二阶连续可微整体变截面涡旋机械型线设计理论

Design of environmental-friendly, high efficiency and energy saving scroll fluid machine is a hot issue of concern to many countries these days. Scroll profile is one of the most significant influences of comprehensive performances. However, traditional uniform-profile scrolls under pressure are distorted significantly in environmental-friendly refrigerant. In addition, they are not capable of meeting technical challenges in discharge capacity, leakage loss and material usage rate. From a standpoint of creative profile design，the proposed project aims to obtain the concise mathematical model for basic profile units by optimally selecting and geometrically expanding the circular vector function. Subsequently, mathematical model for second-order continuously differentiable overall non-uniform profile will be established based on estimated properties and adaptable design of overall engaging path of scroll profiles to achieve excellent performances of geometry, dynamics and workability. Furthermore, the potential superiority of overall non-uniform scroll profile will be explored in terms of refrigerant adaptation, discharge capacity, leakage loss and material usage rate. Therefore, design theory on second-order continuously differentiable overall non-uniform profile for scroll fluid machine will be founded so as to provide the basis for the design and manufacture of high efficiency and energy saving scroll compressor. Meanwhile, it will supply new ideas and methods for designing other types of mechanical products which are based on scroll principle.

环境友好、高效节能型涡旋机械设计是当前世界各国关心的热点问题。涡旋型线是影响涡旋机械性能的关键因素之一。然而，传统等截面型线涡旋零件在环保制冷介质中受力和变形严重，且不能很好应对在排量、泄漏损失、材料利用率等方面的技术挑战。本项目旨在从涡旋型线创新设计视角出发，通过对圆矢量函数的优选和几何尺度扩展，获得基础型线单元的精简数学模型；对涡旋全齿啮合轨迹进行性能预估和适应性设计，构建基于二阶连续可微几何边界条件的整体变截面型线数学模型，使之具有良好的几何、动力和加工等综合性能。并进一步探索整体变截面型线涡旋压缩机在适应环保制冷剂、增大排量、减少泄漏损失、提高材料利用率等方面的潜在优势。在此基础上构建二阶连续可微整体变截面涡旋型线设计理论，为高效节能型涡旋压缩机的设计与制造提供理论依据和实证支持，同时也将为其它以涡旋原理为工作机理的机械产品的设计提供新的思路和方法。

涡旋型线是影响涡旋机械性能的关键因素之一。然而，传统等截面型线涡旋零件在环保制冷介质中受力和变形严重，且不能很好应对排量、泄漏损失、材料利用率等方面的技术挑战。本项目研究了基于圆矢量函数的涡旋型线固有特征及其描述方法，基于压缩机数值模拟和实验测试获取预估载荷-变形-泄漏特性的动静涡旋啮合轨迹，构建了二阶连续可微整体变截面涡旋型线数学模型。开展了二阶连续变截面涡旋压缩机内部流场的数值模拟与分析、涡旋盘热-结构耦合应力和变形分析、涡旋盘模态分析和谐响应分析、动涡旋盘的几何与力学特性等多项综合研究。结果表明：主轴转角θ=30°~150°区间内，二阶连续整体变截面圆渐开线压缩腔流场速度下降幅度最大，说明变截面圆渐开线压缩腔在曲率变化较小的情况下，最大程度地对腔内气体进行了压缩；在与实际工况更为吻合的热-力耦合作用下，整体变截面涡旋齿的刚度和强度都优于等截面涡旋齿；稳态简谐载荷作用下变截面涡旋盘的动态响应随频率的变化比较平缓，响应峰值远小于等截面涡旋盘，力学特性优越；在基圆半径相同条件下，几何特性模拟显示：二阶连续变截面涡旋型线较一阶连续型线压缩比平均高22%、径向气体载荷波动小8%。应用多目标遗传算法研究了整体变截面涡旋型线在排量、材料利用率等方面的潜在优势，结果表明二阶连续整体变截面涡旋型线的行程容积和面积利用系数分别较等截面涡旋型线高27.21%和9.35%。建立了二阶连续连续变截面涡旋型线完整齿廓的三维实体模型并完成实体加工。利用三坐标测量机获取涡旋盘的表面点云数据，并运用Geomagic Qualify三维检测软件对数据进行检测，进行了涡旋盘数字化模型的二维分析、三维误差分析和形位公差评估，结果表明二阶连续整体变截面涡旋零件加工精度符合要求。利用机械故障综合模拟实验平台，研究了信息熵值与压缩机振动、涡旋零件加工质量和装配质量之间的对应关系，为其结构设计的优化和改进提供了依据。