Low Engine Speed Torque Improvement in Natural Gas Engine: Experimental Observations

Abstract

Diesel engines have always been the first choice as prime movers for commercial vehicles since a long time. However, for the past 20 years, many cities have adopted natural gas–powered vehicles with an aim of reducing air pollution. Thereafter, natural gas–operated engines, have experienced rapid development. With the adoption of natural gas engines many newer technologies were integrated which effectively contributed for reducing engine emissions within target limits. However, with requirements for enhanced comfort features like an air conditioner, pneumatic door, and shock absorbers, and other electric accessories, commercial and passenger CNG vehicles need to have better traction. In many cases, the maximum vehicle speed is limited. The objective of this paper is to study, evaluate, and summarize various approaches, strategies, and technologies developed for enhancing the torque of the engine. Most of these are applicable for a complete range of engine speeds. Integrating them for improving torque at slow engine speeds is a core objective here. Experimental results of a specimen CNG engine are presented, which shows enhancement in the torque as well as engine power at slow engine speed region with turbocharged configurations.