Small fuel oil rotational flow combustion device with air assisting structure

Abstract

The small fuel oil rotational flow combustion device with the air assisting structure comprises a shell, a rotational flow generator and a nozzle, a combustion cavity, a main air inlet cavity and an auxiliary air cavity which are coaxial are formed in the shell, the main air inlet cavity is arranged at the front end of the combustion cavity and communicated with the combustion cavity, and the auxiliary air cavity is annular and arranged on the outer side of a combustion chamber; the side wall of the combustion chamber is provided with an auxiliary air inlet hole communicating with the auxiliary air cavity and achieving air inlet combustion supporting. The rotational flow generator is arranged between the main air inlet cavity and the combustion chamber and can enable air exhausted by the main air inlet cavity to generate rotational flow and then enter the combustion chamber; the nozzle is arranged in the combustion cavity, is coaxial with the rotational flow generator and is used for spraying oil. According to the small fuel oil rotational flow combustion device with the air assisting structure, the main flow air volume and the air assisting volume are controlled through a reasonable flow field, rotational flow combustion flow field distribution of liquid fuel is regulated and controlled, efficient and sufficient combustion of the liquid fuel in a small space range is achieved, and emission of harmful gas is reduced or avoided.

Description

Technical Field

[0001] The invention relates to a combustion heating device, in particular to a small fuel oil swirl combustion device with a wind-assisting structure. Background Art

[0002] Compared with gaseous fuels, liquid fuels have higher energy density and more stable storage and transportation characteristics. However, since liquid fuels need to undergo a process of fragmentation, atomization and evaporation before combustion, and the droplet diameter and spatial distribution directly affect the combustion efficiency and product pollutant emissions, such as unburned hydrocarbons and carbon monoxide, the combustion of liquid fuels is more complicated. In addition, liquid fuels are prone to flame instability and carbon accumulation on the burner surface during combustion, especially in small burners with limited space. Summary of the invention

[0003] Technical issues to be solved

[0004] The technical problem to be solved by the present invention is to provide a small fuel swirl combustion device with an auxiliary wind structure, which can control the mainstream air volume and auxiliary wind volume through a reasonable flow field, regulate the swirl combustion flow field of liquid fuel, effectively improve the combustion efficiency of the fuel, and effectively control the emission of pollutants.

[0005] Technical solutions to the problem

[0006] The present invention provides a small fuel swirl combustion device with a wind-assisting structure, comprising:

[0007] A shell, wherein a coaxial combustion chamber, a main air intake chamber 40a and an auxiliary air chamber 70a are formed in the shell, wherein the main air intake chamber 40a is arranged at the front end of the combustion chamber and communicated therewith, the auxiliary air chamber 70a is annular and arranged outside the combustion chamber, and the side wall of the combustion chamber is provided with an auxiliary air intake hole 701 which communicates with the auxiliary air chamber 70a and realizes air intake to assist combustion;

[0008] A swirl generator 6 is disposed between the main air intake cavity 40a and the combustion chamber, and can generate a swirl flow in the air discharged from the main air intake cavity 40a before entering the combustion chamber;

[0009] A nozzle 3, arranged in the combustion chamber and coaxial with the swirl generator 6, for injecting oil;

[0010] An igniter is arranged in the combustion chamber and is used for ignition.

[0011] Furthermore, the combustion chamber includes a combustion chamber I70b and a combustion chamber II80 that are coaxially arranged and interconnected, the combustion chamber II80 is located downstream of the combustion chamber I70b and its diameter is larger than the diameter of the combustion chamber I70b, the nozzle 3 is arranged upstream of the combustion chamber I70b and facing the combustion chamber II80, and the auxiliary air intake hole 701 is arranged on the side wall of the combustion chamber I70b.

[0012] Furthermore, the auxiliary air inlet holes 701 are multiple and evenly distributed circumferentially and located downstream of the outlet plane of the nozzle.

[0013] Furthermore, the shell includes a combustion tube 8 with open ends and a wind tube 4 installed at the head of the combustion tube 8, the combustion chamber and the auxiliary wind chamber 70a are arranged in the combustion tube 8, the wind tube 4 is coaxially provided with an inner wind tube 43 to form the main air intake chamber 40a, and the auxiliary air intake chamber 40b connected to the auxiliary air intake chamber 70a, the side wall of the auxiliary air intake chamber 40b is provided with an auxiliary air intake hole 401, the air intake direction of the auxiliary air intake hole 401 is tangent to the inner wall of the auxiliary air intake chamber 40b and forms a swirl.

[0014] Furthermore, a circular rectifying plate 5 is provided between the secondary air inlet cavity 40b and the auxiliary air cavity 70a, and rectifying holes 501 are evenly distributed circumferentially on the rectifying plate 5 to achieve communication between the secondary air inlet cavity 40b and the auxiliary air cavity 70a.

[0015] Furthermore, the swirl generator 6 is fixedly installed at the center of the rectifier plate 5 .

[0016] Furthermore, the swirl generator 6 includes a circular swirl plate, the center hole of the swirl plate is provided with a nozzle mounting hole for mounting the nozzle 3, and a swirl hole group 601 is evenly distributed circumferentially on the swirl plate, and the swirl hole group 601 includes a main hole 6011 and a secondary hole 6012 arranged on one side of the main hole 6011, and the diameter of the secondary hole is smaller than the diameter of the main hole 6011 and can generate a pressure difference to form a rotating airflow.

[0017] Furthermore, the auxiliary holes 6012 are multiple and unevenly distributed.

