Engineering Thermodynamics SPPU Endsem Question Paper May 2024

Questions

1. Q1

   1. a)

      Define: i) Dead State ii) Exergy

      [4]
   2. b)

      The metal block of 5 kg in mass with specific heat 0.4 kJ/kgK at temperature 450 K is thrown in a water tank at temperature 20°C. Calculate the change in entropy of the universe.

      [8]
   3. c)

      State and prove the Principle of Increase of Entropy.

      [5]
   OR

2. Q2

   1. a)

      Show that entropy is property of the system.

      Also asked:Nov 2025

      [5]
   2. b)

      A heat engine receives 600 kJ of heat from a high temperature reservoir at a temperature of 1000K during a cycle. It converts 150 kJ of this heat into net work and rejects the remaining 450 kJ heat to a low temperature sink at 300 K temperature. Determine if this heat engine violates the second law of Thermodynamics on the basis of i) Clausius Inequality ii) Carnot Theorem

      [8]
   3. c)

      Define: i) Available Energy ii) Unavailable Energy 2

      Also asked:Nov 2025

      [4]

3. Q3

   1. a)

      Define dryness fraction. Draw neat sketch of throttling calorimeter and derive the formula for dryness fraction measurement by throttling calorimeter.

      [6]
   2. b)

      This part has equations that don’t show as text. Open the PDF to read it.

      [8]
   3. c)

      Explain Rankine vapour power cycle with the help of T-S diagram.

      Also asked:Nov 2025

      [4]
   OR

4. Q4

   1. a)

      2 kg of steam is at 8 bar pressure and 0.85 dry. Determine i) Total enthalpy of steam ii) Total volume of the steam iii) Total entropy of steam. This steam is further heated at the same pressure till it becomes completely dry saturated. Estimate a total change in enthalpy to the steam during the process.

      [6]
   2. b)

      A throttling calorimeter is used to measure dryness fraction of the steam in the steam mains which has steam flowing at a pressure of 8 bar. The steam after passing through the calorimeter is at 1 bar pressure and 115 deg centigrade temperatures. Calculate the dryness fraction of the steam in the mains. Take specific heat of superheated steam as 2.1 kJ/kg K.

      [8]
   3. c)

      Write difference between Carnot and Rankine cycle. 3

      Also asked:Nov 2025

      [4]

5. Q5

   1. a)

      Define the following terms. i) Mass fraction ii) Mole fraction

      [4]
   2. b)

      Explain Boy’s Gas Calorimeter with a neat schematic diagram.

      Also asked:Nov 2025

      [5]
   3. c)

      Determine the Air-Fuel ratio and the theoretical mass of air required for complete combustion of a fuel containing 85% of Carbon, 8% of Hydrogen, 3% of Oxygen, 1% of Sulpher and remaining ash by mass. If 40% of excess air is used, what volume of air at 27deg centigrade and 1.05 bar pressure, does this represent per kg of fuel.

      [8]
   OR

6. Q6

   1. a)

      Define: i) Stoichiometric Air ii) Stoichiometric Mixture

      [4]
   2. b)

      Write a note on ‘Orsat Apparatus’ used for volumetric analysis of Dry Exhaust Gases.

      [5]
   3. c)

      This part has equations that don’t show as text. Open the PDF to read it.

      [8]

7. Q7

   1. a)

      Give the function and location of the following (Any two)? i) Super heater ii) Air pre heater iii) Fusible plug

      [4]
   2. b)

      A water tube boiler produces 6000 kg/hour of steam at a pressure of 10.5 bar and consumes coal at a rate of 10.83 kg/min. The steam produced has a temperature of 250°C. The calorific value of fuel is 30500 kJ/kg. The water initially enters into the economizer and has temperature of 49°C at the economizer outlet. Determine i) Boiler Efficiency ii) Equivalent Evaporation

      [8]
   3. c)

      Derive the formula for: i) Equivalent Evaporation ii) Boiler efficiency 4

      [6]
   OR

8. Q8

   1. a)

      Define steam generator. Write down classification of boiler.

      [4]
   2. b)

      The following results obtained from boiler trial: i) Feed water per hour = 700 kg at 27°C ii) Steam pressure = 8 bar of dryness 0.97 iii) Coal consumption = 100 kg/hr iv) C.V. of coal = 25000kJ/kg v) Unburnt coal collected = 7.5 kg/hr vi) Flue gas formed per kg of fuel = 17.3 kg at 327°C (Cp of flue gas = 1.025 kJ/kgK) vii) Room temperature = 16°C Draw heat balance sheet kJ/min basis & Boiler Efficiency.

      [8]
   3. c)

      Explain the boiler heat balance sheet with formulas used. 

      [6]