Comparative Study of Three Modes of Flue Gas Treatment for Power Plants

Abstract

Flue gas treatment systems have been widely installed in power plants to recover the remaining energy from the exhaust flue gas and to address pollutant emissions by heating the cleaned flue gas. In this study, three modes of flue gas treatment are compared by economic analysis in which the capital cost of the added equipment is taken into account. In addition, the influence of the flue gas treatment system on the operational pressure of the condenser is also analyzed. The results show that flue gas treatment systems can heat the cleaned flue gas effectively. Treatment system with feedwater-gas and steam-gas heaters can obtain remarkable economic benefit and have good adaptability to different operational parameters. In addition, the capital cost of the added heat exchangers is acceptable. Under 100% turbine heat acceptance conditions, the relative variation ratio of the thermal efficiency could be increased by 0.33%, whereas it can be decreased by 0.18% when the outlet temperature of the cleaned flue gas increases by 8°C.