The physical performance of recycled asphalt was used as the main evaluation index to study the optimal range of a self-made rejuvenator.Through the penetration,viscosity and gel permeation chromatography(GPC)tests,th...The physical performance of recycled asphalt was used as the main evaluation index to study the optimal range of a self-made rejuvenator.Through the penetration,viscosity and gel permeation chromatography(GPC)tests,the diffusion degree of the rejuvenator under different temperatures and time process was analyzed,and the diffusion efficiency of the rejuvenator was evaluated from the macro and micro perspective.The regeneration mechanism of the rejuvenator in the aged asphalt was also analyzed using the Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and chemical composition tests.The research results showed that the optimum rejuvenator content was about 3%.Higher temperature and longer time were beneficial to improving the permeability and diffusion of the rejuvenator.During the aging process,the light components were reduced,and more macromolecular asphaltenes were generated as well as a large number of carbonyl and sulfoxide.After diffusion and regeneration,the light components in the asphalt were supplemented,the wrinkles and gullies of the aged asphalt were almost improved to the surface state of the matrix asphalt.展开更多
China has a large solid waste stockpile and a low resource utilisation rate,and the utilisation of solid waste resources is of great significance in promoting sustainable social development.In order to further promote...China has a large solid waste stockpile and a low resource utilisation rate,and the utilisation of solid waste resources is of great significance in promoting sustainable social development.In order to further promote the green and efficient development of China's road field,an overview of the current status of the application,research progress,hot frontiers,problems and their countermeasures based on the three aspects of industrial solid wastes,engineering solid wastes and municipal solid wastes in highway engineering was conducted,and the development prospect of the resourceful utilisation of solid waste in highway engineering was outlooked,with a view to promoting the development of China's green roads.Statistics on the stockpile,utilisation and comprehensive utilisation rate of industrial solid wastes in China are presented,and the optimal mixing amount,production process and application technology of industrial solid wastes for road base materials are systematically summarised.Based on the concept of high-value utilisation of solid waste,the mechanical properties,durability,construction technology and quality control standards of engineering solid waste applied in roadbed engineering are summarised,and the difficulties in the application of engineering solid waste in road engineering are summarised.Finally,the feasibility,mechanical properties and environmental characteristics of municipal solid waste domestic waste incinerator slag,waste tyres and plastics applied in road engineering are summarised.This review can provide references and lessons for the design and development of green roads,and promote the innovation and development of greening road engineering.展开更多
Utilizing oil extracted from waste engine oil and waste plastics, by pyrolysis, as a filel for internal combustion engines has been demonstrated to be one of the best available waste management methods. Separate blend...Utilizing oil extracted from waste engine oil and waste plastics, by pyrolysis, as a filel for internal combustion engines has been demonstrated to be one of the best available waste management methods. Separate blends of fuel from waste engine oil and waste plastic oil was prepared by mixing with diesel and experimental investigation is conducted to study engine performance, combustion and exhaust emissions. It is observed that carbon monoxide （CO） emission increases by 50% for 50% waste plastic oil （50WPO：50D） and by 58% for 50% waste engine oil （50WEO：50D） at full load as compared to diesel. Unburnt hydrocarbon （HC） emission increases by 16% for 50WPO：50D and by 32% for 50WEO：50D as compared to diesel at maximum load. Smoke is fotmd to decrease at all loading conditions for 50WPO：50D operation, but it is comparatively higher for 50WEO：50D operation. 50WPO：50D operation shows higher brake thermal efficiency for all loads as compared to 50WEO：50D and diesel fuel operation. Exhaust gas temperature is higher at all loads tbr 50WPO：50D and 50WEO：50D as compared to diesel fuel operation.展开更多
Employing a CO_(2)power generation system to recover waste heat from engines can reduce fuel consumption and CO_(2)emissions by producing additional electric power.Nevertheless,the fluctuation in engine operating cond...Employing a CO_(2)power generation system to recover waste heat from engines can reduce fuel consumption and CO_(2)emissions by producing additional electric power.Nevertheless,the fluctuation in engine operating conditions would cause variations in waste heat sources and affect system performances largely.Hence,an experimental performance test at various engine conditions was implemented by the construction of a small-scale(10 kW)CO_(2)power generation system.Key components,including the turbine expander and printed circuit heat exchanger,were specifically designed and constructed.The steady-state and transient performances of critical components and the integrated system were carried out.Experimental results of the turbine expander at varying engine conditions revealed the potential for long-term and stable operation under dynamic mass flow rate,inlet temperature,and pressure ratio.The maximum total generation power and efficiency reached 11.55 kW and 58.92%.The printed circuit heat exchanger used to exploit engine exhaust gas showed satisfactory performances in balancing the trade-off between heat transfer and pressure drop.The total pressure drop of engine exhaust gas was lower than 4 kPa determined by both exhaust mass flow and temperature,considering all the variable engine conditions.Despite that a performance penalty was observed at the off-design operation of the integrated system because of the decrease in the waste heat input,the maximum net power and thermal efficiency reached 10.57 kW and 6.59%,respectively,at the engine condition of 1100 rpm,1200 N m,with a relative improvement of 6.3%in engine brake thermal efficiency.展开更多
基金Funded by the Science and Technology Project of Henan Department of Transportation(No.2020J-2-3)Shaanxi Transportation Science and Technology Project(Nos.17-05K,19-10K,19-28K)。
文摘The physical performance of recycled asphalt was used as the main evaluation index to study the optimal range of a self-made rejuvenator.Through the penetration,viscosity and gel permeation chromatography(GPC)tests,the diffusion degree of the rejuvenator under different temperatures and time process was analyzed,and the diffusion efficiency of the rejuvenator was evaluated from the macro and micro perspective.The regeneration mechanism of the rejuvenator in the aged asphalt was also analyzed using the Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and chemical composition tests.The research results showed that the optimum rejuvenator content was about 3%.Higher temperature and longer time were beneficial to improving the permeability and diffusion of the rejuvenator.During the aging process,the light components were reduced,and more macromolecular asphaltenes were generated as well as a large number of carbonyl and sulfoxide.After diffusion and regeneration,the light components in the asphalt were supplemented,the wrinkles and gullies of the aged asphalt were almost improved to the surface state of the matrix asphalt.
