It is necessary to reduce hydrogen consumption to meet increasingly strict environmental and product-quality regulations for refinery plants. In this paper, the concentration potential concepts proposed for design of ...It is necessary to reduce hydrogen consumption to meet increasingly strict environmental and product-quality regulations for refinery plants. In this paper, the concentration potential concepts proposed for design of water-using networks are extended to synthesis of hydrogen networks with multiple contaminants. In the design procedure, the precedence of processes is determined by the values of concentration potential of demands.The usage of complementary source pair(s) to reduce utility consumption is investigated. Three case studies are presented to illustrate the effectiveness of the method. It is shown that the design procedure has clear engineering meaning.展开更多
A new trough imaging solar collector with multiple compounding curved surfaces has been designed. Its working principle and design parameters have been introduced. The experimental curve of temperature rising of the s...A new trough imaging solar collector with multiple compounding curved surfaces has been designed. Its working principle and design parameters have been introduced. The experimental curve of temperature rising of the system with time under the real weather has been given. The system efficiency and the relation between efficiency and temperature have been calculated. The test result shows that the system has the advantages of high collecting temperature and not obvious variety of the collecting efficiency with the operating temperature. Therefore, this collector is a quite ideal medium temperature solar collector.展开更多
Air-coupled ultrasonic transducers(ACUTs)have been applied in industrial non-destructive testing,structural health monitoring,and medical ultrasound.However,conventional passive focusing methods often result in undesi...Air-coupled ultrasonic transducers(ACUTs)have been applied in industrial non-destructive testing,structural health monitoring,and medical ultrasound.However,conventional passive focusing methods often result in undesired effects on sensitivity due to variations in acoustic impedance matching conditions,which are critical in ACUT design,where sensitivity is the top priority.Accordingly,a novel active focusing method for ACUTs is proposed in this study.The key idea is to create multiple concentric ring electrode patterns on a bulk planar piezoelectric plate so that a quarter-wavelength acoustic impedance matching layer of uniform thickness can be attached onto the plate.The initial structural parameters of the electrode patterns are determined based on the design methodology of a Fresnel zone plate(FZP).Those parameters are optimized through finite element simulation,with the transducer’s sensitivity as the objective function,while ensuring only slight variations to the focal length and lateral resolution.Single-sided multiple concentric ring electrode patterns are then fabricated on 1-3 piezoelectric fiber/epoxy resin composite plate by screen printing and combined with a high-performance acoustic impedance matching layer made from epoxy resin composite filled with hollow glass microspheres.The planar active focusing ACUT is developed,while two types of conventional passive focusing ACUTs using FZP and concave lens are fabricated with the same piezoelectric and acoustic matching materials.Comparative experimental testing is carried out.The developed planar active-focusing ACUT achieves significant sensitivity improvements of 7.1 and 17.4dB,respectively,while maintaining comparable radial and axial full-width at half maximum.The results of this study offer a novel approach for the design of high-performance ACUTs.展开更多
基金Supported by the National Natural Science Foundation of China(21176057)the National Basic Research Program of China(2012CB720305)the State Key Laboratory of Chemical Engineering(Open Research Project Skloche-K-2011-04)
文摘It is necessary to reduce hydrogen consumption to meet increasingly strict environmental and product-quality regulations for refinery plants. In this paper, the concentration potential concepts proposed for design of water-using networks are extended to synthesis of hydrogen networks with multiple contaminants. In the design procedure, the precedence of processes is determined by the values of concentration potential of demands.The usage of complementary source pair(s) to reduce utility consumption is investigated. Three case studies are presented to illustrate the effectiveness of the method. It is shown that the design procedure has clear engineering meaning.
基金Acknowledgments This work is supported by the National Natural Science Foundation of China （No.50576004） and National ＂863＂ Hi-Tech Development Program of China （No.2007AA05Z433）.
文摘A new trough imaging solar collector with multiple compounding curved surfaces has been designed. Its working principle and design parameters have been introduced. The experimental curve of temperature rising of the system with time under the real weather has been given. The system efficiency and the relation between efficiency and temperature have been calculated. The test result shows that the system has the advantages of high collecting temperature and not obvious variety of the collecting efficiency with the operating temperature. Therefore, this collector is a quite ideal medium temperature solar collector.
基金supported by the National Natural Science Foundation of China(Grant No.52205564)the Foundation of Natural Science Foundation of Hubei Province,China(Grant No.2022CFB898).
文摘Air-coupled ultrasonic transducers(ACUTs)have been applied in industrial non-destructive testing,structural health monitoring,and medical ultrasound.However,conventional passive focusing methods often result in undesired effects on sensitivity due to variations in acoustic impedance matching conditions,which are critical in ACUT design,where sensitivity is the top priority.Accordingly,a novel active focusing method for ACUTs is proposed in this study.The key idea is to create multiple concentric ring electrode patterns on a bulk planar piezoelectric plate so that a quarter-wavelength acoustic impedance matching layer of uniform thickness can be attached onto the plate.The initial structural parameters of the electrode patterns are determined based on the design methodology of a Fresnel zone plate(FZP).Those parameters are optimized through finite element simulation,with the transducer’s sensitivity as the objective function,while ensuring only slight variations to the focal length and lateral resolution.Single-sided multiple concentric ring electrode patterns are then fabricated on 1-3 piezoelectric fiber/epoxy resin composite plate by screen printing and combined with a high-performance acoustic impedance matching layer made from epoxy resin composite filled with hollow glass microspheres.The planar active focusing ACUT is developed,while two types of conventional passive focusing ACUTs using FZP and concave lens are fabricated with the same piezoelectric and acoustic matching materials.Comparative experimental testing is carried out.The developed planar active-focusing ACUT achieves significant sensitivity improvements of 7.1 and 17.4dB,respectively,while maintaining comparable radial and axial full-width at half maximum.The results of this study offer a novel approach for the design of high-performance ACUTs.
