def calculate_eff(q_cap, work_fl, amb_work_fl_cond, amb_work_fl_evap, t_cond,
overc_cond, t_evap, overh_evap, press_bef_turb,
temp_bef_turb, pr_evap, amb_pr_evap, pr_cond, amb_pr_cond,
pr_boil, amb_t_evap_in, amb_t_evap_out, amb_t_cond_in,
amb_t_cond_out, amb_p_evap_out, amb_p_cond_out,
isent_eff_turb, isent_eff_pump, elec_eff_pump,
isent_eff_comp, eff_boil, fuel_heat_val, eff_turboeq):
# The functions starts with creating tables to collect values of important attributes, each of them has 11 places:
# indexes 1,2,3,4 for refrigeration cycle (1 is before the compressor, 4 is before evaporator),
# indexes 5,6,7,8 - for power cycle (5 is before the turbine, 8 is before the boiler)
# indexes 9, 10 - for condenser applied for both cycles
pres = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
temp = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
enth = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
entr = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
temp[10] = t_cond - overc_cond
temp[3] = temp[10]
temp[7] = temp[10]
temp[4] = t_evap
pres[5] = press_bef_turb
temp[5] = temp_bef_turb
pres[8] = press_bef_turb / pr_boil
# Calculation of the refrigeration cycle starts from throttling valve, as for the next step the value of enthalpy
# in two-phase zone is needed.
throttling_valve = ThrottlingValve(temp_in=temp[3],
overc_cond=overc_cond,
temp_out=temp[4],
work_fl=work_fl)
throttling_valve.calculate()
enth[3] = throttling_valve.enth_in
entr[3] = throttling_valve.entr_in
enth[4] = throttling_valve.enth_out
entr[4] = throttling_valve.entr_out
pres[3] = throttling_valve.press_in
pres[4] = throttling_valve.press_out
enth[10] = throttling_valve.enth_in
entr[10] = throttling_valve.entr_in
pres[10] = pres[3]
pres[7] = pres[3]
pres[9] = pres[10] / pr_cond
pres[2] = pres[9]
pres[6] = pres[9]
# The next step is evaporator:
evaporator = Evaporator(enth_in=enth[4],
temp_in=temp[4],
overh=overh_evap,
q_cap=q_cap,
work_fl=work_fl,
amb_work_fl=amb_work_fl_evap,
pr=pr_evap,
amb_pr=amb_pr_evap,
amb_temp_in=amb_t_evap_in,
amb_temp_out=amb_t_evap_out,
amb_press_out=amb_p_evap_out)
evaporator.set_attr_refr_cyc()
evaporator.calculate()
temp[1] = evaporator.temp_out
pres[1] = evaporator.press_out
enth[1] = evaporator.enth_out
entr[1] = evaporator.entr_out
throttling_valve.mass_fl = evaporator.mass_fl
# The next step, after calculating output of evaporator, is a compressor.
compressor = Compressor(press_in=pres[1],
entr_in=entr[1],
enth_in=enth[1],
work_fl=work_fl,
press_out=pres[2],
isent_eff=isent_eff_comp,
mass_fl=evaporator.mass_fl)
compressor.calculate()
temp[2] = compressor.temp_out
enth[2] = compressor.enth_out
entr[2] = compressor.entr_out
# With the compressor power demand calculated, it is possible to calculate the power demand of the turbine using
# the class Turboequipment, which was created for the purpose of the combined cycle.
# Turbine:
turbine = Turbine(cycle_name="cycle",
press_in=pres[5],
temp_in=temp[5],
press_out=pres[6],
work_fl=work_fl,
isent_eff=isent_eff_turb)
turbine.calculate()
entr[5] = turbine.entr_in
enth[5] = turbine.enth_in
entr[6] = turbine.entr_out
enth[6] = turbine.enth_out
temp[6] = turbine.temp_out
turboequipment = Turboequipment(compressor=compressor,
turbine=turbine,
eff=eff_turboeq)
turboequipment.calculate()
# Pump:
pump = Pump(cycle_name="cycle",
mass_fl=turbine.mass_fl,
press_in=pres[7],
press_out=pres[8],
temp_in=temp[7],
work_fl=work_fl,
isent_eff=isent_eff_pump,
elec_eff=elec_eff_pump)
# For the instance of class Pump received mass flow as argument, the function calculate() will calculate powers.
# Using additionally function Pump.calculate_powers() is unnecessary.
pump.calculate()
enth[7] = pump.enth_in
entr[7] = pump.entr_in
entr[8] = pump.entr_out
enth[8] = pump.enth_out
temp[8] = pump.temp_out
# The last step is creating an instance of class Boiler in order to calculate the value of fuel demand.
boiler = Boiler(temp_in=temp[8],
temp_out=temp[5],
press_out=pres[5],
work_fl=work_fl,
mass_fl=turbine.mass_fl,
fuel_heat_val=fuel_heat_val,
eff=eff_boil,
pr=pr_boil)
boiler.calculate_fuel_dem()
# In order to calculate required mass flow of the ambient air in condenser:
mixer = Mixer(press_in=pres[6],
enth_in_1=enth[6],
enth_in_2=enth[2],
mass_fl_in_1=turbine.mass_fl,
mass_fl_in_2=compressor.mass_fl,
work_fl=work_fl)
mixer.calculate()
temp[9] = mixer.temp_out
pres[9] = mixer.press_out
enth[9] = mixer.enth_out
entr[9] = mixer.entr_out
# To be sure, that the TESPy software will read the points properly (it's unsure what phase the fluid will be),
# the refrigeration condenser will be calculated, as it uses values of enthalpies in the function calculate(),
# which, in combination with pressures, ensures proper choice of the parameters points on the p-h plot.
condenser = Condenser(enth_out=enth[10],
enth_in=enth[9],
press_in=pres[9],
mass_fl=mixer.mass_fl_out,
work_fl=work_fl,
amb_work_fl=amb_work_fl_cond,
pr=pr_cond,
amb_pr=amb_pr_cond,
amb_temp_in=amb_t_cond_in,
amb_temp_out=amb_t_cond_out,
amb_press_out=amb_p_cond_out)
condenser.set_attr_combined_cycle()
condenser.calculate_combined_cyc()
temp_in_cond = evaporator.generate_enthalpies_data(accuracy=10)
efficiency = round(
evaporator.q_cap / (boiler.fuel_dem * boiler.fuel_heat_val), 8)
print(efficiency)
return efficiency
