Investigating the influence of length and cross sectional area in heat storage thermal stratification

In order to overcome the limitations imposed by the intermittent nature of solar radiation on its different applications, energy storage is an important component of any solar system. More specifically, the incorporation of thermal energy storage makes it possible to store the collected solar thermal energy and use it during off-sun periods, for multiple domestic needs (e.g. cooking, heating, etc). For this to happen, heat must be extracted from the storage to the utility. In order for the extraction process to be done in an efficient way, thermal stratification of heat storage is beneficial. Through comparison of hourly temperature profiles of three different rock-bed heat storages, this paper discusses the influence of length and cross-sectional area of the storage on its thermal stratification. Preliminary findings suggest that by increasing length and reducing diameter of the storage, its thermal stratification is enhanced.