Turbocharger temperature PID cooperative control method and parameter optimization system

Abstract

The invention relates to the technical field of turbocharger temperature cooperative control, and provides a turbocharger temperature PID cooperative control method and parameter optimization system.The turbocharger temperature PID cooperative control method comprises the steps that temperature data are collected at a preset temperature measuring point of a turbocharger, inlet and outlet water of cooling water and inlet and outlet of lubricating liquid; the actual temperature distribution coefficient of the turbocharger is determined, a numerical model of the turbocharger is obtained, and the simulated temperature distribution coefficient of the turbocharger is determined; the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under the preset number of working conditions are calculated, the simulated value serves as the value of the working condition, the actual value of the working condition is determined, the target function of the working condition is determined, the target function of the working condition is optimized, and the optimal working condition is obtained; and according to the optimal working condition, the temperature PID parameter optimization of the turbocharger is realized. According to the invention, the actual operation temperature of the turbocharger can be accurately controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature collaborative control of turbochargers, and particularly to a temperature PID collaborative control method and parameter optimization system for turbochargers. Background Art

[0002] A turbocharger can increase the intake pressure, improve the power output of the engine, optimize the combustion process, improve fuel economy, and reduce pollutant emissions. Controlling the operating temperature of the turbocharger can ensure its safe and stable operation. To achieve accurate temperature control, it is necessary to study the temperature field of the turbocharger.

[0003] Numerical simulation uses the control variable method and can provide relatively comprehensive temperature field information. However, the actual operation of the turbocharger is affected by the coupling results of various influencing factors, with complexity and dynamics, often making it difficult to directly apply the numerical simulation results to actual control. Therefore, there is an urgent need for a temperature control method for turbochargers applicable to the actual coupling environment to ensure the safe and stable operation of the turbocharger. Summary of the Invention

[0004] The present invention provides a temperature PID collaborative control method and parameter optimization system for turbochargers to solve the problem that the actual operating temperature of the turbocharger is affected by the coupling of various influencing factors and the temperature control cannot be directly carried out according to the numerical simulation results. The specific technical solutions adopted are as follows: In the first aspect, an embodiment of the present invention provides a temperature PID collaborative control method for a turbocharger. The method includes the following steps: Collect temperature data at all preset temperature measurement points on the turbine main shaft of the turbocharger, the inlet and outlet positions of the cooling water, and the inlet and outlet positions of the lubricating fluid; Determine the actual temperature distribution coefficient of the turbocharger according to the change trend of the temperature data collected at different temperature measurement points at the same collection moment, the difference between the temperature data collected at the same temperature measurement point, the difference between the temperature data collected at the inlet and outlet positions of the cooling water, and the difference between the temperature data collected at the inlet and outlet positions of the lubricating fluid. Perform numerical simulation on the turbocharger to obtain a numerical model of the turbocharger, and according to the numerical model, obtain the simulated values of all temperature data, and determine the simulated temperature distribution coefficient of the turbocharger; Calculate the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a preset number of working conditions. According to the difference between different working conditions, take the simulated value as the value of the working condition to determine the actual value of the working condition. According to the actual temperature distribution coefficient corresponding to the actual value of the working condition and the simulated temperature distribution coefficient corresponding to the working condition, determine the objective function of the working condition, and optimize the objective function of the working condition to obtain the optimal working condition; Optimize the temperature PID parameters of the turbocharger according to the optimal working conditions.

[0005] Furthermore, based on the change trends of the temperature data collected at different temperature measurement points at the same acquisition moment, the differences between the temperature data collected at the same temperature measurement point, the differences between the temperature data collected at the inlet and outlet positions of the cooling water, and the differences between the temperature data collected at the inlet and outlet positions of the lubricating fluid, determine the actual temperature distribution coefficient of the turbocharger. The specific method includes: Determine the cumulative comprehensive area according to the change trends of the temperature data collected at each temperature measurement point at the same acquisition moment. Denote the variance of all the temperature data collected at the same temperature measurement point as the temperature fluctuation value of the temperature measurement point; denote the mean value of the temperature fluctuation values of all the temperature measurement points as the mean temperature fluctuation. Determine the average temperature difference based on the differences between the outlet and inlet temperature data of the cooling water at all acquisition moments, and the differences between the outlet and inlet temperature data of the lubricating fluid at all acquisition moments. Denote the product of the cumulative comprehensive area and the mean temperature fluctuation as the first product, and denote the ratio of the first product to the average temperature difference as the actual temperature distribution coefficient of the turbocharger.

