PREDICTION OF HEAT TRANSFER AND PRESSURE DROP IN HELICALLY PERFORATED TWISTED TAPE HEAT EXCHANGER TUBE USING FUZZY LOGIC

2020 ◽  
Vol 19 (1) ◽  
pp. 175-184
Author(s):  
Sunil Kumar ◽  
Robin Thakur ◽  
Neeraj Gandotra ◽  
Sorabh Aggarwal ◽  
Arvind Singhy ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fuzzy Logic ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Twisted Tape ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Heat, Mass, and Momentum Transfer Inside Frosted Tubes—Experiment and Theory

1964 ◽  
Vol 86 (3) ◽  
pp. 334-340 ◽  
Author(s):  
M. M. Chen ◽  
W. Rohsenow
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Momentum Transfer ◽  
Theoretical Study ◽  
Heat Exchanger Tube ◽  
Frost Layer ◽  
Theoretical Results ◽  
Exchanger Tube

The paper presents a combined experimental and theoretical study on the heat, mass, and momentum transfer in a frosted heat exchanger tube. Experimental evidence suggests that the behavior of the frosted tube is largely determined by the surface roughness of the frost layer. Based on simple stability considerations and the well-known rough pipe results of Nikuradse and von Karman, a theory is presented which predicts the frost surface roughness as functions of RePrkkf and the frost thickness. The theoretical results are shown to be in qualitative agreement with observed results. Heat-transfer and pressure drop calculations based on the predicted roughness are also found to be in fair agreement with observed results.

scholarly journals Fluid flow and heat transfer enhancement in wings with combined solid ring twisted tape inserts circular heat exchanger tube

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 3893-3903
Author(s):  
Ravi Datt ◽  
Mangal Bhist ◽  
Alok Kothiyal ◽  
Rajesh Maithani ◽  
Anil Kumar
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Hydrodynamic Performance ◽  
Turbulent Heat Transfer ◽  
Twisted Tape ◽  
Turbulent Heat ◽  
Heat Exchanger Tube ◽  
Circular Heat ◽  
Exchanger Tube

Experimental examination is carried out to study the turbulent heat transfer and fluid-flow characteristics in circular heat exchanger tube using combined wing with solid ring twisted tape inserts. A series of experiments has been performed with the range of Reynolds number varied from 3000 to 21000, number of twisted taped inserts, NTT, varied from 1.0 to 4.0 with constant value of other twisted tape parameters such as rings pitch ratio, dR /DT = 1.0, wing pitch ratio, PW /WT = = 3.0, and wing depth ratio, Wd /WT = 1.67. Based on the examined, turbulent heat transfer and fluid-flow in wing with combined solid ring twisted tape inserts results are compared with plain circular tube under same operating conditions. The experimental results show that the heat transfer is increased around 5.66 times than plane circular heat exchanger tube. The thermal and hydrodynamic performance parameter based on equal pumping power, ?p, was found to be highest for NTT = 3.0. The optimum value of thermal and hydrodynamic performance has been found to be 2.74 for Reynolds mumber of 3000 within the range of the parameters investigated. Multiple wings with solid rings twisted tape inserts have been also shown to be thermally as well as hydraulically better in comparison to other similar twisted tape insert geometries.

Development of new correlations for heat transfer and friction loss of solid ring with combined square wing twisted tape inserts heat exchanger tube

2018 ◽  
Vol 32 (2) ◽  
pp. 179-200 ◽  
Author(s):  
Ravi Datt ◽  
Mangal Singh Bhist ◽  
Alok Darshan Kotiyal ◽  
Rajesh Maithani ◽  
Anil Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Friction Loss ◽  
Twisted Tape ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Sensitivity Analysis of a Heat Exchanger Tube Fitted With Cross-Cut Twisted Tape With Alternate Axis

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
M. E. Nakhchi ◽  
J. A. Esfahani
Keyword(s):  
Heat Transfer ◽  
Sensitivity Analysis ◽  
Reynolds Number ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Diameter Ratio ◽  
Design Parameters ◽  
Twisted Tape ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Numerical simulations are used to analyze the thermal performance of turbulent flow inside heat exchanger tube fitted with cross-cut twisted tape with alternate axis (CCTA). The design parameters include the Reynolds number (5000<Re<15,000), cross-cut width ratio (0.7<b/D<0.9), cross-cut length ratio (2<s/D<2.5), and twist ratio (2<y/D<4). The objective functions are the Nusselt number ratio (Nu/Nus), the friction factor ratio (f/fs), and the thermal performance (η). Response surface method (RSM) is used to construct second-order polynomial correlations as functions of design parameters. The regression analysis shows that heat transfer ratio decreased with increasing both the Reynolds number and the width to diameter ratio of the twisted tape. This means that the twisted tape has more influence on heat transfer at smaller inlet fluid velocities. Sensitivity analysis reveals that among the effective input parameters, the sensitivity of Nu/Nus to the Reynolds number is the highest. The results reveal that thermal performance enhances with increasing the width to diameter ratio of the twisted tape (b/D). The maximum thermal performance factor of 1.531 is obtained for the case of Re=5000, b/D=0.9, s/D=2.5, and y/D=4.

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