Cheope: A Tool for the Optimal Design of Compact Recuperators

This paper presents the organization, theoretical background and application of a new software tool for the optimization of the technical and economical design of microturbine recuperators. The code called CHEOPE (Compact Heat Exchanger Optimization and Performance Evaluation) considered two types of recuperator concept, which proved to be the most promising for microturbine applications: the furnace-brazed plate-fin type and the welded primary surface type. The general design rules for performance evaluation of gas-gas heat exchangers are summarized and specifically applied to these two types of recuperator. Moreover, the cost equation, employed to estimate the capital cost of these types of heat exchanger, is discussed. CHEOPE can be used both for solving the sizing problem and the rating problem. With regard to the former, the code is capable of a special optimization of the recuperator matrix, which takes into account the compactness, the pressure drops and the expected cost of the device. The objective function can be customized according to the designer’s priorities. The tests performed for the validation are presented, and three case studies are illustrated for three different microturbine sizes, for a 50kW, a 100kW and a 500kW machine.Copyright © 2004 by ASME