[0006] Furthermore, the specific method for determining the cumulative comprehensive area according to the change trends of the temperature data collected at each temperature measurement point at the same acquisition moment includes: Take the order of the temperature measurement points where the temperature data is collected along the direction of the turbo main shaft as the independent variable, and take the temperature data collected at each temperature measurement point at the same acquisition moment as the dependent variable for curve fitting to obtain the fitting curve; take the number 0 as the lower limit of integration and the number of temperature measurement points as the upper limit of integration, integrate the fitting curve, and denote the integration result as the cumulative area at the acquisition moment; denote the mean value of the cumulative areas at all acquisition moments as the cumulative comprehensive area.

[0007] Furthermore, the specific method for determining the average temperature difference based on the differences between the outlet and inlet temperature data of the cooling water at all acquisition moments, and the differences between the outlet and inlet temperature data of the lubricating fluid at all acquisition moments includes: Denote the difference between the mean value of the outlet temperature data of the cooling water and the mean value of the inlet temperature data at all acquisition moments as the average temperature difference between the inlet and outlet of the cooling water; denote the difference between the mean value of the outlet temperature data of the lubricating fluid and the mean value of the inlet temperature data at all acquisition moments as the average temperature difference between the inlet and outlet of the lubricating fluid; denote the sum of the average temperature difference between the inlet and outlet of the cooling water and the average temperature difference between the inlet and outlet of the lubricating fluid as the average temperature difference.

[0008] Further, the different working condition conditions are different cooling parameters, and the cooling parameters include the inlet temperature of the cooling water, the outlet temperature of the cooling water, the inlet temperature of the lubricating fluid, and the outlet temperature of the lubricating fluid.

[0009] Further, according to the differences between different working condition conditions, taking the simulated value as the value of the working condition condition to determine the actual value of the working condition condition, the specific method included is: Calculate the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a variety of preset working condition conditions, and according to the simulated temperature distribution coefficient of the turbocharger and all cooling parameters under a variety of preset working condition conditions, respectively obtain the correlation degree between each cooling parameter and the simulated temperature distribution coefficient, where represents the second preset threshold; Denote the difference between the actual value of each cooling parameter in the working condition condition and the simulated value in the numerical model as the first difference between the actual value and the simulated value of the cooling parameter, and denote the product of the correlation degree between the cooling parameter and the simulated temperature distribution coefficient and the first difference as the value error between the actual value and the simulated value of the cooling parameter; Take the simulated value of the cooling parameter as the value of the working condition condition, and denote the actual value of the cooling parameter corresponding to the minimum value of the value error corresponding to the working condition condition as the actual value of the working condition condition.

[0010] Further, according to the difference between the working condition condition and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition condition, obtaining the objective function of the working condition condition, the specific method included is: Denote the absolute value of the difference between the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition condition and the simulated temperature distribution coefficient of the turbocharger corresponding to the working condition condition as the first absolute value of the working condition condition, and denote the power with the natural constant as the base and the first absolute value of the working condition condition as the exponent as the first power value of the working condition condition; Obtain the objective function of the working condition condition according to the first power value of the working condition condition, the working condition condition, and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition condition.

[0011] Further, the specific steps for obtaining the objective function of the working condition condition according to the first power value of the working condition condition, the working condition condition, and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition condition are: Take the first preset parameter, the second preset parameter, and the third preset parameter as the weights of the first power value of the working condition condition, the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition condition, and the simulated temperature distribution coefficient of the turbocharger corresponding to the working condition condition respectively, and perform weighted summation to obtain the objective function of the working condition condition.

[0012] Furthermore, according to the optimal operating conditions, the optimization of the temperature PID parameters of the turbocharger is realized, and the specific method includes: Determine the actual value of the optimal operating conditions according to the optimal operating conditions; Input the optimal operating conditions and the actual value of the optimal operating conditions into the PID controller, and use the PID controller to obtain the control signal corresponding to the optimal operating conditions.

[0013] In a second aspect, an embodiment of the present invention also provides a system for optimizing the temperature PID parameters of a turbocharger, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of the method described in any one of the above are implemented.

[0014] The beneficial effects of the present invention are: When the cold quantity supply is sufficient and the flow rate is stable and appropriate, the heat exchange at the turbine outlet housing is relatively sufficient, the temperature of the turbine outlet housing is significantly lower, and the difference between the temperature data at the same temperature measurement point at different acquisition times is relatively small, and the temperature difference between the inlet and outlet of the cooling water and lubricating fluid is relatively large. According to this feature, the necessity of controlling the temperature of the turbocharger is evaluated, the actual temperature distribution coefficient of the turbocharger is obtained, and the turbocharger is numerically simulated to obtain the numerical model of the turbocharger. Then, the simulated temperature distribution coefficient of the turbocharger is determined according to the numerical model. The optimal parameters are determined according to the actual temperature distribution coefficient and the simulated temperature distribution coefficient, combining the actual parameter values and the simulated data values, and the parameter optimization under different working conditions can be realized under the coupling of multiple factors, enhancing the accuracy and precision of the temperature control of the turbocharger.

