Numerical Study of Emission Control of Rural Kitchen for Healthy Environment

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
M. Hamidur Rahman ◽  
A. K. M. Sadrul Islam ◽  
M. Ruhul Amin
Keyword(s):  
Environmental Protection Agency ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Ventilation System ◽  
Three Dimensional ◽  
Exhaust System ◽  
Health Concern ◽  
Healthy Environment ◽  
Wisconsin Department ◽  
Department Of Health

Abstract There is a major health concern for people who use biomass as a fuel for cooking in rural residential kitchens of developing countries. The quality of life is greatly affected due to exposure to exhaust flume. In this study, a typical single-burner conventional stove was used to model a rural kitchen. The overall dimension of the model kitchen is 3.50 m × 2.20 m × 1.85 m. A three-dimensional cfd code was adopted to perform steady-state simulations with appropriate boundary conditions. Numerical accuracy was tested for optimum grid as well. In this study, varying intensity of emissions of CO, CO2, and particulate matter (PM) from different kinds of biofuel burning have been investigated. Dispersions of these pollutants in the kitchen space have been investigated for with and without natural ventilation. The natural ventilation in turn has been investigated with and without hood systems. It has been observed that CO (95 PPM), CO2 (2200 PPM), and PM (750 µg/m3) concentration exceed by significant amount than the safe threshold (Wisconsin Department of Health Services, USA, and Environmental Protection Agency (EPA), USA) (CO ≤ 10 PPM, CO2 ≤ 1000 PPM, and PM ≤ 150 µg/m3) for no ventilation case. Even the natural ventilation condition through roof top chimney fails to keep the concentration below the safe limit. Only natural ventilation can reduce CO, CO2, and PM concentrations by 18%, 10%, and 65%, respectively. However, a significant improvement was observed under natural ventilation for the kitchen with the addition of a suction hood along with the roof top chimney. In this exhaust system, the reduction of CO, CO2, and PM10 are seen to be 68%, 55%, and 80%, respectively. Consequently, to overcome the long-term effect of exposure to all harmfull hazardous emissions, it is recommended for any rural kitchen to utilize efficient forced ventilation exhaust system if affordable or an advanced natural ventilation system as proposed in this study utilizing suction hood.

scholarly journals Three-Dimensional Simulation of Wind-Driven Ventilation Through a Windcatcher With Different Inlet Designs

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Peter Abdo ◽  
Rahil Taghipour ◽  
B. Phuoc Huynh
Keyword(s):  
Wind Speed ◽  
Average Velocity ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Cfd Modeling ◽  
Ansys Fluent ◽  
Wind Velocities ◽  
Dimensional Simulation ◽  
Convergent Inlet

Abstract Windcatcher is an effective natural ventilation system, and its performance depends on several factors including wind speed and wind direction. It provides a comfortable and healthy indoor environment since the introduced fresh air decreases the moisture content and reduces the pollutant concentration. Since the wind speed and its direction are generally unpredictable, it is important to use special inlet forms and exits to increase the efficiency of a windcatcher. In this study, computational fluid dynamics (CFD) modeling is implemented using ansys fluent to investigate the airflow entering a three-dimensional room through a windcatcher with different inlet designs. Three designs are studied which are a uniform inlet, a divergent inlet, and a bulging-convergent inlet. The airflow pattern with all inlets provided adequate ventilation through the room. With all the applied wind velocities (1, 2, 3, and 6 m/s) at the domain's inlet, the divergent inlet shape has captured the highest airflow through the room and provided higher average velocity at 1.2 m high enhancing the thermal comfort where most of the human occupancy occurs. With 6 m/s wind velocity, the divergent inlet has captured 2.55% more flow rate compared to the uniform inlet and 4.70% compared to the bulging-convergent inlet, and it has also provided an average velocity at 1.2 m high in the room of 7.16% higher than the uniform inlet and 8.44% higher than the bulging-convergent inlet.

