SCR (Selective Catalytic Reduction) denitration system

Abstract

The utility model discloses an SCR (Selective Catalytic Reduction) denitration system which comprises a boiler, a first smoke exhaust pipe is arranged at the upper end of the boiler, one end of the first smoke exhaust pipe is provided with an SCR reactor through a smoke analyzer and a first mixer, one side of the first mixer is connected with an ammonia gas conveying pipe, and one end of the ammonia gas conveying pipe is provided with an ammonia storage tank through a flow valve; the flue gas analyzer is arranged at one end of the first flue gas discharge pipe and used for analyzing components of flue gas discharged by the boiler to detect the content of nitric oxide, the ammonia gas discharge pipe is arranged at the other end of the first flue gas discharge pipe, a second mixer and an air delivery pipe are further arranged in the ammonia gas delivery pipe, and the flue gas analyzer and the flow valve are both electrically connected with a controller outside the boiler. The size of the flow valve is controlled according to the content of nitric oxide in the flue gas, then the input amount of the ammonia gas is adjusted, the situation that when the content of nitric oxide in the flue gas is small, large ammonia gas conveying is matched is prevented, the usage amount of the ammonia gas is conveniently saved, and the energy-saving effect is good.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of SCR denitration technology, and specifically relates to a SCR denitration system. BACKGROUND

[0002] The boiler needs to use the SCR denitration equipment to carry out denitration treatment in the use process, and the selective catalytic reduction method (SCR) refers to the method that uses the reducing agent (such as NH3, liquid ammonia, urea) to "selectively" react with NOx in flue gas and generate nontoxic and non-polluting N2 and H2O under the action of a catalyst. The SCR technology has very remarkable control effect on the NOx in boiler flue gas, and the technology is relatively mature, and has become the most widely used and most effective flue gas denitration technology in the world. Under the condition of reasonable arrangement and temperature range, the removal rate can reach 80~90%.

[0003] The prior art application number for a kind of SCR denitration system. The system can be transported to economizer with circulating water in heat storage device and carry out heat exchange with the flue gas generated during the initial stage of boiler ignition start, heat the flue gas, realize the purpose that SCR denitration system can normally run during the initial stage of boiler ignition start to grid-connected, but, cannot timely adjust ammonia input according to the content of nitrogen oxides in flue gas, when the content of nitrogen oxides in flue gas is less, it is easy to cause a large amount of ammonia waste when matching larger ammonia delivery. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of SCR denitration system, to solve the problem that ammonia input cannot be timely adjusted according to the content of nitrogen oxides in flue gas in prior art, when the content of nitrogen oxides in flue gas is less, it is easy to cause a large amount of ammonia waste when matching larger ammonia delivery.

[0005] To achieve the above object, the utility model provides the following technical scheme: a kind of SCR denitration system, including boiler, the first flue pipe is equipped on the upper end of the boiler, the first flue pipe one end is equipped with SCR reactor by flue gas analyzer and first mixer, the first mixer one side is connected with ammonia delivery pipe, the ammonia delivery pipe one end is equipped with ammonia storage tank by flow valve, and ammonia delivery pipe inside is also equipped with second mixer and air delivery pipe, and flue gas analyzer and flow valve are electrically connected with the controller outside boiler.

[0006] Further, one-way valve is provided on the first flue pipe, dilution fan and electric control valve are provided on the air delivery pipe.

[0007] Further, the bottom of the SCR reactor is equipped with the second flue pipe, the bottom one side of the boiler is equipped with fuel air pipe, air preheater is connected on the second flue pipe and fuel air pipe.

[0008] Further, the first mixer and the second mixer each comprise a mixing shell, and a first flow blocking baffle is arranged in the mixing shell.

[0009] Further, one side of the mixing shell is provided with an air inlet, and the other side of the mixing shell is provided with an air outlet.

[0010] Further, a second flow blocking baffle is arranged in the middle of the first flow blocking baffle, and the second flow blocking baffle is an arc-shaped plate.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] The utility model discloses a flue gas analyzer is arranged at one end of the first flue gas pipe, the flue gas analyzer and flow valve all with the controller of boiler outside electric connection, and the flue gas analyzer is used for analyzing the content of nitrogen oxides to the flue gas composition of boiler discharge, and the detection information is passed to the controller, and the size of flow valve is controlled according to the content of nitrogen oxides in flue gas, and then the input of ammonia gas is adjusted, prevents the content of nitrogen oxides in flue gas from matching larger ammonia gas delivery when being less, and the use amount of ammonia gas is conveniently saved, and the energy-saving effect is better.

[0013] The utility model discloses a first flue gas pipe one end is equipped with SCR reactor through the first mixer, is used for the sufficient contact mixing of ammonia gas and nitrogen oxides in flue gas, and the efficiency of denitration is conveniently improved, and the inside of ammonia gas delivery pipe is also equipped with second mixer and air delivery pipe, and ammonia gas is conveniently diluted with air evenly.

[0014] The utility model discloses a first mixer and second mixer each comprise the mixing shell that is equipped with, and the first flow blocking baffle is arranged in the mixing shell, the first flow blocking baffle forms S type mixing channel, the second flow blocking baffle is arranged in the middle of the first flow blocking baffle, and the second flow blocking baffle is arc-shaped plate, and the second flow blocking baffle increases the flow time of gas in the mixing shell, thereby conveniently improve the efficiency of mixing. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the utility model, and constitute a part of the specification, and are used to explain the utility model together with embodiments of the utility model, and do not constitute the limitation to the utility model.In the drawings:

[0016] Figure 1 It is first perspective structure schematic drawing of the utility model for the first perspective structure schematic drawing of the utility model;

[0017] Figure 2 It is second perspective structure schematic drawing of the utility model for the second perspective structure schematic drawing of the utility model;

[0018] Figure 3 It is the internal structure schematic drawing of the mixer of the utility model for the internal structure schematic drawing of the mixer of the utility model.

