JP7053393B2 - Denitration device and denitration method, exhaust gas treatment equipment and exhaust gas treatment method - Google Patents

Description

The present invention relates to a denitration device and a denitration method, and an exhaust gas treatment facility and an exhaust gas treatment method.

For example, in thermal power generation, nitrogen oxides (hereinafter, also referred to as “NOx”) are generated in the exhaust gas generated in the combustion process of fuel. NOx in the exhaust gas selectively reacts with the denitration agents ammonia (NH ₃ ) and urea by the denitration catalyst at the denitration facility installed in the flue, and nitrogen (N ₂ ) and water (H ₂ O). It is decomposed into harmless.

The denitration catalyst is used for a long period of time and is poisoned by the catalyst (for example, (1) due to the adhesion of alkaline components and arsenic, (2) due to sintering at high temperature, and (3) due to thermal power generation. Due to the formation of dust such as soot and ash adhering to the catalyst surface), the activity is reduced. In particular, in pulverized coal-fired power generation equipment, catalyst deterioration due to produced ash is the main cause of the decrease in the activity of the denitration catalyst.

Since the denitration catalyst is expensive, various regeneration methods have been proposed. As a method for regenerating the denitration catalyst, for example, the methods described in Patent Documents 1 to 3 are known.
In Patent Document 1, after removing the dust component physically attached from the surface of the catalyst, the catalyst is washed with water and dried, and the catalyst is impregnated with an aqueous solution of a vanadium compound or a tungsten compound together with an acid such as oxalic acid and dried. Then, a method for regenerating the denitration catalyst, which is regenerated by firing at 300 ° C. to 600 ° C., is described.
Patent Document 2 describes a method in which the hydrofluoric acid concentration in the cleaning liquid is 0.3% by weight to 3% by weight, the temperature of the cleaning liquid is maintained at 20 ° C. to 80 ° C., the catalyst is washed, and the denitration catalyst is regenerated. A method of cleaning the denitration catalyst under the above conditions, drying the cleaning catalyst, and then impregnating and supporting the catalyst with a catalytically active component to regenerate the denitration catalyst is described.
Patent Document 3 describes the regeneration of a denitration catalyst that activates the catalyst by immersing the catalyst in an aqueous medium containing hydrogen fluoride, ammonium hydrogen fluoride and / or alkali hydrogen fluoride, washing with water, and drying. The method is described.

Japanese Unexamined Patent Publication No. 2004-74106 Japanese Unexamined Patent Publication No. 10-235209 Japanese Patent No. 2659802

However, the methods for regenerating the denitration catalyst described in Patent Documents 1 to 3 still have problems such as treatment of harmful substances generated during regeneration, shortening of catalyst life after regeneration, deterioration of base material, and the like. was there. Further, the above-mentioned method for regenerating the denitration catalyst has a problem that it is necessary to remove the catalyst at the time of periodic opening inspection, carry it out to the factory of the manufacturer, and carry out the regeneration work after confirming the performance.

The present invention has been made in view of the above circumstances, and is a denitration device capable of preventing the denitration catalyst from being blocked due to adhesion of dust, extending the life of the denitration catalyst, and operating safely. It is an object of the present invention to provide a denitration method, and an exhaust gas treatment facility and an exhaust gas treatment method equipped with a denitration device.

[1] A denitration device installed in a flue and equipped with a denitration catalyst that reduces nitrogen oxides in the exhaust gas flowing through the flue and decomposes them into nitrogen and water. A denitration device including a denitration agent spraying means for spraying a denitration agent on the exhaust gas, and a charge applying means for imparting a charge having the same polarity as the denitration catalyst to the dust in the exhaust gas.
[2] Electricity that is installed after the denitration device according to the above [1] and the dust that has passed through the denitration device and is attracted to an electrode having a polarity opposite to the electric charge to collect dust. Exhaust gas treatment equipment equipped with a dust collector.
[3] The exhaust gas treatment equipment according to the above [2], wherein a heat exchanger is provided between the denitration device and the electrostatic precipitator.
[4] A denitration method comprising a denitration step of reducing nitrogen oxides in an exhaust gas flowing through a flue to decompose them into nitrogen and water. Before the denitration step, a denitration agent is sprayed on the exhaust gas. A denitration method comprising a denitration agent spraying step and a charge applying step of imparting a charge having the same polarity as the denitration step to the dust in the exhaust gas.
[5] The denitration method according to the above [4], and an electrostatic precipitator step of attracting and collecting the dust that is not decomposed in the denitration step with a charge having a polarity opposite to the charge after the denitration method. And, with an exhaust gas treatment method.
[6] The exhaust gas treatment method according to [5], which has a heat exchange step between the denitration step and the electrostatic precipitator step.

According to the present invention, a denitration device and a denitration method capable of preventing the denitration catalyst from being blocked due to adhesion of dust, extending the life of the denitration catalyst, and operating safely, and a denitration device are provided. Exhaust gas treatment equipment and exhaust gas treatment methods can be provided.

It is a schematic diagram which shows the schematic structure of the pulverized coal-fired power generation facility. It is sectional drawing which shows the schematic structure of the denitration apparatus of 1st Embodiment of this invention. It is sectional drawing which shows the schematic structure of the denitration apparatus of the 2nd Embodiment of this invention. It is sectional drawing which shows the schematic structure of the denitration apparatus of the 3rd Embodiment of this invention. It is sectional drawing which shows the schematic structure of the denitration apparatus of the 4th Embodiment of this invention. It is sectional drawing which shows the schematic structure of the denitration apparatus of the 5th Embodiment of this invention. It is sectional drawing which shows the schematic structure of the denitration apparatus of the 6th Embodiment of this invention. It is a schematic diagram which shows the schematic structure of the exhaust gas treatment equipment of 7th Embodiment of this invention. It is a schematic diagram which shows the schematic structure of the exhaust gas treatment equipment of 8th Embodiment of this invention.

An embodiment of the denitration device and the denitration method of the present invention, and the exhaust gas treatment equipment and the exhaust gas treatment method will be described.
It should be noted that the present embodiment is specifically described in order to better understand the gist of the invention, and is not limited to the present invention unless otherwise specified.

The denitration device and denitration method of the present embodiment, and the exhaust gas treatment equipment and the exhaust gas treatment method are applied to, for example, a pulverized coal-fired power generation facility as shown in FIG. The pulverized coal-fired power generation facility is a facility that ejects and burns pulverized coal from a burner into a furnace by air transportation, creates high-temperature and high-pressure steam with a boiler, and rotates a turbine with the steam to generate electricity. That is, the pulverized coal-fired power generation equipment, the denitration device and the denitration method, and the exhaust gas treatment equipment and the exhaust gas treatment method are operated (implemented) under atmospheric pressure.

