CN113311099A

CN113311099A - Experimental device for condensation of mixed acid steam of boiler tail flue gas

Info

Publication number: CN113311099A
Application number: CN202110495670.5A
Authority: CN
Inventors: 魏伟; 赵保峰; 程屾; 于贺伟; 张兴宇; 郭畅; 魏玉洁; 李培金; 张亚飞; 王文飞
Original assignee: Qilu University of Technology; Energy Research Institute of Shandong Academy of Sciences
Current assignee: Qilu University of Technology; Energy Research Institute of Shandong Academy of Sciences
Priority date: 2021-05-07
Filing date: 2021-05-07
Publication date: 2021-08-27

Abstract

The invention provides a condensation experimental device for mixed acid steam of boiler tail flue gas, belonging to the technical field of research on condensation characteristics of mixed acid steam of boiler tail flue gas.A gas distribution unit prepares a plurality of acid gases and controls the content of each acid gas; the water quantity control unit controls the content of water vapor mixed with the mixed acid vapor and the particulate matters; the feeding unit provides particles mixed with the mixed acid steam and the water steam and controls the supply amount of the particles; the heating unit heats a mixture consisting of the mixed acid steam, the water vapor and the particulate matters; the condensing unit condenses the heated mixture and controls the reaction temperature of condensation; the absorption unit absorbs the unreacted acid gas. The method simulates the condensation process of the mixed acid in the flue gas, can perform condensation characteristic experiments of single acid gas and dynamic characteristic experiments under different influence factors, ensures the data measurement accuracy, and provides a reliable experimental data basis for the low-temperature corrosion characteristic exploration of the actual engineering of the boiler.

Description

Experimental device for condensation of mixed acid steam of boiler tail flue gas

Technical Field

The invention relates to the technical field of research on condensation of mixed acid steam of boiler tail flue gas, in particular to a condensation experimental device for the mixed acid steam of the boiler tail flue gas, which is used for researching an influence mechanism of factors such as water content, mixed acid steam, temperature, fly ash particles and the like in coal-fired flue gas on the condensation characteristic of the mixed acid.

Background

In order to improve the heat efficiency of a large boiler, realize clean utilization of coal, better utilize renewable energy sources for grid-connected power generation and promote 'carbon peak reaching' and 'carbon neutralization', the 'ultralow emission', 'energy-saving modification' and 'flexibility modification' work of the boiler is imperative. The three modifications require deep reduction of the temperature of the flue gas at the tail of the boiler. However, when the smoke temperature is below the acid dew point, SO in the flue gas after coal combustion_xThe acid gases such as HCl and H₂Reaction of O to H₂SO₄HCl and is condensed into acid solution; the heat exchange tube bundle can also react with fly ash particles and heat exchange wall surfaces to cause cohesive dust deposition and low-temperature corrosion, so that blockage occurs between the heat exchange tube bundles, the operation load of a draught fan is increased, and the safe and efficient operation of a boiler is not facilitated. Therefore, the development of the condensation simulation experiment system of the acid gas at the tail part of the boiler is beneficial to exploring the characteristics of caking ash deposition and low-temperature corrosion, meets the operation regulation and control requirements of the boiler, ensures the safe and efficient operation of the tail part heat exchange equipment, and has higher economic significance and higher economic significanceSocial significance.

The prior research shows that the condensation of tail flue gas acid gas is the key to cause cohesive dust deposition and low-temperature corrosion. SO in flue gas₃Is the root cause of the occurrence of cementitious ash deposits and low temperature corrosion; firstly, condensing sulfuric acid on the surface of superfine fly ash particles; as the temperature decreases, the increase in sulfuric acid condensation leads to increased corrosion; when the wall temperature is lower than 60 ℃, other acids such as hydrochloric acid (HCl) are condensed in addition to the sulfuric acid.

It follows that the condensation characteristics of the acid vapors at the boiler tail are the main factors affecting the cementitious soot formation and low temperature corrosion. Due to the complex characteristics of tail flue gas components, the acid condensation characteristic of the tail of the boiler is influenced by various factors such as the content of mixed acid gas, the content of water vapor, fly ash particles, temperature and the like in the flue gas components. At present, the research on the condensation characteristic of mixed acid at the tail part of a boiler is very few, particularly, the condensation characteristic of the mixed acid of various parameters under the actual operation condition is simulated through an experimental means, and the method and the equipment are not available at present.

Disclosure of Invention

The invention aims to provide a boiler tail flue gas mixed acid steam condensation experimental device which can simulate the condensation characteristic of boiler mixed acid steam, fully considers the influence factors of mixed acid condensation, ensures the measurement accuracy, can perform condensation characteristic experiments of single acid gas and mixed acid gas, and provides a reliable experimental data basis for researching the caking ash deposition and low-temperature corrosion characteristics of the actual engineering of a boiler, so as to solve at least one technical problem in the background technology.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a condensation experimental device for mixed acid steam of boiler tail flue gas, which comprises:

the gas distribution unit is used for preparing various acidic gases in a condensation experiment, controlling the content of each acidic gas and simulating the acidic gas in the tail flue gas of the boiler;

the water quantity control unit is used for controlling the content of water vapor mixed with the mixed acid vapor and the particulate matters and simulating the water content in the flue gas at the tail of the boiler;

the feeding unit is used for providing particulate matters mixed with the mixed acid steam and the water vapor, controlling the supply quantity of the particulate matters and simulating fly ash particles in the tail smoke of the boiler;

the heating unit is used for simulating the temperature of the flue gas at the tail part of the boiler and heating a mixture consisting of mixed acid steam, water vapor and particulate matters;

the condensation unit simulates a low-temperature heating surface of a tail flue of the boiler and is used for condensing the heated mixture and controlling the condensation reaction temperature;

and the absorption unit is used for absorbing the unreacted acid gas.

Preferably, the air distribution unit includes:

acid vapor supply means for supplying different acid vapors; the acid steam supply device is connected with a gas mixer, and the gas mixer is connected with the heating unit.

Preferably, the acid vapor supply device includes:

the first carrier gas cylinder is connected with a sulfuric acid solution bottle, and the sulfuric acid solution bottle is connected with the gas mixer; the first carrier gas cylinder is used for providing a sulfuric acid vapor carrier; a first pressure reducing valve, a first check valve and a first flowmeter are sequentially connected between the first carrier gas bottle and the sulfuric acid solution bottle; and a first calibration sampling port is arranged between the sulfuric acid solution bottle and the gas mixer.

