Simulation of Performance of Direct Injection Diesel Engine Fuelled with Oxygenate Blended Diesel 2007-01-0070
Blending an oxygenate with diesel fuel modifies chemical and physical properties that can alter the engine operating parameters, combustion and emission levels. In this paper an effort has been made to simulate the performance of a direct injection diesel engine fuelled with oxygenate blended diesel. In this simulation the CI engine cycle was simulated for both diesel and oxygenate blended diesel fuel with a closer duration of each crank angle degree. The thermodynamic property at each crank angle is calculated based on the first law of thermodynamics. The fluid motion inside the engine cylinder is considered for simulation.
Heat release was calculated using WIEBE's heat release model considering two-zone combustion. The gas-wall convection heat transfer is calculated using ANNAND's heat transfer model considering combustion chamber temperature swings. In the gas exchange model, gas flow rates during intake and exhaust systems were calculated.
To validate the simulated results, experiments were conducted in a single cylinder direct injection diesel engine using a blend of 1.5%(by volume) of Diethylene glycol dimethyl ether (Diglyme) oxygenate and diesel. Addition of oxygenate has resulted in considerable decrease in the fuel consumption and increase in the thermal efficiency for the power outputs equivalent to that of diesel fuel. The combustion and performance parameters were studied and their trends are found to be satisfactory.
Findings from the present work include:
An oxygenate correction factor has been formulated as the ratio of oxygenate blended fuel input to the base fuel input in order to calculate the equivalent power output as that of the base fuel.
A load correction factor has been formulated as the ratio of base fuel input for a power output to the base fuel input for the optimum power output in order to calculate the power output at various fuel inputs.
Combustion parameters such as peak pressure, peak cycle temperature, heat release rate and heat transfer were calculated for various fuel input.
The synthesized results of performance such as fuel consumption and thermal efficiency for various power output have been found and they are closely agreed with the experimental investigations.