def __init__(self):
"""
Load up the necessary sub-structures to be filled with
the code that follows
"""
self.Compressor = CompressorClass()
#Outdoor coil is a Condenser in cooling mode and evaporator in heating mode
self.Condenser = CondenserClass()
self.Condenser.Fins = FinInputs()
self.Evaporator = EvaporatorClass()
self.Evaporator.Fins = FinInputs()
self.CoolingCoil = CoolingCoilClass()
self.CoolingCoil.Fins = FinInputs()
self.Pump = PumpClass()
#Add both types of internal heat exchangers
self.CoaxialIHX = CoaxialHXClass()
self.PHEIHX = PHEHXClass()
self.LineSetSupply = LineSetClass()
self.LineSetReturn = LineSetClass()
#Make IHX an empty class for holding parameters common to PHE and Coaxial IHX
class struct:
pass
self.IHX = struct()
def Evaporator_DOE_HP(type='wCircuitry'):
#define parameters for evaporator as used in DOE HP
Evaporator=EvaporatorClass()
Fins=FinInputs()
#--------------------------------------
#--------------------------------------
# Evaporator
# -> see Condenser and GUI for explanations
#--------------------------------------
#--------------------------------------
Fins.Tubes.NTubes_per_bank=48
Fins.Tubes.Nbank=2
Fins.Tubes.Ncircuits=10
Fins.Tubes.Ltube=in2m(105.) #measured fin pack length
#tube diameters from D:\Purdue\CEC BERG PROJECT\bachc\components\heat pump\ACHP\25HCC560-FV4C006-Data.xlsx
Fins.Tubes.OD=mm2m(7.3) #measured 25HCC560 (same for HNB560); data for HCC unit indicated 7mm, actually larger
Fins.Tubes.ID=mm2m(6.3) #measured 25HCC560 (assuming same for HNB560); data for HCC unit didn't make sense
Fins.Tubes.Pl=cm2m(2.) #depth of each fin-sheet (measured)
Fins.Tubes.Pt=in2m(0.83) #48tubes, 40-1/8 total distance between first and last tube
Fins.Fins.FPI=20 #from datasheet
Fins.Fins.Pd=0.001 #since fins are lanced, this value is meaningless - tune to fit to data
Fins.Fins.xf=0.001
Fins.Fins.t=mm2m(0.11) #measurement with callipper,
Fins.Fins.k_fin=237 #Pure aluminum (Incropera, Sixth edition)
Fins.Air.Vdot_ha=cfm2cms(4668) #high flow value of HNB960 D:\Purdue\DOE Project\HP-design\datasheets\HNB960A300.pdf
#Fins.Air.Vdot_ha=cfm2cms(4209.0) #high flow value of HNB960
Fins.Air.Tmean=C2K(8.33) #update according to your requirement
Fins.Air.Tdb=Fins.Air.Tmean
Fins.Air.p=101.325 #Air pressure
Fins.Air.RH=0.48
Fins.Air.RHmean=0.48
Fins.Air.FanPower=HP2W(1.0/5.0) #rated HP according to HNB960 datasheet
#now swap the evaporator against a multi circuited one
if type=='MCE':
from MultiCircuitEvaporator import MultiCircuitEvaporatorClass
Evaporator=MultiCircuitEvaporatorClass() #use multi circuit evaporator
elif type=='wCircuitry':
Evaporator=MultiCircuitEvaporator_w_circuitryClass() #use multi circuit evaporator
elif type=='standard':
Evaporator=EvaporatorClass() #use "normal" evaporator
else:
print "unsupported evaporator type"
raise
Evaporator.Fins=Fins
params={
'Verbosity':0,
'DT_sh':5.0, #initial setting, update according to requirement
'Ref':'R410A'
}
Evaporator.Update(**params)
return Evaporator
def __init__(self):
"""
Load up the necessary sub-structures to be filled with
the code that follows
"""
self.Compressor=CompressorClass()
self.Condenser=CondenserClass()
self.Condenser.Fins=FinInputs()
self.Evaporator=EvaporatorClass()
self.Evaporator.Fins=FinInputs()
self.LineSetSupply=LineSetClass()
self.LineSetReturn=LineSetClass()
0.0708,
'psat_r':
PropsSI('P', 'T', 282.0, 'Q', 1.0, 'R410A'),
'Fins':
FinsTubes,
'FinsType':
'WavyLouveredFins', #Choose fin Type: 'WavyLouveredFins' or 'HerringboneFins'or 'PlainFins'
'hin_r':
PropsSI('H', 'P', PropsSI('P', 'T', 282.0, 'Q', 1.0, 'R410A'), 'Q', 0.15,
'R410A'), #*1000
'Verbosity':
0,
'Backend':
'HEOS' #choose between: 'HEOS','TTSE&HEOS','BICUBIC&HEOS','REFPROP','SRK','PR'
}
Evap = EvaporatorClass(**kwargs)
Evap.Calculate()
print 'Evap Q=' + str(Evap.Q) + ' W'
#This uses the multi-circuited evaporator model but with no mal-distribution
kwargs = {
'Ref':
'R410A',
'mdot_r':
0.0708,
'psat_r':
PropsSI('P', 'T', 282.0, 'Q', 1.0, 'R410A'),
'Fins':
FinsTubes,
'FinsType':
'WavyLouveredFins', #Choose fin Type: 'WavyLouveredFins' or 'HerringboneFins'or 'PlainFins'
class DXCycleClass():
def __init__(self):
"""
Load up the necessary sub-structures to be filled with
the code that follows
"""
self.Compressor=CompressorClass()
self.Condenser=CondenserClass()
self.Condenser.Fins=FinInputs()
self.Evaporator=EvaporatorClass()
self.Evaporator.Fins=FinInputs()
self.LineSetSupply=LineSetClass()
self.LineSetReturn=LineSetClass()
def OutputList(self):
"""
Return a list of parameters for this component for further output
It is a list of tuples, and each tuple is formed of items:
[0] Description of value
[1] Units of value
[2] The value itself
"""
Output_List=[]
#append optional parameters, if applicable
if hasattr(self,'TestName'):
Output_List.append(('Name','N/A',self.TestName))
if hasattr(self,'TestDescription'):
Output_List.append(('Description','N/A',self.TestDescription))
if hasattr(self,'TestDetails'):
Output_List.append(('Details','N/A',self.TestDetails))
Output_List_default=[ #default output list
('Charge','kg',self.Charge),
('Condensation temp (dew)','K',self.Tdew_cond),
('Evaporation temp (dew)','K',self.Tdew_evap),
('Condenser Subcooling','K',self.DT_sc),
('Primary Ref.','-',self.Ref),
('COP','-',self.COP),
('COSP','-',self.COSP),
('Net Capacity','W',self.Capacity),
('Net Power','W',self.Power),
('SHR','-',self.SHR),
('Imposed Variable','-',self.ImposedVariable),
]
for i in range(0,len(Output_List_default)): #append default parameters to output list
Output_List.append(Output_List_default[i])
return Output_List
def Calculate(self,DT_evap,DT_cond):
"""
Inputs are differences in temperature [K] between HX air inlet temperature
and the dew temperature for the heat exchanger.
