Stirling Refrigerating Machine Modeling Using Schmidt and Finite Physical Dimensions Thermodynamic Models: A...

Area of Science:

• Thermodynamics
• Refrigeration Engineering
• Energy Systems

Background:

• Stirling refrigeration machines are vital for cooling applications.
• Accurate thermodynamic modeling is crucial for optimizing performance.
• Irreversibilities in heat exchangers and regeneration significantly impact efficiency.

Purpose of the Study:

• To demonstrate the efficacy of two simplified thermodynamic models in predicting refrigerating machine behavior.
• To analyze irreversibilities in a beta-type Stirling refrigeration machine.
• To validate a proposed finite physical dimensions thermodynamics (FPDT) model.

Main Methods:

• Application of the finite physical dimensions thermodynamics (FPDT) method.
• 0-D modeling using the Schmidt model with imperfect regeneration.
• Inclusion of irreversibility from imperfect regeneration and finite temperature differences.
• Exergy balance analysis of the Stirling refrigerator.

Main Results:

• The regenerator exhibits greater irreversibility than the heat exchangers.
• Exchanged energies are expressed using practical engineering parameters.
• The FPDT model shows good agreement with experimental results.
• Validation of the FPDT model for functional and constructive parameters.

Conclusions:

• Simplified thermodynamic models can effectively indicate refrigerating machine behavior.
• The FPDT model provides a validated approach for analyzing Stirling refrigeration machines.
• Understanding and quantifying irreversibilities is key to improving refrigeration efficiency.