高压含气液体驱动的金属膜片在变接触边界条件下往复运动及变形的动力学特性研究

With the rapid development of the hydrogen energy and nuclear energy, the metal diaphragm compressor is highlighted as one of the key equipment in these green energy industry. However, the further development of the diaphragm compressor is constrained by its poor performance, low security and metal diaphragm’s short fatigue life. The existing researches on the diaphragm compressor are all based on the ideal movement and contact, which ignored the actual motion of the metal diaphragm drove by the alternate forces in a narrow space. In this project, the theoretical and experimental investigation will been studied which focus on the air sac generating process in a changeable narrow space. Moreover, the stress caused by the large deflection of the diaphragm when it contacted to the cavity surface and the stress caused by the small deflection of the diaphragm when the air sac occurred will be investigated by theoretical and experimental methods. Meanwhile, the visualization experimental technique and numerical simulation method have been applied to study the characteristics of the metal diaphragm’s reverse deflection phenomenon which drove by the alternate forces and the influences on the stress distribution of the metal diaphragm when it comes to the perforated plate. Furthermore, the dynamic characteristics of the diaphragm in an entire working cycle could be obtained through these three parts researches. Finally, a new design theory of the diaphragm compressor’s cavity profile which considered the effect of the metal diaphragm’s actual motion will be presented to improve the safety and economy efficiency of the metal diaphragm compressor.

随着氢能源的高速发展，作为产业中核心压缩设备之一的金属隔膜压缩机更加受到重视。但安全性差、膜片寿命低、性能不高等问题严重制约了隔膜压缩机的进一步发展。现有对隔膜压缩机的研究均以金属膜片的理论运动和贴合状态为前提，忽略了膜片在工作腔内在气体工质和含气液压油交替驱动下往复运动的复杂性。本项目在前期大量研究的基础上，对气液两相超高压压缩过程及特性进行理论和实验研究，并以此为基础对金属膜片在含气液压油驱动下与支板非线性接触、碰撞过程中的膜片形态和应力分布规律进行理论和实验研究。通过数值模拟和可视化实验手段对气液共同驱动下金属膜片在非接触状态下的应力与位移进行研究，揭示隔膜压缩机工作时金属膜片在一个完整周期内的运动规律和变形过程，掌握膜片内部应力变化和分布特性，提出先进的膜腔设计准则和评价方法，从根本上提高隔膜压缩机的安全性和经济性。

隔膜压缩机是制氢充装、加氢站加压的关键装备，膜片寿命低、压缩率不高、安全性差等技术难题需要突破。本项目构建了气-固-液多场协同的隔膜压缩机热-动力学仿真模型，聚焦含气液压油对气体压缩过程及效率的影响机制，液压油驱动膜片运动与变形中与膜腔的线性接触过程与应力分布特性。研究结果表明，油气动态压力伴随关系是决定其性能的关键，油压过高会造成膜片拍击气侧缸壁产生附加应力，影响膜片寿命，而油压过低则导致膜片运动不充分，降低隔膜压缩机流量与效率；液压油的可压缩性是影响高压隔膜压缩机效率的关键因素，隔膜压缩机余隙容积和液压油膨胀造成的容积损失分别达到29.2%和27.5%，容积效率随着液压油的增加而降低，随着排气压力增加，下降趋势更加明显，在排气压力为45MPa，55MPa和65MPa时，总油量增加一个行程容积，压缩机的容积效了分别下降2.7%，3.5%和4.4%，随着溢油压力与排气压力的比值从1.1增大到1.3，隔膜压缩机的容积效率下降了6.1%，项目研究中完善了高压隔膜压缩机的理论设计方法，提出的数值模拟方法与模型能够准确预测隔膜压缩机的重要结构参数对性能的影响，研究提出的无损监测方法为高温高压临氢环境下的压缩机状态监测提供了重要基础。