Abstract
Geothermal energy resources are abundant in Japan, and are expected to actively use. But most of the geothermal resources are liquid dominated and have been delayed development. The porpouse of this work is effective energy conversion from geothermal resources. In order to apply the helical screw expander to the total flow geothermal system, influence of the quality at the expansion process are investigated. Then, the practical relationship between the built in pressure ratio and the expansion ratio at the adequate expansion process are obtained. This expression facilitates the computation of the theoretical work and the theoretical efficiency and is useful for understanding the performance of the screw expander.
