Analysis of Regenerative Heat Exchanger for Microturbine

A “regenerator” is a special purpose counter-flow heat exchanger used to recover waste heat from exhaust gases. In such heat exchangers the energy storage medium is alternately heated by hot combustion products and cooled by the air supplied to the combustion chamber. This type of heat exchanger can have a thermal efficiency of over 90%, transferring almost all the relative heat energy from one flow direction to the other. The study is aimed at the development of an efficient regenerative system for gas turbine engines. The proposed design is based on static chambers regenerator with porous ceramic foam as heat transfer/storage media. A numerical model was developed for theoretical analysis and identification of the parameters controlling the performance of a regenerator. The pressure drop and the heat transfer efficiency were calculated and compared for two porous media types: foam type and squared honeycomb.