Exhaust Smoke Research Articles

The mathematical model of kitchen smoke exhaust system in high-rise residential buildings considering the Influence of Stack effect

In high-rise buildings with large indoor and outdoor temperature difference, neglecting the effect of stack effect in smoke exhaust shafts may cause calculation error of the fluid network model. In this paper, the mathematical model of kitchen smoke exhaust system considering the influence of stack effect was put forward and it can be inserted different range hood sub-models. Compared with the results of six working conditions of the model without considering the stack effect, the error of the proposed model were reduced by 7.6%, 4.3%, 4.1%, 2.8%, 2.4%, and 2.1%. While the indoor and outdoor temperature difference varies from −5 °C to 49 °C, the effect of stack effect on the pressure in the flue and the flow rate for each user was studied for six operating rates s. The results show that under the combined effect of stack effect and flue resistance, the static pressure of the kitchen smoke exhaust system showed a low-high-low distribution, and the maximum static pressure in the flue moved toward the bottom with the increase of temperature difference. User flow rates exhibit a low-high-low-high distribution, with an increased flow rate in the bottom users and the largest flow rate in the top users.

Dimethyl ether fuel injection system development for a compression ignition engine for increasing the thermal efficiency and reducing emissions

In this study, a dedicated fuel injection equipment (FIE) for a 100% dimethyl ether (DME)-fueled three-cylinder engine was developed. DME has a cetane number (>55) higher than baseline diesel (40–50), making it a promising compression ignition (CI) engine fuel. However, some physicochemical properties of DME, namely lubricity, viscosity, density, calorific value, vapour pressure, incompatibility with elastomers, etc., necessitate modifications in the existing FIE to deliver a power output equivalent to baseline diesel fuelled engine. Modifications included customized DME storage tanks, supply lines, return lines, and a pneumatic pre-supply feed pump. In addition, a customized high-pressure pump (HPP) (inline mechanical pump) and a set of modified injectors with larger nozzle hole diameters were used for the DME engine. The engine speed was varied from 1000 to 2000 rpm, and off-road operating conditions were simulated using a non-road steady cycle (NRSC). A detailed evaluation of the FIE for its comparative combustion, performance, and emissions characteristics of DME was conducted vis-à-vis baseline diesel. The DME-fuelled engine showed an increase of ∼4.7% in brake thermal efficiency (BTE) under full load conditions and an increase of ∼8.32% BTE under simulated non-road-testing conditions. In addition, the DME-fuelled engine exhibited no visible smoke and negligible soot in the engine exhaust. DME combustion reduced HC emissions by ∼50% at low and medium engine speeds, and a ∼100% reduction was seen at higher engine speeds compared to baseline diesel engine. The CO emission decreased by ∼90%, and the CO2 emissions were ∼15% lower for DME. Lower exhaust gas temperature (EGT) and lower heat release rate (HRR) during premixed combustion indicated that DME-fuelled engine acted as a low heat rejection (LHR) engine. This study demonstrated a 100% DME-fueled engine with a customized FIE, delivering higher thermal efficiency and lower emissions than conventional diesel engines for on- and off-road applications.

Theoretical model for predicting smoke back-layering length downstream of centralised ceiling exhaust vent in tunnel fires

Passing a certain amount of smoke through a centralised ceiling exhaust vent with an acceptable back-layering length can considerably reduce the smoke exhaust rate of a centralised exhaust system. Accordingly, this study conducted a theoretical analysis of the back-layering length of smoke downstream of the centralised ceiling exhaust vent and proposed a theoretical prediction model considering the smoke exhaust efficiency, exhaust vent layout, and the distance between the fire source and vent. This model can be applied across multiple exhaust vent layouts with a wide range of smoke exhaust rates. In addition, the theoretical prediction model was verified with a series of reduced-scale experiments. Thereafter, we compared the proposed theoretical model with existing relevant models. The results revealed that the existing models are applicable only for a specific range of the smoke exhaust rate because these models were either empirically derived for a particular range of smoke exhaust rate or developed assuming pure smoke flow in the vent. Furthermore, the proposed model was employed to quantitatively analyse the influence of the exhaust rate, exhaust vent layout, and the distance between the exhaust vent and fire source on the smoke back-layering length. Finally, we discussed the contribution of the proposed model for optimising the exhaust vent layout and reducing the smoke exhaust rate of the system.