[0015] To control the temperature of the turbocharger, it is necessary to make the temperature of the turbocharger infinitely close to the temperature value and operating conditions obtained from the numerical model of the turbocharger, and make the actual temperature distribution coefficient as small as possible to ensure the sufficiency and stability of the cold quantity supply. Since there are differences between the operating conditions in the numerical model and the actual operating conditions, it is impossible to ensure complete identity. Therefore, this application determines the corresponding relationship between the operating conditions in the numerical model with differences and the actual operating conditions, that is, obtains the actual value of the operating conditions, and determines the objective function of the operating conditions according to the actual temperature distribution coefficient corresponding to the actual value of the operating conditions and the simulated temperature distribution coefficient corresponding to the operating conditions, and optimizes the objective function of the operating conditions to obtain the optimal operating conditions.

[0016] Finally, considering that directly using the optimal operating conditions for turbocharger temperature regulation will cause the temperature control to be affected by the above errors, therefore, the PID controller is further used to optimize the optimal operating conditions, realize the optimization of the PID parameters of the turbocharger temperature, further reduce the errors, and enhance the accuracy of the turbocharger temperature control and parameter regulation. To solve the problem that the actual operating temperature of the turbocharger is affected by the coupling of various influencing factors and cannot be directly controlled according to the numerical simulation results, the actual operating temperature of the turbocharger can be accurately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic flow chart of the turbocharger temperature PID collaborative control method provided by an embodiment of the present invention; Figure 2 It is a flowchart for obtaining the actual temperature distribution coefficient provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0020] Please refer to Figure 1 , which shows a flowchart of the turbocharger temperature PID collaborative control method provided by an embodiment of the present invention. The method includes the following steps: Step S001, collect temperature data at all preset temperature measurement points on the turbine main shaft of the turbocharger, the inlet and outlet positions of the cooling water, and the inlet and outlet positions of the lubricating fluid.

[0021] The main structure of the turbocharger includes a turbine inlet housing, a turbine outlet housing, a compressor end housing, a turbine main shaft, a turbine, an impeller, a turbine end bearing body, and a compressor end bearing body. The working principle of the turbocharger is to input the exhaust gas discharged from the engine into the turbine, where it expands and does work to drive the turbine to rotate. At the same time, it drives the coaxial impeller to rotate. The air is compressed by the compressor impeller and input into the engine cylinder, enabling the fuel in the cylinder to burn fully and increasing the work power. During the operation of the turbocharger, the input exhaust gas is a high-temperature and high-pressure gas, and the high temperature will have a relatively serious impact on the structure, components, and lubrication of the turbocharger. Therefore, efficient and accurate temperature control is required during the operation of the turbocharger.

[0022] Starting from one side of the turbine end on the turbine main shaft of the turbocharger, a certain number of temperature measurement points are sequentially selected at equal intervals on the turbine main shaft. A thermocouple sensor is set at each temperature measurement point to collect the temperature data of each temperature measurement point on the turbine main shaft using the thermocouple sensor. Thermocouple sensors are respectively set at the inlet and outlet positions of the cooling water and the inlet and outlet positions of the lubricating fluid, and the thermocouple sensors are used to collect the temperature data of the inlet of the cooling water, the outlet of the cooling water, the inlet of the lubricating fluid, and the outlet of the lubricating fluid respectively.

[0023] Among them, represents the first preset threshold, and the value of the first preset threshold in this embodiment is 13.

[0024] Thus, the temperature data of all temperature measurement points on the turbine main shaft of the thermocouple sensor, the inlet and outlet positions of the cooling water, and the inlet and outlet positions of the lubricating fluid are obtained.

[0025] Step S002: According to the change trend of the temperature data collected at different temperature measurement points at the same acquisition moment, the difference between the temperature data collected at the same temperature measurement point, the difference between the temperature data collected at the inlet and outlet positions of the cooling water, and the difference between the temperature data collected at the inlet and outlet positions of the lubricating fluid, determine the actual temperature distribution coefficient of the turbocharger, perform numerical simulation on the turbocharger to obtain the numerical model of the turbocharger, according to the numerical model, obtain the simulated values of all temperature data, and determine the simulated temperature distribution coefficient of the turbocharger.

