An ignition oil gun for pulverized coal boiler

Abstract

The present invention discloses an ignition oil gun for a pulverized coal boiler, which includes a gun head comprising a housing, a spray hole head and a two-phase flow equalizing chamber. The spray hole head is arranged at the top end inside the housing. The two-phase flow equalizing chamber is sleeved inside the housing, and its front end is connected to the end of the spray hole head. The end of the two-phase flow equalizing chamber is successively connected with a two-phase flow mixer and a two-phase flow generator. In the flow channel for the two-phase flow formed axially at the center of the gun head of the present invention, a uniform micro oil film bubble flow can be formed. When the oil film bubble flow exits the spray hole, the bubbles burst, causing the oil film to break and atomize. This method overcomes the surface tension of the fuel, only requires a relatively low fuel pressure, can effectively utilize the gas energy during the atomization process, achieves the best atomization effect, enables the fuel to burn intensively and fully, increases the contact area between the fuel and air, and improves the evaporation speed. When the particle size of the well-atomized fuel is extremely fine, the evaporation and vaporization speed of the fuel is extremely rapid, which is more conducive to rapid gasification and intense combustion, forming a violent high-temperature flame.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid fuel combustion, and particularly to an ignition oil gun for a pulverized coal boiler. Background Art

[0002] Large oil guns are important equipment and means for ignition startup, stable combustion at low loads, unit sliding shutdown, emergency of the coal pulverizing system failure, and assisting combustion with fuel oil when at low loads or burning inferior coal, so as to stabilize the combustion of the boiler or prevent fire during deep peak shaving of the boiler. Stable and reliable operation, energy conservation and environmental protection are relatively basic technical requirements.

[0003] Currently, the ignition method of pulverized coal boilers in power stations in China generally uses large oil guns with mechanical atomization for ignition. Taking the tangentially fired pulverized coal boiler commonly used in power stations as an example, among multiple layers of secondary air nozzles, several layers are selected to arrange ignition oil guns. Generally, two layers of ignition oil guns are arranged. For large pulverized coal boilers, three layers, four layers or more layers of ignition oil guns may be set. For the ignition of boilers with tangential swirl pulverized coal burners arranged on the front and rear walls in a counter-jet manner, it is generally inclined to arrange ignition oil guns in the central pipes of each tangential burner. For pulverized coal boilers with different combustion methods, although the arrangements of ignition oil guns are different, the oil gun technology with mechanical atomization is generally adopted.

[0004] During cold furnace startup ignition, generally multiple layers and multiple ignition oil guns are put into use simultaneously to heat the furnace. After the furnace temperature is higher than the pulverized coal ignition temperature, primary air pulverized coal combustion is then put into use. After the pulverized coal flame burns stably, the ignition oil guns stop injecting oil. The heat (output) contributed by the combustion of the ignition oil guns is generally designed to be about 30% of the thermal energy of the rated load. Therefore, it is particularly important to ensure the full combustion of oil after ignition.

[0005] For a long time, there have been many drawbacks in the performance of this traditional ignition oil gun: generally, high-pressure jet mechanical atomization technology is used to atomize oil, and the Sauter mean diameter (SMD) of its oil droplets is about 120 μm. The atomization quality is unstable. When the atomization quality decreases, the combustion efficiency decreases; the system pressure requirement is high, maintaining a circulating state for a long time, with high energy consumption, the equipment is easily damaged, and the maintenance workload is large; when the air supply of the ignition oil gun is insufficient and the oil atomization effect is not good, it will cause incomplete combustion of the oil, resulting in relatively high heat loss; during the ignition process, the oil atomization is not good, the flame is generally not bright enough, and sometimes the flame temperature is below 1100 °C, resulting in the phenomenon that a large amount of black smoke is entrained by the flame front; seriously, there will even be flowing fuel on the cold ash hopper and the water-cooled wall tubes, which is also the fundamental reason why the chimney emits black smoke and the electrostatic precipitator cannot be put into operation during the cold-state ignition of the boiler; at the same time, the above factors lead to incomplete combustion of the oil in the ignition oil gun, and the unburned oil droplets and carbonized particles in the flue gas will affect the normal operation of the denitration SCR equipment, resulting in catalyst blockage and deactivation, and further affecting stable denitration; moreover, the unburned oil droplets and carbonized particles will also affect the desulfurization effect of limestone in the desulfurization tower. Obviously, the traditional oil gun atomization technology can no longer meet the current requirements of generator sets for environmental protection performance and economic performance. Summary of the Invention

[0006] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title, but such simplifications or omissions shall not be used to limit the scope of the present invention.

