Amount of condensate formed of start up
Amount of condensate formed of start up
(OP)
Can anyone point me in the right direction on how to calculate the amount of condensate generated on start up of a cold pipeline.
I have superheated steam being piped 800 odd metres. I need to calculate how much condensate is going to be produced on start up assuming a cold pipeline.
Obviously this is going to be a tranisent analysis, but beyond that I am a bit lost as to where to start. I am also a bit scared of how to deal with phase change, superheated to saturated and saturated to condensate.
Any nudges or pointers in the right direction would be greatly appreciated.
I have superheated steam being piped 800 odd metres. I need to calculate how much condensate is going to be produced on start up assuming a cold pipeline.
Obviously this is going to be a tranisent analysis, but beyond that I am a bit lost as to where to start. I am also a bit scared of how to deal with phase change, superheated to saturated and saturated to condensate.
Any nudges or pointers in the right direction would be greatly appreciated.





RE: Amount of condensate formed of start up
Good luck,
Latexman
RE: Amount of condensate formed of start up
RE: Amount of condensate formed of start up
how much steam/energy will it take to heat the piping from ambient temp to operating temp or above the condensing temp? because at least (most likely more) that much steam will condense. once the piping is at normal operating temps, then the rate of condensate should diminish.
use caution when warming up cold steam piping.
hope this helps!
-pmover
RE: Amount of condensate formed of start up
You've already received a valid tip by pmover.
You might find useful info at the link below.
h
RE: Amount of condensate formed of start up
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Good luck,
Latexman
RE: Amount of condensate formed of start up
RE: Amount of condensate formed of start up
So be conservative in your calculations and don't forget valves or other appurtences in the piping that have to heat up too.
rmw
RE: Amount of condensate formed of start up
RE: Amount of condensate formed of start up
RE: Amount of condensate formed of start up
Typically, auxiliary steam is used to pre-heat the piping at very low flows
Letting superheated steam directly into the piping will create such a thermal shock that could easily cause the pipe to break and damage supports and other equipment.
So: check the start-up sequence of the plant, see what steam is used for start up and pre-heating.
Once the system is pre-heated, then superheated steam will be allowed.
There are two completely different condensation rates:
1. pre-heating (aux steam) - high condensation, low flow
2. normal operation (super heated steam) - low condensation, high flow
saludos.
a.
RE: Amount of condensate formed of start up
Large valves will need drain points themselves - I've often seen these blended in with the bypass piping. Example: you warm up the piping upstream of MS-1 (between the boiler outlet and the turbine cutout valve) by blowing the condensate out through a drain point in the bypass piping around MS-1. The steam trap for the piping can be at the same tie-in point.
RE: Amount of condensate formed of start up
Abeltio,
Yes, the lines will be preheated, but beyond that, no start up sequence has be determined. Preheat rates and durations are yet to be worked out. I guess I am just trying to get a rough idea of how much condensate could form in the line for preliminary steam trap design.