/
sco2_turbinesplitflow_cycle.cpp
1247 lines (1033 loc) · 52.5 KB
/
sco2_turbinesplitflow_cycle.cpp
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/*
BSD 3-Clause License
Copyright (c) Alliance for Sustainable Energy, LLC. See also https://github.com/NREL/ssc/blob/develop/LICENSE
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "sco2_turbinesplitflow_cycle.h"
#include "sco2_cycle_components.h"
#include "CO2_properties.h"
#include "fmin.h"
// ********************************************************************************** C_sco2_tsf_core CORE MODEL
void C_sco2_tsf_core::initialize_solve()
{
m_outputs.Init();
}
int C_sco2_tsf_core::solve()
{
initialize_solve();
m_outputs.m_error_code = -1;
// Apply scaling to the turbomachinery here
{
m_outputs.m_mc_ms.m_r_W_dot_scale = m_inputs.m_W_dot_net_design / 10.E3; //[-]
m_outputs.m_t.m_r_W_dot_scale = m_outputs.m_mc_ms.m_r_W_dot_scale; //[-]
m_outputs.m_t2.m_r_W_dot_scale = m_outputs.m_mc_ms.m_r_W_dot_scale; //[-]
}
// Initialize Recuperators
{
// LTR
m_outputs.mc_LT_recup.initialize(m_inputs.m_LTR_N_sub_hxrs, m_inputs.m_LTR_od_UA_target_type);
// HTR
m_outputs.mc_HT_recup.initialize(m_inputs.m_HTR_N_sub_hxrs, m_inputs.m_HTR_od_UA_target_type);
}
// Initialize a few variables
{
m_outputs.m_temp[C_sco2_cycle_core::MC_IN] = m_inputs.m_T_mc_in; //[K]
m_outputs.m_pres[C_sco2_cycle_core::MC_IN] = m_inputs.m_P_mc_in;
m_outputs.m_pres[C_sco2_cycle_core::MC_OUT] = m_inputs.m_P_mc_out;
m_outputs.m_temp[C_sco2_cycle_core::TURB_IN] = m_inputs.m_T_t_in; //[K]
}
// Apply pressure drops to heat exchangers, fully defining the pressures at all states
{
// LTR_HP_OUT
if (m_inputs.m_DP_LTR[0] < 0.0)
m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_OUT] - m_outputs.m_pres[C_sco2_cycle_core::MC_OUT] * std::abs(m_inputs.m_DP_LTR[0]); // relative pressure drop specified for LT recuperator (cold stream)
else
m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_OUT] - m_inputs.m_DP_LTR[0]; // absolute pressure drop specified for LT recuperator (cold stream)
if ((m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA && m_inputs.m_LTR_UA < 1.0E-12)
|| (m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::TARGET_UA && m_inputs.m_LTR_UA < 1.0E-12)
|| (m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::TARGET_MIN_DT && m_inputs.m_LTR_min_dT < 1.0E-12)
|| (m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::TARGET_EFFECTIVENESS && m_inputs.m_LTR_eff_target < 1.0E-12))
m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_OUT]; // If there is no LT recuperator, there is no pressure drop
// TURB_IN
if (m_inputs.m_DP_PHX[0] < 0.0)
m_outputs.m_pres[C_sco2_cycle_core::TURB_IN] = m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT] - m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT] * std::abs(m_inputs.m_DP_PHX[0]); // relative pressure drop specified for PHX
else
m_outputs.m_pres[C_sco2_cycle_core::TURB_IN] = m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT] - m_inputs.m_DP_PHX[0]; // absolute pressure drop specified for PHX
// HTR_HP_OUT
if (m_inputs.m_DP_HTR[0] < 0.0)
m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_OUT] - m_outputs.m_pres[C_sco2_cycle_core::MC_OUT] * std::abs(m_inputs.m_DP_HTR[0]); // relative pressure drop specified for HT recuperator (cold stream)
else
m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_OUT] - m_inputs.m_DP_HTR[0]; // absolute pressure drop specified for HT recuperator (cold stream)
if ((m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA && m_inputs.m_HTR_UA < 1.0E-12)
|| (m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::TARGET_UA && m_inputs.m_HTR_UA < 1.0E-12)
|| (m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::TARGET_MIN_DT && m_inputs.m_HTR_min_dT < 1.0E-12)
|| (m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::TARGET_EFFECTIVENESS && m_inputs.m_HTR_eff_target < 1.0E-12))
m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_OUT]; // If there is no HT recuperator, there is no pressure drop
// MIXER_OUT
if (m_inputs.m_DP_PC_main[1] < 0.0)
m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_IN] / (1.0 - std::abs(m_inputs.m_DP_PC_main[1])); // relative pressure drop specified for precooler: P1=P9-P9*rel_DP => P1=P9*(1-rel_DP)
else
m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MC_IN] + m_inputs.m_DP_PC_main[1];
// LTR_LP_OUT
m_outputs.m_pres[C_sco2_cycle_core::LTR_LP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT]; // Assume no pressure drop in mixer
// HTR_LP_OUT
m_outputs.m_pres[C_sco2_cycle_core::HTR_LP_OUT] = m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT]; // Assume no pressure drop in mixer
// TURB_OUT
if (m_inputs.m_DP_HTR[1] < 0.0)
m_outputs.m_pres[C_sco2_cycle_core::TURB_OUT] = m_outputs.m_pres[C_sco2_cycle_core::HTR_LP_OUT] / (1.0 - std::abs(m_inputs.m_DP_HTR[1])); // relative pressure drop specified for HT recuperator (hot stream)
else
m_outputs.m_pres[C_sco2_cycle_core::TURB_OUT] = m_outputs.m_pres[C_sco2_cycle_core::HTR_LP_OUT] + m_inputs.m_DP_HTR[1]; // absolute pressure drop specified for HT recuperator (hot stream)
if ((m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA && m_inputs.m_HTR_UA < 1.0E-12)
|| (m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::TARGET_UA && m_inputs.m_HTR_UA < 1.0E-12)
|| (m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::TARGET_MIN_DT && m_inputs.m_HTR_min_dT < 1.0E-12)
|| (m_inputs.m_HTR_target_code == NS_HX_counterflow_eqs::TARGET_EFFECTIVENESS && m_inputs.m_HTR_eff_target < 1.0E-12))
m_outputs.m_pres[C_sco2_cycle_core::TURB_OUT] = m_outputs.m_pres[C_sco2_cycle_core::HTR_LP_OUT]; // if there is no HT recuperator, there is no pressure drop
// TURB2_OUT
if (m_inputs.m_DP_LTR[1] < 0.0)
m_outputs.m_pres[C_sco2_cycle_core::TURB2_OUT] = m_outputs.m_pres[C_sco2_cycle_core::LTR_LP_OUT] / (1.0 - std::abs(m_inputs.m_DP_LTR[1])); // relative pressure drop specified for LT recuperator (hot stream)
else
m_outputs.m_pres[C_sco2_cycle_core::TURB2_OUT] = m_outputs.m_pres[C_sco2_cycle_core::LTR_LP_OUT] + m_inputs.m_DP_LTR[1]; // absolute pressure drop specified for HT recuperator (hot stream)
if ((m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA && m_inputs.m_LTR_UA < 1.0E-12)
|| (m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::TARGET_UA && m_inputs.m_LTR_UA < 1.0E-12)
|| (m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::TARGET_MIN_DT && m_inputs.m_LTR_min_dT < 1.0E-12)
|| (m_inputs.m_LTR_target_code == NS_HX_counterflow_eqs::TARGET_EFFECTIVENESS && m_inputs.m_LTR_eff_target < 1.0E-12))
m_outputs.m_pres[C_sco2_cycle_core::TURB2_OUT] = m_outputs.m_pres[C_sco2_cycle_core::LTR_LP_OUT]; // if there is no LT recuperator, there is no pressure drop
}
// Determine equivalent isentropic efficiencies for main compressor and turbine, if necessary.
