Gas Stagnation Conditions

[JoeChem]

Greetings,

I am attempting to model a steam distribution system - lots of pipe, elbows, valves, etc. The system essentially boils down to a 10 in main steam supply header feeding (28) 2 inch distribution lines each terminating with a perforated pipe sparger.

Ideally, one would assume the T & P conditions in the 10 inch pipe to be stagnant and allow the compressible gas flow solution for the 2 inch lines to develop based on inlet conditions. As the conditions in the 10 inch pipe are not really stagnant, I am unsure how to evaluate if the zero flow assumption is reasonably valid for my system.

Will a comparison of the static pressure head and velocity head of the flowing steam in the 10 inch line be an appropriate tool for the analysis?

Any help/insight will be greatly appreciated.

JoeChemn

 

[TD2K]

I would calculate the flow through the 2" lines as you suggested, assuming stagnant conditions in the 10" header. Then, go back with the sum of the individual flows through the 2" headers and see if that total flowrate through the 10" supply header significantly affects the inlet pressure to each 2" lateral.

If it does, you'll need to do some trial and error work. If it doesn't, you are finished.