CP_FLUID_PARAM

This function fetches fluid metadata text from CoolProp for a given fluid name and parameter key. It is useful for displaying identifiers and descriptive attributes in spreadsheet reports.

The lookup is:

s = g(\text{fluid}, \text{param})

where the output s is a string metadata value returned by the CoolProp database.

Excel Usage

=CP_FLUID_PARAM(fluid, param)

fluid (str, required): CoolProp fluid identifier (for example Water or R134a).
param (str, required): Requested metadata key (for example formula or CAS).

Returns (str): Metadata string value for the requested fluid parameter.

Example 1: Water chemical formula string

Inputs:

fluid	param
Water	formula

Excel formula:

=CP_FLUID_PARAM("Water", "formula")

Expected output:

"H_{2}O_{1}"

Example 2: Water CAS metadata string

Inputs:

fluid	param
Water	CAS

Excel formula:

=CP_FLUID_PARAM("Water", "CAS")

Expected output:

"7732-18-5"

Example 3: R134a aliases metadata string

Inputs:

fluid	param
R134a	aliases

Excel formula:

=CP_FLUID_PARAM("R134a", "aliases")

Expected output:

"R134A"

Example 4: Carbon dioxide InChI string

Inputs:

fluid	param
CO2	INCHI_String

Excel formula:

=CP_FLUID_PARAM("CO2", "INCHI_String")

Expected output:

"InChI=1S/CO2/c2-1-3"

Python Code

Show Code

import CoolProp.CoolProp as CP

def cp_fluid_param(fluid, param):
    """
    Retrieve a CoolProp metadata string for a specified fluid and metadata field.

    See: https://coolprop.org/apidoc/CoolProp.CoolProp.html#CoolProp.CoolProp.get_fluid_param_string

    This example function is provided as-is without any representation of accuracy.

    Args:
        fluid (str): CoolProp fluid identifier (for example Water or R134a).
        param (str): Requested metadata key (for example formula or CAS).

    Returns:
        str: Metadata string value for the requested fluid parameter.
    """
    try:
        # CoolProp uses case-sensitive metadata keys. Accept common variations from spreadsheet users.
        def normalize_param(p):
            if not isinstance(p, str):
                return p
            p = p.strip()
            if not p:
                return p

            # Handle common InChI name variations (e.g. INCHI_String, inchi_string)
            low = p.lower().replace("_", "").replace(" ", "")
            if "inchi" in low:
                return "InChIKey" if "key" in low else "InChI"

            # Common metadata keys in CoolProp are typically case-sensitive.
            # Try removing underscores/spaces and using the value as-is.
            return p.replace("_", "").replace(" ", "")

        try:
            return str(CP.get_fluid_param_string(fluid, param))
        except Exception:
            normalized = normalize_param(param)
            if normalized != param:
                try:
                    return str(CP.get_fluid_param_string(fluid, normalized))
                except Exception:
                    pass
            # last effort: try lower-case key
            try:
                return str(CP.get_fluid_param_string(fluid, str(param).lower()))
            except Exception as e:
                return f"Error: {str(e)}"
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

fluid *

CoolProp fluid identifier (for example Water or R134a).

param *

Requested metadata key (for example formula or CAS).