Investigations on the Condensation Heat Transfer Performance of Stainless Steel Edge-Shaped Finned Tubes

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Zhen-ping Wan ◽  
Xiao-wu Wang ◽  
Xiao-xia Zhang ◽  
Yong Tang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Temperature Difference ◽  
Heat Transfer Performance ◽  
Three Dimensional ◽  
Condensation Heat Transfer ◽  
Transfer Performance ◽  
Shell Side ◽  
Finned Tubes

The third-generation enhanced heat transfer technologies, such as three-dimensional fin and dimple, are still important means of improving energy efficiency. This paper analyzes the condensation heat transfer performances of three edge-shaped finned tubes that were fabricated using the plowing–extruding process. Experimental results show that the shell-side heat transfer coefficient decreases with increases of heat flux and temperature difference between wall and vapor. The edge-shaped finned tubes exhibit better heat transfer performance than smooth tubes. At the identical temperature difference between the wall and the vapor, the shell-side heat transfer coefficient of the edge-shaped finned tubes is approximately 1.7–2.6 times larger than that of the smooth tubes. At the identical temperature difference between the wall and the vapor, the shell-side heat transfer coefficient of edge-shaped finned tubes is also higher than the reported value in the literature. The excellent performance of the edge-shaped finned tubes comes from the coordination of enhancement from the three-dimensional fins, dimples, and grooves. Finned tubes with grooves fabricated along the left direction have higher and thinner fins and therefore show better heat transfer performance. The shell-side heat transfer coefficients of edge-shaped finned tubes increase with plowing–extruding depth and feed increasing.

Experimental Investigation of Shell-Side Flow Condensation on Three-Dimensional Enhanced Surface Tubes

2020 ◽  
Author(s):  
Desong Yang ◽  
Zhichuan Sun ◽  
Wei Li
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Mass Flux ◽  
Three Dimensional ◽  
Condensation Heat Transfer ◽  
Shell Side ◽  
Plain Tube ◽  
Side Flow ◽  
The Heat Transfer Coefficient

Abstract An experimental investigation of shell-side flow condensation heat transfer was performed on advanced three-dimensional surface-enhanced tubes, including a herringbone micro-fin tube and a newly-developed 1-EHT tube. An equivalent plain tube was also tested for performance comparison. All of the test tubes have similar geometry parameters (inner diameter 11.43mm, outer diameter 12.7mm). Tests were conducted using R410A as the working fluid at a condensation saturation temperature of 45 °C, covering the mass flux range of 10–55 kg/(m2·s) with an inlet quality of 0.8 and an outlet quality of 0.1. Experimental results showed that the plain tube exhibits a better condensation heat transfer performance when compared to the enhanced tubes. Moreover, the mass flux has a significant influence on the heat transfer coefficient for shell-side condensation: the condensation heat transfer coefficient of plain tube decreases when the refrigerant mass flux becomes larger, while the heat transfer coefficient of herringbone tube shows a non-monotonic trend and the heat transfer coefficient of the 1-EHT tube gets higher with increasing refrigerant mass flux. Besides, A new prediction model based on the Cavallini’s equation was developed to predict the condensing coefficient of the three test tubes, and the mean absolute error of the improved equations is less than 4%.

Study on the Effect of the Evaporator Area on the Heat Transfer Performance in the Gravity Feed Liquid Refrigeration System

2013 ◽  
Vol 441 ◽  
pp. 112-115 ◽  
Author(s):  
Qing Jiang Liu ◽  
Fang Han
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Temperature Difference ◽  
Heat Transfer Performance ◽  
System Optimization ◽  
Transfer Performance ◽  
Refrigeration System ◽  
Original Design ◽  
The Heat Transfer Coefficient

In order to study the effect on heat transfer performance of evaporator in the gravity feed liquid refrigeration system the different evaporator area, the simulation procedure is worked out. The procedure uses the visual basic language. The procedure can figure out the heat transfer coefficient and the temperature difference in different evaporator area and evaporating temperature with the required refrigerating capacity. Through simulation calculation, when the area is 80% of the original design area of evaporator, the evaporator of the heat transfer coefficient and heat transfer temperature difference is the most reasonable and the evaporator of the refrigerating capacity can meet the requirements of cold storage. The program provides the reliable data for the gravity feed liquid cooling system optimization.

