Evaluation of Radiant Heat Transfer Influence on the Temperature Field of Fuel Element Microcell of Pressurized Water-Cooled Nuclear Reactor

Abstract

Optimization of the core composition of the pressurized water reactors is associated with the calculation of the temperature fields of heat exchange microcells containing separate fuel elements. Taking into account the radiation-conductive heat transfer inside the fuel element is based on the statement that the helium gap between the column of fuel pellets and the wall of the fuel element has the properties of a black body. This is not true as helium is a monatomic gas, it neither absorbs nor emits, i.e. transparent to heat radiation. The article substantiates the physical and mathematical model of a microcell of a fuel element of a pressurized water-cooled nuclear reactor, taking into account radiation heat transfer. The model takes into account that helium is transparent to thermal radiation, and the fuel element is cooled by a flow-through system of the coolant. The implementation of the model is carried out analytically using the Karman-Pohlhausen integral relations method. The temperature fields of the column of fuel pellets and the coolant channel are calculated, the temperatures of the side surfaces of the cell are determined, and the effect of radiation heat transfer on the temperature distribution in the cell is estimated.

Keywords

• микроячейка твэла
• температурное поле
• метод кармана-польгаузена
• сложный кондуктивно-радиационный теплообмен
• среднемассовая температура теплоносителя