Effect of Bed Particle Size on Thermal Performance of a Directly-Irradiated Fluidized Bed Gas Heater

Processes

MinJi Lee¹  ChaeEun Yeo¹  SaeHan Park¹  SungWon Kim¹ 

[1] School of Chemical and Material Engineering, Korea National University of Transportation, Chungju-si 27469, Chungbuk, Korea;

关键词: solar thermal energy;    fluidized bed;    gas heater;    silicon carbide;    particle size;   

DOI  :  10.3390/pr8080967

来源: DOAJ

【 摘 要 】

There is a growing interest in a fluidized bed particle receiver that directly irradiates sunlight to particles in the fluidized bed as a solar thermal collector for heating. Thermal performance of directly-irradiated fluidized bed gas heater is strongly affected by the physical properties of the particles. The effect of SiC particle size on heat transfer characteristics in the solar fluidized bed gas heater (50 mm-ID × 100 mm high) has been determined. The outlet gas temperatures showed a maximum value with increasing gas velocity due to the particles motion by bubble behavior in the bed, and the maximum values were found at 3.6 times of U_mf for fine SiC and less than 2.0 times of U_mf for coarse SiC. Heat absorption from the receiver increased with increasing gas velocity, showing with maximum 18 W for the fine SiC and 23 W for the coarse SiC at 4.5 times of U_mf. The thermal efficiency of the receiver increased with increasing gas velocity, but was affected by the content of finer particles. The maximum thermal efficiency of the receiver was 14% for fine SiC and 20% for coarse SiC within the experimental range, but showing higher for the fine SiC at the same gas velocity. A design consideration was proposed to improve the thermal efficiency of the system.

【 授权许可】

Unknown