Page 560 - Design and Operation of Heat Exchangers and their Networks

Appendix 543

if (p_c_out < p_min)
p_c_out = p_min;
end
ml_h = h_fs_h / 2 ∗ sqrt(2 ∗ alpha_h ∗ (1 + delta_f_h / l_s_h) ...
/ lambda_f / delta_f_h);
eta_f_h = tanh(ml_h) / ml_h;
eta_0_h = 1 - (1 - eta_f_h) ∗ beta_h;
ml_c = h_fs_c / 2 ∗ sqrt(2 ∗ alpha_c ∗ (1 + delta_f_c / l_s_c) ...
/ lambda_f / delta_f_c);
eta_f_c = tanh(ml_c) / ml_c;
eta_0_c = 1 - (1 - eta_f_c) ∗ beta_c;

kA_h = 1 / (1 / (alpha_h ∗ eta_0_h ∗ A_h) ...
+ (delta_p + (delta_f_h + delta_f_c) / 2) ...
/(2 ∗ lambda_f ∗ N_fl_h ∗ L_h ∗ L_c) ...
+ 1 / (alpha_c ∗ eta_0_c ∗ A_c));
C_h = m_h ∗ cp_h;
C_c = m_c ∗ cp_c;
NTU_h = kA_h / C_h;
R_h = C_h / C_c;
epsilon_h = crossflow_t_h_m(NTU_h, R_h ∗ NTU_h);
smax = T_c_in + epsilon_h ∗ (T_h_in - T_c_in) - T_h_out;
T_h_out = T_h_out + smax;
Q_cal = C_h ∗ (T_h_in - T_h_out);
s = T_c_in + Q_cal / C_c - T_c_out;
T_c_out = T_c_out + s;
if (abs(smax) < abs(s))
smax = s;
end
if (abs(smax) < 1E-6)
break;
end
end
% objective function
C_A = 100; % $/m2
n_A = 0.6;
C_el = 30E-6; % $/Wh
tau = 6500; % h/yr