A Thin Rod Narrow Gap Wall Temperature Measuring Device Used in Sports Conditions

Abstract

The invention discloses a thin rod narrow gap wall temperature measuring device under the condition of motion, which comprises a heating element tube, at least one armored thermocouple, and at least A temperature measuring hole, the compensation wire of the armored thermocouple passes through the heating element tube and extends outward, and the outer wall of each compensation wire of the armored thermocouple is wrapped with high-temperature insulating coating and high-temperature insulating tape in turn, and the inside of the heating element tube Filled with high temperature insulating silicone. Through the above technical solution, the wall temperature at different positions of each heating element tube of the high-temperature thin rod bundle narrow gap fuel assembly can be accurately measured under the condition of motion, and the armored thermocouple will not fall off or the insulation will fail, because the temperature measuring part is in the rod bundle The temperature measurement inside the heating element tube will not interfere with the flow field and temperature field near the heating element tube, and the thermal performance parameters such as the heat transfer coefficient and critical heat flux density of the fuel assembly can be accurately obtained by carrying out the heat transfer experiment of the fuel assembly under moving conditions.

Description

technical field [0001] The invention relates to the technical field of thermal-hydraulic research of reactors, in particular to a thin-rod narrow-gap wall temperature measuring device under motion conditions. Background technique [0002] The thin rod bundle fuel assembly is a new type of advanced core assembly. The design of the fuel assembly reduces the volume of the reactor core by using thin fuel element rods and reducing the distance between the fuel element rods, which greatly improves the power density and fuel consumption of the core. consumption depth. Floating nuclear power plants, marine nuclear power and other reactor core structures can use thin rod bundle structure fuel assemblies, but these nuclear power plants will be affected by ocean motion conditions during operation, and the external force field generated by motion conditions will change the inlet and outlet of coolant channels The effective height difference and acceleration field can change the charact...

AI Technical Summary

Problems solved by technology

In view of the particularity of the structure of the existing rod bundle fuel assemblies and the complexity of the component flow field and temperature field under motion conditions, which leads to the difficulty in obtaining thermal parameters such as the wall temperature of the fuel assembly, the applicant simulated the rod bundle fuel assembly When carrying out the experimental research on heat transfer characteristics, the metal round tube is used as the heating element tube, and at least one temperature measuring hole is set in the heating element tube, and the armored thermocouple is placed in the temperature measuring hole after passing through the heating element tube. Inside, the outer wall of the compensation wire of the armored thermocouple is wrapped with a high-temperature insulating layer and a high-temperature insulating tape in sequence. By filling the heating element tube with high-temperature insulating silica gel, the armored thermocouple and the heating element tube are combined into a whole. After the armored thermocouple is installed, a plurality of heating element tubes are welded into a thin rod bundle fuel assembly to determine the temperature measurement point, and then the temperature measurement hole is opened at the temperature measurement point, and then the temperature starts from the inside of the heating element tube. Detection, to achieve accurate measurement of the temperature of the local wall surface of the heating element tube by the armored thermocouple in the moving state; among them, the heating element tube needs to be energized to generate heat in the heat transfer experiment of the fuel assembly, and the shell of the armored thermocouple is usually made of stainless steel Material, thin rod bundle simulates the internal and external gaps of the element rods of the fuel assembly are very small. When the heating element tube is in motion, the armored thermocouple shell is easy to contact with the inner wall of the heating element tube and become charged. Once the armored thermocouple shell Electric conduction cannot guarantee the accuracy of thermocouple measurement. For this, the applicant opened a temperature measurement hole on the outer wall of the heating element tube, and the end part of the armored thermocouple is placed in the temperature measurement hole and protrudes from the temperature measurement hole. The innermost part can not only fix the armored thermocouple on the inner wall of the heating element tube to realize the positioning of the armored thermocouple, but also prevent the temperature measurement component from interfering with the flow field and temperature field of the external flowing medium of the heating element tube , and finally realize the accurate measurement of the wall temperature at different positions of the heating element tube in the heat transfer experiment of the fuel assembly

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