A numerical case study on identifying the optimum number of buckets for a Pelton turbine is presented. Three parameters： number of buckets, bucket radial position and bucket angular position are grouped since they ar...A numerical case study on identifying the optimum number of buckets for a Pelton turbine is presented. Three parameters： number of buckets, bucket radial position and bucket angular position are grouped since they are found to be interrelated. By identifying the best combination of the radial and angular position for each number of buckets it is shown that reduction in the number of buckets beyond the limit suggested by the available literature can improve the efficiency and be beneficial with regard to the manufacturing complexity and cost perspective. The effect of this reduction in the number of buckets was confirmed experimentally.展开更多
The layout of the buckets for tunnel boring machine(TBM)directly affects the muck removal efficiency of cutterhead during excavation.In order to improve the muck removal performance for TBM,the optimal design of bucke...The layout of the buckets for tunnel boring machine(TBM)directly affects the muck removal efficiency of cutterhead during excavation.In order to improve the muck removal performance for TBM,the optimal design of bucket layout was investigated.The whole muck transfer process was simulated by discrete-element method(DEM),including the muck falling,colliding,pilling up,shoveling and transferring into the hopper.The muck model was established based on size distribution analysis of muck samples from the water-supply tunnel project in Jilin Province,China.Then,the influence of the bucket number and the interval angle between buckets on muck removal performance was investigated.The results indicated that,as the number of buckets increased from four to eight,the removed muck increased by 29%and the residual volume decreased by 40.5%,and the process became steadier.Different interval angles between buckets were corresponding to different removed muck irregularly,but the residual muck number increased generally with the angles.The optimal layout of buckets for the cutterhead in this tunnel project was obtained based on the simulation results,and the muck removal performance of the TBM was verified by the actual data in the engineering construction.展开更多
The concept of sustainable agricultural village was proposed in this study,and its major economic pattern was summarized as:with the sustainable agriculture,grain production and processing as core contents,to enhance ...The concept of sustainable agricultural village was proposed in this study,and its major economic pattern was summarized as:with the sustainable agriculture,grain production and processing as core contents,to enhance the attraction of agricultural regions and establish more effective connections between rural and urban areas by properly developing eco-agricultural sightseeing and organizing satellite sustainable agricultural villages into an urban peripheral network.Dajidian Sustainable Agricultural Village in Baoding City,Hebei Province was taken for an example to elaborate the overall design concepts,and analyze the strategies for planning the village as an integrated system,including social,ecological and economic dimensions,which are specifically demonstrated as:the development of sustainable agriculture,the establishment of diversified circulation system,the independence of energy utilization,the soundness of public service system,the improvement of agricultural villages as communities.Through studying the planning of sustainable agricultural villages,this research aimed at realizing the sustainable development of overall environment system in both cities and rural areas,and guiding the improvement of the new countryside construction.展开更多
A scheme with two superconducting RF cavities is designed to upgrade electron storage rings with odd buckets to multi-length bunches. In this paper, the Hefei Light Source（HLS） is given as an example for odd buckets...A scheme with two superconducting RF cavities is designed to upgrade electron storage rings with odd buckets to multi-length bunches. In this paper, the Hefei Light Source（HLS） is given as an example for odd buckets. As it is designed for 45 buckets, which is a multiple of 3, simultaneous generation of three different lengths of bunches is proposed with the presently applied user optics. The final result, without low-α optics, is to fill HLS with long bunches of length 50 ps, medium bunches of 23 ps and short bunches of 6 ps. Every third bucket can be filled with short bunches, of which the current limit is up to 6.6 m A, more than 60 times the limit for low-α mode.Moreover, particle tracking simulations to examine the beam dynamics, performed by ELEGANT, and calculations of the beam instabilities are presented in this paper.展开更多
为解决不确定性能源发电给配电网带来的隐患和经济性问题,研究含间歇分布式能源的虚拟电厂(virtual pow er plant,VPP)接入配电网的联合优化调度对提高系统安全和促进新能源消纳具有十分重要的意义。综合考虑风电及储能的运行特性,提出...为解决不确定性能源发电给配电网带来的隐患和经济性问题,研究含间歇分布式能源的虚拟电厂(virtual pow er plant,VPP)接入配电网的联合优化调度对提高系统安全和促进新能源消纳具有十分重要的意义。综合考虑风电及储能的运行特性,提出一种改进的Buckets方法,建立了考虑风电不确定性和含储能的虚拟电厂参与配电网调度的优化机组组合模型,基于6节点系统研究了改进的Buckets方法对发电成本和机组组合的影响。与传统Buckets方法相比,采用所提方法使得模型的发电成本及开机时段减少,表明该方法能够实现发电成本最优、风电的充分消纳以及储能的灵活运用。展开更多
基金the support of Lancaster University Renewable Energy Group and Fluid Machinery Group
文摘A numerical case study on identifying the optimum number of buckets for a Pelton turbine is presented. Three parameters： number of buckets, bucket radial position and bucket angular position are grouped since they are found to be interrelated. By identifying the best combination of the radial and angular position for each number of buckets it is shown that reduction in the number of buckets beyond the limit suggested by the available literature can improve the efficiency and be beneficial with regard to the manufacturing complexity and cost perspective. The effect of this reduction in the number of buckets was confirmed experimentally.
