This study aims to develop a thermosyphon inserted vacuum tube type solar heat collector, in order to remedy shortcomings of the U-tube type solar heat collector which is mostly dependant on imports.
In thus study, Absorbing coating which is considered in priority for an optimal design factor. It was produced through electroless plating, and surfaces of absorber elements and heat absorption capabilities were analysed.
Then, for a study on thermal performance, the U-tube type solar heat collector was selected as a control group, and it was compared with the thermosyphon inserted vacuum tube type solar heat collector and analysed through solar heat collector performance experiment and computational analysis. The research results are as below.
(1) When analyzing the temperature rise rate and maximum temperature of absorber elements, the non glossing black chrome showed the greatest property at 43.3℃. This is because the absorption rate of the non glossing with a low heat reflection effect of light is relatively favorable, and black color has high heat absorption property and low emissivity itself.
(2) According to the experiment under the normal condition and the computational analysis, the thermosyphon inserted vacuum tube type solar heat collector showed an maximum error of 5.93 %, and the U-tube type solar heat collector showed an maximum error of 6.62 % in temperature distribution.
(3) According to the computational analysis, the fluid velocity increased more in the top of the U-tube type solar heat collector, but it was hardly changed inside the thermosyphon inserted vacuum tube type solar heat collector. It is supposed that is because there was a stagnation with no density difference inside the evacuated tube, due to lamina flow and turbulent flow.
(4) The experiment result showed that the thermosyphon inserted vacuum tube type solar heat collector gain was 449.179kcal/m2, and the U-tube type solar heat collector gain was 826.805 kcal/m2.
(5) The experiment of solar collector performance displayed that the thermosyphon inserted vacuum tube type solar heat collector efficiency was approximately 53 % ∼ 60 %, and the U-tube type solar heat collector efficiency was approximately 68 % ∼ 69 %.
(6) In general, collector efficiency increased, as heat loss decreased, and solar heat gain remarkably reduced, as collector temperature rose.