As shown in FIG. 1, the pulverized coal-fired power generation facility 1 has, for example, a boiler 3 provided with a burner 2 inside and a flue (not shown) for discharging the exhaust gas generated by the boiler 3 to the outside. It includes a denitration device 4, a heat exchanger 5, an electrostatic dust collector 6, a desulfurization device 7, a chimney 8, and a turbine (not shown) driven by high-temperature and high-pressure steam obtained from the boiler 3. ..

(1) First Embodiment [Denitration device]
FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the denitration device of the present embodiment.
As shown in FIG. 2, the denitration device 10 of the present embodiment includes a charge applying means 20, a denitration agent spraying means 30, and a denitration catalyst 40. Further, in the denitration device 10 of the present embodiment, the charge applying means 20, the denitration agent spraying means 30, and the denitration catalyst 40 are arranged in this order along the length direction (direction in which the exhaust gas flows) of the flue 100. Have been placed.
The denitration device 10 is installed at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside, for example. That is, it can be used as the denitration device 4 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

The charge applying means 20 controls a charged mesh 21 that imparts an electric charge having the same polarity as that of the denitration catalyst 40 to the dust in the exhaust gas flowing through the flue 100, and a charge polarity and an amount of the electric charge applied to the dust in the charged mesh 21. The charge control device 22 is provided. Further, the charge mesh 21 and the charge control device 22 are electrically connected via the electric wire 23.
In the charged mesh 21, a positive (+) charge or a negative (−) charge can be applied (charged) to the dust depending on the polarity of the denitration catalyst 40.
Dust is soot, ash, etc. contained in exhaust gas and generated by thermal power generation.

As shown in FIG. 2, the charge applying means 20 is arranged in the flue 100 in front of the denitration agent spraying means 30 and the denitration catalyst 40 (in the flue 100, on the upstream side of the exhaust gas). In particular, the charged mesh 21 of the charge applying means 20 is arranged in the flue 100 in front of the denitration agent spraying means 30 and the denitration catalyst 40. Further, the charged mesh 21 is arranged so that the portion through which the exhaust gas passes (unit grid described later) faces the direction in which the exhaust gas flows (the length direction of the flue 100).

Examples of the charged mesh 21 include a honeycomb-shaped mesh in which a large number of unit grids (openings) through which exhaust gas flowing through the flue 100 passes are arranged without gaps. The shape when the unit cell is viewed in a plane (shape seen from the direction in which the exhaust gas flows) is not particularly limited, and examples thereof include a regular hexagonal shape and a square shape. The size (opening diameter) of the unit cell is not particularly limited as long as it can pass the exhaust gas, and is appropriately adjusted according to the flow rate of the exhaust gas and the like. Further, the width of the charged mesh 21 (the length in the length direction of the flue 100) is not particularly limited, and is appropriately adjusted according to the flow rate of the exhaust gas and the like.

The material constituting the charged mesh 21 is not particularly limited as long as it can apply the charge generated by the charge control device 22 to the dust, and a general conductive material is used.

In the present embodiment, the charged mesh 21 is exemplified as a portion for applying a charge to the dust in the charging means 20, but the present embodiment is not limited to this. In the present embodiment, a discharge needle capable of performing corona discharge, an electrode capable of performing arc discharge, or the like may be used as a portion for applying an electric charge to the dust.

Corona discharge is a continuous discharge caused by the generation of a non-uniform electric field around a sharp electrode (such as a discharge needle).
The arc discharge includes a discharge by a hot cathode arc in which the negative electrode is heated by electron emission from the negative electrode and a hot cathode arc by thermionic emission, and a discharge by an electric field arc in which electrons are directly emitted by a very strong electric field existing on the surface of the negative electrode. ..

The denitration agent spraying means 30 is provided with a plurality of spray nozzles 31 for spraying a denitration agent composed of ammonia, ammonia water, urea, urea water, etc., and a spray nozzle 31 on the exhaust gas that has passed through the charged mesh 21. The supply header 32 that supplies the denitration agent to 31, the denitration agent tank 33 that houses the denitration agent, and the amount of the denitration agent that is supplied from the denitration tank 33 to the spray nozzle 31 (the denitration agent that is sprayed onto the exhaust gas from the spray nozzle 31). A denitration agent supply amount control device (not shown) for controlling the amount of the denitration agent is provided. Further, the supply header 32 and the denitration agent tank 33 are connected to each other via the supply path 34.

As shown in FIG. 2, the denitration agent spraying means 30 is arranged between the charge applying means 20 and the denitration catalyst 40 in the flue 100. In particular, the spray nozzle 31 and the supply header 32 of the denitration agent spraying means 30 are arranged between the charge applying means 20 and the denitration catalyst 40 in the flue 100.

The shape of the spray nozzle 31 is not particularly limited as long as the denitration agent can be sprayed on the exhaust gas, and is appropriately adjusted according to the flow rate of the exhaust gas and the like. Further, the number of spray nozzles 31 and the interval (pitch) when a plurality of spray nozzles 31 are provided are not particularly limited as long as the denitration agent can be sprayed on the exhaust gas, and are appropriately adjusted according to the flow rate of the exhaust gas and the like. Will be done.

The denitration catalyst 40 reduces the active energy of nitrogen oxides (NOx) in the exhaust gas sprayed with the denitration agent by the spray nozzle 31, and selectively reduces the nitrogen oxides (NOx) to nitrogen (NOx). It is not particularly limited as long as it can be decomposed into N ₂ ) and water (H ₂ O). Examples of the denitration catalyst 40 include those used in a general denitration device.

As shown in FIG. 2, the denitration catalyst 40 is arranged in the flue 100 at the rear stage of the charge applying means 20 and the denitration agent spraying means 30 (in the flue 100, on the downstream side of the exhaust gas). Further, the denitration catalyst 40 is arranged so that the portion through which the exhaust gas passes (unit grid described later) faces the direction in which the exhaust gas flows (the length direction of the flue 100). Further, the denitration catalyst 40 may include means for applying an electric charge (not shown).

