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

Abstract

Provided in the present application are a control method for an air conditioning system, and an air conditioning system and a vehicle. The control method comprises: measuring a pressure value at an outlet of a heat exchanger; 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; and on the basis of the difference, adjusting the opening degree of an expansion valve and adjusting a pulse cycle of the expansion valve, such that the pressure value at the outlet of the heat exchanger is within the target pressure range.

Description

Air conditioning system control methods, air conditioning systems and vehicles

[0001] This application claims priority to Chinese Patent Application No. 202411222197.3, filed on August 30, 2024, entitled "Control Method for Air Conditioning System, Air Conditioning System and Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of vehicle technology, and in particular to a control method for an air conditioning system, an air conditioning system, and a vehicle. Background Technology

[0003] In related technologies, the superheat at the outlet of the heat exchanger is adjusted by regulating the opening of the expansion valve. However, this method has limited temperature control capabilities for the heat exchanger, resulting in poor temperature uniformity. Summary of the Invention

[0004] This application provides a control method for an air conditioning system, an air conditioning system, and a vehicle, which can solve at least some of the above-mentioned technical problems.

[0005] In a first aspect, this application provides a control method for an air conditioning system, the air conditioning system including an expansion valve and a heat exchanger, the heat exchanger including a heat exchanger inlet and a heat exchanger outlet, and the expansion valve being disposed at the heat exchanger inlet. The control method includes:

[0006] Detect the pressure value at the outlet of the heat exchanger;

[0007] Determine whether the pressure value is within the target pressure range;

[0008] When the pressure value is not within the target pressure range, determine the difference between the pressure value and the target pressure range;

[0009] 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.

[0010] In some embodiments of this application, adjusting the opening degree of the expansion valve and the pulse period of the expansion valve based on the difference includes:

[0011] The opening degree and pulse period are obtained from the difference and the correspondence table, where the correspondence table records the correspondence between the difference, the opening degree and the pulse period;

[0012] Adjust the opening degree and pulse period of the expansion valve according to the opening degree and pulse period.

[0013] In some embodiments of this application, after adjusting 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 heat exchanger outlet is within the target pressure range, the control method includes:

[0014] The expansion valve maintains its current opening and current pulse cycle;

[0015] The real-time pressure value at the heat exchanger outlet is detected at preset intervals.

[0016] If the pressure value at the heat exchanger outlet is not within the target pressure range, then the difference between the real-time pressure value and the target pressure range is determined again. Based on the difference, the opening degree of the expansion valve and the pulse period of the expansion valve are adjusted so that the pressure value at the heat exchanger outlet is within the target pressure range.

[0017] In some embodiments of this application, the control method further includes, before detecting the pressure value at the heat exchanger outlet:

[0018] Detect the temperature and pressure values ​​at the heat exchanger outlet;

[0019] The superheat at the heat exchanger outlet is determined based on the temperature and pressure values.

[0020] Adjust the opening of the expansion valve according to the superheat to ensure that the superheat at the heat exchanger outlet is within the target superheat range.

[0021] In some embodiments of this application, the air conditioning system further includes a compressor, and the heat exchangers are all connected to the compressor. The control method further includes:

[0022] Determine the total cooling capacity in the refrigeration circuit of the air conditioning system;

[0023] The compressor speed is determined based on the total cooling capacity;

[0024] Adjust the compressor speed to the determined speed.

[0025] In some embodiments of this application, the heat exchanger includes a direct cooling plate and an evaporator, which are connected in parallel and then connected to the compressor. The expansion valve includes a first expansion valve and a second expansion valve. The first expansion valve is connected to the branch where the direct cooling plate is located and is located at the inlet of the direct cooling plate. The second expansion valve is connected to the branch where the evaporator is located and is located at the inlet of the evaporator. The direct cooling plate is used to cool the vehicle battery, and the evaporator is used to cool the vehicle cabin. The air conditioning system also includes a throttling orifice located at the outlet of the direct cooling plate.

[0026] In some embodiments of this application, determining the total cooling capacity on the refrigeration circuit of the air conditioning system includes:

[0027] Determine the primary target cooling capacity of the branch where the direct cooling plate is located;

[0028] Determine the second target cooling capacity for the branch where the evaporator is located;

[0029] The total cooling capacity is determined based on the first target cooling capacity and the second target cooling capacity.

[0030] In some embodiments of this application, determining the first target cooling capacity of the branch where the direct cooling plate is located includes:

[0031] Detect the battery temperature and charging power.

[0032] The first target cooling capacity of the branch containing the direct cooling plate is determined based on the battery temperature and charging power values; and / or,

[0033] Determine the second target cooling capacity for the branch containing the evaporator, including:

[0034] Detect the outside temperature, the inside temperature, and the set temperature of the air conditioning system.

