Using charmaps with Turbocompressor component

[ronitd07]

Hello,

I wanted to use the characteristic map for eta_s for modelling the turbocompressor in my heat pump model. My simulation works fine when I set the igva value to 0 °. But i would like to run my simulation with igva = 'var' and using only efficiency charmap and not pressure char map. Is it possible to run with variable igva and eta_s char map and not using pr char map ?

when i tried i get error
The following variables of your problem are not in connection with any equation: (7, 'igva')

Thanks,
Ronit

[fwitte]

Hi Ronit,

Can you post a minimum example to reproduce the error?

[ronitd07]

Hi Francesco,

Please find attached the example attached. It is for a 2 stage compressor with a flash tank.

heatpump_simple.py

Thanks,
Ronit

[fwitte]

There are at least two things broken in the offdesign:

• it is impossible to set saturated state x and superheating td_dew simultanously
• you set the c4 pressure, should that not be the result of the condenser UA?

Furthermore, you make a lot of changes in parameters between design and first off-design calculation. I'd advise you to change the specifications only one at a time (one offdesign parameter replacing one other specification) and without modifying any other values to get your offdesign to work incrementally. You have to think about, which design specification cannot be controlled in off-design anymore and is instead a result of a different input (e.g. the resulting UA value of the design case).

Best