Design and Analysis of a Fuel Preheating Device for Evaluation of Ethanol Based Biofuel Blends in a Diesel Engine Application

摘要

With the alarming increase in vehicular population, there is depletion of fossil fuel availability. Hence to overcome the difficulties, alternative fuels are tested and used in parts of the world. One of the difficulties with usage of alternate fuels is their high viscosity in comparison to fossil fuels. To overcome this, preheating of biofuel is a good option as it makes the fuel less viscous. In our research, we have used a helical coil heat exchanger to preheat the inlet fuel using the engine’s exhaust gas, making the system more sustainable since no external energy is used. In order to evaluate the effectiveness of preheating device a simulation study has been carried for the ethanol based biofuels. For simulation work, a set of boundary conditions has been arrived based on the experimental analysis. The results from the experiment such as velocity of air and fuel inlet were utilized as input for simulation work. The simulation study was carried out using Fluent solver, to compare the effectiveness of proposed preheating device for the ethanol blends (E20 and E30). The simulations results are obtained for various temperature and pressure profiles for air outlet, fuel outlet & outer wall of preheating device. These were analyzed and a comparative study between ethanol blends. The result shows that the temperature profile of E30 is slightly higher than E20, this is solely due to viscosity of E20 being higher than E30. With the preheating device the fuel’s viscosity reduces which helps in better fuel flow and improved atomization. Also the preheating of ethanol leads to improve vaporization characteristic and hence the improved combustion can be accomplished. Hence preheating is a viable solution for in biofuels. The focus of the research is to validate the effectiveness of preheating device.