Power Engineering 4B Exam Question Bank, Complete With 2000 Questions And Correct Answers, Latest

Power Engineering 4B Exam Question Bank, Complete With 2000 Questions And Correct Answers, Latest The steam engine will have the steam supply to the cylinder shut off once the piston has travelled: 25 to 35% of its stroke. A prime mover is: Steam turbine. Best Small A single device which converts enough will source of energy into mechanical motion is a/an: A prime mover. Advantages of a steam engine include: It is possible to change the direction of rotation without the use of gearing. They are simple and rugged. They have a slow rotational speed without the need for reduction gearing. A routine daily maintenance operating steam engine should cover first and foremost. The lubricators. One of the first ways to detect the fault in a reciprocating engine is: By sound. Thinking of the steam engine and it's construction, what does eccentric mean? Out of center. A steam engine piston: Has greater driving force on it at the beginning of it stroke. Large power production plants tend to be of the thermal type because they can burn solid fuel and: The heat cycle they use is the most efficient. On a steam engine, what is the purpose of a flywheel? It dampens speed fluctuations. It carries the engine over dead center. What is the main advantage of using the expensive properties of steam? Economy. A gasoline engine is a heat engine. What is its working fluid? Combustion gases and air mixture. What is the purpose of a turbine thrust bearing? To transfer turbine thrust to the load. Shaft sealing carbon glands are: Self lubricating In a turbine with a pressure lubrication system, The high-pressure oil generally goes to the governor system. Where is the low-pressure oil led? To the bearings. What holds a turbines carbon packing rings axially? Spring pressure. Steam pressure. For what purpose is lubricating oil required on a turbine, beside lubrication? To carry heat away from the bearings. In an impulse turbine: The steam pressure is reduced in the nozzles. Reaction turbines: Have a pressure dropped through the moving and stationary blades. Blades or Buckets form the rotor flow passages in the impulse turbines. A steam turbine should trip or shut down when normal operating speed is exceeded by: 10 to 15%. The handwheel used to adjust the turbine speed on the governor is known as the. Speeder. How many basic types of turbines are there? Two. A large reaction turbine will have: Steam pressure dropping through moving and stationary sections Impulse turbines: Have no pressure drop through the moving blades. What do the stationary nozzles of an impulse turbine convert the thermal energy of the steam into? Kinetic energy. The steam turbines exhaust can often supply the process with steam because: It is free of oil. When the steam pressure drop occurs in only the stationary members or components of a turbine, the turbine is known as: An impulse unit. Most turbine overspeed trips operate by: Centrifugal force. A large reaction turbine will have: Steam pressure dropping through moving and stationary section Starting from the boiler and simple power generation cycle, numbering the following components in the order in which the steam/water flows through the cycle. One - boiler feed pump Two - condenser Three- turbine Four - condensate pump Five- feed water heater The great majority of turbine governors are of the Mechanical centrifugal type Turbine overspeed trip: Will close the steam stop valve to the turbine Turbine lubricating oil : Can be used to operate the turbine governor The turbine overspeed trip: Prevents the turbine exceeding the maximum rated speed. Will close the steam stop valve. What is the purpose of the nozzles in the turbine? To increase steam velocities In the turbine with the pressure lubrication system, the high-pressure oil generally goes to the governor system. Where is the low pressure oil led? To the bearings. The overspeed trip of a steam turbine: Is installed on all turbines. The purpose of the turbine glands is to prevent: Steam escaping from the turbine. What is the purpose of a turbine thrust bearing? To transfer turbine thrust to the load. When warming up a turbine: Warm-up is done slowly. The turbine is slowly rotated. The warm-up must be done so that warping is prevented. What are some advantages of the pressure system on the turbine? Minimal maintenance required. Reliable service. Long bearing life. The shrouding installed on the blading of the steam turbine serves to: Confine the steam to the blades. When preparing a turbine for starts, why is it warmed up slowley? To prevent warping. What gives wood its strength? Cellulose. Natural draft cooling towers operate most