Design method of steel sleeve crack arrestor for high-grade steel gas pipeline

Abstract

The invention discloses a design method of a steel sleeve crack arrestor for a high-grade steel gas pipeline, which comprises the following steps: calculating a pressure reduction wave curve and a material resistance curve under the service condition of the pipeline according to pipeline technical indexes, and calculating the fracture speed Vf of the pipeline under the working condition through the pressure reduction wave curve and the material resistance curve; changing the fracture resistance f in the material resistance curve, and obtaining the minimum fracture speed Vmin of the pipeline inthe crack arresting process through calculation according to the tangent point of the pressure reduction wave curve and the material resistance curve; judging whether the current steel sleeve crack arrestor design method is applicable or not; selecting crack arrest equipment, DWTT shearing area requirement and clearance degree; calculating the thickness of the steel sleeve crack arrestor; and calculating crack arrestor length. The invention provides the design method of the steel sleeve crack arrestor for the X80 / X90 gas pipeline, and the steel sleeve crack arrestor designed by the method canrealize the crack arrestor function of high-speed crack expansion through verification of a full-size gas explosion test.

Description

technical field [0001] The invention belongs to the technical field of fracture control of natural gas transmission pipelines, and in particular relates to a design method for a steel sleeve crack stopper used in high-grade steel gas transmission pipelines. Background technique [0002] Natural gas is a clean energy, but also a flammable and explosive dangerous medium, which is usually transported by pipeline. During the long-term service of the pipeline, due to formation pressure, corrosion, fatigue, external mechanical damage, etc., it is easy to cause accidents such as pipeline cracking and leakage. Once the gas pipeline is cracked, the high-pressure gas in the tube cannot be emptied immediately, but a decompression wave is generated from the breaking point to both sides and propagates to the far end. Since the gas decompression wave velocity is lower than the crack growth velocity, the crack tip will maintain a continuous high-stress state, and the crack will continue t...

AI Technical Summary

Problems solved by technology

The crack arrest process involves the interaction of high-speed dynamic crack growth, natural gas decompression waves, pipeline resistance, and external constraints of the crack arrester. Both finite element calculation and full-scale blasting test verification are very complicated, and there is currently no recognized formula at home and abroad. / method / standard can be used in the design of external crack arresters for high-grade steel gas pipelines

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