Thermal performance and thermal stress analysis of a 600 MWth solar cylinder external receiver

The thermal stress plays an important role to assess the security of the solar receiver and is mainly affected by the temperature gradient. To study the thermal stress of the receiver, a MATLAB program was developed to study the distribution of temperature and thermal stress numerically, and the program was verified on the lab-scale receiver and it was found that the error between the calculated result and the experimental result did not exceed 10%. Then the in-house code was applied to a 600 MWth receiver to study its thermal performance and thermal stress numerically. The three-dimensional temperature and thermal stress distribution of the 600 MWth receiver were present in this work, and the maximum temperature of the tube and the maximum stress appeared in the last and first panel respectively. It was also found that the outlet temperature of the receiver obtained by the code was 574 °C, very close to the designed temperature 565 °C. The component stresses in tangential, radial and axial direction were analyzed, and the thermal stress in the tangential direction and the axial direction both had a transition from compressive stress to tensile stress along the radial direction, and thermal stress in the radial direction can be almost negligible. Besides, the thermal stress of the receiver in one day was studied, and the average thermal stress and the thermal stress ratio R were respectively 145 MPa and 1.843, and the maximum thermal stress of the receiver decreased 45.74% from 12:00 to 18:00 on the vernal equinox.