[0007] In view of the problems existing in the above-mentioned existing ignition oil guns for pulverized coal boilers, the present invention is proposed.

[0008] Therefore, the object of the present invention is to provide an ignition oil gun for a pulverized coal boiler, aiming to solve the problem of incomplete combustion of oil caused by various factors such as poor atomization in the existing ignition oil gun, so as to achieve an ideal atomization effect and ignition combustion effect for the ignition oil gun.

[0009] To solve the above technical problems, the present invention provides the following technical solutions: A pulverized coal boiler ignition oil gun, comprising a gun head, a gun body, and a gun tail. The gun head includes a housing, a spray hole head, and a two-phase flow equalizing chamber. The spray hole head is disposed at the top end inside the housing. The two-phase flow equalizing chamber is sleeved inside the housing, and its front end is connected to the end of the spray hole head. The end of the two-phase flow equalizing chamber is sequentially connected to a two-phase flow mixer and a two-phase flow generator; The gun body includes a spray head rear seat and an inner sleeve. The spray head rear seat is disposed at the end of the gun head and is connected to the two-phase flow equalizing chamber in a matching manner. The inner sleeve is connected to the tail of the two-phase flow generator in a matching manner. An outer sleeve is sleeved outside the inner sleeve; And the gun tail includes an elbow and an oil inlet pipe. One end of the elbow is communicated with the tail of the inner sleeve, and the oil inlet pipe is disposed at the tail of the elbow.

[0010] As a preferred embodiment of the pulverized coal boiler ignition oil gun of the present invention, wherein: The spray hole head is in the shape of a forward convex frustum. A plurality of two-phase flow spray holes are circumferentially formed on the conical surface, and a plurality of two-phase flow spray holes are also formed on the forward convex table surface. A plurality of secondary air channels and small nozzles are provided on the outer edge of the conical surface.

[0011] As a preferred embodiment of the pulverized coal boiler ignition oil gun of the present invention, wherein: The two-phase flow generator is in the shape of a bowl. A plurality of oil inlet holes are formed in the middle of the bottom thereof. A plurality of air inlet holes are formed on the circumferential side wall of the oil inlet holes. The oil inlet holes and the air inlet holes are distributed at an approximate 90-degree angle.

[0012] As a preferred embodiment of the pulverized coal boiler ignition oil gun of the present invention, wherein: An external thread is provided on the outer side of the end of the two-phase flow equalizing chamber, and an internal thread is provided on the inner wall of the front end of the spray head rear seat. The spray head rear seat is connected to the two-phase flow equalizing chamber through the internal thread and the external thread.

[0013] As a preferred embodiment of the pulverized coal boiler ignition oil gun of the present invention, wherein: A plurality of groups of axial ventilation holes are circumferentially arranged between the tubular outer wall of the two-phase flow equalizing chamber and the external thread.

[0014] As a preferred embodiment of the pulverized coal boiler ignition oil gun of the present invention, wherein: A copper gasket is provided on the outer side of the connection between the two-phase flow equalizing chamber and the spray head rear seat, and a copper gasket is provided at the connection between the inner sleeve and the two-phase flow generator.

[0015] As a preferred embodiment of the pulverized coal boiler ignition oil gun of the present invention, wherein: The gun body further includes a support ring and an end cover. The support ring is clamped between the inner sleeve and the outer sleeve and is connected to the inner sleeve and the outer sleeve; The end cover is annular and is fixedly connected to the tail end of the outer sleeve.

