Risk analysis of maintenance ship collisions with offshore wind turbines

A large number of offshore wind farms are planned to be built in remote deep-sea areas over the next five years. Though offshore wind sites are often located away from commercial ship traffic, the increased demand for repair or replacement services leads to high traffic densities of “maintenance ships”. To date, the risk analysis of collision between maintenance ship vessels and offshore wind turbines has received very little attention. In this paper, we propose a methodology to evaluate and prioritise the collision risks associated with various kinds of ships used for carrying out maintenance tasks on different subassemblies of wind turbines in an offshore wind farm. It is also studied how the risks of ship collision with wind turbines are distributed between two main types of maintenance tasks, namely corrective and preventative. The proposed model is tested on an offshore wind turbine with seventeen components requiring five kinds of ships to perform the maintenance tasks. Our results indicate that collision risks are mostly associated with maintenance of few components of the wind turbine and in particular, those undergoing a corrective maintenance (replacement). Finally, several mitigation strategies are introduced to minimise the risk of maintenance ship collisions with offshore wind turbines.     

Econometric analysis of the R&D performance in the national hydrogen energy technology development for measuring relative efficiency: The fuzzy AHP/DEA integrated model approach

Hydrogen energy technology can be one of the best key players related to the sector of the United Nations Framework Convention on Climate Change (UNFCCC) and the hydrogen economy. Comparing to other technologies, hydrogen energy technology is more environmentally sound and friendly energy technology and has great potential as a future dominant energy carrier. Advanced nations including Korea have been focusing on the development of hydrogen energy technology R&D for the sustainable development and low carbon green society. In this paper, we applied the integrated fuzzy analytic hierarchy process (Fuzzy AHP) and the data envelopment analysis (DEA) for measuring the relative efficiency of the R&D performance in the national hydrogen energy technology development. On the first stage, the fuzzy AHP effectively reflects the vagueness of human thought. On the second stage, the DEA approach measures the relative efficiency of the national R&D performance in the sector of hydrogen energy technology development with economic viewpoints. The efficiency score can be the fundamental data for policymakers for the well focused R&D planning.     

A fuzzy analytic hierarchy process approach for assessing national competitiveness in the hydrogen technology sector

As it is more environmentally sound and friendly than conventional energy technologies that emit carbon dioxide, hydrogen technology can play a key role in solving the problems caused by the greenhouse gas effect and in coping with the hydrogen economy. Numerous countries around the world, including Korea, have increasingly focused on R&D where hydrogen technology development is concerned. This paper focuses on the use of the fuzzy analytic hierarchy process (fuzzy AHP), which is an extension of the AHP method and uses interval values to reflect the vagueness of human thought, to assess national competitiveness in the hydrogen technology sector. This analysis based on the AHP and fuzzy AHP methods revealed that Korea ranked 6th in terms of national competitiveness in the hydrogen technology sector.     

中国海洋能专利研究

专利是除论文外的又一非常重要的科技成果.目前专利申请工作并未得到足够重视,并且文献中对专利技术成果的反映甚少.文章对中国国家知识产权局(SIPO)专利数据库中海洋能专利授权情况进行了分类统计.介绍了波浪能、潮汐能、温差能的最新专利,并指出了该领域专利申请的热点和空白领域.最后根据统计数据从专利的角度分析了中国海洋能研究的进展和前景.     

波浪能、潮流能发电场电力系统研究

海洋能(波浪能、潮流能)发电场的电力系统是整个发电场的核心部分,因此电力系统拓扑的设计应能够满足海洋能发电装置实海况并网发电、安全可靠输送的要求。首先,分析了发电场电力系统的构成,并从经济性和可靠性方面对几种发电机组区内集电系统拓扑结构进行对比分析,并给出2种区间拓扑结构,结合实际工程经验,提出了新的发电装置集电系统拓扑结构。同时,对比分析交流系统、高压直流以及柔性直流等3种海洋能发电场输电系统的设计方案。分析表明,输电系统和机组集电系统的设定受到建设环境、系统容量、离岸距离、技术方式等的影响,需进行经济性、技术性的综合比较后确定。文章可为实现国内海洋能发电场或测试场建设提供技术依据。     