[0018] Furthermore, the auxiliary air inlet holes 701 are arranged in multiple rows and sequentially along the axial direction, and each row of the auxiliary air inlet holes 701 has multiple auxiliary air inlet holes 701 that are evenly distributed in the circumferential direction.

[0019] Furthermore, the auxiliary air inlet holes 701 are arranged in 2-5 rows and are equidistantly disposed along the axial direction.

[0020] Furthermore, the distance between two adjacent rows of the auxiliary air inlet holes 701 is 1.5-2 times the diameter of the auxiliary air inlet holes.

[0021] Furthermore, the number of holes in each row of the auxiliary air inlet holes is 12-36.

[0022] Furthermore, the diameter of the auxiliary air inlet hole 701 is 3 mm-10 mm.

[0023] Furthermore, the rectifying holes 501 are arranged in multiple rows and are sequentially arranged along the diameter direction of the rectifying plate 5 , and each row of the rectifying holes 501 has multiple rectifying holes 501 that are evenly distributed in the circumferential direction.

[0024] Furthermore, the distances between two adjacent rows of the rectifying holes are the same.

[0025] Furthermore, the rectifying holes are arranged in 2-5 rows.

[0026] Furthermore, the number of holes in each row of the rectifying holes 501 is 24-48.

[0027] Furthermore, the distance between two adjacent rows of rectifying holes 501 is 1.5-2 times of the diameter of the rectifying holes.

[0028] Furthermore, the rectifying holes 501 in two adjacent rows are arranged in a staggered manner.

[0029] Furthermore, the diameter of the rectifying hole 501 is 2 mm-4 mm.

[0030] Furthermore, an inner cylinder 7 is coaxially arranged inside the combustion cylinder 8, and an annular rectifying plate 5 is fixed to the combustion cylinder 8 and the head of the inner cylinder 7. The tail of the inner cylinder 7 is radially bent outward to form a retaining ring 72, thereby dividing the combustion cylinder 8 into combustion chamber I 70b, combustion chamber II 80 and auxiliary air chamber 70a, and the auxiliary air inlet hole 701 is opened on the side wall of the inner cylinder 7.

[0031] Furthermore, there is a gap between the edge of the retaining ring 72 and the inner wall of the combustion tube 8, and the gap is 0.5mm-1mm.

[0032] Furthermore, the retaining ring 72 is circumferentially evenly provided with air holes connected to the combustion chamber II 80 .

[0033] Furthermore, the air holes are arranged in 1-5 rows and are arranged sequentially along the diameter direction of the combustion chamber II 80 .

[0034] Furthermore, the diameter of the pores is 2 mm-5 mm.

[0035] Furthermore, the total area of ​​the air holes is smaller than the total area of ​​the auxiliary air inlet holes 701;

[0036] Furthermore, the main hole and the auxiliary hole are inclined holes.

[0037] Beneficial Effects

[0038] The small fuel swirl combustion device with an air-assisting structure of the present invention comprises a combustion chamber, an air intake structure, a swirl structure and a fuel injection nozzle structure, and its working process is as follows: first, fuel and mainstream air (main air intake chamber) are supplied, and the fuel is ejected through the nozzle 3. The mainstream air passes through the swirl generator to form a swirling airflow and enters the combustion chamber I. Under the action of the swirl air, the droplets and air in the combustion chamber I are fully mixed. In order to improve the ignition success rate, the supplied oil and gas are relatively high; the premixed oil and gas are ignited by the ignition device, but at this time the oil and gas are relatively high, the combustion is incomplete, and the flame is a diffuse orange-red color; then, the mainstream air intake is adjusted, the mainstream air intake is gradually increased, and the air intake of the air-assisting (auxiliary air chamber) is started; the secondary air intake passes through the rectifier plate and enters the auxiliary air chamber 70a outside the combustion chamber I, and it enters the auxiliary air chamber 7 after being rectified by the rectifier holes on the rectifier plate 0a, and enters combustion chamber I through the auxiliary air inlet hole on the inner cylinder, and the combustion chamber I serves as the main combustion zone; the retaining ring structure at the end of the inner cylinder can better force the wind to enter the combustion chamber I along the tangential annular hole, and mix with the central swirl mainstream, strengthen the mainstream swirl process, make the fuel spray and air undergo more intense mixing and shearing, further promote the droplet breakup, atomization and evaporation as well as the mixing of fuel and air, and the radial air intake can also force the flame length to shorten and converge to the center, at which time the flame gradually turns into a fully burned blue flame; the small-scale fuel swirl combustion device with an air-assisting structure of the present invention controls the mainstream air volume and the air-assisting volume through a reasonable flow field, regulates the swirl combustion flow field distribution of the liquid fuel, realizes efficient and full combustion of the liquid fuel in a small space, and reduces or avoids the emission of harmful gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic structural diagram of a small fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0040] Figure 2 It is a schematic diagram of the explosion structure of a small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0041] Figure 3 It is a cross-sectional view of a small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0042] Figure 4 Another angle sectional view of the small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0043] Figure 5 This is a schematic diagram of the internal structure of a small fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0044] Figure 6 This is a cross-sectional view of the internal structure of a small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0045] Figure 7 A cross-sectional view of the air inlet cavity of a small fuel swirl combustion device with an air-assisting structure according to the present invention;

