Air conditioning system, method and device for controlling evaporator outlet pressure and medium

Abstract

The application discloses an air conditioning system, an evaporator outlet pressure control method and device and a medium. The system comprises a controller connected with an electronic expansion valve, an evaporator outlet pressure sensor, a pulse electromagnetic valve, a first electronic back pressure valve and a second electronic back pressure valve, and is used for acquiring a first outlet pressure value of the evaporator through the evaporator outlet pressure sensor, and controlling the first outlet pressure value to be equal to a first preset target value by adjusting valve steps of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve. The technical scheme of the embodiment can expand the adjustment range of the evaporator outlet pressure control and improve the adjustment precision by directly adopting the outlet pressure value of the evaporator as a parameter adjustment index and adopting the control device composed of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to an air conditioning system, a method, device and medium for controlling the outlet pressure of the evaporator. Background Technology

[0002] As customers' demands for air conditioning products continue to increase, there is a need to verify the heat exchange performance of air conditioning products under different evaporation pressures. Therefore, how to achieve a wide adjustment range and high precision control of the evaporator outlet pressure has gradually become one of the important research directions.

[0003] Currently, existing methods for controlling evaporator outlet pressure typically employ mechanical evaporator pressure regulating valves, rather than directly using the evaporator outlet refrigerant pressure as a precise control indicator. However, in existing technologies, once a certain pressure protection value is set at the factory, it is generally not adjusted further, resulting in problems such as a narrow adjustment range and poor adjustment accuracy. Summary of the Invention

[0004] This invention provides an air conditioning system, a method, device, and medium for controlling the outlet pressure of an evaporator, which can expand the adjustment range of the evaporator outlet pressure control and improve the adjustment accuracy.

[0005] According to one aspect of the present invention, an air conditioning system is provided, comprising an electronic expansion valve, an evaporator, an evaporator outlet pressure sensor, a pulse solenoid valve, a first electronic back pressure valve, a second electronic back pressure valve, and a controller;

[0006] The electronic expansion valve is connected to the input end of the evaporator, the evaporator outlet pressure sensor and the second electronic back pressure valve are connected to the output end of the evaporator, the first electronic back pressure valve is connected to the output end of the evaporator through the pulse solenoid valve, and the second electronic back pressure valve is connected in parallel with the first electronic back pressure valve and the pulse solenoid valve.

[0007] The controller is connected to the electronic expansion valve, the evaporator outlet pressure sensor, the pulse solenoid valve, the first electronic back pressure valve, and the second electronic back pressure valve, respectively. It is used to obtain the first outlet pressure value of the evaporator through the evaporator outlet pressure sensor, and control the first outlet pressure value to be equal to the first preset target value by adjusting the valve steps of the electronic expansion valve, the pulse solenoid valve, the first electronic back pressure valve, and the second electronic back pressure valve.

[0008] Optionally, the air conditioning system also includes a variable frequency compressor, a condenser, a variable frequency condenser fan, and a condenser outlet pressure sensor. The output end of the variable frequency compressor is connected to the electronic expansion valve through the condenser, and the forced airflow of the condenser is used to improve the heat dissipation of the condenser.

[0009] The condenser outlet pressure sensor is connected with the output end of the condenser and the controller respectively, and is used for obtaining a second outlet pressure value of the condenser and sending the second outlet pressure value to the controller.

[0010] The controller is connected with the variable frequency condensing fan and the variable frequency compressor respectively, and is further used for controlling a pressure difference value between the first outlet pressure value of the evaporator and the first preset target value to be within a first preset deviation range by adjusting the first frequency of the variable frequency compressor, and controlling a pressure difference value between the second outlet pressure value and a second preset target value to be within a second preset deviation range by adjusting the second frequency of the variable frequency condensing fan.

[0011] Optionally, the air conditioning system further comprises a liquid accumulator, a drying filter, a liquid level mirror, an electromagnetic valve and a gas-liquid separator; one end of the liquid accumulator is connected with the output end of the condenser, and the other end is connected with the electronic expansion valve through the drying filter, the liquid level mirror and the electromagnetic valve; one end of the gas-liquid separator is connected with the first electronic back pressure valve and the second electronic back pressure valve, and the other end is connected with the input end of the variable frequency compressor.

[0012] The liquid accumulator is used for storing liquid components in the refrigerant output by the condenser.

[0013] The drying filter is used for absorbing water in the refrigerant after passing through the liquid accumulator.

[0014] The liquid level mirror is used for displaying the liquid level of the refrigerant.

[0015] The electromagnetic valve is used for allowing or limiting the flow of the refrigerant according to the on-off electric condition.

[0016] The gas-liquid separator is used for containing liquid components in the refrigerant output by the first electronic back pressure valve and the second electronic back pressure valve.

[0017] Optionally, the air conditioning system further comprises an evaporating fan, and an air duct of the evaporating fan passes through the evaporator.

[0018] The evaporating fan is used for transferring the cold energy of the refrigerant in the evaporator to the air.

[0019] According to another aspect of the present application, an evaporator outlet pressure control method is provided, which is applied to the controller in the air conditioning system according to any one of the embodiments of the present application, and comprises the following steps.

[0020] The first outlet pressure value of the evaporator is obtained through an evaporator outlet pressure sensor.

[0021] if it is detected that the pressure difference between the first outlet pressure value and a first preset target value is within a first preset deviation range, then when it is detected that the first outlet pressure value is greater than the first preset target value and the valve step of the electronic expansion valve is in a preset non-dead zone, adjusting the valve step of the electronic expansion valve so that the first outlet pressure value is equal to the first preset target value;

[0022] if it is detected that the first outlet pressure value is less than the first preset target value and the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in a preset non-dead zone, then adjusting the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve so that the first outlet pressure value is equal to the first preset target value.

