In this paper, a prototype rod baffle shell-and-tube heat exchanger (RB-STHX) was designed and fabricated for concentrating solar power (CSP). In order to investigate the heat transfer characteristics of molten salt in the shell side, the RB-STHX was experimentally studied. A ternary salt Hitec and an oil were adopted as the heat transfer fluids in the shell and tube sides, respectively. Experimental data was firstly obtained with the salt temperature of 212.7~279.6oC, where the corresponding Prandtl number is in the range of 14.2~23.3. The flow is in the turbulent region with the Reynolds number of 2,697 to 12,517. The average heat transfer rate ranges from 117 kW to 364 kW. Then, the experimental data were compared with two exiting correlations. The results indicate that an average error of -9.1 ~ -12.3% between the Nusselt numbers predicted by the two exiting correlations and the experiment data was found. Finally, for predicting the heat transfer characteristics of the molten salt in the shell side more accurately, two modified heat transfer correlations which show satisfactory agreements with the experimental data were developed. The average deviation between the experiment data and the modified correlations are around ±4.4 ~ ±4.6%. Results from present study will offer the reliable experimental data, useful correlations and helpful guidance for the design and operation of realistic molten salt RB-STHXs in the CSP systems.
展开▼
