Construction Technology of Lightning Protection Devices in Building Electrical Installation Engineering

To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction technology.These aspects include the lightning protection classification of buildings,air terminals,down conductors,grounding devices,division of lightning protection zones,and lightning electromagnetic pulse shielding.Through the introduction of this article,readers can gain a comprehensive understanding of the application and value of lightning protection grounding construction technology in building electrical installation projects.

Radar Echo and Lightning Characteristics Analysis on A Strong Thunderstorm Weather in Fuxin

Based on the radar data and lightning position indicator data of strong thunderstorm weather which happened in Fuxin on July 8,2007,the relationship between the lightning activity and the radar echo was analyzed.The results showed that Fuxin area located in the cross position of T-shaped trough and was affected by the cold air which continuously glided down.The corresponding warm front on the ground advanced southward and arrived here.It was the weather background of this thunderstorm weather.The position variation of lightning occurrence was closely related to the strong echo movement of squall line,and the velocity echo clearly reflected and predicted the movement tendency of the radar echo.

Convective Storm VIL and Lightning Nowcasting Using Satellite and Weather Radar Measurements Based on Multi-Task Learning Models

Convective storms and lightning are among the most important weather phenomena that are challenging to forecast.In this study,a novel multi-task learning(MTL)encoder-decoder U-net neural network was developed to forecast convective storms and lightning with lead times for up to 90 min,using GOES-16 geostationary satellite infrared brightness temperatures(IRBTs),lightning flashes from Geostationary Lightning Mapper(GLM),and vertically integrated liquid(VIL)from Next Generation Weather Radar(NEXRAD).To cope with the heavily skewed distribution of lightning data,a spatiotemporal exponent-weighted loss function and log-transformed lightning normalization approach were developed.The effects of MTL,single-task learning(STL),and IRBTs as auxiliary input features on convection and lightning nowcasting were investigated.The results showed that normalizing the heavily skew-distributed lightning data along with a log-transformation dramatically outperforms the min-max normalization method for nowcasting an intense lightning event.The MTL model significantly outperformed the STL model for both lightning nowcasting and VIL nowcasting,particularly for intense lightning events.The MTL also helped delay the lightning forecast performance decay with the lead times.Furthermore,incorporating satellite IRBTs as auxiliary input features substantially improved lightning nowcasting,but produced little difference in VIL forecasting.Finally,the MTL model performed better for forecasting both lightning and the VIL of organized convective storms than for isolated cells.

Study on the Lightning-Protection of Ancient Buildings

By reviewing ancient buildings that were destroyed by lightning strike or fire caused by lightning,lightning protection of ancient buildings was discussed,ancient architectural complex in Dagu Mountain,a provincial-level scenic area of Liaoning,was taken for an example to detect potential safety hazards in lightning-protection of those ancient buildings,5 types of potential safety hazards were summarized.By studying the classification of ancient buildings' lightning-protection,protection level,lightning-protection measures,design basis of lightning-protection engineering,construction and new construction technology,relevant technical specifications were taken as references for proposing 4 countermeasures against those potential safety hazards from the perspectives of exterior and interior parts of ancient buildings,lightning-protection of ancient trees and so on.In view of actual conditions of the ancient architectural complex in Dagu Mountain,construction plan,personnel placement,labor planning,construction quality control system,acceptance of works,technical documentation and such matters were specifically discussed to give useful support to the future lightning-protection of ancient buildings.

Characteristics of Cloud-to-ground Lightning during a Squall Line Process outside of the Subtropical High

Based on the monitoring data of cloud-to-ground( CG) lightning positioning network and Doppler weather radar as well as MICAPS1°× 1° objective analysis field,a squall line process outside of the subtropical high in low-latitude plateau on May 7,2010 was analyzed. The results showed that wind direction shear between low and high levels and low-level convergence zones provided favorable circulation background for the strong thunderstorm process,while high energy and high humidity,strong thermal instability and ascending motion at low and middle levels offered beneficial environmental conditions for the formation of the thunderstorm. 9 620 return strokes of cloud-to-ground lightning were monitored by the lightning positioning network,and cloud-to-ground lightning was distributed like bands between 584 and 586 hP a. The occurrence of cloud-to-ground lightning was mainly related to echo top and echo intensity at-10 ℃ stratification height,and it mainly appeared in zones where echo top height was larger than 13 km and echo intensity at-10 ℃ stratification height was 35-40 dB Z. Wind convergence and maintaining of high radial velocity were favorable for the development of convective echoes and occurrence of cloud-to-ground lightning.