[0023] According to another aspect of the present application, there is provided a control device for outlet pressure of an evaporator, applied to a controller in an air conditioning system according to any one of the embodiments of the present application, comprising:

[0024] an evaporator pressure value acquisition module, configured to acquire a first outlet pressure value of the evaporator through an evaporator outlet pressure sensor;

[0025] a first valve step adjustment module, configured to, if it is detected that the pressure difference between the first outlet pressure value and a first preset target value is within a first preset deviation range, then when it is detected that the first outlet pressure value is greater than the first preset target value and the valve step of the electronic expansion valve is in a preset non-dead zone, adjusting the valve step of the electronic expansion valve so that the first outlet pressure value is equal to the first preset target value;

[0026] a second valve step adjustment module, configured to, if it is detected that the first outlet pressure value is less than the first preset target value and the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in a preset non-dead zone, then adjusting the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve so that the first outlet pressure value is equal to the first preset target value.

[0027] According to another aspect of the present application, there is provided a computer readable storage medium, which stores computer instructions for causing a processor to execute a control method for outlet pressure of an evaporator according to any one of the embodiments of the present application.

[0028] The technical scheme of the embodiment of the present application, the controller acquires the first outlet pressure value of the evaporator through the evaporator outlet pressure sensor, and controls the first outlet pressure value to be equal to the first preset target value by adjusting the valve steps of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve; by directly using the outlet pressure value of the evaporator as a parameter adjustment index, and using the control device composed of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve, the adjustment range of the evaporator outlet pressure control can be expanded, and the adjustment precision can be improved.

[0029] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0031] Figure 1A is a structural schematic diagram of an air conditioning system according to the first embodiment of the present application;

[0032] Figure 1B is a structural schematic diagram of another air conditioning system according to the first embodiment of the present application;

[0033] Figure 1C is a structural schematic diagram of another air conditioning system according to the first embodiment of the present application;

[0034] Figure 1D is a structural schematic diagram of another air conditioning system according to the first embodiment of the present application;

[0035] Figure 1E is a structural schematic diagram of another air conditioning system according to the first embodiment of the present application;

[0036] Figure 2 is a flow chart of a control method of an evaporator outlet pressure according to the second embodiment of the present application;

[0037] Figure 3 is a structural schematic diagram of a control device of an evaporator outlet pressure according to the third embodiment of the present application. DETAILED DESCRIPTION

[0038] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work should belong to the protection scope of the present application.

[0039] It should be noted that the terms "first", "second", "target" and the like in the description, claims, and drawings of the present application are intended to distinguish similar objects, and do not necessarily indicate a particular order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0040] Embodiment one

[0041] Figure 1A A structural schematic diagram of an air conditioning system is provided for the first embodiment of the present application, wherein the air conditioning system 100 can include an electronic expansion valve 101, an evaporator 102, an evaporator outlet pressure sensor 103, a pulse solenoid valve 104, a first electronic back pressure valve 105, a second electronic back pressure valve 106, and a controller 107.

[0042] The electronic expansion valve 101 is connected to the input end of the evaporator 102, the evaporator outlet pressure sensor 103 and the second electronic back pressure valve 106 are connected to the output end of the evaporator 102, the first electronic back pressure valve 105 is connected to the output end of the evaporator 102 through the pulse solenoid valve 104, and the second electronic back pressure valve 106 is connected in parallel with the first electronic back pressure valve 105 and the pulse solenoid valve 104. Wherein, the first electronic back pressure valve 105 is connected in series with the pulse solenoid valve 104, and the series branch is connected in parallel with the second electronic back pressure valve 106.

[0043] In the embodiment, the refrigerant passes through the electronic expansion valve 101 and enters the evaporator 102. After flowing out of the evaporator 102, the refrigerant enters the branch circuit in which the first electronic back pressure valve 105 and the pulse solenoid valve 104 are connected in series, and the branch circuit in which the second electronic back pressure valve 106 is located. It can be understood that the air conditioning system 100 can also include other conventional devices, such as a compressor, a condenser, etc., which can constitute a closed loop circuit of the refrigerant, and the refrigerant completes a refrigeration cycle by flowing in the closed loop circuit.

[0044] The controller 107 is connected to the electronic expansion valve 101, the evaporator outlet pressure sensor 103, the pulse solenoid valve 104, the first electronic back pressure valve 105 and the second electronic back pressure valve 106, respectively, for obtaining the first outlet pressure value of the evaporator 102 through the evaporator outlet pressure sensor 103, and controlling the first outlet pressure value to be equal to a first preset target value by adjusting the valve steps of the electronic expansion valve 101, the pulse solenoid valve 104, the first electronic back pressure valve 105 and the second electronic back pressure valve 106.

[0045] The evaporator outlet pressure sensor 103 is arranged at the output end of the evaporator 102, for monitoring the pressure of the refrigerant at the outlet of the evaporator 102 in real time and sending the detected pressure value to the controller 107. The controller 107 can be a functional module with data processing capability, such as a central processing unit, etc. In the embodiment, the type of the pressure sensor is not specifically limited.

[0046] In the embodiment, the controller 107 can be connected to each device by wired connection or wireless connection. Typically, the controller 107 can send controller signals to each valve to control the valve steps of each valve. The valve step can be the opening degree of each valve. Typically, in the initial state, each valve can be in the fully open state by default.

