RU207337U1 - LOW-TOXIC VORTEX CHARCOAL BURNER WITH POINT SPREADERS AND AIRMIX FLOW SWITCHER - Google Patents

Abstract

The utility model relates to the field of heat power engineering and can be used as a pulverized coal burner for boilers of thermal power plants and industrial boiler houses. The vortex pulverized coal burner contains, interconnected by means of spacer elements: a central pipeline for placing a ignition device, sequentially located around the central pipeline coaxially with it, at least one pipeline for supplying air mixture with flow dividers installed in each of them evenly around the circumference, each of which made with a pointed inlet divider, and at least one secondary air pipeline with a vane swirler installed in each of them. In this case, a groove is located in the flat wall of each divider. Moreover, in each pipeline for supplying the air mixture in front of the splitters, an axial-blade swirler is fixed, the blades of which are installed in such a way as to ensure the swirl of the flow of the air mixture towards the bottoms of the splitters troughs. In this case, the ratio of the number of blades of the axial blade swirler to the number of pointed inlet diffusers in each pipeline for supplying the air mixture is 2: 1. The technical result is to ensure an increase in the concentration of coal particles in the troughs of the pointed inlet spargers and at the boundary of the primary air stream. 1 wp f-ly, 11 ill.

Description

Scope of use

The utility model relates to the field of heat power engineering and can be used as a pulverized coal burner for boilers of thermal power plants and industrial boiler houses.

State of the art

Known adopted as a prototype of the claimed utility model vortex pulverized coal burner, containing interconnected by means of spacer elements: a central pipeline for placing a ignition device, sequentially located around the central pipeline coaxially with it at least one pipeline for direct-flow air mixture supply with installed in each of them evenly around the circumference with flow dividers, each of which is made with a pointed inlet divider, and at least one secondary air pipeline with a vane swirler installed in each of them. In this case, a groove is located in the flat wall of each divider (RU 139936 U1, F23D 1/02, published: 04/27/2014 hereinafter - [1]).

The disadvantage of the vortex pulverized coal burner known from [1] is that its design does not sufficiently ensure the redirection of the flow of the air mixture flowing through the pipeline into the grooves of the pointed inlet spargers. This leads to a decrease in the concentration of coal particles in the troughs and at the boundary of the primary air stream and, as a consequence, reduces the efficiency of suppressing the formation of fuel nitrogen oxides (NO _x ).

Disclosure of a utility model

The objective of the claimed utility model is to improve the ecological characteristics of the boiler plant by reducing the emission of fuel NO _x , and the technical result is to ensure an increase in the concentration of coal particles in the gutters of the pointed inlet spargers and at the boundary of the primary air stream.

The solution of this problem by achieving the specified technical result in relation to the claimed utility model is provided by the fact that the vortex pulverized coal burner contains interconnected by means of spacer elements: a central pipeline for placing the ignition device, sequentially located around the central pipeline coaxially with it at least one pipeline for supplying the air mixture with flow dividers installed in each of them evenly around the circumference, each of which is made with a pointed inlet divider, and at least one secondary air pipeline with a vane swirler installed in each of them. In this case, a groove is located in the flat wall of each divider. Moreover, in each pipeline for supplying the air mixture in front of the splitters, an axial-blade swirler is fixed, the blades of which are installed in such a way as to ensure the swirl of the flow of the air mixture towards the bottoms of the splitters troughs. In this case, the ratio of the number of blades of the axial blade swirler to the number of pointed inlet diffusers in each pipeline for supplying the air mixture is 2: 1.

The causal relationship between the set of essential features of the claimed utility model and the achieved technical result is as follows.