double eta_mc_isen = std::numeric_limits<double>::quiet_NaN();
double eta_t_isen = std::numeric_limits<double>::quiet_NaN();
{
if (m_inputs.m_eta_mc < 0.0)
{
int poly_error_code = 0;
isen_eta_from_poly_eta(m_outputs.m_temp[C_sco2_cycle_core::MC_IN], m_outputs.m_pres[C_sco2_cycle_core::MC_IN], m_outputs.m_pres[C_sco2_cycle_core::MC_OUT], std::abs(m_inputs.m_eta_mc),
true, poly_error_code, eta_mc_isen);
if (poly_error_code != 0)
{
m_outputs.m_error_code = poly_error_code;
return m_outputs.m_error_code;
}
}
else
eta_mc_isen = m_inputs.m_eta_mc;
if (m_inputs.m_eta_t < 0.0)
{
int poly_error_code = 0;
isen_eta_from_poly_eta(m_outputs.m_temp[C_sco2_cycle_core::TURB_IN], m_outputs.m_pres[C_sco2_cycle_core::TURB_IN], m_outputs.m_pres[C_sco2_cycle_core::TURB_OUT], std::abs(m_inputs.m_eta_t),
false, poly_error_code, eta_t_isen);
if (poly_error_code != 0)
{
m_outputs.m_error_code = poly_error_code;
return m_outputs.m_error_code;
}
}
else
eta_t_isen = m_inputs.m_eta_t;
}
// Determine the outlet state and specific work for the main compressor and turbine.
// Main compressor
m_outputs.m_w_mc = std::numeric_limits<double>::quiet_NaN();
{
int comp_error_code = 0;
calculate_turbomachinery_outlet_1(m_outputs.m_temp[C_sco2_cycle_core::MC_IN], m_outputs.m_pres[C_sco2_cycle_core::MC_IN], m_outputs.m_pres[C_sco2_cycle_core::MC_OUT], eta_mc_isen, true,
comp_error_code, m_outputs.m_enth[C_sco2_cycle_core::MC_IN], m_outputs.m_entr[C_sco2_cycle_core::MC_IN], m_outputs.m_dens[C_sco2_cycle_core::MC_IN], m_outputs.m_temp[C_sco2_cycle_core::MC_OUT],
m_outputs.m_enth[C_sco2_cycle_core::MC_OUT], m_outputs.m_entr[C_sco2_cycle_core::MC_OUT], m_outputs.m_dens[C_sco2_cycle_core::MC_OUT], m_outputs.m_w_mc);
if (comp_error_code != 0)
{
m_outputs.m_error_code = comp_error_code;
return m_outputs.m_error_code;
}
}
// Turbine
m_outputs.m_w_t = std::numeric_limits<double>::quiet_NaN();
{
int turbine_error_code = 0;
calculate_turbomachinery_outlet_1(m_outputs.m_temp[C_sco2_cycle_core::TURB_IN], m_outputs.m_pres[C_sco2_cycle_core::TURB_IN], m_outputs.m_pres[C_sco2_cycle_core::TURB_OUT], eta_t_isen, false,
turbine_error_code, m_outputs.m_enth[C_sco2_cycle_core::TURB_IN], m_outputs.m_entr[C_sco2_cycle_core::TURB_IN], m_outputs.m_dens[C_sco2_cycle_core::TURB_IN], m_outputs.m_temp[C_sco2_cycle_core::TURB_OUT],
m_outputs.m_enth[C_sco2_cycle_core::TURB_OUT], m_outputs.m_entr[C_sco2_cycle_core::TURB_OUT], m_outputs.m_dens[C_sco2_cycle_core::TURB_OUT], m_outputs.m_w_t);
if (turbine_error_code != 0)
{
m_outputs.m_error_code = turbine_error_code;
return m_outputs.m_error_code;
}
}
// Solve HTR_HP_OUT Temp (iteratively)
{
// Make monotonic solver
C_mono_tsf_core_HTR_des HTR_des_eq(this);
C_monotonic_eq_solver HTR_des_solver(HTR_des_eq);
// Bounds
double T_HTR_HP_out_lower = m_outputs.m_temp[C_sco2_cycle_core::MC_OUT]; //[K] Coldest possible temp
double T_HTR_HP_out_upper = m_outputs.m_temp[C_sco2_cycle_core::TURB_IN]; //[K] Coldest possible temp (probably is TURB_OUT)
// Solution Guess
double T_HTR_HP_out_guess_lower = 0.25 * (T_HTR_HP_out_upper - T_HTR_HP_out_lower) + T_HTR_HP_out_lower; // [K]
double T_HTR_HP_out_guess_upper = 0.75 * (T_HTR_HP_out_upper - T_HTR_HP_out_lower) + T_HTR_HP_out_lower; // [K]
// Optimization Settings
HTR_des_solver.settings(m_inputs.m_des_tol* m_outputs.m_temp[C_sco2_cycle_core::MC_IN], 1000, T_HTR_HP_out_lower, T_HTR_HP_out_upper, false);
// Optimization Output variables
double tol_T_HTR_HP_out_solved;
double T_HTR_HP_out_solved = tol_T_HTR_HP_out_solved = std::numeric_limits<double>::quiet_NaN();
int iter_T_HTR_LP_out = -1;
// Optimize
int T_HTR_HP_out_code = HTR_des_solver.solve(T_HTR_HP_out_guess_lower, T_HTR_HP_out_guess_upper, 0,
T_HTR_HP_out_solved, tol_T_HTR_HP_out_solved, iter_T_HTR_LP_out);
// Check if converged
if (T_HTR_HP_out_code != C_monotonic_eq_solver::CONVERGED)
{
m_outputs.m_error_code = 25;
return m_outputs.m_error_code;
}
// Run Calculated HTR HP Out (to set correct temps)
double dummy;
solve_HTR(T_HTR_HP_out_solved, &dummy);
}
// Complete HTR_HP_OUT and HTR_LP_OUT co2 properties
{