[0047] The electronic expansion valve 101 is used to control the injection of liquid refrigerant from the condenser 109 into the evaporator 102, and can realize the isenthalpic pressure reduction of the refrigerant and the control of the refrigerant flow according to the controller signal when the refrigerant passes through the electronic expansion valve 101. By using the electronic expansion valve 101, the superheat degree at the outlet of the evaporator 102 can be maintained at a certain level, so that the liquid refrigerant can be prevented from leaving the evaporator 102 and entering the compressor. The evaporator 102 is used to evaporate the low-pressure and low-temperature gas-liquid mixed refrigerant throttled by the electronic expansion valve 101 into low-pressure and medium-temperature gas. Since the evaporation process absorbs heat, the evaporator 102 is a device for evaporating refrigerant liquid into refrigerant gas. The pulse electromagnetic valve 104 can be rapidly cycled in a short time, so as to maintain a very close temperature, and is used to realize the refrigerant flow regulation under the premise that the pressure is basically unchanged. The electronic back pressure valve is used to rapidly adjust the refrigerant pressure when the environmental or system conditions change.

[0048] In a specific example, when the controller 107 detects that the first outlet pressure value of the evaporator 102 is not equal to the preset target pressure value, the valve steps of the valves can be adjusted according to the preset adjustment rule to adjust the first outlet pressure value, so that the first outlet pressure value is finally equal to the preset target value. For example, if it is detected that the first outlet pressure value is greater than the first preset target value, the valve step of the electronic expansion valve 101 can be adjusted based on the PID (Proportion, Integral and Differential) algorithm to reduce the refrigerant flow entering the evaporator 102, so as to reduce the first outlet pressure value to equal the preset target value. Alternatively, if it is detected that the first outlet pressure value is less than the first preset target value, the valve steps of the second electronic back pressure valve 106, the first electronic back pressure valve 105 and the pulse electromagnetic valve 104 can be sequentially reduced in order based on the PID algorithm, so that the first outlet pressure value is equal to the first preset target value.

[0049] The technical scheme of the embodiment of the present application can obtain the first outlet pressure value of the evaporator through the evaporator outlet pressure sensor, and control the first outlet pressure value to be equal to the first preset target value by adjusting the valve steps of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve. By directly using the outlet pressure value of the evaporator as a parameter adjustment index, and using the control device composed of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve, the adjustment range of the evaporator outlet pressure control can be expanded, and the adjustment accuracy can be improved.

[0050] Optionally, as shown in FIG. 1, the control device further comprises a second outlet pressure sensor 103, which is arranged at the second outlet of the evaporator 102 and is used to detect the second outlet pressure value of the evaporator 102. Figure 1BAs shown, the air conditioning system 100 can further include a variable frequency compressor 108, a condenser 109, a variable frequency condenser fan 110 and a condenser outlet pressure sensor 111, wherein an output end of the variable frequency compressor 108 is connected with the electronic expansion valve 101 through the condenser 109, and the variable frequency condenser fan 110 forces air to flow through the condenser 109 to increase heat dissipation of the condenser 109;

[0051] The condenser outlet pressure sensor 111 is connected with the output end of the condenser 109 and the controller 107 respectively, for obtaining a second outlet pressure value of the condenser 109 and sending the second outlet pressure value to the controller 107;

[0052] The controller 107 is connected with the variable frequency condenser fan 110 and the variable frequency compressor 108 respectively, and is further configured to control a pressure difference between the first outlet pressure value of the evaporator 102 and the first preset target value to be within a first preset deviation range by adjusting a first frequency of the variable frequency compressor 108, and control a pressure difference between the second outlet pressure value and a second preset target value to be within a second preset deviation range by adjusting a second frequency of the variable frequency condenser fan 110.

[0053] The variable frequency compressor 108 is the power core of the air conditioning system 100, which can compress the low-temperature and low-pressure refrigerant vapor into high-pressure and high-temperature superheated vapor, so as to create the condition of condensation at a higher temperature, can transport and push the refrigerant to flow in the system to complete the refrigeration cycle, and can achieve the purpose of refrigeration through heat work conversion. Secondly, by adopting the variable frequency effect (changing the power frequency), the different heating power of the customer and the requirement of the customer on the response time can be quickly responded, so as to ensure that the air conditioning system 100 can reach the required operating state and boundary condition in a short time, and also has the advantage of energy saving.

[0054] The condenser 109 is used for condensing the high-pressure and high-temperature refrigerant vapor delivered by the variable frequency compressor 108 into high-pressure and high-temperature liquid. The condensation process is a heat dissipation process, so the condenser 109 is a device for condensing the refrigerant vapor into refrigerant liquid. The variable frequency condenser fan 110 is used for transferring the heat dissipated by the refrigerant in the condenser 109 to the air through the fan, so as to keep the condensation temperature and condensation pressure within a reasonable range. In this embodiment, by adjusting the power frequency of the variable frequency condenser fan 110, the fan speed can be controlled, so that the control of the outlet pressure value of the condenser 109 can be realized.

[0055] It should be noted that the premise of controlling the outlet pressure value of the evaporator 102 to remain stable is that the outlet pressure value of the condenser 109 remains stable and cannot have large fluctuations. In the present embodiment, the controller 107 can perform frequency adjustment on the variable condenser fan 110 based on a PID algorithm according to the second preset target value, that is, adjust the second frequency (power frequency) of the variable condenser fan 110, to ensure that the pressure difference between the second outlet pressure value and the second preset target value always remains within the second preset deviation range. The preset deviation range can be a preset pressure value deviation range, for example, it can be [-A, +A].

