Power And Industrial Plant Engineering-Alcorcon Thermodynamics Questions PDF
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This document contains a set of practice questions on thermodynamics for an engineering course. It covers topics such as pressure, temperature, and energy calculations relevant to power plants and industrial applications. A variety of problems are included, from basic concepts to more complex calculations.
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POWER AND INDUSTRIAL PLANT ENGINEERING-ALCORCON THERMODYNAMICS 1. What is the pressure 8,000 ft. (2000m) below the surface of the ocean? Neglect the compressibility factor, SI units. Answer: B A. 21.4 B. 20.1 C....
POWER AND INDUSTRIAL PLANT ENGINEERING-ALCORCON THERMODYNAMICS 1. What is the pressure 8,000 ft. (2000m) below the surface of the ocean? Neglect the compressibility factor, SI units. Answer: B A. 21.4 B. 20.1 C. 21.0 D. 22.3 2. What temperature at which water freezes using the Kelvin scale? Answer: B A. 373 B. 273 C. 278 D. 406 3. The SI units of temperature is: Answer: B A. oF B. oK C. BTU D. oR 4. The pressure reading of 35 psi in kpa is: Answer: A A. 342.72 B. 724.00 C. 273.40 D. 427.30 5. 1 torr is equivalent to pressure Answer: D A. 1 atm B. 2mm Hg C. 14.7 D. 1/760 atm 6. What is the standard temperature in the US? Answer: A A. Fahrenheit B. Rankine C. Celsius D. Kelvin 7. Given steam pressure of 900 lb/ft2, temperature of 300oF, specific volume of 5.8 ft3/lb. If the specific enthalpy is 9500 ft-lb/lb, what is the internal energy per lb of the system? Answer: D A. 4400 B. 3900 C. 3600 D. 4280 8. The barometer reads 29.0 inches (737 mm) of mercury. What is the absolute pressure if a vaccum gage reads 9.5 psi (66 kpa) in SI? Answer: A A. 32.02 kpa B. 33.04 kpa C. 31.36 kpa D. 31.86 kpa 9. A fluid with a vapor pressure of 0.2 Pa and a specific gravity of 12 is used in a barometer. If the fluid column height is 1m, what is the atmospheric pressure? Answer: D A. 150.6 kpa B. 115.5 kpa C. 144.4 kpa D. 117.7 kpa 10. What is the atmospheric pressure on a planet if the pressure is 100 kpa and the gage pressure is 10 kpa? Answer: D A. 10 kpa B. 100 kpa C. 80 kpa D. 90 kpa 11. A column of water 200 cm high will give a pressure equivalent to: Answer: D A. 9810 dyne/cm2 B. 0.1 atm C. 0.10 bar D. 19,620 N/m2 12. What is the equivalent oR of 400ok? Answer: A A. 720.60oR B. 851.15oR C. 670.27oR D. 344.25oR 13. If the temperature inside the furnaces is 700 oK, what is the corresponding reading in oF? Answer: D A. 700.60 B. 750.60 C. 860.60 D. 800.60 14. If the oF scale is twice the oC scale, what will be the corresponding reading in each scale? Answer: B A. 22oC and 44oF B. 160oC and 320oF C. 40oC and 80oF D. 100oC and 200oF 15. Water enters the condenser at 25oC and leaves at 40oC. What temperature difference in oF? Answer: C A. 25 B. 26 C. 27 D. 28 16. Water enters the heater with 28oC and leaves at 75oC. What is the temperature change in oF? Answer: C A. 74.80 B. 38.29 C. 84.80 D. 57.36 17. The specific gravity of mercury relative to water is 13.55. What is the specific weight of mercury? The specific weight of water is 62.4 lb per cubic foot. Answer: B A. 102.3 KN/m3 B. 132.9 KN/m3 C. 150 KN/m3 D. 82.2 KN/m3 18. An iron block weighs 5 N and has a volume of 200 cm3. What is the density of the block? Answer: C A. 988 kg/m3 B. 1255 kg/m3 C. 2550 kg/m3 D. 800 kg/m3 19. The suction pressure of a pump reads 540 mmHg vaccum. What is the absolute pressure in kpa? Answer: D A. 40 B. 3.3 C. 60 D. 29.3 20. A boiler installed where the atmospheric pressure is 755 mmHg. Has a pressure 12 Kg/cm 2. What is the absolute pressure in Mpa? Answer: B A. 1.350 B. 1.277 C. 1.200 D. 1,700 21. A storage tank contains oil with specific gravity of 0.88 and depth of 20 m. What is the hydrostatic pressure at the bottom of th tank in kg/cm2? Answer: A A. 1.76 B. 2.0 C. 6.0 D. 3.0 22. A batch of concrete consisted of 200 lbs fine aggregate, 350 lbs coarse aggregate, 94 lbs, cement, and 5 gallons water. The specific gravity of the sand and gravel may be taken as 2.65 and that of the cement as 3/10/ What was the weight of concrete in place per cubic foot? Answer: D A. 172 lbs B. 236 lbs C. 162 lbs D. 153 lbs 23. A batch of concrete consisted of 200 lbs fine aggregate, 350 lbs coarse aggregate, 94 lbs, cement, and 5 gallons water. The specific gravity of the sand and gravel may be taken as 2.65 and that of the cement as 3.10. How much by weight of cement is required to produce one cubic yard? Answer: D A. 765 B. 657 C. 675 D. 567 24. A cylindrical tank 2 m diameter, 3 m high is full of oil. If specific gravity of oil is 0.9, what is the mass of oil in the tank? Answer: A A. 8482 kg B. 4500 kg C. 1800 kg D. 7000 kg 25. 100 g of water are mixed with 150 g of alcohol (w = 790 kg/m 3). What is the specific volume of the resulting mixtures, assuming the fluids mixed completely? Answer: D A. 0.82 cm3/kg B. 0.88 cm3/kg C. 0.63 cm3/kg D. 1.20 cm3/kg 26. 100 g of water are mixed with 150 g of alcohol (w = 790 kg/m 3). What is the specific gravity of the resulting mixtures, assuming the fluids mixed completely? Answer: D A. 0.96 B. 0.63 C. 0.82 D. 0.86 27. A spherical tank is full of water that has a total mass of 10,000 kg. If the outside diameter of the tank is 2722 mm, how thick is the wall of the tank? Answer: B A. 50 mm B. 25 mm C. 30 mm D. 35 mm 28. A cylindrical tank is filled with water at the rate of 5000 gal/min. The height if the water in the tank after minutes is 20.42 ft. What is the diameter of the tank? Answer: B A. 30 ft B. 25 ft C. 20 ft D. 9 m 29. Water is flowing through a 1 foot diameter pipe at the rate of 10 m/s. What is the volume flow of water flowing? Answer: C A. 7.50 ft3/sec B. 7.95 ft3/sec C. 7.85 ft3/sec D. 0.22 ft3/sec 30. A certain fluid is flowing in a 0.5 m x 0.3 m channel at the rate of 3 m/sec and has a specific volume of 0.0012 m3/kg. Determine the mass of water flowing in kg/sec. Answer: C A. 380 kg/sec B. 390 kg/sec C. 375 kg/sec D. 370 kg/sec 31. One useful equation used is the change of enthalpy of compressible liquid with constant specific heat is: hsub2 - hsub1 = c(Tsub2 – Tsub1) + v(Psu2 – Psub1) where: Tsubn = Temperature at state n Psubn = Pressure at state n V = specific volume of liquid Water with enthalpy with csubp = 4.187 KJ/kg-oK and v = 1.00 x 10 -3 m3/kg has the following states: State I: Tsub1= 19oC Psub1 = 1. 013 x 105 o State II: Tsub2 = 30 C Psub2 = 0.113 Mpa What is the change in enthalpy from state I to state II? Answer: C A. 46.0 kpa/kg B. 56.0 KJ/kg C. 46.0 KJ/kg D. 46.0 KN/kg 32. What is the potential energy of a 500 kg body if it is dropped to a height of 100 m? Answer: A A. 490.50 KJ B. 765.50 KJ C. 560.50 KJ D. 645.48 KJ 33. The flow energy of 124 li/min of a fluid passing a boundary to a system is 2 KJ/sec. What is the pressure at this point. Answer: B A. 100 kpa B. 140.30 psi C. 1000 kpa D. 871 KJ 34. Steam at 1000 lb/ft3 pressure and 330oR has a specific volume of 6.5 ft 3/lb and a specific enthalpy of 9800 ft-lb/lb. Find the internal energy per pound mass of steam. Answer: B A. 5400 B. 3300 C. 6400 D. 2500 35. Air and fuel enter a furnace used for home heating. The air has an enthalpy of 302 KJ//kg and the fuel has an enthalpy of 43,207 KJ/kg. The gases leaving the furnace have an enthalpy of 616 KJ/kg. of fuel. The house requires 17.6 KW of heat. What is the fuel consumption per day? Answer: B A. 85 kg B. 41 kg C. 45 kg D. 68 kg 36. The power plant furnace burns coal at the rate of 108,200 kg/hr. Air at 100.8 kpa, 28 oC is supplied at the rate of 13.8 kg/kg coal. Determine the volume flow rate of air flow in m 3/min. Answer: A A. 21,327 m3/min B. 19,414.63 m3/min C. 20,435.26 m3/min D. 24,535.54 m3/min 37. The enthalpy of air is increased by 139.586 KJ/kg in a compressor. The rate of air flow is 16.42 kg/min. The power output is 48.2 KW. Which of the following values most nearly equals the heat loss from the compressor in KW? Answer: A A. -10 B. +10.2 C. -9.95 D. +9.95 38. A steam turbine receives 70 pounds of steam per minute with an enthalpy of 1600 Btu per pound and velocity of 100 ft/sec. It leaves the turbine at 900 ft/sec and 1320 Btu/lb enthalpy. The radiation loss is 84,000 Btu/hr. Find the horsepower output. Answer: A A. 403 hp B. 400hp C. 380 hp D. 410 hp 39. Steam enters a turbine stage with enthalpy of 3628 KJ/kg 70 m/sec and leaves the same stage with an enthalpy of 2846 KJ/kg and a velocity of 124 m/sec. Calculate the work done by the steam. Answer: A A. 776.76 KJ/kg B. 873 KJ/kg C. 567.23 KJ/kg D. 923.34 KJ/kg 40. Steam with an enthalpy of 800 kcal/kg enters a nozzle at a velocity of 80 m/sec. Find the velocity of the steam at the exit of the nozzle if its enthalpy is reduced tp 750 kcal/kg. assuming the nozzle is horizontal