Measured and Predicted Performance of a Downsized, Medium Duty, Natural Gas Engine
With environmental policies becoming ever more stringent, there is heightened interest in natural gas (NG) as a viable fuel for medium to heavy duty engines. Typically, the industry has seen minor changes to the base engine when converting to run on NG, which, in turn historically provides degraded performance. In utilizing the positive properties of NG, Westport Fuel Systems has developed the High Efficiency Spark Ignition (HESI) combustion technology that has been shown to significantly improve performance. The HESI technology leverages a proven combustion system that is capable of generating a knock resistant charge motion while cooling the flame face. In conjunction with high boost for driving high pressure exhaust gas recirculation (EGR), this technology demonstrates the possibility for downsizing strategies while maintaining performance.