Required Inputs:
DT_evap:
Difference in temperature [K] between evaporator air inlet temperature and refrigerant dew temperature
DT_cond:
Difference in temperature [K] between condenser air inlet temperature and refrigeant dew temperature
"""
if self.Verbosity>1:
print 'DTevap %7.4f DTcond %7.4f,' %(DT_evap,DT_cond)
Tdew_cond=self.Condenser.Fins.Air.Tdb+DT_cond#the values (Tin_a,..) come from line 128ff
Tdew_evap=self.Evaporator.Fins.Air.Tdb-DT_evap
psat_cond=Props('P','T',Tdew_cond,'Q',1,self.Ref)
psat_evap=Props('P','T',Tdew_evap,'Q',1,self.Ref)
Tbubble_evap=Props('T','P',psat_evap,'Q',0,self.Ref)
self.Tdew_cond=Tdew_cond
self.Tdew_evap=Tdew_evap
#If the user doesn't include the Mode, fail
assert hasattr(self,'Mode')
if self.Mode=='AC':
if not hasattr(self.Compressor,'mdot_r') or self.Compressor.mdot_r<0.00001:
# The first run of model, run the compressor just so you can get a preliminary value
# for the mass flow rate for the line set
params={ #dictionary -> key:value, e.g. 'key':2345,
'pin_r': psat_evap,
'pout_r': psat_cond,
'Tin_r': Tdew_evap+self.Evaporator.DT_sh,
'Ref': self.Ref
}
self.Compressor.Update(**params)
self.Compressor.Calculate()
params={
'pin': psat_evap,
'hin': Props('H','T',Tdew_evap+self.Evaporator.DT_sh,'P',psat_evap,self.Ref)*1000,
'mdot': self.Compressor.mdot_r,
'Ref': self.Ref
}
self.LineSetReturn.Update(**params)
self.LineSetReturn.Calculate()
params={ #dictionary -> key:value, e.g. 'key':2345,
'pin_r': psat_evap-self.DP_low,
'pout_r': psat_cond+self.DP_high,
'Tin_r': TrhoPhase_ph(self.Ref,psat_evap,self.LineSetReturn.hout,Tbubble_evap,Tdew_evap)[0],
'Ref': self.Ref
}
self.Compressor.Update(**params)
self.Compressor.Calculate()
if self.Verbosity>1:
print 'Comp DP H L',self.DP_low,self.DP_high
params={
'mdot_r': self.Compressor.mdot_r,
'Tin_r': self.Compressor.Tout_r,
'psat_r': psat_cond,
'Ref': self.Ref
}
self.Condenser.Update(**params)
self.Condenser.Calculate()
params={
'pin':psat_cond,
'hin':self.Condenser.hout_r,
'mdot':self.Compressor.mdot_r,
'Ref':self.Ref
}
self.LineSetSupply.Update(**params)
self.LineSetSupply.Calculate()
params={
'mdot_r': self.Compressor.mdot_r,
'psat_r': psat_evap,
'hin_r': self.LineSetSupply.hout,
'Ref': self.Ref
}
self.Evaporator.Update(**params)
self.Evaporator.Calculate()
self.Charge=self.Condenser.Charge+self.Evaporator.Charge+self.LineSetSupply.Charge+self.LineSetReturn.Charge
self.EnergyBalance=self.Compressor.CycleEnergyIn+self.Condenser.Q+self.Evaporator.Q
resid=np.zeros((2))
self.DP_HighPressure=self.Condenser.DP_r+self.LineSetSupply.DP
self.DP_LowPressure=self.Evaporator.DP_r+self.LineSetReturn.DP
resid[0]=self.Compressor.mdot_r*(self.LineSetReturn.hin-self.Evaporator.hout_r)
if self.ImposedVariable=='Subcooling':
resid[1]=self.Condenser.DT_sc-self.DT_sc_target
elif self.ImposedVariable=='Charge':
resid[1]=self.Charge-self.Charge_target
if self.Verbosity>1:
print resid
self.Capacity=self.Evaporator.Capacity
self.Power=self.Compressor.W+self.Evaporator.Fins.Air.FanPower+self.Condenser.Fins.Air.FanPower
self.COP=self.Evaporator.Q/self.Compressor.W
self.COSP=self.Evaporator.Capacity/self.Power
self.SHR=self.Evaporator.SHR
self.DT_sc=self.Condenser.DT_sc
elif self.Mode=='HP':
params={ #dictionary -> key:value, e.g. 'key':2345,
'pin_r': psat_evap-self.DP_low*1,
'pout_r': psat_cond+self.DP_high*1,
'Tin_r': Tdew_evap+self.Evaporator.DT_sh,
'Ref': self.Ref
}
self.Compressor.Update(**params)
self.Compressor.Calculate()
params={
'pin': psat_cond,
'hin': self.Compressor.hout_r,
'mdot': self.Compressor.mdot_r,
'Ref': self.Ref
}
self.LineSetSupply.Update(**params)
self.LineSetSupply.Calculate()
params={
'mdot_r': self.Compressor.mdot_r,
'Tin_r': self.Compressor.Tout_r,
'psat_r': psat_cond,
'Ref': self.Ref
}
self.Condenser.Update(**params)
self.Condenser.Calculate()
params={
'pin': psat_cond,
'hin': self.Condenser.hout_r,
'mdot': self.Compressor.mdot_r,
'Ref': self.Ref
}
self.LineSetReturn.Update(**params)
self.LineSetReturn.Calculate()
params={
'mdot_r': self.Compressor.mdot_r,
'psat_r': psat_evap,
'hin_r': self.LineSetReturn.hout,
'Ref': self.Ref
}
self.Evaporator.Update(**params)
self.Evaporator.Calculate()
self.Charge=self.Condenser.Charge+self.Evaporator.Charge+self.LineSetSupply.Charge+self.LineSetReturn.Charge
self.EnergyBalance=self.Compressor.CycleEnergyIn+self.Condenser.Q+self.Evaporator.Q
resid=np.zeros((2))
resid[0]=self.Compressor.mdot_r*(self.Compressor.hin_r-self.Evaporator.hout_r)
if self.ImposedVariable=='Subcooling':
resid[1]=self.Condenser.DT_sc-self.DT_sc_target
elif self.ImposedVariable=='Charge':
