Study of Heat Transfer for CO2 Flow Boiling in Horizontal Small Diameter Tubes

Study of CO₂ in-tube flow boiling heat transfer character and precise prediction of its heat transfer coefficient is essential for the design of a compact and efficient evaporator. Several correlations for flow boiling heat transfer of CO₂ published were discussed in this paper and compared with available experimental results in the literature. The effect of mass velocity, saturation temperature, tube diameter on heat transfer coefficient is discussed. Deviation between the predicted values and experimental values shows that Yoon2004 and Jung correlation has relatively high prediction precision before dryout happens. And all correlations for post-dryout heat transfer need to be improved for the predicted values have large deviation.