Solar concentrators with two reflection mirrors are numerically designed by using a ray-tracing method to obtain higher concentration ratio when the concentrator tracing error is existed. The primary reflection mirror adopts paraboloidal mirror; the secondary mirror adopts hyperboloidal or ellipsoidal mirror. The optimal designed shape parameters for hyperboloidal and ellipsoidal cases are obtained, respectively. It is found that, when the concentrator tracing errors are 0 degrees, 0.5 degrees and 1 degrees, the concentration ratios for hyperboloidal case are about 5837, 1954 and 1127 at f-number(1) = 0.22 and NA(2) = 0.62 and the one for ellipsoidal case are about 5860, 1993 and 1193 at f-number(1) = 0.25 and NA(2) = 0.62, respectively. Obviously, the concentrator with the ellipsoidal mirror is slightly better than the one with the hyperboloidal mirror. (C) 2009 Elsevier GmbH. All rights reserved.