int prop_error_code = CO2_TP(m_outputs.m_temp[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT], &m_co2_props);
if (prop_error_code != 0)
{
m_outputs.m_error_code = prop_error_code;
return m_outputs.m_error_code;
}
m_outputs.m_enth[C_sco2_cycle_core::HTR_HP_OUT] = m_co2_props.enth;
m_outputs.m_entr[C_sco2_cycle_core::HTR_HP_OUT] = m_co2_props.entr;
m_outputs.m_dens[C_sco2_cycle_core::HTR_HP_OUT] = m_co2_props.dens;
prop_error_code = CO2_TP(m_outputs.m_temp[C_sco2_cycle_core::HTR_LP_OUT], m_outputs.m_pres[C_sco2_cycle_core::HTR_LP_OUT], &m_co2_props);
if (prop_error_code != 0)
{
m_outputs.m_error_code = prop_error_code;
return m_outputs.m_error_code;
}
m_outputs.m_enth[C_sco2_cycle_core::HTR_LP_OUT] = m_co2_props.enth;
m_outputs.m_entr[C_sco2_cycle_core::HTR_LP_OUT] = m_co2_props.entr;
m_outputs.m_dens[C_sco2_cycle_core::HTR_LP_OUT] = m_co2_props.dens;
}
// Simulate LTR
{
m_outputs.mc_LT_recup.design_for_target__calc_outlet(m_inputs.m_LTR_target_code,
m_inputs.m_LTR_UA, m_inputs.m_LTR_min_dT, m_inputs.m_LTR_eff_target,
m_inputs.m_LTR_eff_max,
m_outputs.m_temp[C_sco2_cycle_core::MC_OUT], m_outputs.m_pres[C_sco2_cycle_core::MC_OUT], m_outputs.m_m_dot_t, m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT],
m_outputs.m_temp[C_sco2_cycle_core::TURB2_OUT], m_outputs.m_pres[C_sco2_cycle_core::TURB2_OUT], m_outputs.m_m_dot_t2, m_outputs.m_pres[C_sco2_cycle_core::LTR_LP_OUT],
m_inputs.m_des_tol,
m_outputs.m_Q_dot_LT, m_outputs.m_temp[C_sco2_cycle_core::LTR_HP_OUT], m_outputs.m_temp[C_sco2_cycle_core::LTR_LP_OUT]);
}
// Complete LTR_HP_OUT and LTR_LP_OUT co2 properties
{
int prop_error_code = CO2_TP(m_outputs.m_temp[C_sco2_cycle_core::LTR_HP_OUT], m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT], &m_co2_props);
if (prop_error_code != 0)
{
m_outputs.m_error_code = prop_error_code;
return m_outputs.m_error_code;
}
m_outputs.m_enth[C_sco2_cycle_core::LTR_HP_OUT] = m_co2_props.enth;
m_outputs.m_entr[C_sco2_cycle_core::LTR_HP_OUT] = m_co2_props.entr;
m_outputs.m_dens[C_sco2_cycle_core::LTR_HP_OUT] = m_co2_props.dens;
prop_error_code = CO2_TP(m_outputs.m_temp[C_sco2_cycle_core::LTR_LP_OUT], m_outputs.m_pres[C_sco2_cycle_core::LTR_LP_OUT], &m_co2_props);
if (prop_error_code != 0)
{
m_outputs.m_error_code = prop_error_code;
return m_outputs.m_error_code;
}
m_outputs.m_enth[C_sco2_cycle_core::LTR_LP_OUT] = m_co2_props.enth;
m_outputs.m_entr[C_sco2_cycle_core::LTR_LP_OUT] = m_co2_props.entr;
m_outputs.m_dens[C_sco2_cycle_core::LTR_LP_OUT] = m_co2_props.dens;
}
// Simulate Mixer
{
m_outputs.m_enth[C_sco2_cycle_core::MIXER_OUT] = ((1.0 - m_inputs.m_split_frac) * m_outputs.m_enth[C_sco2_cycle_core::HTR_LP_OUT])
+ (m_inputs.m_split_frac * m_outputs.m_enth[C_sco2_cycle_core::LTR_LP_OUT]);
int prop_error_code = CO2_PH(m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT], m_outputs.m_enth[C_sco2_cycle_core::MIXER_OUT], &m_co2_props);
if (prop_error_code != 0)
{
m_outputs.m_error_code = prop_error_code;
return m_outputs.m_error_code;
}
m_outputs.m_temp[C_sco2_cycle_core::MIXER_OUT] = m_co2_props.temp; //[K]
m_outputs.m_entr[C_sco2_cycle_core::MIXER_OUT] = m_co2_props.entr; //[kJ/kg-K]
m_outputs.m_dens[C_sco2_cycle_core::MIXER_OUT] = m_co2_props.dens; //[kg/m^3]
}
// Calculate total work and heat metrics
{
// Work
m_outputs.m_W_dot_mc = m_outputs.m_w_mc * m_outputs.m_m_dot_mc;
m_outputs.m_W_dot_t = m_outputs.m_w_t * m_outputs.m_m_dot_t;
m_outputs.m_W_dot_t2 = m_outputs.m_w_t2 * m_outputs.m_m_dot_t2;
m_outputs.m_W_dot_net = m_outputs.m_W_dot_mc + m_outputs.m_W_dot_t + m_outputs.m_W_dot_t2;
// Air Cooler (heat rejection unit)
m_outputs.m_W_dot_air_cooler = m_inputs.m_frac_fan_power * m_outputs.m_W_dot_net;
m_outputs.m_Q_dot_air_cooler = m_outputs.m_m_dot_mc * (m_outputs.m_enth[C_sco2_cycle_core::MIXER_OUT] - m_outputs.m_enth[C_sco2_cycle_core::MC_IN]);
// Total heat entering sco2
m_outputs.m_Q_dot_PHX = m_outputs.m_m_dot_t * (m_outputs.m_enth[C_sco2_cycle_core::TURB_IN] - m_outputs.m_enth[C_sco2_cycle_core::LTR_HP_OUT]);
m_outputs.m_Q_dot_total = m_outputs.m_Q_dot_PHX;
// LTR
