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Maximum efficiency of absorption refrigerators at arbitrary cooling power.

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This study reveals that the efficiency of absorption refrigerators significantly increases when their cooling power is slightly reduced from maximum. This finding applies to low-dissipation refrigerators in most practical scenarios.

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Area of Science:

  • Thermodynamics
  • Refrigeration Technology

Background:

  • Absorption refrigerators integrate heat engines and refrigerators.
  • Carnot-type systems define theoretical efficiency limits.

Purpose of the Study:

  • To derive the maximum efficiency at a given power (MEGP) for absorption refrigerators.
  • To analyze the relationship between cooling power and efficiency in these systems.

Main Methods:

  • Theoretical derivation of MEGP for combined engine-refrigerator systems.
  • Analysis of low-dissipation (LD) absorption refrigerators as a specific case.

Main Results:

  • MEGP of absorption refrigerators is the product of internal engine and refrigerator MEGPs.
  • Cooling power is limited by both internal engine and refrigerator power.
  • Efficiency increases non-linearly with decreased power, except in specific diverging power ratio cases.

Conclusions:

  • Efficiency of LD absorption refrigerators significantly improves with a slight decrease in cooling power from its maximum.
  • The findings provide bounds for MEGP in LD absorption refrigerators.