RU2421659C1 - Liquid fuel combustion method - Google Patents

Abstract

FIELD: power industry. ^ SUBSTANCE: liquid fuel combustion method involves obtaining of flammable mixture in burner by supplying fuel jet from the channel to spraying surface and mixing of sprayed fuel with air; surface has cusp form and is installed on the edge of spraying zone, and fuel channel is arranged so that its axis passes through cross point of burner axis with surface and focus of the latter. Surfaces transmit electric charge. Fuel channel is filled with liquid and solid combustible components. Fuel channel is made as an integral part of mixer and injector. Pole of the jet is aligned with focus of the surface. ^ EFFECT: higher reliability, efficiency and quality of combustion process. ^ 5 cl, 2 dwg

Description

The invention relates to a power system and can be used for burning liquid and mixed fuels.

A known method of burning liquid fuel, including pre-heating the fuel, then spraying it into the gasification chamber, mixing with air and burning [1].

The disadvantages of this method are:

- lack of reliability in operation of a device that implements the method, due to the fact that powerful thermal radiation acts on the atomizer (nozzle) and causes its coking;

- the impossibility of using mixed fuel, for example liquid and solid, to increase the luminosity of the torch, since the spray nozzle causes the presence of small diameter holes in it that impede the passage of solid particles;

- limited performance of the burner, limited by the small diameter of the hole, generating the inability to achieve large thermal stresses in the furnace space.

The prototype is a method of burning liquid fuel, including the supply through the channels of fuel and air at an angle to the spray surface, the formation of a combustible mixture and subsequent combustion [2].

The disadvantages of the prototype are:

- lack of reliability in the operation of the device that implements the method, due to the fact that the surface in the spray zone is exposed to thermal radiation, as a result of which coking occurs, which leads to a change in the formation conditions of the flare jet, in addition, the presence of a surface (obstacle) on the way the movement of the air stream affects the aerodynamic properties of the burner;

- the complexity of setting the operating mode of the burner associated with the selection of the desired angle of the surface relative to the jets of fuel and air.

The objective of the invention is to increase the reliability, efficiency and quality of the combustion process.

The problem is solved in that in a method of burning liquid fuel, which includes receiving a combustible mixture in a burner by supplying a jet of fuel to the spraying surface from the channel and mixing the sprayed fuel with air, the surface is parabolic in shape and placed on the edge of the spray zone, and the fuel channel is placed so that its axis passes through the point of intersection of the axis of the burner with the surface and the focus of the latter.

Surfaces report an electric charge. The fuel channel is filled with liquid and solid combustible components. The fuel channel is performed in one with a mixer and a supercharger. The pole of the jet is combined with the focus of the surface.

The invention is reflected in the operations:

- the surface is made parabolic in shape and placed on the edge of the spray zone, and the fuel channel is placed so that its axis passes through the point of intersection of the axis of the burner with the surface and the focus of the latter;

- surfaces report an electric charge;

- the fuel channel is filled with liquid and solid combustible components;

- the fuel channel is performed in one with a mixer and a supercharger;

- the pole of the jet is combined with the focus of the surface.

The installation of the surface at the edge of the spray zone, its parabolic shape and placement of the fuel channel so that its axis passes through the point of intersection of the axis of the burner with the surface and the focus of the latter, increase the reliability of the combustion process. Placing the channel in this way allows the droplets resulting from breaking the jet on the surface to give movement along the axis of the burner. In this case, the surface is cooled all the time, as a result of which its coking is prevented. Placing this surface on the edge of the spray zone further reduces the possibility of coking, since part of the radiation is absorbed by the moving drops. Even less thermal radiation acts on the fuel channel, which completely eliminates its coking. In addition, the installation of the surface at the edge of the spray zone does not violate the aerodynamics of the jet, therefore, air can be supplied both at the mouth of the burner and at a distance from it, for example, in the gasification chamber and when leaving it. Moreover, depending on the specific conditions, the feed can be carried out in the usual way, tangentially, through an annular channel, etc., which increases the efficiency of the combustion process.

The communication surface of the electric charge allows you to better maintain a small spray of fuel, preventing the merger of individual drops in the process of movement. This, in turn, contributes to a better evaporation of droplets, increases the burning rate, as a result of which it becomes possible to reduce the volume of the furnace and increase thermal stresses in it, which ultimately increases the efficiency and quality of the combustion process as a whole.

Filling the fuel channel with liquid and solid combustible components improves fuel combustion. On the surface of solid particles, such as coal, a film of liquid fuel is formed, and the combustion of such a mixture occurs differently than usual. When using traditional liquid fuel, the amount of evaporating liquid is reduced due to the reduction of the surface of the droplet. As the combustion process and oxygen consumption develop, the individual remaining unevaporated volumes of droplets may be in the zone of reaction products and, being ballasted with carbon dioxide, will not burn if they are not mixed with unspent oxygen residues. In the case of using a mixture of liquid and solid fuels, the picture changes. First, the liquid fuel film covering the coal particle evaporates and burns, and then the coal particle is already heated to a high temperature. If at the first stage the burning rate is limited by evaporation of the liquid and diffusion mixing of the formed vapors with the surrounding air (oxygen), then at the second stage (reaction of the coal particle) the combustion process will practically not be inhibited by the physical stage and will only be determined by the rate of the chemical reaction itself, since the surrounding particle medium will already be warmed up. Moreover, in conditions where oxygen is not able to reach the carbon surface, carbon dioxide becomes the oxygen carrier. Carbon dioxide diffuses into a coal particle and in the high temperature range it can be restored at a high speed by a carbon surface, forming a combustible gas - carbon monoxide. Water vapor in the combustion products completes the process, providing a reaction for the conversion of carbon monoxide to dioxide. It should also be noted that a coal particle contributes to a better absorption of a drop of thermal radiation, which increases its evaporation rate. In addition, the presence of carbon frequencies increases the luminosity of the torch and, consequently, the heat transfer by radiation. All this increases the efficiency and quality of the furnace process.

