Supercritical CO2/Xe mixtures demonstrate promising application potential in novel supercritical Brayton cycle power generation systems. However

the heat transfer behavior of CO2/Xe mixtures in printed circuit heat exchangers (PCHEs) has not been extensively investigated. Therefore

this study employs numerical simulation methods to analyze the flow and heat transfer characteristics

along with their underlying mechanisms

of CO2/Xe mixtures in a straight-channel PCHE under various mixing ratios (CO2/Xe: 100/0

100/10

100/20

100/30)

inlet pressures

mass flow rates

and inlet temperatures. The results indicate that under supercritical pressure conditions

the addition of Xe to CO2 generally reduces its overall heat transfer performance. As the Xe mass fraction increases

the heat transfer capacity of the mixture gradually weakens

particularly in the pseudo-critical region. However

beyond the pseudo-critical point

the incorporation of Xe contributes to enhanced heat transfer capability. With increasing operating pressure

the peak value of the local heat transfer coefficient decreases and shifts toward higher temperatures

which is primarily attributed to changes in the constant-pressure specific heat of the fluid. Increasing the mass flow rate effectively improves the heat transfer coefficient

while the influence of inlet temperature on the heat transfer coefficient is negligible. Furthermore

a heat transfer correlation for CO2/Xe mixtures is developed

with relative error (eA)

mean absolute error (eR)

and root mean square error (eS) values of 4.61%

15.45%

and 6.90%

respectively. These findings provide theoretical guidance for the design and optimization of PCHEs utilizing CO2/Xe mixtures.