Consider a process with the following streams:

(a) Compute \(\Delta T_{\text {thres }}\) as well as the minimum external heating and cooling requirements as a function of \(\Delta T_{\text {min }}\).

(b) Design a HEN to meet the MER targets with \(N_{H X, \min }^{M E R}\) heat exchangers for \(\Delta T_{\text {min }}=20^{\circ} \mathrm{F}\). Show the heat duties and temperatures for each heat exchanger.

Stream Ts (F) T' (F) C (x10 Btu/hrF) H1 480 250 2.0 H2 430 180 3.0 C1 100 400 2.5 C2 150 360 2.5 C3 200 400 2.5