Examples of the denitration catalyst 40 include a honeycomb-shaped catalyst in which a large number of unit lattices (openings) through which exhaust gas flowing through the flue 100 passes are arranged without gaps. The shape when the unit cell is viewed in a plane (shape seen from the direction in which the exhaust gas flows) is not particularly limited, and examples thereof include a regular hexagonal shape and a square shape. The size (opening diameter) of the unit cell is not particularly limited as long as it can pass the exhaust gas, and is appropriately adjusted according to the flow rate of the exhaust gas and the like. Further, the width of the denitration catalyst 40 (the length in the length direction of the flue 100) is not particularly limited, and is appropriately adjusted according to the flow rate of the exhaust gas and the like.

According to the denitration device 10 of the present embodiment, after the denitration catalyst 40 is provided with the charge applying means 20 in front of the denitration catalyst 40, the dust in the exhaust gas flowing through the flue 100 is charged with the same polarity as the denitration catalyst 40. Since the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. Dust to which a charge having the same polarity as that of the denitration catalyst 40 is applied repels the denitration catalyst 40 when passing through the denitration catalyst 40, so that the dust does not adhere to the denitration catalyst 40. Further, according to the denitration device 10 of the present embodiment, it is possible to prevent dust from adhering to a portion of the denitration catalyst 40 on the inlet side (upstream side of the exhaust gas in the flue 100). Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 10 can be operated.

[Denitration method]
The denitration method of the present embodiment will be described in detail with reference to FIG.
The denitration method of the present embodiment is a charge applying step of imparting a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100, and a denitration of nitrogen oxides in the exhaust gas after the charge imparting step. It has a denitration agent spraying step of spraying the agent, and a denitration step of reducing nitrogen oxides in the exhaust gas to decompose them into nitrogen and water after the denitration agent spraying step.

In the charge applying step, the charge mesh 21 of the charge applying means 20 applies a charge having the same polarity as the denitration catalyst 40 in the denitration step described later to the dust in the exhaust gas passing through the charge mesh 21. In the charge applying step, the charge applied to the dust is set to have the same polarity as the charge of the denitration catalyst 40 in the denitration step. That is, when the denitration catalyst 40 has a positive (+) charge, a positive (+) charge is given to the dust, while when the denitration catalyst 40 has a negative (-) charge, the dust has a negative (-) charge. ) Apply an electric charge.

Further, in the charge applying step, the charge control device 22 controls the polarity and the amount of charge applied to the dust in the charged mesh 21.

In the present embodiment, the case where the electric charge is applied to the dust by the charged mesh 21 is exemplified in the electric charge applying step, but the present embodiment is not limited to this. In the present embodiment, the exhaust gas may be ionized by a corona discharge using a discharge needle or the like or an arc discharge using a negative electrode, and an electric charge may be applied to the dust through the ionized exhaust gas. ..

In the denitration agent spraying step, the denitration agent is sprayed onto the nitrogen oxide in the exhaust gas that has undergone the charge applying step by the spray nozzle 31 of the denitration agent spraying means 30. As the denitration agent, ammonia, ammonia water, urea, urea water and the like are used.

In the denitration agent spraying step, the amount of the denitration agent sprayed from the spray nozzle 31 onto the nitrogen oxides in the exhaust gas is controlled by the denitration agent supply amount control device (not shown).

In the denitration step, the denitration catalyst 40 selectively reduces nitrogen oxides in the exhaust gas that has undergone the denitration agent spraying step, and decomposes them into nitrogen and water.
In the denitration step, the denitration reaction represented by the following formulas (1) to (3) occurs. Here, the case where ammonia is used as the denitration agent is illustrated.

Further, in the denitration step, the denitration catalyst 40 has a positive (+) charge or a negative (−) charge. When the denitration catalyst 40 has a positive (+) charge, a positive (+) charge is applied to the charged mesh 21 by the charge applying means 20 in the charge applying step. When the denitration catalyst 40 has a negative (−) charge, a negative (−) charge is applied to the charged mesh 21 by the charge applying means 20 in the charge applying step. As a result, the dust to which the charge having the same polarity as that of the denitration catalyst 40 is applied repels the denitration catalyst 40 when passing through the denitration catalyst 40, so that the dust does not adhere to the denitration catalyst 40. Therefore, in the denitration catalyst 40, only the reduction reaction of nitrogen oxides in the exhaust gas is performed.

According to the denitration method of the present embodiment, in the charge application step performed before the denitration step, after the dust in the exhaust gas flowing through the flue 100 is charged with the same polarity as the denitration step by the charge application means 20. In the denitration step, the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, so that dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. According to the denitration device 10 of the present embodiment, it is possible to prevent dust from adhering to a portion of the denitration catalyst 40 on the inlet side (upstream side of the exhaust gas in the flue 100). Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 10 can be operated.

(2) Second Embodiment [Denitration device]
FIG. 3 is a schematic cross-sectional view showing a schematic configuration of the denitration device of the present embodiment. In FIG. 3, the same components as those of the denitration device of the first embodiment shown in FIG. 2 are designated by the same reference numerals, and duplicate description will be omitted.
As shown in FIG. 3, the denitration device 200 of the present embodiment includes a charge applying means 20, a denitration agent spraying means 30, and a denitration catalyst 40.
The denitration device 200 is installed at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside, for example. That is, it can be used as the denitration device 4 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

The denitration device 200 of the present embodiment differs from the denitration device 10 of the first embodiment described above with the denitration agent spraying means 30 along the length direction of the flue 100 (the direction in which the exhaust gas flows). The point is that the charge applying means 20 and the denitration catalyst 40 are arranged in this order.

According to the denitration device 200 of the present embodiment, after the denitration catalyst 40 is provided with the charge applying means 20 in front of the denitration catalyst 40, the dust in the exhaust gas flowing through the flue 100 is charged with the same polarity as the denitration catalyst 40. Since the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 200 can be operated.

[Denitration method]
The denitration method of the present embodiment will be described in detail with reference to FIG.
The denitration method of the present embodiment is the same as the denitration step of spraying the denitration agent on the nitrogen oxides in the exhaust gas flowing through the flue 100, and the denitration step on the dust in the exhaust gas after the denitration spray step. It has a charge applying step of imparting a polar charge, and a denitration step of reducing nitrogen oxides in the exhaust gas to decompose them into nitrogen and water after the charge applying step.

In the denitration method of the present embodiment, the denitration agent spraying step, the charge applying step, and the denitration step are performed in the same manner as in the first embodiment described above.

According to the denitration method of the present embodiment, in the charge application step performed before the denitration step, after the dust in the exhaust gas flowing through the flue 100 is charged with the same polarity as the denitration step by the charge application means 20. In the denitration step, the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, so that dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 200 can be operated.

