Vacuum Effect on the Performance of Solar Air Collector with Micro-Channel Absorber Plate


n this study, the effect of vacuum with micro-channeltechnique on solar air collector performance is investigated experimentally.Vacuum space reduces the loss of heat for the absorption plate by conductionand thus improves the solar collector performance.It has been demonstrated that the solar collector is evacuated to 0.1 bar of pressurefor absorber-to-cover spacing of 4cm. An absorber plate was manufactured from Aluminum metal with 30 rectangular micro-channels (length 0.9, width 0.004, height 0.0008 m) is constructed with measurements facilities of velocity, temperature and differential pressure. The tests are carried out indoor using solar simulator. Results showed that the performance of solar collector increases with vacuum about 2-5% than gained with non-vacuum utilizing amicro-channel absorber plate-black surface.