Thermal Analysis and Cost Evaluation of Boilers Considering Different Insulation Materials and Fuel Oil

Abstract

The energy cost of heat transferred across the walls of a gas-fired and water tube boiler adopting the fibreglass and calcium silicate as insulating materials is analyzed adopting finite volume numerical scheme. A two-dimensional view of the heat transfer process is analyzed considering varied insulation thickness across the walls where results show from the point of critical thickness that the fibreglass material is a better energy saver compared with the calcium silicate material for varying insulation across the boiler walls. Result reveals the annual energy cost accrued per litre of fuel consumed at critical insulation point are ₦6.630 and ₦8.250 respectively for the gas-fired boiler utilizing LPFO for Fibreglass (FG) and Calcium silicate (CS) respectively. While the annual energy cost accrued per litre of fuel consumed at critical insulation points are ₦17.004 and ₦21.511 respectively utilizing Diesel Oil for FG and CS materials of insulation respectively for a gas-fired boiler. This paper reveals the cost of energy required using the LPFO with fibreglass insulation for gas-fired boiler is more economically viable compared with water tube boilers. However, the pollutants emission produced from LPFO is higher compared to diesel oil leaving a higher footprint in the environment.