Compressor pressure ratio protection method, system, module and medium

Abstract

The invention relates to a compressor pressure ratio protection method and system, a module and a medium. The method comprises the steps that compressor state data of a compressor body, real-time pressure data of a refrigerant flowing into the compressor body and temperature requirement data of a whole vehicle are obtained; whether pressure ratio protection control is started or not is judged based on the compressor state data and the temperature demand data; when the pressure ratio protection control is started, the opening degree of an expansion valve is determined based on the real-time pressure data and the temperature demand data; and the expansion valve is controlled based on the opening degree of the expansion valve, and the refrigerant on the high-pressure side of the compressor body is guided out, so that pressure ratio protection is achieved. The pressure ratio of the refrigerant at the inlet and the outlet of the compressor can be effectively controlled, so that the purpose of protecting the compressor is achieved.

Description

Technical Field

[0001] The present invention relates to the field of thermal management technology, and in particular to a compressor pressure ratio protection method, system, module and medium. Background Art

[0002] With the rapid development of electric vehicle technology in my country, the market's energy consumption requirements for electric vehicles are getting higher and higher, and the complexity of the vehicle thermal management system has increased accordingly. Especially in cold environments, electric vehicles need to be effectively heated, which places higher demands on the coolant and refrigerant systems. In winter, the pressure at the low-pressure end of the refrigerant system is low, while the pressure at the high-pressure end is high, resulting in an increase in the compression ratio (pressure ratio).

[0003] Too high a compression ratio will bring challenges to the design of the compressor. When the compression ratio is too high, the compressor will bear a greater load during startup and operation, which will not only affect its performance, but may also cause the system exhaust temperature to be too high. In addition, the compressor may overheat due to insufficient cooling, affecting the stability and life of the system. These problems increase the difficulty of electric vehicles operating in low-temperature environments and also put forward higher technical requirements for the design of compressors. Summary of the invention

[0004] In view of the shortcomings of the prior art mentioned above, the present invention provides a compressor pressure ratio protection method, system, module and medium, which can effectively control the pressure ratio of the inlet and outlet refrigerant of the compressor to achieve the purpose of protecting the compressor, increase the operating range of the compressor, and improve the energy utilization rate of the whole vehicle.

[0005] To achieve the above purpose, the present invention adopts the following technical solution.

[0006] In a first aspect, the present invention provides a compressor pressure ratio protection method, which is applied to the protection of the compressor body and adopts the following technical solution: Acquiring compressor status data of the compressor body, real-time pressure data of the refrigerant flowing into the compressor body, and temperature demand data of the entire vehicle; Determining whether to start pressure ratio protection control based on the compressor status data and the temperature demand data; When the pressure ratio protection control is turned on, the expansion valve opening is determined based on the real-time pressure data and the temperature demand data; and the expansion valve is controlled based on the expansion valve opening to export the refrigerant on the high-pressure side of the compressor body to achieve the pressure ratio protection.

[0007] Furthermore, in the above compressor pressure ratio protection method, the compressor status data at least includes a heating mode and / or a waste heat recovery mode, and the temperature demand data at least includes a cabin demand air temperature and a corresponding ambient temperature; The determining whether to start the pressure ratio protection control based on the compressor state data and the temperature demand data includes: Determining a required high pressure of the compressor body based on the required cabin air temperature; determining a required low pressure of the compressor body based on the ambient temperature; Determining a required pressure ratio of the compressor body based on the required high pressure and the required low pressure; Furthermore, when the compressor body is in the heating mode and / or the waste heat recovery mode, and the required pressure ratio is greater than a preset pressure ratio threshold, the pressure ratio protection control is turned on.

[0008] Furthermore, in the compressor pressure ratio protection method, determining the required high pressure of the compressor body based on the required cabin air temperature includes: Based on the required cabin air temperature, the required water temperature corresponding to the required cabin air temperature is determined according to a preset first calibration coefficient; based on the required water temperature matching corresponding refrigerant saturation pressure, the corresponding required high pressure is determined according to a preset second calibration coefficient.

[0009] Furthermore, in the compressor pressure ratio protection method, the step of determining the required low pressure of the compressor body based on the ambient temperature includes: The corresponding refrigerant saturation pressure is matched based on the ambient temperature, and the corresponding required low pressure is determined according to a preset third calibration coefficient.