[0026] During the operation of a turbocharger, the turbocharger receives high-temperature exhaust gas from the engine, causing the turbocharger to operate in a high-temperature environment, which affects the viscosity of the lubricating oil, the friction between bearings, and the safety of components. Therefore, efficient and accurate temperature control is required during the operation of the turbocharger. The most important part of the temperature control process is to analyze the temperature field of the turbocharger. Generally, numerical simulation methods are used to determine the temperature field of the turbocharger. Among them, numerical simulation uses the method of controlling variables, which can provide relatively comprehensive temperature field information. However, the actual operation of the turbocharger is affected by the coupling results of various influencing factors, with complexity and dynamics, often making it difficult to directly apply the numerical simulation results to actual control. Therefore, it is necessary to further optimize the turbocharger temperature control method to achieve accurate turbocharger temperature control even in a coupling environment.

[0027] There are flow channels for cooling water and lubricating oil on the turbine outlet housing of the turbocharger. The cooling water and lubricating oil can dissipate heat from the turbocharger during its operation. By controlling the flow rate and temperature of the cooling water and the temperature of the lubricating oil, the heat dissipation control of the turbocharger can be achieved, thereby realizing the regulation of the operating temperature of the turbocharger, which helps to ensure the stability and safety of the turbocharger operation.

[0028] The main source of heat during the operation of a turbocharger is the temperature of the exhaust gas entering the turbocharger. Therefore, along the direction of the exhaust gas movement on the turbo main shaft, the temperature decreases successively. That is to say, the exhaust gas enters the turbocharger from the turbo inlet housing, and the temperature at the exhaust gas inlet position of the turbocharger is the highest. Due to the heat dissipation effect of the cooling water and lubricating oil, the temperature of the turbo outlet housing gradually decreases. Further, the air compression passage also takes away a part of the heat transferred from the turbine end, and the temperature of the turbocharger housing further decreases. Therefore, starting from the turbine end side of the turbo main shaft, the temperature data of each temperature measurement point set on the turbo main shaft also has the same temperature change characteristics. It should be further noted that the cooling quality of the cooling device will affect the temperature change of each structural position of the turbocharger. Therefore, when the cooling parameters are different, there are certain differences in the temperature change characteristics between different positions. For example: when the cooling capacity is insufficient, a large amount of heat is transferred to the housing of the turbocharger, and the temperature is relatively high. Since the housing position of the turbocharger is not in direct contact with the heat source, when the cooling parameters are adjusted, the temperature gradient of the housing of the turbocharger will change significantly; when the cooling water flow rate is too fast, the cooling water fails to fully conduct heat exchange, and the heat conducted along the main shaft direction cannot be effectively reduced. At this time, the increase in the cooling water flow rate only results in a weakening of the cooling quality. The influence of the above various factors on the temperature of the turbocharger can be determined by numerical simulation. However, when multiple influences are coupled, there will be differences between the results of the numerical simulation and the actual operating temperature distribution characteristics. This difference is manifested as differences in the temperature distribution of different temperature measurement points along the turbo main shaft direction of the turbocharger, or may also be manifested as changes in the time series change characteristics of the temperature data collected at the same temperature measurement point. Therefore, it is necessary to control the temperature of the turbocharger by combining the actual operating temperature distribution characteristics and the numerical simulation temperature distribution characteristics.

[0029] Determine the actual temperature distribution coefficient of the turbocharger according to the change trend of the temperature data collected at different temperature measurement points at the same acquisition moment, the difference between the temperature data collected at the same temperature measurement point, the difference between the temperature data collected at the inlet and outlet positions of the cooling water, and the difference between the temperature data collected at the inlet and outlet positions of the lubricating fluid.

[0030] Arrange the temperature data collected at each temperature measurement point at the same collection moment in the order of the temperature measurement points set along the direction of the turbine main shaft on the turbine end side to obtain the temperature sequence at the same collection moment. Perform curve fitting on the temperature sequence at the same collection moment to obtain the fitting curve of the temperature sequence at the same collection moment. Take the number 0 as the lower limit of integration and the number of temperature measurement points as the upper limit of integration, integrate the fitting curve of the temperature sequence at the collection moment, and record the integration result as the cumulative area at the collection moment. Denote the mean value of the cumulative areas at all collection moments as the cumulative comprehensive area. Denote the variance of all the temperature data collected at the same temperature measurement point as the temperature fluctuation value of the temperature measurement point; denote the mean value of the temperature fluctuation values of all temperature measurement points as the mean temperature fluctuation. Denote the difference between the mean value of the temperature data of the outlet water of the cooling water and the mean value of the temperature data of the inlet water at all collection moments as the average temperature difference between the inlet and outlet of the cooling water; denote the difference between the mean value of the temperature data of the outlet of the lubricating fluid and the mean value of the temperature data of the inlet at all collection moments as the average temperature difference between the inlet and outlet of the lubricating fluid; denote the sum of the average temperature difference between the inlet and outlet of the cooling water and the average temperature difference between the inlet and outlet of the lubricating fluid as the average temperature difference.