Preferably, the acid vapor supply device further includes:

the hydrogen chloride gas cylinder is connected with the gas mixer, and a second pressure reducing valve, a second check valve and a second flowmeter are sequentially connected between the hydrogen chloride gas cylinder and the gas mixer; and a second calibration sampling port is arranged between the second flowmeter and the gas mixer.

Preferably, the experimental apparatus further comprises:

the second carrier gas cylinder is connected with the heating unit, and a third pressure reducing valve, a third check valve and a third flowmeter are sequentially connected between the second carrier gas cylinder and the heating unit.

Preferably, the water amount control unit includes:

the water storage tank and the peristaltic pump communicated with the water storage tank control the state of the peristaltic pump through a PID controller, and the flow of deionized water in the water storage tank flowing into the heating unit is adjusted, so that the adjustment of the water vapor content is realized.

Preferably, the water amount control unit includes:

the first temperature control constant-temperature water bath tank is internally provided with a water storage bottle, the second carrier gas bottle is communicated with the water storage bottle, and the water storage bottle is communicated with the heating unit; the second carrier gas cylinder is used for providing a water vapor carrier; and a proportional regulating valve is arranged between the third pressure reducing valve and the third check valve, and the opening degree of the proportional regulating valve is controlled by the PID controller to regulate the flow of the gas flowing out of the second carrier gas cylinder.

Preferably, the feeding unit comprises a micro-feeder which adjusts the feeding amount of the particulate matter by the control of a PID controller; the micro feeder is connected with the heating unit; the heating unit comprises the temperature control tube type heating furnace, and the heating temperature of the temperature control tube type heating furnace is adjusted through the control of a PID controller.

Preferably, the condensing unit includes with the straight type condenser pipe of heating unit intercommunication, the second control by temperature change constant temperature water tank is connected at the both ends of the outer tube of straight type condenser pipe, be equipped with the circulating pump between second control by temperature change constant temperature water bath and the outer tube.

Preferably, the absorption unit comprises a tail gas absorption bottle, and the inner pipe of the straight condensation pipe is connected with the tail gas absorption bottle.

The invention has the beneficial effects that: influence factors of mixed acid coagulation are fully considered, and the measurement accuracy is ensured; simulating the condensation characteristic of the mixed acid steam; the condensation characteristic test of single acid gas and mixed acid gas and the dynamic characteristic test under different influence factors can be carried out; and a reliable test data basis is provided for the research of the caking ash deposition and low-temperature corrosion characteristics of the actual engineering of the boiler.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a structural diagram of a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler according to embodiment 1 of the present invention.

Fig. 2 is a structural diagram of a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler according to embodiment 2 of the present invention.

Fig. 3 is a structural diagram of a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler according to embodiment 3 of the present invention.

Fig. 4 is a structural diagram of a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler according to embodiment 4 of the present invention.

Wherein: 1-a gas mixer; 2-a first carrier gas cylinder; 3-sulfuric acid solution bottle; 4-a first pressure relief valve; 5-a first check valve; 6-a first flow meter; 7-a first calibrated sampling port; 8-hydrogen chloride gas cylinder; 9-a second pressure reducing valve; 10-a second check valve; 11-a second flow meter; 12-a second calibrated sampling port; 13-ion chromatography tester; 14-a second carrier gas cylinder; 15-a water storage tank; 16-a third pressure relief valve; 17-a third check valve; 18-a third flow meter; 19-a micro-feeder; 20-a PID controller; 21-temperature control tube type heating furnace; 22-straight condenser tube; 23-a second temperature-control constant-temperature water bath tank; 24-a circulation pump; 25-tail gas absorption bottle; 26-a water inlet; 27-a third calibrated sampling port; 28-proportional solenoid valve; 29-peristaltic pump; 30-a first temperature-control constant-temperature water bath tank; 31-water storage bottle.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by way of the drawings are illustrative only and are not to be construed as limiting the invention.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

In the description of the present specification, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present specification, the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, only for convenience of description and simplification of description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present technology.

Unless expressly stated or limited otherwise, the terms "mounted," "connected," "coupled," and "disposed" are intended to be inclusive and mean, for example, that they may be fixedly coupled or disposed, or that they may be removably coupled or disposed, or that they may be integrally coupled or disposed. The specific meaning of the above terms in the present technology can be understood by those of ordinary skill in the art as appropriate.

For the purpose of facilitating an understanding of the present invention, the present invention will be further explained by way of specific embodiments with reference to the accompanying drawings, which are not intended to limit the present invention.

It should be understood by those skilled in the art that the drawings are merely schematic representations of embodiments and that the elements shown in the drawings are not necessarily required to practice the invention.

Example 1

As shown in fig. 1, embodiment 1 of the present invention provides a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler, including:

and the absorption unit is used for absorbing the unreacted acid gas.

In this embodiment 1, the air distribution unit includes: an acid vapor supply device for supplying a plurality of different acid vapors; the acid steam supply device is connected with a gas mixer 1, and the gas mixer 1 is connected with the heating unit.

In this embodiment 1, the acid vapor supply device includes:

the first carrier gas bottle 2 is connected with a sulfuric acid solution bottle 3, and the sulfuric acid solution bottle 3 is connected with the gas mixer 1; the first carrier gas cylinder 2 is used for providing a sulfuric acid vapor carrier; a first pressure reducing valve 4, a first check valve 5 and a first flow meter 6 are sequentially connected between the first carrier gas bottle 2 and the sulfuric acid solution bottle 3.

In this embodiment 1, the gas in the first carrier gas cylinder 2 is nitrogen, and the first pressure reducing valve 4 reduces the pressure of the gas, so as to adjust the flow rate; the first check valve 5 prevents the nitrogen from flowing backward; the first flow meter 6 measures the flow rate of the nitrogen gas flowing into the sulfuric acid solution bottle 3, and the first pressure reducing valve 4 is adjusted according to the measurement of the first flow meter 6 to obtain the required sulfuric acid vapor content.