文摘China has a large solid waste stockpile and a low resource utilisation rate,and the utilisation of solid waste resources is of great significance in promoting sustainable social development.In order to further promote the green and efficient development of China's road field,an overview of the current status of the application,research progress,hot frontiers,problems and their countermeasures based on the three aspects of industrial solid wastes,engineering solid wastes and municipal solid wastes in highway engineering was conducted,and the development prospect of the resourceful utilisation of solid waste in highway engineering was outlooked,with a view to promoting the development of China's green roads.Statistics on the stockpile,utilisation and comprehensive utilisation rate of industrial solid wastes in China are presented,and the optimal mixing amount,production process and application technology of industrial solid wastes for road base materials are systematically summarised.Based on the concept of high-value utilisation of solid waste,the mechanical properties,durability,construction technology and quality control standards of engineering solid waste applied in roadbed engineering are summarised,and the difficulties in the application of engineering solid waste in road engineering are summarised.Finally,the feasibility,mechanical properties and environmental characteristics of municipal solid waste domestic waste incinerator slag,waste tyres and plastics applied in road engineering are summarised.This review can provide references and lessons for the design and development of green roads,and promote the innovation and development of greening road engineering.
文摘Utilizing oil extracted from waste engine oil and waste plastics, by pyrolysis, as a filel for internal combustion engines has been demonstrated to be one of the best available waste management methods. Separate blends of fuel from waste engine oil and waste plastic oil was prepared by mixing with diesel and experimental investigation is conducted to study engine performance, combustion and exhaust emissions. It is observed that carbon monoxide （CO） emission increases by 50% for 50% waste plastic oil （50WPO：50D） and by 58% for 50% waste engine oil （50WEO：50D） at full load as compared to diesel. Unburnt hydrocarbon （HC） emission increases by 16% for 50WPO：50D and by 32% for 50WEO：50D as compared to diesel at maximum load. Smoke is fotmd to decrease at all loading conditions for 50WPO：50D operation, but it is comparatively higher for 50WEO：50D operation. 50WPO：50D operation shows higher brake thermal efficiency for all loads as compared to 50WEO：50D and diesel fuel operation. Exhaust gas temperature is higher at all loads tbr 50WPO：50D and 50WEO：50D as compared to diesel fuel operation.
文摘Employing a CO_(2)power generation system to recover waste heat from engines can reduce fuel consumption and CO_(2)emissions by producing additional electric power.Nevertheless,the fluctuation in engine operating conditions would cause variations in waste heat sources and affect system performances largely.Hence,an experimental performance test at various engine conditions was implemented by the construction of a small-scale(10 kW)CO_(2)power generation system.Key components,including the turbine expander and printed circuit heat exchanger,were specifically designed and constructed.The steady-state and transient performances of critical components and the integrated system were carried out.Experimental results of the turbine expander at varying engine conditions revealed the potential for long-term and stable operation under dynamic mass flow rate,inlet temperature,and pressure ratio.The maximum total generation power and efficiency reached 11.55 kW and 58.92%.The printed circuit heat exchanger used to exploit engine exhaust gas showed satisfactory performances in balancing the trade-off between heat transfer and pressure drop.The total pressure drop of engine exhaust gas was lower than 4 kPa determined by both exhaust mass flow and temperature,considering all the variable engine conditions.Despite that a performance penalty was observed at the off-design operation of the integrated system because of the decrease in the waste heat input,the maximum net power and thermal efficiency reached 10.57 kW and 6.59%,respectively,at the engine condition of 1100 rpm,1200 N m,with a relative improvement of 6.3%in engine brake thermal efficiency.
