Why is it that a working fluid with a high heat of vaporization is used? wouldn't u want to make as large a volume of gas as possible per unit heat? it seems like a high flow rate is what would be conducive as the turbine is spinning at a grater rate.
replied to: skittlesmonkey
Replied to: Why is it that a working fluid with a high heat...
An ideal working fluid has a low heat of vaporization because an ORC works with lower temperatures. With a low vaporization temperature can the fluid vaporize on low temperatures and so will the vapor easily drive the turbine.
A High density is necessary for absorbing more energy from the source, a sufficiently high density at the (low) condensation temperature, so the construction of a large turbine and condenser would be avoided. The difference in temperature between condensation temperature and vaporization temperature is small, so the pressure drop will be smaller.
A high boiling point, a high critical temperature and a low critical pressure of the fluid are also necessary, so the temperature varies between these.