Improving the performance of shell-and-tube heat exchangers by the addition of swirl

Heat exchanger is a component which is used to transfer the heat from one medium to another efficiently. Generally, they occupy a large space compared to other components and such bulky designs are not attractive in the modern industrial applications due to several constraints. Therefore, it is invaluable to develop compact heat exchangers but with the improved performance. In this work, an investigation was made on the possibility of reducing the size of a shell-and-tube heat exchanger by addition of swirl. Swirl was generated by using a twisted-tape which inserted inside tube and the effects of these tapes on the heat transfer rate and pressure drop were theoretically studied. The results showed that a half-length regular spaced twisted-tape insert gave the lowest Nusselt number while a full-length twisted-tape insert gave the maximum Nusselt number and hence the highest rate of heat transfer. The length of the heat exchanger could be reduced by 13.3% with a full-length twisted tape and this would be result in 6.8% of reduction of the fabrication cost. Therefore, addition of swirl into the fluid flow should help to design compact and low cost heat exchanges with improved performance but the pressure drop increased leading to an increase of the required pumping power. A prototype shell-and-tube heat exchanger was designed and fabricated based on the theoretical results. Studies are underway to experimentally investigate the overall effectiveness of the use of twisted-tape inserts for enhancing the heat transfer rate by considering all the related benefits and drawbacks.

[1]  Chinaruk Thianpong,et al.  Turbulent heat transfer enhancement by counter/co-swirling flow in a tube fitted with twin twisted tapes , 2010 .

[2]  S. Eiamsa-ard,et al.  Convective heat transfer in a circular tube with short-length twisted tape insert , 2009 .

[3]  B. N. Prasad,et al.  Investigation of twisted tape inserted solar water heaters—heat transfer, friction factor and thermal performance results , 2000 .

[4]  Liangbi Wang,et al.  Convective Heat Transfer Enhancement in a Circular Tube Using Twisted Tape , 2009 .

[5]  Yanzhong Li,et al.  An experimental investigation of heat transfer enhancement for a shell-and-tube heat exchanger , 2009 .

[6]  Dogan Eryener,et al.  Thermoeconomic optimization of baffle spacing for shell and tube heat exchangers , 2006 .

[7]  Chinaruk Thianpong,et al.  Heat transfer enhancement in a tube using delta-winglet twisted tape inserts , 2010 .

[8]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[9]  T. Radhakrishnan,et al.  Experimental studies on heat transfer and friction factor characteristics of forced circulation solar water heater system fitted with helical twisted tapes , 2009 .

[10]  A. E. Bergles,et al.  Heat Transfer and Pressure Drop in Tape-Generated Swirl Flow of Single-Phase Water , 1969 .

[11]  N. K. Sane,et al.  Heat Transfer Enhancement in a Circular Tube Twisted with Swirl Generator: A Review , 2010 .

[12]  Cengiz Yildiz,et al.  Influence of fluid rotation on the heat transfer and pressure drop in double-pipe heat exchangers , 1996 .

[13]  Vijay K. Dhir,et al.  Mechanisms of heat transfer enhancement and slow decay of swirl in tubes using tangential injection , 1995 .

[14]  Animesh Dutta,et al.  Friction and heat transfer characteristics of laminar swirl flow through a circular tube fitted with regularly spaced twisted-tape elements , 2001 .

[15]  A. Zohir,et al.  Heat transfer characteristics and friction of turbulent swirling air flow through abrupt expansion , 2010 .

[16]  S. F. Al-Fahed,et al.  Pressure drop and heat transfer comparison for both microfin tube and twisted-tape inserts in laminar flow , 1998 .

[17]  Chinaruk Thianpong,et al.  Heat transfer augmentation by helically twisted tapes as swirl and turbulence promoters , 2012 .

[18]  Qiang Liao,et al.  Augmentation of convective heat transfer inside tubes with three-dimensional internal extended surfaces and twisted-tape inserts , 2000 .