[0010] Furthermore, in the compressor pressure ratio protection method, the step of determining the expansion valve opening based on the real-time pressure data and the temperature demand data includes: Acquiring a limit pressure ratio of the compressor body, and determining a target suction pressure of the compressor body based on the limit pressure ratio and the required high pressure; The high-pressure side pressure and the low-pressure side pressure of the compressor body are acquired, and the expansion valve opening is determined based on the high-pressure side pressure, the low-pressure side pressure and the real-time pressure data.

[0011] Furthermore, in the compressor pressure ratio protection method, the step of controlling the expansion valve based on the expansion valve opening to derive the refrigerant on the high-pressure side of the compressor body includes: The expansion valve is controlled based on the error between the target suction pressure and the real-time pressure data using a preset feedback control algorithm.

[0012] Furthermore, in the above compressor pressure ratio protection method, the feedback control algorithm adopts one-dimensional fuzzy PI control.

[0013] Furthermore, the compressor pressure ratio protection method further includes: Acquiring the high-pressure side temperature of the compressor body, and when the high-pressure side temperature is higher than a preset exhaust temperature threshold, reducing the expansion valve opening based on a preset first speed value; The low-pressure side temperature of the compressor body is obtained, and when the low-pressure side temperature is higher than a preset intake temperature threshold, the expansion valve opening is reduced based on a preset second speed value.

[0014] In a second aspect, the present invention provides a compressor pressure ratio protection system, the system comprising: A data acquisition module, at least used to acquire compressor status data of the compressor body, real-time pressure data flowing into the compressor body, and temperature demand data of the whole vehicle; A function judgment module, at least used to judge whether to start the pressure ratio protection control based on the compressor state data and the temperature demand data; an opening determination module, at least for determining the expansion valve opening based on the real-time pressure data and the temperature demand data when the pressure ratio protection control is turned on; and The control execution module is at least used to control the expansion valve based on the expansion valve opening to export the refrigerant on the high-pressure side of the compressor body to achieve the pressure ratio protection.

[0015] In a third aspect, the present invention provides a compressor pressure ratio protection module, the module comprising: A temperature and pressure sensor is arranged on the low-pressure side of the compressor body; A bypass circuit connected in parallel with the compressor body, the bypass circuit comprising an exhaust pipe, an expansion valve and a return air pipe; An expansion valve controller that is reused with the vehicle thermal management controller; an expansion valve driver reused with the compressor driver of the compressor body; Wherein, the expansion valve driver, under the control of the expansion valve controller, drives the expansion valve to perform pressure ratio protection on the compressor body based on the compressor pressure ratio protection method as described in any one of claims 1 to 8.

[0016] In a fourth aspect, the present invention provides a readable storage medium, which adopts the following technical solution: A readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, a compressor pressure ratio protection method as described in any one of the first aspects above is implemented.

[0017] In summary, compared with the prior art, the present invention includes at least one of the following beneficial technical effects: The present invention obtains compressor status data, refrigerant pressure data and vehicle temperature demand data in real time, determines whether to turn on pressure ratio protection control, and dynamically adjusts the expansion valve opening to derive the refrigerant on the high-pressure side of the compressor, thereby effectively controlling the pressure ratio. Compared with the prior art, the present invention can more accurately adjust the compressor inlet pressure under low-temperature and high-pressure ratio conditions, thereby avoiding problems such as compressor overload and insufficient cooling, expanding the working range of the compressor, improving the efficiency and reliability of the vehicle thermal management system, and extending the service life of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a flowchart of a specific embodiment of a compressor pressure ratio protection method of the present invention.

[0020] Figure 2 It is a flowchart of another specific embodiment of a compressor pressure ratio protection method of the present invention.

[0021] Figure 3 It is a flow chart of a specific embodiment of a compressor pressure ratio protection method of the present invention.

[0022] Figure 4 It is a structural schematic diagram of a specific embodiment of a compressor pressure ratio protection system of the present invention.

[0023] Figure 5 It is a structural schematic diagram of a specific embodiment of a compressor pressure ratio protection module of the present invention. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0025] It should be noted that the description order of the following embodiments is not intended to limit the preferred order of the embodiments of the present application. In addition, in the following embodiments, the description of each embodiment has its own emphasis, and for parts not described in detail in one embodiment, reference can be made to the relevant description of other embodiments.

[0026] The method steps described in the embodiments of the present invention may be executed in the order described in the specific implementation manner, or the execution order of each step may be adjusted according to actual needs and on the premise that the technical problem can be solved, which will not be listed here one by one.

