the total cooling capacity, the heat exchanger 300 can work better, thereby enabling the air conditioning system 1 to reduce the temperature better.

[0100] Specifically, such as Figure 3 As shown in the structural diagram of the air conditioning system 1, the first sensor 15 detects the temperature and pressure values ​​of the direct cooling plate outlet 122. The pressure value is the evaporation pressure. Based on these values, the opening of the first expansion valve 16 is adjusted to ensure the superheat of the direct cooling plate outlet 122 is within the target superheat range. This reduces the temperature difference between the direct cooling plate inlet 121 and the outlet 122, improving the temperature uniformity of the direct cooling plate 12 and consequently improving the temperature uniformity of the battery. This controls the battery temperature within a suitable range. Furthermore, when the heat load is too low, the evaporation temperature of the direct cooling plate outlet 122 will also be too low, leading to overcooling of the battery. Conversely, when the heat load is too high, the evaporation temperature of the direct cooling plate outlet 122 will be too high, causing the battery temperature to exceed 40°C. Both excessively high and low battery temperatures affect the battery's cycle life. Therefore, continuous adjustment of the opening of the first expansion valve 16 and its pulse cycle is necessary to mitigate the risk of lithium plating in the battery and improve its quality. The change in heat load at the outlet 122 of the direct cooling plate is determined by factors such as the charging power of the battery.

[0101] Meanwhile, the evaporator outlet sensor 19 detects the temperature and pressure values ​​of the evaporator outlet 182, and adjusts the opening of the second expansion valve 17 according to the temperature and pressure values, so that the superheat of the evaporator outlet 182 is within the target superheat range, thereby reducing the temperature difference between the evaporator outlet 182 and the evaporator outlet 182, and improving the temperature uniformity of the evaporator 18.

[0102] Please refer to Figure 10 , Figure 10 This is a flowchart of a control method for an air conditioning system according to another embodiment of the present application. The air conditioning system 1 further includes an input module, and the control method further includes:

[0103] S51: Based on the vehicle's operating status and the opening and closing of the first expansion valve and / or the second expansion valve, identify the current mode of the air conditioning system;

[0104] S52: When the air conditioning system is in the first mode, the first expansion valve operates to regulate the temperature of the direct cooling plate to cool the charging battery.

[0105] S53: When the air conditioning system is in the second mode, the first expansion valve operates to regulate the temperature of the direct cooling plate to cool the charging battery, and the second expansion valve operates to regulate the temperature of the evaporator to cool the vehicle cabin.

[0106] S54: When the air conditioning system is in the third mode, the first expansion valve operates to cool the battery during driving, and the second expansion valve operates to cool the vehicle cabin.

[0107] Therefore, identifying the current mode of the air conditioning system 1 and performing corresponding operations can make the air conditioning system 1 more intelligent and improve the applicability of different modes.

[0108] In some embodiments, the first mode is a single-pole DC fast charging cooling mode, the second mode is a dual-pole DC fast charging cooling mode, and the third mode is a dual-pole driving cooling mode. Specifically, in the single-pole DC fast charging cooling mode, when the vehicle 100 is parked and the battery is fast charging, the cooling gas output by the compressor 11 passes only through the first expansion valve 16. In the dual-pole DC fast charging cooling mode, when the vehicle 100 is parked and the battery is fast charging, the cooling gas output by the compressor 11 passes through the first expansion valve 16 and / or the second expansion valve 17. In the dual-pole driving cooling mode, when the vehicle 100 is in motion, the cooling gas output by the compressor 11 passes through the first expansion valve 16 and / or the second expansion valve 17.

