scholarly journals Mathematical modeling of air velocity in technological module for growing broilers using tunnel ventilation system

2020 ◽  
Author(s):  
Ilya Plaksin ◽  
Alexey Trifanov ◽  
Sergei Plaksin
Keyword(s):  
Mathematical Modeling ◽  
Ventilation System ◽  
Air Velocity ◽  
Tunnel Ventilation ◽  
Technological Module

A New Advance in Tunnel Ventilation Design Planning

2017 ◽  
Author(s):  
Mark P. Colino ◽  
Elena B. Rosenstein
Keyword(s):  
Ventilation System ◽  
National Fire Protection Association ◽  
Capital Cost ◽  
Smooth Transition ◽  
Mechanical Equipment ◽  
Tunnel Ventilation ◽  
Tunnel Fire ◽  
Ventilation Shaft ◽  
Emergency Ventilation ◽  
Ventilation Fan

The new train signaling, traction power and tunnel ventilation system coordination guidelines enacted in National Fire Protection Association (NFPA) Standard 130 have brought the necessity and cost of tunnel ventilation fan shafts into greater focus. The guidelines were aimed at coordinating the three aforementioned rail systems to control the number of trains that could be between successive ventilation shafts during an emergency — in recognition of the fact that the best protection to both incident and non-incident train passengers and crew is to allow no more than one train in each ventilation zone. Though based in safety, these new NFPA guidelines can substantially expand the capital cost and environmental impact of new rail tunnel projects by adding more ventilation shafts and tunnel fan equipment to the scope of work. In addition, the resulting increase in the required number of ventilation shafts and tunnel fan equipment can hinder existing railroad properties as they seek to either increase their train throughput rates, or reduce their tunnel electrical infrastructure. Fortunately, a new kind of emergency ventilation shaft has been developed to facilitate compliance with the NFPA 130 Standard without the excessive capital cost and far-reaching environmental impacts of a traditional emergency ventilation shaft. This new kind of emergency ventilation shaft is called the Crossflue. The Crossflue is a horizontal passage between parallel rail tunnels with a single ventilation fan-motor unit installation. The Crossflue fan is designed to transfer air/smoke flows from one (occupied, incident) tunnel to another (unoccupied, non-incident) tunnel — thereby protecting the incident tunnel at the expense of the non-incident tunnel. The Crossflue passage has angled construction to allow a smooth transition of airflows both into and out of the adjoining tunnels. In addition to the fan, the Crossflue contains a ventilation damper, sound attenuators, ductwork transitions and flexible connectors within the fan equipment line-up; the functionality of all this mechanical equipment is described in the paper. To preserve underground space and minimize the rock excavation, the Crossflue fan is both remotely-powered and remotely-controlled; the fan is only operated as part of a pre-programmed response to tunnel fire events. The methodology utilized to design the Crossflue was taken from the Subway Environmental Design Handbook (SEDH); the SEDH [1] was specifically developed for rail tunnel ventilation design and is the preeminent reference volume in the industry. In summary, the Crossflue provides a dual benefit of achieving NFPA 130 compliance, while at the same time minimizing the construction, equipment, environmental, and energy costs of a traditional tunnel ventilation shaft.

Evaluation of Indoor Climate in Big Lecture Hall

2019 ◽  
Vol 887 ◽  
pp. 475-483
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Ventilation System ◽  
Winter Season ◽  
Point Of View ◽  
Lecture Hall ◽  
Experimental Measurements ◽  
Optimal Parameters ◽  
Indoor Climate ◽  
Air Velocity ◽  
Operation System

The paper is oriented on the evaluation of the indoor climate in the big lecture hall. Providing the optimal parameters of the thermal comfort and the CO2 concentration is immensely important for the students in the interiors of a university. Meeting these parameters is inevitable not only from physiological point of view but also for achieving the desirable students' performance. The high CO2 concentration is related to incorrect and insufficient ventilation in the lecture hall and causes distractibility and feeling of tiredness of students. Experimental measurements were carried out in the winter season in 2016 in the big lecture hall in order to evaluate the thermal comfort and the CO2 concentration. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, CO2 concentration are presented in the charts. Mechanical ventilation system and operation system of the big university lecture hall were evaluated on the basis of the parameters of the thermal comfort and on the basis of the CO2 concentration. Based on the findings, design recommendations for new big university lecture halls are derived. Furthermore, there are presented recommendations how to operate the existing big university lecture halls.

