def get_sHeatSupplied(self, returnExpression: bool = False):
"""Returns the value of the total specific heat supplied by the HeatDevices of the flow. If returnExpression, returns the expression that gives the value when added in a LinearEquation."""
self._sHeatSupplied = float('nan')
expression_LHS = [(-1, (self, '_sHeatSupplied'))]
for device in set(
device for device in self.heatDevices
if isinstance(device, (
Boiler, ReheatBoiler, Combustor,
GasReheater))): # if not isinstance(device, HeatExchanger)
expression_LHS += device.get_sHeatSuppliedExpression(
forFlow=self, constant_c=self.constant_c)
expression = LinearEquation(LHS=expression_LHS, RHS=0)
expression.source = 'Flows.get_sHeatSupplied'
if expression.isSolvable():
assert expression.get_unknowns()[0][0] == (self, '_sHeatSupplied')
# Linear equation is solvable if only there is only one unknown. If there is only one unknown, it must be the self._net_sWorkExtracted since we know it is unknown for sure
result = list(expression.solve().values())[0]
return result
else:
if returnExpression:
return expression.isolate([(self, '_sHeatSupplied')])
else:
return float('nan')
def get_sHeatSupplied(self, returnExpression: bool = False):
self._sHeatSupplied = float('nan')
expression_LHS = [ (-1, (self, '_sHeatSupplied')) ]
for device in set(device for device in self.heatDevices if isinstance(device, Boiler) or isinstance(device, ReheatBoiler)): # if not isinstance(device, HeatExchanger)
expression_LHS += device.get_sHeatSuppliedExpression(forFlow=self)
# expression_LHS += [ (1, (device.state_out, 'h')), (-1, (device.state_in, 'h')) ]
expression = LinearEquation(LHS=expression_LHS, RHS=0)
expression.source = 'Flows.get_sHeatSupplied'
if expression.isSolvable():
assert expression.get_unknowns()[0][0] == (self, '_sHeatSupplied')
# Linear equation is solvable if only there is only one unknown. If there is only one unknown, it must be the self._net_sWorkExtracted since we know it is unknown for sure
result = list(expression.solve().values())[0]
return result
else:
if returnExpression:
return expression.isolate( [(self, '_sHeatSupplied')] )
else:
return float('nan')
def get_net_sWorkExtracted(self, returnExpression: bool = False):
"""Returns the value of the total specific work extracted by the WorkDevices of the flow. If returnExpression, returns the expression that gives the value when added in a LinearEquation."""
self._net_sWorkExtracted = float('nan')
expression_LHS = [(-1, (self, '_net_sWorkExtracted'))]
for device in self.workDevices:
stateBefore, stateAfter = self.get_surroundingItems(
device, includeNone=True
) # returned list will have None values if there is no item in the spot before / after
if stateBefore is None and isinstance(device, Turbine):
stateBefore = device.state_in # A turbine (commonly in steam cycles) may have multiple flows coming out of it. The state_in may not belong to the same flow as the state_out.
if stateBefore is not None and stateAfter is not None:
if not self.constant_c:
expression_LHS += [
(1, (stateBefore, 'h')), (-1, (stateAfter, 'h'))
] # effectively adds (h_in - h_out) to the equation
else: # constant c analysis
expression_LHS += [
(1, (self.workingFluid.cp), (stateBefore, 'T')),
(-1, (self.workingFluid.cp), (stateAfter, 'T'))
]
else:
continue
expression = LinearEquation(
LHS=expression_LHS, RHS=0
) # -1 * self._net_sWorkExtracted + state_in.h - state_out.h = 0
expression.source = 'Flows.get_net_sWorkExtracted'
if expression.isSolvable():
assert expression.get_unknowns()[0][0] == (self,
'_net_sWorkExtracted')
# Linear equation is solvable if only there is only one unknown. If there is only one unknown, it must be the self._net_sWorkExtracted since we know it is unknown for sure
result = list(expression.solve().values())[0]
return result
else:
if returnExpression:
return expression.isolate([(self, '_net_sWorkExtracted')])
else:
return float('nan')
def get_net_sWorkExtracted(self, returnExpression: bool = False):
self._net_sWorkExtracted = float('nan')
expression_LHS = [ (-1, (self, '_net_sWorkExtracted')) ]
for device in self.workDevices:
stateBefore, stateAfter = self.get_surroundingItems(device, includeNone=True) # returned list will have None values if there is no item in the spot before / after
if stateBefore is None and isinstance(device, Turbine):
stateBefore = device.state_in
if stateBefore is not None and stateAfter is not None:
expression_LHS += [ (1, (stateBefore, 'h')) , (-1, (stateAfter, 'h')) ] # effectively adds (h_in - h_out) to the equation
else:
continue
expression = LinearEquation(LHS=expression_LHS, RHS=0) # -1 * self._net_sWorkExtracted + state_in.h - state_out.h = 0
expression.source = 'Flows.get_net_sWorkExtracted'
if expression.isSolvable():
assert expression.get_unknowns()[0][0] == (self, '_net_sWorkExtracted')
# Linear equation is solvable if only there is only one unknown. If there is only one unknown, it must be the self._net_sWorkExtracted since we know it is unknown for sure
result = list(expression.solve().values())[0]
return result
else:
if returnExpression:
return expression.isolate( [(self, '_net_sWorkExtracted')] )
else:
return float('nan')