Measurement and control of natural gas mass flow in a dual-fuel engine operating at partial load through sonic nozzles
In this paper, the part load operation of a dual fuel engine operating at 1500 m above sea level and its control using sonic flow meters for natural gas fuelling are presented. Dual fuel operation was established by retrofitting the intake system of a commercial Diesel engine with a port-injected gaseous fuels system, which was comprised by calibrated orifices working under sonic flow conditions. Natural gas mass flow rates throughout the orifices were estimated assuming the isentropic one-dimensional theory for perfect gases.