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Applied Warmth past Exam Questions 1 ) An Ammonia refrigerator is usually to produce two tonne of ice each day at -4°C from drinking water at 20°C. if the temp range inside the compressor can be between 25°C and -6°C, Calculate hp required to obtain the converter.
Latent High temperature of ice = 70 kcal/kg, and specific high temperature of ice= 0. five 2 . A compressor draws 42. 5 m3 of air per minute inside the cylinder, at a pressure of 1. 05 kg/cm abs. It is pressurized Polytropically pV1. 3=C to a pressure some. 2 kg/cm2 abs, ahead of being sent to a recipient. Assuming a mechanical efficiency of 80% Calculate: a.
Indicated hp, b. The whole length horse power, and c. Total isothermal efficiency. 3. An individual stage behavioral instinct turbine has a speed of 1000rpm and a mean cutting tool ring size of sixty cm. The nozzles are inclined at 22° to the aircraft of rotation and the particular enthalpy drop is 190 KJ/kg. Identify: a. The relative speed of the steam at outlet, and b. The cutting tool inlet angle. 4. The motor engine consumes energy of calorific value 44MJ/Kg at a rate of 45tonne/day. That the mentioned thermal performance is 39% and break thermal effectiveness is 33%. Calculate: a. The indicated power, w. The braking system power, and. The power lost to scrubbing. 5. Air in a ship’s saloon can be maintained in 19°C which is changed two times every hour from the outside ambiance which is for 7°C. The saloon is usually 27m simply by 15m by simply 3m high. Calculate the kilowatt launching to heat this surroundings taking the saloon to be at atmospheric Pressure = 1 ) 013 club. R to get air =0. 287 KJ/kg K. 6. 0. 23kg of air has an primary pressure of just one. 7 MN/m2 and a temperature of 200°C. it can be expanded into a pressure of 0. thirty four MN/m2 legally speaking pV 1 . 35 = Constant. Decide the work transmitted during the expansion. Take R = zero. 29 KJ/kg K. 7.
The equivalent evaporation of a central heating boiler from with 100°C is 10. some kg steam/kg fuel. The calorific value of the gas is 29800KJ/kg. Determine the efficiency in the boiler. If the boiler makes 15000 kg of heavy steam per hour in 24 club from nourish water of 40°C as well as the fuel consumption is 1650 kg/h, identify the condition of the steam produced. 8. A single-cylinder, twice acting heavy steam engine is 250mm bore by 300mm stroke and runs for 3. 5rev/s, steam is supplied at 1035 KN/m2 and the back pressure is 34 KN/m2 and the diagram factor is 0. seventy eight. Determine the indicated benefits of the engine. a. If perhaps cut off is in 0. five stroke, m. If cut off is at zero. 5 heart stroke. 9. Surroundings enters a nozzle with a pressure of 700 KN/m2 and having a temperature of 180°C. Quit pressure is definitely 100 KN/m2. The law attaching pressure and specific volume level during the expansion in the nozzle is pV1. 3=Constant. Determine the velocity in exit in the nozzle. Have Cp= 1 ) 006 KJ/kg K and Cv=0. 717 KJ/kg T. 10. A single row, instinct turbine has a mean knife speed of 215 m/s. Nozzle entry angle reaches 30° to the plane of rotation of the blades. The steam velocity from the valve is 550 m/s. There exists 15% loss in relative speed due to rubbing across blades.
The absolute velocity at the exit is over the axis of the turbine. The steam circulation through the turbine is at the speed of 700 kg/h. Identify: a. The inlet and exit angles of the rotor blades, b. The velocity of the steam for exit, c. The power outcome of the generator. 11. The high temperature of any Carnot pattern is 400°C and the routine has a energy efficiency of 55%. The amount ration with the isothermal processes is two: 8: 1 ) Determine to get the pattern: a. The lower temperature, b. The volume bout of the adiabatic processes, c. The overall energy efficiency. Consider r sama dengan 1 . 4 12.