潮流发电技术的发展现状及趋势

介绍了潮流发电的基本原理和关键技术,对国内外潮流发电的关键设备水轮机的发展和成果进行了评述,分析了今后潮流发电技术的发展趋势。潮流发电作为一种最新的可再生新能源利用技术,具有很好的发展前景。     

后掠式水平轴潮流能水轮机的载荷与获能特性研究

针对双向潮流能有效利用问题,设计一种基于对称翼型的新型后掠式水平轴潮流能水轮机,并研究其水动力性能。根据对称翼型升阻力特性与叶片展向攻角变化,采用变截面设计优化后掠式对称翼型叶片,并基于Buhl修正模型分析不同后掠偏移叶片所受推力与获能特性。通过3D建模与水槽实验,研究不同后掠偏移叶片的载荷与获能情况。模型实验研究表明,同一尖速比下,后掠偏移量为10%和15%的水轮机相对于偏移量为5%的水轮机所受推力最大分别降低4%和13.3%,获能效率最多分别减小3.8%和11.1%,其中推力比获能效率减幅更大。实验结果与理论分析变化趋势吻合,但减幅比理论值偏高。此外,该水轮机3种后掠偏移量下对应获能效率随桨距角的增大分别降低18%、14%和6%,获能效率下降显著,与300 kW样机实海况运行情况变化趋势相同。     

固定偏角垂直轴潮流能水轮机叶片安装位置试验研究

叶片安装位置是影响固定偏角垂直轴潮流能水轮机水动力性能的关键参数之一,为了研究其对水轮机性能影响的基本规律,建立了垂直轴水轮机水槽模型试验系统,设计了垂直轴水轮机性能和载荷测试方法。通过试验结果的分析,得到了叶片安装位置对水轮机能量利用率、推力系数、侧向力系数和合力系数的影响规律,为水轮机设计提供了试验依据。     

海洋波浪潮流能实验场发展现状及建议

随着我国发展海洋强国战略目标的确定,建设海洋能实验场对提高我国海洋能开发技术有着关键性的作用。以潮流能、波浪能实验场的建设发展为例,本文着重介绍了国外海洋能实验场发展现状和运行情况,并对其发展进行总结分析。同时对国内海洋能实验场的建设进展进行概述,从选址、匹配等方面探讨了我国新建成的海洋能实验场的功能特点,根据国际先进海上实验场的建设经验对我国发展海洋能实验场所面临的难点提出发展建议。     

Tidal stream energy resource assessment in the Qiantang River Estuary,China

A tidal stream energy resource assessment can be achieved through direct measurements of tidal elevations or flow velocities, theoretical formulas, and numerical models. This paper first described the development of renewable energy in China. Then, the tidal stream energy resource in the Qiantang River Estuary was assessed. The present work established a 2D numerical model for calculating the power density in the estuary and validated it with in situ water level, tidal current, and suspended sediment concentration measurements. Three possible sites found near the Hangzhou Bay Bridge were selected for detailed resource assessment. The results indicated that if only 50 turbines are deployed to each site, the tidal stream energy output by all turbines would be 7.5?GWh/year. Finally, building a tidal stream power generation device into an existing bridge structure was proposed at the Qiantang River Estuary.     

潮流能研究现状2013

21世纪以来,面对常规能源日益枯竭、环境恶化的局面,各国将目光转向可再生能源。海洋潮流能因为优越的可再生性、环保性及巨大的贮藏量而成为重点研究对象。至2013年,海洋潮流能利用在技术上取得了长足的进步,而且发展十分迅速,新概念、新技术和新装置层出不穷。本文从工作原理、技术特征、实验及应用情况等方面对其中具有代表性的潮流能发电装置的模型及实型作了综述和评价,通过对比分析能量转换装置和载体形式的技术特点,指出了当前潮流能开发中存在的主要问题及未来的发展趋势。     

