Unformatted text preview: MEEN 315 Assignment 14 1. An inventor has developed a system that undergoes a cycle while receiving eenrgy from a reservoir at 1000°C and discharges energy to another reservoir at 300°C. A thermal efficiency of 65% is claimed for the cycle. Is this claim possible? Explain. 2. A patent application describes a refrigerator that maintains a refrigerated space at 20°F while operating within the surroundings at 75°F. The coefficient of performance is listed as 9.0. Is this coefficient of performance feasible? Discuss your claim. 3. A heat pump driven by a 1 kW electric motor provides heating for a building whose interior is to be kept at 20°C. On a day when the outside temperature is 0°C and energy is lost through the walls and roof at a rate of 60,000 kJ/h, would the heat pump suffice? Explain. 4. At steady state, a power cycle having a thermal efficiency of 38% generates 100 MW of electricity while discharging energy by heat transfer to cooling water at an average temperarture of 21°C. The average temperature of the steam passing through the boiler is 482°C. Deterrmine the rate at which energy is discharged to the cooling water in MW. 5. Explain in your own words why it is impossible to violate the Kelvin statement. What factors, if any, make violation of this statement impossible. Be thorough in your explanation. Due: Wednesday 07/14/10. 10:00 am ...
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- Summer '07
- Thermal efficiency, heat pump suffice, kW electric motor