and disregarding heat losses. Take g(9.81) m/sec and J = 427 kg-m/kcal. Answer: D A. 561.24 m/s B. 142.5 m/s C. 52.41 m/s D. 652.14 m/s 41. A volume of 450 cc of air is measured at a pressure of 740 mm HG absolute and a temperature of 20oC. What is the volume in cc at 760 mm HG abs. and 0 oC? Answer:B A. 516.12 B. 408.25 C. 620.76 D. 375.85 42. Assuming compression is according to the law PV = constant. Calculate the initial volume of gas at a pressure of 2 bar which will occupy a volume of 6 cubic meters when it is compressed to a pressure of 42 bar. Answer: A A. 126 m3 B. 120 m3 C. 130 m3 D. 136 m3 43. How much heat, KJ must be transferred to 20kg of air to increase the temperature from 20 degrees C to 280 degrees C if the pressure is maintained constant. Answer: C A. 2500 B. 2050 C. 5200 D. 5500 44. If air is at pressure, p, of 3200 lb/ft 2. And at a temperature, T, of 800 oR, what is the specific volume , v? Answer: B A. 14.2 ft3/lb B. 13.3 ft3/lb C. 11.2 ft3/lb D. 9.8 ft3/lb 45. The mass of air in the room 3m x 5m x 20m is known to be 350 kg. Find its density. Answer: C A. 1.617 kg/m3 B. 1.716 kg/m3 C. 1.167 kg/m3 D. 1.176 kg/m3 46. A transportation company specializes in the shipment of pressurized gaseous materials. An order is received for 100 liters of a particular gas at STP (32 oF and 1 atm). What minimum volume tank is necessary to transport the gas at 80oF and a maximum pressure of 8 atm? Answer: B A. 16 liters B. 14 liters C. 10 liters D. 12 liters 47. A bicycle has a volume of 600 cm3. It is inflated with carbon dioxide to pressure of 80 psi at 20 o C. How many grams of carbon dioxide are contained in the fire? Answer: A A. 5.98 g B. 6.43 g C. 4.63 g D. 3.83 g 48. An ideal gas at 0.60 atm. And 87oC occupies 0.450 liters. How many moles are in the sample? (R = 0.0821 atm/mole K) Answer: D A. 0.0002 mole B. 0.0378 mole C. 0.0198 mole D. 0.0091 mole 49. Air compressed in a diesel engine from an initial pressure of 13 psia and a temperature of 120 oF to one twelfth of its original volume. Calculate the final temperature assuming compression to be adiabatic. Answer: D A. 987 B. 980 C. 981 D. 1107 50. The compression ratio of an Otto cycle is 6:1, P sub1 is 14.7 psia, Tsub1 is 68oF. Find the pressure and temperature at state 2. Answer: D A. 180.6 psia, 1081oF B. 180.6 psia, 139 oF C. 180.6 psia, 139 oF D. 180.6 psig, 1081oR 51. An automobile tire is inflated to 30 psig pressure at 50 oF. After being driven, the temperature rise to 75oF. Determine the final gage pressure assuming the volume remains constant. Answer:A A. 32.19 psig B. 55 psig C. 0 psig D. 38.9 psig 52. If 10 m3 of atmospheric air at zero degrees centigrade temperature are compressed to a volume of 1 m3 at 100oC, what will be the pressure of air in kpa? Answer: B A. 1500 B. 1384 C. 2000 D. 1000 53. If 8 lbs of a substance receives 240 Btu of heat at constant colume and undergo a tempearure change of 150oF/ What is the average specific heat of the substance during the process? Answer: D A. 0.30 Btu/lb-oF B. 0.25 Btu/lb-oF C. 0.50 Btu/lb-oF D. 0.20 Btu/lb-oF 54. A certain gas at 101.325 kpa and 16 oC whose volume is 2.83 m3 are compressed into a storage vessel of 0.31 m3 capacity. Before admission, the storage vessel contained the gas at a pressure and temperature at 137.8 kpa and 24 oC; after temperature of the gas in the vessel in Kelvin? Answer: B A. 298.0 B. 319.8 C. 180.0 D. 420.0 55. The temperature of an ideal gas remains constant while the absolute pressure changes from 103.4 kpa to 827.2 kpa. If the initial volume is 80 liters, what is the final volume? Answer:B A. 100 li B. 10 li C. 8 li D. 1000 li 56. What is the density of air under standard condition: Answer: C A. 1.1 kg/m3 B. 1 kg/m3 C. 1.2 kg/m3 D. 1 KN/m3 57. What is the specific volume of an air at 30oC and 150 kpa? Answer: D A. 1 m3/kg B. 0.5 m3/kg C. 1.2 m3/kg D. 0.579 m3/kg 58. The compression ratio of an Otto cycle is 5. If the initial pressure is 100 kpa, determine the final pressure. Answer: B A. 1000 kpa B. 952 kpa C. 300 kpa D. 100 kpa 59. How much work is done when 20 ft3 of an air is initially at a pressure of 15 psia and a temperature of 40oF experience an increase of pressure to 80 psi while volume remains constant? Answer: C A. 1000 Btu B. 3000 Btu C. Zero D. 2000 Btu 60. A perfect gas has a value of R = 58.8 ft-lb/lb- oR and k = 1.26. Btu are added to 5 lbs of this gas at constant volume when initial temperature is 90oF, find the initial temperature. Answer: B A. 100oF B. 104 oF C. 154 oF D. 185 oF 61. While the pressure remains constant and 689.5 kpa, the volume of air changes from 0.567 m 3 to 0.283 m3. What is the work done?Answer: A A. -196 KJ B. 204 KJ C. 206 KJ D. -406 KJ 62. During the polytropic process of an ideal gas, the state changes from 20 psia and 40 oF to 120 psia and 340oF. Determine the value of n. Answer: C A. 1.233 B. 1.255 C. 1.355 D. 1.400 63. A group of 50 persons attend a secret meeting in a room which is 12 meters wide by 10 meters long and a ceiling height of 3 m. The room is completely sealed off and insulated. Each person gives off 120 kcal per hour of heat and occupies a volume of 0.2 m 3. The room has an initial pressure of 101.3 kpa and temperature of 16oC. Calculate the room temperature after 10 minutes. Answer: B A. 36.35 B. 33.10 C. 23.24 D. 76.32 64. The compression ratio of an ideal Otto cycle is 6:1. Initial conditions are 101.3 kpa and 20 oC. Find the pressure and temperature at the end of adiabatic compression. Answer: A A. 1244.5 kpa, 599.96oK B. 1244.5 kpa, gage, 60oC C. 1244.5 kpa, 60oC D. 1244.5 kpa, 599.96oC 65. Ammonia weighing 22 kgs is confirmed inside a cylinder equipped with a piston has an initial pressure of 413 kpa and 38oC. If 2900 KJ if heat is added to the ammonia until its final pressure and temperature are 413 kpa and 100 oC, respectively, what is the amount of work done bt rhe fluid in KJ? Answer: A A. 667 B. 304 C. 420 D. 502 66. Determine the average Cp value in KJ/kg-K of a gas of 522 KJ/kg of heat is necessary to raise the temperature from 300oK to 800oK making the pressure constant: Answer: B A. 1.440 B. 1.044 C. 1.038 D. 1.026 67. A tank contains 80 ft3 of air at a pressure of 350 psi; if the air is cooled until its pressure and temperature decreases to 200 psi and 70 oF respectively, what is the decrease in internal energy? Answer: B A. +4575 B. -5544 C. 5552 D. 0 68. If 10 lbs of water are evaporated at atmospheric pressure until a volume of 288.5 ft 3 is computed , how much work is done? Answer: C A. 1680 Btu B. No work C. 610000 ft-lb D. 550000 ft-lb 69. A large mining company was provided with a 3 m 3 of compressed air tank. Air pressure in the tank drops from 700 kpa to 180 kpa while the temperature remains constant at 28 oC. What percentage has the mass of air in the tank been reduced? Answer: A A. 74 B. 72 C. 76 D. 78 70. In a diesel cycle, the air compressed to one-tenth of its original volume. If the initial temperature of the air is 27oC, what is the final temperature? Answer: D A. 420oC B. 440 oC C. 460 oC D. 480 oC 71. Determine the vacuum efficiency of a surface condenser which operates at a vacuum of 635 mm Hg and exhaust steam enters the condenser at 45.81o. The barometric is 760 mm Hg. Answer: C A. 80.4 % B. 85.2% C. 92.2% D. 98.3% 72. A 4 m3/hr pump delivers water to a pressure tank. At the start, the gage reads 138 kpa until in reads 276 kpa and then the pump was shut off. The volume of the tank is 150 liters. At 276 kpa the water occupied 2/3 of the tank volume. Determine the volume of water that can be taken out unitl the gage reads 138 kpa. Answer: D A. 31.20 liters B. 65.32 liters C. 16.87 liters D. 29.50 liters 73. How much work is necessary to compress air in an insulated cylinder from 0.20 m 3 to 0.01 m3. Use T = 20oC and P1 = 100 kpa. Answer: D A. 113.4 KJ B. 121.4 KJ C. 110.1 KJ D. 115.6 KJ 74. A gas initially 103.4 kpa and 0.0566 m 3 undergoes a process to 620.36 kpa and 0.017 m 3 during which the enthalpy increases by 16.35 KJ, C v = 10.217 KJ/kgoK. Determine the Cp of gas. Answer: A A. 14.33 KJ/kg-oK B. 2.34 Btu/lb-oR C. 13.23 KJ/kg-oK D. 10.76 Btu/lb-oK 75. A perfect gas has a value of R = 5808 ft-lb/lb- oR and k = 1.26. If 20 Btu are added to 5 lb of this gas at constant volume when initial temperature is 90oF, find the final temperature. Answer: C A. 100.76oC B. 167.76 oC C. 103.76 oC D. 145.76 oC 76. While the pressure remains constant at 689.5 kpa the volume of a system of air changes from 0.567 m3 to 0.283 m3. Find the change of internal energy. Answer: B A. 389.68 KJ B. 493.63 KJ C. 678.68 KJ D. 245.68 KJ 77. If initial volume of an ideal gas is compressed to one half its original volume and to twice its original temperature, the pressure. Answer: B A. Doubles B. Quadruples C. Remains constant