Hello,
at the moment I am trying to recalculate the conditions up- and downstream of a gasturbine.
When I use isentropic efficiency of 1, the turbine is just working isentropic and not polytropic, isn't it?
For my calculations I need the Heat capacity value (kappa) the system is using.
Is there a possibility to show the value the system is using for a stream?
I know I could calculate it myself, but just the constant pressure is shown, not the constant volume.
I would be delighted about an answer.
Best wishes
Florian
Heat capacity ratio
Moderator: jasper
Re: Heat capacity ratio
Yes it should be working isentropically. You can check: double click the unit, and go to the balance page. Look at the entropy balance.
The heat capacity as such is not a constant number and not used. The unit performs a PS flash and a PH flash. However you can inspect the heat capacities of the feed and product stream. If they are single phase streams, just tick on the per-phase heat capacity display in the flowsheet configuration (if heatCapacity is exposed, otherwise show enthalpy.Dtemperature, which is numerically the same). For a multi-phase stream however, a change in temperature at constant pressure implies a phase change, and the effictive heat capacity takes into account the enthalpy change due to phase change. You can determine it by perturbation of total stream temperature (at phase equilibrium) for example.
Volume is displayed under the Overall header in a stream display. Feed and product will have different volumes.
The heat capacity as such is not a constant number and not used. The unit performs a PS flash and a PH flash. However you can inspect the heat capacities of the feed and product stream. If they are single phase streams, just tick on the per-phase heat capacity display in the flowsheet configuration (if heatCapacity is exposed, otherwise show enthalpy.Dtemperature, which is numerically the same). For a multi-phase stream however, a change in temperature at constant pressure implies a phase change, and the effictive heat capacity takes into account the enthalpy change due to phase change. You can determine it by perturbation of total stream temperature (at phase equilibrium) for example.
Volume is displayed under the Overall header in a stream display. Feed and product will have different volumes.
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Florian041190
- Posts: 6
- Joined: 02 June 2015, 08:37
Re: Heat capacity ratio
Thank you for the information.
Everything works accurate.
Everything works accurate.
Re: Heat capacity ratio
You are welcome, and glad to hear it.