All:

I am attempting to perform a calculation showing the dynamic effects on a main steam piping system after rapid closure of the turbine emergency stop valves. Any suggestions on how to do this using a simplistic static analysis and a more rigourous dynamic analysis? Does anyone have a spreadsheet which can perform a static analysis to calculate the forces? Can CAESAR perform the dynamic analysis and, if so, how is the method applied?

Many thanks,

Bill Huggan

e-mail: william.huggan@snclavalin.com

Bill, there is an article in COADE's June 1994 newsletter that covers this topic.
It prescribes a method for estimating the unbalanced pressure load, and walks through the time-history analysis.
This link will take you there.
http://www.coade.com/newsletters/jun94.pdf
To conservatively estimate a static equivalent response, I would take the calculated unbalanced load, multiply by 2 and apply it statically. Note that CAESAR II will require that you create the load case(s) containing this force.
Feel free to email me if you need more assistance.

Bill,

You may find the following of interest:

a. Fluid Transients in pipes. Estimation of maximum pressure and forces in steam lines.

http://www.esdu.com/graphics/dataitem/86015a.htm

b. Pipenet - Transient Module - Case Study 2

http://www.sunrise-sys.com/trncase02.htm

c. Bechtel - Technical Paper - Effects of Turbine Stop Valve Characteristics on Steam Hammer Loads in Combined Cycle Power Plants. Julie M. Jarvis, Karen I. Baker, Allen T. Vieira, Bechtel Power Corporation. 1999 ASME Pressure Vessels and Piping Conference, Boston, MA.

regards