Corresponding

Corresponding

Concepts • Correct use of property tables

• Understanding and application of the ideal gas equation.

• Understanding and application of the First Law.

• Understanding and application of types of work, and how they contribute to the Energy Balance for open systems

Comments • Take a look at the examples for steady flow devices first. Go through them and try to understand the use of the formulas. Those will be posted by Saturday night. Until then attempt the first two questions

• Print out the formula sheet and use it for this assignment. Try to understand what the formulas stand for, and how they work.

1) Open System Analysis

Air at 80 kPa and 127oC enters an adiabatic diffuser steadily at a rate of 6000 kg/hr and leaves at 100 kPa. The velocity of the air stream is decreased from 230 m/s to 30 m/s as it passes through the diffuser. Find (a) the exit temperature of the air and (b) the exit area of the diffuser.

[Answers: 425.8 K, 0.0678 m2]

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2) Air is compressed from 100 kPa and 22oC to a pressure of 1MPa while being cooled at a rate of 16 kJ/kg by circulating water through the compressor casing. The volume flow rate of the air at the inlet conditions is 150 m3/min, and the power input to the compressor is 500 kW. Determine (a) the mass flow rate of the air, and (b) the temperature at the compressor exit. [Answers: 2.95 kg/s, 174oC]