Lesson learned during the designing and construction phases of the ORC-plus thermal energy storage system of 20 MWH

A limitation to the expansion of medium sized Concentrating Solar Power (CSP) plants is represented by the lack of technical solutions of Thermal Energy Storage (TES) systems specialized for this size of CSP plants and validated in a relevant industrial environment. In order to make the medium sized CSP systems more competitive than PV systems, the TES system has to allow the operators of the solar power plant to adjust the electricity production for matching consumer demand, so enabling the sale of electricity during peak demand periods for boosting plant revenues. At the same time, there is the need of lowering the TES system weight in the capital costs of the overall system. The ORC-PLUS (Organic Rankine Cycle - Prototype Link to Storage Unit) Project aims to realize a demonstrator of a TES system optimized for a medium sized CSP plant coupled with an ORC (Organic Rankine Cycle) turbine of 1 MWe. In this paper, the difficulties encountered during the manufacturing and commissioning operations of the TES system and their potential impact on capital costs will be reported

Performance evaluation of latent heat TES system-case study:Dimensions improvements of annular fins exchanger

Thermal Energy Storage (TES) is an important challenge for the development and implementation of Concentrated Solar Power (CSP) plants. The heat can be stored in a sensible, thermochemical or latent form. Recently, the latent heat thermal energy storage (LHTES) kind has gained the most of research interest as it has the advantage of increasing the energy density of the current commercial TES systems through the use of a Phase Change Materials (PCM). However, the main limitation of PCMs technology is the low thermal conductivity, which affects the system performances and lead to significant energy losses. In this sense, a good container design can impact positively the system performances. For that sake, several designs have been proposed to overcome the decreasing heat transfer rate. For this purpose, this study propose many enhancements and improvements of the fins method based on the integration of PCM in an exchanger with annular fins. The main objective of this paper is to study the impact of finned exchangers on the total flow transferred and also on the height of these annular fins. Finally, the physical model describing the thermal behavior of the studied system is developed and simulated after 80 min of charging process.</p