非晶合金铁芯配电变压器的结构特点和节电效果

介绍了非晶合金铁芯变压器及其铁芯材料的特点和性能；阐述了推广采用非晶合金铁芯变压器，既可取得节能效益，也可取得环保效益。     

国外高压共轨喷油器电磁阀结构分析

从结构和材料两方面分析了博世公司和电装公司的共轨喷油器电磁阀.分析表明:两家公司的技术路线完全不同.博世公司采用球阀密封,衔铁和衔铁杆分离;铁芯和衔铁材料为合金结构钢;衔铁采用渗碳淬火处理.电装公司采用平面阀密封,预紧力较小;铁芯材料为粉末冶金;衔铁工艺复杂,吸合面为软磁性能较好的粉末冶金材料,撞击面为硬度较高的高速钢...     

节电新方法

人们用电力变压器把电力线路上的电压降到家庭和企业用户的电压等级。但是,电力变压器的转换效率不高,因为变压器的铁芯每秒要磁化和退磁几十次,所以消耗了电能。有一种非晶形金属材料,这种材料的原子是自由排列而不是紧密排成排,因而很容易被磁化和退磁,采用这种材料制作变压器的铁芯可以使电力的转换效率提高。 多年来,由于制造连续带状非晶形金属的工艺问题没有解决,阻碍了高效节能变压器铁芯的发展,因为只有先将非晶形金属制造成带状后,才能卷绕成变压器的铁芯。现在,奥里得一辛纳(Allied-Signal)公司已     

非晶合金铁芯配电变压器

介绍了非晶合金导磁材料的性能以及非晶合金作铁芯的配电变压器的特点及节能效果。     

无芯工频感应炉用平衡电抗器的设计与计算(续)

四、铁芯温升的计算. 此计算公式是根据干式变压器铁芯的温升计算方法,将铁芯和线圈看作互不影响的发热体,求出铁芯之温升τ_o~′,然后再考虑铁芯与通水线圈之温升不同的相互影响,求出铁芯温升校正量Δτ_o,再将所求之温升进行校正,即为所求之实际平均温升τ_o。     

微机励磁涌流抑制器在核电主变启动中的应用研究

CPR1000核电厂主变启动只能以全电压冲击合闸的方式进行,由于变压器铁芯饱和、铁芯材料的非线性及剩磁的存在,会产生励磁涌流,导致差动保护误动,同时可能造成绕组变形。分析铁芯磁通的暂态特性,找出励磁涌流的根本成因,在分析励磁涌流抑制器原理的基础上,利用EMTP/ATP搭建了变压器空载合闸暂态仿真模型,分析合分闸时间的允许误差范围。在阳江核电2号主变首次启动过程中,利用仿真的定量分析,指导涌流抑制装置调试,通过实际验证涌流抑制器的确发挥了良好的抑制效果。     

高压共轨燃油系统涡旋叠片高速电磁铁的研制

介绍了一种新的柴油机高压共轨喷油系统高速电磁铁铁芯 ,新铁芯由许多厚度相等的涡旋形铁片堆叠而成。构成铁芯的方法之一是采用渐开线直纹面作为涡旋形铁片的理论曲面。铁片与铁片之间无间隙 ,电磁铁线圈安放在铁芯的沟槽内。它比常见的E形叠片电磁铁铁芯结构紧凑 ,性能更好。试验结果表明 ,新的电磁铁铁芯能满足ECD -U2高压共轨喷油系统的要求     

非晶合金配电变压器的节能效果分析

非晶合金配电变压器的节能效果分析哈尔滨市市郊农电局范化成哈尔滨重型机器厂范宇飞１概述众所周知，磁路系统是变压器结构的一个主要部分，导磁材料的性能直接影响变压器的技术经济指标。在本世纪内变压器铁芯不断改进。１９６０年美国发现一种新的导磁材料，在制造过程...     