[0109] Specifically, in conjunction with the above embodiments, the opening and closing of the first expansion valve 16 and / or the second expansion valve 17 are controlled according to the operation signal output by the input module. When the occupants do not need to lower the temperature inside the vehicle cabin, the first expansion valve 16 is controlled to open and the second expansion valve 17 is controlled to close. Furthermore, the air conditioning system 1 is determined to be in a single-battery DC fast charging cooling mode based on the battery status. If the battery is in a fast charging state, the air conditioning system 1 is in a single-battery DC fast charging cooling mode; otherwise, it is not in a single-battery DC fast charging cooling mode. When the occupants need to lower the temperature inside the vehicle cabin, the first expansion valve 16 and / or the second expansion valve 17 are controlled to open. Furthermore, the air conditioning system 1 is determined to be in a dual-battery DC fast charging cooling mode or a dual-battery driving cooling mode based on the battery status and the vehicle 100 status, and different method steps are executed according to different modes.

[0110] It is understood that the input module can be an operable device such as a touch screen, button, remote control, or voice input device.

[0111] In other embodiments, the input module may also display various parameter information of the air conditioning system 1 and the current mode information.

[0112] Please refer to Figure 11 , Figure 11 In yet another embodiment of this application Figure 9 A further sub-flowchart of step S41. Determining the total cooling capacity on the refrigeration circuit of the air conditioning system includes:

[0113] S411: Determine the first target cooling capacity of the branch where the direct cooling plate is located;

[0114] S412: Determine the second target cooling capacity of the branch where the evaporator is located;

[0115] S413: Determine the total cooling capacity based on the first target cooling capacity and the second target cooling capacity.

[0116] Therefore, by determining the first target cooling capacity and the second target cooling capacity, the battery can be cooled more effectively, and the temperature inside the vehicle cabin can be lowered more effectively, thereby improving user comfort and battery safety.

[0117] Please refer to Figure 12 , Figure 12 In yet another embodiment of this application Figure 11 A further sub-flowchart of step S411. Determining the first target cooling capacity of the branch where the direct cooling plate is located includes:

[0118] S61: Detect the battery temperature and charging power of the battery;

[0119] S62: Determine the first target cooling capacity of the branch where the direct cooling plate is located based on the battery temperature value and the charging power value; and / or,

[0120] Please refer to Figure 13 , Figure 13 In yet another embodiment of this application Figure 11 A further sub-flowchart of step S412. Determining the second target cooling capacity of the branch where the evaporator is located includes:

[0121] S71: Detect the outside ambient temperature, the inside temperature, and the set temperature of the air conditioning system;

[0122] S72: Determine the second target cooling capacity of the branch where the evaporator is located based on the outside ambient temperature value, the inside temperature value, and the set temperature value.

[0123] Therefore, by determining the first target cooling capacity and the second target cooling capacity, the battery can be cooled more effectively, and the temperature inside the vehicle cabin can be lowered more effectively, thereby improving user comfort and battery safety.

[0124] In some embodiments, when the air conditioning system 1 initially operates in a single-battery DC fast-charging cooling mode, the controller 20 presets the initial opening of the first expansion valve 16 and the rotational speed of the compressor 11 based on the battery temperature, charge level, charging power, and ambient temperature to achieve a preliminary operating state and thus initially cool the battery. Subsequently, steps S31-S33 and steps S11-S15 are executed, wherein the heat exchanger 300 may be equivalent to the direct cooling plate 12.

[0125] In some embodiments, when the air conditioning system 1 is in single-battery DC fast charging cooling mode, the battery temperature and charging power determine the required cooling capacity of the air conditioning system 1 to better absorb the heat generated by the battery during fast charging and thus better cool the battery. Therefore, the speed of the compressor 11 needs to be adjusted according to the battery temperature and charging power by referring to a table to ensure that the total cooling capacity of the air conditioning system 1, i.e., the total cooling capacity generated by the compressor 11, reaches a first target cooling capacity, thereby cooling the battery to a certain temperature range. This allows the direct cooling plate 12 to achieve the best cooling effect on the battery, better cooling the battery during fast charging, thereby stabilizing the battery performance and protecting the battery.

