RVAmeche,
in this forum you can find several references to Prode Properties since the library includes several equilibrium (HEM) and non-equilibrium (HNE) models,
there is an Excel page with VBA code for API HEM (posted by PaoloPemi) but (as far as I know) the procedures included in the library...
the value dT/dP is not constant over a range of pressures,
a better solution is to calculate H1(tin,Pin) and then t(H2,P2) where H2 = H1
for that you need a table with the properties (H) of Silane,
suppliers as AirLiquide can provide these tables.
As alternative you may run a software, for...
Morten,
no problems about different opinions about applications of SRK vs PR equations of state, these EOS are available in almost all simulators and one can test both,
by the way many papers suggest SRK over PR for natural gas mixtures.
At some conditions positive dT/dP may occour but for such...
can't you model the valve with a flash operation such as H-P and a proper EOS such as Soave Redlich Kwong ?
Joule-Thomson calculated at initial t, p provides dT/dP at initial conditions, it is NOT constant over that pressure range,
better to integrate enthalpy or another property to estimate the...
ISO 18453 has the advantage to give a "certified" accuracy within the allowable range of application (both usual and extended) which is good.
As noted by zdas04 a chart may result difficult to read and real accuracy in some cases may be questionable.
Mike,
the original post did ask a method for calculating the latent heat of a mixture
>I am trying to get a value for latent heat of a mixture.
and Hv = SUM(Wi*Hvi) where Wi is the incipient vapor fraction is a correct answer
in my opinion the method proposed by Morten
>Set the pressure to...
Mike,
the method described by apetri Hv = SUM(Wi*Hvi) where Wi is the incipient vapor fraction (see above posts) should returns the same values as that described by Morten, they both return "istantaneous" values (as mentioned by apetri),
You seem to be inferring your conclusion from the...
which version of Mathcad ?
I have read that there is a link with Prode Properties, see
http://communities.ptc.com/community/mathcad/chemical_engineering/blog/2012/12/16/mathcad-links-with-prode-physical-properties
Prode has many features and it should be able to do all what you need.
Paolo,
to answer your question, I do not know of any point in API std. discussing this topic,
perhaps you may contact the API Subcommittee on Pressure-Relieving Systems
http://mycommittees.api.org/standards/cre/scprs/default.aspx
I have read they have been discussing that model (numerical...
thanks BigInch and zdas4, I did suppose something as nonlinear distribution of pressures (and related densities) along the pipe segment but I was unable to explain the origin of the 2/3 rule of thumb.
