Transient Numerical Simulation for Air Distribution of Air Conditioning and Ventilation in Subway Island-Platform

2011 ◽  
Vol 250-253 ◽  
pp. 3107-3114
Author(s):  
Hong Ming Fan ◽  
Kai Yuan He ◽  
Zhi Fang Yin ◽  
Dan Zhang
Keyword(s):  
Numerical Simulation ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Ventilation System ◽  
Simulation Method ◽  
Subway Station ◽  
Air Distribution ◽  
Wind Effect ◽  
Piston Effect ◽  
Transient Numerical Simulation

The typical subway island-platform of Beijing as research object was present in the article. Taking two-equation turbulence model and giving boundary conditions of piston wind and train heat load change with the time, adopting numerical method simulates air distribution of air-conditioning and ventilation system in subway. The results indicate that piston wind effect has significant impact on the area of platform entrance and staircase entrance while station with safety doors can obstruct piston effect at a certain degree. Simultaneity, the supply- exhaust air system offers relatively uniform temperature and velocity field, which meets requirements of transitory comfort for passengers. It is found that numerical simulation method can simulate and forecast air distribution of air conditioning and ventilating system in subway station. In conclusion, it can provide the reference for optimizing air-conditioning and ventilation system, improving thermal environment designing of subway station.

scholarly journals On-site measurement and numerical investigation of thermal environment with different air distribution systems in ice arenas

2021 ◽  
Vol 2069 (1) ◽  
pp. 012096
Author(s):  
Wenyu Lin ◽  
Tao Zhang ◽  
Xiaohua Liu ◽  
Lingshan Li
Keyword(s):  
Thermal Environment ◽  
Ventilation System ◽  
Simulation Method ◽  
Extreme Condition ◽  
Air Distribution ◽  
Jet Ventilation ◽  
Displacement Ventilation ◽  
Air Supply ◽  
Temperature And Humidity ◽  
Ice Field

Abstract It is important to strictly maintain the indoor thermal environment in ice arenas which have very different features to other commercial buildings. Separated air distribution system is widely used to create a dry and cold environment near the ice and a comfortable environment in the view stand. The warm and humid air from the view stand may lead to uneven temperature and humidity distribution in the rink, leading to extra energy consumption, even fog and frost on the ice. Unreasonable air supply in the ice rink zone will also make the spectators feel too cold and uncomfortable. Jet ventilation system is the most extensively used system in the ice rink zone. An innovative ground displacement ventilation system is proposed in the National Aquatics Centre, which will serve as the venue for the curling competition in the 2022 Beijing Winter Olympics. On-site measurement in the arena is carried out and computational fluid dynamics (CFD) simulation method is adopted in the present research. Measured thermal environment above the ice with different ventilation systems are compared and analysed. Result shows that the displacement ventilation system features a more obvious vertical stratification than jet ventilation system in this kind of large space buildings, and thus is more energy-efficient. A CFD model of the ice cube is setup and verified by measured data. The thermal environment in the ice rink with displacement ventilation under extreme condition is studied using the simulation method. The temperature and humidity in the ice field increases by 10.1 °C, 4.5 g/kg without air supply in the view stand, proving that the spectators in the view stand have a great impact on the thermal environment in the ice field.

Study on the Integrated Design of Underground Construction Lighting and Ventilation System

2011 ◽  
Vol 374-377 ◽  
pp. 702-705
Author(s):  
Wei Feng ◽  
Hui Min Li
Keyword(s):  
Numerical Simulation ◽  
Thermal Environment ◽  
Ventilation System ◽  
Integrated Design ◽  
Structure Design ◽  
Light Environment ◽  
System Model ◽  
Underground Construction ◽  
New Type

In the underground building, Light environment and thermal environment is poorer, in order to improve the problem, this paper brings forward a new type of lighting and ventilation system model; discusses the principle and characteristics of transmission; and analyses the question that influences lighting and ventilated effect in the application. Structure design and numerical simulation is the focus of the next step.

scholarly journals Numerical Simulation Study on the Front Shape and Thermal Stresses in Growing Multicrystalline Silicon Ingot: Process and Structural Design

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1053
Author(s):  
Chengmin Chen ◽  
Guangxia Liu ◽  
Lei Zhang ◽  
Guodong Wang ◽  
Yanjin Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Simulation Method ◽  
Power Ratio ◽  
Radial Temperature ◽  
Front Shape ◽  
Simulation Results ◽  
Insulation Block ◽  
Transient Numerical Simulation

In this paper, a transient numerical simulation method is used to investigate the effects of the two furnace configurations on the thermal field: the shape of the melt–crystal (M/C) interface and the thermal stress in the growing multicrystalline ingot. First, four different power ratios (top power to side power) are investigated, and then three positions (i.e., the vertical, angled, and horizontal positions) of the insulation block are compared with the conventional setup. The power ratio simulation results show that with a descending power ratio, the M/C interface becomes flatter and the thermal stress in the solidified ingot is lower. In our cases, a power ratio of 1:3–1:4 is more feasible for high-quality ingot. The block’s position simulation results indicate that the horizontal block can more effectively reduce the radial temperature gradient, resulting in a flatter M/C interface and lower thermal stress.

scholarly journals Evaluation of Thermal Behavior of the Skeleton in a Green Building with the Aid of TABS

2019 ◽  
Vol 111 ◽  
pp. 01085
Author(s):  
Hiroshi Muramatsu ◽  
Tatsuo Nobe
Keyword(s):  
Heat Flux ◽  
Thermal Behavior ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Concrete Slab ◽  
Ventilation System ◽  
Office Building ◽  
Air Conditioning System ◽  
Indoor Thermal Environment