In this embodiment 1, in order to mix the acid, the acid vapor supply device further includes:

a hydrogen chloride gas cylinder 8, the hydrogen chloride gas cylinder 8 is connected with the gas mixer 1, a second pressure reducing valve 9, a second check valve 10 and a second flowmeter 11 are sequentially connected between the hydrogen chloride gas cylinder 8 and the gas mixer 1.

In example 1, the second pressure reducing valve 9 reduces the pressure of the hydrogen chloride gas and adjusts the flow rate; the second check valve 10 can prevent the backflow of the hydrogen chloride gas; the second flow meter 11 can meter the flow of hydrogen chloride gas. The second pressure reducing valve 9 is adjusted to obtain the desired hydrochloric acid vapour content, depending on the metering by the second flow meter 11.

The gas mixer 1 can be used for uniformly mixing two acid steams, namely sulfuric acid steam and hydrochloric acid steam, and flowing the acid steams to a subsequent temperature control tubular heating furnace.

In this embodiment 1, the water amount control unit includes:

the device comprises a water storage tank 15 and a peristaltic pump 29 communicated with the water storage tank 15, wherein deionized water is stored in the water storage tank 15, and the state of the peristaltic pump 29 is controlled by a PID (proportion integration differentiation) controller 20, so that the flow of the deionized water in the water storage tank 15 flowing into a temperature control tube type heating furnace 21 is adjusted, and the adjustment of the water vapor content is realized.

In this embodiment 1, the experimental apparatus further includes a second carrier gas cylinder 14, where the second carrier gas cylinder 14 is used to provide the non-acid gas content in the mixed gas; the second carrier gas bottle 14 is connected with a temperature-controlled tube type heating furnace 21, and a third reducing valve 16, a third check valve 17 and a third flowmeter 18 are sequentially arranged between the second carrier gas bottle 14 and the temperature-controlled tube type heating furnace 21.

In this example 1, the second carrier gas cylinder 14, also storing nitrogen, can be used to adjust the content ratio of the simulated non-acidic flue gas. The third pressure reducing valve 16 is used for reducing the pressure of the gas and regulating the flow; the third check valve 17 prevents the nitrogen from flowing backward; the third flow meter 18 meters the gas flow; the nitrogen gas in the second carrier gas bottle 14 enters the temperature-controlled tubular heating furnace 21 to adjust the flue gas content in the temperature-controlled tubular heating furnace 21.

In this embodiment 1, according to the water vapor content set by the experiment, the on-off state of the peristaltic pump 29 is controlled by the PID controller 20, so as to adjust the content of the deionized water entering the temperature-controlled tubular heating furnace 21 to reach the set water vapor content.

In this embodiment 1, the dosing unit comprises a microdoser 19, which microdoser 19 regulates the amount of particulate matter supplied by control of a PID controller 20; the micro-feeder 19 is connected to the heating unit. According to the experiment requirement, the PID controller is adopted to adjust the using amount of the particles, and the particles with different characteristics are added to the subsequent heating unit.

The heating unit comprises the temperature-controlled tube type heating furnace 21, and the temperature-controlled tube type heating furnace 21 adjusts the heating temperature through the control of the PID controller 20. The PID controller adjusts the heating temperature of the temperature control tube type heating furnace, and temperature requirements of different experiments are met.

The condensing unit comprises a straight condensing pipe 22 communicated with the temperature control pipe type heating furnace 21, two ends of an outer sleeve of the straight condensing pipe 22 are connected with a second temperature control constant temperature water bath tank 23, and a circulating pump 24 is arranged between the second temperature control constant temperature water bath tank 23 and the outer sleeve. The second temperature-controlled constant-temperature water bath tank 23 heats the deionized water to a set temperature according to the cooling temperature requirement of the straight condenser pipe.

The second thermostat bath tank 23 is for controlling the wall surface temperature of the condensing unit by setting the cooling water temperature of the condensing unit.

The absorption unit comprises a tail gas absorption bottle 25, and the inner pipe of the straight condensation pipe 22 is connected with the tail gas absorption bottle 25. The circulation pump 24 is used for adjusting the flow of the deionized water, controlling the water temperature at the inlet and the outlet and adjusting the reaction temperature of the condensation pipe. The straight condenser pipe adopts a temperature control constant temperature water tank to flow out deionized water with specific temperature to cool high-temperature airflow flowing out of the tubular furnace. The tail gas absorption bottle is used for absorbing unreacted residual gas.

In this embodiment 1, the experimental apparatus can simulate the condensation process of the mixed acid in the boiler flue gas, and can perform the condensation characteristic experiment of a single acid gas and the dynamic characteristic experiment under different influence factors, thereby ensuring the accuracy of data measurement and providing a reliable experimental data basis for the low-temperature corrosion characteristic exploration of the actual engineering of the boiler.

Example 2

As shown in fig. 2, embodiment 2 of the present invention provides a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler, including:

and the absorption unit is used for absorbing the unreacted acid gas.

In this embodiment 2, the air distribution unit includes: an acid vapor supply device for supplying a plurality of different acid vapors; the acid steam supply device is connected with a gas mixer 1, and the gas mixer 1 is connected with the heating unit.

In this embodiment 2, the acid vapor supply device includes:

In this embodiment 2, the gas in the first carrier gas cylinder 2 is nitrogen, and the first pressure reducing valve 4 reduces the pressure of the gas, so as to adjust the flow rate; the first check valve 5 prevents the nitrogen from flowing backward; the first flow meter 6 measures the flow rate of the nitrogen gas flowing into the sulfuric acid solution bottle 3, and the first pressure reducing valve 4 is adjusted according to the measurement of the first flow meter 6 to obtain the required sulfuric acid vapor content.

In order to study the precise quantitative relationship between the condensation of the acid and the content of the acid in the flue gas, in this embodiment 2, a first calibration sampling port 7 is provided between the sulfuric acid solution bottle 3 and the gas mixer 1, and the gas is sampled by using the first calibration sampling port 7 for calibrating the content of the sulfuric acid by an ion chromatograph; when the content of the sulfuric acid is calibrated, the ion chromatography tester 13 determines the content of sulfate ions to determine the content of sulfuric acid vapor, and the final calibration value is used for analyzing the working condition.

