Problem: The Lvshuihe Power Station has a Francis turbine with a high water head and sedimented water. The highest water head of the power station is 331m. The original unit's over flow components are seriously worn out. A major overhaul had to be done every two years. After operating for more than 40 years, perforation wear-out occurs at the end of the spiral case leading to serious safety hazard.
Due to the high water head of the power station, the rigidity of the original headcover was not enough, resulting in a large deformation during operation, the unit could not stop without closing the ball valve; bringing great operational and maintenance troubles.
Besides, the efficiency of the turbine was very low. The actual efficiency test of the prototype showed that the maximum efficiency of the original turbine was only 84.88%, a level far below that of similar power plants.
New Runner Model: HLGT106-LJ-144
Solution: GETAI did a whole flow passage CFD simulation, designed a new runner based on the specific station parameters, optimized the hydraulic performance, improved the structure and strength design. Thereafter, the long-and-short blade high efficiency runner was developed. After upgrading the turbine efficiency, the stability, etc. have been greatly improved. The turbine unit efficiency test showed that the efficiency had increased to 92.03% and all the previous stated problems were solved.