A cylindrical glass honeycomb solar collector and its application

SYNOPSIS The structure of an experimental cylindrical glass honeycomb solar collector, the testing system and method for determining instantaneous efficiency are introduced. Experimental results giving the instantaneous efficiency of both the honeycomb collector and a “basic collector” are reported. Results from boiling water tests are also discussed. These indicate that the efficiency of the experimental collector is much greater than that of the “basic collector”. For values of solar irradiation between 600 and 1000 W/m2 and taking the temperature difference between the average working fluid and the environment as 30K, 50K, 70K and 90K, the corresponding instantaneous efficiencies are 57–66%, 41–57%. 24–47% and 8–38%. The method of the theoretical efficiency prediction and calculation are briefly discussed, the measured and calculated data are analysed and compared. As an application, the structure and system as well as experimental results of a solar heating boiling water device, with a 4.6 m2 collector area and a cylindrical glass honeycomb structure, are reported. Finally, the views on the technique, economy and its application are presented. This type of flat-plate solar collector is simple in structure, more convenient in fabrication, lower cost, steadier in performance, and higher in efficiency than conventional flat-plate collectors; it can raise the temperature of the medium to over 100°C.