Areas of Prime Importance

Supplementing Plant Efforts
Solution of Chronic Problems
Development of Hydro suction
  • Used Hydro suction Sedimentation Exclusion System from dam for the first time in India at Salal Power Station. This arrangement has also been used successfully in Tanakpur Power Channel.
Preventive Measures Against Silt Erosion of Under Water Components
Silt Menance
  • Hydroelectric Power Stations located in Himalayan region in general and run-of-the river schemes located in the Northern states of India in particular suffer from silt erosion underwater parts.
  • Particularly in Monsoon Season when 98% of the silt particles of size 0.20 mm and contain smaller quartz with hardness of 7-8 on Moh's scale pass through turbine parts. It is not cost-effective to construct de-silting arrangement to remove this size of silt particles from flowing water.
  • The operation and maintenance of these power stations is indeed a tremendous task and calls for high degree of dedication and motivation on the part of maintenance staff in grappling with the silt related problems.
Field Trials
Silt Erosion
  • Salal & Baira Siul Power Stations of NHPC have been the worst victims of Silt erosion. Field trials with thermal spray coatings, polymeric coatings & plasma nitrding have been carried out at these power stations, out of which HVOF process WC-Co coating gave some success to retard erosion.
  • Field trials in isolation of active involvement of OEM’s are not likely to be fruitful. NHPC will consider to participate in field trials, if proposed by OEM’s. NHPC is taking up the issue with OEM’s for a joint collaboration for finding solution to mitigate silt erosion.
National Perspective Plan on R&D in the Power Sector
  • National R&D Project on “Development of Silt Erosion Resistant Material for Turbines of Hydro Generators” by NML (National Metallurgical Laboratory) Jamshedpur was completed in which NHPC was also one of the participating agencies in conjunction with CPRI & SJVNL.
  • Main objective of the project was to develop a new material having better mechanical properties & erosive wear resistance as compared to the presently used 13Cr-4Ni Stainless Steel.
  • The project was funded by MoP, NHPC Ltd., SJVNL and the approved financial outlay of the project as per (Standing Financial Committee) SFC was Rs. 299.79 Lakhs.
  • MOU was signed between the participating agencies i.e. NHPC, SJVNL, CPRI & National Metallurgical Laboratories (NML) in the Month of Sep 2008.
  • A new alloy was developed by NML and it was found that the tensile strength of the new alloy was better than the original one. In order to carry field tests the new alloy was used in manufacturing of two components i.e. Nozzle set ring and spear with the approved vendors of M/s. Bhabha HEP, Himachal Pradesh and it was observed that the turbine component worked well in silt condition of monsoon period of 2012.
  • NHPC Ltd along-with its collaborative partner’s namely CPRI (Central Power Research Institute), SJVN Ltd (Sutlej Jal Vidyut Nigam Ltd.) and CSIR (Council of Scientific and Industrial Research) has been granted Intellectual Property Right for an invention entitled “A Composition For Erosion Resistance Steel And A Process For The Preparation Thereof” on dated 22/03/2021 by “The Patent Office, Government of India”. It is a first ever patent (Intellectual Property Right) awarded to NHPC Ltd. along with its collaborative partners in the field of Research & Development.
Optimizing Use of Energy & Performance
Energy Audit
  • "Energy Audit " means the verification, monitoring and analysis of use of energy including submission of technical report containing recommendations for improving energy efficiency with cost benefit analysis and an action plan to reduce energy consumption.
  • As per the Energy Conservation Act, 2001, Bureau of Energy Efficiency (BEE) has identified Energy Intensive Industries as designated consumers. Central Govt. may direct, any designated consumer to get Energy Audit conducted by an accredited Energy Auditor. Without any such directive from Central Govt., NHPC voluntarily taken up the Energy Audit of its Power Stations.
  • Energy Audit results in cost savings as well as re-establishing the validating of actual performance vis-a-vis design parameter.
  • Energy Audit has been completed in 18 Power Stations i.e. Baira Siul, Salal, Tanakpur, Loktak, Rangit, Chamera-I, Uri-I, Chamera-II, Chamera- III, Dhauliganga, Dulhasti, Nimmo-Bazgo, TLD-IV, TLD-III, Parbati-III, Teesta-V, Uri-II, Sewa-II Power Stations. Recommendations of Energy Audit has been implemented in respective Power Stations.


Computational Fluid Dynamics: Diverse Applications in Hydro Power
  • CFD analysis has been successfully utilized to provide considerable design support for advance hydropower design. The use of this tool allowed engineers to provide early input to critical design issues, and to refine hydraulic design to a level normally achieved only through the undertaking of physical model studies. The CFD model can also be used to provide insight into any planned physical models, allowing designers to streamline testing program by reducing the number of options to be evaluated.
  • CFD software is used to compute Simulation of Design Applications like Penstock, Spillway design, Simulation of three dimensional flow patterns in the project’s Surge shaft, HRT, & tailrace area; Refinement of cofferdam layouts; Refinement of Power house intake design. Advantages of CFD are as under:
  • Ø Directs focus of experimental work
  • Ø Software tool to replace or support experimental work
  • Ø Cheaper and faster than physical model experiments
  • Ø Accelerates prototyping
  • Ø Correct representation of the geometric mode
  • Ø Shorter design cycles and scale-up
  • Ø Quick testing of new ideas
  • Ø Facilitates trouble-shooting.
    • Computational Fluid Dynamic (CFD) Lab in Corporate office, Faridabad of NHPC has been successfully established in December, 2008 to analyze the flow pattern in the water conductor system. CFD analysis of penstock of Baira-Siul, Power Station. Loktak Power Station & Salal Power Station, CFD Studies & Analysis of Surge Shaft & Pressure Shaft of Teesta-V Power Station and Dam – Spillway of Subansiri HE Project have been completed.
     
    @R&D