Atmospheric air enters the air compressor of a simple combined gas-steam power system at 14.7 psia and 80°F. The air compressor's compression ratio is 10, the gas cycle's maximum temperature is 2100°F, and the air compressor and turbine have an isentropic efficiency of 90 percent. The gas leaves the heat exchanger 50°F hotter than the saturation temperature of the steam in the heat exchanger. The steam pressure in the heat exchanger is 800 psia, and the steam leaves the heat exchanger at 600°F. The steam- condenser pressure is 5 psia, and the isentropic efficiency of the steam turbine is 92 percent. Determine the overall thermal efficiency of this combined cycle. For air, use constant specific heats at room temperature. Use steam tables and the table containing the ideal- gas specific heats of various common gases. The overall thermal efficiency of this combined cycle is %.

Atmospheric air enters the air compressor of a simple combined gas-steam power system at 14.7 psia and 80°F. The air compressor's compression ratio is 10, the gas cycle's maximum temperature is 2100°F, and the air compressor and turbine have an isentropic efficiency of 90 percent. The gas leaves the heat exchanger 50°F hotter than the saturation temperature of the steam in the heat exchanger. The steam pressure in the heat exchanger is 800 psia, and the steam leaves the heat exchanger at 600°F. The steam- condenser pressure is 5 psia, and the isentropic efficiency of the steam turbine is 92 percent. Determine the overall thermal efficiency of this combined cycle. For air, use constant specific heats at room temperature. Use steam tables and the table containing the ideal- gas specific heats of various common gases. The overall thermal efficiency of this combined cycle is %.

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter28: Special Refrigeration Applications

Section: Chapter Questions

Problem 15RQ: Why is two-stage compression popular for extra-low-temperature refrigeration systems?

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