HW8 spring 2011

# HW8 spring 2011 - its work in(kW and its efficiency(10 pts...

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CHEG 2313 Thermo I HW#8 Spring 2011 Due Wednesday, April 6, 2011 in class. 1. One mole of an ideal gas at initial conditions T 1 = 148 ° C and V 1 = 1 m 3 undergoes an expansion to 2 kPa and 2 m 3 , followed by isothermal expansion to 1 kPa, followed a compression that decreases the volume by 25%, and finally isobaric compression back to the initial conditions. a) Sketch the process on the diagram below. (4 pts) b) Shade the area on the diagram above that represents the net amount of expansion/ compression work for this process. (2 pts) c) Is this work being done by the system or being done on the system (i.e. what is the sign of the work)? (1 pt) 2. An ideal gas at 20 bar and 400°C is being fed into an adiabatic turbine to generate electricity at a rate of 278 kmol/hr. The ideal gas will exit the turbine at 2 bar. If a real turbine operating under these conditions has an outlet temperature of 173°C, determine

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Unformatted text preview: its work in (kW) and its efficiency. (10 pts) Given: P C (ideal gas) = 32 K kmol kJ * 3. A ferrier makes a steel horseshoe by heating it to close to the melting temperature so that it can be shaped. Once the horseshoe is shaped, the ferrier hardens and sets the horseshoe by dropping it into a container of water to cool. A 1.13 kg horseshoe at 1420°C is dropped into 25 kg of water in a well-insulated container. The water is initially at 5°C. Given: C P (steel) = 0.49 K kg kJ * ; C P (water) = 4.2 K kg kJ * a) Determine final temperature of the water and the horseshoe. (4 pts) b) Determine the entropy change of the water and the horseshoe in going from their initial states to their final states. (4 pts)...
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## This note was uploaded on 04/01/2011 for the course CHEG 2313 taught by Professor Staff during the Spring '11 term at Arkansas.

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HW8 spring 2011 - its work in(kW and its efficiency(10 pts...

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