Development Of 50 G-level Gas Flowing Tritium Calorimeter

The storage and supply system?SDS?is an important part of the fuel cycle of the fusion reactor.Its main function is to realize the rapid storage and supply of deuterium and tritium fuel.Tritium is radioactive.In order to ensure that the amount of tritium in the reactor is within the limits,it is necessary to measure the tritium inventory in the tritium bed in the SDS system.Among the tritium measurement methods in bed,the gas flowing calorimetry method is the mainstream of current research due to its advantages of safety and convenience.According to the design requirements of ITER in this paper,the tritium measurement time of the tritium storage bed is less than 24 hours and the measurement accuracy is±1%.A key factor was started,the heat transfer process of tritium decay in the bed was simulated,the design of the thin-walled concentric tubular bed structure with excellent heat transfer performance was completed,and Designed and manufactured a 50-gram gas flowing calorimeter,and examined their tritium measurement performance.The main contents of this thesis work are as follows:?1?Thermodynamic numerical analysis of thin-walled concentric tubular bed based on calorimetry of bedThe effects of structural geometry and cooling method on the heat transfer behavior have been systematically studied.CFX numerical analysis results show that the proposed model can effectively characterizes the evolution of the temperature difference of the cooling gas with time during the calorimetric process.Typically,increasing number of the U-shaped cooling tubes,thickness of the metal hydride layer and flow rate of the cooling liquid are beneficial for reducing the thermal equilibrium time.When the number of calorimeter bed cooling tubes is 12,the thickness of the metal hydride layer is 23,and the cooling gas is 20 SLMP of CO2,the thermal equilibrium time is only 4.5h.?2?Structural design of gas flowing tritium calorimeterAccording to the function of the gas flowing tritium calorimeter,it is divided into three subsystems,which are used to store tritium bed absorb/release tritium,bed tritium measurement and waste heat removal.By calculating the design margin,the main container clearance is 900ml,and the 1.67Kg pick cobalt alloy?ZrCo?can effectively store 8.4mol of T2.CAXA and Solidworks drawing software were used to construct the calorimeter structure,and the minimum allowable wall thickness of the vessel was calculated using the ASME VIII Div.1 formula under the maximum operating limit.It was found that the design wall thickness met the safety requirements.?3?Construction and performance study of 50 g-level gas flowing calorimeterThe experimental device of a gas flowing tritium calorimeter was built.The performance of the instrument was studied under the conditions of a vacuum layer pressure of 4.04×10^-6Pa,a cooling medium of helium,and a mass flow rate of 14 SLMP.The experimental results show that the gas flowing tritium calorimeter constructed above meets the requirement of±1%measurement accuracy within 24 hours of measurement time in ITER design.