Numerical Investigation of Miniature Ejector Refrigeration System Embedded with a Capillary Pump Loop

Area of Science:

• Thermodynamics
• Fluid Dynamics
• Mechanical Engineering

Background:

• Miniature steam ejector refrigeration systems with capillary pump loops offer compact solutions for electronics cooling.
• Optimizing ejector geometry is crucial for enhancing system performance and efficiency.

Purpose of the Study:

• To investigate the impact of geometric parameters on miniature steam ejector performance using computational fluid dynamics (CFD).
• To identify optimal design parameters for effective electronics cooling applications.

Main Methods:

• Computational Fluid Dynamics (CFD) simulations were used to analyze ejector performance.
• Key parameters studied include area ratio, constant-area section length, and nozzle exit position (NXP).

Main Results:

• Ejector performance is highly sensitive to the area ratio of the constant-area mixing section to the nozzle throat.
• An area ratio below 16 is recommended for primary flow temperatures of 60 °C for practical applications.
• Nozzle exit position (NXP) significantly influences internal flow phenomena, and constant-area section length affects critical back pressure more than entrainment ratio.

Conclusions:

• The study provides crucial insights for designing miniature steam ejectors for electronics cooling.
• Optimal geometric configurations, particularly area ratio and NXP, are essential for efficient operation.