[0046] Figure 8 It is a structural schematic diagram of the wind tube of the small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0047] Fig. 9 It is a cross-sectional view of the wind tube of the small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0048] Fig.10 It is a schematic diagram of the installation of the nozzle of the small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0049] Fig.11 It is a schematic diagram of the installation of a swirl generator of a small fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0050] Fig.12 It is a schematic structural diagram of a swirl generator of a small fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0051] Fig.13 It is a structural schematic diagram of a rectifying plate of a small fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0052] Fig.14 A cross-sectional view of a rectifying plate of a small fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0053] Fig.15 It is a schematic structural diagram of the inner cylinder of a small-sized fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0054] Fig.16 It is a cross-sectional view of the inner cylinder of the small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0055] Fig.17 It is a structural schematic diagram of the main air inlet cylinder of a small-sized fuel swirl combustion device with an air-assisting structure according to the present invention;

[0056] Fig.18 It is a cross-sectional view of the main air inlet cylinder of the small-sized fuel swirl combustion device with an air-assisting structure of the present invention;

[0057] Fig.19 This is a graph showing the mass fraction of diesel components in a small fuel swirl combustion device with a wind-assisting structure according to the present invention;

[0058] Fig. 20 This is a temperature distribution diagram of the combustion chamber of the small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0059] Fig.21It is a temperature distribution diagram of the transverse section of the small fuel swirl combustion device with a wind-assisting structure of the present invention;

[0060] Fig. 22 This is a velocity distribution diagram of a small fuel swirl combustion device with a wind-assisting structure according to the present invention. DETAILED DESCRIPTION

[0061] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0062] See also Figure 1-Figure 18 The present invention provides a small fuel swirl combustion device with a wind-assisting structure, which includes a shell, a swirl generator 6, a nozzle 3 and an igniter (not shown in the figure).

[0063] The shell serves as a support and mounting carrier, and the swirl generator 6, the nozzle 3 and the igniter are installed in the shell. The shell is cylindrical as a whole, and a combustion chamber, a main air intake chamber 40a and an auxiliary air chamber 70a are formed in the shell. The combustion chamber, the main air intake chamber 40a and the auxiliary air chamber 70a are coaxially arranged. In this embodiment, their cross sections are all circular, wherein the main air intake chamber 40a is arranged at the front end (upstream) of the combustion chamber, and its rear end is open and connected to the combustion chamber, serving as the main air supply (air) end for combustion. The auxiliary air chamber 70a is annular, specifically, circular. The auxiliary air inlet hole 701 is arranged on the side wall of the combustion chamber, and the auxiliary air inlet hole 701 is connected to the auxiliary air cavity 70a to realize auxiliary air (gas) intake, and then realize secondary air supply (air), realize combustion assistance, and improve the combustion rate. In this embodiment, the auxiliary air inlet hole 701 is multiple and evenly distributed circumferentially, and can realize radial air intake. While improving the combustion rate, the radial air intake can make the flame converge to the center and shorten the flame length; the swirl generator 6 is arranged between the main air inlet cavity 40a and the combustion chamber. The air discharged from the main air inlet chamber 40a can generate a swirl (rotating airflow) before entering the combustion chamber. The air inlet end of the main air inlet end 40a is arranged at the end, preferably, coaxial with the swirl emitter; the nozzle 3 is arranged in the combustion chamber, which is arranged at the upstream end of the combustion chamber, that is, close to the air inlet end. The nozzle 3 is coaxial with the swirl generator 6 and is used for oil injection; the nozzle is located at the center of the swirl generator, that is, at the center of the swirl. The swirl can form a vortex in the combustion chamber for the sprayed oil mist, which can refine the diameter of the oil mist and increase the mixing of oil, gas and air. surface area, promoting uniform mixing, thereby achieving more complete combustion, improving thermal efficiency, and reducing harmful exhaust gas emissions; at the same time, the swirl can also effectively promote heat transfer, strengthen air circulation, and accelerate heat diffusion; the igniter is arranged in the combustion chamber for ignition, and generally high-voltage arc discharge ignition, small flame ignition, etc. can be used; the above-mentioned swirl generator 6 can make air enter the combustion chamber in the form of a rotating airflow, thereby enhancing the mixing effect of air and fuel, improving combustion efficiency, achieving complete combustion, and reducing harmful exhaust gas emissions.

[0064] In the present application, the combustion chamber includes a coaxially arranged combustion chamber I70b and a combustion chamber II80, the combustion chamber I70b and the combustion chamber II80 are coaxially arranged, and the combustion chamber II80 is located downstream of the combustion chamber I70b, and its diameter is larger than the diameter of the combustion chamber I70b, and the nozzle 3 is arranged upstream of the combustion chamber I70b, and its injection end faces the combustion chamber II80, and the igniter is arranged in the combustion chamber II80, and is located near one end of the combustion chamber I70b; the auxiliary air chamber 70a is arranged on the outside of the combustion chamber I70b, and the auxiliary air inlet holes 701 are opened on the side wall of the combustion chamber I70b and are evenly distributed in the circumferential direction; an air inlet end is provided at the end or side wall of the auxiliary air chamber 70a, which is used for the auxiliary air chamber 70a When working, the auxiliary wind in the auxiliary air cavity 70a enters the combustion chamber and mixes with the main airflow in the combustion chamber to form a more powerful swirl, so that the fuel spray and the air are more intensely mixed and sheared, further promoting the breakup, atomization and evaporation of droplets, and the mixing of fuel and air. The radial air intake can also force the flame length to shorten and converge to the center, so that the fuel is fully burned and the combustion rate is improved; the auxiliary air intake holes 701 are multiple and circumferentially evenly distributed, and are located downstream of the outlet plane of the nozzle; in the present application, the auxiliary air intake holes 701 are multiple rows and are arranged in sequence along the axial direction of the combustion chamber. Preferably, they are equidistantly arranged in the axial direction, and each row of auxiliary air intake holes has a plurality of rows and is arranged in sequence along the axial direction of the combustion chamber. There are multiple air inlet holes 701 and they are evenly distributed circumferentially. In this embodiment, there are 2-5 rows of auxiliary air inlet holes 701 and they are equidistantly arranged along the axial direction, that is, the distance between two adjacent rows of auxiliary air inlet holes is the same. Preferably, the distance between two adjacent rows of auxiliary air inlet holes 701 is 1.5-2 times the diameter of the auxiliary air inlet holes, wherein the diameter of the auxiliary air inlet holes 701 is 3mm-10mm, and at the same time, the number of holes in each row of auxiliary air inlet holes is 12-36. The wind from the auxiliary air cavity 70a entering the combustion chamber I is radial wind. After entering the combustion chamber I, it mixes with the original airflow in the combustion chamber. Since the arrangement of the holes on the side wall of the cylinder is evenly distributed circumferentially, the airflows from different orifices are mixed by the cylinder after entering the cylinder. Due to different starting positions, different radial velocity components will be generated along the side wall of the cylinder, which will eventually cause the overall airflow to present a rotational motion and produce a swirl. Since there is a swirl inside the combustion chamber I itself, under the action of the airflow inertia, the airflow will want to maintain the original direction of movement according to its own momentum, thereby promoting the formation of the swirl and mixing with the initial airflow to form an enhanced swirl. At the same time, due to its radial air intake, it can force the flame length to shorten and converge to the center, thereby achieving stable control of the flame. At the same time, the fuel is fully mixed with oxygen and burned, and more energy is released to increase the flame temperature. At this time, the flame gradually turns into a fully burned blue flame, which can also reduce or avoid the formation of carbon deposits.

