scholarly journals Influence of Applying Additional Forcing Fans for the Air Distribution in Ventilation Network

2016 ◽  
Vol 23 (3) ◽  
pp. 163-171
Author(s):  
Nikodem Szlązak ◽  
Dariusz Obracaj ◽  
Marek Korzec
Keyword(s):  
Ventilation System ◽  
Underground Mines ◽  
Air Distribution ◽  
Ventilation Network ◽  
Airflow Rate ◽  
Total Resistance ◽  
Subsurface Structure ◽  
Pull Systems ◽  
Underground Workings ◽  
Ventilation Networks

Abstract Mining progress in underground mines cause the ongoing movement of working areas. Consequently, it becomes necessary to adapt the ventilation network of a mine to direct airflow into newly-opened districts. For economic reasons, opening new fields is often achieved via underground workings. Length of primary intake and return routes increases and also increases the total resistance of a complex ventilation network. The development of a subsurface structure can make it necessary to change the air distribution in a ventilation network. Increasing airflow into newly-opened districts is necessary. In mines where extraction does not entail gas-related hazards, there is possibility of implementing a push-pull ventilation system in order to supplement airflows to newly developed mining fields. This is achieved by installing subsurface fan stations with forcing fans at the bottom of downcast shaft. In push-pull systems with multiple main fans, it is vital to select forcing fans with characteristic curves matching those of the existing exhaust fans to prevent undesirable mutual interaction. In complex ventilation networks it is necessary to calculate distribution of airflow (especially in networks with a large number of installed fans). In the article the influence of applying additional forcing fans for the air distribution in ventilation network for underground mine were considered. There are also analysed the extent of overpressure caused by the additional forcing fan in branches of the ventilation network (the operating range of additional forcing fan). Possibilities of increasing airflow rate in working areas were conducted.

scholarly journals Numerical study of the air distribution in the Crew Quarters on board of the International Space Station

2019 ◽  
Vol 85 ◽  
pp. 02015 ◽  
Author(s):  
Charles Berville ◽  
Matei-Răzvan Georgescu ◽  
Ilinca Năstase
Keyword(s):  
Numerical Simulations ◽  
International Space Station ◽  
Numerical Study ◽  
Ventilation System ◽  
Space Station ◽  
Air Distribution ◽  
Thermal Manikin ◽  
Airflow Rate ◽  
International Space ◽  
Airflow Distribution

The current concept of Crew Quarters on board of the International Space Station has several issues according to the crew member’s feedback. Major issues concern noise levels, the accumulation of CO2 and the quality of the air distribution. Our study targets the airflow distribution, to diagnose this issue, we realise a series of numerical simulations (CFD) based on a real scale replica of the Crew Quarters. Simulations were set with a zero-gravity mode and with the theoretical air parameters inside the SSI. The geometry includes a thermal manikin having the neutral posture of a body in the absence of gravity. Numerical simulations were run for the three different air flow rates provided by the current ventilation system. Results have shown that the air distribution inside the Crew Quarter is insufficient for low airflow rates but becomes acceptable for the higher airflow rate, however the higher airflow rate can potentially produce draught discomfort.

scholarly journals Computer simulations in the ventilation network of the Vulcan Mine

2022 ◽  
Vol 354 ◽  
pp. 00050
Author(s):  
Corneliu Boantă ◽  
Cristian Tomescu
Keyword(s):  
Ventilation System ◽  
Health Conditions ◽  
Ventilation Network ◽  
Computing Technology ◽  
Calculation Technique ◽  
Safety And Health ◽  
Mineral Substance ◽  
Mining Works ◽  
Microclimate Conditions ◽  
Ventilation Networks

Maintaining safety and health conditions underground, especially where potentially explosive atmospheres are possible, depends mainly on how the ventilation system is built, applied and operated in the ventilation network. The ventilation networks of a mining unit for the exploitation of the useful mineral substance are mining works that aim to ensure optimal microclimate conditions in the underground. An ventilation network is built of nodes and branches, in order to establish its structure. In order to establish the optimal air flows at branch level, specialized programs are used, with the help of which the modeling, solving and optimization of the ventilation networks can be performed. Optimizing the management of the ventilation system involves in-depth and complex analyzes on the ventilation network that require a huge volume of data that can be processed only with the help of computing technology. The paper presents an analysis of the ventilation network of the Vulcan mine using the calculation technique to simulate situations that may occur in the ventilation system.

scholarly journals The process of closing dynamics applied to the ventilation network of Paroşeni mine

2020 ◽  
Vol 305 ◽  
pp. 00080
Author(s):  
Florin Rădoi ◽  
Doru Cioclea ◽  
Corneliu Boantă ◽  
Cristian Tomescu
Keyword(s):  
Real Time ◽  
Ventilation System ◽  
Ventilation Network ◽  
Real Time Visualization ◽  
Ventilation Networks

The decision to begin the process of closing/preserving a mining objective requires the analysis of a complex of factors that interact and influence the efficiency of decision. Solving the ventilation networks with the help of computing is a huge step forward that allows optimization of the air management and real-time visualization of network changes. The method of solving the ventilation network with the help of the computation, allows the modeling and solving of the ventilation networks as well as any simulations of changes that may occur in the ventilation system regardless of its complexity, during the closing period. This paper will present the process of closing dynamics in a complex ventilation network.

