斜框型磁流体发电机中临界磁场的研究应用

磁流体发电是一种高效、低污染的发电技术,相对于其他发电方式,磁流体发电具有输出功率大、结构紧凑的优点,在短时、高功率电源领域运用有着不可替代的性能优势。认为斜框型磁流体发电机中的电流在一定磁场范围内会产生饱和,并就这一问题首次提出了临界磁场理论并推导出临界磁场的方程式。临界磁场的提出,是在研究磁流体发电机的通道性能问题上提出了新的思路,有利于超导磁体在磁流体发电机上应用问题的研究。     

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。     

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。     

等离子体射流在磁场作用下的特性模拟

磁流体发电是一种高效、低污染的发电技术。相对于其他发电方式，磁流体发电具有输出功率大、结构紧凑的优点，在高功率电源应用领域有不可替代的性能优势。文中提出采用非平衡等离子体射流的方式产生等离子体，进行磁流体发电的设想。通过数值模拟研究了等离子体射流在横向磁场作用下的特性，并通过试验对模型计算结果进行了验证。模拟研究说明横向磁场对等离子体射流有阻滞作用，在没有外电流回路的情况下，射流气体的动能转化为热，随外加磁场强度的增加，阻滞作用越强，速度减慢越明显；等离子体射流在磁场作用下电流密度主要集中在射流出口附近，并随着外加磁场强度增大而增大。     

高压快脉冲电源的几种型式

近二十多年来由于粒子束惯性约束核聚变,激光惯性约束聚变、电磁脉冲、脉冲X射线、离子加速器等等重要科技领域的发展需要,利用秒级放电的电动发电机组,秒级暂冲式磁流体发电机和微秒爆炸压缩磁通发电机作为快脉冲电源都不能满足要求,快脉冲电源因而得到了迅速的发展。当前世界上各种快脉冲电源均己发展到相当高的水平:麻克斯发生器型     

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。     

磁流体发电煤燃烧室研究的进展

一、前言磁流体发电是一种新的发电方式。在磁流体发电机中,等离子体作为工质高速通过磁场把热能直接转换成电能。磁流体发电机的燃烧室,实质上是一种等离子体发生器,这种等离子体电导率的高低和均匀度直接影响发电机的性能,因此它是个十分重要的部件.在燃煤的磁流体发电系统中,煤的燃烧和灰渣引起一系列问题。比如灰渣对等离子体的电离特性、电     

Perkins:发电设备市场的全方位供应商

Perkins一向致力提供最优质的发电用动力系统,多年来Perkins已成为低油耗、高功率发动机的同义词. 4016-61TRG柴油发动机提供卓越的功率密度和紧凑尺寸,开发的目标是提供高性价比的常用及备用发电机的动力系统.     

改进型补偿脉冲发电机电流成形分析

补偿脉冲发电机集能量存储、机电能量转换、脉冲成形于一体,被认为是电炮武器系统的首选高功率脉冲电源。在传统补偿脉冲发电机结构基础上,以能产生较宽平顶波的选择被动式补偿脉冲发电机为研究对象,通过改变电刷和换向片结构,对比分析了在不同点火角度、电枢与励磁绕组相对位置、不同耦合深度下的电流波形特点。仿真计算表明:补偿角度的变化显著影响脉冲峰值的大小;随电枢绕组初相角增大,脉冲初始阶段的一段负脉冲增强;两绕圈耦合深度越大,波形起伏越大。通过计算及有限元模型仿真分析,证明改进后的结构可使电机内电感下降,同时选择被动式补偿脉冲发电机可以获得更高功率的脉冲电流和较理想的频谱分布。     

磁流体发电机微机数据采集与处理系统

本文介绍我国第一台用于磁流体发电研究的微型计算机数据采集与处理系统,包括硬件结构简介和磁流体发电数据处理软件主要功能,并且附有部份磁流体发电机性能分析图表。     

超级电容器用于建立强脉冲磁场的可行性研究

为解决爆炸磁流体发电机应用设计中储能高压脉冲电容器存在的一些缺点,提出了一种以超级电容器替代高压脉冲电容器作为储能器件建立强脉冲磁场的设计方案。在给出脉冲放电回路中超级电容器的等效电路模型、超级电容器模块的设计原则和储能系统管理方案后,对超级电容器模块振荡放电和非振荡放电两种类型进行了分析计算。超级电容器模块和高压脉冲电容器模块的放电电流仿真波形和模块参数的对比结果表明,在产生同样大的脉冲电流下,超级电容器模块放电持续时间更长,在体积和重量上有一定的优势,用于建立强脉冲磁场是可行的。     

Performance and conceptual design of superconducting magnet for disk MHD generator

This paper describes superconducting magnets coupled with two kinds of disk-type MHD generators. One is coupled with a disk generator in the closed-cycle MHD experimental facility FUJI-1. The other is for a full-scale disk MHD generator. These are split-pair magnets. In the magnet for the FUJI-1 facility, a unique structure which supports the coils against the electromagnetic force has been fabricated and the magnet has been operating stably. During MHD power generation experiments, an induced voltage across the terminals of the coil was measured. A magnitude of the Faraday current in the generator was calculated from this induced voltage. A possible construction of magnetics for a full-scale disk MHD generator is indicated. It is suggested that a high performance of the generator (output power density of 0.3-1 GW/m³) can be obtained with high magnetic field up to 10 T.     