Experimental study on fire suppression performance of the high pressure water mist in the engine room of an offshore platform

The total flooding application water mist system is a new type of environmentally-friendly fixed extinguishing system. The optimizing design can improve its fire extinguishing performance. At present, the water mist fire extinguishing system in the engine room of the offshore deepwater semi-submersible support platform has not attracted sufficient attention. In this paper, the water mist in the engine room of a deepwater semi-submersible support platform was studied. It contains the effect of water mist on the heat absorption and oxygen insulation of diesel pool fires. The applicable parameters of the water mist fire extinguishing system were also determined. Moreover, based on the shielding of the fire source in the engine room and the different requirements for water mist extinguishing parameters, a hierarchical multi-parameter combined high-pressure water mist fire extinguishing system was proposed. In the full-scale experimental engine room model, according to the fire extinguishing experiments for diesel pool fires with different areas, this kind of hierarchical multi-parameter water mist system is very effective on shielded and non-shielded fires. In addition, it is still effective even in a non-closed environment coupled with smoke exhausting.

Numerical Study on Coupled Smoke Control Using Longitudinal Ventilation and Naturally Ventilated Shafts during Fires in a Road Tunnel

Longitudinal ventilation and smoke extraction by shaft are common smoke control methods in road tunnel fires. Tunnels often adopt one of these methods in practical engineering. However, it may have a better effect to adopt the method of mixing the two smoke exhaust methods together, which has not been revealed in the previous literature. Hence, the coupled effects of longitudinal ventilation and natural ventilation with shafts on the smoke control in tunnel fires were studied in this work. Numerical simulation was carried out considering different longitudinal ventilation velocities (0–4 m/s) and 4 kinds of typical shaft arrangements (shaft lengths range of 3–12 m, shaft intervals range of 27–60 m). The smoke spread length and smoke exhaust efficiency were analyzed systematically. Results show that (1) with the increase in longitudinal ventilation velocity, the total smoke spread length firstly decreases (V < 1 m/s) and then keeps almost constant (1 m/s < V < 2 m/s), finally increasing significantly (V > 2 m/s). (2) The length of the dangerous area (over 60 °C) at human height is basically 0 for all cases (except for Scenario 4 of shaft arrangement) when the longitudinal ventilation velocity is less than 2 m/s. (3) The CO smoke flow rate through the shaft is relatively high when the longitudinal ventilation velocity is within the range of 1–2 m/s for 4 kinds of shaft arrangement scenarios. Factors such as smoke spread and smoke exhausted through the shaft are comprehensively considered to judge smoke exhaust performance. The following conclusions can be drawn: when the ventilation velocity ranges from 1–2 m/s, it has a positive impact on the smoke control in tunnel fires with natural ventilation with shafts. When the ventilation velocity exceeds 2 m/s, the total smoke spread length and the length of the danger area increase, and the smoke stratification becomes worse, which brings inconvenience to rescue work. The results can provide reference for the design of fire protection in tunnels.

Numerical Simulation on Smoke Temperature Distribution in a Large Indoor Pedestrian Street Fire

In order to study the characteristics of fire smoke spread and temperature distribution of a large indoor pedestrian street under different heat release rates and smoke exhaust modes, this paper focuses on the analysis of fire smoke spread, visibility, smoke temperature distribution and variation curves in an atrium. This paper uses a numerical simulation method to conduct research. PyroSim fire simulation software is used to calculate this project, which is based on a full-scale experimental design scheme. The numerical simulation results show that under the conditions of higher heat release rate, the smoke spread rate is greater than that under the conditions of lower heat release rate. Furthermore, the average temperature of smoke in the atrium is also greater, up to about 400 °C. The conditions of a higher heat release rate also show the characteristics of faster generation, faster spread and a larger volume of smoke. When the smoke exhaust system is turned on, the thickness of the smoke layer and the smoke temperature decrease. There then comes a situation where the stabile section of the fire ends in advance. The simulation results of vertical temperature distribution in an atrium can fit the modified McCaffrey plume model in any case. Under all cases, the smoke temperature reaches the maximum directly above the fire source. The horizontal dimensionless smoke temperature rises under the atrium roof, and decreases exponentially with the dimensionless distance from the fire source. The greater the heat release rate of fire source is, the smaller the attenuation coefficient is, with a more than 50% change. When the smoke exhaust system is turned on, the smoke flow accelerates and the smoke is cooled rapidly. Thus, the attenuation coefficient increases. Additionally, the effect of mechanical smoke exhaust is better than natural smoke exhaust, because mechanical smoke exhaust makes air flow and heat exchange more intense. The variation amplitudes of the attenuation coefficient under natural smoke exhaust and mechanical smoke exhaust are 13% and 22%, respectively.