In this embodiment 2, in order to mix the acid, the acid vapor supply device further includes:

In this example 2, the second pressure reducing valve 9 reduces the pressure of the hydrogen chloride gas and adjusts the flow rate; the second check valve 10 can prevent the backflow of the hydrogen chloride gas; the second flow meter 11 can meter the flow of hydrogen chloride gas. The second pressure reducing valve 9 is adjusted to obtain the desired hydrochloric acid vapour content, depending on the metering by the second flow meter 11.

In order to study the precise quantitative relationship between the condensation of the acid and the content of the acid in the flue gas, in this embodiment 2, a second calibration sampling port 12 is provided between the second flowmeter 11 and the gas mixer 1, and the gas is sampled by using the second calibration sampling port 12 for the ion chromatograph to calibrate the HCl content; when the HCl content is calibrated, the ion chromatography tester 13 determines the chloride ion content to determine the hydrogen chloride content, and the final calibration value is used for experimental analysis.

In this example 2, in the gas mixer 1, two kinds of acid vapors, i.e., sulfuric acid vapor and hydrochloric acid vapor, are uniformly mixed and flow to the subsequent temperature-controlled tubular heating furnace 21.

In this embodiment 2, the water amount control unit includes:

In this embodiment 2, the experimental apparatus further includes a second carrier gas cylinder 14, where the second carrier gas cylinder 14 is used to provide the non-acid gas content in the mixed gas; the second carrier gas bottle 14 is connected with a temperature-controlled tube type heating furnace 21, and a third reducing valve 16, a third check valve 17 and a third flowmeter 18 are sequentially arranged between the second carrier gas bottle 14 and the temperature-controlled tube type heating furnace 21.

In this example 2, the second carrier gas cylinder 14 is also stored with nitrogen, which can be used to adjust the content ratio of the simulated non-acidic flue gas. The third pressure reducing valve 16 is used for reducing the pressure of the gas and regulating the flow; the third check valve 17 prevents the nitrogen from flowing backward; the third flow meter 18 meters the gas flow; the nitrogen gas in the second carrier gas bottle 14 enters the temperature-controlled tubular heating furnace 21 to adjust the flue gas content in the temperature-controlled tubular heating furnace 21.

In this embodiment 2, according to the water vapor content set by the experiment, the on-off state of the peristaltic pump 29 is controlled by the PID controller 20, so as to adjust the content of the deionized water entering the temperature-controlled tubular heating furnace 21 to reach the set water vapor content.

In this embodiment 2, the dosing unit comprises a minifeeder 19, the minifeeder 19 regulating the amount of particulate matter supplied by control of a PID controller 20; the micro-feeder 19 is connected to the heating unit. According to the experiment requirement, the PID controller is adopted to adjust the using amount of the particles, and the particles with different characteristics are added to the subsequent heating unit.

The heating unit comprises the temperature-controlled tube type heating furnace 21, and the temperature-controlled tube type heating furnace 21 adjusts the heating temperature through the control of the PID controller 20. The PID controller adjusts the heating temperature of the temperature control tube type heating furnace 21, and temperature requirements of different experiments are met.

In example 2, a mixed acid coagulation experiment was performed using the experimental apparatus described above. The experiment can be divided into a condensation characteristic experiment of single acid gas and a condensation characteristic experiment of mixed acid steam.

Experiment one: experiment of condensation characteristics of single acid gas

The temperature-controlled tubular heating furnace 21 was turned on, and the heating temperature required for the reaction was set using the PID controller 20 (the set heating temperature was different depending on the acid vapor, ensuring that the set heating temperature was higher than the acid boiling point). After the second temperature-controlled constant-temperature water bath tank 23 is cleaned, deionized water is added through the water inlet 26, and the temperature of the deionized water in the second temperature-controlled constant-temperature water bath tank 23 is set according to the condensation condition. After the temperature is constant, the second carrier gas cylinder 14 is opened, the third pressure reducing valve 16 is adjusted, and the third flow meter 18 is read until the nitrogen flow under the experimental working condition is reached. After the water storage tank 15 is cleaned, deionized water is added, and according to the water vapor content required by the experimental working conditions, the PID controller 20 is adopted to control the peristaltic pump, control the flow of the deionized water flowing out of the water storage tank 15, and adjust the flow of the deionized water flowing into the temperature control tubular heating furnace 21.

And opening the first carrier gas cylinder or the hydrogen chloride gas cylinder, adjusting the pressure reducing valve according to the experimental set working condition, and controlling the flow of the gas path to obtain the content of the single sulfuric acid vapor or the hydrogen chloride gas set by the experiment.

By PID controlThe system 20 precisely controls the specific particle size SO₂The content of the particles and a certain amount of deionized water are fed into a temperature-controlled tubular heating furnace to be heated (the set heating temperature is different according to different acid steam, so that the set heating temperature is higher than the acid boiling point).

The heated mixed gas flows to a straight condensing tube for cooling, the condensation condition of acid steam is observed, and tail gas is introduced into a tail gas absorption bottle.

Experiment two: mixed acid steam condensation characteristic experiment:

on the basis of a single acid condensation experiment, three paths of gases are opened simultaneously, the corresponding flow and the temperature of heating equipment are controlled, and the condensation characteristic experiment of mixed acid steam is carried out. And analyzing the change rule of the condensation characteristic of the mixed acid steam by adjusting the acid steam content, the water vapor content and the particle size of the particles.

Based on the hypothesis of mixed acid coagulation theory, non-alkaline SiO which is high in fly ash content and does not react with acid is selected₂The particulate matter is a reactant that takes into account the coagulation phase to influence the coagulation of the mixed acid.

Designing and building a mixed acid coagulation seed laboratory experiment, and directionally regulating and controlling reaction temperature, acid steam type and content, water vapor content and SiO₂And carrying out a mixed acid condensation experiment under reaction conditions such as particle size of the particles. And the accuracy of a theoretical model is verified by combining the laboratory experiment phenomenon of mixed acid condensation, so that the accurate prediction of the mixed acid gas condensation under the high-humidity environment of the tail flue gas of the coal-fired co-combustion biomass boiler is realized.

Firstly, observing the condensation effect of the straight condensation pipe; weighing the straight condensing pipe to obtain the condensation amount; then carrying out ion test on the condensed liquid in the condensation pipe to obtain the condensation concentration; and (4) performing characterization analysis on the particles to obtain the condensation characteristic of the acid vapor on the surface of the condensation core, and analyzing the influence rule of condensation of the mixed acid vapor.

