Brunel University has signed a major development and licensing agreement with Guangxi Yuchai Machinery Company Ltd, the largest diesel engine manufacturer in China, to develop an eco-friendly and fuel efficient hybrid engine for municipal buses.
The deal will allow Yuchai, which supplies 70 per cent of the Chinese bus engine market, to use Brunel’s innovative hybrid engine technology in buses throughout China.
Brunel University’s Vice-Chancellor, Professor Chris Jenks, and Yuchai Chief Engineer, Mr Jie Shen, signed the agreement at a special event on Brunel’s campus. Speaking at the ceremony, Professor Jenks said: “Yuchai is the market leader for diesel engines in the Chinese market and it has already demonstrated its confidence in Brunel by having set up a joint Research Centre here. We look forward to a long and mutually beneficial relationship.”
Mr Jie Shen added: “We are very pleased to sign the commercial agreement with Brunel University on the use of the hybrid technology. We are very confident that we shall be able to convert the patented technology into production.”
The air hybrid system is based on novel Regenerative Engine Braking Stop/Start technology developed by a team of academics in Brunel’s Centre for Advanced Powertrain and Fuels. It is more efficient than an electric stop/start system and can lead to a 10 per cent fuel saving.
In particular, it is compatible with existing vehicle powertrain systems and the production cost is significantly lower, making it suitable for high volume production.
Professor Hua Zhao, Director of the Centre for Advanced Powertrain and Fuels in the School of Engineering and Design, said the innovative technology works by exploiting the functional capability of a current bus engine to operate temporarily as an air compressor.
"It captures and stores braking energy as compressed air during braking using a production engine braking device commonly installed in heavy goods vehicles. The stored compressed air can then be used to restart the engine through an air starter motor.
"Unlike standard bus engines, this means that the bus can turn off its engine when stationary and then restart it using regeneratively captured braking energy, leading to significant fuel and cost savings.
"In addition, the compressed air can be used to provide instant boost to overcome the turbo-lag that is often associated with the sluggish performance and black smoke seen from city buses."
“The air hybrid system can also minimise the use of the engine-driven air compressor on buses resulting in further fuel saving and reduced maintenance,” explained Brunel’s Dr Tom Ma.
"When it is installed on a city bus, the system is expected to produce a 10 per cent fuel economy benefit. Unlike an electric hybrid system, the Brunel air hybrid system can be added on to production engines and will work with existing transmission systems.
"Our air hybrid system brings the most effective use of compressed air during the braking process, and ultimately leads to lower fuel consumption and less pollutants."
The Brunel-Yuchai team is currently developing a prototype of the air hybrid system. A demonstration vehicle will then be built to highlight the economic and environmental benefits to Chinese bus operators ahead of expected mass production.
The Brunel technology is also attracting interest from parties in the USA and India.