[0056] Further, after ensuring that the pressure difference between the second outlet pressure value and the second preset target value is within the second preset deviation range, the variable condenser fan 110 can be controlled to maintain the current power frequency; and then the variable compressor 108 is controlled to rapidly increase the frequency according to the pressure difference between the first outlet pressure value of the evaporator 102 and the first preset target value, to ensure that the pressure difference between the first outlet pressure value and the first preset target value remains within the first preset deviation range, and the current compressor operating frequency remains unchanged. Finally, the controller 107 can further control the valves corresponding to the evaporator 102 to perform valve step adjustment, so as to finally make the first outlet pressure value equal to the first preset target value.

[0057] Optionally, as shown in Figure 1C The air conditioning system 100 can further include a liquid accumulator 112, a drying filter 113, a sight glass 114, an electromagnetic valve 115, and a gas-liquid separator 116; one end of the liquid accumulator 112 is connected to the output end of the condenser 109, and the other end is connected to the electronic expansion valve 101 through the drying filter 113, the sight glass 114, and the electromagnetic valve 115; one end of the gas-liquid separator 116 is connected to the first electronic back pressure valve 105 and the second electronic back pressure valve 106, and the other end is connected to the input end of the variable compressor 108;

[0058] The liquid accumulator 112 is used to store the liquid component in the refrigerant output by the condenser 109; in the present embodiment, by using the liquid accumulator 112, the load of the condenser 109 can be reduced to adapt to the demand for refrigerant supply amount due to load variation. When the evaporation load increases, the supply amount also increases, and the liquid stored in the liquid accumulator 112 is supplemented; when the evaporation load decreases, the required liquid amount also decreases, and the excess liquid can be stored in the liquid accumulator 112.

[0059] The drying filter 113 is used to absorb the moisture in the refrigerant after passing through the liquid accumulator 112; in addition, the drying filter 113 can also block impurities in the system so that they cannot pass through, and can prevent ice blockage and dirty blockage of the system pipeline.

[0060] The sight glass 114 is used to show the liquid level of the refrigerant. By observing the liquid level of the refrigerant, it can be determined whether the system is running properly, and whether water vapor exists at the rear end of the drying filter 113.

[0061] The electromagnetic valve 115 is used to allow or limit the flow of refrigerant according to the on-off electricity. Typically, when there is no electricity, the flow of refrigerant is limited (usually closed), and when there is electricity, the flow of refrigerant is allowed.

[0062] The gas-liquid separator 116 is used to contain the liquid component in the refrigerant output by the first electronic back pressure valve 105 and the second electronic back pressure valve 106. By using the gas-liquid separator 116, it can prevent liquid hammer to the variable frequency compressor 108 and excessive refrigerant dilution to the compressor oil.

[0063] Optionally, as shown in Figure 1D The air conditioning system 100 can also include an evaporative fan 117, and the air duct of the evaporative fan 117 passes through the evaporator 102.

[0064] The evaporative fan 117 is used to transfer the cold energy emitted by the refrigerant in the evaporator 102 to the air. In this embodiment, the evaporative fan 117 is used to achieve air conditioning refrigeration. In addition, the evaporative fan 117 can be connected with the controller 107, and used to adjust its speed according to the control signal of the controller 107.

[0065] In a specific example, the air conditioning system 100 can be as shown in Figure 1E Wherein, CM- variable frequency compressor 108, COND- condenser 109, FD1- variable frequency condenser fan 110, HTP1- condenser outlet pressure sensor 111, LR- liquid accumulator 112, D1- drying filter 113, SGN- sight glass 114, SV- electromagnetic valve 115, EEV- electronic expansion valve 101, EVAP- evaporator 102, FD2- evaporative fan 117, HTP2- evaporator outlet pressure sensor 103, HSV- pulse electromagnetic valve 104, DX1- first electronic back pressure valve 105, DX2- second electronic back pressure valve 106, RA- gas-liquid separator 116.

[0066] Specifically, the refrigerant is output from the discharge port of the variable frequency compressor 108, passes through the condenser 109, the condenser outlet pressure sensor 111, the liquid accumulator 112, the dry filter 113, the sight glass 114, the electromagnetic valve 115, the electronic expansion valve 101, the evaporator 102, the evaporator outlet pressure sensor 103, and two electronic back pressure valves connected in parallel at the outlet of the evaporator outlet pressure sensor 103, wherein the first electronic back pressure valve 105 is provided with a set of pulse electromagnetic valve 104, and the outlet of the electronic back pressure valve group is connected to a set of gas-liquid separator 116. The refrigerant after the gas-liquid separator 116 enters the variable frequency compressor 108, forming a closed loop.

[0067] The above setting has the benefits that the evaporator 102 outlet pressure can be quickly adjusted, the initial adjustment time is shortened, and the test data during the entire air conditioning product heat exchange effect test process can meet the test requirements; secondly, the stability of the evaporator 102 outlet pressure can be improved, the influence of the evaporator 102 outlet pressure on the system during the entire test process can be accurately judged; the setting range of the evaporator 102 outlet pressure can be expanded, and the limitation of the adjustment interval section is eliminated.

[0068] Embodiment two

[0069] Figure 2 A flowchart of a control method of the evaporator outlet pressure is provided for the second embodiment of the application. The present embodiment is applicable to the case of accurately controlling the refrigerant pressure at the outlet of the evaporator. The method can be executed by the evaporator outlet pressure control device and can be applied to the controller 107 in the air conditioning system 100 described in the first embodiment of the application. As shown in the figure, the method comprises the following steps: Figure 2

[0070] S210, obtaining a first outlet pressure value of the evaporator through an evaporator outlet pressure sensor.

