摘要
为提高多级泵的抗汽蚀性能,改进设计了泵的首级叶轮结构,增加了叶轮进口直径和出口宽度、使叶片进口边向入口方向延伸、增大盖板在进口部分的曲率半径、减小进口处叶片厚度、相应增加吸水室进口直径和扩大吸水室环形空间。利用Fluent软件对多级泵改进前后首级叶轮的内部流场进行数值模拟,模拟结果表明:汽蚀发生区域为叶轮进口背面靠近轮缘处,改进后首级叶轮流道内流动平稳,压力和速度分布均匀。利用数值模拟的方法对改进前后泵汽蚀性能进行预测,并经汽蚀试验验证,相对误差分别为2.6%和2.5%。改进后汽蚀余量减小且小于规定值,汽蚀性能得到提高,达到改进目的。数值模拟结果为多级泵的设计和改进提供了可靠依据。
To enhance the cavitation-resistant performance of a multi-stage pump,the first-stage impeller structure was improved and designed with the inlet diameter and outlet width of the impeller being increased,making the leading edge of the blades extended towards the inlet direction,the curvature radius of the covering plate in the inlet part increased,thickness of the blades at the inlet decreased,the diameter of the water suction chamber at the inlet increased accordingly and the annulus space of the water suction chamber expanded. By using the software Fluent,the flow field inside the first-stage impeller was numerically simulated before and after the improvement. The simulation results show that the area where cavitation phenomena take place is located on the back of the impeller close to the rim and after the improvement,the flow is smooth and stable in the flow path of the first-stage impeller with the pressure and speed distribution being uniform. By adopting the numerical simulation method,the cavitation performance of the pump was predicted before and after the improvement and verified by a cavitation test. The relative errors are 2. 6% and 2. 5% respectively. The cavitation allowance decreases after the improvement and is less than the value stipulated and the cavitation performance is improved,achieving the improvement goals. The numerical simulation results can provide reliable underlying bases for design and improvement of multi-stage pumps.
出处
《热能动力工程》
CAS
CSCD
北大核心
2013年第5期514-517,555,共4页
Journal of Engineering for Thermal Energy and Power
关键词
多级离心泵
首级叶轮
汽蚀性能
CFD
multistage centrifugal pump,first-stage impeller,cavitation performance,CFD