[0065] The shell includes a combustion tube 8 and a wind tube 4. The combustion tube 8 is cylindrical and open at both ends. The wind tube 4 is coaxially arranged with the combustion tube 8 and installed at the head (upstream) of the combustion tube 8. The combustion chamber and the auxiliary wind chamber 70a are arranged in the combustion tube 8. At the same time, an inner wind tube 43 is arranged in the wind tube 4. The inner wind tube 43 is coaxial with the wind tube 4, thereby dividing the interior of the wind tube 4 into a coaxial inner cavity and an outer cavity, wherein the inner cavity is the main air intake cavity 40a, and the outer cavity is the auxiliary air intake cavity 40b. The auxiliary air intake cavity 40b is annular and is located on the outside of the main air intake cavity 40a. The two are coaxial and located on the same radial plane. The end of the auxiliary air intake cavity is connected with the auxiliary air cavity for supplying air (air) to the auxiliary air cavity. An auxiliary air inlet hole 401 is arranged on the side wall of the wind tube. The air intake direction of the auxiliary air inlet hole 401 is tangent to the inner wall of the auxiliary air intake cavity 40b, thereby forming a vortex to reduce wind resistance and wind noise.

[0066] A rectifying plate 5 is provided between the secondary air inlet chamber 40b and the auxiliary air chamber 70a. The rectifying plate 5 is a circular plate body with a center hole 50 in the center thereof to form a circular ring structure, which is located between the secondary air inlet chamber 40b and the auxiliary air chamber 70a. A rectifying hole 501 is provided on the rectifying plate 5, and the secondary air inlet chamber 40b and the auxiliary air chamber 70a are connected through the rectifying hole 501. The rectifying holes 501 are multiple and evenly distributed in the circumferential direction, and their function is to adjust the airflow, reduce turbulence, and make the airflow more stable. The design of the rectifying plate 5 is intended to optimize the distribution of the airflow and achieve rectification; the rectifying holes 501 are multiple rows (circles), preferably 2-5 rows, and the number of holes in each row of rectifying holes 501 is 24-48, and multiple rows of rectifying holes 501 are uniform ... the rectifying holes 501 are uniformly distributed in the circumferential direction, and the rectifying holes 501 are uniformly distributed in the circumferential direction, and the rectifying holes 501 are uniformly distributed in the circumferential direction, and the rectifying holes 501 are uniformly distributed in the circumferential direction, and the rectifying holes 501 are uniformly distributed in the circumferential direction, and the rectifying holes 501 are uniformly The flow holes 501 are arranged in sequence along the diameter direction of the rectifying plate 5. Preferably, when the number is 3 rows or more, the distance between two adjacent rows of rectifying holes 501 is equal, and the distance between two adjacent rows of rectifying holes 501 is 1.5-2 times the diameter of the rectifying holes. In this embodiment, the diameter of the rectifying holes 501 is 2mm-4mm. Through the above-mentioned rectifying hole setting, the uniformity and stability of the airflow are significantly improved, so that it can enter the auxiliary wind cavity evenly and smoothly, and prepare for uniform entry into the combustion chamber; along the diameter direction of the rectifying plate, the farther away from the center of the circle, the larger its diameter. Therefore, in order to further improve the stability of the airflow, in this embodiment, the number of rectifying holes located in the outer circle is greater than the number of rectifying holes located in the inner circle.

[0067] The swirl generator 6 is fixedly installed at the center of the rectifier plate 5. Specifically, the swirl generator 6 includes a circular swirl plate. The center hole of the swirl plate is provided with a hole 60 as a nozzle mounting hole for mounting the nozzle 3. A swirl hole group 601 is evenly distributed circumferentially on the swirl plate. The swirl hole group 601 includes a main hole 6011 and a secondary hole 6012 arranged on one side of the main hole 6011, and the diameter of the secondary hole is smaller than the diameter of the main hole 6011. Therefore, a pressure difference can be generated to form a rotating airflow. There are multiple and unevenly distributed secondary holes 6012 on the same group of swirl hole groups. The number of the secondary holes 6012 is 2-5 and they are arranged on one side of the main hole. The multiple secondary holes can be hole bodies of different diameters to keep the secondary holes on both sides of the main hole unevenly distributed. A pressure difference is generated by relying on the difference in intake air velocity to form a rotating airflow.

