INVESTIGATION OF HEAT FLUX DISTRIBUTION IN LARGE-SCALE POOL FIRES UNDERNEATH THE FUEL SURFACE USING A FIRE DYNAMIC SIMULATOR

2018 ◽  
Vol 49 (6) ◽  
pp. 555-567 ◽  
Author(s):  
Song He ◽  
Qian Li ◽  
Hui Yang ◽  
Huaming Dai ◽  
Xianfeng Chen
Keyword(s):  
Heat Flux ◽  
Large Scale ◽  
Flux Distribution ◽  
Pool Fires ◽  
Heat Flux Distribution ◽  
Fuel Surface ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator

Heat Flux Distribution Over a Solar Central Receiver Using an Aiming Strategy Based on a Conventional Closed Control Loop

2017 ◽  
Author(s):  
Jesús García ◽  
Yen Chean Soo Too ◽  
Ricardo Vasquez Padilla ◽  
Rodrigo Barraza Vicencio ◽  
Andrew Beath ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Control Strategies ◽  
Multiple Input Multiple Output ◽  
Control Loop ◽  
Heat Flux Distribution ◽  
Input Multiple Output ◽  
Solar Receiver ◽  
Solar Field

Solar thermal towers are a maturing technology that have the potential to supply a significant part of energy requirements of the future. One of the issues that needs careful attention is the heat flux distribution over the central receiver’s surface. It is imperative to maintain receiver’s thermal stresses below the material limits. Therefore, an adequate aiming strategy for each mirror is crucial. Due to the large number of mirrors present in a solar field, most aiming strategies work using a data base that establishes an aiming point for each mirror depending on the relative position of the sun and heat flux models. This paper proposes a multiple-input multiple-output (MIMO) closed control loop based on a methodology that allows using conventional control strategies such as those based on Proportional Integral Derivative (PID) controllers. Results indicate that even this basic control loop can successfully distribute heat flux on the solar receiver.

Studies on heat flux distribution on the membrane walls in a 600 MW supercritical arch-fired boiler

2016 ◽  
Vol 103 ◽  
pp. 264-273 ◽  
Author(s):  
Dalong Zhang ◽  
Chenwei Meng ◽  
Hai Zhang ◽  
Pengyuan Liu ◽  
Zhouhang Li ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Distribution ◽  
Heat Flux Distribution

Research on Heat Flux Distribution in Deep Grinding

2008 ◽  
Author(s):  
D. H. Zhu ◽  
B. Z. Li ◽  
J. G. Yang
Keyword(s):  
Heat Flux ◽  
Flux Distribution ◽  
Theoretical Expression ◽  
Uniform Heat Flux ◽  
Heat Transfer Mechanism ◽  
Heat Flux Distribution ◽  
Workpiece Surface ◽  
Quadratic Curve ◽  
Flux Model ◽  
Heat Flux Model

This paper studies the heat transfer mechanism in deep grinding process, especially the heat flux to the workpiece. On the basis of triangle moving heat source, a quadratic curve heat flux model in the grinding zone was developed to determine the heat flux distribution and to estimate the surface temperature of workpiece. From the calculated theoretical expression of heat flux to the workpiece, the quadratic curve heat flux can be understood as the superposition of square law heat flux, triangular heat flux and uniform heat flux in the grinding zone. Then four heat flux models using the determined amount of heat flux were applied to estimate the workpiece surface temperatures which were compared with that measured by the embedded thermocouple. It has been found that the quadratic curve heat flux distribution seems to give the best match with measured and theoretical temperature, although square law heat flux model is good enough to predict the temperature.

scholarly journals Thermal analysis in thin-film fluid regions of rectangular microgroove

2018 ◽  
Vol 22 (2) ◽  
pp. 899-897
Author(s):  
Xiaohong Gui ◽  
Xiange Song ◽  
Baisheng Nie
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Contact Angle ◽  
Film Thickness ◽  
Flux Distribution ◽  
Total Heat ◽  
Heat Flux Distribution ◽  
Total Heat Transfer ◽  
Thin Film Thickness

The effects of contact angle and superheat on thin-film thickness and heat flux distribution occurring in a rectangle microgroove are numerically simulated. Accordingly, physical, and mathematical models are built in detail. Numerical results indicate that meniscus radius and thin-film thickness increase with the improvement of contact angle. The heat flux distribution in the thin-film region increases non-linearly as the contact angle decreases. The total heat transfer through the thin-film region increases with the improvement of superheat, and decreases as the contact angle increases. When the contact angle is equal to zero, the heat transfer in the thin-film region accounts for more than 80% of the total heat transfer. Intensive evaporation in the thin-film region plays a key role in heat transfer for the rectangle capillary microgroove. The liquid with higher wetting performance is more capable of playing the advantages of higher intensity heat transfer in thin- film region. The current investigation will result in a better understanding of thin- -film evaporation and its effect on the effective thermal conductivity in the rectangle microgroove.

scholarly journals Transient Heat Transfer in Rotating Cylinder - Thermography Measurement to Analyse Intense Heat Flux Distribution

2008 ◽  
Author(s):  
J.C. Batsale ◽  
J.P. Lasserre ◽  
M. Varenne-Pellegrini ◽  
V. Desormiere ◽  
L. Authesserre ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flux Distribution ◽  
Rotating Cylinder ◽  
Transient Heat Transfer ◽  
Heat Flux Distribution ◽  
Intense Heat

Buoyancy Effects in the Entrance Region of an Inclined Multirectangular-Channel Solar Collector

1983 ◽  
Vol 105 (2) ◽  
pp. 157-162 ◽  
Author(s):  
S. M. Morcos ◽  
M. M. M. Abou-Ellail
Keyword(s):  
Heat Flux ◽  
Nusselt Number ◽  
Solar Collector ◽  
Flux Distribution ◽  
Rectangular Channel ◽  
Numerical Procedure ◽  
Side Wall ◽  
Entrance Region ◽  
Heat Flux Distribution ◽  
Constant Property

A numerical procedure is presented for the entrance region of an inclined multirectangular-channel solar collector with significant buoyancy effects. The upper wall heat flux is taken to be uniform, while the lower wall is assumed to be insulated. The heat flux distribution on the side wall of the rectangular channel is obtained by coupling a heat-conduction numerical procedure in the metallic region surrounding the channel to the main numerical procedure which solves the hydrodynamic and energy equations of the flow inside the channel. Numerical results are presented for water flowing in a multirectangular-channel solar collector with an aspect ratio AR = 4 inclined at an angle α = 30 deg to the horizontal. The resulting variable heat flux distribution on the side wall enhances the intensity of the secondary flow. The effects of the nonuniform heat flux distribution and the spacing between the rectangular channels on the variation of Nusselt number in the entrance region are presented for different values of Rayleigh number. At a value of Ra = 5 × 105, Nusselt number is more than 300 percent above the constant property prediction.

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