[0016] As a preferred embodiment of the ignition oil gun for pulverized coal boilers of the present invention, the following features are provided: a through hole is formed near the end of the outer sleeve, and the through hole is connected to an air inlet pipe;

[0017] The outer wall of the end of the fuel inlet pipe is provided with a second external thread, and the outer wall of the end of the air inlet pipe is provided with a third external thread.

[0018] As a preferred embodiment of the ignition oil gun for pulverized coal boilers of the present invention, the following features are provided: a secondary air flow passage and secondary air nozzles are formed among the two-phase flow generator, the two-phase flow mixer, the two-phase flow equalizing chamber, the spray hole head housing, and the spray head rear seat; the interior of the two-phase flow mixer is a Venturi-shaped tubular flow passage.

[0019] As a preferred embodiment of the ignition oil gun for pulverized coal boilers of the present invention, the following features are provided: the amount of compressed air flowing into the two-phase flow generator is 3% - 5% of the fuel mass flow rate, and the amount of compressed air entering the secondary air flow passage is 7% - 9% of the fuel mass flow rate.

[0020] Advantages of the present invention:

[0021] In the flow passage where a two-phase flow is formed along the central axis of the gun head of the present invention, a uniform micro oil film bubble flow can be formed. When the oil film bubble flow exits the spray hole, the bubbles burst, causing the oil film to break and atomize. This method overcomes the surface tension of the fuel, only requires a relatively low fuel pressure, can effectively utilize the gas energy during the atomization process, achieves the best atomization effect, enables the fuel to burn intensively and fully, increases the contact area between the fuel and air, and improves the evaporation rate. When the particle size of the well-atomized fuel is extremely fine, the evaporation and vaporization speed of the fuel is extremely rapid, which is more conducive to rapid gasification, intense combustion, and the formation of a violent high-temperature flame. Description of the drawings

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0023] Figure 1 It is a schematic cross-sectional view of the overall structure of the ignition oil gun for pulverized coal boilers of the present invention.

[0024] Figure 2 It is for the ignition oil gun for pulverized coal boilers of the present invention Figure 1 The enlarged structural schematic diagram at position A.

[0025] Figure 3 It is a schematic diagram of the spray hole head structure of the ignition oil gun for pulverized coal boilers of the present invention.

[0026] Figure 4 This is a cross-sectional view of the spray hole head of the ignition oil gun for the pulverized coal boiler of the present invention.

[0027] Figure 5 This is a schematic structural diagram of the two-phase flow equalizing chamber of the ignition oil gun for the pulverized coal boiler of the present invention.

[0028] Figure 6 This is a sectional view and a front view of the two-phase flow generator of the ignition oil gun for the pulverized coal boiler of the present invention.

[0029] Figure 7 This is a sectional view and a front view of the two-phase flow mixer of the ignition oil gun for the pulverized coal boiler of the present invention.

[0030] Figure 8 This is a schematic structural diagram of the two-phase flow equalizing chamber of the ignition oil gun for the pulverized coal boiler of the present invention.

[0031] Figure 9 This is a front view of the support ring of the ignition oil gun for the pulverized coal boiler of the present invention. Detailed implementation manners

[0032] To make the above objects, features and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention in conjunction with the drawings of the specification.

[0033] In the following description, many specific details are set forth to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0034] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that can be included in at least one implementation manner of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that exclude each other with other embodiments.

[0035] Thirdly, the present invention is described in detail in conjunction with the schematic diagrams. When detailing the embodiments of the present invention, for the convenience of explanation, the sectional views showing the device structure will be enlarged locally out of the general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width and depth should be included.