Experiment three: dynamic experiment of variable working conditions for simulating caking property dust deposition:

in this example 2, a dynamic test of a variable behavior simulating the adhesive deposition was also performed using the above-described experimental apparatus. The experimental process is similar to the process of mixed acid coagulation, compared with the process of mixed acid coagulation, the amount of particles is increased, the types and the proportion of the particles are changed, and the types, the mixing proportion and the particle size distribution of the micro-feeder are changed according to experimental working conditions.

On the basis of a mixed acid condensation experiment table, the dynamic experiment for simulating the caking deposition is carried out by directionally regulating and controlling the gas distribution, the particulate matters and the reaction temperature and dynamically simulating the action process of condensing the mixed acid liquid and the composite fly ash particles.

Selecting pure oxide SiO with standard grain diameter₂Representing the first non-alkaline oxide in the actual coal ash particles, CaO representing the most representative high-content alkali metal compound in the actual coal ash particles, and sampling the fly ash particles after an air preheater, designing mixed particulate matters with different proportions, respectively carrying out variable working condition laboratory experiments, and accurately measuring the change rule of the acid-ash action amount along with the reaction conditions. And respectively sampling the reacted particles, performing characterization test, and inspecting the characteristic changes of the acid-ash reaction product such as microscopic characteristics, element components, crystalline phase distribution and the like under different wall surface temperatures, smoke components and particle size distribution.

Firstly, the agglomeration effect of the condensed acid liquid and the particulate matters of the straight condensing pipe is observed. Weighing the straight condensing pipe to obtain the reaction amount of the condensed acid and the particles; and sampling the acid-ash reaction product after reaction in the condenser tube, performing characterization test to obtain characteristic changes such as microscopic characteristics, element components, crystal phase distribution and the like, and analyzing the action degree of physical adsorption and chemical reaction.

Example 3

In the first and second embodiments, the content of water vapor in the mixed gas can be calculated to obtain the accurate molar concentration, the volume concentration of the acid vapor is adopted, the two are mixed and then expressed by using the volume concentration, when the molar concentration of the water vapor is converted into the volume content, errors can be brought due to uncertainty of temperature, and in order to more accurately obtain the influence of the water vapor content on acid condensation, the third embodiment provides another water vapor adding mode and calibrates the volume concentration of the water vapor.

As shown in fig. 3, embodiment 3 of the present invention provides a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler, including: the gas distribution unit is used for preparing various acidic gases in a condensation experiment, controlling the content of each acidic gas and simulating the acidic gas in the tail flue gas of the boiler; the water quantity control unit is used for controlling the content of water vapor mixed with the mixed acid vapor and the particulate matters and simulating the water content in the flue gas at the tail of the boiler; the feeding unit is used for simulating fly ash particles in the flue gas at the tail part of the boiler, providing particulate matters mixed with the mixed acid steam and the water vapor and controlling the supply amount of the particulate matters; the heating unit is used for simulating the temperature of the flue gas at the tail part of the boiler and heating a mixture consisting of mixed acid steam, water vapor and particulate matters; the condensation unit simulates a low-temperature heating surface of a tail flue of the boiler and is used for condensing the heated mixture and controlling the condensation reaction temperature; and the absorption unit is used for absorbing the unreacted acid gas.

In this embodiment 3, the air distribution unit includes: an acid vapor supply device for supplying a plurality of different acid vapors; the acid steam supply device is connected with a gas mixer 1, and the gas mixer 1 is connected with the heating unit.

In this embodiment 3, the acid vapor supply device includes: the first carrier gas bottle 2 is connected with a sulfuric acid solution bottle 3, and the sulfuric acid solution bottle 3 is connected with the gas mixer 1; the first carrier gas cylinder 2 is used for providing a sulfuric acid vapor carrier; a first pressure reducing valve 4, a first check valve 5 and a first flow meter 6 are sequentially connected between the first carrier gas bottle 2 and the sulfuric acid solution bottle 3.

In this embodiment 3, the gas in the first carrier gas cylinder 2 is nitrogen, and the first pressure reducing valve 4 reduces the pressure of the gas, so as to adjust the flow rate; the first check valve 5 prevents the nitrogen from flowing backward; the first flow meter 6 measures the flow rate of the nitrogen gas flowing into the sulfuric acid solution bottle 3, and the required sulfuric acid vapor content can be obtained according to the gas flow rate.

In this embodiment 3, in order to realize the mixed acid, the acid vapor supply device further includes: a hydrogen chloride gas cylinder 8, the hydrogen chloride gas cylinder 8 is connected with the gas mixer 1, a second pressure reducing valve 9, a second check valve 10 and a second flowmeter 11 are sequentially connected between the hydrogen chloride gas cylinder 8 and the gas mixer 1.

In example 3, the second pressure reducing valve 9 reduces the pressure of the hydrogen chloride gas and adjusts the flow rate; the second check valve can prevent the backflow of the hydrogen chloride gas; the second flow meter 11 can meter the flow of hydrogen chloride gas. The second pressure reducing valve 9 is adjusted to obtain the desired hydrochloric acid vapour content, depending on the metering by the second flow meter 11.

The heating unit comprises a temperature control tube type heating furnace 21, and the temperature control tube type heating furnace 21 adjusts the heating temperature through the control of a PID controller 20.

In this embodiment 3, in the gas mixer 1, two kinds of acid vapors, i.e., sulfuric acid vapor and hydrochloric acid vapor, are uniformly mixed to obtain mixed acid vapor, and the mixed acid vapor flows to the subsequent temperature-controlled tubular heating furnace 21.

In this embodiment 3, the water amount control unit includes:

a second carrier gas cylinder 14, said second carrier gas cylinder 14 for providing a water vapour carrier; the second carrier gas cylinder 14 is connected with a first temperature-control constant-temperature water bath tank 30, and a third pressure reducing valve 16, a third check valve 17 and a third flow meter 18 are sequentially arranged between the second carrier gas cylinder 14 and the first temperature-control constant-temperature water bath tank 30; the first temperature-controlled constant-temperature water bath tank 30 is connected to the heating unit.

A water storage bottle 31 is arranged in the first temperature-control constant-temperature water bath tank 30, the second carrier gas bottle 14 is communicated with the water storage bottle 31, and the water storage bottle 31 is communicated with the heating unit; deionized water is stored in the water storage bottle 31.

