DESIGN AND INVESTIGATIONS OF A MICRO-TURBINE FLOW PART

摘要

The co-generative micro-power plant with the HFE7100 as a working medium was designed and built for experimental investigations. The heat output of the plant was assumed equal to 20 kW, while the electric output amounted to about 3kW. In the paper a multi-stage micro-turbine with partial admission of all the stages is described in detail and the results of the particular experimental investigations and numerical calculations are shown, followed by an appropriate discussion and conclusions. The flow calculations were performed using ANSYS package and finally the axial multistage turbine was chosen. This allowed to apply typical nozzle and blade profiles. The turbine consists of 5 similar (almost identical) stages with constant section blades, the only difference being the increase of the admission arc (number of nozzles) in the successive stages. The rotor speed was assumed equal to 8000 rpm, mean rotor diameter -100 mm and blade height -10 mm. The stream lines, pressure and temperature distribution in the nominal and off-design conditions are presented and discussed in the paper. The micro-turbine was built and tested experimentally. The turbine performance was calculated for HFE7100 but also for air and nitrogen as a working medium for testing purposes. In the first stage of experiments the turbine behaviour was checked using these gases and the results were compared with the calculation data. The results of the experiments correspond very well with the appropriate CFD calculation data.