一种超临界二氧化碳布雷顿循环

为提高布雷顿循环热效率,在现有超临界二氧化碳布雷顿循环的基础上,提出一种基于回热技术的分级压缩与分级膨胀相结合的再压缩布雷顿循环方案,运用热力学计算软件EES对该循环参数进行热力学分析。结果表明,当分流系数约为0.47,透平入口温度为950 K,透平入口压力为29.0 MPa时,循环热效率为59%。当透平入口温度一定,分流系数在0.47～0.48时,循环热效率最高。在透平入口压力从20.0往29.0 MPa升高的过程中,最佳分流系数从0.39逐渐增加到0.47。在回热度从0.5增长到0.6的过程中,最佳分流系数从0.47增长到0.50。     

通风定压旁通阀装置介绍

简要介绍通风定压旁通阀装置的技术背景、产品构成、动作原理及应用领域。     

并联电容器组熔断器“群爆”故障分析

首先对变电站内可能引起并联电容器组熔断器"群爆"的因素进行了详细的分析,根据其呈现的现象和特征,指出了导致故障的根源以及整改方案;通过整改方案的落实,避免或减少变电站电容器组熔断器"群爆"故障的发生。     

并联混合型有源电力滤波器的系统参数设计及应用研究

根据大容量谐波抑制兼无功功率补偿的要求，从达到滤波效果和经济成本最小两个方面考虑，该文提出了一种并联混合型注入式有源电力滤波器（Hybrid Active Power Filter, HAPF）结构，并对该新型有源电力滤波器有源和无源部分的参数设计进行了研究，形成了一套混合型大容量有源滤波器的参数设计方法。以该方法设计的HAPF在某冶炼厂谐波治理工程中得以应用，体现出较好的滤波效果和优良的性价比，具有良好的工程推广应用前景。由于目前国内有源滤波器的工程应用实例极少，因此该套设计方法对其它HAPF的研究与应用还可起到一定的指导和借鉴作用。     

自愈式高压并联电容器的内熔丝保护和寿命试验研究(续)

对自愈式高压并联电容器运行中的主要缺陷进行了研究 ,明确了局部放电是影响寿命的主要原因 ,采取了新的保护措施 ,使得自愈式高压并联电容器元件顺利地通过了耐久性试验。     

三相并联电容器在油田线路分散补偿中的应用

阐述了高压三相并联电容器主要技术性能指标。分析了它在油田线路上分散补偿的优点 ,补偿容量的分配及实际应用中的各个参数的变化。说明三相并联电容器在线路分散补偿中 ,具有运行稳定可靠 ,补偿效果明显 ,在全国各油田及部分农电线路上运行取得较好的节能效果。     

关于金属化膜高压并联电容器几个问题的探讨

对金属化膜高压并联电容器内熔丝的考核方法、不自愈时的保护以及与断路器开断时间的配合等问题进行了讨论。     

Ideal 4H-SiC pn junction and its characteristic shunt

The results of a study of forward current–voltage characteristics of 4H-SiC pn structures produced by various methods are presented in this paper. In all pn structure types a forward current was identified which is consistent with the model of recombination in the space charge region via a deep level: J=J_o exp(qU/nkT), where J_o=J_o^* exp[−E_a/(kT)] (or J=J_o^* exp[(qU−2E_a)/nkT)]) with the ideality factor n=2. The values of the other parameters are as follows: J_o(293 K)(10⁻²⁴–10⁻²⁵) A cm⁻², E_a≈1.75 eV, J_o^*(10⁵–10⁶) A cm⁻². In the absence of other leaks, this current represents a natural (intrinsic) shunt for the diffusion current at low biases and determines the value of the injection coefficient of a pn junction. In many of the pn structures the forward current, while showing an exponential dependence on voltage and temperature, was significantly higher than the current described above. The ideality factor, in some instances, was close to unity. A situation with such characteristics can be considered as an ideal extrinsic (due to nonuniformities) barrier type shunt. The potential barrier height of this shunt is ≈1.4 eV. This sort of shunt is characteristic of SiC; earlier a similar object, presumably of the same origin, was identified in 6H-SiC pn structures.     

Magnetic alloy cores for the HIRFL-CSRm compressor cavity

Four types of magnetic alloy cores,labeled as V1,V2,A1 and A2,were produced by Liyuan Corp.Ltd.,for the radio frequency compression cavity of HIRFL-CSRm.In this work,their permeability,quality factor (Q value) and shunt impedance were measured before installing them into the cavity.The results show that the V1,V2 and A2 have higher permeability and shunt impedance,and lower Q value,and are suitable to the radio frequency compression cavity.     

10kV电力电容器跳闸故障的原因解析

介绍了某无人值班变电所10kV电力电容器开关跳闸的经过，阐述了跳闸的原因，通过电力电容器保护整定分析和电容器容量与升压值的计算，合理利用并联电容器在系统中的调压作用。