scholarly journals A BASIC STUDY ON THE ROOM AIR DISTRIBUTION (IV) : Downward Air-Supply System with Multi-Nozzles

1981 ◽  
Vol 310 (0) ◽  
pp. 82-87
Author(s):  
HIDEKI KUBOTA
Keyword(s):  
Supply System ◽  
Air Distribution ◽  
Basic Study ◽  
Air Supply

Effect of Air Distribution on Solid Fuel Bed Combustion

1997 ◽  
Vol 119 (2) ◽  
pp. 120-128 ◽  
Author(s):  
J. T. Kuo ◽  
W.-S. Hsu ◽  
T.-C. Yo
Keyword(s):  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Air Distribution ◽  
Gas Temperature ◽  
One Dimensional ◽  
Supply And Distribution ◽  
Air Supply ◽  
Burning Rates ◽  
Side Walls ◽  
Detailed Chemical

One important aspect of refuse mass-burn combustion control is the manipulation of combustion air. Proper air manipulation is key to the achievement of good combustion efficiency and reduction of pollutant emissions. Experiments, using a small fix-grate laboratory furnace with cylindrical combustion chamber, were performed to investigate the influence of undergrate/sidewall air distribution on the combustion of beds of wood cubes. Wood cubes were used as a convenient laboratory surrogate of solid refuse. Specifically, for different bed configurations (e.g., bed height, bed voidage, bed fuel size, etc.), burning rates and combustion temperatures at different bed locations were measured under various air supply and distribution conditions. One of the significant results of the experimental investigation is that combustion, with air injected from side walls and no undergrate air, has the maximum combustion efficiency. On the other hand, combustion with undergrate air achieves higher combustion rates but with higher CO emissions. A simple one-dimensional model was constructed to derive correlation of combustion rate as a function of flue gas temperature and oxygen concentration. Despite the fact that the model is one-dimensional and many detailed chemical and physical processes of combustion are not considered, comparisons of the model predictions and the experimental results indicate that the model is appropriate for quantitative evaluation of bed-burning rates.

Thermal and mechanical improvement of the air supply system of a turbocharged piston engine

2021 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
Y. M. Brodov ◽  
L. V. Plotnikov ◽  
K. O. Desyatov
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Local Heat Transfer ◽  
Supply System ◽  
Scale Model ◽  
Piston Engine ◽  
Intake System ◽  
Gas Dynamic ◽  
Air Supply ◽  
Air Flows

A method of thermomechanical improvement of pulsating air flows in the intake system of a turbocharged piston engine is described. The main objective of this study is to develop a method for suppressing the rate of heat transfer to improve the reliability of a piston turbocharged engine. A brief review of the literature on improving the reliability of piston engines is given. Scientific and technical results were obtained on the basis of experimental studies on a full-scale model of a piston engine. The hot-wire anemometer method was used to obtain gas-dynamic and heatexchange characteristics of gas flows. Laboratory stands and instrumentation facilities are described in the article. The data on gas dynamics and heat exchange of stationary and pulsating air flows in gas-dynamic systems of various configurations as applied to the air supply system of a turbocharged piston engine are presented. A method of thermomechanical improvement of flows in the intake system of an engine based on a honeycomb is proposed in order to stabilize the pulsating flow and suppress the intensity of heat transfer. Data were obtained on the air flow rate and the local heat transfer coefficient both in the exhaust duct of the turbocharger compressor (i.e., without a piston engine) and in the intake system of a supercharged engine. A comparative analysis of the data has been carried out. It was found that the installation of a leveling grid in the exhaust channel of a turbocharger leads to an intensification of heat transfer by an average of 9%. It was found that the presence of a leveling grid in the intake system of a piston engine causes the suppression of heat transfer within 15% in comparison with the baseline values. It is shown that the use of a modernized intake system in a diesel engine increases its probability of failure-free operation by 0.8%. The data obtained can be extended to other types and designs of air supply systems for heat engines.

Compressed air supply system of vibro‐isolated tools

1992 ◽  
Vol 91 (5) ◽  
pp. 3083-3083
Author(s):  
Marian W. Dobry ◽  
Czeslaw Cempel ◽  
Wieslaw Garbatowski
Keyword(s):  
Supply System ◽  
Compressed Air ◽  
Air Supply

scholarly journals Numerical Study on Coupled Operation of Stratified Air Distribution System and Natural Ventilation under Multi-Variable Factors in Large Space Buildings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang
Keyword(s):  
Thermal Comfort ◽  
Working Conditions ◽  
Distribution System ◽  
Distribution Systems ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Air Distribution ◽  
Large Space ◽  
Air Conditioners ◽  
Air Supply

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.

scholarly journals Thermal Comfort and Energy Analysis of a Hybrid Cooling System by Coupling Natural Ventilation with Radiant and Indirect Evaporative Cooling

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7825
Author(s):  
Pradeep Shakya ◽  
Gimson Ng ◽  
Xiaoli Zhou ◽  
Yew Wah Wong ◽  
Swapnil Dubey ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Hybrid System ◽  
Natural Ventilation ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Supply System ◽  
Hybrid Cooling ◽  
Air Supply ◽  
Radiant Cooling ◽  
Indirect Evaporative Cooling

A hybrid cooling system which combines natural ventilation with a radiant cooling system for a hot and humid climate was studied. Indirect evaporative cooling was used to produce chilled water at temperatures slightly higher than the dew point. With this hybrid system, the condensation issue on the panel surface of a chilled ceiling was overcome. A computational fluid dynamics (CFD) model was employed to determine the cooling load and the parameters required for thermal comfort analysis for this hybrid system in an office-sized, well-insulated test room. Upon closer investigation, it was found that the thermal comfort by the hybrid system was acceptable only in limited outdoor conditions. Therefore, the hybrid system with a secondary fresh air supply system was suggested. Furthermore, the energy consumptions of conventional all-air, radiant cooling, and hybrid systems including the secondary air supply system were compared under similar thermal comfort conditions. The predicted results indicated that the hybrid system saves up to 77% and 61% of primary energy when compared with all-air and radiant cooling systems, respectively, while maintaining similar thermal comfort.

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