MEEN 301 Thermodynamics Name:_-f/<:"";::' ::...:oe•••••~'7/ _

Dr.Shana Spring 2013 Date: _

1. (25 points)

A Carnot engine operates between two temperature reservoirs maintained at 200°C and 20°C,

respectively. If the desired output of the engine is 15 kW. Determine the heat transfer from the

high-temperature reservoir and the heat transfer from the low-temperature reservoir.

1

2. (25 points)

After a combustion process in a cylinder, the pressure is 1200 kPa and the temperature is

350°C. The gases are expanded to 140 kPa with a reversible adiabatic process. Calculate the

work done by the gases, assuming they can be approximated by air with constant specific heats.ort -W~

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2

3. (25 points)

A piston-cylinder device contains 0.75 kg of nitrogen gas at 140 kPa and 3rc.The gas is compressed slowly in a polytropic process during whichPV1.3= constant. The process ends when the volume is reduced by one-half.Determine the entropy change of nitrogen during this process.

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4. (25 points)

An inventor has proposed the insulated device shown which operates with H20 as the medium.

Determine T3.

"rnj= 3.03 kg/sP1=4 MPar,= 5000 C

Insulated

4