High Instantaneous Efficiency and High Flow Rate Slotted-Plate Solar Collectors
With the highlight of less regards to insulation measures and the key factor of the flow rates, slotted-plate solar collectors possess rather lower thickness and lighter mass, higher heat production, and better matching with various buildings compared with the common plate solar collectors. Results show that a much higher instantaneous efficiency could be obtained by increasing the flow rates suitably in a low-temperature working environment. The average efficiency could reach up to 51% with the maximum instantaneous efficiency of 61%. Based on the analysis of the relation between instantaneous efficiency and flow rates or the relation between instantaneous efficiency and the temperature difference of the inlet and the outlet water, a experiential formula for the optimal flow rate is proposed to improve the heating-up rates and working efficiency. The performances investigation of slotted-plate solar collectors would pave a way for their widespread and positive applications in the near future.