resid[1]=self.Charge-self.Charge_target
self.Capacity=-self.Condenser.Q+self.Condenser.Fins.Air.FanPower
self.DT_sc=self.Condenser.DT_sc
self.Power=self.Compressor.W+self.Evaporator.Fins.Air.FanPower+self.Condenser.Fins.Air.FanPower
self.COP=-self.Condenser.Q/self.Compressor.W
self.COSP=self.Capacity/self.Power
self.SHR=self.Evaporator.SHR
self.DP_HighPressure=self.Condenser.DP_r+self.LineSetSupply.DP
self.DP_LowPressure=self.Evaporator.DP_r+self.LineSetReturn.DP
else:
ValueError("DX Cycle mode must be 'AC', or 'HP'")
if self.Verbosity>1:
print 'DTevap %7.4f DTcond %7.4f Qres % 12.6e DTsc: % 12.6e Charge %10.4f SC: %8.4f' %(DT_evap,DT_cond,resid[0],resid[1],self.Charge,self.Condenser.DT_sc)
self.DT_evap=DT_evap
self.DT_cond=DT_cond
return resid
def PreconditionedSolve(self):
"""
Solver that will precondition by trying a range of DeltaT until the model
can solve, then will kick into 2-D Newton Raphson solve
The two input variables for the system solver are the differences in
temperature between the inlet air temperature of the heat exchanger and the
dew temperature of the refrigerant. This is important for refrigerant blends
with temperature glide during constant-pressure evaporation or condensation.
Good examples of common working fluid with glide would be R404A or R410A.
"""
def OBJECTIVE_DXCycle(x):
"""
A wrapper function to convert input vector for fsolve to the proper form for the solver
"""
try:
resids=self.Calculate(DT_evap=float(x[0]),DT_cond=float(x[1]))#,DP_low=float(x[2]),DP_high=float(x[3]))
except ValueError:
raise
return resids
# Use the preconditioner to determine a reasonably good starting guess
DT_evap_init,DT_cond_init=DXPreconditioner(self)
GoodRun=False
while GoodRun==False:
try:
self.DP_low=0
self.DP_high=0
DP_converged=False
while DP_converged==False:
#Actually run the Newton-Raphson solver to get the solution
x=Broyden(OBJECTIVE_DXCycle,[DT_evap_init,DT_cond_init])
delta_low=abs(self.DP_low-abs(self.DP_LowPressure)/1000)
delta_high=abs(self.DP_high-abs(self.DP_HighPressure)/1000)
self.DP_low=abs(self.DP_LowPressure)/1000
self.DP_high=abs(self.DP_HighPressure)/1000
#Update the guess values based on last converged values
DT_evap_init=self.DT_evap
DT_cond_init=self.DT_cond
if delta_low<1 and delta_high<1:
DP_converged=True
if self.Verbosity>4:
print self.DP_HighPressure/1000,self.DP_LowPressure/1000,'DPHP'
GoodRun=True
except AttributeError:
# This will be a fatal error !! Should never have attribute error
raise
except:
print "-------------- Exception Caught ---------------- "
print "Error of type",sys.exc_info()[0]," is: " + sys.exc_info()[1].message
raise
if self.Verbosity>0:
print 'Capacity: ', self.Capacity
print 'COP: ',self.COP
print 'COP (w/ both fans): ',self.COSP
print 'SHR: ',self.SHR
print 'UA_r_evap',self.Evaporator.UA_r
print 'UA_a_evap',self.Evaporator.UA_a
print 'UA_r_cond',self.Condenser.UA_r
print 'UA_a_cond',self.Condenser.UA_a
class SecondaryCycleClass():
def __init__(self):
"""
Load up the necessary sub-structures to be filled with
the code that follows
"""
self.Compressor=CompressorClass()
#Outdoor coil is a Condenser in cooling mode and evaporator in heating mode
self.Condenser=CondenserClass()
self.Condenser.Fins=FinInputs()
self.Evaporator=EvaporatorClass()
self.Evaporator.Fins=FinInputs()
self.CoolingCoil=CoolingCoilClass()
self.CoolingCoil.Fins=FinInputs()
self.Pump=PumpClass()
#Add both types of internal heat exchangers
self.CoaxialIHX=CoaxialHXClass()
self.PHEIHX=PHEHXClass()
self.LineSetSupply=LineSetClass()
self.LineSetReturn=LineSetClass()
#Make IHX an empty class for holding parameters common to PHE and Coaxial IHX
class struct: pass
self.IHX=struct()
def OutputList(self):
"""
Return a list of parameters for this component for further output
It is a list of tuples, and each tuple is formed of items:
[0] Description of value
[1] Units of value
[2] The value itself
"""
return [
('Charge','kg',self.Charge),
('Condenser Subcooling','K',self.DT_sc),
('Primary Ref.','-',self.Ref),
('Secondary Ref.','-',self.SecLoopFluid),
('Imposed Variable','-',self.ImposedVariable),
('IHX Type','-',self.IHXType),
('COP','-',self.COP),
('COSP','-',self.COSP),
('Net Capacity','W',self.CoolingCoil.Capacity),
('Net Power','W',self.Power),
('SHR','-',self.SHR),
('Condensation temp (dew)','K',self.Tdew_cond),
('Evaporation temp (dew)','K',self.Tdew_evap),
]
def Calculate(self,DT_evap,DT_cond,Tin_CC):
"""
Inputs are differences in temperature [K] between HX air inlet temperature
and the dew temperature for the heat exchanger.
