A detailed review on the role of critical heat flux in micro-channel dryout phenomena and strategies for heat transfer enhancement

The study of mini/micro-channel flow boiling is increasingly crucial due to the rising demands for effective thermal management devices and systems. While two-phase flow boiling offers significantly higher heat transfer coefficients compared to that of single-phase flow, it also introduces challenges such as Critical Heat Flux (CHF) limitations and dryout phenomena, which can impede system performance. This review thoroughly examines the mechanisms leading to refrigerant dryout in mini/micro-channel, exploring its onset point, experimental testing methods, and the theoretical models that describe its occurrence. Key techniques for enhancing CHF, preventing dryout, and improving the heat transfer coefficient are discussed, including advanced geometric designs, micro/nano-scale surface modifications, and nanoparticle-induced fluids. Additionally, this paper critically assesses the prediction accuracy of empirical CHF correlations through a comparative analysis using Mean Absolute Error (MAE), and Mean Error (ME) metrics against experimental data. This detailed review provides insights into the current state of research on mini/micro-channel flow boiling, offering both theoretical perspectives and practical solutions for enhancing heat transfer through the prevention or delay of dryout in these systems.