scholarly journals Conjugate Heat Transfer Characteristics in a Highly Thermally Loaded Film Cooling Configuration with TBC in Syngas

Aerospace ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 16
Author(s):  
Jing Ren ◽  
Xueying Li ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Radiative Heat ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Plate Temperature ◽  
Total Percentage ◽  
Barrier Coating

Future power equipment tends to take hydrogen or middle/low heat-value syngas as fuel for low emission. The heat transfer of a film-cooled turbine blade shall be influenced more by radiation. Its characteristic of conjugate heat transfer is studied experimentally and numerically in the paper by considering radiation heat transfer, multicomposition gas, and thermal barrier coating (TBC). The Weighted Sum of Gray Gases Spectral Model and the Discrete Transfer Model are utilized to solve the radiative heat transfer in the multicomposition field, while validated against the experimental data for the studied cases. It is shown that the plate temperature increases significantly when considering the radiation and the temperature gradient of the film-cooled plate becomes less significant. It is also shown that increasing percentage of steam in gas composition results in increased temperature on the film-cooled plate. The normalized temperature of the film-cooled plate decreases about 0.02, as the total percentage of steam in hot gas increases 7%. As for the TBC effect, it can smooth out the temperature distribution and insulate the heat to a greater extent when the radiative heat transfer becomes significant.

scholarly journals Conjugate Heat Transfer Characteristics in a Highly Thermally Loaded Film Cooling Configuration with TBC in Syngas

2018 ◽  
Author(s):  
Jing Ren ◽  
Xueying Li ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Radiative Heat ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Plate Temperature ◽  
Total Percentage ◽  
Heat Value

The future power equipment tends to take hydrogen or middle/low heat-value syngas as fuel for low emission. The heat transfer of film cooled turbine blade shall be influenced more by radiation. Its characteristic of conjugate heat transfer is studied experimentally and numerically in the paper by considering radiation heat transfer, multi-composition gas and TBC. The Weighted Sum of Gray Gases spectral model and Discrete Transfer Model are utilized to solve the radiative heat transfer in the multi-composition field, while validated against the experimental data for the studied cases. It is shown that the plate temperature increases significantly when considering the radiation and the temperature gradient of the film cooled plate becomes larger. It is also shown that increasing percentage of steam in gas composition results in increased temperature on the film-cooled plate. The normalized temperature of the film-cooled plate decreases about 0.02, as the total percentage of steam in hot gas increases per 7%. As for the TBC effect, it can smooth out the the temperature distribution and insulate the heat to a greater extent when the radiative heat transfer becomes significant.

Effect of the Hot Gas Composition on a Highly Thermally Loaded Film Cooling System

2011 ◽  
Author(s):  
Peng Sun ◽  
Wenping Wang ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Temperature Rise ◽  
Radiative Heat Transfer ◽  
Film Cooling ◽  
Radiative Heat ◽  
Fuel Cycle ◽  
Cooling System ◽  
Transfer Model ◽  
Gas Composition ◽  
Hot Gas

To reduce the CO2 emission, three types of the coal-based power generation system are promising: IGCC, the hydrogen-fired turbine cycle and the oxy-fuel cycle. The thermal characteristics of the turbines are expected to be dependent on the different hot and wet gases. For studying the effect of the hot gas composition on the highly thermally loaded cooling system, both the experimental and the numerical studies are carried out in the present work. Five hot gases are focused in the study, which are corresponding to the combustion products of the liquefied petroleum gas, the natural gas, the syngas, the hydrogen and the oxy-fuel gas. A highly thermally loaded film cooling test rig is built up in Tsinghua University. The Discrete Transfer Model (DTM) and the Weighted Sum of Gray Gases (WSGG) spectral model are employed to solve the radiative heat transfer in the multi-composition field. By comparing the experimental and the numerical data, it is resulted that the implemented thermal conduction/convection/radiation method is valid for the studied cases. The results show that the temperature rise on the plate top surface is about 50∼60 K under the condition of the five hot gas compositions due to the radiative heat transfer. The magnitude of the temperature rise is the reverse of the mole fraction of the radiative gases (CO2+H2O) in the hot gas. Furthermore, the local temperature gradient is weakened in the five hot gas compositions cases. It means that the thermodynamics of the film cooling system in the multi-composition hot gas has its own characteristics. It may play a role in the future coal-based turbine technology.

