Turbocharger temperature PID collaborative control method and parameter optimization system

Abstract

The present invention relates to the technical field of turbocharger temperature coordinated control, and proposes a turbocharger temperature PID coordinated control method and parameter optimization system, comprising: collecting temperature data at preset temperature measurement points, cooling water inlet and outlet, and lubricating fluid inlet and outlet of the turbocharger; determining the actual temperature distribution coefficient of the turbocharger, obtaining a numerical model of the turbocharger, and determining a simulated temperature distribution coefficient of the turbocharger; calculating the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a preset number of operating conditions, taking the simulated values ​​as the values ​​of the operating conditions, determining the actual values ​​of the operating conditions, determining the objective function of the operating conditions, optimizing the objective function of the operating conditions, and obtaining the optimal operating conditions; and optimizing the turbocharger temperature PID parameters based on the optimal operating conditions. The present invention can accurately control the actual operating temperature of the turbocharger.

Description

Technical Field

[0001] The present invention relates to the technical field of turbocharger temperature coordinated control, and in particular to a turbocharger temperature PID coordinated control method and a parameter optimization system. Background Art

[0002] Turbochargers increase intake pressure, boosting engine power output and optimizing the combustion process, improving fuel economy and reducing pollutant emissions. Controlling the operating temperature of a turbocharger ensures safe and stable operation. To achieve accurate temperature control, research into the turbocharger's temperature field is essential.

[0003] Numerical simulations using the control variable method can provide comprehensive temperature field information. However, the actual operation of a turbocharger is affected by the coupling of various influencing factors, resulting in complexity and dynamics, which often makes it difficult to directly apply the numerical simulation results to actual control. Therefore, a turbocharger temperature control method suitable for actual coupling environments is urgently needed to ensure safe and stable operation of the turbocharger. Summary of the Invention

[0004] The present invention provides a turbocharger temperature PID coordinated control method and parameter optimization system to solve the problem that the actual operating temperature of the turbocharger is affected by the coupling of multiple influencing factors and the temperature cannot be directly controlled based on numerical simulation results. The technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present invention provides a turbocharger temperature PID coordinated control method, the method comprising the following steps:

[0006] Collect temperature data at all preset temperature measurement points on the turbocharger's turbine main shaft, at the cooling water inlet and outlet, and at the lubricating fluid inlet and outlet.

[0007] Based on the changing trend of temperature data collected at different temperature measurement points at the same collection time, the difference between temperature data collected at the same temperature measurement point, the difference between temperature data collected at the cooling water inlet and outlet, and the difference between temperature data collected at the lubricating fluid inlet and outlet, the actual temperature distribution coefficient of the turbocharger is determined, a numerical simulation is performed on the turbocharger to obtain a numerical model of the turbocharger, and based on the numerical model, simulated values ​​of all temperature data are obtained to determine the simulated temperature distribution coefficient of the turbocharger;

[0008] calculating the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a preset number of operating conditions, taking the simulated value as the value of the operating condition based on the differences between the different operating conditions, determining the actual value of the operating condition, determining the objective function of the operating condition based on the actual temperature distribution coefficient corresponding to the actual value of the operating condition and the simulated temperature distribution coefficient corresponding to the operating condition, and optimizing the objective function of the operating condition to obtain the optimal operating condition;

[0009] According to the optimal operating conditions, the turbocharger temperature PID parameters are optimized.

[0010] Furthermore, the actual temperature distribution coefficient of the turbocharger is determined based on the changing trend of the temperature data collected at different temperature measurement points at the same collection time, the difference between the temperature data collected at the same temperature measurement point, the difference between the temperature data collected at the cooling water inlet and outlet, and the difference between the temperature data collected at the lubricating fluid inlet and outlet, including the specific method of:

[0011] Determine the cumulative comprehensive area based on the changing trend of the temperature data collected at all temperature measurement points at the same collection time;

[0012] The variance of all temperature data collected at the same temperature measuring point is recorded as the temperature fluctuation value of the temperature measuring point; the mean of the temperature fluctuation values ​​of all temperature measuring points is recorded as the temperature fluctuation mean;

[0013] Determine the average temperature difference based on the difference between the cooling water outlet and inlet temperature data at all sampling moments, and the difference between the lubricating fluid outlet and inlet temperature data at all sampling moments;

[0014] The product of the accumulated comprehensive area and the mean value of the temperature fluctuation is recorded as the first product, and the ratio of the first product to the average temperature difference is recorded as the actual temperature distribution coefficient of the turbocharger.

