CN211936311U - Gas power generation boiler waste gas desulfurization and denitrification system - Google Patents

Abstract

The utility model discloses a gas-fired power generation boiler waste gas desulfurization and denitrification system, which comprises a pure dry desulfurization tower, a dust removal and denitrification integrated reactor and a booster fan. The pure dry desulfurization tower is connected with a dedusting and denitrification integrated reactor through a pipeline, and the dedusting and denitrification integrated reactor is connected with a booster fan. The dedusting and denitration integrated reactor includes a cloth bag, an injection system, an ash hopper, a flue gas homogenization module 1, an auxiliary heating system, an ammonia injection grille, a flue gas homogenization module 2 and a denitration catalyst. The inside of the integrated dedusting and denitrification reactor is sequentially installed with a cloth bag, a flue gas homogenization module 1, an auxiliary heating system, an ammonia injection grille, a flue gas homogenization module 2 and a denitration catalyst from bottom to top. It can achieve the purpose of efficiently removing SO ₂ , dust and low-temperature SCR denitrification in flue gas, and there is no secondary pollution during system operation, easy maintenance, low energy consumption, small footprint, and easy operation.

Description

A gas-fired power generation boiler waste gas desulfurization and denitrification system

technical field

The utility model relates to the technical field of waste gas desulfurization and denitration equipment, in particular to a gas-fired power generation boiler waste gas desulfurization and denitration system.

Background technique

With the continuous deepening of the industrialization process in my country, coal-fired gas and other industries emit a large amount of harmful soot and harmful gases, such as sulfur dioxide and various nitrogen-containing compounds, which lead to the formation of acid rain and photochemical smog in local areas. In recent years, the proportion of SO ₂ and NO _x in environmental pollutants is increasing. For long-term sustainable development, the state's emission standards for pollutants are becoming more and more stringent.

In recent years, with the frequent occurrence of smog in China, more attention has been paid to the pollutant emissions of key industries such as thermal power generation. Since 2016, China's coal-fired power plants have gradually implemented ultra-low emission transformation. After the transformation, their main pollutants (smoke, SO ₂ and NO _x ) can meet the national emission limit requirements for gas-fired units, and the NO _x emission concentration of some power plants A level of 25 mg/m ³ has been reached. As we all know, due to different fuel characteristics, gas-fired power generation is cleaner and more efficient than coal-fired power generation. However, with the implementation of ultra-low emission transformation of coal-fired power plants, the environmental advantages of gas-fired power plants are challenged. Especially in recent years, the installed capacity of gas power has rapidly expanded, and gas-fired power plants are mainly located in economically developed and environmentally sensitive areas, so their environmental protection problems have become increasingly prominent. Therefore, we need to use desulfurization and denitrification equipment to remove these pollutants as much as possible and meet the emission standards.

The existing flue gas filtration system is difficult to satisfy the high-efficiency desulfurization, dust removal and denitrification at the same time, and also causes secondary pollution. At the same time, the simple integration of other separate desulfurization, dust removal and denitrification on the market has the disadvantages of high energy consumption, large land occupation and cumbersome equipment operation. After testing, the Chinese patent 201420179488.6 is named: A desulfurization and denitrification treatment system for a power plant boiler. The application includes a desulfurization tower, a spray device, a flue gas cooling device, an oxidation fan and a boiler cyclone separator. In the desulfurization tower, the flue gas cooling device is connected to the dust outlet of the power plant boiler, the boiler cyclone is connected to the other end of the flue gas cooling device, and the oxidation fan is connected to the desulfurization tower. However, this application adopts ammonia spray for denitrification, and the stated temperature of 45-55°C cannot effectively reduce nitrogen oxides with ammonia to achieve the purpose of high denitration rate. In addition, the wet desulfurization technology it adopts will produce waste water and cause secondary pollution. Can not meet the increasingly stringent environmental protection requirements.

In addition, the temperature of the exhaust gas at the outlet of the economizer is relatively low, in order to avoid reheating during the denitration process and increase the energy consumption. Therefore, it is urgent to find a desulfurization and denitrification equipment with low energy consumption, small footprint, easy operation, and low temperature denitrification to efficiently remove pollutants in flue gas. This not only meets market demand, but also contributes to environmental protection.

Utility model content

The purpose of the utility model is to provide a gas-fired power generation boiler waste gas desulfurization and denitration system, which can achieve the purpose of efficiently removing SO ₂ , dust and low-temperature SCR denitrification in the flue gas, and has no secondary pollution during the operation of the system, which is convenient for maintenance. Low energy consumption, small footprint, and easy operation solve the problems in the prior art.