[0035] The second target cooling capacity of the branch where the evaporator is located is determined based on the ambient temperature outside the vehicle, the temperature inside the vehicle, and the set temperature.

[0036] In some embodiments of this application, the compressor includes a compressor inlet and a compressor outlet, and the control method further includes:

[0037] Detect the pressure values ​​at the compressor inlet and compressor outlet;

[0038] The target compression ratio of the compressor is calculated based on the pressure values ​​at the compressor inlet and outlet, and the compressor compression ratio is controlled and adjusted to the target compression ratio.

[0039] In some embodiments of this application, the air conditioning system further includes an input module, and the control method further includes:

[0040] 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;

[0041] When the air conditioning system is in the first mode, the first expansion valve works to regulate the temperature of the direct cooling plate to cool the charging battery.

[0042] When the air conditioning system is in the second mode, the first expansion valve works to regulate the temperature of the direct cooling plate to cool the charging battery, and the second expansion valve works to regulate the temperature of the evaporator to cool the vehicle cabin.

[0043] 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.

[0044] Secondly, this application provides an air conditioning system applied to a vehicle, comprising:

[0045] A heat exchanger, the heat exchanger including a heat exchanger inlet and a heat exchanger outlet;

[0046] A sensor is provided at the outlet of the heat exchanger to detect the pressure value at the outlet of the heat exchanger.

[0047] An expansion valve is provided at the inlet of the heat exchanger;

[0048] The controller is used to determine whether the pressure value is within the target pressure range;

[0049] When the pressure value is not within the target pressure range, determine the difference between the pressure value and the target pressure range;

[0050] 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.

[0051] In some embodiments of this application, the air conditioning system further includes a compressor, a heat exchanger including a direct cooling plate and an evaporator connected in parallel to the compressor, an expansion valve including a first expansion valve and a second expansion valve, the first expansion valve being connected to the branch where the direct cooling plate is located and located at the direct cooling plate inlet of the direct cooling plate, and the second expansion valve being connected to the branch where the evaporator is located and located at the evaporator inlet of the evaporator, the direct cooling plate being used to cool the vehicle battery, the evaporator being used to cool the vehicle cabin, and the air conditioning system further includes a throttling orifice located at the direct cooling plate outlet of the direct cooling plate.

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

[0053] Thirdly, this application provides a vehicle, including:

[0054] The aforementioned air conditioning system.

[0055] Fourthly, this application provides a controller, including: a processor and a memory, the memory being connected to the processor, the memory storing a computer program, and the processor running the computer program to execute the steps of the above-described air conditioning system control method.

[0056] Fifthly, this application provides a computer-readable storage medium storing a computer program, which, when called by a processor, executes the steps of the above-described air conditioning system control method. Beneficial effects

[0057] This application provides a control method for an air conditioning system, an air conditioning system, and a vehicle. The air conditioning system includes an expansion valve and a heat exchanger. The heat exchanger includes a heat exchanger inlet and a heat exchanger outlet, and the expansion valve is located at the heat exchanger inlet. The control method includes detecting the 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 the difference between the pressure value and the target pressure range; and adjusting 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 heat exchanger outlet is within the target pressure range. In the air conditioning system of this application, as the heat load at the heat exchanger outlet changes, the pressure value at the heat exchanger outlet will change. The change in pressure value will cause fluctuations in the superheat at the heat exchanger outlet. Therefore, by adjusting the opening degree and pulse period of the expansion valve according to the pressure value, so that the pressure value at the heat exchanger outlet is within the target pressure range, the fluctuations in superheat at the heat exchanger outlet can be reduced, thereby ensuring the uniformity of the heat exchanger's cooling. Compared to simply adjusting the opening of the expansion valve, adjusting both the opening and the pulse cycle allows the expansion valve to have a wider range of refrigerant flow regulation. This means that even when the pressure at the heat exchanger outlet fluctuates more, the pressure at the outlet can be adjusted to maintain it within the target pressure range. Therefore, this increases the expansion valve's ability to regulate the temperature of the heat exchanger and ensures the heat exchanger's temperature uniformity. Attached Figure Description

[0058] Figure 1 is a schematic block diagram of a vehicle in one embodiment of this application.

[0059] Figure 2 is a schematic diagram of the structure of an air conditioning system according to an embodiment of this application.

[0060] Figure 3 is a schematic diagram of the air conditioning system in another embodiment of this application.

[0061] Figure 4 is a schematic diagram of the air conditioning system in another embodiment of this application.

[0062] Figure 5 is a flowchart of a control method for an air conditioning system according to an embodiment of this application.

