A micro-oil ignition and combustion-supporting system for boilers

Abstract

The present invention relates to a micro-oil ignition and combustion-supporting system for a boiler, comprising an air compressor, a mixer, an oil tank, and a nozzle; the mixer is cylindrical and thin in the middle and thick at both ends; one end of the mixer is connected to the air compressor, the other end of the mixer is connected to the nozzle, and the middle of the mixer is connected to the bottom of the oil tank via an oil suction pipe; the oil tank is filled with fuel. The mixer comprises an air intake straight pipe, an air intake cone pipe, an intermediate thin pipe, an oil suction pipe, a mixed gas cone pipe, a throttling orifice plate, a mixed gas straight pipe, and an oil intake pressure regulating device; the beneficial effect of the present invention is that, through the provided oil intake pressure regulating device, compressed air enters the oil tank and exerts pressure on the surface of the fuel, thereby pressurizing the fuel, and the amount of fuel entering the mixer increases, making the oil mist thicker and allowing the oil and compressed air to be better mixed.

Description

Technical Field

[0001] The invention relates to the technical field of combustion-supporting devices, in particular to a micro-oil ignition and combustion-supporting system for boilers. Background Art

[0002] When a coal-fired boiler is cold-started, the furnace temperature is very low, and it is difficult to ignite pulverized coal directly. Oil burners are generally used to heat the furnace and maintain stable combustion. After a few hours of heating, the furnace temperature rises before pulverized coal is added. In addition, when the boiler is running at low load, the furnace temperature drops, the pulverized coal ignition is unstable, and the flame pulsates. At this time, oil burners are also needed to stabilize combustion.

[0003] The fuel oil system in a thermal power plant has two main functions: first, it uses auxiliary fuel oil for ignition during the startup phase of the coal-fired boiler; second, it uses fuel oil to stabilize combustion when the boiler is under low load or using inferior coal, improves the combustion conditions in the furnace, and prevents abnormal fire extinguishing of the boiler;

[0004] The oil burner is equipped with an atomizing nozzle. The fuel enters the atomizing nozzle through a high-pressure oil pump to form fine oil droplets, which are mixed with air and ignited. In this method, the oil droplets and air are mixed outside the nozzle without spatial restrictions. The air and oil droplets are mixed unevenly and cannot burn at the same time, wasting a lot of fuel and posing a challenge to subsequent air management. Therefore, there is an urgent need for a device that can fully mix and atomize the fuel and air to make the combustion more complete, concentrate firepower to ignite the coal powder, and maintain stable combustion.

[0005] Among the existing patents, the closest prior art is the patent with application number CN201410819452.2, which is a patent for a micro-oil ignition device arranged on the arch of a long-life W-flame boiler that is easy to modify. The patent discloses a micro-oil ignition pipeline, a micro-oil ignition pipeline baffle valve, a micro-oil gun, a fire detector, a concentrated coal powder pipeline and a concentrated coal powder pipeline baffle valve; the micro-oil ignition pipeline and the concentrated coal powder pipeline are led from the same concentrated separation pipeline, the concentrated coal powder pipeline baffle valve is arranged above the concentrated coal powder pipeline, the micro-oil ignition pipeline baffle valve is arranged above the micro-oil ignition pipeline, the micro-oil gun and the fire detector are sequentially arranged on the micro-oil ignition pipeline, the micro-oil gun is located below the micro-oil ignition pipeline baffle valve, and the micro-oil gun installation position on the micro-oil ignition pipeline forms an oil combustion chamber; the patent does not disclose the detailed structure of the micro-oil ignition, but only discloses the installation position of the micro-oil ignition, which is incomplete;

[0006] There is also a patent with application number CN201910688935.6, a coal powder and micro-oil ignition device; it discloses a micro-oil igniter and a coal powder burner, the micro-oil igniter includes a main heat small oil gun, a combustion-supporting air tube, an ignition gun, a flame detector, a stable combustion hood, etc., the coal powder burner includes a coal powder burner body and a transition flange for connecting with the micro-oil igniter. In order to prevent the combustion tube from burning and improve the heat exchange efficiency, the small oil gun and the conduit, the ignition gun and the conduit, the stable combustion hood, etc. are lengthened and shifted respectively, and the oil gun flame is directly sent into the coal powder burner to directly heat the coal; the patent only discloses how to ignite coal powder, and there is no detailed oil and gas mixing structure, so people don’t know how to mix oil and gas to achieve sufficient combustion, which is imperfect. Summary of the Invention

[0007] In order to overcome the shortcomings of the existing technology, the present invention provides a micro-oil ignition and combustion-supporting system for boilers, which can fully mix the fuel and air, and an atomizing device to make the combustion more complete, and can concentrate the firepower to ignite the coal powder; maintain the stability of combustion, and can avoid the original extensive addition of fuel, which causes fuel waste.

