共查询到20条相似文献,搜索用时 93 毫秒
1.
2.
3.
4.
5.
英国标准BS6351-1983表面电加热第2部分:表面电加热系统设计指南(续)附录B螺距的计算通常是每米管道所需的瓦数要比单根直槽的电缆(带)所能提供的瓦数多。解决这个问题的两种最通常的办法是,电缆(带)沿着许多直线糟走或在管道上呈螺旋状。螺距可从表... 相似文献
6.
针对铂金通道电加热控制系统,选用带VSC调节功能的调功器,通过PROFIBUS-DP通信卡件建立现场级工业通讯网络,由西门子PCS7上位系统对铂金通道进行加热控制设定和温度的PID整定。通过合理的计算选型和控制模式的选择,提高铂金通道温度控制的精度和系统可靠性。 相似文献
7.
饮水行业推广全自动电热膜沸水器节能效果好淮北矿务局朔里煤矿黄儒林全自动电热膜沸水器,采用的是电热膜加热元件和气液两相流提升原理。在饮水行业中是当今新一代科技产品,热效率高,节能效果好。它比传统式电加热热水器,各项性能都优越。传统式电加热热水器,冷热水... 相似文献
8.
9.
10.
基于太阳敏感器的移动式太阳跟踪控制系统研究 总被引:1,自引:0,他引:1
针对移动设备太阳能供电需求问题,开展了高精度移动式太阳跟踪控制系统研究。采用一种新型的大视场、高精度太阳敏感器,基于双轴跟踪方式研制了移动式太阳跟踪装置;并针对移动平台不间断晃动、非直线行驶、转弯导致跟踪不稳、精度降低甚至跟踪目标丢失等问题,结合太阳敏感检测特点,提出了选择性位置式PID跟踪控制策略。对跟踪系统进行了车载试验,结果表明,相比于传统的四象限传感器跟踪,基于太阳敏感器的跟踪系统搜寻视野达120°,精度达±0.5°,具有响应速度快、跟踪精度高、稳定性好、目标丢失后找回快等优点。本文为移动式太阳跟踪提供了一种可靠可行的新方案,该方案稍加改进还可用于高空太阳电池标定等领域。 相似文献
11.
12.
Self-regulating ceramic heating systems that operate without conventional thermostatic controls are now being designed into heated appliances. The result is longer life, lower cost, and more streamlined appliance packaging. The development appropriately comes at a time when end of life safety is receiving increased attention, cost reductions in heater-thermostat systems are producing diminishing returns, and the volume of heated portable appliances for personal care and food warming is growing rapidly. The Semiconducting barium titanate heaters undergo a crystalline phase change and resultant resistivity increase in the vicinity of the ferro-electric curie temperature. This characteristic provides high initial power at which point the sharply increasing heater resistance reduces power to the required steady-state level. Positive temperature coefficient (PTC) barium titanate has been used since the 1950's for low voltage sensors, but was only made available for appliance heaters by the recent development of line voltage materials for a different segment of industry?color television. One third of all color sets now use 120-V PTC degaussing elements. The paper discusses the complex thermal design considerations involved in the development of a PTC heater for 10-200 W appliances and reviews the application of a PTC heater to a food warmer. 相似文献
13.
14.
针对目前普遍使用的便携式烟气分析仪存在因烟气中水蒸汽结露冷凝而严重影响测量结果的缺陷,提出"电加热+稀释"取样法,开发出双气路加热枪,设计出一套准确、简单、成本低的SO2测试采样装置. 相似文献
15.
针对传统的水质检测仪器存在因体积过大使用不便,检测参数单一以及不能对水质进行实时监控显示的问题,设计了一款便携式水质在线检测仪.设计以STC8A8K64S4A12单片机为控制器,由温度采集模块、pH测量模块、TDS检测模块等完成水质的温度、pH及TDS参数的检测;通过ESP8266无线模块、手机App模块的设计与应用,... 相似文献
16.
Baird P.J. Herman H. Stevens G.C. Jarman P.N. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2006,13(2):293-308
A portable fiber-optic spectroscopic system (TRANSPEC) has been developed for nondestructive measurement of aged transformer insulating paper. Following successful measurement of degree of polymerization (DP) of a range of transformer-aged paper samples, the system has now been shown to separate the oil and paper information for measurement of DP in oil-wetted paper samples. In addition, the system has been shown to be capable of the prediction of both oil and water content of paper to a high accuracy, and is also capable of identifying and quantifying different water species. Spectroscopic measurements have been used together with gravimetric water adsorption measurements to investigate the kinetics of uptake of water vapour into paper from air in the case of nominally dry and oil-impregnated samples. Relationships between water adsorption parameters and properties of the paper insulation have also been investigated using measurements under controlled conditions. 相似文献
17.
以上海220 kV济南站为例,对220 kV全地下变电站火灾危险性进行分析,结合规范确定消防灭火系统的技术原则和策略,介绍了室内外消火栓、预作用自动喷水灭火、主变水喷雾灭火、烟烙尽全淹没气体灭火、移动式灭火、火灾探测报警和消防排水等系统;以及济南站消防系统设计的方法、经验,并对消防系统的优化提出建议。 相似文献
18.
为研究1000kV交流输电线路带电作业的保护间隙,确定了它的设计原则和电极结构,根据该保护间隙工频击穿、工频耐压、操作冲击放电试验的结果得出了不同海拔高度下1000kV输电线路带电作业保护间隙间隙距离的最大允许值;在11塔窗中模拟带电作业各实际工况,采用升降法对保护间隙与作业间隙的绝缘配合进行了操作冲击放电试验,验证了保护间隙对带电作业间隙的保护性能,并计算了1000kV带保护间隙带电作业的危险率。最后证明加装保护间隙不仅可提高作业的安全性,而且能有效地减小塔头尺寸。 相似文献
19.
随着无线电能传输技术的不断发展,其在便携式设备中展现出良好的应用前景。相比传统的有线充电,便携式设备无线充电的方式具有灵活、便捷、高通用性等优点,但在实际应用中又存在其特殊性。为此,该文对便携式设备无线充电技术的发展现状进行了梳理,首先介绍了现有的便携式设备无线充电产品的主流标准;然后给出了系统的基本结构,并归纳了其特点;接着根据上述特点从平面线圈设计、空间无线电能传输、异物检测、多负载、电磁问题等方面论述了便携式设备无线充电关键技术的研究现状;最后展望了便携式设备无线充电技术今后进一步的发展方向。 相似文献