(3) Third Embodiment [Denitration device]
FIG. 4 is a schematic cross-sectional view showing a schematic configuration of the denitration device of the present embodiment. In FIG. 4, the same components as those of the denitration device of the first embodiment shown in FIG. 2 are designated by the same reference numerals, and duplicate description will be omitted.
As shown in FIG. 4, the denitration device 300 of the present embodiment includes a charge applying means 20, a denitration agent spraying means 30, and a denitration catalyst 40.
The denitration device 300 is installed at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside, for example. That is, it can be used as the denitration device 4 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

The denitration device 300 of the present embodiment is different from the denitration device 10 of the first embodiment described above in that the charge applying means 20 and the denitration agent spraying means 30 are integrated. That is, the spray nozzle 31 constituting the denitrifying agent spraying means 30 and the charge control device 22 constituting the charge applying means 20 are electrically connected via the electric wire 23. As a result, the denitration agent sprayed from the spray nozzle 31 by the charge control device 22 is charged, and the dust in the exhaust gas to which the denitration agent is attached is charged.

According to the denitration device 300 of the present embodiment, the denitration catalyst is added to the dust in the exhaust gas flowing through the flue 100 by the charge applying means 20 integrated with the denitration agent spraying means 30 provided in front of the denitration catalyst 40. After applying a charge having the same polarity as 40, the denitration catalyst 40 selectively reduces the nitrogen oxides in the exhaust gas, so that dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is blocked by the dust. There is nothing to do. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 300 can be operated.

[Denitration method]
The denitration method of the present embodiment will be described in detail with reference to FIG.
The denitration method of the present embodiment includes a charge applying step of imparting a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100, and a denitration agent for spraying the denitration agent on the nitrogen oxides in the exhaust gas. It has a charge-imparting / denitration agent spraying step in which the spraying step is performed at the same time, and a denitration step in which nitrogen oxides in the exhaust gas are reduced and decomposed into nitrogen and water after the charge-imparting / denitration agent spraying step.

In the charge-imparting / denitration agent spraying step, the denitration agent sprayed from the spray nozzle 31 is charged with the charge-imparting means 20, and at the same time, the denitration agent is sprayed on the exhaust gas by the spray nozzle 31 of the denitration agent spraying means 30. As a result, the denitration agent is sprayed on the nitrogen oxide in the exhaust gas, and the dust in the exhaust gas is given a charge having the same polarity as in the denitration step.

In the denitration method of the present embodiment, the denitration step is performed in the same manner as in the first embodiment described above.

According to the denitration method of the present embodiment, in the charge-imparting / denitration agent spraying step performed before the denitration step, the charge-imparting means 20 applies a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100. In addition, after spraying the denitration agent on the nitrogen oxides in the exhaust gas by the denitration agent spraying means 30, in the denitration step, the denitration catalyst 40 selectively reduces the nitrogen oxides in the exhaust gas, so that the denitration catalyst is used. No dust adheres to 40, and the denitration catalyst 40 is not blocked by dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 300 can be operated.

(4) Fourth Embodiment [Denitration device]
FIG. 5 is a schematic cross-sectional view showing a schematic configuration of the denitration device of the present embodiment. In FIG. 5, the same components as those of the denitration device of the first embodiment shown in FIG. 2 are designated by the same reference numerals, and duplicate description will be omitted.
As shown in FIG. 5, the denitration device 400 of the present embodiment includes a charge applying means 20, a denitration agent spraying means 30, and a denitration catalyst 40.
The denitration device 400 is installed, for example, at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside as described above. That is, it can be used as the denitration device 4 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

The denitration device 400 of the present embodiment differs from the denitration device 300 of the third embodiment described above in that the charge control device 22 constituting the charge applying means 20 is electrically connected to the denitration catalyst 40 via the electric wire 401. It is a point that has been done. As a result, the denitration agent sprayed from the spray nozzle 31 by the charge control device 22 and the denitration catalyst 40 are charged with the same polarity.

According to the denitration device 400 of the present embodiment, the dust and the denitration catalyst in the exhaust gas flowing through the flue 100 are provided by the charge applying means 20 integrated with the denitration agent spraying means 30 provided in front of the denitration catalyst 40. After applying the same charge to the denitration catalyst 40, the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, so that dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is blocked by the dust. Never. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 400 can be operated.

[Denitration method]
The denitration method of the present embodiment will be described in detail with reference to FIG.
The denitration method of the present embodiment includes a charge applying step of imparting a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100, and a denitration agent for spraying the denitration agent on the nitrogen oxides in the exhaust gas. It has a charge-imparting / denitration agent spraying step in which the spraying step is performed at the same time, and a denitration step in which nitrogen oxides in the exhaust gas are reduced and decomposed into nitrogen and water after the charge-imparting / denitration agent spraying step.

In the charge-imparting / denitration agent spraying step, the denitration agent sprayed from the spray nozzle 31 and the denitration catalyst 40 are imparted with the same polarity by the charge-imparting means 20, and at the same time, the exhaust gas is applied by the spray nozzle 31 of the denitration agent spray means 30. By spraying the denitration agent on the exhaust gas, the denitration agent is sprayed on the nitrogen oxides in the exhaust gas, and the dust in the exhaust gas is given a charge having the same polarity as in the denitration step.

In the denitration method of the present embodiment, the denitration step is performed in the same manner as in the first embodiment described above.

According to the denitration method of the present embodiment, in the charge-imparting / denitration agent spraying step performed before the denitration step, the charge-imparting means 20 applies a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100. In addition, after spraying the denitration agent on the nitrogen oxides in the exhaust gas by the denitration agent spraying means 30, in the denitration step, the denitration catalyst 40 selectively reduces the nitrogen oxides in the exhaust gas, so that the denitration catalyst is used. No dust adheres to 40, and the denitration catalyst 40 is not blocked by dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 400 can be operated.

(5) Fifth Embodiment [Denitration device]
FIG. 6 is a schematic cross-sectional view showing a schematic configuration of the denitration device of the present embodiment. In FIG. 6, the same components as those of the denitration device of the first embodiment shown in FIG. 2 are designated by the same reference numerals, and duplicate description will be omitted.
As shown in FIG. 6, the denitration device 500 of the present embodiment includes a charge applying means 20, a denitration agent spraying means 30, a denitration catalyst 40, and a gas analyzer 510.
The denitration device 500 is installed at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside, for example. That is, it can be used as the denitration device 4 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

The denitration device 500 of the present embodiment is different from the denitration device 10 of the first embodiment described above in that the gas analyzer 510 is electrically connected to the charge control device 22 of the charge applying means 20 via the signal line 514. It is a point connected to.