Development and Experimental Study of Mobile Fire Smoke Decontamination System

Fire smoke decontamination equipment, such as fire-fighting robots and smoke exhaust robots, is mainly used in long and narrow spaces such as underground garages. In several recent decades, the study of fire smoke spread in narrow spaces and fire smoke decontamination equipment stimulated the interests of many researchers. However, present equipment cannot eliminate insoluble toxic gases such as CO and may decrease the height of the smoke layer, causing great difficulty to rescue. In this study, a novel mobile fire smoke decontamination process and system are proposed. The experimental study and theoretical prediction of the system are conducted. The results show that the developed equipment is able to eliminate fire smoke particles and CO, cool the space, and improve the visibility of the fire site. The developed equipment can reduce the space temperature to below 60 °C, reduce the CO concentration to below 145 ppm, and enhance the visibility to more than 50 m in the rectangular tunnel after operating for 30 min under 4 MW fire condition.

Hydroquinone triggers pyroptosis and endoplasmic reticulum stress via AhR-regulated oxidative stress in human lymphocytes

Benzene is a frequent component of environmental pollution and is abundant in petrochemicals, decorative materials, motor vehicle exhaust and cigarette smoke. Benzene is a well-known carcinogen in humans and animals, but the molecular mechanism has not yet been elucidated. Our earlier research indicated that hydroquinone (HQ), one of the main reactive metabolites of benzene, could activate aryl hydrocarbon receptor (AhR), which is essential for HQ-induced toxicity, including apoptosis and DNA damage. Since AhR is an important regulator of the immune system that integrates the environmental stimulus and immune response, we examined whether and how HQ-induced AhR activity could lead to NLRP3 inflammasome-dependent pyroptosis in JHP cells. Our results showed that HQ could cause inflammation process and resultant pyroptosis. In JHP cells, HQ also induced endoplasmic reticulum stress (ERS) by releasing excessive reactive oxygen species (ROS). The activation of pyroptosis induced by HQ treatment was reversed by an antioxidant (NAC) and an ERS inhibitor (4-PBA). Interestingly, the treatment of CH223191, an AhR inhibitor, reversed HQ-induced oxidative stress, ERS and pyroptosis. These data suggested that AhR-mediated HQ-induced ERS, ROS and inflammasome activation may play vital roles in the toxic effects of benzene. This work provides insights and prospective strategies into potential mechanisms for reducing benzene-induced hematotoxicity.

Analysis of the Operation of Smoke Exhaust Ventilation in the Metro’s Technological Corridor Based on Numerical Simulation of Selected Locations of Fire

The aim of the paper is to analyze the effectiveness of smoke exhaust ventilation for the protection of metro technical personnel. Therefore, the specified technological corridor as a part of the underground station was chosen. The Fire Dynamics Simulator (FDS) was used to carry out numerical simulations. Due to the low fire hazard, the heat release rate (HRR) was set at 1 MW after 250 s. Four cases were analyzed: three differing in the location of the fire source and a reference case in which the smoke exhaust ventilation is turned off. The analysis took into account temperature distributions and gas flow speeds, and qualitative verification of visibility. It was shown that the variant in which the fire source was located in the middle of the corridor turned out to be the most unfavorable variant in terms of the effectiveness of smoke exhaust ventilation. The operation of the smoke exhaust ventilation improved visibility, and reduced the temperature from 270 °C to 120–155 °C, depending on the variant, with local maximum flow speeds not exceeding 10 m/s. It was shown that properly designed smoke exhaust ventilation enables the evacuation of employees within the required safe evacuation time (RSET).

PM2.5: Epigenetic Alteration in Lung Physiology and Lung Cancer Pathogenesis.

Particulate matter (PM) has a very negative impact on human health, specifically the respiratory system. PM comes in many forms, among these is PM2.5,which is a major risk factor for lung cancer and other cardiovascular diseases. PM is inherent in emissions from industrial production, manufacturing, vehicle exhaust, mining, and cigarette smoking. For this reason, the composition of PM differs from area to area although its primary constituents are heavy metals and petroleum elements. PM has a long and toxic impact on human health. After extended exposure to PM2.5 the mortality rate for lung cancer patients increases. Already, lung cancer is the leading cause of death globally with the highest mortality rate. PM2.5 creates epigenetic changes in miRNA, histone modification, and DNA methylation, causing tumorigenesis followed by lung cancer.

