Coupled simulation of the combustion and fluid heating of a 300 MW supercritical CO₂ boiler

This paper presents a numerical simulation of the coupled heat transfer between combustion and fluid heating of a 300 MW supercritical CO₂ boiler. The results show that there are two peak temperature zones on each wall of the spiral wall heater, whose maximum temperature is about 900 K. The maximum wall temperature of wall re-heater is about 35 K lower than that of the spiral wall heater. Arranging a wall re-heater at the upper part of the furnace is beneficial to avoiding the overheating of tube walls. The heat transfer coefficients change mildly both in the spiral wall heater and the wall re-heater, which are different from those in traditional stream boilers. The heat transfer coefficient increases with the increase of S-CO₂ fluid temperature, mainly because of the increasing of thermal conductivity due to temperature rise. The detailed results of this work are beneficial to a full understanding of the heat transfer process and optimizing design of a 300 MW S-CO₂ boiler.