Wind-driven power harvestings attract attentions since their target wind speeds are quite low less than the so-called cut-in wind speed, which is generally recognized as around 3 m/s. The extant power harvestings driv...Wind-driven power harvestings attract attentions since their target wind speeds are quite low less than the so-called cut-in wind speed, which is generally recognized as around 3 m/s. The extant power harvestings driven by wind-induced-air-column-resonations (i.e. acoustic-pressures) are still lacking simplicity, scale flexibility and solid strategies for practical applications. Therefore, the piezoelectric power harvesters via acoustic-pressures driven by low-speedwind-forces with resonating-tubes and wind-collectors were invented so as to complement all the lacks. The wind-collector as well as the resonating-tube contributed to upraise the power harvesting density. The champion power harvesting density of 19.5 nW/dm2 could be procured at 2.3 m/s of an artificial wind and the optimal resonating-tube and wind-collector. Power harvesting proofs from the natural wind with low mean speeds down to about 0.6 m/s were successfully obtained. The cut-in wind speed of the prototype piezoelectric power harvester was found to be quite low as about 0.4 m/s, signifying its ubiquity. Finally, a multi-bundle pendant-type piezoelectric power harvester was specifically presented together with professing the solid and multiple strategies for practical applications.展开更多
The goal of this study is to model the effects of wind on Cylindrical Trough Collectors (CTCs). Two major areas are discussed in this paper: 1) heat losses due to wind flow over receiver pipe and 2) average forces app...The goal of this study is to model the effects of wind on Cylindrical Trough Collectors (CTCs). Two major areas are discussed in this paper: 1) heat losses due to wind flow over receiver pipe and 2) average forces applied on the collector’s body. To accomplish these goals a 2D modeling of CTC was carried out using commercial codes with various wind velocities and collector orientations. Ambient temperature was assumed to be constant at 300 K and for specific geometries different meshing methods and boundary conditions were used in various runs. Validation was done by comparing the simulation results for a horizontal collector with empirical data. It was observed that maximum force of 509.1 Newton per Meter occurs at +60 degrees. Nusselt number is almost the constant for positive angles while at negative angles it varies considerably with the collector’s orientation.展开更多
集电系统拓扑优化是大型海上风电场规划建设的核心问题,本质上是一个涉及多约束、多目标的复杂混合整数优化问题。针对该问题,提出了一种基于大语言模型(large language model,LLM)辅助的大型海上风电场集电系统拓扑优化方法。首先,基...集电系统拓扑优化是大型海上风电场规划建设的核心问题,本质上是一个涉及多约束、多目标的复杂混合整数优化问题。针对该问题,提出了一种基于大语言模型(large language model,LLM)辅助的大型海上风电场集电系统拓扑优化方法。首先,基于大语言模型辅助对风电机组群进行聚类,通过链式提示法使LLM理解优化目标,并利用LLM将大型海上风电场分割为若干小型区域,以降低优化问题维度,提升求解速度和质量。然后,构建集电系统拓扑优化模型,基于混合整数线性规划求解器,获得海上风电场的最优集电系统拓扑设计方案。最后,利用1个含有75台风电机组的大型海上风电场系统进行方法性能验证,仿真结果表明:与传统优化技术相比,所提方法获得的聚类风机数量更加均衡,在考虑拓扑功率损耗的同时,生成的拓扑方案经济性最优。LLM在集电系统拓扑辅助优化中具有较高的有效性,为海上风电场集电系统拓扑设计优化提供了一种新思路。展开更多
In order to enhance the atomization efficiency of atomizer, a new type of wind-spray dust controller combining the rotary-atomization and colliding broken of droplets was designed by the method of opening the water ci...In order to enhance the atomization efficiency of atomizer, a new type of wind-spray dust controller combining the rotary-atomization and colliding broken of droplets was designed by the method of opening the water circulation within the blades. The experiment test for dust controller was conducted by adjusting the following parameters: rotating speed, diversion hole-exit diameter, and colliding tooth angle. Results show that the atomization efficiency increases firstly then decreases with them. And the optimal parameters are obtained with rotating speed 1500-2200 r/min, diversion hole-exit diameter 2-2.5 mm and colliding tooth angle 30°-40°, and under these conditions the corresponding atomization efficiency tops to 95%. Then, the atomization situation under the optimal parameters is held from the aspect of simulation internal flow field and the results of droplet size(30-80 μm) are got, which indicates that the conclusion on the optimized parameters of dust controller is reasonable. The collecting efficiencies of different dust concentrations are determined, ranging from 85% to 98.4%, which shows that the designed dust controller can obtain a good atomizing effect and achieve well dustfall efficiency for the wetting dust control of coal mine.展开更多
