CN101334393A - Analysis and Treatment Method of Salt Accumulation and Fouling Components of Steam Turbine Blades - Google Patents

Abstract

The invention discloses a steam turbine blade salt accumulation and scaling component analysis and treatment method. It solves the problems of the current conventional steam turbine blades such as salt accumulation and fouling sample detection and analysis errors, and cannot accurately express the analysis results. It has the advantages of simple method, accurate result analysis, and can meet the actual detection needs. The method is as follows: 1) Determination of the weight percentage of loss on ignition in the scale sample; 2) Determination of the weight percentage content of ^Cl- % of chloride ion and ^F- % of fluoride ion in the scale sample, respectively by NaCl % and NaF%, and the calculation method is: NaCl%=1.648×Cl ^- %; NaF%=2.211×F ^- %; 3) Determination of the Na ₂ O weight percentage in the scale sample. The calculation method is: Na ₂ O%=1.348×(Na ⁺ %-0.648×Cl ^- %-1.211× ^F- %); 4) Record the calculation results in the set test table for analysis.

Description

Analysis and Treatment Method of Salt Accumulation and Fouling Components of Steam Turbine Blades

technical field

The invention relates to an analysis method, in particular to a method for analysis and treatment of steam turbine blade salt accumulation and scaling components.

Background technique

The components of salt accumulation and scaling on steam turbine blades are complex, and the samples include water-soluble substances, acid-soluble substances and alkali-soluble substances. The detection process is generally divided into three steps: one is to dissolve the sample and prepare multiple analytical test solutions; the second is to analyze the content of various components in the analytical test solution; the third is to analyze and process the analysis results of various component contents. There are three methods of sample dissolution: water-soluble method, acid-soluble method and alkali-fusion method. The water-soluble method is suitable for water-soluble substances, including sodium hydroxide, sodium carbonate, sodium bicarbonate, chlorides, fluorides, phosphates and soluble silicates, etc. The components of these substances need to be decomposed in the process of acid dissolution or alkali fusion Or a chemical reaction, so it cannot be determined by the acid-soluble method or the alkali-fusion method, and the water-soluble sample must be measured. The acid-dissolving method is suitable for scale samples with a large content of metal oxides, including sodium salts and oxides such as iron, aluminum, calcium, and magnesium. These substances are dissolved in acid, and certain components can be determined by dissolving the sample in acid; Conventional complexometric titration or atomic absorption spectrophotometry. The alkali fusion method is suitable for a wide range, and has a good decomposition effect on scale and corrosion products, especially for copper, silicon and other simple substances or compounds that cannot be dissolved by water or acid, and can only be dissolved by alkali fusion. The scale sample is dissolved, and then the composition determination is carried out.

The conventional method for component analysis of steam turbine blade salt deposits and scaling is: weigh out four scale samples, one for water content X%, one for ignition loss S1%, S2% content; one for water-soluble Sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium oxide, chloride, fluoride, phosphate and soluble silicate content, etc.; one part is used for metal oxides in alkali fusion scale samples such as aluminum oxide and iron oxide , calcium oxide, magnesium oxide, silicon dioxide, copper oxide, phosphoric anhydride, sulfuric anhydride, etc. In the test, it is found that there are three problems in the existing analytical method: 1) Although the same scale sample is dissolved in different ways, in the process of sample analysis and processing, some items have repeated measurement errors; such as the determination of sodium hydroxide , sodium carbonate, sodium bicarbonate, sodium chloride, and sodium oxide content, the sodium ion content is repeatedly used in the analysis and processing process, resulting in errors in the analysis results of the sample components; 2) loss on ignition and carbonate, bicarbonate and sodium hydroxide content are repeatedly used during analysis and processing, resulting in errors in the analysis results of sample components; 3) lack of correct expression formulas for anions such as chloride ions and fluoride ions. Due to the above three reasons, the analysis results of steam turbine blade salt accumulation and fouling components are in error, and the sum is 120% or 130%, which exceeds the requirement that the sum of the analysis results is within 100±5%. Therefore, it is necessary to study the "analysis and processing method of steam turbine blade scale components" in order to correctly detect the content of scale components and accurately express the analysis results.

Contents of the invention

The purpose of the present invention is to solve the problems of the current conventional steam turbine blades such as salt accumulation and fouling sample detection and analysis errors, which cannot accurately express the analysis results, etc., and provide a method with simple methods, accurate result analysis, and can meet actual detection needs, etc. Advantages of steam turbine blade salt accumulation, scaling component analysis and treatment method.

To achieve the above object, the present invention adopts the following technical solutions:

A method for analyzing and treating steam turbine blade salt accumulation and fouling components, the method is as follows:

1) Measure the loss on ignition of the scale sample at 450°C in a high-temperature furnace, expressed as S ₁ %, and measure the loss on ignition at 900°C, expressed as S ₂ %;

2) Utilize the silver nitrate volumetric method or ion chromatography to detect the chloride ion weight percentage content ^Cl- % in the scale sample, and express the chloride ion weight percentage content ^Cl- % with NaCl%; Utilize the ion selective electrode method or ion chromatography Detect the weight percentage ^F- % of the fluoride ion in the scale sample, express the ^F- % weight percentage of the fluoride ion in NaF%.

The calculation method is:

NaCl%=1.648× ^Cl- %; NaF%=2.211× ^F- %;

3) Using electrode method or atomic absorption spectrophotometry to detect the sodium ion Na ⁺ weight percent content in the acid-dissolved scale sample, and express the Na ⁺ weight percent content in Na ₂ O%.

The calculation method is: Na ₂ O%=1.348×(Na ⁺ %-0.648×Cl ^- %-1.211×F ^- %);

4) Register the calculation results in the set test form for analysis.

