Air pollution from bus exhaust （one of main sources of urban haze） in Shantou City, Guangdong Province was surveyed, and the purification effect of a new device for removing soot particulates from bus exhaust was an...Air pollution from bus exhaust （one of main sources of urban haze） in Shantou City, Guangdong Province was surveyed, and the purification effect of a new device for removing soot particulates from bus exhaust was analyzed. The results show that the smoke intensity of all buses surveyed averages 3.59 m-1, exceeding the limit, and the maximum is 5.7 times higher than the limit. Among the buses inspected, the smoke intensity of 37% of buses is not up to standard. The removal rate of soot particulates from various buses equipped with the purification devJce averages 63.6%, and some buses are up to standard after their exhaust are purified, showing that the device has good purification effect. Therefore, installing the purification device in a bus is an effective way to control air pollution from bus exhaust and haze in a city.展开更多
The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation （EGR）, thermal reactor and catalytic conver...The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation （EGR）, thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite （S.I.） engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.展开更多
It is presented that eliminating and controlling the current automotive exhaust emission should be important and urgent in China, and the Chinese state emission standards have been getting stricter and stricter. Also ...It is presented that eliminating and controlling the current automotive exhaust emission should be important and urgent in China, and the Chinese state emission standards have been getting stricter and stricter. Also the present purification technologies for automotive exhaust are elucidated. It is indicated that the development and the commercialization of Rare Earth based on three way catalytic converters is pretty necessary and urgent to address the current harsh automotive exhaust emission problems in China. In addition, the future automotive exhaust purification technologies are prospected.展开更多
The volumetric flow rate of smoke generated from the fire in large space often reaches to hundreds of thousands CMH because of extended floor height and as it’s more difficult to isolate the smoke to the limited area...The volumetric flow rate of smoke generated from the fire in large space often reaches to hundreds of thousands CMH because of extended floor height and as it’s more difficult to isolate the smoke to the limited area, comparing to normal-scale building, design and operation of effective smoke control system for large space is more than important. In this study, with the analysis model for such a large space as exhibition hall or conference room in conventional center, design of mechanical smoke exhaust system was conducted based on currently-available design standard which was then followed by numerical analysis of the design using 3D numerical analysis method. For conference room at 2.0 MW heat release rate, 99,173 CMH flow rate is required, if smoke layer is maintained at 60% of the floor height and for exhibition hall at 8.8 MW with 80% of floor height, flow rate required is 219,802 CMH, which are incorporated into the design. In view of 3D numerical analysis, accuracy of the design according to algebraic expression is sufficient.展开更多
A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and t...A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.展开更多
基金Supported by the Science and Technology Project of Shantou City([2013]96)
文摘Air pollution from bus exhaust （one of main sources of urban haze） in Shantou City, Guangdong Province was surveyed, and the purification effect of a new device for removing soot particulates from bus exhaust was analyzed. The results show that the smoke intensity of all buses surveyed averages 3.59 m-1, exceeding the limit, and the maximum is 5.7 times higher than the limit. Among the buses inspected, the smoke intensity of 37% of buses is not up to standard. The removal rate of soot particulates from various buses equipped with the purification devJce averages 63.6%, and some buses are up to standard after their exhaust are purified, showing that the device has good purification effect. Therefore, installing the purification device in a bus is an effective way to control air pollution from bus exhaust and haze in a city.
基金This project is supported by Provincial Natural Science Foundation of Guangdong, China and Provincial Environmental Protection Science Foundation of Guangdong, China(No.320-D38000).
文摘The working principle of a kind of compositive emission control system is inquired into, which includes exhaust heater, secondary air supplement, exhaust gas recirculation （EGR）, thermal reactor and catalytic converter, etc. The purification effect of CO, HC and NOx emission of the gasoline spark ignite （S.I.） engine is studied. The entire vehicle driving cycle tests based on the national emission standard and a series of the gasoline engine-testing bench tests including full load characteristic experiment, load characteristic experiment and idle speed experiment are done. The results show that the system has a very good emission control effect to CO, HC and NOx of gasoline engine. The construction of the system is very simple and can be mounted on the exhaust pipe conveniently without any alteration of the vehicle-use gasoline engine.
文摘It is presented that eliminating and controlling the current automotive exhaust emission should be important and urgent in China, and the Chinese state emission standards have been getting stricter and stricter. Also the present purification technologies for automotive exhaust are elucidated. It is indicated that the development and the commercialization of Rare Earth based on three way catalytic converters is pretty necessary and urgent to address the current harsh automotive exhaust emission problems in China. In addition, the future automotive exhaust purification technologies are prospected.
文摘The volumetric flow rate of smoke generated from the fire in large space often reaches to hundreds of thousands CMH because of extended floor height and as it’s more difficult to isolate the smoke to the limited area, comparing to normal-scale building, design and operation of effective smoke control system for large space is more than important. In this study, with the analysis model for such a large space as exhibition hall or conference room in conventional center, design of mechanical smoke exhaust system was conducted based on currently-available design standard which was then followed by numerical analysis of the design using 3D numerical analysis method. For conference room at 2.0 MW heat release rate, 99,173 CMH flow rate is required, if smoke layer is maintained at 60% of the floor height and for exhibition hall at 8.8 MW with 80% of floor height, flow rate required is 219,802 CMH, which are incorporated into the design. In view of 3D numerical analysis, accuracy of the design according to algebraic expression is sufficient.
基金Supported by Diesel Engine Development Program of MIIT(DEDP-1004)Natural Science Foundation of BIT(3030012211428)
文摘A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.
