Ventilation Situation Research Articles

Research on the Simulation and Optimization of Wind Environment in School Canteen based on Airpak

In order to explore the ventilation status of the school canteen, maintain the freshness of the air in the densely populated area, investigate the natural ventilation situation, formulate the corresponding natural ventilation strategy, and maintain a good ventilation effect, the simulation and optimization study of the canteen wind environment was carried out based on Airpak, and the simulation results were evaluated according to the analysis and evaluation of indoor wind environment parameters, and the ventilation strategy was optimized.

A Numerical Study on the Smoke Dispersion and Temperature Distribution of a Ship Engine Room Fire Based on OpenFOAM

To further study the smoke dispersion and the temperature distribution in ship engine room fires, the fire dynamics solver buoyantReactingFOAM in the software OpenFOAM-10 is used to conduct a numerical simulation study on a pool fire caused by fuel oil leakage in a ship engine room. The applicability of this solver in simulating ship-engine-room-scale fires is validated by comparing it with experimental data. The impact of the mechanical ventilation, fire area, and fire position on the smoke dispersion and the temperature distribution in the ship engine room during the fire are considered in the simulation study, with a focus on the control room and the escape exit. The simulation results of buoyantReactingFOAM agree well with the experimental data. The simulated results of the case study show that for both in the control room and near the escape exit, among the factors of fire position, fire area, and the ventilation situation, the fire position affects the temperature distribution and the smoke dispersion most heavily, followed by the fire area and then the ventilation situation, which has the least influence on them. But, compared to the control room, the influence degree of the ventilation air velocity in the escape exit is larger than that in the control room. With an increase in the fire area, the spread rate of high temperature and high smoke concentration increases. With an increase in the ventilation air velocity, the aggregation degree of smoke and temperature decreases, but its decreasing range is very small when the ventilation air velocity is larger than 2 m/s.

A ventilation early warning system (VEWS) for diaphanous workspaces considering COVID-19 and future pandemics scenarios

The COVID-19 pandemic has generated new needs due to the associated health risks and, more specifically, its rapid infection rate. Prevention measures to avoid contagions in indoor spaces, especially in office and public buildings (e.g., hospitals, public administration, educational centres, etc.), have led to the need for adequate ventilation to dilute the possible concentration of the virus. This article presents our contribution to this new challenge, namely the Ventilation Early Warning System (VEWS) which has aims to adapt the operation of the current Heating, Ventilating and Air Conditioning (HVAC) systems to the ventilation needs of diaphanous workspaces, based on a Smart Campus Digital Twin (SCDT) framework approach, while maintaining sustainability. Different technologies such as the Internet of Things (IoT), Building Information Modelling (BIM) and Artificial Intelligence (AI) algorithms are combined to collect and integrate monitoring data (historical records, real-time information, and location-related patterns) to carry out forecasting simulations in this digital twin. The generated outputs serve to assist facility managers in their building governance, considering the appropriate application of health measures to reduce the risk of coronavirus contagion in combination with sustainability criteria. The article also provides the results of the implementation of the VEWS in a university workspace as a case study. Its application has made it possible to detect and warn of inadequate ventilation situations for the daily flow of people in the different controlled zones.

포스트 코로나 시대의 대학교 주변 원룸형 주택에 대한 실내 공기질 분석 및 위해성 평가

In this study, in order to grasp the current situation of indoor environmental pollution and indoor ventilation in one-room around the university in the post-corona era, we analyzed the experimental data and conducted a questionnaire survey on university students. By analyzing the content, the effects of formaldehyde, dust and other pollution on the human body, which are usually not easily detectable, are digitized and more easily taken into account. Among the experimental results, the concentration of VOC and HCHO, gas pollutants among indoor pollutants, exceeded the recommended criteria of the Ministry of Environment in most studio apartments. Overall, the average CO2 concentration was lower than the Ministry of Environment's maintenance standard (1000ppm), but it was relatively high in summer and winter, and it is believed to be caused by cooling and heating in an enclosed space. The levels of PM2.5 and PM10, particulate pollutants, increased in November and December, and it is believed that ventilation defects due to degradation in external temperature. There was no clear difference between the two types, and there was a very high correlation between PM2.5 and PM10, HCHO and VOC. It was found that temperature was closely correlated with all sources except CO2, and humidity was closely correlated with all sources except PM2.5 and PM10. Health risk assessment was conducted for formaldehyde. The average ECR of studio R2 in May was 3.91E-4, and the ECR figure in September was 3.65E-4, which was very high compared to other residential spaces. The R2 level was calculated as 4 people per 10,000 people in the lifetime risk of cancer of residents, exceeding the allowable risk. R8 also showed higher ECR results than other spaces after R2, especially in October, 2.01E-4, six times higher than R7 measured in October, and 1.87E-4 in July, four times higher than R9.

