Final State Tank Homework: Solving E_out,mass Integral

[Art_]

Homework Statement

Given a tank filled with gas, you are to pump out a given amount and find the final state of the tank. Given the volume, gas (non-ideal), amount of gas in tank, flow rate, temperature and pressure, all at state 1. We can find density at state 2 from the tables, but we need another quantity. So we can also solve for enthalpy.

Homework Equations

E_out,mass = $\int h + V/2 + gz dm$
The KE and PE can be neglected due to high flow rate, so the equation simplifies to
E_out,mass = $\int h dm$
but since h is not constant I am confused how to integrate this, and find h.

The Attempt at a Solution

I am trying to integrate numericaly but am not sure how to approch finding the intermidiate values of h.

Thank you for the help.

 

[Simon Bridge]

Well what does h depend on?

 

[Art_]

Well h=u+pv, with u being the internal energy and p pressure and volume is constant for the tank.

 

[Simon Bridge]

Well you need to express the things that change with m in terms of m... or, express dm in terms of the things that change.