Speed of sound in natural gas

[gaswell]

for a piping network (transient simulation with method of characteristics) the engineer requires to produce tables of sound speeds and bulk modulus at different temperatures and pressures, then the program is able to fit values and generate the simulation,
previously we did use constant values from literature,
now my problem being a simple way to estimate these values (speed of sound and bulk modulus) not easily available in GPA manual.
Could you help ?

 

[apetri]

Usually with our tools we put constant values, too.
I do not know simple procedures to estimate these values or extend the range of application (altough they may exist), when required I calculate these values with a equation of state and Prode Properties, see

http://www.prode.com/en/properties.htm

You may do some tests with different equations of state to see how calculated values match those in literature (with our streams we have found good agreement with BWRS)

 

[ione]

http://www.mysolv.com/AGA10CalcOut.asp

Regards

 

[zdas04]

This is a joke, right? Bulk modulus is the reciprocal of compressibility and the literature is full of ways to predict compressibility. For mixtures containing low levels of CO2, H2S, and N2, the GPSA Field Data Book has a very effective closed form technique. If your input gas can have these then use the Hall Yarborough technique with the Turek modification.

The equation for sonic velocity is even easier. You only have to know the adiabatic constant ("k" or "[γ]"), SG, and temperature.

We treated compressibility and speed of sound as constants back when we did these kinds of calculations on slide rules, but I haven't done that within a program in over 20 years.

David

 

[gaswell]

apetri,
I was used to input these values as constants, it seems that this software requires a table of values.
Thanks for the link.

ione, zdas04
I need to estimate properties for liquid phase (see transient simulation with method of characteristics), the request came from the company doing some consulting work for us.
Thank you for the comments, possibly I could calculate points for liquid densities, fit a generic correlation and differentiate to calculate bulk modulus and speed of sound but that doesn't appear very practicable.

 

[zdas04]

The title of this thread is "Speed of Sound in Natural Gas". Forgive us for assuming that you were interested in gas properties. Usually when people want liquid properties of natural gas they ask about LNG. If they are concerned about the properties of other fluids, the specify them.

David

 

[BigInch]

Why have a consultant that can't figure that out?

Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso