阅读说明：本技术 一种在线烟气三氧化硫间歇式监测设备及方法 (Online flue gas sulfur trioxide intermittent monitoring equipment and method ) 是由 王建峰 李壮 张杨 杨用龙 王丰吉 朱跃 于 2021-05-28 设计创作，主要内容包括：本发明公开了一种在线烟气三氧化硫间歇式监测设备及方法,监测设备包括加热烟枪、异丙醇溶液储存器、SO-(3)吸收器、废气处理器、数字转化器、BaCl-(2)溶液储存器、NaOH溶液储存器、温度控制箱和测量装置等,监测方法为：烟气经吸收器后经相应管路进入测量装置,通过NaOH调整溶液pH之后,使用SO-(4)～(2-)电极监测测量溶液中该离子浓度变化,通过相应试剂浓度及使用量折算烟气中三氧化硫浓度,同时依据烟气体积流量计算烟气中三氧化硫浓度。反应完成之后使用去离子水冲洗测量装置,保证装置清洁,该设备可在线间歇式监测烟气中三氧化硫浓度,具有测量精确度高、使用寿命长等特点。(The invention discloses on-line flue gas sulfur trioxide intermittent monitoring equipment and a method thereof, wherein the monitoring equipment comprises a heating smoke gun, an isopropanol solution storage device and an SO 3 Absorber, waste gas processor, digital converter, BaCl 2 The monitoring method comprises the following steps of: the flue gas enters a measuring device through a corresponding pipeline after passing through an absorber, and SO is used after the pH of the solution is adjusted through NaOH 4 2‑ The electrode monitors the change of the ion concentration in the measuring solution, converts the concentration of sulfur trioxide in the flue gas through the concentration of corresponding reagent and the usage amount, and calculates the concentration of sulfur trioxide in the flue gas according to the volume flow of the flue gas. Use deionized water to wash measuring device after the reaction is accomplished, guarantee that the device is clean, sulfur trioxide concentration in this equipment can the online intermittent type formula monitoring flue gas has characteristics such as measurement accuracy height, long service life.)

1. An on-line flue gas sulfur trioxide intermittent monitoring device is characterized by comprising a heating smoke gun (1), an isopropanol solution storage device (3) and SO₃Absorber (5), waste gas processor (7), digital converter (9), BaCl₂A solution storage (10), a NaOH solution storage (11), a temperature control box (18) and a measuring device (19), wherein the smoke outlet of the heating smoke gun (1) is connected to SO through a one-way valve (2)₃Flue gas inlet of absorber (5), SO₃The absorber (5) is arranged in a temperature control box (18), and the solution of the isopropanol solution storage tank (3)The outlet is provided with a #1 flowmeter (4), and the solution outlet of the isopropanol solution storage (3) is connected to SO₃Solution inlet of absorber (5), SO₃The flue gas outlet of the absorber (5) is connected to a waste gas processor (7) through a flue gas volume flow meter (6) and a suction pump (20), and the SO is₃The solution outlet of the absorber (5) is connected to a measuring device (19) through an electric valve (8); the BaCl₂The outlet of the solution reservoir (10) is equipped with a #3 flow meter (12), and the BaCl₂The outlet of the solution storage (10) is connected to a measuring device (19), a #2 flow meter (13) is installed at the outlet of the NaOH solution storage (11), the outlet of the NaOH solution storage (11) is connected to the measuring device (19), a stirrer (16) is arranged in the measuring device (19), and pH and SO are installed in the measuring device (19)₃ ^2-Electrodes (14), the flue gas volume flow meter (6), #3 flow meter (12) and the pH and SO₃ ^2-The electrode (14) is connected with the digital converter (9), a deionized water flushing valve (15) is installed at a flushing water inlet of the measuring device (19), and a waste liquid emptying valve (17) is installed at a waste liquid outlet of the measuring device (19).

2. The on-line sulfur trioxide intermittent monitoring device of claim 1 wherein the SO₃The absorber (5) is provided with a plurality of SO₃The absorbers (5) are connected in series in sequence.

3. An operating method of the on-line flue gas sulfur trioxide intermittent monitoring equipment as claimed in claim 1 or 2, characterized in that the process is as follows: before the test is started, injecting SO into the isopropanol absorption liquid from an isopropanol solution storage tank (3) through a #1 flow meter (4)₃An absorber (5) for absorbing SO₃The absorber (5) is arranged in the temperature control box (18) and the temperature is adjusted; the heating smoke pipe (1) is arranged in the flue, and the smoke enters the SO through the heating smoke pipe (1) through the one-way valve (2)₃Absorber (5), SO₃After being washed in the absorber (5)The flue gas enters a waste gas processor (7) through a flue gas volume flow meter (6) and an air pump (20) and is then emptied; after the flue gas absorption is finished, an electric valve (8) is opened, isopropanol solution absorbing sulfur trioxide in the flue gas flows into a measuring device (19), a #2 flowmeter (13) is started to inject NaOH solution in a NaOH solution storage (11) into the measuring device (19), the solution fully reacts under the stirring action of a stirrer (16), and the pH value and the SO value are measured₃ ^2-The electrode (14) monitors the pH of the solution to 7.0, the #2 flow meter (13) is closed, the #3 flow meter (12) is opened to introduce BaCl₂BaCl in a solution reservoir (10)₂The solution is injected into a measuring device (19), and the solution is fully reacted under the stirring action of a stirrer (16) and passes through pH and SO₃ ^2-Electrode (14) monitoring SO₄ ^2-Measurement of SO in solution by potential change₄ ^2-A change in concentration of (c); according to the concentration value of each solution, the concentration value is input in a digital converter (9) in advance, and BaCl of a #3 flowmeter (12) is accessed₂And calculating the concentration of sulfur trioxide in the flue gas by using the usage amount, the accumulated volume of the flue gas volume flowmeter (6) and the flue gas moisture and oxygen of the on-line flue gas CEMS monitoring system.

4. The working method of the on-line flue gas sulfur trioxide intermittent monitoring equipment according to the claim 3, characterized in that the one-way valve (2) prevents the flue gas from flowing back, and the #1 flow meter (4) quantificationally supplies a plurality of SO₃100ml of isopropanol absorption liquid is respectively injected into the absorber (5) and closed in time; after 45min of absorption, the air pump (20) is closed, the electric valve (8) is opened, the isopropanol solution enters the measuring device (19), and the #1 flowmeter (4) is started to inject fresh isopropanol absorption liquid.

5. The working method of the on-line intermittent monitoring equipment for sulfur trioxide in flue gas as defined in claim 3 is characterized in that after the measurement device (19) completes the measurement, the waste liquid emptying valve (17) is opened to discharge the waste liquid, and the deionized water flushing valve (15) is opened to clean the measurement device (19) so as to ensure the cleanness of the measurement device (19).

6. The working method of the on-line intermittent monitoring equipment for sulfur trioxide in flue gas as claimed in claim 3, wherein the temperature of the temperature control box (18) is controlled to be 0 ℃, and the temperature of the temperature control box (18) is accurately controlled to ensure SO₃The absorption effect of the absorber (5).

7. The working method of the on-line flue gas sulfur trioxide intermittent monitoring equipment as claimed in claim 3, wherein the isopropanol absorption liquid is 80% isopropanol aqueous solution, and the pumping flow rate is 5L/min-8L/min.

8. The working method of the on-line flue gas sulfur trioxide intermittent monitoring equipment according to the claim 3, characterized in that the heating temperature of the heating smoke gun (1) is more than 250 ℃, and a particulate matter filter is arranged at the rear end of the heating smoke gun (1).

Technical Field

The invention relates to on-line flue gas sulfur trioxide intermittent monitoring equipment and a method.

Background

Various domestic boilers finish the reformation of conventional pollutants, NOx and SO in the flue gas₂And the smoke dust can basically meet the national requirement of ultralow emission limit, but the phenomenon that the smoke dust becomes the domestic haze phenomenon along with the atmospheric diffusion condition in autumn and winter always occurs, SO that the domestic smoke dust can not be polluted by the conventional pollutants (SO)₃、NH₃Soluble salts and Hg) monitoring.

At present, SO in flue gas of thermal power plant is basically adopted for monitoring the concentration of sulfur trioxide in flue gas of large power station₃Test methods control condensation Method (DL/T1990-2019) and SO specified in EPA Method 8-Determination of sulfuric acid mist and sulfuric dioxide emission from stationary sources₃The isopropanol absorption method is adopted, and both basic field sampling and laboratory analysis can not realize on-line automatic monitoring. Therefore, in order to improve the automatic level of sulfur trioxide monitoring in the flue gas of a large-scale power station, a safe and stable online measurable device and method for monitoring sulfur trioxide in the flue gas are required.

Comprehensively, due to instability of sulfur trioxide in the flue gas, no open online continuous monitoring equipment/method is provided at present, and sampling is based on the American EPA standard.

Disclosure of Invention

The invention aims to overcome the defects of the existing flue gas sulfur trioxide measurement technology, provides on-line flue gas sulfur trioxide intermittent monitoring equipment and a method aiming at the existing power station coal-fired unit, and has the advantages of reasonable structural design, high absorption efficiency, strong monitoring accuracy and high automation degree, and the detection period of sulfur trioxide in flue gas can be effectively shortened.

The technical scheme adopted by the invention for solving the problems is as follows: a kind ofAn on-line intermittent monitoring device for sulfur trioxide in flue gas is characterized by comprising a heating smoke gun, an isopropanol solution storage device and an SO₃Absorber, waste gas processor, digital converter, BaCl₂The solution storage device, the NaOH solution storage device, the temperature control box and the measuring device are arranged on the cigarette heating gun, and the smoke outlet of the cigarette heating gun is connected to SO through a one-way valve₃Flue gas inlet of absorber, SO₃The absorber is arranged in the temperature control box, a #1 flowmeter is installed at a solution outlet of the isopropanol solution storage, and the solution outlet of the isopropanol solution storage is connected to the SO₃Solution inlet of absorber, SO₃The flue gas outlet of the absorber is connected to a waste gas processor through a flue gas volume flow meter and a suction pump, and the SO is₃The solution outlet of the absorber is connected to the measuring device through an electric valve; the BaCl₂A #3 flow meter is installed at the outlet of the solution reservoir, and the BaCl₂The outlet of the solution storage is connected to a measuring device, a #2 flow meter is installed at the outlet of the NaOH solution storage, the outlet of the NaOH solution storage is connected to the measuring device, a stirrer is arranged in the measuring device, and the measuring device is internally provided with pH and SO₃ ^2-Electrodes, the flue gas volume flowmeter, #3 flowmeter and pH and SO₃ ^2-The electrodes are all connected with a digital converter, a deionized water flushing valve is installed at a flushing water inlet of the measuring device, and a waste liquid emptying valve is installed at a waste liquid outlet of the measuring device.

Further, the SO₃The absorber is provided with a plurality of SO₃The absorbers are connected in series in sequence.

The working method comprises the following steps: before the test is started, injecting SO into the isopropanol absorption liquid from an isopropanol solution storage through a #1 flowmeter₃Absorber of SO₃The absorber is arranged in a temperature control box and the temperature is adjusted; the heating smoke gun is arranged in the flue, and the smoke enters the SO through the heating smoke gun through the one-way valve₃Absorber, SO₃The washed flue gas in the absorber enters a waste gas processor through a flue gas volume flow meter and an air suction pump, and then is evacuated; after the flue gas absorption is finished, the electric valve is opened to absorb the trioxane in the flue gasThe isopropanol solution of the sulfur sulfide flows into the measuring device, the #2 flowmeter is started to inject the NaOH solution in the NaOH solution storage into the measuring device, the solution fully reacts under the stirring action of the stirrer, and the pH value and the SO value are obtained through the reaction₃ ^2-The pH value of the solution is monitored by an electrode to be about 7.0, the flow meter #2 is closed, and the flow meter #3 is opened to enable BaCl₂BaCl in solution reservoir₂Injecting the solution into a measuring device, and allowing the solution to react under the stirring action of a stirrer through pH and SO₃ ^2-Electrode monitoring of SO₄ ^2-Measurement of SO in solution by potential change₄ ^2-A change in concentration of (c); according to the concentration value of each solution, the concentration value is input in a digital converter in advance, and BaCl of a #3 flowmeter is connected₂And calculating the concentration of sulfur trioxide in the flue gas by using the usage amount, the accumulated volume of the flue gas volume flowmeter and the flue gas moisture and oxygen amount of the on-line flue gas CEMS monitoring system.

Further, a one-way valve prevents the flue gas from flowing back, and a #1 flow meter quantificationally leads to a plurality of SO connected in series₃100ml of isopropanol absorption liquid is injected into each absorber and closed in time. And after 45min of absorption, closing the air pump, opening the electric valve, enabling the isopropanol solution to enter the measuring device, and simultaneously opening the #1 flowmeter to inject fresh isopropanol absorption liquid.

Furthermore, after the measurement device completes measurement, the waste liquid emptying valve is opened to discharge waste liquid, and the deionized water flushing valve is opened to clean the measurement device, so that the cleanness of the measurement device is ensured.

Furthermore, the temperature control box controls the inside of the temperature control box to be 0 ℃, and the temperature control box accurately controls the temperature to ensure SO₃The absorption effect of the absorber.

Furthermore, the waste gas processor effectively processes unabsorbed toxic gas in the flue gas, and effectively reduces the corrosion of other unabsorbed waste gas to peripheral equipment and environmental air pollution in the measuring process.

Furthermore, the isopropanol absorption liquid is 80% isopropanol water solution, and the air extraction flow rate is 5L/min-8L/min.

Further, the heating temperature of the heating smoke gun is higher than 250 ℃, and a particulate filter is arranged at the rear end of the heating smoke gun and is convenient to replace.

Further, the apparatus utilizes a high precision pH electrode and SO₄ ^2-The electrodes are supported, and all parts are controlled by logic to ensure that the electrodes are switched on and off in a correct sequence through solution SO₄ ^2-Calculating SO in solution by using potential values generated by different concentrations₄ ^2-Through a digitizer, using the volume of the extracted flue gas, BaCl₂Concentration and amount of solution, SO₄ ^2-And reading the concentration of sulfur trioxide in the flue gas through potential change.

Compared with the prior art, the invention has the following advantages and effects:

1. the invention adopts a sulfur trioxide isopropanol absorption method specified by the American EPA method 8 standard and relies on high-precision SO₄ ^2-The electrode technology lays a foundation for online monitoring of the concentration of sulfur trioxide in the flue gas.

2. The invention adopts a multistage isopropanol absorption system, and improves the accuracy of sulfur trioxide monitoring data in the flue gas.

3. SO of the invention₃The absorber is arranged in the temperature control box, so that the sulfur trioxide in the flue gas can be fully absorbed by the isopropanol solution, and the accuracy of the measured data is improved.

4. The numerical value converter can input the concentration of each additional solution and can process the flow rate of extracted flue gas and BaCl₂The volume of the solution can be calculated according to the humidity and oxygen content of the flue gas monitored by CEMS, and the SO in the flue gas can be automatically converted₃The concentration of (c).

5. The stirrer runs in the whole measuring process and the cleaning process of the measuring device, so that the accuracy of data in the measuring process and the cleanliness in the cleaning process are ensured.

6. The deionized water flushing device of the measuring device is arranged, so that the cleanliness of the measuring device after each measurement can be ensured, the residue of waste liquid is avoided, and the accuracy of test data is ensured.

7. The waste gas processor can effectively reduce the corrosion of other waste gases which are not absorbed in the measuring process to peripheral equipment and the environmental air pollution.

Drawings

Fig. 1 is a schematic structural diagram of the monitoring device of the present invention.

In the figure: heating smoke gun 1, one-way valve 2, isopropanol solution reservoir 3, #1 flowmeter 4, SO₃Absorber 5, flue gas volume flowmeter 6, waste gas processor 7, electric valve 8, digital converter 9 and BaCl₂Solution reservoir 10, NaOH solution reservoir 11, #3 flow meter 12, #2 flow meter 13, pH and SO₃ ^2-Electrode 14, deionized water flush valve 15, stirrer 16, waste liquid emptying valve 17, temperature control box 18, measuring device 19 and air pump 20.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.

