Pinch design method of heat exchanger networks(HEN)can be done for a specific operational condition

however the operational condition always fluctuates in a certain range.During practical process operation

it is often difficult to implement optimal control

since operating pinch point and the minimum temperature difference deviate from the design values.Therefore the study of pinch technology and the bypass optimal control of HEN have caught more attention

but integration of pinch technology with HEN optimal control is still not well established.The operating pinch point was studied for a given HEN

and the change of operating pinch point was qualitatively analyzed.Bypass optimal control was proposed and the bypasses were placed around the operating pinch point.Through the bypass optimal control of HEN

to which pinch point technology was applied

the total utility cost was minimized

and at the same time the commands on control performance could be reached

which was shown by the simulation of a heat exchanger network.