# Thermodynamics - Calculate power and dimensions of piping

1. Sep 29, 2013

### NathanLeduc1

1. The problem statement, all variables and given/known data
500 kg/hr of steam drives a turbine. The steam enters the turbine at 60 bara and 500C at a linear velocity of 5.0 m/s. After driving a set of turbine wheels to generate shaft power, the steam exhausts from a pipe that is 10 m below the entrance pipe at 35.0 m/s and at 2.5 bara and 225C. The turbine has an exposed area of 20 m^2 with an average temperature (Ts) of 105F while the factory average air temperature is 75F. The average heat transfer coefficient, h, is 2.5Btu/(hr*ft^2*F) and the heat loss form the turbine can be calculated by q = hA(Ts - Tair).
a) How much power (rate of work) is delivered to the turbine's shaft?
b) What is the area of the pipe at the inlet and outlet?

2. Relevant equations
q=hA(Ts - Tair)
U + (1/2)v^2 + gz = Q - w

3. The attempt at a solution
I've calculated the heat loss from the turbine to be 16150 Btu/hr. However, I have absolutely no idea where to go from here. I would love to provide a more detailed attempt but I am completely at a loss as to how to even begin this problem. Thank you.