Q. A regenerative air cooled system is used for an air plane to take 23 tons of refrigeration loads. The ambient air at pressure 0.95 bar and temperature 10°C is rammed till the pressure rises to 1.34 bar. The air bled off the main compressor at 5.12 bar is cooled by ram air in the first heat exchanger whose effectiveness is 77.6 % and 73% of enthalpy of air discharge from first heat exchanger is removed in the regenerative heat exchanger with a portion of the air bled after expansion in the cooling turbine. The cabin is maintained at a temperature of 25°C and a pressure of 1 bar. Assume the isentropic efficiency for ramming 85%, for compression 90 % and for expansion 80 %. Find: the mass of the air bled from cooling turbine to be used for regenerative cooling, Power required and COP of the system. Assume the temperature of air leaving to atmosphere from the regenerative heat exchanger as 98°C. Draw the schematic and temperature-entropy diagram of the system. Take for air Co=1 k.J/kg Y=1 4

Q. A regenerative air cooled system is used for an air plane to take 23 tons of refrigeration loads. The ambient air at pressure 0.95 bar and temperature 10°C is rammed till the pressure rises to 1.34 bar. The air bled off the main compressor at 5.12 bar is cooled by ram air in the first heat exchanger whose effectiveness is 77.6 % and 73% of enthalpy of air discharge from first heat exchanger is removed in the regenerative heat exchanger with a portion of the air bled after expansion in the cooling turbine. The cabin is maintained at a temperature of 25°C and a pressure of 1 bar. Assume the isentropic efficiency for ramming 85%, for compression 90 % and for expansion 80 %. Find: the mass of the air bled from cooling turbine to be used for regenerative cooling, Power required and COP of the system. Assume the temperature of air leaving to atmosphere from the regenerative heat exchanger as 98°C. Draw the schematic and temperature-entropy diagram of the system. Take for air Co=1 k.J/kg Y=1 4

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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