The Development of Control Algorithm for the Dual-Fuel Engine of a Biogas Tractor (Part 1)

Basic Engine Data and Prototype Algorithm

Abstract

Using biogas to partially replace diesel fuel in agriculture tractors seems a good solution to reduce greenhouse gases and other pollutants. For this reason, a research project to convert a tractor to dual-fuel operation was initiated; this paper's specific aim was to develop a control algorithm feeding biogas to the engine's intake manifold. The effect of biogas addition on engine performance, focusing on break specific heat consumption and fuel replacement rates, was first studied. Then several load estimation methods were assessed and the Manifold Absolute Pressure (MAP) sensor was chosen as a main load detector. Finally, a prototype algorithm was built upon an engine control unit and was tested. The algorithm was able to change biogas flow with engine speed and load, without knock and misfire.