[0027] Reference Figure 1 An embodiment of the present invention provides a compressor pressure ratio protection method, which is applied to the protection of the compressor body and includes the following steps.

[0028] S1, acquiring compressor status data of the compressor body, real-time pressure data of the refrigerant flowing into the compressor body, and temperature demand data of the entire vehicle.

[0029] Specifically, the compressor status data can be obtained by reading the compressor's operating status, working mode and diagnostic information through the compressor controller; the real-time pressure data of the refrigerant flowing into the compressor body can be obtained by monitoring the pressure value in real time through a temperature and pressure sensor (PT sensor) installed at the compressor inlet; and the vehicle temperature demand data can be obtained by obtaining data such as the passenger compartment temperature, ambient temperature and target wind temperature from the vehicle's thermal management system to determine whether the current compressor needs to turn on the pressure ratio protection function.

[0030] S2: Determine whether to start compression ratio protection control based on the compressor status data and the temperature demand data.

[0031] Specifically, the current operating mode of the compressor (such as heating mode or waste heat recovery mode) is read to determine whether the start-up conditions are met; the required pressure ratio is calculated using temperature demand data (such as target air temperature, passenger compartment heat load), and compared with the preset pressure ratio threshold; when the required pressure ratio exceeds the set safety range or reaches the trigger condition of the pressure ratio protection, the pressure ratio protection control is automatically turned on.

[0032] S3, when the pressure ratio protection control is turned on, determining the expansion valve opening based on the real-time pressure data and the temperature demand data.

[0033] Specifically, the ideal suction pressure of the compressor is calculated based on the real-time pressure data obtained by the temperature and pressure sensor in step S1 and combined with the temperature demand data of the whole vehicle; then, adjustments are made based on the deviation between the real-time pressure data and the target suction pressure, and the opening value of the expansion valve is calculated. The calculated expansion valve opening is used as an execution instruction to adjust the refrigerant flow in the return pipe to keep the compressor running within a reasonable pressure ratio range.

[0034] S4, controlling the expansion valve based on the expansion valve opening, and exporting the refrigerant on the high-pressure side of the compressor body to achieve the pressure ratio protection.

[0035] Specifically, step S4 drives the expansion valve to accurately adjust its opening and closing degree through the calculated expansion valve opening instruction, thereby controlling the flow of high-pressure refrigerant entering the bypass circuit; when the expansion valve opening increases, more high-pressure refrigerant is guided to the return air pipe to reduce the compressor inlet pressure, thereby effectively reducing the pressure ratio; at the same time, the feedback state of the expansion valve is monitored in real time to ensure that its execution opening is consistent with the control instruction, so as to achieve stable adjustment of the compressor pressure ratio and maintain the system operation within a safe operating range.

[0036] Based on this, the compressor pressure ratio protection method described in the embodiment of the present invention realizes the precise monitoring and dynamic adjustment of the compressor pressure ratio, effectively expands the working range of the compressor, avoids the equipment load and overheating risks caused by excessively high pressure ratio, thereby significantly improving the reliability of the compressor and the energy efficiency of the vehicle thermal management system.

[0037] Furthermore, in step S1, the compressor status data at least includes a heating mode and / or a waste heat recovery mode, and the temperature requirement data at least includes a required cabin air temperature and a corresponding ambient temperature.

[0038] The compressor status data refers to various information about the current operating status of the compressor, including the compressor's operating mode (such as heating, cooling, dehumidification, etc.), operating speed, load level, start and stop status, diagnostic information (such as whether there is a fault or abnormality), etc. These data reflect the real-time operating status of the compressor and are an important basis for determining whether the system needs pressure ratio protection. They are used to optimize the control and protection strategy of the compressor to ensure that it operates within a reasonable and safe range. In an embodiment of the present invention, the compressor status data includes at least a heating mode. In some other embodiments, in addition to the heating mode, the compressor status data may also include a waste heat recovery mode.

[0039] Temperature demand data refers to the temperature information required by the vehicle thermal management system based on the passenger compartment comfort requirements and environmental conditions, usually including target air temperature, target water temperature, passenger compartment heat load, ambient temperature, etc. These data are used to calculate the required compressor output pressure and pressure ratio to meet the current heating or cooling requirements, and provide a basis for the compressor pressure ratio protection system to ensure that the compressor's operating state and expansion valve opening can be adjusted according to the actual temperature control requirements, thereby achieving efficient temperature control. In an embodiment of the present invention, the temperature demand data at least includes the required cabin air temperature and the corresponding ambient temperature.

