Natural convective heat transfer characteristics of one side heated vertical rectangular channel

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). Thus, a gas cooling system with natural circulation is considered as a candidate for the VCS of the VHTR. The objective of this study is to investigate not only heat transfer and fluid flow characteristics of natural convection but also effectiveness of thermal radiation in a one side heated vertical rectangular channel. It is also to evaluate an amount of transferred heat from heated side wall in order to apply to the passive cooling system of the VHTR-VCS. The final goal of this study is to develop a numerical model which simulated the passive VCS for the VHTR such as the 300MWe gas turbine high temperature reactor (Gas Turbine High Temperature Reactor 300 for Cogeneration, GTHTR300C). This paper describes the heat transfer and fluid flow characteristics from the results obtained by the experiment and numerical analysis in the one side heated vertical rectangular channel. From the numerical results, it was found that it is important to obtain the amount of heat removed by the other walls of rectangular channel. (author)