[0071] In the present embodiment, the controller 107 can send a parameter reading instruction to the pressure sensor pre-deployed at the outlet of the evaporator 102 to obtain the pressure value of the refrigerant at the outlet of the evaporator 102 at different times as the first outlet pressure value.

[0072] S220, if the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, adjusting the valve step of the electronic expansion valve when it is detected that the first outlet pressure value is greater than the first preset target value and the valve step of the electronic expansion valve is in the preset non-dead zone, so that the first outlet pressure value is equal to the first preset target value.

[0073] ​In the embodiment, after ensuring that the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, the electronic expansion valve 101 and the electronic back pressure valve can be used to perform synchronous control on the outlet pressure of the evaporator 102. Specifically, when it is detected that the first outlet pressure value is greater than the first preset target value, i.e., in the upper deviation, and the valve step of the electronic expansion valve 101 is in the preset non-dead zone, the valve step of the electronic expansion valve 101 can be controlled according to the first preset target value based on the PID algorithm, so as to stabilize the first outlet pressure value at the first preset target value.

[0074] Optionally, after determining that the valve step of the electronic expansion valve 101 is in the preset non-dead zone, it can be further judged whether the pressure difference is within the preset adjustment range; if yes, the valve step of the electronic expansion valve 101 can be adjusted.

[0075] The preset non-dead zone can be a preset adjustable valve step range. When the valve step is in the preset non-dead zone, the valve step is adjustable. When the valve step is out of the preset non-dead zone, the current valve step is not adjustable.

[0076] S230, if it is detected that the first outlet pressure value is less than the first preset target value, and the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in the preset non-dead zone, the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is adjusted, so that the first outlet pressure value is equal to the first preset target value.

[0077] In the embodiment, after ensuring that the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, if it is detected that the first outlet pressure value is less than the first preset target value, i.e., in the lower deviation, and the valve step of the pulse electromagnetic valve 104, the first electronic back pressure valve 105 or the second electronic back pressure valve 106 is in the preset non-dead zone, the valve step of the corresponding valve can be adjusted according to the preset adjustment rule (for example, the valve step is adjusted according to the preset valve sequence, or the valve step of the valve in the preset non-dead zone is adjusted, etc.) based on the PID algorithm, so as to control the first outlet pressure value to be stabilized at the first preset target value.

[0078] Optionally, if the pressure difference between the first outlet pressure value and the first preset target value is out of the first preset deviation range, or each valve is in the adjustment limit, the frequency conversion compressor 108 can be adjusted to increase the frequency, so as to ensure that the outlet pressure value of the evaporator 102 remains stable, and the air conditioning system 100 is always in a dynamic balance adjustment process.

[0079] In an optional implementation of the embodiment, adjusting the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve to make the first outlet pressure value equal to the first preset target value can include:

[0080] According to a preset step length, gradually reducing the valve step of the second electronic back pressure valve, and when detecting that the second electronic back pressure valve is adjusted to a preset minimum valve step, controlling the second electronic back pressure valve to keep the preset minimum valve step;

[0081] According to a preset step length, gradually reducing the valve step of the first electronic back pressure valve, and when detecting that the first electronic back pressure valve is adjusted to a preset minimum valve step, controlling the first electronic back pressure valve to keep the preset minimum valve step;

[0082] According to a preset adjustment value, gradually reducing the control signal value of the pulse electromagnetic valve until detecting that the first outlet pressure value is equal to the first preset target value or the control signal value is equal to 0.

[0083] In the embodiment, when initially starting the adjustment, each electronic back pressure valve is in a fully open state by default, and the control signal value of the pulse electromagnetic valve 104 is 100%. When adjusting the valve, the valve step is adjusted according to the priority of the second electronic back pressure valve 106, the first electronic back pressure valve 105 and the pulse electromagnetic valve 104 in turn.

[0084] Specifically, first, the controller 107 gradually reduces the valve step of the second electronic back pressure valve 106 according to a preset step length, and keeps the valve steps of the first electronic back pressure valve 105 and the pulse electromagnetic valve 104 unchanged. During this process, if it is detected that the first pressure value is equal to the first preset target value, the valve step adjustment can be stopped. If it is always detected that the first pressure value is not equal to the first preset target value, the second electronic back pressure valve 106 can be kept at a preset minimum valve step when the second electronic back pressure valve 106 is adjusted to the preset minimum valve step, and the valve step of the first electronic back pressure valve 105 can be adjusted.

[0085] Then, the valve step of the pulse electromagnetic valve 104 is kept unchanged, and the valve step of the first electronic back pressure valve 105 is gradually reduced according to a preset step length. Similarly, if the outlet pressure value of the evaporator 102 is still not equal to the preset target value during this process, the first electronic back pressure valve 105 can be kept at a preset minimum valve step when the first electronic back pressure valve 105 is adjusted to the preset minimum valve step.

[0086] Finally, the control signal value of the pulse electromagnetic valve 104 can be gradually reduced according to the preset adjustment value until the first outlet pressure value is detected to be equal to the first preset target value in the process; otherwise, the current valve adjustment is ended when the control signal value is adjusted to 0. In the embodiment, if the first outlet pressure value is still not equal to the first preset target value after the adjustment of each valve, the variable frequency compressor 108 can be controlled to intervene in the adjustment.