m_outputs.m_Q_dot_LTR_LP = m_outputs.m_m_dot_t2 * (m_outputs.m_enth[C_sco2_cycle_core::TURB2_OUT] - m_outputs.m_enth[C_sco2_cycle_core::LTR_LP_OUT]);
m_outputs.m_Q_dot_LTR_HP = m_outputs.m_m_dot_t * (m_outputs.m_enth[C_sco2_cycle_core::LTR_HP_OUT] - m_outputs.m_enth[C_sco2_cycle_core::MC_OUT]);
// LTR
m_outputs.m_Q_dot_HTR_LP = m_outputs.m_m_dot_t * (m_outputs.m_enth[C_sco2_cycle_core::TURB_OUT] - m_outputs.m_enth[C_sco2_cycle_core::HTR_LP_OUT]);
m_outputs.m_Q_dot_HTR_HP = m_outputs.m_m_dot_t2 * (m_outputs.m_enth[C_sco2_cycle_core::HTR_HP_OUT] - m_outputs.m_enth[C_sco2_cycle_core::MC_OUT]);
// Thermal Efficiency
m_outputs.m_eta_thermal = m_outputs.m_W_dot_net / m_outputs.m_Q_dot_total;
// Back Calculate Heat In
double Q_in_calc = m_outputs.m_W_dot_net + m_outputs.m_Q_dot_air_cooler;
}
// Define Heat Exchangers and Air Cooler
{
// PHX
C_HeatExchanger::S_design_parameters PHX_des_par;
PHX_des_par.m_DP_design[0] = m_outputs.m_pres[C_sco2_cycle_core::LTR_HP_OUT] - m_outputs.m_pres[C_sco2_cycle_core::TURB_IN];
PHX_des_par.m_DP_design[1] = 0.0;
PHX_des_par.m_m_dot_design[0] = m_outputs.m_m_dot_t;
PHX_des_par.m_m_dot_design[1] = 0.0;
PHX_des_par.m_Q_dot_design = m_outputs.m_m_dot_t * (m_outputs.m_enth[C_sco2_cycle_core::TURB_IN] - m_outputs.m_enth[C_sco2_cycle_core::LTR_HP_OUT]);
m_outputs.m_PHX.initialize(PHX_des_par);
// Air Cooler
C_HeatExchanger::S_design_parameters PC_des_par;
PC_des_par.m_DP_design[0] = 0.0;
PC_des_par.m_DP_design[1] = m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT] - m_outputs.m_pres[C_sco2_cycle_core::MC_IN];
PC_des_par.m_m_dot_design[0] = 0.0;
PC_des_par.m_m_dot_design[1] = m_outputs.m_m_dot_mc;
PC_des_par.m_Q_dot_design = m_outputs.m_m_dot_mc * (m_outputs.m_enth[C_sco2_cycle_core::MIXER_OUT] - m_outputs.m_enth[C_sco2_cycle_core::MC_IN]);
m_outputs.m_PC.initialize(PC_des_par);
}
m_outputs.m_error_code = 0;
return m_outputs.m_error_code;
}
int C_sco2_tsf_core::finalize_design(C_sco2_cycle_core::S_design_solved& design_solved)
{
// Design Main Compressor
{
int mc_design_err = m_outputs.m_mc_ms.design_given_outlet_state(m_inputs.m_mc_comp_model_code, m_outputs.m_temp[C_sco2_cycle_core::MC_IN],
m_outputs.m_pres[C_sco2_cycle_core::MC_IN],
m_outputs.m_m_dot_mc,
m_outputs.m_temp[C_sco2_cycle_core::MC_OUT],
m_outputs.m_pres[C_sco2_cycle_core::MC_OUT],
m_inputs.m_des_tol);
if (mc_design_err != 0)
{
m_outputs.m_error_code = mc_design_err;
return m_outputs.m_error_code;
}
}
// Size Turbine
{
C_turbine::S_design_parameters t_des_par;
// Set turbine shaft speed
t_des_par.m_N_design = m_inputs.m_N_turbine;
t_des_par.m_N_comp_design_if_linked = m_outputs.m_mc_ms.get_design_solved()->m_N_design; //[rpm] m_mc.get_design_solved()->m_N_design;
// Turbine inlet state
t_des_par.m_P_in = m_outputs.m_pres[C_sco2_cycle_core::TURB_IN];
t_des_par.m_T_in = m_outputs.m_temp[C_sco2_cycle_core::TURB_IN];
t_des_par.m_D_in = m_outputs.m_dens[C_sco2_cycle_core::TURB_IN];
t_des_par.m_h_in = m_outputs.m_enth[C_sco2_cycle_core::TURB_IN];
t_des_par.m_s_in = m_outputs.m_entr[C_sco2_cycle_core::TURB_IN];
// Turbine outlet state
t_des_par.m_P_out = m_outputs.m_pres[C_sco2_cycle_core::TURB_OUT];
t_des_par.m_h_out = m_outputs.m_enth[C_sco2_cycle_core::TURB_OUT];
// Mass flow
t_des_par.m_m_dot = m_outputs.m_m_dot_t;
int turb_size_error_code = 0;
m_outputs.m_t.turbine_sizing(t_des_par, turb_size_error_code);
if (turb_size_error_code != 0)
{
m_outputs.m_error_code = turb_size_error_code;
return m_outputs.m_error_code;
}
}
// Size Secondary Turbine
{
C_turbine::S_design_parameters t2_des_par;
// Set turbine shaft speed
t2_des_par.m_N_design = m_inputs.m_N_turbine;
t2_des_par.m_N_comp_design_if_linked = m_outputs.m_mc_ms.get_design_solved()->m_N_design; //[rpm] m_mc.get_design_solved()->m_N_design;
// Turbine inlet state
t2_des_par.m_P_in = m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT];
t2_des_par.m_T_in = m_outputs.m_temp[C_sco2_cycle_core::HTR_HP_OUT];
t2_des_par.m_D_in = m_outputs.m_dens[C_sco2_cycle_core::HTR_HP_OUT];
t2_des_par.m_h_in = m_outputs.m_enth[C_sco2_cycle_core::HTR_HP_OUT];