In this example 3, the second carrier gas cylinder 14 stores nitrogen gas, and the third pressure reducing valve 16 is used to reduce the pressure of the gas and adjust the flow rate of the nitrogen gas; the third check valve 17 prevents the nitrogen from flowing backward; the third flow meter 18 meters the gas flow; the nitrogen gas in the second carrier gas cylinder 14 flows through the first temperature-controlled constant-temperature water bath 30.

In the embodiment 3, a proportional control valve 28 is arranged between the third reducing valve 16 and the third check valve 17, and the proportional control valve 28 is controlled by the PID controller 20 to control the opening degree, so that the flow rate of the nitrogen in the second carrier gas cylinder 14 is accurately controlled, and the water vapor content is accurately controlled.

In this embodiment 3, the temperature of the deionized water is set by using the first temperature-controlled constant-temperature water bath 30, and the flow rate of the nitrogen gas is adjusted according to the calibrated water vapor content required by the experiment. The adjusted nitrogen gas carries the water vapor with the set content to the subsequent temperature control tubular heating furnace 21 after passing through the deionized water.

In embodiment 3, as shown in fig. 3, a third calibration sampling port 27 is provided in the pipeline between the first temperature-controlled constant-temperature water bath 30 and the temperature-controlled tube-type heating furnace 21. When the water vapor is quantified, a water vapor sample is taken out through the third calibration sampling port 27, a national standard gas moisture content testing method is adopted, a drying agent is used for absorbing and weighing, the water vapor content is measured, and the final measured value is used as the data of experimental working condition analysis.

In this embodiment 3, in order to make the contents of the mixed acid steam and the water vapor simulated in the temperature-controlled tubular heating furnace more accurate, a linkage control unit is further provided.

The dosing unit comprises a micro-feeder 19, the micro-feeder 19 regulating the amount of particulate matter supplied by control of a PID controller 20; the micro-feeder 19 is connected to the heating unit.

The condensing unit include with the straight condenser pipe 22 of heating unit intercommunication, second control by temperature change constant temperature water bath 23 is connected at the both ends of the outer tube of straight condenser pipe 22, be equipped with circulating pump 24 between second control by temperature change constant temperature water bath 23 and the outer tube. The second temperature-controlled constant-temperature water bath tank 23 heats the deionized water to a set temperature according to the cooling temperature requirement of the straight condenser pipe.

In example 3, a mixed acid coagulation experiment was performed using the experimental apparatus described above. The experiment can be divided into a condensation characteristic experiment of single acid gas and a condensation characteristic experiment of mixed acid steam.

In this embodiment 3, the experimental device can simulate the condensation process of the mixed acid in the boiler flue gas, can perform the condensation characteristic experiment of a single acid gas and the dynamic characteristic experiment under different influence factors, ensures the accuracy of data measurement, and provides a reliable experimental data basis for the low-temperature corrosion characteristic exploration of the actual engineering of the boiler.

Example 4

As shown in fig. 4, embodiment 4 of the present invention provides a condensation experimental apparatus for mixed acid vapor in tail flue gas of a boiler, including: the gas distribution unit is used for preparing various acidic gases in a condensation experiment, controlling the content of each acidic gas and simulating the acidic gas in the tail flue gas of the boiler; the water quantity control unit is used for controlling the content of water vapor mixed with the mixed acid vapor and the particulate matters and simulating the water content in the flue gas at the tail of the boiler; the feeding unit is used for simulating fly ash particles in the flue gas at the tail part of the boiler, providing particulate matters mixed with the mixed acid steam and the water vapor and controlling the supply amount of the particulate matters; the heating unit is used for simulating the temperature of the flue gas at the tail part of the boiler and heating a mixture consisting of mixed acid steam, water vapor and particulate matters; the condensation unit simulates a low-temperature heating surface of a tail flue of the boiler and is used for condensing the heated mixture and controlling the condensation reaction temperature; and the absorption unit is used for absorbing the unreacted acid gas.

In this embodiment 4, the air distribution unit includes: an acid vapor supply device for supplying a plurality of different acid vapors; the acid steam supply device is connected with a gas mixer 1, and the gas mixer 1 is connected with the heating unit.

In this embodiment 4, the acid vapor supply device includes: the first carrier gas bottle 2 is connected with a sulfuric acid solution bottle 3, and the sulfuric acid solution bottle 3 is connected with the gas mixer 1; the first carrier gas cylinder 2 is used for providing a sulfuric acid vapor carrier; a first pressure reducing valve 4, a first check valve 5 and a first flow meter 6 are sequentially connected between the first carrier gas bottle 2 and the sulfuric acid solution bottle 3.

In this embodiment 4, the gas in the first carrier gas cylinder 2 is nitrogen, and the first pressure reducing valve 4 reduces the pressure of the gas, so as to adjust the flow rate; the first check valve 5 prevents the nitrogen from flowing backward; the first flow meter 6 measures the flow rate of the nitrogen gas flowing into the sulfuric acid solution bottle 3, and the required sulfuric acid vapor content can be obtained according to the gas flow rate.

In this embodiment 4, a first calibration sampling port 7 is disposed between the sulfuric acid solution bottle 3 and the gas mixer 1, and the first calibration sampling port 7 is used to sample gas for calibrating the sulfuric acid content by an ion chromatograph; when the content of the sulfuric acid is calibrated, the ion chromatography tester 13 determines the content of sulfate ions to determine the content of sulfuric acid vapor, and the final calibration value is used for analyzing the working condition.

In this embodiment 4, in order to realize the mixed acid, the acid vapor supply device further includes: a hydrogen chloride gas cylinder 8, the hydrogen chloride gas cylinder 8 is connected with the gas mixer 1, a second pressure reducing valve 9, a second check valve 10 and a second flowmeter 11 are sequentially connected between the hydrogen chloride gas cylinder 8 and the gas mixer 1.

In example 4, the second pressure reducing valve 9 reduces the pressure of the hydrogen chloride gas and adjusts the flow rate; the second check valve can prevent the backflow of the hydrogen chloride gas; the second flow meter 11 can meter the flow of hydrogen chloride gas. The second pressure reducing valve 9 is adjusted to obtain the desired hydrochloric acid vapour content, depending on the metering by the second flow meter 11.