[0087] The technical scheme of the embodiment of the application, the controller obtains the first outlet pressure value of the evaporator through the evaporator outlet pressure sensor; then, if the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, when the first outlet pressure value is detected to be greater than the first preset target value and the valve step of the electronic expansion valve is in the preset non-dead zone, the valve step of the electronic expansion valve is adjusted to make the first outlet pressure value equal to the first preset target value; or, if the first outlet pressure value is detected to be less than the first preset target value and the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in the preset non-dead zone, the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is adjusted to make the first outlet pressure value equal to the first preset target value; by directly using the outlet pressure value of the evaporator as a parameter adjustment index, and using the control device composed of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve, the adjustment range of the evaporator outlet pressure control can be expanded, and the adjustment precision can be improved.

[0088] In another optional embodiment of the embodiment, before detecting that the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, the following can also be included:

[0089] The second outlet pressure value of the condenser is obtained through the condenser outlet pressure sensor;

[0090] If the pressure difference between the second outlet pressure value and the second preset target value is not within the second preset deviation range, the second frequency of the variable frequency condensing fan is adjusted to make the pressure difference between the second outlet pressure value and the second preset target value within the second preset deviation range.

[0091] In this embodiment, maintaining a stable outlet pressure of the condenser 109 is a prerequisite for maintaining a stable outlet pressure of the evaporator 102. Therefore, the controller 107 can obtain the second outlet pressure value of the condenser 109 in advance through the condenser outlet pressure sensor 111. At this time, if the pressure difference between the second outlet pressure value and the second preset target value is detected to be outside the second preset deviation range, the power supply frequency of the variable frequency condenser fan 110 can be adjusted according to the second preset target value based on the PID algorithm, thereby adjusting the speed of the variable frequency condenser fan 110 and thus adjusting the second outlet pressure value so that the pressure difference between it and the second preset target value is always kept within the second preset deviation range.

[0092] In another optional embodiment of this example, after adjusting the second frequency of the variable frequency condenser fan to ensure that the pressure difference between the second outlet pressure value and the second preset target value is within the second preset deviation range, the method may further include:

[0093] If the pressure difference between the first outlet pressure value and the first preset target value is detected to be outside the first preset deviation range, the first frequency of the variable frequency compressor is adjusted so that the pressure difference between the first outlet pressure value of the evaporator and the first preset target value is within the first preset deviation range.

[0094] In this embodiment, after the outlet pressure of the condenser 109 reaches the required level, if the controller 107 detects that the pressure difference between the first outlet pressure value and the first preset target value is not within the first preset deviation range, it can control the variable frequency compressor 108 to adjust the power supply frequency for rapid frequency increase. If the controller detects that the pressure difference between the current first outlet pressure value and the first preset target value is within the first preset deviation range, it can maintain the current compressor operating frequency to ensure that the pressure difference always remains within the preset deviation range.

[0095] Example 3

[0096] Figure 3 This is a schematic diagram of a device for controlling the outlet pressure of an evaporator according to Embodiment 3 of the present invention. Figure 3 As shown, this device can be applied to the controller 107 in the air conditioning system 100 described in Embodiment 1 of the present invention, and may include: an evaporator pressure value acquisition module 310, a first valve step adjustment module 320, and a second valve step adjustment module 330; wherein,

[0097] Evaporator pressure value acquisition module 310 is used to acquire the first outlet pressure value of the evaporator through the evaporator outlet pressure sensor;

[0098] The first valve step adjusting module 320 is configured to, if it is detected that the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, adjust the valve step of the electronic expansion valve to make the first outlet pressure value equal to the first preset target value when it is detected that the first outlet pressure value is greater than the first preset target value and the valve step of the electronic expansion valve is in the preset non-dead zone.

[0099] The second valve step adjusting module 330 is configured to, if it is detected that the first outlet pressure value is less than the first preset target value and the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in the preset non-dead zone, adjust the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve to make the first outlet pressure value equal to the first preset target value.

[0100] The technical scheme of the embodiment of the present application comprises the following steps: the controller acquires the first outlet pressure value of the evaporator through the evaporator outlet pressure sensor; then, if it is detected that the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, the valve step of the electronic expansion valve is adjusted to make the first outlet pressure value equal to the first preset target value when it is detected that the first outlet pressure value is greater than the first preset target value and the valve step of the electronic expansion valve is in the preset non-dead zone; or, if it is detected that the first outlet pressure value is less than the first preset target value and the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in the preset non-dead zone, the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is adjusted to make the first outlet pressure value equal to the first preset target value; by directly adopting the outlet pressure value of the evaporator as a parameter adjustment index and adopting the control device composed of the electronic expansion valve, the pulse electromagnetic valve, the first electronic back pressure valve and the second electronic back pressure valve, the adjustment range of the evaporator outlet pressure control can be expanded and the adjustment precision can be improved.

[0101] Optionally, the second valve step adjusting module 330 is specifically configured to control the second electronic back pressure valve to gradually reduce the valve step according to a preset step length, and control the second electronic back pressure valve to keep the preset minimum valve step when it is detected that the second electronic back pressure valve is adjusted to the preset minimum valve step.

[0102] The first electronic back pressure valve is controlled to gradually reduce the valve step according to a preset step length, and the first electronic back pressure valve is controlled to keep the preset minimum valve step when it is detected that the first electronic back pressure valve is adjusted to the preset minimum valve step.

[0103] The control signal value of the pulse electromagnetic valve is gradually reduced according to a preset adjustment value until it is detected that the first outlet pressure value is equal to the first preset target value or the control signal value is equal to 0.