[0015] Furthermore, the cumulative comprehensive area is determined based on the change trend of the temperature data collected at all temperature measurement points at the same collection time, including the following specific methods:

[0016] The order in which the temperature measurement points for collecting temperature data are arranged along the turbine main shaft is taken as the independent variable, and the temperature data collected at each temperature measurement point at the same collection time is taken as the dependent variable for curve fitting to obtain the fitting curve; the number 0 is taken as the lower limit of integration, and the number of temperature measurement points is taken as the upper limit of integration. The fitting curve is integrated, and the integration result is recorded as the cumulative area at the collection time; the average of the cumulative areas at all collection times is recorded as the cumulative comprehensive area.

[0017] Furthermore, the average temperature difference is determined based on the difference between the temperature data of the cooling water outlet and the cooling water inlet at all sampling moments, and the difference between the temperature data of the lubricating fluid outlet and the lubricating fluid inlet at all sampling moments, including the specific method of:

[0018] The difference between the mean of the cooling water outlet temperature data and the mean of the inlet temperature data at all sampling moments is recorded as the average temperature difference of the cooling water inlet and outlet; the difference between the mean of the lubricating fluid outlet temperature data and the mean of the inlet temperature data at all sampling moments is recorded as the average temperature difference of the lubricating fluid inlet and outlet; the sum of the average temperature difference of the cooling water inlet and outlet and the average temperature difference of the lubricating fluid inlet and outlet is recorded as the average temperature difference.

[0019] Furthermore, the different operating 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.

[0020] Furthermore, the method of taking the simulated value as the value of the working condition according to the difference between different working conditions to determine the actual value of the working condition includes the following specific methods:

[0021] calculate The actual temperature distribution coefficient and simulated temperature distribution coefficient of the turbocharger under the preset working conditions are The simulated temperature distribution coefficient and all cooling parameters of the turbocharger under the preset working conditions are obtained, and the correlation between each cooling parameter and the simulated temperature distribution coefficient is obtained, wherein, represents a second preset threshold;

[0022] The difference between the actual value of each cooling parameter in the working condition and the simulated value in the numerical model is recorded as the first difference between the actual value and the simulated value of the cooling parameter, and the product of the correlation between the cooling parameter and the simulated temperature distribution coefficient and the first difference is recorded as the value error between the actual value and the simulated value of the cooling parameter; the simulated value of the cooling parameter is taken 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 recorded as the actual value of the working condition.

[0023] Furthermore, the objective function of the operating condition is obtained based on the difference between the operating condition and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition, including the specific method of:

[0024] 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 recorded as the first absolute value of the operating condition, and the first absolute value of the operating condition is raised to the power of the natural constant as the exponent, which is recorded as the first power value of the operating condition;

[0025] An objective function of the operating condition is obtained according to the first power value of the operating condition, the operating condition, and an actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition.

[0026] Furthermore, the objective function of the operating condition is obtained according to the first power value of the operating condition, the operating condition, and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition, including the specific steps of:

[0027] The first preset parameter, the second preset parameter, and the third preset parameter are respectively used as 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 weight of the simulated temperature distribution coefficient of the turbocharger corresponding to the operating condition, and a weighted sum is performed to obtain the objective function of the operating condition.

[0028] Furthermore, the turbocharger temperature PID parameter optimization is achieved according to the optimal operating conditions, including the specific method of:

[0029] According to the optimal working conditions, determine the actual value of the optimal working conditions;

[0030] The optimal working condition and the actual value of the optimal working condition are input into the PID controller, and the PID controller is used to obtain a control signal corresponding to the optimal working condition.

[0031] In a second aspect, an embodiment of the present invention further provides a turbocharger temperature PID parameter optimization system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above methods when executing the computer program.

