Safe self-reinforcing pressure vessel

Abstract

The present invention relates to a safe autofrettaged pressure vessel for improving the safety and bearing capability of the vessel and overcoming the technical problem such as unsafety which maybe caused by complex or imprecise calculation of the design of the prior art. The essential points of the technical scheme of the safe autofrettaged pressure vessel are as follows: the depth of a plastic area is calculated according to a formula: k<2>lnk2<j> - k<2> - k2<j> + 2=0, in order to ensure that reverse yield cannot be generated; the bearing capability is calculated according to the graphic formula: P / sigma y =(k<2>-1) / k<2> or P / sigma y =2*(k<2>-1) / (3<1 / 2>*k<2>), in order to ensure Sigma ej <= Sigma y and Sigma ei <= Sigma y, wherein, k is a ratio between external and internal radiuses of the safe autofrettaged pressure vessel; k<j> is a radio between the radius of an elastic-plastic interface and the internal radius; sigma y is a yield strength of the material; p is an internal pressure borne by the vessel; pe is the maximum elastic bearing capability of a non-autofrettaged vessel; Sigma ej is an equivalent stress of a total stress at the elastic-plastic interface; Sigma ei is the equivalent stress of the total stress at the inner wall surface. When k is less than a value determined by a formula of (k<2> / (k<2>-1))*lnk=1, no matter how large the k<j> is, the container cannot generate reverse yield after autofrettaged pressure is released, and at the moment, the maximum bearing capability of the autofrettaged vessel can reach the full yield pressure, namely the formula of p / sigma y =lnk or p / sigma y =(2 / (3<1 / 2>))*lnk.

Description

technical field [0001] The invention relates to a safe self-strengthening pressure vessel, which belongs to the fields of mechanical science and technology, chemical industry and the like. Background technique [0002] Pressure vessels are special equipment widely used in many industrial sectors, such as machinery, chemical industry, pharmaceuticals, energy, materials, food, metallurgy, petroleum, construction, aviation, aerospace, weapons and other departments. Self-strengthening technology is an important and effective means to improve the carrying capacity and safety of pressure vessels. The self-reinforcement technology of the pressure vessel is to pressurize it before operation (the pressure generally exceeds the operating pressure), so that the inner layer of the cylinder yields, produces plastic deformation, and forms a plastic zone, while the outer layer is still in an elastic state. Release the pressure after maintaining the pressure for a period of time. After th...

AI Technical Summary

Problems solved by technology

These methods are either too rough (such as the diagram method and estimation method) and cannot reflect the essence of the problem; or are too cumbersome (such as the trial and error method) and cannot reflect the essence of the problem

And it cannot overcome some disadvantages, such as the reverse yield problem, that is, after the pressure applied during the self-reinforcing treatment is removed, the inner layer may produce secondary compression yield due to excessive compression

this is very unfavorable

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