scholarly journals SOLUTION OF THE PROBLEM OF TRANSIENT AIR DISTRIBUTIONIN VENTILATION NETWORKS OF MINES, TAKING INTO ACCOUNT THERMODYNAMIC AIR FLOW PARAMETERS

2020 ◽  
Vol 2 ◽  
pp. 138-147
Author(s):  
Stanislav A. Pavlov
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Air Temperature ◽  
Mine Working ◽  
Air Flow ◽  
Air Distribution ◽  
Ventilation Network ◽  
Mine Workings ◽  
Volume Method ◽  
Ventilation Networks

This paper highlights the importance of calculating transient air distribution in mine ventilation networks, taking into account heat ventilation parameters of mine working atmosphere. The change in the temperature of an air flow as it moved along a working with a constant wall temperature was studied. For the network mathematical model of transient air distribution in a ventilation network of the mine, a new resolver was developed which takes into account the revealed regularities of change in air flow temperature from its velocity, temperature and cross-sectional area of mine workings, and allows calculating the change in air temperature as it moves along mine workings. The results of change in air temperature during its movement along the mine working were compared with analytical calculation method and in solving the problem by finite volume method. The obtained simulation results have good convergence. The deviation values obtained in the network model of transient air distribution from the finite volume method do not exceed 7 %.

scholarly journals Evaluating the cooling capacity of diffuse ceiling ventilation system – Full-scale experimental study

2019 ◽  
Vol 111 ◽  
pp. 02006 ◽  
Author(s):  
Samira Rahnama ◽  
Peter Vilhelm Nielsen ◽  
Alireza Afshari ◽  
Niels Christian Bergsøe ◽  
Hicham Johra ◽  
...  
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Ventilation System ◽  
Cooling Capacity ◽  
Full Scale ◽  
Air Distribution ◽  
Controlled Environment ◽  
Airflow Rate ◽  
Heat Sources ◽  
Partial Coverage

Diffuse ceiling ventilation system is an air distribution system in which part of the suspended ceiling made of perforated panels is used as an air diffuser for the supply of fresh air. This method has been proven to have a higher cooling capacity compared to conventional air distribution systems. The cooling capacity of the system, however, depends on several parameters. This paper presents evaluation results regarding the cooling capacity of the diffuse ceiling ventilation system in connection to two essential parameters, i.e. the distribution of heat sources in the room and the ratio of perforated to non-perforated panels in the ceiling. The evaluation is based on full-scale experiments performed in a laboratory controlled environment and using a design chart which expresses the limits on the supply airflow rate and temperature. The experimental results indicate that the highest cooling capacity is achieved when the heat sources are distributed evenly and the perforated panels cover the entire ceiling. In the case of partial coverage, the cooling capacity is reduced when the heat sources are placed below the perforated panels. The system can have a higher cooling capacity in the partial coverage configuration compared to the full coverage one depending on the supply airflow rate.

Numerical and Experimental Modeling of Indoor Air Quality Inside a Conditioned Space with Mechanical Ventilation and DX-Air Conditioner

2020 ◽  
Vol 38 (9A) ◽  
pp. 1257-1275
Author(s):  
Wisam M. Mareed ◽  
Hasanen M. Hussen
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Ventilation System ◽  
Thermal Conditions ◽  
Airflow Rate ◽  
Air Conditioner ◽  
Breathing Zone ◽  
Lecture Room ◽  
Ventilation Performance

 Elevated CO2 rates in a building affect the health of the occupant. This paper deals with an experimental and numerical analysis conducted in a full-scale test room located in the Department of Mechanical Engineering at the University of Technology. The experiments and CFD were conducted for analyzing ventilation performance. It is a study on the effect of the discharge airflow rate of the ceiling type air-conditioner on ventilation performance in the lecture room with the mixing ventilation. Most obtained findings show that database and questionnaires analyzed prefer heights between 0.2 m to 1.2 m in the middle of an occupied zone and breathing zone height of between 0.75 m to 1.8 given in the literature surveyed. It is noticed the mismatch of internal conditions with thermal comfort, and indoor air quality recommended by [ASHRAE Standard 62, ANSI / ASHRAE Standard 55-2010]. CFD simulations have been carried to provide insights on the indoor air quality and comfort conditions throughout the classroom. Particle concentrations, thermal conditions, and modified ventilation system solutions are reported.

scholarly journals CFD-Based Determination of the Optimal Blowing and Suction Air Volume Ratio of Dual-Radial Swirl Shielding Ventilation in a Fully Mechanized Excavation Face

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kuan Wu ◽  
Shiliang Shi ◽  
Yijie Shi ◽  
Yong Chen
Keyword(s):  
Ventilation System ◽  
Volume Ratio ◽  
Simulation Method ◽  
Dust Concentration ◽  
Dust Control ◽  
Underground Mines ◽  
Physical And Mental Health ◽  
Control Effect ◽  
Air Curtain ◽  
Air Volume

