Page 556 - Design and Operation of Heat Exchangers and their Networks

Appendix 539

dh_2_h = 2 ∗ h_fs_h ∗ s_ff_h / (h_fs_h + s_fs_h ...
+ h_fs_h ∗ delta_f_h / l_s_h); % hydraulic diameter (2), m
dh_2_c = 2 ∗ h_fs_c ∗ s_ff_c / (h_fs_c + s_fs_c ...
+ h_fs_c ∗ delta_f_c / l_s_c);
Ac_h = FPM_h ∗ L_c ∗ N_fl_h ∗ h_fs_h ∗ s_fs_h; % crossflow area, m2
Ac_c = FPM_c ∗ L_h ∗ N_fl_c ∗ h_fs_c ∗ s_fs_c;
H = N_fl_h ∗ (h_f_h + delta_p) + N_fl_c ∗ (h_f_c + delta_p) + delta_p;
% total height of the exchanger, m
sigma_h = Ac_h / (H ∗ L_c);
sigma_c = Ac_c / (H ∗ L_h);
beta_h = h_fs_h ∗ (l_s_h + delta_f_h) / ((h_fs_h + s_fs_h) ∗ l_s_h ...
+ (h_fs_h + s_ofs_h - delta_f_h) ∗ delta_f_h);
% ratio of the secondary surface area to the total heat transfer surface area
beta_c = h_fs_c ∗ (l_s_c + delta_f_c) / ((h_fs_c + s_fs_c) ∗ l_s_c ...
+ (h_fs_c + s_ofs_c - delta_f_c) ∗ delta_f_c);
A_h = 2 ∗ N_fl_h ∗ FPM_h ∗ L_h ∗ L_c ∗ (h_fs_h + s_fs_h ...
+ (h_fs_h + s_ofs_h - delta_f_h) ∗ delta_f_h / l_s_h);
A_c = 2 ∗ N_fl_h ∗ FPM_c ∗ L_h ∗ L_c ∗ (h_fs_c + s_fs_c ...
+ (h_fs_c + s_ofs_c - delta_f_c) ∗ delta_f_c / l_s_c);

G_1_h = m_h / Ac_h;
G_2_h = G_1_h ∗ s_fs_h / s_ff_h;
% mass flux based on minimum free flow area, kg/m2s
G_1_c = m_c / Ac_c;
G_2_c = G_1_c ∗ s_fs_c / s_ff_c;

[rho_h_in, mu_h_in] = ...
refpropm('DV','T', T_h_in, 'P', p_h_in, ...
'nitrogen', 'oxygen', 'water', 'CO2', c_mass);
Re_1_h_in = G_1_h ∗ dh_1_h / mu_h_in;
s = log(Re_1_h_in);
Kc_h = (-0.4287 ∗ sigma_h + 0.05972) ∗ sigma_h + 0.3737 ...
+ (9.5455 / s - 0.008106) / s;
dp_in_h = G_1_h ^ 2/2/ rho_h_in ∗ (1 - sigma_h ^ 2 + Kc_h);
[rho_c_in, mu_c_in] = refpropm('DV','T', T_c_in, 'P', p_c_in, 'air');
Re_1_c_in = G_1_c ∗ dh_1_c / mu_c_in;
s = log(Re_1_c_in);
Kc_c = (-0.4287 ∗ sigma_c + 0.05972) ∗ sigma_c + 0.3737 ...
+ (9.5455 / s - 0.008106) / s;
dp_in_c = G_1_c ^ 2/2/ rho_c_in ∗ (1 - sigma_c ^ 2 + Kc_c);