The gas analyzer 510 includes an analyzer 511, a gas measuring unit (sensor) 512 arranged at the rear stage of the denitration catalyst 40 (downstream side of the exhaust gas in the flue 100), an analyzer 511, and a gas measuring unit 512. It includes a signal line 513 that is electrically connected, and a signal line 514 that electrically connects the analysis device 511 and the charge control device 22. Further, the gas analyzer 510 may include a gas densitometer or a display unit (monitor) for displaying a gas concentration (dust concentration), a dust type, a dust temperature, a dust humidity, and the like.
As the gas analyzer 510, for example, a laser gas analyzer and a light transmission type dust densitometer are used.

According to the denitration device 500 of the present embodiment, after the denitration catalyst 40 is provided with the charge applying means 20 in front of the denitration catalyst 40, the dust in the exhaust gas flowing through the flue 100 is charged with the same polarity as the denitration catalyst 40. Since the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 500 can be operated.

Further, according to the denitration device 500 of the present embodiment, the analysis result by the gas analyzer 510 (concentration of dust in the exhaust gas passing through the denitration catalyst 40, type of dust, temperature of dust, humidity of dust, etc.) is obtained. It is possible to feed back to the charge control device 22 and control the amount of charge applied to the dust by the charge applying means 20 based on the analysis result. This makes it possible to optimize the amount of charge applied to the dust.

[Denitration method]
The denitration method of the present embodiment will be described in detail with reference to FIG.
The denitration method of the present embodiment is a charge applying step of imparting a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100, and a denitration of nitrogen oxides in the exhaust gas after the charge imparting step. After the denitration agent spraying step of spraying the agent, the denitration step of reducing nitrogen oxides in the exhaust gas to decompose it into nitrogen and water, and the exhaust gas that has undergone the denitration step are analyzed. It has a gas analysis step of feeding back the measurement result to the charge applying step.

In the denitration method of the present embodiment, the charge applying step, the denitration agent spraying step, and the denitration step are performed in the same manner as in the first embodiment described above.

In the gas analysis step, the gas measuring unit 512 arranged after the denitration catalyst 40 measures the concentration of dust in the exhaust gas that has passed through the denitration catalyst 40, the type of dust, the temperature of dust, the humidity of dust, and the like. , The measurement data is sent to the analyzer 511 via the signal line 513. The analyzer 511 analyzes the measurement data and obtains analysis results such as the concentration of dust in the exhaust gas that has passed through the denitration catalyst 40, the type of dust, the temperature of dust, and the humidity of dust on a gas densitometer or a display unit. It is output to (monitor) and fed back to the charge applying step (charge control device 22). The charge control device 22 controls the amount of charge applied to the dust by the charge applying means 20 based on the concentration of the dust. Specifically, when the concentration of dust decreases, it is determined that the dust has adhered to the denitration catalyst 40, and the amount of charge is increased.

According to the denitration method of the present embodiment, in the charge application step performed before the denitration step, after the charge application means 20 applies a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100. In the denitration step, the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, so that dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 500 can be operated.

Further, according to the denitration method of the present embodiment, the analysis result by the gas analyzer 510 in the gas analysis step (concentration of dust in the exhaust gas passing through the denitration catalyst 40, type of dust, temperature of dust, humidity of dust, etc. ) Is fed back to the charge applying step, and based on the analysis result, the amount of charge applied to the dust by the charge applying means 20 in the charge applying step can be controlled. This makes it possible to optimize the amount of charge applied to the dust.

(6) Sixth Embodiment [Denitration device]
FIG. 7 is a schematic cross-sectional view showing a schematic configuration of the denitration device of the present embodiment. In FIG. 7, the same configurations as those of the denitration device of the first embodiment shown in FIG. 2 and the denitration device of the fifth embodiment shown in FIG. 6 are designated by the same reference numerals and duplicated. Is omitted.
As shown in FIG. 7, the denitration device 600 of the present embodiment includes a charge applying means 20, a denitration agent spraying means 30, a denitration catalyst 40, a gas analyzer 510, and a temperature / humidity / pressure gauge 610. Be prepared.
The denitration device 600 is installed, for example, at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside as described above. That is, it can be used as the denitration device 4 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

The denitration device 600 of the present embodiment is different from the denitration device 500 of the fifth embodiment described above in that the temperature / humidity / pressure gauge 610 is a charge control device 22 of the charge applying means 20 via the signal line 614. It is a point that is electrically connected to.

The temperature / humidity / pressure gauge 610 analyzes the analysis device 611 and the temperature / humidity / pressure measuring unit (sensor) 612 arranged in front of the charging means 20 (upstream side of the exhaust gas in the flue 100). It includes a signal line 613 that electrically connects the device 611 and the temperature / humidity / pressure measuring unit 612, and a signal line 614 that electrically connects the analysis device 611 and the charge control device 22. Further, the temperature / humidity / pressure gauge 610 may be provided with a display unit (monitor) for displaying the temperature, humidity and pressure (atmospheric pressure) of the gas.
As the temperature / humidity / pressure gauge 610, one equipped with a general thermometer, a hygrometer and a pressure gauge is used.

According to the denitration device 600 of the present embodiment, after the denitration catalyst 40 is provided with the charge applying means 20 in front of the denitration catalyst 40, the dust in the exhaust gas flowing through the flue 100 is charged with the same polarity as the denitration catalyst 40. Since the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 600 can be operated.

Further, according to the denitration device 600 of the present embodiment, the analysis result by the gas analyzer 510 (concentration of dust in the exhaust gas passing through the denitration catalyst 40, type of dust, temperature of dust, humidity of dust, etc.) is obtained. It is possible to feed back to the charge control device 22 and control the amount of charge applied to the dust by the charge applying means 20 based on the analysis result. This makes it possible to optimize the amount of charge applied to the dust.

Further, according to the denitration device 600 of the present embodiment, the charge control device 22 obtains the analysis result (the temperature, humidity and pressure (atmospheric pressure) of the exhaust gas before passing through the denitration catalyst 40) by the temperature / humidity / pressure meter 610. The amount of charge applied to the dust can be controlled by the charge applying means 20 based on the analysis result. This makes it possible to optimize the amount of charge applied to the dust.

