SUMMER INDUSTRIAL TRAINING PRESENTATION

PRESENTED BY:

YOGESH THAKUR

B.TECH (ME) 4THYEAR

SJVN LTD. (INTRODUCTION)

• SJVN Limited, a Schedule 'A' Mini Ratna CPSE, is a joint venturebetween the Govt. of India & Govt. of Himachal Pradesh withauthorized capital of INR 7000 crore.

• Business:

• Hydroelectric Projects in Himachal Pradesh, Uttarakhand,Arunachal Pradesh and in the neighboring countries of Nepaland 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 capacityis the country’s largest hydropower plant on River Satluj inShimla district of Himachal Pradesh.

OBJECTIVE OF INTERNSHIP

The main objectives of internship were:

• To study and understand various mechanical and associatedsystems of dam and powerhouse at NJHPS, SJVN Ltd.

• To study various facilities available at Hard Coating Workshopin NJHPS, SJVN Ltd.

STUDY METHODOLOGY

• Technical discussions with various engineers andexecutives

• Study various drawings available of different parts andcomponents

• On-site visit of powerhouse and dam

• Understanding cooling and drainage systems on Jhakrisite

• Understanding working of control systems of NJHPS

• Study of different systems in hard coating facility

• Study of measures taken for safer operation of HydroPower Plant

HYDRO POWER PROJECT

Dam

Powerhouse

Transmission

THE DAM

• This project has a straight gravity type dam of 62.5m height onthe Satluj River at Nathpa, Kinnaur district in HimachalPradesh.

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

• This stored water is diverted into conduit which runs up to27.4 km which carries 405 cumecs of water through fourintakes.

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

POWERHOUSE

• Nathpa Jhakri project has an underground power house (200m 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 coatsturbines and other mechanical parts using robotic arm.

• Hard coating facility works on the principle of High VelocityOxygen Fueled Tungsten Carbide Coating (Thermal FlameSpraying).

HARD COATING FACILITY

• In continuous combustion HVOF thermal spray process, a fuelgas and oxygen are combusted in a high pressure chamberreaching a temperature about 2600 degree Celsius. Theresulting hot, high pressure gas is ejected through a smalldiameter nozzle and accelerated down a long barrel atsupersonic speeds.

• The extreme velocities ( about Mach 5) provide kinetic energywhich help produce coatings that are very dense and very welladhered 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 changethe direction of the flow momentum in upward direction, sothat it could not erode walls of the pathway or bed of the river.

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

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

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

• 8 Stop locks are used to stop flow while maintenance of gatesin dam and maintenance of two gates can be donesimultaneously.

FINDINGS: POWERSTATION

• To decrease bulkiness of cooling system, powerhouse cooling system isdivided into two parts : primary and secondary.

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

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

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

• Automatic lubricating systems are employed for lubricating the variouscomponents of the powerhouse.

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

FINDINGS: HARD COATING FACILITY

• A 6 degree of freedom Robotic arm is employed to spraymolten Tungsten Carbide on the given job.

• In hard coating facility, suitable safety measures are takenand the special sensors are used to check for hydrogenleakage, which can cause a major hazard.

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

• Wet scrubber is used to capture stray Tungsten Carbideparticles.

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 thepowerhouse 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 culturaland traditional changes in the nearby areas due tomigration of people.

• During tunnel formation, roads in nearby areas aredamaged thus travel time and dust pollution is increasedwhich is a big problem for locals and tourists.

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

• The electricity generated plays an important role in the lifeof people living in the rural areas near the hydro powerproject.

ENVIRONMENTAL IMPACTS

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

• The average rainfall in Kinnaur is increasing but in unevenmanner. Due to this farmers started growing fruits.Decrement in cold desert vegetation like chilgoza is alsoobserved .

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

OTHER IMPACTS

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

• Dams affects the aquatic lives present in the rivers. Variousspecies may extinct or suffer heavy losses during and afterdam construction.

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

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

CONCLUSIONS

• An efficient and less vibration producing technology NewAustrian Tunneling Method (NATM) can be used forconstruction of tunnels.

• Proper rehabilitation and compensation should be given tothe affected people.

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

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