Computational assessment for local and total heat transfer characteristics of supercritical CO2 in horizontal heated Micro-Channel

Supercritical CO2 power cycles have a wide range of possible uses in energy efficiency structures, where one of the key concerns is the supercritical CO2 heat transfer. This paper used an assessment method for studying local heat transfer performance(HTP) by combining the Richardson number Ri and effective thermal resistance. A performance evaluation factor for total HTP was developed and used. The influence of various working conditions on the HTP were analyzed by utilizing the developed method. The findings showed that larger mass flux, smaller inlet temperature, smaller heat flux and inlet pressure can result in better local HTP. The smaller inlet temperature and heat flux can achieve better total HTP at the same flow resistance. Compared with viscosity entropy generation rate, thermal entropy generation rate has larger effect on the irreversibility. This paper could offer a direction in the optimization of the heat exchangers.