Abstract
In order to improve efficiency of micro gas turbine system, it is imperative to decrease compression work for introducing air. The present study aims to develop an evaporative cooling system applied to a micro centrifugal compressor in order to reduce the compression work. In this paper, the effects of mist introducing conditions, such as mist quantity, mist introducing position in inlet duct, and inlet air temperature, are examined experimentally. In experimental setup, a number of ultrasonic vibrators, which can provide water mist of 3μm number mean diameter, are installed in the mist introducing duct. Experimental results show that the inlet air temperature has noted effects on compressor performance, through the effects on the quantity of evaporated water. The present evaporative cooling system has been proven quite valuable at high inlet temperature condition. There exists a trend that reduction rate of compression work depends strongly on the quantity of evaporated water, which is correlated with the inlet air temperature. Concerning about the introducing position of the mist in the duct, the introduction closer to compressor inlet seems to have a bit of advantage for improving compressor performance than the introduction far upstream.
