Membrane method to analyze the accelerated corrosion degree of water vapor system flow in supercritical unit

Abstract

The invention relates to a method for analyzing the flow accelerated corrosion degree of a water vapor system of a supercritical unit. The method comprises the following steps: (1) making a standard color chart, and representing the colloidal iron content by taking the color of residues on each filter membrane as the color of the standard color chart; (2) directly connecting a sampling head with a water sample; (3) mounting the filter membrane, connecting the sampling head with a test point sampling pipe, filtering the water sample, enriching colloidal iron in the water sample, and drying; (4) collecting and testing the color chart of the water sample of the unit on site, emphatically the water sample with a relatively large amount of residues in the color chart, pointedly acquiring scale quantity analysis data of unit maintenance, and building a flow accelerated corrosion degree evaluation set; (5) comparing the color of the residues on the filter membrane with the color chart, quantifying the content of colloidal iron in different water samples, and quantitatively determining the flow accelerated corrosion degree according to the flow accelerated corrosion degree evaluation sample set. Compared with the prior art, the method is relatively high in accuracy, simple, feasible, low in analysis cost and relatively institutive in analysis result.

Description

technical field [0001] The invention relates to an analysis and evaluation method of flow-accelerated corrosion, in particular to a method for analyzing the degree of flow-accelerated corrosion of a water vapor system of a supercritical unit by a filter membrane method. Background technique [0002] Iron in the water vapor system of supercritical units generally exists in colloidal and dissolved states, that is, in the form of oxides, including ferric oxide and ferric oxide. Iron in the water vapor system is an important corrosion product, and the corrosion mechanism includes oxygen corrosion, electrochemical corrosion, and flow-accelerated corrosion. Especially in the waste heat boilers of supercritical units and combined cycle units, flow-accelerated corrosion is the main form under the operating conditions of the units, especially the suitability of the chemical conditions of feed water and high hydrophobicity, which determines the degree of flow-accelerated corrosion of ...

AI Technical Summary

Problems solved by technology

[0003] At present, the detection method of iron content in the water vapor system is generally: reducing colloidal and granular iron to ionic ferric iron or ferrous iron, and then measuring and analyzing by atomic absorption spectrometry or phenanthroline colorimetry , although the accuracy is high, the detection method is cumbersome, the detection time is long, it is harmful to the human body, and the detection cost is high