Page 558 - Design and Operation of Heat Exchangers and their Networks

Appendix 541

else
f_h = (1 - gamma_h) ∗ f_h_cr_l + gamma_h ∗ f_h_cr_t;
j_h = (1 - gamma_h) ∗ j_h_cr_l + gamma_h ∗ j_h_cr_t;
end
alpha_h = j_h ∗ cp_h ∗ G_2_h / Pr_h ^ (2 / 3);

T_c_m = (T_c_in + T_c_out) / 2;
p_c_m = (p_c_in + p_c_out) / 2;
[rho_c, cp_c, lambda_c, mu_c] = ...
refpropm('DCLV','T', T_c_m, 'P', p_c_m, 'air');
Pr_c = mu_c ∗ cp_c / lambda_c;

Re_2_c = G_2_c ∗ dh_2_c / mu_c;
Re_2_c_cr = 257 ∗ (l_s_c / s_fs_c) ^ 1.23 ...
∗ (delta_f_c / l_s_c) ^ 0.58 ∗ dh_2_c ...
/ (delta_f_c + 1.328 ∗ sqrt(l_s_c ∗ dh_2_c / Re_2_c));
gamma_c = (Re_2_c - Re_2_c_cr) / 1000;
f_c_l = 8.12 / (Re_2_c ^ 0.74 ∗ (l_s_c / dh_2_c) ^ 0.41 ...
∗ (s_fs_c / h_fs_c) ^ 0.02);
f_c_cr_l = 8.12 / (Re_2_c_cr ^ 0.74 ∗ (l_s_c / dh_2_c) ^ 0.41 ...
∗ (s_fs_c / h_fs_c) ^ 0.02);
f_c_cr_t = 1.12 / ((Re_2_c_cr + 1000) ^ 0.36 ...
∗ (l_s_c / dh_2_c) ^ 0.65 ∗ (delta_f_c / dh_2_c) ^ 0.17);
f_c_t = 1.12 / ((Re_2_c) ^ 0.36 ...
∗ (l_s_c / dh_2_c) ^ 0.65 ∗ (delta_f_c / dh_2_c) ^ 0.17);
j_c_l = 0.53 / (Re_2_c ^ 0.5 ∗ (l_s_c / dh_2_c) ^ 0.15 ...
∗ (s_fs_c / h_fs_c) ^ 0.14);
j_c_cr_l = 0.53 / (Re_2_c_cr ^ 0.5 ∗ (l_s_c / dh_2_c) ^ 0.15 ...
∗ (s_fs_c / h_fs_c) ^ 0.14);
j_c_cr_t = 0.21 / ((Re_2_c_cr + 1000) ^ 0.4 ...
∗ (l_s_c / dh_2_c) ^ 0.24 ∗ (delta_f_c / dh_2_c) ^ 0.02);
j_c_t = 0.21 / ((Re_2_c + 1000) ^ 0.4 ...
∗ (l_s_c / dh_2_c) ^ 0.24 ∗ (delta_f_c / dh_2_c) ^ 0.02);
if (Re_2_c <= Re_2_c_cr)
f_c = f_c_l;
j_c = j_c_l;
elseif (Re_2_c >= Re_2_c_cr + 1000)
f_c = f_c_t;
j_c = j_c_t;