Technical Innovation Of The Unit On Weituo Hydropower Station

Weituo hydropower station,located in Weituo town,Hechuang District,Chongqing,about 23km from the confluence of the Pei River to Jialing River,is a comprehensive utilization project combining power generation and shipping.Weituo hydropower station originally equipped with two Bulb Turbine Units.Design head:H_p=8.5m,maximum head:H_max=11.0m,minimum head:H_min=3.0m,capacity:2×15MW.Caojie Pivotal project for Navigation and Power began in 2005.The normal working water level is 203.0m for the built Caojie Power Station,leading to a gross head less than 3m for Weituo hydropower.Therefore if we do not transform the original unit,it cannot generate power in this condition,not only Weituo station will be scrapped,but also we need to arrange special personnel to manage the running and maintenance of locks.For the state-owned assets and to make full use of the remaining 3m head,this paper aims to demonstrate the feasibility of transformation of the original electromechanical equipment in this working condition.Weituo transformation program should not only make full use of water resources to meet Weituo station,but also minimize costs.After successful transformation of electromechanical equipment,it can both effectively utilize the already built spillway,sluice,plant,locks and other facilities,and take advantage of the range of 2-4m head.The detailed contents and conclusions are as follows:1.Analyzing the basic situation of water resources before and after the transformation of power plants adequately and doing a multi-program comparison,finally to make a decision that using the original turbine runner and transforming the four-blade turbine into a two-blade turbine.According to the model testing results of Andritz Hydro,aiming at Weituo turbine production plants in 1990s and through the technical and economic comparison,it is feasible to use the existing runner and turbine generator set,change the four-blade rotor blades into two and retain the original turbine wheels,unchanged wheel diameter and use two puree positions without using the same consistent linear wheel hub cap.On this basis,it requires the development of two blade runner based on the successful tests on Andritz three bidders.2.The implementing scheme of power units for Weituo station includes technology design,model test with the real machine installation.The results show that after the transformation,power plant of axial thrust,cavitation or abrasion damage,runaway characteristics,regulating that ensure operational stability and noise,reliability assurance and major components such as the forces do not occur on run adverse circumstances,proving that the parameter of two blade runner unit performance is reliable,consistent with the actual situation of Weituo transformation.It proposes to strengthen the unit transformation model test and inspection work,focusing on energy targets and crew turbine blade vibration problems in the preliminary design;The successful bidder shall be committed to these two parameters through model test to ensure that the Weituo station can achieve a stable operation after the transformation.3.Vibratory characteristics test of real machine.In order to verify the correctness of the transformation program by testing,monitoring and analyzing the vibration of unit,it can be seen from the entire testing data that the unit runs in good condition;vibration data is within the scope of the national standard and the vibration of tail pipe has been reduced after transformation;there is no noticeable vibratory area with a full load;the unit vibration data are in line with national standards in the process of idling,no-load and with a load.Through shafting unit stress analysis,monitoring data from the entire test,the unit runs in good condition,the unit’s vibration data are within the scope of the national standard.Results of this study may provide some guidance for the future development of low head water resources and the promotion and application of the two blades Bulb Turbine Unit.