OPTIMUM COGENERATION STRATEGIES FOR A REFRIGERATION PLANT

The operation of an idealized industrial refrigeration plant having cogeneration capacity is analyzed using the linear programming model ELMO. The optimum operating strategies for the chilling sets and the steam turbine are determined for a simple time-of-use electricity tariff and for various refrigeration loads. The refrigeration load required for a manufacturing process, along with steam and electricity loads, can be met by a combination of electric and steam-driven centrifugal chillers and an absorption refrigerator operating on low pressure steam. A pass-out turbo-alternator can generate some of the plant electricity needs using high pressure steam from a gas boiler. The marginal production cost of chilled water varies considerably as the load increases, reflecting a varying minimum cost operating strategy for the different chillers.