The Use of Saliva Sample Evaluating PaO2, PaCO2, pH, and HCO3 Values in Traumatic Patients under Mechanical Ventilation; As a Non-Invasive Approach than the Arterial Blood Gas Sampling

Background: Arterial Blood Gas (ABG) analysis is a commonly ordered test to investigate respiratory, circulatory, and metabolic status in traumatic patients with inappropriate perfusion and ventilation situations. Difficult sampling, hemorrhage risk of arterial puncture, and other vascular complications lead us to use saliva sampling as a safer non-invasive approach to evaluate PaO2, PaCO2, pH, and HCO3 values.
 This study was aimed to evaluate the correlation of PaO2, PaCO2, pH, and HCO3 values between ABG and saliva gas in traumatic patients under mechanical ventilation.
 Methods: This was a retrospective cross-sectional study of 18-85-year-old traumatic patients under mechanical ventilation conducted in an academic medical hospital. They were investigated based on age, sex, and ABG values as well their saliva gases values. The Paired t-test, Pearson χ2, and Pearson correlation were used to evaluate the correlation between the gases values in ABG and saliva. Data were analyzed using Mann–Whitney U test and Kolmogorov–Smirnov test.
 Results: There were 120 patients including 53 men and 67 women enrolled. None of the factors of arterial and salivary gases were significantly different between men and women. And the amount of these factors is homogeneous in both groups (P <0.05). The mean factors of arterial PaCO2 and HCO3 and saliva PaCO2 and HCO3 were significantly different between smokers and non-smokers.
 Conclusion: The values of salivary gases correlated with these of ABG. This can expand the use of salivary gases analysis as an alternative to ABG analysis in clinical settings to reduce the logistic burden of arterial sampling as well as to better perform ventilator device settings. These results were aligned with previous studies.

P 7 SARS-CoV2 infection causes a worsening of the modified ranking scale (mRS) in patients with neuromuscular diseases – first results of the German covid19-nme registry

Background: Patients with neuromuscular diseases (NMD) are classified as risk groups for a potentially severe course of a SARS-CoV-2 infection. An online registry (www.covid19-nme.com) was developed to gather information about the severity of COVID19, a potential progression of NMD through the SARS-CoV-2 infection and the possible influence of medication on the course of the infection.Methods: Since February 2021, patients of all ages (children, adolescents and adults) with NMD and an infection with SARS-CoV-2 have been included in this register. In addition to demographic data, pre-existing diseases and therapies, information about the NMD, the course of the SARS-CoV-2 infection as well as the clinical findings before and after the infection are recorded.Results: So far 94 patients (37% female, age: median 60 years (1-94 years)) from Germany and Austria have been recorded. The diagnoses represent the entire spectrum of NMD: different forms of polyneuropathies (PN) including CIDP and hereditary PN, ICUAW, myasthenic syndromes, motor neuron diseases (SMA and ALS) as well as various muscle diseases such as dystrophinopathies and myotonic syndromes. The collected mRS (measure for description of neurological impairment) depicts a significant worsening after the SARS-CoV2 infection (p = 0.02; Wilcoxon), whereby the patients with ICUAW were excluded from the analysis. The duration of symptoms showed a positive correlation with age (r = 0.343; p = 0.005) and weight (r = 0.291; p = 0.030), but not with the type of NMD. In total, 13 patients deceased due to the SARS-CoV2 infection. The probability of a fatal outcome of COVID19 correlates with increasing age (r = 0.313; p = 0.004) but not the type of NMD. The ventilation situation did not change in NMD patients due to the infection with SARS-CoV2.Summary: The first results of the evaluation of the covid-19.nme registry indicate that the clinical symptoms of NMD progress due to an infection with SARS-CoV2. The underlying cause for this remains unclear. Autoimmunological processes and a possible neurotropy can be considered as pathophysiological mechanisms.