scholarly journals Optimizing air velocity for the underfloor forced ventilation to protect a refrigerated warehouse from frost heaving

2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Frost Heave ◽  
Forced Ventilation ◽  
Air Velocity ◽  
Set Up

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.

scholarly journals Numerical simulations for the optimisation of ventilation system designed for wine cellars

2019 ◽  
Vol 50 (4) ◽  
pp. 180-190 ◽  
Author(s):  
Enrica Santolini ◽  
Alberto Barbaresi ◽  
Daniele Torreggiani ◽  
Patrizia Tassinari
Keyword(s):  
Natural Ventilation ◽  
Ventilation System ◽  
Climatic Conditions ◽  
Mold Growth ◽  
Critical Factors ◽  
Air Velocity ◽  
Wine Production ◽  
First Case ◽  
Dynamics Modelling ◽  
Optimal Configurations

The wine-ageing process is one of the most important phases of the wine production and it can be considerably affected by the micro-climatic conditions inside the ageing rooms. Underground wine cellars in small-medium wineries are designed with natural ventilation systems, able to maintain optimal indoor condition. However, critical factors emerge, such as mold growth or wine evapo-transpiration, where ventilation proved to be poorly designed, insufficient in the first case or excessive in the second one. The zones around the wooden barrels proved to be the most sensitive and problematic. These areas are the most investigated in terms of temperature and humidity values but surprisingly not in terms of air velocity. In this paper, a ventilation system has been designed and optimised to support the lack of ventilation, by means of computational fluid dynamics modelling. Eight configurations have been performed and analysed, identifying the best two according to the air velocity range. Specific parameters have been defined to appreciate the application limits of each configuration. These parameters can be used as reference for system design in similar studies and applications and can help scholars and professionals to identify the optimal configurations for the implementation and proper placement of the system inside a cellar.

Analysis of a new strategy for emergency ventilation and escape scenario in long railway tunnels in the fire mode

2018 ◽  
Vol 233 (3) ◽  
pp. 239-250 ◽  
Author(s):  
Behtash Hakimzadeh ◽  
Mohammad Reza Talaee
Keyword(s):  
Ventilation System ◽  
Control Panel ◽  
Fire Dynamics ◽  
Railway Tunnel ◽  
Rescue Operation ◽  
Tunnel Ventilation ◽  
Precise Control ◽  
Ventilation Shaft ◽  
Emergency Ventilation ◽  
Safe Path

The creation of a safe path for evacuating passengers from a tunnel during fire accidents is an important function of a mechanical ventilation system in tunnels. In this work, the operation of emergency ventilation in the fire mode in a long railway tunnel with push–pull ventilation shafts is analyzed using a fire dynamics simulator. As the passenger trains are lengthy – and so is a tunnel – when trains pass through a tunnel, the position of fire on the train becomes an important parameter for rescuing the passengers through a safe path. The novelty of this study is in the design of emergency ventilation scenarios that consider the position of fire on the train in addition to the tunnel ventilation shafts. For this case study, a lengthy (8 km) urban railway tunnel in Tehran with four rail tracks and eight ventilation shafts is considered for designing emergency ventilation scenarios and control of fire products. The fire source is a passenger train wagon with a 25-MW heat release rate. It is shown that, during the rescue operation of the passengers, the location of fire on the train may lead to reverse the ventilation scenario compared with the traditional ones that use only the tunnel shafts. Also, it is observed that there is a region with 50 m radius around each ventilation shaft, i.e. the absolute exhaust zone, where the ventilation system must be set at the exhaust mode due to the presence of fire, to minimize the spreading of fire products downstream. All the logical scenarios of the tunnel ventilation system are designed and demonstrated to create a critical ventilation velocity in the tunnel, which would help in developing a more precise control panel of the tunnel in the fire mode.

3631 Development of Simulation Tool for Evaluation of Tunnel Ventilation System

2006 ◽  
Vol 2006.2 (0) ◽  
pp. 355-356
Author(s):  
Tadashi KOZU ◽  
Hayato SHIMIZU ◽  
Kenji TANAKA ◽  
Kunihiro ASANUMA
Keyword(s):  
Ventilation System ◽  
Simulation Tool ◽  
Tunnel Ventilation
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