[0032] The beneficial effects of the present invention are:

[0033] When the cooling capacity 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 of the same temperature measuring point at different collection times is small, and the temperature difference between the cooling water and lubricating fluid inlets and outlets is relatively large. Based on this feature, the present application evaluates the necessity of controlling the temperature of the turbocharger, obtains the actual temperature distribution coefficient of the turbocharger, and performs numerical simulation on the turbocharger to obtain a numerical model of the turbocharger, and then determines the simulated temperature distribution coefficient of the turbocharger according to the numerical model, and determines the optimal parameters according to the actual temperature distribution coefficient and the simulated temperature distribution coefficient. By combining the actual parameter values ​​and the simulated data values, the parameter optimization under different working conditions can be achieved under the coupling of multiple factors, thereby enhancing the accuracy and precision of the turbocharger temperature control.

[0034] To control the temperature of the turbocharger, it is necessary to make the temperature of the turbocharger as close as possible to the temperature value and operating conditions obtained by the numerical model of the turbocharger, and make the actual temperature distribution coefficient as small as possible to ensure sufficient and stable supply of cooling capacity. Since the operating conditions in the numerical model and the actual operating conditions are different, it is impossible to ensure that they are exactly the same. Therefore, this application determines the correspondence between the operating conditions in the numerical model with differences and the actual operating conditions, that is, obtains the actual value of the operating condition, and determines the objective function of the operating condition based on the actual temperature distribution coefficient corresponding to the actual value of the operating condition and the simulated temperature distribution coefficient corresponding to the operating condition, optimizes the objective function of the operating condition, and obtains the optimal operating condition.

[0035] Finally, considering that directly using the optimal operating conditions for turbocharger temperature regulation would affect the temperature control with the above-mentioned errors, the PID controller is further utilized to further optimize the optimal operating conditions, achieving turbocharger temperature PID parameter optimization, further reducing errors and enhancing the accuracy of turbocharger temperature control and parameter adjustment. This solves the problem that the actual operating temperature of the turbocharger is affected by the coupling of multiple influencing factors and cannot be directly controlled based on the numerical simulation results. The actual operating temperature of the turbocharger can be accurately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 A schematic flow chart of a turbocharger temperature PID coordinated control method provided by one embodiment of the present invention;

[0038] Figure 2 A flowchart for obtaining the actual temperature distribution coefficient provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] See also Figure 1, which shows a flow chart of a turbocharger temperature PID coordinated control method provided by one embodiment of the present invention, the method comprising the following steps:

[0041] Step S001 , collecting 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.

[0042] The main structure of a turbocharger includes the turbine inlet housing, turbine outlet housing, compressor housing, turbine main shaft, turbine wheel, turbine impeller, turbine end bearing, and compressor end bearing. The turbocharger's operating principle is to feed exhaust gas from the engine into the turbine, where it expands and generates work, driving the turbine's rotation and simultaneously rotating the coaxial impeller. The air is compressed by the compressor impeller and fed into the engine cylinder, allowing the fuel in the cylinder to fully combust and increase power. During turbocharger operation, the input exhaust gas is high-temperature, high-pressure gas. This high temperature has a significant impact on the turbocharger's structure, components, and lubrication. Therefore, efficient and accurate temperature control is required during turbocharger operation.

[0043] Starting from the turbine end of the turbocharger's turbine main shaft, select the Temperature measurement points are set up at each temperature measurement point, and a thermocouple sensor is set up at each temperature measurement point. Thermocouple sensors are used to collect temperature data at each temperature measurement point on the turbine main shaft. Thermocouple sensors are set up at the inlet and outlet of the cooling water and the inlet and outlet of the lubricating fluid. Thermocouple sensors are used to collect temperature data of the cooling water inlet, cooling water outlet, lubricating fluid inlet, and lubricating fluid outlet respectively.

[0044] in, represents the first preset threshold. In this embodiment, the value of the first preset threshold is 13.

[0045] At this point, 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.

[0046] Step S002, based on the changing trend of temperature data collected at different temperature measuring points at the same collection time, the difference between the temperature data collected at the same temperature measuring point, the difference between the temperature data collected at the cooling water inlet and outlet positions, and the difference between the temperature data collected at the lubricating fluid inlet and outlet positions, determine the actual temperature distribution coefficient of the turbocharger, perform numerical simulation on the turbocharger, obtain a numerical model of the turbocharger, obtain simulated values ​​of all temperature data based on the numerical model, and determine the simulated temperature distribution coefficient of the turbocharger.