[0063] Figure 6 is a further sub-flowchart of step S13 of Figure 5 in one embodiment of this application.

[0064] Figure 7 is a further sub-flowchart of step S13 of Figure 5 in another embodiment of this application.

[0065] Figure 8 is a flowchart of a control method for an air conditioning system according to another embodiment of this application.

[0066] Figure 9 is a flowchart of a control method for an air conditioning system in another embodiment of this application.

[0067] Figure 10 is a flowchart of a control method for an air conditioning system in another embodiment of this application.

[0068] Figure 11 is a further sub-flowchart of step S41 of Figure 9 in another embodiment of this application.

[0069] Figure 12 is a further sub-flowchart of step S411 of Figure 11 in another embodiment of this application.

[0070] Figure 13 is a further sub-flowchart of step S412 of Figure 11 in another embodiment of this application.

[0071] Figure 14 is a flowchart of a control method for an air conditioning system according to another embodiment of this application.

[0072] Figure 15 is a pressure-enthalpy diagram of the air conditioning system in one embodiment of this application.

[0073] Figure 16 is a schematic block diagram of the controller in an embodiment of this application.

[0074] Explanation of reference numerals in the attached drawings: 100, Vehicle; 1, Air conditioning system; 200, Sensor; 300, Heat exchanger; 301, Heat exchanger inlet; 302, Heat exchanger outlet; 400, Expansion valve; 11, Compressor; 111, Compressor inlet; 112, Compressor outlet; 113, Compressor inlet sensor; 114, Compressor outlet sensor; 12, Direct cooling plate; 121, Direct cooling plate inlet; 122, Direct cooling plate outlet; 13, Condenser; 14, Throttling orifice; 15, First sensor; 16, First expansion valve; 17, Second expansion valve; 18, Evaporator; 181, Evaporator inlet; 182, Evaporator outlet; 19, Evaporator outlet sensor; 20, Controller; 201, Processor; 202, Memory. Detailed Implementation

[0075] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0076] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0077] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0078] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0079] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0080] Please refer to Figure 1, which 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.

[0081] Please refer to Figure 2, which 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 to detect the pressure value at the 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. The arrows in Figure 2 indicate the flow direction of the refrigerant within the air conditioning system 1.

[0082] In some embodiments of this application, as shown in FIG2, 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. An 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 to a liquid state. 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 down.

[0083] Please refer to Figure 3, which is a schematic diagram of the structure of the air conditioning system 1 in another embodiment of this application. The heat exchanger 300 includes a direct cooling plate 12 and an evaporator 18, which are connected in parallel 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.

[0084] The throttle orifice 14 can increase the pressure value at the outlet 122 of the direct cooling plate to reduce the superheat of the outlet 122. This makes it easier to adjust the superheat of the outlet 122 of the direct cooling plate by adjusting the opening of the first expansion valve 16, ensuring that the superheat of the outlet 122 of the direct cooling plate is within the target superheat range. It can also improve the temperature uniformity of the direct cooling plate 12 and reduce the temperature difference of the battery during the cooling process, thereby further controlling the battery temperature to maintain within a suitable temperature range, improving battery quality, extending battery capacity and service life, and preventing battery damage. Furthermore, the evaporator 18 and the second expansion valve 17 can cool the vehicle cabin to improve the comfort of the user inside the vehicle cabin.

[0085] 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 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 both 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 in the compressor 11, reducing maintenance costs, and saving energy. The superheat at the outlet 122 of the direct cooling plate is the same as the superheat before the throttling orifice 14, and the pressure at the outlet 122 of the direct cooling plate is the evaporation pressure.

[0086] In some embodiments of this application, 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.

[0087] In some embodiments of this application, the suitable temperature range for the battery is 15°C-25°C.

[0088] In some embodiments of this application, the diameter of the throttling orifice 14 is 1.6-2.6 mm;

[0089] In some embodiments of this application, the orifice diameter of the throttling orifice 14 remains unchanged.

[0090] Therefore, this application adds a fixed-diameter throttling orifice 14, which requires minimal modification to the air conditioning system 1, is very space-friendly, and improves practicality.

[0091] In some embodiments of this application, the diameter of the throttling orifice 14 is set to 2.2 mm.

[0092] 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.

[0093] In some embodiments of this application, as shown in FIG3, the air conditioning system 1 further includes a condenser 13, and a compressor 11 including 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, a first expansion valve 16 is disposed between the condenser 13 and the direct cooling plate inlet 121, and a 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 reduce 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 pressure of the refrigerant, thereby increasing the boiling point of the refrigerant gas and preventing the refrigerant from vaporizing and absorbing heat at excessively low temperatures.