[0040] Further, as an embodiment of the present invention, refer to Figure 2 , step S2, judging whether to turn on the pressure ratio protection control based on the compressor status data and the temperature demand data, includes the following sub-steps.

[0041] S21, determining a required high pressure of the compressor body based on the required cabin air temperature.

[0042] Specifically, step S21 includes: based on the required cabin air temperature, determining the required water temperature corresponding to the required cabin air temperature according to a preset first calibration coefficient; matching the corresponding refrigerant saturation pressure based on the required water temperature, and determining the corresponding required high pressure according to a preset second calibration coefficient.

[0043] When calculating the required high pressure, the heat load of the passenger compartment, that is, the amount of heating or cooling required for the cabin, needs to be considered. In an embodiment of the present invention, based on the required cabin air temperature, the required water temperature corresponding to the required cabin air temperature is determined according to a preset first calibration coefficient, and the first calibration coefficient can be set to 1.15, that is: Required water temperature = required cabin air temperature × 1.15.

[0044] Based on the required water temperature matching the corresponding refrigerant saturation pressure, and determining the corresponding required high pressure according to the preset second calibration coefficient, the second calibration coefficient can be set to 1.2, that is: Required high pressure = refrigerant saturation pressure corresponding to required water temperature × 1.2. Among them, the refrigerant saturation pressure corresponding to the required water temperature can be obtained through the refrigerant's pressure-temperature (PT) characteristic curve or table lookup method. Specifically, the required water temperature is used as the target water temperature, and the saturation pressure value corresponding to the temperature is found in the refrigerant's PT characteristic table, or the corresponding saturation pressure is calculated by the target water temperature using the system's built-in algorithm. This saturation pressure reflects the equilibrium pressure of the refrigerant at this temperature, which can be used to guide the calculation and adjustment of the required high pressure of the compressor, ensuring that the thermal management system maintains a stable operating state while meeting temperature control requirements.

[0045] S22, determining the required low pressure of the compressor body based on the ambient temperature.

[0046] Specifically, step S22 includes: matching the corresponding refrigerant saturation pressure based on the ambient temperature, and determining the corresponding required low pressure according to a preset third calibration coefficient.

[0047] When calculating the required low pressure, the required low pressure is related to the vehicle state. In this embodiment, when the compressor is in heating mode or waste heat recovery, the corresponding refrigerant saturation pressure is matched based on the ambient temperature, and the corresponding required low pressure is determined according to the preset third calibration coefficient. The third calibration coefficient can be set to 0.8, that is: Required low pressure = refrigerant saturation pressure corresponding to ambient temperature × 0.8. Among them, the method for obtaining the refrigerant saturation pressure corresponding to the ambient temperature is similar to the method for obtaining the refrigerant saturation pressure corresponding to the required water temperature, which will not be repeated here.

[0048] S23, determining a required pressure ratio of the compressor body based on the required high pressure and the required low pressure.

[0049] Specifically, the demand pressure ratio is the ratio of the demand high pressure to the demand low pressure, that is: Demand pressure ratio = demand high pressure / demand low pressure.

[0050] S24, when the compressor body is in the heating mode and / or the waste heat recovery mode, and the required pressure ratio is greater than a preset pressure ratio threshold, starting the pressure ratio protection control.

[0051] Specifically, when the compressor is in heating mode or waste heat recovery mode, the current required pressure ratio is calculated according to the actual working conditions and compared with the preset pressure ratio threshold. If the required pressure ratio exceeds the pressure ratio threshold, it indicates that the compressor may face the risk of over-pressure ratio, thereby increasing the instability of the load and thermal management system. At this time, the pressure ratio protection control is automatically turned on to protect the safe operation of the compressor and ensure that the system meets the temperature control requirements in an efficient and stable state.

[0052] Furthermore, as an embodiment of the present invention, in step S3, determining the expansion valve opening based on the real-time pressure data and the temperature demand data includes: obtaining the limiting pressure ratio of the compressor body, and determining the target suction pressure of the compressor body based on the limiting pressure ratio and the required high pressure; obtaining the high-pressure side pressure and the low-pressure side pressure of the compressor body, and determining the expansion valve opening based on the high-pressure side pressure, the low-pressure side pressure and the real-time pressure data.