[0031] Calculating the integral of the fitting curve and using the polynomial fitting technique for curve fitting are both well-known techniques and will not be elaborated here. In this embodiment, the polynomial fitting technique is used for curve fitting. In the actual application process, as other implementation manners, on the basis of achieving the purpose of curve fitting, the implementer can use other existing techniques such as the least squares method and other methods to fit the curve, and this application does not make special restrictions.

[0032] Determine the actual temperature distribution coefficient of the turbocharger according to the cumulative comprehensive area, the mean temperature fluctuation, and the average temperature difference. The actual temperature distribution coefficient of the turbocharger has a positive correlation with both the cumulative comprehensive area and the mean temperature fluctuation, and has a negative correlation with the average temperature difference.

[0033] Denote the product of the cumulative comprehensive area and the mean temperature fluctuation as the first product, and denote the ratio of the first product to the average temperature difference as the actual temperature distribution coefficient of the turbocharger.

[0034] The flowchart for obtaining the actual temperature distribution coefficient is as Figure 2 shown.

[0035] It can be understood that the positive correlation and negative correlation in this application refer to the relationship between the independent variable and the dependent variable. The positive correlation means that the dependent variable increases (decreases) as the independent variable increases (decreases), and it can be an additive relationship, a multiplicative relationship, etc.; the negative correlation means that the dependent variable decreases (increases) as the independent variable increases (decreases), and it can be an inverse ratio relationship, a subtractive relationship, etc.

[0036] It can be understood that when the cold energy supply is sufficient and the flow rate is stable and appropriate, the heat exchange at the turbine outlet housing is relatively sufficient, the temperature of the turbine outlet housing is significantly lower, and the difference between the temperature data at the same temperature measurement point at different acquisition times is relatively small. Due to the sufficient heat exchange of the turbocharger, the temperature difference between the inlet and outlet of the cooling water and the lubricating fluid is relatively large. Therefore, the cumulative comprehensive area and the average value of temperature fluctuations are relatively small, the average temperature difference is relatively large, and the actual temperature distribution coefficient of the turbocharger is relatively small.

[0037] Use the simulation method of numerical fluid mechanics to numerically simulate the fluid flow law and heat transfer characteristics of the turbocharger to obtain the numerical model of the turbocharger. According to the numerical model of the turbocharger, obtain the simulated values of the temperature data at all temperature measurement points, the inlet and outlet positions of the cooling water, and the inlet and outlet positions of the lubricating fluid. According to the method of obtaining the actual temperature distribution coefficient of the turbocharger, use the simulated values of the temperature data as the values of the temperature data. According to the change trend of the simulated values of the temperature data at different temperature measurement points at the same acquisition time, the difference between the simulated values of the temperature data at the same temperature measurement point, the difference between the simulated values of the temperature data at the inlet and outlet positions of the cooling water, and the difference between the simulated values of the temperature data at the inlet and outlet positions of the lubricating fluid, determine the simulated temperature distribution coefficient of the turbocharger.

[0038] Among them, numerically simulating the turbocharger to obtain the numerical model is a well-known technology in the art, and the specific details will not be elaborated here.

[0039] So far, the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger are obtained.

[0040] Step S003: Calculate the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a preset number of working conditions. According to the differences between different working conditions, use the simulated values as the values of the working conditions to determine the actual values of the working conditions. According to the actual temperature distribution coefficient corresponding to the actual values of the working conditions and the simulated temperature distribution coefficient corresponding to the working conditions, determine the objective function of the working conditions, optimize the objective function of the working conditions, and obtain the optimal working conditions.

[0041] Generally, the temperature of a turbocharger can be controlled in two ways. The first way requires installing various sensors on the turbocharger and controlling the temperature of the turbocharger according to the changes in the monitoring data of the sensors. However, this way cannot determine the optimal control under each working condition. Therefore, a fixed threshold method is often used to adjust the parameters of the cooling system. That is to say, this way can only roughly control the temperature of the turbocharger and has certain limitations. The second way uses numerical simulation to model the turbocharger, adjusts the parameters according to the model, and determines the influence of different factors on the temperature of the turbocharger. This way can simulate the working conditions under any conditions and enhance the adaptability of the temperature control scheme. However, when analyzing the influencing factors in this way, the control variable method must be adopted to obtain relatively accurate analysis results, and the analysis results corresponding to the situation where multiple factors change simultaneously cannot be obtained. This leads to the fact that the analysis results obtained by using the numerical simulation model are often difficult to be directly applied to actual control. At the same time, due to the certain error between the data in actual operation and the data in the numerical simulation model, the optimal parameters cannot be obtained directly by using the collected data and the simulated data.

