Available energy operation decisions

On this basis, a cost or value of the available energy flows at the various junctures within the system can be determined (iteratively). Then if, for example, a particular component needs to deliver some specified output, knowing the unit cost of the availability supplied to the component, the component and its operating conditions can be selected (or designed) so that the total costs—of availability supplied thereto and of capital costs thereof, (etc.)—can be minimized. Typical parameters (decision variables) of a component which can be adjusted in order to attain the optimum system are efficiency, operating pressure and temperature, speed, and so on and so forth. 

Maintenance and Operation Decisions. The determination of an appropriate cost of available energy at various junctures of a system in a manner similar to that described above for Design Optimization is useful not only in design but also allows decisions regarding the repair or replacement of a specific subsystem to be readily made (9, 10). The amortized cost of such improvements can be easily compared with the cost of the additional available energy that will be dissipated if a component is left to operate in the given condition. The proper decision then becomes very apparent. 

Retrofit strategy and procedure for minimizing the operating cost of multi-stage SJE, LRVP, DVP, SJE-LRVP and SJE-DVP systems are discussed in this section. They are illustrated with two case studies in the subsequent sections. There are several ways to reduce the energy cost or increase capacity of a vacuum system. Engineers often find it difficult to make correct revamp decisions as most of the information is vendor specific. This chapter illustrates the use of simple techniques, based on available literature, to revamp a vacuum system easily and quickly. 

Thermal Insulation, properly applied, assures effective operation of process equipment and conserves valuable heat. There is always a wide variety of insulating materials for a given situation and careful consideration must be given to each type so that an intelligent decision may be made. Thermal insulation should be the simplest, most generally accepted, cost-effective method of saving energy immediately available to a plant owner. 

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