Investigation on Oxygen Gas-liquid Mass Transfer in Sewage Pipelines Under Enhanced Ventilation

The anaerobic environment of sewers is the main cause of the production of toxic and harmful gases such as hydrogen sulfide and methane. The installation of septic-tanks between the drainage standpipes and municipal sewage pipes has aggravated the current situation of poor ventilation in sewage pipes. A system of enhanced ventilation has been formed. By connecting the drainage standpipes and sewage pipes, the system of enhanced ventilation can ameliorate the ventilation of sewage pipes and improve the gas-phase space environment. The experimental and computational fluid dynamics (CFD) simulation methods were established to explore the law of oxygen gas-liquid mass transfer under the different sewage flow rates or wind speeds. This study aimed to seek a method to enhance the oxygen mass transfer, suppress the anaerobic environment, and achieve the purpose of long-term control of harmful gases. The results showed that increasing the gas-liquid flow rates can accelerate the oxygen mass transfer, and the volumetric mass transfer coefficient increased by 3.5×10-4 min-1 for every increase of 0.1 m·s-1. However, the faster sewage reduced hydraulic retention time. The mass transfer time of oxygen was also shortened, and the promotion effect was not as good as that by enhancing the gas velocity in the pipelines. At the same time, when the average gas velocity increased by 0.1 m·s-1, the lengths of pipes where dissolved oxygen could effectively inhibit H2S increased by 25 m.

Modeling the Airborne Transmission of SARS-CoV-2 in Public Transport

This study presents the transmission of SARS-CoV-2 in the main types of public transport vehicles and stations to comparatively assess the relative theoretical risk of infection of travelers. The presented approach benchmarks different measures to reduce potential exposure in public transport and compares the relative risk between different means of transport and situations encountered. Hence, a profound base for the selection of measures by operators, travelers and staff is provided. Zonal modeling is used as the simulation method to estimate the exposure to passengers in the immediate vicinity as well as farther away from the infected person. The level of exposure to passengers depends on parameters such as the duration of stay and travel profile, as well as the ventilation situation and the wearing of different types of masks. The effectiveness of technical and behavioral measures to minimize the infection risk is comparatively evaluated. Putting on FFP2 (N95) masks and refraining from loud speech decreases the inhaled viral load by over 99%. The results show that technical measures, such as filtering the recirculated air, primarily benefit passengers who are a few rows away from the infected person by reducing exposure 84–91%, whereas near-field exposure is only reduced by 30–69%. An exception is exposure in streetcars, which in the near-field is 17% higher due to the reduced air volume caused by the filter. Thus, it can be confirmed that the prevailing measures in public transport protect passengers from a high theoretical infection risk. At stations, the high airflows and the large air volume result in very low exposures (negligible compared to the remaining means of transport) provided that distance between travelers is kept. The comparison of typical means of transport indicates that the inhaled quanta dose depends primarily on the duration of stay in the vehicles and only secondarily on the ventilation of the vehicles. Due to the zonal modeling approach, it can also be shown that the position of infected person relative to the other passengers is decisive in assessing the risk of infection.

Theory of RPOD adjustment of air volume for mine intelligent ventilation

The intelligentization of mine ventilation is the inevitable development trend of ventilation system. Rapid, precise, and on-demand (RPOD) adjustment of air volume is one of the main problems that need to be solved in mine intelligent ventilation. In order to realize RPOD adjustment of air volume, the concepts of target branch, active branch and passive branch were elaborated and an algorithm was proposed. Then active branches were sorted based on the sensitivity theory, and the adjustment range of the active branches were calculated using the sensitivity attenuation rate theory and the minimum air volume principle. Finally, the specific active branch and adjustment range were determined according to the total air volume that the passive branch. The theory was verified based on the actual ventilation situation of Wuyang Coal Mine in Shanxi Province. The research results will provide theoretical guidance for the RPOD adjustment for mine intelligent ventilation.

Natural ventilation strategy and related issues to prevent coronavirus disease 2019 (COVID-19) airborne transmission in a school building