[0042] The simulated temperature distribution coefficient is calculated based on the temperature distribution characteristics of the turbocharger and the influence of various influencing factors on the temperature distribution. The temperature distribution characteristics are measured from two perspectives: the actual parameter values and the simulated data values. Therefore, it is not necessary to correspond the actual data and the simulated data one by one. That is to say, the optimal parameters are determined according to the simulated temperature distribution coefficient, which combines the actual parameter values and the simulated data values. Under the condition of coupling the influence of multiple factors, the parameter optimization under different working conditions can be realized, enhancing the accuracy and precision of the temperature control of the turbocharger.

[0043] Calculate the actual temperature distribution coefficient of the turbocharger under various working conditions. Among them, the different working conditions refer to different cooling parameters, and the cooling parameters specifically include the inlet temperature of the cooling water, the outlet temperature of the cooling water, the inlet temperature of the lubricating fluid, and the outlet temperature of the lubricating fluid. If any one of the cooling parameters is different, it means the cooling parameters are different. According to the numerical model of the turbocharger, obtain the simulated temperature distribution coefficient of the turbocharger under various working conditions. Arrange the simulated temperature distribution coefficients of the turbocharger under various working conditions in the set order of the working conditions to obtain a simulated temperature distribution coefficient sequence.

[0044] Among them, represents the second preset threshold, and the value of the second preset threshold in this embodiment is 100; the working conditions corresponding to the actual temperature distribution coefficient and the simulated temperature distribution coefficient are the same; in this embodiment, it is artificially set by experts in this field The specific values of the cooling parameters corresponding to different working conditions.

[0045] The The inlet temperature of the cooling water, the outlet temperature of the cooling water, the inlet temperature of the lubricating fluid, and the outlet temperature of the lubricating fluid obtained from the numerical model of the turbocharger under different working conditions are arranged in the set order corresponding to the working conditions, respectively obtaining the inlet temperature sequence of the cooling water, the outlet temperature sequence of the cooling water, the inlet temperature sequence of the lubricating fluid, and the outlet temperature sequence of the lubricating fluid. The simulated temperature distribution coefficient sequence, the inlet temperature sequence of the cooling water, the outlet temperature sequence of the cooling water, the inlet temperature sequence of the lubricating fluid, and the outlet temperature sequence of the lubricating fluid are respectively normalized. The simulated temperature distribution coefficient sequence, the inlet temperature sequence of the cooling water, the outlet temperature sequence of the cooling water, the inlet temperature sequence of the lubricating fluid, and the outlet temperature sequence of the lubricating fluid after being respectively normalized are processed by grey relational analysis to obtain the correlation degrees between the inlet temperature of the cooling water, the outlet temperature of the cooling water, the inlet temperature of the lubricating fluid, and the outlet temperature of the lubricating fluid and the simulated temperature distribution coefficient, respectively.

[0046] It should be noted that in this embodiment, the Z-Score standard normalization method is used for normalization. In actual application, implementers can use other methods of existing technologies, such as the maximum-minimum normalization method, sigmoid function, etc. for normalization, which are not limited herein; normalization is a well-known technology and will not be elaborated; obtaining the correlation degree by grey relational analysis is a well-known technology and will not be elaborated.

[0047] The difference between the actual value and the simulated value of each cooling parameter in the working condition is denoted as the first difference between the actual value and the simulated value of the cooling parameter. The product of the correlation degree between the cooling parameter and the simulated temperature distribution coefficient and the first difference is denoted as the value error between the actual value and the simulated value of the cooling parameter.

[0048] Controlling the temperature of the turbocharger means making the temperature of the turbocharger as close as possible to the temperature value obtained from the numerical model of the turbocharger and the working conditions, and making the actual temperature distribution coefficient as small as possible to ensure sufficient and stable cold quantity supply. Since there are differences between the working conditions in the numerical model and the actual working conditions and it is impossible to ensure they are exactly the same, it is necessary to determine the corresponding relationship between the working conditions in the numerical model with differences and the actual working conditions. Specifically: the determined working conditions mean that the simulated value of the cooling parameter is determined. The simulated value of the cooling parameter is used as the value of the working condition, and the actual value of the cooling parameter corresponding to the minimum value of the value error corresponding to the working condition is denoted as the actual value of the working condition.

[0049] It can be understood that the actual value of the operating condition is the value of the actual operating condition that is closest to the operating condition in the numerical model.