[0068] An inner cylinder 7 is coaxially arranged in the combustion cylinder 8. The combustion cylinder 8 and the head of the inner cylinder 7 are fixed on the annular rectifying plate 5. The tail of the inner cylinder 7 is radially bent outward by 90 degrees to form a retaining ring 72. The edge of the retaining ring 72 fits the inner wall of the combustion cylinder 8, or there is a certain gap, which is 0.5mm-1mm. It is not only convenient for assembly, but also forms an annular air supply channel to provide air for the downstream flame and improve the combustion rate. The inner cylinder 7 divides the combustion cylinder 8 into combustion chamber I 70b, combustion chamber II 80 and auxiliary air chamber 70a, wherein combustion chamber I 70b is located upstream, combustion chamber II is located downstream, and the end of combustion chamber I 70b is open. It is connected to combustion chamber II and can allow the tail of the flame to enter combustion chamber II. The auxiliary wind chamber is located on the outside of combustion chamber I, and the auxiliary air inlet hole 701 is opened on the side wall of the inner cylinder 7; at the same time, air holes can be set on the retaining ring 72. The air holes are multiple and evenly distributed on the retaining ring in the circumferential direction. They are connected to combustion chamber II 80 to provide air for the rear end flame to achieve combustion assistance. The diameter of the air holes is 2mm-5mm; in order to ensure the stability of air supply and avoid turbulence, in this embodiment, the air holes are 1-5 rows, which are arranged in sequence along the diameter direction of combustion chamber II 80; in order to ensure the air intake of the auxiliary air inlet holes, in this application, the total area of ​​the air holes is smaller than the total area of ​​the auxiliary air inlet holes 701.

[0069] The following is a detailed description of a small fuel swirl combustion device with a wind-assisting structure of the present invention, comprising a coaxially arranged end cover 1, a nozzle mounting seat 2, a nozzle 3, a wind tube 4, a rectifying plate 5, a swirl generator 6, an inner cylinder 7 and a combustion cylinder 8.

[0070] See also Figure 8-Figure 9The wind tube 4 is cylindrical and includes a cylindrical outer wind tube 41. The head of the outer wind tube 41 is radially bent outward by 90 degrees to form a circular first connecting portion. A mounting hole is provided on the first connecting portion to form a first flange 411. The tail of the outer wind tube 41 is bent inward by 90 degrees to form an end face 42. The edge of the end face extends axially, specifically, extends (bends) toward the first flange 411 to form an inner wind tube 43. The inner wind tube 43 is coaxial with the outer wind tube. Both are cylindrical bodies and have a certain distance between them to form an annular chamber with one end open for forming Auxiliary air inlet chamber 40b, the edge of the inner air cylinder 41 is radially bent inward to form a second connecting portion, a mounting hole is provided on the second connecting portion, and a second flange 431 is formed. The second flange and the first flange are located on the same plane; a lug 432 is provided on the inner wall of the inner air cylinder, and a mounting hole is opened on the lug for fixing the nozzle mounting seat 2. An air inlet pipe is provided on the side wall of the outer air cylinder 41, and an auxiliary air inlet hole 401 is formed at its inlet end. The air inlet pipe is tangent to the inner wall of the outer air cylinder, so that wind energy enters the auxiliary air inlet chamber 40b in a tangential direction, thereby further optimizing the air flow and reducing wind noise.

[0071] See also Figure 17-Figure 18 The end cover 1 is a cylinder with one end open, and a chamber 10 is formed inside. The diameter of the chamber 10 is slightly larger than the diameter of the inner wind tube. The chamber 10 is fixed to the end of the wind tube 4. Specifically, the head of the end cover is radially bent outward by 90 degrees to form a third connecting portion. A mounting hole is opened on the third connecting portion to form a third flange. The third flange is fixed to the end face of the wind tube, and the interior of the third flange is connected to the inner wind tube to form a main air inlet cavity. A main air inlet hole 101 is provided at the end of the end cover 1, which is coaxially arranged with the combustion chamber, the nozzle, and the swirl generator. The main air inlet hole 101 serves as the main air inlet end. Therefore, the end cover serves as the main air inlet tube.

[0072] See also Figure 13-14The rectifying plate 5 is annular as a whole, and its inner diameter is the same as the outer diameter of the first flange 411, and its inner diameter is the same as the inner diameter of the second flange 431, and it is fixed on the first flange 411 and the second flange 431, so that the cavity between the outer wind cylinder 41 and the inner wind cylinder 43 forms an auxiliary air inlet chamber 40b, and a rectifying hole 501 is opened on the rectifying plate 5, which is used to connect the auxiliary air chamber 70a at its rear end (downstream), and the rectifying holes 501 are multiple and evenly distributed in the circumferential direction, and their function is to adjust the airflow, reduce turbulence, make the airflow more stable, and realize rectification; the rectifying holes 501 are multiple rows (circles), preferably, 2-5 rows, and the number of holes in each row of rectifying holes 501 is 24-48, and the multiple rows of rectifying holes 501 are arranged along the diameter direction of the rectifying plate 5 according to The rectifying holes 501 are arranged in a row. Preferably, when the number is 3 rows or more, the distances between adjacent rows of rectifying holes 501 are equal, and the distance between two adjacent rows of rectifying holes 501 is 1.5-2 times of the diameter of the rectifying holes. In the present embodiment, the diameter of the rectifying holes 501 is 2mm-4mm, that is, the rectifying holes are radially arranged on the rectifying plate 5 as a whole; in the present application, a first annular protrusion 51 and a second annular protrusion 52 are provided on the end face of the rectifying plate 5, the first annular protrusion 51 and the second annular protrusion 52 are coaxially arranged, and the first annular protrusion 51 is located on the outside of the second annular protrusion 52, which are both located at the rear end of the rectifying plate for installation and positioning of the combustion cylinder and the inner cylinder; the rectifying hole 501 is located between the first annular protrusion and the second annular protrusion.

