Case study plant performances are summarized in Figs. 45.3 and 45.4. The energy generated ranges from 240,000 to 460,000 MWH. Water production varied between 3,000,000 and 4,800,000 m3 per month. The power to water ratio ranged between 51.6 and 151.3 kWh/m3.
Plant capabilities and availabilities are characteristics of the cogeneration power and water production plant. Plant availability statistics are usually a function of maintenance planning and implemented strategies. In this study, the only aspect of capability discussed is the flexibility of the cogeneration power and water production plant in terms of possible power to water ratios and in terms of
Fig. 45.4 Variations of water produced in the case study plant for a one year operation
■ Actual Fuel Used Reference Fuel Utilization ■ Potential Fuel Saving
the ability to deliver varying capacities. In general, cogeneration power and water production plants are less flexible than single purpose plants due to the economic pressure to maximize the combined production of water and power. Therefore, the design of cogeneration power and water production plants may reduce the plant flexibility which ultimately results in indirect penalties . In addition, cogeneration plants usually have a lower availability factor since any incident interrupting the output of one of the two products may lead to a disturbance or stoppage in the production of the other, thus increasing the cost per unit products. On the other hand, plant capabilities can be considered to be a measure of a given plant’s ability to generate power or produce water over a range of required percentages within the confines of the plant design limits.