[0008] The present invention provides the following technical solutions:

[0009] A micro-oil ignition and combustion-supporting system for a boiler comprises an air compressor, a mixer, an oil tank and a nozzle; the mixer is cylindrical with a thin middle and thick ends; one end of the mixer is connected to the air compressor, the other end of the mixer is connected to the nozzle, and the middle of the mixer is connected to the bottom of the oil tank through an oil suction pipe; the oil tank is filled with fuel.

[0010] Furthermore, the mixer includes an intake straight pipe connected to the air compressor, an intake conical pipe connected to the intake straight pipe, an intermediate thin pipe connected to the intake conical pipe, a mixed gas conical pipe connected to the intermediate thin pipe, and a mixed gas straight pipe connected to the mixed gas conical pipe; the mixed gas straight pipe is connected to the nozzle, and the intermediate thin pipe is connected to the bottom of the oil tank through an oil suction pipe.

[0011] Furthermore, the mixer also includes an oil inlet pressure regulating device; the oil inlet pressure regulating device includes an oil inlet pressure regulating tube connected to an intermediate thin tube near one end of the intake cone tube, and the outlet of the oil inlet pressure regulating tube faces the top surface of the oil tank.

[0012] Furthermore, the oil inlet pressure regulating pipe is provided with a valve and a pressure gauge in sequence from top to bottom.

[0013] Furthermore, the valve is an electric valve; and the pressure gauge is an electric contact pressure gauge.

[0014] Furthermore, the oil inlet pressure regulating device also includes a controller; the controller is respectively connected to the electric contact pressure gauge and the electric valve signal.

[0015] Furthermore, the oil inlet pressure regulating device also includes a throttle orifice plate arranged in the intermediate capillary tube and used to regulate the air pressure in the intermediate capillary tube; the throttle orifice plate is arranged between the oil inlet pressure regulating tube and the oil suction pipe; the throttle orifice plate is a circular plate with a through hole in the middle; the outer circle of the circular plate is welded to the inner wall of the intermediate capillary tube.

[0016] Furthermore, the oil inlet pressure regulating tube is U-shaped; one end is tightly connected to one end of the middle thin tube close to the conical air inlet pipe; the other end leads to the oil tank, with the pipe opening facing the top surface of the oil tank.

[0017] Furthermore, the through hole of the throttle orifice plate is a tapered hole; the large end of the tapered hole faces the air intake straight pipe.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The mixer uses the Venturi tube principle to generate suction at the junction of the middle thin tube and the oil suction pipe, sucking the fuel into the middle thin tube and fully mixing it with the compressed air to form oil mist. When igniting the pulverized coal, the amount of oil used is reduced compared to direct fuel injection.

[0020] Through the oil inlet pressure regulating device, compressed air enters the fuel tank and exerts pressure on the fuel surface, which can pressurize the fuel. The amount of fuel entering the mixer will increase, making the oil mist thicker and the oil and compressed air better mixed. After using the oil inlet pressure regulating device, the coal powder can be ignited faster, saving time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 Schematic diagram of the structure of the mixer;

[0023] Figure 3 for Figure 2 A magnified view of point A;

[0024] Figure 4 This is a structural schematic diagram of the throttling orifice plate of Example 3 of the present invention.

[0025] In the figure, 1. air compressor; 2. mixer; 3. oil inlet pressure regulating pipe; 4. oil suction pipe; 5. valve; 6. pressure gauge; 7. oil tank; 8. nozzle; 21-intake straight pipe; 22-intake cone pipe; 23. throttle orifice plate; 24. middle thin tube; 25. mixture cone pipe; 26. mixture straight pipe. DETAILED DESCRIPTION

[0026] First, it should be noted that any discussion of any embodiment of the present invention is for illustrative purposes only and is not intended to limit the scope of the present disclosure (including the claims) to these examples. Numerous other variations exist for various aspects of the present invention described above, which, for the sake of clarity, are not provided in detail. Therefore, other embodiments are also within the scope of protection of the corresponding claims.

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] Example 1

[0029] like Figure 1-4 As shown,

[0030] A micro-oil ignition and combustion-supporting system for a boiler includes an air compressor 1, a mixer 2, an oil tank 7, and a nozzle 8. The mixer 2 is cylindrical, narrow in the middle and wide at both ends. One end of the mixer 2 is connected to the air compressor 1, and the other end is connected to the nozzle 8. The middle of the mixer 2 is connected to the bottom of the oil tank 7 via an oil suction pipe 4. The oil tank 7 is filled with fuel. The lower end of the oil suction pipe 4 is close to the oil tank 7 to absorb more fuel and avoid emptying it.

