Page 550 - Design and Operation of Heat Exchangers and their Networks

Appendix 533

% objective function
L_t = N_t ∗ L;
f = L_t + 1E6 ∗ (max(delta_p_s / 1E5 - delta_p_s_max, 0) ...
+ max(delta_p_t / 1E5 - delta_p_t_max, 0) ...
+ max(t_s_out - t_s_out_max, 0));

if (n_output == 1)
fprintf('%%f =%f, C_RF =%4.2f, L_t =%f, dp_t =%f, dp_s =%f,
ts_out =%f, tt_out =%f, L =%f, d_s =%f, l_c =%f, l_bc =%f, N_t =%d, N_b =%
d, l_bio =%f\n', ...
f, C_RF, L_t, delta_p_t / 1E5, delta_p_s / 1E5, t_s_out, ...
t_t_out, L, d_s, l_c, l_bc, N_t, N_b, l_bi);
fprintf('x = [%f %f %f %f];\n', x(1) ∗ scale(1), ...
x(2) ∗ scale(2), x(3) ∗ scale(3), x(4) ∗ scale(4));
end
end

% rho: seawater density at p = 1 bar, kg/m3
% cp: seawater heat capacity, J/kgK
% lambda: seawater thermal conductivity, W/mK
% mu: seawater dynamic viscosity, sPa
% t: temperature, °C, 0<t<180°C
% S: salinity of seawater, kg/kg, 0<S< 0.16,
function [rho, cp, lambda, mu] = seawater_properties (t, S)
T_68 = (1.000293 - 3.894E-7 ∗ t) ∗ t + 273.15;
Sp = S ∗ 1000; % g/kg

a = [999.9, 0.02034, -6.162E-3, 2.261E-5, -4.657E-8];
b = [802.0, -2.001, 0.01677, -3.060E-5, -1.613E-5];
rho = a(5) ∗ t ^ 4 + b(5) ∗ (S ∗ t) ^ 2;
for i=1:4
rho = rho + (a(i) + S ∗ b(i)) ∗ t ^ (i - 1);
end

a0 = (4.04E-4 ∗ Sp - 9.76E-2) ∗ Sp + 5.328;
a1 = (-3.15E-6 ∗ Sp + 7.351E-4) ∗ Sp - 6.913E-3;
a2 = (8.23E-9 ∗ Sp - 1.927E-6) ∗ Sp + 9.6E-6;
a3 = (-7.125E-12 ∗ Sp + 1.666E-9) ∗ Sp + 2.5E-9;
cp = (((a3 ∗ T_68 + a2) ∗ T_68 + a1) ∗ T_68 + a0) ∗ 1000;