t2_des_par.m_s_in = m_outputs.m_entr[C_sco2_cycle_core::HTR_HP_OUT];
// Turbine outlet state
t2_des_par.m_P_out = m_outputs.m_pres[C_sco2_cycle_core::TURB2_OUT];
t2_des_par.m_h_out = m_outputs.m_enth[C_sco2_cycle_core::TURB2_OUT];
// Mass flow
t2_des_par.m_m_dot = m_outputs.m_m_dot_t2;
int turb_size_error_code = 0;
m_outputs.m_t2.turbine_sizing(t2_des_par, turb_size_error_code);
if (turb_size_error_code != 0)
{
m_outputs.m_error_code = turb_size_error_code;
return m_outputs.m_error_code;
}
}
// Design air cooler
{
// Structure for design parameters that are dependent on cycle design solution
C_CO2_to_air_cooler::S_des_par_cycle_dep s_air_cooler_des_par_dep;
// Set air cooler design parameters that are dependent on the cycle design solution
s_air_cooler_des_par_dep.m_T_hot_in_des = m_outputs.m_temp[C_sco2_cycle_core::MIXER_OUT]; // [K]
s_air_cooler_des_par_dep.m_P_hot_in_des = m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT]; // [kPa]
s_air_cooler_des_par_dep.m_m_dot_total = m_outputs.m_m_dot_mc; // [kg/s]
// This pressure drop is currently uncoupled from the cycle design
double cooler_deltaP = m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT] - m_outputs.m_pres[C_sco2_cycle_core::MC_IN]; // [kPa]
if (cooler_deltaP == 0.0)
s_air_cooler_des_par_dep.m_delta_P_des = m_inputs.m_deltaP_cooler_frac * m_outputs.m_pres[C_sco2_cycle_core::MIXER_OUT]; // [kPa]
else
s_air_cooler_des_par_dep.m_delta_P_des = cooler_deltaP; // [kPa]
s_air_cooler_des_par_dep.m_T_hot_out_des = m_outputs.m_temp[C_sco2_cycle_core::MC_IN]; // [K]
s_air_cooler_des_par_dep.m_W_dot_fan_des = m_inputs.m_frac_fan_power * m_outputs.m_W_dot_net / 1000.0; // [MWe]
// Structure for design parameters that are independent of cycle design solution
C_CO2_to_air_cooler::S_des_par_ind s_air_cooler_des_par_ind;
s_air_cooler_des_par_ind.m_T_amb_des = m_inputs.m_T_amb_des; // [K]
s_air_cooler_des_par_ind.m_elev = m_inputs.m_elevation; // [m]
s_air_cooler_des_par_ind.m_eta_fan = m_inputs.m_eta_fan; // [-]
s_air_cooler_des_par_ind.m_N_nodes_pass = m_inputs.m_N_nodes_pass; // [-]
if (m_inputs.m_is_des_air_cooler && std::isfinite(m_inputs.m_deltaP_cooler_frac) && std::isfinite(m_inputs.m_frac_fan_power)
&& std::isfinite(m_inputs.m_T_amb_des) && std::isfinite(m_inputs.m_elevation) && std::isfinite(m_inputs.m_eta_fan) && m_inputs.m_N_nodes_pass > 0)
{
try
{
m_outputs.mc_air_cooler.design_hx(s_air_cooler_des_par_ind, s_air_cooler_des_par_dep, m_inputs.m_des_tol);
}
catch (...)
{
m_outputs.m_error_code = C_sco2_cycle_core::E_cycle_error_msg::E_AIR_COOLER_CONVERGENCE;
return m_outputs.m_error_code;
}
}
}
// Get 'design_solved' structure from component classes
design_solved.ms_mc_ms_des_solved = *m_outputs.m_mc_ms.get_design_solved();
design_solved.ms_t_des_solved = *m_outputs.m_t.get_design_solved();
design_solved.ms_t2_des_solved = *m_outputs.m_t2.get_design_solved();
design_solved.ms_LTR_des_solved = m_outputs.mc_LT_recup.ms_des_solved;
design_solved.ms_HTR_des_solved = m_outputs.mc_HT_recup.ms_des_solved;
design_solved.ms_mc_air_cooler = *m_outputs.mc_air_cooler.get_design_solved();
// Set solved design point metrics
design_solved.m_temp = m_outputs.m_temp;
design_solved.m_pres = m_outputs.m_pres;
design_solved.m_enth = m_outputs.m_enth;
design_solved.m_entr = m_outputs.m_entr;
design_solved.m_dens = m_outputs.m_dens;
design_solved.m_eta_thermal = m_outputs.m_eta_thermal;
design_solved.m_W_dot_net = m_outputs.m_W_dot_net;
design_solved.m_m_dot_mc = m_outputs.m_m_dot_mc;
design_solved.m_m_dot_t = m_outputs.m_m_dot_t;
design_solved.m_m_dot_t2 = m_outputs.m_m_dot_t2;
design_solved.m_turbine_split_frac = m_inputs.m_split_frac;
design_solved.m_UA_LTR = m_inputs.m_LTR_UA;
design_solved.m_UA_HTR = m_inputs.m_HTR_UA;
design_solved.m_W_dot_t = m_outputs.m_W_dot_t; //[kWe]
design_solved.m_W_dot_t2 = m_outputs.m_W_dot_t2; //[kWe]
design_solved.m_W_dot_mc = m_outputs.m_W_dot_mc; //[kWe]
design_solved.m_is_rc = false;
design_solved.m_W_dot_cooler_tot = m_outputs.mc_air_cooler.get_design_solved()->m_W_dot_fan * 1.E3; //[kWe] convert from MWe
return 0;
}
