Refrigeration cycles — reversed Joule (Brayton) identification The reversed form of the Joule (Brayton) cycle used for air refrigeration (gas-cycle refrigeration) is commonly known as:

Introduction / Context:Refrigeration cycles can be realized by reversing power cycles. When the Joule (Brayton) gas turbine cycle is run in reverse, it forms a gas-cycle refrigeration system widely known in aviation and early refrigeration history as the Bell–Coleman cycle.

Given Data / Assumptions:

• Working fluid is a gas (often air) treated approximately as ideal.
• Key components: compressor, heat exchanger(s), expander/turbine.
• Reversed operation relative to the power-producing Brayton cycle.

Concept / Approach:In the reversed Brayton (Bell–Coleman) cycle, air is compressed, rejected heat to the surroundings at high pressure, expanded in a turbine to a lower temperature, and then absorbs heat from the refrigerated space before recompression. The performance metric is the coefficient of performance based on desired cooling effect over net work input.

Step-by-Step Solution:Identify the forward power cycle: Joule/Brayton (compressor → heat addition at constant pressure → turbine → heat rejection at constant pressure).Reverse the sequence for refrigeration: compressor → reject heat → turbine expansion to produce cooling → absorb heat at low temperature.Recognize the historical name: Bell–Coleman cycle.

Verification / Alternative check:Aircraft air-cycle cooling packs use the same principle: compressed bleed air is cooled, expanded through a turbine to produce low-temperature air for cabin cooling.

Why Other Options Are Wrong:Carnot is the theoretical maximum efficiency cycle; Rankine is a vapor cycle; Stirling is an external-combustion isothermal/isochoric cycle; Gifford–McMahon is a cryogenic cooler using a displacer and valves, not the reversed Brayton arrangement.

Common Pitfalls:Confusing reversed Brayton with reversed Rankine (vapor-compression) commonly used in household refrigeration; mixing gas-cycle and vapor-cycle terminology.

Final Answer:Bell–Coleman cycle