Karwa R., Karwa N., Misra R., Agarwal P.C.
Department of Mechanical Engineering, Faculty of Technology, Addis Ababa University, P.O. Box 385, Addis Ababa, Ethiopia; Department of Mechanical Engineering, Indian Institute of Technology, Delhi, 110 016, India; Department of Mechanical Engineering, Faculty of Engineering, Jai Narain Vyas University, Jodhpur, 342 011, India
Karwa, R., Department of Mechanical Engineering, Faculty of Technology, Addis Ababa University, P.O. Box 385, Addis Ababa, Ethiopia; Karwa, N., Department of Mechanical Engineering, Indian Institute of Technology, Delhi, 110 016, India; Misra, R., Department of Mechanical Engineering, Faculty of Engineering, Jai Narain Vyas University, Jodhpur, 342 011, India; Agarwal, P.C., Department of Mechanical Engineering, Faculty of Engineering, Jai Narain Vyas University, Jodhpur, 342 011, India
This paper presents results of a theoretical study carried out to investigate the effect of flow maldistribution, caused by the manufacturing imperfections and tolerances, on the thermal efficiency of a solar air heater array with subcollectors in parallel. The air mass flow rate, ambient temperature, solar insolation and wind heat transfer coefficient have been systematically varied to study the effect under a wide range of these parameters. The collector length, duct height, and plate emissivity were also changed to study their effect. It has been found that the maximum reduction in thermal efficiency due to flow maldistribution is less than about 3% for an array with a commercial grade finish of duct surfaces and ±10% manufacturing tolerance for the duct height. © 2006 Elsevier Ltd. All rights reserved.
Heat transfer coefficients; Natural convection; Solar collectors; Thermal effects; Flow imbalance; Solar air heater array; Subcollectors in parallel; Thermal performance; Solar heating; Heat transfer coefficients; Natural convection; Solar collectors; Solar heating; Thermal effects; air mass; flow pattern; performance assessment; photovoltaic system