[0094] The pressure is reduced by the throttling orifice 14 to increase the superheat of the gas-liquid mixture after heat absorption 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.

[0095] In some embodiments of this application, 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 at least one of the opening degree of the first expansion valve 16 and the pulse period of the second expansion valve 17.

[0096] In some embodiments of this application, 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.

[0097] Please refer to Figure 4, which is a schematic diagram of the structure 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. The thermostatic expansion valve adjusts its opening degree by relying on its own superheat, so there is no need for the evaporator outlet sensor 19, which can save a sensor, thereby reducing costs and simplifying the control method.

[0098] In some embodiments of this application, 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.

[0099] In some embodiments of this application, the air conditioning system 1 also includes an electric fan, which is located near 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, so that the refrigerant in the condenser 13 can dissipate more heat, thereby reducing the condensing pressure, so as to increase the cooling capacity and reduce the power consumption of the compressor 11, and enable the compressor 11 to have better performance.

[0100] Please refer to Figure 5, which 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 any of the air conditioning systems shown in Figures 2, 3, and 4 above, or other types of air conditioning systems 1, and is not limited here. The steps of the control method can be added, removed, or adjusted in sequence according to actual needs, and are not limited here. 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 located at the heat exchanger inlet 301. The control method of the air conditioning system includes:

[0101] S11: Detects the pressure value at the heat exchanger outlet;

[0102] S12: Determine if the pressure value is within the target pressure range; if yes, proceed to S13; otherwise, proceed to S14.

[0103] 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 shall not be adjusted;

[0104] S14: When the pressure value is not within the target pressure range, determine the difference between the pressure value and the target pressure range;

[0105] 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 heat exchanger outlet is within the target pressure range.

[0106] 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 temperature uniformity of the heat exchanger 300. Compared to adjusting only 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 more widely, the pressure value at the outlet 302 can 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 temperature uniformity of the heat exchanger 300.

[0107] 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, which will in turn change the evaporation temperature at the heat exchanger outlet 302, 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 cycle of the expansion valve 400.

[0108] The pressure value at the outlet 302 of the heat exchanger is detected by sensor 200. 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 will be 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 will be positive. At this time, the opening degree and pulse period of the expansion valve 400 are adjusted so that the pressure value is stabilized within the target pressure range by periodically adjusting the opening degree of the expansion valve 400. This stabilizes the evaporation temperature and superheat within a certain range, preventing the evaporation temperature from being too high or too low while the pressure value exceeds the target pressure range, thus ensuring the temperature uniformity of the heat exchanger 300.

[0109] 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, and the pressure value is also within the target pressure range, then there is no need to control the expansion valve 400.

[0110] Please refer to Figure 6, which is a further sub-flowchart of step S13 of Figure 5 in one embodiment of this application. Adjusting the opening degree of the expansion valve and the pulse period of the expansion valve according to the difference includes:

[0111] S131: Obtain the opening degree and pulse period based on the difference and the correspondence table, where the correspondence table records the correspondence between the difference, opening degree and pulse period;

[0112] S132: Adjust the opening degree and pulse period of the expansion valve according to the opening degree and pulse period.

[0113] 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 kept 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.

[0114] The correspondence table is a data table obtained through a large number of experiments. The correspondence table can also be fitted into a linear regression formula through linear regression.

[0115] Please refer to Figure 7, which is a further sub-flowchart of step S13 of Figure 5 in another embodiment of this application. After adjusting 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 heat exchanger outlet is within the target pressure range, the control method includes:

[0116] S21: The expansion valve maintains its current opening and current pulse cycle;

[0117] S22: Detect the real-time pressure value at the heat exchanger outlet once every preset cycle time;

[0118] S23: Determine if the pressure value is within the target pressure range; if yes, proceed to S24; otherwise, proceed to S25.

[0119] S24: If the pressure value at the heat exchanger outlet is within the target pressure range, the opening degree of the expansion valve and the pulse period of the expansion valve shall not be adjusted.

[0120] S25: If the pressure value at the heat exchanger outlet is not within the target pressure range, then determine the difference between the real-time pressure value and the target pressure range again, and 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 heat exchanger outlet is within the target pressure range.

[0121] Therefore, the pressure value at the heat exchanger outlet 302 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 heat exchanger outlet 302 is within the target pressure range, thereby ensuring the uniformity of the cooling of the heat exchanger 300.

[0122] 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 the obtained pulse cycle are then used to adjust the opening and pulse cycle of the expansion valve 400. For example, if the pulse cycle is 25 seconds, the expansion valve 400 is opened 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 and pulse cycle of the expansion valve 400. 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.