[0047] During turbocharger operation, the turbocharger receives high-temperature exhaust gas from the engine, causing it to operate in a high-temperature environment. This affects the viscosity of the lubricating oil, friction between bearings, and component safety. Therefore, efficient and accurate temperature control is necessary during turbocharger operation. The most important aspect of temperature control is analyzing the turbocharger's temperature field. Numerical simulation is generally used to determine the turbocharger's temperature field. Numerical simulation employs the control variable method, which can provide more comprehensive temperature field information. However, the actual operation of a turbocharger is affected by the coupling of various influencing factors, resulting in complexity and dynamics. This often makes it difficult to directly apply numerical simulation results to actual control. Therefore, it is necessary to further optimize turbocharger temperature control methods to achieve accurate turbocharger temperature control even in a coupled environment.

[0048] There are circulation 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 operation. Controlling the flow rate and temperature of the cooling water, as well as the temperature of the lubricating oil, can achieve heat dissipation control of the turbocharger, thereby adjusting the operating temperature of the turbocharger, which helps to ensure the stability and safety of the turbocharger operation.

[0049] The main source of heat during turbocharger operation is the temperature of the exhaust gas entering the turbocharger. Therefore, the temperature on the turbine main shaft decreases sequentially along the direction of exhaust gas movement. That is, the exhaust gas enters the turbocharger from the turbine inlet housing, and the temperature at the exhaust gas entry point of the turbocharger is the highest. Due to the heat dissipation effect of cooling water and lubricating oil, the temperature of the turbine outlet housing gradually decreases. Furthermore, the air compression channel also removes some of the heat transferred from the turbine end, further reducing the temperature of the turbocharger housing. Therefore, starting from the turbine end side of the turbine main shaft, the temperature data at each temperature measurement point set along the turbine main shaft have the same temperature change characteristics. It is further noted that the cooling quality of the cooling device will affect the temperature changes at various structural locations of the turbocharger. Therefore, when the cooling parameters are different, there are certain differences in the temperature change characteristics between different locations. For example, when the cooling capacity is insufficient, a large amount of heat is transferred to the turbocharger housing, causing the temperature to be relatively high. Since the turbocharger housing is not directly in contact with the heat source, the temperature gradient of the turbocharger housing will change significantly when the cooling parameters are adjusted. When the cooling water flow rate is too fast, the cooling water fails to fully exchange heat, and the heat conducted along the main axis cannot be effectively reduced. In this case, increasing the cooling water flow rate can only lead to a decrease in cooling quality. The impact of the above-mentioned factors on the temperature of the turbocharger can be determined through numerical simulation. However, when multiple influences are coupled, the results of the numerical simulation and the temperature distribution characteristics of actual operation will differ. This difference is manifested as a difference in the temperature distribution at different temperature measurement points along the main axis of the turbocharger, or it may be manifested as a change in the time series variation characteristics of the temperature data collected at the same temperature measurement point. Therefore, it is necessary to combine the temperature distribution characteristics of actual operation with the temperature distribution characteristics of numerical simulation to control the temperature of the turbocharger.

[0050] The actual temperature distribution coefficient of the turbocharger is determined based on the changing trend of temperature data collected at different temperature measurement points at the same collection time, the difference between temperature data collected at the same temperature measurement point, the difference between temperature data collected at the cooling water inlet and outlet positions, and the difference between temperature data collected at the lubricating fluid inlet and outlet positions.

[0051] Arrange the temperature data collected at each temperature measurement point at the same collection time in the order in which the temperature measurement points are set along the turbine main shaft on the turbine end side to obtain a temperature sequence at the same collection time. Perform curve fitting on the temperature sequence at the same collection time to obtain a fitting curve for the temperature sequence at the same collection time. Integrate the fitting curve of the temperature sequence at the collection time, using 0 as the lower limit of integration and the number of temperature measurement points as the upper limit of integration. Record the integration result as the cumulative area at the collection time. Record the mean of the cumulative areas at all collection times as the cumulative integrated area. Record the variance of all temperature data collected at the same temperature measurement point as the temperature fluctuation value of the temperature measurement point; record the mean of the temperature fluctuation values ​​of all temperature measurement points as the temperature fluctuation mean. Record the difference between the mean of the cooling water outlet temperature data and the mean of the inlet temperature data at all collection times as the cooling water inlet and outlet temperature mean difference. Record the difference between the mean of the lubricating fluid outlet temperature data and the mean of the inlet temperature data at all collection times as the lubricating fluid inlet and outlet temperature mean difference. Record the sum of the cooling water inlet and outlet temperature mean difference and the lubricating fluid inlet and outlet temperature mean difference as the average temperature difference.

