RT info:eu-repo/semantics/article
T1 Thermal-hydraulic performance assessment of a micro shell-and-tube heat exchanger operating under part-load conditions in the NET Power cycle recuperator
A1 Velázquez Palencia, Iván
A1 Demeyer, Frederiek
A1 Reyes Serrano, Miriam
K1 Net Power cycle
K1 Oxy-combustion
K1 Microtube heat exchanger
K1 Supercritical carbon dioxide
K1 Heat transfer
K1 33 Ciencias Tecnológicas
AB This paper numerically investigates the thermal-hydraulic performance of a micro shell-and-tube heat exchanger(MSTHE) for application in the thermal recuperator of the innovative oxy-combustion-based NET Power cycle,operating under cycle-relevant part-load conditions. The aim is to support the technological transition from theestablished printed circuit heat exchangers (PCHE) to MSTHE, which offer a lower inertia, cost-effective, andmaintenance-friendly high-performance alternative. To this end, a thermal-hydraulic computational model of theMSTHE was developed, capable of capturing the rapid variation of the supercritical CO2 (scCO2) properties andthe partial filmwise condensation of the turbine exhaust gases. Results show that the MSTHE must contain atleast 60,000 tubes so that the pressure drop on the tube-side is lower than 1 bar at nominal conditions. TheMSTHE effectiveness decreases from 89.2% to 65.1% as the cycle load is reduced from 100% to 20%. The overallheat transfer coefficient decreases gradually between 100% and 40% cycle load, drops sharply between 40% and30%, and then stabilizes between 30% and 20% cycle load. This stabilization is attributed to the abrupt localincrease of the heat capacity on the scCO2-side during the pseudo-critical phase transition, which also enhanceslocal condensation heat release and thickens the condensate film on the shell-side. However, it was found thatthis phenomenon induces strong axial temperature gradients that may induce thermal stresses, representing atrade-off to the proposed compact design. While the floating microtube bundle of MSTHEs can accommodatethese thermal stresses, the rigid compact block structure of PCHE is more prone to damage, revealing an addi-tional key advantage of MSTHEs.
PB Elsevier
SN 0017-9310
YR 2026
FD 2026
LK https://uvadoc.uva.es/handle/10324/82679
UL https://uvadoc.uva.es/handle/10324/82679
LA eng
NO International Journal of Heat and Mass Transfer, 2026, vol. 260, p. 128419
NO Producción Científica
DS UVaDOC
RD 04-mar-2026