solar collectors, with and without

solar collectors, with and without honeycomb, has been carried out. In this paper some innovative results have been reached:
 - natural convection can be suppressed using honeycomb between the glazing and absorber plate;
 - the bottom gap thickness is more influent than the top gap thickness;
 - the honeycomb panel in the field of solar thermal collectors can reduce the transmission of solar radiation and the top heat loss (of 52%).
For values of the reduced temperature less than 0.026, the optical efficiency of the collectors with honeycomb panel is less than that of the collectors without honeycomb (of about 14%), for values of the reduced temperature higher than 0.026, the thermal efficiency of the collectors with honeycomb panel is higher than the one of the collectors without (at reduced temperature of 0.03, the value of the efficiency is 40% and 30% respectively).
Al-Madani [23] evaluated the performance of a cylindrical solar water heater. The proposed model consists of a cylindrical glass receiver, with a copper coil. After describing the physical characteristics of the glass tube as receiver and of the copper coil as collector, measures of the thermal efficiency have been performed and the maximum value of the obtained averaged efficiency was 41.8%, during a year with a maximum temperature of 45.6 °C and with a minimum temperature of 8 °C.
Ozgen et al. [24] carried out an experimental investigation about thermal performance of a double-flow solar air heater (SAH), with aluminum cans. Three types of solar thermal collectors have been analyzed:
- Type I: cans placed as zigzag on the absorber plate;
 - Type II: cans arranged in order on the absorber plate;
 - Type III: absorber plate without cans.

By introducing aluminum cans on the plate absorber, the heattransfer area is increased and a good airflow over and under the absorber plates is ensured, because cans create turbulence and reduce the dead zones in the collector. Experimental data of the efficiencies for two different mass flow rates (0.05 and 0.03 kg/s) have been recorded for the three types of solar thermal collectors. The first type of the proposed model has the maximum value of efficiency of 72% at 0.05 kg/s mass flow rate. The second type, with cans arranged in orderon the absorber plate,has a lower efficiency (59%) than the first one and it has higher efficiency than the third model at 0.05 kg/s mass flow rate.
The same trend is presented at 0.03 kg/s mass flow rate. This phenomenon is due to the high turbulence created by cans on the absorber plate.

ผลลัพธ์ (แอฟริกา) 1:

sonkollektors, met en sonder heuningkoek is uitgevoer. Sommige resultate innoverende was in hierdie vraestel bereik:
? - Natuurlike konveksie kan onderdruk met behulp van heuningkoek tussen die glas en demper Plaat;
? - Gap Dikte is meer in die onderste as die top vlot FL Gap Dikte;
? - Die heuningkoek paneel in die fi ELD van Solar Thermal Versamelaars kan verminder die oordrag van sonstraling en die top hitteverlies (van 52%).
Vir waardes van die verminderde temperatuur Minder as 0,026, die optiese Doeltreffende van die Versamelaars met heuningkoek paneel is minder. as dié van die versamelaars sonder heuningkoek (van ongeveer 14%), vir waardes van die verminderde temperatuur hoër as 0,026, die termiese Doeltreffende van die versamelaars met heuningkoek paneel is hoër as die een van die versamelaars sonder (teen verlaagde temperatuur van 0,03, die. waarde van die Doeltreffende is 40% en 30% onderskeidelik).
Al-Madani [23] geëvalueer die Solar Water Heater voordra van 'n silindriese. Die voorgestelde model bestaan uit 'n silindriese glas ontvanger, met 'n koper spoel. Na die beskrywing van die fisiese eienskappe van die glasbuis as ontvanger en die koper spoel as versamelaar, het maatreëls van die hitte Doeltreffende uitgevoer en die maksimum waarde van die verkry gemiddeld Doeltreffende was 41,8%, gedurende 'n jaar met 'n maksimum temperatuur van 45,6 °. C en met 'n minimum van 8 ° C temperatuur.
Ozgen et al. [24] uitgevoer 'n eksperimentele ondersoek oor termiese prestasie van 'n dubbel- vloei son lug verwarmer (SAH), met 'n aluminium blikkies. Drie tipes zonnewarmte versamelaars ontleed:
-? Tik ek: Geplaas blikkies as zigzag op die demper Plaat;
? - Tipe II: Orde in blikkies gereël op die demper Plaat;
? - Tipe III:. Demper Plaat Sonder blikkies

Deur die instelling van aluminium blikkies op die bord demper, is die Heattransfer Area toegeneem en 'n goeie Air vloei oor en onder die absorbeerder plate is verseker, want blikkies skep Turbulensie en Verminder die dooie sones in die versamelaar. Eksperimentele data van die ef fi tekorte vir twee verskillende massa vloei pryse (0.05 en 0.03 kg / s) is aangeteken vir die drie tipes zonnewarmte versamelaars. Die eerste tipe van die voorgestelde model het die maksimum waarde van Doeltreffende van 72% op 0,05 kg / s massa vloei tempo. Die tweede soort, met blikkies gereël in Orderon die demper Plaat, het 'n laer Doeltreffende (59%) as die eerste een en dit het 'n hoër Doeltreffende as die derde model op 00:05 kg / s massa vloei tempo.
Dieselfde tendens word by 1203 voormiddag .. kg / s massa vloei tempo. Hierdie verskynsel is as gevolg van die hoë turbulensie geskep deur blikkies op die demper plaat.