Required Inputs:
DT_evap:
Difference in temperature [K] between cooling coil air inlet temperature and refrigerant dew temperature
DT_cond:
Difference in temperature [K] between condenser air inlet temperature and refrigerant dew temperature
Tin_CC:
Inlet "glycol" temperature to line set feeding cooling coil
"""
if self.Verbosity>1:
print 'Inputs: DTevap %7.4f DTcond %7.4f fT_IHX %7.4f'%(DT_evap,DT_cond,Tin_CC)
#Store the values to save on computation for later
self.DT_evap=DT_evap
self.DT_cond=DT_cond
self.Tin_CC=Tin_CC
#If the user doesn't include the Mode, set it to Air Conditioning
if not hasattr(self,'Mode'):
self.Mode='AC'
if self.Mode=='AC':
self.Tdew_cond=self.Condenser.Fins.Air.Tdb+DT_cond
self.Tdew_evap=self.CoolingCoil.Fins.Air.Tdb-DT_evap
elif self.Mode=='HP':
self.Tdew_cond=Tin_CC+DT_cond
self.Tdew_evap=self.Evaporator.Fins.Air.Tdb-DT_evap
else:
raise ValueError('Mode must be AC or HP')
psat_cond=Props('P','T',self.Tdew_cond,'Q',1,self.Ref)
psat_evap=Props('P','T',self.Tdew_evap,'Q',1,self.Ref)
self.Tbubble_evap=Props('T','P',psat_evap,'Q',0,self.Ref)
self.Tbubble_cond=Props('T','P',psat_cond,'Q',0,self.Ref)
if self.Mode=='AC':
params={ #dictionary -> key:value, e.g. 'key':2345,
'pin_r': psat_evap+self.DP_low,
'pout_r': psat_cond-self.DP_high,
'Tin_r': self.Tdew_evap+self.PHEIHX.DT_sh, # TrhoPhase_ph(self.Ref,psat_evap,self.LineSetReturn.hout,self.Tbubble_evap,self.Tdew_evap)[0],
'Ref': self.Ref
}
self.Compressor.Update(**params)
self.Compressor.Calculate()
params={
'mdot_r': self.Compressor.mdot_r,
'Tin_r': self.Compressor.Tout_r,
'psat_r': psat_cond,
'Ref': self.Ref
}
self.Condenser.Update(**params)
self.Condenser.Calculate()
params={
'mdot': self.Pump.mdot_g,
'hin': Props('H','T',Tin_CC,'P',self.Pump.pin_g,self.SecLoopFluid)*1000,
}
self.LineSetSupply.Update(**params)
self.LineSetSupply.Calculate()
#Now run CoolingCoil to predict inlet glycol temperature to IHX
params={
'mdot_g': self.Pump.mdot_g,
'Tin_g': self.LineSetSupply.Tout,
}
self.CoolingCoil.Update(**params)
self.CoolingCoil.Calculate()
params={
'mdot': self.Pump.mdot_g,
'hin': Props('H','T',self.CoolingCoil.Tout_g,'P',self.Pump.pin_g,self.SecLoopFluid)*1000,
}
self.LineSetReturn.Update(**params)
self.LineSetReturn.Calculate()
if self.IHXType=='Coaxial':
params={
'mdot_g': self.Pump.mdot_g,
'Tin_g': self.CoolingCoil.Tout_g,
'pin_r': psat_evap,
'hin_r': self.Condenser.hout_r,
'Ref_r': self.Ref,
'mdot_r': self.Compressor.mdot_r,
}
self.CoaxialIHX.Update(**params)
self.CoaxialIHX.Calculate()
self.IHX.Charge_r=self.CoaxialIHX.Charge_r
self.IHX.Q=self.CoaxialIHX.Q
self.IHX.Tout_g=self.CoaxialIHX.Tout_g
self.IHX.DP_g=self.CoaxialIHX.DP_g
self.IHX.hout_r=self.CoaxialIHX.hout_r
self.IHX.DP_r=self.CoaxialIHX.DP_r
if hasattr(self,'PHEIHX'):
del self.PHEIHX
