Confined bed metal particulate heat exchanger

摘要

A recuperative heat exchanger is provided for the efficient transfer of heat between two fluids of differing initial temperatures. In a preferred embodiment, a cross-flow heat exchanger includes an array of parallel tubes that are further disposed within one or more beds of confined metal particulates confined by screens and through which a relatively cold fluid flows. A second relatively hot fluid is directed through the particulate beds in a direction perpendicular to the tube array. Because of the high thermal conductivity of the particulates, heat is conducted across the beds to walls of the tubes which comprise the walls of the confined beds in a direction substantially transversely to the fluid flow. In an alternative embodiment, a counter-flow heat exchanger preferably includes a number of adjacent beds of conductive particulates confined at their top and bottom by screens and on their sides by parallel solid plates. Adjacent plate beds are connected with plenums at opposite ends. A first relatively hot fluid flows between alternating beds in one direction and a second relatively cold fluid flows through alternating beds in an opposite "counter-flow" direction. In all alternative configurations of the heat exchanger, the relative temperatures of the fluids may be reversed.