IIT Delhi Previous Year Question Papers

I need the ME Energy Conversion exam paper issued by Indian Institute of Technology, Delhi for that I need your help also?

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I will get the ME Energy Conversion exam paper issued by Indian Institute of Technology, Delhi so that you can solve easily.

Here is the paper
1. An enthusiastic student of MEL241 decides to make the desert cooler effective in monsoon by adding a refrigerating system with its evaporator coil submerged in the sump of the cooler. On a hot, humid day with outdoor temperature 38oC and relative humidity 70%, he designs that the room should be maintained at 27 oC and 50% relative humidity. If the air entering the room is at saturated condition,

a) Determine the temperature at which air should enter the room, if the room load is 1.4 kW sensible and 0.6 kW latent heat.

b) Show the process on a schematic and psychrometric diagram.

c) What would you call the process that the air goes through in the modified cooler?
Describe the phenomenon.

d) Find the airflow rate through the cooler in kg/s, cooling capacity of the refrigerating coil in TR.

e) If the COP of the refrigeration cycle is half of the COP of the Carnot cycle whose evaporator and condenser coils work with a temperature difference of 10oC between the refrigerant and the corresponding surroundings, find the additional power input the modified cooler now takes owing to the addition of the refrigeration system.

f) Is this process likely to be more energy intensive or less, compared to that in conventional air-conditioners for the same conditions of room and outdoor? Give reasons for your answer.

2. Another student of MEL241, who decides not to waste exergy by throttling the refrigerant in an expansion device, modifies her domestic refrigerator. The refrigerator can be assumed originally to operate on an ideal refrigeration cycle of R134a. She decides to replace the throttling device with an isentropic turbine. The refrigeration cycle has an evaporator temperature of -25oC and condenser saturation temperature is 45oC, in both original and modified cycles. The original refrigeration system has a cooling capacity of 300 W, and the same mass flow rate of refrigerant can be assumed to prevail in the modified system as well. Compute:

a) Power output of the isentropic turbine.

b) Refrigerating capacity and COP of the modified cycle. Compare the COP with that of the original cycle.

c) Show the system on a schematic diagram and the processes on the sketch of a p-h diagram, carefully labelling all relevant parts and processes. Tabulate all relevant properties at the state points of the cycle.

ME Energy Conversion exam paper




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