Description : What are the factors to be considered for choosing the method of cooling?
Last Answer : The choice of cooling method depends on KVA rating of transformer, size, application and the site conditions where it will be installed.
Description : In accordance with Coast Guard Regulations (46 CFR), a circuit breaker located in the machinery space and installed in a 440V AC system must _____________. A. be dependent upon mechanical ... the maximum asymmetrical shortcircuit current available at the point of application D. all of the above
Last Answer : Answer: C
Description : If overloading a DC machine becomes necessary in an emergency, you should ____________. A. cool the machine with portable blowers and fans B. hold thermal overload relays open with blocks of ... the windings for cooling D. increase the residual magnetism value of windings to reduce eddy currents
Last Answer : Answer: A
Description : Two contributors of electronic console failures are heat and vibration. To combat some of their effects, preventive maintenance procedures should include ______________. A. systematic rotation of circuit cards with those ... bolts and changing of the air in the control room D. all of the above
Last Answer : Answer: B
Description : What type of cooling is provided for Generator in power plant?
Last Answer : Hydrogen gas cooling is employed for large size generators because of better heat carrying ability of the hydrogen. Hydrogen cooling is provided for rotors and core of the generator. Water cooling is provided for the stator of the alternator.
Description : Why cooling towers require in the Steam power plant ?
Last Answer : Cooling towers cool the warm water discharged from the condenser and feed the cooled water back to the condenser. There are two types of cooling methods provided in the cooling towers, they can be either ... finned tubes over which cooling air is passed. Heat is rejected to air as water is cooled
Description : What are the types of cooling systems it transformers?
Last Answer : A. 1. ONAN (oil natural, air natural) 2. ONAF (oil natural, air forced) 3. OFAF (oil forced, air forced) 4. ODWF (oil direct, water forced) 5. OFAN (oil forced, air forced)
Description : Discuss how the ventilation and cooling of large high speed alternator is carried out.
Last Answer : For high speed alternator two cooling methods are available and they are conventional cooling and direct cooling. In conventional cooling methods, radial and axial ventilating ducts are provided in the ... oil or hydrogen are circulated in the ducts to remove the heat directly from the conductors.
Description : How the heat dissipation is improved by providing the cooling tubes?
Last Answer : The cooling tubes will improve the circulation of oil. The circulation of oil is due to effective pressure heads produced by columns of oil in tubes. The improvement in cooling is accounted by taking the specific heat dissipation due to convection as 35% more than that without tubes.
Description : Why cooling tubes are provided?
Last Answer : Cooling tubes are provided to increase the heat dissipating area of the tank.
Description : List some methods of cooling of transformers.
Last Answer : A:Air natural, Air blast, Oil Natural, Oil natural air forced, Oil natural water forced, Oil forced, Oil forced air natural, Oil forced air natural, Oil forced water forced.
Description : Why transformer oil is used as a cooling medium?
Last Answer : When transformer oil is used as a coolant the heat dissipation by convection is 10 times more than the convection due to air. Hence transformer oil is used as a cooling medium.
Description : What is the working principle of Cooling Towers?
Last Answer : The hot water is sprayed from the top of the tower, while the air is made to flow from the bottom of the tower to the top. This air cools the hot water in the cooling tower. Air vaporises ... and leaves at the top of the tower and cooled water leaves at the bottom and recirculated to the condenser.
Description : What is meant by cooling Towers?
Last Answer : It is a tower or building like device in which atmospheric air circulates in direct or indirect contact with warmer water and water is thereby cooled. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid
Description : What consists of cooling water circuit and coal & ash circuit in steam power plant?
Last Answer : The cooling water circuit consists of a pump, condenser and cooling tower. The coal and ash circuit consists of coal delivery, preparation of coal, handling of coal to the boiler furnace, ash handling and ash storage.
Description : What are the types of oil used for in transformer for cooling?
Last Answer : Paraffin based and naphtha based (in INDIA)
Description : How selection of cooling fluid in GT done?
Last Answer : a) There are 5 factors are there. b) Density c) Coefficient of thermal expansion d) Viscosity e) Specific heat f) Thermal conductivity.
Description : How cooling is done for slip ring and brush gear?
Last Answer : A centrifuge fan is mounted on the shaft in between two slip rings for ventilation of the slip rings and brush gear.
Description : In MAPS Unit # 1 end-shield cooling system has got heaters. Why?
Last Answer : Unit # 1 end-shield is made of nickel steel, which had a nil ductility temperature of -100°C while commissioning. After 30 years of operation this will rise to +32°C, because of radiation exposure. ... #2 this problem is not existed because in this unit end-shields are made up of stainless steel.
Description : During loca how the cooling of fuel bundle is achieved?
Last Answer : During loca there is provision for taking D2O from the moderator system, which is connected to PHT system for fuel cooling and there is one more option for the cooling of the fuel from the fire water system.
Description : What is the cooling water used in moderator heat exchanger during normal operation? And during class IV failure?
Last Answer : During normal operation process LP water is used in moderator heat exchangers, which transfers heat to seawater. During class IV failure firewater is used for the moderator heat exchanger.
Description : What is the cooling medium for different parts of the turbo generator?
Last Answer : Stator – DM water. Rotor – Hydrogen. Bearing – Oil.
Description : What are the types of cooling in transformer?
Last Answer : 1. Natural cooling. a. Air natural cooling (Dry type). b. Oil immersed natural cooling. c. Oil immersed, forced oil circulation with natural cooling. 2. Artificial cooling. a. Oil immersed forced ... This is the method of cooling combining oil natural, water, air natural, air blast and forced oil.
Description : Pick out the wrong statement. (A) Different solids have different equilibrium moisture curves (B) Total condenser or reboiler is considered equivalent to one theoretical plate in McCabe-Thiele method of ... (D) Even a forced draft cooling tower cannot cool water below the wet bulb temperature
Last Answer : (C) Heat removal load on cooler remains constant, even with increase of the reflux ratio in a distillation column
Description : Which of the following is the simplest method of cooling the condenser water? • Spray cooling pond • Cooling tower • Indirect air cooling • Hyperbolic cooling tower
Last Answer : Spray cooling pond
Description : Which of the following is the simplest method of cooling the condenser water? a. Spray cooling pond b. Cooling tower c. Indirect air cooling d. Hyperbolic air cooling
Last Answer : a. Spray cooling pond
Description : Which of the following is the simplest method of cooling the condenser water? A] Spray cooling pond B] Cooling tower C] Indirect air cooling D] Hyperbolic cooling tower
Last Answer : A] Spray cooling pond
Description : Machines cooled by direct cooling method may be called (a) "supercharged" (b) "inner cooled" (c) "conductor cooled" (d) any of the above
Last Answer : (d) any of the above
Description : Classify I. C. Engine on the basis of -Cycle of operation -Method of cooling
Last Answer : Classification of I. C. Engine on the basis of -Cycle of operation: a) Otto cycle engine b) Diesel cycle engine c) Duel combustion engine or semi-diesel cycle engine -Method of cooling: a) air cooled engine b) water cooled engine
Last Answer : A common method of cooling a power transformer is oil cooling.