int C_sco2_tsf_core::solve_HTR(double T_HTR_HP_OUT_guess, double* diff_T_HTR_HP_out)
{
// Set HTR_HP_OUT temp
m_outputs.m_temp[C_sco2_cycle_core::HTR_HP_OUT] = T_HTR_HP_OUT_guess;
// Simulate Secondary Turbine
{
// Determine equivalent isentropic efficiencies for secondary turbine, if necessary
double eta_t2_isen = std::numeric_limits<double>::quiet_NaN();
{
if (m_inputs.m_eta_t2 < 0.0)
{
int poly_error_code = 0;
isen_eta_from_poly_eta(m_outputs.m_temp[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_pres[C_sco2_cycle_core::TURB2_OUT], std::abs(m_inputs.m_eta_t2),
false, poly_error_code, eta_t2_isen);
if (poly_error_code != 0)
{
m_outputs.m_error_code = poly_error_code;
return m_outputs.m_error_code;
}
}
else
eta_t2_isen = m_inputs.m_eta_t2;
}
// Simulate Secondary Turbine
{
int turbine2_error_code = 0;
calculate_turbomachinery_outlet_1(m_outputs.m_temp[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_pres[C_sco2_cycle_core::TURB2_OUT], eta_t2_isen, false,
turbine2_error_code, m_outputs.m_enth[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_entr[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_dens[C_sco2_cycle_core::HTR_HP_OUT], m_outputs.m_temp[C_sco2_cycle_core::TURB2_OUT],
m_outputs.m_enth[C_sco2_cycle_core::TURB2_OUT], m_outputs.m_entr[C_sco2_cycle_core::TURB2_OUT], m_outputs.m_dens[C_sco2_cycle_core::TURB2_OUT], m_outputs.m_w_t2);
if (turbine2_error_code != 0)
{
m_outputs.m_error_code = turbine2_error_code;
return m_outputs.m_error_code;
}
}
}
// Calculate Mass Flow Rates
m_outputs.m_m_dot_mc = m_inputs.m_W_dot_net_design
/ (((m_outputs.m_w_t * (1.0 - m_inputs.m_split_frac))
+ (m_outputs.m_w_t2 * m_inputs.m_split_frac)
+ (m_outputs.m_w_mc))
* m_inputs.m_eta_generator); //[kg/s]
m_outputs.m_m_dot_t = m_outputs.m_m_dot_mc * (1.0 - m_inputs.m_split_frac); //[kg/s]
m_outputs.m_m_dot_t2 = m_outputs.m_m_dot_mc * m_inputs.m_split_frac; //[kg/s]
// Solve HTR
double T_HTR_HP_out_calc = std::numeric_limits<double>::quiet_NaN();
m_outputs.mc_HT_recup.design_for_target__calc_outlet(m_inputs.m_HTR_target_code,
m_inputs.m_HTR_UA, m_inputs.m_HTR_min_dT, m_inputs.m_HTR_eff_target,
m_inputs.m_HTR_eff_max,
m_outputs.m_temp[C_sco2_cycle_core::MC_OUT], m_outputs.m_pres[C_sco2_cycle_core::MC_OUT], m_outputs.m_m_dot_t2, m_outputs.m_pres[C_sco2_cycle_core::HTR_HP_OUT],
m_outputs.m_temp[C_sco2_cycle_core::TURB_OUT], m_outputs.m_pres[C_sco2_cycle_core::TURB_OUT], m_outputs.m_m_dot_t, m_outputs.m_pres[C_sco2_cycle_core::HTR_LP_OUT],
m_inputs.m_des_tol,
m_outputs.m_Q_dot_HT, T_HTR_HP_out_calc, m_outputs.m_temp[C_sco2_cycle_core::HTR_LP_OUT]);
*diff_T_HTR_HP_out = T_HTR_HP_OUT_guess - T_HTR_HP_out_calc;
return 0;
}
void C_sco2_tsf_core::reset()
{
this->m_inputs = S_sco2_tsf_in();
this->m_outputs.Init();
}
// ********************************************************************************** END C_sco2_tsf_core
// ********************************************************************************** PRIVATE C_TurbineSplitFlow_Cycle (: C_sco2_cycle_core)
/// <summary>
/// Core function to optimize cycle (fixed total UA)
/// </summary>
void C_TurbineSplitFlow_Cycle::auto_opt_design_core(int& error_code)
{
// Create 'ms_opt_des_par' for Design Variables
S_opt_design_parameters opt_par;
{
// Max Pressure
double best_P_high = m_P_high_limit; //[kPa]
double PR_mc_guess = 2.5; //[-]
opt_par.m_fixed_P_mc_out = ms_auto_opt_des_par.m_fixed_P_mc_out; //[-]
if (!opt_par.m_fixed_P_mc_out)
{
double P_low_limit = std::min(m_P_high_limit, std::max(10.E3, m_P_high_limit * 0.2)); //[kPa]
//best_P_high = fminbr(P_low_limit, m_P_high_limit, &fmin_cb_opt_des_fixed_P_high, this, 1.0);
best_P_high = m_P_high_limit;
}
opt_par.m_P_mc_out_guess = best_P_high; //[kPa]
//ms_opt_des_par.m_fixed_P_mc_out = true;
// Pressure Ratio (min pressure)
opt_par.m_fixed_PR_HP_to_LP = ms_auto_opt_des_par.m_fixed_PR_HP_to_LP; //[-]
if (opt_par.m_fixed_PR_HP_to_LP)
{
opt_par.m_PR_HP_to_LP_guess = ms_auto_opt_des_par.m_PR_HP_to_LP_guess; //[-]
}
else
{
opt_par.m_PR_HP_to_LP_guess = PR_mc_guess; //[-]
}
// Is recompression fraction fixed or optimized?
