Power Plant Engineering Set 2

Answer: false

Explaination:
there are larger deposits of nuclear fuel available all over the world. therefore, such plants can ensure continued supply of electrical energy for thousands of years.

Answer: near load centre but at reasonable distance

Explaination:
these plants can be located near the load centre because of the negligible

Answer: true

Explaination:
cost of fuel in nuclear power plant is taken as the capital cost. the the total operating cost involves wages and the salaries of operating and maintenance staff only, cost of disposal of waste etc.. the cost of transport and handling of coal for conventional thermal power plant is much higher than the cost of nuclear fuel.

Answer: to separate the light dust from the coal

Explaination:
because of the brittle nature of the coal, it is a common nature of coal to emit light dust/coal dust during transportation, mining and machine handling. this dust needs to be cleared out and it is performed by coal breaker.

Answer: railway

Explaination:
the railway is preferred since it is quite economical as well as loading and unloading of coal is easy. and at stretch tons of coal can be transported by goods train from one place to another place. coal is considered as a bulk commodity value which falls in category of minerals and ores. if roadways

Answer: hopper

Explaination:
hopper is the conical shaped slow coal dispenser to the furnace. it is placed right above the furnace and a live feeder mechanism is set at end of hopper for a controlled flow. there is no requirement of any external power/force since this works on gravity force.

Answer: to separate the lighter dust particles

Explaination:
cyclone separators use air to swirl around the ash that has been dispensed into them. due to centrifugal action heavier ash settles down, where as lighter dust/ash particles is collected in hopper and dumped out. the air flows in helical pattern which makes easy for the heavier dust particle to settle down easily without interrupting the airflow.

Answer: air

Explaination:
in pneumatic ash handling system, air is used to carry ash to long distance at a capacity of 5 to 30 tonnes per hour. and the air used for this purpose is easily cleanable and can be exhausted back into atmosphere after the complete filtration processes.

Answer: pneumatic ash handling system

Explaination:
the air is made to pass at very high pressure in order to carry out the ash for long distance. since the air is moving at high speed at high velocity in the conveying pipes, it tends to create a lot of noise by hitting the walls of pipe at swift turns and curves.

Answer: water

Explaination:
water is used as the medium to carry ash at high velocity. depending on water pressure the system is divided as low pressure system and high pressure system. in low pressure system, sloped sumps are used to move the ash at low velocity and in high pressure system nozzle sprays used to ram up the speed of ash flow.

Answer: 500m

Explaination:
low pressure system moves the ash mixed in water at a distance of 3 to 5 m/s in a sloped pump made of reinforced constituents and this movement is continuous. so, it has the ability to carry the ash for such long distance. there is no requirement any auxiliary source to move the ash mixed with water.

Answer: 50 tonnes/hour

Explaination:
the capacity of low pressure hydraulic ash handling system is 50tonnes/hour at a speed of 3m/s. since the ash produced is mixed in water and dumped, the water has the ability to dissolve and intake more amount of ash. and this mixture is spread throughout the sump.

Answer: draught

Explaination:
the term ‘draught’ is used to define the static pressure in the furnace, in the various ducts and the stack.

Answer: Δp = gh(ρa-ρg)

Explaination:
the draught produced is given by Δp = gh(ρa-ρg).

Answer: actuated draft

Explaination:
the three types of mechanical drafts are balanced, induced and forced drafts.

Answer: controlling the excess air

Explaination:
excess amount of air leads to significant losses in energy due to heat loss through flue gases.

Answer: all of the mentioned

Explaination:
all these reasons lead to clinkering.

Answer: air is sucked in, so air leaks are more and hence furnace efficiency is reduced

Explaination:
a positive pressure exists in the furnace employing forced draught.

Answer: axial fans

Explaination:
axial fans have the highest cost.

Answer: electronically adjustable turbine drive

Explaination:
except ‘electronically adjustable turbine drive’, all other are a type of drive in variable speed control.

Answer: condensed steam and small percentage from natural resources

Explaination:
the steam coming out of turbines is condensed and the condenset is fed back to the boiler. some of water losses due

Answer: to remove solid matter and impurities

Explaination:
mechanical method of water

Answer: steam is directly taken from main turbine and used to heat it feed water

Explaination:
open and contact type haters are in small power plants. such heaters recives steam from back pressure turbine. in large modern power plants heaters bleed steam from the main turbine and use it for heating of feed water.

Answer: dissolved carbon dioxide and other gases

Explaination:
thermal treatment method involves distillation and derative heating of feed water. during distillation water is evaporated then condensed and collected. during derating heating water is broken up into fine droplets and heated to produced vapour within the deaerator. during these process carbon dioxide and other days of devices separated from feet water.

Answer: carbonate and carbon dioxide

Explaination:
chemical treatment involvs line treatment, soda treatment, lime and soda treatment. zeolite treatment and demineralisation. iime treatment is done for treatment of carbonate hardness, carbon dioxide in water. soda treatment is done for treatment of water containing non carbonate hardness and line soda treatment is used when both carbonate and none carbonate hardness for feed water.