Pollution Research Paper

DIESEL-TO-NATURAL GAS ENGINE CONVERSION WITH LOWER COMPRESSION RATIO

GEORG GEORGOVICH TER-MKRTICHIAN, ANDREY MIKHAILOVICH SAYKIN, KIRILL EVGENIEVICH KARPUKHIN, ALEXEY STANISLAVOVICH TERENCHENKO AND JULIA GEORGOVNA TER-MKRTICHIAN

Abstract

While converting diesel to gas engine the power decrease is compensated by forced induction. In order to prevent detonation geometric compression ratio is decreased, which results in decreased indicated efficiency. The difference between geometrical and actual compression ratios is analyzed. Intake valve closing by the same value before or after bottom dead center causes similar decrease in actual compression ratio in comparison with geometrical compression ratio. Filling parameters are compared upon standard and reduced intake periods. It is demonstrated that early opening of input valve makes it possible to decrease actual compression ratio, decreasing detonation threshold and preserving high geometrical compression ratio and high indicated efficiency. Short intake provides increase in mechanical efficiency due to decrease in pumping losses.