Assimilation of Radar and Cloud-to-Ground Lightning Data Using WRF-3DVar Combined with the Physical Initialization Method——A Case Study of a Mesoscale Convective System

Radar data, which have incomparably high temporal and spatial resolution, and lightning data, which are great indicators of severe convection, have been used to improve the initial field and increase the accuracies of nowcasting and short-term forecasting. Physical initialization combined with the three-dimensional variational data assimilation method(PI3 DVarrh) is used in this study to assimilate two kinds of observation data simultaneously, in which radar data are dominant and lightning data are introduced as constraint conditions. In this way, the advantages of dual observations are adopted. To verify the effect of assimilating radar and lightning data using the PI3 DVarrh method, a severe convective activity that occurred on 5 June 2009 is utilized, and five assimilation experiments are designed based on the Weather Research and Forecasting(WRF) model. The assimilation of radar and lightning data results in moister conditions below cloud top, where severe convection occurs;thus, wet forecasts are generated in this study.The results show that the control experiment has poor prediction accuracy. Radar data assimilation using the PI3 DVarrh method improves the location prediction of reflectivity and precipitation, especially in the last 3-h prediction, although the reflectivity and precipitation are notably overestimated. The introduction of lightning data effectively thins the radar data, reduces the overestimates in radar data assimilation, and results in better spatial pattern and intensity predictions. The predicted graupel mixing ratio is closer to the distribution of the observed lightning,which can provide more accurate lightning warning information.

“工业上楼”建筑电气设计要点浅析

随着经济的发展,城市产业发展往往面临产业转型升级加速和土地资源紧张的双重压力,“工业上楼”举措成为了当今城市产业发展的趋势和研究方向。“工业上楼”面向的产业类型较多,不同产业类型对电气设计的需求也不同,因此“工业上楼”建筑电气设计也相对复杂,对电气设计也带来一定挑战。本文将针对“工业上楼”建筑电气设计关键要点进行探索,以供参考。

新型透波接闪杆在X波段天气雷达防护中的应用

针对X波段天气雷达受金属接闪杆或金属引下线干扰时出现反射率、差分反射率等参数劣化的问题,本文采用精细设计的非连续片段式金属箔片阵列作为引下线的导流结构,与高性能复合材料杆相结合设计了新型透波接闪杆,成功解决了透波与雷电通流的难题:接闪杆导流结构接闪时受雷电电场激发形成连续等离子体通道,成为承载雷电流通路;非连续的金属箔片大幅降低了雷达反射率。为验证新型透波接闪杆防护与透波能力,开展了试验测试:①高压附着接闪与冲击通流能力测试,结果表明新型透波接闪杆平均击穿阈值为4.45 kV/cm,冲击通流能力大于150 kA(±10%,10/350μs波形),满足GB50057和QX/T2-2016标准规定的第二类建筑雷电防护要求;②实地安装试验测试,结果表明相较于金属接闪杆,新型透波接闪杆对雷达反射率、差分反射率等关键参数的影响大幅降低。本文研究的新型透波接闪杆能够降低避雷系统对雷达探测性能的影响,可以在类似相控阵雷达直击雷防护中进一步应用和推广。

三星堆博物馆新馆智能防雷监测系统设计与实践

针对三星堆博物馆新馆建筑特点和所处环境,设置智能防雷监测系统,利用信息化手段,对博物馆周边气候环境、新馆外部防雷装置、电涌保护器等防雷设施进行实时在线监测,并通过技术手段实现雷电预警和实时推送,有效提升了博物馆的雷电防护水平。

超高层异形综合体防雷设计研究

针对现阶段超高层异形建筑防雷接地设计进行了总结和分析。现场踏勘了本项目及其周边400 m范围内的建筑坐落情况,分析了本项目防雷接地的设计方案,总结了异形建筑防雷接地所应考虑的等效面积、防雷接地措施等必要条件,通过计算年预计雷击次数和查询各地防雷办参数,本项目展开防雷工程设计研究,研究方式及结果将对项目自身防雷设计具有复核及完善价值,并增强了建筑物防雷可靠性。

武汉剧院保护修缮电气设计要点简析

针对文物建筑保护修缮设计的特点,以武汉剧院为例,分析文物建筑保护修缮时的设计难点;从电气用房、供配电系统、照明系统、设备和管线安装、防雷接地系统、火灾自动报警系统等方面阐述文物建筑保护修缮电气设计要点及相应解决措施。