[0126] In some embodiments, when the air conditioning system 1 is in the single-battery DC fast-charging cooling mode, the battery is in a fast-charging state, so the charging power value is not zero. Therefore, when the charging power value is not zero, the air conditioning system 1 checks whether the pressure value of the direct cooling plate outlet 122 is within the target pressure range, and checks whether the total cooling capacity of the air conditioning system 1 reaches the first target cooling capacity, to complete the self-test of the air conditioning system 1. If the above conditions are not met, the speed of the compressor 11 and the opening degree and pulse cycle of the first expansion valve 16 need to be adjusted to make the total cooling capacity of the air conditioning system 1 reach the first target cooling capacity, and to make the pressure value of the direct cooling plate outlet 122 within the target pressure range. When the charging power value is zero, the battery is not in a fast-charging state, and the air conditioning system 1 is not in the single-battery DC fast-charging cooling mode, and therefore will not perform a self-test.

[0127] In some embodiments, the self-test cycle of the air conditioning system 1 may be 5s-10s.

[0128] In some embodiments, when the air conditioning system 1 starts in the dual-on DC fast charging cooling mode, the initial opening degree of the second expansion valve 17 and the rotation speed of the compressor 11 are preset according to the ambient temperature value, the vehicle interior temperature value and the set temperature value. The initial opening degree of the first expansion valve 16 and the rotation speed of the compressor 11 are preset according to the battery temperature value, the battery charge value, the charging power value and the ambient temperature value, so as to achieve the initial working state and perform initial cooling of the battery and the air in the vehicle cabin.

[0129] In some embodiments, when the air conditioning system 1 is in dual-on DC fast charging cooling mode, the target interior temperature value is obtained by looking up a table based on the ambient temperature value and the set temperature value. The interior temperature value is compared with the target interior temperature value. If the interior temperature value is not equal to the target interior temperature value, the interior temperature value needs to reach the target interior temperature value. Therefore, the difference between the interior temperature value and the target interior temperature value is calculated, and the opening degree of the second expansion valve 17 and the speed of the compressor 11 are adjusted based on this difference to make the interior temperature value equal to the target interior temperature value, thereby controlling the cooling effect of the air conditioning system 1 on the vehicle cabin and meeting the comfort needs of the occupants. When the interior temperature value is equal to the target interior temperature value, there is no need to adjust the opening degree of the second expansion valve 17 and the speed of the compressor 11. Then, steps S31-S33 and steps S11-S15 are executed, wherein the heat exchanger 300 can be equivalent to the direct cooling plate 12.

[0130] In practice, the opening of the second expansion valve 17 is adjusted based on the vehicle's internal heat load. However, since the internal heat load includes the vehicle's internal temperature and various other parameters (light intensity, occupant heat dissipation, vehicle interior volume, etc.), it is difficult to quantify it into specific parameters for adjusting the opening of the second expansion valve 17. Furthermore, since the internal temperature can be affected by various other parameters (light intensity, occupant heat dissipation, vehicle interior volume, etc.), the process is simplified to determining the difference between the current internal temperature and the target internal temperature. Based on this difference, the opening of the second expansion valve 17 and the speed of the compressor 11 are adjusted. Prioritizing user comfort, the internal temperature must first be adjusted to the target internal temperature before operating the branch containing the direct cooling plate 12.

[0131] In some embodiments, when the external light is strong, the light shines through the car window onto the human body, which can cause discomfort. Therefore, the light intensity is detected by the light sensor, and the opening of the second expansion valve 17 and the speed of the compressor 11 are adjusted according to the light intensity to increase the cooling capacity and quickly reduce the impact of strong light, thereby improving the user's comfort.