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

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

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

Three Dimensional Simulation of Ventilation Flow Through a Solar Windcatcher

2019 ◽  
Author(s):  
Peter Abdo ◽  
Rahil Taghipour ◽  
B. P. Huynh
Keyword(s):  
Natural Ventilation ◽  
Air Flow ◽  
Ventilation System ◽  
Three Dimensional ◽  
Windward Side ◽  
Efficient Design ◽  
Indoor Space ◽  
Wind Speeds ◽  
Air Stream ◽  
Stack Ventilation

Abstract Natural ventilation is the process of supplying and removing air through an indoor space by natural means. There are two types of natural ventilation occurring in buildings: winddriven ventilation and buoyancy driven or stack ventilation. The most efficient design for natural ventilation in buildings should implement both types of natural ventilation. Stack ventilation which is temperature induced is driven by buoyancy making it less dependent on wind and its direction. Heat emitted causes a temperature difference between two adjoining volumes of air, the warmer air will have lower density and be more buoyant thus will rise above the cold air creating an upward air stream. Combining the wind driven and the buoyancy driven ventilation will be investigated in this study through the use of a windcatcher natural ventilation system. Stack driven air rises as it leaves the windcatcher and it is replaced with fresh air from outside as it enters through the positively pressured windward side. To achieve this, CFD (computational fluid dynamics) tool is used to simulate the air flow in a three dimensional room fitted with a windcatcher based on the winddriven ventilation alone, buoyancy driven ventilation alone, and combined buoyancy and winddriven ventilation. Different wind speeds between 0 up to 2.5 m/s are applied and the total air flow rate through the windcatcher is investigated with and without temperature of 350 K applied at the windcatcher’s outlet wall. As the wind speed increased the efficiency of the solar windcatcher decreased.

Numerical simulation of dispersion and distribution behaviors of hydrogen leakage in the garage with a crossbeam

SIMULATION ◽  
2019 ◽  
Vol 95 (12) ◽  
pp. 1229-1238 ◽  
Author(s):  
Yunhao Li ◽  
Juncheng Jiang ◽  
Yuan Yu ◽  
Qingwu Zhang
Keyword(s):  
Mole Fraction ◽  
Natural Ventilation ◽  
Stokes Equations ◽  
Ventilation System ◽  
Three Dimensional ◽  
Dynamics Simulation ◽  
Navier Stokes ◽  
Explosion Hazard ◽  
Safety Issues ◽  
Set Up

A three-dimensional computational fluid dynamics simulation model resolved by the unsteady Reynolds-Averaged Navier–Stokes equations was developed to predict hydrogen dispersion in an indoor environment. The effect of the height of the crossbeam (Hc) on hydrogen dispersion and distribution behaviors in a four-car garage was numerically investigated under fully confined and natural ventilation conditions. For the fully confined condition, the garage was almost completely filled with a flammable hydrogen cloud at t=600 s. In addition, the volumetric ratio of the flammable region, thickness of the hydrogen stratification, and hydrogen mole fraction all increased as Hc increased. When two symmetric ventilation openings were set up, the volumetric ratio of the flammable region decreased by 50% at t=600 s. Moreover, Hc had evident influence on the vertical distribution of hydrogen mole fraction. In addition, there existed little explosion hazard under the height of 1.6 m. The results show that Hc was a non-negligible factor for the safety design of hydrogen in the garage and Hc=0.12 m was the optimal height of the crossbeam. Furthermore, the ventilation system in the present study cannot completely eliminate the risk of hydrogen explosion. The present risk assessment results can be useful to analyze safety issues in automotive applications of hydrogen.

Numerical Study of Carbon Dioxide Gas Emission From an Urban Residential Kitchen in Developing Countries

2012 ◽  
Author(s):  
M. Hamidur Rahman ◽  
A. K. M. Sadrul Islam ◽  
M. Ruhul Amin
Keyword(s):  
Carbon Dioxide ◽  
Developing Countries ◽  
Numerical Study ◽  
Three Dimensional ◽  
Oxygen Deficit ◽  
Health Concern ◽  
Breathing Zone ◽  
High Concentration ◽  
Gas Emission ◽  
Carbon Dioxide Gas

Lack of proper ventilation of exhaust fumes from gas fired stoves in residential kitchens is a major health concern for some populations. It could even cause destruction of property, reduced quality of life and lifespan. In this study, a typical kitchen having a standard dimension of 21.3 m × 24.3 m × 30.5 m was modeled with single open door exit. Two heat sources were used for modeling the kitchen that resembles the double burner gas stove of an urban residential kitchen in developing countries. Steady state simulations were performed using a three dimensional CFD code with appropriate boundary conditions. The present numerical method was validated by comparing with the experimental data reported by Posner et al. [1]. The comparison showed very reasonable agreement. A grid independence test was also performed to determine the optimum grid resolution reflecting the accuracy of the numerical solution. The results are presented for carbon dioxide gas emission from the stove exhaust and dispersion within the kitchen space. A comparative analysis between the ventilation (natural and forced) and no ventilation conditions is also reported in this study. The location of the breathing zone was at a height of 73 cm and at a distance of 33 cm from the center of the two burners. Very high concentration (above 5000 PPM) of carbon dioxide gas was observed at the plane passing the breathing zone. Exposure to this environment for longer time may cause serious health damage of the occupants [2]. As per Wisconsin Department of Health Services of USA [2], over 5,000 PPM exposures to CO2 lead to serious oxygen deficit resulting in permanent brain damage, coma and even death.

