TAMPINES Steam Tables

In house steam tables for the Thermo-hydraulic Artificial intelligence Multi-Phase INtegrated Emulator System (TAMPINES) solver.

This relies heavily upon the Rust-steam library licensed using the MIT license.

However, Rust-steam is incomplete for now. Moreover, it does not use the units of measure library. This set of steam-tables is meant to used dimensioned units by default. It will also incorporate verification tests from the following reference:

Kretzschmar, H. J., & Wagner, W. (2019). International steam tables. Springer Berlin Heidelberg.

Significant portions of code will be copied from the rust-steam package. Hence, I am putting the rust-steam license here.

Changelog

v0.1.1

Starting the h,s flash algorithms.

Also, copied some openfoam algorithms which will form the basis for which the steam tables in tampines are used to solve two phase flow in transient scenarios. Since OpenFOAM is licensed under GNU GPLv3, tampines-steam-tables will also be licensed under GNU GPL v3.

Note that for points near boundaries, correction factors have not been applied for (p,h) and (p,s) flashes. (h,s) flashes have only been partly implemented.

Near critical point for (h,s) flashing backward eqns, the temperature, volume and all may be less accurate for backward equations, temperatures may be off by as much as 5 degrees c, and volumes may differ by 10% enthalpy of vapourisation may differ by up to 5% compared to steam table data compared to steam table data... so beware... Though in the first place, the sat temperature equations were never meant for this critical region..

Thermal conductivity for (h,s) flash off by about 8%. Also basic temperature equations also tend to fail to be accurate around the saturation line for bubble point, but not sure about dew point. Sometimes, dew point doesn't work as in for 8 bar

Also, pressure equations fail to be accurate at low pressures such as 0.1 bar, 1 bar up to 10 bar. At 0.1 bar, 1 bar, only expect the pressure to be accurate to within 20% at least within region 1. Accuracy up to 8% was observed for 2 bar pressure, 5% for 4 bar and 6 bar. 4% for 8 bar, 2% for 10 bar and 20 bar.

For triple point pressure, hs flash doesn't work.

Moreover, not all of (h,s) flash works for region 4. The equations only work over a certain entropy bound.

Kappa should not be trusted for hs flash at low temps. Quality for hs test should not be trusted past supercritical pressure. Though at that pressure, we don't really care about quality anymore. Kind of meaningless because liquid and vapour properties are indistinguishable.

hs flash also fails near boundaries, eg 800C or 1073.15K isotherm.

v0.1.0

Added dielectric constant and surface tension functions. Didn't yet test across the whole steam table, but it works for the small unit tests.

v0.0.9 Implemented thermal conductivity for ps flash. However, for 160 bar and 220 bar steam tables, the max error is 30 and 40% respectively. For the 220 bar steam tables, it is quite near critical point, so thermal conductivity equations were not meant to be accurate there. However, for 160 bar, it is sufficiently far from critical point that this shouldn't be the case. But i'm leaving it as such for now, till such time there is a better reference for such properties.

Near critical temperatures and pressures, eg. 180 bar about 357+ degrees C, the speed of sound, isentropic exponent the specific heat capacity are not accurate to within 1%. Some discrepancies are larger than 5-10% esp near critical region for these properties.

The thermal conductivity and dynamic viscosity also have similar-ish degrees of uncertainty.

v0.0.8 Implemented thermal conductivity for ph flash. However, for 160 bar and 220 bar steam tables, the max error is 30 and 40% respectively. For the 220 bar steam tables, it is quite near critical point, so thermal conductivity equations were not meant to be accurate there. However, for 160 bar, it is sufficiently far from critical point that this shouldn't be the case.

I'm quite puzzled as to why that is the case. But this is a bug that needs to be fixed.

v0.0.7

Starting development of an interface for the forward and backward flash. First using functional programming, then object oriented programming. OOP not implemented in this version yet.

Firstly, (p,T) flash, then (p,H) flash. This is done for all steam table values except for 1000 bar. There is a problem for (p,T) and (p,H) flashing at 1000 bar as the algorithm complains it's out of range. Will take some debugging to settle.

Dynamic viscosity added, can reproduce steam table to within 2%. Thermal conductivity can reproduce steam table values to within 1% except for regions near critical point (220 bar) and from 100 bar up to 200 bar. Thermal conductivity yet to be implemented for (p,H) flash, requires some debugging.

v0.0.6 beginning the addition of backwards eqns

First, pressure and enthalpy (p,h) flash. This is applicable for

region 1, which forward equations are (p,t) flash:

• T(p,h)

region 2, which forward eqns are (p,t) flash:

• T(p,h)

region 3, which forward equations are (v,t) flash, so it accounts for quality:

• T(p,h)
• V(p,h)

once (p,h) flash is done for regions 1,2 and 3, then you can get T, for region 1 and 2 or (V,T) for region 3

and then get all your other thermodynamic variables

the ps3 equations (enthalpy to pressure equations) are also added

However, the interface for an overall ph flash or tp flash is not yet available.

v0.0.5 Add Region 5 equations (no backwards equations here)

v0.0.4 Added region 4 vapour liq saturation temp and pressure line up to critical point. This includes triple point, normal boiling point (100C at 1 atm) and critical point of water.

v0.0.3 Added region 3, and the saturation temperature and pressure boundary equation p23 and b23. Only forward eqns added. That is (T,P) flash.

v0.0.2

Added region 2, including metastable, dimensioned equations, with verification tests. Only forward eqns added. That is (T,P) flash.

v0.0.1

Added region 1 dimensioned equations, with verification tests. Only forward eqns added. That is (T,P) flash.

Rust-steam license:

Copyright 2023

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