[0123] 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 and performs 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.

[0124] Please refer to Figure 8, which 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 heat exchanger outlet, the control method further includes:

[0125] S31: Detect the temperature and pressure values ​​at the heat exchanger outlet;

[0126] S32: Determine the superheat at the heat exchanger outlet based on the temperature and pressure values;

[0127] 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.

[0128] Therefore, the superheat at the heat exchanger outlet 302 is calculated, and the opening of the expansion valve 400 is adjusted accordingly to control the superheat within the target superheat range by controlling the refrigerant flow rate, 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.

[0129] Sensor 200 detects the temperature and pressure values ​​at the heat exchanger outlet 302. 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. The superheat is compared to the target superheat. If the superheat does not equal 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 target superheat, the opening of the expansion valve 400 is adjusted again to guide the superheat at the heat exchanger outlet 302 to be within the target superheat range, thereby reducing the temperature difference between the heat exchanger inlet 301 and the heat exchanger outlet 302, and improving the temperature uniformity of the heat exchanger 300. When the superheat equals the target superheat, no adjustment of the opening of the expansion valve 400 is required.

[0130] In some embodiments of this application, 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 the 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.

[0131] In some embodiments of this application, the target superheat is 2K-5K.

[0132] Please refer to Figure 9, which is a flowchart of a control method for an air conditioning system according to another embodiment of this application. The air conditioning system 1 also includes a compressor 11, and heat exchangers 300 are all connected to the compressor 11. The control method further includes:

[0133] S41: Determine the total cooling capacity on the refrigeration circuit of the air conditioning system;

[0134] S42: Determine the compressor speed based on the total cooling capacity;

[0135] S43: Adjust the compressor speed to the determined speed according to the determined speed.

[0136] 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.

[0137] As shown in the structural diagram of the air conditioning system 1 in Figure 3, 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 the temperature and pressure values, the opening of the first expansion valve 16 is adjusted to ensure that the superheat of the direct cooling plate outlet 122 is within the target superheat range, thereby reducing the temperature difference between the direct cooling plate inlet 121 and the direct cooling plate outlet 122, improving the temperature uniformity of the direct cooling plate 12, and consequently improving the temperature uniformity of the battery. This helps control 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 battery overcooling. 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, it is necessary to continuously adjust the opening of the first expansion valve 16 and the pulse cycle to avoid the risk of lithium plating in the battery, thereby improving battery 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.

[0138] 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.

[0139] Please refer to Figure 10, which 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 an input module, and the control method further includes:

[0140] S51: Identify the current mode of the air conditioning system based on the vehicle's operating status and the opening and closing of the first expansion valve and / or the second expansion valve;

[0141] S52: When the air conditioning system is in the first mode, the first expansion valve works to regulate the temperature of the direct cooling plate to cool the charging battery.

[0142] S53: When the air conditioning system is in the second mode, the first expansion valve works to regulate the temperature of the direct cooling plate to cool the charging battery, and the second expansion valve works to regulate the temperature of the evaporator to cool the vehicle cabin.

[0143] 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.

[0144] Therefore, identifying the current mode of the air conditioning system 1 and performing the corresponding operation can make the air conditioning system 1 more intelligent and improve the applicability of different modes.

[0145] In some embodiments of this application, the first mode is a single-open battery DC fast charging cooling mode, the second mode is a dual-open DC fast charging cooling mode, and the third mode is a dual-open driving cooling mode. Specifically, in the single-open battery DC fast charging cooling mode, when the vehicle 100 is parked and the battery is in fast charging mode, the cooling gas output by the compressor 11 only passes through the first expansion valve 16. In the dual-open DC fast charging cooling mode, when the vehicle 100 is parked and the battery is in fast charging mode, 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-open 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.

[0146] Based on 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 opened and the second expansion valve 17 is closed. The system determines whether the air conditioning system 1 is 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 opened. The system determines whether the air conditioning system 1 is 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 executes different method steps according to different modes.

[0147] It is understandable that the input module can be an operable device such as a touch screen, button, remote control, or voice input device.

[0148] In other embodiments, the input module may also display various parameter information of the air conditioning system 1 and the current mode information.

[0149] Please refer to Figure 11, which is a further sub-flowchart of step S41 of Figure 9 in another embodiment of this application. Determining the total cooling capacity on the refrigeration circuit of the air conditioning system includes:

[0150] S411: Determine the first target cooling capacity of the branch where the direct cooling plate is located;

[0151] S412: Determine the second target cooling capacity of the branch where the evaporator is located;

[0152] S413: Determine the total cooling capacity based on the first target cooling capacity and the second target cooling capacity.

