Research on single layer quasi-ordered air vortex inside flat plate solar collectors

As one of the basic components in the low-temperature heat utilization of solar energy, flat plate solar collectors are also the leading products in the world solar energy market. Due to their simple manufacturing process, high reliability, and easy integration with buildings, they have received attentions. This article studied the heat dissipation problem caused by air flow inside the flat plate solar collector cavity, and the air forms the single layer quasi-ordered vortex. Which is similar structures and same sizes between two cold sources, and among cold source and boundary, the vortex near the cold source occupy two-thirds of position and near the boundary occupy one-third. The losses efficiency of 6.6-18.3 % caused by convection is about five times than thermal conductivity, which can improve 15%-thermal efficiency under the condition of forming thermal conductivity. The research results provide a theoretical basis for the optimization technologies such as honeycomb structures and insulation films in air cavity. It also indicates that the heat transfer method is changed from convection to conduction by optimizing the structure of the air cavity to obstruct vortex motion, which will become a strategy to improve thermal efficiency.