[0132] In some embodiments, when the air conditioning system 1 is in dual-on DC fast charging cooling mode, the battery temperature and the charging power determine the cooling capacity of the direct cooling plate 12 to better absorb the heat generated by the battery during fast charging and to better cool the battery. The vehicle interior temperature determines the cooling capacity of the evaporator 18. Therefore, the speed of the compressor 11 needs to be adjusted according to the vehicle interior temperature to make the cooling capacity of the air conditioning system 1, that is, the cooling capacity generated by the compressor 11, reach the target cooling capacity required for cooling the vehicle cabin and lowering the vehicle interior temperature to the target temperature value. Then, the increment of the compressor speed is calculated according to the battery temperature and the charging power to make the cooling capacity of the air conditioning system 1 reach the target cooling capacity required for cooling the vehicle cabin and cooling the battery, so as to cool the battery to a certain temperature range. This allows the direct cooling plate 12 to achieve the best cooling effect on the battery, better cool the battery during fast charging, thereby stabilizing the battery performance and protecting the battery, and also allows the evaporator 18 to better reduce the temperature inside the vehicle cabin, thus meeting the comfort needs of the occupants.

[0133] In some embodiments, when the air conditioning system 1 is in dual-on DC fast charging cooling mode, the battery is still in fast charging mode, so the charging power value is not zero. At this time, the air conditioning system 1 checks whether the pressure value at the direct cooling plate outlet 122 is within the target pressure range, whether the total cooling capacity of the air conditioning system 1 reaches the target cooling capacity, and whether the interior temperature reaches the target interior temperature value, in order to complete the self-test of the air conditioning system 1. If the above conditions are not met, the speed of the compressor 11, the opening degree and pulse period of the first expansion valve 16, and the opening degree of the second expansion valve 17 need to be adjusted so that the total cooling capacity of the air conditioning system 1 reaches the target cooling capacity, the pressure value at the direct cooling plate outlet 122 is within the target pressure range, and the interior temperature reaches the target interior temperature value. If the charging power value is zero, the battery is not in fast charging mode, the air conditioning system 1 is not in dual-on DC fast charging cooling mode, and therefore will not perform a self-test.

[0134] In some embodiments, when the air conditioning system 1 starts in dual-operation driving cooling mode, the initial opening degree of the second expansion valve 17 and the speed of the compressor 11 are preset according to the ambient temperature value, the in-vehicle temperature value and the set temperature value.

[0135] In some embodiments, when the air conditioning system 1 is in dual-operation driving cooling mode, firstly, the target interior temperature value is obtained by looking up a table based on the ambient temperature value and the set temperature value. The interior temperature value is then compared with the target interior temperature value. If the interior temperature value is not equal to the target interior temperature value, the opening of the second expansion valve 17 is adjusted according to the interior temperature value, and the rotation speed of the compressor 11 is adjusted according to the interior temperature value, so that the cooling capacity of the air conditioning system 1, i.e., the cooling capacity generated by the compressor 11, reaches the target cooling capacity, thereby making the interior temperature value equal to the target interior temperature value. This controls the cooling effect of the air conditioning system 1 on the vehicle cabin, thus meeting the comfort needs of the occupants. When the interior temperature value is equal to the target interior temperature value, there is no need to adjust the opening of the second expansion valve 17 or the rotation speed of the compressor 11.

[0136] Next, it is determined whether the battery needs to be cooled. If the battery temperature is not within a suitable temperature range, then the battery needs to be cooled. Based on the battery temperature, the initial opening of the first expansion valve 16 and the rotational speed of the compressor 11 are preset, and then steps S31-S33 and steps S11-S15 are executed. The heat exchanger 300 can be equivalent to the direct cooling plate 12. If the battery does not need to be cooled, the first expansion valve 16 does not need to be opened. Then, the increment of the compressor rotational speed is calculated based on the battery temperature to ensure that the cooling capacity of the air conditioning system 1 reaches the target cooling capacity required for cooling the vehicle cabin and the battery, thereby cooling the battery to a certain temperature range.

[0137] Therefore, when the vehicle 100 is in motion, the air in the vehicle cabin needs to be cooled. Thus, the opening of the second expansion valve 17 and the speed of the compressor 11 need to be adjusted so that the air conditioning system 1 can reduce the interior temperature to the target interior temperature value, thereby improving the comfort of the occupants. Furthermore, cooling is only required when the battery needs to be cooled, which saves energy.

[0138] When the battery is fast charging or the vehicle is traveling at a high speed (100 km / h), the resistive elements inside the battery generate a lot of heat, causing the battery temperature to rise and requiring cooling.

