| Abstrakt: |
Solar air heater represents one of the substantial thermal systems that is utilized for collecting the heat of the solar radiation to be used for space air heating and farming products drying. This study aims to investigate the thermal performance of the solar air heater (SAH) with a multiple air pass using different arrangements of the corrugated absorber plate with a metal mesh and phase change material (PCM) as a thermal storage system experimentally. The test rig of SAH was consisted of an external insulated container, absorber corrugated plate, double glass sheets, air fan, and measuring devices. A black-coated corrugated Aluminum sheet of 900 mm in length, 500 mm in width, and thickness of 1 mm was installed inside the SAH container as absorber plate and supplied with 20 kg of Paraffin wax as PCM for thermal storage. Four cases of the SAH with a corrugated absorber plate at different arrangements are evaluated experimentally in April 2022 under Baghdad city climatic conditions to investigate optimal thermal performance of the SAH. Double pass and triple pass air flow SAH are examined in the first and second cases respectively. While a triple pass with a metal mesh and PCM assisted absorber plate are tested in the third and fourth cases respectively. The results revealed that the enhancement in the SAH outlet air temperature for case 4 was 21% compared with other test cases during low solar radiation hours. A relatively low air flowrate of 0.0095 kg/s has reflected a higher outlet air temperature by about 12 % compared with the other air flowrates 0.012 and 0.0134 kg/s considered in this work. Higher thermal efficiency for the solar air heater was 74, 73, 71.6, and 70% for cases 3, 2, 1, and 4 respectively at peak solar radiation hours, while at low solar radiation period, case 4 reflected a higher efficiency by about 15% compared with other test cases. [ABSTRACT FROM AUTHOR] |