取能电流互感器的有限元分析

为解决取能电流互感器的在线取能电源设计时,当一次电流较大导致取能铁芯饱和从而使铁芯输出功率难以量化计算分析的问题,利用有限元方法对电流互感器取能电源进行了建模及分析,通过对一实际开口铁芯取能电源进行建模仿真,得到了不同母线电流及负载下铁芯的输出功率及负载电压波形,利用取能铁芯的磁感应强度云图定量分析了铁芯饱和情况。模型仿真结果与实际开口铁芯电源的实测结果的对比验证了模型的正确性。该模型可用于指导实际电源的参数设计。     

基于对称绕组的水轮发电机定子铁损试验中圆周磁场的分析

为分析对称绕组布置形式的适用性,以某40 MW水轮发电机为例,根据麦克斯韦电磁场基本原理,建立了基于有限元法的定子铁芯仿真模型,在忽略集肤效应等影响因素的情况下计算了铁损试验中对称绕组的定子铁芯在不同磁导率、不同位置的电磁参数,并结合现场试验数据与计算结果进行了对比。结果证明,在相同的激励源情况下,圆周磁场内特定两点位置的磁场强度比值较小,圆周磁场强度与相对磁导率变化成正比关系,对称绕组布置方法对于不同材料的该型定子铁芯均有较强的适应性。研究结果可为铁损试验分析及诊断提供参考。     

可变偏心距风力机应力应变特性研究

针对新型可变偏心距风力机,通过数值模拟及实验测试的方法,研究偏心距离对风轮、塔筒及侧偏调节机构受力的影响。结果表明,在来流风速增大的条件下,可变偏心距风力机通过增大偏心距可减小叶片受力,风轮向右侧偏心100 mm时叶片最大应力是未偏心工况的86%;随着偏心距离的增大,塔筒在俯仰方向受力增长趋势放缓,受风轮偏转角增大的影响,塔筒在侧弯方向受力处于持续增大的状态;在向右偏心距离增大的过程中,风轮侧偏调节机构应力及应变逐渐向右侧集中,最大应力、应变始终处于中间部位,结果验证了偏心距调节方式的可行性及安全性。     

亚临界锅炉集箱水压试验工艺

本文主要阐述了亚临界锅炉集箱水压试验的难度及解决方案 ,如集箱上小管接头、大管接头密封问题 ,集箱上三通、弯头、敞口集箱的密封问题 ,水压试验场地问题 ,集箱水压后三通、弯头、敞口集箱的机加问题 ,制造成本和生产周期问题。此项研究的成功 ,使我公司的集箱制造水平有了很大的提高 ,保证了所有集箱焊缝不泄露 ,使我公司的产品质量进一步得到用户的认可     

基于钻孔CT溢洪道底部溶洞稳定性影响参数敏感性分析

溶洞分布具随机性,为研究岸边式溢洪道底部溶洞的稳定性及溶洞的应力、位移的敏感性,首先用钻孔CT对溢洪道底部分布的溶洞进行探测,根据探测结果,利用有限元ANSYS软件建立模型,采用单一变量法分析了溶洞分布于溢洪道底板不同位置时溶洞自身的应力、位移敏感性。结果表明,溶洞的宽度大于闸室宽度情况下,溶洞位置越靠近溢洪道底板,溶洞应力、位移最大值逐渐增大,溶洞顶板距溢洪道底板的距离小于等于溢洪道底板宽度的18.42%情况时,属敏感距离,溶洞宽度大于等于溢洪道底板宽度的80.0%情况时,属敏感宽度。     

O形橡胶密封圈封油结构研究

对O形橡胶密封圈的密封机理、密封形式进行了介绍,并阐述了其封油结构设计要点。结合理论对J11系列涡轮增压器O形橡胶密封圈封油结构进行改进,减少了增压器润滑油泄漏的可能性。同时,为J8系列涡轮增压器封油结构的改进作了有益的探索。     

Economie d'énergie en trigénération

Trigeneration is defined as the production of three useful forms of energy—heat, cold and power—from a primary source of energy such as natural gas or oil. For instance, trigeneration systems typically produce electrical power via a reciprocating engine or gas turbine and recover a large percentage of the heat energy retained in the lubricating oil, exhaust gas and coolant water systems to maximize the utilization of the primary fuel. The heat produced can be totally or partially used to fuel absorption refrigerators. Therefore, trigeneration systems enjoy an inherently high efficiency and have the potential to significantly reduce the energy-related operation costs of facilities. In this paper, we describe a model of characterization of trigeneration systems trough the condition of primary energy saving and the quality index, compared to the separate production of heat, cold and power. The study highlights the importance of the choice of the separate production reference system on the level of primary energy saving and emissions reduction.     