D. Halves 78. What horsepower is required to isothermally compress 800 ft 3 of air per minute from 14.7 psia to 120 psia? Answer: D A. 13900 Hp B. 28 Hp C. 256 Hp D. 108 Hp 79. An ideal gas at 45 psig and 80oF is heated in a closed container to 130 oF. What is the final pressure?Answer 80. A Carnot engine requires 35 KJ/sec from the hot source. The engine produces 15 kw of power ant the temperature of the sink 26oC. What is the temperature of the hot source? Answer C A. 245.57 B. 210.10 C. 250.18 D. 260.68 81. A Carnot engine receives 130 Btu of heat from a hot reservoir at 700 oF and rejects 49 Btu of heat. Calculate the temperature of the cold reservoir. Answer: D A. -21.9oF B. -24.2 oF C. -20.8 oF D. -22.7 oF 82. The maximum thermal efficiency possible for a power cycle operating between 1200 oF and 225 oF is: A. 58% B. 58.73% C. 57.54% D. 57.40% 83. A heat engine is operated between temperature limits of 1370 oC and 260oC. Engine supplies with 14,142 KJ per KWH. Find the Carnot cycle efficiency in percent.Answer: C A. 70.10 B. 65.05 C. 67.56 D. 69.32 84. An Otto cycle has clearance volume of 7%. It produces 300 kw power. What is the amount of heat rejected in KW? Answer: C A. 170 B. 160 C. 152 D. 145 85. A closed vessel contains air at a pressure of 160 KN/m 2 gauge and temperature of 30oC. The air is heated at constant volume of 60oC with the atmospheric pressure as 759 mm Hg. What is the final gauge pressure? Answer: C A. 174 B. 169 C. 185.8 D. 172 86. An air standard engine has a compression ratio of 20 and cut-off ratio of 5. If the intake air pressure and temperature are 100 kpa and 27oC, find the work in KJ per kg. Answer: B A. 2976 B. 2166 C. 2437 D. 2751 87. The thermal efficiency of a particular engine operating on an ideal cycle is 35%. Calculate the heat supplied per 1200 watt-hr of work developed in KJ. Answer:A A. 12343 B. 10216 C. 14218 D. 11108 88. In an air standard Otto cycle, the clearance volume is 18% of the displacement volume. Find the compression ratio and or thermal efficiency. Answer: C A. 0.52 B. 0.53 C. 0.55 D. 0.60 89. The clearance of a diesel cycle is 1.0%. If initial temperature is 27 oC, determine the final temperature. Answer: A A. 510oC B. 610 oC C. 540 oC D. 1000 oC 90. For an ideal cycle with overall value of k = 1.33, compression ratio is 15 and cur-off ratio of 2.1, determine the cycle efficiency.Answer: B A. 50.62% B. 52.90% C. 46% D. 49% 91. An ideal Otto cycle with 15% clearance operates on 0.227 kg/sec of air with k = 1.32. Determine the efficiency of the cycle. Answer: D A. 50.65% B. 43.84% C. 41.32% D. 47.89% 92. An ideal Otto cycle, operating in hot air with k = 1.34 has compression ratio of 5. Determine the efficiency of the cycle. Answer: A A. 42.14% B. 62.27% C. 64.27% D. 36.46% 93. An engine operates on the air standard Otto cycle. The cycle work is 900 KJ/kg, the maximum cycle temperature at the end of isentropic compression is 600 oC. Determine the engines compression ratio. Answer: A A. 6.388 B. 10.45 C. 8.67 D. 7.87 94. In an air standard diesel cycle, compression start at 100 kpa and 300 oK. The compression ratio is 16 to 1. The maximum cycle temperature is 2031oK. Determine the cycle efficiency. Answer: C A. 60.34% B. 56.23% C. 65.98% D. 45.45% 95. A diesel engine is operating on a 4-stroke cycle, has a heat rate of 11315.6 KJ/KW-hr brake. The compression ratio is 13. The cut-off ratio is 2. Using k = 1.32, what is the brake engine efficiency. Answer: A A. 63.5% B. 51.2% C. 73.5% D. 45.3% 96. Determine the air-standard efficiency of an engine operating on the diesel cycle with clearance of 8% when the suction pressure is 99.97 kpa and the fuel is injected for 6% of the stroke. Assume k = 1.4. Answer: D A. 63.5% B. 51.2% C. 73.5% D. 60.02% 97. A heat engine ( Carnot cycle ) has its intake and exhaust temperature if 157 oC and 100oC, respectively. What is its efficiency? Answer: D A. 12.65% B. 14.75% C. 15.35% D. 13.25% 98. Find the enthalpy of 100 psi and 97% quality, hf = 298.55 Btu/lb; hfg = 889.119 Btu/lb. Answer: B A. 1170 Btu/lb B. 1161 Btu/lb C. 1734 Btu/lb D. 1803 Btu/lb 99. 180 grams of saturated water of temperature 95 oC undergoes evaporation process until all vapor completely vaporized. Determine the changed in volume. At 95 oC, vf= 0.0010397 m3/kg. Answer: D A. 0.1656 m3 B. 0.4235 m3 C. 0.2565 m3 D. 0.3656 m3 100. Five kilograms of saturated liquid at kpa is heated until its moisture content is 5%. Find the work done for this process. Answer A A. 813.59 KJ/kg B. 643.23 KJ/kg C. 542.34 KJ/kg D. 753.12 KJ/kg 101. Twenty kilograms of water at 40 oC is confined in a rigid vessel. The heat is supplied until all the water is completely vaporized. Find the heat added in KJ. Answer: C A. 45,422 KJ B. 43,122 KJ C. 45,252 KJ D. 65,233 KJ 102. Steam at 2 Mpa and 250oC in a rigid cylinder is cooled until the quality is 50%. Find the heat rejected from the cylinder. At 2 Mpa and 250oC V = 0.11144 m3/kg u = 2679.6 KJ/kg At 2 Mpa, (saturated) Vf = 0.0011767 m3/kg vg = 0.09963 m3/kg uf = 906.44 1693.8 Answer: B A. -432.23 KJ/kg B. -926.26 KJ/kg C. -834.55 KJ/kg D. 1082.34 KJ/kg 103. At 1.3 Find the entropy in KJ/kg-K at 90% moisture of a 1 Mpa steam-water mixture? At 1 Mpa: sg = 6.5865 sfg = 4.4478 A. 4.87 B. 6.34 C. 2.583 D. 4.36 104. At 1.3 Mpa, mixture steam and water has an entropy of 4 KJ/kg-K. Find the enthalpy of the mixture. At 1.3 Mpa: sf = 2.2515, sg = 6.4953, hf = 514.93, hfg = 1972.7 Answer: A A. 1627.71 KJ/kg B. 1533.33 KJ/kg C. 1234.45 KJ/kg D. 1734.45 KJ/kg 105. Mixture with 80% quality at 500 kpa is heated isothermally until its pressure is 300 kpa. Find the heat added during the process. At 500 kpa: sf = 1.8607, sfg = 4.9606 At 300 kpa and 151.86oC: s = 7.0888 KJ/kg Answer: B A. 652.34 KJ/kg B. 535.16 KJ/kg C. 983.44 KJ/kg D. 765.34 KJ/kg 106. A tank contains exactly one kilogram of water consisting of liquid and vapor in equilibrium at 1 Mpa. If the liquid and vapor each occupy one-half the volume of the tank, what is the enthalpy of the content of the tank? Answer: B A. 644.40 KJ/kg B. 774.40 KJ/kg C. 833.40 KJ/kg D. 435.29 KJ/kg 107. A vessel with a volume of 1 m3 contains liquid water and water vapor in equilibrium at 600 Kpa. The liquid water has a mass of 1 kg. Using steam tables, calculate the mass of water vapor. Answer: A A. 3.16 kg B. 0.99 kg C. 1.57 kg D. 1.89 kg 108. Water substance at 70 bar and 65oC enters a boiler tube of constant inside diameter of 25 mm. The water leaves the boiler tube at 50 bar and 700 oK at velocity of 100 m/s. Calculate the inlet velocity(m/sec) Answer: C A. 1.56 B. 2.12 C. 1.672 D. 3.230 109. Water substance at 70 bar and 65 oC enters a boiler tube of constant inside diameter of 25 mm. The water leaves the boiler tube at 50 bar and 700 oK at velocity of 100 m/s. Calculate the inlet volume of 100 m/s. Calculate the inlet volume flow (li/sec) Answer: A A. 0.821 B. 1.561 C. 0.344 D. 2.133 110. One lb (0.455kg) of a mixture of steam and water at 160 psia(1103.2 kpa) is in rigid vessel. Heat is added to the vessel until the content are at 560 psia (3861.2 kpa) and 600 oF (315.55oC). Determine the quantityof heat in KJ added to the water and steam in the tank. Answer: A A. 1423.70 B. 1392.34 C. 1562.34 D. 1294.45 111. Steam at the rate of 600 kg/hr is produced by a steady flow system boiler from feedwater entering at 40oC. Find the rate at which heat is transformed in Kcal per hour if enthalpy of steam is 660 Kcal/kg and of the feedwater at 40 Kcal/kg. Answer: A A. 372000 B. 387000 C. 345200 D. 312444 112. Steam leaves and industrial boiler at 827.4 kpa and 171.6 oC. A portion of the steam is passed through a throttling calorimeter and is exhausted to the atmosphere when the calorimeter pressure is 101.4 kpa. How much moisture does the steam leaving the boiler contain if the temperature is 115.6oC? Answer: B A. 3.78% B. 3.08% C. 4.56% D. 2.34% 113. Steam enters a throttling calorimeter at a pressure of 1.03 Mpa. The calorimeter downstream pressure and temperature are respectively 0.100 Mpa and 125 oC. What is the percentage moisture if the supply steam? Properties of steam: P, Mpa hf hfg hg 1.03 2010.7 2779.25 Note: @ 0.1.. Mpa and 125oC: h = 2726.6 KJ/kg. Answer: A A. 2.62 B. 5.21 C. 3.15 D. 1.98 114. A vessel of 0.058 m3 capacity is well insulated and is divided equally by a rigid conducting diaphragm. Initially both halves contain air at pressure of 137.8 kpa and 413.4 kpa and temperature 27oC and 177oC respectively. What is the increase of entropy of the system in KJ/ oC? Answer: C A. 1.002 B. 0.5080 C. 0.00173 D. 0.1080 115. Using steam table. Find the enthalpy of steam at kpa if its specific volume is 0.3598 m 3/kg. Answer: A A. 1625.86 KJ/kg B. 1785.34 KJ/kg C. 1543.45 KJ/kg D. 1687.55 KJ/kg 116. A throttling calorimeter is connected to