Experimental study on thermal performance improvement of solar air heater using piezoelectric fan

摘要

This paper presents experiment research about piezoelectric fan array in solar air heater (SAH) at the frequencies 45-60Hz by using lamp array as solar radiation simulator. The effectively heat transfer coefficient (HTC) of the traditional method such as strip rib on the solar collector and enhancement by piezoelectric fan are compared in detail with different mass flow rate of the air. A prototype solar collector with dimension of 300(L)x150(W)mm is fixed in a wind tunnel in the experiment. Three configurations of piezoelectric fan array have been tested, the results show that the piezoelectric fan can increase the HTC effectively, the HTC is increased 3-3.5 times compared with smooth plate and the additional power consumption of the piezoelectric fan as low as 0.6W for 2x2 piezoelectric fan array, whereas for the pressure drop of the SAH increased no more than 5%. The resonance frequencies of the two types of piezoelectric fans in experiment are 55Hz and 53Hz respectively, the maximum amplitude and the HTC achieved at the resonance frequency. It's an effective way for SAH application compares to other methods of heat transfer enhancement in SAH and rarely be reported in the area of SAH.