The Single-Blow Transient Testing Technique for Compact Heat Exchanger Surfaces

1967 ◽  
Vol 89 (1) ◽  
pp. 29-38 ◽  
Author(s):  
P. F. Pucci ◽  
C. P. Howard ◽  
C. H. Piersall
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Compact Heat Exchanger ◽  
Experimental Facility ◽  
Nickel Plate ◽  
Heat Transfer Characteristics ◽  
Power Penalty ◽  
Testing Technique ◽  
Flow Friction

The single-blow, transient testing technique for determining the heat transfer characteristics of heat exchanger surfaces, with a summary of the underlying theory, a description of an experimental facility, and comments on the applicability of the technique, are presented. Heat transfer and flow friction data are presented for plate-fin type surfaces fabricated of perforated nickel plate. The data indicate that perforations increase heat transfer performance without a large frictional power penalty.

scholarly journals Numerical Study on the Effect of Tube Rows on the Heat Transfer Characteristic of Dimpled Fin

2014 ◽  
Vol 6 ◽  
pp. 637052 ◽  
Author(s):  
Xuehong Wu ◽  
Lihua Feng ◽  
Dandan Liu ◽  
Hao Meng ◽  
Yanli Lu
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Characteristic ◽  
Average Nusselt Number ◽  
Heat Transfer Performance ◽  
Numerical Study ◽  
Transfer Characteristic ◽  
Transfer Performance ◽  
Heat Transfer Characteristics ◽  
Tube Heat Exchanger

The dimpled fin has excellent heat transfer performance and has attracted a lot of attention to apply on the fin and tube heat exchanger. A study presents to investigate the effects of number of tube rows on the air-side heat transfer characteristics of dimpled fin for velocity ranging from 1 to 3 m/s. The Q/Δ P and Q/((Δ P × V)) are used to evaluate the heat transfer performance of the heat exchanger. The results show that the dimpled arrangement can change the mainstream direction, increase the disturbance, and enhance the heat transfer. With the increase of the number of tube rows, the average Nusselt number decreases and Q/Δ P and Q/((Δ P × V)) increase gradually. Compared with the multipipe tube rows, the performance of two-row tube is better.

Numerical Modeling of Conjugate Heat Transfer on Complex Geometries With Diagonal Cartesian Method, Part II: Applications

1999 ◽  
Vol 121 (2) ◽  
pp. 261-267 ◽  
Author(s):  
K. D. Carlson ◽  
W. L. Lin ◽  
C.-J. Chen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Conjugate Heat Transfer ◽  
Complex Geometries ◽  
Compact Heat Exchanger ◽  
Temperature Analysis ◽  
Heat Transfer Characteristics ◽  
Reduced Pressure ◽  
Diagonal Cartesian Method

Part I of this study discusses the diagonal Cartesian method for temperature analysis. The application of this method to the analysis of flow and conjugate heat transfer in a compact heat exchanger is given in Part II. In addition to a regular (i.e., Cartesian-oriented) fin arrangement, two complex fin arrangements are modeled using the diagonal Cartesian method. The pressure drop and heat transfer characteristics of the different configurations are compared. It is found that enhanced heat transfer and reduced pressure drop can be obtained with the modified fin arrangements for this compact heat exchanger.

Investigation of the Effect of Cross Section on the Convective Heat Transfer Performance of Nanoemulsion in Microchannel Heat Exchanger

2021 ◽  
Author(s):  
Takele Gameda ◽  
M. Mehdi Kabir ◽  
Jiajun Xu
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cross Section ◽  
Cross Sections ◽  
Heat Transfer Performance ◽  
Operating Conditions ◽  
Transfer Performance ◽  
Heat Transfer Characteristics ◽  
Microchannel Heat Exchanger ◽  
Transfer Characteristics

Abstract The present study aims to numerically investigate the effect of cross section on the heat transfer performance of single-phase flow of Ethanol/Polyalphaolefin nanoemulsion fluid with ethanol concentrations of 8 wt.% in a microchannel heat exchanger. While the exterior geometry of the microchannels’ solid structure remains the same, four different cross sections of channels including: circular, upward semi-circular, rectangular, and trapezoidal, are designed with keeping the channels’ wetted perimeters, mass flow rate, and Reynolds number constant for comparison purposes. In the present study, the hydrodynamic and heat transfer characteristics, including local Nusselt number, heat transfer coefficient, and velocity profile, were investigated under a uniform wall heat flux boundary conditions within the laminar flow regime. The channel models of different cross sections were developed by the COMSOL-Multiphysics for numerical analysis. The heat transfer characteristics were then compared for different cross sections under the same operating conditions, and the effect of aspect ratio for rectangular and trapezoidal cross sections were also studied.