elif self.IHXType=='PHE':
params={
'mdot_h': self.Pump.mdot_g,
'hin_h': Props('H','T',self.CoolingCoil.Tout_g,'P',self.PHEIHX.pin_h,self.SecLoopFluid)*1000,
'mdot_c': self.Compressor.mdot_r,
'pin_c': psat_evap,
'hin_c': self.Condenser.hout_r,
}
self.PHEIHX.Update(**params)
self.PHEIHX.Calculate()
self.IHX.Charge_r=self.PHEIHX.Charge_c
self.IHX.Q=self.PHEIHX.Q
self.IHX.Tout_g=self.PHEIHX.Tout_h
self.IHX.DP_g=self.PHEIHX.DP_h
self.IHX.DP_r=self.PHEIHX.DP_c
self.IHX.hout_r=self.PHEIHX.hout_c
if hasattr(self,'CoaxialIHX'):
del self.CoaxialIHX
params={
'DP_g': self.IHX.DP_g+self.CoolingCoil.DP_g+self.LineSetSupply.DP+self.LineSetReturn.DP,
'Tin_g': self.CoolingCoil.Tout_g
}
self.Pump.Update(**params)
self.Pump.Calculate()
self.Charge=self.Condenser.Charge+self.IHX.Charge_r
self.EnergyBalance=self.Compressor.CycleEnergyIn+self.Condenser.Q+self.IHX.Q
self.DT_sc=(Props('H','T',self.Tbubble_cond,'Q',0,self.Ref)*1000-self.Condenser.hout_r)/(Props('C','T',self.Tbubble_cond,'Q',0,self.Ref)*1000)
deltaH_sc=self.Compressor.mdot_r*(Props('H','T',self.Tbubble_cond,'Q',0,self.Ref)*1000-Props('H','T',self.Tbubble_cond-self.DT_sc_target,'P',psat_cond,self.Ref)*1000)
# ## Plot a p-h plot
# Ph(self.Ref,hbounds=(100,500))
# pylab.plot([self.Compressor.hin_r/1000,self.Compressor.hout_r/1000,self.Condenser.hout_r/1000,self.PHEIHX.hin_c/1000,self.Compressor.hin_r/1000],[psat_evap,psat_cond,psat_cond,psat_evap,psat_evap])
# pylab.show()
resid=np.zeros((3))
resid[0]=self.Compressor.mdot_r*(self.Compressor.hin_r-self.IHX.hout_r)
if self.ImposedVariable=='Subcooling':
resid[1]=self.Condenser.DT_sc-self.DT_sc_target
elif self.ImposedVariable=='Charge':
resid[1]=self.Charge-self.Charge_target
# resid[2]=self.IHX.Q-self.CoolingCoil.Q+self.Pump.W
self.residSL=self.IHX.Q-self.CoolingCoil.Q+self.Pump.W+self.LineSetSupply.Q+self.LineSetReturn.Q
resid[2]=self.residSL
if self.Verbosity>7:
print 'Wcomp % 12.6e Qcond: % 12.6e QPHE %10.4f ' %(self.Compressor.W,self.Condenser.Q,self.IHX.Q)
if self.Verbosity>1:
print 'Qres % 12.6e Resid2: % 12.6e ResSL %10.4f Charge %10.4f SC: %8.4f' %(resid[0],resid[1],self.residSL,self.Charge,self.Condenser.DT_sc)
self.Capacity=self.CoolingCoil.Capacity
self.COP=self.CoolingCoil.Q/self.Compressor.W
self.COSP=self.CoolingCoil.Capacity/(self.Compressor.W+self.Pump.W+self.CoolingCoil.Fins.Air.FanPower+self.Condenser.Fins.Air.FanPower)
self.SHR=self.CoolingCoil.SHR
self.Power=self.Compressor.W+self.Pump.W+self.CoolingCoil.Fins.Air.FanPower+self.Condenser.Fins.Air.FanPower
self.DP_high_Model=self.Condenser.DP_r #[Pa]
self.DP_low_Model=self.IHX.DP_r #[Pa]
elif self.Mode=='HP':
if psat_evap+self.DP_low<0:
raise ValueError('Compressor inlet pressure less than zero ['+str(psat_evap+self.DP_low)+' kPa] - is low side pressure drop too high?')
