Onal claims in published maps and institutional affiliations.Copyright: 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is definitely an open access report distributed below the terms and conditions of the Creative Commons Attribution (CC BY) license (licenses/by/ 4.0/).Energies 2021, 14, 7392. 10.3390/enmdpi/journal/energiesEnergies 2021, 14,two ofa vessel named the dispenser that acts as a feeder tank. In the dispenser, the particles are fluidized and an upward particle flow within the tubes is obtained by applying a stress inside the freeboard from the dispenser. This type of flow differs greatly from risers, broadly studied within the literature, considering the fact that it truly is not merely the velocity from the carrier phase (i.e., air) that generates the upward flow of particles but a mixture in the latter along with a stress gradient in between the dispenser as well as the collector. As a result, the solid volume fraction of your generated upward flow varies within a wide range. This idea, additional detailed in Section 2.1, presents various technological advantages. 1st, the use of a tubular receiver which is similar to those made use of with molten salts. Second, particles aren’t limited to a certain operating temperature variety, contrary to molten salts. Third, precisely the same medium might be made use of as HTF and storage material. At big scale and high temperature (700 C), the usage of a cavity is required to enhance thermal efficiency by decreasing thermal losses [6]. Additionally, high operation temperatures open the route for high-temperature thermodynamic cycles that increase the heat-to-electricity efficiency [7]. Further benefits are financial and environmental. Depending around the chosen particles, it could considerably minimize the expenses of the HTF and storage medium: around 15000 /ton, i.e., significantly significantly less than molten salts [8]. Finally, the usage of mineral particles enables a reduction within the environmental footprint in the power plant [9]. Various papers have been published inside the framework on the Concentrated Solar Power in Particles (CSP2) and also the Next-CSP European projects [10,11]. The studied configurations concentrate on 1 or a number of tubes, with irradiated heights of 1 m and with aeration flow prices and particles mass fluxes as much as 0.7 sm3 /h and 110 kg/m2 s respectively [125]. Wall-to-fluidized bed heat transfer coefficients up to 1200 W/m2 K happen to be observed experimentally with finned tubes. These articles emphasize that the thermal performances from the solar receiver are strongly correlated for the hydrodynamics in the two-phase flow. Two transitions of regime have already been identified in this type of tube: from bubbling to wall slugging and then to axisymmetric slugging [16,17]. Since the formation of axisymmetric slugs result in a significant lower in the wall-to-bed heat transfer since of a reduction of particle mixing, the identification from the fluidization regime is essential for solar applications [18,19]. Even so, those prior experimental research focus mostly on the proof of concept and on international understanding of your heat transfer beneath solar irradiation [125]. Experimental 4-Methylbenzoic acid Autophagy set-ups were richly Pramipexole dihydrochloride site instrumented in thermocouples but poorly when it comes to pressure probes along the receiver, which prevented the identification with the different fluidization regimes. In a lot more current studies, fluidization regimes were analysed by suggests of a highspeed camera [16,19]. Even so, in [19] the authors studied only a particle non-circulating configuration. The usage of temporal stress signals, which can be.
