RT info:eu-repo/semantics/article
T1 Experimental investigation on heat transfer to supercritical CO2 in a microtube up to 30 MPa for application in the NET Power cycle
A1 Velázquez Palencia, Iván
A1 Cantero Sposetti, Danilo Alberto
A1 Demeyer, Frederiek
A1 Reyes Serrano, Miriam
K1 NET power cycle
K1 Oxy-combustion
K1 Compact heat exchangers
K1 Neural network
K1 Heat transfer
K1 Supercritical carbon dioxide
K1 Microtube heat exchanger
K1 33 Ciencias Tecnológicas
AB Microtube heat exchangers represent a high-performance alternative to conventional printed circuit designs forthe thermal recuperator of the innovative oxy-combustion NET Power cycle, offering potential improvements inboth system efficiency and compactness. To support this technology transition, this study presents an experi-mental investigation of heat transfer in CO2 at supercritical pressures up to 30 MPa. Experiments were conductedusing a 1700 mm long, 0.88 mm inner diameter, uniformly heated horizontal microtube designed to replicate theoperating conditions of a microtube heat exchanger. An experimental setup was built to measure local heattransfer coefficients of CO2, with a parametric analysis performed to evaluate the influence of mass flux, heatflux, inlet temperature, buoyancy, and flow acceleration. Tests were conducted at pressures of 10, 15, 20, 25 and30 MPa. Results show that the heat transfer improves with increasing mass flux. At 10 MPa, the heat transfercoefficient exhibits a peak near the pseudo-critical temperature, followed by a deterioration and subsequentrecovery. With increasing thermal input, the peak is attenuated, while heat transfer performance improves athigher pressures. Raising inlet temperatures enhances heat transfer in the thermal inflow region, reduces thepeak value at 10 MPa, and causes the heat transfer coefficients to converge across different pressures. Buoyancyeffects are most pronounced at 10 MPa and become weaker as pressure increases. Moreover, a new deep neuralnetwork model was developed to predict heat transfer coefficients, demonstrating an average deviation of 6.34%. The present study substantially expands the existing experimental database, provides new physical in-terpretations of key phenomena, and translates these findings into a predictive tool applicable to engineeringdesign
PB Elsevier
SN 1359-4311
YR 2026
FD 2026
LK https://uvadoc.uva.es/handle/10324/80694
UL https://uvadoc.uva.es/handle/10324/80694
LA eng
NO Applied Thermal Engineering, 2026, vol. 285, p. 129206
NO Producción Científica
DS UVaDOC
RD 11-ene-2026