the desuoerheated steam line supplying steam to the auxiliary feed pump on a ship. The line pressure measures 2.5 Mpa. The calorimeter pressure of 137.8 kpa and 413.4 kpa and temperature of 27oC and 177oC respectively. What is the increase of entropy of the system in KJ/oC? Answer: C A. 6.8 KJ/kg-oK B. 7.2 KJ/kg-oK C. 6.6 KJ/kg-oK D. 7.5 KJ/kg-oK 117. Steam enters an isothermal compressor at 400 oC and 100 kpa. The exit pressure is 10 Mpa, determine the change of enthalpy. Answer: D A. 198 KJ/kg B. 178 KJ/kg C. 187 KJ/kg D. 182 KJ/kg 118. Steam enters an adiabatic at 300 oC and 400 kpa. It exits as a saturated vapor at 30 kpa. Determine the work done. Answer: B A. 476.34 KJ/kg B. 441.50 KJ/kg C. 436.33 KJ/kg D. 524.34 KJ/kg 119. A 0.5 m3 tank contains saturated steam at 300 kpa. Heat is transferred until pressure reaches 100 kpa. Find the final temperature.Answer: C A. 94.45oC B. 83.23oC C. 99.63oC D. 103.2oC 120. A 500 li contains a saturated mixture of steam and water at 300 oC. Determine the mass of vapor if their volumes are equal. Answer: A A. 11.54 kg B. 10.34 kg C. 13.45 kg D. 16.34 kg 121. A 1 kg steam-water mixture at 1.0 Mpa is contained in an inflexible tank. Heat is added until the pressure rises to 3.5 Mpa and 400oC. Determine the heat added. Answer: A A. 1378.64 KJ B. 1532.56 KJ C. 1456.78 KJ D. 1635.45 KJ 122. Atmospheric pressure boils at 212 oF. At the vacuum pressure at 24 in Hg, the temperature is 142oF. Find the boiling temperature when the pressure is increased by 45 psia. Answer: C A. 342.34oF B. 526.34oF C. 479.13oF D. 263.45oF 123. What is the temperature in degree C of 2 liters of water at 30 oC after 500 calories of heat have been added to? Answer: B A. 35.70 B. 30.25 C. 38.00 D. 39.75 124. A mass of 0.36 kg metal having a temperature of 100 oC is plunged into 0.04 kg if water at 20 oC. The temperature of the water and metal becomes 48 oC. The latent heat of ice at 0oC is 335 KJ.kg- o K, Assuming no heat loss to the surroundings, determine the specific heat capacity of the metal in KJ/kg-oK. Answer: D A. 0.234 B. 0.564 C. 0.754 D. 0.451 125. What is the total energy required heating in raising the temperature of a given amount of water when the energy applied is 1000 KWH with heat losses of 25%? Answer: C A. 1000 B. 1500 C. 1333 D. 1250 126. A 30 kg iron was put in a container with 14.33 kg water. The water is at 10 oC and the iron has an initial temperature of 439oK until the iron was in thermal equilibrium with water. Find the change in entropy. (Cp = 0.4 KJ/kgoK) Answer: D A. -12.56 KJ/oK B. -43.58 KJ/oK C. -25.78 KJ/oK D. -6.6 KJ/oK FUELS & COMBUSTION 1. A diesel power plant consumes 650 liters of fuel at 26 oC in 24 hours with 28 oAPI. Find the fuel rate in kg/hr. Answer: A A. 23.83 B. 24.85 C. 22.85 D. 26.85 2. A boiler burns fuel oil with 15% excess air. The fuel oil may be represented by C 14H34. Calculate the molal air fuel ratio. Answer: B A. 14 B. 117.69 C. 102.34 D. 17.14 3. A diesel power plant uses fuel that has a density of 892.74 kg/m 3 at 15.67oC. Find the heating value of fuel. Answer: A A. 44,900 KJ/kg B. 19,301 Btu/lb C. 43,000 KJ/kg D. 4356.2 KJ/kg 4. A certain coal has the following ultimate analysis: C = 69% N2 = 5% H2 = 2.5% S = 7% Moisture = 8% O2 = 3.5% Ash = 5% Determine the heating value of fuel used.Answer: A A. 26,961.45 KJ/kg B. 45,256 KJ/kg C. 25,002.4 KJ/kg D. 26,000 KJ/kg 5. A diesel power plant uses fuel with heating value of 45,038.8 KJ/kg. What is the density of fuel used at 30°C?Answer: D A. 0.900 kg/li B. 0.887 kg/li C. 0.850 kg/li D. 0.878 kg/li 6. A diesel engine consumed 945 liter of fuel per day at 30°C. If the fuel was purchased at 15.5°C and 30° API at P5.00/li, determined the cost of fuel to operate the engine per day. Answer: B A. P5677.50 B. P4677.50 C. P4888.90 D. P5000.00 7. A cylindrical tank 3 m long and 2 m diameter is used for oil storage. How many days can the tank supply the engine having 27° API with fuel consumption of 60 kg/hr. Answer: B A. 4.84 B. 5.84 C. 7.84 D. 8.84 8. Determine the minimum volume of day tank in m 3 of 28° API fuel having a fuel consumption of 200 kg/hr. Answer: B A. 10.43 m3 B. 5.41 m3 C. 6.87 m3 D. 7.56 m3 9. Given the following ultimate analysis: C = 70% O2 = 4% N2 = 5% S2 = 6% Moisture = 8% H2 = 3% Ash = 5% Using 25% excess air, determine the actual air fuel ratio. Answer: A A. 11.46 B. 24.85 C. 23.85 D. 26.85 10. A 650 Bhp diesel engine uses fuel oil of 28° API gravity, fuel consumption is 0.65 lb/Bhp-hr. Cost of fuel is P7.95 per liter. For continuous operation, determine the minimum volume of cubical day tank in cm3, ambient temperature is 45°C. Answer: A A. 5,291,880 cm3 B. 5,391,880 cm3 C. 5,491,880 cm3 D. 5,591,880 cm3 11. A 650 Bhp diesel engine uses fuel oil of 28° API gravity, fuel consumption is 0.65lb/Bhp-hr. Cost of fuel is P7.95 per liter. For continuous operation, determine the cost of fuel per day at 45°C. Answer: B A. P42,870.45 B. P42,070.45 C. P42,570.45 D. P42,170.45 12. A logging firm in Isabela operates a Diesel Electric Plant to supply its electric energy requirements. During a 24 hour period, the plant consumed 250 gallons of fuel at 80°F and produced 2700 KW-Hrs. Industrial fuel used is 30° API and was purchased at P3.00li/at 60°F. Determine cost of fuel to produce one Kwh. Answer: C A. P3,043/KW-h B. P4,043/KW-h C. P1,043/KW-h D. P2,043/KW-h 13. A logging firm in Isabela operates a Diesel Electric Plant to supply its electric energy requirements. During a 24 hour period, the plant consumed 250 gallons of fuel at 80°F and produced 2700 KW-hrs. Industrial fuel used is 30° API and was purchased at P3.00/li at 60°F. Determine the overall thermal efficiency of the plant. Answer: A A. 26.08% B. 43.23% C. 43.12% D. 18.46% 14. A diesel electric plant in one of the remote provinces in the south utilized diesel fuel with an °API of 28 at 15.6°C. The plant consumes 680 liters of diesel fuel at 26.6°C in 24 hrs, while the power generated for the same period amounts to 1,980KW-hrs. Determine overall thermal efficiency of the plant. Answer: A A. 26.47% B. 12.34% C. 23.45% D. 34.34% 15. A circular fuel tank 45 feet long and 5.5 feet diameter is used for oil storage. Calculate the number of days the supply tank can hold for continuous operation the following conditions: Steam flow = 2000 lbs/hr Steam dry and saturated at 200 psia Feedwater temperature = 230°F Boiler Efficiency = 75% Fuel oil = 34° API Answer: B A. 12.34 B. 17.58 C. 13.45 D. 23.44 16. A steam generator burns fuel oil with 20% excess air. The fuel oil may be represented by C 14 H30. The fuel gas leaves the preheater at 0.31 Mpa. Determine the actual air-fuel ratio in kg air per kg fuel. Answer: A A. 17.89 B. 15.67 C. 12.34 D. 19.45 17. A steam generation burns fuel oil with 20% excess air. The fuel oil may be represented by C 14H30. The fuel gases leave the preheater at 0.31 Mpa. Determine partial pressure of H 2O. Answer: C A. 23.34 kpa B. 29.34 kpa C. 35.7 kpa D. 32.34 kpa 18. In the boiler design, it is desired to have the flue gas exit temperature above the dew point. Estimate the dew point temperature of the flue gas produced by combustion having the gravimetric analysis of: Answer: D N2 = 71.84% CO2 = 20.35% O2 = 3.61% H2O = 4.20% A. 32°C B. 23°C C. 45°C D. 39°C 19. A flue gas has following volumetric analysis: CH4 = 68% C2H6 = 32% Assume a complete combustion with 15% excess air at 101.325 Kpa, what is the partial pressure of water vapor in Kpa. Answer: A A. 15.95 B. 23.12 C. 12.45 D. 27.34 20. The dry exhaust gas from oil engine has the following gravimetric analysis: CO2 = 21.6% O2 = 4.2% N2 = 74.2% Specific heat at constant pressure for each components of the exhaust gas in Kcal/kg °C are: CO2 = 0.203 O2 = 0.219 N2 = 0.248 Calculate the gas constant in J/kg°K.Answer: A A. 272 C. 274 B. 276 D. 278 21. The dry exhaust gas from oil engine has the following gravimetric analysis: CO2 = 21.6% O2 = 4.2% N2 = 74.2% Specific heat at constant pressure for each component of the exhaust gas in Kcal/kg °C are: CO2 = 0.203 O2 = 0.219 N2 = 0.248 Calculate the specific gravity if the molecular weight of air is 28.97 kg/kg-mol. Answer: C A. 0.981 B. 1.244 C. 1.055 D. 0.542 22. The dry gas from oil engine has the following gravimetric analysis: CO2 = 21.6% O2 = 4.2% N2 = 74.2% Specific heat at constant pressure for each component of the exhaust gas in Kcal/kg °C are: CO2 = 0.203 O2 = 0.219 N2 = 0.248 Calculate the specific heat for the gas in KJ/kg - °K. Answer: B A. 0.872 B. 0.992 C. 0.452 D. 0.673 23. A bituminous coal has the following composition: C = 71.5% H = 5.0% O = 7.0% N = 1.3 S = 3.6% Ash = 8.2% W = 3.4% Determine the theoretical weight of Oxygen in lb/lb of coal. Answer: C A. 2.870 B. 3.120 C. 2.274 D. 6.233 24. There are 20 kg of flue gases formed per kg of fuel