Power from a hot gas stream with multiple superheaters and reheaters

Abstract

In this paper we explore the opportunity to maximize the production of power in a steam-turbine power plant by properly configuring the hardware at the interface between the stream of hot gas produced by the furnace and the steam that circulates through the power producing cycle. The interface consists of four heat exchangers, superheaters and reheaters, in parallel flow and counter flow. The search for better configurations is based on constructal design, and consists of searching for the distribution of heat exchanger surface (number of heat exchangers, types, sizes) such that the total power output of the turbines is maximum, subject to fixed total size for the heat transfer surface, and fixed maximum allowable steam heat exchanger wall temperature. The emergence of the more effective configurations is documented along with the migration of the spot of maximum temperature along the flow path.