[0139] In some embodiments, when the air conditioning system 1 is in dual-operation driving cooling mode and the battery needs to be cooled, the air conditioning system 1 checks whether the pressure value at the direct cooling plate outlet 122 is within the target pressure range, whether the total cooling capacity of the air conditioning system 1 reaches the target cooling capacity, and whether the interior temperature reaches the target interior temperature, to complete the self-test of the air conditioning system 1. When the air conditioning system 1 is in dual-operation driving cooling mode and the battery does not need to be cooled, the air conditioning system 1 checks whether the total cooling capacity of the air conditioning system 1 reaches the target cooling capacity, and whether the interior temperature reaches the target interior temperature, to complete the self-test of the air conditioning system 1. If the air conditioning system 1 exits the dual-operation driving cooling mode, the air conditioning system 1 will not perform a self-test.

[0140] In some embodiments, when the air conditioning system 1 is in dual-mode DC fast charging cooling or dual-mode driving cooling, the opening of the second expansion valve 17 is adjusted according to the temperature and pressure values ​​of the evaporator outlet 182 to control the refrigerant flow into the evaporator 18. In turn, the opening of the second expansion valve 17 controls the superheat of the evaporator outlet 182, reduces the temperature difference between the evaporator outlet 182 and the evaporator inlet 181, and improves the temperature uniformity and heat exchange efficiency of the evaporator 18.

[0141] Please refer to Figure 14 , Figure 14 This is a flowchart illustrating a control method for an air conditioning system according to another embodiment of this application. The compressor 11 includes a compressor inlet 111 and a compressor outlet 112, and the control method further includes:

[0142] S81: Detect the pressure value at the compressor inlet and the pressure value at the compressor outlet;

[0143] S82: Calculate the target compression ratio of the compressor based on the pressure value at the compressor inlet and the pressure value at the compressor outlet, and control and adjust the compression ratio of the compressor to the target compression ratio.

[0144] Therefore, by calculating the target compression ratio of the compressor 11 using the pressure value at the compressor inlet 111 and the pressure value at the compressor outlet 112, and then controlling the compressor 11 to reach the target compression ratio, the performance of the compressor 11 can be optimized, energy consumption can be reduced, and operating costs can be lowered.

[0145] The compression ratio of the compressor 11 is the ratio of the pressure at the compressor outlet 112 to the pressure at the compressor inlet 111. The higher the rotational speed of the compressor 11, the higher the energy consumption and the higher the compression ratio. An excessively high compression ratio will cause the compressor 11 to generate too much heat during operation, leading to overheating and even damage. Therefore, the compression ratio needs to be adjusted to a target compression ratio (generally 3-5).

[0146] In some embodiments, the temperature value of the compressor inlet 111 can also be detected, and the compression ratio of the compressor 11 can be adjusted according to the detected temperature value to make the superheat of the compressor inlet 111 reach the target superheat, so as to avoid the compressor 11 being liquid slugging. The temperature value of the compressor outlet 112 can also be detected, and the compression ratio of the compressor 11 can be adjusted according to the detected temperature value to avoid the internal temperature of the compressor 11 being too high and carbonizing the lubricating oil, thereby avoiding damage to the compressor 11.

[0147] Please see Figure 15 , Figure 15 This is a pressure-enthalpy diagram of the air conditioning system 1 operating in one embodiment of this application. For example... Figure 15 As shown, with pressure on the vertical axis and enthalpy on the horizontal axis, the graph is divided into three regions based on a parabola, representing the liquid, gas-liquid mixture, and gaseous states, respectively. This parabola is a saturation curve. Within the closed arc region, the refrigerant reaches thermal equilibrium and exists in the form of vapor and liquid, which is the gas-liquid mixture state. The vapor content of the gas-liquid mixture state changes from 0% (left side of the saturation curve) to 100% (right side of the saturation curve). On the left outer side of the saturation curve, the refrigerant exists in liquid form, and on the right outer side of the saturation curve, the refrigerant exists in gaseous form, which is the refrigerant gas.

