Experimental and modeling studies on thermosiphon domestic solar water heaters with flat-plate collectors at clear nights

Polymeric Materials for Solar Energy Utilization: A Comparative Experimental Study and Environmental Aspects

“…Reverse circulation, featured in thermosiphon solar HWSS, as mentioned in several studies [11,13] never occurred in the present research, mainly because the bottom of the tankaccumulator was 40 cm higher than the top of the tested SCs.…”

“…A control panel (13) equipped with different instrumentation and various standard components, such as a pyrometer (14) for solar radiation intensity measurement and an anemometer (15) for the air velocity estimation, was also used in the construction of the test rig.…”

Polymeric Materials for Solar Energy Utilization: A Comparative Experimental Study and Environmental Aspects

“…In the spring and autumn, the durations of the first and second zones were longer due to lower solar irradiation. Reverse circulation, featured in thermosiphon solar HWSS, as mentioned in several studies [11,13] never occurred in the present research, mainly because the bottom of the tankaccumulator was 40 cm higher than the top of the tested SCs. Higher efficiency of the traditional SC-A can be explained by the superior transparency of the glass compared to the honeycomb PC panel and by the worse thermal conductivity of PC compared to aluminum.…”

Heating Performance Study on a Passive Solar Heater

“…Same relation is applicable for tangential stress in hot water tank (σ t ′ = P T ′ D T ′ 2t ⁄ ), where P T ′ is internal pressure of hot water tank and P T is internal pressure of cold water tank. In the given heater design, P T , P T ′ , σ t and σ t ′ were calculated about 8820 N m 2 ⁄ , 1910.6 N m 2 ⁄ , 7.9 MPa and 3.8 MPa, respectively. Since the water tanks were closed, the longitudinal stress σ 1 was also taken into account due to the water pressure on ends of the tanks.…”

“…During this period, climate vary from very low to high temperatures. The residents of Faisalabad use flat plates (black coated solar collectors) to maximize the absorption of radiant energy [1][2][3]. However, such models have failed in least sunny days of winter season.…”