Abstract
A prototype machine for a next generation microturbine system applying a simplified humid air turbine system has been developing for its laboratory evaluation. Design target of electric output is 150kW, electrical efficiency is 35% LHV. A low NO_x combustor which applied a lean-lean zone combustion concept and water lubricated bearings were developed for the prototype machine, and power conversion system was integrated with water cooling Insulated Gate Bipolar Transistor. The main feature of this microturbine system is utilization of water for improvement of its electric output and electrical efficiency. Full speed test with no load, and rated load test without WAC and HAT were done successfully. 135kW electric output with the efficiency of more than 33% was obtained in the rated load test. Operation tests for WAC and HAT which were carried out under the condition of 63% load as a preliminary test showed significant effects on increase in electrical efficiency of 3.0 point% and electric output of 20%.