In this study, an office building in Japan that incorporates energy-saving features and environmental technologies was investigated. This office building features a green façade, natural ventilation, a concrete slab with no suspended ceilings, and thermo-active building systems. Two airconditioning systems were installed in this building—a ceiling radiation air-conditioning system and a whole floor-blow off air conditioning system. In addition, a natural ventilation system was installed. We surveyed the heat flux of the ceiling surface and indoor thermal environment of this building from 2015 through 2016. The ceiling using the heat storage amount of concrete maintains a constant temperature in the workplace during as well as after office hours. We also performed detailed measurements of the heat flux of the ceiling surface and indoor thermal environment in the summer of 2017. The results showed that the ceiling radiation air-conditioning system provided a stable thermal environment. Furthermore, we report that making use of the thermal behavior of the skeleton improved the operation of the ceiling radiation airconditioning system.

Research on the Effect of Natural Ventilation on Buses in Summer Based on CFD Numerical Simulation Method

2011 ◽  
Vol 361-363 ◽  
pp. 1056-1060 ◽  
Author(s):  
Bao Lin ◽  
Xue Ting Wang ◽  
Xiao Hu
Keyword(s):  
Numerical Simulation ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Air Flow ◽  
Cost Effective ◽  
Simulation Method ◽  
Computational Domain ◽  
Cfd Numerical Simulation ◽  
Different Parts

Because of the relatively narrow space and high density distribution of the passengers, the bus interior environment deteriorates in summer. Natural ventilating introduces a fresh natural freeze, provides the bus interior with appropriate distribution of air supply temperature and velocity field. Making good use of natural ventilation is an operating strategy ideal for improving passengers’ satisfaction, which is considered as an environmental friendly and cost effective approach. Based on CFD numerical simulation, with a whole-domain approach, this paper predicts air flow and thermal comfort in naturally ventilated bus. The outside and inside airflow is modelled simultaneously and within the same computational domain. The thermal environment in different parts of the bus interior is compared. Different vehicle velocities and conditions of windows are taken into account, analysis are made regarding to the effect of both of them on the interior thermal comfort. The result shows, air disturbance at the bus rear parts are intenser than the other parts with better thermal satisfaction; the quality of air flow in different parts makes the temperature difference in bus achieve as high as 3°C; the use of roof openings distributes the temperature more evenly.

A Numerical Simulation of an Air Conditioning System in Office Using Weak Airflow

2003 ◽  
Author(s):  
Sensuke Shimizu ◽  
Haruo Terasaka ◽  
Akira Yamada
Keyword(s):  
Numerical Simulation ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
The People

The objective in this study is to evaluate thermal environment of a room with an advanced ceiling hidden type air-conditioner using numerical simulation. As the characteristic of the air-conditioner, it supplies a weak airflow from a large inlet to a room. Circulator fans are fixed on the ceiling. Numerical simulation is performed to a room with the air-conditioner. PMV [1] is calculated from the obtained data and thermal sensation of the people is investigated. From the PMV distribution, it was found that this sensation was improved by the advanced air-conditioner.

Model Experimental Study on Stratified Air Distribution with 2D-PIV for High Ceiling Industrial Plant

2011 ◽  
Vol 374-377 ◽  
pp. 610-617
Author(s):  
Jian Shen ◽  
An Gui Li ◽  
Yu Jiao Zhao
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Air Conditioning ◽  
Vertical Direction ◽  
Industrial Plant ◽  
Air Distribution ◽  
Air Supply ◽  
Stratification Effect ◽  
Experimental Findings ◽  
Real Scale

At present, the research ways of stratified air-conditioning technology mainly have two types, experimental study and numerical simulation. In this paper, a transparent Plexiglas model was designed, of which the size was supposed to be 1/50 of the real scale. PIV technology was innovatively applied into the experiment to measure the air distribution of an industrial plant. Different air supply velocities and different kinds of air supply outlets were taken into account to discuss the influence of them. Results revealed that as the jet velocity increased gradually, the airflow’s stratification effect became more evident. When the aspect ratio changed from 1:2 to 1:8, the diffusion degree in vertical direction increased obviously. In comparison with the rectangular air supply outlet, the circular one had lower decay, longer jet distance and better contractibility. The experimental findings are useful for optimizing the design of air distribution in high ceiling industrial plant.

scholarly journals Study on the Thermal Environment Inside a Fully-Enclosed Subway Noise Barrier

2020 ◽  
Vol 143 ◽  
pp. 01044
Author(s):  
Lei Liu ◽  
Lianghan Zhang ◽  
Zhongxu Kang ◽  
Kun Yao
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Air Temperature ◽  
Thermal Environment ◽  
Simulation Method ◽  
Internal Environment ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Noise Barrier ◽  
Air Vent

The thermal environment inside a fully-enclosed subway noise barrier shall be designed according to underground section tunnel standards. This article constructs a model using practical examples, simulates calculations on fully-enclosed noise barrier installations both with and without air vents via a threedimensional numerical simulation method, and then conducts a comparative analysis of the effects noise barrier lengths and air vent widths have on an internal thermal environment. The calculation results show that when the length of the fully-enclosed noise barrier without air vents was 100m, the internal thermal environment exceeded the limit; as the width of the air vents increased, the temperature in the internal environment gradually decreased, but the reduction was less once the air vent width exceeded 2 m; When the top air vent width was 2 m, and the noise barrier length was 100m, the thermal environment was found to meet requirements. As the noise barrier length increased, the internal air temperature exceeded the standards by varying degrees.

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