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.

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.

A CFD SIMULATION OF PM1 AND CO AIR CONTAMINANTS IN A BUS PASSENGER COMPARTMENT

2015 ◽  
Vol 77 (30) ◽  
Author(s):  
Noor Emilia Ahmad Shafie ◽  
Haslinda Mohamed Kamar ◽  
Nazri Kamsah
Keyword(s):  
Carbon Monoxide ◽  
Particulate Matter ◽  
Distribution Systems ◽  
Cfd Simulation ◽  
Ventilation System ◽  
Air Distribution ◽  
Passenger Compartment ◽  
Displacement Ventilation ◽  
Three Dimensional Model ◽  
Air Contaminants

Air distribution systems inside a bus compartment are important for providing healthy and comfortable environment for passengers. Lack of ventilation inside the bus passenger compartment causes an increase level of air contaminants concentration. Particulate matters and carbon monoxide are indoor air contaminants which can affect the passenger’s health such as respiratory problem and lung cancer. This article reports the results of a CFD simulation on transport of carbon monoxide and particulate matter 1 inside a passenger compartment of a university’s shuttle bus. Fluent CFD software was used to develop a simplified three-dimensional model of the bus passenger compartment. Flow analysis was carried out using RNG k-e turbulent model for air flow, discrete phase and species transport for the air contaminants. Four variations of ventilation system namely two mixing ventilation types, combined mixing with displacement ventilation and combined mixing ventilation with underfloor air distribution was examined. The CFD simulation results show that the use of the combined mixing and displacement ventilation and also the combined mixing and underfloor ventilation types are capable of reducing the concentration of carbon monoxide and particulate matter 1 inside the bus passenger compartment by 81% and 54%, respectively.

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.

Energy Use Comparison of Air Distribution Systems Serving a Section of a School Building

2012 ◽  
Author(s):  
Stillman Jordan ◽  
Randall D. Manteufel
Keyword(s):  
Total Energy ◽  
Distribution System ◽  
Energy Recovery ◽  
Distribution Systems ◽  
Energy Savings ◽  
Ventilation System ◽  
Space Distribution ◽  
Air Distribution ◽  
Displacement Ventilation ◽  
Humid Climate

An optimal air distribution design accomplishes both comfort and ventilation requirements while consuming as little energy as possible. This paper analyzes four different air distribution systems and technologies including single duct variable air volume air handlers, chilled beam cooling systems, total energy recovery wheels, displacement ventilation, and dedicated outside air systems; in an effort to determine the best air distribution system for a representative section of a school in hot and humid climate. The effectiveness of the air distribution systems is evaluated by analyzing how the different technologies take advantage of the natural convective properties of air to create a comfortable environment for the occupied region of the space. Distribution effectiveness and energy consumption must be weighed against considerations such as system complexity and ease of operation. This paper compares several alternative air distribution systems to a baseline single inlet VAV system that is commonly used in new schools designed today. Calculations show that the total energy recovery wheels result in a 16% energy savings over the baseline air distribution system because of the large amount of outside air required in school buildings. Chilled beams are not well suited for schools because of the large amount of outside air required by the space and the sophisticated design and operation needed to prevent condensation from occurring at the chilled beam. The results show that the air distribution system that consumes the least amount of energy is a displacement ventilation system. The system also inherently promotes better indoor air quality as it allows air to naturally rise out and return out of the space with minimal mixing of contaminates that may be recirculated within the room for others to breath. The displacement ventilation system’s overall energy savings of 20% over the baseline is mainly attributed to its total energy recovery wheel and the system’s ability to drastically reduce the cooling load seen by the air cooled chiller by effectively ventilating spaces using less outside air.