The World Health Organization (WHO) announced that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may spread through aerosols, so-called airborne transmission, especially in a poorly ventilated indoor environment. Ventilation protects the occupants against airborne transmission. Various studies have been performed on the importance of sufficient ventilation for diluting the concentration of virus and lowering any subsequent dose inhaled by the occupants. However, the ventilation situation can be problematic in public buildings and other shared spaces, such as shops, offices, schools, and restaurants. If ventilation is provided by opening windows, the outdoor airflow rate depends strongly on the specific local conditions (opening sizes, relative positions, climatic and weather conditions).This study uses field measurements to analyze the natural ventilation performance in a school building according to the window opening rates, positions, and weather conditions. The ventilation rates were calculated by the tracer gas decay method, and the infection risk was assessed using the Wells-Riley equation. Under cross-ventilation conditions, the average ventilation rates were measured at 6.51 h−1 for 15% window opening, and 11.20 h−1 for 30% window opening. For single-sided ventilation, the ventilation rates were reduced to about 30% of the values from the cross-ventilation cases. The infection probability is less than 1% in all cases when a mask is worn and more than 15% of the windows are open with cross-ventilation. With single-sided ventilation, if the exposure time is less than 1 h, the infection probability can be kept less than 1% with a mask. However, the infection probability exceeds 1% in all cases where exposure time is greater than 2 h, regardless of whether or not a mask is worn. Also, when the air conditioner was operated with a window opening ratio of 15%, power consumption increased by 10.2%.

Numerical simulation and analysis of outdoor wind environment in a high-rise community with matrix layout model based on computational fluid dynamics

The wind environment is an important factor affecting the comfort of the outdoor environment in high-rise residential communities. The numerical simulation of ventilation situation in the outdoor environment could provide scientific bases for the design of various elements in a community, including space layout, roads, activity spaces, water system, and plants. Taking the Changqingteng community, Xinxiang as the object, this paper numerically simulates the wind environment in summer, winter, and the transition season on THSware VENT2018, and analyzes the wind speed amplification factors, wind speed vector diagrams, and wind speed cloud maps on the outdoor environment of the community. The results show that both wind speed and wind speed amplification factor fall into the comfortable ranges in most places of the community throughout the year. In summer, only a few windless activity spaces are uncomfortable on hot and humid days. In winter, multiple wind corridors appear in the north of the community. These corridors greatly suppress the comfort of residents, owing to their fast wind speed and large wind speed amplification factor. The following measures could be taken to optimize the outdoor environment of the community: adding leisure spaces around the water system to improve comfort in summer, and setting up wind barriers by planting dense evergreen plants between the buildings on the north side to improve comfort in winter.

Value of lung ultrasound examination in making decision of severe acute respiratory distress syndrome receiving prone ventilation

To investigate the ideal persistence time of prone position ventilation in patients with severe acute respiratory distress syndrome (ARDS). Collect 78 cases of severe ARDS admitted to the ICU unit of Sichuan Provincial People's Hospital from October 2012 to June 2014, all the ARDS patients needed to receive 8 h/day prone position continuous 5 day. For each of the prone position ventilation, ultrasound patterns were recorded and the aeration scores were calculated at the beginning of the prone position (T0) and 2 h (T1), 4 h (T2), 6 h (T3), 8 h (T4) later. The correlation of the aeration score variation (ASV) and the arterial blood gas indexes (pH, PaO(2), PaCO(2), PaO(2)/FiO(2)) were recorded also. The adverse reactions, ventilator situation and oxygen fraction after 7 days, 28-day mortality were monitored. The aeration score of the lung at T1, T2, T3, T4 was significantly reduced than T0 all, the ventilation situation of mainly areas was improved after 2 h PPV (P < 0.05), 4 h later it was not distinguished (P > 0.05); the value of PaO(2), PaO(2)/FiO(2) was greater at T1, T2, T3, T4 than T0 (P < 0.05), the value of the oxygen fraction was significant increased at T2 than T1 (t = 2.840, P < 0.05); the number of patients with oxygen fractions > 300 mmHg after 5 days PPV was 65 (83.3%); there were 30 (38.5%) patients free of mechanical ventilation after 7 days; the 28-day mortality was 7 (8.97%). In patients with severe ARDS, applicating 2-4 hours validity of prone position ventilation significantly improves the pulmonary ventilation, more than 4 h PPV do not better for patients probably.

Study on integration of real-time atmospheric monitoring system data and MFIRE simulation

