Replies: 4 comments
-
This could be solved by nested properties (der_compr = f(p,T)) |
Beta Was this translation helpful? Give feedback.
-
We could also consider a generic description of Z, for example by applying the CNGA-method that calculates Z from pressure, temperature and relative density. An example is [Liu et al., 2020] |
Beta Was this translation helpful? Give feedback.
-
We will compare our results to other tools and if we find that it makes sense, we change the approach, otherwise we stay with der_comp=-0.022 which is at 0°C. |
Beta Was this translation helpful? Give feedback.
-
According to Clees et al., 2021, the GERG-2008 EoS [Kunz & Wagner, 2012] yields best results for mixtures and pure hydrogen. An implementation would be way more complex than the linear approach. |
Beta Was this translation helpful? Give feedback.
-
I would like to discuss the default-compressibility factors that are stored in properties/[fluid name]/compressibility.txt in the format slope, offset.
For H and L natural gas, the slope (=der_comp) is currently -0.0022, i.e. Z=0.78 @ 100bar. According to this figure on ResearchGate this means that we are on the 0° C isothermal curve. At 25 °C, Z would be 0.85, according to the chart.
We could also choose the 10 °C curve (-0.0019) as default since it seems closer to real operational conditions. In the long term, we could also implement different factors for a range of temperatures. What do you think?
This is in particular relevant for the calculation of high pressure networks, as the error is proportional to the pressure.
Beta Was this translation helpful? Give feedback.
All reactions