A combined monitoring system and method for corrosive ions in water vapor

Abstract

The invention discloses a combined monitoring system and method for corrosive ions in water vapor. The outlet of a water sample input pipeline is divided into two routes, wherein one route is connected to a trace chloride ion analyzer, and the other route is connected to a #1 inlet of a hydrogen conductivity meter. The #1 outlet of the hydrogen conductivity meter is connected to a first opening of a #1 three-way valve, a second opening of the #1 three-way valve is connected to an inlet of a TOCi analyzer, a third opening of the #1 three-way valve is connected to an ion chromatograph, an outlet of the TOCi analyzer is connected to a first opening of a #2 three-way valve, a second opening of the #2 three-way valve is connected to an #2 inlet of the hydrogen conductivity meter, a third opening of the #2 three-way valve is connected to an ion chromatograph, an #2 outlet of the hydrogen conductivity meter is connected to a first opening of a #3 three-way valve, and a third opening of the #3 three-way valve is connected to an ion chromatograph. The system and method can comprehensively monitor all ions in water vapor that may cause corrosion of thermal equipment.

Description

Technical Field

[0001] The invention belongs to the field of corrosion prevention and control of water vapor systems in power plants, and relates to a combined monitoring system and method for corrosive ions in water vapor. Background Art

[0002] With the increase in the parameters and capacity of thermal power generating units, the corrosion protection of thermal equipment has received more and more attention. Chloride ions are the most harmful corrosive anions in water vapor. Trace amounts of chloride ions are enough to destroy the protective oxide film on the metal surface, causing corrosion damage to thermal equipment. In addition, organic pollutants are also an important source of corrosive ions in water vapor. Organic matter decomposes under the high temperature and high pressure environment of the boiler. The decomposition products may contain a variety of corrosive anions, which lead to an increase in the hydrogen conductivity of water vapor, causing acid corrosion of the low-pressure cylinder of the turbine, and even low-pressure cylinder blade fracture accidents in severe cases.

[0003] At present, the fine treatment system and water vapor system of my country's power plants lack both instruments for online monitoring of chloride ions and means for monitoring the total organic carbon ion TOCi of organic pollutants. There is also no method for comprehensively analyzing the corrosive anions in water vapor, resulting in the inability to comprehensively and systematically evaluate and diagnose the corrosive tendency of water vapor to thermal equipment. Domestic power plants have successively encountered many problems such as chlorine leakage in the fine treatment system, unclear endpoint of mixed bed failure, and high steam hydrogen conductivity, which poses a great risk of corrosion damage to boiler tubes and turbine blades. Accidents such as turbine corrosion of generator sets and boiler corrosion and tube bursts occur from time to time, seriously affecting the safe production and economic operation of power plants. If a combined monitoring system for corrosive ions in water vapor can be constructed, it can analyze and monitor all "explicit" and "implicit" corrosive ions in water vapor, help power plants to adjust operating conditions in a timely manner, and significantly improve the reliability of chemical supervision, but there is no similar disclosure in the prior art. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a system and method for monitoring corrosive ions in water vapor. The system and method can comprehensively monitor all ions in water vapor that may cause corrosion of thermal equipment.

[0005] To achieve the above-mentioned purpose, the combined monitoring system for corrosive ions in water vapor of the present invention comprises a water sample input pipeline, a trace chloride ion analyzer, a hydrogen conductivity meter, a #1 three-way valve, a TOCi analyzer, an ion chromatograph, a #2 three-way valve and a #3 three-way valve;

[0006] The outlet of the water sample input pipeline is divided into two routes, one of which is connected to the trace chloride ion analyzer, and the other is connected to the #1 inlet of the hydrogen conductivity meter, the #1 outlet of the hydrogen conductivity meter is connected to the first opening of the #1 three-way valve, the second opening of the #1 three-way valve is connected to the inlet of the TOCi analyzer, the third opening of the #1 three-way valve is connected to the ion chromatograph, the outlet of the TOCi analyzer is connected to the first opening of the #2 three-way valve, the second opening of the #2 three-way valve is connected to the #2 inlet of the hydrogen conductivity meter, the third opening of the #2 three-way valve is connected to the ion chromatograph, the #2 outlet of the hydrogen conductivity meter is connected to the first opening of the #3 three-way valve, the second opening of the #3 three-way valve is connected to the drain pipe, and the third opening of the #3 three-way valve is connected to the ion chromatograph.