effectively in large open spaces and: Where wind is relatively constant. Water contained in the airstream at the discharge of the cooling tower is removed: With drift eliminators. Induced draft crossflow cooling tower. In cooling towers, protective films and sacrificial metals are two methods of protecting against what? Corrosion. What is the purpose of the cooling tower? To reduce the temperature of cooling water For water temperatures up to 70°, increase of temperatures of 15 to 30° cause corrosion rates and cooling towers: To double. Micro organisms require carbon to develop. Where would they get this carbon from in the cooling tower? From the cellulose in the wood. Which of the following methods could be used to circulate air in a cooling tower? Induced draft fans. Natural draft. Convection currents. What could happen if the initial treatment of film forming chemicals, in the cooling tower, is to weak? Severe corrosion in unprotected areas is possible. The average amount of water volume, which evaporates from a cooling tower is: 5%. What is steel corrosion in cooling towers mainly due to? Dissolved oxygen. Delignification in a cooling towers wood is the result of: Chemicals such as chlorine. What are advantages of Venturi towers? No fan is required. It is quiet. No fill is required. Reduced maintenance requirements. At about this water temperature, corrosion rates in cooling towers are relatively unaffected. 70°C. What are the two classifications of mechanical draft cooling towers? Forced draft. Induced draft. What makes cooling tower such a good environment for biological growth? An oxygen-rich atmosphere. Warm water. In cold climates, ice formation in a cooling tower may be dealt with by: Slowing the fans down. Reversing the fans. Compared to a crossflow tower, a counterflow tower: Occupies less floorspace. What are splash bars and different chemical methods used to protect the cooling tower against? Biological fouling. How many general methods are there to circulate air in the cooling tower? There are four. Excessive water drift in the cooling tower could be the result of a drift eliminators being out of place or: The water flow rate is too high. How are microbiological organisms most effectively killed in the cooling tower water system? By temporarily raising the concentration of the chemicals to a high-level. Chemical methods used to prevent biological fouling in cooling towers include: Oxidizing chemicals. Non-oxidizing chemicals. Heavy metals. How many subclasses of mechanical drafting cooling towers are there? There are two. In a Venturi type cooling tower, how is airflow created? By spray nozzles. Compared to a crossflow tower, a counterflow tower: Occupies less floorspace. What purpose do both water softener and the addition of sulphuric acid to cooling tower water service? They treat scaling. Approximately how much of a gas turbines power is used to drive it's compressor? 2/3 Dirty air filters on a gas turbine could lead to what alarm? High differential pressure, air intake. The operating power of the gas turbine is directly related to the: Mass of gas passing through the turbine per second. The low installation cost of the gas turbine is: Because less auxiliary equipment is needed. The purpose of a regenerator is: To improve the efficiency of the turbine. What affect would a reduction in air density have on a gas turbine? Power output would be reduced. If a gas turbine operates on natural gas, what may be required? Gas compressor. What fire extinguisher in media are fitted in gas turbine automatic firefighting systems? Halon. Carbon dioxide A gas turbine compressor is usually: An axial design. Many typical steam plant auxiliaries are limited with a gas turbine due to its: Simplicity. The majority of gas turbines are of what style? Single shaft. Simple. Open cycle. The gas turbine is not self starting. It must be rotated at 20% to 30% of its maximum speed before fuel is turned on. Gas turbines are very popular where: Water is scarce. Put the following gas turbine starting operations in the correct sequence. Cranking. Purging. Firing. Acceleration. Early gas turbines were handicapped by: Metals not standing the high temperatures involved. A gas turbine performs most effectively if: Ambient air temperature is low. Which of the following are disadvantages of gas turbines? Noise. Low thermal efficiency. What type of lubrication pump is most commonly used in gas turbines? A gear lubrication pump. What is injected into the air intake of the gas turbine to clean the blades? A detergent. The compressor of a gas turbine: Can be driven by the turbine. Regarding a combined steam - gas turbine plant, which of the following may apply? The gas turbine may exhaust to the boiler.