A 3D simulation model was constructed for a low-speed dual-fuel marine engine based on Converge and the modelling accuracy was verified through engine bench test.The engine operation process under different pre-chamber passage structures and natural gas injection valve structures were simulated,and the potential of parame-ter optimization to improve combustion and reduce emissions was analyzed.The research results on the pre-chamber passage structure show that appropriately increasing the diameter and length of the pre-chamber channel will pro-mote the ignition of the pilot fuel and accelerate the combustion process of the main combustion chamber.However,an excessive diameter will increase NOx emissions and an excessive length will inhibit ignition and in-crease ignition energy loss.Increasing the channel angle also accelerates combustion,but when it is consistent with the scavenging angle,the larger the angle,the higher the NOx emissions.Research results on natural gas injection valves show that lowering the valve position,increasing the injection angle and reducing the valve diameter will reduce methane escape.The injection angle has a great influence on the swirl ratio of the main chamber.When the injection angle is opposite to the scavenging angle,the larger the injection angle,the faster the combustion and the lower the NOx emissions.Moderately reducing the valve diameter can increase the natural gas jet velocity,thereby accelerating combustion.
关键词
双燃料发动机/预燃室/天然气喷射阀/排放特性
Key words
dual-fuel engine/pre-chamber/natural gas injection valve/emission characteristics
维普
万方数据