標題: The New Mathematical Models for Plain Fin-and-Tube Heat Exchangers With Dehumidification 作者: Pirompugd, WorachestWang, Chi-ChuanWongwises, Somchai機械工程學系Department of Mechanical Engineering 關鍵字: finite circular fin method;fin-and-tube heat exchanger;lumped approach;partially wet condition 公開日期: 1-三月-2015 摘要: For evaluating performance of fin-and-tube heat exchangers under dehumidifying conditions, the recent lumped approach models are based on the enthalpy potential or equivalent dry bulb temperature. This study proposes a new lumped approach model based on the dry bulb temperature difference. The concept of dry bulb temperature was first presented by McQuiston for derivation of fin efficiency under dehumidifying conditions in 1975. This concept is simpler than the concepts of enthalpy potential and equivalent dry bulb temperature. Nevertheless, it cannot be found that this concept is applied to the fin-and-tube heat exchangers. Moreover, this study also presents the finite circular fin method (FCFM) based on the dry bulb temperature and equivalent dry bulb temperature. The FCFM was first presented in our published literature but it was based on the enthalpy potential. The FCFM is done by dividing the fin-and-tube heat exchanger into many small segments. Then, the segments are divided into three cases: fully dry condition, fully wet condition, and partially wet condition. From the results, the new lumped approach model based on dry bulb temperature gives a good result. It is the simplest method for evaluating heat transfer performance of fin-and-tube heat exchangers under fully wet conditions. For the FCFM, the heat and mass transfer characteristics obtained by dry bulb temperature and equivalent dry bulb temperature are nearly the same as those obtained by the enthalpy potential. However, the heat and mass transfer characteristics by the FCFM based on equivalent dry bulb temperature are higher than those obtained by the FCFM based on dry bulb temperature. This is because of the effect of the nonconstant term in the two methods. The correlations applicable for both fully wet and partially wet conditions for the FCFMs based on equivalent dry bulb temperature and dry bulb temperature are proposed to describe the heat and mass transfer characteristics for the present plain fin configuration. URI: http://dx.doi.org/10.1115/1.4029037http://hdl.handle.net/11536/124530 ISSN: 0022-1481 DOI: 10.1115/1.4029037 期刊: JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME Volume: 137 顯示於類別： 期刊論文