[19]  F. Vera-García,et al.  A simplified model for shell-and-tubes heat exchangers: Practical application , 2010 .

[20]  Anupam Dewan,et al.  Review of passive heat transfer augmentation techniques , 2004 .

[21]  Mengna Hong,et al.  Compound Heat Transfer Enhancement of a Converging-Diverging Tube with Evenly Spaced Twisted-tapes * , 2007 .

[22]  R. M. Manglik,et al.  Heat Transfer and Pressure Drop Correlations for Twisted-Tape Inserts in Isothermal Tubes: Part II—Transition and Turbulent Flows , 1993 .

[23]  Sujoy Kumar Saha,et al.  Thermohydraulic Study of Laminar Swirl Flow Through a Circular Tube Fitted With Twisted Tapes , 2001 .

[24]  S. Sarada,et al.  Enhancement of heat transfer using varying width twisted tape inserts , 2011 .

[25]  U. N. Gaitonde,et al.  Heat transfer and pressure drop characteristics of turbulent flow in a circular tube fitted with regularly spaced twisted-tape elements , 1990 .

[26]  Abhijit Date,et al.  Friction and heat transfer characteristics of flow through square duct with twisted tape insert , 2003 .

[27]  S. Saha,et al.  Numerical prediction of laminar flow and heat transfer characteristics in a tube fitted with regularly spaced twisted-tape elements , 1990 .

[28]  Smith Eiamsa-ard,et al.  3-D Numerical simulation of swirling flow and convective heat transfer in a circular tube induced by means of loose-fit twisted tapes☆ , 2009 .

[29]  A. W. Date,et al.  Heat transfer and pressure drop in a spirally grooved tube with twisted tape insert , 2009 .

[30]  Enhancement C. Nithiyesh Kumar,et al.  Review on Twisted Tapes Heat Transfer , 2012 .

[31]  Anirudh Gupta.  Review of Heat Transfer Augmentation Through Different Passive Intensifier Methods , 2012 .

[32]  A. Yadav.  Effect of Half Length Twisted-Tape Turbulators on Heat Transfer and Pressure Drop Characteristics inside a Double Pipe U-Bend Heat Exchanger , 2009 .

[33]  S. Wongwises,et al.  An experimental investigation of the heat transfer and pressure drop characteristics of a circular tube fitted with rotating turbine-type swirl generators , 2013 .

[34]  Pongjet Promvonge,et al.  Enhancement of heat transfer in a tube with regularly-spaced helical tape swirl generators , 2005 .

[35]  M. Siddique,et al.  Recent Advances in Heat Transfer Enhancements: A Review Report , 2010 .

[36]  Arthur E. Bergles,et al.  AUGMENTATION OF TUBESIDE LAMINAR FLOW HEAT TRANSFER BY MEANS OF TWISTED-TAPE INSERTS, STATIC-MIXER INSERTS, AND INTERNALLY FINNED TUBES , 1978 .

[37]  S. W. Hong,et al.  Augmentation of Laminar Flow Heat Transfer in Tubes by Means of Twisted-Tape Inserts , 1974 .

[38]  Mohamed A. Habib,et al.  Heat transfer characteristics in a sudden expansion pipe equipped with swirl generators , 2011 .

[39]  Paisarn Naphon,et al.  Heat transfer and pressure drop in the horizontal double pipes with and without twisted tape insert , 2006 .

[40]  R. M. Manglik,et al.  Heat Transfer and Pressure Drop Correlations for Twisted-Tape Inserts in Isothermal Tubes: Part I—Laminar Flows , 1993 .

[41]  Aydın Durmuş,et al.  Effect of propeller type swirl generators on the entropy generation and efficiency of heat exchangers , 2007 .

[42]  A. W. Date,et al.  Prediction of fully-developed flow in a tube containing a twisted-tape , 1974 .