Performance Evaluation Criteria for Two-Phase Heat Exchangers

2004 ◽  
pp. 75-88
Author(s):  
Ralph L. Webb ◽  
Nae-Hyun Kim
Keyword(s):  
Performance Evaluation ◽  
Heat Exchangers ◽  
Evaluation Criteria ◽  
Two Phase

Performance Evaluation Criteria for Heat Exchangers Based on First Law Analysis

2005 ◽  
Vol 12 (2) ◽  
pp. 121-158 ◽  
Author(s):  
M. Yilmaz ◽  
O. Comakli ◽  
S. Yapici ◽  
O. N. Sara
Keyword(s):  
Performance Evaluation ◽  
Heat Exchangers ◽  
Evaluation Criteria

scholarly journals Assessment of economic, thermal and hydraulic performances a corrugated helical heat exchanger filled with non-Newtonian nanofluid

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Ibrahim ◽  
Ebrahem A. Algehyne ◽  
Tareq Saeed ◽  
Abdallah S. Berrouk ◽  
Yu-Ming Chu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Exchanger ◽  
Economic Analysis ◽  
Evaluation Criteria ◽  
Methyl Cellulose ◽  
Hydraulic Performance ◽  
Two Phase ◽  
Heat Transfer Efficiency ◽  
Helical Heat Exchanger

AbstractImproved heat transfer efficiency with considering economic analysis in heating systems is an interesting topic for researchers and scientists in recent years. This research investigates the heat transfer rate (HTR) and flow of non-Newtonian water-Carboxyl methyl cellulose (CMC) based Al2O3 nanofluid in a helical heat exchanger equipped with common and novel turbulators using two-phase model. The requirements for dimensions and cost reduction and also energy saving in thermal systems are the main goal of this study. According to gained results usage of corrugated channel in helical heat exchanger has a considerable influence on thermal and hydraulic performance evaluation criteria (THPEC) index of helical heat exchanger and can improve the THPEC index. Thus, Re = 5000 is obtained as an optimum value, in which the maximum THPEC value is achieved. As it is found in this paper, in case of using novel heat exchanger instead of the basic smooth system, the thermal properties (by considering Nusselt number) increases about 210%, the hydraulic performance (friction factor) reduces about 28%, performance evaluation criteria index increases about 57% and the material consumption (in case of similar THPEC) decreases about 31%. In another word, with considering economic analysis for the basic and novel system which has same efficiencies, the novel one has lower length and consequently 31% lower material.

scholarly journals Performance evaluation of tube-in-tube heat exchangers with heat transfer enhancement in the annulus

2006 ◽  
Vol 10 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Ventsislav Zimparov ◽  
Plamen Penchev ◽  
Joshua Meyer
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Evaluation Criteria ◽  
Relative Reduction ◽  
Geometrical Parameters ◽  
Twisted Tape ◽  
Transfer Enhancement ◽  
Finned Tubes

Different techniques as angled spiraling tape inserts, a round tube in side a twisted square tube and spiraled tube in side the annulus have been used to enhance heat transfer in the annulus of tube-in-tube heat exchangers. The heat transfer enhancement in the shell can be supplemented by heat transfer augmentation in tubes using twisted tape inserts or micro-finned tubes. The effect of the thermal resistance of the condensing refrigerant could also be taken into consideration. To assess the benefit of using these techniques extended performance evaluation criteria have been implemented at different constraints. The decrease of the entropy generation can be combined with the relative in crease of the heat transfer rate or the relative reduction of the heat transfer area to find out the geometrical parameters of the tubes for optimal thermodynamics performance. The results show that in most of the cases considered, the angled spiraling tube insert technique is the most efficient.

A Study About Performance Evaluation Criteria of Tube Banks With Various Shapes and Arrangements Using Numerical Simulation

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Amin Jodaei ◽  
Kamiar Zamzamian
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Exchangers ◽  
Three Dimensional ◽  
Evaluation Criteria ◽  
Cross Flow ◽  
Transfer Coefficients ◽  
Tube Bank ◽  
Shaped Tube ◽  
Tube Banks

Tube bank heat exchangers are designed to efficiently transfer heat between two fluids. Shapes and arrangements of tubes in heat exchangers have significant effects in heat transfer and pressure drop of fluid. In this study, the three-dimensional (3D) numerical investigation is performed to determine heat transfer coefficients, friction factor, and performance evaluation criteria (PEC) of cam-shaped tube banks in aerodynamic and inverse aerodynamic directions in the cross flow air and compared with those of elliptical tube banks in heat exchanger. The arrangements of tubes are aligned and staggered with longitudinal pitch of 44.88 mm and transverse pitch of 28.05 mm. Reynolds number in the range of 11,500–18,500 was used, and the tube surface temperature was fixed and considered 352 K. Results indicate the superior heat transfer of elliptical tube bank over the cam-shaped tube banks in inverse aerodynamic and aerodynamic directions in both arrangements. Moreover, the PEC of the cam-shaped tube banks with inverse aerodynamic and aerodynamic directions and elliptical tube bank in aligned arrangement are approximately 1.4, 1.1, and 1.6, respectively. The obtained results for staggered arrangements are also 1.5, 1.3, and 1.8, respectively.

Thermal-Hydraulic Performance Analysis by Means of Rectangular Winglet Vortex Generators in a Channel: An Experimental Study

2021 ◽  
Vol 6 (3) ◽  
pp. 150-153
Author(s):  
Oktarina Heriyani ◽  
Mohamad Djaeni ◽  
. Syaiful
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Performance Evaluation ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Rectangular Channel ◽  
Evaluation Criteria ◽  
Hydraulic Performance ◽  
Vortex Generators ◽  
Fluid Flow Velocity

Vortex generators (VGs) are one of the effective passive models used to increase the heat transfer rate in heat exchangers. In this experiment, heat transfer from six cylinders heated to the airflow was improved by attaching rectangular winglet vortex generators (RWVGs) to a plate in a rectangular channel. The installation aimed to increase the value of the thermal-hydraulic performance evaluation criteria in the line. This experimental study was carried out by varying the fluid flow velocity from 0.4 m/s to 2 m/s with an interval of 0.2 m/s in the channel. Three pairs of VGs were arranged in both in-line and staggered configurations. The experimental results show that the thermal-hydraulic performance evaluation criteria for three pairs of vortex generators in the staggered configuration was 15.17% higher than the baseline, while the thermal-hydraulic performance of the in-line arrangement was 1.54% higher than the staggered one.

Comparative Performance of Rippled Fin Plate Fin and Tube Heat Exchangers

1989 ◽  
Vol 111 (1) ◽  
pp. 21-28 ◽  
Author(s):  
J. D. Maltson ◽  
D. Wilcock ◽  
C. J. Davenport
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Wind Tunnel ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Evaluation Criteria ◽  
Performance Characteristics ◽  
Published Data ◽  
Transfer Enhancement ◽  
Comparative Performance

Continuous rippled fins are preferred to interrupted fins in applications where fouling by fibrous matter or insects is a problem. The performance characteristics of three rippled fin heat exchangers have been measured in a thermal wind tunnel. The results of these measurements are reported and comparisons are made with published data on similar surfaces. The performance evaluation criteria used as the basis for the comparisons were those recommended by Shah (1978). The tested rippled fin surfaces were found to have a higher performance than a similar surface reported in Kays and London (1984). The heat transfer enhancement was found to be dependent upon the profile of the fin.

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