[0050] The absolute value of the difference between the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition and the simulated temperature distribution coefficient of the turbocharger corresponding to the operating condition is denoted as the first absolute value of the operating condition. The power with the natural constant as the base and the first absolute value of the operating condition as the exponent is denoted as the first power value of the operating condition. The first preset parameter, the second preset parameter, and the third preset parameter are respectively used as the weights of the first power value of the operating condition, the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition, and the simulated temperature distribution coefficient of the turbocharger corresponding to the operating condition for weighted summation to obtain the objective function of the operating condition.

[0051] Among them, the first preset parameter, the second preset parameter, and the third preset parameter are all preset parameters. In this embodiment, the values of the first preset parameter, the second preset parameter, and the third preset parameter are 0.6, 0.2, and 0.3 respectively. The sum of the values of the first preset parameter, the second preset parameter, and the third preset parameter should be 1, and the value of the first preset parameter should be greater than 0.5 and less than 1.

[0052] The operating condition and the objective function of the operating condition are input into the optimization algorithm to obtain the optimal operating condition. Among them, the optimization algorithm can adopt the gradient descent method, the Newton method, and the conjugate gradient method. The iteration direction is determined according to the optimization algorithm, and the iteration step size can be obtained through exact line search, the Wolfe criterion, and the Armijo criterion. In this embodiment, the value of the maximum number of iterations is 100.

[0053] Thus, the optimal operating condition is obtained.

[0054] Step S004, according to the optimal operating condition, realize the optimization of the temperature PID parameters of the turbocharger.

[0055] Since there is a difference between the obtained optimal operating condition and the actual value of the operating condition, directly using the optimal operating condition for turbocharger temperature regulation will cause the temperature control to be affected by the above error. Therefore, further use the PID controller to further optimize the optimal operating condition to further reduce the error and enhance the accuracy of turbocharger temperature control and parameter regulation.

[0056] According to the optimal operating condition, determine the actual value of the optimal operating condition. Input the optimal operating condition and the actual value of the optimal operating condition into the PID controller, and use the PID controller to obtain the control signal corresponding to the optimal operating condition.

[0057] In this embodiment, the values of the proportional gain, derivative gain, and integral gain of the PID controller are 0.5, 0.45, and 0.6 respectively. Obtaining the control signal corresponding to the parameters only using the PID controller is a well-known technology and will not be elaborated further.

[0058] Thus, the optimization of the PID parameters for the turbocharger temperature is achieved.

[0059] Based on the same inventive concept as the above method, an embodiment of the present invention also provides a system for optimizing the PID parameters of the turbocharger temperature, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above methods for the collaborative control method of the turbocharger temperature PID.

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. Turbocharger temperature PID collaborative control method, characterized in that The method includes the following steps: Collect temperature data at all preset temperature measurement points on the turbine main shaft of the turbocharger, at the inlet and outlet positions of the cooling water, and at the inlet and outlet positions of the lubricating fluid respectively; Determine the actual temperature distribution coefficient of the turbocharger according to the change trend of the temperature data collected at different temperature measurement points at the same collection moment, the difference between the temperature data collected at the same temperature measurement point, the difference between the temperature data collected at the inlet and outlet positions of the cooling water, and the difference between the temperature data collected at the inlet and outlet positions of the lubricating fluid. Conduct numerical simulation on the turbocharger to obtain the numerical model of the turbocharger. According to the numerical model, obtain the simulated values of all temperature data, and determine the simulated temperature distribution coefficient of the turbocharger; Calculate the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a preset number of working conditions. According to the difference between different working conditions, take the simulated value as the value of the working condition, determine the actual value of the working condition. According to the actual temperature distribution coefficient corresponding to the actual value of the working condition and the simulated temperature distribution coefficient corresponding to the working condition, determine the objective function of the working condition, and optimize the objective function of the working condition to obtain the optimal working condition; According to the optimal working condition, realize the optimization of the temperature PID parameters of the turbocharger.

2. The turbine supercharger temperature PID collaborative control method according to claim 1, wherein The specific method for determining the actual temperature distribution coefficient of the turbocharger according to the change trend of the temperature data collected at different temperature measurement points at the same collection moment, the difference between the temperature data collected at the same temperature measurement point, the difference between the temperature data collected at the inlet and outlet positions of the cooling water, and the difference between the temperature data collected at the inlet and outlet positions of the lubricating fluid is as follows: Determine the cumulative comprehensive area according to the change trend of the temperature data collected at each temperature measurement point at the same collection moment; Record the variance of all the temperature data collected at the same temperature measurement point as the temperature fluctuation value of the temperature measurement point; record the mean value of the temperature fluctuation values of all temperature measurement points as the mean temperature fluctuation; Determine the average temperature difference according to the difference between the outlet and inlet temperature data of the cooling water at all collection moments and the difference between the outlet and inlet temperature data of the lubricating fluid at all collection moments; Record the product of the cumulative comprehensive area and the mean temperature fluctuation as the first product, and record the ratio of the first product to the average temperature difference as the actual temperature distribution coefficient of the turbocharger.

