Conceptual Process Design Suite Reference Guide

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2.1 IntroductionThe Operations Mode is a tool available in ExchangerNet for the analysis of the performance of an existing heat exchanger network (HEN) design when the operating conditions change. Decrease in the exchanger's heat transfer due to fouling, removal of an exchanger from service, changes in inlet temperatures or mass flowrate of process streams are among the possible operating variables you may consider to modify. Results showing the impact in the design are automatically provided when new values for one or more of these operating variables are entered.
2.2.1 Process StreamsThe process streams are the streams containing the fluid you want to heat or cool.In Operations mode, the inlet temperature and mass flow rate values of the process streams are taken from the specified values in the Design mode. There are two types of outlet temperature for the process stream: Calculated and Target.
• The Calculated outlet temperature is a calculated value based on the specified conditions of the heat exchanger and inlet stream temperature.
• The Target outlet temperature is the specified/desired value from the Design mode.
For example, in a refinery plant the refinery operators try to maintain the crude outlet temperature from a heat exchanger at 330?ヮ Unfortunately, the crude outlet temperature from the exchanger is usually around 310?ムdue to fouling in the exchanger.