scholarly journals Optimization of the ventilation scheme for increasing production capacity of underground mines

2022 ◽  
pp. 89-93
Author(s):  
N.D. Iliinov ◽  
A.M. Mazhitov ◽  
A.B. Allaberdin ◽  
K.V. Vazhdaev
Keyword(s):  
Flow Rate ◽  
Underground Mining ◽  
Critical Path ◽  
Air Flow ◽  
Ventilation System ◽  
Production Capacity ◽  
Underground Mines ◽  
Air Flow Rate ◽  
Mining Operations ◽  
Mine Workings

Currently, many underground mines are revising their design solutions to increase their production capacity. This tendency is explained by the decreasing ore grades, as well as by the extensive introduction of mechanization in underground mining operations that has improved the output of mobile equipment by increasing the box capacity and engine power. Dieselpowered mobile vehicles are the most common in underground mining practice. The advantages of such engines are obvious as they generate more power than other types of engines. However, the high air demand for mine ventilation limits their application. This is associated with the need to increase the cross-sections of permanent mine workings in order to comply with the standard air flow rate with account of the increased ventilation capacity along with an increase in the inventory of mobile equipment in order to ensure the specified output of the mine. The specific features of mining operations are defined by the stage-wise character of commissioning various blocks of the deposit. Managing of production and development works provides an opportunity to ventilate the mine sections due to their consecutive commissioning, locally, with an isolated stream of air by means of mine workings that do not have the intersection of air streams. This provides a reduction of critical path of air travel up to 30% and reduction of the general mine ventilating pressure drop by at least 20% at constant air flow rate. The results of the work can be used in designing the ventilation system of underground mines both under construction and in operation.

Test and analysis of air flow rate adaptive performance in a distributed fan ventilation system

2021 ◽  
pp. 014362442098600
Author(s):  
Fa-Li Ju ◽  
Qinrong Sun ◽  
Changlei Hou ◽  
Xue Huang ◽  
Xiaoping Yu ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Engineering Design ◽  
Flow Rate ◽  
Air Flow ◽  
Ventilation System ◽  
Adaptive Performance ◽  
Air Flow Rate ◽  
Branch Duct ◽  
Rate Adaptive ◽  
Adaptive Ability

In this study, adaptive branch fan performance in a distributed fan ventilation system was tested. The results demonstrate that the adaptive branch fan stabilises the branch air flow rate within a certain air pressure range corresponding to the branch duct inlet, and this range becomes increasingly narrow as the fan control signal is adjusted to reduce the speed of the fan. The adaptive branch fan is less affected by the main fan and other branch fans in the distributed fan ventilation system because it has a good self-adaptive ability of ventilation duct resistance characteristics and anti-interference ability of the air flow rate. Furthermore, the hydraulic characteristics of the branch fans in the distributed fan ventilation system were analysed. The new performance characterisation parameters and method for modifying the engineering design for the adaptive branch fan were presented. Practical application: This study investigates the adaptive performance of the branch fan in a distributed fan ventilation system. Our results demonstrate that the new branch fan can stabilise the air flow rate in a mechanical ventilation system. More importantly, we not only propose performance characterisation parameters of the adaptive branch fan that are important for understanding the operation of a mechanical ventilation system, but also present a method of engineering design application. This study can guide the design and operation of mechanical ventilation systems.

Calculation of Air Flows Stability in the Mine Workings by the Factor of Thermal Depression in the Analytical Complex «Aeroset»

2020 ◽  
pp. 24-32
Author(s):  
M.D. Popov ◽  
◽  
D.S. Kormshchikov ◽  
M.A. Semin ◽  
L.Yu. Levin ◽  
...  
Keyword(s):  
Air Flow ◽  
Ventilation System ◽  
Numerical Algorithms ◽  
Mine Ventilation ◽  
Heat Emission ◽  
Graphical Analysis ◽  
Ventilation Network ◽  
Mining Operations ◽  
Mine Workings ◽  
The Stability

Underground fires are one of the most serious emergencies that occur during mining operations. Analysis of possible scenarios for its development is a mandatory measure when designing new mine workings and when developing a plan for immediate elimination of accidents at the existing mine workings. The main danger that an underground fire creates for the mine ventilation system is a change in the ventilation mode and, accordingly, a change in the direction of movement of the air and harmful gases released during combustion. It is almost impossible to calculate in manual mode all the possible scenarios for the development of an emergency for different places where underground fires occur. This confirms the need to develop algorithms for automated assessment of the effect of thermal depression from a fire on the stability of the air flow in all mine workings of the mine ventilation network. The authors consider two numerical algorithms implemented in the «Aeroset» analytical complex and solving two independent problems. The first of them is determining the air flow stability in the mine on the whole in the presence of a fire of a given heat emission rate in any place of the mine working. The second task is to find the critical rate of fire heat generation in stationary workings, leading to a loss of stability of the air flow in the mined-out spaces of the mine. The techniques of increasing the speed of calculations of algorithms are studied. The article also describes the developed tools for graphical analysis of the calculation results. Examples of using such tools in practice are given. It is concluded that the developed software tools allow to quickly model the stability of air distribution in the mine ventilation networks of arbitrary topology in the presence of underground fires, and conveniently visualize the calculations.

