Calibration and Improvement of a Fuel Reformer Vaporization System

Abstract

The combustion of fossil fuels in the presence of nitrogen produces Nitrogen Dioxide (NO2) and Nitric Oxide (NO), together referred to as NOx, which are harmful to both human health and the environment. Exhaust gas recirculation (EGR) mixes vaporized fuel with exhaust to increase the heat capacity of the gas, which lowers the combustion temperature and with it, the peak operating temperature of the engine. This reduces NOx emissions and is standard in many engines. EGR can be used in conjunction with reformation, which converts exhaust gas into another source of energy using the hydrogen in the fuel. A testing system was designed, built, and tested to characterize a reformer fueling system. Trials were conducted at various operating pressures to calibrate the micrometer handle metered valve with the fuel mass flow rate. This data will be used to deliver specific amounts of fuel into the reformer depending on desired engine conditions. In addition to the characterization of the valve, the existing vaporizer was redesigned to ensure that the fuel is fully vaporized over the characterized range of mass flow rates. A more powerful 500 Watt vaporizer was designed. In the future, the characterized system will be evaluated in engine tests using a non-oxygenated #2 ultra-low sulfur diesel (ULSD) over a modified type C1 off-road vehicle ISO 8178 eight-point testing cycle.