Performance of Mini-Ecoboy

The figure to the right shows one of the experimental results of the relationship between engine speed, indicated and generated power at 600 and 700 deg C of heater wall temperature and 0.8 MPa of mean pressure. Helium is used as the working gas. In this figure, indicated power increases in proportion with increasing of engine speed. Also, when the heater wall temperature was set to 600 deg C, the maximum generated power reached about 2 W at 1550 rpm of engine speed. Oppositely, when the heater wall temperature was set to 700 deg C, the maximum generated power reached about 5 W at 1880 rpm.

However, the Mini-Ecoboy has not reached to target performance yet. Because, the friction loss of the piston drive mechanism is too strong, and the performance of the seal devices is not enough.