A diesel engine has a compression ratio of 14: one particular and an efficiency ratio of 0. 7 when known the air standard efficiency. The fuel intake is five. 65 kg/h. Take r=1. 4 and calorific benefit of the gas oil can be 44500 KJ/kg. Determine the indicated electrical power developed. 13. The evaluation of a gasoline oil is definitely 85. five per cent carbon, 10. 9% hydrogen, 1 . 6% oxygen and 1% impurities. Calculate the proportion of co2 in the flue gasses, a. When the quantity of air delivered is the bare minimum for complete combustion, and b. When the excess surroundings over the minimal is: (i) 25% (ii) 50% iii) 75% 16. In an compressor the air is compressed for the law pVn=constant. The compressor takes in 105 m3/min of air in 1 . zero bar 27°C. If the pressure ratio is 5 to at least one, calculate, a. The index of compression, b. Electricity absorbed by compressor. 15. A single operating opposed piston 6 tube two heart stroke engine possess mechanical productivity of 86% when jogging at one zero five rpm with mean powerful pressure of 7. 24 club, produces brake pedal power of 4326 kW. The mass with the top appui with its hooking up parts is definitely 25% greater than that of lower part piston plus the combined cerebrovascular accident is 2340 mm.
In the event the stroke of piston may differ inversely because the masses of the reciprocating parts. Determine, (i) The stroke of the top and bottom appui, (ii) The cylinder diameter. 16. The mass analysis of a fuel is 86% carbon, 14. 5% hydrogen and installment payments on your 5% o2. If for complete combustable 25% excess air comes per kilogram of energy burnt, determine: a. The mass of flue gas, b. Amount of air by 1 . 0 bar and 15°C. Take R intended for air sama dengan 0. 287 kJ/kgh. 17. The size of an air compressor cylinder is definitely 140 logistik, the cerebrovascular accident is one hundred and eighty mm, as well as the clearance volume level is 77cm. he pressure in the canister at the beginning of the stroke can be 1 .
You read ‘Applied Heat Past Examination Questions’ in category ‘Papers’ 0 bar and through delivery is constant in 4. almost 8 bar. Taking the law of compression since pV1. 25=Constant, calculate, the distance moved by piston during the delivery period and exhibit this since fraction of the heart stroke. 18. A turbine flower consists of L. P. and L. L. stages and is supplied with steam at 12-15 bar 300°C. The heavy steam is broadened in the L. P. and leaves by 2 . 5 bar zero. 97 dried. Some of the heavy steam is bled off to the feed heaters and outstanding passes to L. S. where it really is expanded to 0. 12-15 bar zero. 84 dry out.
If the same volume of work copy takes place in each product, calculate the amount of steam savane off portrayed as percentage of the steam supplied. nineteen. 7. 08 liters of air for a pressure 1 . 79 bar and temperature of 333°C is definitely expanded by law pV 1 . 3 sama dengan constant plus the final pressure 1 . 206 bar, determine: a. Amount at the end of expansion, m. Work copy from the air flow and, c. The heat at the end of expansion. twenty. Steam leaves the nozzle and makes its way into the blade wheel of your single stage impulse generator at a velocity of 840 m/s and at a great angle of 20° for the plane of rotation.
The blade speed is 350 m/s and the exit angle of the blade is 25°12′. Due to chaffing the steam looses 20% of its rotational velocity across the cutting blades, calculate, a. The cutting tool inlet perspective and, b. The degree and the way of overall velocity of steam for exit. 21. In a Freon-12 refrigerating grow, Freon leaves the fondre with a certain enthalpy of 50kJ/kgK. The pressure inside the evaporator is usually 1 . 826 bars as well as the refrigerant leaves the evaporator at this pressure at a rate of 0. 4 Kg/s and a heat of 0°C. Calculate, a. Dryness small percentage of Freon at outlet of the evaporator, b.
