Water alkalinity on-line measuring device based on solution image technology and measuring method thereof

Abstract

The invention relates to a water alkalinity on-line detection device, a water alkalinity on-line measuring device based on solution image technology and a measuring method thereof, and is characterized in that according to the invention, based on the detection of solution image RGB values during the titration of water to be detected by a HCl solution, an image RGB value-titration solution volume measuring curve is plotted, and the water alkalinity of the solution to be detected is calculated according to the titration solution volume corresponding to an inflection point of the image RGB value measuring curve. With computer image processing technology, the invention establishes a mathematical model of solution RGB values with the change of the titration solution volume during titration, determines the titration end point automatically, establishes a color constancy algorithm model based on a neural network algorithm, and thus increases the precision and reliability of alkalinity measurement. With the device of the invention, on-line measurement of phenolphthalein alkalinity and total alkalinity can be performed optionally, and the operation is convenient. The device is applicable to industry of electric power, petroleum, chemical industry, metallurgy, etc.

Description

technical field [0001] The invention relates to an online detection device for water quality alkalinity applied in the fields of industrial water treatment and environmental monitoring. Background technique [0002] Alkalinity refers to the total amount of substances in water that can neutralize strong acids, such substances include strong bases, weak bases, strong bases and weak salts, etc. In the field of industrial water treatment, alkalinity is one of the indicators to measure the quality of circulating cooling water and boiler water. During the circulating cooling process of water, due to the evaporation of water, the concentration of dissolved salts, the escape of carbon dioxide, the entry of external pollutants, etc. Reasons, such as scaling, corrosion and bacteria and algae reproduction, will seriously affect the normal operation of the circulating water system, and even cause imbalances in the production process. Among them, the water alkalinity is one of the import...

AI Technical Summary

Problems solved by technology

[0004] 1. Acid-base indicator titration, also known as visual colorimetry or alkalinity volumetric method, this method can use a variety of indicators, standard solutions, buffer solutions to visually compare the titration end point (or color mutation point) However, when the color difference of the mutation point of water quality alkalinity is small or the water body is colored, human errors are likely to occur in the judgment of the titration end point and the calculation of the amount of titrant, the manual operation is complicated, and the processing of the analysis results is cumbersome, and the online measurement of water quality alkalinity cannot be realized.

[0005] 2. Potentiometric titration method, using the automatic potentiometric measurement curve mutation point to detect water quality alkalinity, the color of the water body will not affect the judgment of the end point, and the accuracy is high, but different titration methods and calculation formulas are used for different alkalinity, and the operation is cumbersome

[0006] 3. The pH value method is simple and fast, but the CO 2 It will affect the determination of pH value, resulting in large errors in the measurement results

[0007] 4. Alkalinity detection test paper method can quickly detect the alkalinity of water quality, but the detection sensitivity is low and the relative error is large, which is not suitable for precise measurement

Literature [E.da Nobrega Gaiao, V.Lacerda Martins, W.da Silva Lyre, et al.Digital image-based titrations.ANALYTICA CHIMICA ACTA, 2006 (570): 283-290] proposed alkalinity titration based on digital image Analysis method, which uses a conventional burette to manually add hydrochloric acid and chromogenic agent, uses a peristaltic pump to inject the measured solution into the image detector, judges the titration end point according to the RGB value of the image, and manually calculates the amount of hydrochloric acid added and the alkalinity of the water quality. This method exists Disadvantages such as scattered equipment, cumbersome operation steps, many influencing factors, and low degree of automation

Literature [Wu Yuejian, Zhang Ting, Sun Mojie, Cao Shengxian. Research on the Alkalinity Measurement Device of Circulating Cooling Water Based on Image Technology. The Tenth Youth Academic Conference of the Chinese Society for Electrical Engineering, September 2008. Jilin proposed the use of visual Observing the abrupt change point of the RGB value of the image as the end point of the titration, manually visually measuring the amount of titrant and alkalinity, also has the disadvantages of cumbersome operation steps, many influencing factors, and low degree of automation.

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