The Development of Control Algorithm for the Dual-fuel Engine of a Biogas Tractor (Part 2)

——Biogas Flow Optimization Based on Engine Parameters——

Abstract

Environmental problems and high fossil fuel prices have encouraged the authors to build a biogas-diesel dual fuel agricultural tractor. In this paper, finding the optimal biogas flow answering a multi-objective function was targeted. Four engine parameters were taken into consideration and thoroughly studied : brake specific heat consumption, diesel reduction rate, nitrogen oxide (NO_x) emissions and carbon monoxide (CO) emissions. Extensive engine testing was done to assess the effects of biogas addition on these parameters ; and based on the results an algorithm was developed to find the optimal biogas flow for specified objectives. Several objectives were set and corresponding biogas flow look-up tables were generated using the optimization algorithm. An engine task simulation was used to test the look-up tables and the results were considered satisfactory.