[0052] Calculating the integral of the fitted curve and using polynomial fitting technology to perform curve fitting are both well-known technologies and will not be described in detail. This embodiment uses polynomial fitting technology to perform curve fitting. In actual application, as other implementation methods, on the basis of achieving the purpose of curve fitting, the implementer can use other existing methods such as least squares method to fit the curve. This application does not impose any special restrictions.

[0053] The actual temperature distribution coefficient of the turbocharger is determined based on the cumulative comprehensive area, the mean temperature fluctuation, and the average temperature difference. The actual temperature distribution coefficient of the turbocharger is positively correlated with the cumulative comprehensive area and the mean temperature fluctuation, and negatively correlated with the average temperature difference.

[0054] The product of the accumulated comprehensive area and the mean value of the temperature fluctuation is recorded as the first product, and the ratio of the first product to the average temperature difference is recorded as the actual temperature distribution coefficient of the turbocharger.

[0055] The actual temperature distribution coefficient acquisition flow chart is as follows Figure 2 shown.

[0056] 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 is that the dependent variable increases (decreases) as the independent variable increases (decreases), which can be an additive relationship, a multiplicative relationship, etc.; the negative correlation is that the dependent variable decreases (increases) as the independent variable increases (decreases), which can be an inverse relationship, a subtractive relationship, etc.

[0057] It can be understood that when the cooling capacity is adequately supplied 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 collection times is small. Since the turbocharger has sufficient heat exchange, the temperature difference between the cooling water and lubricating fluid inlet and outlet is relatively large. Therefore, the cumulative comprehensive area and temperature fluctuation mean are small, the average temperature difference is large, and the actual temperature distribution coefficient of the turbocharger is relatively small.

[0058] The fluid flow patterns and heat transfer characteristics of the turbocharger are numerically simulated using numerical fluid dynamics simulation methods to obtain a numerical model of the turbocharger. Based on the numerical model of the turbocharger, simulated values ​​of temperature data are obtained for all temperature measurement points, the cooling water inlet and outlet locations, and the lubricating fluid inlet and outlet locations. Following the method for obtaining the actual temperature distribution coefficient of the turbocharger, the simulated values ​​of the temperature data are used as the temperature data values. The simulated temperature distribution coefficient of the turbocharger is determined based on the changing trends of the simulated values ​​of the temperature data at different temperature measurement points at the same acquisition time, the differences between the simulated values ​​of the temperature data at the same temperature measurement point, the differences between the simulated values ​​of the temperature data at the cooling water inlet and outlet locations, and the differences between the simulated values ​​of the temperature data at the lubricating fluid inlet and outlet locations.

[0059] Here, performing numerical simulation on the turbocharger and obtaining a numerical model are well-known technologies in the art, and the specific details are not repeated here.

[0060] At this point, the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger are obtained.

[0061] Step S003, calculate the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a preset number of working conditions, take the simulated value as the value of the working condition according to the difference between different working conditions, determine the actual value of the working condition, determine the objective function 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, optimize the objective function of the working condition, and obtain the optimal working condition.

[0062] Generally, there are two ways to control the temperature of a turbocharger. The first method requires installing various sensors on the turbocharger and controlling the turbocharger temperature based on changes in sensor monitoring data. However, this method cannot determine the optimal control under every operating condition. Therefore, a fixed threshold method is often used to adjust the parameters of the cooling system. In other words, this method can only achieve rough control of the turbocharger temperature and has certain limitations. The second method uses numerical simulation to model the turbocharger, adjust parameters based on the model, and determine the impact of different factors on the turbocharger temperature. This method can simulate operating conditions under any conditions, enhancing the adaptability of the temperature control scheme. However, when analyzing the influencing factors, this method must use the control variable method to obtain relatively accurate analysis results. It is impossible to obtain analysis results corresponding to situations where multiple factors change simultaneously. This also makes the analysis results obtained using numerical simulation models often difficult to directly apply to actual control. At the same time, due to the certain errors between the actual operating data and the data of the numerical simulation model, it is impossible to directly use the collected data and simulated data to obtain the optimal parameters.

