Engineering Thermodynamics SPPU Endsem Question Paper May 2023

Questions

1. Q1

   1. a)

      Explain the concept of Available and Unavailable energy. When does the system become dead?

      [8]
   2. b)

      1 Kg of air at a pressure of 8 bar and a temperature of 100° C undergoes a reversible Polytropic process following the law pv 1.2 = constant. If the final pressure is 1.8 bar determine the increase in entropy, work done and heat transfer of the system?

      [9]
   OR

2. Q2

   1. a)

      State Boyle’s law and Charle’s law and derive an equation of the state for a perfect gas?

      Also asked:Nov 2023

      [8]
   2. b)

      A system at 500 K receives 7200 KJ/min from a source at 1000 K. The temperature of atmosphere is 300 K. Assuming that the temperature of system and source remain constant during heat transfer, Determine: i) The entropy produced during heat transfer. ii) The decrease in available energy after heat transfer.

      Also asked:Nov 2023

      [9]

3. Q3

   1. a)

      Explain the constructional details & working of Separating & Throttling calorimeter?

      Also asked:Nov 2025 ·Nov 2023

      [10]
   2. b)

      Explain the following terms: (i) Saturated steam,(ii) Dry saturated steam, (iii) Wet steam, (iv) superheated steam, (v) Dryness fraction of steam,(vi) Specific volume of steam, and (vii) Saturated water. 2

      Also asked:Nov 2023

      [8]
   OR

4. Q4

   1. a)

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

      [12]
   2. b)

      Find the external work done during evaporation, internal latent enthalpy and internal energy per kg of steam at a pressure of 15 bar (1,500 kPa) when the steam is i) 0.9 dry,and ii) dry saturated

      [6]

5. Q5

   1. a)

      Describe with the help of neat sketch (any one) the following calorimeters used for the determination of heating values i) Bomb Calorimeter ii) Junker gas calorimeter

      [11]
   2. b)

      What do you mean by Stochiometric Air Fuel ratio (A/F ratio) and explain the advantages/disadvantages of excess air supplied for the combustion?

      [6]
   OR

6. Q6

   1. a)

      What are the advantages of using Liquid fuels over Soild fuels? List out minimum six advantages with justification?

      [6]
   2. b)

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

      [11]

7. Q7

   1. a)

      What is the function of Boiler Mountings? Explain with neat sketches any three of the mountings?

      [8]
   2. b)

      A steam generator evaporates 18000 Kg/hr of steam at 12.5 bar and a quality of 0.97 from feed water at 105 ° C, when coal is fired at the rate of 2040 Kg/hr. If the HCV of the coal is 27400 KJ/Kg, Determine: i) The heat rate of boiler in KJ/Hr; ii) The Equivalent Evaporation; iii) The thermal effciency of the Boiler.

      [10]
   OR

8. Q8

   1. a)

      What do you mean by Boiler Draught and how are they classified. Enumerate the advantages of Mechanical Draught?

      [6]
   2. b)

      A steam generator delivers steam at 100 bar,500°C (Enthalpy, h=3373.7KJ/Kg). The feed water inlet temperature is 160°C (h=677 KJ/ Kg). The enthalpies of saturated liquid and saturated vapour at 100 bar are 1407.65 KJ/Kg and 2724.7 KJ/Kg respectively. The steam generation rate is 100000 Kg/hr and the steam generator efficiency is 88%. Estimate: i) The fuel burning rate in Kg/hr, if the calorific value of fuel is 21 MJ/Kg; ii) The percentage of total heat absorbed in the economizer, evaporator and superheater. Assume that only latent heat is absorbed in the Evaporator (Boiler drum) and neglect any pressure drop. 

      [12]