Account for fuel LHV in fuel enthalpy about pycycle HOT 2 OPEN

# CONSTANTS ===============================================================
C_calToJoule = 4.184     # J/cal, conversion constant
C_lbmToGram = 453.59     # g/lbm, conversion constant
C_BTUtoCal = 252.16      # cal/BTU, conversion constant
C_BTUtoJoule = 1055.056  # J/BTU, conversion constant
hof_CO2 = -393510.      # heat of formation of CO2, J/mol
hof_H2O = -241826.      # heat of formation of water, J/mol
 
MW_C = 12.0107        # molar weight of Carbon, g/mol
MW_H = 2.01588/2.     # molar weight of Hydrogen, g/mol
MW_O2 = 31.9988       # molar weight of DIatomic Oxygen, g/mol
MW_N = 28.0134/2.     # molar weight of Nitrogen, g/mol
 
MW_air = 28.965116    # molar weight of air
fAir_O2 = 0.23141563  # fraction of air that is O2 by mass

#  air is defined by CEA on a molar basis as:
#  78.0840 mol N2    20.9476 mol O2    0.9365 mol Ar    0.0319 mol CO2
# uncomment the following lines if a different air composition is desired
# MW_air = (78.084*(MW_N*2.) + 20.9476*MW_O2 + 0.9365*39.948 + 0.0319*44.0095 )/100.;
# fAir_O2 = (20.9476*MW_O2/100. ) / MW_air;
 
 
# INPUTS ==================================================================
Carbon = 0.         # number of Carbon atoms in the fuel
Hydrogen = 2     # number of Hydrogen atoms in the fuel
Oxygen = 0.         # number of Oxygen atoms in the fuel
Nitrogen = 0.       # number of Nitrogen atoms in the fuel

fuelHOF = -218000   # heat of formation of the fuel, J/mol e.g. -45940 J/mol for NH3
                    # hydrogen: 218,000 J/mol

effComb = 1.        # combustion efficiency
 
 
# molar weight of fuel from input definition
MW_fuel = Carbon*MW_C + Hydrogen*MW_H + Nitrogen*MW_N + Oxygen*MW_O2/2.;


# OUTPUTS =================================================================
# MW_fuel              # molar weight of the fuel, g/mol
# mFuel                # mass of fuel from stoichiometric reaction
# mO2                  # mass of Oxygen from stoichiometric reaction
# OFratio              # Oxygen-to-fuel mass ratio
# LHV                  # fuel lower heating value, BTU/lbm
# FARstoich            # stoichiometric fuel-to-air mass ratio
 
 
 
#  J/mol  cal/J  g/lbm  BTU/cal  mol/g = BTU/lbm
LHV = (( fuelHOF - Carbon*(hof_CO2) - Hydrogen*(hof_H2O)/2. )
       /C_calToJoule * C_lbmToGram / C_BTUtoCal / MW_fuel / effComb)
 
 
# assumed stoichiometric reaction, fuel is defined as CxHyNwOz
#  xC yH wN zO + qO2 --> xCO2 + (y/2)H2O + (w/2)N2    where q = x + y/4 - z/2
mFuel = Carbon*MW_C + Hydrogen*MW_H + Nitrogen*MW_N + Oxygen*MW_O2/2.;
mO2 = ( Carbon + Hydrogen/4. - Oxygen/2. )*MW_O2;
OFratio = mO2 / mFuel;
FARstoich = fAir_O2 / OFratio;
 
print("LHV =", LHV, " BTU/lbm ")
print("FAR stoich = " ,FARstoich)

# CONSTANTS ===============================================================
C_calToJoule = 4.184     # cal/J, conversion constant
C_lbmToGram = 453.59     # g/lbm, conversion constant
C_BTUtoCal = 252.16      # cal/BTU, conversion constant
C_BTUtoJoule = 1055.056  # BTU/J, conversion constant
hof_CO2 = -393510.      # heat of formation of CO2, J/mol
hof_H2O = -241826.      # heat of formation of water, J/mol
 
MW_C = 12.0107        # molar weight of Carbon, g/mol
MW_H = 2.01588/2.     # molar weight of Hydrogen, g/mol
MW_O2 = 31.9988       # molar weight of Diatomic Oxygen, g/mol
MW_N = 28.0134/2.     # molar weight of Nitrogen, g/mol
 
MW_air = 28.965116    # molar weight of air
fAir_O2 = 0.23141563  # fraction of air that is O2 by mass

#  air is defined by CEA on a molar basis as:
#  78.0840 mol N2    20.9476 mol O2    0.9365 mol Ar    0.0319 mol CO2
# uncomment the following lines if a different air composition is desired
# MW_air = (78.084*(MW_N*2.) + 20.9476*MW_O2 + 0.9365*39.948 + 0.0319*44.0095 )/100.;
# fAir_O2 = (20.9476*MW_O2/100. ) / MW_air;
 
 
# INPUTS ==================================================================
Carbon = 12         # number of Carbon atoms in the fuel
Hydrogen = 23     # number of Hydrogen atoms in the fuel
Oxygen = 0         # number of Oxygen atoms in the fuel
Nitrogen = 0       # number of Nitrogen atoms in the fuel
effComb = 1.        # combustion efficiency
 
# molar weight of fuel g/mol
fuelMW = Carbon*MW_C + Hydrogen*MW_H + Nitrogen*MW_N + Oxygen*MW_O2/2.;

print("fuel molar weight (g/mol): ",fuelMW)


# OUTPUTS =================================================================
# mFuel                # mass of fuel from stoichiometric reaction
# mO2                  # mass of Oxygen from stoichiometric reaction
# OFratio              # Oxygen-to-fuel mass ratio
# LHV                  # fuel lower heating value, BTU/lbm
# FARstoich            # stoichiometric fuel-to-air mass ratio
 

fuelLHV = 18529.6813 # BTU/lbm

fuelHOF = fuelLHV*fuelMW*effComb/C_lbmToGram*C_BTUtoJoule + Carbon*(hof_CO2) + Hydrogen*(hof_H2O)/2.
# fuelHOF = fuelLHV*fuelMW*effComb/C_lbmToGram*C_BTUtoCal + Carbon*(-94051.15) + Hydrogen*(-57797.8)/2.

print("fuelHOF (J/mol): ", fuelHOF)
print("fuelHOF (cal/mol): ", fuelHOF/C_calToJoule)

fuel_h = fuelHOF/fuelMW # J/g
 
print('fuel_h (J/g): ', fuel_h)
print('fuel_h (BTU/lbm): ', fuel_h/C_BTUtoJoule*C_lbmToGram)