The refrigerating impact per minute. twenty two. A glass tube of uniform bore is closed at on end and available at the other. It contains air imprisoned by a column of mercury 40. 7 logistik long. When the tube is held top to bottom with close end at the bottom, the length of mid-air column is definitely 227. 6mm. Taking 1mm of mercury = 133. 5N/m2 and atmospheric pressure = 101. 5 kN/m2. Calculate the size of the air steering column if the pipe is held vertically with the closed end at the top. twenty-three. A single behaving gas engine of lose interest 190 logistik and cerebrovascular accident 380 mm has an mentioned power of 13 kW when developing brake power of 9 kW delete word 125 explosions per minute.
The intake of gas of calorific value 1 . 76 MJ/m3 is usually 6. 8m3/hour. Calculate the mechanical and indicated cold weather efficiencies, plus the mean powerful pressure. twenty four. A 6 cylinder, four stroke, internal combustion engine is required to build a brake of 176 kW under the following conditions: Velocity 200rev/min, brake pedal m. at the. p. 8 bars, stroke/bore ratio 1 . 25/1. Break specific gas consumption zero. 262 Kg/KWh. Calculate: – a. The cylinder measurements, and m. Fuel usage kg/h 25. Carbon dioxide leaves a a fridge condenser using a total high temperature of 156kJ/kg.
After throttling it passes through the evaporator from and it leaves with a dryness fraction of 0. 98. At the evaporator pressure the liquid warmth is 12kJ/kg and the latent heat can be 280kJ/kg. If 13. 8 kg of refrigerant circulates per minute, estimate: – a. The dryness fraction at the inlet towards the evaporator, and b. Heat absorbed in the evaporator in 24 hours. 26. Steam is definitely generated via feed water at a temperature of 93. 3° C the following: In herb A the steam made is 17. 25 bar dry over loaded. In flower B the steam generated is 17. 25 club 0. being unfaithful dry and, In Flower C the steam made is 17. 5 tavern 82°C extremely heat. Calculate the percentage enhancements made on the consumption using flower A while the base. 27. A hydrocarbon fuel cellular is completely burned with 12. 5 percent excess air. Compute the Volume of air used to burn 1Kg of fuel, measured at 1 . 01 bars and 18°C. Atmosphere contains twenty three percent o2 by mass. Atomic mass relationship: Hydrogen=2, Carbon=12, Oxygen=16. 28. An oil engine has a volumetric compression ratio of 13: 1 . On the commencement of compression air in the canister is at you bar and 15. 6°C. Calculate the temperature and pressure at the conclusion of compression if the index of compression is 1 . 8. 30. A single behaving air compressor operating without measurement has a 220mm bore and 200mm heart stroke. The suction conditions will be 1 club 27°C and running acceleration is 10 rev/sec. if compression is usually according to the law pV1. 3=Constant plus the discharge pressure is 10 bar. Determine, a. The mass of air compressed per hour, and b. The discharge temperature. 30. Estimate the final temperatures and last total heat of the two (a) and (b). a. Water in 65. six °C having a mass of 45. 36 kg is definitely cooled by simply placing 5. 536 kg of ice cubes at -8. 9°C into the water. n. Water for 65. 6°C having a mass of fifty four. 1 kilogram is cooled down by addition of 22. 68 kg of water by 26. 7°C. 31. An impulse heavy steam turbine works at 50rev/sec. The imply blade suggestion diameter can be 0. 6m. The cutter exit perspective is 30° and the velocity of the heavy steam relative to the blade for blade quit is three hundred m/s. Compute or determine by any other means the kinetic energy of steam giving the blades per kg of heavy steam flow. 32. A perfect gas at several. 1 bar and 30°C is pressurized according to the law pV1. 3=constant until its temp increases to 215°C. Drawing the process over a p-V plan and calculate: a.
