Thermal analysis of fluidized particle flows in a finned tube solar receiver

• Published in: Solar energy Vol. 191; pp. 19 - 33
• Main Authors: Le Gal, A., Grange, B., Tessonneaud, M., Perez, A., Escape, C., Sans, J-L., Flamant, G.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01-10-2019; Pergamon Press Inc; Elsevier
• Subjects: Concentrated solar energy; Engineering Sciences; Finned tube; Fluidized particles; Fluidizing; Heat transfer; Heat transfer coefficient; Heat transfer coefficients; Particle mass; Particle solar receiver; Solar energy; Solar flux; Solar furnaces; Sun; Temperature measurement; Thermal analysis; Thermocouples; Thermodynamic efficiency; Uncertainty; Wall temperature; Concentrated solar energy; Heat transfer coefficient; Fluidized particles; Finned tube; Particle solar receiver
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2019.08.062

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•Thermal behavior of a one-meter long fluidized particle absorber is analyzed.•Large ranges of particle mass flow rate and solar flux density are examined.•Wall temperature measurements accuracy during on-sun experiments are discussed.•Fluidized particle-to-wall heat transfer coefficient can be enhanced using finned tubes.
This paper addresses experimental results on fluidized particle-in-tube solar receiver using a finned tube in order to increase wall-to-particle heat transfer. On-sun tests of a single finned tube solar receiver were performed at the focus of the 1 MW solar furnace of Odeillo. Several solar flux densities and distributions (mean values 236–485 kW/m2) and particle mass flux densities (G = 20–110 kg/m2·s) were tested. A detailed analysis of tube wall and particle temperature distributions and temperature measurement accuracy is proposed. The power extracted by the particle suspension ranges between 17.8 kW and 32 kW and the typical thermal efficiency of this lab-scale solar receiver is about 75%. The mean global wall-to-fluidized particle heat transfer coefficient is calculated as 1200 ± 400 W/m2·K for G in the range 30–110 kg/m2·s. The main uncertainty on the heat transfer coefficient is due to uncertainty on wall temperature measurement during on-sun experiments. The range of this uncertainty is estimated by comparing infra-red camera measurements and wall-welded thermocouple data.