Abstract：In order to solve the problem of non-uniform exhaust temperature of each cylinder of a 16-cylinder diesel engine, a one-dimensional thermodynamic model is established to simulate and analyze the causes of non-uniformity of each cylinder. An optimization strategy is proposed to use the intermediate pipe and the constant pressure exhaust pipe to reduce the non-uniform of the exhaust back pressure and improve the distribution of the exhaust temperature of each cylinder. The constant pressure pipe scheme has been further optimized. The result of simulation calculation shows that the main reason for the non-uniform exhaust temperature is the interference of the exhaust gas of each cylinder caused by the firing sequence of the diesel engine and the design of the pulse exhaust pipe. The use of the intermediate pipe scheme can improve the mutual influence of the exhaust gas of each cylinder, and the extreme difference of the exhaust temperature of each cylinder is reduced by about 28% compared with the original scheme. The constant pressure exhaust pipe scheme can reduce the non-uniformity of exhaust back pressure of each cylinder, and the exhaust temperature range of each cylinder is reduced by about 40% compared with the original scheme. With the increasing of the total pipe diameter of the constant pressure pipe, the specific fuel consumption of the engine firstly decreases and then increases. The optimized constant pressure exhaust pipe scheme shows that the various indicators of the engine are nearly the same as the original engine, and the exhaust temperature range of each cylinder is reduced by more than 40%, which effectively reduces the non-uniform of exhaust temperature of each cylinder.
Keywords:non-uniformity of exhaust temperature；pulse exhaust pipe；constant pressure exhaust pipe；exhaust interference；specific fuel consumption