Establishing the Method of Evaluation and Layout Optimization of Crank Case Blow-by Circuit for 3 Cylinder Diesel Engine

摘要

The objective of the diesel engine development program is not only providing the maximum thermal efficiency but also to meet future stringent emission targets. The focus should be on controlling and reducing the unburned emissions, especially blow-by emission apart from controlling burnt emissions. In some extreme cases blow-by may contribute up to 50% of the total oil consumption of the engine. These blow-by emissions are the responsible phenomena for the engine operation, the economy and ecology expressed through the oil consumption and oil change interval rates. Engine breathing system is the most complex circuit within the engine, the air entrapment into space above oil in engine system is pushing more oil from sump. This should be avoided. In effect of controlling these factors the engine breathing system should be properly designed and maintained. In addition the oil content in the blow-by gas which is supplied to the separator and leads back to the intake manifold has a significant influence on the oil consumption and emissions if not separated and drained back. This paper discusses the experimental study aimed at a better understanding of empirical relationship between the gravitational forces with respect to engine tilt angle for evaluating the accurate blow-by measurement and various circuit possibilities for controlled oil throw from the engine. Viable option from the world best practices to control the oil thrown out is discussed in this paper.