ABSTRACT The past several decades have seen a steady increase in the use of atmospheric monitoring systems (AMS) in underground mines as sensor technology has advanced and costs for this technology have decreased. The AMS is a reliable tool for early mine fire warning by detecting gaseous products of combustion in underground mines. During a mine fire emergency, mine decision makers rely heavily on prompt and accurate knowledge of the ventilation and fire situation in the mine, such as fire location, fire size, and the spread of smoke to make effective and efficient decisions on firefighting strategies and miner evacuation. Meanwhile, a prediction of the potential for fire development at a later time, such as whether the currently designated mine escapeways will be contaminated by smoke and toxic gases with the progress of the fire, is critical for effective decision making to save lives that are in danger. The AMS monitoring data, including carbon monoxide concentration, airflow rate, smoke spread, etc., can provide information as to whether the smoke has reached the locations where AMS sensors are installed and if a mine-wide smoke spread has occurred. The National Institute for Occupational Safety and Health has undertaken a task to integrate real-time AMS monitoring data with the mine fire simulation program, MFIRE, to simulate and predict the spread of smoke and toxic gas in a ventilation network based on the real-time AMS data. This article reports the developed real-time method for characterizing the size and location of an underground mine fire and for predicting the spread of contaminants throughout the mine ventilation network using sensor data from the AMS.

Ecological renovation process of Nanjing’s housing stock built between 1840 and 1949, China

ABSTRACTNumerous in number and mostly still in use, buildings built between 1840 and 1949 are valuable assets in the rapid development and renovation of Chinese cities. However, due to lack of maintenance and being inhabited mainly by the elderly and people with low incomes, many of these buildings are in poor condition and have much higher possibilities of being demolished. The objectives of ecological renovation presented in this paper are to improve building performance and to achieve higher levels of comfort and lower levels of energy consumption. The housings in Zhong-nong-li block in Nanjing are used as an example in this paper to show how a strategy of “basic” renovation and “thorough” renovation is used in the ecological renovation of housing stock between 1840 and 1949 in China. The paper demonstrates that these are very practical steps for this building stock in China and could not only help to balance social and economic factors in practice, but also improve the living conditions of the residents, and endow the old houses with a new, long life. Numerical simulations of the natural day lighting and ventilation situations before and after renovation are made to show the improvement in building performance after renovation.

Monitoring and analysis of subway tunnel thermal environment: A case study in Guangzhou, China

Tunnel thermal environment has a great impact on the energy consumption and safety in the subway system. Due to the complexity of subway network structure and the influence of piston effect, analytical and numerical methods are limited in showing the real situation. In comparison, full-scale experiments are effective in verifying models and presenting the real situation in subway tunnels. In this study, the experimental method was adopted. The tunnel wall and air temperature were monitored in 5 subway lines in Guangzhou, China for more than 1 year. These selected tunnels have different operation conditions; namely operation year, train density, passenger number, and ventilation form. Based on long-term and multipoint monitoring, the temperature profiles were obtained. In aspect of time-varying features, it was found that the daily temperature profiles present different shapes nder different heat sources and ventilation situations. The temperature profiles in a typical year show 60 and 30–60 days delayed effect compared to outdoor temperature in winter and summer, respectively. In regard to the temperature distribution features, it was revealed that the temperature distribution within a tunnel is not sensitive to the length of tunnel but susceptible to ventilation condition; the tunnel temperature differences between two ends are 0.1-0.8℃ and 1.4-1.6℃ in high-ventilation and low-ventilation tunnels, respectively. Moreover, the possible influencing factors, including operation year, train density, passenger flow, and ventilation condition were analyzed. It was discovered that the factors related to the heat source (train density and passenger flow) have the most important impact, and the ventilation condition takes second place, while the operation years almost have no impact on the thermal environment in subway tunnels. The monitoring data are useful for both analytical and numerical studies and this study provides first-hand research data for subway operators.

Reduced-scale study of the coupling between thermal and wind effects on the ventilation systems of nuclear facilities

To study heat and mass transfers inside nuclear facilities equipped with ventilation systems, a methodology was developed to carry out reduced-scale experiments for studying flows induced by thermal and wind effects simultaneously. The methodology was numerically validated on simple configurations and applied to a reference configuration representative of nuclear facilities. The effects of wind and thermal phenomena on heat and mass transfers in various ventilation situations (normal ventilation or ventilation switched off) and scenarios of heat supply were studied in wind tunnel experiments. The thermal sources that could be generated by an industrial process were reproduced experimentally with a helium injection. The objectives of this article are to present the scaling-down methodology and the main experimental results concerning the influence of thermal effects on airflows in the reduced-scale model. The effects of heat with or without wind on loss of building containment were also highlighted and analysed. Finally, the reliability of SYLVIA simulation software, which was used to support safety assessments in nuclear facilities, was analysed using the experimental results.