if (ms_auto_opt_des_par.m_is_turbinesplit_ok <= 0.0)
{ // fixed
opt_par.m_split_frac_guess = std::abs(ms_auto_opt_des_par.m_is_turbinesplit_ok);
opt_par.m_fixed_split_frac = true;
}
else
{ // optimized
opt_par.m_split_frac_guess = 0.5;
opt_par.m_fixed_split_frac = false;
}
// LTR HTR UA Ratio
opt_par.m_LT_frac_guess = 0.5;
opt_par.m_fixed_LT_frac = false;
if (ms_auto_opt_des_par.m_LTR_target_code != NS_HX_counterflow_eqs::OPTIMIZE_UA || ms_auto_opt_des_par.m_HTR_target_code != NS_HX_counterflow_eqs::OPTIMIZE_UA)
{
opt_par.m_fixed_LT_frac = true;
}
// Set Design Method
if (opt_par.m_fixed_LT_frac == true)
opt_par.m_design_method = 3;
else
opt_par.m_design_method = 2;
}
C_sco2_tsf_core::S_sco2_tsf_in optimal_inputs_out;
error_code = optimize_par(ms_auto_opt_des_par, opt_par, optimal_inputs_out);
if (error_code != 0)
return;
// Run Optimal Case
m_optimal_tsf_core.set_inputs(optimal_inputs_out);
error_code = m_optimal_tsf_core.solve();
if (error_code != 0)
return;
// Finalize Design (pass in reference to solved parameters)
error_code = m_optimal_tsf_core.finalize_design(ms_des_solved);
}
/// <summary>
/// Core function to optimize cycle for target eta (variable total UA)
/// </summary>
void C_TurbineSplitFlow_Cycle::auto_opt_design_hit_eta_core(int& error_code, const double eta_thermal_target)
{
return;
}
/// <summary>
/// Optimize Total Recuperator UA
/// totalUA -> bp -> UA split, pressure, recomp
/// </summary>
/// <param name="auto_par"></param>
/// <param name="opt_par"></param>
/// <param name="optimal_inputs"></param>
/// <returns></returns>
int C_TurbineSplitFlow_Cycle::optimize_totalUA(const S_auto_opt_design_parameters& auto_par,
const S_opt_design_parameters& opt_par,
C_sco2_tsf_core::S_sco2_tsf_in& optimal_inputs)
{
return -1;;
}
/// <summary>
/// Optimize internal variables (UA split, pressure, recomp)
/// totalUA -> bp -> UA split, pressure, recomp
/// </summary>
/// <param name="auto_par"></param>
/// <param name="opt_par"></param>
/// <param name="core_inputs"></param>
/// <param name="optimal_inputs"></param>
/// <returns></returns>
int C_TurbineSplitFlow_Cycle::optimize_par(const S_auto_opt_design_parameters& auto_par,
const S_opt_design_parameters& opt_par,
C_sco2_tsf_core::S_sco2_tsf_in& optimal_inputs)
{
// Set up baseline core inputs
C_sco2_tsf_core::S_sco2_tsf_in core_inputs;
{
// From Auto Opt Design Parameters
core_inputs.m_LTR_target_code = ms_auto_opt_des_par.m_LTR_target_code;
core_inputs.m_LTR_UA = ms_auto_opt_des_par.m_LTR_UA;
core_inputs.m_LTR_min_dT = ms_auto_opt_des_par.m_LTR_min_dT;
core_inputs.m_LTR_eff_target = ms_auto_opt_des_par.m_LTR_eff_target;
core_inputs.m_LTR_eff_max = ms_auto_opt_des_par.m_LTR_eff_max;
core_inputs.m_LTR_od_UA_target_type = ms_auto_opt_des_par.m_LTR_od_UA_target_type;
core_inputs.m_HTR_target_code = ms_auto_opt_des_par.m_HTR_target_code;
core_inputs.m_HTR_UA = ms_auto_opt_des_par.m_HTR_UA;
core_inputs.m_HTR_min_dT = ms_auto_opt_des_par.m_HTR_min_dT;
core_inputs.m_HTR_eff_target = ms_auto_opt_des_par.m_HTR_eff_target;
core_inputs.m_HTR_eff_max = ms_auto_opt_des_par.m_HTR_eff_max;
core_inputs.m_HTR_od_UA_target_type = ms_auto_opt_des_par.m_HTR_od_UA_target_type;
core_inputs.m_des_tol = ms_auto_opt_des_par.m_des_tol;
core_inputs.m_is_des_air_cooler = ms_auto_opt_des_par.m_is_des_air_cooler;
// From Constructor
core_inputs.m_LTR_N_sub_hxrs = m_LTR_N_sub_hxrs; // Comes from constructor (constant)
core_inputs.m_HTR_N_sub_hxrs = m_HTR_N_sub_hxrs; // Comes from constructor (constant)
core_inputs.m_W_dot_net_design = m_W_dot_net; // Comes from constructor (constant)
core_inputs.m_T_mc_in = m_T_mc_in; // Comes from constructor (constant)
core_inputs.m_T_t_in = m_T_t_in; // Comes from constructor (constant)
core_inputs.m_DP_LTR = m_DP_LTR; // Comes from constructor (constant)
core_inputs.m_DP_HTR = m_DP_HTR; // Comes from constructor (constant)
core_inputs.m_DP_PC_main = m_DP_PC_main; // Comes from constructor (constant)
core_inputs.m_DP_PHX = m_DP_PHX; // Comes from constructor (constant)
core_inputs.m_eta_mc = m_eta_mc; // Comes from constructor (constant)
core_inputs.m_eta_t = m_eta_t; // Comes from constructor (constant)
core_inputs.m_eta_t2 = m_eta_t2; // Comes from constructor (constant)
core_inputs.m_eta_generator = m_eta_generator; // Comes from constructor (constant)
core_inputs.m_frac_fan_power = m_frac_fan_power; // Comes from constructor (constant)
core_inputs.m_eta_fan = m_eta_fan; // Comes from constructor (constant)
core_inputs.m_deltaP_cooler_frac = m_deltaP_cooler_frac; // Comes from constructor (constant)
core_inputs.m_T_amb_des = m_T_amb_des; // Comes from constructor (constant)
core_inputs.m_elevation = m_elevation; // Comes from constructor (constant)
core_inputs.m_N_nodes_pass = m_N_nodes_pass; // Comes from constructor (constant)
core_inputs.m_mc_comp_model_code = m_mc_comp_model_code; // Comes from constructor (constant)
core_inputs.m_N_turbine = m_N_turbine; // Comes from constructor (constant)
// Handle design variables (check if fixed or free)
{
// Turbine Split Fraction
if (opt_par.m_fixed_split_frac == true)
core_inputs.m_split_frac = opt_par.m_split_frac_guess;
// MC Outlet Pressure
if (opt_par.m_fixed_P_mc_out == true)