Installation of an axial-blade swirler in each pipeline for supplying the air mixture in front of the splitters, made with the possibility of swirling the flow of the air mixture towards the bottoms of the splitters troughs, with blades, the ratio of the number of which to the number of pointed inlet splitters in each pipeline for supplying the air mixture is 2: 1, provides an increase in the concentration of coal particles in the gutters of the pointed inlet spargers and at the boundary of the primary air stream. As a result, the ignition of coal dust when using the inventive burner is carried out at a lower concentration of oxygen (O ₂ ) than during the operation of the burner known from [1], which leads to an increase in the environmental characteristics of the boiler plant by increasing the level of reduction of fuel NO _x emissions, since the process The combustion of volatile products will take place in an atmosphere depleted of O ₂ , and the nitrogen-containing components of volatile products, as laboratory studies have shown, will go mainly not into NO _x , but into molecular nitrogen.

Brief Description of Drawings

FIG. 1 shows a view of a vortex pulverized coal burner from the outlet side. FIG. 2 shows a view of a vortex pulverized coal burner in section A-A. FIG. 3 is a side view of a swirl pulverized coal burner. FIG. 4 shows a view of a vortex pulverized coal burner in section BB. FIG. 5 shows a view of a vortex pulverized coal burner in section B-B. FIG. 6 is a side view of the flow divider from the chute side. FIG. 7 is a top view of the flow divider. FIG. 8 is a bottom view of the flow divider. FIG. 9 is an end view of the flow divider. FIG. 10 is a perspective view of the flow divider. FIG. 11 shows a diagram of the distribution of jets of coal dust and primary air at the outlet from the air mixture channels between the flow dividers.

List of drawing positions:

1 - central pipeline for placing the ignition device;

2.1 - a cylindrical pipe turned at an angle of 90 °;

2.2 - straight cylindrical pipe;

3 - flow dividers;

4 - axial blade swirler;

5.1 - straight cylindrical pipe with rectangular inlet;

5.2 - tapered cylindrical pipe;

5.3 - straight cylindrical pipe;

6 - blade swirler;

7 - gutter;

8.9 - spacer elements.

Implementation of the utility model

Below is a particular example of the design of the inventive swirl pulverized coal burner and the principle of its operation.

The vortex pulverized coal burner contains interconnected: a central pipeline for placing the ignition device 1, one pipeline for supplying the air mixture and one pipeline for secondary air, arranged in series around the central pipeline coaxially with it. The central pipeline for accommodating the ignition device 1 is a straight cylindrical pipe. The pipeline for feeding the air mixture consists of two pipes connected in series: a cylindrical pipe 2.1 turned at an angle of 90 ° and a straight cylindrical pipe 2.2. The secondary air pipeline consists of three pipes connected in series: a straight cylindrical pipe with a lateral rectangular inlet 5.1, a tapered cylindrical pipe 5.2 and a straight cylindrical pipe 5.3. The central pipeline for placing the ignition device 1 passes through a hole in the cylindrical pipe 2.1 turned at an angle of 90 ° and is welded to it. Straight cylindrical pipeline 2.2 passes through a hole in the end wall of a straight cylindrical pipe with a rectangular inlet 5.1 and is welded to it (Fig. 1, 2, 3). Straight cylindrical pipe 2.2 is located around the central pipeline 1 coaxially with it. A straight cylindrical pipe with a lateral rectangular inlet 5.1, a tapered cylindrical pipe 5.2 and a straight cylindrical pipe 5.3 are located around a straight cylindrical pipe 2.2 coaxially with it. The central pipeline 1 is connected to a straight cylindrical pipeline 2.2 by means of a spacer 9 made in the form of a plate. Straight cylindrical pipeline 2.2 is connected to straight cylindrical pipeline 5.3 by means of a spacer 8 made in the form of a plate. In a straight cylindrical pipe 2.2, ten flow dividers 3 are evenly installed around the circumference, each of which has a groove 7 with a depth-to-width ratio H equal to 0.3 (the ratio can be selected in the range of 0.2-0.4) (Fig. 4, nine). Each divider 3 is made with a pointed inlet divider in the shape of a blade with a one-sided oblique cut. The cut angle can be selected in the range of 20-60 ° (in this example, the cut angle is α = 45 °) (Fig. 6, 7, 8, 9, 10). In a straight cylindrical pipe 2.2, an axial-blade swirler 4 is fixed in front of the splitters, the blades of which are installed in such a way as to ensure the swirling of the air mixture flow towards the bottoms of the splitters troughs (Figs. 5, 6). Axial-blade swirler 4 contains twenty blades. A bladed swirler 6 is installed in a straight cylindrical pipe 5.3. The central pipeline for placing the ignition device 1, a pipeline for feeding the air mixture, flow dividers 3, an axial-blade swirler 4, a secondary air pipeline, a vane swirler 6 and spacers 8, 9 are made of Steel 20 (ST20, GOST 1050-2013).

