【作者】 丰琳琳；

【导师】 邓康耀；

【作者基本信息】 上海交通大学 ， 动力机械及工程， 2007， 硕士

【摘要】 二冲程低速柴油机工作过程与增压系统的研究对我国实现自主配机和性能改进提高具有重要的意义。本文以上海沪东重机股份有限公司制造的MAN B&W公司二冲程低速柴油机7K90MC-C为主要研究对象,在详细分析了该机主要结构的基础上,建立了计算模型,实现其性能仿真。通过对二冲程低速柴油机模拟计算中的主要子模型的详细分析,建立了对其进行准确性能模拟的方法。文中分析了二冲程低速柴油机的扫气模型对发动机模拟计算的影响,并指明了采用“组合排气”模型可以实现对7K90MC-C扫气过程的精确模拟;探讨了现代二冲程低速柴油机的放热规律模型,根据7S60MC-C和6S70MC两种机型的气缸压力试验数据,分析了放热规律特征参数,建立了二冲程低速柴油机放热规律模型,结果证明该模型与试验结果相吻合;建立了涡轮增压器配机方法,按该方法选取的7K90MC-C柴油机涡轮增压器参数与国外提供的设计参数相符。在建立模型的基础上,对船用二冲程低速柴油机7K90MC-C的额定负荷和部分负荷进行了计算,结果表明计算与试验结果具有较好的一致性,验证了计算模型的正确性。并对该机的排气正时进行了优化分析,探讨了降低扫气口高度对二冲程柴油机扫气过程的影响。以解决二冲程低速柴油机的起动及低负荷问题为目的,计算研究了其鼓风机匹配问题,进行了鼓风机的选型和优化分析,探讨了鼓风机两台全开和只开一台时的切换规律。更多还原

【Abstract】 Study on work process and turbocharging system of two-stroke low-speed diesel engine is significant for marine engine matching and performance improving of our country. Based on the analysis of engine structure, an engine performance simulation model was developed according to the MAN B&W 7K90MC-C two-stroke low-speed diesel engine, which was made by Shanghai Hudong Heavy Machinery Co., Ltd...The sub-models in the simulation of two-stroke low-speed diesel engine were analyzed in detail and the method to accurate simulation was developed. This paper studied the effects of different scavenging models on simulation. The results showed that the“combined scavenging”model is more suitable for the 7K90MC-C diesel engine. The combustion model of nowadays two-stroke low-speed diesel engine was discussed. According to the measured cylinder pressure of 7S60MC-C and 6S70MC diesel engines, the characteristics of heat release rate were analyzed. A new combustion model was set up and the results were consistent with experiments. Turbocharger matching method was developed. The turbocharger parameters of 7K90MC-C diesel engine chosen by this method were similar with the data provided by the foreign company.The performances of 7K90MC-C diesel engine at part and rated load were simulated using the developed model. The results showed that the更多还原