水平轴潮流能水轮机尾流特性研究

文章以水平轴潮流能水轮机为研究对象,采用CFD方法对水轮机的尾流特性进行分析。通过网格无关性验证与已发表文献的比对,验证了CFD方法的精度。通过不同叶尖速比下的水轮机性能曲线,进一步分析了水轮机的尾流场速度分布特征。通过分析尾流场中轴向、径向和切向速度的分布特点,研究了水平轴潮流能水轮机尾流的微观结构特征及其演化规律。研究结果表明:尾流横向影响范围在以中心轴线为中心的1D范围内;在近尾流处,尾流速度具有周期性,轴向速度随着尾流下移而逐渐减小;在尾流旋转过程中,径向速度向外扩散并逐渐衰减,切向速度分量沿轴向逐渐衰减。     

我国能源发展的风险影响因素与预警系统分析

本文从3个角度分析了我国能源发展中存在的风险;以能源资源储量、能源生产效率、可再生能源开发、政治能源外交、国际能源交易等为主的能源供给角度;以经济增长方式、能源利用效率、节能政策与节能设备等为主的能源利用角度;以能源环境污染、清洁替代能源等为主的环境保护角度。在此基础上,讨论了以能源供需平衡和价格波动、单位产值能耗、能源需求增长速度等为指标的预警系统构建思路。     

舟山群岛新区新能源开发应用现状及发展建议

舟山群岛新区常规能源匮乏,目前的能源现状远远不能满足新区建设的需要.面对丰富的可再生资源,开发利用新能源已成为舟山能源发展的必然趋势.舟山拥有丰富的风能资源,占全省风能资源的1/3,目前已建成风电装机容量9.78×104kW,占浙江省总装机容量的26.6％,2015年将达到87× 104kW.同时,舟山也是我国潮流能资源最为丰富的地区,在潮流能发电示范应用方面也走在了全国前列.舟山属于我国太阳能中等资源区,秋冬季太阳能资源丰富,近年来除了在原有基础上继续做好太阳能的推广利用之外,还开辟了许多新的思路.此外,海上运输的便利也使舟山在利用外部生物质能、LNG等方面具有独特优势.舟山在新能源产业发展过程中需要注意合理安排、适度开发、有序推进,在科学规划的基础上,开发与保护并重.今后应着重做好资源调查与评估、建立健全能源规划、重视技术创新、注重产业联动、加大政策扶持力度等几方面工作.     

潮流能发电装置输出功率异常数据识别方法研究及应用

在分析潮流能发电装置输出功率数据存在异常值的原因的基础上,讨论潮流能发电装置输出功率异常数据的判别方法,采用潮流流速区间精细划分和四分位判别相结合的方法,对每个潮流流速区间内的潮流能发电装置输出功率异常值进行识别与剔除。结果表明,该异常数据识别方法不仅能使得剔除异常数据后的潮流能发电装置输出功率图谱能更真实地表征被测试潮流能发电装置的输出功率特性,而且可提高潮流能发电装置平均输出功率和平均转换效率的计算准确度。     

潮流能水轮机叶片翼型水动力性能的数值模拟研究

鉴于潮流能水轮机叶轮叶片性能的好坏关系到叶轮的捕能效果,而叶片翼型的水动力性能是叶片设计的基础,基于CFD软件ANSYS CFX对部分翼型的水动力性能进行了分析。首先在不同湍流模型下对NACA2412翼型的部分水动力特性进行数值模拟并与试验值做对比分析;然后在SST湍流模型下,对NACA64421翼型在攻角为0°时,探讨了边界层网格对数值模拟结果的影响;并对其在攻角为-2°~20°情形下的水动力性能进行了数值模拟。结果表明,湍流模型的选用、边界层网格划分及近壁尺寸的选取对数值模拟结果的影响均较大,并通过数值模拟得到了NACA64421翼型的升力系数、阻力系数、最佳攻角、失速角等水动力性能参数,可为水轮机叶片设计时翼型的选取提供参考。     

煤炭价格风险与能源风险管理(二)

本文对能源风险管理的产生及在欧美国家的发展作了回顾,并对与能源风险管理密切相关的金融衍生工具产品作了简要介绍。用假设案例说明煤炭生产和消费企业如何控制煤炭价格风险。对我国如何开展能源风险管理提出了建议。