Low Cost Recuperator Concept for Microturbine Applications

Abstract

Currently there is a lot of interest in microturbines, with projections that these small turbogenerators will be produced in large quantities in response to the needs of the deregulated power generation market. First generation, low pressure ratio microturbines, based on state-of-the-art technology, require a recuperator to achieve an efficiency of 30 percent. With the recuperator representing 25–30 percent of the turbogenerator cost, major efforts are underway to establish new heat exchanger concepts, with low cost being paramount. In this paper a simple primary-surface recuperator concept is suggested that meets the major requirements, which include compact size and light weight, minimum number of parts, amenable to high volume automated fabrication, and packaging flexibility in either a wrap-around annular geometry or rear mounted cube form. This paper includes recuperator background information, technology bases, details of the proposed surface geometry, fabrication considerations, specific size and weight, cost target goals, and heat exchanger configurations for integration with microturbines in the power range of 5 to 75 kW.