In this embodiment 4, a second calibration sampling port 12 is disposed between the second flowmeter 11 and the gas mixer 1, and the second calibration sampling port 12 is used to sample gas for calibrating the HCl content by the ion chromatograph; when the HCl content is calibrated, the ion chromatography tester 13 determines the chloride ion content to determine the hydrogen chloride content, and the final calibration value is used for experimental analysis.

In the gas mixer 1, sulfuric acid steam and hydrochloric acid steam are uniformly mixed to obtain mixed acid steam, and the mixed acid steam flows to a subsequent temperature control tubular heating furnace.

In this embodiment 4, the water amount control unit includes:

In this embodiment 4, the second carrier gas cylinder 14 stores nitrogen gas, and the third pressure reducing valve 16 is used to reduce the pressure of the gas and adjust the flow rate of the nitrogen gas; the third check valve 17 prevents the nitrogen from flowing backward; the third flow meter 18 meters the gas flow; the nitrogen gas in the second carrier gas cylinder 14 flows through the first temperature-controlled constant-temperature water bath 30.

In the embodiment 4, a proportional control valve 28 is arranged between the third reducing valve 16 and the third check valve 17, and the proportional control valve 28 is controlled by the PID controller 20 to control the opening degree, so that the flow rate of the nitrogen in the second carrier gas cylinder 14 is accurately controlled, and the water vapor content is accurately controlled.

In this embodiment 4, the temperature of the deionized water is set by using the first temperature-controlled constant-temperature water bath 30, and the flow rate of the nitrogen gas is adjusted according to the calibrated water vapor content required by the experiment. The adjusted nitrogen gas carries the water vapor with the set content to the subsequent temperature control tubular heating furnace 21 after passing through the deionized water.

In the present embodiment 4, as shown in fig. 3, the third calibration sampling port 27 is provided in the pipeline between the first temperature-controlled constant temperature water bath 30 and the temperature-controlled tube heating furnace 21. When the water vapor is quantified, a water vapor sample is taken out through the third calibration sampling port 27, a national standard gas moisture content testing method is adopted, a drying agent is used for absorbing and weighing, the water vapor content is measured, and the final measured value is used as the data of experimental working condition analysis.

The dosing unit comprises a micro-feeder 19, the micro-feeder 19 regulating the amount of particulate matter supplied by control of a PID controller 20; the micro-feeder 19 is connected to the heating unit. The heating unit comprises a temperature control tube type heating furnace 21, and the temperature control tube type heating furnace 21 adjusts the heating temperature through the control of a PID controller 20. The condensing unit include with the straight condenser pipe 22 of heating unit intercommunication, second control by temperature change constant temperature water bath 23 is connected at the both ends of the outer tube of straight condenser pipe 22, be equipped with circulating pump 24 between second control by temperature change constant temperature water bath 23 and the outer tube. The second temperature-controlled constant-temperature water bath tank 23 heats the deionized water to a set temperature according to the cooling temperature requirement of the straight condenser pipe.

In example 4, a mixed acid coagulation experiment was performed using the experimental apparatus described above. The experiment can be divided into a condensation characteristic experiment of single acid gas and a condensation characteristic experiment of mixed acid steam.

Experiment one: experiment of condensation characteristics of single acid gas

The temperature-controlled tubular heating furnace 21 was turned on, and the heating temperature required for the reaction was set using the PID controller 20 (the set heating temperature was different depending on the acid vapor, ensuring that the set heating temperature was higher than the acid boiling point). After the second temperature-controlled constant-temperature water bath tank 23 is cleaned, deionized water is added through the water inlet 26, and the temperature of the deionized water in the second temperature-controlled constant-temperature water bath tank 23 is set according to the condensation condition. After the first temperature-controlled water bath tank 30 is cleaned, deionized water is added from the water inlet 26, and after the temperature of the second temperature-controlled constant-temperature water bath tank 23 is constant, the second carrier gas cylinder 14 is opened according to the water vapor content of the experimental working condition, the third pressure reducing valve 16 is adjusted, the third flow meter 18 is read, and the control of the proportional control valve 28 is combined with the PID controller 20 until the nitrogen flow of the experimental working condition is reached.

Accurately regulating and controlling specific particle size SO by PID controller 20₂The content of the particulate matter is introduced into the temperature-controlled tubular heating furnace 21 together with the steam to be heated (the set heating temperature is different depending on the acid steam, and the set heating temperature is higher than the acid boiling point).

Experiment two: mixed acid steam condensation characteristic experiment:

In example 3, the experimental parameters of the mixed acid vapor condensation characteristics experiment are shown in table 1.

TABLE 1

in this example 3, a dynamic behavior experiment for simulating the cohesive soot deposition was also performed using the above-described experimental apparatus. The experimental process is similar to the process of mixed acid coagulation, compared with the process of mixed acid coagulation, the amount of particles is increased, the types and the proportion of the particles are changed, and the types, the mixing proportion and the particle size distribution of the micro-feeder are changed according to experimental working conditions.

On the basis of a mixed acid condensation experiment table, according to data in table 2, gas distribution, particulate matters and reaction temperature are directionally regulated and controlled, the action process of condensing mixed acid liquid and composite fly ash particles is dynamically simulated, and a dynamic experiment for simulating caking deposition is carried out.

TABLE 2 reaction conditions for acid-Ash Effect experiments

In summary, the experimental apparatus for condensing the mixed acid vapor in the flue gas at the tail of the boiler, provided by the embodiment of the invention, comprises a gas distribution unit, a gas supply unit and a gas control unit, wherein the gas distribution unit is used for preparing a plurality of acid gases in a condensation experiment, controlling the content of each acid gas and simulating the acid gas in the flue gas at the tail of the boiler; the gas distribution unit is connected with the gas mixer 1, and the configured acid gas flows into the gas mixer 1. The water quantity control unit is used for controlling the content of water vapor mixed with the mixed acid vapor and the particulate matters and simulating the water content in the flue gas at the tail of the boiler; the water quantity control unit is connected with the gas mixer 1, and the water vapor generated by the water quantity control unit also flows into the gas mixer 1. The feeding unit is used for providing particulate matters mixed with the mixed acid steam and the water vapor, controlling the supply quantity of the particulate matters and simulating fly ash particles in the tail smoke of the boiler; the feed unit is likewise connected to a gas mixer into which the prepared particulate material flows. Various mixed acid vapors, such as sulfuric acid vapor, hydrochloric acid vapor, and the like, as well as water vapor and particulates are mixed in a gas mixer. The gas mixer is communicated with a temperature control tube type heating furnace 21 of the heating unit, and the mixture flows into the temperature control tube type heating furnace 21 for heating. The rear end of the temperature control tube type heating furnace 21 is connected with a condensing unit, the condensing unit simulates a low-temperature heating surface of a tail flue of a boiler and is used for condensing the heated mixture and controlling the condensation reaction temperature; for example, the rear end of the temperature-controlled tube heating furnace 21 is connected to the inlet end of a straight condensing tube 22 of the condensing unit, and the heated mixture is condensed in the straight condensing tube. The rear end of the straight condensing pipe 22 is communicated with a tail gas absorption bottle to absorb unreacted acid gas.

