Performance intensification of tubular heat exchangers using compound twisted-tape and twisted-tube

Author(s):  
Morteza Khoshvaght-Aliabadi ◽  
Amir Feizabadi
2017 ◽  
Author(s):  
Boris V. Dzyubenko ◽  
Guenrikh A. Dreitser

2020 ◽  
Vol 1448 ◽  
pp. 012010
Author(s):  
J G Ardila M ◽  
M Valdes ◽  
M R Cabal ◽  
A Castro ◽  
J G Quintero

Author(s):  
R. Saravanan ◽  
M. Karuppasamy ◽  
M. Chandrasekaran ◽  
V. Muthuraman

Heat transfer improvement is the main parameter in a heat exchanging equipment. Few methods to increase the coefficient of heat transfer is by creating the turbulence in heat exchanging elements and changing the heat transfer fluids. For current analysis of tube heat exchangers, tape inserts containing balls are implemented with nano-fluids in Carbon Nano Tubes (CNT) and ethylene glycol. 3D modelling and simulation of twisted tape heat exchanger with balls were carried out using Solidworks and ANSYS Workbench. Heat transfer rate, friction factor, temperature difference in the heat exchangers, Reynolds number and Nusselt number variations are assessed in this work.


Author(s):  
Hussain H. Al-Kayiem ◽  
Muna S. Kassim ◽  
Saud T. Taher

Nanoadditives are a type of heat transfer enhancement techniques adopted in heat exchangers to improve the performance of industrial plants through improvement of the thermal properties of base fluids. Recently, various types of inserts with nanofluids are adopted to enhance the thermal performance of double pipe heat exchangers. In the current article, TiO2/water nanofluid with multiple twisted tape inserts was investigated as a hybrid enhancement technique of heat transfer in straight pipes. The investigations were carried out experimentally and numerically at Reynolds numbers varied from 5000 to 20,000. Using nanofluid with 0.1% TiO2 nanoparticles volume fraction demonstrated enhanced heat transfer with slight increase in pressure drop. Results are showing a maximum increase of 110.8% in Nusselt number in a tube fitted with quintuple twisted tape inserts with 25.2% increase in the pressure drop. However, as the article is representing a part of specified book on heat exchangers, the literature has been extended to provide sufficient background to the reader on the use of nanotech, twisted inserts, and hybrid of compound nanofluids and inserts to enhance heat transfer processes.


2014 ◽  
Vol 6 ◽  
pp. 250354 ◽  
Author(s):  
S. Tabatabaeikia ◽  
H. A. Mohammed ◽  
N. Nik-Ghazali ◽  
B. Shahizare

Heat transfer enhancement has been always a significantly interesting topic in order to develop high efficient, low cost, light weight, and small heat exchangers. The energy cost and environmental issue are also encouraging researchers to achieve better performance than the existing designs. Two of the most effective ways to achieve higher heat transfer rate in heat exchangers are using different kinds of inserts and modifying the heat exchanger tubes. There are different kinds of inserts employed in the heat exchanger tubes such as helical/twisted tapes, coiled wires, ribs/fins/baffles, and winglets. This paper presents an overview about the early studies on the improvement of the performance of thermal systems by using different kinds of inserts. Louvered strip insert had better function in backward flow compared to forward one. Modifying the shape of twisted tapes led to a higher efficiency in most of the cases excpet for perforated twisted tape and notched twisted tape. Combination of various inserts and tube with artificial roughness provided promising results. In case of using various propeller types, heat transfer enhancement was dependent on higher number of blades and blade angle and lower pitch ratio.


2019 ◽  
Vol 8 (3) ◽  
pp. 3059-3062

The heat transfer enhancement is one of the essential factors to be considered in the design of heat exchangers. The rate of heat transfer can be enhanced by inserting and modifying the geometric configuration of the turbulators in the tube of heat exchangers. In our present work we conducted the experiment to investigate the rate of heat transfer enhancement in a tubular in a heat exchanger by using rotating twisted tape turbulator of twist ratio 3.27 using water and Al2O3 nanofluid as a testing fluid at the flow rate of 1, 2, and 3 LPM. The range of Reynolds number used is 2000<Re<10000, the heat transfer rate calculated for each case of rotating TTT with the speed of 0 to 300 RPM with the step of 100 RPM. The obtained results are compared between water and Al2O3 nanofluid, with and without rotating TTT. From the comparisons, it was found that the TTT with U-cut and the use of Al2O3 nanofluid gives the better rise in the heat transfer rate of about 39.63%. The augmented rate of heat transfer is due to the more turbulence when the rotating TTT is used and replacing the water with nanofluid as the testing fluid which of high thermal properties.


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