Evaluation of perforated plate solar air heater

Perforated plates had been successfully used in recent years to achieve high heat transfer coefficient from the absorber plate to the flowing air stream in solar air heaters. Since pumping pressure to maintain a particular flow in the solar air heater utilizing this type of absorber has significant influence on collected energy, so the design of perforated plate configuration must be based on the net energy gained from that collector which is the difference between energy collected and energy paid to overcome pumping pressure. A mathematical model had been constructed and validated experimentally for perforated plate solar air heater to study the effect of plate configurations and airflow rate on both energy gained and pressure loss. The results show that, the flow rate of air and plate configurations have a great effect on net energy gained from the air heater. The results also show that a plate of certain configurations operates most efficiently at certain flow rate and more than one configurations can give optimum value of net energy gained for a particular flow rate.