[0031] The mixer 2 includes an air intake straight pipe 21 connected to the air compressor 1, an air intake conical pipe 22 connected to the air intake straight pipe 21, an intermediate thin pipe 24 connected to the air intake conical pipe 22, a mixed gas conical pipe 25 connected to the intermediate thin pipe 24, and a mixed gas straight pipe 26 connected to the mixed gas conical pipe 25; the mixed gas straight pipe 26 is connected to the nozzle 8, and the middle part of the intermediate thin pipe 24 is connected to the bottom of the oil tank 7 through the oil suction pipe 4.

[0032] like Figure 2 As shown, a more detailed technical solution is that the intake straight pipe 21 and the mixture straight pipe 26 have the same size and shape; the intake cone pipe 22 and the mixture cone pipe 25 have the same size, structure and shape, but are arranged in opposite directions; the small ends of the intake cone pipe 22 and the mixture cone pipe 25 are respectively connected to the two ends of the intermediate capillary tube 24; the inner diameter of the intermediate capillary tube 24 is equal to the inner diameter of the small ends of the intake cone pipe 22 and the mixture cone pipe 25; the inner diameter of the mixture straight pipe 26 and the intake straight pipe 21 is equal, and the inner diameter of the intake straight pipe 21 is at least three times the inner diameter of the intermediate capillary tube 24. This structure ensures that the fuel suction pipe 4 fully absorbs fuel.

[0033] When the above structure is used, it is found that the combustion temperature of the mixed gas is not high enough and the amount of ignited coal powder is not large, which affects the combustion speed in the initial stage. In order to make the mixer 2 work better, the mixer 2 is improved as follows: an oil inlet pressure regulating device is added, that is, the fuel in the fuel tank 7 is pressurized; so that the oil output of the oil suction pipe 4 is increased. The specific structure is as follows:

[0034] like Figure 2 As shown, the mixer 2 also includes an oil inlet pressure regulating device; the oil inlet pressure regulating device includes an oil inlet pressure regulating pipe 3 connected to the intermediate thin pipe 24 near one end of the intake cone pipe 22, and the outlet of the oil inlet pressure regulating pipe 3 faces the top surface of the oil tank 7.

[0035] The fuel inlet pressure regulating tube 3 is U-shaped; one end is tightly connected to the end of the intermediate capillary tube 24 near the tapered intake pipe; the other end leads to the fuel tank 7, with the tube opening facing the top surface of the fuel tank 7. This is to prevent the downward-facing outlet of the fuel inlet pressure regulating tube 3 from causing some air to be mixed with the fuel and then be sucked into the intermediate capillary tube 24 through the oil suction pipe 4, thereby reducing the fuel quantity and affecting combustion.

[0036] The oil inlet pressure regulating pipe 3 is provided with a valve 5 and a pressure gauge 6 in sequence from top to bottom.

[0037] The valve 5 and pressure gauge 6 are set according to the combustion conditions of the coal. The opening degree of the valve 5 is determined according to the reading of the pressure gauge 6. If the combustion is not ideal, the valve 5 is opened to increase the fuel pressure in the fuel tank 7, thereby increasing the fuel supply and achieving a balance. If the combustion is good, the valve 5 can be closed to reduce the fuel supply.

[0038] During the working process of the present invention, the air compressor 1 is turned on, and the compressed air flows into the air intake straight pipe 21 along the pipeline, passes through the air intake cone 22, and flows into the intermediate thin pipe 24. The pressure of the compressed air flowing into the intermediate thin pipe 24 increases and the flow rate becomes faster.

[0039] A small amount of compressed air enters the fuel tank 7 through the oil inlet pressure regulating pipe 3 to apply pressure to the fuel; most of the compressed air continues forward to form suction at the oil suction pipe 4, sucking the fuel in and mixing it thoroughly with the air; the fuel is atomized through the mixture cone pipe 25 and the mixture straight pipe 26, and sprayed through the nozzle 8. The igniter ignites the atomized oil and gas, forming a local high-temperature fire core to ignite the coal powder, which breaks and burns, causing a chain reaction and rapid combustion of the coal powder.

[0040] Example 2

[0041] The structure of this embodiment is basically the same as that of embodiment 1, except that the valve 5 is an electric valve and the pressure gauge 6 is an electric contact pressure gauge.

[0042] It also includes a controller; the controller is respectively connected to the electric contact pressure gauge and the electric valve signal.

[0043] By setting up the controller, electric contact pressure gauge and electric valve, the value required for pressurizing the fuel in the fuel tank 7 can be stored in the electric contact pressure gauge based on experience. A maximum value and a minimum value are set on the electric contact pressure gauge. When the maximum value is reached, the electric contact pressure gauge sends a signal to the controller, and the controller sends a signal to the electric valve, and the electric valve closes. When the pressure in the fuel tank 7 reaches the minimum value, the electric contact pressure gauge sends a signal to the controller, and the controller controls the electric valve to open, charge and replenish air to ensure continuous combustion. This setting replaces manual observation and adjustment and realizes intelligence.

