Capacitive type online corrosion monitoring device and method

Abstract

The invention relates to a capacitive type online corrosion monitoring device and method, and belongs to the technical field of monitoring on corrosion of gas conveying pipelines and equipment. The capacitive type online corrosion monitoring device is characterized in that hollow cylindrical corrosion coupon pairs are designed; two to eight groups of corrosion coupon pairs of different sizes are installed; according to the change of the corrosion areas of the corrosion coupon pairs of different sizes under the corrosion environment along with time, the capacitance of a variable capacitor in acorrosion monitoring circuit is changed, so as to complete the online monitoring on the corrosion state of the gas conveying pipeline. A corrosion monitoring method is designed and is characterized inthat the corrosion coupons of different sizes form one to seven groups of variable capacitors; by utilizing the change of output voltage in the corrosion monitoring circuit, the corrosion type, corrosion depth and corrosion rate of the gas conveying pipeline can be monitored on line, so as to provide the reliable basis for the safety early warning, corrosion control and the like on the pipeline.The capacitive type online corrosion monitoring device and method have the advantages that a heat exchange box is arranged on a ground pipeline of a station; the gas in the pipeline is heated by fluegas of a water jacket furnace, so as to reduce the influence to the monitoring effects of the corrosion monitoring device by the sulfur deposition of a sulfur-containing pipeline.

Description

technical field [0001] The invention relates to a capacitive corrosion on-line monitoring device and method, belonging to the technical field of corrosion monitoring of gas pipelines and equipment. Background technique [0002] Corrosion is a phenomenon in which metal materials and the surrounding environment are destroyed by chemical or electrochemical reactions. Corrosion problems exist in almost all walks of life, but they are particularly prominent in petroleum refining and chemical enterprises. The loss caused by corrosion is very large, and the damage caused by pitting corrosion is the most serious. Although pitting is only concentrated in a few points (corrosion pits or pits), as time goes by, the holes continue to develop in depth, forming small hole-like corrosion pits. Difficult to detect, pitting corrosion is invisible and destructive when left unchecked, causing holes in the metal until the entire structure is destroyed. [0003] The loss of metal materials is ...

AI Technical Summary

Problems solved by technology

Pitting corrosion is very difficult to detect, it is invisible and very destructive, if left unchecked it can lead to perforation of the metal until the entire structure is destroyed

[0003] The loss of metal materials is only a part of the total loss. What is more serious is its potential harm and environmental pollution, the public nuisance caused by the loss of toxic substances, and the explosion and poisoning accidents caused by corrosion. The losses are often immeasurable.

For example, steel pipes transporting oil, water, and gas often suffer from small hole corrosion when they are corroded in the soil. In severe cases, the pipe wall is perforated, a large amount of oil, water, and gas are lost, and sometimes even serious accidents such as fire and explosion are caused.

Although the current detection methods can avoid some accidents caused by corrosion, the related costs are quite high and detection is difficult

In addition, in the high-sulfur gas pipeline, the corrosion rate of the coupons is greatly increased due to the deposition of elemental sulfur on the surface of the coupons, resulting in a large difference between the corrosion measurement results and the actual corrosion data

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