The execution of the fuel channel in one with a mixer and a supercharger increases the reliability of the combustion process by simplifying the fuel equipment.

The combination of the jet pole with the focus of the spray surface allows you to maintain the direction of movement of the atomized fuel (droplets) when changing the angle of the jet opening due to varying burner performance (fuel pressure in the channel), which improves the quality of atomization and mixing with air and, therefore, improves the combustion process.

The invention is illustrated by drawings.

Figure 1 shows a diagram of a burner that implements the method. Figure 2 shows the device of the fuel channel.

The burner contains a mouth 1 with a tube 2, through which a fuel jet 5 flows from the channel 3 to the spray surface 4 having focus F, while the axis 6 of the channel passes through the focus and the intersection point of the axis 7 of the burner with the surface. The jet is divided into droplets 8, which in the gasification chamber 9 are mixed with air entering the openings 10. The end of the channel 11 can be placed in the mixer housing 12, into which the liquid 13 and solid 14 components are placed in certain proportions, and connected to the outlet pipe 15 chamber 16 of the supercharger, enclosed together with the inlet pipe 17 in the housing. A wheel 18 with blades 19, kinematically connected with rollers 20 having recesses 21 for passage of blades, is rotatably mounted in the chamber.

The method is implemented as follows.

The surface 4 of the spray perform a parabolic shape and set it on the mouth 1 of the burner, i.e. on the edge of the spray zone, and the fuel channel 3 is placed so that its axis 6 passes through the point of intersection of the axis 7 of the burner with surface 4 and its focus F (Fig. 1). From the channel, through the tube 2, fuel is sprayed onto the spray surface 5, which is divided into small droplets 8 moving along the axis 7 of the burner into the gasification chamber 9, where they are mixed with air coming in through openings 10. The resulting fuel mixture is burned.

The spray surfaces 4 impart an electric charge, as a result of which the droplets 8 are charged with the same name and do not touch each other during movement into the gasification chamber.

The fuel channel is filled with liquid 13 and solid 14 combustible components by mixing, for example, fuel oil and crushed coal (figure 2).

The fuel channel is performed in one with a mixer and a supercharger, as a result of which mixed fuel is obtained directly during the operation of the burner. To do this, the wheel 18 is rotated (for example, by the engine), with which the rollers 20 are rotated. When the blade 19 approaches the roller, it turns out to be a recess 21, through which the blade passes through the roller during rotation. At the same time, mixed fuel located in the chamber 16 between the inlet 17 and the outlet 15 nozzles cannot leak out through the rollers, since it is restrained from alternating between the rollers and the blades. As a result, the fuel located in the upper part of the chamber 16 is driven (pumped) by the blades 19 into the channel, the end 11 of which is connected to the outlet pipe. When the blade moves from the right (in Fig. 2) to the left roller, it mixes the liquid 13 and solid 14 components in the lower part of the mixer body 12, which are then sucked in by the inlet pipe 17. When the burner is in variable output mode, the jet 5 pole is aligned with focus F surface. It should be noted that if the burner productivity varies insignificantly and the jet is relatively small in diameter, then the jet pole can be placed on the channel axis (coinciding with the jet polar axis) behind the focus, as shown in Fig. 1, reducing the effect of thermal radiation. By moving the jet pole along the channel axis relative to the focus, the shape of the spray can be changed.

The implementation of the invention will improve the efficiency and quality of the combustion process when burning liquid and mixed fuels in small-volume furnaces.

Information sources

1. Knorre G.F. The study of combustion processes of natural fuel. - L .: Gosenergoizdat, 1948. S.217-220 - analogue.

2. A.S. USSR No. 567016, IPC F23D, 7/00, 1977 - prototype.

Claims (5)

1. A method of burning liquid fuel, including obtaining a combustible mixture in a burner by applying a jet of fuel to the spraying surface from the channel and mixing the sprayed fuel with air, characterized in that the surface is parabolic in shape and placed on the edge of the spray zone, and the fuel channel is placed so that its axis passes through the point of intersection of the axis of the burner with the surface and the focus of the latter. 2. The method according to claim 1, characterized in that the surface imparts an electric charge. 3. The method according to claim 1, characterized in that the fuel channel is filled with liquid and solid combustible components. 4. The method according to claim 1, characterized in that the fuel channel is integral with the mixer and the supercharger. 5. The method according to claim 1, characterized in that the jet pole is aligned with the focus of the surface.

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