柴油机有效压缩比与参数变化之探讨

探讨双燃循环大型海运低速柴油机其重要参数的名义压缩比与有效压缩比[1]、理想绝热压缩压力与实际压缩压力[2]的差异,利用精确量测间隙容积(Clearance volume),探讨理想与实际的压缩压力比较差异,利用此一正确的机器设计参数,探讨如何加强维持最大有效压缩比以达设计最高压缩压力,提高低速柴油机正常出力。     

Scavenging a sub-chamber type CNG fueled engine

The sub-chamber type gasoline engine was suggested to be a type of clean engine, but the presence of residual gas in the sub-chamber was a serious fault. In this experimental study, the CNG direct injection method was applied to scavenge residual gas from the sub-chamber. The CVC (constant volume chamber) is divided into the sub-chamber and main-chamber and used as the main experimental apparatus. Because each combustion chamber of the CVC has an injector, the injector can be used freely, at the same time or individually. Therefore, the scavenging efficiency can be improved by changing injection times for the sub-chamber. The experimental results demonstrated that when all the fuel was injected into the sub-chamber, the combustion duration was shortened by 30% compared to that of injection into the main-chamber. Although residual gas was observed in the CVC, when the frequency of injections into the sub-chamber increased, good combustion characteristics were obtained.     

QN-1型全流消光式烟度计有效光路的试验研究

对近期所研制的QN—1型全流消光式烟度计有效光路的测定进行了较为详细的叙述。通过试验方法确定了QN—1型消光式烟度计的有效光路。从试验结果分析，QN—1型消光式烟度计的有效光路定为15．88较为合理，汽油机的清新空气扫气压力为0．15MPa以下。通过ZDC—20kW NF125发动机台架重复试验看出，所得结果基本一致。