[0063] 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: actual parameter values ​​and simulated data values. Therefore, there is no need to make a one-to-one correspondence between actual data and simulated data. In other words, the optimal parameters are determined based on the simulated temperature distribution coefficient. By combining the actual parameter values ​​and simulated data values, parameter optimization under different working conditions can be achieved under the coupling of multiple factors, thereby enhancing the accuracy and precision of turbocharger temperature control.

[0064] calculate The actual temperature distribution coefficient of the turbocharger under different working conditions, where different working conditions are different cooling parameters, which specifically include the cooling water inlet temperature, cooling water outlet temperature, lubricating fluid inlet temperature and lubricating fluid outlet temperature. A difference in any one of the cooling parameters is considered a different cooling parameter. According to the numerical model of the turbocharger, obtain The simulated temperature distribution coefficient of the turbocharger under various working conditions. The simulated temperature distribution coefficients of the turbocharger under various working conditions are arranged according to the set order of the working conditions to obtain a simulated temperature distribution coefficient sequence.

[0065] in, represents the second preset threshold value. In this embodiment, the value of the second preset threshold value is 100. The actual temperature distribution coefficient and the simulated temperature distribution coefficient correspond to The working conditions are the same; this embodiment is set by experts in this field The specific values ​​of cooling parameters corresponding to various working conditions.

[0066] Will The cooling water inlet temperature, cooling water outlet temperature, lubricating fluid inlet temperature, and lubricating fluid outlet temperature data obtained from the numerical model of the turbocharger under various operating conditions are arranged in the order of the corresponding operating conditions, resulting in the cooling water inlet temperature sequence, cooling water outlet temperature sequence, lubricating fluid inlet temperature sequence, and lubricating fluid outlet temperature sequence. The simulated temperature distribution coefficient sequence, cooling water inlet temperature sequence, cooling water outlet temperature sequence, lubricating fluid inlet temperature sequence, and lubricating fluid outlet temperature sequence are normalized. Grey correlation analysis is then used to analyze the normalized simulated temperature distribution coefficient sequence, cooling water inlet temperature sequence, cooling water outlet temperature sequence, lubricating fluid inlet temperature sequence, and lubricating fluid outlet temperature sequence to determine the correlation between the cooling water inlet temperature, cooling water outlet temperature, lubricating fluid inlet temperature, and lubricating fluid outlet temperature and the simulated temperature distribution coefficient.

[0067] It should be noted that this embodiment uses the Z-Score standard normalization method for normalization. In actual application, the implementer can use other existing methods such as maximum and minimum value normalization method, sigmoid function, etc. for normalization, which is not limited here; normalization is a well-known technology and will not be described in detail; the use of gray correlation analysis to obtain correlation degree is a well-known technology and will not be described in detail.

[0068] The difference between the actual value of each cooling parameter in the working condition and the simulated value in the numerical model is recorded as the first difference between the actual value and the simulated value of the cooling parameter, and the product of the correlation between the cooling parameter and the simulated temperature distribution coefficient and the first difference is recorded as the value error between the actual value and the simulated value of the cooling parameter.

[0069] The temperature of the turbocharger is controlled to ensure that the temperature of the turbocharger is as close as possible to the temperature value and operating conditions obtained by the numerical model of the turbocharger, and to minimize the actual temperature distribution coefficient to ensure sufficient and stable cooling supply. Since the operating conditions in the numerical model and the actual operating conditions are different and cannot be guaranteed to be exactly the same, it is necessary to determine the correspondence between the operating conditions in the numerical model and the actual operating conditions. Specifically, the determined operating conditions are the simulated values ​​of the cooling parameters, and the simulated values ​​of the cooling parameters are used as the values ​​of the operating conditions. The actual value of the cooling parameter corresponding to the minimum value of the value error corresponding to the operating condition is recorded as the actual value of the operating condition.

[0070] 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.

