Nanoscale surface morphology modifications for next-generation supercritical CO2 heat exchangers: Review and perspective
Year: 2025
Type: article
Abstract: Carbon nanotube (CNT) pin fin arrays, CNT, or nanoparticle coating have emerged in recent decades as novel techniques for enhancing heat transfer and reducing drag. In this paper, the suitability of these techniques is reviewed specifically for heat transfer enhancement and drag reduction in the gas side of supercritical carbon dioxide (SCO2) counterflow tube-in-tube or plate type heat exchangers for applications in CO2 refrigeration systems. The methodology and the applicability of various approaches for predicting the heat transfer rates and the frictional pressure drop associated with flow over a nanocoated surface have been reviewed. Findings from both experimental and numerical studies highlight critical limitations, including a lack of fundamental knowledge about flow over superhydrophobic surfaces and the absence of experimental data for crucial parameters such as temperature jump at the wall, velocity and temperature shifts, and the Reynolds analogy factor for nanotube or nanoparticle coatings in turbulent flow regimes. These limitations significantly hamper the predictive capabilities of both single-scale and multi-scale models for frictional pressure drops and heat transfer coefficients. To enhance the accuracy of these models, it is essential to consider surface parameters such as arithmetic mean roughness ( Ra ), root-mean-square roughness ( Rq ), effective slope ( Es ), skewness ( Sk ), and kurtosis ( ku ).
Authors: Wenguang Li, Sambhaji Kadam, Jian Song, Surya Narayan, Christos N. Markides, Zhibin Yu
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
Estimated APC paid: $3,920
Awards: GREEN-ICEs: Generation of REfrigerated ENergy Integrated with Cold Energy storage, G2256386489, An Adsorption-Compression Cold Thermal Energy Storage System (ACCESS), Thermally Driven Heat Pump Based on an Integrated Thermodynamic Cycle for Low Carbon Domestic Heating (Therma-Pump), Flexible Air Source Heat pump for domestic heating decarbonisation (FASHION), Supergen Storage Network Plus 2019, Geothermally Sourced Combined Power and Freshwater Generation for Eastern Africa (Combi-Gen), BOiliNg flows in SmAll and mIcrochannels (BONSAI): From Fundamentals to Design, Integrated Development of Low-Carbon Energy Systems (IDLES): A Whole-System Paradigm for Creating a National Strategy, SaFEGround - Sustainable, Flexible and Efficient Ground-source heating and cooling systems, Dynamic Organic Rankine Cycle for Recovering Industrial Waste Heat, Decentralised water technologies
OpenAlex ID: W4413423222