Performance and an optimisation control scheme of a heavy-duty diesel engine fuelled with LNG-diesel dual-fuel

Natural gas is one of the most promising alternative fuels owing to the abundant sources, low price, environment friendly and high octane number. Compared with compressed natural gas, liquid natural gas (LNG) is more suitable for heavy-duty vehicles because of the high energy density. In order to study the performance and exhaust emissions of LNG-diesel dual-fuel heavyduty engine equipped with a common rail injection system, the brake specific fuel consumption (BSFC), smoke density, HC, CO, CO2 and NOx emissions of the dual-fuel and diesel are compared and analysed based on bench tests of a diesel engine. Experimental results show that, the BSFC, HC and CO emissions of dual-fuel increase sharply compared with diesel under light loads. In order to improve the performance and exhaust emissions under light loads, an optimisation control scheme, in which the dual-fuel engine runs in the original diesel mode under light loads and in dual-fuel mode under medium and heavy loads, is proposed and analysed. © 2018 Inderscience Enterprises Ltd.