RU2327928C2 - Burner device - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: burner device incorporates a central fuel jet and coaxial circular rings forming air feeding channels provided differently directed blade swirlers and tapered deflectors arranged at the output of every channel to deflect air flows from the center to periphery. Here, the swirler adjacent blade inclination angles are set be different with the 0.5 to 0.8 ratio.

EFFECT: higher uniformity of heating the furnace space by intensifying air turbulence in crossing its swirled flows.

3 dwg

Description

The invention relates to a device for burning fuel, and can be used in heating furnaces and combustion chambers of gas turbine plants.

A burner device is known that contains a central fuel nozzle, several sequentially located tangential blade multidirectional air swirls, equipped with curved reflectors at the outlet, converting the movement of air from initially directed radially inward to axial. The fuel jet from the central nozzle, crossing the air flow, enters the system of annular protrusions of curvilinear reflectors, during this movement spraying, evaporation and mixing of fuel with air are provided, after which the prepared mixture enters the combustion chamber (Patent GB No. 2272756, MKI F23R 3 / fourteen).

The disadvantage of this device is the inability to burn the air-fuel mixture in the form of a flat torch, as well as the fact that the device only forms the air-fuel mixture, and therefore cannot be used to heat the working volume, for example, of a furnace.

Known burner device, adopted as a prototype, containing a Central fuel nozzle, coaxial annular shells forming air supply channels equipped with multidirectional blade swirls, the outer shell is made in the form of a fuel manifold, the fuel supply holes of which are directed perpendicular to the holes of the central nozzle, and conical at the exit of each channel with the possibility of deviation of air flows from the center to the periphery (Paten RU №2183798, MCI F23R 3/14).

This burner device allows you to create a system of parallel swirling fan flows of air, in the contact points of which an increase in the intensity of the flow turbulence is observed, which provides quick mixing of fuel with air and, in combination with the indicated direction of the fuel jets, allows you to organize a flat torch with improved organization of combustion of the air-fuel mixture, which allows heating furnace volume to the set temperature.

However, in this burner device, the jets emerging from adjacent (adjacent) swirl channels interact with each other, and, due to the standard, equal angle of inclination of the swirl blades, the resulting coaxial jets are created. This does not provide enough high-quality mixing of the air flows from adjacent channels between themselves and with the fuel, as a result of which the torch has too much dispersion and a central zone into which cold air is ejected from the periphery of the furnace, as a result of which the temperature field created by the torch is not evenly distributed.

The problem solved by the invention is to increase the uniformity of heating of the furnace volume by increasing the intensity of air turbulence due to the crossing of its fan swirling flows.

This problem is solved as follows.

In a known burner device containing a central fuel nozzle and coaxial annular shells forming air supply channels equipped with multidirectional blade swirls, as well as conical reflectors installed at the outlet of each channel with the possibility of deviation of air flows from the center to the periphery, according to the invention, the angle of inclination of the blades of adjacent the swirl channels are made of different sizes with a ratio of 0.5-0.8.

The sequential decrease or increase in the angle of inclination of the blades of the swirls within the specified limits, as well as an arbitrary combination of this condition ensures the optimal angle of intersection of the jets emerging from adjacent channels and the high quality of mixing air flows with fuel.

Figure 1 shows a General view of the proposed burner device.

Figure 2 shows a vector diagram of the air flows leaving the adjacent channels of the swirlers.

Figure 3 presents a thermal image of the torch of the proposed burner device.

The burner device contains a central fuel nozzle 1 with fuel supply holes 2, annular shells - outer 3, inner 4 and intermediate 5. In the coaxial cavities 6 between the shells there are blades 7, 8, 9, forming multidirectional swirl channels 10, 11, 12. The angle the inclination β of the blades 8 is 0.5-0.7 of the same angle α of the blades 7, and the angle of inclination γ of the blades 9 is 0.5-0.7 of the same angle β of the blades 8. At the exit of the coaxial cavities 6 at the ends of the inner and intermediate shells 4 and 5 reflectors 13 are made in the form of ar binders conical ends 14 which are placed over the fuel feed nozzle holes 2 1. Burner device is mounted in an end wall 15 of the combustion chamber 16.

An example of a specific implementation with a sequential decrease in the angle of inclination of the blades:

α = 45 °

β = 30 °

γ = 15 °

The number of swirl channels is limited by the limit value of the angle γ = 15 ° and the limit value of the angle α = 75 °.

For β <0.5 α and γ <0.5 β, the following occurs: the intersection angle of the resulting air jets emerging from adjacent channels becomes too large, which leads to a decrease in the momentum of the resulting stream. This adversely affects the mixing of fuel with air.

For β> 0.8 α and γ> 0.8 β, the following occurs: the resulting air jets leaving adjacent channels exit almost in parallel, which impairs mixing.

An example of a specific design with a sequential increase in the angle of inclination of the blades:

α = 15 °

β = 30 °

γ = 45 °

The number of swirl channels is limited by the limiting angle α = 15 ° and the limiting angle γ = 75 °.

An example of a specific performance with an arbitrary combination of the declared ratio of the angle of inclination of the blades:

α = 15 °

β = 30 °

γ = 15 °

χ = 30 °

φ = 45 °

λ = 60 °

The number of swirl channels is unlimited.

The burner device operates as follows.

The fuel enters from the central fuel nozzle 1 into the combustion chamber 16 in the form of a system of fan jets mixed with air streams leaving the multidirectional scapular channels 10, 11, 12. At the same time, air streams deviate radially from the center to the periphery by conical reflectors 13 and propagate in the form of intersecting jets. A consistent decrease in the angle of inclination of the blades of the swirls within the specified limits provides the optimal angle of intersection of the jets emerging from adjacent channels and high quality mixing of air flows with fuel. A sharp increase in the intensity of the turbulence of the flow occurs in the junction areas of the jets, which ensures good mixing of air with fuel and a quick burnout of the mixture.

The proposed burner device allows you to create a highly turbulent torch with a uniform distribution of the temperature field at a distance of 2-3 calibers from the cut of the burner device.

Claims (1)

A burner device containing a central fuel nozzle and coaxial annular shells forming air supply channels equipped with multidirectional blade swirls, as well as conical reflectors installed at the outlet of each channel with the possibility of deviation of air flows from the center to the periphery, characterized in that the inclination angles of the blades are adjacent the swirl channels are made of different sizes with a ratio of 0.5-0.8.

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