Application and Analysis Chilling Ceiling Combined with Displacement Ventilation System in Office Buildings

2010 ◽  
Vol 160-162 ◽  
pp. 294-300
Author(s):  
Ling Wang ◽  
Wei Yang Qi ◽  
Ri Chao Liu ◽  
Shun Jun He
Keyword(s):  
Indoor Air ◽  
Thermal Stratification ◽  
Ventilation System ◽  
Displacement Ventilation ◽  
Airflow Velocity ◽  
Indoor Airflow ◽  
Air Supply ◽  
Computational Fluid Dynamics Cfd ◽  
Save Energy ◽  
Lower Temperature

Using the method of computational fluid dynamics (CFD), numerically simulates office building with chilling ceiling /displacement ventilation (CC/DV) and analyzes indoor airflow velocity field, temperature field and thermal stratification height of the building. Consider that the CC/DV system can improve indoor air quality and save energy. And the CC/DV system could solve many constraints of displacement ventilation system. when the cooling load is large, due to the limit of air supply and temperature supply the displacement ventilation system can not be used, but the CC/DV system could well satisfied the requirement of body. The CC/DV system also has the problem of lower thermal stratification height because the chilling ceiling has a lower temperature.

scholarly journals Modelling of air flow supply in a room at variable regime by using both K - E and spalart – allmaras turbulent model

2017 ◽  
Vol 12 (2) ◽  
pp. 15-22
Author(s):  
Vadim Korbut ◽  
Orest Voznyak ◽  
Iryna Sukholova ◽  
Khrystyna Myroniuk
Keyword(s):  
Air Flow ◽  
Ventilation System ◽  
Air Distribution ◽  
Experimental Investigations ◽  
Human Organism ◽  
Ansys Fluent ◽  
Air Jets ◽  
Air Supply ◽  
Experimental Researches ◽  
Variable Regime

Abstract The abstract is to The article is devoted to the decision of actual task of air distribution efficiency increasing with the help of swirl and spread air jets to provide normative parameters of air in the production apartments. The mathematical model of air supply with swirl and spread air jets in that type of apartments is improved. It is shown that for reachin of air distribution maximal efficiency it is necessary to supply air by air jets, that intensively extinct before entering into a working area. Simulation of air flow performed with the help of CFD FLUENT (Ansys FLUENT). Сalculations of the equation by using one-parameter model of turbulence Spalart-Allmaras are presented. The graphical and the analytical dependences on the basis of the conducted experimental researches, which can be used in subsequent engineering calculations, are shown out. Dynamic parameters of air flow that is created due to swirl and spread air jets at their leakage at variable regime and creation of dynamic microclimate in a room has been determined. Results of experimental investigations of air supply into the room by air distribution device which creates swirl air jets for creation more intensive turbulization air flow in the room are presented. Obtained results of these investigations give possibility to realize engineer calculations of air distribution with swirl air jets. The results of theoretical researches of favourable influence of dynamic microclimate to the man are presented. When using dynamic microclimate, it’s possible to decrease conditioning and ventilation system expenses. Human organism reacts favourably on short lasting deviations from the rationed parameters of air environment.

Numerical Simulation of Air Distribution and Particle Movement in a Displacement Ventilated Room

2014 ◽  
Vol 919-921 ◽  
pp. 1350-1353 ◽  
Author(s):  
Ze Bei Wang ◽  
Bao Qing Wang ◽  
Rong Hui Chen ◽  
Shu Yao
Keyword(s):  
Numerical Simulation ◽  
Indoor Air ◽  
Particle Distribution ◽  
Simulation Method ◽  
Air Distribution ◽  
Coarse Particles ◽  
Particle Movement ◽  
Displacement Ventilation ◽  
Airflow Field ◽  
New Type

As people spend more time indoors, indoor air quality becomes more and more important. Displacement ventilation, as a new type of air-conditioning strategy, has showed remarkable advantages on many occasions. In this paper, the air movement and particle distribution in a displacement ventilation room is studied and analyzed through CFD numerical simulation method. The results show that the airflow field and the temperature field all have obvious hierarchical structure, and the coarse particles have more obvious settling character.

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