Investigation of heat transfer and pressure drop in a concentric heat exchanger with snail entrance

被引:113
作者
Durmus, A [1 ]
Durmus, A [1 ]
Esen, M [1 ]
机构
[1] Firat Univ, Dept Mech Educ, TR-23119 Elazig, Turkey
关键词
experimental; concentric heat exchanger; snail; swirl flow; swirling angle; heat transfer enhancement; pumping power;
D O I
10.1016/S1359-4311(01)00078-3
中图分类号
O414.1 [热力学];
学科分类号
摘要
In this study, in order to increase heat transfer in concentric double-pipe heat exchangers by passive method, snail which is mounted at inlet of the inner pipe and assumed as a swirl generator was used. In the experimental set-up, cold air in ambient conditions was passed through the inner pipe while hot water was flowing through the annulus. The effects of a snail on the heat transfer and pressure drop were investigated for parallel and counter-flow, and obtained Nusselt numbers (Nu) were compared with those found, using a standard correlation such as Dittus-Boelter equation given for axial flows in smooth pipes. The results were correlated in the form of Nusselt number as a function of Reynolds number, Prandtl number and the swirling angle. An augmentation of up to 120% in Nusselt number was obtained in the swirl flow for counter-flow and 45 swirling angle. Though the swirl flow effect of the snail caused some increase in pressure drop, this effect was unimportant compared with the improvement in heat transfer capacity. (C) 2002 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:321 / 332
页数:12
相关论文
共 15 条
[1]  
[Anonymous], 1984, TUNBRIDGE WELLS
[2]  
Bergles AE, 1996, J ENHANC HEAT TRANSF, V4, P1
[3]   MECHANISMS OF HEAT-TRANSFER ENHANCEMENT AND SLOW DECAY OF SWIRL IN TUBES USING TANGENTIAL INJECTION [J].
CHANG, F ;
DHIR, VK .
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, 1995, 16 (02) :78-87
[4]   SINGLE-PHASE AND 2-PHASE HEAT-TRANSFER IN TANGENTIAL INJECTION-INDUCED SWIRL FLOW [J].
GUO, Z ;
DHIR, VK .
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, 1989, 10 (03) :203-210
[5]  
Incropera F.P., 1990, FUNDAMENTALS HEAT MA
[6]  
Kays W.M., 1993, Convective Heat and Mass Transfer
[7]   EXPERIMENTAL-STUDY OF TURBULENT SWIRLING FLOW IN A STRAIGHT PIPE [J].
KITOH, O .
JOURNAL OF FLUID MECHANICS, 1991, 225 :445-479
[8]  
Kreith F., 1959, Flow Turbulence and Combustion, V8, P457, DOI [DOI 10.1007/BF00411769, 10.1007/BF00411769]
[9]   HEAT-TRANSFER AND PRESSURE-DROP CORRELATIONS FOR TWISTED-TAPE INSERTS IN ISOTHERMAL TUBES .2. TRANSITION AND TURBULENT FLOWS [J].
MANGLIK, RM ;
BERGLES, AE .
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, 1993, 115 (04) :890-896
[10]  
McCabe WL, 1993, Unit operations of chemical engineering