A study on reducing temperature rise of twin-glass evacuated tube solar collector during summer time

Abstract

A s t u d yo nr e d u c i n gt e mp e r a t u r er i s eo ft wi n -g l a s se v a c u a t e dt u b e s o l a rc o l l e c t o rd u r i n gs u mme rt i me 배상은* ․배철호* * †․남현규* * * ․신기열* * * * ․유인호* * * * * B a i S a n g -E u n * ,B a i C h e o l -H o * * †,N a m H y u n -K y u * * *a n dS h i nK i -Y e o l * * * * ( S u b mi td a t e :2 0 1 3 .1 .1 8 . J u d g me n td a t e :2 0 1 3 .1 .2 8 . P u b l i c a t i o nd e c i d ed a t e :2 0 1 2 .0 4 .2 2 . ) Abstract：Th er e f l e c t i o np l a t ei nt wi n -g l a s se v a c u a t e dt u b es o l a rc o l l e c t o ri sc o n t r o l l e dt or e d u c et h eo v e r h e a t d u r i n g t h e s u mme rt i me .Th e s l i d i n g t y p e a n d f o l d i n g t y p e s a r e s u g g e s t e d a n d t e s t e d .Th e s l i d i n g t y p ec h a n g e st h ep l a t ea n g l ea n dt h ef o l d i n g t y p ec h a n g e st h eo p e n i n g a n g l eo ft h er e f l e c t i o np l a t e .By s c a t t e r i n g t h ef o c u so ft h er e f l e c t e dr a d i a t i o nf r o m t h er e f l e c t i o np l a t e ,t h et e mp e r a t u r er i s eo ft h ewo r k i n g f l u i dc a nb e r e d u c e d .Th es l i d i n gt y p es h o wst h eb e s tr e s u l t si no v e r h e a tr e d u c t i o n .Wh e ns o l a rr a d i a t i o ni

Analysis of the Optimum Solar Collector Installation Angle from the Viewpoint of Energy Use Patterns

“…This is to compensate for the lack of meteorological data (cloud information was not provided as mentioned in the introduction). Figure 3 The equation describing the efficiency of the solar collector is: In this case, it is possible to estimate the heat collecting efficiency of the solar collector by using a quadratic expression formed with its inlet and outlet temperatures and the solar radiation striking it [23]: The equation describing the efficiency of the solar collector is: [28] is used on the solar irradiance on the inclined surface (Equation (2)). This is to compensate for the lack of meteorological data (cloud information was not provided as mentioned in the introduction).…”

“…This is to compensate for the lack of meteorological data (cloud information was not provided as mentioned in the introduction). Figure 3 The equation describing the efficiency of the solar collector is: In this case, it is possible to estimate the heat collecting efficiency of the solar collector by using a quadratic expression formed with its inlet and outlet temperatures and the solar radiation striking it [23]: In this case, it is possible to estimate the heat collecting efficiency of the solar collector by using a quadratic expression formed with its inlet and outlet temperatures and the solar radiation striking it [23]:…”

“…Solutions to prevent overheating include covering the solar collector panel with a sun shade, discharging overheated water from the heat storage tank, or operating a heat sink cooling fan (the latter is displayed in Figure 1) [22]. Bai et al [23] researched limiting temperature rises by adjusting the angle of the reflector to prevent a double vacuum tube type solar collector from overheating. Aside from this, due to wintry or rainy weather conditions, the temperature of the solar heat storage tank could fail to rise to the temperature level needed for the hot water supply.…”