Abstract C019: Evaluation of genes for glutathione-S-transferase genetic polymorphism in drivers exposed to air pollution

Abstract Air pollution and its possible impact on human health is attracting growing interest around the world. It remains a serious threat of premature death. Multiple source of pollution are present in the outdoor and indoor air such as exhaust gases, industry, pesticides, gasoline, fuels, incense, air fresheners, insecticides, smoke, cosmetics and maintenance products…. These sources emited pollutants such as PM, CO, NO, VOC, PAH, O3 which are responsible for headaches, dizziness, eye irritation, hepatitis, respiratory and cardiac diseases and cancers (breast, blood, cervix, prostate…). These pathologies are due to the homozygous deletion of the glutathione-S-transferase (GST) genes. GST protects the body against toxicants by neutralizing electrophiles and makes toxic metabolites more soluble. Objective: To evaluate the genes of the glutathione-S-transferase genetic polymorphism GSTM1 and GSTT1 in pollutant-exposed motorcycle drivers. Materials & methods The study group is made up of 60 motorcycle drivers, including 30 professionals and 30 non-professionals. Blood samples are taken into the EDTA tube and DNA was extracted by the phenol/chloroform method. PCR was chosen to determine the presence or absence of GSTM1 and GSTT1. Results Our results showed that the percentage of GSTM1 null genotype was a significant difference (P=0.02), while the percentage of GSTT1 null genotype was not significant (P=0.76) between the two groups. The deletion of both genes is greater in professional than non-professional drivers. Conclusion In sum, air pollution in Cotonou appears to influence GSTM1 and GSTT1 gene suppression at a higher percentage in professional motorcycle drivers. This population could be predisposed to develop cancers. We recommend the consumption of fruits, organic vegetables and plants rich in antioxidants to strengthen the immune system. Citation Format: Firmin Houénoukpo Sagbo, Mènonvè Atindehou, Boris Cachon. Evaluation of genes for glutathione-S-transferase genetic polymorphism in drivers exposed to air pollution [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C019.

Application of the Bernoulli Effect for Improving Smoke Exhaust Efficiency in Tunnel Fires

Application of the Bernoulli Effect for Improving Smoke Exhaust Efficiency in Tunnel Fires

Проветривание частично открытых автостоянок

Purpose. The article evaluates the effectiveness of the natural ventilation system of partially open car parks using numerical simulation in the Fire Dynamics Simulator software package. In large shopping centers, along with open and closed car parks, there are car parks, whose open doorways areas are comparable to the areas of enclosing structures. The study is due to the lack of requirements for smoke protection of partially open car parks in the current regulatory documents. Methods. The authors have carried out numerical simulation in the Fire Dynamics Simulator software package, which implements a field model of a fire in the room. Findings. The study has showed that the efficiency of the system with natural draft induction (with natural ventilation) and with mechanical draft induction (exhaust smoke ventilation systems) is almost the same. The combustion temperature of a car reaches 816 °С, the temperature of the combustion products drops to the level of the average value of a car park area (24 °С) at a distance of no more than 2 m. Research application field. The results of the study can be used in the development of regulatory requirements for smoke protection of partially open car parks. Conclusions. The conducted research allowed the authors to draw a number of conclusions. 1. For a partially open car park in “Mega-Khimki” shopping mall the use of natural ventilation is effective: the temperature of combustion products and the visibility distance inside the car park practically do not differ from the corresponding values outside the building. The distance from the burning car to the point where the temperature of combustion products drops to about 20 °С is no more than 9 m. 2. The distance from the burning car to the point where the temperature of the combustion products drops to about 20 °С is no more than 9 m. 3. Taking into consideration the possible variety of planning solutions and sizes of partially open car parks, it is advisable to support the requirements of current regulatory documents with calculations using a field mathematical model.

