Effects of Preheating of Honne Oil (HO) on Injection System, Performance and Emission of a Diesel Engine

摘要

Honne oil (HO) is one of the vegetable oils that have potential for use as fuels for diesel engines. HO is renewable, and is safe and easy to handle. However, at room temperature (30-40℃) HO has a viscosity about 10 times higher than that of diesel. To lower HO's viscosity to the level of diesel's viscosity, a heating temperature of at least 90℃ is needed. At this temperature, there is a concern that the close-fitting parts of the injection system might be affected. This study focused on finding out the effects of preheating of fuel on the injection system. Results show that preheating of HO lowered HO's viscosity and provided smooth fuel flow, but did not affect the injection system, even heating up to 100℃. Nevertheless, heating up to such a high temperature offered no benefits in terms of engine performance. However, heating is necessary for smooth flow and to avoid fuel filter clogging. Both can be achieved by heating HO to 60℃. Combustion analyses comparisons between HO and diesel found that HO produced a lower peak pressure of 26%, a lower maximum heat release rate and a longer combustion period. Over the entire load range, HO combustion produced average CO emissions that were 11% higher, compared with those from diesel combustion.