[Denitration method]
The denitration method of the present embodiment will be described in detail with reference to FIG. 7.
The denitration method of the present embodiment is a charge applying step of imparting a charge having the same polarity as the denitration step to the dust in the exhaust gas flowing through the flue 100, and a denitration of the nitrogen oxide in the exhaust gas after the charge imparting step. After the denitration agent spraying step of spraying the agent, the denitration step of reducing the nitrogen oxide in the exhaust gas to decompose it into nitrogen and water, and the concentration of dust in the exhaust gas after the denitration step. The temperature, humidity and pressure (pressure) of the exhaust gas flowing through the flue 100 are measured before the gas analysis step and the charging step of feeding back the measurement result to the charging step, and the measurement result is charged. It has a temperature / humidity / pressure measurement process that feeds back to the application process.

In the denitration method of the present embodiment, the charge applying step, the denitration agent spraying step, and the denitration step are performed in the same manner as in the first embodiment described above. Further, the gas analysis step is performed in the same manner as in the fifth embodiment described above.

In the temperature / humidity / pressure measuring step, the temperature / humidity / pressure measuring unit 612 of the temperature / humidity / pressure gauge 610 arranged in front of the charging means 20 determines the exhaust gas before passing through the charging means 20. The temperature, humidity and pressure (pressure) are measured, and the measurement data is sent to the analyzer 611 via the signal line 613. The analysis device 611 analyzes the measurement data, outputs the temperature, humidity and pressure (atmospheric pressure) of the exhaust gas before passing through the charge applying means 20 to the display unit, and also outputs the charge application step (charge control device 22). ). The charge control device 22 controls the amount of charge applied to the dust by the charge applying means 20 based on the temperature, humidity, and pressure (atmospheric pressure) of the exhaust gas.

Here, a method of controlling the amount of electric charge according to the temperature of the exhaust gas will be described.
For example, when an electric charge is applied to dust (including ash such as fly ash) by corona discharge, the dust has different characteristics of electric resistance of ash depending on the type of coal used as fuel. In particular, it is known that the electrical resistance of dust varies greatly depending on the temperature (Reference (Toshiaki Misaka, "Application of atmospheric pressure non-equilibrium plasma to environmental engineering", Journal of the Japan Society of Plasma Science and Technology, Vol. 74, No. 74). No. 2, February 1998, p.128-133), p.130-130 and FIG. 6).

Therefore, the temperature of the exhaust gas is monitored, and the electric charge is applied to the dust in the temperature range where the electric resistance of the dust becomes low. When the denitration device 600 is used, for example, in the pulverized coal-fired power generation facility 1 as described above, since the pulverized coal-fired power generation facility 1 has many heat exchangers, the heat exchangers are controlled to control the electric resistance of dust. Charges the dust in the low temperature range. Further, for example, the temperature of dust is controlled by controlling the amount of heat collected in an economizer or the like provided at the outlet of the boiler 3 of the pulverized coal-fired power generation facility 1.

Alternatively, the temperature of the exhaust gas is monitored to control the voltage value or current value suitable for the electric resistance value of the dust, and the dust is charged by corona discharge or the like. For example, when corona discharge is used as a method of applying electric charge, the required electricity consumption differs depending on the temperature. By optimally controlling the electricity consumption according to the exhaust gas temperature or the catalyst temperature, the electricity consumption can be minimized.

A method of controlling the amount of electric charge according to the humidity of the exhaust gas will be described.
When the relative humidity decreases in the discharged state, both positive and negative discharges are promoted. This is thought to be mainly due to the increase in ion mobility due to the increase in relative humidity.
For example, when the amount of water-rich coal (bitumen, lignite) used increases relatively, the water partial pressure in the exhaust gas rises and the discharge start voltage rises, so the voltage applied to the dust in the exhaust gas. It is necessary to increase (the amount of charge given to the dust). On the other hand, when the humidity of the exhaust gas is low, the partial pressure of water in the exhaust gas is low and the discharge start voltage is also low, so that the voltage applied to the dust in the exhaust gas (the amount of charge applied to the dust) is lowered. , Reduce energy consumption.

A method of controlling the amount of electric charge according to the pressure of the exhaust gas will be described.
The lower the density of the exhaust gas, the lower the discharge starting voltage and the faster the discharge. This is because the pressure (atmospheric pressure) of the exhaust gas decreases, the density of the exhaust gas decreases, the collision frequency of dust in the exhaust gas decreases, and the corona discharge is likely to occur. This lowers the corona critical voltage. Therefore, when the pressure (atmospheric pressure) of the exhaust gas is low, the discharge start voltage is also low, so that the voltage applied to the dust in the exhaust gas (the amount of charge applied to the dust) is reduced to suppress the energy consumption. .. On the other hand, when the pressure (atmospheric pressure) of the exhaust gas is high, the discharge start voltage rises, so that it is necessary to increase the voltage applied to the dust in the exhaust gas (the amount of charge applied to the dust).

Further, in the present embodiment, the analysis result by the gas analysis step is fed back to the charge applying step as in the fifth embodiment. The gas analysis step and the temperature / humidity / pressure measurement step may be performed at the same time, or any one of them may be performed if necessary.

According to the denitration method of the present embodiment, in the charge application step performed before the denitration step, after the dust in the exhaust gas flowing through the flue 100 is charged with the same polarity as the denitration step by the charge application means 20. In the denitration step, the nitrogen oxides in the exhaust gas are selectively reduced by the denitration catalyst 40, so that dust does not adhere to the denitration catalyst 40 and the denitration catalyst 40 is not blocked by the dust. Therefore, the life of the denitration catalyst 40 can be extended. Further, it is safe because it is possible to prevent the denitration catalyst 40 from being blocked by the adhesion of dust and making it difficult for the exhaust gas to flow in the flue 100, or to prevent the dust from covering the denitration catalyst 40 and reducing the catalytic activity. The denitration device 600 can be operated.

Further, according to the denitration method of the present embodiment, the analysis result by the temperature / humidity / pressure gauge 610 in the temperature / humidity / pressure measurement step (the temperature, humidity and pressure (pressure) of the exhaust gas before the charge applying step) can be obtained. The charge control device 22 in the charge application step feeds back, and the amount of charge applied to the dust can be controlled by the charge application means 20 in the charge application step based on the temperature, humidity and pressure (pressure) of the exhaust gas. This makes it possible to optimize the amount of charge applied to the dust.