oil burned in the combustion of a fuel oil C12H26. What is the excess air in percent?Answer: A A. 26.67% B. 18.34% C. 12.34% D. 20.45% 25. A gaseous fuel mixture has a molal analysis: H2 = 14% CH4 = 3% CO = 27% O2 = 0.6% CO2 = 4.5% N2 = 50.9% Determine the air-fuel ratio for complete combustion on molal basis.Answer: C A. 2.130 B. 3.230 C. 1.233 D. 1.130 26. A steam generation burns fuel oil that has the following chemical analysis by mass in percent: Answer: C C = 85.3 H2 = 14.1 S = 0.5 N2 = 0.1 A. 19.85 C. 17.93 B. 11.14 D. 14.20 27. Calculate the theoretical air needed for the complete combustion of ethane C 2H6 for 20 kg fuel. Answer: D A. 432.23 kg B. 287.45 kg C. 234.45 kg D. 320.32 kg 28. A fuel oil burned with 50 percent excess air, and the combustion characteristics of the fuel oil are similar to C12H26. Determine the volumetric (molal) analysis of CO2 in the production of combustion. Answer: B A. 9.34% B. 8.66% C. 6.34% D. 7.45% 29. Fuel oil, C12H26 is burned in air at atmospheric pressure. The Orsat analysis of the products of combustion yields. CO2 : 12.8% O2 : 3.5% CO : 0.2% N2 : 83.5% Determine the percent excess air. Answer: C A. 12.34% B. 8.34% C. 10.52% D. 18.45% 30. An unknown fuel has the following Orsat analysis: CO2 : 12.5 CO : 0.3% O2 : 3.1% N2 : 84.1% Determine the actual air – fuel in kg air per kg fuel. Answer: A A. 17.13 B. 12.34 C. 19.23 D. 23.23 31. What mass of liquid oxygen is required to completely burned 1000kg of liquid butane, C 4H10 on a rocket ship? Answer: C A. 4568 B. 2746 C. 3586 D. 6345 32. A volumetric analysis of a gas mixture is as follows: CO2 : 12.5% O2 : 4% N2 : 82% CO : 2% What is the percentage of CO on a mass basis? Answer: D A. 1.0% B. 1.5% C. 1.2% D. 1.9% 33. What is the percent theoretical air for a combustion process to which the fuel and combustion gas analysis are known as follows:Answer: A Fuel: % by volume CO2 : 12.4% CO : 27% H2 : 2.2% N2 : 58.4% Combustion gas: % by volume CO2 : 24.6% O2 : 1.0% H2 : 74.4% A. 111 B. C.116 C. 121 D. D.126 VARIABLE LOAD 1. A 50 MW power plant has an average load of 31,500 KW and a factor of 70%. Find the reserve over peak. Answer: C A. 4 MW B. 3 MW C. 5 MW D. 6 MW 2. The daily energy produced in a certain power is 280,000 KW – hrs. What is the daily average load? Answer: D A. 10 MW B. 15 MW C. 25 MW D. 20 MW 3. The annual energy produced in a 100 MW power plant is 438,000,000 KW – hrs. What is the annual capacity factor of the plant? Answer: B A. 40% B. 50% C. 35% D. 60% 4. A power plant has a use factor of 50% and factor of 44%. How many hours did it operate during the year? Answer: C A. 7700 hrs. B. 7800 hrs. C. 7709 hrs. D. 7805 hrs. STEAM CYCLE 1. In a Rankine cycle steam enters the turbine at 2.5 Mpa (enthalpies & entropies given) and condenser of 50 Kpa (properties given), what is the thermal efficiency of the cycle. Answer A At 2.5 Mpa: hg = 2803.1 KJ/kg sg = 6.2575 At 50 kpa: sf = 1.0910 sfg = 6.5029 hf = 340.49 hfg = 2305.4 vf = 0.0010300 A. 25.55% B. 45.23% C. 34.23% D. 12.34% 2. In an ideal Rankine cycle, the steam throttle condition is 4.10 Mpa and 440 0C. If turbine exhaust is 0.105 Mpa, determine the pump work in Kj per kg. Answer C A. 6.34 B. 5.34 C. 4.17 D. 2.12 3. A thermal power plant generates 5 MW has also 300 OW power needed for auxiliaries. If the heat generated by fuel is 13,000 KJ/sec, determine the net thermal efficiency. Answer B A. 35.78% B. 36.15% C. 30.56% D. 33.67 4. In an ideal Rankine cycle, the steam throttle condition is 4.10 Mpa and 440 0C. If turbine exhaust is 0.105 Mpa, determine the thermal efficiency of the cycle. Answer B A. 20.34% B. 27.55% C. 34.44% D. 43.12% 5. In a Rankine cycle, saturated liquid water at 1 bar is compressed isentropically to 150 bar. First by heating in a boiler, and then by superheating at constant pressure of 150 bar, the water substance is brought to 7500K. After adiabatic reversible expansion in a turbine to 1 bar, it is then cooled in a condenser to saturated liquid. What is the thermal efficiency of the cycle(%)?Answer C A. 23.45% B. 16.23% C. 34.24% D. 18.23% 6. A steam generating plant has two 20 MW turbo-generators. Steam is supplied at 1.7 Mpa and 3200C. Exhaust is 0.006 MPa. Daily average load factor is 80%. The steam generating units operate at 70% efficiency when using bunker fuel having a heating value of 31,150 KJ/kg and an average steam rate of 5 kg steam/KW-hr. Calculate the Mtons of fuel oil/bunker fuel required per 24 hours. Answer A A. 515 B. 432 C. 6.17 D. 762 7. A back pressure steam turbine of 100,000 KW serves as a prime mover in a cogeneration system. The boiler admits the return water at a temperature of 66 0C and produces the steam at 6.5 Mpa and 4550C. Steam then enters a back pressure turbine and expands to the pressure of the process, which is 0.52 Mpa. Assuming a boiler efficiency of 80% and neglecting the effect of pumping and the pressure drops at various location, what is the incremental heat rate of electric? The following enthalpies have been found; turbine entrance = 3306.8 KJ/kg, exit = 2700.8; boiler entrance = 276.23 KJ/kg, exit =3306.8. Answer B A. 21,504 KJ/KW-hr B. 22,504 KJ/KW-hr C. 23,504 KJ/KW-hr D. 24,504 KJ/KW-hr 8. A coal-fired power plant has a turbine-generator rated at 1000 MW gross. The plant required about 9% of this power for its internal operations. It uses 9800 tons of coal per day. The coal has a heating value of 6,388.9 Kcal/kg and the steam generator efficiency is 86%. What is the net station efficiency of the plant in percent? Answer C A. 30% B. 25% C. 33% D. 38% 9. A superheat steam Rankine cycle has a turbine inlet conditions of 17.5 Mpa and 530 0C expands in a turbine to 0.007 Mpa. The turbine and pump polytropic efficiencies are 0.9 and 0.7 respectively, pressure between pump and turbine inlet are 1.5 Mpa. What shoul be the pump work in KJ/kg. Answer B A. 17.3 B. 27.3 C. 37.3 D. 47.3 10. A steam plant operates with initial pressure of 1.70 Mpa and 370 0C temperature and exhaust to a heating syste at 0.17 Mpa. The Condensate from the heating system is returned to the boiler at 65.50C and the heating system utilizes from its intended purpose 90% of the energy transferred from the steam it receives. The n T is 70%. If boiler efficiency is 80%, what is the cogeneration efficiency of the system in percent. Neglect pump work. Answer D Steam Properties: At 1.70 Mpa and 3700C: h = 3187.1 KJ/kg s = 7.1081 At 0.17 Mpa: hf = 483.20 sf=1.4752 hg = 2216.0 sg=5.7062 At 65.50C: hf = 274.14 A. 78 B. 102.10 C. 91.24 D. 69 11. In a cogeneration plant, steam enters the turbine at 4 Mpa and 400 0C. One fourth of the steam is extracted from the turbine at 600 Kpa pressure for process heating. The remaining steam continues to expand to 10 Kpa. The extracted steam is then condensed and mixed with feedwater are constant pressure and the mixture is pumped to the boiler pressure of 4 Mpa. The mass flow rate of steam through the boiler is 30 kg/sec. Disregarding any pressure drops and heat losses in the piping, and assuming the turbine and pump to be isentropic, how much process heat is required in KW? Answer A Steam properties: At 4 Mpa and 4000C: h = 3213.6 KJ/kg, s = 6.7690 At 600 Kpa: hf = 670.56 sf = 1.9312 hfg = 2086.3 sfg = 4.8288 A. 15,646.8 B. 2,458.2 C. 1.9312 D. 1,027.9 12. In an ideal Reheat cycle, the steam throttled condition is 8 Mpa and 480 0C. The steam is then reheated to 2 Mpa and 4600C, determine cycle efficiency. Answer A A. 38.3% B. 24.3% C. 34.3% D. 45.2% 13. A reheat steam cycle has 13,850 Kpa throttle pressure at the turbine inlet and a 2800 Kpa reheat pressure, the throttle and reheat temperature of the steam is 540 0C, condenser pressure is 3.4 Kpa, engine efficiency of high and low pressure is 75% find the cycle thermal efficiency. Answer A A. 34.46% B. 38.40% C. 36.49% D. 43.45% 14. Steam is delivered to turbine at 5.4 Mpa and 6000C. Before condensation at 310C, steam is extracted for feedwater heating at 0.6 Mpa. For an ideal regenerative cycle, find the thermal efficiency. Answer D A. 23.45% B. 34.34% C. 28.34% D. 44.14% 15. A steam condenser receives 10 kg/s of steam with an enthalpy of 2570 KJ/kg. Steam condenses into a liquid and leaves with an enthalpy of 160 KJ/kg. Cooling water passes through the condenser with temperature increases from 13 degrees C to 24 0C/ Calculate the water flow rate in kg/s. Answer C A. 533 B. 518 C. 523 D. 528 16. In an open feedwater heater for a steam plant, saturated steam at 7 bar is mixed with subcooled liquid at 7 bar and 250C. Just enough steam is supplied to ensure that the mixed steam leaving the heater will be saturated liquid at 7 bar when heater efficiency is 90%. Calculate the mass flow rate of subcooled liquid if steam flow rate is 0.865 kg/s. Steam Properties are: Answer A At 7 