Page 555 - Design and Operation of Heat Exchangers and their Networks

538 Appendix

T_h_in = 513; % hot fluid inlet temperature, K
T_c_in = 277; % cold fluid inlet temperature, K
p_h_in = 100; % hot fluid inlet pressure, kPa
p_c_in = 100; % cold fluid inlet pressure, kPa
delta_p = 0.0008; % plate thickness, m
lambda_f = 150; % thermal conductivity of fin material, W/mK
Q = 160000; % heat duty of the exchanger, W
p_min = 50;

c_mol = [0.77 0.07 0.04 0.12]; % N2, O2, H2O, CO2, mol/mol
c_mass = zeros(1, 4);
M = zeros(1, 4);
% molecular weight, kg/kmol
M(1) = refpropm('M', 'T', 373.15, 'P', 100, 'nitrogen');
M(2) = refpropm('M', 'T', 373.15, 'P', 100, 'oxygen');
M(3) = refpropm('M', 'T', 373.15, 'P', 100, 'water');
M(4) = refpropm('M', 'T', 373.15, 'P', 100, 'CO2');
M_mix = 0;
for i=1: 4
M_mix = M_mix + c_mol(i) ∗ M(i);
end
for i=1: 4
c_mass(i) = c_mol(i) ∗ M(i) / M_mix;
end

N_fl_c = N_fl_h + 1; % number of fin layers for cold fluid
h_fs_h = h_f_h - delta_f_h; % fin free spacing in height? m
h_fs_c = h_f_c - delta_f_c;
s_f_h = 1 / FPM_h; % fin pitch, m
s_f_c = 1 / FPM_c;
s_ofs_h = s_f_h / 2; % fin strip offset, m
s_ofs_c = s_f_c / 2; % fin strip offset, m
s_fs_h = s_f_h - delta_f_h; % fin free spacing in width, m
s_fs_c = s_f_c - delta_f_c;
s_ff_h = max(s_fs_h - delta_f_h, s_ff_min);
s_ff_c = max(s_fs_c - delta_f_c, s_ff_min);
dh_1_h = 2 ∗ h_fs_h ∗ s_fs_h / (h_fs_h + s_fs_h);
% hydraulic diameter (1), m
dh_1_c = 2 ∗ h_fs_c ∗ s_fs_c / (h_fs_c + s_fs_c);