def _TwoPhase_Forward(self, w_2phase):
DWS = DWSVals() #DryWetSegment structure
# Store temporary values to be passed to DryWetSegment
DWS.Fins = self.Fins
DWS.FinsType = self.FinsType
DWS.A_a = self.Fins.A_a * w_2phase
DWS.cp_da = self.Fins.cp_da
DWS.eta_a = self.Fins.eta_a
DWS.h_a = self.Fins.h_a * self.h_a_tuning #Heat transfer coefficient, not enthalpy
DWS.mdot_da = self.mdot_da * w_2phase
DWS.pin_a = self.Fins.Air.p
DWS.Tdew_r = self.Tdew_r
DWS.Tbubble_r = self.Tbubble_r
DWS.Tin_a = self.Tin_a
DWS.RHin_a = self.Fins.Air.RH
DWS.Tin_r = self.Tsat_r
DWS.A_r = self.A_r_wetted * w_2phase
DWS.Rw = self.Rw / w_2phase
DWS.cp_r = 1.0e15 #In the two-phase region the cp is infinite, use 1e15 as a big number;
DWS.pin_r = self.psat_r
DWS.mdot_r = self.mdot_r
DWS.IsTwoPhase = True
#Target heat transfer to go from inlet quality to saturated vapor
Q_target = self.mdot_r * (self.xout_2phase - self.xin_r) * self.h_fg
if Q_target < 0:
raise ValueError('Q_target in Evaporator must be positive')
# Average Refrigerant heat transfer coefficient
try:
if self.AS.name() in 'CarbonDioxide':
h_r = KandlikarEvaporation_average(self.xin_r,
self.xout_2phase, self.AS,
self.G_r, self.ID,
self.psat_r,
Q_target / DWS.A_r,
self.Tbubble_r, self.Tdew_r)
else:
h_r = ShahEvaporation_Average(self.xin_r, self.xout_2phase,
self.AS, self.G_r, self.ID,
self.psat_r, Q_target / DWS.A_r,
self.Tbubble_r, self.Tdew_r)
except:
h_r = ShahEvaporation_Average(self.xin_r, self.xout_2phase,
self.AS, self.G_r, self.ID,
self.psat_r, Q_target / DWS.A_r,
self.Tbubble_r, self.Tdew_r)
DWS.h_r = h_r * self.h_tp_tuning #correct refrigerant side convection heat transfer
#Run the DryWetSegment to carry out the heat and mass transfer analysis
DryWetSegment(DWS)
self.Q_2phase = DWS.Q
self.Q_sensible_2phase = DWS.Q_sensible
self.h_r_2phase = DWS.h_r
self.fdry_2phase = DWS.f_dry
self.Tout_a_2phase = DWS.Tout_a
rho_average = TwoPhaseDensity(self.AS,
self.xin_r,
self.xout_2phase,
self.Tdew_r,
self.Tbubble_r,
slipModel='Zivi')
self.Charge_2phase = rho_average * w_2phase * self.V_r
#Frictional pressure drop component
DP_frict = LMPressureGradientAvg(
self.xin_r, self.xout_2phase, self.AS, self.G_r, self.ID,
self.Tbubble_r, self.Tdew_r) * self.Lcircuit * w_2phase
#Accelerational pressure drop component
try:
if self.AS.name() in 'CarbonDioxide':
DP_accel = AccelPressureDrop(
self.xin_r,
self.xout_2phase,
self.AS,
self.G_r,
self.Tbubble_r,
self.Tdew_r,
D=self.ID,
slipModel='Premoli') * self.Lcircuit * w_2phase
else:
DP_accel = AccelPressureDrop(
self.xin_r,
self.xout_2phase,
self.AS,
self.G_r,
self.Tbubble_r,
self.Tdew_r,
slipModel='Zivi') * self.Lcircuit * w_2phase
except:
DP_accel = AccelPressureDrop(
self.xin_r,
self.xout_2phase,
self.AS,
self.G_r,
self.Tbubble_r,
self.Tdew_r,
slipModel='Zivi') * self.Lcircuit * w_2phase
self.DP_r_2phase = DP_frict + DP_accel
if self.Verbosity > 7:
print(w_2phase, DWS.Q, Q_target, self.xin_r,
"w_2phase,DWS.Q,Q_target,self.xin_r")
return DWS.Q - Q_target
def _TwoPhase_Forward(self,w_2phase):
