08-16-2017, 10:03 PM
sir,
The present energy situation has stimulated active research interest in non-petroleum, renewable, and non-polluting fuels. some of the options considered by researcher's as an alternative fuel for SI engine are Hydrogen ethanol blend, DME blended LPG fuel, alcohol gasoline fuel blends etc..
The performance and pollutant emission of a four-stroke spark ignition engine using hydrogen ethanol blends as fuel have been studied by Department of Mechanical Engineering, College of Engineering, University of Babylon, Babylon, Iraq. The tests were performed using 2, 4, 6, 8, 10
and 12 mass% hydrogen ethanol blends. Gasoline fuel was used as a basis for comparison. The effect of using different blends of hydrogen ethanol on engine power, specific fuel consumption, CO and NOx emission was studied. The results show that the supplemental hydrogen in the ethanol air mixture improves the combustion process and hence improves the combustion
efficiency, expands the range of combustibility of the ethanol fuel, increases the power, reduces the s.f.c., and reduces toxic emissions. The important improvement of hydrogen addition is to reduce the s.f.c. of ethanol engines.
In another study, a spark ignition engine operated with DME blended LPG fuel was experimentally investigated. In particular, performance, emissions characteristics (including hydrocarbon, CO, and NOx emissions), and combustion stability of an SI engine fuelled with DME blended LPG fuel were examined at 1800 and 3600 rpm. Results showed that stable engine operation was possible for a wide range of engine loads up to 20% by mass DME fuel. up to 10% DME, output engine power was comparable to that of pure LPG fuel. Exhaust emissions measurements showed that hydrocarbon and NOx emissions were slightly increased when using the blended fuel at low engine speeds. However, engine power output was decreased and break specific fuel consumption (BSFC) severely deteriorated with the blended fuel since the energy content of DME is much lower than that of LPG. Furthermore, due to the high cetane number of DME fuel, knocking was significantly increased with DME.
In another[/size] study, the effects of ethanol gasoline (E5, E10) and methanol gasoline (M5, M10) fuel blends on the performance and combustion characteristics of a spark ignition (SI) engine were investigated. In the experiments, a vehicle having a four-cylinder, four-stroke, multi-point injection system SI engine was used. The tests were performed on a chassis dynamometer while running the vehicle at two different vehicle speeds (80 km/h and 100 km/h), and four different wheel powers (5, 10, 15, and 20 kW). The results obtained from the use of alcohol gasoline fuel blends were compared to those of gasoline fuel. The results indicated that when alcohol gasoline fuel blends were used, the brake specific fuel consumption increased; cylinder gas pressure started to rise later than gasoline fuel. Almost in the all test conditions, the lowest peak heat release rate was obtained from the gasoline fuel use.