[0007] When the water sample enters from the #1 inlet of the hydrogen conductivity meter, the #2 outlet of the hydrogen conductivity meter is closed, and the water sample only flows out from the #1 outlet of the hydrogen conductivity meter;

[0008] When the water sample enters from the #2 inlet of the hydrogen conductivity meter, the #1 outlet of the hydrogen conductivity meter is closed, and the water sample only flows out from the #2 outlet of the hydrogen conductivity meter;

[0009] The TOCi analyzer includes an oxidation unit.

[0010] It also includes a control system, wherein the control system is connected with a trace chloride ion analyzer, a hydrogen conductivity meter, a #1 three-way valve, a TOCi analyzer, an ion chromatograph, a #2 three-way valve and a #3 three-way valve.

[0011] The method for monitoring corrosive ions in water vapor according to the present invention comprises the following steps:

[0012] The water sample output from the water sample input pipeline is divided into two paths, one of which enters the trace chloride ion analyzer for chloride ion concentration detection, and the other enters the #1 inlet of the hydrogen conductivity meter for hydrogen conductivity detection; when the hydrogen conductivity detection value is greater than or equal to the first control value, the first opening and the third opening of the #1 three-way valve are turned on, and the second opening of the #1 three-way valve is closed. After the water sample flows out from the #1 outlet of the hydrogen conductivity meter, it enters the ion chromatograph for multiple anion detection. When the hydrogen conductivity detection value is less than the first control value, the first opening and the second opening of the #1 three-way valve are turned on, and the third opening of the #1 three-way valve is closed. After the water sample flows out from the #1 outlet of the hydrogen conductivity meter, it enters the TOCi analyzer for water sample oxidation and TOCi detection. When the TOCi detection value is greater than or equal to the second control value, the first opening and the third opening of the #2 three-way valve are turned on, and the second opening of the #2 three-way valve is closed. The oxidized water sample flows out from the outlet of the TOCi analyzer and enters the ion chromatograph for multiple anion detection. When the TOCi detection value is less than the second control value, the first and second openings of the #2 three-way valve are turned on, and the third opening of the #2 three-way valve is closed. The oxidized water sample flows out from the outlet of the TOCi analyzer and enters the #2 inlet of the hydrogen conductivity meter for hydrogen conductivity detection. When the hydrogen conductivity detection value of the oxidized water sample is greater than or equal to the third control value, the first and third openings of the #3 three-way valve are turned on, and the second opening of the #3 three-way valve is closed. The water sample flows out from the #2 outlet of the hydrogen conductivity meter and enters the ion chromatograph for multiple anion detection. When the hydrogen conductivity detection value of the oxidized water sample is less than the third control value, the first and second openings of the #3 three-way valve are turned on, and the third opening of the #3 three-way valve is closed. The water sample flows out from the #2 outlet of the hydrogen conductivity meter and is discharged through the drain pipe.

[0013] The present invention has the following beneficial effects:

[0014] The system and method for monitoring corrosive ions in water vapor described in the present invention can comprehensively monitor all factors in water vapor that may cause corrosion of thermal equipment during specific operation, and can detect the chloride ion concentration, hydrogen conductivity, TOCi and hydrogen conductivity of water sample after oxidation (organic matter decomposition) in water vapor; specifically, when the hydrogen conductivity exceeds the standard, the ion chromatograph is used to detect various anions in water vapor, such as SO4 2- 、NO3 - 、F - 、CH3COO - HCOO - 、NO2 - PO4 3-Etc., combined with the chloride ion concentration test results of the chloride ion analyzer, the types and concentrations of corrosive anions that cause hydrogen conductivity to exceed the standard are analyzed; when TOCi exceeds the standard, the ion chromatograph is further used to detect the various anions after the water sample is oxidized (organic matter decomposition), and the types and concentrations of organic pollution that cause TOCi to exceed the standard are analyzed; when the hydrogen conductivity of the water sample after oxidation exceeds the standard, the ion chromatograph is further used to detect the various anions after the water sample is oxidized, and the hydrogen conductivity increment before and after the water sample is oxidized is combined to analyze the types and concentrations of decomposable organic matter heteroatoms that cause the hydrogen conductivity to increase, so as to achieve the purpose of comprehensively monitoring all ions in water vapor that may cause corrosion of thermal equipment. In addition, it should be noted that since the ion chromatograph needs to detect multiple anions, it takes a long time. Only when the hydrogen conductivity, TOCi or hydrogen conductivity of the water sample after oxidation exceeds the standard, the system will perform corresponding further ion chromatography detection. When the monitoring indicators are all qualified, the water sample can quickly pass the detection, which is convenient and simple to operate, and effectively improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention.

[0016] Among them, 1 is the water sample input pipeline, 2 is the trace chloride ion analyzer, 3 is the hydrogen conductivity meter, 4 is the #1 three-way valve, 5 is the TOCi analyzer, 6 is the ion chromatograph, 7 is the #2 three-way valve, and 8 is the #3 three-way valve. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0018] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0019] refer to Figure 1The combined monitoring system for corrosive ions in water vapor of the present invention comprises a water sample input pipeline 1, a trace chloride ion analyzer 2, a hydrogen conductivity meter 3, a #1 three-way valve 4, a TOCi analyzer 5, an ion chromatograph 6, a #2 three-way valve 7 and a #3 three-way valve 8; the outlet of the water sample input pipeline 1 is divided into two paths, one of which is connected to the trace chloride ion analyzer 2, and the other is connected to the #1 inlet of the hydrogen conductivity meter 3, the #1 outlet of the hydrogen conductivity meter 3 is connected to the first opening of the #1 three-way valve 4, and the second opening of the #1 three-way valve 4 is connected to the TOCi The inlet of the analyzer 5 is connected, the third opening of the #1 three-way valve 4 is connected to the ion chromatograph 6, the outlet of the TOCi analyzer 5 is connected to the first opening of the #2 three-way valve 7, the second opening of the #2 three-way valve 7 is connected to the #2 inlet of the hydrogen conductivity meter 3, the third opening of the #2 three-way valve 7 is connected to the ion chromatograph 6, the #2 outlet of the hydrogen conductivity meter 3 is connected to the first opening of the #3 three-way valve 8, the second opening of the #3 three-way valve 8 is connected to the drain pipe, and the third opening of the #3 three-way valve 8 is connected to the ion chromatograph 6;

[0020] When the water sample enters from the #1 inlet of the hydrogen conductivity meter 3, the #2 outlet of the hydrogen conductivity meter 3 is closed, and the water sample only flows out from the #1 outlet of the hydrogen conductivity meter 3;

[0021] When the water sample enters from the #2 inlet of the hydrogen conductivity meter 3, the #1 outlet of the hydrogen conductivity meter 3 is closed, and the water sample only flows out from the #2 outlet of the hydrogen conductivity meter 3;

[0022] The TOCi analyzer 5 includes an oxidation unit, through which the water sample is oxidized to decompose organic matter in the water sample.

[0023] The method for monitoring corrosive ions in water vapor according to the present invention comprises the following steps:

[0024] The water sample output from the water sample input pipeline 1 is divided into two paths, one of which enters the trace chloride ion analyzer 2 for chloride ion concentration detection, and the other enters the #1 inlet of the hydrogen conductivity meter 3 for hydrogen conductivity detection; when the hydrogen conductivity detection value is greater than or equal to the first control value, the first opening and the third opening of the #1 three-way valve 4 are turned on, and the second opening of the #1 three-way valve 4 is closed. After the water sample flows out from the #1 outlet of the hydrogen conductivity meter 3, it enters the ion chromatograph 6 for multiple anion detection. When the hydrogen conductivity detection value is less than the first control value, the first opening and the second opening of the #1 three-way valve 4 are turned on, and the third opening of the #1 three-way valve 4 is closed. After the water sample flows out from the #1 outlet of the hydrogen conductivity meter 3, it enters the TOCi analyzer 5 for water sample oxidation and TOCi detection. When the TOCi detection value is greater than or equal to the second control value, the first opening and the third opening of the #2 three-way valve 7 are turned on, and the second opening of the #2 three-way valve 7 is closed. The oxidized water sample flows out from the outlet of TOCi analyzer 5 and enters the ion chromatograph 6 for multiple anion detection. When the TOCi detection value is less than the second control value, the first opening and the second opening of the #2 three-way valve 7 are turned on, and the third opening of the #2 three-way valve 7 is closed. The oxidized water sample flows out from the outlet of TOCi analyzer 5 and enters the #2 inlet of the hydrogen conductivity meter 3 for hydrogen conductivity detection. When the hydrogen conductivity detection value of the oxidized water sample is greater than or equal to the third control value, the first opening and the third opening of the #3 three-way valve 8 are turned on, and the second opening of the #3 three-way valve 8 is closed. The water sample flows out from the #2 outlet of the hydrogen conductivity meter 3 and enters the ion chromatograph 6 for multiple anion detection. When the hydrogen conductivity detection value of the oxidized water sample is less than the third control value, the first opening and the second opening of the #3 three-way valve 8 are turned on, and the third opening of the #3 three-way valve 8 is closed. The water sample flows out from the #2 outlet of the hydrogen conductivity meter 3 and is discharged through the drain pipe.

[0025] It should be noted that the present invention detects the chloride ion concentration in the water vapor through the trace chloride ion analyzer 2, detects the hydrogen conductivity through the hydrogen conductivity meter 3, oxidizes the water sample and performs TOCi detection through the TOCi analyzer 5, and detects the hydrogen conductivity of the water sample after oxidation through the hydrogen conductivity meter 3; when the hydrogen conductivity exceeds the standard, the ion chromatograph 6 detects various anions in the water vapor, such as SO4 2- 、NO3 - 、F - 、CH3COO - HCOO - 、NO2 - PO4 3-Etc., combined with the chloride ion concentration detection result of the chloride ion analyzer 2, the type and concentration of corrosive anions causing the hydrogen conductivity to exceed the standard are analyzed; when TOCi exceeds the standard, the various anions after the water sample is oxidized (organic matter decomposition) are further detected by the ion chromatograph 6 to analyze the type and concentration of organic pollution causing the TOCi to exceed the standard; when the hydrogen conductivity of the water sample after oxidation exceeds the standard, the various anions after the water sample is oxidized are further detected by the ion chromatograph 6, and combined with the hydrogen conductivity increment before and after the oxidation of the water sample, the type and concentration of decomposable organic heteroatoms causing the hydrogen conductivity to increase are analyzed, providing a basis for finding the source of pollution.

[0026] The present invention realizes the effective monitoring of key indicators reflecting corrosion tendency in water vapor, namely chloride ions, hydrogen conductivity, TOCi and hydrogen conductivity of water samples after oxidation, changes the current situation that some key corrosion indicators of power plants are in the monitoring blind spot, improves the reliability of chemical supervision, and can further analyze the specific types and concentrations of corrosive anions, providing a basis for finding the source of pollutants.

[0027] The present invention realizes comprehensive detection of corrosive ions in water vapor, helps power plants analyze water pollution sources, and adjust operating conditions in a timely manner to avoid problems such as thermal equipment corrosion, excessive steam hydrogen conductivity, and chlorine leakage in fine treatment caused by excessive corrosive ions and organic matter, thereby providing protection for the safe and economical operation of the generator set.

