Most aero derivative combustion turbine produce less than: A. 20 MW C. 30 MW B. 40 MW D. 50 MW The compression ratio based on pressures in the compression stage in a gas turbine is typically: A. 11 to 16 C. 5 to 8 B. 12 to 18 D. 8 to 14 The compression ratio based on pressures of heavy duty gas turbine is in the range of ________. A. 14 to 15 C. 19 to 21 B. 11 to 16 D. 16 to 18 Aero derivative combustion turbine has higher compression ratios typically: A. 14 to 15 C. 19 to 21 B. 11 to 16 D. 16 to 18 Most heavy-duty combustion turbines have higher compression ratios typically: A. 14 to 16 C. 18 to 20 B. 10 to 12 D. 16 to 18 The temperature of the gas entering the expander section is typically: A. 1200 C to 1290 C C. 1000 C to 1200 C B. 1500 C to 1490 C D. 1300 C to 1390 C The exhaust temperature which makes the exhaust an ideal heat source for combined cycles is typically: A. 540 C to 590 C C. 600 C to 650 C B. 300 C to 350 C D. 440 C to 490 C Most combustion turbines have: A. 2 to 3 expander stages C. 3 to 4 expander stages B. 4 to 5 expander stages D. 1 to 2 expander stages The exhaust flow rate in modern heavy-duty turbines per 100 MW is approximately: A. 240 to 250 kg/s C. 140 to 150 kg/s B. 340 to 350 kg/s D. 440 to 450 kg/s The Brayton gas turbine cycle is also known as: A. Joule cycle C. Stirling Cycle B. Ericsson Cycle D. Atkinson Cycle Approximately how many percent of the turbine power is used to drive the high efficiency compressor? A. 50 to 75 % C. 60 to 85 % B. 45 to 70 % D. 30 to 55 % Depending on the turbine construction details, the temperature of air entering the turbine will be between: A. 650 C to 1000 C C. 750 C to 1100 C B. 550 C to 950 C D. 850 C to 1200 C a parallel flow heat exchanger Which of the following is an effect of having a regenerator? A. turbine work is increased B. thermal efficiency B. 30 to 55 % D. compressor and turbine work C. control efficiency In a Brayton Cycle. turbine work C. a mixed flow heat exchanger B. 34 to 34.5 % B. back work ratio B. Which of the following engines are typically used by turbo jet and turboprop? A. Open Combustors C.5 % Aero derivative turbines commonly achieve efficiencies up to : A. a cross flow heat exchanger D. 36 to 36.5 % C. 42% or 41% C. limit thermal efficiency B. network . compressor work is increased A regenerator in a gas turbine has no effect in: A. 26 to 28 % New combustion turbines on the cutting edge of technology (Advanced turbine systems) are able to achieve A. reheating and intercooling will: A. 30 to 32 % B. 40 to 65 % B. back-work ratio D. thermal efficiency B. A. increase thermal efficiency C. High Combustors The full load thermal efficiency of existing heavy duty combustion turbines in simple cycles is approximately: A. heat added D. heat added C. 40 to 42 % D. 40 to 40. reheating has no effect in: A. a counterflow heat exchanger C. compressor work is reduced D. 38 to 38. decrease thermal efficiency D. intercooling has no effect in: A.5 % D. increase thermal efficiency C. Turbo Combustors D. combustor In a Brayton cycle multiple stages of compression and expansion will _________. less heat added C. limit thermal efficiency B. Network In a Brayton cycle. control efficiency In a Brayton cycle. 35 to 60 % Which of the following is an example of regenerator? A. 35% Which of the following is the typical back work ratio of gas turbines? A. thermal efficiency D. decrease thermal efficiency D. 45% D. Close Combustors B. 38% B. 34 to 36 % C. 50 to 75 % C. Tensile strength of shell C. 1/4 D. Quantity of steam A high pressure chamber or a device in which the paths of rapidly moving particles can be observed and photographed. Boiler pressure C. 160 – 180 °F D. Wc / Wt B. 2 B. water walls D. Type of fuel available B. A. 1/2 C. 4 D. Air chamber The formation of gas bubbles in a liquid is called A. Wt . baffles C. Thickness of shell D. A. Combustion chamber D. 1/3 B. 4 The water level inside the boiler is indicated by the A. 1/5 . Factor of safety B. Atmosphere B. foaming B. Diameter of the shell B. Critical pressure D. Tensile strength of the shell C. 3 D. 240 – 260 °F B. 1 C. 2 C. Thickness of the shell D. Shear strength of shell material Which of the factors does working pressure of boiler doesn’t depend? A. fusible plug B. Wt x Wc C. Physical limitations usually preclude more than how many stages of intercooling and reheating? A. Priming D. Quantity of steam to be generated D. Type of fuel being fired Total solid impurities in feed water for a boiler depend upon A. 3 B. Peak pressure What is the average fuel – oil temperature range of the oil in the discharge line to the boiler? A. 140 – 160 °F The lowest permissible water level of a boiler without internal furnace is ____ the height of the shell. Fission chamber B. 180 – 200 °F C. 5 If Wt is the turbine power and Wc is the compressor power then the network is: A. bubbling C. water column What is the highest pressure under which distinguishable liquid and vapor phases can exist in equilibrium? A. Maximum pressure C.Wc D. Wt + Wc Which of the following factors does bursting pressure of boiler doesn’t depend? A. Cloud chamber C. Carryover How many check valves should be provided between any feed pump and boiler? A. dynamic temperature B. supersonic aircraft . pressure at cut off to mean