Thermal-Hydraulic Analysis of Heat Pipe Heat Exchanger in a Nuclear Power Plant Using CFD Method

Using heat pipe-cooled micro-reactors in power plants is one of the newest technologies in small power plants. In these power plants, heat is taken from the reactor by several heat pipes and transferred to the working fluid in the main heat exchanger of the power plant. The purpose of this study is the design and thermal-hydraulic analysis of heat pipes and the main heat exchanger of the power plant. The reactor's thermal power is ۵ MW and its heat is transferred to carbon dioxide as the working fluid in the heat exchanger by ۱۹۲ potassium heat pipes. The Computational Fluid Dynamics (CFD) method is used for thermal-hydraulic analysis. ANSYS-CFX code, which is a high-performance and reliable tool, is also used for simulation. The results show that the maximum temperature of potassium vapor inside the hottest heat pipe is ۹۱۳.۶ °C. Also, the minimum temperature of the liquid inside the wick structure of this heat pipe is ۹۱۰.۰۱ °C. Also, the average temperature and pressure of carbon dioxide in the outlet section of the heat exchanger are ۶۴۹.۵ °C and ۱۴.۱۳۴۲۵ MPa under normal operating conditions. In this situation, carbon dioxide is in a supercritical state and it is possible to use it in the power plant gas cycle.

Keywords:

potassium Heat pipe , heat exchanger , CFD , Thermal-Hydraulic Simulation , Ansys-CFX , Supercritical carbon dioxide