XSolarSalt

Solar Molten Salt properties according to A.B. Zavoico, "Report No. SAND2001-2100", Sandia Labs. Salt composition: 60% NaNO3 - 40% KNO3.

Solar Molten Salt properties according to Sandia Labs, Report No. SAND2001-2100 (see References).

By Fabio Aste, www.linkedin.com/in/fabio-aste/

Visit us at: vast.energy

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Description:

The function determines various thermodynamic properties of Solar Molten Salts composed by 60% NaNO3 - 40% KNO3. Properties are based on Sandia Laboratories data and correlations.

Different possibilities exist for the combinations between the input/output properties:

- h-->T {'H2T','h2T'}. for Temperature [°C] as a function of Enthalpy [kJ/kg].

- T-->h {'T2H','T2h'}. for Enthalpy [kJ/kg] as a function of Temperature [°C].

- T-->rho {'T2rho'}. for Density [kg/m3] as a function of Temperature [°C].

- T-->Cp {'T2Cp','T2cp'}. for Specific Heat [kJ/kg.K] as a function of Temperature [°C].

- T-->mu {'T2mu'}. for Dynamic Viscosity [Pa.s] as a function of Temperature [°C].

- T-->k {'T2k'}. for Thermal Conductivity [W/m.K] as a function of Temperature [°C].

The function is thought to be applied to Molten Salts in their liquid phase, therefore the maximum temperature range is about 220°C-650°C. The advised working range is 260°C-621°C. The correlations validity field is 300-600°C.

Despite XSolarSalt can handle values outside validity field without resulting in an error, it does not mean that they are precise or, more in general, possible.

Solidification occurs at 221°C and crystallisation starts at 238°C.

The average of heat of fusion is: hsl = 161 kJ/kg.

The density variation upon melting is estimated in: +4.6% (Vliquid = 1.046 * Vsolid).

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References:

- Zavoico, A.B., Sandia Labs, Report No. SAND2001-2100, July 2001, “Solar Power Tower Design Basis Document”.

- "Scientific Report: DLR-FB-2021-19 31.08.2021"

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Procedure:

The user shall input the desired function mode and related input. The function will assess that the range is respected, and eventually force the input to fit within, then determine the output.

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Inputs:

The function accepts a thermodynamic property according to the following list:

- Temperature [°C] Range: (220) 246-565 (650) [°C]

- Entalphy [kJ/kg] Range: (329) 351-835 (865) [kJ/kg]

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Outputs:

- Temperature [°C] T

- Enthalpy [kJ/kg] h

- Specific heat (isobaric) [kJ/kg.K] Cp

- Density [kg/m3] rho

- Dynamic Viscosity [Pa.s] mu

- Thermal Conductivity [W/m.K] k

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Copyright (c) 2025, Fabio Aste, Vast Renewables Ltd.

Version: 1.0.

This software is licensed under the MIT License (2023).

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.