Method for quickly evaluating leakage rate of multi-layer pressure-bearing shell based on flow conservation theorem

Abstract

The invention discloses a method for quickly evaluating the leakage rate of a multilayer pressure-bearing shell based on a flow conservation theorem, and belongs to the field of evaluation of the leakage rate of a damaged pressure-bearing structure. The main principle of the method is as follows: based on an ideal elastic-plastic constitutive, considering the cracking process and the failure mechanism of the multilayer pressure-bearing shell, quickly estimating the circumferential strain distribution of each layer of shell, and estimating the circumferential crack opening on the basis of exceeding the tensile limit strain of the material; and based on the flow conservation theorem, calculating the overall leakage rate of the shell structure with inconsistent cracking degree of each layer.According to the method, the cracking condition of the multi-layer pressure-bearing shell under the action of the internal pressure of a serious accident can be estimated, and the gas leakage rate ofthe multi-layer shell walls with different cracking degrees can be quickly estimated.

Description

technical field [0001] The invention belongs to the field of leakage rate assessment of damaged pressure bearing structures, and in particular relates to a rapid assessment method for the leakage rate of multilayer pressure bearing shells based on the principle of flow conservation. Background technique [0002] Pressure-bearing reinforced concrete structures represented by nuclear power containment vessels are widely used in industrial buildings. Under normal conditions, the internal pressure working value is not high, slightly higher than the ambient pressure outside the shell structure, so as to avoid external factors interfering with the internal working environment due to negative pressure. [0003] However, when a major accident occurs inside the shell, resulting in a substantial increase in internal pressure, the shell wall will play a key shielding role to prevent internal hazardous radiation or hazardous gases from escaping to the external environment. [0004] In ...

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Problems solved by technology

At this time, the key issue is how to quickly calculate the crack propagation and cracking degree of the multilayer shell structure under internal pressure in a severe accident, and how to calculate the leakage rate of the multilayer shell when the crack opening in the thickness direction is different. There is no means for this

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