[0053] Specifically, first, obtain the compressor's limit pressure ratio (i.e., the maximum pressure ratio for safe operation of the compressor), and calculate the compressor's target suction pressure based on this limit pressure ratio and the required high pressure to ensure that the compressor operates within the ideal suction pressure range. Then, obtain the pressure data of the high-pressure and low-pressure sides of the compressor in real time, and calculate the opening of the expansion valve in combination with the real-time pressure value measured by the temperature control sensor to adjust the refrigerant flow entering the compressor. Based on this expansion valve opening, the expansion valve is controlled to accurately adjust the compressor's inlet pressure so that its pressure ratio remains within a safe range, thereby protecting the compressor from the effects of excessively high pressure ratios and achieving stable operation.

[0054] The target inspiratory pressure is calculated as: Target suction pressure = required high pressure / limit pressure ratio. Among them, the limit pressure ratio is obtained according to the compressor working range curve provided by the compressor manufacturer.

[0055] The expansion valve opening is calculated as: Feedforward opening = (PT sensor pressure - system low pressure) / (system high pressure - system low pressure) * calibrated feedforward coefficient. Among them, the feedforward opening is the expansion valve opening, the PT sensor pressure is the implementation pressure data, and the system low pressure and system high pressure are the pressure data of the high-pressure side and the low-pressure side of the thermal system respectively.

[0056] Furthermore, as an embodiment of the present invention, step S4, controls the expansion valve based on the expansion valve opening to export the refrigerant on the high-pressure side of the compressor body, including: using a preset feedback control algorithm to control the expansion valve based on the error between the target suction pressure and the real-time pressure data.

[0057] Specifically, the preset feedback control algorithm is used to dynamically adjust the opening of the expansion valve according to the error between the target suction pressure and the real-time pressure data. First, the inlet pressure of the compressor is monitored in real time by the PT sensor, which is compared with the target suction pressure to calculate the pressure error. Then, the error value is input into the feedback control algorithm (such as PI control or fuzzy control) to generate an opening adjustment instruction for the expansion valve. When the error increases, the opening of the expansion valve will increase accordingly, more high-pressure refrigerant will be discharged, and the inlet pressure will be reduced; when the error decreases, the opening of the expansion valve will decrease accordingly. In this way, the expansion valve is dynamically adjusted to ensure that the compressor inlet pressure is stable within the target range, thereby achieving effective protection of the compressor pressure ratio.

[0058] Furthermore, as a specific implementation of the present invention, the feedback control algorithm adopts one-dimensional fuzzy PI control.

[0059] Specifically, the real-time pressure data at the compressor inlet is obtained through the PT sensor and compared with the target suction pressure to calculate the pressure difference between the two, i.e. the control error. The error is processed using a one-dimensional fuzzy PI control method, where "fuzzy" means dividing the size and rate of change of the error into fuzzy sets (such as "small", "medium", and "large"), and adjusting the PI control parameters through fuzzy rules to make its response to the error more flexible and adaptable. This fuzzy PI control algorithm combines the accuracy of traditional PI control with the flexibility of fuzzy control, and can dynamically adjust the expansion valve opening under complex working conditions to stabilize the compressor inlet pressure and ensure that the system operates within the ideal pressure ratio range.

[0060] Further, as an embodiment of the present invention, the compressor pressure ratio protection method also includes: Acquiring the high-pressure side temperature of the compressor body, and when the high-pressure side temperature is higher than a preset exhaust temperature threshold, reducing the expansion valve opening based on a preset first speed value; The low-pressure side temperature of the compressor body is obtained, and when the low-pressure side temperature is higher than a preset intake temperature threshold, the expansion valve opening is reduced based on a preset second speed value.

[0061] Specifically, under some special working conditions, the expansion valve may introduce too much refrigerant flow during opening, causing the internal temperature of the system to rise, thereby bringing the risk of overheating. Therefore, system protection logic needs to be added to prevent this situation. Specific protection measures include exhaust temperature protection, that is, when the compressor exhaust temperature is too high, the expansion valve opening is gradually reduced to lower the temperature; and compressor suction superheat protection, that is, when the compressor suction temperature is too high, the expansion valve opening is also reduced accordingly to reduce the heat inhaled. These protection logics can effectively prevent compressor damage or system efficiency reduction caused by excessive temperature, and ensure the safe operation of the system.

