جستجوی مقالات مرتبط با کلیدواژه « pollution dispersion » در نشریات گروه « مکانیک »

The CO concentration is an important parameter for design of ventilation systems in enclosed parking lots. By using the initial estimation of CO concentration and investigating the CO removal effectiveness, the ventilation system with low energy consumption and high indoor air quality could be designed. In this paper, by using the principle of mass conservation and the definition of CO removal effectiveness, an analytical relation for estimation of CO concentration is obtained. This relation is estimate the variation of CO with time by using the main functional parameters of parking lot. In spite to the physics of flow, the increasing of air quality is obtained by reducing the idle cars and the mass flow rate of CO exhausted from this cars and increasing the parking lot volume and the ventilation flow. This trend is consistent with the proposed relation of this paper and so the results of this paper could be used as the criteria for estimation of CO concentration and enhancement of ventilation system design. The comparison between results of the proposed relation and experimental and numerical results are represents good accuracy of proposed relation. Furthermore, the amount of energy reduction by enhancing the flow pattern is expressed by using the proposed relation of this paper. In the last section, the approach of different standards is expressed and the modifying suggestions for enhancement of them are expressed.

By using the initial estimation of CO concentration in enclosed parking lots, the designer could design a ventilation system with assurance of producing good air quality. In this paper, the practical correlation of CO increasing due to cars and time in enclosed parking lots is proposed. The proposed model is represents the variation of CO concentration in parking lot according to functional parameters. In addition to air flow ventilation, the effect of CO removal effectiveness on the air quality of enclosed parking lots is expressed in the proposed relation.

The intense increasing of pollutions from cars in the enclosed residential parking lots is an important challenge. Forecast and estimate of generated pollution from cars is applicable for proper design of residential car parks. In this article, the pollution concentration in a residential parking lot is measured experimentally and the results are used for validation of numerical solution. In the second part, the pollutions are simulated in several parking lots and the equation of pollution incensement with time is proposed and offered in the form of analytical equation. By using this equation, the allowable time of man’s presence in these parking lots is offered.

The management of air quality in enclosed parking lots has many challenges such as increasing pollution concentration and pollution movement between floors. In this article, the complete calculation of ventilation system in multilevel parking lots is presented and the effect of supply and exhaust vents height on pollution concentration and movement is investigated by using numerical simulation. Also a new criterion for recognition of flow pattern is presented. In the numerical simulation, the conservation equations are solved by using openFoam. For validating the numerical simulation, the results are compared with available experimental results. The comparison of results is showed good accuracy of numerical simulation. After that, the common multilevel parking lots are introduced and the effect of supply and exhaust vent heights on the amount of pollution in these parking lots are investigated. The results showed that, if the supply vents are installed on the non-dimensional heights of about 0.55 and exhaust vents are installed on the non-dimensional heights of about 0.55 to 0.7, the best ventilation flow pattern in the multilevel parking lots is obtained. Furthermore, by using the novel method of this paper, the ideal bulk flow velocity for development of piston flow in parking lot is obtained and the flow pattern is tend to piston flow by optimizing the supply and exhaust vent heights.

The correct placement of supply air inlets and pollution extraction outlets play an important role in increasing indoor air quality and reducing the amount of pollution in enclosed car parks. In this paper the effect of exhaust locations, exhaust height and parking dimensions on indoor air quality of car park is investigated with numerical simulation. For this purpose conservation equations are solved with openFoam. For validation, air flow and pollution is simulated in a simple car park and compared with experimental results. In the next section, the effect of exhaust vent locations on increasing indoor air quality is investigated and is compared with other solutions. The result of numerical simulation indicates that, if inlets and exhausts are located in end sides of car park and if exhaust vent locations are in the optimized height, the indoor air quality in the car park is increased.in this paper, the graph of CO concentration in different heights is explained and by using it, the optimum range for exhaust vent locations is proposed. Moreover the standard criteria for using jet fans is expressed and the results showed that, for ventilation of car parks with length more than criterion, jet fans should be used.