params={ #dictionary -> key:value, e.g. 'key':2345,
'pin_r': psat_evap+self.DP_low,
'pout_r': psat_cond-self.DP_high,
'Tin_r': self.Tdew_evap+self.Evaporator.DT_sh, # TrhoPhase_ph(self.Ref,psat_evap,self.LineSetReturn.hout,self.Tbubble_evap,self.Tdew_evap)[0],
'Ref': self.Ref
}
self.Compressor.Update(**params)
self.Compressor.Calculate()
params={
'mdot': self.Pump.mdot_g,
'hin': Props('H','T',Tin_CC,'P',self.Pump.pin_g,self.SecLoopFluid)*1000,
}
self.LineSetSupply.Update(**params)
self.LineSetSupply.Calculate()
#Now run CoolingCoil to predict inlet glycol temperature to IHX
params={
'mdot_g': self.Pump.mdot_g,
'Tin_g': self.LineSetSupply.Tout,
}
self.CoolingCoil.Update(**params)
self.CoolingCoil.Calculate()
params={
'mdot': self.Pump.mdot_g,
'hin': Props('H','T',self.CoolingCoil.Tout_g,'P',self.Pump.pin_g,self.SecLoopFluid)*1000,
}
self.LineSetReturn.Update(**params)
self.LineSetReturn.Calculate()
params={
'mdot_h': self.Compressor.mdot_r,
'hin_h': self.Compressor.hout_r,
'pin_h': psat_cond,
'mdot_c': self.Pump.mdot_g,
'hin_c': Props('H','T',self.LineSetReturn.Tout,'P',self.PHEIHX.pin_c,self.SecLoopFluid)*1000,
}
self.PHEIHX.Update(**params)
self.PHEIHX.Calculate()
params={
'mdot_r': self.Compressor.mdot_r,
'psat_r': psat_evap,
'hin_r': self.PHEIHX.hout_h,
'Ref': self.Ref
}
self.Evaporator.Update(**params)
self.Evaporator.Calculate()
params={
'DP_g': self.PHEIHX.DP_c+self.CoolingCoil.DP_g,
'Tin_g': self.CoolingCoil.Tout_g
}
self.Pump.Update(**params)
self.Pump.Calculate()
self.Charge=self.Evaporator.Charge+self.PHEIHX.Charge_h
#Calculate an effective subcooling amount by deltah/cp_satL
#Can be positive or negative (negative is quality at outlet
self.DT_sc=self.PHEIHX.DT_sc_h#(Props('H','T',self.Tbubble_cond,'Q',0,self.Ref)*1000-self.PHEIHX.hout_h)/(Props('C','T',self.Tbubble_cond,'Q',0,self.Ref)*1000)
deltaH_sc=self.Compressor.mdot_r*(Props('H','T',self.Tbubble_cond,'Q',0,self.Ref)*1000-Props('H','T',self.Tbubble_cond-self.DT_sc_target,'P',psat_cond,self.Ref)*1000)
resid=np.zeros((3))
resid[0]=self.Compressor.mdot_r*(self.Compressor.hin_r-self.Evaporator.hout_r)
if self.ImposedVariable=='Subcooling':
resid[1]=self.DT_sc-self.DT_sc_target
elif self.ImposedVariable=='Charge':
resid[1]=self.Charge-self.Charge_target
self.residSL=self.PHEIHX.Q+self.CoolingCoil.Q+self.Pump.W+self.LineSetSupply.Q+self.LineSetReturn.Q
resid[2]=self.residSL
if self.Verbosity>1:
print 'Qres % 12.6e Resid2: % 12.6e ResSL %10.4f Charge %10.4f SC: %8.4f' %(resid[0],resid[1],self.residSL,self.Charge,self.DT_sc)
self.Capacity=-self.CoolingCoil.Q+self.CoolingCoil.Fins.Air.FanPower
self.COP=-self.CoolingCoil.Q/self.Compressor.W
self.COSP=self.Capacity/(self.Compressor.W+self.Pump.W+self.CoolingCoil.Fins.Air.FanPower+self.Evaporator.Fins.Air.FanPower)
self.Power=self.Compressor.W+self.Pump.W+self.CoolingCoil.Fins.Air.FanPower+self.Evaporator.Fins.Air.FanPower
self.SHR=-self.CoolingCoil.SHR
self.DP_high_Model=self.PHEIHX.DP_h #[Pa]
self.DP_low_Model=self.Evaporator.DP_r #[Pa]
self.DT_evap=DT_evap
self.DT_cond=DT_cond
return resid
def PreconditionedSolve(self,PrecondValues=None):
'''
PrecondValues = dictionary of values DT_evap, DT_cond and Tin_CC
'''
def OBJECTIVE(x):
"""
Takes the place of a lambda function since lambda functions do not bubble error properly
"""
return self.Calculate(x[0],x[1],x[2])
def OBJECTIVE2(x,Tin):
"""
Takes the place of a lambda function since lambda functions do not bubble error properly
"""
return self.Calculate(x[0],x[1],Tin)
def OBJECTIVE_SL(Tin_CC):
"""
Objective function for the inner loop of the vapor compression system
Using the MultiDimNewtRaph function will re-evaluate the Jacobian at
every step. Slower, but more robust since the solution surfaces aren't
smooth enough
Note: This function is not currently used!
"""
x=MultiDimNewtRaph(OBJECTIVE2,[self.DT_evap,self.DT_cond],args=(Tin_CC,))
# Update the guess values for Delta Ts starting
# at the third step (after at least one update away
# from the boundaries)
if self.OBJ_SL_counter>=0:
self.DT_evap=x[0]
self.DT_cond=x[1]
pass
self.OBJ_SL_counter+=1
return self.residSL
def PrintDPs():
print 'DP_LP :: Input:',self.DP_low,'kPa / Model calc:',self.DP_low_Model/1000,'kPa'
print 'DP_HP :: Input:',self.DP_high,'kPa / Model calc:',self.DP_high_Model/1000,'kPa'
#Some variables need to be initialized
self.DP_low=0 #The actual low-side pressure drop to be used in kPa
self.DP_high=0 #The actual low-side pressure drop to be used in kPa
self.OBJ_SL_counter=0
#Run the preconditioner to get guess values for the temperatures
if PrecondValues is None:
self.DT_evap,self.DT_cond,Tin_CC=SecondaryLoopPreconditioner(self)
else:
self.DT_evap=PrecondValues['DT_evap']