Dust is one of the main pollutants in coal mines, which seriously affects the physical and mental health of workers, as well as the safe production in underground mines. Dual-radial swirl shielding ventilation is a new ventilation method for a fully mechanized excavation face and can effectively reduce the dust concentration in the underground. The dust control effect of dual-radial swirl shielding ventilation is mainly affected by the thickness and integrity of the shielding air curtain, as well as the disturbance of the flow field near the air curtain. By changing the blowing and suction air volume ratio of the air duct, the strength of the radial air curtain can be improved, and the dust control effect of the dual-radial swirl shielding ventilation system can be effectively improved. In order to determine the optimal operating parameters of the dual-radial swirl shielding ventilation system, a numerical simulation method was used to conduct an in-depth study on the blowing and suction air volume ratio of the system. The results showed that when the blowing and suction air volume ratio of the air duct was 1.5, the radial air curtain had the highest strength. Under this condition, the dust concentration at the driver’s position of the roadheader was the lowest, and the dual-radial swirl shielding ventilation system can achieve an ideal dust control effect.

scholarly journals Construction Network Ventilation System for Underground LPG Storage Cavern

2018 ◽  
Vol 4 (7) ◽  
pp. 1521 ◽  
Author(s):  
Fang Lin
Keyword(s):  
Ventilation System ◽  
Ventilation Network ◽  
Road Tunnel ◽  
Axial Fan ◽  
Completion Status ◽  
Co Concentration ◽  
Ventilation Technique ◽  
Fluent Software ◽  
Ventilation Performance ◽  
Two Stages

Construction ventilation system is divided into two stages based on completion status of shafts in the underground petroleum storage project in Jinzhou, China. With the help of theoretical analysis and numerical simulations by using FLUENT software, in the first stage, reasonable construction ventilation is designed and cases with different outside temperature are discussed to investigate the effect of ventilation performance. It is found that with temperature difference increases, peak value of CO concentration, exhausting time of dirty air and required time to meet the CO concentration qualification decrease, but the influence degree is quite limited. Gallery-type network ventilation technique (GNVT) refined from theories of operation ventilation for road tunnel and mining ventilation network, is proposed to conduct the second stage construction ventilation. Ventilation performance of different ventilation schemes with various shafts’ states and diverse arrangements of fans are also analyzed in this study. It turns out that Axial-GNVT with shafts taking in fresh air and access tunnel ejecting dirty air has much better performance than traditional forced ventilation from access tunnel. Improved energy saving scheme is finally adopted to guide the construction. In addition, it is worth mentioning that there is no need to build middle ventilation shafts and construct shafts as large and long as possible. Field test of wind speed, dust, poisonous gas, atmospheric pressure, temperature are performed to detect ventilation effectiveness. Reduction coefficient =0.69is obtained from the test results in consideration of super-large section and it also indicates that there is no difference if the axial fan is at the shaft mouth or in the bottom.

Update of the Ventilation Network Related to Livezeni Mine

Mining Revue ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 1-5
Author(s):  
Eva Biro ◽  
Sorin Mihai Radu ◽  
Doru Cioclea ◽  
Ion Gherghe
Keyword(s):  
Underground Mining ◽  
Ventilation Network ◽  
International Level ◽  
Mineral Substances ◽  
Air Flows ◽  
Mining Works ◽  
Mining Work ◽  
Over Time ◽  
Ventilation Networks

Abstract The ventilation networks are associated with the set of underground mining works used for the extraction of useful mineral substances. Over time, the ventilation networks involve a change in the structure due to either the expansion or restriction of the mining works structure. For the establishment of air flows at the level of each active mining work, specialized programs are used at international level. These programs allow the modelling and solving of complex ventilation networks. The most advanced specialized programs are those from the VENTSIM range. The paper presents the updating of the ventilation network related to Livezeni mine, with the help of the VENTSIM program.

Modeling the Applicability of a Displacement Ventilation System

2021 ◽  
Vol 11 (1) ◽  
pp. 63-89
Author(s):  
Edgar C. Ambos ◽  
Evan Neil V. Ambos ◽  
Lanndon A. Ocampo
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Heat Load ◽  
Ventilation System ◽  
Internal Heat ◽  
The Philippines ◽  
Airflow Rate ◽  
Displacement Ventilation ◽  
Tropical Country

Due to its significant role in improving indoor air quality, displacement ventilation system is widely adopted in current literature. This paper proposes a displacement ventilation system for room conditions with ceilings that are relatively low, internal heat load could be high, walls could be sunlit, and occupants doing the low physical activity. These conditions are prevalent in the Philippines, being a tropical country. Input parameters to the design process such as heat load, the height of the ceiling, comfort, and indoor air quality requirements were generated, and the main output parameters are the stratification height and ventilation airflow rate. To demonstrate the proposed displacement ventilation system, four cases were generated. Results show that the ventilation airflow rates obtained from the four cases were greater than the minimum outdoor air requirements for health in conference rooms and large assembly areas which are 17.5 and 3.5 liters/sec*person respectively, for smoking and no smoking rooms.

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