[0073] See also Figure 10-11 The nozzle mounting seat 2 is fixed in the inner wind cylinder 43. Specifically, it includes a cylindrical mounting seat body 21, a mounting hole for mounting the nozzle 3 is opened at the end of the mounting seat body, and a circular mounting bracket ring 22 is arranged at the rear end of the mounting seat body, which is fixedly connected to the mounting seat 21 through a plurality of connecting rods 23. A mounting hole is opened on the mounting bracket ring 22, which corresponds to the lug in the inner wind cylinder 43 and is fixed to the lug by bolts, thereby realizing the fixed installation of the nozzle mounting seat 2 in the wind cylinder. The mounting seat body 21 is coaxially arranged with the wind cylinder, and the nozzle is installed on the mounting seat body 21, and its injection end is facing away from the end cover direction and is coaxial with the wind cylinder.

[0074] See also Figure 11-Figure 12The swirl generator 6 is a circular plate-shaped structure as a whole, which is arranged at the center of the air outlet end of the inner wind cylinder, and its diameter matches the diameter of the inner wind cylinder. Specifically, a center hole is opened on the swirl generator 6, and the inner wall of the center hole extends axially in the direction of the wind cylinder to form a sleeve structure 61, which can be sleeved on the mounting seat body 21 of the nozzle mounting seat and can accommodate the nozzle 3. The assembled nozzle 3 is located in the combustion chamber I, so that the injection direction of the nozzle matches the swirl direction generated by the swirl generator 6, so as to achieve the purpose of optimizing the airflow distribution and improving the combustion efficiency; in the present application, a swirl hole group 601 is uniformly distributed circumferentially on the swirl plate, and the swirl hole group 601 includes a main hole 6011 and a secondary hole 6012 arranged on one side of the main hole 6011. The diameter of the secondary hole is smaller than the diameter of the main hole 6011. Therefore, a pressure difference can be generated, thereby forming a rotating airflow. The secondary hole 6012 is multiple and unevenly distributed. Preferably, the secondary hole 6012 is 2-5, which is arranged On one side of the main hole, the auxiliary holes on both sides of the main hole are kept unevenly distributed, and a pressure difference is generated by relying on the difference in the inlet gas velocity to form a rotating airflow. The swirl generator is used to form a swirl coaxial with the nozzle, improve the strength and stability of the rotating airflow, and thus improve the combustion efficiency; during operation, when the gas passes through the swirl generator, the large hole and the small hole will cause different resistances to the airflow respectively. Since the large hole is wider than the small hole, the resistance of the airflow through the large hole is smaller and the speed is faster; while the resistance of the airflow through the small hole is larger and the speed is slower, resulting in an uneven speed distribution; due to the difference in airflow speed, different pressures are formed in the large hole and the small hole respectively, and the pressure on one side of the large hole outlet is slightly lower, and the pressure on one side of the small hole outlet is slightly higher. This pressure difference constitutes a pressure difference to form a swirl; at the same time, in the present application, the above-mentioned swirl hole group 601 is an inclined hole, that is, the main hole 6011 and the auxiliary hole 6012 are both inclined holes, and they have the same direction. The inclined hole cooperates with the pressure difference between the large and small holes to form a more stable and powerful swirl. In addition, the design of the swirl generator 6 can also effectively reduce the airflow noise during the combustion process and improve the working environment.

[0075] See also Figure 3-Figure 6 The combustion tube 8 is cylindrical as a whole, and its two ends are bent radially outward to form a flange structure. Its end is fixedly mounted on the rectifying plate 5, and its inner side contacts the first annular protrusion 51 on the rectifying plate 5 to achieve rapid radial positioning and ensure stable installation of the combustion tube.

[0076] See also Figure 15-16The inner cylinder 7 is arranged in the combustion cylinder 8 and is coaxial with the combustion cylinder 8. Specifically, the inner cylinder 7 includes an inner cylinder body 71, both ends of which are penetrated by through holes 70 to form a cylindrical structure, whose diameter is smaller than the diameter of the combustion cylinder, and whose length is smaller than the length of the combustion cylinder. Specifically, its length is 1 / 3-1 / 2 of the length of the combustion cylinder, and its head is radially bent outward to form a fourth connecting portion, and a mounting hole is opened on the fourth connecting portion to form a fourth flange 73. The fourth flange 73 is fixedly mounted on the rectifying plate, and the inner wall contacts the second annular protrusion 52 on the rectifying plate to achieve fast and accurate radial positioning, while maintaining the installation stability of the inner cylinder 7; the tail of the inner cylinder body 71 is radially bent outward by 90 degrees to form a retaining ring 72, the edge of the retaining ring 72 is in contact with the inner wall of the combustion cylinder 8, or there is a certain gap, the gap is 0.5mm-1mm, which is not only convenient for assembly, but also forms an annular air supply channel to provide a downstream flame air, improve the combustion rate; the inner cylinder 7 divides the combustion cylinder 8 into combustion chamber I 70b, combustion chamber II 80 and auxiliary air chamber 70a. Specifically, the auxiliary air chamber 70a is formed between the outer wall of the inner cylinder 7, the retaining ring and the inner wall of the combustion cylinder 8, the combustion chamber I 70b is formed in the inner cylinder 7, and the combustion chamber II 80 is formed between the outer side (rear end) of the retaining ring and the inner wall of the combustion cylinder 8. It is located downstream of the combustion chamber I, and the diameter of the combustion chamber II 80 is larger than the diameter of the combustion chamber I 70b; the auxiliary air chamber 70a is formed between the outer wall of the retaining ring and the inner wall of the combustion cylinder 8. The air hole 701 is opened on the side wall of the inner cylinder 7, specifically, it is arranged at the rear end (downstream) of the combustion chamber I; at the same time, an air hole can be set on the retaining ring 72, and the air hole is multiple and evenly distributed on the retaining ring in the circumferential direction. It is connected to the combustion chamber II 80 to provide air for the rear end flame to achieve combustion assistance. The diameter of the air hole is 2mm-5mm; in order to ensure the stability of the air supply and avoid turbulence, in this embodiment, the air holes are 1-5 rows, which are arranged in sequence along the diameter direction of the combustion chamber II 80.