Heat-Transfer and Flow-Friction Characteristics of Skewed-Passage and Glass-Ceramic Heat-Transfer Surfaces

1965 ◽  
Vol 87 (1) ◽  
pp. 72-86 ◽  
Author(s):  
C. P. Howard
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Convective Heat Transfer ◽  
Gas Turbine ◽  
Convective Heat ◽  
Glass Ceramic ◽  
Compact Heat Exchanger ◽  
Friction Characteristics ◽  
Transfer Data ◽  
Flow Friction

Experimental results for convective heat-transfer and flow-friction characteristics of three skewed-passage and four glass-ceramic compact heat-exchanger surfaces are presented which should be of practical use, particularly in the design of gas-turbine regenerators. The heat-transfer data were obtained by the transient technique.

Research of Heat Transfer Performance on Tablet Microstructure Heat Exchanger Used for LED Lamps

2013 ◽  
Vol 380-384 ◽  
pp. 3082-3085 ◽  
Author(s):  
Jian Zhuang ◽  
Wei Hu ◽  
Da Ming Wu ◽  
Ya Jun Zhang ◽  
Zhong Li Zhao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Simulation Software ◽  
Heat Transfer Characteristics ◽  
Metal Base ◽  
Transfer Characteristics ◽  
Micro Heat Exchanger ◽  
The Impact ◽  
Core Problem

With successful development of LED lamps, the dissipation of LED lamps has become the core problem. If the heat produced during the work cant be loss in time, the high temperature of the lamps will affect their service lives or even damage the LED permanently. In this paper, based on the principle of finite element method, using thermal simulation software, the effect of the geometric characteristics micro-structure of the heat exchanger combining polymer micro-scale fins and metal base on the heat transfer characteristics was simulated. The impact of the fin width, wing fin pitch, fin height and thickness of the substrate on the tablet microstructure heat transfer characteristics was analyzed. The results provide some technical reference for the design and application of the micro heat exchanger.

Heat Transfer of Aluminium-Oxide Nanofluids in a Compact Heat Exchanger

2013 ◽  
Vol 465-466 ◽  
pp. 622-628
Author(s):  
Faiza Mohamed Nasir ◽  
Mohd. H. Bahari ◽  
Y. Aiman
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Superior Performance ◽  
Compact Heat Exchanger ◽  
Transfer Performance ◽  
Test Rig ◽  
Custom Made ◽  
Experimental Works ◽  
Set Up

Experimental works were conducted to investigate the effect of Al2O3 sizes and volumeconcentration on the rate of nanofluids heat transfer in a compact heat exchanger. Two sizes ofAl2O3 nanoparticle, 40 nm and 100 nm, were mixed with demineralized water at 2% and 10%volume concentrations. Sodium Lauryl Sulphate (SLS) powder was added to enhance the mixingprocess and stabilize the dispersion of the nanofluids. A custom-made closed loop test rig weredesigned, fabricated and tested for these experiments. The test rig was set-up to represent the actualapplication of the nanofluids in cooling of a compact heat exchanger. Experimental runs wereconducted which include the runs for water, 40 nm Al2O3-water and 100 nm Al2O3-water. Theresults indicate that Al2O3-water gave better heat transfer performance than water alone. Nanofluidswith 40 nm- Al2O3 gives better heat transfer performance as compared to 100 nm- Al2O3 nanofluids.The results of the current work generally indicate that nanofluids have the potential to enhance theheat transfer of a compact heat exchanger if properly designed. This superior performance of thenanofluids would only be produced if smaller diameter of nanoparticles were used (less than 100nm). No enhancement in heat transfer can be observed by using nanofluids with particle size of 100nm or at higher volume loading (more than 5%).

An Experimental Study of Heat Transfer Characteristics of Microencapsulated Phase Change Material Slurry in a Coil Heat Exchanger

2013 ◽  
Author(s):  
Minsuk Kong ◽  
Jorge L. Alvarado ◽  
Ehsan M. Languri
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Heat Transfer Characteristics ◽  
Coil Heat Exchanger ◽  
Change Material ◽  
Coil Heat

The use of microencapsulated phase change material (MPCM) slurry as an enhanced heat transfer fluid is considered to be very promising for saving energy in thermal energy systems. However, little is known how MPCM may exhibit enhanced heat transfer performance in coil heat exchanger. Coil heat exchangers are extensively used in industrial applications including heating, ventilating and air conditioning (HVAC) systems because of their superior heat transfer performance and compactness. In this study, the heat transfer characteristics of MPCM slurry in a coil heat exchanger have been investigated experimentally. Thermal properties of MPCM slurry were measured using a differential scanning calorimeter. Pressure drop, overall heat transfer coefficient and heat transfer effectiveness in a coil heat exchanger were determined by considering different flow rates. It was found that heat transfer characteristics were positively affected by the phase change process of the phase change material in MPCM, even though MPCM exhibit reduced turbulence and increased pressure drop. The overall heat transfer coefficient for MPCM slurry is in the range of 5,000 to 9,000 W/m2-K over a Dean number range from 1,600 to 4,000 (equivalent Reynolds number range of 6,000 to 15,000). The enhancement in heat transfer performance is about 17% when compared to that for water. In addition, durability tests of MPCM slurry were conducted to evaluate the MPCM’s ability to withstand continuous pumping conditions, which is critically important in the implementation of MPCM slurry in industrial applications.

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