Solar trough collector tracking angle

How do parabolic trough collectors work?

Most parabolic trough collectors adopt north-south axis tracking and only track the solar azimuth angle rather than the solar elevation angle. Both the solar azimuth angle and the solar elevation angle determine the solar incidence angle, i.e., the angle between the sun’s rays and the normal vector to the aperture of the collector surface.

Why is the parabolic trough collector not used in winter?

For the northern hemisphere, the parabolic trough collector has a smaller solar elevation angle in winter, resulting in a larger solar incidence angle and serious cosine loss, and thus part of the solar incidence sunlight is not concentrated and not further utilized [13], [14], [15].

Does a parabolic trough concentrating collector receive direct solar radiation?

Therefore, for the purpose of optimizing the tracking mode of the parabolic trough concentrating collectors, the current work applied Hottel’s clear-day radiation model with an aim to study the amount of direct solar radiation received by the parabolic mirror within a year under different tracking modes in Shanghai.

How to improve the annual solar-to-heat efficiency of parabolic trough collector technology?

For this reason, the annual solar-to-heat efficiency of parabolic trough collector technology can be improved. By adopting the rotatable axis tracking: The variation of the solar irradiance from 12:00 to 16:10 is plotted in Fig. 8 a, in the afternoon test.

How to reduce the cosine loss of the parabolic trough collector?

To reduce the cosine loss of the parabolic trough collector using the north-south tracking mode, Donald [16] proposed that, if the tilt angle of the solar collector could be adjusted monthly, the collector would maintain a higher solar elevation angle all throughout the year and thus obtain a higher annual performance.

What is the energy loss of the solar parabolic trough collector?

The energy loss of the solar parabolic trough collector mainly exists as optical loss, thermal loss and cosine loss. The optical loss is mainly caused by the materials of the mirror and glass envelope. The thermal loss occurs via radiation and convection due to the difference in temperature between the absorber tube and the ambient environment.