单缸涡流室柴油机净化消声器的设计与研究

Design and research of purifier muffler of single-cylinder swirl chamber diesel engine

非道路柴油机排放标准的不断提高,仅靠机内净化单缸柴油机很难达到排放标准的要求。为了降低单缸涡流室柴油机的排放和噪声,设计优化具有净化和消声作用的净化消声器,以R180涡流室柴油机消声器为研究对象,通过Fluent 14.0软件模拟计算和试验的方法优化催化剂载体内部流场,并对其空气动力学性能、消声性能和催化性能展开研究。试验结果表明:安装净化消声器的整机CO、HC、PM比排放(八工况循环)分别为0.38、0.20、0.48 g/(kW·h),相比于原机分别降低了82.8%、54.0%、14.4%。通过催化剂载体内部流场优化,CO、HC、PM比优化前分别降低了22.7%、26.0%、6.3%;柴油机整机声功率级较原机降低了0.5 d B(A)。均匀的内部流场提高了催化剂的转化效率,延长催化剂的使用寿命。劣化试验后柴油机排放满足非道路柴油机国Ⅲ标准要求,研究成果有助于单缸柴油机降低整机排放和噪声。

Because of the continuous improvement of emission standards for non-road diesel engines,single-cylinder diesel engine is hard to meet the emission standards by using the way of internal purification only. A purifier muffler that has the function of purification and noise elimination is designed and optimized to reduce the emissions and noise of single-cylinder swirl chamber diesel engine. Based on the research of original muffler of single-cylinder swirl chamber diesel R180,the flow field of internal catalytic converter carrier was optimized by simulation analysis and test with Fluent 14. 0,and the aerodynamic performance,acoustic performance and catalytic performance were analyzed by testing. The results of overall emission test showed that the test prototype with the purifier muffler had the advantage of low exhaust emission. With the purifier muffler,the measured values of carbon monoxide( CO),hydrocarbon( HC) and particulate matter( PM) were 0. 38,0. 20 and 0. 48 g/( k W · h) respectively,which were reduced by 82. 8%,54. 0% and 14. 4%respectively,compared with the original muffler. With the purifier muffler that the flow field was optimized for uniformity,the measured values of carbon monoxide( CO),hydrocarbon( HC) and particulate matter( PM) were reduced by 22. 7%,26. 0% and 6. 3% respectively. The engine noise of the purifier muffler was 104. 8 d B( A),which was decreased by 0. 5 d B( A) compared with the original muffler. The results of overall performance test showed that the test prototype with the purifier muffler had the advantages of low power loss,low flow resistance and high noise elimination.The conversion efficiency and life of the catalyst were improved by uniform flow field. After the endurance test,the exhaust emission of the purifier muffler still met the third phase limits. The research results will be helpful to reduce the emissions and noise of single-cylinder diesel engine.