Further, according to the denitration method of the present embodiment, the analysis result by the gas analyzer 510 in the gas analysis step (concentration of dust in the exhaust gas passing through the denitration catalyst 40, type of dust, temperature of dust, humidity of dust, etc. ) Is fed back to the charge control device 22 in the charge application step, and the amount of charge applied to the dust can be controlled by the charge application means 20 in the charge application step based on the analysis result. This makes it possible to optimize the amount of charge applied to the dust.

(7) Seventh Embodiment [Exhaust gas treatment equipment]
FIG. 8 is a schematic diagram showing a schematic configuration of the exhaust gas treatment equipment of the present embodiment. In FIG. 8, the same components as those of the denitration apparatus of the first to sixth embodiments shown in FIGS. 2 to 7 are designated by the same reference numerals, and duplicate description will be omitted.
As shown in FIG. 8, the exhaust gas treatment equipment 700 of the present embodiment has the denitration devices 10, 200, 300, 400, 500, 600 of the first to sixth embodiments described above (hereinafter, the description is simplified. Therefore, it is referred to as "denitration device 10") and an electrostatic precipitator installed after the denitration device 10 that attracts and collects dust that has passed through the denitration device 10 to an electrode having a polarity opposite to the charge. 710 and.
The exhaust gas treatment facility 700 is installed, for example, at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside as described above. That is, the exhaust gas treatment facility 700 can be used as the denitration device 4 and the electrostatic precipitator 6 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

As the electrostatic precipitator 710, a general one is used. Examples of the electrostatic precipitator 710 include a pair of plate-shaped dust collecting electrodes grounded and arranged in parallel, and a needle-shaped discharge electrode arranged between the dust collecting electrodes.
In the electrostatic precipitator 710, dust is collected by attracting dust to a dust collecting electrode having a charge having a polarity opposite to that of the charge applied to the dust by the charge applying means 20 of the denitration device 10, and the dust is collected in the exhaust gas. Dust can be removed. Further, since the dust contained in the exhaust gas does not adhere to the denitration catalyst 40, it can be sufficiently removed by the electrostatic precipitator 710. This improves the efficiency of removing dust in the exhaust gas.

According to the exhaust gas treatment facility 700 of the present embodiment, the charge applying means 20 provided in front of the denitration catalyst 40 imparts a charge having the same polarity as that of the denitration catalyst 40 to the dust in the exhaust gas flowing through the flue 100. After that, the denitration catalyst 40 reduces the nitrogen oxides in the exhaust gas, and the dust contained in the exhaust gas that has passed through the denitration catalyst 40 is collected by the electrostatic precipitator 710. Therefore, the dust contained in the exhaust gas is sufficient. It can be removed to improve the efficiency of removing dust in the exhaust gas.

"Exhaust gas treatment method"
The exhaust gas treatment method of the present embodiment will be described in detail with reference to FIG.
In the exhaust gas treatment method of the present embodiment, after the denitration method of the first to sixth embodiments described above and the denitration method, dust that is not decomposed in the denitration step is attracted by a charge having a polarity opposite to the charge thereof. It has an electric dust collecting process for collecting dust.

In the exhaust gas treatment method of the present embodiment, the denitration method is performed in the same manner as in the first to sixth embodiments described above.

In the electrostatic precipitator, dust is collected by attracting dust to a dust collecting electrode having a charge having a charge opposite to the polarity of the charge applied to the dust by the charge applying means 20 of the denitration device 10, and the denitration step is performed. It is possible to remove dust in the exhaust gas that is not decomposed. Further, since the dust contained in the exhaust gas does not adhere to the denitration catalyst 40, it can be sufficiently removed by the electrostatic precipitator 710. This improves the efficiency of removing dust in the exhaust gas.

According to the exhaust gas treatment method of the present embodiment, in the charge applying step performed before the denitration step, the dust in the exhaust gas flowing through the flue 100 by the charge applying means 20 has the same polarity as the denitration catalyst 40 in the denitration step. After applying a charge, the nitrogen oxides in the exhaust gas are reduced by the denitration catalyst 40 in the denitration step, and the dust contained in the exhaust gas that has passed the denitration step is collected by the electrostatic precipitator 710 in the electrostatic precipitator. Therefore, it is possible to sufficiently remove the dust contained in the exhaust gas and improve the efficiency of removing the dust in the exhaust gas.

(8) Eighth embodiment [exhaust gas treatment equipment]
FIG. 9 is a schematic diagram showing a schematic configuration of the exhaust gas treatment equipment of the present embodiment. In FIG. 9, the same configurations as those of the denitration device of the first to sixth embodiments shown in FIGS. 2 to 7 and the exhaust gas treatment facility shown in FIG. 8 are designated by the same reference numerals and overlapped with each other. The explanation is omitted.
As shown in FIG. 9, the exhaust gas treatment equipment 800 of the present embodiment has the denitration devices 10, 200, 300, 400, 500, 600 of the first to sixth embodiments described above (hereinafter, the description is simplified. Therefore, it is referred to as "denitration device 10"), and a heat exchanger 810 that is installed after the denitration device 10 and exchanges heat between the exhaust gas flowing through the flue and the air supplied to the boiler. It is provided with an electric dust collector 710, which is installed after the vessel 810 and attracts the dust that has passed through the denitration device 10 to an electrode having a polarity opposite to the charge and collects the dust. That is, the heat exchanger 810 is provided between the denitration device 10 and the electrostatic precipitator 710.
The exhaust gas treatment facility 800 is installed, for example, at an arbitrary position in the middle of the flue 100 for discharging the exhaust gas generated in the boiler 3 of the pulverized coal-fired power generation facility 1 to the outside as described above. That is, the exhaust gas treatment facility 800 can be used as the denitration device 4, the heat exchanger 5, and the electrostatic precipitator 6 constituting the pulverized coal-fired power generation facility 1 shown in FIG.

As the electrostatic precipitator 710, the same one as in the eighth embodiment is used.

Examples of the heat exchanger 810 include those generally used in thermal power generation equipment. Specifically, as the heat exchanger 810, a general rotary total heat exchanger or a static total heat exchanger is used.
In the heat exchanger 810, heat is exchanged between the exhaust gas flowing through the flue and, for example, the air supplied to the boiler of the above-mentioned pulverized coal-fired power generation facility 1. As a result, for example, in the above-mentioned pulverized coal-fired power generation facility 1, the air supplied to the boiler can be preheated, so that the temperature inside the boiler furnace is raised to generate high-temperature and high-pressure steam to generate electricity by the steam turbine. You can reduce the energy to do.

