Three-dimensional numerical study of heat transfer characteristics of parabolic trough receiver

Highlights: • A coupled transient model for parabolic trough receiver was developed. • Detailed temperature of parabolic trough receiver is obtained. • Temperature difference change inversely with HTF velocity. • Stagnation temperature of parabolic trough receiver increase linearly with time. - Abstract: Parabolic trough receivers are the key component of parabolic trough solar plants, and they typically account for 30% of the cost of the construction of a solar field. The receiver's reliability is still a major item which affects the plant's cost. The temperature distribution of the parabolic trough receivers is required to identify the causation of parabolic trough receiver's failure, and is the prerequisite to design and optimize the parabolic trough receiver's structure. In this study, the detailed temperature distribution of a parabolic trough receiver is successfully simulated by combining a MCRT code and FLUENT software. The heat transfer fluid flow, conduction and radiation heat transfers are jointly considered. Temperature-dependent properties of the heat transfer fluid, the wavelength-dependent optical properties of the receiver surfaces and the glass envelope's absorption of the solar radiation energy are also taken into account. Comparison with indoor experimental results show the average difference is within 6%. In addition, the transient behaviors of parabolic trough receiver under direct concentrated solar irradiance are investigated. The information from this study is of great importance to the design and the optimization of the structure of parabolic trough receiver, as well as to identify the causation of parabolic trough receiver's failure