effective pressure D. Polytrophic B. conduction C. pressure at cut off to supply pressure B. steam condenses as soon as it leaves the cylinder D. radiation The flow through the nozzle is: A. Atmospheric pressure When the back pressure is reduced to lowest exit pressure. In case of steam engine the cut off ratio is the ratio of A. decrease in the static enthalpy of fluid B. converging nozzle D. adiabatic expansion B. Negative B. Choked B. condensed steam is supplied B. subsonic aircraft C. increase in the static enthalpy of fluid C. Stagnant pressure C. Back pressure B. Isentropic C. Isobaric D. diverging nozzle C. decrease in the internal energy of fluid D. Isovolumic If the reservoir is sufficiently large. zero Which of the following is the pressure applied at the nozzle discharge section? A. Critical pressure D. exhaust steam is condensed in a condenser Flows through the nozzles and diffusers with increasing fluid velocity will create an equivalent A. Positive D. high temperature D. the mass flow reaches a maximum value and the flow is said to be: A. none of these A converging – diverging nozzle is the standard equipment in: A. Stacked C. Stuck-up D. kinetic temperature C. elevation temperature All of the following mechanism can supply heat to a thermodynamic system except A. steam condenses inside cylinder C. fraction of piston stroke which the piston has travelled when cut off occurs In a condensing steam engine A. natural convection D. converging – diverging nozzle B. decrease in the dynamic enthalpy of fluid The term V²/2cp responds to the temperature rise during such a process and is called the A. Maximum C. the nozzle inlet velocity is: A. pressure at cut off to exhaust pressure C. Clog-up An increased in stagnation pressure will increase the mass flux through the: A. Straight Line B. tidal wave B. 3000 rpm C. Willian’s Line D. Cutting Line D. 4000 rpm D. one standard atmosphere Mechanism designed to lower the temperature of air passing through it. the salinity of the steam is too great C. abrupt changes in fluid properties occur in a very thin section of converging – diverging nozzle under supersonic flow conditions. Rankine Line An inventor proposes to develop electrical power by withdrawing heat from the geyser fields of northern Californian and converting it all to work in power turbines. 1000 rpm B. Air cycle . the ratio of actual to ideal energy extracted B. none of the above A liquid boils when its vapor pressure equals A. Willian’s Line B. Air spill over D. Freh Line B. Fanno Line C. the ratio of ideal to actual energy extracted D. Dalton’s Line C. the ratio of actual of ideal energy inputted C. ultrasonic aircraft For back pressure valves. hyper sonic aircraft D. the ambient pressure D. shock wave D. Air defense B. it violates the second law of thermodynamics The isentropic efficiency of a turbine is given by A. Rayleigh Line Generally steam turbines in power station operate at A. This scheme will not work because: A. A. 575 rpm Which of the following shows the relationship of the steam consumption and the load of steam turbine – generator? A. sound wave C. the critical pressure C. creating A. Cross cut Line Combination of mass and momentum equations into a single equation and plotted in h-s plane yield a curve called: A. the gage pressure B. the geyser fields have only a limited lifetime B. Jonval’s Line D. it violates the first law of thermodynamics D. Air cooler C. B. Fair Line C. none of these Is the locus of states which have the same value of stagnation enthalpy and mass flux are called: A. Open cycle gas turbine with inter cooling. gases from generator D. over 150 MW B. equal to rankine cycle efficiency D. axial flow type D. Brayton cycle D. Open cycle type with reheating. reciprocating type What type of gas turbine is used in air craft? A. Closed cycle type with reheating C. 5 to 8 B. Ericsson cycle C. Closed type with reheating and regeneration D. less than Diesel cycle efficiency B. heat air from intercooler C. One C. Large units gas turbine regularly operate: A. recover heat from exhaust gases B. reheating and regeneration D. regeneration and intercooling In a gas turbine combined cycle plant. below 150 MW Brayton cycle cannot be used in reciprocating engines even for same adiabatic compression ratio and work output because: A. Simple open cycle gas turbine B. 3 to 5 C. large volume of low pressure air cannot be efficiently handled in reciprocating engines Which of the following compressors is generally used for gas turbines? A. lobe type C. 12 to 20 A constant volume combustion gas turbine operates on: A. Open cycle B. Brayton Cycle is less efficient C. in 50 to 100 MW range D. Open cycle gas turbine with intercooling and reheating C. equal to Carnot Cycle efficiency C. Atkinson cycle Heat may be transferred in how many ways? A. more than Otto or Diesel cycle efficiency Which of the following turbine has least weight per bhp developed? A. Two D. none of the above Overall efficiency of a gas turbine is: A. Brayton Cycle is for slow speed engines only D. Three B. centrifugal type B. 8 to 12 D. Otto cycle is highly efficient B. in 100 to 200 MW range C. Close cycle gas turbine The range of compression ratio in a gas turbine is: A. a waste heat boiler is used to: A. Four . Joule cycle B.