Exhaust Smoke Validity of Vertical Shaft in Restrooms using the Stack Effect

This study is performed to validate a quantitative relationship between the exhaust rate through vertical shaft, which are used for restroom ventilation, and smoke generation based on NFSC 501. The exhaust rate is calculated using heat balance equations and is based on the input and exhaust air temperatures. The neutral plan in the vertical shaft was formed at approximately 46% of the total height. Because the smoke that is exhausted through the vertical shaft is more than 20% of the minimum smoke generation suggested by NFSC 501, the smoke exhaust through the vertical shaft is considered to be possible.

Numerical assessment on aerodynamic free area of natural smoke and heat exhaust ventilator without and with side wind

As a convenient means for modeling the dynamics of fluids, computational fluid dynamics has not yet been fully applied in the refined quantitative analysis of the effectiveness of individual smoke ventilator. Previous related numerical simulation studies were short of the overall consideration of various verification scenarios involving all aspects of performance of testing device and accuracy of testing results without and with side wind. In this paper, a comprehensive numerical assessment process containing seven typical simulation scenarios is established for determining the aerodynamic free area of a roof mounted ventilator without and with side wind. Compared with related on-site testing platform, the geometric construction of testing apparatus is reasonably optimized to obtain more uniform flow field inside the settling chamber and more appropriate coverage of side-wind field acting on the ventilator; some measurement positions of air speed, which are unspecified in the testing standard, are designed properly in the simulation. Six types of regression equations on the relationship between discharge coefficient and pressure difference are established and compared for exploring the best goodness of fit of curve fitting. Good agreement of simulation results with reference data demonstrates the feasibility and validity of the numerical assessment process developed in this study.

Toxic effects due to exposure heavy metals and increased health risk assessment (leukemia).

Heavy metals (HM) are among the elements that are rare in nature and threaten human health, animals, and the environment. Fix sources including (power plants, industries, homes) and mobile sources include (cars and motorcycles) are the main sources production and emission of HM. It is important to understand the main information about sources of emission, chemical processes (reactions, oxidation, and leaching), and how they precipitate. The aim of this study was to evaluation an increased risk of leukemia due to exposure to HM. In this article narrative, the first literature search was performed with 580 articles according to different databases: Elsevier, PubMed, Web of science, Spring, and Google Scholar databases. 70 articles were included in the analysis process. Finally, 8 full-text articles were selected in this research. The search was restricted to English-language papers published between 2000 and 2021. In final stage literature, there is a notable health effect (carcinogenic) because of exposure to heavy metals. According to the results of this research natural procedures and human activities (industrial processes, car exhaust, and cigarette smoke) are the most important of ways that heavy metals can enter the natural cycle. Air, food, soil, water, and groundwater are the main sources of heavy metals that can cause severe disorders in the human body. After entering the body through ingestion heavy metals produce stable bio-toxic compounds. These compounds by disrupting biological processes, interrupt the body's functions and cause various cancers in the human body. The results of this study can help to politicians for make comprehensive decisions to solve theproblem and increase public awareness of the use of protective equipment.

Mixed ventilation approach combined with single-shaft complementary system for highway tunnels

Highway tunnel ventilation systems are associated with high civil construction and operation costs, as well as large differences in the total required air volume for uphill and downhill tunnels. Thus, in the current study, a complementary ventilation system is applied to the shaft segmented longitudinal ventilation mode to form the mixed ventilation mode of the complementary combined ventilation shaft. The mixed ventilation formula is derived based on the tunnel ventilation theory. Combined with the design process of tunnel ventilation, the design process from the location of the ventilation shaft, design air volume, the air interchange channel location, the air exchange ratio of air interchange channel to pollutant concentration is determined, and the mixed ventilation mode conditions are analyzed. Moreover, an engineering example is employed to analyze the mixed ventilation, and to compare the traffic wind utilization rate, operation energy consumption and the civil construction scale between conventional segmented longitudinal ventilation and mixed ventilation. The results reveal that compared with the conventional segmented longitudinal ventilation mode, the mixed ventilation mode effectively improves the utilization rate of traffic wind, reduces the adverse effect of surplus traffic wind pressure on tunnel ventilation and minimizes mechanical power usage. In terms of operating energy consumption, taking a vehicle speed of 60 km/h as an example, the mixed ventilation method fully utilizes the traffic wind pressure in the tunnel. Although it is necessary to turn on the jet fan in the tunnel to increase the power, the energy consumption of the axial flow fan is reduced by 31.9 %, and the total power is reduced by 9.5 %, greatly lowering the energy consumption of the tunnel operation. Despite the addition of the traverse ventilation channels by the mixed ventilation method, reductions are observed in the construction of a ventilation shaft, the connecting channels, the overall ventilation civil engineering volume, and the initial civil construction investment cost. Moreover, the mixed ventilation method includes a smoke exhaust channel, thus solving the smoke exhaust problem of tunnel fires.

