Heat Transfer Enhancement in Absorber Tube of Parabolic Trough Concentrators Using Wire-Coils Inserts

Ketan Diwan,M S Soni

doi:10.13189/ujme.2015.030305

Abstract

Heat transfer enhancement technology provides many advantages in heat exchanger applications. In the present paper, the heat transfer characteristics and the pressure drops of the absorber tube of Parabolic Trough Concentrators with wire-coils inserts are investigated. Water is used as a heat transfer fluid and simulations are carried out in COMSOL Multiphysics® 4.4, for various flow rates of water as well as for different pitch values of wire-coils insert. It is observed that introduction of wire coils increases the turbulence inside the tube, thereby increasing the Reynolds number and hence the Nusselt number. Value of Nusselt number is observed to be increased by 104% to 330% which indicates the increase in the value of convective heat transfer coefficient and hence the heat transfer rates.

Highlights

Tube insert devices include twisted tape inserts, wire coils inserts, extended surface inserts, mesh inserts, and etc. out of which the use of twisted tapes and wire coils inserts is more common
Wire coils are the type of inserted devices which present some unique advantages compared to other enhancement techniques viz. they may be installed and that to with low cost in an existing smooth tube of heat exchanger and it keeps the mechanical strength of the smooth tube
Wire coils are used for full length of tube and simulations are carried out for different pitch values and for different mass flow rates and optimum range of pitch value is proposed

Summary

Introduction

Tube insert devices include twisted tape inserts, wire coils inserts, extended surface inserts, mesh inserts, and etc. out of which the use of twisted tapes and wire coils inserts is more common. Tube insert devices include twisted tape inserts, wire coils inserts, extended surface inserts, mesh inserts, and etc. Out of which the use of twisted tapes and wire coils inserts is more common. Most of the work available today is based on the different twisted tape geometries. Wire coils are the type of inserted devices which present some unique advantages compared to other enhancement techniques viz. They may be installed and that to with low cost in an existing smooth tube of heat exchanger and it keeps the mechanical strength of the smooth tube Wire coils are the type of inserted devices which present some unique advantages compared to other enhancement techniques viz. they may be installed and that to with low cost in an existing smooth tube of heat exchanger and it keeps the mechanical strength of the smooth tube

Methods

Results

Conclusion