148 lines
5.4 KiB
Python
148 lines
5.4 KiB
Python
from functools import reduce
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import cantera as ct
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# Air stream Temperatures and Mass flow rates
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t = list(map(float, ''' 348.15 315.65 600.79 308.54 318.03 306.11 339.45 '''.split()))
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m = list(map(float, ''' 114.4 6.94 362.92 7.25 7.25 7.25 7.25 '''.split()))
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coalT = 348.15
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coalMfr = 56.8813
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moist = 0.1551
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vm = 0.3047
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fc = 0.4347
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ash = 0.1055
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vm_fc = 1. - moist - ash
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fuelMfr = coalMfr
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gri_species = {S.name: S for S in ct.Species.listFromFile('gri30.cti')}
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nasa_species = {S.name: S for S in ct.Species.listFromFile('nasa_gas.cti')}
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nasa_species.update(gri_species)
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system_species = [nasa_species[S] for S in (str.split(' C S H2 O2 N2 CO CO2 H2O SO2 '))]
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"""#############################################################################
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Calculate averaged air property
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#############################################################################"""
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gases = [ct.Solution(thermo='IdealGas', species=system_species) for i in range(7)]
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for i, gas in enumerate(gases):
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gas.TPY = t[i], ct.one_atm, "O2: 0.233, N2: 0.767"
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airs = [
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ct.Quantity(gas, constant='HP', mass=m[i])
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for i, gas in enumerate(gases)
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]
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for i, air in enumerate(airs):
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print("air {}, T = {}, mass flow rate = {}".format(i+1, air.T, air.mass))
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airmix = reduce(lambda a, b: a+b, airs)
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print("Total Air flow rate = ", airmix.mass)
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"""#############################################################################
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Dummy gaseous coal object containing elementary composition
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mass of moisture and ash contents is added to N2
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#############################################################################"""
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coal = ct.Solution(thermo='IdealGas', species=system_species)
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coal.TPY = 348.15, ct.one_atm, '''\
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C: 81.41,
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H2: 5.47,
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O2: 10.83,
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N2: 36.9647930755,
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S: 0.57
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'''
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"""#############################################################################
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Coal + v O2 = (Y_C/W_C) CO2 + (Y_H/W_H/2) H2O + (Y_S/W_S) SO2 + (Y_N/W_N) N2
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Heating value = Sum(Product Enthalpy of Formation) - Sum(Reactant Enthalpy of Formation)
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#############################################################################"""
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# coal heating value = 5761 Kcal/kg * 4.184 kJ/kcal
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coalHV = - 5761 * 4.184 # J/kg, with Moisture and Ash
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coalHVdaf = - 5761 * 4.184 / vm_fc # kJ/kg, Dry and Ash Free, Negative since exothermic
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print("HV of Coal , kJ/kg = ", coalHV)
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print("HV of Coal(daf), kJ/kg = ", coalHVdaf)
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# sum product of 1kg coal enthalpy of formation - kJ/kg
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sum_product_hf = (
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- 32762.45348 * coal.mass_fraction_dict()['C']
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- 141887.60121 * coal.mass_fraction_dict()['H2']
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- 8919.38250 * coal.mass_fraction_dict()['S'])
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print("Sum(Hf_product), kJ/kg = ", sum_product_hf)
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sum_coal_hf = - coalHV + sum_product_hf
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print("Sum(Hf_reactant), kJ/kg = ", sum_coal_hf)
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"""#############################################################################
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Coal Enthalpy at 348.15 K = \Delta H_f + (H(348.15) - H(298.15))
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- Use graphite's Cp to calculate H difference (H(348.15) - H(298.15))
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#############################################################################"""
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gr = ct.Solution('graphite.cti')
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gr.TP = coalT, ct.one_atm
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coal_preheat_enthalpy = gr.enthalpy_mass / 1000. # kJ/kg
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print("Coal preheat H , kJ/kg = ", coal_preheat_enthalpy)
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coal_enthalpy = sum_coal_hf + coal_preheat_enthalpy
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print("Coal enthalpy , kJ/kg = ", coal_enthalpy)
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print("Dummy Coal H , kJ/kg = ", coal.enthalpy_mass/1000.)
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"""#############################################################################
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Can't Set coal object's H to coal_enthalpy since it is composed of gaseous
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C S H2 O2 N2 and can't have H=coal_enthalpy with T >= 0 K.
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Therefore only difference between real coal enthalpy and dummy gas coal is
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caculated and enthalpy difference will be added later.
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#############################################################################"""
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enthalpy_added_after_mixing = (coal_enthalpy*1000 - coal.enthalpy_mass) * fuelMfr # J
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print("enthalpy to add later = ", enthalpy_added_after_mixing)
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################################################################################
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## Adiabatic Flame Temperature
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## - also adjust enthalpy difference btw dummy gas fuel and real solid fuel
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################################################################################
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reactant = airmix + ct.Quantity(coal, constant='HP', mass=fuelMfr)
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print("Total Mass flow rate = ", reactant.mass)
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################################################################################
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## Adiabatic Flame Temperature
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## - also adjust enthalpy difference btw dummy gas fuel and real solid fuel
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################################################################################
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reactant.equilibrate("HP")
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reactant.HP = reactant.enthalpy/reactant.mass + enthalpy_added_after_mixing/reactant.mass, ct.one_atm
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reactant.equilibrate("HP")
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print("")
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print("Chemical Equilibrium")
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reactant.phase()
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################################################################################
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## Heat Transfer to pipes and walls
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################################################################################
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heatXferPipe = 677656911.111 # J/s
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heatXferWall = 592070866.667 # J/s
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reactant.HP = reactant.enthalpy/reactant.mass - (heatXferWall+heatXferPipe)/reactant.mass, ct.one_atm
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print("After Heat Transfer")
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reactant.phase()
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note_ref='''\
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Reference for Estimation of Coal Enthalpy of Formation
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Eqn (14) and (15) of
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Sciazko, M. (2013). Rank-dependent formation enthalpy of coal. Fuel, 114, 2-9. doi:10.1016/j.fuel.2012.06.099
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'''
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