[0062] For example, refer to Figure 3 , a compressor pressure ratio protection method according to an embodiment of the present invention includes: First, obtain the real-time operation data of the compressor, including compressor status data, real-time pressure data of the refrigerant, and temperature demand data of the vehicle. These data will serve as the basis for subsequent judgment and calculation; Then, after acquiring the data, the system determines whether the pressure ratio protection function needs to be turned on based on the compressor status and temperature demand data. For example, when the compressor is in heating mode or waste heat recovery mode, and the required pressure ratio exceeds the preset pressure ratio threshold, the system will start the pressure ratio protection control; If the judgment result meets the opening condition, the expansion valve is instructed to open, and the opening degree of the expansion valve is calculated through the PI feedback control algorithm to control the flow of the refrigerant, thereby adjusting the pressure at the compressor inlet and reducing the pressure ratio of the system; During the expansion valve opening process, the operating status is continuously monitored. If an overheating risk such as excessive temperature is detected, the system protection logic will be activated to gradually reduce the opening of the expansion valve to prevent the compressor from being damaged due to excessive temperature or pressure; When it is determined that pressure ratio protection is no longer required, the expansion valve is commanded to close, stopping the flow of refrigerant in the bypass circuit and restoring the thermal system to normal operation.

[0063] Through the above steps, the control process of the pressure ratio protection of the compressor under different working conditions is realized, from data collection to pressure ratio judgment, and then to expansion valve adjustment and protection logic, which is conducive to the effective protection of the compressor and the stable operation of the system.

[0064] The embodiment of the present invention also discloses a compressor pressure ratio protection system.

[0065] Reference Figure 4A compressor pressure ratio protection system includes a data acquisition module 1, a function judgment module 2, an opening determination module 3 and a control execution module 4.

[0066] The data acquisition module 1 collects the compressor status data (such as operation mode, speed and diagnostic information) in real time through sensors and controllers to understand the current working status of the compressor; monitors the refrigerant pressure and temperature data flowing into the compressor through the PT sensor, provides real-time pressure information to evaluate the inlet load condition of the compressor; obtains temperature demand data from the vehicle thermal management system, such as target air temperature, ambient temperature and passenger compartment heat load demand, to determine the high and low pressure ratio required for the compressor output. These data are transmitted to the function judgment module through the data acquisition module to support the judgment and subsequent execution of the pressure ratio protection control.

[0067] The function judgment module 2 receives the compressor status data and temperature demand data from the data acquisition module 1, and first determines whether the conditions for starting the pressure ratio protection are met through the working mode of the compressor (such as heating mode or waste heat recovery mode); then, the required high pressure and required low pressure of the compressor are calculated according to the temperature demand data, and then the required pressure ratio is calculated; finally, the required pressure ratio is compared with the pressure ratio threshold set by the system. If the required pressure ratio is greater than the threshold, the pressure ratio protection control is triggered and started, thereby ensuring the safe operation of the compressor under high pressure ratio conditions.

[0068] After the pressure ratio protection control is turned on, the opening determination module 3 receives real-time pressure data and temperature demand data, and first calculates the target suction pressure based on the compressor's limit pressure ratio and required high pressure; then, obtains the real-time pressure values ​​of the compressor's high-pressure side and low-pressure side, compares the target suction pressure with the current actual suction pressure, and calculates the pressure difference; based on the pressure difference, uses the preset PI feedback control algorithm to dynamically calculate the expansion valve opening instruction to ensure that the expansion valve opening adapts to the current pressure ratio requirement, thereby maintaining the compressor's inlet pressure within the target range and achieving precise control and protection of the pressure ratio.

[0069] The control execution module 4 drives the expansion valve to achieve precise opening and closing adjustment according to the expansion valve opening instruction calculated by the opening determination module 3. The refrigerant flow on the high-pressure side of the compressor is derived by adjusting the expansion valve opening in real time, thereby effectively controlling the inlet pressure of the compressor. When the system detects that the actual opening of the expansion valve is consistent with the command opening, the control execution module continuously monitors the operating status to ensure that the compressor operates within the ideal pressure ratio range; if there is a deviation, the expansion valve is automatically adjusted to the target opening, thereby achieving dynamic protection of the compressor pressure ratio and ensuring the stable operation of the system.

[0070] The embodiment of the present invention also discloses a compressor pressure ratio protection module.

[0071] Reference Figure 5 , the compressor pressure ratio protection module includes: A temperature and pressure sensor is arranged on the low-pressure side of the compressor body; A bypass circuit connected in parallel with the compressor body, the bypass circuit comprising an exhaust pipe, an expansion valve and a return air pipe; An expansion valve controller that is reused with the vehicle thermal management controller; An expansion valve driver is reused with the compressor driver of the compressor body.

