Patent ID: 8364327

Claim:
A method to synthesize a grass-roots heat exchanger network for a plurality of process streams including a plurality of hot process streams to be cooled and a plurality of cold process streams to be heated and to identify optimal heat exchanger network topology, the method comprising the steps of: identifying a lower and an upper boundary value for a target temperature defining a target temperature range interval for each separate one of a plurality of hot process streams and for each separate one of a plurality of cold process streams that substantially identify all anticipated possible combinations of substantial variations of target temperature for a process; determining a plurality of temperature step intervals, each temperature step interval having an input interval indicating heat extracted collectively from the plurality of hot process streams, an output interval indicating heat collectively applied to the plurality of cold process streams, and an output interval indicating surplus heat available for a next of the plurality of temperature step intervals; performing an economic evaluation on target temperature of one of a plurality of process streams, to include: collapsing the temperature step interval for the one of the plurality of process streams under evaluation to render the discrete target temperature boundary values, the target temperature range interval for each other of the plurality of process streams remaining in interval form, identifying the target temperature value of the respective process stream under evaluation rendering a global minimum of a desired energy utility target, synthesizing a heat exchanger network responsive to the identified target temperature value, calculating capital costs associated with the synthesized heat exchanger network, calculating operating costs associated with the synthesized heat exchanger network, and calculating process-impact-costs of a deviation in the respective target temperature range interval for the respective process stream under evaluation on process economics associated with the synthesized heat exchanger network for other portions of the process; repeating the step of performing an economic evaluation on target temperature for each other of the plurality of process streams; and selecting an optimal stream-specific set of target temperature values rendering an optimal heat exchanger network design responsive to the economic evaluation on target temperature for each of the plurality of hot process streams.