Heat transfer characteristics of one side heated vertical rectangular channel applied as vessel cooling system of VHTR

Abstract

A Very High Temperature Reactor (VHTR) is a next generation nuclear reactor system. From a view point of safety characteristic, a passive cooling system should be designed for the VHTR as a best way of a reactor vessel cooling system (VCS). Therefore, a gas cooling system with natural circulation is considered as a candidate for the VCS of the VHTR. Japan Atomic Energy Agency (JAEA) is advancing a technological development of the VHTR using the HTTR and is now pursuing design and development of commercial systems such as the 300MWe gas turbine high temperature reactor (Gas Turbine High Temperature Reactor 300 for Cogeneration, GTHTR300C). The objective of this study is to investigate heat transfer characteristics of natural convection in a vertical rectangular channel inserting porous materials with high porosity. It is also to examine heat transfer characteristics of natural circulation in one side heated vertical rectangular channel in order to apply to the passive cooling system of the VCS of the VHTR. This paper describes the heat transfer coefficient and the amount of removed heat in the proposed channel. To enhance heat transfer, a porous material was inserted into the vertical channel with high porosity. From the analytical results, it was found that the amount of removed heat by this method was larger than that of the channel without the porous material.

Keywords

• natural circulation
• vessel cooling system
• vhtr
• vertical rectangular channel
• porous material