Engine Performance and Emission Characteristics of Dual-Fuel Diesel Engines with Biodiesel and Low-Calorie Gas Fuels

摘要

Engine tests were conducted by using dual-fuel diesel engine fuelled by low-calorie gas which simulates wood-pyrolysis gas and biodiesel. Effects of operational parameters such as the fuel-quantity ratio, or the injection start timing, etc. on engine performances and exhaust emissions were clarified. The results show that under a constant-load condition, an increase in gas-fuel quantity causes a decrease in a break thermal efficiency due to a decrease in combustion efficiency and due to a decrease in specific heat ratio. However, when the equivalence ratio of gas fuel is more than a certain value around 0.25, a decrease in unburned emissions is observed.