The feasibility of performing high-temperature radiant cooling in tropical buildings when coupled with a decentralized ventilation system

2013 ◽  
Vol 19 (8) ◽  
pp. 992-1000 ◽  
Author(s):  
Rupesh S. Iyengar ◽  
Esmail Saber ◽  
Forrest Meggers ◽  
Hansjürg Leibundgut
Keyword(s):  
High Temperature ◽  
Ventilation System ◽  
Radiant Cooling

scholarly journals Flow-Field Characteristics of High-Temperature Annular Buoyant Jets and Their Development Laws Influenced by Ventilation System

2013 ◽  
Vol 2013 ◽  
pp. 1-11
Author(s):  
Yi Wang ◽  
Yanqiu Huang ◽  
Jiaping Liu ◽  
Hai Wang ◽  
Qiuhan Liu
Keyword(s):  
High Temperature ◽  
Flow Field ◽  
Cross Section ◽  
Flow Rate ◽  
Ventilation System ◽  
Volumetric Flow Rate ◽  
Outer Diameter ◽  
Exhaust Hood ◽  
Buoyant Jets ◽  
Flow Field Characteristics

The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to −5 Pa.

CFD Investigation for Indoor Environment of a District Standard Room in Jinan City

2014 ◽  
Vol 548-549 ◽  
pp. 1706-1711
Author(s):  
Dong Yang ◽  
Qing Mei Wen ◽  
Cong Ju Zhang ◽  
Xue Ting Liu ◽  
Shi Jun Wei
Keyword(s):  
Composite System ◽  
Ventilation System ◽  
Simulation Method ◽  
Displacement Ventilation ◽  
Air Velocity ◽  
Vertical Temperature ◽  
Airflow Velocity ◽  
Indoor Airflow ◽  
Radiant Cooling ◽  
Air Speed

This paper introduces the principle and characteristics of roof radiant cooling and displacement ventilation system, using numerical simulation method, the indoor airflow velocity and temperature field of the typical bedroom which uses the composite system in Ji'nan City under the different supply air velocity was calculated. The experimental results show that when the air temperature is 295.15K, to keep the indoor vertical temperature less than 3 °C, air speed should be greater than 0.1m/s and less than or equal to 0.3m/s, to provide reference for the application of roof radiant cooling and displacement ventilation system.

Lateral ventilation performance for removal of pulsating buoyant jet under the influence of high-temperature plume

2019 ◽  
Vol 29 (4) ◽  
pp. 543-557 ◽  
Author(s):  
Yi Wang ◽  
Lei Cao ◽  
Yanqiu Huang ◽  
Yingxue Cao
Keyword(s):  
High Temperature ◽  
Ventilation System ◽  
Capture Efficiency ◽  
Buoyant Jet ◽  
Buoyant Jets ◽  
Future Design ◽  
Two Factors ◽  
Building Ventilation ◽  
Ventilation Performance ◽  
Instantaneous Increase

Lateral exhaust systems have commonly been applied to capture polluted buoyant jets in many industrial processes, such as casting and metallurgy. Compared with the normal conditions of design manuals, the capture efficiency of a lateral exhaust hood (LEH) is often weakened by two factors in actual processes: the unsteady buoyant jet released from the operating surface, and the plume formed above a high-temperature workpiece placed between the LEH and the operating surface. In this study, through experiments and numerical simulations, a pulsatile phenomenon was found in the velocity and concentration distribution of the unsteady buoyant jet. Results show that the contaminate escape ratio is pulsatile; it rises with the instantaneous increase in the buoyant jet velocity and gradually decreases to a constant value. This study not only reveals the air distribution of pulsating buoyant jet but also analyses the effect of the pulsating buoyant jet and high-temperature plume on lateral ventilation system capture efficiency and provides a possible guidance for future design of new building ventilation technologies.

The Development and Summer Test of a New Ceiling Radiant Cooling Panel

2010 ◽  
Vol 160-162 ◽  
pp. 273-279
Author(s):  
Li Ma ◽  
Dai Xiao Wei
Keyword(s):  
High Temperature ◽  
Water Supply ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Cooling Capacity ◽  
Cooling Efficiency ◽  
Radiant Cooling ◽  
The Face ◽  
Radiant Panel

The main application problems of radiant panel in summer include lower cooling capacity owing to high temperature of water supply and condensation. A new radiant panel was developed. Water duct and panel are straight forming which eliminates the thermal contact resistance .The panel are installed in an angle in order to discharge condensate water. The guiding gutter in the face of panel and condensate pipe are to collect and outlet condensate water. The summer test was done. The results show that the new radiant panel has higher cooling efficiency compare with conventional panel .The cooling efficiency is above 1000w/m2, and condensate water can be discharged quickly. Although new Ceiling Radiant Cooling Panel is still not perfect, but it is provides us with more choice.

scholarly journals Human response to thermal environment and perceived air quality in an office room with individually controlled convective and radiant cooling systems

2021 ◽  
Vol 246 ◽  
pp. 15002
Author(s):  
Weixin Zhao ◽  
Simo Kilpeläinen ◽  
Risto Kosonen ◽  
Juha Jokisalo ◽  
Sami Lestinen ◽  
...  
Keyword(s):  
Air Quality ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Airflow Rate ◽  
Human Response ◽  
Indoor Climate ◽  
Cooling Systems ◽  
Radiant Cooling ◽  
Radiant Panel ◽  
Indoor Conditions

The purpose of this study is to analyse the human response to the indoor climate with two individually controlled convective and radiant cooling systems: a low velocity unit combined with radiant panel system (LVRP) and a personalized ventilation system combined with a radiant panel system (PVRP). As a reference system without individual control, diffuse ceiling ventilation combined with a radiant panel system (DCV-RP) was also studied. In laboratory conditions, 10 males and 10 females gave subjective response to the indoor climate during various office activities. The results show that with the reference DCV-RP system, the indoor conditions were worse than with the LVRP and PVRP systems. The thermal sensation and perceived air quality with the PVRP system was better than the LVRP system. After a medium activity task, the thermal acceptability reverts faster with the PVRP than LVRP system. Compared with the PVRP system, the subjects preferred the higher airflow rate at the workstation with the LVRP system. Males preferred a higher airflow rate than females under the same conditions with both micro-environment systems. This research found that there was significant variation in the control preferences of the human subjects concerning the micro-environment, and this emphasizes the need for personalized control to ensure that all occupants are satisfied with the indoor conditions.

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