Optimization of Electric Injera Baking Pan by Appending Gray Cast Iron Powder and Performance Evaluation through CFD Simulation

Abstract

In Ethiopia injera is the most dominant meal but, injera baking is an energy intensive process. Currently, electrical energy source is used in and around cities to bake injera, due to environmental impact, health issue, production and consumption time and GHG emission of biomass energy. The convectional injera baking pan (Mitad) is inefficient because of thermal energy loss to the ambient, poor thermo-physical properties of baking pan and geometry of the pan. This research paper intended to optimize the material of the baking pan by forming a composite matrix of Clay soil and Gray Cast Iron powder to reduce the power consumption and time required for injera baking. To attain the main aim of the proposed system, composaite matrix of Clay Soil and Gray Cast Iron with 0%,5%,10%,15%,20%, 25%,30%,35% and 40% ratio were taken to formed injera baking pan. The thermo-physical properties of the composite material were determined to analyze heat transfer interaction of injera baking system. Initial heat up time and temperature distribution over the top surface of the baking pan were investigated through ANSYS Fluent simulation. The optimum ratio of composite matrix was selected through comparative method based on heat up time and temperature parameters. The simulation result was valideted by comparing it with related previous experimental work. The simulation result revales that as the composite matrix ratio increases the heat up time required to achieve 180℃ decreases. At 9.667 𝑚𝑖𝑛 time period the baking pan reachs the desired temperature when the amount of gray cast iron is above 15%. The heat up time highly decline when the amount of gray cast iron increase from 15% up to 25%, but further increasing the amount, only 1.3 second decreases. When the pan thickness increases the heat up time increases and also when the electrical power input increases the heat up time decreases. The result revels that, the optimum combination of thermo-physical proprties which gives lower time and uniform temperature distribution over the baking pan is obtained when the composition ratio is 25%, when the baking pan thickness is 15 𝑐𝑚 and electrical power input is 3 𝐾𝑊. The heat up efficiency of the selected composite matrix ratio (25%) reaches 80.5%. The result clearly indicates the time required for heat up, idle and baking as well as the temperature distribution mainly affected by the thermo-physical properties, thickness and power input