FLOWRATE OF OIL OUT BY TRV VALVE FOR SUN RADIATION OF A PIPELINE

[petrona]

THERE IS A PIPE L = 100 METERS,
TWO VALVE ARE CLOSED AT ITS ENDS,

I MUST CALCULATE THE FLOWRATE IN THE TRV VALVE WHEN THE TEMPERATURE OF THE FLUID (OIL) INSIDE RISES BY RADIATION OF TUBE. (Ti=30°C, Tair=40°C, DN 150, L 100m).
SOMEONE CAN GIVE ME A METHOD?

IT FOLLOW MY FIRST APPROXIMATION METHOD
1 SUN RADIATION IS REDUCT BY ATMOSPHERE TO 800W/M2
2 I SUPPOSE THE SURFACE REFLECTS 10% SO REMAIN 720 W/M2
3 I SUPPOSE THAT THERE ARE NOT OTHER HEAT CONVECTION WITH AIR AND ALL THIS POWER IS ABSORBED BY THE FLUID.

De=0.168M, Di=0.154M
L*=1M2/0.168M=5.9524M (ESPOSITION SURFACE)
V*=0.1108M3
MASS*= V*xDENSITY= 0.1108x750= 83KG
DELTAT=Q*/(CpxMASS*)=619/(0.42x83)=18°C
FINAL TEMPERATURE = 48°C
I SUPPOSE THAT THE PIPE DON'T SOTTRACT HEAT TO RISE ITS T
THEN
DELTA V = V°(1+3gDELTAT)=0.0965 M3
FLOWRATE = 0.0965 M3/H = 73 KG/H

THANKS
BYE

 

[Latexman]

petrona,

This is commonly referred to as thermal expansion by ambient heating. It is a well covered topic here. Use the search function and you will find plenty of threads on it.

It is acceptable to provide a small (3/4" or 1") PSV for this case without any supporting calculations.

Good luck,
Latexman

 

[Latexman]

Oh yeah, search in the Safety Relief Valve forum.

Good luck,
Latexman

 

[dcasto]

the flowrate will have no meaning. The relief valve will open and will flow at the rate considering the pressure and physical properties of the fluid. It will only relieve as long as the pressure is exceeded and it will take less than a few 1000's of a % of the lines volume to relieve the pressure.