1.a. Explain the concept of i) Heat Engine , ii)Heat pump and iii)Refrigerator with neat sketch and write down the expression for Efficiency or COP as applicable.

1.b A copper block of mass 1 kg at 500K is immersed in lake at 300 K till it reaches thermal equilibrium with water. Find the total i)Total heat transferred to the lake, ii) Change in entropy of Copper (Cp of copper = 0.386 kJ/kgK, Cp of water = 4.187 kJ/kgK.

2.a Explain the principle of increase of entropy and write down the formula for change in entropy for i)Reversible process ii) Irreversible process and iii) Impossible process.

2.b During a Thermodynamics cycle heat transfer during various process is : 120 kJ, -16 kJ, 48 kJ and 12 kJ. Find the net work done during the cycle.

3.a Show the following cycles with neat sketch

1.Carnot cycle on T-s diagram.

2.Otto Cycle on P-v diagram.

3.Diesel Cycle on P-v diagram.

4.Dual Cycle on P-v diagram.

5.Brayton cycle on P-v diagram.

6.Reversed cycle on P-v diagram.

3.b Find the enthalpy of 1 kg of steam at 12 bar when ,

i) Saturated liquid condition

ii) Steam is dry saturated,

iii) Steam is 22% dry

iv) steam is 50% dry

v) steam is superheated to 250°C

vi) sub-cooled to 100°C(Cp=2.25 kJ/kgK)

4.a Explain process of formation of steam on T-h diagram starting from -10°C (ice state ) to 120°C (Superheated condition) at atmospheric pressure.

4.b An engine is working on Otto cycle. The pressure and temperature at the beginning of compression stroke are 1 bar and 300K and the temperature at the end of compression stroke is 600K. if the temperature at t he end of constant volume heat addition process is 1800 K. Calculated the air standard efficiency, heat addition per kg of air and heat rejected per kg of air.

5.a Give the function and location of ant 3 of the following.

i)Super heater

ii) Air pre heater

iii) Fusible plug

iv) Water level indicator.

v) Spring loaded safety valve.

5.b 5500 kg/hr steam is produced at a pressure of 76 bar in a boiler with a dryness fraction of 0.98. The amount of coal burnt is 650 kg having C.V. of 3500kg. Determine the following

i)Boiler efficiency ii) Equivalent evaporation per kg of fuel burnt.

6.a Explain the Boiler heat balance sheet with formulas used.

6.b The boiler trial following observations are recorded mass of fuel is 1520 kg/hr. the temperature of feed water is 30°C. Dryness fraction of steam is 0.95. The pressure of steam is 8.5 bar, Coal burns per hour = 200 kg, CV of 2000 kJ/kg. The mass of flue gases is 17.73 kg/kg of coal burnt . The temperature is 330°C. The boiler room temperature is 27°C. Specific heat of the flue gases 1 kJ/kgK. Draw Boiler heat balance sheet per kg of fuel burnt and calculate the efficiency of the boiler.

7.a Define Human Comfort condition and discuss the factors affecting human comfort.

7.b Atmospheric air at 30°C. DBT and 18°C WBT is cooled to 20°C DBT without changing its moisture content. Find

i)Initial enthaply and specific humidity of air

ii)Final relative humidity of air and WBT

iii) Sensible heat removed per kg of air.

8.a Draw following processes on sketch of Pscychrometric chart

i) Sensible cooling

ii) Sensible heating

iii) Heating and Humidification

iv) Heating and Dehumidification

v) cooling and Humidification

vi) Cooling and dehumidification

8.b Moist air enters a steam heating coil at 10°C, 50% RH which is heated sensibly and leaves the coil at 30°C. The mass flow rate of the moist air is 50 kg/s. Find :

i) Sensible heat gained by air

ii) Mass flow rate of the steam in the coil if the steam enters the coil as saturated steam and the condensate leaves the coil at 85°C at atmospheric pressure.