Performance evaluation of non-edible vegetable oils as substitute fuels inlow heat rejection diesel engines

Search for renewable fuels such as vegetable oils, in particular non-edible vegetable oils, has become more pertinent in the context of the fossil fue l crisis and vehicle population explosion. The drawbacks associated with ve getable oils for use in diesel engines call for a hot combustion chamber. T he concept of the low heat rejection diesel engine is gaining prominence fo r adopting vegetable oils as substitute fuels for conventional diesel fuel. Non-edible vegetable oils such as Pongamia oil and Jatropha curcas oil are found to be effective substitute fuels in the low heat rejection diesel eng ine. Esterification, preheating and increase in injection pressures have be en tried for effective utilization of the vegetable oils. Performance param eters such as the brake specific energy consumption (b.s.e.c.) and exhaust gas temperature (EGT) have been reported for varying magnitudes of brake me an effective pressure (b.m.e.p.) with different non-edible vegetable oils a s substitute fuels. The pollution levels of black smoke and NO, have been r ecorded. Combustion diagnosis is also carried out with the: aid of a miniat ure piezoelectric pressure transducer and TDC (top dead centre) encoder.