[0148] Figure 15 The trapezoidal section in the diagram represents the refrigeration cycle process. The position of the diagram should also refer to the distribution of the three regions of the saturation curve to observe the state of the refrigerant in each process. The upper right vertex of the trapezoidal section represents the discharge of high-temperature and high-pressure gas from the compressor outlet 112. The line segment between the upper right vertex and the upper left vertex represents the process of the high-temperature and high-pressure gas discharged from the compressor outlet 112 entering the condenser 13 and releasing heat. Due to the heat release, the enthalpy value decreases, and the state of the refrigerant changes from gaseous to gas-liquid mixture, and finally becomes liquid refrigerant. The upper left vertex represents the liquid formed after the heat release enters the first expansion valve 16. The first expansion valve 16 depressurizes it, so the pressure value of the gas decreases. As the pressure decreases, the liquid refrigerant gradually changes to a gas-liquid mixture.

[0149] like Figure 15As shown, in the section from the lower left vertex to the upper right vertex, the solid line represents throttling without a plate, i.e., no throttling orifice 14 is provided, while the dashed line represents throttling with a plate, i.e., with a throttling orifice 14 provided. In the system without the throttling orifice 14, the pressure value of the solid line drops directly to the lower left vertex position, indicating that the pressure value of the direct cooling plate 12 is low, i.e., the evaporation pressure is low, resulting in a lower evaporation temperature and higher superheat, thus leading to poor temperature uniformity between the direct cooling plate 12 and the battery. In the system with the throttling orifice 14, the pressure value of the dashed line drops slightly above the lower left vertex position, indicating that the pressure value of the direct cooling plate 12 is higher than without the throttling orifice 14, i.e., the evaporation pressure is higher, resulting in a higher evaporation temperature and lower superheat, thus showing that providing the throttling orifice 14 can improve the temperature uniformity between the direct cooling plate 12 and the battery.

[0150] The straight dashed and solid lines at the bottom center indicate that the refrigerant absorbs heat from the battery within the direct cooling plate 12, thereby increasing its enthalpy. The gas-liquid mixture represented by the dashed line is depressurized after reaching a point on the right, i.e., after passing through the throttling orifice 14, and becomes a gaseous refrigerant gas. Therefore, the pressure value will directly decrease to the same position as the pressure value of the solid line. Afterward, the high-temperature, low-pressure gas represented by both the solid and dashed lines enters the compressor 11. The compressor 11 performs work to compress the low-pressure, high-temperature gas into a high-pressure, high-temperature gas to complete the refrigeration cycle.

[0151] Please refer to Figure 16 , Figure 16 This is a schematic block diagram of the controller 20 in an embodiment of this application. The controller 20 includes a processor 201 and a memory 202. The memory 202 is connected to the processor 201 and stores a computer program. The processor 201 runs the computer program to execute the control method of the air conditioning system described above.

[0152] Therefore, the controller 20 controls the expansion valve 400 to adjust the pressure value at the heat exchanger outlet 302, thereby improving the temperature uniformity of the heat exchanger 300.

[0153] The processor 201 may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The memory 202 may be volatile memory or non-volatile memory, or may include both. For example, it may be, but is not limited to, a flash drive, read-only memory (ROM), random access memory (RAM), a hard disk, or an optical disk. The processor 201 is connected to the memory 202.

[0154] This application also provides a computer-readable storage medium storing a computer program, which is invoked by a processor 201 to execute the control method of the air conditioning system as described above.

[0155] The computer storage medium in this application embodiment can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0156] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0157] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0158] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A control method of an air conditioning system, the air conditioning system (1) comprising an expansion valve (400) and a heat exchanger (300), the heat exchanger (300) comprising a heat exchanger inlet (301) and a heat exchanger outlet (302), the expansion valve (400) being provided at the heat exchanger inlet (301), characterized in that, The control method comprises: detecting a pressure value of the heat exchanger outlet (302); judging whether the pressure value is within a target pressure range; when the pressure value is not within the target pressure range, determining a difference between the pressure value and the target pressure range; adjusting an opening degree of the expansion valve (400) and a pulse period of the expansion valve (400) according to the difference, so that the pressure value at the heat exchanger outlet (302) is within the target pressure range.

