Coadunation of technologies: Cogeneration and thermal energy storage.

摘要

Cogeneration is playing an increasingly important role in providing an independent and on-site high-efficiency source of power generation and thermal energy for space heating and cooling, as well as industrial process heat applications. However, the range of applications of cogeneration technology could be further extended if the generation of electricity could be decoupled from the generation of thermal energy for process use or space conditioning. The technology of thermal energy storage (TES) provides just such a decoupling that allows for the production of dispatchable power while fully utilizing the thermal energy available from the prime mover of the cogeneration system. The thermal energy from the prime mover exhaust can be stored either as sensible heat or as latent heat and used during peak demand periods to produce electric power or process steam/hot water. However, the additional materials and equipment necessary for a TES system will add to the capital as well as maintenance costs. Therefore, the economic benefits of adding TES to a conventional cogeneration system would have to outweigh the increased costs of the combined system. This paper addresses some of the TES systems that are readily applicable to be combined with cogeneration systems, as well as provide an update on the current status of these TES systems. TES allows a cogeneration facility to (1) provide dispatchable electric power while providing a constant thermal load, and (2) increase peak capacity by providing economical cooling of the combustion turbine inlet air. The particular systems addressed are high-temperature diurnal TES, and TES for cooling the combustion turbine inlet air.