Power and angle analyses on a solar parabolic trough

Solar concentrators have been analysed and experimented in our laboratory since 1997. Optical configurations with increased complexity from simple parabolic concentrators to lens mirror combinations have been studied [1-7]. The possible applications relate to Photo Voltaic sector, thermal field and internal illumination. Solar linear mirrors, commonly indicated as solar trough collector, with parabolic profile have been analysed using ray tracing simulations. The configuration includes a parabolic trough that concentrates the light over an absorber represented by a metal pipe surrounded by a glass tube. Figure 1 presents an overview of the solar trough collector. While Figure 2 shows parabolic mirror profile and circular absorber section, whose centre is located in the parabola focus. The paper summarises the results of several studies investigating the interactions between angles and collected light. The aspects analysed are light distribution over the absorber, acceptance angle and effects of collector tilt. The complete series of ray tracing simulations examines the linear parabolic collector and its possible modifications. These geometrical variations are combined to misalignments and tracking errors. The reference configuration for the solar trough collector is shown in Fig. 2 and it contains a linear parabolic mirror with focal length f=800mm. The dimensions of mirror aperture are: width W=1.8m; length L=5m. The metal pipe has external diameter DM=50mm and length L=5m. The glass tube has external diameter DG=60mm and thickness T=3mm.