Detrimental effects of tiny silt particles on large hydro power stations and some remedies

摘要

Summary Emergence of silt conscious designs of hydro power plants is an great challenge which calls for pooling the experiences of concerned. It also under lines the desirability of silt consciousness during investigations, design, operation, maintenance, refurbishment and upgrading. Due to inherent weak geology, rock instability, population explosions and deforestation, all rivers emanating from Himalayas carry enormous quantity of silt during heavy runoff of monsoon from June to September. Hydro Power stations located in Himalayan region face heavy silt problems during high inflow periods. Siul River carries heavy silt concentration of the order of 30,000 PPM (Part Per Million) (4) affecting generation, eroding turbines and cooling water system, requiring heavy cost towards maintenance of Baira Siul project. Similarly Chenab River on which Salal Project is located also carries enormous quantity of silt affecting shut down, damage to glacis to the tune of 15 cm to 20 cm, and severe damages to turbines and cooling water system of the project. Remedial measures have been taken like replacing the metallurgy of stainless steel for runner, guide vanes by 13 Cr Ni4 and hydro siphoning from the reservoir to maintain the generation. A series of other experiments were also tried on these projects by using modern technology. Some of them are successful to some extent.