Page 570 - Design and Operation of Heat Exchangers and their Networks

Appendix 553

tcE_out(2) = tcE_in(2) + QE(2) / CcE(2);
tcE_in(1) = (tcE_out(2) ∗ CcE(2) + tcE_out(3) ∗ CcE(3)) / CcE(1);
tcE_out(1) = tcE_in(1) + QE(1) / CcE(1);
% hot utility
thE_in(5) = tHU_in;
thE_out(5) = tHU_out;
CcE(5) = C_c(1);
tcE_in(5) = tcE_out(1);
tcE_out(5) = tc_out(1);
QE(5) = CcE(5) ∗ (tcE_out(5) - tcE_in(5));

% cold utility
thE_in(6) = thE_out(2);
thE_out(6) = th_out(1);
ChE(6) = C_h(1);
tcE_in(6) = tCU_in;
tcE_out(6) = tCU_out;
QE(6) = ChE(6) ∗ (thE_in(6) - thE_out(6));

% heat exchanger area
CE = 0;
for i=1:1:6
s = (thE_in(i) - tcE_out(i)) - (thE_out(i) - tcE_in(i));
if (abs(s) < 0.000001)
dtE(i) = (thE_in(i) - tcE_out(i) + thE_out(i) - tcE_in(i)) / 2;
else
dtE(i) = s / log((thE_in(i) - tcE_out(i)) ...
/ (thE_out(i) - tcE_in(i)));
end
AE(i) = QE(i) / dtE(i) / kE(i);
CE = CE + C_E_a + C_E_b ∗ AE(i) ^ C_E_c;
end
CU = C_U_H ∗ QE(5) + C_U_C ∗ QE(6);
TAC = CE + CU;
fprintf("dtm, t_h_pinch, Ch_E4, Cc_E3, QE1, QE2, QE3, QE4,QHU, QCU, TAC\n");
fprintf("%f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %20.10f\n", ...
dtm, t_h_pinch, ChE(4), CcE(3), ...
QE(1), QE(2), QE(3), QE(4), QE(5), QE(6), TAC);