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http://dx.doi.org/10.7836/kses.2019.39.1.077

Research on the Heat Transfer and Pressure Drop by Installation Conditions of Rectangular Obstacle in a Solar Air Heater Based on CFD  

Choi, Hwi-Ung (Graduate School of Refrigeration and Air-conditioning Engineering, Pukyong National University)
Kim, Young-Bok (Dept. of Mechanical System Engineering, Pukyong National University)
Son, Chang-Hyo (Dept. of Refrigeration and Air-conditioning Engineering, Pukyong National University)
Yoon, Jung-In (Dept. of Refrigeration and Air-conditioning Engineering, Pukyong National University)
Choi, Kwang-Hwan (Dept. of Refrigeration and Air-conditioning Engineering, Pukyong National University)
Publication Information
Journal of the Korean Solar Energy Society / v.39, no.1, 2019 , pp. 77-89 More about this Journal
Abstract
The solar air heater has various performances according to an obstacle installed in the air duct. Many studies on thermal performance have been conducted. But many of these studies were using a kind of rib type obstacle attached at the bottom of absorbing plate, but they are so hard to be manufactured. In this study, characteristics of the heat transfer and pressure drop in the solar air heater with various horizontal rectangular obstacles was investigated by CFD (Computational Fluid Dynamics) analysis. As a result, the heat transfer performance was improved from 1.2 to 3.32 times depending on installation conditions of rectangular obstacle. The pressure drop, however, also increased with increment of heat transfer performance from 2.8 to 180 times only by changing installation conditions of rectangular obstacle. Thus, the performance factor presenting the thermal performance enhancement on the same pressure drop was also confirmed. As a result, the highest value of 0.828 as better performance factor was obtained at the lower height of rectangular obstacle and this value has started to decrease with increment of heat transfer performance. In the end, it could be confirmed that the pressure drop was carried higher than the quantity of improvement of the heat transfer performance when the heat transfer performance was increased by change of installation conditions of rectangular obstacle. Both heat transfer enhancement and pressure drop to be required for system need to be considered before the rectangular obstacles are applied to the solar air heater.
Keywords
Solar thermal system; Solar collector; Solar air heater; Computational fluid dynamic; Energy saving;
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Times Cited By KSCI : 3  (Citation Analysis)
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