self.DT_cond=PrecondValues['DT_cond']
Tin_CC=PrecondValues['Tin_CC']
#Remove the other, non-used IHX class if found
if self.IHXType=='PHE':
if hasattr(self,'CoaxialIHX'):
del self.CoaxialIHX
else:
if hasattr(self,'PHEIHX'):
del self.PHEIHX
#Remove the condenser if in heating mode and condenser found
if self.Mode=='HP':
if hasattr(self,'Condenser'):
del self.Condenser
iter=1
max_error_DP=999
#Outer loop with a more relaxed convergence criterion
while max_error_DP>0.5:
iter_inner=1
#Inner loop to determine pressure drop for high and low sides
while max_error_DP>0.05 and iter_inner<10:
#Run to calculate the pressure drop as starting point
OBJECTIVE([self.DT_evap,self.DT_cond,Tin_CC])
#Calculate the max error
max_error_DP=max([abs(self.DP_low_Model/1000-self.DP_low),abs(self.DP_high_Model/1000-self.DP_high)])
if self.Verbosity>0:
PrintDPs()
print 'Max pressure drop error [inner loop] is',max_error_DP,'kPa'
#Update the pressure drop terms
self.DP_low=self.DP_low_Model/1000
self.DP_high=self.DP_high_Model/1000
iter_inner+=1
if self.Verbosity > 0:
print "Done with the inner loop on pressure drop"
# Use Newton-Raphson solver
(self.DT_evap,self.DT_cond,Tin_CC)=MultiDimNewtRaph(OBJECTIVE,[self.DT_evap,self.DT_cond,Tin_CC],dx=0.1)
#Calculate the error
max_error_DP=max([abs(self.DP_low_Model/1000-self.DP_low),abs(self.DP_high_Model/1000-self.DP_high)])
if self.Verbosity>0:
PrintDPs()
print 'Max pressure drop error [outer loop] is',max_error_DP,'kPa'
if self.Verbosity>1:
print 'Capacity: ', self.Capacity
print 'COP: ',self.COP
print 'COP (w/ both fans): ',self.COSP
print 'SHR: ',self.SHR
return
def Calculate(self):
#Check that the length of lists of mdot_r and FinsTubes.Air.Vdot_ha
#match the number of circuits or are all equal to 1 (standard evap)
Ncircuits = int(self.Fins.Tubes.Ncircuits)
# Make Ncircuits copies of evaporator classes defined
# by the inputs to the MCE superclass
EvapDict = self.__dict__
self.Evaps = []
for i in range(Ncircuits):
# Make a deep copy to break all the links between the Fins structs
# of each of the evaporator instances
ED = copy.deepcopy(EvapDict)
#Create new evaporator instanciated with new deep copied dictionary
E = EvaporatorClass(**ED)
#Add to list of evaporators
self.Evaps.append(E)
#Upcast single values to lists, and convert numpy arrays to lists
self.Fins.Air.Vdot_ha = np.atleast_1d(self.Fins.Air.Vdot_ha).tolist()
self.mdot_r = np.atleast_1d(self.mdot_r).tolist()
if Ncircuits != len(self.mdot_r) and len(self.mdot_r) > 1:
print "Problem with length of vector for mdot_r for MCE"
else:
if len(self.mdot_r) == 1: #Single value passed in for mdot_r
if hasattr(self, 'mdot_r_coeffs'):
if len(self.mdot_r_coeffs) != Ncircuits:
raise AttributeError("Size of array mdot_r_coeffs: " +
str(len(self.mdot_r_coeffs)) +
" does not equal Ncircuits: " +
str(Ncircuits))
elif abs(np.sum(self.mdot_r_coeffs) -
1) >= 100 * np.finfo(float).eps:
raise AttributeError(
"mdot_r_coeffs must sum to 1.0. Sum *100000 is: "
+ str(100000 * np.sum(self.mdot_r_coeffs)))
else:
# A vector of weighting factors multiplying the total mass flow rate is provided with the right length
for i in range(Ncircuits):
self.Evaps[i].mdot_r = self.mdot_r[
-1] * self.mdot_r_coeffs[i]
else:
# Refrigerant flow is evenly distributed between circuits,
# give each evaporator an equal portion of the refrigerant
for i in range(Ncircuits):
self.Evaps[i].mdot_r = self.mdot_r[-1] / Ncircuits
else:
for i in range(Ncircuits):
self.Evaps[i].mdot_r = self.mdot_r[i]
# Deal with the possibility that the quality might be varied among circuits
if hasattr(self, 'mdot_v_coeffs'):
if len(self.mdot_v_coeffs) != Ncircuits:
raise AttributeError("Size of array mdot_v_coeffs: " +
str(len(self.mdot_v_coeffs)) +
" does not equal Ncircuits: " +
str(Ncircuits))
elif abs(np.sum(self.mdot_v_coeffs) -
1) >= 10 * np.finfo(float).eps:
raise AttributeError(
"mdot_v_coeffs must sum to 1.0. Sum is: " +
str(np.sum(self.mdot_v_coeffs)))
else:
hsatL = PropsSI('H', 'P', self.psat_r, 'Q', 0.0, self.Ref)
hsatV = PropsSI('H', 'P', self.psat_r, 'Q', 1.0, self.Ref)
x_inlet = (self.hin_r - hsatL) / (hsatV - hsatL)
mdot_v = x_inlet * sum(self.mdot_r)
for i in range(Ncircuits):
mdot_v_i = self.mdot_v_coeffs[i] * mdot_v
x_i = mdot_v_i / self.Evaps[i].mdot_r
self.Evaps[i].hin_r = PropsSI('H', 'P', self.psat_r, 'Q',
x_i, self.Ref)
#For backwards compatibility, if the coefficients are provided in the FinInputs class, copy them to the base class
if hasattr(self.Fins.Air, 'Vdot_ha_coeffs'):
self.Vdot_ha_coeffs = self.Fins.Air.Vdot_ha_coeffs
print "Warning: please put the vector Vdot_ha_coeffs in the base MCE class, accesssed as MCE.Vdot_ha_coeffs"
if Ncircuits != len(self.Fins.Air.Vdot_ha) and len(
