NOx and soot emissions from diesel engines can be greatly reduced by pressure wave supercharging(PWS).The diesel engine matched with PWS needs redesigning its exhaust pipes.Except for meeting the installation requirem...NOx and soot emissions from diesel engines can be greatly reduced by pressure wave supercharging(PWS).The diesel engine matched with PWS needs redesigning its exhaust pipes.Except for meeting the installation requirements,the exhaust gas must be stable in pressure before rushing into PWS.In this paper the lateral and center ported divergent exhaust pipes are designed,modeled geometrically and analyzed structurally based on a 3-D design software-CATIA to determine the structure of two exhaust pipes having the required inner volume.Then flow analysis for two exhaust pipes is done using a flow analysis software-ANASYS.Moreover,the optimal exhaust pipes are determined comprehensively and cast for engine test.Engine test results show that PWS is superior to turbocharging at low engine speeds and inferior to turbocharging in power and emissions at medium-to-high engine speeds.The performance of PWS engine under high speed operating conditions can be improved by contriving larger surge volume intake and exhaust pipes.展开更多
With net zero carbon emissions targets approaching over the next 20 to 30 years, the water industry must act now to develop energy efficient techniques and designs to reduce emissions and reduce the carbon footprint o...With net zero carbon emissions targets approaching over the next 20 to 30 years, the water industry must act now to develop energy efficient techniques and designs to reduce emissions and reduce the carbon footprint of water utility providers. There is also the potential for significant energy and therefore financial savings to be realised from the adoption of more energy efficient designs approaches. Water utility providers account for a significant proportion of national electricity consumption. The purpose of this research is to determine if, over the long term, opting for a larger diameter pipe at design stage can lead to significant financial and emissions savings for water utility providers when considering pumping mains. Pumping mains are widely used throughout the water and wastewater industry where a gravity solution is not possible. 72 hypothetical water main design scenarios were analysed and the long term financial and environmental impact of each hypothetical water main was assessed. It was found across all design scenarios that larger diameter water mains were capable of delivering the same rate of flow of smaller diameter pipes at a much reduced velocity and requiring reduced pumping power. It was concluded that pumped mains of larger diameters can ultimately be more energy efficient and cost effective over the long term when selected in favour of smaller diameter pumped mains in otherwise identical design scenarios.展开更多
An intelligent design software system for the power station pipe-prefabrication (PPDS) has been developed in the paper,which is taking pipe material database as core and developed on the platform of AutoCAD and Borlan...An intelligent design software system for the power station pipe-prefabrication (PPDS) has been developed in the paper,which is taking pipe material database as core and developed on the platform of AutoCAD and Borland C++. Whereas design and construction of power plants in China belong to different deportments,the input and recognition problem of pipeline system disposition chart must be solved firstly for the prefabrication design.Based on AI technology,the model fast building subsystem (MFBS) was established for entering the 3-D pipeline graph data,so that the problems of reconstruction of pipeline digital model and computer identification of original 2-D design data can be solved. The optimization design scheme in the pipe-prefabrication process has been studied and also the corresponding algorithm put forward.The technique and system mentioned can effectively raise the pipe-prefabrication design quality and efficiency in the con- struction of large scale power plants,reduce the period of design and the waste of raw material.PPCADS has still offered the functions such as the construction design for pipeline prefabricated process,the detailing drawing for manufacturing pipe section and automatic generating the technical files for the completed project.展开更多
文摘NOx and soot emissions from diesel engines can be greatly reduced by pressure wave supercharging(PWS).The diesel engine matched with PWS needs redesigning its exhaust pipes.Except for meeting the installation requirements,the exhaust gas must be stable in pressure before rushing into PWS.In this paper the lateral and center ported divergent exhaust pipes are designed,modeled geometrically and analyzed structurally based on a 3-D design software-CATIA to determine the structure of two exhaust pipes having the required inner volume.Then flow analysis for two exhaust pipes is done using a flow analysis software-ANASYS.Moreover,the optimal exhaust pipes are determined comprehensively and cast for engine test.Engine test results show that PWS is superior to turbocharging at low engine speeds and inferior to turbocharging in power and emissions at medium-to-high engine speeds.The performance of PWS engine under high speed operating conditions can be improved by contriving larger surge volume intake and exhaust pipes.
文摘With net zero carbon emissions targets approaching over the next 20 to 30 years, the water industry must act now to develop energy efficient techniques and designs to reduce emissions and reduce the carbon footprint of water utility providers. There is also the potential for significant energy and therefore financial savings to be realised from the adoption of more energy efficient designs approaches. Water utility providers account for a significant proportion of national electricity consumption. The purpose of this research is to determine if, over the long term, opting for a larger diameter pipe at design stage can lead to significant financial and emissions savings for water utility providers when considering pumping mains. Pumping mains are widely used throughout the water and wastewater industry where a gravity solution is not possible. 72 hypothetical water main design scenarios were analysed and the long term financial and environmental impact of each hypothetical water main was assessed. It was found across all design scenarios that larger diameter water mains were capable of delivering the same rate of flow of smaller diameter pipes at a much reduced velocity and requiring reduced pumping power. It was concluded that pumped mains of larger diameters can ultimately be more energy efficient and cost effective over the long term when selected in favour of smaller diameter pumped mains in otherwise identical design scenarios.
文摘An intelligent design software system for the power station pipe-prefabrication (PPDS) has been developed in the paper,which is taking pipe material database as core and developed on the platform of AutoCAD and Borland C++. Whereas design and construction of power plants in China belong to different deportments,the input and recognition problem of pipeline system disposition chart must be solved firstly for the prefabrication design.Based on AI technology,the model fast building subsystem (MFBS) was established for entering the 3-D pipeline graph data,so that the problems of reconstruction of pipeline digital model and computer identification of original 2-D design data can be solved. The optimization design scheme in the pipe-prefabrication process has been studied and also the corresponding algorithm put forward.The technique and system mentioned can effectively raise the pipe-prefabrication design quality and efficiency in the con- struction of large scale power plants,reduce the period of design and the waste of raw material.PPCADS has still offered the functions such as the construction design for pipeline prefabricated process,the detailing drawing for manufacturing pipe section and automatic generating the technical files for the completed project.