[0036] Embodiment 1

[0037] Refer to Figure 1 and Figure 2, which is the first embodiment of the present invention, provides a pulverized coal boiler ignition oil gun. This device includes a gun head 100, a gun body 200, and a gun tail 300. The gun head 100 includes a housing 101, a spray hole head 102, and a two-phase flow equalizing chamber 103. The spray hole head 102 is arranged at the top end inside the housing 101. The two-phase flow equalizing chamber 103 is sleeved inside the housing 101, and its front end is connected to the end of the spray hole head 102. The end of the two-phase flow equalizing chamber 103 is sequentially connected with a two-phase flow mixer 104 and a two-phase flow generator 105. The gun body 200 includes a spray head rear seat 201 and an inner sleeve 202. The spray head rear seat 201 is arranged at the end of the gun head 100 and is cooperatively connected with the two-phase flow equalizing chamber 103. The inner sleeve 202 is cooperatively connected with the tail of the two-phase flow generator 105. An outer sleeve 203 is sleeved outside the inner sleeve 202. And the gun tail 300 includes an elbow 301 and an oil inlet pipe 302. One end of the elbow 301 is communicated with the tail of the inner sleeve 202, and the oil inlet pipe 302 is arranged at the tail of the elbow 301.

[0038] Among them, a through hole 203a is opened near the end of the outer sleeve 203, and an air inlet pipe 303 is connected to the through hole 203a. Fuel enters through the oil inlet pipe 302, and compressed air enters through the air inlet pipe 303. The components of this device are made of stainless steel and have the properties of corrosion resistance and high temperature resistance.

[0039] During the use process, fuel enters through the oil inlet pipe 302, passes through the elbow 301 and the inner sleeve 202 in sequence, and enters the inside of the gun head 100 through the two-phase flow generator 105. Compressed air flows towards the gun head through the annular flow channel formed by the air inlet pipe 303, the outer sleeve 203, and the inner sleeve 202.

[0040] Embodiment 2

[0041] Referring to Figures 1 to 7 , which is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that: the spray hole head 102 is in the shape of a forward convex frustum. A number of two-phase flow spray holes 102a are circumferentially arranged on the conical surface, and a number of two-phase flow spray holes 102a are also arranged on the forward convex table surface. A number of secondary air flow channels 102b and small nozzles 102c are arranged on the outer edge of the conical surface. The two-phase flow generator 105 is in the shape of a bowl. A number of oil inlet holes 105a are opened in the middle of the bottom. A number of air inlet holes 105b are opened on the circumferential side wall of the oil inlet holes 105a. The oil inlet holes 105a and the air inlet holes 105b are distributed at an approximate 90-degree angle.

[0042] Compared with Example 1, further, a first external thread 103a is provided on the outer side of the end of the two-phase flow equalizing chamber 103, and an internal thread 201a is provided on the inner wall of the front end of the nozzle rear seat 201. The nozzle rear seat 201 is connected to the two-phase flow equalizing chamber 103 through the internal thread 201a and the first external thread 103a; a plurality of groups of axial vents 103b are arranged along the circumferential direction between the tubular outer wall of the two-phase flow equalizing chamber 103 and the external thread 103a.

[0043] Furthermore, a copper gasket 106 is provided on the outside of the connection between the two-phase flow equalizing chamber 103 and the nozzle rear seat 201 , and a copper gasket 204 is provided on the connection between the inner sleeve 202 and the two-phase flow generator 105 .

[0044] The remaining structures are the same as those of Example 1.

[0045] The copper washer 106 makes the connection between the two-phase flow equalizing chamber 103 and the nozzle rear seat 201 more secure, and the copper gasket 204 makes the connection between the inner sleeve 202 and the two-phase flow generator 105 more secure.

[0046] Specifically, the number and flow cross-section of the plurality of oil inlet holes 105a of the two-phase flow generator 105 in the middle of the bowl bottom are calculated according to the output of the oil gun. The two-phase flow spray holes 102a on the conical surface of the spray head 102 are purged by the lateral secondary airflow, which can make nearly 90% of the fuel obtain ultra-fine atomization; the plurality of spray holes on the small protruding table cannot obtain the lateral purge of the secondary airflow, and will not be ultra-finely atomized. The relatively large oil droplets have forward momentum, which can maintain a longer length of the oil flame and better flame rigidity.

[0047] During use, the fuel enters the gun head from the central oil inlet hole 105a at the bottom of the bowl of the two-phase flow generator 105, and a portion of the compressed air enters the central flow channel of the gun head 100 from the circumferential air inlet hole 105b on the bowl wall of the two-phase flow generator 105; at the same time, in the two-phase flow generator 105, multiple fine jets of fuel and compressed air impact each other to form an oil film bubble two-phase flow. After the oil film bubble flow passes through the two-phase flow mixer 104 and the two-phase flow homogenizing chamber 103, a more uniform micro-oil film bubble flow is formed. When the oil film bubble flow is ejected from the nozzle of the nozzle head 102, the equilibrium condition of the oil film bubble is broken, the bubble bursts, and the oil film is crushed and atomized.