Development of capacitive-coupled hall-type MHD generator

We have demonstrated a capacitively coupled Hall-type MHD generator using ECR plasma. To clarify the characteristics of the fabricated MHD generator, we measured the power generation characteristics as a function of magnetic field strength using a DC Hall-type MHD power generation experiment. The results showed that the output power decreased due to magnetic pressure at the higher magnetic field. However, the output power corresponded to the theoretical value at the lower magnetic field. An AC Hall-type MHD power generation experiment was conducted using an AC magnetic field. As a result, full-wave rectification voltage was observed as per theory. Finally, capacitively coupled Hall-type MHD power generation experiments were conducted, and full-wave rectified waveforms were observed as in AC Hall-type MHD power generation. These waveforms were similar to the output waveforms predicted from theory. These results show that the capacitively coupled Hall-type MHD generator is feasible.     

Power Generation Experiments with a High Temperature Inert Gas Plasma Faraday Type MHD Generator

MHD power generation experiments have been conducted by using a single‐pulsed shock‐tunnel facility, where a high‐temperature inert gas (pure argon) at a fixed total temperature of 9000 K is introduced into a linear Faraday generator without seeding. The fluctuations in the output power and light emission from the plasma are found to be small, and the pure inert gas plasma seems to be rather consistently free of ionization instability. The output power is improved by increasing the magnetic flux density in near‐quadric fashion and the enthalpy extraction ratio does not depend on the inlet total pressure (11.2% to 12.9% for 0.063 MPa to 0.105 MPa). The generator performance obtained is competitive with or superior to that of existing seed plasma MHD generators.     

kV/ MHz 高重频可重构脉冲产生技术研究

针对当前超快脉冲和超高重频脉冲产生技术需求,基于固态半导体开关技术和脉冲合成技术,提出了一种基于延时触发控制的高重频可重构脉冲产生方法,研制了kV/MHz高重频可重构脉冲源原理型装置。测试结果表明,该脉冲源能够稳定输出幅度为1 kV、重复频率1 MHz、前沿时间约700 ps的亚纳秒脉冲,通过精确调节各脉冲触发时间顺序还可灵活改变脉冲前沿、脉宽和波形等参数,并能实现1～50 MHz重复频率的参数调节,可有效满足电子对抗、超宽带探测及通信等行业领域的应用需求。     

用于产生非平衡等离子体的纳秒级脉冲电源研制

为了给非平衡等离子体相关实验提供ns级高压脉冲,研制了一台基于传输线变压器(transmission linetransformer,TLT)原理的高压重频ns脉冲电源,通过在传输线外套加磁环增加二次阻抗,提高TLT的输出电压和能量传输效率。同时设计了一种电容-开关-传输线的紧凑化同轴结构。实验表明,在连接匹配负载条件下,电源输出脉冲电压峰值可以达到26kV,脉宽100ns,上升时间25ns,可在500Hz频率下稳定运行。同时成功地将其应用于大气压氩气等离子射流实验,发现与正弦电压相比,相同电压峰值下,脉冲电源作用下的等离子体射流长度更长,但2种电源作用下的射流长度均出现饱和现象,同时电源频率对射流长度无明显影响。     

Power control of coupled nonequilibrium disk MHD generator and line-commutated inverter system

A new power control method is proposed which is suitable for the MHD power generation system which consists of nonequilibrium disk generator and line-commutated inverter. The thermal input of the generator is controlled by changing the inlet stagnation pressure, whereas the seed mass flow rate instead of the inlet stagnation pressure is utilized as a manipulated variable of power control system. It is possible that the proposed method can realize both high performance for part load operation and fast output power control of which the time constant is much shorter than the response time of thermal input. Numerical simulations are carried out for the MHD power generation system connected to infinite bus and then it is confirmed that the system is stable and shows excellent power control performance.     

Three-Dimensional Flow Analysis in a Faraday-Type MHD Generator

This paper studies the development and analysis of the 3-D flow fields in a Faraday-type magnetohydrodynamic (MHD) generator. A large-scale pulsed MHD generator with a Faraday channel of 4.5 m has demonstrated the maximum electric power output of 510 MW. The results of the present development and simulation are compared with the experimental results of the pulsed “Sakhalin” MHD Generator power generation system. As a result, they show close agreement with experimental ones. The development of the 3-D flow, current density distribution, and generated power are presented as well.      

New power consolidation-inversion-control system for faraday MHD generator

The authors propose a new power consolidation-inversion-control system for the Faraday MHD generator using the voltage source PWM inverters. The dc output power for each electrodes pair of the MHD generator is at first inverted into three-phase ac power by a voltage source PWM inverter, and then the ac powers are consolidated by transformers. The proposed system does not need such expensive equipment as an ac filter or phase modifier and can independently and simultaneously control the active and reactive powers provided to the electric power system. Numerical simulations of the whole system, including the Faraday MHD generator, the proposed power consolidation-inversion-control system, and the electric power system, show that the proposed system can stably and steadily transmit and control the electric power from the MHD generator to the electric power system. It is also confirmed that the proposed system can independently and simultaneously control the active and reactive powers and can be used as a fast power controller.     

Numerical Study on Periodic Structure Evolution of Output Power in MHD Generator by Using Pulse‐Assisted Ionization Discharge

A pulse‐assisted ionization discharge applied to a magnetohydrodynamic (MHD) generator is proposed as a technique to increase an electrical conductivity of working fluid. In this study, a periodic structure of output power in the MHD generator by using pulse‐assisted ionization discharge was evaluated. As a result, the discharge electrode length and the velocity of working fluid affect the discharge current distribution. The periodic structure of output power was observed in the several conditions. When the velocity of working fluid is roughly same as the sound speed, the periodic structure of output power was not observed.