Development of Radiative Heat Transfer Model for Pulverized Coal Combustion

2008 ◽  
Vol 34 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Toshimitsu Asotani ◽  
Toru Yamashita ◽  
Hiroaki Tominaga ◽  
Yoshinori Itaya ◽  
Shigekatu Mori
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Coal Combustion ◽  
Radiative Heat ◽  
Heat Transfer Model ◽  
Pulverized Coal ◽  
Transfer Model ◽  
Pulverized Coal Combustion

Comparison of Film Effectiveness and Cooling Uniformity of Conical and Cylindrical-Shaped Film Hole With Coolant-Exit Temperature Correction

2010 ◽  
Author(s):  
Cuong Q. Nguyen ◽  
Perry L. Johnson ◽  
Bryan C. Bernier ◽  
Son H. Ho ◽  
Jayanta S. Kapat
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Temperature Correction ◽  
Coolant Temperature ◽  
Transfer Model ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Injection Angle ◽  
Film Cooling Holes

Data from conical-shaped film cooling holes is extremely sparse in open literature, especially the cooling uniformity characteristic, an important criterion for evaluating any film cooling design. The authors will compare the performance of conical-shaped holes to cylindrical-shaped holes. Cylindrical-shaped holes are often considered a baseline in terms of film cooling effectiveness and cooling uniformity coefficient. The authors will study two coupons with conical-shaped holes, which have 3° and 6° diffusion angles, named CON3 and CON6 respectively. A conjugate heat transfer computational fluid dynamics model and an experimental wind tunnel will be used to study these coupons. The three configurations: cylindrical baseline, CON3, and CON6, have a single row of holes with an inlet metering diameter of 3mm, length-to-nominal diameter of 4.3, and an injection angle of 30°. In this study, the authors will also take into account the heat transfer into the coolant flow from the coolant channel. In other words, coolant temperature at the exit of the coolant hole will be different than that measured at the inlet, and the conjugate heat transfer model will be used to correct for this difference. For the numerical model, the realizable k-ε turbulent model will be applied with a second order of discretization and enhanced wall treatment to provide the highest accuracy available. Grid independent studies for both cylindrical-shaped film cooling holes and conical-shaped holes will be performed and the results will be compared to data in open literature as well as in-house experimental data. Results show that conical-shaped holes considerably outperform cylindrical-shaped holes in film cooling effectiveness at all blowing ratios. In terms of cooling uniformity, conical-shaped holes perform better than cylindrical-shaped holes for low and mid-range blowing ratios, but not at higher levels.

Anomalous Heat Diffusion in a Chain of Large Particles Through Radiative Heat Transfer

2019 ◽  
Author(s):  
B. K. Liu ◽  
J. M. Zhao ◽  
L. H. Liu
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Radiation Heat Transfer ◽  
Heat Diffusion ◽  
Far Field ◽  
Radiation Heat ◽  
Diffusive Regime ◽  
Particulate System ◽  
Anomalous Heat

Abstract Radiative heat transfer in particulate system has many applications in industry. Recently, the anomalous heat diffusion was reported for particulate system in near field thermal radiation heat transfer, and the existence of heat super-diffusive regimes was observed and the spread of heat can be described by Levy flight. In this work, attention is paid to investigate whether there is anomalous heat diffusion in far-field radiative heat transfer or not. Specifically, this study is focused on the radiative heat transport of a system, consisting of optically large particles, in the geometric optic range. Those particles are arranged in a linear chain surrounded by reflective walls and all particles are identical and equally spaced. The effect of the boundary type and particle surface emissivity on the heat diffusion is also investigated. The heat diffusion behavior in the far-field is studied based on Monte Carlo ray tracing method and the fractional diffusion equation in one dimension. The result indicates the existence of anomalous heat diffusion in the far-field by analyzing the asymptotic behavior of radiation distribution function (RDF). It’s shown that the distribution of RDF decays in power law and can be divided into two parts: for near the source particle, heat diffusive regime is super-diffusive (according to the analysis of fractional diffusion equation), while for far from the source particle, heat diffusive regime becomes sub-diffusive. Moreover, the kind of boundary type and particle wall emissivity have a significant influence on the heat diffusion of the far-field radiation heat transfer. This work will help the understanding of radiation heat transfer in particulate system in the far-field.

Analysis of Radiative Heat Transfer Model for Pulverized Coal Combustion

2004 ◽  
Vol 2004 (0) ◽  
pp. 331-332
Author(s):  
Akinori GOTO ◽  
Hideto HAGIYA ◽  
Yoshio Morozumi ◽  
Hideyuki AOKI ◽  
Takatoshi MIURA
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Coal Combustion ◽  
Radiative Heat ◽  
Heat Transfer Model ◽  
Pulverized Coal ◽  
Transfer Model ◽  
Pulverized Coal Combustion
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