scholarly journals RESEARCH EFFICIENCY OF NATURAL VENTILATION SYSTEM OF APARTMENT BUILDING

2019 ◽  
Vol 4 (7) ◽  
pp. 49-56
Author(s):  
Ф. Абдразаков ◽  
Fyarid Abdrazakov ◽  
А. Поваров ◽  
Andrey Povarov
Keyword(s):  
Natural Ventilation ◽  
Ventilation System ◽  
Exhaust System ◽  
Field Studies ◽  
Apartment Building ◽  
Apartment House ◽  
Ventilation Ducts ◽  
Controlled Flow ◽  
Research Efficiency ◽  
Ventilation Systems

The analysis of existing research in the field of ventilation systems is performed and the current shortcomings of the ventilation systems of secondary apartment houses of series 114–85 are identified. The instability of the natural ventilation system of an apartment building characterized by variable air exchange and overturning ventilation in the ventilation ducts is demonstrated. Field studies of the natural ventilation system efficiency of an apartment house series 114–85 located in Saratov are carried out. According to the research results, the absence of traction and the presence of reverse traction in the exhaust ducts of the ventilation system are revealed. The initial reason for the lack of normal traction in the ventilation system associated with its calculation in the project of building a house series 114-85 for open mode operation is stablished. The increased tightness of windows and doors of apartments is determined, resulting in a reversed traction and the impossibility of uniform distribution of air vertically of the house, therefore installing only the exhaust system of the natural ventilation of an apartment building is inefficient. It is established that the ventilation channel in the kitchen is constantly working to extract air from the premises of the apartments, since the bathroom door is tightly closed that does not correspond to the normative indicators. The analysis of ventilation system on the example of three-bedroom apartments shows the need for additional supply devices for controlled flow of outside air into the premises of apartments. The use of supply wall valves of KIV-125 brand and window ventilation valves of Air Box Comfort brand is provided. A methodology of selection the modern, highly efficient energy saving models of turbo ventilators is presented, increasing traction in exhaust ventilation ducts at 40 % and independent of direction and wind gusts.

Numerical Study of Carbon Dioxide Gas Emission From an Urban Residential Kitchen in Developing Countries

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
M. Hamidur Rahman ◽  
A. K. M. Sadrul Islam ◽  
M. Ruhul Amin
Keyword(s):  
Carbon Dioxide ◽  
Developing Countries ◽  
Numerical Study ◽  
Three Dimensional ◽  
Oxygen Deficit ◽  
Health Concern ◽  
Breathing Zone ◽  
High Concentration ◽  
Gas Emission ◽  
Co2 Gas

Lack of proper ventilation of exhaust fumes from gas fired stoves in residential kitchens is a major health concern for some populations. It could even cause destruction of property, and reduce quality of life and lifespan. In this study, a typical kitchen having a standard dimension of 2.13 m × 2.43 m × 3.05 m was modeled with single open door exit. Two heat sources were used for modeling the kitchen that resembles the double burner gas stove of an urban residential kitchen in developing countries. Steady-state simulations were performed using a three-dimensional computational fluid dynamics (cfd) code with appropriate boundary conditions. The present numerical method was validated by comparing with the experimental data reported by Posner et al. (2003, “Measurement and Prediction of Indoor Air Flow in a Model Room,” J. Energy Build., 35(5), pp. 515–526). The comparison showed very reasonable agreement. A grid independence test was also performed to determine the optimum grid resolution reflecting the accuracy of the numerical solution. The results are presented for carbon dioxide (CO2) gas emission from the stove exhaust and dispersion within the kitchen space. A comparative analysis between the ventilation (natural and forced) and no ventilation conditions is also reported in this study. The location of the breathing zone was at a height of 73 cm and at a distance of 33 cm from the center of the two burners. Very high concentration (above 5000 ppm) of CO2 gas was observed at the plane passing the breathing zone. Exposure to this environment for longer time may cause serious health damage of the occupants (http://www.dhs.wisconsin.gov/eh/chemfs/fs/carbondioxide.htm). As per the Wisconsin Department of Health Services of USA, over 5000 ppm exposures to CO2 lead to serious oxygen deficit resulting in permanent brain damage, coma, and even death.

