【作者】 李胜；

【导师】 饶波；

【作者基本信息】 华中科技大学 ， 电气工程， 2022， 硕士

【摘要】 HFRC(HUST Field Reversed Configuration)装置是基于场反位形等离子体对碰融合与磁压缩概念而设计搭建的实验装置,其由电源系统、磁体系统、脉冲注气系统、真空抽气系统及控制系统等共同组成。由于在电离气体时刻的气压条件会影响到形成的等离子体参数,因此脉冲注气系统需要与电源系统在时序上相互配合。本文的主要工作是对脉冲注气系统的设计及初步搭建。本文首先分析了脉冲注气系统的设计要求,并提出利用超声注气实现气体分布控制的思路。围绕这一思路,分析了注气的四种气路方案,通过仿真结果确定了最优气路结构,即在脉冲阀的气体出口接上扩张型喷嘴,和脉冲阀内部气路共同形成类似拉瓦尔喷嘴的结构。其次,本文针对脉冲阀动作时间的评估,研究了气压的快速测量方法。通过对脉冲阀出口气压的监测能够判断出脉冲阀的开通和关断时间。紧接着本文完成了对脉冲阀的驱动电源及磁屏蔽体的设计。在原电路基础上,通过提升驱动电压、优化电路结构、多阀并联工作,将脉冲阀开通时间由2.3 ms缩短至0.8 ms,关断时间由12.3ms缩短至1.6 ms。脉冲阀的安装位置存在较强背景磁场(0.2 T),通过实验研究发现,背景磁场会加快或延迟脉冲阀的开通和关断。根据实验结果提出了将磁场屏蔽到8 m T以下的屏蔽目标,设计了磁屏蔽体并完成测试,验证了屏蔽方案的可行性。在此基础上,对HFRC装置上脉冲阀的磁屏蔽体进行了优化设计并完成加工。最后,通过实验和仿真研究了脉冲注气过程中真空室内的气体扩散过程,揭示了气压演化规律。实验和仿真结果说明了脉冲注气方案能够有效实现超声注气和气压轴向分布。对于采用氢气作为电离气体的放电实验中,预测注气和电离时间应在3ms内为宜。通过仿真对未来可能采用的双侧注气方案进行了分析。脉冲注气系统是HFRC装置的重要部件,本文完成了HFRC脉冲注气系统的设计与测试,为HFRC装置的成功运行奠定了基础。更多还原

【Abstract】 The HFRC(HUST Field Reversed Configuration)device is an experimental device designed and built based on the concept of collisional merging and magnetic compression of FRC(Field Reversed Configuration)plasma,which consists of power supply system,magnet system,pulse gas injection system,vacuum pumping system and remote control system.Since the gas pressure at the moment of ionization of the gas affect the parameters of formed plasma,the pulse gas injection system needs to be coordinated with the power supply system in terms of timing.The main work of this paper is to complete the design and preliminary construction of the pulse gas injection system.This paper first analyzes the design requirements of the pulse gas injection system and proposes the idea of using supersonic gas injection to control gas distribution.Based on this idea,in this paper,the four gas pipeline solutions for gas injection are analyzed through simulation,and the optimal gas pipeline structure is determined.It is formed a structure similar to the Laval nozzle by the internal nozzle of the pulse valve and an expansion nozzle which is connected after the outlet of the pulse valve.Secondly,the rapid measurement method of gas pressure is studied for the evaluation of the pulse valve operation time.The opening and closing time of the pulse valve can be determined by monitoring the gas pressure at the outlet of the pulse valve.On this basis,the design of the power supply and magnetic shield of pulse valve was completed.Based on the original circuit,the opening time of the pulse valve was shortened from 2.3 ms to 0.8 ms and the closing time from 12.3 ms to 1.6 ms by increasing the driving voltage,optimizing the circuit structure,and operating multiple valves in parallel.The strong background magnetic field(0.2 T)exists at the installation location of the pulse valve,and by The experimental study found that the background magnetic field accelerates or delays the opening and closing of the pulse valve.Based on the experimental results,a shielding target of shielding the magnetic field to below 8 m T was proposed,and the magnetic shield was initially designed and tested,which proved the feasibility of the shielding scheme.Based on this,a complete design of the magnetic shielding body of the pulse valve on the HFRC device was carried out and machining was completed.Finally,the gas diffusion process in the vacuum chamber during the pulse gas injection process was studied through experiments and simulations to reveal the law of gas pressure evolution.The experimental and simulation results illustrate that the pulsed gas injection scheme can effectively achieve supersonic gas injection and axial distribution of gas pressure.For formal discharge experiments using hydrogen as the ionizing gas,the predicted gas injection and ionization time should be within 3ms.The possible future dualside gas injection scheme was analyzed by simulation.The pulse gas injection system is an important component of the HFRC device.The design and test of the HFRC pulse gas injection system are completed in this paper,laying the foundation for the successful operation of the HFRC device.更多还原