Examples

Referring to fig. 1, in this embodiment, an online intermittent monitoring device for sulfur trioxide in flue gas includes a heating pipe 1, an isopropyl alcohol solution storage 3, and an SO₃Absorber 5, waste gas processor 7, digital converter 9 and BaCl₂A solution storage 10, a NaOH solution storage 11, a temperature control box 18 and a measuring device 19, wherein the smoke outlet of the heating smoke gun 1 is connected to SO through a one-way valve 2₃Flue gas inlet of absorber 5, SO₃The absorber 5 is arranged in a temperature control box 18, SO₃The absorber 5 is provided with a plurality of SO₃The absorbers 5 are sequentially connected in series, a #1 flowmeter 4 is arranged at a solution outlet of the isopropanol solution reservoir 3, and a solution outlet of the isopropanol solution reservoir 3 is connected to SO₃Solution inlet of absorber 5, SO₃The flue gas outlet of the absorber 5 is connected to a waste gas processor 7, SO, via a flue gas volume flow meter 6 and a suction pump 20₃The solution outlet of the absorber 5 is connected to a measuring device 19 through an electric valve 8; BaCl₂The outlet of the solution reservoir 10 is fitted with a #3 flow meter 12, and BaCl₂The outlet of the solution reservoir 10 is connected to a measuring device 19, the outlet of the NaOH solution reservoir 11 is equipped with a #2 flow meter 13, and the outlet of the NaOH solution reservoir 11 is connected to the measuring device 19, measuringA stirrer 16 is arranged in the device 19, and pH and SO are arranged in the measuring device 19₃ ^2-Electrode 14, flue gas volume flow meter 6, #3 flow meter 12 and pH and SO₃ ^2-The electrodes 14 are all connected with the digital converter 9, a deionized water flushing valve 15 is arranged at a flushing water inlet of the measuring device 19, and a waste liquid emptying valve 17 is arranged at a waste liquid outlet of the measuring device 19.

The working method comprises the following steps:

1. before the start of the test, SO is metered from an isopropanol solution reservoir 3 via a #1 flow meter 4₃Adding isopropanol absorption liquid into the absorber 5, and adding SO₃The absorber 5 is placed in a temperature control box 18.

2. The heating smoke gun 1 is arranged in the flue, the smoke is provided with negative pressure by the air pump 20 and enters the SO in a bubbling mode through the heating smoke gun 1 and the one-way valve 2₃And the absorber 5 measures the volume of the extracted flue gas after the flue gas is washed by the flue gas volume flowmeter 6, and the flue gas is exhausted after being treated by the waste gas processor 7.

3. After the absorption of the flue gas is finished, the electric valve 8 is opened, the isopropanol solution which absorbs the sulfur trioxide in the flue gas is discharged into a measuring device 19 and passes through pH and SO₃ ^2-The electrode 14 monitors the pH value of the solution, the #2 flowmeter 13 is automatically started to inject the NaOH solution in the NaOH solution storage 11 into the measuring device 19, and the SO in the solution is stirred by the stirrer 16₃Fully reacts with strong alkali to generate SO₄ ^2-The solution pH was adjusted to about 7.0 and the #2 flow meter 13 was automatically closed.

4. Turn on #3 flowmeter 12 to add BaCl₂BaCl in solution reservoir 10₂The solution is poured into the measuring device 19, and Ba in the solution is stirred by the stirrer 16²⁺With SO₄ ^2-Fully react to generate BaSO₄Precipitation, SO in solution₄ ^2-The concentration decreases rapidly by SO₄ ^2-The electrode transmits the signal to the digital converter 9 to calculate SO in the solution₄ ^2-Degree of reaction of (c).

5. Signal, pH and SO through #3 flowmeter 12₃ ^2-Signals of the electrodes 14, signals of the flue gas volume flow meter 6, existing on-line monitoringHumidity and oxygen content of flue gas and BaCl₂Calculating the concentration of the solution to extract SO in the flue gas within the measurement time₃The concentration of (c).

6. After the measurement is finished, the waste liquid is drained through the waste liquid drain valve 17, the deionized water flushing valve 15 is opened to flush the measuring device 19, and the measuring device 19 is kept clean.

Specifically, the one-way valve 2 prevents the flue gas from flowing back, and the #1 flow meter 4 quantifies the SO in a plurality of serial-connected SO pipes₃The absorbers 5 were each filled with 100ml of isopropanol absorption solution and closed in time. After 45min of absorption, the suction pump 20 is closed, the electric valve 8 is opened, the absorption liquid enters the measuring device 19, and the #1 flow meter 4 is opened to inject fresh isopropanol absorbent. The temperature control box 18 controls the internal temperature to be 0 ℃, and the temperature control box 18 accurately controls the temperature to ensure SO₃The absorption effect of the absorber 5. The isopropanol absorption liquid adopts 80% isopropanol water solution, and the air extraction flow rate is 5L/min-8L/min. The heating temperature of the heating cigarette gun 1 is more than 250 ℃, a particulate filter is arranged at the rear end of the heating cigarette gun 1, and the heating cigarette gun is convenient to replace.

Those not described in detail in this specification are well within the skill of the art.

Although the present invention has been described with reference to the above embodiments, it should be understood that the scope of the present invention is not limited thereto, and that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the present invention.