[0153] Therefore, determining the first and second target cooling capacities allows for better cooling of the battery and better reduction of temperature inside the vehicle cabin, thereby improving user comfort and battery safety.

[0154] Please refer to Figure 12, which is a further sub-flowchart of step S411 of Figure 11 in another embodiment of this application. Determining the first target cooling capacity of the branch where the direct cooling plate is located includes:

[0155] S61: Detects the battery temperature and charging power.

[0156] S62: Determine the first target cooling capacity of the branch where the direct cooling plate is located based on the battery temperature value and charging power value; and / or,

[0157] Please refer to Figure 13, which is a further sub-flowchart of step S412 of Figure 11 in another embodiment of this application. Determining the second target cooling capacity of the branch where the evaporator is located includes:

[0158] S71: Detects the outside temperature, inside temperature, and set temperature of the air conditioning system;

[0159] S72: Determine the second target cooling capacity of the branch where the evaporator is located based on the ambient temperature outside the vehicle, the temperature inside the vehicle, and the set temperature.

[0160] Therefore, determining the first and second target cooling capacities allows for better cooling of the battery and better reduction of temperature inside the vehicle cabin, thereby improving user comfort and battery safety.

[0161] In some embodiments of this application, when the air conditioning system 1 starts in the single-battery DC fast charging cooling mode, the controller 20 presets the initial opening degree of the first expansion valve 16 and the speed of the compressor 11 based on the battery temperature value, power value, charging power value and ambient temperature value to achieve a preliminary working state and perform preliminary cooling of the battery. Then, method steps S31-S33 and method steps S11-S15 are executed, wherein the heat exchanger 300 can be equivalent to the direct cooling plate 12.

[0162] In some embodiments of this application, when the air conditioning system 1 is in a 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, so that the total cooling capacity of the air conditioning system 1, that is, the total cooling capacity generated by the compressor 11, reaches the first target cooling capacity 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 cooling the battery during fast charging, thereby stabilizing battery performance and protecting the battery.

[0163] In some embodiments of this application, 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 has reached the first target cooling capacity, 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 and the opening degree and pulse cycle of the first expansion valve 16 need to be adjusted so that the total cooling capacity of the air conditioning system 1 reaches the first target cooling capacity, and the pressure value of the direct cooling plate outlet 122 is 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, so it will not perform a self-test.

[0164] In some embodiments of this application, the self-test cycle of the air conditioning system 1 may be 5s-10s.

[0165] In some embodiments of this application, 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 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 speed of the compressor 11 are preset according to the battery temperature value, the power 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.

[0166] In some embodiments of this application, 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 and the target interior temperature value are compared. 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 according to the 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. Subsequently, method steps S31-S33 and method steps S11-S15 are executed, wherein the heat exchanger 300 can be equivalent to the direct cooling plate 12.

[0167] 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, because 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 circuit containing the direct cooling plate 12.

[0168] In some embodiments of this application, 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.

[0169] In some embodiments of this application, when the air conditioning system 1 is in dual-on DC fast charging cooling mode, the battery temperature and 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 thus better cool the battery. The vehicle interior temperature determines the cooling capacity of the evaporator 18. Therefore, the compressor 11 speed needs to be adjusted according to the vehicle interior temperature to ensure 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 required for cooling the vehicle cabin, thus lowering the vehicle interior temperature to the target temperature value. Subsequently, the compressor speed increment is calculated based on the battery temperature and charging power 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. 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 battery performance and protecting the battery, and enabling the evaporator 18 to better lower the temperature inside the vehicle cabin, thus meeting the comfort needs of the occupants.

[0170] In some embodiments of this application, 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 cycle 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.

[0171] In some embodiments of this application, when the air conditioning system 1 starts in the dual-opening 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.

[0172] In some embodiments of this application, 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 degree of the second expansion valve 17 and the rotation speed of the compressor 11 are adjusted according to the interior temperature value. This ensures 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 equals the target interior temperature value, there is no need to adjust the opening degree of the second expansion valve 17 or the rotation speed of the compressor 11.

[0173] 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. Here, 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.

[0174] Therefore, when the vehicle 100 is in motion, the air in the vehicle cabin needs to be cooled. This requires adjusting the opening of the second expansion valve 17 and the speed of the compressor 11 so that the air conditioning system 1 can lower the interior temperature to the target interior temperature, thus improving the comfort of the occupants. Furthermore, cooling is only required when the battery needs to be cooled, which saves energy.

[0175] In particular, when the battery is fast charging or the vehicle is traveling at a high speed of 100 km / h, the resistive elements inside the battery generate a lot of heat, thus raising the battery temperature and requiring cooling.

