Control of Utility Exchangers

Armed with the thermodynamic fundamentals of heat management, we now take a closer look at the unit operation control loops for heat exchangers. We start with utility exchangers. These are used when heat is supplied to, or removed from, the process. Examples are steam-heated reboilers, electric heaters, fuel-fired furnaces, water-cooled condensers, and refrigerated coolers. 

In some situations the heat load without adjusting the utility flow, a distillation column shown in Fig 

Occasionally utility exchangers need no control loops at all. For example, the distillation column in Fig. 5.6 uses an uncontrolled cooling water condenser. The water-cooled condenser reduces the expensive 

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