Direct-buried steam pipeline caisson structure and construction method

Abstract

The invention discloses a direct-buried steam pipeline caisson structure and a construction method. The direct-buried steam pipeline caisson structure comprises a well body vertically extending downwards to the underground from the ground, and a steam pipeline buried underground and penetrating through the well body. The well body is formed by welding steel plates. The steam pipeline comprises a working pipe, a composite heat preservation layer, an inert gas protection layer, a polyurethane foaming layer and an outer sheath, wherein the composite heat preservation layer, the inert gas protection layer, the polyurethane foaming layer and the outer sheath are sequentially arranged outside the working pipe. A compensation section of the part, penetrating through the well body, of the steam pipeline comprises a straight pipe part and a bent pipe part. An inner rolling pipe support assembly is arranged on a buried section of the part, buried underground, of the steam pipeline. Waterproof heat insulation assemblies are arranged at the joint of a corrugated compensator and the compensation section and the joint of the other end of the compensation section and the buried section. According to the direct-buried steam pipeline caisson structure and the construction method, the heat preservation layer can be effectively prevented from being affected with damp, steel can be effectively prevented from being corroded, inspection is convenient, compensator faults are easy to handle, the friction coefficient is reduced, the compensation distance is increased, and the problem that a direct-buried pipe deforms due to different internal and external pressure is solved.

Description

technical field [0001] The invention relates to a directly buried steam pipeline caisson structure and a construction method. Background technique [0002] There are two ways of laying steam pipelines, overhead laying and direct buried laying. Aerial laying is the main laying method, but direct buried laying is used in bustling cities or areas where aerial laying is not suitable. With the rapid development of urbanization in my country, especially in some important cities, relevant policies have been issued to prohibit the construction of steam pipelines and other municipal / industrial pipelines on the ground, so the importance of direct buried steam pipeline construction technology is increasing year by year, and therefore It is particularly important to carry out continuous innovative research on the difficulties involved in directly buried steam pipelines. [0003] Among them, the digestion and absorption of the elongation and shrinkage of directly buried steam pipelines ...

AI Technical Summary

Problems solved by technology

However, due to frequent expansion and contraction, the bellows metal is prone to fatigue or cracking, so the bellows compensator is a vulnerable part and needs regular maintenance

Usually, the bellows compensator for directly buried steam pipelines is inspected and repaired through the repair well. Since the repair well is prone to groundwater penetration or rainwater ingress, the insulation layer of the working pipe will be damp; and if the bellows compensator is exposed during the manufacturing process Defects, which will not be exposed in the short term, but frequent expansion and contraction in long-term operation will accelerate its damage or leakage. its damp

Once the above problems occur, if they are not dealt with in time, the high temperature and humid working conditions will cause the polyurethane foam layer of the working pipe to age rapidly and lose the insulation effect, which will lead to the failure of the insulation layer of the entire working pipe network, and even cause more serious consequences

[0004]In addition, due to the limitation of the structure of the bellows compensator, its compensation amount is extremely limited, and multiple bellows compensators need to be set between adjacent fixed points of the steam pipeline to To meet the compensation requirements, this greatly increases the workload and difficulty of inspection and maintenance, and is not conducive to troubleshooting and handling

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