According to the exhaust gas treatment facility 800 of the present embodiment, the exhaust gas flowing through the flue and, for example, the above-mentioned pulverized coal-fired power generation facility 1 are provided by the heat exchanger 810 provided between the denitration device 10 and the electrostatic collector 710. Since heat can be exchanged with the air supplied to the boiler and the air can be preheated by the heat of the exhaust gas, the temperature inside the boiler is raised to generate high-temperature and high-pressure steam by the steam turbine. It is possible to reduce the energy for generating electricity.

Further, according to the exhaust gas treatment facility 800 of the present embodiment, the charge applying means 20 provided in front of the denitration catalyst 40 causes the dust in the exhaust gas flowing through the flue 100 to have the same polarity as the denitration catalyst 40. Is applied, the nitrogen oxides in the exhaust gas are reduced by the denitration catalyst 40, and the dust contained in the exhaust gas that has passed through the denitration catalyst 40 is collected by the electrostatic precipitator 710, so that the dust contained in the exhaust gas is collected. Can be sufficiently removed and the efficiency of removing dust in the exhaust gas can be improved.

"Exhaust gas treatment method"
The exhaust gas treatment method of the present embodiment will be described in detail with reference to FIG.
The exhaust gas treatment method of the present embodiment includes a heat exchange step between the denitration step in the denitration method of the first to sixth embodiments described above and the electrostatic precipitator step of the seventh embodiment described above.

In the exhaust gas treatment method of the present embodiment, the denitration method is performed in the same manner as in the first to sixth embodiments described above. Further, in the exhaust gas treatment method of the present embodiment, the electrostatic precipitator step is performed in the same manner as in the above-mentioned seventh embodiment.

In the heat exchange step, the heat exchanger 810 exchanges heat between the exhaust gas that has undergone the denitration step and, for example, the air supplied to the boiler of the above-mentioned pulverized coal-fired power generation facility 1, and the heat of the exhaust gas causes heat exchange. Preheat the air.

According to the exhaust gas treatment method of the present embodiment, the heat exchange step is performed by the heat exchanger 810 between the denitration step and the electrostatic dust collection step, so that the exhaust gas flowing through the flue and, for example, the above-mentioned pulverized coal fire Since heat can be exchanged with the air supplied to the boiler of the power power generation facility 1 and the air can be preheated by the heat of the exhaust gas, the temperature inside the boiler furnace is raised to generate high-temperature and high-pressure steam. It is possible to reduce the energy required to generate heat by the steam turbine.

Further, according to the exhaust gas treatment method of the present embodiment, in the charge applying step performed before the denitration step, the dust in the exhaust gas flowing through the flue 100 by the charge applying means 20 is the same as the denitration catalyst 40 in the denitration step. After applying a polar charge, the nitrogen oxides in the exhaust gas are reduced by the denitration catalyst 40 in the denitration step, and the dust contained in the exhaust gas that has passed the denitration step is collected by the electrostatic precipitator 710 in the electrostatic precipitator. Since it is dusty, it is possible to sufficiently remove the dust contained in the exhaust gas and improve the efficiency of removing the dust in the exhaust gas.

The present invention relates to a denitration device and a denitration method for preventing deterioration of a denitration catalyst for controlling a denitration reaction for removing nitrogen oxides (NOx) contained in exhaust gas, and extends the life of the denitration catalyst and denitration. Contributes to stable operation of the device.

1 pulverized coal-fired power generation equipment 2 burner 3 boiler 4,10,200,300,400,500,600 denitration device 5,810 heat exchanger 6,710 electrostatic dust collector 7 desulfurization device 8 chimney 20 charging means 21 charging mesh 22 charging Control device 23,401 Electric wire 30 Denitration agent spraying means 31 Spray nozzle 32 Supply header 33 Denitration agent tank 34 Supply path 40 Denitration catalyst 100 Chimney 510 Gas analyzer 511 Analysis device 512 Gas measurement unit 513, 514, 613,614 Signal line 610 Temperature / Humidity / Pressure Gauge 611 Analyst 612 Temperature / Humidity / Pressure Measuring Unit 700,800 Exhaust Gas Treatment Equipment

Claims (8)

It is a denitration device installed in the flue and equipped with a denitration catalyst that reduces nitrogen oxides in the exhaust gas flowing through the flue and decomposes them into nitrogen and water.
The stage before the denitration catalyst is provided with a denitration agent spraying means for spraying the denitration agent on the exhaust gas, and a charge applying means for imparting a charge having the same polarity as the denitration catalyst to the dust in the exhaust gas .
A gas analyzer for analyzing the exhaust gas is provided after the denitration catalyst.
The charge applying means controls the amount of charge applied to the dust in the exhaust gas based on the analysis result of the gas analyzer.
A denitration device characterized by that . A measuring unit for measuring the temperature, humidity, and pressure of the exhaust gas is provided in front of the denitration catalyst.
The charge applying means controls the amount of charge applied to the dust in the exhaust gas based on the measurement result of the measuring unit.
The denitration device according to claim 1. The denitration device according to claim 1 or 2 ,
An electrostatic precipitator installed after the denitration device and attracting the dust that has passed through the denitration device to an electrode having a polarity opposite to the charge and collecting the dust.
Exhaust gas treatment equipment characterized by being equipped with. The exhaust gas treatment equipment according to claim 3 , wherein a heat exchanger is provided between the denitration device and the electrostatic precipitator. It is a denitration method that has a denitration step that reduces nitrogen oxides in the exhaust gas flowing through the flue and decomposes them into nitrogen and water.
Prior to the denitration step, there is a denitration agent spraying step of spraying the denitration agent on the exhaust gas, and a charge applying step of imparting a charge having the same polarity as the denitration step to the dust in the exhaust gas.
After the denitration step, a gas analysis step for analyzing the exhaust gas is provided.
Based on the analysis result of the gas analysis step, the amount of charge given to the dust in the exhaust gas in the charge applying step is controlled.
A denitration method characterized by that . Prior to the denitration step, a measurement step of measuring the temperature, humidity, and pressure of the exhaust gas is provided.
Based on the measurement result of the measurement step, the amount of charge given to the dust in the exhaust gas in the charge applying step is controlled.
The denitration method according to claim 5, wherein the method is characterized by the above. The denitration method according to claim 5 or 6 ,
After the denitration method, an electrostatic precipitator step of attracting and collecting the dust that is not decomposed in the denitration step with a charge having a polarity opposite to the charge.
An exhaust gas treatment method comprising. The exhaust gas treatment method according to claim 7 , further comprising a heat exchange step between the denitration step and the electrostatic precipitator step.

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