[0072] Specifically, the compressor pressure ratio protection module is a specially designed component system used to protect the safe operation of the compressor under high pressure ratio conditions. The module includes a temperature and pressure sensor installed on the low-pressure side of the compressor body, which is used to monitor the pressure and temperature at the compressor inlet in real time; the bypass loop is connected in parallel with the compressor, and consists of an exhaust pipe, an expansion valve and a return air pipe, which is used to adjust the flow of refrigerant on the high-pressure side to control the inlet pressure of the compressor. The module also includes an expansion valve controller, which is reused with the vehicle's thermal management controller to control the opening of the expansion valve; the expansion valve driver is reused with the compressor driver and is responsible for executing the opening and closing action of the expansion valve. Through the coordinated operation of various components, the module can dynamically adjust the pressure ratio of the compressor to ensure that it operates within a reasonable range, thereby improving the reliability of the compressor and the energy efficiency of the system.

[0073] In the compressor pressure ratio protection module, the expansion valve driver, under the instruction of the expansion valve controller, accurately drives the opening and closing adjustment of the expansion valve based on the compressor pressure ratio protection method described in any of the above embodiments, thereby achieving effective control and protection of the compressor pressure ratio. Specifically, the expansion valve controller calculates the ideal opening of the expansion valve through a feedback control algorithm based on the acquired real-time temperature and pressure data, the required pressure ratio and the target suction pressure. The expansion valve driver executes the opening instruction and adjusts the opening and closing state of the expansion valve to control the refrigerant flow in the bypass circuit and reduce the pressure at the compressor inlet. In this way, by adjusting the expansion valve opening in real time, the expansion valve driver ensures that the pressure ratio of the compressor remains within a safe range, thereby effectively protecting the safe operation of the compressor and the stability of the system.

[0074] Compared with the general compressor system, the embodiment of the present invention adds an exhaust pipe, an expansion valve, a return pipe and a temperature and pressure sensor through a compressor pressure ratio protection module. As the power source of the whole vehicle thermal management system, a general compressor discharges high-pressure refrigerant upward into the whole vehicle thermal management system, and finally returns to the compressor from the bottom to complete the cycle. On this basis, the present invention adds a set of bypass loops to form a module with the compressor. The refrigerant part flows through the expansion valve through the exhaust pipe, controls the opening of the expansion valve to control throttling, flows through the return pipe, and flows back to the compressor with the refrigerant returned from the general thermal management system. The real-time status of the compressor inlet is read by the PT sensor, the opening of the expansion valve is calculated, and the pressure of the refrigerant in the return pipe is adjusted, thereby playing the function of adjusting the compressor inlet pressure, and then controlling the refrigerant pressure ratio. The compressor driver is generally only responsible for the driving, communication and diagnosis of the compressor. In the present invention, the compressor driver is also responsible for the driving, communication and diagnosis of the expansion valve and the reading and diagnosis of the PT sensor, and communicates with the main controller at the same time.

[0075] The calculation logic corresponding to the compressor pressure ratio protection method described in the above embodiments is completed by the main controller application layer, and the drive and diagnosis of each component are the responsibility of the compressor controller. In this design, the main controller does not need to update the controller hardware, mainly considering the reusability of the main controller. The main controller can be a domain controller, a thermal management controller, or a heat pump controller.

[0076] The embodiment of the present invention also discloses a readable storage medium.

[0077] A readable storage medium stores a computer program, which implements the steps of the method described in any one of the above embodiments when executed by a processor. The computer-readable storage medium may include: any entity or device capable of carrying a computer program, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), and a software distribution medium, etc. The computer program includes a computer program code. The computer program code may be in source code form, object code form, an executable file, or some intermediate form, etc. The computer-readable storage medium may include: any entity or device capable of carrying a computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), and a software distribution medium, etc.

[0078] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0079] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus or device (such as a computer-based system, a system including a processing module, or other system that can fetch instructions from an instruction execution system, apparatus or device and execute instructions), or used in combination with these instruction execution systems, apparatuses or devices.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compressor pressure ratio protection method, applied to the protection of the compressor body, characterized in that: include: Acquiring compressor status data of the compressor body, real-time pressure data of the refrigerant flowing into the compressor body, and temperature demand data of the entire vehicle; Determining whether to start pressure ratio protection control based on the compressor status data and the temperature demand data; When the pressure ratio protection control is turned on, determining the expansion valve opening based on the real-time pressure data and the temperature demand data; And, based on the expansion valve opening, the expansion valve is controlled to export the refrigerant on the high-pressure side of the compressor body to achieve the pressure ratio protection.