[0048] Example 3

[0049] Reference Figures 1 to 9, which is the third embodiment of the present invention. The difference between this embodiment and the second embodiment is that the gun body 200 further includes a support ring 205 and an end cap 206. The support ring 205 is clamped between the inner sleeve 202 and the outer sleeve 203 and is connected to the inner sleeve 202 and the outer sleeve 203. The end cap 206 is annular and is fixedly connected to the tail end of the outer sleeve 203. The outer wall of the end of the fuel inlet pipe 302 is provided with a second external thread 302a, and the outer wall of the end of the air inlet pipe 303 is provided with a third external thread 303a

[0050] Compared with Embodiment 2, further, a secondary air flow channel and a secondary air small nozzle are formed between the two-phase flow generator 105, the two-phase flow mixer 104, the two-phase flow equalizing chamber 103, the housing 101 of the spray hole head 102, and the nozzle rear seat 201. The inside of the two-phase flow mixer 104 is a Venturi-shaped tubular flow channel.

[0051] Furthermore, the amount of compressed air flowing into the two-phase flow generator 105 is 3% - 5% of the fuel mass flow rate, and the amount of compressed air entering the secondary air flow channel is 7% - 9% of the fuel mass flow rate.

[0052] The remaining structure is the same as that of Embodiment 2.

[0053] The formed secondary air flow channel and the secondary air small nozzle can eject a high-speed secondary air flow. Under the impact of the high-speed secondary air flow and under the supersonic shock wave oscillation, the oil film is broken and atomized more finely. A uniform micro oil film bubble flow can be formed in the flow channel of the two-phase flow formed along the axial center of the gun head. When the oil film bubble flow exits the spray hole, the bubbles burst and the oil film is broken and atomized. This way of breaking and atomizing the oil film by the bursting of bubbles overcomes the surface tension of the fuel and only requires a fuel pressure of about 0.5 Mpa; instead of overcoming the fuel viscosity like mechanical atomization, the fuel pressure in the oil gun is as high as 2 Mpa - 4 Mpa.

[0054] During use, a part of the compressed air enters the secondary air flow channel, flows to the secondary air small nozzle, passes through the annular flow channel formed between the inside of the nozzle rear seat 201 and the outer walls of the two-phase flow generator 105 and the two-phase flow mixer 104, passes through the connection channel and the annular flow channel on the outer periphery of the two-phase flow equalizing chamber 103, and flows to the secondary air small nozzle outside the spray hole head 102 inside the housing 101. At this time, the secondary air can generate a high-speed jet and a shock wave, further deepening the breaking and atomization of the oil film. The secondary breaking or multiple breaking of the transverse air flow is very important and the effect is very obvious. Ultra-fine and tiny atomized oil droplets can be obtained, and the Sauter mean diameter SMD of the oil droplets < 25 μm, and can reach 15 μm. In a large number of experimental studies and engineering practices, 30% of the fuel can be directly gasified during the atomization process of this technology, and a combustion flame temperature of 1800°C - 2000°C can be obtained.

[0055] Importantly, it should be noted that the construction and arrangement of the present application shown in multiple different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those skilled in the art who refer to this disclosure should easily understand that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application (e.g., changes in the dimensions, scales, structures, shapes and proportions of various elements, as well as parameter values (such as temperature, pressure, etc.), installation arrangements, use of materials, colors, orientations, etc.). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature, number or position of discrete elements may be altered or changed. Accordingly, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or re-ordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures that perform the recited function herein, and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present invention. Therefore, the present invention is not limited to a particular embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0056] In addition, to provide a concise description of the exemplary embodiments, all features of the actual embodiments may not be described (i.e., those features that are not relevant to the currently contemplated best mode of carrying out the present invention or those that are not relevant to the implementation of the present invention).

