problem about reheat rakie cycle

[diego-atehortua]

hello @fwitte.
in the attached image you can see a rankine cycle with reheating. the idea is to solve it with the python tespy library. the problem occurs in the reheater, since making the connections of the components and once the python code is executed, an error appears saying that the reheater is waiting for an output connection. i attach images of the problem:
these are the connections defined for the problem:

from tespy.networks import Network
fluid_list = ['water']
steam_plant = Network(fluids=fluid_list)
steam_plant.set_attr(T_unit='C', p_unit='kPa', m_unit='kg / s', h_unit='kJ / kg')
from tespy.components import (CycleCloser, Pump, Condenser, Turbine,
                              HeatExchangerSimple,Desuperheater ,Source, Sink)

cc = CycleCloser('cycle closer')
sg = HeatExchangerSimple('steam generator')
ds = Desuperheater('Desuperheater')
co = Condenser('condenser')
tu1 = Turbine('High pressure steam turbine ')
tu2 = Turbine('Low pressure steam turbine ')
p = Pump('pump')
cwso = Source('cooling water source')
cwsi = Sink('cooling water sink')




from tespy.connections import Connection


c0 = Connection(sg, 'out1', cc, 'in1', label='0')
c1 = Connection(co, 'out1', p, 'in1', label='1')
c2 = Connection(p, 'out1', sg, 'in1', label='2')
c3 = Connection(cc, 'out1', tu1, 'in1', label='3')
c4 = Connection(tu1, 'out1', ds, 'in2', label='4')
c5 = Connection(ds, 'out1', tu2, 'in1',label='5')
c6 = Connection(tu2, 'out1', co, 'in1', label='6')
c7 = Connection(cwso, 'out1', co, 'in2', label='7')
c8 = Connection(co, 'out2', cwsi, 'in1', label='8')
steam_plant.add_conns(c0, c1, c2, c3, c4, c5, c6, c7, c8)

[diego-atehortua]

hello sir. @fwitte

can you help me with this error, explaining me what I am doing wrong, or how I should connect the reheater in the programming so that it is according to the image presented in the exercise.@fwitte

[fwitte]

Hi @diego-atehortua,

please be aware, that I can only do so much here, as this is currently a non-funded open source project I am basically dedicating my free time to. Sometimes answers might therefore take a little bit longer ;).

To your issue: You are using the desuperheater component, but what you want to do here is to reheat the steam. To model the amount of heat required for reheating you can use the HeatExchangerSimple in this case, just as for the steam generator:

from tespy.networks import Network
from tespy.components import CycleCloser, Source, Sink, HeatExchangerSimple,Condenser, Pump, Turbine
from tespy.connections import Connection, Bus


fluid_list = ['water']
steam_plant = Network(fluids=fluid_list)
steam_plant.set_attr(T_unit='C', p_unit='kPa', m_unit='kg / s', h_unit='kJ / kg')

cc = CycleCloser('cycle closer')
sg = HeatExchangerSimple('steam generator')
re = HeatExchangerSimple('reheater')
co = Condenser('condenser')
tu1 = Turbine('High pressure steam turbine ')
tu2 = Turbine('Low pressure steam turbine ')
p = Pump('pump')
cwso = Source('cooling water source')
cwsi = Sink('cooling water sink')

c0 = Connection(sg, 'out1', cc, 'in1', label='0')
c1 = Connection(co, 'out1', p, 'in1', label='1')
c2 = Connection(p, 'out1', sg, 'in1', label='2')
c3 = Connection(cc, 'out1', tu1, 'in1', label='3')
c4 = Connection(tu1, 'out1', re, 'in1', label='4')
c5 = Connection(re, 'out1', tu2, 'in1',label='5')
c6 = Connection(tu2, 'out1', co, 'in1', label='6')
c7 = Connection(cwso, 'out1', co, 'in2', label='7')
c8 = Connection(co, 'out2', cwsi, 'in1', label='8')
steam_plant.add_conns(c0, c1, c2, c3, c4, c5, c6, c7, c8)