高性能磁流体发电机发电通道的工程问题

本文概括地叙述了高性能发电通道工程发展的关键问题,特别是近年来国内的进展。     

烧煤磁流体发电机发电通道结构改进

本文叙述电功率百千瓦级烧煤磁流体发电机发电通道的结构改进要点，指出发电通道结构设计和加工装配中值得注意的技术细节，并讨论磁流体发电机结构设计的关键问题及发展趋势。     

爆炸磁流体发电机研究进展及其关键问题

磁流体发电是一种直接发电方式。对高功率脉冲电源需求领域而言，爆炸磁流体发电机的比功率很高，在10MW／kg上下，是可行的高功率微秒级脉冲电源。与其它种类脉冲储能装置相比，ED-MHD发电机的功率密度最高。从磁流体发电机通道的基本理论来看，其功率密度和效率的提高还有较大的空间。     

脉冲磁流体发电机

本文简介了脉冲MHD发电机的发展概况和工作原理,并讨论了一些典型脉冲MHD的概念,最后指出作为高功率脉冲电源的优点和应用潜力。     

一种新的脉冲磁流体发电机

在综合国内外研究的基础上,提出了一种新的毫秒级脉冲磁流体发电机(PMHDG)的设计方案,给出了电物理模型,并在电路的物理设计上采用了适当的高能密度电容作为辅助储能器,以便形成一种发电机-电容器联合的高功率脉冲电源,可供电炮直接应用。     

磁流体发电

磁流体发电是将热能直接转换成电能的新型发电方式。它的基本工作原理仍然是法拉弟电磁感应定律,与一般发电机不同的是用导电流体代替固体导体,并使导电流体以一定速度通过与其相互垂直的磁场,切割磁力线,从而产生电能。     

磁流体发电机测量系统数学模型

本文提出了一种方法,它应用以概率论为基础的误差理论,可判析微机数据采集测量系统的数据质量,并可在定标时自动建立采集系统的数学模型。经实验证明有效地提高了测量控制的精确度。     

燃煤磁流体发电通道的关键问题及其进展

本文简要介绍了目前磁流体发电技术已由实验室研究进入到工程研究发展以及燃煤磁流体发电通道区别于干净燃料通道的主要特点。重点论述了在工程研究发展阶段中燃煤磁流体发电通道的关键问题及国内外的进展情况。     

低压电网信道容量的研究

首先给出了低压电网信道模型在1MHz～10MHz频带内噪声特性的指数规律拟合公式与衰减特性的三阶自回归模型;然后应用信息论的输入功率最优分配算法计算出两种环境下的信道容量,分别为110Mbit／s和170Mbit／s;最后,基于给出的信道模型,给出了应用自适应正交频分复用(OFDM)的低压电网通信系统,在误码率为10^-6时,可达到约100Mbit／s的传输速率。结果表明,在1MHz～10MHz频带内利用中国低压电网实现高速数据的传输是完全可行的。     

Production of nonequilibrium plasma and MHD interaction in disk MHD channel

The production of nonequilibrium plasma and the fluid flow with the MHD interaction are examined experimentally with a shock‐tube driven disk channel with no loading electrodes. For low magnetic flux density and low seed fraction, where nonuniform and unsteady plasma is generated, the static pressure decreases monotonically in the radial direction, although the pressure increases in the entire region of the channel in comparison with the value under no MHD interaction. For magnetic flux density and seed fraction above some critical values, a fairly uniform plasma is produced. The static pressure, however, is found to increase abruptly in the channel and the total pressure is considerably reduced at the location, where the abrupt pressure increase occurs. These facts imply that steady and uniform plasma should be produced without locally constricted strong Lorentz force to improve the adiabatic efficiency of a disk MHD generator. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 42–49, 2002; DOI 10.1002/eej.1137     

Configuration optimization for a coupled 200-MWe MHD channel and magnet coil system

This paper reports on the results of the optimization of the cross-sectional shape of a magnet coil system including an MHD channel. This optimization was carried out for a 200-MWe supersonic Faraday-type MHD generator. It was shown that the channel length can be shortened more than 30 percent, without the decrease of the enthalpy extraction by the optimization of the coil shape from the crescent shape coil producing a uniform magnetic field. It was estimated also that the capital cost for a commercial MHD/steam combined plant can be decreased more than 6 percent by this coil shape optimization.     

串联混合有源电力滤波器的新型控制方法

带基波电流旁路通道的串联混合有源电力滤波器为电网电流中的基波成分提供了一个无源通道,因而可以大大降低有源部分的容量.然而,原有的基于Pq理论的控制方法在负载或电网不平衡时,基波旁路通道和逆变器之间会发生基波谐振,使得逆变器仍然会流过大量的基波电流.逐相dq变换法可以完整地将基波或谐波检测出来.文中提出了基于逐相dq变换的控制方法,使得不论电网电压和负载电流是否平衡,基波旁路通道和逆变器之间均不会发生基波谐振现象,逆变器只需承担电网谐波电流和提供谐波电压,提高了系统的性价比.5 kW的模型试验证明了新方法的可行性.     

尾气煤气化磁流体--蒸汽联合循环的研究课题

本文对尾气煤气化磁流体－蒸汽联合循环的概述及研究方案进行了探讨,对联合循环的质量和能量平衡及效果进行了分析。     

磁流体发电机电极消耗规律的实验研究

本文叙述关于磁流体发电机电极消耗规律的实验研究结果，实验乃利用中科院电工所的电极单元试验装置，在模拟工况条件下进行，实验着重考察了放电以及熔渣层的影响。     

Stability of large-scale coal-fired MHD channels

Stability of large-scale coal-fired MHD channels is studied by (1) linearized stability analysis, and (2) time-dependent 1-D analysis. The channel length is 15 m with 600 electrode pairs, and the output power ranges from 220.6 MW through 258.7 MW. Linearized stability analyses show that the Faraday channels operated with fixed loading resistance are stable, whereas the two waves of u and u–a (u, a: gas and sound velocity) become unstable in the Faraday channel with fixed loading factor. Two waves of u and u–a are unstable in the diagonal channel with fixed loading current and the u + a wave becomes unstable in the diagonal channel with fixed electrode current. Time-dependent one-dimensional analyses indicate that the Faraday channels with fixed load resistance are smooth without growth of fluctuation. The diagonal channels with fixed electrode current are smooth with no fluctuation, though the linear theory indicates that the u + a wave is unstable. The diagonal channel with fixed load current suffers large disturbance along the latter half of the channel, being consistent with the linearized analysis which indicates that the u - a and u waves are unstable.     

Measurement of Faraday current in a disk MHD generator

The Faraday current flowing in a circumferential direction in a disk MHD generator was successfully measured using the Rogowski coil method. This fact allowed us to estimate the radial distributions of fluid and electrical properties, such as the gas flow velocity, Hall parameter, and electrical conductivity, from the experimental data. In this paper, a system for measuring the Faraday current measuring system and its calibration method are described in detail. As an example of the experimentally estimated properties, factors governing total pressure reduction along the radial direction are described. © 1998 Scripta Technica, Electr Eng Jpn, 125(4): 19–25, 1998