船用柴油机相继增压系统进气均匀性提升仿真设计

Simulation Design of Air Intake Uniformity Improvement For Marine STC Diesel Engine

为了确保V型相继增压柴油机在改变工作增压器数量时,两侧中冷器的进气能够保持均匀性,对某船用相继增压柴油机进气系统进行了多轮设计与计算流体动力学(Computational Fluid Dynamics,CFD)仿真优化。在此过程中,重点评估了柴油机在单增压模式和三增压模式下,两侧气流分布的均匀性、中冷器进气截面气流流速的均匀性以及压降情况。经过结构优化后,两侧进气流量的最大偏差仅为0.23%,两侧中冷器进气截面流速均匀性指标的最小值达到了0.883,集气腔和中冷器端盖的最大压降为18.2kPa,这些指标处于较优水平。随后,进行了试验验证,其结果表明,在不同增压模式下,两侧中冷器进气的均匀性趋势与仿真结果较为吻合,满足实际使用需求。

In order to ensure the uniformity of the air intake of the two side intercoolers when changing the number of working turbo-chargers in a V-type sequential turbocharged diesel engine,multiple rounds of design and CFD simulation optimization were conducted on the air intake system of a certain marine sequential turbocharged diesel engine.During this process,the uniformity of air flow distri-bution on both sides,the uniformity of air flow velocity in the air intake section of the intercooler,and the pressure drop condition were emphatically evaluated under single turbocharging and triple turbocharging modes.After structural optimization,the maximum deviation of air flow on both sides was only 0.23%,and the minimum value of uniformity index of air flow velocity in the air intake section of both side intercoolers reached 0.883.The maximum pressure drop of the gas collection chamber and the intercooler end cover was 18.2kPa,which was at a relatively optimal level.Subsequently,experimental verification was also conducted,and the results showed that under different turbocharging modes,the uniformity trend of air intake on both sides was in line with simulation results,meeting practical use requirements.