[0176] In some embodiments of this application, when the air conditioning system 1 is in dual-operation 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 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 cooling mode, the air conditioning system 1 will not perform a self-test.

[0177] In some embodiments of this application, 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.

[0178] Please refer to Figure 14, which is a flowchart of 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. The control method further includes:

[0179] S81: Detects the pressure values ​​at the compressor inlet and compressor outlet;

[0180] S82: Calculate the target compression ratio of the compressor based on the pressure values ​​at the compressor inlet and outlet, and control and adjust the compressor compression ratio to the target compression ratio.

[0181] Therefore, by calculating the target compression ratio of the compressor 11 using the pressure values ​​at the compressor inlet 111 and 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, reducing energy consumption and lowering operating costs.

[0182] The compression ratio of compressor 11 is the ratio of (pressure value at compressor outlet 112 / pressure value at compressor inlet 111). The higher the speed of compressor 11, the higher the energy consumption and the higher the compression ratio. An excessively high compression ratio will cause compressor 11 to generate too much heat during operation, which may lead to overheating or even damage to compressor 11. Therefore, the compression ratio needs to be adjusted to the target compression ratio (generally 3-5).

[0183] In some embodiments of this application, 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 so that the superheat of the compressor inlet 111 reaches the target superheat, thereby preventing the compressor 11 from being liquid-sluged. 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, so as to prevent the internal temperature of the compressor 11 from being too high and carbonizing the lubricating oil, thereby preventing the compressor 11 from being damaged.

[0184] Please refer to Figure 15, which is a pressure-enthalpy diagram of the air conditioning system 1 in one embodiment of this application. As shown in Figure 15, with pressure as the vertical axis and enthalpy as the horizontal axis, the figure is divided into three regions based on a parabola, representing the liquid state, the gas-liquid mixture state, and the gas state, respectively. The 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.

[0185] The trapezoidal section in Figure 15 represents the refrigeration cycle process. The position drawn 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 release of heat, 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.

[0186] As shown in Figure 15, in the section from the lower left vertex to the upper right vertex, the solid line represents throttling without a plate, i.e., without a throttling orifice 14, while the dashed line represents throttling with a plate, i.e., with a throttling orifice 14. In the system without a throttling orifice 14, the pressure value of the solid line drops directly to the lower left vertex, indicating a lower pressure of the direct cooling plate 12, i.e., a lower evaporation pressure, 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 a throttling orifice 14, the pressure value of the dashed line drops slightly above the lower left vertex, indicating a higher pressure of the direct cooling plate 12, i.e., a higher evaporation pressure, resulting in a higher evaporation temperature and lower superheat, thus demonstrating that the throttling orifice 14 improves the temperature uniformity between the direct cooling plate 12 and the battery.

[0187] The straight dashed and solid lines at the bottom center indicate that the refrigerant absorbs heat from the battery in the direct cooling plate 12, thereby increasing the enthalpy value. The gas-liquid mixture in the dashed line is depressurized after reaching a point on the right, that is, after passing through the throttling orifice 14, and becomes a gaseous refrigerant gas. Therefore, the pressure value will directly drop to the same position as the pressure value of the solid line. After that, the high-temperature and low-pressure gas in both the solid and dashed lines enter the compressor 11. The compressor 11 does work to compress the low-pressure and high-temperature gas into a high-pressure and high-temperature gas to complete the refrigeration cycle.

[0188] Please refer to Figure 16, which 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.

[0189] 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.

[0190] The processor 201 can 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 can be volatile memory or non-volatile memory, or may include both. For example, it can 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0196] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A control method for an air conditioning system, the air conditioning system (1) including an expansion valve (400) and a heat exchanger (300), the heat exchanger (300) including a heat exchanger inlet (301) and a heat exchanger outlet (302), the expansion valve (400) being disposed at the heat exchanger inlet (301), the control method comprising: Detect the pressure value at the outlet (302) of the heat exchanger; Determine whether the pressure value is within the target pressure range; When the pressure value is not within the target pressure range, determine the difference between the pressure value and the target pressure range; Adjust 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.

2. The control method for the air conditioning system according to claim 1, wherein, The step of adjusting the opening degree of the expansion valve (400) and adjusting the pulse period of the expansion valve (400) according to the difference includes: The opening degree and pulse period are obtained based on the difference and the correspondence table, wherein the correspondence table records the correspondence between the difference, the opening degree and the pulse period; The opening degree and pulse period of the expansion valve (400) are adjusted according to the opening degree and pulse period.