The experimental device for the condensation of the mixed acid steam in the flue gas at the tail part of the boiler simplifies the condensation process of the mixed acid in the flue gas and ensures the measurement accuracy on the basis of meeting the characteristics of complex flue gas components and fly ash particles at the tail part of the boiler; simulating the mixed acid steam content, the water content, the fly ash particle characteristic and the condensation temperature in the smoke components according to the actual working condition of the power plant system, and simulating the condensation characteristic of the mixed acid steam; the condensation characteristic experiment of single acid gas and the dynamic characteristic experiment under different influence factors can be carried out; the method provides a reliable test data base for researching the caking ash deposition and low-temperature corrosion characteristics of the actual engineering of the boiler, and researches the change characteristics of the condensation and corrosion characteristics of the mixed acid along with different factors.

The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure, and various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Although the present disclosure has been described with reference to the specific embodiments shown in the drawings, it is not intended to limit the scope of the present disclosure, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive faculty based on the technical solutions disclosed in the present disclosure.

Claims

1. The utility model provides a boiler afterbody flue gas mixed acid steam experimental apparatus that condenses which characterized in that includes:

and the absorption unit is used for absorbing the unreacted acid gas.

2. The experimental apparatus for condensation of mixed acid vapor in flue gas at the tail of a boiler according to claim 1, wherein the gas distribution unit comprises:

an acid vapor supply device and a gas mixer (1) for supplying different acid vapors; the acid steam supply device is connected with a gas mixer (1), and the gas mixer (1) is connected with the heating unit.

3. The experimental device for condensation of mixed acid vapor in flue gas at the tail of a boiler according to claim 2, wherein the acid vapor supply device comprises:

the first carrier gas bottle (2), the first carrier gas bottle (2) is connected with a sulfuric acid solution bottle (3), and the sulfuric acid solution bottle (3) is connected with the gas mixer (1); the first carrier gas cylinder (2) is used for providing a sulfuric acid vapor carrier; a first pressure reducing valve (4), a first check valve (5) and a first flowmeter (6) are sequentially connected between the first carrier gas bottle (2) and the sulfuric acid solution bottle (3); a first calibration sampling port (7) is arranged between the sulfuric acid solution bottle (3) and the gas mixer (1).

4. The experimental apparatus for condensation of mixed acid vapor in flue gas at the tail of a boiler according to claim 3, wherein the acid vapor supply device further comprises:

the hydrogen chloride gas cylinder (8), the hydrogen chloride gas cylinder (8) is connected with the gas mixer (1), and a second pressure reducing valve (9), a second check valve (10) and a second flowmeter (11) are sequentially connected between the hydrogen chloride gas cylinder (8) and the gas mixer (1); a second calibration sampling port (12) is arranged between the second flowmeter (11) and the gas mixer (1).

5. The experimental device for condensation of mixed acid steam in flue gas at the tail of a boiler according to claim 4, characterized in that the experimental device further comprises:

the second carrier gas cylinder (14) is connected with the heating unit, and a third reducing valve (16), a third check valve (17) and a third flow meter (18) are sequentially connected between the second carrier gas cylinder (14) and the heating unit.

6. The experimental apparatus for condensation of mixed acid vapor in flue gas at the tail of a boiler according to claim 5, wherein the water amount control unit comprises:

the water storage tank (15) and a peristaltic pump (29) communicated with the water storage tank (15) are used for controlling the state of the peristaltic pump (29) through a PID controller (20) and adjusting the flow of deionized water in the water storage tank (15) flowing into the heating unit so as to realize the adjustment of the water vapor content.

7. The experimental device for condensation of the mixed acid steam in the flue gas at the tail of the boiler according to the claim 5, wherein the water quantity control unit comprises a first temperature-control constant-temperature water bath tank (30), and a water storage bottle (31) is arranged in the first temperature-control constant-temperature water bath tank (30);

the second carrier gas cylinder (14) is communicated with the water storage bottle (31), and the second carrier gas cylinder (14) is used for providing a water vapor carrier; the water storage bottle (31) is communicated with the heating unit;

a proportional regulating valve (28) is arranged between the third reducing valve (16) and the third check valve (17), and the opening degree of the proportional regulating valve (28) is controlled by the PID controller (20) to regulate the flow of the gas flowing out of the second carrier gas cylinder (14).

8. The experimental device for the condensation of the mixed acid vapor in the tail flue gas of the boiler as claimed in claim 6 or 7, wherein the feeding unit comprises a micro feeder (19), and the micro feeder (19) adjusts the feeding amount of the particulate matters through the control of a PID controller (20); the micro-feeder (19) is connected with the heating unit; the heating unit comprises a temperature control tube type heating furnace (21), and the temperature control tube type heating furnace (21) adjusts the heating temperature through the control of a PID controller (20).

9. The experimental device for condensation of mixed acid steam in flue gas at the tail of a boiler according to claim 8, wherein the condensing unit comprises a straight condensing pipe (22) communicated with the heating unit, two ends of an outer sleeve of the straight condensing pipe (22) are connected with a second temperature-controlled constant-temperature water tank (23), and a circulating pump (24) is arranged between the second temperature-controlled constant-temperature water tank (23) and the outer sleeve.

10. The experimental apparatus for condensation of mixed acid vapor in flue gas at the tail of a boiler according to claim 9, wherein the absorption unit comprises a tail gas absorption bottle (25), and an inner pipe of the straight condensation pipe (22) is connected with the tail gas absorption bottle (25).