Air-based refrigeration cycles operate thermodynamically on_____________________?
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Answer: E. Brayton cycle
Explanation
Air-based refrigeration systems operate thermodynamically on the reversed Brayton cycle, which is also known as the Joule cycle. This thermodynamic cycle utilizes gas compression, heat rejection, expansion, and refrigeration heat absorption in a closed loop. Using air as the working fluid requires high pressure ratios because gases do not undergo phase change within standard operating temperatures. Thermodynamic refrigeration cycles are evaluated using pressure-enthalpy and temperature-entropy diagrams to determine efficiency. The Brayton cycle forms the theoretical basis for gas turbine engines and is reversed for air-cycle cooling applications. Air refrigeration systems offer significant environmental and safety advantages because air is non-toxic, cheap, and readily available.
Option A Carnot cycle represents an idealized thermodynamic limit rather than the practical operating cycle for air refrigeration. Option B reversed Carnot cycle serves as a theoretical performance benchmark for vapor compression systems rather than gas-turbine air loops. Option C Rankine cycle governs vapor-power generation plants using condensing fluids rather than gaseous air refrigeration loops.
- Subject
- Engineering
- Category
- Mechanical Engineering
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- —
- Difficulty
- medium
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