Ray tracing and simulation for the beam-down solar concentrator

The ray tracing equations for the beam-down solar concentrator have been derived in this paper. Based on the equations, a new module for the simulation of the beam-down solar concentrating system has been developed and incorporated into the code HFLD. To validate the ray tracing equations, a simple beam-down solar concentrating system consisting of 3 heliostats and a hyperboloid reflector is simulated. The concentrated spots at the lower focal point of the hyperboloid reflector for the beam-down system are calculated by the modified code HFLD and then compared with that calculated by the commercial software Zemax. It is found that the calculated results coincide with each other basically. Furthermore, a beam-down solar concentrator consisting of 31 heliostats, a tower reflector and a CPC is designed and simulated by using the modified code HFLD. The concentrated spots of the beam-down solar concentrator are calculated.