Monitoring blade loads for a floating wind turbine in wave basin model tests using Fiber Bragg Grating sensors: A feasibility study

The blade loading contains sufficient information about the unsteady aerodynamics of Floating Wind Turbines (FWTs), and it serves as the basis for advanced controller developments. Wave basin model test is among the most reliable and economical methods for FWT investigations. However, few FWTs were reported being able to monitor the blade loads during wave basin tests. The main obstacles include strict space/mass limitations in model manufacturing and problems associated with signal transmission between rotating blades and stationary signal processing unit. In this paper, the feasibility of detecting blade loads for model FWT in wave basin tests is investigated. An on-line monitoring system is developed based on Fiber Bragg Grating (FBG) sensors and a Fiber Optical Rotary Joint (FORJ). Extensive validation tests are conducted under different environmental and operational conditions. Results show that the proposed FBG-FORJ sensing system presents impressive feasibility and reliability. As the authors know, it is among the first attempts to monitor the blade loads in real-time for model FWTs in wave basin tests. The present study will serve to enrich the knowledge about unsteady aerodynamics of FWTs and lay the foundation for experimental studies on advanced FWT controllers.     

Design,modelling, and analysis of a large floating dock for spar floating wind turbine installation

Installation of floating wind turbines at the offshore site is a challenging task. A significant part of the time efficiency and costs are related to the installation methods which are sensitive to weather conditions. This study investigates a large floating dock concept, which can be used to shield a floating wind turbine during installation of tower, nacelle, and rotor onto a spar foundation. In this paper, the concept is described in detail, and a design optimisation is carried out using simple design constraints. Hydrodynamic analysis and dynamic response analysis of the coupled system of the optimum dock and spar are conducted. Two spars of different sizes are considered, and the motion responses of the spars with and without the dock in irregular waves are compared. Through analysis of the motion spectra and response statistics, dynamic characteristics of the coupled system is revealed. The present design of the dock reduces the platform-pitch responses of the spars and potentially facilitates blade mating, but may deteriorate the heave velocity of the spars in swell conditions. Finally, future design aspects of the floating dock are discussed.     

风机机舱火灾热流场特性数值研究

为研究风机机舱发生火灾后的热流场特性规律,建立适用于风机机舱火灾计算的数学物理模型,对描述质量、动量和能量运输的通用方程进行简化和变形,用数值程序进行了求解,得到火灾发生后热释放速率及机舱内温度、热流、烟气高度等参数数据;分析典型火灾工况下各参数变化的反应延迟时间和变化规律、以及典型工况下特征参数的阈值,通过分析火灾流场特性变化规律,为风机消防设计提供参考。     

Stochastic dynamic load effect and fatigue damage analysis of drivetrains in land-based and TLP,spar and semi-submersible floating wind turbines

This paper deals with the feasibility of using a 5 MW drivetrain which is designed for a land-based turbine, on floating wind turbines. Four types of floating support structures are investigated: spar, TLP and two semi-submersibles. The fatigue damage of mechanical components inside the gearbox and main bearings is compared for different environmental conditions, ranging from cut-in to cut-out wind speeds. For floating wind turbines, representative wave conditions are also considered. All wind turbines are ensured to follow similar power curves, but differences in the control system (integral to different concepts) are allowed. A de-coupled analysis approach is employed for the drivetrain response analysis. First, an aero-hydro-servo-elastic code is employed for the global analysis. Next, motions, moments and forces from the global analysis are applied on the gearbox multi body model and the loads on gears and bearings are obtained. The results suggest that the main bearings sustain more damage in floating wind turbines than on land-based. The highest main bearing damage is observed for the spar floating wind turbine. The large wave induced axial load on the main shaft is found to be the primary reason of this high damage in the spar wind turbine. Apart from the main bearings - which are located on the main shaft outside the gearbox - other bearings and gears inside the gearbox hold damages in floating wind turbines equal or even less than in the land-based turbine. It is emphasized that the results presented in this study are based on a drivetrain with two main bearings, which considerably reduces the non-torque loads on the gearbox.     

叶轮级数对一种潮流水轮机水动力性能的影响研究

为了进一步提高潮流能水轮机叶轮的能量捕获性能(获能效率),对一种多级获能潮流水轮机叶轮进行了研究。利用ANSYS16.0 中的CFX流体仿真模块对一种潮流水轮机的叶轮级数进行了数值计算,对不同级数的叶轮进行水动力性能模拟,考察一、二、三级叶轮在不同流速下呈现的速度、压力分布以及流场压差变化情况,并通过样机实验进行了验证。结果表明,叶轮级数的增加可以提高轮机对水流能量的捕获性能；就各个流速工况下的整体获能系数而言,三级叶轮最佳,但启动性能有所下降,三级叶轮启动流速在0.75m/s左右；三级叶轮的最优水速在1.5m/s左右,理想状态下获能效率可达51%上下。     

海洋平台大型透平发电机安装工艺方案设计

目前,海洋平台上大都采用大型透平发电机来供电。以SOLAR Taurus 60透平发电机为例,详细介绍了透平发电机的安装工艺及步骤,并且归纳了安装中需要注意的问题。     

联调试验中考核汽轮发电机组单机动态特性的试验方法

介绍了汽轮发电机组联调试验单机动态试验中存在的问题,提出在汽轮发电机组出厂、联调等试验中可广泛应用的“并车带载考核单机动态特性”试验方法.     

舰用燃气轮机研制过程中的试验研究

足够的试验是舰用燃气轮机研制过程中的必要环节,除进行常规的燃气轮机试验外,还要进行满足海上运行条件要求的试验.阐述舰用燃气轮机研制过程中的部分重要试验项目,分析了这些重要试验项目的试验目的和技术要求,最后介绍了几型具有代表性舰用燃气轮机研制过程中的试验情况.