self.Fins.Air.Vdot_ha) > 1:
print "Problem with length of vector for Vdot_ha for MCE"
else:
if len(self.Fins.Air.Vdot_ha) == 1:
if hasattr(self, 'Vdot_ha_coeffs'):
if len(self.Vdot_ha_coeffs) != Ncircuits:
raise AttributeError("Size of array Vdot_ha_coeffs: " +
str(len(self.Vdot_ha_coeffs)) +
" does not equal Ncircuits: " +
str(Ncircuits))
elif abs(np.sum(self.Vdot_ha_coeffs) -
1) >= 10 * np.finfo(float).eps:
raise AttributeError(
"Vdot_ha_coeffs does not sum to 1.0! Sum is: " +
str(np.sum(self.Vdot_ha_coeffs)))
else:
# A vector of factors multiplying the total volume flow rate is provided
for i in range(Ncircuits):
self.Evaps[
i].Fins.Air.Vdot_ha = self.Fins.Air.Vdot_ha[
-1] * self.Vdot_ha_coeffs[i]
else:
# Air flow is evenly distributed between circuits,
# give each circuit an equal portion of the air flow
for i in range(Ncircuits):
self.Evaps[i].Fins.Air.Vdot_ha = self.Fins.Air.Vdot_ha[
-1] / Ncircuits
else:
for i in range(Ncircuits):
self.Evaps[i].Fins.Air.Vdot_ha = self.Fins.Air.Vdot_ha[i]
# Distribute the tubes of the bank among the different circuits
# If Tubes per bank is divisible by the number of circuits, all the
# circuits have the same number of tubes per bank
# The circuits are ordered from fewer to more if they are not evenly distributed
NTubes_min = int(floor(self.Fins.Tubes.NTubes_per_bank / Ncircuits))
NTubes_max = int(ceil(self.Fins.Tubes.NTubes_per_bank / Ncircuits))
if NTubes_min == NTubes_max:
#If evenly divisible, use the tubes per circuit from the division
A = Ncircuits
else:
# Total number of tubes per bank is given by
A = (self.Fins.Tubes.NTubes_per_bank -
Ncircuits * NTubes_max) / (NTubes_min - NTubes_max)
for i in range(Ncircuits):
if i + 1 <= A:
self.Evaps[i].Fins.Tubes.NTubes_per_bank = NTubes_min
else:
self.Evaps[i].Fins.Tubes.NTubes_per_bank = NTubes_max
for i in range(Ncircuits):
self.Evaps[i].Fins.Tubes.Ncircuits = 1
#Actually run each Evaporator
self.Evaps[i].Calculate()
#Collect the outputs from each of the evaporators individually
#Try to mirror the outputs of each of the evaporators
self.Q = np.sum([self.Evaps[i].Q for i in range(Ncircuits)])
self.Charge = np.sum([self.Evaps[i].Charge for i in range(Ncircuits)])
self.Charge_superheat = np.sum(
[self.Evaps[i].Charge_superheat for i in range(Ncircuits)])
self.Charge_2phase = np.sum(
[self.Evaps[i].Charge_2phase for i in range(Ncircuits)])
self.DP_r = np.mean([self.Evaps[i].DP_r
for i in range(Ncircuits)]) #simplified
self.DP_r_superheat = np.mean([
self.Evaps[i].DP_r_superheat for i in range(Ncircuits)
]) #simplified
self.DP_r_2phase = np.mean(
[self.Evaps[i].DP_r_2phase for i in range(Ncircuits)]) #simplified
self.Tin_r = np.mean([self.Evaps[i].Tin_r
for i in range(Ncircuits)]) #simplified
self.h_r_superheat = np.mean([
self.Evaps[i].h_r_superheat for i in range(Ncircuits)
]) #simplified, really should consider flowrate
self.h_r_2phase = np.mean([
self.Evaps[i].h_r_2phase for i in range(Ncircuits)
]) #simplified, really should consider flowrate
self.w_superheat = np.sum(
[self.Evaps[i].w_superheat
for i in range(Ncircuits)]) / float(Ncircuits)
self.w_2phase = np.sum(
[self.Evaps[i].w_2phase
for i in range(Ncircuits)]) / float(Ncircuits)
self.hout_r = 0.0
for i in range(Ncircuits):
self.hout_r += self.Evaps[i].hout_r * self.Evaps[i].mdot_r
self.hout_r = (self.hout_r / sum(self.mdot_r))
self.Tin_a = self.Evaps[
0].Fins.Air.Tdb #assuming equal temperature for all circuits
self.Tout_a = 0.0
for i in range(Ncircuits):
self.Tout_a += self.Evaps[i].Tout_a * self.Evaps[i].Fins.Air.Vdot_ha
self.Tout_a = (self.Tout_a / sum(self.Fins.Air.Vdot_ha))
Pout_r = self.psat_r + self.DP_r / 1.0
hsatV_out = PropsSI('H', 'P', Pout_r, 'Q', 1.0, self.Ref)
hsatL_out = PropsSI('H', 'P', Pout_r, 'Q', 0.0, self.Ref)
if self.hout_r > hsatV_out:
self.Tout_r = PropsSI('T', 'H', self.hout_r, 'P', Pout_r,
self.Ref) #superheated temperature at outlet
else:
xout_r = ((self.hout_r - hsatL_out) / (hsatV_out - hsatL_out))
self.Tout_r = PropsSI(
'T', 'P', Pout_r, 'Q', xout_r,
self.Ref) #saturated temperature at outlet quality
self.Capacity = np.sum([self.Evaps[i].Q for i in range(Ncircuits)
]) - self.Fins.Air.FanPower
self.SHR = np.mean([self.Evaps[i].SHR for i in range(Ncircuits)])
self.UA_a = np.sum([self.Evaps[i].UA_a for i in range(Ncircuits)])
self.UA_r = np.sum([self.Evaps[i].UA_r for i in range(Ncircuits)])
self.Q_superheat = np.sum(
[self.Evaps[i].Q_superheat for i in range(Ncircuits)])
self.Q_2phase = np.sum(
[self.Evaps[i].Q_2phase for i in range(Ncircuits)])
#Convert back to a single value for the overall evaporator
self.Fins.Air.Vdot_ha = float(self.Fins.Air.Vdot_ha[-1])
if self.Verbosity > 0:
print chr(127), #progress bar