A simple energy balance to determine heat transfer coefficients from low temperature measurements in a fluidised bed

2006 ◽  
Vol 161 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Y. Suyadal
Keyword(s):  
Heat Transfer ◽  
Energy Balance ◽  
Low Temperature ◽  
Temperature Measurements ◽  
Fluidised Bed ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients

An Experimental Investigation of Convective Heat Transfer at the Leading Edge of a Gas Turbine Airfoil

1992 ◽  
Author(s):  
S. Gendron ◽  
N. J. Marchand ◽  
C. Korn ◽  
J. P. Immarigeon ◽  
J. J. Kacprzynski
Keyword(s):  
Heat Transfer ◽  
Leading Edge ◽  
Temperature Measurements ◽  
Transfer Coefficients ◽  
Testing Conditions ◽  
Heat Transfer Coefficients ◽  
Hot Gas ◽  
Surface Temperatures ◽  
Double Edge

This paper describes the experimental methods used to determine the surface temperatures and heat-transfer coefficients at the leading edge, and elsewhere over the surface, of a specially designed double-edge wedge shell specimen subjected to cyclic heating in a high velocity hot gas stream generated by a burner rig. The methods included temperature measurements with thermocouples (embedded below the surface) as well as surface temperature measurements by optical pyrometry. The experiments were carried-out at gas temperatures between 806 to 1323 °C and velocities in the range from Mach 0.32 to Mach 0.39. The calibration procedures for each method, the various testing conditions to which the airfoil-like specimen was exposed and the results pertaining to the determination of the surface temperatures and heat-transfer coefficients are described and discussed.

scholarly journals On the Computation of Heat Transfer Coefficients from Energy-Balance Gradients on a Glacier

1979 ◽  
Vol 22 (87) ◽  
pp. 263-272 ◽  
Author(s):  
Michael Kuhn
Keyword(s):  
Heat Transfer ◽  
Energy Balance ◽  
Friction Velocity ◽  
Turbulent Flux ◽  
Mean Value ◽  
Stability Function ◽  
Transfer Coefficients ◽  
Glacier Surface ◽  
Heat Transfer Coefficients ◽  
Thermal Influence

AbstractThe turbulent flux of sensible heat in the energy balance of a glacier surface is assumed to be proportional to the temperature difference between the glacier surface and the atmosphere at the same level but outside the thermal influence of the glacier. The factor of proportionality between them is first explained in terms of friction velocity, roughness height, and stability function of the logarithmic wind and temperature profile. It is then derived from climatological records and measurements of the energy balance and its altitudinal gradients at Hintereisferner. Examples of the energy-balance components and their change with altitude are given for the entire ablation season as well as for short periods. The heat transfer coefficients derived have a mean value of 1.7±0.2 MJ m−2d−1K−1(40 ± 5 ly d−1K−1).

Analysis of a Triple-Effect Low Temperature Distillation Desalination Process

2011 ◽  
Vol 204-210 ◽  
pp. 2001-2006
Author(s):  
Li Xi Zhang ◽  
Li Xi Zhang ◽  
He Fei Zhang
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Total Heat ◽  
Utilization Rate ◽  
Transfer Coefficients ◽  
Total Heat Transfer ◽  
Heat Transfer Coefficients ◽  
New Process ◽  
Heat Loads ◽  
Source Flow

A new process of low temperature triple-effect distillation desalination is designed. Firstly, the appropriate effect number is determined. The total heat transfer coefficients and the heat loads of each evaporator are calculated. When the pressure differences between near effects are equal to △P, the freshwater outputs and the heat transfer coefficients of every effect would be increased as △P improved; if △P is too low, the seawater un-evaporated in the last evaporator would be difficult to flow into the next one. By analysis, the appropriate value of △P is 0.005 MPa. If the seawater flowing into the first effect is preheated by the heat source flow outpouring the unit, the total heat utilization rate and the freshwater output would be enhanced.

scholarly journals Film Condensation of R-22 and R-410A on Horizontal Enhanced Tubes

1997 ◽  
Author(s):  
W. Y. Cheng ◽  
Y. Z. Robert Hu ◽  
C. C. Wang
Keyword(s):  
Heat Transfer ◽  
Energy Balance ◽  
Air Conditioning ◽  
Film Condensation ◽  
Transfer Coefficients ◽  
Average Heat ◽  
Heat Transfer Coefficients ◽  
Enhanced Tubes

This study experimentally investigates the film condensation of R-22 and R-410A on two horizontal enhanced tubes. The test tubes include a GEWA-C and a GEWA-TWX. Data was measured at three different saturation temperatures (35°C, 40°C and 45°C) in accordance with the range of practical condensation conditions in the air-conditioning and refrigeration applications. Average heat transfer coefficients were determined by overall heat transfer coefficients based on energy balance. The comparisons of heat transfer coefficients between R-22 and R-410A for both test tubes were presented.

scholarly journals On the Computation of Heat Transfer Coefficients from Energy-Balance Gradients on a Glacier

1979 ◽  
Vol 22 (87) ◽  
pp. 263-272 ◽  
Author(s):  
Michael Kuhn
Keyword(s):  
Heat Transfer ◽  
Energy Balance ◽  
Friction Velocity ◽  
Turbulent Flux ◽  
Mean Value ◽  
Stability Function ◽  
Transfer Coefficients ◽  
Glacier Surface ◽  
Heat Transfer Coefficients ◽  
Thermal Influence

AbstractThe turbulent flux of sensible heat in the energy balance of a glacier surface is assumed to be proportional to the temperature difference between the glacier surface and the atmosphere at the same level but outside the thermal influence of the glacier. The factor of proportionality between them is first explained in terms of friction velocity, roughness height, and stability function of the logarithmic wind and temperature profile. It is then derived from climatological records and measurements of the energy balance and its altitudinal gradients at Hintereisferner. Examples of the energy-balance components and their change with altitude are given for the entire ablation season as well as for short periods. The heat transfer coefficients derived have a mean value of 1.7±0.2 MJ m−2 d−1 K−1 (40 ± 5 ly d−1 K−1).

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