3. The turbine supercharger temperature PID collaborative control method according to claim 2, wherein The specific method for determining the cumulative comprehensive area according to the change trend of the temperature data collected at each temperature measurement point at the same collection moment is as follows: Take the order of the temperature measurement points where the temperature data is collected along the direction of the turbine main shaft as the independent variable, and take the temperature data collected at each temperature measurement point at the same collection moment as the dependent variable for curve fitting to obtain the fitting curve; take the number 0 as the lower limit of integration and the number of temperature measurement points as the upper limit of integration, integrate the fitting curve, and record the integration result as the cumulative area at the collection moment; record the mean value of the cumulative areas at all collection moments as the cumulative comprehensive area.

4. The turbine supercharger temperature PID collaborative control method according to claim 2, characterized in that Determining the average temperature difference based on the differences between the outlet and inlet temperature data of the cooling water and the differences between the outlet and inlet temperature data of the lubricating oil at all acquisition moments, and the specific method included is as follows: Denote the difference between the average value of the outlet temperature data of the cooling water and the average value of the inlet temperature data of the cooling water at all acquisition moments as the average temperature difference between the inlet and outlet of the cooling water; denote the difference between the average value of the outlet temperature data of the lubricating oil and the average value of the inlet temperature data of the lubricating oil at all acquisition moments as the average temperature difference between the inlet and outlet of the lubricating oil; denote the sum of the average temperature difference between the inlet and outlet of the cooling water and the average temperature difference between the inlet and outlet of the lubricating oil as the average temperature difference.

5. The turbine supercharger temperature PID collaborative control method according to claim 1, wherein The different working conditions are different cooling parameters, and the cooling parameters include the inlet temperature of the cooling water, the outlet temperature of the cooling water, the inlet temperature of the lubricating oil, and the outlet temperature of the lubricating oil.

6. The turbine supercharger temperature PID collaborative control method according to claim 5, characterized in that Determining the actual value of the working condition by taking the simulated value as the value of the working condition according to the differences between different working conditions, and the specific method included is as follows: Calculation the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a variety of preset operating conditions, and according to the simulated temperature distribution coefficient of the turbocharger and all cooling parameters under a variety of preset operating conditions, respectively obtain the correlation degree between each cooling parameter and the simulated temperature distribution coefficient, where represents a second preset threshold value; Denote the difference between the actual value of each cooling parameter in the working condition and the simulated value in the numerical model as the first difference between the actual value and the simulated value of the cooling parameter, and denote the product of the correlation degree between the cooling parameter and the simulated temperature distribution coefficient and the first difference as the value error between the actual value and the simulated value of the cooling parameter; take the simulated value of the cooling parameter as the value of the working condition, and denote the actual value of the cooling parameter corresponding to the minimum value of the value error corresponding to the working condition as the actual value of the working condition.

7. The turbine supercharger temperature PID collaborative control method according to claim 1, wherein Obtaining the objective function of the working condition according to the differences between the working condition and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition, and the specific method included is as follows: Denote the absolute value of the difference between the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition and the simulated temperature distribution coefficient of the turbocharger corresponding to the working condition as the first absolute value of the working condition, and denote the power with the natural constant as the base and the first absolute value of the working condition as the exponent as the first power value of the working condition; Obtain the objective function of the working condition according to the first power value of the working condition, the working condition, and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition.

8. The turbine supercharger temperature PID collaborative control method according to claim 7, wherein The steps for obtaining the objective function of the working condition according to the first power value of the working condition, the working condition, and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition include: Take the first preset parameter, the second preset parameter, and the third preset parameter as the weights of the first power value of the working condition, the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the working condition, and the simulated temperature distribution coefficient of the turbocharger corresponding to the working condition respectively, and perform weighted summation to obtain the objective function of the working condition.

9. The turbine supercharger temperature PID collaborative control method according to claim 1, characterized in that Optimizing the temperature PID parameters of the turbocharger according to the optimal working condition, and the specific method included is as follows: Determine the actual value of the optimal working condition according to the optimal working condition; Input the optimal working condition and the actual value of the optimal working condition into the PID controller, and use the PID controller to obtain the control signal corresponding to the optimal working condition.

10. Turbocharger temperature PID parameter optimization system, including a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1-9 are implemented.

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