Effect of Intake Air and Fuel Heating with Integrated Waste Heat Recovery System for Small Diesel Engine Performance

Abstract

The internal combustion engines are the main consumer among the fossil fuel consumers in the world. 30 to 40% heat of the total heat supplied to the engine in the form of fuel, is converted into mechanical power and the remaining heat is emitted to the environment through exhaust gases and engine cooling systems. This results in to waste of heat, entropy increase and serious environmental pollution, so it is required to utilise waste heat for improving engine system efficiency, power and reduce harmful effects on environment. In this study, experiments were conducted by designing a heat exchanger to heat engine intake air and fuel within predefined temperature range. The effect of air and fuel heating on engine power, bsfc, thermal efficiency and engine smoke intensity is observed. It is observed that by heating incoming air to engine the smoke intensity reduces by almost 50% i.e. from 4-7 BSU to 2-4 BSU, however the effect of air heating on engine power and thermal efficiency is by 2% and 8% respectively. The results of fuel heating have shown that the fuel heating by waste heat recovery system improved engine performance and reduced engine emission. The results of fuel heating have shown that the brake power improved by 12%, thermal efficiency by 8% and reduction in smoke intensity by 62%.