The pressure by the end of compression. b. The changes in enthalpy and inside energy per kilogram of gas. 33. In an ideal constant volume cycle the temperature at the outset of compression is 50°C. the volumetric compression ratio is 5: 1 ) If the high temperature supplied during the bible is 930 KJ/Kg of functioning fluid, calculate: a. The most temperature achieved on the pattern, b. Work done during the cycle/kg of operating fluid, and c. The thermal effectiveness of the pattern. Take? =1. 4 and Cv= zero. 1717 KJ/Kg K. 34. A fuel has a mass analysis of carbon 87 percent, hydrogen 5. percent and the rest ash. The calorific worth of carbon dioxide and hydrogen are 34MJ/kg and one hundred forty five MJ/kg correspondingly. Calculate for just one kilogram of fuel: a. The calorific value, b. The mass of exhaust system gas if 35 percent excess surroundings is supplied. The moment burning fuel, why is surplus air employed? Air is made up of 23 percent oxygen simply by mass Atomic mass interactions: hydrogen=1, oxygen=16, carbon=12. thirty-five. One kg of dry out saturated heavy steam at some bars is definitely contained in a cylinder when you have a piston. The vapor rejects 320 KJ of heat energy by constant pressure is 1 . 4 pubs. Calculate: a.
The condition of the steam upon completion of chilling at regular pressure, w. The condition of the steam upon completion of cooling at frequent volume, and c. The quantity of heat energy rejected during constant volume level cooling. 36. A vapor turbine which operates in 50rev/s contains a mean blade-ring diameter of 1m for a certain level. The cutting blades are designed for 50 percent reaction and enjoying the exit and inlet angles at 30° and 50° respectively. The turbine is supplied with vapor at the proportion of 166. 67kg/s and the stage efficiency is 85 percent. Determine or determine by any means: a.
The ability output from the stage, and b. The precise enthalpy drop in the level. 37. In Ammonia refrigeration plant the refrigerant leaves the condenser at 22°C as saturated liquid. The evaporator pressure is 2 . 077bar and refrigerant leaves the evaporator 0. 98 dry saturated. For a chilling load of 40kW, compute: a. The interest rate of blood circulation of the refrigerant (kg/s), n. The effective swept volume of the air compressor (m3) if perhaps its rate is one particular rev/s. 35. A copper bar of 75mm diameter, 13m long is warmed by a direct current flowing through the bar. The steady electrical input to the bar is 500W.
Assuming the bar is well-insulated and neglecting louage heat loss at the potential clients, calculate the wires considered for the temperature with the bar to boost from 5°C to 365°C. 39. A single stage dual acting compressor deals with 18. 2m3 of air per minute measured in conditions of 1. 61325 pub 15°C. The condition at the beginning of compression is zero. 965 pub 27°C plus the discharge pressure is four. 82 bars. The compression is by law pV1. 32=constant. If the mechanical efficiency of the compressor is 0. on the lookout for calculate the input electrical power required to travel the converter. 40.
In a steady flow process the working fluid makes its way into and leaves a lateral system with negligible speed. The temperature drop from inlet to outlet is definitely 480°C and the heat loss from the system are 10KJ/kg of fluid. Determine the energy output from your system to get a fluid movement of 1. 7kg/s. For substance Cp=900 J/kgK. 41. A four stroke single tube engine taking care of constant volume cycle, develops 7. your five KW(Brake) at 60 rev/s, the mechanised efficiency getting 0. 8. The pressure at the “beginning of compression” is zero. 97 bar. The engine has a volumetric compression rate of 7 and the maximum pressure reached in the cycle can be 34 pub.
If the two compression and expansion can be according to the law pV1. 38=constant. Estimate: a. The indicated indicate effective pressure, and b. The size of the canister if stroke/bore ratio can be 1 . twenty-five. 42. A boiler builds steam for 40 pub 400°C and supplied to a steam turbine at the price of 14 kg/s. due to frictional and heat loss the steam at the turbine inlet reaches 37 club 350°C. In the event the steam speed leaving the boiler is definitely 30 m/s and the change in the kinetic energy of steam is negligible. Determine: a. The diameter from the steam supply pipe, and b. The warmth loss through the steam source pipe.