mojo4king
Chemical
- Sep 6, 2009
- 4
Hi,
20m straight length horizontal pipe (60 mm internal diameter), steam flows at rate 0.5 kg/s, at midpoint there is a valve in the line. inlet pressure to this section of line is 5 bar (gauge), pressure at end of line is 3 bar (gauge). mass quality of steam is 0.8 and 2 phase flow occurs in the line.
I have calculated the mass flow of liquid and vapor in the line, the frictional pressure drop (N/m2) for the horizontal tube (without valve) using lockart martinelli correlation and also predicted the flow pattern at entry to the valve.
However,k the part I am having a problem with is..When calculating the pressure drop across the valve.After calculating the homogeneous parameters and inserting them into the pressure drop equation which is: -dp/dz= [?*u *du/dz] + [2*f*?*u^2/d] + ?*g*sin?
First term in the equation i took equal to zero (no change in velocity assumed), but for the last term (in bold), do i take theta(?) as equal to zero as it is a horizontal pipe?
My solution is attached.
Thanks for any help!
20m straight length horizontal pipe (60 mm internal diameter), steam flows at rate 0.5 kg/s, at midpoint there is a valve in the line. inlet pressure to this section of line is 5 bar (gauge), pressure at end of line is 3 bar (gauge). mass quality of steam is 0.8 and 2 phase flow occurs in the line.
I have calculated the mass flow of liquid and vapor in the line, the frictional pressure drop (N/m2) for the horizontal tube (without valve) using lockart martinelli correlation and also predicted the flow pattern at entry to the valve.
However,k the part I am having a problem with is..When calculating the pressure drop across the valve.After calculating the homogeneous parameters and inserting them into the pressure drop equation which is: -dp/dz= [?*u *du/dz] + [2*f*?*u^2/d] + ?*g*sin?
First term in the equation i took equal to zero (no change in velocity assumed), but for the last term (in bold), do i take theta(?) as equal to zero as it is a horizontal pipe?
My solution is attached.
Thanks for any help!
