An Experimental Investigation of R600a Condensation in a Multiport Microchannel

Area of Science:

• Thermodynamics
• Heat Transfer
• Refrigeration Engineering

Background:

• Accurate heat transfer data is crucial for efficient refrigeration system design.
• R600a (isobutane) is an environmentally friendly refrigerant gaining prominence.
• Microchannel heat exchangers offer enhanced thermal performance.

Purpose of the Study:

• To determine condensation heat transfer coefficients for R600a (isobutane).
• To investigate the influence of mass flux, saturation temperature, and vapor quality.
• To analyze flow behavior within multiport microchannels.

Main Methods:

• Experimental determination of heat transfer coefficients using an aluminum multiport microchannel.
• Controlled variations in mass flux (50-98 kg/m²·s) and saturation temperatures (35-45 °C).
• Observation of flow conditions through a transparent microchannel cover.

Main Results:

• Condensation heat transfer coefficient increases with decreasing saturation temperature.
• Higher inlet vapor quality leads to improved heat transfer.
• Heat transfer coefficient increases with mass flux up to a critical point.
• Inlet vapor quality's effect becomes pronounced at lower qualities due to flow fluctuations.

Conclusions:

• R600a condensation heat transfer is sensitive to operating parameters like temperature, quality, and mass flux.
• Microchannel geometry facilitates efficient heat exchange for R600a.
• Findings provide critical data for optimizing R600a-based refrigeration systems.