High temperature heat exchangers for power plants: Performance of advanced metallic recuperators

An overview is given of recent high temperature heat exchangers technology developments, both in the thermal-fluid dynamic innovative solutions and in the materials. Gas turbine recuperative cycles, microturbine systems, indirectly fired cycles and high temperature gas cooled nuclear reactors are the investigated fields where this kind of heat exchangers is used. Some common technological features join all of them, namely: new surface geometry design and burdensome material requirements. The most important difficulties arising from the specific conditions of each heat exchange system are pointed out, together with their possible solutions. A comparison among them is presented and some suggestions are proposed about expanding the boundaries of the individual research fields, to get a wider understanding of common critical issues. Finally, the paper focuses on the main current challenges to be faced in the near future in order to get a competitive development of such systems.