To achieve the above object, the utility model provides the following technical solutions:

The utility model is a gas-fired power generation boiler waste gas desulfurization and denitrification system, in order to achieve the purpose of desulfurization, denitrification and dust removal, it includes a pure dry desulfurization tower, a dust removal and denitrification integrated reactor, a booster fan, and the gas power generation boiler waste gas SO ₂ content is not high, Dry desulfurization is adopted. Due to the low outlet temperature of the economizer during the production process of the gas-fired power boiler, in order to avoid the increase in energy consumption caused by the reheating of the flue gas, a low-temperature SCR denitration catalyst is used to catalyze the removal of NO _x in the flue gas. However, considering that SO ₂ in the exhaust gas and alkali metals, alkaline earth metals and heavy metals in the flue gas dust have a great clogging and poisoning effect on the low-temperature SCR denitration catalyst, the desulfurization tower and the bag filter are arranged upstream of the denitration reactor. In addition, in order to reduce the footprint of the equipment, an integrated device for dust removal and denitrification is adopted. The pure dry desulfurization tower is connected with a dedusting and denitrification integrated reactor through a pipeline, and the top of the dedusting and denitrification integrated reactor is connected with a booster fan through a pipeline;

The pure dry desulfurization tower comprises a desulfurization tower main body, a grinding system and a desulfurization agent spray gun, and the desulfurization agent spray gun is installed on the side wall of the denitration tower main body and is connected with the grinding system;

The dedusting and denitrification integrated reactor includes a cloth bag, an injection system, an ash hopper, a flue gas homogenization module 1, an ammonia injection grille, a flue gas homogenization module 2 and a denitration catalyst. From bottom to top, a cloth bag, a flue gas homogenization module 1, an auxiliary heating system, an ammonia injection grille, a flue gas homogenization module 2 and a denitration catalyst are installed in sequence. An ash hopper is installed at the lower end of the reactor.

Preferably, a dust collector inlet is provided on the side wall between the ash hopper and the cloth bag, and the pure dry desulfurization tower is connected to the inner cavity of the integrated dedusting and denitrification reactor through the dust collector inlet.

Preferably, the first flue gas homogenization module and the second flue gas homogenization module are multi-layer orifice plates, the orifice plates are provided with through holes, and the through holes on adjacent orifice plates are staggered.

Preferably, the denitration catalyst is a low temperature SCR denitration catalyst.

Preferably, the auxiliary heating system is used to control the temperature of the exhaust gas, so that the catalyst is in an optimal temperature activity window.

Compared with the prior art, the beneficial effects of the present utility model are as follows:

The gas-fired power generation boiler waste gas desulfurization and denitrification system of the utility model adopts dry desulfurization, which saves the cost, and can simultaneously realize desulfurization, dust removal and denitrification. The use of low-temperature SCR denitration catalyst solves the problem that the flue gas temperature at the exit of the economizer is low and it is difficult to efficiently remove _NOx , and also avoids the waste of resources caused by exhaust gas reheating and denitration. The exhaust gas passes through the pure dry desulfurization tower 1 and the dust removal section in turn, and then passes through the denitration section, which can effectively reduce the clogging and poisoning of the denitration catalyst by dust, SO ₂ , alkali metals, alkaline earth metals and heavy metals in the exhaust gas, and increase the denitration catalyst 12 service life. The integrated reactor for dust removal and denitration is adopted, which occupies a small area, simplifies the equipment, is easy to operate, requires less investment, and has no secondary pollution.

Description of drawings

Fig. 1 is the overall structure diagram of the utility model;

Fig. 2 is the pure dry process desulfurization tower structural diagram of the present utility model;

Fig. 3 is the structure diagram of the integrated dedusting and denitrification reactor of the utility model;

FIG. 4 is a structural diagram of a first flue gas homogenization module and a second flue gas homogenization module of the present invention.

