Search Results

Homogeneous charge compression ignition (HCCI) combustion enables higher thermal efficiency and lower NOx emission to be achieved in internal combustion engines when compared with conventional combustion systems. Control of proportion of high cetane number and low cetane number fuels is an effective technique for controlling ignition timing and load in HCCI combustion. The aim of this paper is to analyze the characteristics of the HCCI combustion of hydrogen, carbon monoxide and dimethyl ether (DME) in a single cylinder engine. A mixture of hydrogen and carbon monoxide with a composition of 67% hydrogen and 33% carbon monoxide called methanol-reformed gas (MRG) was used as the low cetane number fuel and DME as the high cetane number fuel. Both MRG and DME can be reformed from methanol in endothermic reactions. The endothermic reactions make waste heat recovery in fuel reforming possible by using the heat from the exhaust gases.

Homogeneous charge compression ignition (HCCI) combustion enables higher thermal efficiency and lower NOx emission to be achieved in internal combustion engines compared with conventional combustion systems. Adjusting the proportion of high cetane number fuel and high octane number fuel is an effective technique for controlling ignition timing in HCCI combustion. The authors have proposed a new homogeneous charge compression ignition combustion engine system fueled with dimethyl ether (DME) with high cetane number and methanol-reformed gas (MRG) with high octane number in previous research. In the system, both DME and MRG are to be produced from methanol by onboard reformers utilizing exhaust heat from the engine. The research has shown high thermal efficiency of the system over a wide operable range of equivalence ratio.