2. The control method of the air conditioning system according to claim 1, characterized by, The adjusting of the opening degree of the expansion valve (400) and the pulse period of the expansion valve (400) according to the difference comprises: obtaining an opening degree and a pulse period according to the difference and a correspondence table, wherein the correspondence table records a correspondence among a difference, an opening degree, and a pulse period; adjusting the opening degree of the expansion valve (400) and the pulse period of the expansion valve (400) according to the opening degree and the pulse period.

3. The control method of the air conditioning system according to claim 1, characterized by, After the adjusting of the opening degree of the expansion valve (400) and the pulse period of the expansion valve (400) according to the difference, so that the pressure value at the heat exchanger outlet (302) is within the target pressure range, the control method comprises: the expansion valve (400) maintains a current opening degree and a current pulse period; detecting a real-time pressure value of the heat exchanger outlet (302) every interval of a preset period of time; if the pressure value of the heat exchanger outlet (302) is not within the target pressure range, determining a difference between the real-time pressure value and the target pressure range again, and adjusting the opening degree of the expansion valve (400) and the pulse period of the expansion valve (400) according to the difference, so that the pressure value at the heat exchanger outlet (302) is within the target pressure range.

4. The control method of the air conditioning system according to claim 1, characterized by, Before the detecting of the pressure value of the heat exchanger outlet (302), the control method further comprises: detecting a temperature value and a pressure value of the heat exchanger outlet (302); determining a superheat degree of the heat exchanger outlet (302) according to the temperature value and the pressure value; adjusting the opening degree of the expansion valve (400) according to the superheat degree, so that the superheat degree of the heat exchanger outlet (302) is within a target superheat degree range.

5. The control method of an air conditioning system according to claim 1, wherein The air conditioning system (1) further comprises a compressor (11), and the heat exchanger (300) is connected to the compressor (11); the control method further comprises: determining a total refrigerating capacity on a refrigerating circuit of the air conditioning system (1); determining a rotating speed of the compressor (11) according to the total refrigerating capacity; adjusting the rotating speed of the compressor (11) to the determined rotating speed according to the determined rotating speed. 6.The control method of an air conditioning system according to claim 5, characterized in that, The heat exchanger (300) comprises a direct cooling plate (12) and an evaporator (18), the direct cooling plate (12) and the evaporator (18) are connected in parallel after being connected to the compressor (11), the expansion valve (400) comprises a first expansion valve (16) and a second expansion valve (17), the first expansion valve (16) is connected to the branch where the direct cooling plate (12) is located and is located at the direct cooling plate inlet (121) of the direct cooling plate (12), the second expansion valve (17) is connected to the branch where the evaporator (18) is located and is located at the evaporator inlet (181) of the evaporator (18), the direct cooling plate (12) is used for refrigerating vehicle battery, the evaporator (18) is used for refrigerating vehicle cabin, and the air conditioning system (1) further comprises a throttle hole (14), the throttle hole (14) is arranged at the direct cooling plate outlet (122) of the direct cooling plate (12).

7. The control method of the air conditioning system according to claim 6, characterized by, The total refrigeration capacity on the refrigeration circuit of the air conditioning system (1) is determined, comprising: determining a first target refrigeration capacity of the branch where the direct cooling plate (12) is located; determining a second target refrigeration capacity of the branch where the evaporator (18) is located; determining the total refrigeration capacity according to the first target refrigeration capacity and the second target refrigeration capacity.

