In large mines,single fan is usually not enough to ventilate all the working areas.Single mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantit...In large mines,single fan is usually not enough to ventilate all the working areas.Single mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantities associated with each fan in the network.Accordingly,each fan in a multiple-fan system has its own mine characteristic curve,or a subsystem curve.Under some consideration,the conventional concept of a mine characteristic curve of a single-fan system can be directly extended to that of a particular fan within a multiple-fan system.In this paper the mutual effect of the fans on each other and their effect on the stability of the ventilation network were investigated by Hardy Cross algorithm combined with a switching-parameters technique.To show the validity and reliability of this algorithm,the stability of the ventilation system of Abu-Tartur Mine(one of the largest underground mine in Egypt)has been studied.展开更多
Natural ventilation is recognized for improving the thermal comfort of the built environment and indoor air quality.It provides comfortable conditions for building occupants and reduces energy consumption for air-cond...Natural ventilation is recognized for improving the thermal comfort of the built environment and indoor air quality.It provides comfortable conditions for building occupants and reduces energy consumption for air-conditioning.Therefore,it is important to study and explore effective means of ventilation to improve the building designs.This study investigates the thermal comfort of a naturally ventilated hostel operational building in the composite climate of Jaipur,India using Computational Fluid Dynamics(CFD)simulation tool‘Cradle scSTREAM’.A 3D building model has been developed to analyze the thermal comfort for different natural ventilation strategies with advanced mesh algorithms which generate fewer mesh elements and maintain good mesh quality.A field study was carried out to collect the actual data and to validate the model which was further used to evaluate the thermal comfort range based on the ASHRAE-55 standard.Several design strategies have been applied to enhance thermal comfort.It was found that an increase in air velocity up to 0.5 m/s was achieved by Cross Ventilation while a drop of 2.0-2.5℃in the air temperature was found using Night Ventilation.It can be stated that cross ventilation increases the air movement while night ventilation gives comparatively higher comfort regarding air temperature and relative humidity.展开更多
文摘In large mines,single fan is usually not enough to ventilate all the working areas.Single mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantities associated with each fan in the network.Accordingly,each fan in a multiple-fan system has its own mine characteristic curve,or a subsystem curve.Under some consideration,the conventional concept of a mine characteristic curve of a single-fan system can be directly extended to that of a particular fan within a multiple-fan system.In this paper the mutual effect of the fans on each other and their effect on the stability of the ventilation network were investigated by Hardy Cross algorithm combined with a switching-parameters technique.To show the validity and reliability of this algorithm,the stability of the ventilation system of Abu-Tartur Mine(one of the largest underground mine in Egypt)has been studied.
文摘Natural ventilation is recognized for improving the thermal comfort of the built environment and indoor air quality.It provides comfortable conditions for building occupants and reduces energy consumption for air-conditioning.Therefore,it is important to study and explore effective means of ventilation to improve the building designs.This study investigates the thermal comfort of a naturally ventilated hostel operational building in the composite climate of Jaipur,India using Computational Fluid Dynamics(CFD)simulation tool‘Cradle scSTREAM’.A 3D building model has been developed to analyze the thermal comfort for different natural ventilation strategies with advanced mesh algorithms which generate fewer mesh elements and maintain good mesh quality.A field study was carried out to collect the actual data and to validate the model which was further used to evaluate the thermal comfort range based on the ASHRAE-55 standard.Several design strategies have been applied to enhance thermal comfort.It was found that an increase in air velocity up to 0.5 m/s was achieved by Cross Ventilation while a drop of 2.0-2.5℃in the air temperature was found using Night Ventilation.It can be stated that cross ventilation increases the air movement while night ventilation gives comparatively higher comfort regarding air temperature and relative humidity.
