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Globally, many jurisdictions are working toward greenhouse gas (GHG) emissions standards for medium- and heavy-duty vehicles that will take effect in the next decade and require GHG reductions of up to 25% from 2017 legislated levels. While diesel engines will require increasingly complex improvements, high pressure direct injection (HPDI) of natural gas can provide GHG reductions of approximately 20% (75% or more with renewable natural gas / bio-methane) while preserving the same power density, torque and performance as diesel. This paper will provide an overview of the improvements in the Westport™ HPDI 2.0 components as well as performance and emissions results demonstrated to-date. The potential and challenges of higher injection pressures will be explored while also investigating sources of and methods to eliminate methane venting on the vehicle.

Development status and insight on a “research level” piezoelectric direct injection fuel injection system for prototype hydrogen Internal Combustion Engines (ICEs) is described. Practical experience accumulated from specialized material testing, bench testing and engine operation have helped steer research efforts on the fuel injection system. Recent results from a single cylinder engine are also presented, including demonstration of 45% peak brake thermal efficiency. Developing ICEs to utilize hydrogen can result in cost effective power plants that can potentially serve the needs of a long term hydrogen roadmap. Hydrogen direct injection provides many benefits including improved volumetric efficiency, robust combustion (avoidance of pre-ignition and backfire) and significant power density advantages relative to port-injected approaches with hydrogen ICEs.