[0071] 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 recorded as the first absolute value of the operating condition, and the power with the natural constant as the base and the first absolute value of the operating condition as the exponent is recorded as the first power value of the operating condition; the first preset parameter, the second preset parameter, and the third preset parameter are 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, respectively, and the objective function of the operating condition is obtained by weighted summation.

[0072] 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.

[0073] Input the operating conditions and their objective function into the optimization algorithm to obtain the optimal operating conditions. The optimization algorithm can use gradient descent, Newton's method, or conjugate gradient method. The iteration direction is determined by the optimization algorithm, and the iteration step size can be determined using exact line search, Wolfe criterion, or Armijo criterion. In this implementation, the maximum number of iterations is set to 100.

[0074] At this point, the optimal working conditions are obtained.

[0075] Step S004: optimizing the turbocharger temperature PID parameters according to the optimal operating conditions.

[0076] Since there is a difference between the optimal operating conditions and the actual values ​​of the operating conditions, directly using the optimal operating conditions to adjust the turbocharger temperature will cause the temperature control to be affected by the above-mentioned error. Therefore, the PID controller is further used to further optimize the optimal operating conditions, further reduce the error, and enhance the accuracy of turbocharger temperature control and parameter adjustment.

[0077] Based on the optimal working condition, the actual value of the optimal working condition is determined. The optimal working condition and the actual value of the optimal working condition are input into the PID controller, and the PID controller is used to obtain the control signal corresponding to the optimal working condition.

[0078] In this embodiment, the proportional gain, differential gain and integral gain of the PID controller are set to 0.5, 0.45 and 0.6 respectively. It is a well-known technology to use only the PID controller to obtain the control signal corresponding to the parameters, which will not be repeated here.

[0079] At this point, the turbocharger temperature PID parameter optimization is achieved.

[0080] Based on the same inventive concept as the above method, an embodiment of the present invention also provides a turbocharger temperature PID parameter optimization system, 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 any one of the above-mentioned turbocharger temperature PID collaborative control methods are implemented.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A turbocharger temperature PID coordinated control method, characterized in that: The method comprises the following steps: Collect temperature data at all preset temperature measurement points on the turbocharger's turbine main shaft, at the cooling water inlet and outlet, and at the lubricating fluid inlet and outlet. Based on the changing trend of temperature data collected at different temperature measurement points at the same collection time, the difference between temperature data collected at the same temperature measurement point, the difference between temperature data collected at the cooling water inlet and outlet, and the difference between temperature data collected at the lubricating fluid inlet and outlet, the actual temperature distribution coefficient of the turbocharger is determined, a numerical simulation is performed on the turbocharger to obtain a numerical model of the turbocharger, and based on the numerical model, simulated values ​​of all temperature data are obtained to determine the simulated temperature distribution coefficient of the turbocharger; calculating the actual temperature distribution coefficient and the simulated temperature distribution coefficient of the turbocharger under a preset number of operating conditions, taking the simulated value as the value of the operating condition based on the differences between the different operating conditions, determining the actual value of the operating condition, determining the objective function of the operating condition based on the actual temperature distribution coefficient corresponding to the actual value of the operating condition and the simulated temperature distribution coefficient corresponding to the operating condition, and optimizing the objective function of the operating condition to obtain the optimal operating condition; According to the optimal operating conditions, the turbocharger temperature PID parameters are optimized.

2. The turbocharger temperature PID coordinated control method according to claim 1, characterized in that: The actual temperature distribution coefficient of the turbocharger is determined based on the change trend of the temperature data collected at different temperature measurement points at the same collection time, the difference between the temperature data collected at the same temperature measurement point, the difference between the temperature data collected at the cooling water inlet and outlet, and the difference between the temperature data collected at the lubricating fluid inlet and outlet, including the following specific methods: Determine the cumulative comprehensive area based on the changing trend of the temperature data collected at all temperature measurement points at the same collection time; The variance of all temperature data collected at the same temperature measuring point is recorded as the temperature fluctuation value of the temperature measuring point; the mean of the temperature fluctuation values ​​of all temperature measuring points is recorded as the temperature fluctuation mean; Determine the average temperature difference based on the difference between the cooling water outlet and inlet temperature data at all sampling moments, and the difference between the lubricating fluid outlet and inlet temperature data at all sampling moments; The product of the accumulated comprehensive area and the mean value of the temperature fluctuation is recorded as the first product, and the ratio of the first product to the average temperature difference is recorded as the actual temperature distribution coefficient of the turbocharger.

