多场耦合作用下单螺杆压缩机空间啮合特性的冷热态协同控制方法研究

In the single screw compressor, the space meshing pairs comprised by screw rotor and star-wheel are the core working parts. The coupling effects between the transient temperature/pressure field, the three-dimensional irregular structure field and the unsteady flow field will occur under the load conditions. These coupling effects mutate the surface features and the meshing characteristics of meshing pairs, and then serious deteriorate the performance and reliability of single screw compressor. So in order to reveal the mechanism of thermal-elastic deformation and achieve the precise control of meshing characteristic under the load conditions, a numerical calculation model of the space meshing process in single screw compressor is established in this project based on surface-body coupling strategy and time correction coupling strategy. The fluid-thermal-structure coupling effect is taken into account in the numerical calculation model. By using this model, the transfer-accumulation characteristics of the thermal-elastic deformation are researched. The coupling relationship between thermal deformation and elastic deformation are analyzed by using Gray Relational Degree Theory. Combining with these research results, genetic programming and genetic algorithm are employed to establish the quantitative characterization model of the meshing clearance under the load conditions for describing the thermal-elastic deformation transfer-accumulation characteristics. On this basis, the intrinsic relationship between the meshing clearance under the load conditions and the thermal-elastic deformation are explored. Then a new cold-hot collaborative control method combined cold compensation design and thermal compensation processing for the single screw compressor meshing characteristics is put forward. Finally the thermal-elastic deformations of the meshing pairs are tested to verify the calculation results and correct the mathematical models. This project is of academic significance to rich meshing pair profile design method and to form a complete all-conditions theoretical performance analysis system of single screw compressor.

单螺杆压缩机核心工作部件是螺杆和星轮组成的空间啮合副，负载工况下流-热-固复杂耦合场作用导致啮合副型面特征与啮合特性发生变异并严重劣化压缩机性能。为揭示啮合副的热力变形机理，实现负载工况啮合特性的精确控制，本项目拟结合面体耦合与时间修正耦合策略，建立基于多场耦合的单螺杆压缩机空间啮合过程数值计算模型，研究负载工况下啮合副热力变形在时间和空间上的传递和累积特性，并运用灰色关联度理论，分析热力变形间的耦合关系。在数值模拟数据基础上，采用遗传规划和遗传算法构建反映热力变形传递和累积特性的热态啮合间隙定量表征模型，探究热态啮合间隙与热力变形的内在联系，据此提出冷态补偿设计与热态补偿加工相结合的单螺杆压缩机空间啮合特性的冷热态协同控制方法，最后开展实验来验证计算结果并修正数学模型。本项目实施可为丰富空间啮合副型面设计方法奠定理论基础，对于构建完备的单螺杆压缩机全工况性能分析理论体系具有重要学术意义。

单螺杆压缩机核心工作部件是螺杆和星轮组成的空间啮合副，负载工况下流-热-固复杂耦合场作用导致啮合副型面特征与啮合特性发生变异并严重劣化压缩机性能。为揭示啮合副的热力变形机理，实现负载工况啮合特性的精确控制，本项目结合面体耦合与时间修正耦合策略，建立了基于多场耦合的单螺杆压缩机空间啮合过程数值计算模型，研究了多物理场耦合作用下单螺杆压缩机三维不规则螺旋形腔体内部非定常流动特性、负载工况下啮合副的热态啮合特性以及热力变形在时间和空间上的传递和累积特性，基于此提出了啮合副型面优化设计方法。在数值模拟数据基础上，采用遗传规划和遗传算法构建了反映热力变形传递和累积特性的热态啮合间隙定量表征模型，探究了热态啮合间隙与热力变形的内在联系。结合啮合装配关系及机壳、主轴、星轮支架和啮合副等主要元件材料的热膨胀特性，以热态啮合间隙为约束条件，确定了冷态补偿设计和热态补偿加工过程中为保证啮合副安装及运行所需的冷态设计补偿量（补偿弹性变形及部分热变形）和热态加工补偿量（补偿部分热变形）。据此构建了热-切削同步控制的热态加工模型及具有热力响应补偿的冷态补偿设计模型，提出了冷态补偿设计与热态补偿加工相结合的单螺杆压缩机空间啮合特性的冷热态协同控制方法，最后开展实验来验证计算结果并修正数学模型。本项目实施可为丰富空间啮合副型面设计方法奠定理论基础，对于构建完备的单螺杆压缩机全工况性能分析理论体系具有重要学术意义。