Effect of Fin Geometry on Condensation of R407C in a Staggered Bundle of Horizontal Finned Tubes

2003 ◽  
Vol 125 (4) ◽  
pp. 653-660 ◽  
Author(s):  
H. Honda ◽  
N. Takata ◽  
H. Takamatsu ◽  
J. S. Kim ◽  
K. Usami
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Vapor Phase ◽  
Mass Velocity ◽  
Three Dimensional ◽  
Condensation Heat Transfer ◽  
Finned Tubes ◽  
Fin Tubes ◽  
Condensation Heat Transfer Coefficient

Experimental results are presented that show the effect of fin geometry on condensation of downward flowing zeotropic refrigerant mixture R407C in a staggered bundle of horizontal finned tubes. Two types of conventional low-fin tubes and three types of three-dimensional-fin tubes were tested. The refrigerant mass velocity ranged from 4 to 23 kg/m2 s and the condensation temperature difference from 3 to 12 K. The measured condensation heat transfer coefficient was lower than the previous results for R134a, with the difference being more significant for smaller mass velocity. The effect of fin geometry on the condensation heat transfer coefficient was less significant for R407C than for R134a. The effect of condensate inundation was more significant for the three-dimensional-fin tubes than for the low-fin tubes. By using the dimensionless heat transfer correlation for the condensate film that was based on the experimental data for R134a, a superficial vapor-phase heat transfer coefficient was obtained for condensation of R407C. The vapor-phase heat transfer coefficient showed characteristics similar to the vapor-phase mass transfer coefficient that was obtained in the previous study for R123/R134a.

Fabrication of copper-based ZnO nanopencil arrays with high-efficiency dropwise condensation heat transfer performance

RSC Advances ◽  
2016 ◽  
Vol 6 (64) ◽  
pp. 59405-59409 ◽  
Author(s):  
Mengnan Qu ◽  
Jia Liu ◽  
Jinmei He
Keyword(s):  
Heat Transfer ◽  
Zinc Oxide ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Transfer Performance ◽  
High Efficiency ◽  
Condensation Heat Transfer ◽  
Transfer Performance ◽  
Dropwise Condensation ◽  
Condensation Heat Transfer Coefficient

A copper-based zinc oxide nanopencil array film was reported. Compared with hydrophobic flat Cu surface, it exhibits condensate microdrop self-propelling function and maximal ∼140% enhancement in dropwise condensation heat transfer coefficient.

scholarly journals Experimental investigation on effect of helical grooves on condensation heat transfer performance of vertically oriented copper tubes

2019 ◽  
Vol 128 ◽  
pp. 06001
Author(s):  
Jyothish Abraham ◽  
Venugopal G ◽  
Rajkumar M R
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Transfer Performance ◽  
Condensation Heat Transfer ◽  
Transfer Performance ◽  
Helical Groove ◽  
Helical Grooves ◽  
Condensation Heat Transfer Coefficient

An experimental investigation was conducted to study the influence of pitch of helical grooves on condensation heat transfer performance on vertically oriented copper tubes. The condensation heat transfer coefficient of bare as well as grooved copper tubes of various pitches ranging from 2.54 mm to 22.4mm were studied. The investigation revealed that copper tube with groove pitch ≤ 6.35 mm has an adverse effecton the heat transfer performance in comparison to bare copper. The helical groove with pitch > 6.35 mm showed improvement in heat transfer coefficient. The helical groove with pitch 8.47 mm showed a maximum enhancement of 68.4% in condensation heat transfer coefficient at ∆T = 40°C.

Enhancement of Heat Transfer Performance Using Ultrasonic Evaporation

2019 ◽  
Vol 15 (5-6) ◽  
Author(s):  
Jitian Song ◽  
Yongxia Feng ◽  
Wei Tian ◽  
Jianbo Liu ◽  
Yening Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Temperature Difference ◽  
Heat Transfer Performance ◽  
Tap Water ◽  
Ultrasonic Power ◽  
Transfer Performance ◽  
Ultrasonic Technology ◽  
The Heat Transfer Coefficient

AbstractThe ultrasonic evaporator is a new type of evaporation equipment which uses ultrasonic technology to assist evaporation of liquid materials. Due to the lack of mechanism of ultrasonic technology to enhance the heat transfer in evaporation process, there are few reports on the use of ultrasonic evaporator in industrial production. The tap water was selected as experimental material and the heat transfer performance of ultrasonic evaporator was studied. It could be obtained from the single factor analysis that the heat transfer coefficient increased first and then decreased with the increase of ultrasonic power density. The increase of heat transfer due to the increase of temperature difference is basically stable at 20 %. When the ultrasonic wave acts on evaporator, the heat transfer coefficient would increase about 17.06 %–29.85 %. According to the orthogonal test and analysis of variance, it can be obtained that the influence of temperature difference on heat transfer coefficient is the largest, the second is feed flow rate, and evaporation time has the least influence.

