【作者】 陈晨；

【导师】 杨庆俊；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2020， 硕士

【摘要】 氢氧质子交换膜燃料电池是一种具有高转换效率和高功率密度的电化学发电装置,在军事上有着广泛的应用前景。电气比例减压阀作为燃料电池供气系统中主要的压力控制元件,其稳压特性直接影响到整个燃料电池系统的工作性能,对于膜两侧压力的高精度控制是保证燃料电池安全运行的重要环节。目前国内现有电气比例减压阀的性能较国外仍有一定差距,对于压力控制特性的研究尚不全面,因此本课题以氢氧燃料电池的供气系统为研究背景,完成了一组适用于氢氧气体环境的高精度电气比例减压阀结构设计与特性分析,并通过元件特性匹配、闭环控制等方式,实现氢氧双路压力的同步控制,确保燃料电池安全稳定高效运行。首先,结合燃料电池的供气回路的工况需求与氢气、氧气的气体特性,设计了一种以波纹管代替反馈腔的无溢流电气比例减压阀,完成了整体结构设计与材料选择,并针对关键感压结构波纹管组件进行了结构设计与力值特性试验测试。在此基础上,完成对电气比例减压阀整体数学模型的建立,在Matlab/Simulink中搭建了电气比例减压阀非线性仿真模型,实现了对比例减压阀的开环动静特性分析,深入分析了关键结构参数与上游及负载工况变化对动静态特性的影响,实现了机械响应性能提升。在此基础上,建立了抗饱和PI闭环控制,实现高精度、高稳定性的压力响应特性。并利用Fluent仿真软件建立流场仿真模型,实现了对阀口附近的压力分布以及阀的流量特性分析,对阀的设计起到指导作用。最后,针对燃料电池双路压差控制问题,提出了双路压力同步控制策略。对氢气阀、氧气阀进行了结构参数与控制特性上的匹配,获得双路的响应同步性。提出了主从闭环控制策略、基于PI的双路压力耦合控制策略和基于模糊PI的双路压力耦合控制策略三种双路压力耦合控制策略,研究了不同工况下双路压力差的自主控制,为燃料电池双路压力同步控制提供了思路。更多还原

【Abstract】 Hydrogen-oxygen Proton Exchange Membrane Fuel Cell(PEMFC)is an electrochemical power generation device with high conversion efficiency and power density which has broad application prospects in the military.As the main pressure control element in the fuel cell gas supply system,the electric proportional pressure reducing valve directly affects the performance of the entire fuel cell system.The high-precision control of the pressure on both sides of the membrane is important to ensure the safe operation of the PEMFC system.At present,The research on pneumatic proportional pressure valves is still not comprehensive,and the pressure control performance is dissatisfactory.Based on the research background of the hydrogen-oxygen fuel cell gas supply system,the paper designed a group of hydrogen-oxygen pneumatic proportional pressure valves with high-precision and high-stability,and realize the optimization of structural design and characteristic analysis.The matching of response characteristics and closed-loop control law applied to the valve stystem to achieve pressure synchronous control between the hydrogen and oxygen valve which ensure safe,stable and efficient operation of the fuel cell.First of all,a new type of non-overflowing pneumatic proportional pressure valve with a bellows feedback cavity was designed,combining the requirements of the working conditions in the gas supply system and the gas characteristics of hydrogen and oxygen.The whole structural design and material selection were completed.The force characteristics of bellows components were tested which is the key pressure-sensitive structure in the valve.Then,the mathematical model of the pneumatic proportional pressure valve was established,and a nonlinear simulation model of the valve was built in Matlab/Simulink to realize the open-loop dynamic and static characteristics analysis.The influence of key structural parameters and changes of upstream and load conditions on dynamic and static characteristics is analyzed,and the mechanical response performance is optimized.On this basis,anti-windup PI closed-loop control law is presented to achieve high-precision and high-stability pressure response characteristics.At the same time,establish a flow field simulation model in Fluent,which realized the analysis of the pressure distribution near the valve port and the flow characteristics of the valve in order to play a guiding role in the design of the valve.Finally,this paper presented a pressure synchronous control strategy for the pressure deviations between cathode and anode.By matching the structural parameters and control characteristics of the hydrogen valve and the oxygen valve,the response synchronization between two valves is obtained.And further presentsed double-loops coupling pressure control strategy,presented a masterslave closed-loop control strategy,PI-based double-loops coupling pressure control strategy and fuzzy PI-based double-loops coupling pressure control strategy,to achieve the adaptive control of the pressure deviations between cathode and anode during multiple disturbances,and realize the synchronous control of pressure between cathode and anode.更多还原