core_inputs.m_P_mc_out = opt_par.m_P_mc_out_guess;
// Recuperator split fraction
double LT_frac_local = opt_par.m_LT_frac_guess;
if (ms_auto_opt_des_par.m_LTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA || ms_auto_opt_des_par.m_HTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA)
{
core_inputs.m_LTR_UA = ms_auto_opt_des_par.m_UA_rec_total * LT_frac_local;
core_inputs.m_HTR_UA = ms_auto_opt_des_par.m_UA_rec_total * (1.0 - LT_frac_local);
}
else
{
core_inputs.m_LTR_UA = ms_auto_opt_des_par.m_LTR_UA; //[kW/K]
core_inputs.m_HTR_UA = ms_auto_opt_des_par.m_HTR_UA; //[kW/K]
}
// Pressure Ratio is calculated in callback
}
}
// Add applicable design variables to Optimizer
int index = 0;
std::vector<double> x(0);
std::vector<double> lb(0);
std::vector<double> ub(0);
std::vector<double> scale(0);
if (!auto_par.m_fixed_P_mc_out)
{
x.push_back(opt_par.m_P_mc_out_guess);
lb.push_back(100.0);
ub.push_back(m_P_high_limit);
scale.push_back(500.0);
index++;
}
if (!auto_par.m_fixed_PR_HP_to_LP)
{
x.push_back(opt_par.m_PR_HP_to_LP_guess);
lb.push_back(0.0001);
double PR_max = m_P_high_limit / 100.0;
ub.push_back(PR_max);
scale.push_back(0.2);
index++;
}
if (!opt_par.m_fixed_split_frac)
{
x.push_back(opt_par.m_split_frac_guess);
lb.push_back(0.0);
ub.push_back(0.99);
scale.push_back(0.05);
index++;
}
if (!opt_par.m_fixed_LT_frac)
{
x.push_back(opt_par.m_LT_frac_guess);
lb.push_back(0.0);
ub.push_back(1.0);
scale.push_back(0.05);
index++;
}
// Make Optimizer (if there are variables to be optimized)
int error_code = 0;
C_sco2_tsf_core::S_sco2_tsf_in optimal_inputs_internal;
if (index > 0)
{
// Set up instance of nlopt class and set optimization parameters
nlopt::opt opt_des_cycle(nlopt::LN_SBPLX, index);
opt_des_cycle.set_lower_bounds(lb);
opt_des_cycle.set_upper_bounds(ub);
opt_des_cycle.set_initial_step(scale);
opt_des_cycle.set_xtol_rel(auto_par.m_des_opt_tol);
opt_des_cycle.set_maxeval(50);
// Set up core model that will be passed to objective function
C_sco2_tsf_core tsf_core;
tsf_core.set_inputs(core_inputs);
// Make Tuple to pass in parameters
std::tuple<C_TurbineSplitFlow_Cycle*, const S_auto_opt_design_parameters*, const S_opt_design_parameters*, C_sco2_tsf_core*> par_tuple = { this, &auto_par, &opt_par, &tsf_core };
// Set max objective function
opt_des_cycle.set_max_objective(nlopt_tsf_optimize_par_func, &par_tuple);
double max_f = std::numeric_limits<double>::quiet_NaN();
// Optimize
nlopt::result result_des_cycle = opt_des_cycle.optimize(x, max_f);
// Check if forced stop
int flag = opt_des_cycle.get_force_stop();
if (flag == true)
{
error_code = -1;
return error_code;
}
// Get Optimal Input Case
error_code = x_to_inputs(x, auto_par, opt_par, core_inputs);
if (error_code != 0)
return error_code;
}
// Nothing to optimize
else
{
// Define P_mc_in (because pressure ratio and mc_out are constant)
core_inputs.m_P_mc_in = core_inputs.m_P_mc_out / opt_par.m_PR_HP_to_LP_guess;
// Simulate Case (don't actually need to run...)
C_sco2_tsf_core core_model;
core_model.set_inputs(core_inputs);
error_code = core_model.solve();
}
// Set Optimal Inputs
optimal_inputs = core_inputs;
return error_code;
}
/// <summary>
/// Take optimizer array 'x', write appropriate values to S_sco2_tsf_in
/// </summary>
int C_TurbineSplitFlow_Cycle::x_to_inputs(const std::vector<double>& x,
const S_auto_opt_design_parameters auto_par,
const S_opt_design_parameters opt_par,
C_sco2_tsf_core::S_sco2_tsf_in& core_inputs)
{
// 'x' is array of inputs either being adjusted by optimizer or set constant
// Finish defining core_inputs based on current 'x' values
int error_message = 0;
int index = 0;
// Main compressor outlet pressure
if (!auto_par.m_fixed_P_mc_out)
{
double P_mc_out = x[index];
if (P_mc_out > m_P_high_limit)
return -1;
index++;
// assign P_mc_out
core_inputs.m_P_mc_out = P_mc_out;
}
// Main compressor pressure ratio
double PR_mc_local = -999.9;
double P_mc_in = -999.9;
if (!opt_par.m_fixed_PR_HP_to_LP)
{
PR_mc_local = x[index];
if (PR_mc_local > 50.0)
return -1;
index++;
P_mc_in = core_inputs.m_P_mc_out / PR_mc_local;
}
else
{
if (opt_par.m_PR_HP_to_LP_guess >= 0.0)
{
PR_mc_local = opt_par.m_PR_HP_to_LP_guess;
P_mc_in = core_inputs.m_P_mc_out / PR_mc_local; //[kPa]
}
else
{
P_mc_in = std::abs(opt_par.m_PR_HP_to_LP_guess); //[kPa]
}
}
if (P_mc_in >= core_inputs.m_P_mc_out)
return -1;
if (P_mc_in <= 100.0)
return -1;
core_inputs.m_P_mc_in = P_mc_in;
// Turbine split fraction
if (!opt_par.m_fixed_split_frac)
{
core_inputs.m_split_frac = x[index];
if (core_inputs.m_split_frac < 0.0)
return -1;
index++;
}
// Recuperator split fraction
double LT_frac_local = -999.9;
double LTR_UA, HTR_UA;
if (!opt_par.m_fixed_LT_frac)
{
LT_frac_local = x[index];
if (LT_frac_local > 1.0 || LT_frac_local < 0.0)
return -1;
index++;
if (auto_par.m_LTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA || auto_par.m_HTR_target_code == NS_HX_counterflow_eqs::OPTIMIZE_UA)
{
LTR_UA = auto_par.m_UA_rec_total * LT_frac_local;
HTR_UA = auto_par.m_UA_rec_total * (1.0 - LT_frac_local);
// ASSIGN LTR_UA and HTR_UA
core_inputs.m_LTR_UA = LTR_UA;
core_inputs.m_HTR_UA = HTR_UA;
}
}
return 0;
}
/// <summary>
/// Set optimized variables to NaN, to protect them from misuse