Performance evaluation of compact solar water heater with black chromium coating
Having blessed with abundance sunlight and high solar radiation level, Malaysian is tempted to the' green' solar technology. Yet, application of solar water heating system in Malaysia is not so popular. Facing with the unique Malaysian climate, hot and humid, more cloudy and rainy than cle...
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| Format: | Thesis |
| Language: | English |
| Published: |
2007
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| Subjects: | |
| Online Access: | https://eprints.ums.edu.my/id/eprint/6369/1/mt0000000143.pdf |
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| Summary: | Having blessed with abundance sunlight and high solar radiation level, Malaysian is tempted to the' green' solar technology. Yet, application of solar water heating system in Malaysia is not so popular. Facing with the unique Malaysian climate, hot and humid, more cloudy and rainy than clear day and of course, a high initial cost, designers and engineers are challenged to come out with a cost efficient Solar Water Heater (SWH). In this study, a compact SWH prototype has been developed and tested. This unit is equipped with a perforated tube (inserted in the lower header tube) which has different number of hole (in ascending order) in each opening to riser tubes, intended to curb the bottleneck problem. The water circulates by thermosiphon principles. During the heating process, the water flow in the riser tube is more uniform with the presence of the perforated tube. In addition, the absorber plate is coated with black chromium selective coating which enhances the thermal radiation absorption (J.Idris et.al., 2003). Problem that often occurs which reduces the efficiency is the heat loss through solar collector panel (especially the top panel) and connecting pipes. The developed compact prototype not only reduces the heat losses but also reduces the usage of material and hence cost. Experimental results showed that the UTM IV prototype has overall heat loss coefficient reduced from 6.91 to 6.83 W/m2K, and instantaneous efficiency rise from 69.4% to 82%, an increase about 12.6%, compared to the UTM II prototype. |
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