文摘Wind-driven power harvestings attract attentions since their target wind speeds are quite low less than the so-called cut-in wind speed, which is generally recognized as around 3 m/s. The extant power harvestings driven by wind-induced-air-column-resonations (i.e. acoustic-pressures) are still lacking simplicity, scale flexibility and solid strategies for practical applications. Therefore, the piezoelectric power harvesters via acoustic-pressures driven by low-speedwind-forces with resonating-tubes and wind-collectors were invented so as to complement all the lacks. The wind-collector as well as the resonating-tube contributed to upraise the power harvesting density. The champion power harvesting density of 19.5 nW/dm2 could be procured at 2.3 m/s of an artificial wind and the optimal resonating-tube and wind-collector. Power harvesting proofs from the natural wind with low mean speeds down to about 0.6 m/s were successfully obtained. The cut-in wind speed of the prototype piezoelectric power harvester was found to be quite low as about 0.4 m/s, signifying its ubiquity. Finally, a multi-bundle pendant-type piezoelectric power harvester was specifically presented together with professing the solid and multiple strategies for practical applications.
文摘The goal of this study is to model the effects of wind on Cylindrical Trough Collectors (CTCs). Two major areas are discussed in this paper: 1) heat losses due to wind flow over receiver pipe and 2) average forces applied on the collector’s body. To accomplish these goals a 2D modeling of CTC was carried out using commercial codes with various wind velocities and collector orientations. Ambient temperature was assumed to be constant at 300 K and for specific geometries different meshing methods and boundary conditions were used in various runs. Validation was done by comparing the simulation results for a horizontal collector with empirical data. It was observed that maximum force of 509.1 Newton per Meter occurs at +60 degrees. Nusselt number is almost the constant for positive angles while at negative angles it varies considerably with the collector’s orientation.
文摘集电系统拓扑优化是大型海上风电场规划建设的核心问题,本质上是一个涉及多约束、多目标的复杂混合整数优化问题。针对该问题,提出了一种基于大语言模型(large language model,LLM)辅助的大型海上风电场集电系统拓扑优化方法。首先,基于大语言模型辅助对风电机组群进行聚类,通过链式提示法使LLM理解优化目标,并利用LLM将大型海上风电场分割为若干小型区域,以降低优化问题维度,提升求解速度和质量。然后,构建集电系统拓扑优化模型,基于混合整数线性规划求解器,获得海上风电场的最优集电系统拓扑设计方案。最后,利用1个含有75台风电机组的大型海上风电场系统进行方法性能验证,仿真结果表明:与传统优化技术相比,所提方法获得的聚类风机数量更加均衡,在考虑拓扑功率损耗的同时,生成的拓扑方案经济性最优。LLM在集电系统拓扑辅助优化中具有较高的有效性,为海上风电场集电系统拓扑设计优化提供了一种新思路。
基金Project(U1261107)supported by the Joint Funds of the National Natural Science Foundation of China
文摘In order to enhance the atomization efficiency of atomizer, a new type of wind-spray dust controller combining the rotary-atomization and colliding broken of droplets was designed by the method of opening the water circulation within the blades. The experiment test for dust controller was conducted by adjusting the following parameters: rotating speed, diversion hole-exit diameter, and colliding tooth angle. Results show that the atomization efficiency increases firstly then decreases with them. And the optimal parameters are obtained with rotating speed 1500-2200 r/min, diversion hole-exit diameter 2-2.5 mm and colliding tooth angle 30°-40°, and under these conditions the corresponding atomization efficiency tops to 95%. Then, the atomization situation under the optimal parameters is held from the aspect of simulation internal flow field and the results of droplet size(30-80 μm) are got, which indicates that the conclusion on the optimized parameters of dust controller is reasonable. The collecting efficiencies of different dust concentrations are determined, ranging from 85% to 98.4%, which shows that the designed dust controller can obtain a good atomizing effect and achieve well dustfall efficiency for the wetting dust control of coal mine.
