Effects of geometric configurations on the thermal-mechanical properties of parabolic trough receivers based on coupled optical-thermal-stress model

An optical-thermal-stress coupled analysis model of the Parabolic Trough Receiver (PTR) was built based on the Monte Carlo Ray Tracing method and Computational Fluid Dynamics. The temperature field and stress field of the PTR were studied by numerical simulation, and the absorber deformation and the Kovar ring failure were analyzed. Furthermore, the effects of the aperture width (W) and focal length (f) across the entire receiver temperature gradient and thermal stress field were studied. The results showed that the effect of width and focal length on the temperature field was mainly reflected in the change in the high-temperature distribution of the absorber. The maximum collector efficiency were 81.02% and 70.4% when W = 13 m and f = 1.84 m, respectively. The maximum deformation on the absorber reached 17.85 mm at W = 7 m. High deformation and high Von Mises stress were maintained with f from 3.5 m to 5.5 m. The trends of maximum temperature dif-ference and average temperature on bellows, Kovar ring and glass tube were similar. The results also showed that width and focal length mainly affected the axial stress on Kovar rings and bellows.