Power Plant Engineering (PPE) MCQs | Page - 3

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

 mechanical method of water

 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.

 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.

 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.

 the pressurizer is a pressure vessel with a heater at the bottom and water spray at the top. the top of the pressurizer is filled with steam at primary system pressure. if the primary loop pressure drops, the heater is energized to increase the steam content in the pressurizer and thus increases the pressure of primary cooling system.

 presence of high temperature and high pressure water, the corrosion is severe. this means use of stainless steel adds to further costing. when γ- radiations pass through the pressure vessel it results in uneven heating which induces thermal stresses on vessels.

 the light water reactor is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator – furthermore a solid fissile element is used as fuel. these are most common type of thermal-neutron reactors.

 in boiling water reactor, the coolant is in direct contact with the heat producing nuclear fuel and boils in the same compartment in which the fuel is located. the reactor pressure is maintained at 70bar. the coolant thus serves the triple function of coolant, moderato and working fluid.

 there are three different types of bwr cycles commonly used: