2.4 Thermal Energy Storage

The use of cool thermal storage equipment, in conjunction with the water chiller or ice maker equipment, should be given serious consideration for any CTIAC system design. Thermal storage designs allow the generation and storage of a heat sink material that functions either to satisfy the whole cooling load of the CTIAC system or part of it. The generation of the heat sink, a cool storage media such as ice or chilled water, during off-peak hours when there is decreased demand on the electric generation capacity of the turbine, allows for the decrease or elimination of cooling power consumption during the cooling demand periods. A schematic of an ice storage CTIAC system is given in Figure 18 and for chilled water storage in Figure 19.

Figure 18: Schematic of a typical CTIAC system using ice storage, chilled water SFC air cooling.

Figure 19: Schematic of a typical CTIAC system using chilled water storage SFC.

One advantage of thermal storage systems, then, is the downsizing of chiller equipment, since the cooling load can be spread over an extended period of time and it does not have to meet the peak cooling demand of the CTIAC system. The greater the on-peak generating hours, the larger the size of the thermal storage that will be required. In a detailed study by Brown el al. (1996b), which primarily considered peaking turbine installations, the most economical CTIAC systems included thermal storage in their design. The inclusion of thermal storage, especially ice...