- #1
aznkid310
- 109
- 1
Homework Statement
Steam flows through an uninsulated pipe at 0.5 kg/s, entering at 5 bar, 440 C and exiting at 3 bar, 320 C. How much energy is lost from the steam per hour?
Homework Equations
Which terms in the energy eqn can drop out? I'm having trouble with that.
Is there only one W?
The Attempt at a Solution
Starting w/ the full energy eqn:
de/dt = Q - W_ + (m_i)[u_i + (p_i)(v_i) + (v_i)^2 + g*z_i] - (m_e)[u_v + (p_e)(v_) + (v_e)^2 + g*z_e]
where Q = vol. flow rate
W = work rate
m = mass flow rate
subscript e = out
subscript i = in
v = velocity
u = specific internal energy
p = pressure
So z_i = z_e = 0
Q = mv = (0.5)(0.6548) = 0.3274?