Optimal operating conditions for wet ethanol in a HCCI engine using exhaust gas heat recovery

This study explores optimal operating conditions for power generation from wet ethanol in a HCCI engine using exhaust gas heat recovery. Wet ethanol is a difficult fuel to ignite as it requires high compressed gas temperatures to achieve ignition causing the requirement for substantial intake charge heating. A heat exchanger is retrofitted to a HCCI engine in this study to recover excess heat from the exhaust gases to provide the energy input for intake charge heating. This study builds on prior experimental research by focusing on optimal operating conditions for wet ethanol in HCCI with exhaust gas heat recovery. Operating points include intake pressures of 1.8 and 2.0bar absolute, equivalence ratios of 0.50 and 0.55, combustion timings from just before TDC to misfire, and fuel mixtures from 70% to 100% ethanol (with water being the balance).