[0077] In order to intuitively understand the combustion effect of the combustion device of the present invention, the burner is simulated and analyzed and interpreted. Figure 19-22 ;

[0078] In the above simulation, the equivalence ratio of the main combustion zone (combustion chamber I) is 0.8, the main air intake (main air intake cavity) speed is 5 m / s, and the auxiliary air intake (auxiliary air intake cavity) speed is 4 m / m;

[0079] See also Fig.19 , which is a graph of the mass fraction of diesel components. It can be seen from the figure that the oil mist sprayed from the nozzle at the center is distributed at the edge of the combustion chamber I under the action of the spiral wind. It is distributed in an 'L' shape in the longitudinal section. There is less oil mist near the axis of the combustion chamber I. The oil mist at the edge of the combustion chamber I is consumed in the form of a neck along the direction of the wind. A small amount of oil mist enters the combustion chamber II and is completely consumed at 1 / 2 of the combustion chamber, with a good combustion effect.

[0080] See also Fig. 20 , which is a temperature distribution diagram of the combustion chamber. It can be seen from the figure that in combustion chamber I, high temperature (above 1800K) is basically concentrated in the center, and the diameter of the high temperature distribution is about 1 / 4 of the diameter of combustion chamber I, and it expands outward in a triangular form with the injection direction; when it reaches the junction of combustion chamber I and combustion chamber II, its high temperature diameter is the largest, and the diameter of the high temperature distribution is about 3 / 4 of the diameter of combustion chamber I, and it basically maintains this high temperature diameter and enters combustion chamber II, with good linearity, both located in the center, when located at 2 / 8-4 / 8 of combustion chamber II, the temperature and diameter reach the peak, and both remain at about 2100K, when it reaches 1 / 2 of combustion chamber II, the diameter is reduced at a small angle, and the internal temperature remains basically unchanged.

[0081] See also Fig.21 , the figure is a temperature distribution diagram of a transverse section of combustion chamber I. Specifically, taking the inlet end of combustion chamber I as the reference plane, the section is 30mm away from the reference plane. It can be seen from the figure that the high temperature is concentrated at the center of the circle, with a temperature of about 1700K-1900K. The high temperature distribution diameter is 1 / 7-2 / 7 of the diameter of combustion chamber I. Near the edge, that is, near the auxiliary air inlet, the temperature is relatively low, at 1580K-1700K, and is distributed in an inclined Y shape. Under the action of the auxiliary air intake, the temperature converges toward the center in a counterclockwise direction, forming a high-temperature reflux.

[0082] See also Fig. 22 , which is a velocity distribution diagram. It can be seen from the figure that under the action of the auxiliary air inlet, the swirl area of ​​the main combustion zone is forced to flow toward the swirl center, and a low-speed zone is generated in the center to stabilize the flame; in combustion chamber I, from upstream to downstream, the speed is increasing, specifically, gradually increasing from 4-5m / s to 10-12m / s; when reaching the junction of combustion chamber I and combustion chamber II, the speed increases instantaneously to 14-15m / s, and the center and edge speed increase the most, presenting an inverted "mountain" shape, and the speed at the center reaches 17-19m / s; when entering combustion chamber II, the above-mentioned high-speed state is maintained, and gradually decreases outward; the high-speed (above 15m / s) diameter is slightly smaller than the diameter of combustion chamber I, and is 2 / 7-3 / 7 of the diameter of combustion chamber II, and the highest speed diameter (17-19m / s) in the center is about 1 / 14 of the diameter of combustion chamber II, with excellent linearity.

[0083] It can be seen from the above analysis diagram that after adopting the above structure, the flame has high stability and good centralization, basically concentrated at the center, can achieve complete combustion, high combustion efficiency and good effect.