scholarly journals Sustainable Smoke Extraction System for Atrium: A Numerical Study

2021 ◽  
Vol 13 (13) ◽  
pp. 7406
Author(s):  
Martin Lyubomirov Ivanov ◽  
Wei Peng ◽  
Qi Wang ◽  
Wan Ki Chow
Keyword(s):  
Mechanical Ventilation ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Ventilation System ◽  
High Heat ◽  
Fire Dynamics ◽  
Sustainable Environment ◽  
Design Fire ◽  
Smoke Layer ◽  
Computational Fluid Dynamics Cfd

Smoke extraction systems, either static with natural ventilation, or dynamic with mechanical ventilation are required to keep smoke layer at high levels in many tall atria. It is observed that a design fire with high heat release rate (HRR) is commonly used for designing natural vents, but a low HRR is used for mechanical ventilation system. This will not produce a sustainable environment. There are no internationally agreed on design guides to determine the HRR in the design fire for different extraction systems and scenarios. This issue will be studied using a Computational Fluid Dynamics (CFD)-based software, the Fire Dynamics Simulator (FDS) version 6.7.1. Simulations on natural smoke filling, static and dynamic smoke extractions were carried out in a big example atrium. CFD-FDS predictions were compared with previous full-scale burning tests. Results confirmed that static smoke extraction is a good option for big fires, and a dynamic system is best for small fires. A sustainable new hybrid design combining the advantages of static and dynamic systems is proposed, which could result in a lower smoke temperature and higher smoke layer interface height, indicating a better extraction design.

scholarly journals The Influence of Ventilation Arrangement on the Mechanism of Dust Distribution in Woxi Pithead

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Zhiyong Zhou ◽  
Pei Hu ◽  
Chongchong Qi ◽  
Tianpei Niu ◽  
Ming Li ◽  
...  
Keyword(s):  
Numerical Study ◽  
Numerical Models ◽  
Ventilation System ◽  
Three Dimensional ◽  
Sensitivity Study ◽  
Concentration Data ◽  
Two Phase ◽  
Air Volume ◽  
Working Face ◽  
Dust Distribution

Suppressing and removing mine dust from the working face is an important task for underground mines worldwide. In this paper, a numerical study was carried out to investigate the influence of ventilation arrangement on the mechanism of dust distribution. The Woxi Pithead of Hunan Chenzhou Mining Co., Ltd, China, was used as a case study, which adopted a widely used far-pressing-near-absorption (FPNA) ventilation system. Based on the theory of gas-solid two-phase flow, the program ANSYS Fluent was utilized, and the three-dimensional airflow migration and dust diffusion numerical models were simulated. The established computational fluid dynamics (CFD) models were validated using the airflow velocity data and the dust concentration data monitored at different positions from the operating coal mine. A comprehensive sensitivity study was conducted to investigate the influence of four parameters on dust suppression, including the distance of pressure air duct outlet from working face (Lp-outlet), the distance of exhaust air duct inlet from working face (Le-inlet), the ratio of pressing air volume to lab sorption air volume (K), and the installation height of the air duct (H). The optimum ventilation layout parameters were obtained through the simulation of the wind field and dust behaviour. The results show that there were four regions during the airflow field, namely, the jet zone, the recirculation zone, the vortex zone, and the mixing zone of pressure and exhaust airflow. All four parameters were found to have an important influence on the mass concentration of dust, and the optimum ventilation layout parameters were determined to be Lp-outlet = 18 m, Le-inlet = 3 m, K = 1.2, and H = 1.6 m.

EXPERIMENTAL AND NUMERICAL STUDY OF THREE-DIMENSIONAL NATURAL CONVECTION AND FREEZING IN WATER

1994 ◽  
Author(s):  
C. Abegg ◽  
Graham de Vahl Davis ◽  
W.J. Hiller ◽  
St. Koch ◽  
Tomasz A. Kowalewski ◽  
...  
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Three Dimensional
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