Abstract
The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.
Highlights
With the challenges of fossil fuel depletion and global warming, utilization of renewable energy attracted extensive attention over the whole world
The solar collector is usually installed on building’s roof with a surface slope, which is equal to the local geographical latitude with an addition of 10 degrees
The TRNSYS Type 45 model is adopted to discuss the effects of azimuth angles and slope angles of solar collectors on solar radiation collection for the thermosyphon solar water heaters (TSWH)
Summary
With the challenges of fossil fuel depletion and global warming, utilization of renewable energy attracted extensive attention over the whole world. The collectors of balcony split type solar water heaters are usually attached on high-rise building external walls or balcony rails. Ong and Tiwari [22,23,24] developed simulation methods and test performance of solar water heating systems under the thermosyphon mode between the collectors and the storage tank. The Transient System Simulation Program, TRNSYS [25, 26], was utilized to analyze the effects of surface orientation and surface slope of solar collectors on solar radiation collection in six typical cities of China with different geographic latitudes. The effects of the water cycle mode of the solar water heater, the reverse slope placement of the solar collector, and the installation height of the water tank on the efficiency of the solar heaters were studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