[0084] The small fuel swirl combustion device with an air-assisting structure of the present invention comprises a combustion chamber, an air intake structure, a swirl structure and a fuel injection nozzle structure, and its working process is as follows: first, fuel and mainstream air (main air intake chamber) are supplied, and the fuel is ejected through the nozzle 3. The mainstream air passes through the swirl generator to form a swirling airflow and enters the combustion chamber I. Under the action of the swirl air, the droplets and air in the combustion chamber I are fully mixed. In order to improve the ignition success rate, the supplied oil and gas are relatively high; the premixed oil and gas are ignited by the ignition device, but at this time the oil and gas are relatively high, the combustion is incomplete, and the flame is a diffuse orange-red color; then, the mainstream air intake is adjusted, the mainstream air intake is gradually increased, and the air intake of the air-assisting (auxiliary air chamber) is started; the secondary air intake passes through the rectifier plate and enters the auxiliary air chamber 70a outside the combustion chamber I, and it enters the auxiliary air chamber 7 after being rectified by the rectifier holes on the rectifier plate 0a, and enters combustion chamber I through the auxiliary air inlet hole on the inner cylinder, and the combustion chamber I serves as the main combustion zone; the retaining ring structure at the end of the inner cylinder can better force the wind to enter the combustion chamber I along the tangential annular hole, and mix with the central swirl mainstream, strengthen the mainstream swirl process, make the fuel spray and air undergo more intense mixing and shearing, further promote the droplet breakup, atomization and evaporation as well as the mixing of fuel and air, and the radial air intake can also force the flame length to shorten and converge to the center, at which time the flame gradually turns into a fully burned blue flame; the small-scale fuel swirl combustion device with an air-assisting structure of the present invention controls the mainstream air volume and the air-assisting volume through a reasonable flow field, regulates the swirl combustion flow field distribution of the liquid fuel, realizes efficient and full combustion of the liquid fuel in a small space, and reduces or avoids the emission of harmful gases.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A small fuel swirl combustion device with a wind-assisting structure, characterized in that: include: A shell, wherein a coaxial combustion chamber, a main air intake chamber 40a and an auxiliary air chamber 70a are formed in the shell, wherein the main air intake chamber 40a is arranged at the front end of the combustion chamber and communicated therewith, the auxiliary air chamber 70a is annular and arranged outside the combustion chamber, and the side wall of the combustion chamber is provided with an auxiliary air intake hole 701 which communicates with the auxiliary air chamber 70a and realizes radial air intake; A swirl generator 6 is disposed between the main air intake cavity 40a and the combustion chamber, and can generate a swirl flow in the air discharged from the main air intake cavity 40a before entering the combustion chamber; The nozzle 3 is arranged in the combustion chamber and is coaxial with the swirl generator 6, and is used for injecting oil.

2. The small fuel swirl combustion device with a wind-assisting structure according to claim 1, characterized in that: The combustion chamber includes a combustion chamber I70b and a combustion chamber II80 which are coaxially arranged and interconnected. The combustion chamber II80 is located downstream of the combustion chamber I70b and its diameter is larger than the diameter of the combustion chamber I70b. The nozzle 3 is arranged upstream of the combustion chamber I70b and facing the combustion chamber II80. The auxiliary air intake hole 701 is arranged on the side wall of the combustion chamber I70b.

3. The small fuel swirl combustion device with a wind-assisting structure according to claim 1, characterized in that: The auxiliary air inlet holes 701 are multiple and evenly distributed circumferentially and located downstream of the outlet plane of the nozzle.

4. The small fuel swirl combustion device with a wind-assisting structure according to claim 1, characterized in that: The shell includes a combustion tube 8 with open ends and a wind tube 4 installed on the head of the combustion tube 8, the combustion chamber and the auxiliary wind chamber 70a are arranged in the combustion tube 8, the wind tube 4 is coaxially provided with an inner wind tube 43 to form the main air intake chamber 40a, and the auxiliary air intake chamber 40b connected to the auxiliary air intake chamber 70a, the side wall of the auxiliary air intake chamber 40b is provided with an auxiliary air intake hole 401, the air intake direction of the auxiliary air intake hole 401 is tangent to the inner wall of the auxiliary air intake chamber 40b and forms a swirl.

5. The small fuel swirl combustion device with a wind-assisting structure according to claim 1, characterized in that: A circular rectifying plate 5 is provided between the secondary air inlet cavity 40b and the auxiliary air cavity 70a. Rectifying holes 501 are evenly distributed circumferentially on the rectifying plate 5 to achieve communication between the secondary air inlet cavity 40b and the auxiliary air cavity 70a.

6. The small fuel swirl combustion device with a wind-assisting structure according to claim 1, characterized in that: The swirl generator 6 includes a circular swirl plate, the center hole of the swirl plate is provided with a nozzle mounting hole for mounting the nozzle 3, a swirl hole group 601 is evenly distributed circumferentially on the swirl plate, the swirl hole group 601 includes a main hole 6011 and a secondary hole 6012 arranged on one side of the main hole 6011, the diameter of the secondary hole is smaller than the diameter of the main hole 6011 and can generate a pressure difference to form a rotating airflow.

7. The small fuel swirl combustion device with a wind-assisting structure as claimed in claim 6, characterized in that: The auxiliary holes 6012 are multiple and unevenly distributed.

8. The small fuel swirl combustion device with a wind-assisting structure according to claim 1, characterized in that: An inner cylinder 7 is coaxially arranged inside the combustion cylinder 8, and an annular rectifying plate 5 is fixed to the combustion cylinder 8 and the head of the inner cylinder 7. The tail of the inner cylinder 7 is radially bent outward to form a retaining ring 72, thereby dividing the combustion cylinder 8 into combustion chamber I 70b, combustion chamber II 80 and auxiliary air chamber 70a. The auxiliary air inlet hole 701 is opened on the side wall of the inner cylinder 7.

9. The small fuel swirl combustion device with a wind-assisting structure according to claim 6, characterized in that: The main hole and the auxiliary hole are both inclined holes.

10. The small fuel swirl combustion device with a wind-assisting structure according to claim 8, characterized in that: The retaining ring 72 is circumferentially uniformly provided with air holes connected to the combustion chamber II 80 .

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