Description : The propeller shaft speed in a turbo-electric, synchronous, propulsion drive motor is changed by varying the __________. A. turbine speed B. number of motor poles C. field strength of the generator D. field strength of the motor
Last Answer : Answer: A
Description : The torque produced by a motor when its shaft will not turn, even though rated voltage is applied to the stator, is known as _____________. A. locked-rotor torque B. pullout torque C. breakdown torque D. torque margin
Description : High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process: ... (C) Δ H ≠ 0 and ΔS ≠ 0 (D) Δ H = 0 and ΔS ≠ 0
Last Answer : (B) Δ H ≠ 0 and ΔS = 0
Description : What is the remedy for a bent steam turbine shaft causing excessive vibration?
Last Answer : 1. The run-out of the shaft near the center as well as the shaft extension should be checked. 2. If the run-out is excessive, the shaft is to be replaced.
Description : Why is a shaft coupler used between turbine and generator ?
Last Answer : For easy transmission torque or rotation angle and can also use for the protection of the safety devices shaft cannot be separated from the shaft during motion coupling will be damaged first so as avoid to the damaged of motor or other transmission parts.
Description : The twisting force developed by a motor and applied to a shaft is called _____________. A. magnetism B. electromotive force C. torque D. voltage
Last Answer : Answer: C
Description : The conversion of the throttle command voltage to the signal necessary to achieve the desired shaft RPM is accomplished by the _____________. A. ahead or astern function generator of the ... circuit C. operational amplifiers in the autorotation circuit D. long time constant amplifier circuit
Description : What is the necessity of shaft voltage measurement?
Last Answer : It is to observe insulation of bearing 6 & 7 and hydrogen seal assembly. It requires minimum leakage current (<100mA) through bearings and shaft seals to avoid pitting of bearings. ... >100mA, clean the insulation provided between bearing pedestal and seal housing with earth.
Description : Saturated steam at 1 atm is discharged from a turbine at 1200 kg/h. Superheated steam at 300 0C and 1 atm is needed as a feed to a heat exchanger. To produce it, the turbine discharge ... amount of superheated steam at 300 0C produced and the volumetric flow rate of the 400 0C steam.
Last Answer : Solution 1. Mass balance of water 1200 + m1 = m2 ………………………………………… (1) …………………….1 mark 2. Energy balance (1200 kg/h)(2676 kJ/kg) + m1(3278 kJ/kg)
Description : Over voltage protection is recommended for (a) hydro-electric generators (b) steam turbine generators (c) gas turbine generators (d) all of the above (e) none of the above
Last Answer : (d) all of the above
Description : Which power plant has minimum operating cost? a) Hydroelectric power plant b) Thermal power plant c) Nuclear power plant d) Gas Turbine Power Plant Ans: A 42. Which of the following have ... a) Hydroelectric power plant b) Thermal power plant c) Nuclear power plant d) Solar electric power plant
Last Answer : Ans: B
Description : As a result of a mechanical malfunction in one of the ship's service generators operating in parallel, you must secure that generator. In order to prevent a possible overload to the ... feeder circuit breakers, the malfunctioning prime mover turbine throttle trip, and the generator circuit breaker.
Last Answer : Answer: B
Description : In the illustration, moving the engine room reference in the direction indicated will _________. SE-0002 A. cause a positive signal to be sent to the ahead function generator creating a more ... the ahead valve to open until the negative signal exceeds the low lube oil pressure override signal
Description : Turbine-Generator Lubrication Oil System Function
Last Answer : Turbine-Generator Lubrication Oil System Function For large turbine-generators forced lubrication system and water cooling system should be continuously required during the operation of the turbine-generator and ... when the oil pressure is low. A second backup dc pumps are sometimes provided.
Description : State the factors, for the choice of electrical system for an aero turbine.
Last Answer : A:The choice of electrical system for an aero turbine is guided by three factors: Type of electrical output: dc, variable- frequency ac, and constant- frequency ac. Aero turbine ... energy output: in conjunction with battery or other form of storage, or interconnection with power grid.
Description : What are the working fluids in gas turbine?
Last Answer : 1.Air 2.Helium 3.Argon 4.Carbon dioxide
Description : Explain reaction turbine in terms of head:
Last Answer : High head- Francis Medium head- Propeller Low head- Kaplan
Description : What is the purpose of TOPP (turbine oil purification plant)?
Last Answer : The purpose of TOPP is to remove the water ingress in turbine oil system from the gland leaks, cooler leakage, and solid metal particles, which are produced due to rust, wear of bearings and to normalize the ... capacity of TOPP is, for solids - 5 microns and for water - 300 to 500 parts per milli.
Description : State turbine governor setting.
Last Answer : On 2560 rpm turbine governor becomes effective and on 2760 rpm is turbine governor take over speed.
Description : What is the type turbine installed in KGS?
Last Answer : Tandem compounded to expansion of steam, impulse reaction type.
Description : What type of governing system used in turbine and what are the purposes of the system?
Last Answer : Hydraulic governing system of centrifugal (speed) governer type is adopted in turbine. Sensitive oil pressure to actuate centrifugal governer is 6.1 kg/cm2 (max). At 6.7 kg/cm2 relief valve ... speeder gear from BPC signal. Once synchronised the grid frequency and speeder gear controls the speed.
Description : Write critical speeds of turbine generator?
Last Answer : Generator rotor 1st critical speed 1283 rpm 2nd critical speed 3600 rpm Combined turbine generator 1st critical speed 1938 rpm 2nd critical speed 2120 rpm 3rd critical speed 2385 rpm 4th critical speed 2837 rpm
Description : What are the futures of turbine generator?