Full-scale experimental and numerical study of smoke spread characteristics in a long-closed channel with one lateral opening

This paper aims to study the characteristics of smoke flow in a long-closed channel with one lateral opening at one end. A series of full-scale experiments with different longitudinal positions and heat release rates of fire sources were carried out. And, the corresponding numerical simulations were conducted to help explain the law of smoke flow field. The characteristics of the smoke spread on both sides of the fire source, the thermal plume distribution within the channel, and the maximum ceiling excess temperature were analyzed. Results show that the existence of the end walls in the long channel causes the smoke to accumulate, which further results in the smoke settlement going through three stages. The lateral opening causes a significant difference of smoke flow and other characteristics from the channel with both ends open. When the fire source approaches the closed end without opening, the vertical fire-induced plume inclines to the closed end because of the asymmetrical air supplementation. Due to the limited air supply, the combustion will change to ventilation-controlled as the fire source heat release rate increases. The maximum ceiling excess temperature is higher than that with both ends open and is basically not influenced by fire positions studied in this work. It has been verified that the dimensionless maximum ceiling excess temperature of the smoke is also proportional to the dimensionless heat release rate. This study can provide a reference for fire prevention and smoke exhaust strategies for long channels.

Effect of using borax decahydrate as nanomaterials additive diesel fuel on diesel engine performance and emissions

Today, the increase in fuel consumption with the increasing number of vehicles has increased the efforts to make the engines more efficient. Diesel engines are subject to severe restrictions due to the emission problem. Although there is an emission problem, it is widely used especially in freight transportation. Many studies on diesel engines emission problems are made by academicians and manufacturers. In this sense, many studies have been carried out by adding nanomaterials to diesel fuel to reduce emissions in diesel engines. In this study, borax decahydrate as a fuel additive was studied in a diesel single-cylinder engine. Borax decahydrate was dissolved in 500 ml of methanol, 5 gr, 15 gr and 25 gr, and methanol was added to 10% diesel. To be 90% Diesel +10% Methanol (D90M10) 90% Diesel 10% Methanol + 1 gr Borax decahydrate (D90M10B1) 90% Diesel 10% Methanol + 3 gr Borax decahydrate (D90M10B2) 90% Diesel 10% Methanol + 5 gr Borax decahydrate (D90M10B3) four different fuel mixtures were tested. The experimental test measured in-cylinder pressure, heat release rate, fuel consumption, power, torque, exhaust gas temperature, smoke opacity, and exhaust emissions. Due to the rich oxygen content of borax decahydrate, it has been observed to reduce emissions, excluding NOx emissions. There was an increase in exhaust temperature, nitrogen oxides (NOx), and carbon dioxide (CO2) emissions and a serious decrease in HC, CO, brake-specific fuel consumption, and smoke opacity values. Studies should be expanded and enriched with different mixing ratios and usage patterns of boron-doped fuels in the future.

Numerical investigation on the smoke extraction performance through natural ventilation via board-coupled shaft in tunnel with multiple burial depth

Previous studies have discovered that board-coupled shaft (BCS) can eliminate the plug-holing phenomenon that usually occurs in the traditional shaft and could be applied in shallow-buried and deep-buried tunnels. However, the impact of tunnel burial depth on the smoke exhaust performance with BCS is unknown at present. To better understand this question, 42 simulations were conducted, and the effects of buried depths and board locations on the smoke extraction performance of BCS were investigated. The results indicated that: (a) when the buried depth of the tunnel is large enough (≥10 m) that a plug-holing phenomenon occurs, the overall performance of BCS is better than that of the traditional shaft; (b) the smoke extraction performance of the BCS is controlled by both the buried depth of tunnels and the board locations when the shaft height is lower than 10 m, but mainly dominated by the board position when the shaft height is larger than 30 m; (c) the BCS can achieve a maximum 65.5% improvement in smoke extraction performance over the traditional shaft when the shaft height is 10 m. Besides that, a semi-empirical equation was developed to predict the correlation between non-dimensional volume flow rate and buried depth. These studies can guide extending the application scenarios of shafts and providing technical support.