An analytical study to evaluate the impact of distributed zone fans on the air flow rate in a mechanical ventilation system

2019 ◽  
Vol 41 (4) ◽  
pp. 507-516
Author(s):  
Fa-Li Ju ◽  
Liying Liu ◽  
Xiaoping Yu
Keyword(s):  
Mechanical Ventilation ◽  
Flow Rate ◽  
Pressure Ratio ◽  
Air Flow ◽  
Ventilation System ◽  
Theoretical Expression ◽  
Air Flow Rate ◽  
Rate Testing ◽  
Fan Speed ◽  
The Impact

Based on air flow rate testing of each branch fan in a distributed fan ventilation system under different branch air duct inlet static pressures, the conclusion can be drawn that there is a branch fan air flow rate deviation phenomenon. The air flow rate of the branch fan increases with the branch air duct inlet static pressure at the same branch fan speed, and the branch fan hinders the air flow rate in some cases. In this study, a theoretical expression of the deviation of the branch air duct design air flow rate was established, and the influencing factors of the deviation were determined to include the branch air duct resistance characteristics, branch fan performance, and branch air duct inlet pressure ratio. A graphic analytical method for determining the deviation of the branch fan design air flow rate was also proposed. Both methods can provide a theoretical basis for calculating and analysing the deviation of the branch fan design air flow rate in a distributed fan ventilation system. Practical application: This paper provides new data on the performance of a distributed fan ventilation system. Our results could be used to evaluate the impact of distributed zone fans on the air flow rate in a mechanical ventilation system. Crucially, we not only propose two types of methods that can be applied to predict deviations of the air flow rate in a distributed fan ventilation system caused by the branch air duct inlet static pressures but also obtain the factors that are important for understanding the true impact of the deviation of the branch fan air flow rate. This study lays an important foundation for the design and operation of building mechanical ventilation systems.

scholarly journals Active Disturbance Rejection Control of a Longitudinal Tunnel Ventilation System

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1871
Author(s):  
Liyun Si ◽  
Wenping Cao ◽  
Xiangping Chen
Keyword(s):  
Flow Rate ◽  
Disturbance Rejection ◽  
Air Flow ◽  
Ventilation System ◽  
Active Disturbance Rejection Control ◽  
Air Flow Rate ◽  
Long Distance ◽  
Tunnel Ventilation ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

This paper proposes an innovative approach for controlling pollutant release in a long-distance tunnel via longitudinal ventilation. Enhanced by an active disturbance rejection control (ADRC) method, a ventilation controller is developed to regulate the forced air ventilation in a road tunnel. As a result, the pollutants (particulate matter and carbon monoxide) are reduced by actively regulating the air flow rate through the tunnel. The key contribution of this study lies in the development of an extended state observer that can track the system disturbance and provide the system with compensation via a nonlinear state feedback controller equipped by the ADRC. The proposed method enhances the disturbance attenuation capability in the ventilation system and keeps the pollutant concentration within the legitimate limit in the tunnel. In addition to providing a safe and clean environment for passengers, the improved tunnel ventilation can also achieve better energy saving as the air flow rate is optimized.

scholarly journals Alleviating Aural Discomfort of Passengers on Shinkansen by Controlling Air Flow Rate in Ventilation System.

1997 ◽  
Vol 63 (614) ◽  
pp. 3294-3301
Author(s):  
Minoru KOBAYASHI ◽  
Yasufumi SUZUKI ◽  
Katsunori AKUTSU ◽  
Satoru OZAWA
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Ventilation System ◽  
Air Flow Rate

scholarly journals Geological CO2 quantified by high-temporal resolution stable isotope monitoring in a salt mine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexander H. Frank ◽  
Robert van Geldern ◽  
Anssi Myrttinen ◽  
Martin Zimmer ◽  
Johannes A. C. Barth ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Underground Mining ◽  
Stable Carbon Isotope ◽  
Underground Mines ◽  
Background Concentration ◽  
High Temporal Resolution ◽  
Salt Mine ◽  
Gas Migration ◽  
Mining Operations ◽  
Anthropogenic Contributions

AbstractThe relevance of CO2 emissions from geological sources to the atmospheric carbon budget is becoming increasingly recognized. Although geogenic gas migration along faults and in volcanic zones is generally well studied, short-term dynamics of diffusive geogenic CO2 emissions are mostly unknown. While geogenic CO2 is considered a challenging threat for underground mining operations, mines provide an extraordinary opportunity to observe geogenic degassing and dynamics close to its source. Stable carbon isotope monitoring of CO2 allows partitioning geogenic from anthropogenic contributions. High temporal-resolution enables the recognition of temporal and interdependent dynamics, easily missed by discrete sampling. Here, data is presented from an active underground salt mine in central Germany, collected on-site utilizing a field-deployed laser isotope spectrometer. Throughout the 34-day measurement period, total CO2 concentrations varied between 805 ppmV (5th percentile) and 1370 ppmV (95th percentile). With a 400-ppm atmospheric background concentration, an isotope mixing model allows the separation of geogenic (16–27%) from highly dynamic anthropogenic combustion-related contributions (21–54%). The geogenic fraction is inversely correlated to established CO2 concentrations that were driven by anthropogenic CO2 emissions within the mine. The described approach is applicable to other environments, including different types of underground mines, natural caves, and soils.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

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