RU96111551A - METHOD FOR DETERMINING TEMPERATURES OF FUEL ASSEMBLIES OF A NUCLEAR REACTOR - Google Patents

Claims (1)

A method for determining the temperatures of fuel rods of a fuel assembly of a nuclear reactor, including the use of an assembly model drawn from real fuel rods without heat generation or their layouts, and a replaceable layout with a heat source replaced by a replaceable layout of each fuel rod or its layout sequentially, as well as measuring the temperature field of the assembly after each change heat release, while the interchangeable layout is made of a material with thermal conductivity much lower than the thermal conductivity of the coolant, the heat source is point or linear, they are pressed onto the surface of the interchangeable layout and move it, then the interchangeable layout is replaced with a real fuel rod and heat dissipation is created in it, similar to the real one, its surface is isolated, except for the part where the heat sink is created, and the position of this drain is changed, characterized in that, with In order to increase the accuracy of temperature determination, on the assembly model, the temperature sensor is moved from the source downstream of the coolant to the boundary of the sensor sensitivity zone, this distance is measured to determine the temperature effects on in the interval outside the sensitivity zone of the sensor, the axial and lateral coolant flow rates in the inter-channel channel split cells and the temperature difference of the surface area of the fuel element layouts and the coolant temperature at the inlet of the assembly, for layers starting from 1 layer outside the sensitivity zone, are measured at the boundary of the sensitivity zone (i = n + 1), determine the corrected temperature difference between the sites for partitioning the surface of the fuel element mock-ups and the temperature of the coolant at the inlet of the assembly from the action of the source located in loe in according to the formula

after which, to find the desired temperatures, they solve a system of equations similar to that recorded for the n + 1 layer

despite the fact that, starting from the layer i = n + 2, the temperature component (determined by the third term on the right side of the first equation of the above system of equations) will consist of two components: the first, due to the action of sources in the in layer and determined similarly to the layer i-1, and the second, due to the action of sources in the in-1 layer, to determine which the system of equations of intercellular exchange in the fuel assembly is solved, in which the initial temperature values are temperatures Δt $\genfrac{}{}{0ex}{}{\text{core}}{\text{st2-vkh}}$ for the previous i-1 layer.