Westport Innovations says it's introduced the first generation of enhanced spark-ignited (ESI) natural gas system. This new approach to natural gas combustion technology is designed provide a "downsized" natural gas solution that is cost competitive while providing similar levels of power, torque, and fuel economy to a larger diesel engine.
Using 100% dedicated natural gas as fuel, Westport's new technology optimizes the combustion and thermal efficiencies of the engine by taking advantages of the positive properties of natural gas.
Westport's new combustion system and components have been undergoing testing and offer ready integration into OEM applications globally. The Westport ESI combustion system is targeted at sub-9-liter engines for Class 6 and 7 trucks applications and is also adaptable for sub-2-liter applications for use in automotive and non-automotive applications.
The new technology is optimized for spark-ignited engines, and improvements in combustion and thermal management compared to typical spark-ignited natural gas engines ultimately enhance the engine's reliability, Westport says.
The new technology is designed to provide up to 10% improvement in power and torque over the base diesel engine. Higher performance from a spark-ignited natural gas engine compared to a diesel engine potentially allows a 4-liter natural gas engine to replace a 6-liter diesel engine, which results in substantial mass reduction.
Westport says the new technology will allow it to achieve comparable fuel economy to a diesel engine, with the help of cooled exhaust gas recirculation. It's designed to provide up to 40% brake thermal efficiency (a measurement of how much fuel is converted to useful energy.) Typical spark ignited natural gas engines have approximately 25-30% brake thermal efficiency and diesel engines have approximately 41% brake thermal efficiency.
The new technology also is designed to provide up to 5% weight reduction compared to the base diesel engine.
By using 100% natural gas, there is no requirement for diesel particulate filter or selective catalytic reduction systems. This allows cost and weight reduction over base diesel engine.
Westport is currently in various stages of development and negotiation with several vehicle and engine OEMs for ESI applications in medium-duty truck and automotive applications.