11.1 Four streams are to be cooled or heated: Stream Ts (°C) T₁ (°C) C (kW°C) H1 180 60 3 H2 150 30 C1 30 135 C2 80 140 125 (a) For AT min = 10°C, find the minimum heating and cooling utilities. What are the pinch temperatures? (b) Design a heat exchanger network for MER on both the hot and cold sides of the pinch.