8. The control method of the air conditioning system according to claim 7, characterized by, The determination of the first target refrigeration capacity of the branch where the direct cooling plate (12) is located comprises: detecting a battery temperature value and a charging power value of the battery; determining the first target refrigeration capacity of the branch where the direct cooling plate (12) is located according to the battery temperature value and the charging power value; and / or, The determination of the second target refrigeration capacity of the branch where the evaporator (18) is located comprises: detecting an outdoor environment temperature value, an indoor temperature value and a set temperature value of the air conditioning system (1); determining the second target refrigeration capacity of the branch where the evaporator (18) is located according to the outdoor environment temperature value, the indoor temperature value and the set temperature value. 9.The control method of an air conditioning system according to claim 5, characterized by, The compressor (11) comprises a compressor inlet (111) and a compressor outlet (112), and the control method further comprises: detecting a pressure value of the compressor inlet (111) and a pressure value of the compressor outlet (112); calculating a target compression ratio of the compressor (11) according to the pressure value of the compressor inlet (111) and the pressure value of the compressor outlet (112), and controlling the compression ratio of the compressor (11) to be adjusted to the target compression ratio. 10.The control method of an air conditioning system according to claim 6, characterized in that, The air conditioning system (1) further comprises an input module, and the control method further comprises: identifying the mode in which the air conditioning system (1) currently locates according to the working state of the vehicle (100) and the opening and closing of the first expansion valve (16) and / or the second expansion valve (17); when the air conditioning system (1) is in a first mode, the first expansion valve (16) works to regulate the temperature of the direct cooling plate (12) to refrigerate the charging battery; when the air conditioning system (1) is in a second mode, the first expansion valve (16) works to regulate the temperature of the direct cooling plate (12) to refrigerate the charging battery, and the second expansion valve (17) works to regulate the temperature of the evaporator (18) to refrigerate the vehicle cabin. When the air conditioning system (1) is in the third mode, the first expansion valve (16) works to cool the battery during driving, and the second expansion valve (17) works to cool the vehicle cabin.

11. An air conditioning system (1) applied to a vehicle (100), characterized in that, Comprise: A heat exchanger (300) comprising a heat exchanger inlet (301) and a heat exchanger outlet (302); A sensor (200) arranged at the heat exchanger outlet (302) for detecting a pressure value of the heat exchanger outlet (302); An expansion valve (400) arranged at the heat exchanger inlet (301); A controller (20) for determining whether the pressure value is within a target pressure range; When the pressure value is not within the target pressure range, determining the difference between the pressure value and the target pressure range; According to the difference, adjusting the opening of the expansion valve (400) and adjusting the pulse period of the expansion valve (400), so that the pressure value at the heat exchanger outlet (302) is within the target pressure range.

12. The air conditioning system of claim 11, wherein, The air conditioning system (1) further comprises a compressor (11), the heat exchanger (300) comprises a direct cooling plate (12) and an evaporator (18), the direct cooling plate (12) and the evaporator (18) are connected in parallel after being connected to the compressor (11), the expansion valve (400) comprises a first expansion valve (16) and a second expansion valve (17), the first expansion valve is connected to the branch where the direct cooling plate (12) is located and is located at the direct cooling plate inlet (121) of the direct cooling plate (12), the second expansion valve (17) is connected to the branch where the evaporator (18) is located and is located at the evaporator inlet (181) of the evaporator (18), the direct cooling plate (12) is used to cool the vehicle battery, the evaporator (18) is used to cool the vehicle cabin, and the air conditioning system (1) further comprises a throttle hole (14) arranged at the direct cooling plate outlet (122) of the direct cooling plate (12).

13. The air conditioning system of claim 12, wherein, The diameter of the throttle hole (14) is 1.6-2.6mm; and / or the diameter of the throttle hole (14) remains unchanged.

14. A vehicle (100), characterized in that Comprise: The air conditioning system (1) according to any one of claims 11-13.

15. A controller (20) characterized by, Comprise: A processor (201) and a memory (202) connected with the processor (201), the memory (202) stores a computer program, and the processor (201) executes the computer program to perform the control method of the air conditioning system according to any one of claims 1-10.

16. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, which is called by the processor (201) to perform the control method of the air conditioning system according to any one of claims 1-10.

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