The work of a vortex pulverized coal burner is carried out as follows.

A removable ignition device (not shown in the figure), equipped with an FGTM-2000 steam-mechanical nozzle, through which a steam-oil mixture is fed into the furnace, is placed in the central pipeline 1 and ignited. After the boiler is fired up, the supply of the steam-oil mixture through the nozzle is stopped and the ignition device is removed from the central pipeline. In this case, an aeromixture is fed into the cylindrical pipe 2.1 rotated at an angle of 90 °, and secondary air is fed into the cylindrical pipe with a lateral rectangular inlet 5.1 through the inlet. The flow of secondary air in a straight cylindrical pipe 5.3 is swirled with a vane swirler 6. The flow of an aeromixture in a straight cylindrical pipe 2.2 is swirled with an axial-vane swirler 4 towards the downstream of the aeromixture flow the bottoms of the chutes 7 of the spargers (Figs. 2, 4, 5). Moving along a straight cylindrical pipe 2.2, the swirling flow of the air mixture is divided by means of several dividers 3 into separate jets. When entering the furnace, due to the spaces between the jets formed by the dividers 3, each jet of the air mixture is surrounded by high-temperature combustion products with a low oxygen content recirculating to the axial zone. Since the dividers 3 are made with pointed inlet dividers, jets of an asymmetric structure are formed at the outlet to the furnace. In these jets, solid fuel particles are concentrated at the boundary of the stream of primary air transporting them. The presence of grooves 7 at the splitter and the swirling of the flow of air mixture towards the bottoms of the grooves 7 allows for an increased concentration of coal particles at the boundary of the jet, compared to the prototype [1] (Fig. 11). Particles of solid fuel, hitting the splitter, not only slide along the flat wall, but also accumulate in the chute 7, as a result of which a zone of increased concentration of particles is formed at the entrance to the furnace at the boundary of the primary air stream. As a result, when using the inventive burner, the process of ignition and burnout of volatile products occurs at a lower oxygen concentration (O ₂ ) than during the operation of the burner known from [1], which leads to an increase in the environmental characteristics of the boiler plant by increasing the level of reduction of fuel NO _{x emissions} , since the nitrogen-containing components of volatile products, as laboratory studies have shown, will go mainly not into NO _x , but into molecular nitrogen.

Industrial applicability

The claimed swirl pulverized coal burner meets the condition of "industrial applicability". The essence of the technical solution is disclosed in the formula, description and drawings clearly enough for understanding and industrial implementation by the relevant specialists, and the means used are simple and available for industrial implementation in the field of heat power engineering.

Claims (2)

1. Vortex pulverized coal burner, containing interconnected by means of spacer elements: a central pipeline for placing the ignition device, sequentially located around the central pipeline coaxially with it, at least one pipeline for supplying air mixture with flow dividers evenly installed in each of them around the circumference, each of which is made with a pointed inlet divider, and at least one secondary air pipeline with a vane swirler installed in each of them, while a chute is located in the flat wall of each divider, characterized in that in each pipeline for supplying the air mixture in front of the splitters it is axially fixed - a vane swirler, the blades of which are installed in such a way as to ensure the swirl of the air mixture flow towards the bottoms of the splitter troughs. 2. Vortex pulverized coal burner according to claim 1, characterized in that the ratio of the number of blades of the axial blade swirler to the number of pointed inlet diffusers in each pipeline for supplying the air mixture is 2: 1.

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