Simulation And Test Verification Of Two-stage Sequential Turbocharging Performance Of TBD234V12 Diesel Engine

Two-stage supercharging technology can greatly increase the supercharging ratio to achieve the purpose of high supercharging.Successive supercharging technology can effectively resolve the contradiction between the diesel engine and the supercharger under low load,and improve the performance of non-design matching working conditions.The supercharging technology combines the advantages of two-stage supercharging and sequential supercharging,which not only can greatly increase the supercharging ratio,but also can change the number of superchargers in operation,thereby improving the working performance of the diesel engine under low load and expanding.The operating range of the diesel engine.In this paper,the TBD234V12 diesel engine transformed into a two-stage sequential supercharging system was tested and optimized for pipe diameter.It was compared with the original engine before being converted into a two-stage sequential supercharging system.The coupling technology of one-dimensional and three-dimensional software was used.The flow field of the exhaust system is further analyzed and studied.The details are as follows:(1)The TBD234V12 diesel engine was tested under steady state and universal characteristics.The GT-Power software was used to establish a one-dimensional simulation model of the TBD234V12 diesel engine.The accuracy of the simulation model was verified based on the test data.(2)The test data obtained under the propulsion characteristics and universal characteristics are compared with the performance parameters obtained from the original machine tests under this characteristic,and it is concluded that the diesel engine uses a two-stage sequential supercharging system in terms of economy and mechanical load.(3)Introduced three common supercharging methods: constant pressure supercharging,pulse supercharging and MPC supercharging,and established one-dimensional simulation of constant pressure supercharging and MPC supercharging models,and optimized structural parameters through one-dimensional simulation calculation.And further multi-variable simultaneous optimization by DOE method to obtain the best structural parameters.Comparing the performance of the optimized constant pressure supercharging model with theMPC supercharging model and the original impulse supercharging model to determine the supercharging method adopted by this machine.(4)Establish a three-dimensional model of the exhaust system,divide the mesh,and import it into the three-dimensional software.By establishing a one-dimensional coupling model for the one-dimensional model;setting up the three-dimensional coupling for the three-dimensional model,Therefore,the coupling between one-dimensional and three-dimensional is performed,and the 2TC mode at 100% condition and the 1TC mode and2 TC mode at 25% condition are simulated and compared.The flow field of the exhaust system is obtained by iterative calculation and convergence.