What does dead state temperature mean How to determine dead

What does dead state temperature mean? How to determine dead state temparature in a binary organic rankine cycle plant?

What does bottom cycle temparture mean? How to determine bottom cycle temperature in binary organic rankine cycle plant?

How to set the pressure on a binary organic rankine cycle plant if the brine pressure at the outlet of separator is 7.8 bara.

Thanks you for your kind attention and help. Best regards. Handoko

Solution

Dead state is a state of system when,

- System is in equillibrium with pressure and temperature with surrounding,

- System is in chemical equilibrium with surrounding, and

- When system has minimum potential energy and zero velocity.

In brief a state of a system in which EXERGY of a system is equal to null that is 0 is called dead state.

Determining Dead state temperature

Below equation is given to get Exergy of a system which is divided into sub parts,

E= E_k + E_p +E_ph + E₀

E_k= Kinetic exergy

E_p= Potential exergy

E_ph= Physical exergy flow

E₀= Chemical exergy

It is needed to note that, stream does not change its chemical composition; means chemical exergy remains unchanged for inlet and outlet. So we can say that, change of physical exergy that is equal to change in the exergy of stream.

E_ph= h₁-h₀-T₀(s₁-s₀)

Here T₀ is dead state temperature where as, h is enthalpy at inlet and outlet, s is entropy at inlet and outlet, 1 denotes inlet and 0 denotes dead state