Research on thermal-structural coupling and structural optimization of switching valve in booster system

Turbocharging technology is the second milestone in the development of internal combustion engine, which has become an inseparable part of engine technology and has a significant impact on the power and economy of internal combustion engine. The switching valve is a key component in the sequential turbocharging system, which plays a key role in realizing the energy distribution of the parallel turbocharger, the pressure ratio with different engine conditions, the flow regulation and the matching of the full working conditions. In order to explore the influence of different driving torque, gas pressure and temperature on the switching valve of the pressurization system, the steady-state statics and thermal-structural coupling simulation of the switching valve at room temperature were carried out by ANSYS Workbench software. Based on the central composite design method and Kriging method, the size combination and multi-objective response surface optimization model of 15 groups of switching valve design variables are obtained. Under the same conditions, the multi-objective genetic algorithm is used for simulation calculation. The results show that the deformation of the switching valve mainly occurs on the valve plate and the valve shaft under different driving torque and temperature, and it is symmetrically distributed. The distribution of deformation, stress, contact pressure and friction stress of the switching valve under different driving torques are the same. With the increase of driving torque and temperature, the deformation, stress, contact pressure and friction stress of the switching valve increase gradually, and the temperature effect is the most obvious. Compared with the original design size, the optimized structure size can effectively reduce the contact pressure of the switching valve and significantly improve the service life of the switching valve.