南水北调东线工程水泵选择研究

The eastern route project of South-to-North Water Transfer Project transfers water from the Changjiang River to Shandong, Anhui, Hebei Province and Tianjin city along the Beijing-to-Hangzhou Great Canal. There will be 30 pumping stations belonging to 13 steps from the Changjiang River to the southern bank of the Yellow.River, passing by Hongze Lake, Luoma Lake, Nansi Lake, Dongping Lake to adjust and store the volume of water. Large step pumping stations are the heart of the project.国家自然科学基金资助项目结题报告4Large pump units are the key parts of stations. Suitable pump units were selected to improve reliability and economy of equipments and reduce the cost of operation,.maintenance and transferring water ..The structures and functions of large low-head pump units were compared on.reliability, economy and maintenance. The influences of key parts such as guide bearings of pumps, thrust bearings of electric engines and systems adjusting operation.of pump units were analyzed. The influences of outlet diffuer on waterpower performance of discharge pipe were studied. Reasonable structures and functions of pump units were advanced according to characteristics and requirements of the.project, 40 years’ construction and administration experiences in large pumping stations of our country derived.Vertical pump units will be the best selection in step pumping stations of the project.Mix-flow pumps with impeller diameter from 2.0m to 3.1m, large vertical electric engines with power from1000 kW to 3000 kW and direct transmission will be the best selections. Half well-canister structures and nonmetal rinsing-lubricated guide bearings with protected pipes should be applied in pumps. Power of electric engines.should be selected according to the highest operation head of the station with standby coefficient K=1.22~1.54. Reasonable design and selection of thrust bearings,reasonable collocation of cooler and adequate cooling capacity are necessary.Air-cooler compelled ventilation will be applied in stators. Necessary fixing functions will be setted in electric engines. Frequency conversion timing will be applied in.headwaters stations and angle-adjusting will be applied in others. Mechanical.angle-adjusting system is superier to hydraulic pressure system if the former is reliable. With regard to pump stations, in which head changes frequently, adjustable inlet diffuser could improve the operational efficiency. Through the optimal design of outlet diffuser, outlet swirl of pumps will be optimal, head loss in discharge pipe will be minimized, system efficiency will increase by from 3% to 5%.The structures of large pump units and systems were analyzed and mended. Aiming at characteristics of the eastern route project of South-to-North Water Transfer Project,.considering factors in all aspects, reasonable pump units were selected to improve reliability, maintainability and efficiency. Study methods on comparison,improvement and reasonable selection of large complex mechanism systems were advanced. It has great science significance. Improving reliability and cutting down costs of transferring water will bring considerable economic and social benefits.

从技术适用性、经济性、可靠性和运行维护及安装检修方便性等方面分析大型低扬程水泵各种结构型式和应用功能特点。重点研究泵出流水力特性和导轴承、叶片调节等关键部件和功能。针对南水北调东线工程各类梯级泵站运行条件和要求，提出合理选用水泵的方法。本课题对该项国家大型工程水泵合理选用，提高其效能和供水可能性有重大意义。