Association of Single-Nucleotide Polymorphism REX1 rs6815391, OCT4 rs13409 or rs3130932, and CTBP2 rs3740535 with Primary Lung Cancer Susceptibility: A Case-Control Study in a Chinese Population

The purpose of the current study is to explore the contribution of single-nucleotide polymorphisms (SNPs) of REX1 rs6815391, OCT4 rs13409 or rs3130932, and CTBP2 rs3740535 to the risk of lung cancer. A questionnaire survey was used to obtain basic information of the included subjects. A case control study was performed in 1121 patients and 1121 controls. All subjects were subjected to blood sampling for genomic DNA extraction and genotyping of the cancer stem cell-associated gene SNPs, including REX1 rs6815391, OCT4 rs13409 or rs3130932, and CTBP2 rs3740535 by real-time PCR. The association with the risk of primary lung cancer and interaction with environmental factors were assessed using unconditional logistic regression for the odds ratios and corresponding 95% confidence intervals. The genotype frequency distribution of OCT4 rs13409 loci was statistically significant, but there was no significant difference in the rest of the loci between lung cancer patients and healthy controls. The OCT4 gene was also related with lung cancer susceptibility in the genetic model after adjusting for lung cancer-related factors. Despite the presence of the dominant or recessive model, the four loci polymorphisms were associated with pollution near the place of residence, house type, worse ventilation situation, smoking, passive smoking, cooking oil fumes (COF), and family history of cancer, which increased the risk of lung cancer. Nonmarried status, 18.5≤BMI, COF, smoking, passive smoking, family history of cancer, and history of lung disease were independent risk factors of lung cancer susceptibility. Additionally, college degree or above, no pollution near the place of residence, protective genotype 1 or 2, and well ventilation can reduce the occurrence of lung cancer. There is an interaction between the four loci and environmental factors, and OCT4 rs13409 is a risk factor of primary lung cancer.

Comparison of CO2- and SF6- based tracer gas methods for the estimation of ventilation rates in a naturally ventilated dairy barn

Livestock production is a source of numerous environmental problems caused by pollutant gas emissions. In naturally ventilated buildings, estimating air flow rate is complicated due to changing climatic conditions and the difficulties in identifying inlets and outlets. To date no undisputed reference measurement method has been identified. The objective of this paper was to compare CO2- and SF6-based tracer gas methods for the estimation of ventilation rates ( V R C O 2 vs. V R S F 6 ) in naturally ventilated dairy barns both under conventional and very open ventilation situations with different spatial sampling strategies. Measurements were carried out in a commercial dairy barn, equipped with an injection system for the controlled release of SF6, and measurement points for the monitoring of SF6 and CO2 concentrations to consider both horizontal and vertical variability. Methods were compared by analysing daily mean V R C O 2 / V R S F 6 ratios. Using the average gas concentration over the barn length led to more accurate ventilation rates than using one single point in the middle of the barn. For conventional ventilation situations, measurements in the ridge seem to be more representative of the barn average than in the middle axis. For more open situations, both V R C O 2 and V R S F 6 were increased, V R C O 2 / V R S F 6 ratios being also more variable. Generally, both methods for the estimation of ventilation rates gave similar results, being 10–12% lower with the CO2 mass balance method compared to SF6 based measurements. The difference might be attributed to potential bias in both methods.

The Prediction and Verification of Co Production Rate based on Extended Mixture-Fraction Method

The paper uses both single-step and two-step reaction models to predict the yield of CO in a standard room with the half size of ISO9705 under different ventilation situations, and verify the validity of calculation results with the comparison against experimental data. The results show that the two-step combustion model can predict the yield of CO more precisely as long as under a proper grid and boundary setup. In practical researches of human evacuation and toxic gases, the method of FDS5 simulation can be used to predict gas yields which can do practical instructions.

Mine Gas Flow in the Porous Massif and CFD Tool

There is a still dangerous effect in the form of methane leakage from coal seams in areas where mining activity still continuing or took place in the past. The issue of mining gas flow is still a matter that is necessary to pay attention and try to find new ways to solve this set of phenomena, no matter if it is the mining corridors or the flow in the rock massif. The number of measures to gradually reduce risk has been taken to protect the population. Nevertheless, the current situation is generally rated as serious as those risks still remain valid. Leakage of mine gases depend on many natural and technical mining conditions. With the closure of mines and thus the end of the ventilation situation considerably worse. This paper deals with the flow of dangerous mine gas, methane, through the rock mass using numerical flow modeling using CFD program Fluent. Using CFD codes can gain insight on the phenomenon under review and the results to take appropriate measures in the form of active or passive intervention.