Question: SingleFluidProperties?

[B-LIE]

I' trying to figure out a way to take advantage of Clapeyron.jl to find key properties of substances without having to look up in Poling et al. "The Properties of Gases and Liquids" all the time.

A simple way could be to create a SingleFluid model and read the properties. As an example:

julia> mod = SingleFluid("water")
julia> mod.properties
Clapeyron.SingleFluidProperties(Mw = 18.0153, Tr = 647.096, rhor = 17873.7, lb_volume = 1.44152e-5, Tc = 647.096, Pc = 2.2064e7, rhoc = 17873.7, Ttp = 273.16, ptp = 611.655, rhov_tp = 0.269472, rhol_tp = 55497.0, acentricfactor = 0.344292, Rgas = 8.31437)
julia> mod.properties.Mw
18.015268000000003

So I recognize Mw (molar mass), Tc (critical temperature), Pc (critical pressure), acentricfactor.

Question 1: what are

• Tr ? (same value as critical temperature)
• rhor ?
• lb_volume ? Lower bound for molar volume??? Used to constrain molar volume in computations?
• rhoc? Probably molar density at critical point??
• xtp where x is T, p, rhov, rhol ... triple point values?

Question 2: are any of these parameters related to polarity? I understand that polar forces are important with water...

Question 3: would it be simpler to go into some database/JSON file of Clapeyron.jl to find these values? Instead of looping through substances, creating a model, and then reading the properties...

Question 4: is there a list of substances which work with SingleFluid (or other) EoS:s?

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Why these questions? Two reasons:

• I'm trying to figure out a way to avoid having to "fire up" my Kindle reader to look up values in Poling et al.
• I'd like to try to recreate the "corresponding state" model of Lee et al. for saturation pressure for substances, using SymbolicRegression.jl or similar tools. (Essentially, relating Antoine correlation coefficients to critical values + perhaps some polarity measure)

[longemen3000]

On the property names:

• Tr and rhor are the reducing temperature and density respectively. They are used to calculate τ = Tr/T and δ =rho/rhor. Most newer multiparameter EoS use the critical point as the reducing point, but some older EoS use other values not related to the critical values. It is a property only related to the EoS implementation.
• lb_volume is the lower bound volume, minimum volume that can be evaluated by the EoS. We estimate those based on some heuristics.
• xtp properties: yes, triple point.

None of those properties are related to polarity. In particular, we only store properties useful to calculate fluid properties. For example, we store the triple point because it is the lower limit for the saturation curve ancillary. If a model needs to calculate a saturation pressure under the triple point (not physically possible, but numerically useful) we can use triple point estimates.

I need to check the CoolProp csvs to see if they store any polarity measure.

The list of substances supported by Clapeyron is the same as the substances supported by CoolProp https://coolprop.org/fluid_properties/PurePseudoPure.html#list-of-fluids
om other EoS, it depends on the databases. Probably a function would help in this particular case.

[B-LIE]

The list of substances supported by Clapeyron is the same as the substances supported by CoolProp

Hm. I found, e.g., "Air", "n-Propane", and "Water" in the list of substances at the "coolprop.org" list.

Since SingleFluid("water") works, I thought that SingleFluid("air") and SingleFluid("n-propane") would work. But no such luck.

So I'm curious:

1. Is there a list of supported substances for Clapeyron "out-of-the-box"? Like, obviously "water", "hydrogen", "oxygen", etc.
2. How do I make the substances in CoolProp work with SingleFluid?

NOTE: I extracted out the substances of CoolProp into a vector of strings. Then I cheated and had MS Co-pilot write a Julia function to test which of those substances work with CoolProp, leading to:

13-element Vector{String}:
 "Ammonia"
 "Argon"
 "CarbonDioxide"
 "CarbonMonoxide"
 "Hydrogen"
 "HydrogenChloride"
 "HydrogenSulfide"
 "Methane"
 "Nitrogen"
 "Oxygen"
 "SulfurDioxide"
 "Water"
 "n-Octane"

while 111 of those substances are not supported by SingleFluid.

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Out of curiosity, I compared the properties of SingleFluid vs. CoolProp for "Ammonia":

Overall, SingleFluid seems to use fewer decimals in numbers. There is a slight deviation for triple point pressure. Liquid and gas molar densities are not listed in CoolProp, but appears for SingleFluid.