The detection form of described step 4) is:

Compared with the traditional thermal power plant scale and corrosion product analysis method, the present invention mainly has the following characteristics:

The present invention considers that carbonate, bicarbonate and sodium hydroxide are unstable and easy to decompose at high temperature, so in the process of measuring loss on ignition, the value of loss on ignition is used to replace carbonate and bicarbonate , sodium hydroxide content, overcomes the problem of ignition loss and repeated counting of carbonate, bicarbonate, and sodium hydroxide in the traditional thermal power plant scale and corrosion product analysis method, and avoids the occurrence of sample composition analysis results error.

The chlorine ion weight percentage ^Cl- % in the ^dirt sample provided by the present invention is represented by NaCl% ^; %=2.211×F ^- %; it overcomes the problem that the traditional thermal power plant scale and corrosion product analysis method cannot correctly express the weight percentage of chloride ion and fluoride ion in the scale sample, and provides an accurate calculation formula.

The weight percent content of sodium ion Na ⁺ in the scale sample provided by the present invention is represented by Na ₂ O%, and the calculation method is: Na ₂ O%=1.348×(Na ⁺ %-0.648×Cl ^- %-1.211× ^F- %) ; It overcomes the problems of incorrect calculation and wrong expression of sodium ion content in the traditional thermal power plant scale and corrosion product analysis method, and provides an accurate calculation formula.

The registration form for the results of salt accumulation and fouling component content of steam turbine blades provided by the present invention has a complete and accurate calculation method. According to the above list items, the sum of various analysis results is calculated, and the summary results are within 100±5%. The problem of difficulty in expressing the scale analysis results and large errors in the traditional thermal power plant scale and corrosion product analysis methods is avoided.

The invention has the beneficial effects of simple method and accurate data analysis. According to the calculation formula of the present invention: NaCl%=1.648× ^Cl- %; NaF%=2.211× ^F- %; Na ₂ O%=1.348×(Na ⁺ %-0.648×Cl ^- %-1.211× ^F- %) and Result Registration Form

The analysis of the content of salt accumulation and fouling components in steam turbine blades can be successfully completed, ensuring the accuracy of the analysis data.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments.

Example 1:

1. Analysis of the reduction (increase) amount S ₁ % at 450°C and the reduction (increase) amount S ₂ % at 900°C

Accurately weigh 0.6000 grams of the steam turbine blade scale sample, and do an ignition loss (increase) test in a 450°C high-temperature furnace to obtain an ignition loss S ₁ %=0.50%; ) amount test, the loss on ignition S ₂ % = 1.50%.

2. Chloride ion content Cl ^- % and fluoride ion content F ^- % analysis in scale samples

Accurately weigh 0.5000 g of the steam turbine blade scale sample, measure the chloride ion content Cl ^- % = 1.00%, and the fluoride ion content F ^- % = 0.50% in the water-soluble scale sample, expressed in NaCl% and NaF%: NaCl% = 1.648×Cl ^- % = 1.648 x 1.0% = 1.648%, NaF% = 2.211 x F ^- % = 2.211 x 0.5% = 1.106%.

3. Analysis of the percentage of Na ₂ O in the scale sample

Accurately weigh 0.2000 g of the steam turbine blade scale sample, and measure the sodium ion weight percentage Na ⁺ %=10% in the acid-dissolved scale sample, then _Na2O %=1.348×(Na ⁺ %-0.648×Cl ^- %-1.211 ×F ^- %)=1.348×(10%-0.648×1.0%-1.211×0.5%)=8.75%

4. Analysis of the content of other oxides in the scale sample

The contents of other oxides were measured according to conventional test methods: potassium oxide content K ₂ O% = 0.50%; sulfuric anhydride content SO ₃ % = 3.00%; phosphoric anhydride content P ₂ O ₅ % = 1.00%; iron oxide content Fe ₂ O ₃ %=8.00%; alumina content Al ₂ O ₃ %=0; copper oxide content CuO%=3.00%; calcium oxide content CaO%=1.00%; magnesium oxide content MgO%=0.20%; total silicon content SiO ₂ % = 70.00%

5. The calculation results are registered according to the table

Claims (3)

1. a turbine blade salification, fouling constituent analysis disposal route is characterized in that its method is:

1) weight percentage of burning decrement in the dirty sample of detection;

2) utilize the chlorion weight percentage Cl of silver nitrate volumetric method or sulfate by ion chromatography dirt in the sample ^-%, and represent chlorion weight percentage Cl with NaCl% ^-%; Utilize fluorine ion weight percentage F in ion selective electrode method or the sulfate by ion chromatography dirt sample ^-% represents fluorine ion weight percentage F with NaF% ^-%.

Computing method are:

NaCl％＝1.648×Cl ^-％；NaF％＝2.211×F ^-％；

3) utilize electrode method or atomic absorption spectrophotometry to detect sodion Na in the molten dirty sample of acid ⁺Weight percentage is with Na ₂O% represents Na ⁺Weight percentage.

Computing method are: Na ₂O%=1.348 * (Na ⁺%-0.648 * Cl ^-%-1.211 * F ^-%);

4) result of calculation is registered to set to detect in the form and analyze.

2. turbine blade salification as claimed in claim 1, fouling constituent analysis disposal route is characterized in that, the detection form of described step 4) is:

3. turbine blade salification as claimed in claim 1, fouling constituent analysis disposal route is characterized in that, the weight percentage of described step 1) burning decrement in the time of 450 ℃ burning decrement with S ₁% represents that burning decrement is with S in the time of 900 ℃ ₂%.