SUMMER INDUSTRIAL TRAINING PRESENTATION

PRESENTED BY:NILESH KUMAR SINGH

B.TECH (ME) 4THYEAR

SJVN LTD. (INTRODUCTION)• SJVN Limited, a Schedule 'A' Mini Ratna CPSE, is a joint venture

between the Govt. of India & Govt. of Himachal Pradesh with authorized capital of INR 7000 crore.

• Business: • Hydroelectric Projects in Himachal Pradesh, Uttarakhand,

Arunachal Pradesh and in the neighboring countries of Nepal and Bhutan

• Thermal Power Project in Bihar• Power Transmission Project in Nepal • Wind Power project in Maharashtra• Solar Power Projects in Gujarat & Rajasthan.

NATHPA JHAKRI HYDRO-POWER STATION

• The Nathpa Jhakri Hydroelectric Station of 1500 MW capacity is the country’s largest hydropower plant on River Satluj in Shimla district of Himachal Pradesh.

OBJECTIVE OF INTERNSHIP

The main objectives of internship were: • To study and understand various mechanical and associated

systems of dam and powerhouse at NJHPS, SJVN Ltd. • To study various facilities available at Hard Coating Workshop

in NJHPS, SJVN Ltd.

STUDY METHODOLOGY

• Technical discussions with various engineers and executives • Study various drawings available of different parts and

components • On-site visit of powerhouse and dam • Understanding cooling and drainage systems on Jhakri site • Understanding working of control systems of NJHPS • Study of different systems in hard coating facility • Study of measures taken for safer operation of Hydro

Power Plant

HYDRO POWER PROJECT

Dam

Powerhouse

Transmission

THE DAM

• This project has a straight gravity type dam of 62.5m height on the Satluj River at Nathpa, Kinnaur district in Himachal Pradesh.

• This project is India’s longest Run-off river Hydro-Power Project.

• This stored water is diverted into conduit which runs up to 27.4 km which carries 405 cumecs of water through four intakes.

• Different important parts of Dam are Radial Gates, Spillway Gates, De-silting Chambers, Silt Flashing Gates, Head Race Tunnel, Surge Shaft etc.

POWERHOUSE• Nathpa Jhakri project has an underground power house (200

m below the natural earth level).

The main auxiliaries on this floor are: • Secondary water pump • Oil cooler • Brake Dust Collector • Oil Vapor Collector • Governor • The turbine pit

HARD COATING FACILITY • In India, HCF at NJHPS is the first Laboratory which coats

turbines and other mechanical parts using robotic arm. • Hard coating facility works on the principle of High Velocity

Oxygen Fueled Tungsten Carbide Coating (Thermal Flame Spraying).

HARD COATING FACILITY

• In continuous combustion HVOF thermal spray process, a fuel gas and oxygen are combusted in a high pressure chamber reaching a temperature about 2600 degree Celsius. The resulting hot, high pressure gas is ejected through a small diameter nozzle and accelerated down a long barrel at supersonic speeds.

• The extreme velocities ( about Mach 5) provide kinetic energy which help produce coatings that are very dense and very well adhered in the as-sprayed condition.

HARD COATING FACILITY

Pre-heating

• Pre-heating of the components to about 80 degree Celsius is also done so that layers of coating can adhere to the components.

Coating

• To impart high wear resistant component is coated with Tungsten Carbide.

Finishing

• Final finishing is done for evenly distributed coating and good surface.

FINDINGS: DAM• Flip buckets are used at the dam radial gate outlet to change

the direction of the flow momentum in upward direction, so that it could not erode walls of the pathway or bed of the river.

• To prevent floating things entering in head race tunnel log boom barrier are installed in the reservoir of the dam.

• Two Spillway gates are present on Nathpa dam, which are mechanically balanced so as to stop the water inside the dam to go above a desired maximum height.

• Radial gates in the dam are not leakage proof. Although, 15 liters per minute per meter is the allowed level of seepage .

• 8 Stop locks are used to stop flow while maintenance of gates in dam and maintenance of two gates can be done simultaneously.

FINDINGS: POWERSTATION• To decrease bulkiness of cooling system, powerhouse cooling system is

divided into two parts : primary and secondary.

• Governor mechanism plays an important role in optimized calibration and regulation the powerhouse.

• To avoid flooding in powerhouse, submersible pumps are employed for safety, in case of flooding inside the powerhouse.

• Stray tunnels are present to provide multiple outlets for evacuation in case of emergency.

• Automatic lubricating systems are employed for lubricating the various components of the powerhouse.

• Two servo motors are used to control the amount of water entering the generator by controlling the openings of guide vanes.

FINDINGS: HARD COATING FACILITY• A 6 degree of freedom Robotic arm is employed to spray

molten Tungsten Carbide on the given job. • In hard coating facility, suitable safety measures are taken

and the special sensors are used to check for hydrogen leakage, which can cause a major hazard.

• Mechanism to check the purity of nitrogen is used. Error is calculated of a standard nitrogen sample. This error is used in calculations and calibration for the nitrogen cylinders which is being used for hard-coating.

• Wet scrubber is used to capture stray Tungsten Carbide particles.

CONCLUSIONS

• Practical application of the various theories and concepts, studied in various B.Tech. subjects was seen.

• The unique facility of NJHPS Hard Coating Facility was studied. • The working mechanisms and maintenance procedure of the

powerhouse and dam was studied.

SOCIO-ENVIRONMENTAL IMPACTS OF HYDROPOWER PLANTS

(VOLUNTARY PROJECT)

OBJECTIVE OF THIS STUDY

• To Study the impact of hydro power projects on environment, climate and life of people living in that area.

SOCIAL IMPACTS• When dams are constructed in an area there is a cultural and

traditional changes in the nearby areas due to migration of people.

• During tunnel formation, roads in nearby areas are damaged thus travel time and dust pollution is increased which is a big problem for locals and tourists.

• Hydro-power projects do not provide desired number of jobs to the locals. This problem is more in case of private projects.

• The electricity generated plays an important role in the life of people living in the rural areas near the hydro power project.

ENVIRONMENTAL IMPACTS

• Global warming is increased because of decomposition of leaves and other organic matter present at the bottom of dams by micro-organisms.

• The average rainfall in Kinnaur is increasing but in uneven manner. Due to this farmers started growing fruits. Decrement in cold desert vegetation like chilgoza is also observed .

• The area around Rampur and Kinnaur has become relatively colder. Sometimes snowfall is also observed in Kinnaur in month of April too which was not there a few years ago.

OTHER IMPACTS

• Due to construction of dam ,the rate of evaporation decreases which affected the vegetation in nearby areas.

• Dams affects the aquatic lives present in the rivers. Various species may extinct or suffer heavy losses during and after dam construction.

• Construction of dams and their tunnels produce vibrations. These vibrations adversely affect the local people.

• These vibrations also have negatives impacts on wildlife and their breeding pattern.

CONCLUSIONS

• An efficient and less vibration producing technology New Austrian Tunneling Method (NATM) can be used for construction of tunnels.

• Proper rehabilitation and compensation should be given to the affected people.

• Directly or indirectly, local people should be made an integral part of the organization.

• CSR should be used to increase awareness about flora and fauna conservation.