Performance analysis of an air standard Diesel cycle with Biodiesel/Diesel blends

摘要

This study aims to examine the influences of heat loss characterized by a percentage of fuel's energy on the performance of biodiesel, Diesel, and their compound in an air standard Diesel cycle. The variations in power output and thermal efficiency with compression ratio, and the relations between the power output and the thermal efficiency of the cycle are presented. The results show that the power output as well as the efficiency where maximum power output occurs will decrease with the increase of intake temperature. For a fixed maximum cycle temperature, the diesel has the largest maximum power output and the maximum power output of B20 (20% biodiesel + 80% diesel) is closed to that of biodiesel. Moreover, the relation for the efficiency is: diesel > B20 > biodiesel. The relation for the compression ratio at which the maximum power output (or maximum efficiency) occurs is: biodiesel > B20 > diesel. In other words, for biodiesel fuel, the system has to operate under higher compression ratio. The results obtained in the present study are of importance to provide a good guidance for the performance evaluation and improvement of practical Diesel engines.