CFD model of a molten salt tank with integrated steam generator

Abstract

For each solar technology the dispatchable CSP plant scheme that maximizes the solar to electrical energy conversion and minimizes the costs associated to such transformation is searched. In recent years double tank TES systems are evolving towards more simple configurations of a single tank [1], [2], [3], also known as thermocline tank TES systems and, even going beyond, there are already thermocline tanks in process of development where the steam generator (SG) is integrated into the storage tank (European project OPTS). A prototype with integrated SG has been erected for testing purpose in the Casaccia Research Centre of ENEA (Italy) [4]. The model presented in this paper reproduces the experimental data of such prototype using the CFD commercial code STAR-CCM + [5]. Unlike very few published until now [6]. The simulated system account for molten salts behavior, not only for the bulk molten salts, but also for the circulation of the molten salts inside the SG (with three steam coils). The molten salts move by induced natural convection and the steam temperatures and pressures are up to ∼500° C/40bar. Temperature gauges situated in the bulk and the molten salts mass flow inside the SG are the main variables considered for validating the model. From the numerical point of view is a transient simulation and the model is 2D-axisymmetric. The required features of the system mesh and the physical models used are presented in this work. © 2013 The Authors.