In the figure: 1. Pure dry desulfurization tower; 2. Integrated reactor for dust removal and denitrification; 3. Booster fan; 4. Grinding system; 5. Desulfurizer spray gun; 6. Cloth bag; Bucket; 9. Flue gas homogenization module 1; 10. Ammonia injection grille; 11. Flue gas homogenization module 2; 12. Denitrification catalyst; 13. Main body of desulfurization tower; System; 16. Orifice plate; 17. Through hole.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Please refer to FIG. 1 , a gas-fired power generation boiler waste gas desulfurization and denitrification system, including a pure dry desulfurization tower 1 , a dust removal and denitrification integrated reactor 2 and a booster fan 3 . The upstream of the pure dry desulfurization tower 1 is connected with an economizer, and the economizer is connected with a gas power generation boiler through an induced draft fan. 1 Desulfurization, pure dry desulfurization tower 1 is connected with a dedusting and denitrification integrated reactor 2 through a pipeline, and the top of the dedusting and denitrification integrated reactor 2 is connected with a booster fan 3 through a pipeline, which is powered by the booster fan 3 to make the smoke The gas flows in this system, and then the clean flue gas enters the air preheater, and finally is sent to the chimney to discharge the flue gas.

Please refer to FIG. 2 , the pure dry desulfurization tower 1 includes a desulfurization tower main body 13 , a grinding system 4 and a desulfurization agent spray gun 5 . The desulfurization agent spray gun 5 is installed on the side wall of the desulfurization tower main body 13, and is connected to the grinding system 4, and the exhaust gas reacts with the sulfur dioxide in the pure dry desulfurization tower 1 to realize desulfurization. The exhaust gas generated by the gas-fired power generation boiler is drawn from the outlet of the main economizer through the induced draft fan, and first enters the desulfurization tower. The desulfurization agent is first ground into a certain mesh by the grinding system 4, and then sprayed into the desulfurization tower through the desulfurization agent spray gun 5 to mix with the exhaust gas to achieve desulfurization the goal of. The pure dry desulfurization tower 1 is connected to the internal cavity of the integrated dedusting and denitrification reactor 2 through the air inlet 14 of the dust collector.

Please refer to FIG. 3 , the integrated dedusting and denitrification reactor 2 includes a cloth bag 6 , an injection system 7 , an ash hopper 8 , a flue gas homogenization module 1 9 , an ammonia injection grill 10 , a flue gas homogenization module 2 11 , and a denitration catalyst 12 and auxiliary heating system 15. The dust removal and denitrification integrated reactor 2 is sequentially installed with a cloth bag 6 , a flue gas homogenization module 1 9 , an auxiliary heating system 15 , an ammonia injection grill 10 , a flue gas homogenization module 2 11 and a denitration catalyst 12 from bottom to top. The bag 6, the injection system 7 and the ash hopper 8 are located at the lower end of the main body 13 of the desulfurization tower to form a dedusting section, and the desulfurized exhaust gas enters the dedusting section. Wherein, the upper end of the bag 6 is installed with the injection system 7, the lower end of the integrated denitration and denitration reactor 2 is installed with an ash hopper 8, and the side wall between the ash hopper 8 and the bag 6 is provided with a dust collector air inlet 14. Through the filtering and purifying function of the cloth bag 6, the dust is intercepted on the surface of the filter bag to achieve the effect of dust removal. The dust accumulated on the cloth bag 6 falls into the ash hopper 8 of the dust collector under the regular purging of the injection system 7, and enters the ash storage bin through the ash conveying system for external transportation. The first flue gas homogenization module 9 , the auxiliary heating system 15 , the ammonia injection grill 10 , the second flue gas homogenization module 11 and the denitration catalyst 12 are located at the upper end of the main body 13 of the desulfurization tower to form a denitration section. Among them, the flue gas homogenization module 1 9 and the flue gas homogenization module 2 11 are both multi-layer orifice plates 16, the orifice plate 16 is provided with through holes 17, and the through holes 17 on the adjacent orifice plates 16 are staggered with each other, so that the smoke The air is mixed evenly. The auxiliary heating system 15 is used to control the temperature of the exhaust gas so that the catalyst is in the optimum temperature activity window. The ammonia gas injected through the ammonia injection grid 10 has better dispersibility. The denitration catalyst 12 is a low-temperature SCR denitration catalyst 12. Under the catalytic action of the denitration catalyst 12, _NOx is reduced by ammonia gas under low temperature conditions to achieve the purpose of denitration.