基金Project(51475478)supported by the National Natural Science Foundation of ChinaProject(2012AA041801)supported by the National High Technology Research and Development Program of China+1 种基金Project(2014FJ1002)supported by the Science and Technology Major Project of Hunan Province,ChinaProject(2013CB035401)supported by the National Basic Research Program of China。
文摘The layout of the buckets for tunnel boring machine(TBM)directly affects the muck removal efficiency of cutterhead during excavation.In order to improve the muck removal performance for TBM,the optimal design of bucket layout was investigated.The whole muck transfer process was simulated by discrete-element method(DEM),including the muck falling,colliding,pilling up,shoveling and transferring into the hopper.The muck model was established based on size distribution analysis of muck samples from the water-supply tunnel project in Jilin Province,China.Then,the influence of the bucket number and the interval angle between buckets on muck removal performance was investigated.The results indicated that,as the number of buckets increased from four to eight,the removed muck increased by 29%and the residual volume decreased by 40.5%,and the process became steadier.Different interval angles between buckets were corresponding to different removed muck irregularly,but the residual muck number increased generally with the angles.The optimal layout of buckets for the cutterhead in this tunnel project was obtained based on the simulation results,and the muck removal performance of the TBM was verified by the actual data in the engineering construction.
基金Supported by the Key Project of National Scientific and Technological Supporting Program of the "Eleventh Five-year Plan"(2008BAJ08B04-10)Scientific and Technological Program of the Ministry of Construc-tion(2009-K5-1)Soft Science Research Program of Tianjin Municipal Construction Committee(2008Soft-36)~~
文摘The concept of sustainable agricultural village was proposed in this study,and its major economic pattern was summarized as:with the sustainable agriculture,grain production and processing as core contents,to enhance the attraction of agricultural regions and establish more effective connections between rural and urban areas by properly developing eco-agricultural sightseeing and organizing satellite sustainable agricultural villages into an urban peripheral network.Dajidian Sustainable Agricultural Village in Baoding City,Hebei Province was taken for an example to elaborate the overall design concepts,and analyze the strategies for planning the village as an integrated system,including social,ecological and economic dimensions,which are specifically demonstrated as:the development of sustainable agriculture,the establishment of diversified circulation system,the independence of energy utilization,the soundness of public service system,the improvement of agricultural villages as communities.Through studying the planning of sustainable agricultural villages,this research aimed at realizing the sustainable development of overall environment system in both cities and rural areas,and guiding the improvement of the new countryside construction.
基金Supported by National Natural Science Foundation of China(11327902,11175180,11175182)U.S.DOE(DE-AC02-76SF00515)
文摘A scheme with two superconducting RF cavities is designed to upgrade electron storage rings with odd buckets to multi-length bunches. In this paper, the Hefei Light Source（HLS） is given as an example for odd buckets. As it is designed for 45 buckets, which is a multiple of 3, simultaneous generation of three different lengths of bunches is proposed with the presently applied user optics. The final result, without low-α optics, is to fill HLS with long bunches of length 50 ps, medium bunches of 23 ps and short bunches of 6 ps. Every third bucket can be filled with short bunches, of which the current limit is up to 6.6 m A, more than 60 times the limit for low-α mode.Moreover, particle tracking simulations to examine the beam dynamics, performed by ELEGANT, and calculations of the beam instabilities are presented in this paper.
文摘为解决不确定性能源发电给配电网带来的隐患和经济性问题,研究含间歇分布式能源的虚拟电厂(virtual pow er plant,VPP)接入配电网的联合优化调度对提高系统安全和促进新能源消纳具有十分重要的意义。综合考虑风电及储能的运行特性,提出一种改进的Buckets方法,建立了考虑风电不确定性和含储能的虚拟电厂参与配电网调度的优化机组组合模型,基于6节点系统研究了改进的Buckets方法对发电成本和机组组合的影响。与传统Buckets方法相比,采用所提方法使得模型的发电成本及开机时段减少,表明该方法能够实现发电成本最优、风电的充分消纳以及储能的灵活运用。
