Fuel type estimation using fuel system parameters
Balasubramanian, Shambhavi MSME, Purdue University, May 2016. Fuel Type Estimation Using Fuel System Parameters. Major Professor: Peter H. Meckl, School of Mechanical Engineering. A number of factors are responsible for an increased interest in alternative fuels for transportation and other uses. Alternative fuels, such as biodiesel and vegetable oil, are widely available and both fuels can be used to power a diesel engine. Biodiesel has higher bulk modulus, sonic speed, density and viscosity than regular diesel fuel. The fueling, injection timing, and fuel spray and consequently the emission characteristics of biodiesel are affected by these properties, when used in a diesel engine. Estimation of fuel type is critical to the performance of the engine. Knowing the fuel type allows the engine controller to determine the proper fuel quantity, injection timing, injection duration, amongst other settings, to provide the best balance of performance, emissions and fuel economy. Based on the fuel type, the calorific value will change. Knowing this, the engine controller can use the best air fuel mix and injection pressure for that type of fuel. The type of injection system and the fuel properties (such as the density of fuel, viscosity, bulk modulus and sonic speed) affect fuel injection characteristics. The objective of this project is to estimate fuel properties that can determine whether the fuel is diesel or biodiesel. Bulk modulus is the critical parameter used for characterizing the fuel. This thesis seeks to devise suitable strategies to estimate the bulk modulus to determine the fuel type. Using sensors available on the Cummins XPI fuel system, this is accomplished by observing the effect that bulk modulus has on pressure rise associated with pumping events for different fuels. In this research, the pressure rise is extracted from filtered raw rail pressure data. It has been found