The Innovative Westport HPDI 2.0 Natural Gas Injection System – Delivering Well to Wheel CO₂ Savings in Heavy Duty Commercial Vehicles Fuelled by Liquefied Natural Gas

Authors

K. Philibert-Palmer, C. Dicken, D. Mumford, Westport Fuel Systems, Vancouver, Canada; M. Harper, Delphi Technologies, London

Year

2019

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 811

Summary

With regulatory pressure on CO₂ emissions from heavy duty trucks increasing rapidly, alternative and complementary technologies to today’s diesel powertrains will be required. Whilst electrification will eventually penetrate the commercial vehicle market, the challenges of energy density vs payload, infrastructure and total cost of ownership will undoubtedly limit the reach of pure Battery Electric Vehicles (BEV) into the heavy duty market in the near term. Alternative solutions are therefore required to bridge the gap, particularly for high duty cycle long-haul mission profiles. The Westport High Pressure Direct Injection (HPDI) 2.0 natural gas fuel injection system is in the field today delivering 20-100% real world CO₂ reduction in heavy duty trucks. Westport’s proprietary injector design allows combustion of natural gas in a Diesel cycle thereby delivering equivalent power density and combustion efficiency. This enables the exploitation of the lower CO₂ potential of natural gas without the penalty associated with moving to the Otto cycle. Including liquefied natural gas (LNG) systems, to achieve appropriate energy density, the HPDI 2.0 system makes for a very attractive value proposition. The enabler for the combustion process is the use of a diesel pilot injection with main gas injection from a single injector. This presents some unique challenges to the complete system including the injector design. Some of these challenges and the associated solutions arrived at, through collaboration with Westport’s development partner Delphi Technologies, will be presented.