Optimal control problems heat exchanger

Process simulators contain the model of the process and thus contain the bulk of the constraints in an optimization problem. The equality constraints ( hard constraints ) include all the mathematical relations that constitute the material and energy balances, the rate equations, the phase relations, the controls, connecting variables, and methods of computing the physical properties used in any of the relations in the model. The inequality constraints ( soft constraints ) include material flow limits maximum heat exchanger areas pressure, temperature, and concentration upper and lower bounds environmental stipulations vessel hold-ups safety constraints and so on. A module is a model of an individual element in a flowsheet (e.g., a reactor) that can be coded, analyzed, debugged, and interpreted by itself. Examine Figure 15.3a and b. 

In recent years considerable emphasis has been placed on energy conservation and environmental pollution control. As discussed earlier, the former problem is likely to be solved, at least in part, by the introduction or wider use of more efficient fuels such as biomass or nuclear fuel, coupled with more controlled application of what is at present waste heat from chemical reactions. This is now more than ever possible because of the improved and improving design of heat pumps, boilers, heat exchangers, etc., the use of which is more nearly optimized by computer control. Emissions of gaseous pollutants have been decreasing in recent years by improved methods of condensation, adsorption. 

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