
Tata 5L natural gas engine with Westport GEMDi™ (gas enhanced methane diesel) technology.
Westport Innovations Inc. has unveiled its newest proprietary technology that has shown a significant breakthrough on dual-fuel performance — Westport gas enhanced methane diesel (Westport GEMDi™). Westport GEMDi technology enables engine original equipment manufacturers (OEMs) to offer a fully integrated, high performance engine optimized for dual-fuel operation.
Westport GEMDi technology has been co-developed with Tata Motors on their next generation 5L engine that is targeted for medium-duty trucks and buses in India. This technology provides fuel flexibility, ideal for regions where natural gas infrastructure is emerging, such as India, and is designed to meet Euro IV and V emissions standards.
“Westport GEMDi is an innovative, low-cost, fully integrated solution with advanced dual fuel performance,” said Thomas Rippon, Executive Vice President of Westport. “Westport GEMDi is the right solution for engine OEMs, such as Tata, that are committed to offering sustainable products utilizing natural gas as a primary fuel, while maintaining diesel-like performance and efficiency.”
“Natural gas trucks and buses are gaining traction in India as national natural gas fueling infrastructure continues to develop,” said Rajendra Petkar, Head Power Systems Engineering, ERC of Tata Motors. “With Westport GEMDi technology, we are pioneering the next generation natural gas product that will be efficient, economic, and flexible in fuel, enhancing customers’ driving range.”
Background on Dual-Fuel Technology
A dual-fuel engine typically relies on conventional diesel engine hardware. Modifications to the base diesel engine allow operation with natural gas fuel. Under dual-fuel operation, natural gas is introduced at low pressure and mixed with the intake air. Diesel fuel is introduced directly into the combustion chamber near the end of compression stroke and is used to ignite a lean mixture of natural gas and air (i.e. no spark plugs are required). Since dual-fuel engines are closely configured based on a diesel engine, it allows them to provide higher performance (torque and power) and efficiency on natural gas fuel as compared to a traditional spark ignited natural gas engine. Based on Westport analysis, typically a dual-fuel vehicle would operate at about 60% average fuel substitution ratio (i.e. fraction of total fuel energy contributed by natural gas), with the remaining coming from diesel fuel. Higher fuel substitution ratios are possible through improved engine design and control. Dual-fuel engines are capable of reverting back to 100% diesel operation over the entire engine operating range if required.
Westport GEMDi technology advantages compared to conventional dual-fuel technology:
- Optimized for dual fuel operation: The base diesel engine with Westport GEMDi is optimized for dual-fuel operation through fuel and combustion system modification and sophisticated engine monitoring and control. In typical aftermarket retrofits, the dual-fuel operation may not be fully optimized.
- Fully integrated: Westport proprietary natural gas components will be integrated directly into OEMs’ operations, providing OEMs with the highest quality standards and reliability to customers.
- Higher performance and more robust: Westport GEMDi technology has proven to have power and torque similar to its base diesel engine performance, which is an improvement over conventional dual-fuel technology.
- Improved fuel economy: Westport GEMDi technology is designed to deliver improved fuel economy compared to conventional dual-fuel technology.
Tata’s 5L natural gas engine featuring Westport GEMDi was displayed at India’s Auto Expo in New Delhi, India, from February 7 to 11. Upon successful completion of the development phase, commercialization with Tata Motors is expected to follow, with Westport supplying key natural gas engine components.
(Source: Westport)