Last Answer : a. Low heat drop b. Moisture control (HP-0.26%, LP-3%.) c. Turbine governing system d. 70% steam dumping to the condenser to avoid reactor trip. e. Gland sealing f. LP exhaust hood cooling g. Generator stator and rotor cooling h. Hydrogen sealing i. Static excitation
Description : How dearator pressure is maintained after turbine trip?
Last Answer : Pegging steam is used to maintain dearator pressure after turbine trip.
Description : How turbine oil purification is achieved?
Last Answer : Oil purification is achieved by centrifugal operation.
Description : Explain the main difference between impulse and reaction turbine.
Last Answer : When the inlet pressure of steam to the turbine is equal to outlet pressure of steam from the turbine the turbine is called the impulse turbine. In this type the heat is added is very less. ... than the inlet pressure of the steam. There is reduction in pressure with the increase in kinetic energy.
Description : What is the purpose of turbine governing system?
Last Answer : Turbine governing system governs the speed of the turbine with the help of centrifugal governer. It reduces the steam inlet when turbine over speeds.
Description : What are the methods of removing moisture from turbine?
Last Answer : a. External method by moisture separator and reheater, which separates the moisture and reheates the steam. b. Internally by stainless steel mesh, which reduces moisture (water particles) to 1%. c. By main steam reheat.
Description : Explain the principle of working of impulse steam turbine.
Last Answer : When steam enters the turbine it suffers a change in direction and momentum, which gives rise to the rotation of the turbine. There will be no drop in pressure in impulse steam turbine.
Last Answer : The choice of electrical system for an aero turbine is guided by three factors: Type of electrical output: dc, variablefrequency ac, and constant- frequency ac. Aero turbine rotational speed ... output: in conjunction with battery or other form of storage, or interconnection with power grid.
Description : Flue gases coming out from furnace is first going through a) Turbine b) Economizer c) Air pre-heater d) Chimney
Last Answer : Ans: Economizer
Description : Water hamming effect is occurs in a) Surge tank b) Penstock c) Turbine d) Reservoir
Last Answer : Ans: Penstock
Description : Low head plants generally use (A) Pelton Turbines (B) Francis Turbine (C) Pelton or Francis Turbine (D) Kaplan Turbines
Last Answer : Ans: A In the hysterisis motor, the direction of rotation can be reversed by shifting the shaded pole region with respect to main pole. But not by changing supply lead because it has ac supply.
Description : What is the approximate voltage produced by a nickel-cadmium battery cell? A. 1.25 volts B. 1.50 volts C. 2.20 volts D. 6.05 volts
Description : What is the approximate voltage per cell produced by the nickel-iron (Edison) battery? A. 0.85 volts B. 1.35 volts C. 2.20 volts D. 6.05 volts
Description : What effects are produced by change in voltage?
Last Answer : a) Iron loss.........varies approximately as V2. b) Cu loss.........it also varies as V2 but decreases with an increase in voltage if constant kVA output is assumed. c ... ..for constant kVA output, iron temperatures increase whereas Cu temperatures decrease with increase in voltages and vice-versa.
Description : How over voltage is produced in Field breaker?
Last Answer : Over voltages appear if synchronous generators and motors fall out of step inducing an AC voltage in the field system. Depending on the type of construction of the machine and the slip this ... -permissibly high, for this purpose over voltage protectors are provided in the field breaker cubicle.
Description : According to U. S. Coast Guard Regulations (46 CFR), the motor controller for a submersible electric motor driven bilge pump should be installed _____________. A. in the shaft alley B. at the submersible bilge pump C. above the uppermost continuous deck D. at the engine room emergency control panel
Description : To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. stowed upright on its shaft C. supported by two 'V' notched wood blocks D. returned to the frame as soon as the bearings are removed
Description : Which of the listed conditions will occur if dirt and grease are allowed to accumulate between the commutator segments of a motor? A. A partial short circuit. B. A dead short circuit. C. Misalignment of the motor shaft. D. Overspeeding of the motor.
Description : On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock ... the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings
Last Answer : Answer: D
Description : On some electrical generating equipment one outboard bearing pedestal is insulated from the bedplate. This should be checked with a millivolt meter and a jumper. With the millivolt meter connectd between ... then removed to take a second reading. This eliminates the insulating effect of the bearing.
Description : The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the ... by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work
Description : One of the generator bearing shells is generally insulated from the end housing in order to prevent _____________. A. rapid brush wear B. residual magnetism leak off C. excessive field winding heat D. circulation of shaft currents
Description : One of the generator or motor bearings is generally insulated from the end housing in order to prevent ________. A. rapid brush wear B. current leakage from the shaft C. excessive field winding heat D. circulation of shaft currents induced in the machine's frame
Description : In the illustration, the assembly labeled 2 is a ________. EL-0001 A. wound rotor and shaft for a single phase induction motor B. conduction rotor and shaft for a polyphase induction motor C. ... cage rotor and shaft for a polyphase motor D. squirrel cage rotor for a single phase induction motor
Description : The direction of propeller shaft rotation in a turbo-electric synchronous propulsion drive motor is changed by reversing the _____________. A. polarity of the propulsion motor B. polarity of the propulsion generator C. phase sequence of power to the motor D. phase sequence of power to the generator
Description : When removing ball or roller bearings from the shaft of a motor, you should use a _____________. A. rawhide hammer B. brass mallet C. wheel puller D. soft iron pry bar
Description : A handheld digital tachometer could give a bad reading if ___________________. A. aimed directly at the shaft B. partially aimed at a 60 Hz. fluorescent light C. positioned 5-10 inches from the shaft D. the tape is too shiny
Description : Modern handheld digital tachometers operate by counting light pulses returned to the unit by ______________. A. the tach generator B. either the coupling or shaft C. a small bulb attached to the shaft D. a piece of reflective tape