基于流体网络解耦的潜油电机内全域流体场及热效应研究

The main research object of coupling calculation of temperature field and fluid field in which local model without fluid gravity is established and boundary condition is identified by experience formula and test data is the air cooled electric machine at present. But the deviation of temperature rise prediction will be much bigger by this research results for the electric machine with new structure and aquiform liquid. The variation of fluid resistance loss along with many factors such as fluid density, velocity, viscosity and temperature and the heat transfer mechanism of stator and rotor to the oil gap are explored. Influence law of magnetic isolated segment and rotor bearing size on eddy loss, heat transfer and temperature distribution is discussed by establishing a coupling model of Force-Electric- Thermal of magnetic isolated segment and rotor bearing. For submersible motor, according to the axial multi-section structure and the repeatability of axial flow field and the order of magnitude difference of fluid velocity and pressure in oil gap and cavity of shaft and holes in rotor bearing, the whole fluid field model is established by researching the classification principles of each local decoupling fluid field and coupling method under the full fluid network. The effect of fluid gravity to the whole fluid field is fully considered. The new method that the whole fluid field and thermal effect in submersible motor are researched based on fluid network decoupling is formed in this project. Research results will be the theoretical basis for studying other high-performance special electric motors.

目前电机内流体场温度场耦合计算多以空冷电机为主，对电机局部建模且忽略了流体重力，而边界条件的确定依赖于经验公式和试验数据的配合。因此研究成果对于新结构液态流体电机的温升预测偏差较大。本项目针对潜油电机的特殊结构，探索油隙中流体阻力损耗随流体密度、速度、粘度和温度等众多因素的变化规律及定转子通过油隙的传热机理。建立电机分段处材料的力-电-热耦合特性模型，讨论其尺寸对电机涡流损耗、温度分布及热传递的影响规律。根据潜油电机轴向分段、轴向流场的重复性以及油隙、转轴内腔和扶正轴承甩油孔处的流体流速和压力的数量级不同，充分考虑流体重力对全域流体场的影响，研究电机内各局域解耦流体场的划分原则和在全域流体网络下的耦合方法。形成基于流体网络解耦研究电机内全域流体场及热效应的新方法，研究成果将为其他高性能特种电机的研究奠定理论基础。

项目针对潜油电机特殊结构，通过研究潜油电机内循环油路中各部分流体的流速及压力的数量级的不同，对潜油电机全域流体场进行分区解耦，构建潜油电机全域流体网络。局部典型区域通过三维流场分析，整体考虑电机的轴向分段及重复性，建立流体网络，计算了电机的全域流场及传热效应。最终形成了基于流体网络解耦的潜油电机全域流体场及热效应研究新方法。通过局部流体场分析准确获取了油隙内流体内的流体阻力损耗随流体密度、速度、粘度和温度等因素影响规律，给出了流体重力对各区域解耦流场之间和全域流场的影响规律。建立了潜油电机分段处结构的电磁-热-力耦合特性模型，研究不同金属或合金材料的特性耦合作用机理，得到受力约束条件下的隔磁段、扶正轴承大小对电机涡流损耗和温度分布及热传递的影响规律，提出了改善潜油电机温升的方法。给出了电机全域流体场内各解耦区域的划分原则及耦合方式，形成全新的不再依赖经验公式和试验值的电机温升预测方法。项目通过三角网络合理划分潜油电机内各区域节点，建立了热网络模型，利用热力学第一定律，得到电机稳态时各部分平均温度及温升，并采用免疫遗传算法对电机进行了优化设计，给出了新的潜油电机设计理论。