[0044] Example 3:

[0045] The structure of this embodiment is basically the same as that of embodiment 1.

[0046] The difference is that, during use, it was found that the mixer 2 manufactured based on the principle of the Venturi tube still had unstable fuel combustion due to the pressure fluctuation of the compressed air, and the following improvements were made;

[0047] It also includes a throttle orifice plate 23 arranged in the intermediate capillary tube 24 and used to adjust the air pressure in the intermediate capillary tube 24; the throttle orifice plate 23 is arranged between the oil inlet pressure regulating tube 3 and the oil suction pipe 4; the throttle orifice plate 23 is a circular plate with a through hole in the middle; the outer circle of the circular plate is welded to the inner wall of the intermediate capillary tube 24.

[0048] The improved mixer with the throttle orifice plate 23 has a stronger oil absorption capacity, and the fuel and compressed air are mixed more fully. The time for igniting the pulverized coal is shortened by 30% compared with the original, thereby improving efficiency.

[0049] In order to further increase the amount of oil absorbed, the throttle orifice plate 23 is further improved: the through hole of the throttle orifice plate 23 is a tapered hole; the large end of the tapered hole faces the intake straight pipe 21; after the improvement, the oil absorption amount is larger, and the time for igniting coal powder is shortened by about 5% compared with the through hole, but the fuel consumption is increased by 10% compared with the through hole; further improvements are needed.

[0050] The basic principles, main features and advantages of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention.

[0051] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or changes based on the technical solutions and improved concepts of the present invention shall be covered by the protection scope of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A micro-oil ignition and combustion-supporting system for a boiler, characterized by: It comprises an air compressor (1), a mixer (2), an oil tank (7) and a nozzle (8); the mixer (2) is cylindrical with a thin middle and thick ends; one end of the mixer (2) is connected to the air compressor (1), the other end of the mixer (2) is connected to the nozzle (8), and the middle of the mixer (2) is connected to the bottom of the oil tank (7) through an oil suction pipe (4); the oil tank (7) is filled with fuel; The mixer (2) comprises an air intake straight pipe (21) connected to the air compressor (1), an air intake cone pipe (22) connected to the air intake straight pipe (21), an intermediate thin pipe (24) connected to the air intake cone pipe (22), a mixed gas cone pipe (25) connected to the intermediate thin pipe (24), and a mixed gas straight pipe (26) connected to the mixed gas cone pipe (25); the mixed gas straight pipe (26) is connected to the nozzle (8), and the middle portion of the intermediate thin pipe (24) is connected to the bottom of the oil tank (7) through the oil suction pipe (4); The mixer (2) further comprises an oil inlet pressure regulating device; the oil inlet pressure regulating device comprises an oil inlet pressure regulating pipe (3) connected to an intermediate thin pipe (24) near one end of the intake cone pipe (22), and an air outlet of the oil inlet pressure regulating pipe (3) faces the inner top surface of the oil tank (7).

2. A micro-oil ignition and combustion-supporting system for a boiler according to claim 1, characterized in that: The oil inlet pressure regulating pipe (3) is provided with a valve (5) and a pressure gauge (6) in sequence from top to bottom.

3. A micro-oil ignition and combustion-supporting system for a boiler according to claim 2, characterized in that: The valve (5) is an electric valve; the pressure gauge (6) is an electric contact pressure gauge.

4. A micro-oil ignition and combustion-supporting system for a boiler according to claim 3, characterized in that: It also includes a controller; the controller is respectively connected to the electric contact pressure gauge and the electric valve signal.

5. A micro-oil ignition and combustion-supporting system for a boiler according to claim 4, characterized in that: It also includes a throttle orifice plate (23) disposed in the intermediate thin tube (24) and used to adjust the air pressure in the intermediate thin tube (24); the throttle orifice plate (23) is disposed between the oil inlet pressure regulating tube (3) and the oil suction tube (4); the throttle orifice plate (23) is a circular plate with a through hole in the middle; the outer circle of the circular plate is welded to the inner wall of the intermediate thin tube (24).

6. The micro-oil ignition and combustion-supporting system for a boiler according to claim 1, characterized in that: The oil inlet pressure regulating tube (3) is U-shaped; one end of the oil inlet pressure regulating tube (3) is in sealed communication with the intermediate thin tube (24); the other end of the oil inlet pressure regulating tube (3) leads to the inside of the oil tank (7), with the tube opening facing the inner top surface of the oil tank (7).

7. The micro-oil ignition and combustion-supporting system for a boiler according to claim 5, characterized in that: The through hole of the throttle orifice plate (23) is a tapered hole; the large end of the tapered hole faces the air intake straight pipe (21).

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