3. The control method for the air conditioning system according to claim 1 or 2, wherein, After 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, the control method includes: The expansion valve (400) maintains its current opening and current pulse cycle; The real-time pressure value of the heat exchanger outlet (302) is detected once at a preset cycle time. 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 again, and the opening of the expansion valve (400) and the pulse period of the expansion valve (400) are adjusted 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 for an air conditioning system according to any one of claims 1 to 3, wherein, Before detecting the pressure value at the heat exchanger outlet (302), the control method further includes: The temperature and pressure values ​​at the outlet (302) of the heat exchanger are detected; The superheat of the heat exchanger outlet (302) is determined based on the temperature and pressure values. Adjust the opening of the expansion valve (400) according to the superheat so that the superheat of the heat exchanger outlet (302) is within the target superheat range.

5. The control method for an air conditioning system according to any one of claims 1 to 4, wherein, 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: Determine the total cooling capacity on the refrigeration circuit of the air conditioning system (1); The rotational speed of the compressor (11) is determined based on the total cooling capacity; Adjust the speed of the compressor (11) to the determined speed according to the determined speed.

6. The control method for an air conditioning system according to claim 5, wherein, 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 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 vehicle battery, 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).

7. The control method for an air conditioning system according to claim 6, wherein, Determining the total cooling capacity on the refrigeration circuit of the air conditioning system (1) includes: Determine the first target cooling capacity of the branch where the direct cooling plate (12) is located; Determine the second target cooling capacity of the branch where the evaporator (18) is located; The total cooling capacity is determined based on the first target cooling capacity and the second target cooling capacity.

8. The control method for an air conditioning system according to claim 7, wherein, The determination of the first target cooling capacity of the branch where the direct cooling plate (12) is located includes: The battery temperature and charging power values ​​of the battery are detected. The first target cooling capacity of the branch where the direct cooling plate (12) is located is determined based on the battery temperature value and the charging power value; and / or, Determining the second target cooling capacity of the branch where the evaporator (18) is located includes: The ambient temperature outside the vehicle, the temperature inside the vehicle, and the set temperature of the air conditioning system (1) are detected. The second target cooling capacity of the branch where the evaporator (18) is located is determined based on the outside ambient temperature, the inside temperature, and the set temperature.

9. The control method for an air conditioning system according to any one of claims 5 to 8, wherein, The compressor (11) includes a compressor inlet (111) and a compressor outlet (112), and the control method further includes: The pressure values ​​at the compressor inlet (111) and the compressor outlet (112) are detected; The target compression ratio of the compressor (11) is calculated based on the pressure value at the compressor inlet (111) and the pressure value at the compressor outlet (112), and the compression ratio of the compressor (11) is controlled and adjusted to the target compression ratio.

10. The control method for an air conditioning system according to claim 6, wherein, The air conditioning system (1) further includes an input module, and the control method further includes: Based on the operating status of the vehicle (100) and the opening and closing of the first expansion valve (16) and / or the second expansion valve (17), the current mode of the air conditioning system (1) is identified; When the air conditioning system (1) is in the first mode, the first expansion valve (16) operates to regulate the temperature of the direct cooling plate (12) to cool the charging battery; When the air conditioning system (1) is in the second mode, the first expansion valve (16) operates to regulate the temperature of the direct cooling plate (12) to cool the charging battery, and the second expansion valve (17) operates to regulate the temperature of the evaporator (18) to cool the vehicle cabin. When the air conditioning system (1) is in the third mode, the first expansion valve (16) operates to cool the battery during driving, and the second expansion valve (17) operates to cool the vehicle cabin.

11. An air conditioning system (1) applied to a vehicle (100), comprising: A heat exchanger (300) includes a heat exchanger inlet (301) and a heat exchanger outlet (302); A sensor (200) is disposed at the outlet (302) of the heat exchanger for detecting the pressure value at the outlet (302) of the heat exchanger; An expansion valve (400) is provided at the inlet (301) of the heat exchanger; and Controller (20) is used to determine whether the pressure value is within the target pressure range; When the pressure value is not within the target pressure range, determine the difference between the pressure value and the target pressure range; Adjust 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.

12. The air conditioning system according to claim 11, wherein, The air conditioning system (1) further includes a compressor (11), 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 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, the air conditioning system (1) further includes a throttling orifice (14), the throttling orifice (14) is located at the direct cooling plate outlet (122) of the direct cooling plate (12).

13. The air conditioning system according to claim 12, wherein, 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.

14. A vehicle (100), comprising: The air conditioning system (1) as described in any one of claims 11-13.

15. A controller (20), comprising: A processor (201) and a memory (202) connected to the processor (201), the memory (202) storing a computer program, the processor (201) running 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 storing a computer program, the computer program being invoked by a processor (201) to execute the control method of the air conditioning system according to any one of claims 1-10.

Images