双馈风力发电系统低电压穿越控制的分析研究

文章对国内外的风力发电低电压穿越的现状进行了综述,并对主要的低电压穿越方案进行了分析研究,具有一定的参考意义。     

大跨度桥梁挂篮施工技术研究

文章对挂篮施工技术进行了概述,并在此基础上分析了其施工原理,最后结合工程实例探讨了大跨度桥梁挂篮施工技术．为施工实践提供借鉴。     

风机基础所受波浪抨击力的数值模拟和实验研究

准确预测风机基础所受到的抨击载荷对风机的设计至关重要。在上海交通大学海洋工程国家重点实验室,通过模型实验研究了在聚焦波浪作用下风机基础所受到的抨击载荷,同时研究了聚焦波浪的不同参数对抨击载荷的影响。此外运用计算流体力学软件FLUENT,通过有限体积法求解不可压缩Navier-Stocks方程和体积分数法捕捉自由液面,在数值波浪水池中模拟了聚焦波浪拍击风机立柱的过程。数值模拟与模型试验的结果吻合得较好。最后将模型实验的结果与各种设计准则中采用的预测抨击力的经验公式进行对比,验证了不同准则预测波浪抨击载荷的有效性。     

风力发电用齿轮箱齿根应力测试系统的开发

针对风电齿轮箱研制中检验修形效果的难点,提出了齿根应力测试技术,可同时测出齿根处,齿向载荷分布系数和载荷不均匀系数.论述了风机齿轮箱应力测试系统的原理及其主要组成部分,给出了典型的应力分布和均载测试结果;重点分析了测试系统中关键的程控放大模块和I2C总线通信.运行实践表明,该应力测试系统能够对齿轮箱的啮合状态进行定量分析,测试结果对齿轮修形及结构设计等有重要的参考价值.     

Relationship between phytoplankton bloom and wind stress in the sub-polar frontal area of the Japan/East Sea

The seasonal dynamics of phytoplankton blooms in the central Japan/East Sea (JES) show pronounced year-to-year variability based on Sea-viewing Wide Field-of-view Sensor (SeaWiFS; 19972003) and Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra (20002003) observations. Wind seems to strongly influence this variability. To study the relationship between wind and bloom initiation, we analyzed daily, remotely sensed wind stress data (Active Microwave Instrument–wind [AMI–wind], NASA Scatterometer [NSCAT], and Quick Scatterometer [QuickSCAT]: 19972003) and daily chlorophyll concentrations based on ocean color data (SeaWiFS and MODIS). The results agreed well with the hypotheses; in spring, blooms began 615 days after wind stress weakened. Fall blooms started 39 days after wind strengthened. We also simulated seasonal changes using a simple light–nutrient model using two values for the respiration ratio: 10% and 20%. The use of 20% seemed to reproduce the timing of the spring bloom quite well but underestimated the absolute level of chlorophyll concentration. On the other hand, using 10% produced a better estimation of the chlorophyll concentration but failed to match the timing. Neither of the model runs reproduced the timing of the fall bloom well.     

海上风机导管架基础钢管桩稳桩平台结构强度分析

海上风机导管架基础钢管桩沉桩施工通常需要专门的稳桩平台辅助进行。结合作业工艺要求、海洋环境条件和相关规范,对钢管桩稳桩平台进行结构设计。采用SESAM软件和ANSYS Workbench软件分别对稳桩平台整体结构强度和吊耳局部结构强度进行计算分析,并根据规范对计算结果进行评估。结果表明,稳桩平台整体结构强度和吊耳局部结构强度均满足规范要求。该计算分析方法同样适用于海上升压站导管架基础、海上单桩基础稳桩平台或其他类似导管架结构的强度评估。     

风力发电机塔架的有限元分析

利用有限元分析软件ANSYS对某型风力发电机组的塔架结构进行整体强度、门段强度、模态以及屈曲分析,其中门段细节分析主要针对门洞附近应力集中进行讨论;计算塔架在Ⅱ类风场极限载荷作用下的最大应力、动力特性和屈曲载荷.计算结果表明:塔架整体结构满足强度要求,门段局部结构不满足强度要求,正常工作时塔架与风轮不会发生共振,从而为塔架结构设计和优化提供依据.     

隧道掘进施工通风风量计算与设备选择

给出了隧道掘进施工通风所需风量、选配通风机械设备时相关参数的计算方法,阐明了如何根据相关参数选配通风机械设备的基本知识,就日常通风技术管理和安全管理措施做了简要的介绍.     

Effects of Tuned Mass Damper on Wind-Induced Vibration of Free Standing Pylon by Wind Tunnel Test

In order to assess the effects of tuned mass dampers (TMDs) on wind actions, an aeroelastic model with a scale of 1:60 was constructed. Tests were performed in an atmospheric boundary layer wind tunnel to investigate the buffeting response of the pylon with a TMD fixed by a wire rope instead of a spring. The model was tested under different levels of damping. The experimental and numerical results showed that with the TMD in the optimal condition, the buffeting response was reduced by 47%.     

微型燃气轮机应用中的高速永磁机损耗

高速永磁机因其结构紧凑、坚固、效率高的特点在微型燃气轮机应用中得到使用。高速永磁机与涡轮机集成,并以相同速度旋转。通过详细讨论高速永磁机的损耗,给出了一种设计用于微型燃气轮机应用中的典型高速永磁机损耗的详细计算方法。同时也讨论了各种损耗的验证方法。