bar, saturated vapor: hg = 2763.5 KJ/kg At 7 bar, and 250C: hf = 105.5 KJ/kg At 7 bar, saturated liquid: hf = 697.22 KJ/kg A. 2.725 B. 3.356 C. 2.286 D. 3.948 ` 17. Steam expands adiabatically in a turbine from 2000 Kpa, 400 0C to 400 Kpa, 2500C. What is the effectiveness of the process in percent assuming an atmospheric pressure of 15 0C. Neglect changes in kinetic and potential energy. Answer C Steam Properties are: At 2000 Kpa and 4000C. h = 3247.6 KJ/kg s = 7.1270 KJ/kg-K At 400 Kpa and 2500C. h = 2964.2 KJ/kg s=7.3789 KJ/kg-K A. 82 B. 84 C. 80 D. 86 19. Steam enters the turbine of a cogeneration plant at 0.7 Mpa and 500 0C. Steam at a flow rate of 7.6 kg/s is extracted from the turbine at 600 Kpa pressure for process heating. The remaining steam continues to expand to 10 Kpa. The recovered condensates are pumped back to the boiler. The mass flow rate of steam that enters the turbine is 30 kg/s. Calculate the cogeneration efficiency in percent. Answer No exact answer in the choices Steam Properties At 7.0 Mpa and 5000C: h = 3410.3 s = 6.7976 At 600 Kpa: hf = 670.56 hfg = 2086.3 sfg = 4.8288 At 10 Kpa: hf = 191.83 hfg = 2392.8 sf = 0.6493 sfg = 7.5009 A. 60 B. 50 C. 65 D. 55 20. A heat exchanger was installed purposely to cool 0.50 kg of gas per second. Molecular weight is 28 and k = 1.32. The gas is cooled from 150 0C to 800C. Water is available at the rate of 0.30 kg/s and at a temperature of 120C. Calculate the exit temperature of the water in 0C. Answer A A. 48 B. 42 C. 46 D. 44 21. Pump work of Rankine cycle is 15 KJ/kg. Density of water entering the pump is 958 kg/m 3. If condenser pressure is 100 Kpa, what is the pressure at the entrance of the turbine? Answer A A. 14.47 Mpa B. 20.48 Mpa C. 15.67 Mpa D. 17.77 Mpa 22. In a Rankine cycle the turbine work is 1,000 KJ/kg and pump work of 13 KJ/kg. If heat generated by generator is 2800 KJ/kg, what is the efficiency of the cycle? Answer A A. 35.25% B. 4.75% C. 38.65% D. 30.25% 23. In a Reheat power plant the difference in enthalpy at the entrance and exit is 550 KJ/kg for first stage and second stage is 750 KJ/kg. If both stages has an efficiency of 92% and heat added to boiler is 3,000 KJ/kg. Determine the plant cycle efficiency neglecting the pump work. Answer C A. 30% B. 35% C. 40% D. 45% 24. An adiabatic feed pump in a steam cycle delivers water to a steam generator at a temperature of 2000C and a pressure of 10 Mpa. The water eneters the pump as a saturated liquid at 180 0C. If the power supplied to the pump is 75 kW, determine the mass flow rate. Answer C A. 6.23 kg/s B. 8.34 kg/s C. 7.39 kg/s D. 9.12 kg/s 25. A condenser receives steam from a turbine at 15 kPa, 90% quality, and with a velocity of 240 m/s. Determine the increase in circulating water required because of high pressure exit velocity if the steam flow rate is 38 kg/s and the cooling water temperature rise is12 0C with an inlet condition of 300C. Answer D A. 11.23 kg/s B. 17.23 kg/s C. 13.23 kg/s D. 21.78 kg/s 26. A steam generator has an exit enthalpy of 3195.7 KJ/kg at the rate of 10 kg/s. The enthalpy available at the turbine inlet is 3000 KJ/kg. Determine the heat lost between boiler outlet and turbine inlet. Answer B A. 1957 kW B. -1957 kW C. 1873 kW D. -1873 kW 27. A Rankine cycle has a turbine with available enthalpy of 800 KJ/kg. The pump has also 10 KJ/kg energy available. Find the net cycle output of the plant if mass flow rate is 5 kg/s. Answer B A. 2619 kW B. 3950 kW C. 8745 kW D. 4234 kW 28. A Rankine cycle, the steam is extracted from the turbine at 2 Mpa and 250 0C for feedwater heating and it is mixed with condenser exit at 30 Kpa after pumping. Find the fraction of vapor extracted from the turbine. Answer A A. 0.23464 B. 0.19338 C. 0.5632 D. 0.3855 29. An adiabatic turbine in a steam generating plant receives steam at a pressure of 7.0 Mpa and 5500C and exhausts at 20 kPa. The turbine inlet is 3 m higher than the turbine exit, the inlet steam velocity is 15 m/s and the exit is 300 m/s. Calculate the turbine work in KJ/kg. Answer B A. 1297.45 B. 1197.10 C. 1093.45 D. 1823.45 30. A steam power plant operates on the Rankine cycle. The steam enters the turbine at 7 Mpa and 5500C with a velocity of 30 m/s. It discharge to the condenser at 20 kpa with a velocity of 90 m/s. Calculate the net work in kW for a flow of 37.8 kg/s. Answer D A. 23.23 MW B. 53.34 MW C. 34.22 MW D. 46.54 MW 31. A Carnot cycle uses steam as the working substance and operates between pressure of 7 Mpa and 7 kpa. Determine the cycle thermal efficiency. Answer A A. 44.17% B. 54.23% C. 34.23% D. 59.4% 32. A supercritical power plant generates steam at 25 Mpa and 560 0C. The condenser pressure is 7.0 kpa. Determine the exit quality of steam if it expands through a turbine in this power plant. Answer D A. 45.66% B. 68.45% C. 56.56% D. 74.26% 33. Steam enters a turbine at 1.4 Mpa and 320 0C. The turbine internal efficiency is 70%, and the total requirement is 800 kW. The exhaust is to the back pressure system, maintained at 175 kpa. Find the steam flow rate. Answer A A. 2.62 kg/s B. 4.23 kg/s C. 3.23 kg/s D. 5.34 kg/s BOILERS 1. The heating surface are of water tube boiler is 200 m 2, what is the equivalent rated boiler horsepower? Answer D A. 217 Hp B. 2365.93 Hp C. 200 Hp D. 219.78 Hp 2. The rated boiler horsepower of a fire tube boiler is 500 Hp. What is the heating surface area of the boiler? Answer D A. 500 m2 B. 300 m2 C. 400 m2 D. 550 m2 3. A water tube boiler has a heating surface area of 500 m 2. For a developed boiler hp of 825. Determine the percent rating of the boiler. Answer C A. 120.15% B. 160.15% C. 150.15% D. 300.15% 4. The factor of evaporation of boiler is 1.1 and a steam rate of 0.79 kg/sec. What is the developed boiler horsepower? Answer B A. 300 B. 200 C. 869 D. 250 5. The percent rating of water tube boiler is 200%, factor of evaporation of 1.08 and heating surface area is 256 m2. Find the rate of evaporation. Answer A A. 8,153.02 kg/hr B. 5,153.02 kg/hr C. 7,200 kg/hr D. 8,500.46 kg/hr 6. The actual specific evaporation of a certain boiler is 10. Factor of evaporation is 1.05. If the heating value of fuel is 30,000 KJ/kg, find the boiler efficiency. Answer A A. 60% B. 65% C. 70% D. 79% 7. The ASME evaporation units of a boiler is 24,827,000 KJ/hr. The boiler auxiliaries consume 1.5 MW. What is the net boiler efficiency if the heat generated by the fuel is 30,000 KJ/kg?Answer A A. 64.75% B. 68.94% C. 62.76% D. 68.54% 8. A 100,000 kg of coal supplied two boilers. One has a capacity of 150 kg/hr. How many days to consume the available fuel if the other boiler consumes 200 kg/hr? Answer D A. 5 days B. 7 days C. 15 days D. 12 days 9. The following coal has the following ultimate analysis by weight: C = 70.5% H2 = 4.5% O2 = 6.0% N2 = 1.0% S = 3.0% Ash = 11% Moisture = 4% A stocker fired boiler of 175,000 kg/hr steaming capacity uses this coal as fuel. Calculate volume of air in m3/hr with air at 600F and 14.7 psia pressure if boiler efficiency is 70% and FE = 1.10. Answer A A. 212,830 m3/hr B. 215,830 m3/hr C. 213,830 m3/hr D. 214,830 m3/hr 10. The following coal has the following ultimate analysis by weight: C = 70.5% H2 = 4.5% O2 = 6.0% N2 = 1.0% S = 3.0% Ash = 11% Moisture = 4% A stocker fired boiler of 175,000 kg/hr steaming capacity uses this coal as fuel. Volume of air in m3/hr with air at 600F and 14.7 psia pressure. Weight in metric tons of cal needed for 24 hours operation at rated capacity if boiler efficiency is 70% and FE = 1.10. Answer D A. 503.443 Mtons B. 508.443 Mtons C. 502.443 Mtons D. 504.443 Mtons 11. Two boilers are operating steadily on 91,000 kg of coal contained in a bunker. One boiler is producing 1591 kg of steam per hour at 1.2 factor of evaporation and an efficiency of 65% and another boiler produced 1364 kg of steam per hour at 1.15 factor of evaporation and an efficiency of 60%. How many hours will the coal in the bunker run the boilers if the heating value of coal is 7590 Kcal/kg.Answer C A. 220.8 hrs B. 256.2 hrs C. 230.8 hrs. D. 453.3 hrs. 12. A steam generating plant consisting of a boiler, an economizer and superheater generates superheated steam at the rate of 50 tons/hr. Feed water enters the boiler at 5 Mpa and 120 0C. Steam leaves the superheater at 4.5 Mpa and 320 0C. If the coal used has a heating value of 30,000 KJ/kg, calculate the number of tons of coal fired per hour for a gross efficiency of 85%. Answer A A. 4.89 B. 6.34 C. 5.34 D. 45.5 13. A water tube boiler has a capacity of 1000 kg/hr of steam. The factor of evaporation is 1.3, boiler rating is 200%, boiler efficiency is 5%, heating surface area is 0.91 m 2/boiler Hp, and the heating value of fuel is 18,400 Kcal/kg. The total coal available in the bunker is 50,000 kg. Determine total number of hours to consume the available fuel. Answer