Abstract
Simulation is carried out to find the temperature distributions of working chamber and the temperature fluctuation at the casing wall for the basic study on the scale adhesion problem and the thermal deformation of the screw expander. Furthermore,the mean temperature of the circumferential and the axial direction were calculated to clarify the temperature characteristics. Influence of internal leakage in the temperature distribution of the working chamber is remarkable after the second half of the expansion process .Mean temperatu re and temperature fluctuations of the casing wall including range mentioned above will be appreciated the influence of leakage. Mean temperature distribution in the axial direction causes a large non-uniformity at the supply port side and the circumferential temperature distribution causing large non-uniformity close to the admission end.