An adiabatic open feedwater heater in an electric power plant mixes 0.2 kg/s of steam at 100 kPa and 160°C with 11.5 kg/s of feedwater at 100 kPa and 50°C to produce feedwater at 100 kPa and 60°C at the outlet. Determine the outlet mass flow

Respuesta :

Answer:

[tex]v=\frac{0.04149}{\pi D^2}[/tex]

Explanation:

-The mass flow rate at the outlet is equal to the sum of the mass flow rates of the constituents:

[tex]\dot m_3=\dot m_1+\dot m_2\\\\=11.5 \ kg/s[/tex]

#Outlet velocity is determined from the outlet's mass flow rate, the outlet area and the specific volume from table A-4

-Let the outlet pipe's diameter be [tex]D[/tex] meters.

-We apply the saturated liquid approximation:

[tex]v_o=\frac{4\dot m_3\alpha_3}{D_3^2\pi}\\\\=\frac{4\times 11.5\times 0.001017}{D^2\pi}\\\\=\frac{0.04149}{\pi D^2}[/tex]

Hence, the outlet's velocity is [tex]v=\frac{0.04149}{\pi D^2}[/tex]