Thermal Storage for Industry
In order to cope with peak demands, the concept of having a smaller boiler operating closer to its maximum output with thermal storage is proposed. This is to avoid the inefficiencies and poor steam quality delivered by an oversized boiler. Also this avoids the thermal stresses on the boiler caused by excessive modulation.
Under this study, a number of thermal storage technologies were discarded because they were designed for much higher temperatures required in a concentrated solar power plant. For this project, thermal storage technologies that were investigated, can deliver steam to around 2-5 bar on demand with an input of 10 bar (≃186oC) of steam.
The mode of energy storage suggested in this project is that superheated steam is passed through a heat exchanger that charges the molten salt storage tank, it is then stored in a steam accumulator. During discharge, the saturated steam from the accumulator is passed through the molten salt where it is superheated to desired pressure. This concept can be validated using simulation and experimentation which was out of scope for this project.
As discussed elsewhere, any large scale thermal storage for use in industry is still in its infancy so industries with a high temperature and demand may struggle to find a solution.
It was hard to find reliable data since thermal storage is still an emerging technology when applied to industries. Most case studies and data is based on small scale experimental demonstration projects.