Solar trough receiver with V-grooved light traps for efficiency improvement
摘要
Parabolic trough collector is a promising technology for both domestic and industrial heat supplies. To enhance the collector efficiency, a modified trough receiver with dozens of V-grooved light traps incorporated into its lower-half absorber was introduced. For assessing the performance of this receiver, a solar-thermal-stress coupled model was established. Using this model, firstly, the effects of the V-grooved light traps were investigated. The results reveal that, compared to the conventional trough receiver, the modified trough receivers equipped with different traps can reduce their optical losses by 81.9–138.0 W m−1 (i.e., 15.0%–25.2%), improving their optical efficiencies by 1.60%–2.69%. However, these traps also result in increased thermal loss from the receiver. Therefore, there is no single optimal modified trough receiver that consistently outperforms all other receivers across all possible conditions. Nonetheless, the MTR30-3 and MTR60-3 receivers emerge as the optimized choices due to their better solar-thermal performance. Subsequently, performance evaluation reveals that the two optimized receivers can enhance the receiver efficiencies within the typical solar irradiance range by 0.02%–2.65% and 0.05%–1.70% when the inlet fluid temperatures are below 488 and 523 K, respectively. Consequently, the collector efficiencies can be improved by 0.02%–2.49% and 0.05%–1.60%, respectively. Additionally, thermal stress analysis verifies that the two optimized receivers remain within safe limits under all typical conditions. Given that the heating temperature of a typical solar collector for domestic or industrial heat supply is typically below 523 K, the integration of the two optimized receivers has the capability to effectively enhance the overall collector efficiency.