Nuclear Reactors and Energy Quiz

Turbines and Steam Condensers

• Velocity compounding method is used in Ratean and Zoelly turbines.
• Optimum blade speed ratio for maximum blade efficiency or maximum work done is given by = cos 2.
• Velocity-compounded impulse turbine has high steam consumption and low efficiency.
• The degree of reaction of reaction turbine stage is defined as the ratio of heat drop over fixed blades to the total heat drop in the stage.
• The efficiency of steam turbine is considerably reduced if throttle governing is carried out at low loads.
• Nozzle control can only be applied to reaction turbines.
• A steam condenser is a device or an appliance in which steam condenses and heat released by steam is absorbed by water.
• In jet condensers, the exhaust steam and water do not come in direct contact with each other.
• In counter-flow type jet condenser, the steam and cooling water enter the condenser from opposite directions.
• Low level counter flow jet condenser is also called barometric condenser.
• In an injector condenser, the exhaust steam and cooling water mix in hollow truncated cones.
• A jet condenser entails high manufacturing cost.

Hydrology and Hydrograph

• Hydrology is a science that deals with the depletion and replenishment of water resources.
• Precipitation includes all the water that falls from the atmosphere to earth's surface.
• Run-off can also be named as discharge or stream flow.
• Hydrograph indicates the power available from the stream at different times of day, week, or year.
• Flow duration curve is plotted between flows available during a period versus the fraction of time.
• The 'firm power' is also known as the primary 'power'.
• A mass curve is the graph of the cumulative values of water quantity (run-off) against time.

Steam Power Plants and Thermodynamics

• Thermal efficiency of steam plants is of the order of 30%.
• Blowing down of boiler water is the process to control the solid concentration in the boiler water by removing some of the concentrated saline water.
• In regenerative air pre-heater, heat is transferred from heating an intermediate material and then heating the air from this material.
• The height of the chimney in a steam power plant is governed by the control of pollution.
• Deaerative heating is done to remove dissolved gases in the water.
• Reheat factor is the ratio of cumulative actual enthalpy drop for the stages to total isentropic enthalpy heat drop.
• The value of the reheat factor is of the order of 0.8 to 1.0.
• Compounding of steam turbine is done for reducing the rotor speed.
• Topping turbines are turbines.

Gas Turbines

• In a two-stage gas turbine plant, reheating after the first stage increases thermal efficiency.
• In a two-stage gas turbine plant, with inter-cooling and reheating, both work ratio and thermal efficiency improve.
• For a jet propulsion unit, ideally the compressor work and turbine work are equal.
• Greater the difference between jet velocity and airplane velocity, greater the propulsive efficiency.
• For starting gas turbines, the turbine rotor is usually motored up to 'coming in' speed which is equal to half of the rated speed of the gas turbine.
• The blades of the gas turbine rotor are made of high nickel alloy (Nimic 80).
• Maximum temperature in a gas turbine is of the order of 1600°C.

Nuclear Power Plants

• A CANDU reactor uses natural uranium as fuel and heavy water as moderator and coolant.
• Fission of U235 releases 200 MeV energy.
• Fast breed reactors are best suited for India because of large thorium deposits.

Power System and Economics

• A load curve indicates average power used during the period.
• Annual depreciation as per straight line method, is calculated by the capital cost minus the salvage value, divided by the number of years of life.
• A consumer has to pay lesser fixed charges in two-part tariff.
• In India, the tariff for charging the consumers for the consumption of electricity is based on two-part tariff.
• In Hopkinson demand rate or two-part tariff, the demand rate or fixed charges are affected by the variation in load factor.

Test your knowledge on nuclear reactors, energy release in fission reactions, suitability of fast breed reactors, and understanding load curves in this quiz.