Boiler output flow rate?

[deangardner]

I have an interesting problem that a few of us in the office have been struggling with.

You have a simple water storage cylinder that is heated to produce steam. It flows through 4" pipework to a pump some 200 meters away and is then exhausted into atmosphere. Trying to work out what the steady state pressure would be x point along the pipe. This seems to rely on knowing the velocity at the 4" exhaust from the boiler. You can calculate this from knowing P1 at the Pump and P2 at the boilder, but the boiler also acts as a pump and will add some additional velocity to the system. The pump is 40m3 at atmospheric conditions and pumps down to 0.001mbar where the velocity will be 2m3/hour.

Essentially we have two pumps in series with no pump curve for the steam generator...

Any help would be greatly appreciated.

 

[deangardner]

Okay the temp the boiler is being heated to is 200 degrees c. It is trace heated at 150 degrees. the pump at 200 meters away has a pump rate of 40 meters cubed per hour at atmospheric conditions and 2 meters cubed per hour at it's ultimate pumping pressure which is 0.001 mbar. The pump will have a continuous pressure from the boiler at 200 degrees C and will not be able to reach 0.001 mbar, and there lies my problem. What will be the steady state pressure though the 4" pipe?

 

[racookpe1978]

The boiler's exhaust goes to a "pump" ?

Or to a steam turbine of what efficiency doing what against what kind of load?

Please make up your problem's mind: Are you running a 4 inch pipe (what schedule) or a metric problem with a 100 mm nominal ID, or a 4 inch "pipe".


A 4 inch pipe 700 feet away won't be a steady-state problem starting from 200 deg C, even if traced heated to 150 deg C - it will lose heat and condense down to saturated water+steam no cooler than 150 C. More likely between 150 C and 200 C. Do you have saturated steam at the boiler outlet? If so, what pressure? (Hey - It's your problem/homework. 8<)

Do you think you have a constant pressure down the pipe through the turbine? How accurate do you need the answer?

 

[IRstuff]

Please refrain from double posting. You posted this question in thread404-375919

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