Estimation of recovery heat and power conversion from exhaust gas in the small-size combustion furnace using water and hydrocarbons as working fluids

Abstract

The heat transfer between exhaust gas and working fluid in a series of helical tube installed in a combustion furnace was analyzed numerically in order to discuss the development of heat recovery system combined with a small size combustion furnace. The dimensions of the equipment were about 0.49 m³ volume chamber with 2.5 m height chimney where the 250 m helical tube piping was available. The assumption of uniform gas side temperature referenced by the CFD simulation was used for simplify of the gas-side analysis. The inside heat transfer rate with phase change of working fluids were estimated numerically. The amounts of generation vapor and the effective tube length of pressure drop and the isentropic theoretical thermal efficiency on T-s diagram for water and hydrocarbons were also analyze for the discussion in comparison.