FinalExam - 2700 K to 3000 K. We wish to determine if the...

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Spring 2006 1 ME 201 Thermodynamics Final Exam Directions: Work all three problems. The exam is open notes and open text book. All problems have equal weight. Note that you may round where appropriate to avoid interpolation. Problem 1 A more realistic model for the compression process in an internal combustion uses a polytropic process followed by an isentropic process instead of a single isentropic process. The engine operates with the following conditions: Six cylinder, four stroke engine with displacement of 2.8 liters Compression ratio: 9.065 Compression ratio for polytropic process: 3 Polytropic exponent for first compression process: 1.203 Initial air conditions: 280 K and 120 kPa Engine speed of 1300 rpm Determine a.) the air temperature at the end of both compression processes b. the heat transfer for the polytropic process b.) the engine power in kW for the two compression processes Problem 2 It has been found that microwave heating of methane gas increases its combustion temperature from
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Unformatted text preview: 2700 K to 3000 K. We wish to determine if the use of microwave heating is cost effective. Consider a power plant that is producing 1 MW of electric power as it operates with a low temperature of 290 K. The electric power sells for and costs $0.04 per kW ⋅ hr, and the heat transfer from the high temperature reservoir costs $0.01 per kW ⋅ hr. To achieve the 300 K increase in combustion temperature, 50 kW of electric power must be used. Determine (a) maximum income per year the plant can generate without the microwave heating (b) maximum income per year the plant can generate with the microwave heating Problem 3 Steam enters the compressor with isentropic efficiency 0.7626 at 50 ° C and 0.01 MPa and exits at 800 kPa. Determine a.) the ideal work input (in kJ/kg) required b.) the actual work input (in kJ/kg) required c.) the exit temperature of the steam...
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This note was uploaded on 07/25/2008 for the course ME 201 taught by Professor Somerton during the Spring '06 term at Michigan State University.

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