World’s first bus powered by liquid nitrogen hybrid engine
31 May 2017
The hybrid bus, called CE Power, runs on both diesel and liquid nitrogen and has completed a series of trials to bring it closer to the road.
CE Power has been built by engineers at HORIBA MIRA as part of an Innovate UK consortium led by Dearman and including Air Products, Cenex, Coventry University, Manufacturing Technology Centre, Productiv Ltd and TRL (Transport Research Laboratory).
The bus is the world’s first to be powered by liquid nitrogen and utilises alternative propulsion to address urban air pollution. It features a high-efficiency, zero emission Dearman engine powered by liquid nitrogen, alongside a conventional diesel engine. Its hybrid system enables the bus to reduce noxious tail-pipe emissions, improving the local air quality.
When driving at 20mph or less, the liquid nitrogen – stored in a low pressure insulated cylinder – is warmed up to the point at boiling point until it creates enough pressure to drive the multi-cylinder Dearman engine. Once the bus reaches 20mph, the diesel engine kicks in because at this speed the bus requires less effort from the engine to operate.
Martin Watkinson, Technical Lead on the project at HORIBA MIRA, said “the hybrid nature of CE Power demanded a sleek systems integration process. Our engineers worked to ensure the liquid nitrogen system operates seamlessly and safely with the diesel engine, in addition to carrying out the whole vehicle thermodynamics modelling and the overall vehicle control and testing.
“The completion of these trials paves the way for the use of liquid nitrogen more widely in the automotive sector, and takes the UK one step closer to stamping out harmful emissions for good.”
David Sanders, Commercial Director at Dearman commented “as the UK wrestles with dangerous levels of urban air pollution, a bus that runs on ‘thin air’ represents a significant breakthrough. The Dearman Engine has the potential to significantly improve the efficiency of both buses and HGVs, reducing fuel consumption and cutting pollution. Crucially it can provide a cost effective alternative to other emerging zero emission technologies, whose environmental performance if often offset by complexity and cost. This successful trial could be the first step towards rolling out a British innovation to the streets of the UK and around the world.”
The trial runs were completed at HORIBA MIRA’s engineering facilities in Nuneaton and included components and full system testing along with an engineered drive cycle to simulate a standard bus route with stops.