SCR Structure Optimization And Simulation Analysis Based On Uniform Design

With the development of the society, environmental pollution caused by human activities is becoming more and more serious. In recent years, the atmospheric pollution such as hazy weather has attracted more and more people’s attention to environmental protection. With the steady growth of motor vehicle ownership, the motor vehicle exhaust emission plays more and more important role in the air pollution. Diesel engines are widely used because of the advantages of good power performance and fuel economy, etc, but particles and NOx emissions are serious, especially NOx emissions, occupied high proportion in the exhaust emissions. In order to satisfy the diesel EURO4emission regulations, the technical solutions of optimize the combustion in cylinder and aftertreatment technology are widely used in domestic.The uniformity of air flow and spray is higher, the nitrogen conversion efficiency of catalytic converters. In this paper, by using the experiment and simulation, factors which influence the uniformity have been studied, optimized the product structure and injection installation location. During the catalytic purifier simulation analysis we take the carrier as a porous medium. The resistance characteristics of a variety of specifications carrier have been studied by experiment. Got the fitting formula on resistance characteristics and its correctness and reliability have been verified.Using the resistance characteristic fitting formula, the flow simulation for the catalytic converter has been carried out, optimized the perforated pipe configuration angle、perforation rate、carrier blocking cover shape、end cover shape and carrier position. For optimized structure which has higher flow uniformity, the spray simulation has been carried out. The injection cases include different injector installation position and angel.Using the spray simulation, we got three injection scheme which have higher uniformity. According to the regulations of GB17691-2005,we carried out the NOx conversion efficiency experiment.