智慧建筑电气安装项目中防雷接地施工技术研究

研究了智慧建筑电气安装项目中防雷接地施工技术。将建筑物中的主体钢筋作为防雷引下线的施工结构,建立防雷引下线的上部和接闪器之间的连接关系;以理想范围接地电阻强度为基础,针对性设计接地体埋深;确定等电位箱设备的位置后,统一防雷装置各支架的具体安装标准。在测试结果中,设计防雷接地施工技术下的接电电阻均达到了建筑的防雷要求,具有良好的应用效果。

雷达天线集成避雷针系统的雷电间接效应分析

有源雷达天线集成避雷针系统的雷击瞬态电磁场分布和雷电感应耦合特性是其进行雷击防护的基础。建立集成系统的三维电磁仿真模型,计算分析系统的雷击瞬态电磁场分布特性,发现天线内部雷击瞬态电磁场在靠近内表面部分相对较大,之后向中心部分快速衰减,天线阵面采用网状结构比采用栅格结构的电磁场屏蔽效果约强2个数量级。进一步通过开展实型天线集成避雷针系统模拟雷击试验,获取了天线系统内部不同端口的感应电压,结果显示,在天线上电状态下内部线缆的感应电压较不上电状态时高,当线缆紧贴天线舱内壁时,其感应电压较悬空布线时的感应电压分别降低了48.1%、68.9%和90.7%。本文取得的相关结果可为有源雷达天线集成避雷针系统的雷电电磁防护设计提供参考。

一种古建筑群的等效雷击截受面积计算方法

为了贯彻“预防为主,防治结合”的科学理念,实现安全可靠、技术先进、经济合理的综合性防雷设计,精确细致的防雷级别判定工作是做好古建筑群防雷保护的重中之重。该文给出一种古建筑群的等效雷击截受面积的计算方法,并以属于省级重点文物保护单位的某古建筑群的防雷级别判定为例,计算古建筑群预计年均受雷击次数,可实现其防雷等级的判定,对古建筑群做一个精确细致的防雷级别判定,为同类古建筑群的防雷等级判定提供参考。

高层建筑防雷检测技术研究

分析、探讨高层建筑雷电危害主要特点、防雷措施及检测技术特点,给出高层建筑尤其是超高层建筑检测中检测基准点的选取方法,从内部防雷、外部防雷、侧击雷防护等方面阐述防雷检测技术的各环节要素及注意细节,提出加强高层建筑防雷设施的日常维护和定期检测。

建筑物和设施外露防雷引下线防接触电压措施研究

分析3部现行国家标准中关于防雷引下线防接触电压的技术条文,研究人员可以接触到的外露引下线防接触电压措施;结合上海世博源这一实际工程案例,从安全可靠、经济合理、切实可行的角度出发,提出建筑物或设施外露防雷引下线防接触电压的措施要求。

既有建筑改造五星级酒店电气设计探讨

本文阐述既有建筑改造面临的规范标准变化、土建条件制约、图纸缺失现场复杂等难题,结合既有建筑改造五星级酒店的实际项目案例,针对变电所改造,发电机方案,消防电气改造,防雷系统改造及其他问题等提出合理可行的解决方案,最后针对既有建筑改造的普通性与特殊性进行总结。

广播电视大楼超高层建筑供配电系统的设计与研究

针对广播电视大楼超高层建筑电子设备易受雷击损害的问题,进行了超高层建筑供配电系统设计。结合某广播电视大楼工程实际,考虑到大楼的用电需求和安全性,进行了超高层建筑的避雷设施设置。结果显示,配备防雷器的直击雷电压为62V,在感应雷的作用下,配备防雷器的感应雷过电压最大值为60V,这两个数值均在变压器的耐受范围内。广播电视大楼超高层建筑供配电系统的设计,有效地保障了超高层建筑在雷电环境下的用电安全和稳定性。

建筑电气安装中的防雷接地施工

在建筑工程项目中,做好防雷接地施工作业对提升建筑电气设备稳定性、安全性有着重要价值。科技水平的不断进步也促进了电气行业的发展,建筑物内部的防雷接地系统施工难度更高。基于此,笔者首先对房屋建筑住宅进行防雷接地处理的必要性展开分析,然后结合实际案例,分别从接地体、引下线等几方面阐述了具体的施工技术要点,并对建筑工程防雷接地施工中的注意事项进行了分析,期望可以保障房屋建筑内部电气设备稳定运行,为用户营造一个安全、舒适的居住环境。

既有建筑改造项目中电气专业设计工作建议

城市更新大环境下,既有建筑改造项目的设计工作越来越多。由于建筑建成年代、建筑自身的特点、新旧规范更替等因素,给电气设计工作带来了一定的挑战。尝试从标准规范、电气专业自身及相关专业、政策法规等方面出发,勾勒出改造项目完整的电气设计工作内容及需要重视的节点。