Advances in Recuperator Technology for Gas Turbine Systems

For high-speed micro gas turbine plants for electrical power and heat generation, a recuperator is needed to obtain a high thermal efficiency. The recuperator receives heat from the exhaust gas and preheats the compressor discharge air before it enters the combustion chamber. Such plants contribute to an ecological and environmentally friendly energy production. This paper considers recent advances in recuperator technology. Recent investigations have shown that with prime surfaces like corrugated wavy channels ones, it would be possible to attain high heat exchanger effectiveness without added weight penalty. However, with efficient heat transfer surfaces, the inlet/outlet manifolds design also become more important for the overall performance of the recuperator. Usually customers require recuperator with high effectiveness and low total pressure drop (within certain design requirements). Also, a request on compactness is commonly at hand. All these matters make recuperator an interesting and challenging device for thermal science investigation. A brief introduction and literature review is presented followed by discussion of recuperator thermal-hydraulic performance modeling and testing. Also surface selection procedure to achieve good balance between heat transfer and pressure drop is described. Other important topics such as material aspect and fabrication methods are also delineated.