The spectrally selective absorbing film plays a key role in determining the collecting capability of solar thermal energy in the application of solar water heater. This research experimentally investigates influences of importance parameters among spray coating process on the solar absorptance, thermal emittance and collection efficiency of the selective absorbing film. Selective parameters include thickness of the selective absorbing film, median diameters of the spray, and the frequency of the coating etc. Results show that thickness of the selective absorbing film has a strong effect on the absorptance and the emittance of the selective absorbing film. The optimum collection performance of the spectrally selective films with absorptance up to 93% while the emittance down to 65% can be achieved at a film thickness of 3.3 μm. Thus, proper selection of the film thickness results in the optimum ratio of the absorptance to the emittance and thus the optimum collection efficiency of thermal solar energy. Results also show that higher median diameters of the spray can increase the absorptance and reduce the emittance, thus has a positive effect of the collection efficiency of thermal solar energy. It is caused by redistribution of carbon particles inside spray flow, the deposition effect onto a substrate, as well as the evaporation of the solvent.
|Publication status||Published - 2015|
|Event||13th International Conference on Liquid Atomization and Spray Systems, ICLASS 2015 - Tainan, Taiwan|
Duration: 2015 Aug 23 → 2015 Aug 27
|Conference||13th International Conference on Liquid Atomization and Spray Systems, ICLASS 2015|
|Period||15-08-23 → 15-08-27|
All Science Journal Classification (ASJC) codes
- Surfaces, Coatings and Films