D A. 533.45 B. 743.12 C. 634.34 D. 853.26 14. A boiler operating at 11 kg/cm2 is required to generate a minimum of 50,000 kj/hr of saturated steam. Feed water enters the boiler at 80 0C. Compute the fore coal at an average rate 4,800 kg/hr and boiler efficiency is 85%. Compute the minimum heating value of local coal that could be used in order to ensure the generation of required steam. Answer B A. 28,464 B. 29,977 C. 23,556 D. 30,976 15. A boiler operating at 11 kg/cm2 is required to generate a minimum of 50,000 kg/hr of saturated steam. Feed water enters the boiler at 80 0C. The furnace is designed to fire coal at an average rate 4,800 kg/hr and boiler efficiency is 85%. Compute the developed boiler horsepower. Answer A A. 3462.56 hp B. 1234.56 hp C. 2345.67 hp D. 4233.34 hp 16. A steam boiler generating 7.1 kg/s of 4.137 Mpa, 426.7 0-C steam is continuously blown at the rate of 0.31 kg/sec. Feed water enters the economizer at 149.9 0C. The furnace burns 0.75 kg coal/sec of 30,470.6 KJ/kg higher heating value. Calculate the overall thermal efficiency of steam boiler. Answer C A. 76.34% B. 84.23% C. 82.78% D. 88.34% STEAM ENGINE 1. A steam engine has 10% brake thermal efficiency and delivers 750 kg/hr steam. The enthalpy of engine entrance is 2800 KJ/kg and condenser exit is 450 KJ/kg. Determine the brake power of the engine. Answer C A. 46 KW B. 47 KW C. 49 KW D. 48 KW 2. The indicated efficiency of a steam engine is 60%. The engine entrance is 2700 KJ/kg and exit is 2000 KJ/kg. If steam consumption is 800 kg/hr and mechanical efficiency is 90%, what is the brake power of the engine? Answer B A. 55 KW B. 84 KW C. 65 KW D. 70 KW 3. A steam engine has bore and stoke of 300 mm x 420 mm running at 250 rpm has mean indicated pressure of the engine is 400 Kpa. Determine the indicate power. Answer D A. 100 KW B. 50 KW C. 65 KW D. 99 KW 4. The crank shaft of a double acting steam engine rotates at 220 rpm. The bore and stroke of the steam engine is 300 mm x 450 mm, and the mean effective pressure acting upon the piston is 4 kg/cm2. Find the indicated horsepower developed in the cylinder. Answer A A. 122.7 hp B. 110.3 hp C. 143.2 hp D. 176.3 hp 5. A steam engine develops 60 Bhp with dry saturated steam at 1034.25 Kpa absolute and exhaust at 124.11 Kpa. Steam consumption is 736.36 kg/hr. Calculate the indicated engine efficiency based on 90% mechanical efficiency. Answer D A. 34.23% B. 54.23% C. 45.23% D. 66.74% 6. A steam engine develops 60 Bhp with dry saturated steam at 1034.25 Kpa absolute and exhaust at 124.1 Kpa. Steam consumption is 736.36 kg/hr. calculate the thermal efficiency of equivalent Rankine engine. Answer A A. 15.59% B. 34.23% C. 12.45% D. 21.34% 7. A 350 mm x 450 mm engine running at 260 rpm has an entrance steam condition of 2 Mpa and 2300C and exit at 0.1 Mpa. The steam consumption is 2,000 kg/hr and mechanical efficiency is 88%. If indicated mean effective pressure is 600 Kpa, determine the brake thermal efficiency. Answer C A. 23.34% B. 18.34% C. 14.66% D. 27.34% 8. A 350 x 450 mm engine running at 260 rpm has an entrance steam condition of 2 Mpa and 230 0C and exit at 0.1 Mpa. The steam consumption is 2,000 kg/hr and mechanical efficiency is 88%. If indicated mean effective pressure is 600 Kpa, determine indicated thermal efficiency. Answer A A. 16.66% B. 34.23% C. 12.34% D. 21.23% 9. Steam is admitted to the cylinder of an engine in such a manner that the average pressure is 120 psi. The diameter of the piston is 10” and the length of stroke is 12”. Answer D A. 171.5 B. 175 C. 173.2 D. 174.4 STEAM TURBINE 1. A steam turbine receives 5,000 kg/hr of steam at 5 Mpa and 400 0C and velocity of 25 m/sec. It leaves the turbine at 0.006 Mpa and 85% quality and velocity of 20 m/sec. Radiation is 10,000 KJ/hr. Find the KW developed. Answer C A. 1273.29 B. 2173.29 C. 1373.29 D. 7231.29 2. An industrial power plant requires 1.5 kg of dry saturated steam per second at 165 0C for heating purposes. This steam may be supplied from an extraction turbine which receives steam at 4 Mpa and 3800C and is exhaust to condenser at the rate of 0.8 kg steam per second at 0.0034 Mpa while rejecting 1400 KW to the cooling water. If mechanical-electrical efficiency is 95% and that the heat loss in the turbine casing is 10 KW, calculate the power generated by the plant. Answer B A. 2,126.44 KW B. 1,556.50 KW C. 3,123.34 KW D. 4,344.33 KW 3. A steam turbine with 90% stage efficiency receives steam at 7 Mpa and 550 0C and exhausts as 20 Kpa. Determine the turbine work. Answer A A. 117 KJ/kg B. 132 KJ/kg C. 123 KJ/kg D. 143 KJ/kg 4. A steam turbine with 90% stage efficiency receives steam at 7 Mpa and 550 0C and exhausts as 20 Kpa. Determine the quality at exhaust. Answer D A. 87.45% B. 76.34% C. 82.34% D. 91.69% 5. A small steam turbine power plant of 5,000 KW capacity has a full load steam rate of 6 kg steam pwer KW-hr. No load steam consumption may be taken as 10% of the full load steam consumption. Write the equations of WILLANS LINE of this turbine and at 60% of rated load, calculate the hourly steam consumption of this unit. Answer C A. 19,100 kg/hr B. 19,300 kg/hr C. 19,200 kg/hr D. 19,400 kg/hr 6. Steam flows into a turbine at the rate of 10 kg/sec and 10 KW of heat are lost from the turbine. Ignoring elevation and kinetic energy effects, calculate the power output from the turbine. Inlet enthalpy is 2739 KJ/kg and exhaust enthalpy is 2300.5 KJ/kg. Answer C A. 4605 KW B. 4973 KW C. 4375 KW D. 4000 KW 7. Steam entering the turbine has a rate of 10 kg/sec with enthalpy of 3400 KJ/kg and 2600 KJ.kg at the exhaust. If 100 KW of heat is rejected from turbine casing, what is the turbine work? Answer A A. 7900 kW B. 7700 KW C. 5600 KW D. 5400 KW 8. A steam turbine of 6 MW capacity has a Willian’s line equation of m s = 5.5L + 3,000 kg/hr. Determine the steam consumption at 70% load. Answer C A. 3564 kg/hr B. 3546 kg/hr C. 26,100 kg/hr D. 58,000 kg/hr 9. A steam turbine has an entrance enthalpy of 3050 KJ/kg. The exit has 2500 KJ/kg. Determine the actual enthalpy after isentropic expansion if stage efficiency is 90%. Answer B A. 1255 KJ/kg B. 2555 KJ/kg C. 2500 KJ/kg D. 2000 KJ/kg 10. Steam enters the turbine at the rate of 2.5 kg/sec with enthalpy of 3200 KJ/kg and exhaust enthalpy of 1100 KJ/kg. Steam is extracted from the turbine at the rate of 1 kg/sec for heating purposes with enthalpy of 2750 KJ/kg. What is the turbine work? Answer D A. 2000 KW B. 2500 KW C. 3000 KW D. 3600 KW 11. A steam turbine has an entrance enthalpy of 3400 KJ/kg and 2500 KJ/kg at exit. If generator generates 2430 KW and has 90% efficiency, what is the mass of steam entering the turbine? Answer D A. 10,400 kg/hr B. 10,600 kg/hr C. 10,700 kg/hr D. 10,800 kg/hr 12. Steam turbine in Rankine cycle has an exhaust enthalpy of 2650 KJ/kg and delivers 0.8 kg/sec of steam. Determine the heat rejected from the condenser if enthalpy at exit is 200 KJ/kg. Answer A A. 1960 KW B. 1940 KW C. 1995 KW D. 1909 KW GEOTHERMAL POWER PLANT 1. Mass low rate of ground water in a geothermal power plant is 1,500,000 kg/hr and the quality after throttling is 30%. Determine the brake power of turbine if the change of enthalpy of steam at inlet and outlet is 700 KJ/kg. Answer B A. 68.5 MW B. 87.5 MW C. 64.5 MW D. 89.5 MW 2. Ground water of geothermal power plant has an enthalpy of 700 KJ/kg and at turbine inlet is 2,750 KJ/kg and enthalpy of hot water in flash tank is 500 KJ/kg. What is the mass of steam flow entering the turbine if mass flow of ground water is 45 kg/sec? Answer C A. 3.27 kg/sec B. 2.27 kg/sec C. 4.27 kg/sec D. 9.27 kg/sec 3. The enthalpy entering the turbine of a geothermal power plant is 2750 KJ.kg and mass rate of 1 kg/sec. The turbine brake power is 1000 KW condenser outlet has enthalpy of 210 KJ/kg. If temperature rise of cooling water in condenser is 8 0C, what is the mass of cooling water requirement? Answer C A. 44 kg/sec B. 45 kg/sec C. 46 kg/sec D. 47 kg/sec 4. In a 12 MW geothermal power plant, the mass flow of steam entering the turbine is 26 kg/sec. The quality after throttling is 25% and enthalpy of ground water is 650 KJ/kg. Determine the overall efficiency of the plant. Answer D A. 7.4% B. 9.6% C. 5.4% D. 15.4% 5. A 16,000 KW geothermal plant has a generator efficiency and turbine efficiency of 90% and 80%, respectively. If the quality after throttling is 20% and each well discharges 200,000 kg/hr, determine the number of wells are required to produce if the change in enthalpy at the entrance and exit of turbine is 500 KJ/kg. Answer A A. 4 wells B. 5 wells C. 6 wells D. 8 wells 6. A geothermal power plant draws pressurized water from a well at 20 Mpa and 300 0C. To produce a steam water mixture in the separator, where the unflashed water is removed, this water is throttled to a