*3.2.2.4 Speed of sound*

Moreover, organic fluids usually have a low speed of sound because of their large molecular weight, thus, the flowing rate is limited in the expander that largely influences the size of ORC turbines [13]; besides, it causes additional shock wave loss on account of the supersonic phenomenon appeared at the nozzle outlet of the expander.

#### *3.2.2.5 Phase diagram*

The thermodynamic property such as the phase diagram is also significant in the analysis and application of ORC.
