Feedback for tespy version 0.9

[fwitte]

Hi all,

I have been putting a lot of work into a refactoring which started quite a while ago. Most of the work is now done with the framework operational again while providing a couple of new features. Among other things, improved debugging capabilities for your models. On top, a lot of simplifications have been implemented in the back-end making future maintenance easier and also allowing the implementation other cool features (you might have already seen this page: tespy development roadmap)

What can you do now?

• You can install the version via pip: https://pypi.org/project/tespy/
• The updated docs are available already here: https://tespy.readthedocs.io/, with the most notable changes listed here: https://tespy.readthedocs.io/en/main/whats_new.html

With that done, I would appreciate any kind of feedback on the changes. Specifically, if you can provide feedback on the following topics:

• Test whether your models are still operational after having applied the necessary changes. If not, report here with a minimal reproducible example.
• Check the new debugging capabilities and try, if they are working well for you.
• ...

Thanks a lot!

Francesco

[Joseph-Garvey]

My model no longer works as of 0.9.
I have a basic R134a ORC : Pump -> Evaporator -> Cycle Closer -> Turbine -> Condenser
The parameters supplied are:
Evaporator heat transfer (400W)
Turbine and pump are ideal (etas=1)
Evap and Condenser are ideal, simple heat exchangers (pr=1)
Pump inlet is a liquid, at ambient 15C
Condenser inlet is a saturated gas at 5 bar.
Turbine inlet is at 70C.
I have also tried switching the pump inlet to a saturated liquid, removing the pressure of the turbine inlet.

In 0.9.3

In 0.8.3

[Joseph-Garvey]

Update - Higher temperatures are fine in 0.9.3, but anything below ~78C won't function, even though it's a valid cycle.

[fwitte]

Hi Joseph! Thank you for reporting this, I will have a look!

[fwitte]

Hmm, I cannot reproduce this, for me it works fine with the following setup:

from tespy.components import SimpleHeatExchanger, Turbine, Pump, CycleCloser
from tespy.connections import Connection
from tespy.networks import Network


nw = Network(T_unit="C", p_unit="bar")

turbine = Turbine("turbine")
condenser = SimpleHeatExchanger("condenser")
pump = Pump("pump")
evaporator = SimpleHeatExchanger("evaporator")
cc = CycleCloser("cc")

c1 = Connection(cc, "out1", turbine, "in1", label="c1")
c2 = Connection(turbine, "out1", condenser, "in1", label="c2")
c3 = Connection(condenser, "out1", pump, "in1", label="c3")
c4 = Connection(pump, "out1", evaporator, "in1", label="c4")
c5 = Connection(evaporator, "out1", cc, "in1", label="c5")

nw.add_conns(c1, c2, c3, c4, c5)

turbine.set_attr(eta_s=1)
pump.set_attr(eta_s=1)
evaporator.set_attr(pr=1, Q=400)
condenser.set_attr(pr=1)

c1.set_attr(fluid={"R134a": 1}, T=70)
c2.set_attr(x=1, p=5)
c3.set_attr(T=15)

nw.solve("design")
nw.print_results()

[Joseph-Garvey]

The setup here is identical, I'll do some more digging!

[Joseph-Garvey]

Running your code works fine on both versions for me.