A thermodynamic approach to the definition of the HAT cycle plant structure

Abstract

An optimization procedure of the Humid Air Turbine (HAT) cycle plant structure is presented here aimed at maximizing the total plant efficiency. The procedure is based on the design optimization of a “basic configuration of the plant” including “basic components” (compressor, turbine, combustion chamber, regenerator and saturator), always existing and connected in the same way in the plant structure, and the heat exchanger section which is viewed as a “black-box” where the heat transfer between hot and cold thermal flows occurs independently of the number and interconnections of the heat exchangers. The optimal boundary conditions between basic components and black-box are determined by means of a suboptimization procedure performed in each step of the main optimization procedure using rules of Pinch Technology and Second Law insights. Rules of pinch technology and second law insights are then used to determine the heat exchanger networks (HENs) within the black-box that fulfill the optimum design conditions at the black-box boundaries. Accordingly, “optimal” structures of the plant are determined by the combination of basic components and “optimal” HENs.