Feasibility Study of an Innovative Micro Gas Turbine With a Swiss-Roll Recuperator

Feasibility of an innovative micro gas turbine with heat recuperation has been studied. The proposed core engine has back-to-back rotor configuration formed by a centrifugal-flow compressor and an axial-flow turbine. A newly Swiss-roll recuperator is wrapped around a can-type combustor to recover the exhaust heat, thus reducing the fuel consumption rate and improving the engine thermal efficiency. From the recuperated cycle analysis, thermodynamic requirements at both inlet and outlet of each component were predetermined to evaluate the engine performance. The conceptual design and preliminary analysis to achieve these requirements were made, component-by-component. The thermal design of the Swiss-roll recuperator was also carried out by theoretical analysis, which gives the thermal characteristics of the recupeator, including the trend of effectiveness, thermal requirement of number-of-transfer-unit (NTU) and the preliminary sizing with the number of turns and the width of the flow channels be determined. The characteristics of Swiss-roll recuperator resemble the counter-flow spiral plate heat exchanger and basically have the excellent performance with high effectiveness and low pressure loss. The performance of the proposed micro gas turbine was investigated, and potentially a compact micro gas turbine with thermal efficiency higher than 20% is possible for the power output less than 10 kW.Copyright © 2006 by ASME