Heat Transfer From Combustion Gases to a Single Row of Closely Spaced Tubes in a Swirl Crossflow Stirling Engine Heater

1982 ◽  
Vol 104 (1) ◽  
pp. 55-61 ◽  
Author(s):  
C. P. Bankston ◽  
L. H. Back
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Stirling Engine ◽  
Operating Conditions ◽  
Experimental Program ◽  
Working Fluid ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Single Row ◽  
Transfer Characteristics

This paper describes an experimental program to determine the heat-transfer characteristics of a combustor and heat-exchanger system in a hybrid solar receiver which utilizes a Stirling engine. The system consists of a swirl combustor with a crossflow heat exchanger composed of a single row of 48 closely spaced curved tubes. In the present study, heat-transfer characteristics of the combustor/heat-exchanger system without a Stirling engine have been studied over a range of operating conditions and output levels using water as the working fluid. Non-dimensional heat-transfer coefficients based on total heat transfer have been obtained and are compared with available literature data. The results show significantly enhanced heat transfer for the present geometry and test conditions. Also, heat transfer along the length of the tubes is found to vary, the effect depending upon test condition.

Experimental Study on the Heat Transfer Characteristics of Cryogenic Micro Channel Heat Exchanger

2010 ◽  
Author(s):  
Seok Ho Yoon ◽  
Duckjong Kim ◽  
Jun Seok Choi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Performance Test ◽  
High Efficiency ◽  
Experimental Studies ◽  
Micro Channel ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Methane Gas ◽  
Transfer Characteristics

In recent years, many researchers investigated micro channel heat exchangers because of its high efficiency and compactness. However, few experimental studies about micro channel heat exchanger in cryogenic environment have been conducted. In this study, micro channel was fabricated by chemical etching and heat exchanger core was made by diffusion bonding method for cryogenic reliability. Performance test was conducted in cryogenic test rig. Working fluids are liquid nitrogen and methane gas. Methane gas was condensed in the micro channel heat exchanger. Heat transfer coefficients and pressure drop were measured and the heat transfer characteristics were investigated. These results can be used to design the heat exchanger of gas liquefaction plant.

Heat Transfer Characteristics of Oscillating Heat Pipe With Ethanol as Working Fluid

2009 ◽  
Author(s):  
Haizhen Xian ◽  
Dengying Liu ◽  
Yongping Yang ◽  
Xiaoze Du
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Inclination Angle ◽  
Effective Conductivity ◽  
Heating Temperature ◽  
Operating Conditions ◽  
Working Fluid ◽  
Experimental Investigations ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

In this paper, experimental investigations on the heat transfer characteristics of OHP with ethanol as working fluid were conducted. The experimental results show that there exists a necessary temperature difference between evaporator and condenser section to keep the heat pipe working. The minimum temperature differences for the optimal operating conditions varied from 1.5 to 2.0°C. The maximum effective conductivity achieved could reach up to 111kW/m•°C. The heat pipe was obviously affected by the filling ratio in some cases but the influence law is irregular and related to inclination angles and heating temperatures. Not all OHPs operated well in the limiting case of a zero inclination angle. In most cases, the optimal value of the inclination angle went up when the heating temperature increased. An appropriate high heating temperature is helpful for the OHP to achieved excellent performances. The startup temperature varied from 40°C to 50°C without considering the horizontal heating mode.

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.

scholarly journals Investigations of Flow and Heat Transfer Characteristics in a Channel Impingement Cooling Configuration with a Single Row of Water Jets

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4327
Author(s):  
Min-Seob Shin ◽  
Santhosh Senguttuvan ◽  
Sung-Min Kim
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Target Surface ◽  
Channel Height ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Impingement Cooling ◽  
Average Heat ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer

The present study experimentally and numerically investigates the effect of channel height on the flow and heat transfer characteristics of a channel impingement cooling configuration for various jet Reynolds numbers in the range of 2000–8600. A single array consisting of eleven jets with 0.8 mm diameter injects water into the channel with 2 mm width at four different channel heights (3, 4, 5, and 6 mm). The average heat transfer coefficients at the target surface are measured by maintaining a temperature difference between the jet exit and the target surface in the range of 15–17 °C for each channel height. The experimental results show the average heat transfer coefficient at the target surface increases with the jet Reynolds number and decreases with the channel height. An average Nusselt number correlation is developed based on 85 experimentally measured data points with a mean absolute error of less than 4.31%. The numerical simulation accurately predicts the overall heat transfer rate within 10% error. The numerical results are analyzed to investigate the flow structure and its effect on the local heat transfer characteristics. The present study advances the primary understanding of the flow and heat transfer characteristics of the channel impingement cooling configuration with liquid jets.

Heat‐transfer characteristics of polymer hollow fiber heat exchanger for vaporization application

AIChE Journal ◽  
2017 ◽  
Vol 64 (5) ◽  
pp. 1783-1792 ◽  
Author(s):  
Jun Liu ◽  
Hong Guo ◽  
Xingxing Zhi ◽  
Lei Han ◽  
Kai Xu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Hollow Fiber ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics
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