Page 565 - Design and Operation of Heat Exchangers and their Networks

548 Appendix

dH_c(i) = (t(i) - t(i + 1)) ∗ C_c_i;
end

% heat inputs and outputs
D = zeros(N_SN, 1);
I = zeros(N_SN, 1);
O = zeros(N_SN, 1);
I(1) = 0;
for i=1: 1: N_SN
D(i) = dH_c(i) - dH_h(i);
O(i) = I(i) - D(i);
if (i < N_SN)
I(i + 1) = O(i);
end
end

% minimum hot and cold utility duties
Q_HU_min = I(1);
for i=1: 1: N_SN
if (O(i) < Q_HU_min)
Q_HU_min = O(i);
end
end
Q_HU_min = - Q_HU_min;
for i=1: 1: N_SN
I(i) = I(i) + Q_HU_min;
O(i) = O(i) + Q_HU_min;
end
Q_CU_min = O(N_SN);

% pinch temperature
t_h_pinch = 0;
for i=1: 1: N_SN
if (I(i) == 0)
t_h_pinch = t(i);
end
end

% hot enthalpy flow rates
s1 = -1E100;