Work

Numerical Investigation on Heat Transfer of Supercritical CO2 in Minichannel with Fins Integrated in Sidewalls

Year: 2025

Type: article

Abstract: Gas coolers play a critical role in CO2 refrigeration and heat pump systems, where their thermohydraulic characteristics substantially influence the overall system performance. To improve the heat transfer performance of gas coolers, minichannels with aligned or offset fins integrated in the channel sidewalls are proposed to enlarge the heat transfer surface and intensify the flow turbulence. Unlike conventional refrigerants, supercritical CO2 exhibits significant variations in thermophysical properties with temperature changes, which results in distinct heat transfer behavior. Three-dimensional numerical models are therefore purposely developed by employing the Shear Stress Transport k-ω turbulent model and including the entrance region effect, NIST real-gas thermophysical properties and buoyancy effect. A constant heat flux boundary is employed on the four-side channel walls to ensure that the temperature of CO2 flowing in the channel exactly decreases from 373.15 K to 308.15 K. The results show that the fins integrated in the channel sidewalls can significantly improve the heat transfer performance, and the heat transfer coefficient significantly increases with increasing mass flux. Compared to the reference smooth channel, the heat transfer performance is enhanced by a factor of 1.85–2.15 with aligned fins and 1.44–1.61 with offset fins.

Source: Processes

DOI: 10.3390/pr13082630

Author: Lei Chai

Institution: Brunel University of London

Language: English

Topic: Heat transfer and supercritical fluids

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Climate action

Open Access status: gold

Estimated APC paid: $2,896