大规模海上风电集中送出建设模式研究

[目的]当前海上风电已成为全球风电发展的研究热点。我国海上风电尚处于起步阶段,而当前的运营模式存在不利于海上风电大规模集中送出等缺点,无法适应新形势下的长远发展。另一方面,欧洲各国对海上风电的补贴政策与我国当前的发展思路有所冲突,可借鉴性不强,且欧洲模式本身仍存在弊端。因此亟需探索适合我国近海深水区海上风电发展的新模式。[方法]首先分析了欧洲各国海上风电发展现状,并对海上风电输电模式进行总结;其次给出了四种海上风电输电技术应用场景;最后对海上风电商业模式进行了可行性分析。[结果]结果表明：在拆分海上发、输电侧环节后,广东省预计“十四五”期间能够实现平价上网;相比于分散式开发,深水区海上风电统筹集约式开发从经济性及环境集约利用层面更具有优势。[结论]形成的研究结论可以为后续大规模海上风电集中送出项目的方案设计和建设模式提供技术支持,具有很好的示范应用前景。     

Effect of specimen thickness on the growth rate of chromia scales on Ni-base alloys in high- and low-pO2 gases

Two types of experiments were carried out to study the oxidation behaviour of NiCr-base model alloys; thermogravimetric measurements for up to 72 h exposure at 1000 °C in synthetic air and isothermal exposures for up to 100 h at 1000 °C in laboratory air and in Ar–4%H₂–2%H₂O. It was found that there is a significant effect of specimen thickness on the oxidation rate of all studied alloys. The growth rates of the chromia scales decrease with increasing specimen thickness in both air and the Ar–H₂–H₂O mixture. Based on the present results in combination with recent literature data for ferritic steels, it is postulated that the decrease in rate is the result of compressive growth stresses in the scales which can relax by plastic deformation of the substrate for thin specimens but are maintained at significant levels for thick specimens.     

电力系统安全稳定校验的信息物理联合仿真方法

  目的  为深入探究电力信息系统故障在信息物理融合系统（CPS）中对工程物理安全的影响机制,并确保研究结果易于复现和推广,  方法  通过开源软件搭建了电力变电站信息物理联合仿真的轻量级测试平台。基于电力监控系统的拓扑结构,通过Mininet搭建了变电站过程层网络的虚拟化框架,并在虚拟主机中调用Scapy模块自定义通信系统的故障类型,根据信息系统仿真结果修改安稳分析程序PSD-BPA的计算文件,外部调用暂稳计算核心求解工程安全结果,实现Mininet与BPA之间的数据联动,得到电力CPS轻量级联合仿真平台。  结果  仿真结果显示:变电站过程层网络中约64%的链路时延增加了10倍或以上,保护设备动作时间延缓至少12周波。根据文中提出的暂态稳定指标,部分站点在仿真周期内出现了严重的失步运行故障。  结论  基于暂态稳定指标的筛选结果成功量化了安稳控制设备的信息故障对电力能源系统的影响。     

直接空冷机组夏季限负荷问题的分析研究

分析了直接空冷机组夏季限负荷问题的原因,结合山西省部分空冷电厂的运行经验与现场试验,提出了在空冷岛布置风向和风速测点、加装尖峰喷雾系统、加装湿式冷却系统等建议,从而保证直接空冷机组夏季安全满发和经济运行。     

Voltage–time behavior of a polymer electrolyte membrane fuel cell stack at constant current discharge

Empirical equations were developed to describe the voltage–time behavior of polymer electrolyte membrane fuel cell (PEMFC) stacks at constant current discharge. When either ambient temperature or discharge current is too high, the experimental voltage–time curves exhibit rapidly falling cell voltage within a short discharge time. Various experimental voltage–time curves have been fitted very well with empirical equations at different discharge currents and ambient temperatures. The effect of parameters of the empirical equations on the shape of voltage–time curve is also analyzed. Inadequate mass-transfer is likely a reason for the voltage falling down rapidly, and polymer electrolyte membrane dehydration is responsible for the inclination of the voltage–time curves. The empirical equations are helpful for forecasting and explaining the long-term discharge performance of the PEMFC stacks.     

Pyrolysis of asphalt in the presence and absence of water

The bitumen used for the embedding of nuclear wastes has been pyrolysed in confined and hydrous systems, in order to evaluate while an elevation of the temperature in the deep geological repository could induce chemical transformations of the bitumen matrix, which could influence its confining properties. The pyrolysates have been extracted in chloroform and the extract has been separated in aliphatic and aromatic hydrocarbons, resins and asphaltenes. These different fractions have been analyzed by GC-MS and μ-IRTF. Few modifications of the bitumen structure are observed up to 300 °C. Above this temperature, the pyrolysis of the bitumen generates light hydrocarbons and an aromatic and condensed insoluble residue. The use of the time–temperature index allows to estimate the temperatures which have to be reached in the repository in order to observe the first transformations of the bitumen.     

电厂脱硫塔增容改造施工技术

中国能源建设集团山西省电力建设四公司此次脱硫塔增容工艺技改,应用了目前比较先进的技术和成熟的经验,收到了很好的经济效益和环保效益,值得推广。     

溴化锂吸收式热泵在热电联产机组中的应用

介绍了溴化锂吸收式热泵在热电联产机组中应用的背景,并以某工程的供热改造为实例,阐述了溴化锂吸收式热泵在热电联产机组中应用的系统参数及系统流程,包括驱动蒸汽系统、余热系统以及供热介质系统,并分析了溴化锂吸收式热泵技术在热电联产机组中应用取得的社会效益、经济效益。     

生物质发电及能源化综合利用

以生物质发电项目为依托,阐述了生物质利用的意义,生物质能源化综合利用技术展望,分析了生物质燃料的特性,生物质燃烧发电技术,生物质气化及发电技术,指明了生物质能综合利用将是未来生物质能利用的主要方向。     

Effect of Two-Level Over-Fire Air on the Combustion and NOx Emission Characteristics in a 600 MW Wall-Fired Boiler

This paper accomplishes a numerical investigation on the effect of two-level over-fire air (OFA) on the combustion and NO_x emission in a supercritical 600 MW wall-fired boiler. Different arrangements of two-level OFA nozzles and different airflow ratios between the two layers are set to examine NO_x emission and the carbon content in fly ash. According to the simulation results, the two-level OFA case releases the NO_x between the single upper layer and the single lower layer of the two-level OFA nozzles in operation. Moreover, the two-level OFA arrangement gives a lower carbon content in fly ash than the single-level OFA cases. In addition, both low NO_x emissions and low carbon content in fly ash can be obtained simultaneously when the two levels of OFAs are injected from Layers 1 and 4 with r_lower at 0.5.