[0104] Optionally, the evaporator outlet pressure control device further comprises:

[0105] a condenser pressure value acquisition module configured to acquire a second outlet pressure value of the condenser via a condenser outlet pressure sensor;

[0106] a fan frequency adjustment module configured to adjust a second frequency of a variable frequency condenser fan if it is detected that a pressure difference between the second outlet pressure value and a second preset target value is not within a second preset deviation range, so that the pressure difference between the second outlet pressure value and the second preset target value is within the second preset deviation range.

[0107] Optionally, the evaporator outlet pressure control device further comprises:

[0108] a compressor frequency adjustment module configured to adjust a first frequency of a variable frequency compressor if it is detected that a pressure difference between the first outlet pressure value and a first preset target value is not within a first preset deviation range, so that the pressure difference between the first outlet pressure value of the evaporator and the first preset target value is within the first preset deviation range.

[0109] The evaporator outlet pressure control device provided by the embodiments of the present application can execute the evaporator outlet pressure control method provided by any of the embodiments of the present application, and has the corresponding function modules and beneficial effects of the execution method.

[0110] Embodiment Four

[0111] In this embodiment, the evaporator outlet pressure control method can be implemented as computer instructions tangibly embodied in a computer-readable storage medium, such as a storage unit. In some embodiments, part or all of the computer instructions can be loaded and / or installed on an electronic device via a ROM and / or a communication unit. When the computer instructions are loaded into the RAM and executed by the processor, one or more steps of the evaporator outlet pressure control method described above can be executed. Alternatively, in other embodiments, the processor can be configured to execute the evaporator outlet pressure control method by any other appropriate means (for example, by means of firmware).

[0112] The various embodiments of the systems and techniques described above can be implemented in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a load programmable logic device (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0113] Computer programs used to implement the processes of the application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer program, when executed, can cause instructions defined in the flow charts and / or block diagrams to be implemented. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as a standalone software package and partially on a remote machine or entirely on a remote machine or server.

[0114] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store computer programs for use by or in connection with an instruction execution system, apparatus, or device. Computer-readable storage media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium will include one or more lines of electrical connections, portable computer disks, hard disk drives, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), optical fibers, portable compact disc read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0115] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0116] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0117] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0118] It should be understood that the various forms of flow shown above can be re-ordered, added to, or deleted from without departing from the scope of the present disclosure. For example, the steps recited in the present disclosure can be executed in parallel, executed in sequence, or executed in a different order, as long as the desired results of the present disclosure are achieved, and the present disclosure is not limited herein.

[0119] The specific embodiments described above are not intended to be limiting, and persons skilled in the art will appreciate that various modifications, combinations, sub-combinations and alternatives can be made to the specific embodiments without departing from the spirit and principles of the disclosure. Accordingly, the disclosure is not limited to the specific embodiments described above, but only by the scope of the appended claims.

Claims

1. An air conditioning system, characterized by, The system comprises an electronic expansion valve, an evaporator, an evaporator outlet pressure sensor, a pulse solenoid valve, a first electronic back pressure valve, a second electronic back pressure valve and a controller. The electronic expansion valve is connected to the input end of the evaporator, the evaporator outlet pressure sensor and the second electronic back pressure valve are connected to the output end of the evaporator, the first electronic back pressure valve is connected to the output end of the evaporator through the pulse solenoid valve, and the second electronic back pressure valve is connected in parallel with the first electronic back pressure valve and the pulse solenoid valve. The controller is connected to the electronic expansion valve, the evaporator outlet pressure sensor, the pulse solenoid valve, the first electronic back pressure valve and the second electronic back pressure valve respectively, is used to acquire the first outlet pressure value of the evaporator through the evaporator outlet pressure sensor, and control the first outlet pressure value to be equal to a first preset target value by adjusting the valve steps of the electronic expansion valve, the pulse solenoid valve, the first electronic back pressure valve and the second electronic back pressure valve. The control of the first outlet pressure value to be equal to the first preset target value by adjusting the valve steps of the electronic expansion valve, the pulse solenoid valve, the first electronic back pressure valve and the second electronic back pressure valve comprises: If the pressure difference between the first outlet pressure value and the first preset target value is within a first preset deviation range, when the first outlet pressure value is detected to be less than the first preset target value and the valve steps of the pulse solenoid valve, the first electronic back pressure valve or the second electronic back pressure valve are in a preset non-dead zone, the second electronic back pressure valve is controlled to gradually reduce the valve step according to a preset step length, and when the second electronic back pressure valve is detected to be adjusted to a preset minimum valve step, the second electronic back pressure valve is controlled to keep the preset minimum valve step; The first electronic back pressure valve is controlled to gradually reduce the valve step according to a preset step length, and when the first electronic back pressure valve is detected to be adjusted to a preset minimum valve step, the first electronic back pressure valve is controlled to keep the preset minimum valve step; The control signal value of the pulse solenoid valve is gradually reduced according to a preset adjustment value until the first outlet pressure value is detected to be equal to the first preset target value or the control signal value is equal to 0. When the adjustment is initially started, each electronic back pressure valve is in a fully open state by default, and the control signal value of the pulse solenoid valve is 100%.

2. The air conditioning system of claim 1, wherein, The system further comprises a variable frequency compressor, a condenser, a variable frequency condenser fan and a condenser outlet pressure sensor, the output end of the variable frequency compressor is connected to the electronic expansion valve through the condenser, and the variable frequency condenser fan forces air to circulate in the condenser to improve the heat dissipation of the condenser. The condenser outlet pressure sensor is connected to the output end of the condenser and the controller respectively, is used to acquire the second outlet pressure value of the condenser, and sends the second outlet pressure value to the controller. The controller is connected with the variable frequency condensing fan and the variable frequency compressor respectively, and is further configured to control a pressure difference between the first outlet pressure value of the evaporator and the first preset target value to be within a first preset deviation range by adjusting a first frequency of the variable frequency compressor, and control a pressure difference between the second outlet pressure value and a second preset target value to be within a second preset deviation range by adjusting a second frequency of the variable frequency condensing fan.