Production Process and Heat Transfer Performance of 10/316 Clad Tube

2014 ◽  
Vol 1081 ◽  
pp. 270-274
Author(s):  
Zui Xian Yu ◽  
Xue Sheng Wang ◽  
Qin Zhu Chen
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Heat Transfer Coefficient ◽  
Carbon Steel ◽  
Transfer Coefficient ◽  
Heat Transfer Performance ◽  
Steel Tube ◽  
Stainless Steel Tube ◽  
Transfer Performance ◽  
Clad Tube

A new preparation technique of carbon steel/stainless steel clad tube was introduced, and the contact surface was well combined. Meanwhile, with the using of tube heat exchanger, the experiment on the heat transfer performance of the clad tube was done. Comparing the 10/316 clad tube and the 316 stainless steel tube, the effects on the heat transfer performance of 316 stainless steel tube attached to carbon steel was evaluated. It is showed that overall heat transfer coefficient of 10/316 clad tubes is higher than that of stainless steel tube. The average heat transfer coefficient of 10/316 clad tubes is about 18.7%~34.4% higher than that of stainless steel tube. Experimental investigation indicates that, by brazing and cold drawing, the 10/316 clad tube was well combined and the thermal conductivity was better than that of stainless steel tube.

Heat Transfer Performance of Different Nanofluids Flows in a Helically Coiled Heat Exchanger

2013 ◽  
Vol 832 ◽  
pp. 160-165 ◽  
Author(s):  
Mohammad Alam Khairul ◽  
Rahman Saidur ◽  
Altab Hossain ◽  
Mohammad Abdul Alim ◽  
Islam Mohammed Mahbubul
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Volume Concentration ◽  
Transfer Performance

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

Research on Heat Transfer Performance of Water Film for Outside the Tubes of the Microscale Evaporative Condenser

2009 ◽  
Author(s):  
Minghui Hu ◽  
Dongsheng Zhu ◽  
Jialong Shen
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Transfer Performance ◽  
Water Film ◽  
Transfer Performance ◽  
Air Velocity ◽  
Microscale Heat Transfer ◽  
High Heat Transfer ◽  
Spray Density

It is requested to develop a microscale and high performance heat exchanger for small size energy equipments. The heat transfer performance of the water film on the condensing coils of the microscale evaporative condenser was studied for a single-stage compressed refrigeration cycle system. Under various operation conditions, the effects of the spray density and the head-on air velocity on the heat transfer performance of the water film were investigated. The results show that the microscale heat transfer coefficient of the water film αw increases with the increase of spray density and decreases with the increase of head-on air velocity. The results indicate that the key factor affecting the microscale heat transfer of the water film is the spray density. As the results, it is measured that the present device attained high heat transfer quantity despite the weight is light. In addition, via regression analysis of the experimental data, the correlation equation for calculating the microscale heat transfer coefficient of the water film was obtained, its regression correlation coefficient R is 0.98 and the standard deviation is 7.5%. Finally, the correlations from other works were compared. The results presented that the experimental correlation had better consistency with the correlations from other works. In general, the obtained experimental results of the water film heat transfer are helpful to the design and practical operation of the microscale evaporative condensers.

Enhanced Condensation Heat-Transfer on Mini or Low Fin Tubes

2006 ◽  
Author(s):  
Adrian Briggs
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermophysical Properties ◽  
Heat Transfer Performance ◽  
Three Dimensional ◽  
Transfer Performance ◽  
Transfer Enhancement ◽  
Shell Side ◽  
Wide Range ◽  
Fin Tubes

This paper presents an overview of the use of low or mini-fin tubes for improving heat-transfer performance in shell-side condensers. The paper concentrates on, but is not limited to, the experimental and theoretical program in progress at Queen Mary, University of London. This work has so far resulted in an extensive data base of experimental data for condensation on single tubes, covering a wide range of tube geometries and fluid thermophysical properties and in the development of a simple to use model which predicts the majority of this data to within 20%. Work is progressing on the effects of vapor shear and on three-dimensional fin profiles; the later having shown the potential for even higher heat-transfer enhancement.

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