[0057] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A pulverized coal boiler ignition oil gun, characterized in that: Including, The gun head (100) includes a housing (101), a spray hole head (102) and a two-phase flow equalizing chamber (103). The spray hole head (102) is arranged at the inner top end of the housing (101). The two-phase flow equalizing chamber (103) is sleeved inside the housing (101), and its front end is connected to the end of the spray hole head (102). The end of the two-phase flow equalizing chamber (103) is sequentially connected with a two-phase flow mixer (104) and a two-phase flow generator (105); The gun body (200) includes a spray head rear seat (201) and an inner sleeve (202). The spray head rear seat (201) is arranged at the end of the gun head (100) and is cooperatively connected with the two-phase flow equalizing chamber (103). The inner sleeve (202) is cooperatively connected with the tail of the two-phase flow generator (105). An outer sleeve (203) is sleeved outside the inner sleeve (202); and, The gun tail (300) includes an elbow (301) and an oil inlet pipe (302). One end of the elbow (301) is communicated with the tail of the inner sleeve (202). The oil inlet pipe (302) is arranged at the tail of the elbow (301); A first external thread (103a) is provided on the outer side of the end of the two-phase flow equalizing chamber (103). An internal thread (201a) is provided on the inner wall of the front end of the spray head rear seat (201). The spray head rear seat (201) is cooperatively connected with the two-phase flow equalizing chamber (103) through the internal thread (201a) and the first external thread (103a); A plurality of groups of axial ventilation holes (103b) are arranged circumferentially between the tubular outer wall of the two-phase flow equalizing chamber (103) and the first external thread (103a); The two-phase flow generator (105) is in a bowl shape. A plurality of oil inlet holes (105a) are provided in the middle of the bottom. A plurality of air inlet holes (105b) are provided on the circumferential side wall of the oil inlet holes (105a). The oil inlet holes (105a) and the air inlet holes (105b) are distributed at an approximate 90-degree angle; A secondary air flow channel and a secondary air small nozzle are formed among the two-phase flow generator (105), the two-phase flow mixer (104), the two-phase flow equalizing chamber (103), the spray hole head (102), the housing (101) and the spray head rear seat (201); The inside of the two-phase flow mixer (104) is a Venturi-shaped tubular flow channel.

2. The pulverized coal boiler ignition oil gun according to claim 1, characterized in that: The spray hole head (102) is in a forward convex frustum shape. A plurality of two-phase flow spray holes (102a) are provided circumferentially on the conical surface. A plurality of two-phase flow spray holes (102a) are also provided on the forward convex table surface. A plurality of secondary air flow channels (102b) and small nozzles (102c) are provided on the outer edge of the conical surface.

3. The pulverized coal boiler ignition oil gun according to claim 1, characterized in that: A copper washer (106) is provided on the outer side of the connection between the two-phase flow equalizing chamber (103) and the spray head rear seat (201). A copper gasket (204) is provided at the connection between the inner sleeve (202) and the two-phase flow generator (105).

4. The pulverized coal boiler ignition oil gun according to claim 1, characterized in that: The gun body (200) further includes a support ring (205) and an end cap (206). The support ring (205) is clamped between the inner sleeve (202) and the outer sleeve (203) and is connected to the inner sleeve (202) and the outer sleeve (203). The end cap (206) is annular and fixedly connected to the tail end of the outer sleeve (203).

5. The pulverized coal boiler ignition oil gun according to claim 1, characterized in that: A through hole (203a) is formed at a position close to the end of the outer sleeve (203), and an air inlet pipe (303) is connected to the through hole (203a). A second external thread (302a) is formed on the outer wall of the end of the fuel inlet pipe (302), and a third external thread (303a) is formed on the outer wall of the end of the air inlet pipe (303).

6. The pulverized coal boiler ignition oil gun according to claim 1, characterized in that: The amount of compressed air flowing into the two-phase flow generator (105) is 3% - 5% of the fuel mass flow rate, and the amount of compressed air entering the secondary air flow channel is 7% - 9% of the fuel mass flow rate.

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