3. The turbocharger temperature PID coordinated control method according to claim 2, characterized in that: The method of determining the cumulative comprehensive area based on the change trend of the temperature data collected at all temperature measurement points at the same collection time includes the following specific methods: The order in which the temperature measurement points for collecting temperature data are arranged along the turbine main shaft is taken as the independent variable, and the temperature data collected at each temperature measurement point at the same collection time is taken as the dependent variable for curve fitting to obtain the fitting curve; the number 0 is taken as the lower limit of integration, and the number of temperature measurement points is taken as the upper limit of integration. The fitting curve is integrated, and the integration result is recorded as the cumulative area at the collection time; the average of the cumulative areas at all collection times is recorded as the cumulative comprehensive area.

4. The turbocharger temperature PID coordinated control method according to claim 2, characterized in that: The method of determining the average temperature difference based on the difference between the cooling water outlet and inlet temperature data at all sampling moments and the difference between the lubricating fluid outlet and inlet temperature data at all sampling moments includes: The difference between the mean of the cooling water outlet temperature data and the mean of the inlet temperature data at all sampling moments is recorded as the average temperature difference of the cooling water inlet and outlet; the difference between the mean of the lubricating fluid outlet temperature data and the mean of the inlet temperature data at all sampling moments is recorded as the average temperature difference of the lubricating fluid inlet and outlet; the sum of the average temperature difference of the cooling water inlet and outlet and the average temperature difference of the lubricating fluid inlet and outlet is recorded as the average temperature difference.

5. The turbocharger temperature PID coordinated control method according to claim 1, characterized in that: The different operating 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.

6. The turbocharger temperature PID coordinated control method according to claim 5, characterized in that: The method of taking the simulated value as the value of the working condition according to the difference between different working conditions to determine the actual value of the working condition includes the following specific methods: calculate The actual temperature distribution coefficient and simulated temperature distribution coefficient of the turbocharger under the preset working conditions are The simulated temperature distribution coefficient and all cooling parameters of the turbocharger under the preset working conditions are obtained, and the correlation between each cooling parameter and the simulated temperature distribution coefficient is obtained, wherein, represents a second preset threshold; The difference between the actual value of each cooling parameter in the working condition and the simulated value in the numerical model is recorded as the first difference between the actual value and the simulated value of the cooling parameter, and the product of the correlation between the cooling parameter and the simulated temperature distribution coefficient and the first difference is recorded as the value error between the actual value and the simulated value of the cooling parameter; the simulated value of the cooling parameter is taken 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 recorded as the actual value of the working condition.

7. The turbocharger temperature PID coordinated control method according to claim 1, characterized in that: The specific method of obtaining the objective function of the operating condition based on the difference between the operating condition and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition is as follows: 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 recorded as the first absolute value of the operating condition, and the first absolute value of the operating condition is raised to the power of the natural constant as the exponent, which is recorded as the first power value of the operating condition; An objective function of the operating condition is obtained according to the first power value of the operating condition, the operating condition, and an actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition.

8. The turbocharger temperature PID coordinated control method according to claim 7, characterized in that: The step of obtaining the objective function of the operating condition according to the first power value of the operating condition, the operating condition, and the actual temperature distribution coefficient of the turbocharger corresponding to the actual value of the operating condition comprises the following specific steps: The first preset parameter, the second preset parameter, and the third preset parameter are respectively used as 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 weight of the simulated temperature distribution coefficient of the turbocharger corresponding to the operating condition, and a weighted sum is performed to obtain the objective function of the operating condition.

9. The turbocharger temperature PID coordinated control method according to claim 1, characterized in that: The specific method for optimizing the turbocharger temperature PID parameters according to the optimal operating conditions is as follows: According to the optimal working conditions, determine the actual value of the optimal working conditions; The optimal working condition and the actual value of the optimal working condition are input into the PID controller, and the PID controller is used to obtain a control signal corresponding to the optimal working condition.

10. A turbocharger temperature PID parameter optimization system, comprising 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 to 9 are implemented.

Images