2. The compressor pressure ratio protection method according to claim 1, characterized in that: The compressor status data at least includes a heating mode and / or a waste heat recovery mode, and the temperature demand data at least includes a cabin demand air temperature and a corresponding ambient temperature; The determining whether to start the pressure ratio protection control based on the compressor state data and the temperature demand data includes: Determining a required high pressure of the compressor body based on the required cabin air temperature; determining a required low pressure of the compressor body based on the ambient temperature; Determining a required pressure ratio of the compressor body based on the required high pressure and the required low pressure; Furthermore, when the compressor body is in the heating mode and / or the waste heat recovery mode, and the required pressure ratio is greater than a preset pressure ratio threshold, the pressure ratio protection control is turned on.

3. The compressor pressure ratio protection method according to claim 2, characterized in that: The step of determining the required high pressure of the compressor body based on the required cabin air temperature comprises: Based on the required cabin air temperature, determining the required water temperature corresponding to the required cabin air temperature according to a preset first calibration coefficient; The corresponding refrigerant saturation pressure is matched based on the required water temperature, and the corresponding required high pressure is determined according to a preset second calibration coefficient.

4. The compressor pressure ratio protection method according to claim 2, characterized in that: The step of determining the required low pressure of the compressor body based on the ambient temperature comprises: The corresponding refrigerant saturation pressure is matched based on the ambient temperature, and the corresponding required low pressure is determined according to a preset third calibration coefficient.

5. The compressor pressure ratio protection method according to claim 2, characterized in that: The determining the expansion valve opening based on the real-time pressure data and the temperature demand data comprises: Acquiring a limit pressure ratio of the compressor body, and determining a target suction pressure of the compressor body based on the limit pressure ratio and the required high pressure; The high-pressure side pressure and the low-pressure side pressure of the compressor body are acquired, and the expansion valve opening is determined based on the high-pressure side pressure, the low-pressure side pressure and the real-time pressure data.

6. The compressor pressure ratio protection method according to claim 5, characterized in that: The method of controlling the expansion valve based on the expansion valve opening to derive the refrigerant on the high-pressure side of the compressor body includes: The expansion valve is controlled based on the error between the target suction pressure and the real-time pressure data using a preset feedback control algorithm.

7. The compressor pressure ratio protection method according to claim 6, characterized in that: The feedback control algorithm adopts one-dimensional fuzzy PI control.

8. The compressor pressure ratio protection method according to claim 1, characterized in that: The method further comprises: Acquiring the high-pressure side temperature of the compressor body, and when the high-pressure side temperature is higher than a preset exhaust temperature threshold, reducing the expansion valve opening based on a preset first speed value; The low-pressure side temperature of the compressor body is obtained, and when the low-pressure side temperature is higher than a preset intake temperature threshold, the expansion valve opening is reduced based on a preset second speed value.

9. A compressor pressure ratio protection system, characterized in that: The system comprises: A data acquisition module, at least used to acquire compressor status data of the compressor body, real-time pressure data flowing into the compressor body, and temperature demand data of the whole vehicle; A function judgment module, at least used to judge whether to start the pressure ratio protection control based on the compressor state data and the temperature demand data; an opening determination module, at least for determining the expansion valve opening based on the real-time pressure data and the temperature demand data when the pressure ratio protection control is turned on; and The control execution module is at least used to control the expansion valve based on the expansion valve opening to export the refrigerant on the high-pressure side of the compressor body to achieve the pressure ratio protection.

10. A compressor pressure ratio protection module, characterized in that: The module comprises: A temperature and pressure sensor is arranged on the low-pressure side of the compressor body; A bypass circuit connected in parallel with the compressor body, the bypass circuit comprising an exhaust pipe, an expansion valve and a return air pipe; An expansion valve controller that is reused with the vehicle thermal management controller; an expansion valve driver reused with the compressor driver of the compressor body; Wherein, the expansion valve driver, under the control of the expansion valve controller, drives the expansion valve to perform pressure ratio protection on the compressor body based on the compressor pressure ratio protection method as described in any one of claims 1 to 8.

11. A readable storage medium, characterized in that: The readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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