20-01-2012, 04:14 PM
FEROZE GANDHI UNCHAHAR THERMAL POWER STATION
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INTRODUCTION OF NTPC
Established in 1975, NTPC the largest power company of the country has been consistently powering the growth of India.
With an installed capacity of 30,144 MW, it contributes 28.6% of the nation’s power generation with only 18.79% of India’s total installed capacity. An ISO 9001:2000 certified company, it is world’s sixth largest thermal power generator and second most efficient in capacity utilization.
Principle of the Steam Power Plant
The working principle of a steam plant is based upon the Rankine cycle. Generally steam is taken as the working medium due to its ability to be stable and that it’s readily stable. The flow of steam in the plant can be very easily be understood by the flow diagram of the plant. A graph plotted between the temperature and the entropy would indicate the technical details of the working by the rankine cycle. The entropy of a system can be understood as an index of degradation of energy.
Basic principal of operation of circuit breaker:
Circuit breaker consists of a fix contact and sliding contact into which moves a moving contact. The end of moving contact it attached to a handle that can be manually operated or may operate automatically with the help of mechanism that has a trip coil energized by secondary of CT. Under normal condition the secondary of CT is not energized sufficiently to trip the coil but under false condition the coil is energized fully to operate the trip coil and the circuit breaker is operated.
Air brake circuit breaker:
The arc interruption process of air- based circuit breaker is based on the natural deionization of gases by cooling action. The arc is resilient and can be stretched, and has a resistance, which can be increased both by length and confinement. Hence the arc resistance is increased by stretching the arc and as the resistance increases to higher value, the short circuit current drops to zero and arc is extinguished.