pressure of 1.5 Mpa. The flashed steam which is dry and saturated passes through the steam collector and enters the turbine at 1.5 Mpa and expands to 1 atm. The turbine efficiency is 85% at a rated power output of 10 MW. Calculate overall plant efficiency. Answer A A. 7.29% B. 12.34% C. 9.34% D. 19.45% 7. A flashed steam geothermal power plant is located where underground hot water is available as saturated liquid at 700 Kpa. The well head pressure is 600 Kpa. The flashed steam enters a turbine at 500 Kpa and expands to 15 Kpa, when it is condensed. The flow rate from the well is 29.6 kg/sec. Determine the power produced in KW. Answer A A. 430.13 kg/s B. 540.23 kg/s C. 370.93 kg/s D. 210.34 kg/s 8. A flashed steam geothermal power plant is located where underground hot water is available as saturated liquid at 700 Kpa. The well head pressure is 600 Kpa. The flashed steam enters a turbine at 500 Kpa and expands to 15 Kpa, when it is condensed. The flow rate from the well is 29.6 kg/sec. Determine the cooling water flow in kg/sec if water is available at 30 0 C and a 100C rise is allowed through the condenser. Answer DIESEL POWER PLANT 1. Determine the indicated mean effective pressure of an engine in psi having a brake mean effective pressure of 750 Kpa and 80% mechanical efficiency. Answer A A. 136 psi B. 137 psi C. 138 psi D. 140 psi 2. Determine the friction power of an engine if the frictional torque developed is 0.3 KN.m running at 1200 rpm. Answer B A. 40.6 KW B. 37.7 KW C. 36.5 KW D. 50.3 KW 3. What is the power developed in the cylinder if indicated thermal efficiency is 44%, the engine uses 0.05 kg/sec fuel with heating value of 44,000 KJ/kg? Answer C A. 1000 KW B. 775 KW C. 968 KW D. 588 KW 4. A 750 KW diesel electric plant has a brake thermal efficiency of 34%. If the heat generated by fuel is 9,000,000 KJ/hr, what is the generator efficiency? Answer D A. 85.33% B. 65.88% C. 75.55% D. 88.23% 5. A 16-cylinder V-type diesel engine is directly coupled to a 5000 KW AC generator. If generator efficiency is 90%, calculate the brake horsepower of the engine. Answer A A. 7447 Hp B. 6468 Hp C. 8542 Hp D. 7665 Hp 6. Determine the brake power of the engine having a brake thermal efficiency of 35% and uses 250API fuel consumption of 40 kg/hr. Answer B or C A. 165.84 KW B. 173.52 KW C. 173.52 KW D. 160.67 KW 7. Determine the specific gravity of fuel oil having a heating value of 44,899.2 KJ/kg. Answer D A. 0.90 B. 0.80 C. 0.877 D. 0.893 8. A 500 KW diesel engine operates at 101.3 Kpa and 27 0C in Manila. If the engine will operate in Baguio having 93 Kpa and 230C, what new brake power will developed if mechanical efficiency is 85%? Answer C A. 600 KW B. 754 KW C. 459 KW D. 971 KW 9. What is the displacement volume of 300 mm x 4400 mm, 4 – stroke, 1200 rpm, 8 cylinder diesel engine? Answer B A. 0.243 m3/sec B. 2.262 m3/sec C. 5.75 kg/sec D. 1.25 m3/sec 10. What is the friction horsepower of a 300 KW diesel engine having a mechanical efficiency of 86%? Answer D A. 86.5 Hp B. 87.5 Hp C. 90.5 Hp D. 65.5 Hp 11. Determine the output power of a diesel power plant if the engine and generator efficiency is 83% and 95%, respectively. The engine uses 25 0API fuel and has a fuel consumption of 0.08 kg/sec. Answer D A. 2795 KW B. 8642 KW C. 9753 KW D. 2815 KW 12. Determine the piston speed of a 250 mm x 300 mm diesel engine running at 1200 rpm. Answer B A. 6 m/sec B. 12 m/sec C. 18 m/sec D. 5 m/sec 13. Determine the speed of a 6-pole generator of 60 hz. Answer C A. 600 rpm B. 1000 rpm C. 1200 rpm D. 3600 rpm 14. A 50 Bhp blast furnace engine uses fuel with 10 ft 3/Bhp-hrs. The heating value of gas is 33,500 KJ/m3. Determine the brake thermal efficiency. Answer D A. 80% B. 50% C. 25.76% D. 28.31% 15. The heat generated by fuel is 2500 KW. If the jacket water loss is 30%. Determine the mass of water circulated in the engine if the temperature rise is 8 0C. Answer B A. 20.5 kg/sec B. 22.4 kg/sec C. 58.5 kg/sec D. 12.3 kg/sec 16. An engine-generator rated 9000 KVA at 80% power factor, 3 phase, 4160 V has an efficiency of 90%. If overall plant efficiency is 25%, what is the heat generated by the fuel. Answer B A. 18,800 KW B. 28,800 KW C. 7500 KW D. 20,000 KW 17. A 4-strok, 8 cylinder diesel engine with bore and stroke of 9 in. x 12 in, respectively and speed of 1000 rpm has a break mean effective pressure of 165 psi. Determine the engine brake horsepower. Answer D A. 1753.34 Hp B. 1850.34 Hp C. 1950.34 Hp D. 1272.34 Hp 18. What torque is developed by the 300 KW engine running at 900 rpm? Answer C A. 2.65 KN.m B. 6.85 KN.m C. 3.18 KN.m D. 5.65 KN.m 19. What is the mechanical efficiency of a diesel engine if friction power is 30 KW and brake power of 150 KW? Answer B A. 85.55% B. 83.33% C. 65.44% D. 75.88% 20. A 3 MW diesel engine consumes 240 liters of 25 0API fuel generates 900 KW-hr. Determine the rate of fuel consumed by the engine. Answer A A. 0.2 kg/sec B. 0.4 kg/sec C. 0.6 kg/sec D. 0.8 kg/sec 21. The indicated thermal efficiency of a two stroke diesel engine is 50%. If friction power is 3% of heat generated, determine the brake thermal efficiency of the engine. Answer D A. 33% B. 34% C. 36% D. 37% 22. During the dynamometer test of an engine for 1 hr steady load, the engine consumes 40 kg fuel having 43,000 KJ/kg heating value. If the torque developed is 2.5 KN-m during the test at 600 rpm, what is the brake thermal efficiency of the engine? Answer B A. 31.22% B. 32.88% C. 55.77% D. 25.99% 23. A waste heat recovery boiler generates 250 kg/hr with h s – hf = 2300 KJ/kg. What is the exhaust loss from the engine if the actual heat developed is 35%? Answer C A. 492.6 KW B. 365.7 KW C. 456.4 KW D. 845.4 KW 24. What maximum power that can be delivered by the 2000 KW engine at 3000 ft elevation considering the pressure effect alone? Answer D A. 1600 KW B. 1700 KW C. 1900 KW D. 1800 KW 25. A 1000 KW diesel engine operates at an altitude of 1500 m elevation. Considering the pressure effect alone, find the power developed by the engine at higher elevation? Answer D A. 753 KW B. 823 KW C. 345 KW D. 983 KW 26. The piston speed of an engine running at 1200 rpm is 12 m/s. Find the stroke of the engine in inches. Answer C A. 15.74 mm B. 16 in C. 300 mm D. 15.75 in 27. The density of air entering the engine is 1.176 kg/m 3 has a volume flow rate of 0.375 m 3/sec. If the air fuel ratio is 21, find the mass flow rate of fuel. Answer B A. 0.10 kg/sec B. 0.02 kg/sec C. 0.30 kg/sec D. 0.40 kg/sec 28. A diesel engine develops a torque of 5 KN-m at 1800 rpm. If the brake thermal efficiency is 31%, find the heat generated by the fuel. Answer B A. 3050.25 KW B. 3040.25 KW C. 3000.25 KW D. 5000 KW 29. In a diesel engine the fuel is injected at 6.5% of the stroke, the clearance volume is 10% of the stroke. Find the cut-off ratio. Answer B A. 1.80 B. 1.65 C. 1.70 D. 1.40 30. A 373 KW (500 Hp) internal combustion engine has a break mean effective pressure of 551.5 Kpa at full load. What is the friction power if mechanical efficiency is 85%? Answer A A. 88.23 hp B. 97.33 hp C. 56.34 hp D. 76.23 hp 31. A 4-stroke 394 mm bore and 534 mm stroke single acting diesel engine with four cylinders is guaranteed to deliver 350 Bhp at 300 rpm. The engine consumed 66.8 kg/hr of fuel with a heating value of 44,251 KJ/kg. Calculate indicated mean effective pressure in Kpa if mechanical efficiency is 89%. Answer A A. 450.8 kpa B. 234.5 kpa C. 345.6 kpa D. 643.2 kpa 32. A 305 mm x 457 mm four stroke single acting diesel engine is rated at 150 KW at 260 rpm. Fuel consumption at rated load is 0.26 kg/KW-hr with a heating value of 43,912 KJ.kg. Calculate brake thermal efficiency. Answer A A. 31.53% B. 27.45% C. 45.34% D. 54.23% 33. A four-stroke, 8 cylinder Diesel engine with bore and stroke of 9 inches and 12 inches, respectively and speed of 950 rpm has a brake effective pressure of 164 psi. The specific fuel consumption is 0.39 lb/bhp-hr and fuel heating value is 18,500 Btu/lb. Determine thermal efficiency. Answer A A. 35.27% B. 45.23% C. 38.23% D. 54.23% 34. A dynamometer test was done for one hour at steady load on a 6 cylinder diesel engine. It was found to use 42 kg of fuel having Qh = 42,000 J/g. Cylinder is 22.8 cm x 27.2 cm, 4-cycle type. Speed, 550 rpm and dynamometer torque at 27000 kg-cm. Determine the brake thermal efficiency. Answer A A. 31.13% B. 43.22% C. 35.34% D. 45.32% 35. A certain diesel engine with the following classification, 8 cylinder, 400 mm x 600 mm, four stroke cycle has a fuel consumption of 0.6 lbs/hp-hr based on 19,100 Btu/lb. Engine speed is 280 rpm with an indicated mean effective pressure 130 psi. If the jacket water carries away an estimated 25% of the heat supplied, find its capacity (gpm) required if the allowable rise is 40 0F. Answer C A. 234 B. 873 C. 242 D. 292 36. Whe
