Study And Application On Retrofit Design For Francis Runner Hl240

The capacity augmentation and innovation of hydropower stations were characterized by small investment and quick return, which has drawn great attention at home and abroad. Hydropower stations that have operated for more than 20 years are all confronted with the innovation problem.Francis Runner HL240 was one type of Soviet water turbines in the 1940' s, which was introduced into China in the middle of 1950' s and was employed by many middle-and-small domestic hydropower stations. The runner has distinctly low level in energy index and discharge capacity as well. The paper lucubrated on retrofit design of Francis Runner HL240. The main research outcomes were as follows:(1) the paper applied quasi-three dimensional design model and optimization design model based on Si flow surface that was effected by runner (impeller) and guide vane jointly. The vortex flow, blade thickness limitation and runner (impeller) blade force functions were taken into account. The paper got the improved runners of HL240 type, which were Runner HLX240d and Runner HLX240e.(2) Retrofitted the small turbine of Tai Pin Shao Hydropower Station in this paper. The results indicated that given the unchanged channels of the original Runner HL240-LJ-120 and satisfied cavitation condition and stability requirement, the electricity generated by the turbine generator increased from 3000KW to 3600KW when the design head was 36. 2m, which arrived at the expectant objective.(3) Based on the study of the retrofit design of the small turbine in Tai Pin Shao, carried out research on the feasibility of the retrofit design of large Francis Runners HL240-LG-410 in Tai Pin Shao in this paper. The results showed that considering the general performance of turbine and the discharge capacity of Runner HL240-LJ-420, when the design head was 36.2m, the electricity generated by turbine generator increases to 4.8 million KW, which was relatively reasonable. When the design head was 37. Om, the electricity generated by turbine generator increased to 5.0 million KW, which was relatively reasonable.(4) In the interest of identifying the efficiency characteristic of the retrofitted turbine runner, based on relative efficiency method, the paper carried out test on the efficiency of the small turbine in Tai Pin Shao. The results indicated that the efficiency of turbine was enhanced obviously, the efficiency curve overcasts the unchanged one completely. Given the same output, the efficiency after retrofit design was higher than that before retrofit design, which was more distinct in high load area. This showed that the retrofit design of the turbine runner was successful and the benefits gained were remarkable, which achieved the expectant goals.