Performances and acoustic noise of micro multi-blade fan

In this paper, the performances and the acoustic noise of the traditional type micro multi-blade fan were investi- gated experimentally and numerically, to optimize the specifications of the fan for the resident circumstances. The acoustic noise level decreases but the efficiency deteriorates slightly with the increase of the blade number of the impeller. Besides, the acoustic noise decreases with the increase of the distance between the impeller outlet and the volute tongue, in accompanying with the increase of the input and the deterioration of the fan efficiency.     

The economic effects of energetic exploitation of straw in Vojvodina

The autonomous province of Vojvodina is an autonomous province in the Republic of Serbia. It is located in the northern part of the country, in the Pannonia plain. Vojvodina is an energy-deficient province.Assessment of the effects of energetic use wheat straw is performed for certain types of systems for storing straw and straw stored specifically in the form of small square bales, and especially for the cylinder-shaped straw bales. The method of evaluation of economic effects is based on the total cost of collecting, transportation, handling and storing, with corrections for the difference in the cost of the energy conversion and combustion.With comparison of the costs of energy production from baled straw to the costs of energy production from hard coal, it was found that the energy obtained from the straw from own farm is cheaper than energy from hard coal by 28%, in the case of the using small square bales and by 34% in the case of the using cylinder-shaped bales. Through sensitivity analysis it was concluded that the two systems of collecting straw, economically, are relatively resistant to changes in prices of the most important inputs. However, there is a relatively high sensitivity to changes in performances of machines with a larger percentage increase of costs for the system with cylinder-shaped bales. However, this system is generally more resistant to changes of influencing factors due to lower basic costs per ton of the pretreated straw. Differential costs analysis, i.e., the development of differential calculations, shows that the energy from straw in the form of small square bales is cheaper than the energy from hard coal by 51%, while the energy from the straw in the form cylinder-shaped bales is cheaper by 60%.     

加氢工艺对异构基础油性质的影响

在微反装置中,考察了反应温度和液时空速(LHSV)对加氢裂化尾油(HTO)、减四线油(VGO)加氢异构基础油性质的影响。通过气相色谱(GC)/质谱联用仪(MS)方法,对HTO、VGO加氢异构产品的族组成和碳数分布进行表征,结果表明:HTO和VGO均可作为通过加氢异构工艺生产APIⅡ+类基础油的原料。基础油的黏度指数随空速的降低而降低,随反应温度的升高而降低。基础油馏分中正构烷烃基本消失,说明所用催化剂具有良好的异构性能,基础油倾点随空速的降低而降低,随反应温度的升高而降低。原料的裂化反应程度随空速的降低而升高,随反应温度的升高而升高。通过族组成分析,推断出对基础油的产品性质发生影响的主要因素有:正构烷烃的异构化反应,异构烷烃的二次异构反应,单、双环化合物的支链异构反应,单、双环化合物的环压缩异构反应,多环烷烃化合物部分开环反应,芳烃化合物加氢饱和和开环反应。此外,加氢裂化反应也可改善产品的低温流动性能,但会损失目的产品收率。     

Entropy stabilization of deformed regions characterized by an excess volume for hydrogen storage applications

A general framework using the universal equation of state is given to quantify the excess entropy present in deformed regions of metals and metal hydrides characterized by an excess volume. The conditions under which the excess entropy leads to a stabilization of the deformed regions with respect to multiple hydriding/dehydriding cycles are determined. The impact of the energy barrier created by the excess entropy on the recrystallization rate of the deformed regions is quantified using a homogeneous nucleation and crystal growth model. At high temperature, due to the energy barrier, metal hydride systems containing a large excess volume can have a recrystallization rate that is several orders of magnitude smaller than the recrystallization rates of regions containing low excess volume. This entropy stabilization can create a regime where the reduced enthalpy of formation of the metal hydride could be maintained over multiple cycles because of the increased stability of the nanostructures responsible for the reduction in the enthalpy of formation.     

李家峡水电站地下洞室围岩稳定探讨

通过对李家峡水电站地下洞室轴线与岩体构造组合关系、影响洞室围岩稳定的因素的探讨 ,提出工程实践中应详细掌握岩体构造、地应力和地下水分布的特点 ,及时调整洞室衬砌和支护方案 ,是保证洞室安全、施工安全、施工进度的关键