Regenerative Heat Exchangers for Microturbines and an Improved Type

The principle of operation of regenerative heat exchangers (“regenerators”) is explained, and the characteristics are compared with those of recuperators. The design rules for heat exchangers in general are stated, and the particular design rules forregenerators are discussed in more detail. Problems in past regenerators have led to an improved type, which is described. Design studies of a regenerator for a typical microturbine at three different effectivenesses are given, and leakage rates estimated. At the highest regenerator effectiveness, and using the improved compressor and turbine design permitted by this effectiveness, it is estimated that a 300-kW microturbine should achieve 50% electrical efficiency.Copyright © 2003 by ASME