Utilizing low grade waste heat in combined-cycle power plant by absorption chiller

Abstract

Performance improvement of a conventional power plant has been received much attention due to energy crisis and global warming problems. Utilization of low-temperature waste heat is considered a promising alternative to enhance the efficiency of power generation. Presently, an absorption chiller has been applied to recover heat from low-temperature energy sources such as bleeding steam and low pressure steam. The aim of this work is to study the use of an exhaust gas from a steam boiler in a power plant, as the low temperature heat source, for an absorption chiller to produce chilled water. Simulations of the absorption chiller process consisting of generator, absorber, condenser and evaporator, were performed using a flowsheet simulator taking into account detailed heat transfer processes. LiBr was represented an absorbent in the absorption chiller. The performance of the absorption chiller process was analyzed. The suitable condition for the absorption chiller operation to recover the waste heat and economic comparison are also identified.