System workflow:

The exhaust gas produced by the gas-fired power boiler is drawn out from the outlet of the economizer through the induced draft fan. First into the desulfurization tower, the desulfurization agent is first ground into a certain mesh by the grinding system 4, and then sprayed into the desulfurization tower through the desulfurization agent spray gun 5 to mix with the exhaust gas to achieve the purpose of desulfurization. Secondly, the exhaust gas after desulfurization enters the integrated dedusting and denitrification reactor 2 from the air inlet 14 of the dust collector, and the dust is intercepted on the surface of the filter bag through the filtering and purifying effect of the cloth bag 6 to achieve the effect of dust removal. The dust accumulated on the cloth bag 6 falls into the ash hopper 8 of the dust collector under the regular purging of the injection system 7, and enters the ash storage bin through the ash conveying system for external transportation. After that, the flue gas after desulfurization and dust removal enters the denitrification section, first through the flue gas homogenization module 1 9 to make the exhaust gas flow rate and flow uniform, and then with the ammonia gas injected through the ammonia injection grill 10 and the auxiliary heating system 15. The hot air is uniformly mixed under the homogenization of the flue gas homogenization module 2 11, and when the gas reaches the catalyst surface, it catalyzes the reaction of NO _x with NH ₃ and O ₂ into a harmless gas, removes NO _x in the exhaust gas, and achieves emission standard.

Finally, the clean flue gas that efficiently removes dust, SO ₂ and NO _x from the exhaust gas is transported to the air preheater through the booster fan 3, and then sent to the chimney for discharge after heat exchange.

To sum up, the gas-fired power generation boiler waste gas desulfurization and denitrification system of the present invention adopts dry desulfurization, which saves the cost. The use of the low-temperature SCR denitration catalyst 12 solves the problem that the flue gas temperature at the exit of the economizer is low and it is difficult to efficiently remove _NOx , and also avoids the waste of resources caused by the reheating and denitration of the exhaust gas. The exhaust gas passes through the pure dry desulfurization tower 1 and the dust removal section in turn, and then passes through the denitration section, which can effectively reduce the clogging and poisoning of the denitration catalyst 12 by dust, SO ₂ , alkali metals, alkaline earth metals and heavy metals in the exhaust gas, and increase the denitration catalyst. 12 service life. The integrated reactor 2 for dust removal and denitrification is adopted, which occupies a small area, simplifies the equipment, is easy to operate, requires less investment, and has no secondary pollution.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus.

Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes and modifications can be made to these embodiments without departing from the principles and spirit of the present invention , alternatives and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (5)

1. A gas-fired power generation boiler waste gas desulfurization and denitration system, comprising a pure dry desulfurization tower (1), a dust removal and denitrification integrated reactor (2) and a booster fan (3), characterized in that: the pure dry desulfurization tower (1) A dedusting and denitrification integrated reactor (2) is connected through a pipeline, and the top of the dedusting and denitrification integrated reactor (2) is connected with a booster fan (3) through a pipeline, and the pure dry desulfurization tower ( 1) comprising a desulfurization tower main body (13), a grinding system (4) and a desulfurization agent spray gun (5), the desulfurization agent spray gun (5) being installed on the side wall of the desulfurization tower main body (13), and being connected with the grinding system (4); ) are connected, and the integrated dedusting and denitrification reactor (2) includes a cloth bag (6), a blowing system (7), an ash hopper (8), a flue gas homogenization module one (9), an ammonia injection grill (10). ), a second flue gas homogenization module (11), a denitration catalyst (12) and an auxiliary heating system (15). The first homogenization module (9), the auxiliary heating system (15), the ammonia injection grid (10), the second flue gas homogenization module (11) and the denitration catalyst (12), the upper end of the cloth bag (6) is provided with a spraying nozzle (12). A blowing system (7), an ash hopper (8) is installed at the lower end of the integrated dedusting and denitration reactor (2). 2. A gas-fired power generation boiler waste gas desulfurization and denitrification system according to claim 1, characterized in that: a dust collector air inlet (14) is provided on the side wall between the ash hopper (8) and the cloth bag (6). ), the pure dry desulfurization tower (1) is connected to the inner cavity of the dust removal and denitrification integrated reactor (2) through the air inlet (14) of the dust collector. 3. A gas-fired power generation boiler waste gas desulfurization and denitrification system according to claim 1, wherein the first (9) flue gas homogenization module and the second (11) flue gas homogenization module are multi-layer orifice plates (16), the orifice plate (16) is provided with through holes (17), and the through holes (17) on adjacent orifice plates (16) are staggered. 4. A gas-fired power generation boiler exhaust gas desulfurization and denitration system according to claim 1, wherein the denitration catalyst (12) is a low temperature SCR denitration catalyst. 5. A gas-fired power generation boiler exhaust gas desulfurization and denitrification system according to claim 1, characterized in that: the auxiliary heating system (15) is used to control the temperature of the exhaust gas, so that the catalyst is in an optimal temperature activity window.

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