DWS=DWSVals() #DryWetSegment structure
# Store temporary values to be passed to DryWetSegment
DWS.Fins=self.Fins
DWS.FinsType = self.FinsType
DWS.A_a=self.Fins.A_a*w_2phase
DWS.cp_da=self.Fins.cp_da
DWS.eta_a=self.Fins.eta_a
DWS.h_a=self.Fins.h_a*self.h_a_tuning #Heat transfer coefficient, not enthalpy
DWS.mdot_da=self.mdot_da*w_2phase
DWS.pin_a=self.Fins.Air.p
DWS.Tdew_r=self.Tdew_r
DWS.Tbubble_r=self.Tbubble_r
DWS.Tin_a=self.Tin_a
DWS.RHin_a=self.Fins.Air.RH
DWS.Tin_r=self.Tsat_r
DWS.A_r=self.A_r_wetted*w_2phase
DWS.Rw=self.Rw/w_2phase
DWS.cp_r=1.0e15 #In the two-phase region the cp is infinite, use 1e15 as a big number;
DWS.pin_r=self.psat_r
DWS.mdot_r=self.mdot_r
DWS.IsTwoPhase=True
#Target heat transfer to go from inlet quality to saturated vapor
Q_target=self.mdot_r*(self.xout_2phase-self.xin_r)*self.h_fg
if Q_target<0:
raise ValueError('Q_target in Evaporator must be positive')
# Average Refrigerant heat transfer coefficient
#Shah correlation
#h_r=ShahEvaporation_Average(self.xin_r,self.xout_2phase,self.AS,self.G_r,self.Dh,self.psat_r,Q_target/DWS.A_r,self.Tbubble_r,self.Tdew_r)
#Bertsch correlation
#h_r=Bertsch_MC_Average(self.xin_r,self.xout_2phase,self.AS,self.G_r,self.Dh,Q_target/DWS.A_r,self.Lcircuit,self.Tbubble_r,self.Tdew_r)
#Kandlikar correlation
#h_r=KandlikarEvaporation_average(self.xin_r,self.xout_2phase,self.AS,self.G_r,self.Dh,self.psat_r,Q_target/DWS.A_r,self.Tbubble_r,self.Tdew_r)
#Kim and Mudawar (2013)
DPDZ_frict_2phase, h_r = KM_Evap_Average(self.xin_r,self.xout_2phase,self.AS,self.G_r,self.Dh,self.Tbubble_r,self.Tdew_r,self.psat_r,self.beta,Q_target/DWS.A_r,self.PH_PF)
DWS.h_r=h_r*self.h_tp_tuning #correct refrigerant side convection heat transfer
#Run the DryWetSegment to carry out the heat and mass transfer analysis
DryWetSegment(DWS)
self.Q_2phase=DWS.Q
self.Q_sensible_2phase=DWS.Q_sensible
self.h_r_2phase=DWS.h_r
self.fdry_2phase=DWS.f_dry
self.Tout_a_2phase=DWS.Tout_a
rho_average=TwoPhaseDensity(self.AS,self.xin_r,self.xout_2phase,self.Tdew_r,self.Tbubble_r,slipModel='Zivi')
self.Charge_2phase = rho_average * w_2phase * self.V_r
#Frictional pressure drop component
#Lockhart-Martinelli correlation
#DP_frict=LMPressureGradientAvg(self.xin_r,self.xout_2phase,self.AS,self.G_r,self.Dh,self.Tbubble_r,self.Tdew_r)*self.Lcircuit*w_2phase
#using the pressure gradient of Kim & Mudawar (2013)
DP_frict=DPDZ_frict_2phase*self.Lcircuit*w_2phase
#Accelerational pressure drop component
if self.Ref in 'CarbonDioxide' or 'CO2' or 'R744': #TODO: self.AS.name() is not available yet for all backends, using self.Ref for now
DP_accel=AccelPressureDrop(self.xin_r,self.xout_2phase,self.AS,self.G_r,self.Tbubble_r,self.Tdew_r,D=self.Dh,slipModel='Premoli')*self.Lcircuit*w_2phase
else:
DP_accel=AccelPressureDrop(self.xin_r,self.xout_2phase,self.AS,self.G_r,self.Tbubble_r,self.Tdew_r,slipModel='Zivi')*self.Lcircuit*w_2phase
self.DP_r_2phase=DP_frict+DP_accel;
if self.Verbosity>7:
print (w_2phase,DWS.Q,Q_target,self.xin_r,"w_2phase,DWS.Q,Q_target,self.xin_r")
return DWS.Q-Q_target