Transferência de calor entre fluido e um leito de partículas sólidas visando a armazenagem e recuperação de energia solar.

Abstract

Heat transmission between fluid and a bed of particles has a large number of technological applications. The use in storage and recovery of solar energy has been cited in several recent works. In the present study we present experimental and analytical results of the dynamic response of a fixed eite air percolated ceramic spheres when subjected to a degree signal at the inlet temperature of the air. The approach used is through the two-phase model. From the experimental solid and fluid temperature profiles the characteristic time and the local heat transmission coefficient were calculated using the differential method proposed by ALSINA & LIRA in 1986. In the analyzed Reynolds number range of 898 and 4130 was found good agreement of the calculated h values ​​with those obtained from correlations available in the literature. However, there was no good agreement with the predictions of the integral method based on the 1981 SPIGA & SPIGA model. This discrepancy was expected due to the use of larger time intervals than those used in a previous work by ALSINA in 1985.