[0019] In the figure: 1, boiler; 2, first flue; 3, one-way valve; 4, flue gas analyzer; 5, first mixer; 6, SCR reactor; 7, air preheater; 8, fuel air pipe; 9, ammonia gas delivery pipe; 10, second mixer; 11, air delivery pipe; 12, dilution fan; 13, flow valve; 14, second flue; 15, first resistance baffle; 16, second resistance baffle; 17, air inlet; 18, air outlet; 19, controller. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] Please refer to Figure 1 , Figure 2 , Figure 3 In the embodiments of the present application, an SCR denitration system comprises a boiler 1, the upper end of the boiler 1 is provided with a first flue 2, one end of the first flue 2 is provided with an SCR reactor 6 through a flue gas analyzer 4 and a first mixer 5, the first mixer 5 is used for fully mixing ammonia gas with nitrogen oxides in flue gas, so as to improve the efficiency of denitration, the first mixer 5 is connected with an ammonia gas delivery pipe 9 on one side, one end of the ammonia gas delivery pipe 9 is provided with an ammonia storage tank through a flow valve 13, and the ammonia gas delivery pipe 9 is further provided with a second mixer 10 and an air delivery pipe 11 inside, the first mixer 5 and the second mixer 10 both comprise a mixing machine shell, and the mixing machine shell is provided with a first resistance baffle 15 inside, the first resistance baffle 15 forms an S-shaped mixing channel, the mixing machine shell is provided with an air inlet 17 on one side, and the mixing machine shell is provided with an air outlet 18 on the other side, the second mixer 10 is used for uniformly diluting ammonia gas with air, and the flue gas analyzer 4 and the flow valve 13 are both electrically connected with a controller 19 outside the boiler 1, the flue gas analyzer 4 is used for analyzing the composition of flue gas discharged by the boiler 1, detecting the content of nitrogen oxides, transmitting the detection information to the controller 19, controlling the size of the flow valve 13 according to the content of nitrogen oxides in the flue gas, and then adjusting the input amount of ammonia gas, so as to prevent matching a large amount of ammonia gas delivery when the content of nitrogen oxides in the flue gas is small, facilitate saving the use amount of ammonia gas, and achieve a good energy-saving effect.

[0022] As shown in Figure 1 and Figure 2 , in order to control the opening and closing of the pipeline, a one-way valve 3 is further arranged on the first flue 2, and a dilution fan 12 and an electric control valve are arranged on the air delivery pipe 11, so as to control the opening and closing of the first flue 2 and the air delivery pipe 11.

[0023] As Figure 1 and Figure 2 In order to improve the heat exchange performance of the boiler 1, the second flue gas pipe 14 is arranged at the bottom of the SCR reactor 6, the fuel air pipe 8 is arranged at one side of the bottom of the boiler 1, and the air preheater 7 is connected to the second flue gas pipe 14 and the fuel air pipe 8, so as to improve the heat exchange performance of the boiler 1 and reduce the energy consumption.

[0024] As Figure 1 and Figure 3 In order to improve the gas mixing efficiency, the second flow blocking baffle 16 is arranged in the middle of the first flow blocking baffle 15, and the second flow blocking baffle 16 is an arc-shaped plate, so that the gas flow time in the mixing machine shell is increased, the gas mixing efficiency is improved, and the denitration efficiency is improved.

[0025] The working principle and use process of the utility model are as follows: when in use, the flue gas generated by the boiler 1 enters the SCR reactor 6 for denitration reaction through the first flue gas pipe 2, the flue gas analyzer 4 arranged at one end of the first flue gas pipe 2, and the flue gas analyzer 4 and the flow valve 13 are electrically connected to the controller 19 outside the boiler 1, the flue gas analyzer 4 is used for analyzing the composition of the flue gas discharged by the boiler 1 and detecting the content of nitrogen oxides, the detection information is transmitted to the controller 19, the controller 19 controls the size of the flow valve 13 according to the content of nitrogen oxides in the flue gas, and then the input amount of ammonia gas is adjusted, so that when the content of nitrogen oxides in the flue gas is small, the ammonia gas delivery is matched, the use amount of ammonia gas is saved, and the energy-saving effect is good.

[0026] Finally, it should be pointed out that: the above-mentioned is only the preferred embodiment of the utility model, and is not used for limiting the utility model, although the utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical scheme recorded in the foregoing embodiments can be modified, or some technical features can be replaced equivalently. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. An SCR De-NOx system comprising a boiler (1), characterized in that: The first flue gas pipe (2) is provided with a one-way valve (3), the air delivery pipe (11) is provided with a dilution fan (12) and an electric control valve.

2. The SCR denitration system according to claim 1, characterized in that: The bottom of the SCR reactor (6) is provided with a second flue gas pipe (14), one side of the bottom of the boiler (1) is provided with a fuel air pipe (8), and the second flue gas pipe (14) and the fuel air pipe (8) are connected with an air preheater (7).

3. The SCR denitration system according to claim 1, characterized in that: The first mixer (5) and the second mixer (10) each comprise a mixing shell, and the mixing shell is internally provided with a first flow blocking baffle (15).

4. The SCR de-NOx system of claim 1, wherein: One side of the mixing shell is provided with an air inlet (17), and the other side of the mixing shell is provided with an air outlet (18).

5. The SCR de-NOx system of claim 4, wherein: The middle of the first flow blocking baffle (15) is provided with a second flow blocking baffle (16), and the second flow blocking baffle (16) is an arc-shaped plate.

6. The SCR de-NOx system of claim 4, wherein: ​

Images