Claims

1. A method for monitoring corrosive ions in water vapor, characterized in that: Based on the combined monitoring system for corrosive ions in water vapor, the combined monitoring system for corrosive ions in water vapor comprises a water sample input pipeline (1), a trace chloride ion analyzer (2), a hydrogen conductivity meter (3), a #1 three-way valve (4), a TOCi analyzer (5), an ion chromatograph (6), a #2 three-way valve (7) and a #3 three-way valve (8); The outlet of the water sample input pipeline (1) is divided into two paths, one of which is connected to the trace chloride ion analyzer (2), and the other is connected to the #1 inlet of the hydrogen conductivity meter (3), the #1 outlet of the hydrogen conductivity meter (3) is connected to the first opening of the #1 three-way valve (4), the second opening of the #1 three-way valve (4) is connected to the inlet of the TOCi analyzer (5), the third opening of the #1 three-way valve (4) is connected to the ion chromatograph (6), and the TOCi analyzer (5) is connected to the inlet of the TOCi analyzer (5). The outlet is connected to the first opening of the #2 three-way valve (7), the second opening of the #2 three-way valve (7) is connected to the #2 inlet of the hydrogen conductivity meter (3), the third opening of the #2 three-way valve (7) is connected to the ion chromatograph (6), the #2 outlet of the hydrogen conductivity meter (3) is connected to the first opening of the #3 three-way valve (8), the second opening of the #3 three-way valve (8) is connected to the drain pipe, and the third opening of the #3 three-way valve (8) is connected to the ion chromatograph (6); The following steps are involved: The water sample output from the water sample input pipeline (1) is divided into two paths, one of which enters the trace chloride ion analyzer (2) for chloride ion concentration detection, and the other enters the #1 inlet of the hydrogen conductivity meter (3) for hydrogen conductivity detection; when the hydrogen conductivity detection value is greater than or equal to a first control value, the first opening and the third opening of the #1 three-way valve (4) are opened, the second opening of the #1 three-way valve (4) is closed, and the water sample flows out from the #1 outlet of the hydrogen conductivity meter (3) and enters the ion chromatograph (6) for multiple anion concentrations. When the hydrogen conductivity detection value is less than the first control value, the first opening and the second opening of the #1 three-way valve (4) are opened, and the third opening of the #1 three-way valve (4) is closed. The water sample flows out from the #1 outlet of the hydrogen conductivity meter (3) and enters the TOCi analyzer (5) for water sample oxidation and TOCi detection. When the TOCi detection value is greater than or equal to the second control value, the first opening and the third opening of the #2 three-way valve (7) are opened, and the second opening of the #2 three-way valve (7) is closed. The oxidation The oxidized water sample flows out of the outlet of the TOCi analyzer (5) and enters the ion chromatograph (6) for multiple anion detection. When the TOCi detection value is less than the second control value, the first opening and the second opening of the #2 three-way valve (7) are opened, and the third opening of the #2 three-way valve (7) is closed. The oxidized water sample flows out of the outlet of the TOCi analyzer (5) and enters the #2 inlet of the hydrogen conductivity meter (3) for hydrogen conductivity detection. When the hydrogen conductivity detection value of the oxidized water sample is greater than or equal to the third control value, The first opening and the third opening of the #3 three-way valve (8) are opened, and the second opening of the #3 three-way valve (8) is closed. The water sample flows out from the #2 outlet of the hydrogen conductivity meter (3) and enters the ion chromatograph (6) for multiple anion detection. When the hydrogen conductivity detection value of the oxidized water sample is less than the third control value, the first opening and the second opening of the #3 three-way valve (8) are opened, and the third opening of the #3 three-way valve (8) is closed. The water sample flows out from the #2 outlet of the hydrogen conductivity meter (3) and is discharged through the drain pipe.

2. The method for monitoring corrosive ions in water vapor according to claim 1, characterized in that: The TOCi analyzer (5) includes an oxidation unit.

3. The method for monitoring corrosive ions in water vapor according to claim 1, characterized in that: It also includes a control system, wherein the control system is connected to a trace chloride ion analyzer (2), a hydrogen conductivity meter (3), a #1 three-way valve (4), a TOCi analyzer (5), an ion chromatograph (6), a #2 three-way valve (7) and a #3 three-way valve (8).

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