3. The air conditioning system of claim 2, wherein, The system further comprises a liquid accumulator, a drying filter, a liquid level gauge, an electromagnetic valve and a gas-liquid separator; one end of the liquid accumulator is connected with an output end of the condenser, and the other end of the liquid accumulator is connected with the electronic expansion valve through the drying filter, the liquid level gauge and the electromagnetic valve; one end of the gas-liquid separator is connected with the first electronic back pressure valve and the second electronic back pressure valve, and the other end of the gas-liquid separator is connected with an input end of the variable frequency compressor; The liquid accumulator is configured to store liquid components in the refrigerant output by the condenser; The drying filter is configured to absorb moisture in the refrigerant after passing through the liquid accumulator; The liquid level gauge is configured to display the liquid level of the refrigerant; The electromagnetic valve is configured to allow or limit the flow of the refrigerant according to the on-off state of electricity; The gas-liquid separator is configured to accommodate liquid components in the refrigerant output by the first electronic back pressure valve and the second electronic back pressure valve.

4. The air conditioning system of claim 3, wherein, The system further comprises an evaporating fan, and an air duct of the evaporating fan passes through the evaporator; The evaporating fan is configured to transfer the cold energy generated by the refrigerant in the evaporator to the air.

5. A method of controlling evaporator outlet pressure, characterized by, The controller is applied to the air conditioning system of any one of claims 1-4, and comprises: an evaporator outlet pressure sensor is configured to acquire a first outlet pressure value of the evaporator; if it is detected that a pressure difference between the first outlet pressure value and a first preset target value is within a first preset deviation range, then when it is detected that the first outlet pressure value is greater than the first preset target value and a valve step of the electronic expansion valve is in a preset non-dead zone, the valve step of the electronic expansion valve is adjusted so that the first outlet pressure value is equal to the first preset target value; if it is detected that the first outlet pressure value is less than the first preset target value and a valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in a preset non-dead zone, then the second electronic back pressure valve is controlled to gradually reduce the valve step according to a preset step length, and when it is detected that the second electronic back pressure valve is adjusted to a preset minimum valve step, the second electronic back pressure valve is controlled to keep the preset minimum valve step; the first electronic back pressure valve is controlled to gradually reduce the valve step according to a preset step length, and when it is detected that the first electronic back pressure valve is adjusted to a preset minimum valve step, the first electronic back pressure valve is controlled to keep the preset minimum valve step; the control signal value of the pulse electromagnetic valve is gradually reduced according to a preset adjustment value until it is detected that the first outlet pressure value is equal to the first preset target value or the control signal value is equal to 0; wherein, when the adjustment is initially started, each electronic back pressure valve is in a fully open state by default, and the control signal value of the pulse electromagnetic valve is set to 100%.

6. The method of claim 5, wherein, before detecting that the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, further comprising: acquiring, by a condenser outlet pressure sensor, a second outlet pressure value of the condenser; if it is detected that the pressure difference between the second outlet pressure value and the second preset target value is not within the second preset deviation range, adjusting a second frequency of the variable frequency condenser fan so that the pressure difference between the second outlet pressure value and the second preset target value is within the second preset deviation range.

7. The method of claim 6, wherein, after adjusting the second frequency of the variable frequency condenser fan so that the pressure difference between the second outlet pressure value and the second preset target value is within the second preset deviation range, further comprising: if it is detected that the pressure difference between the first outlet pressure value and the first preset target value is not within the first preset deviation range, adjusting a first frequency of the variable frequency compressor so that the pressure difference between the first outlet pressure value of the evaporator and the first preset target value is within the first preset deviation range.

8. A control device for the evaporator outlet pressure, characterized in that a controller applied to the air conditioning system of any one of claims 1-4, comprising: an evaporator pressure value acquisition module configured to acquire, by an evaporator outlet pressure sensor, a first outlet pressure value of the evaporator; a first valve step adjustment module configured to, if it is detected that the pressure difference between the first outlet pressure value and the first preset target value is within the first preset deviation range, adjust a valve step of the electronic expansion valve so that the first outlet pressure value is equal to the first preset target value when it is detected that the first outlet pressure value is greater than the first preset target value and the valve step of the electronic expansion valve is in a preset non-dead zone; a second valve step adjustment module configured to, if it is detected that the first outlet pressure value is less than the first preset target value and the valve step of the pulse electromagnetic valve, the first electronic back pressure valve or the second electronic back pressure valve is in a preset non-dead zone, control the second electronic back pressure valve to gradually reduce the valve step according to a preset step length, and control the second electronic back pressure valve to maintain a preset minimum valve step when it is detected that the second electronic back pressure valve is adjusted to the preset minimum valve step; control the first electronic back pressure valve to gradually reduce the valve step according to a preset step length, and control the first electronic back pressure valve to maintain a preset minimum valve step when it is detected that the first electronic back pressure valve is adjusted to the preset minimum valve step; gradually reduce the control signal value of the pulse electromagnetic valve according to a preset adjustment value until it is detected that the first outlet pressure value is equal to the first preset target value or the control signal value is equal to 0; wherein, when initially starting the adjustment, each electronic back pressure valve is in a fully open state by default, and the control signal value of the pulse electromagnetic valve is assigned as 100%.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for causing the processor to execute the evaporator outlet pressure control method of any one of claims 5-7 when executed.

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