RU214920U1 - Double-flow oil-gas burner for steam, hot water or thermal oil boilers - Google Patents

Abstract

The utility model relates to the energy industry, in particular to the combustion devices of gas-oil boilers. The objective of the utility model is to expand the possibilities of adjusting the aerodynamic structure of the flame and the process of mixing gas with air in order to reduce the emission of nitrogen oxides (NOx). The problem is solved by installing in each of the two flows of an air guide device (ADU) a movable tangential bladed air swirler (SA) with a movable bottom, which makes it possible to vary the degree of air swirling over a wide range, as well as by supplying gas through manifolds to the central and peripheral air flows separately, with the redistribution of the total gas flow between them by two control valves, and the gas nozzles of the central manifold have nozzles directed perpendicular to the burner axis and are made 360° rotatable.

Description

The utility model relates to the energy industry, in particular, to combustion devices for oil-gas boilers.

Multi-flow gas, fuel oil and gas-oil burners are known, in which aerodynamic parameters can be adjusted by changing the speed, degree of twist and air flow along the flows, which achieves the formation of a flame with an initial combustion zone with a lack of air (α<1) and a subsequent zone of complete afterburning. Thus, the temperature field of the flame is equalized and the formation of nitrogen oxides (NOx) is reduced. An example of such burners is the VTI-ZIO double-flow oil-gas burners (V.A. Vereshchetin, A.N. Tugov, Yu.M. Usman, V.T. Sidorkin. Development and implementation of low-toxic burners for combustion of standard and non-standard types of liquid and gaseous fuels// Chemical engineering. 2015. No. 7). The burners are made double-flow both for gas and air with the possibility of redistributing the flow of media between flows. Each air channel has an axial air swirler (AS) with a fixed blade angle. The gas enters from two separate torus collectors through pipes with ends bent at right angles so that the outflow occurs perpendicular to the burner axis into the central and peripheral air flows, and the pipes from each collector are directed to only one of the air flows. This type of burners is the closest analogue of the proposed utility model.

An example that is quite close in design is also a gas-oil burner according to patent RU 170 744 U1 (Application 2016132902, 08/09/2016), the distinctive features of which are:

double-flow burner for gas and air;

air distribution between the flows is carried out by a gate in the central flow;

the blades of the pollutants of both flows are made rotary;

gas is supplied to the peripheral flow through L-shaped pipes with tips made of heat-resistant steel.

As an advantage of the burner according to patent RU 170 744 U1 are specified:

expanding the limits of heat output adjustment;

increase in efficiency by improving the aerodynamic parameters of the torch;

applicability on combustion chambers of various geometry;

possibility of use in multi-burner boilers.

The objective of the utility model is to expand the possibilities of adjusting the aerodynamic structure of the torch and influencing the process of mixing gas with air in order to reduce NOx emissions and adapt the torch to furnaces of various shapes.

The task is solved:

1. By installing an air intake with tangential fixed blades both in the peripheral and central flows of the burner, and the regulation of the degree of twist in each stream is possible both in the direction of its decrease up to the forward flow, and in the direction of increase by moving the air intake and using movable bottoms.

2. By supplying combustion gas separately to the peripheral and central air flows through the corresponding gas manifolds with the possibility of redistributing the gas flow between them using valves, and the tips of the central gas manifold have gas nozzles directed perpendicular to the burner axis and the tips are made 360 ° rotatable, which also allows you to adjust the direction of injection of gas jets into any air flow.

Differences between the utility model and burners VTI-ZIO and according to patent RU 170 744 U1:

the ability to adjust the degree of twist of both SGs from zero (forward flow) to maximum. The first is achieved by moving the air intake and supplying air past it, the second - by partially blocking the outlet section of the air intake tangential blades with a movable bottom. Compared to the burner according to patent RU 170 744 U1, this greatly simplifies the design, since there is no complex mechanism for synchronous rotation of the blades, which is used only during commissioning. The possibility of changing the direction of flow twist by rotary blades is not an advantage, since when designing a multi-burner combustion device, the required direction of rotation of the SV is known in advance and it will not change during commissioning;

the distribution of air flow between the central and peripheral flows is carried out by the mentioned movable bottoms, therefore, gates are not required;

while maintaining separate adjustment of gas flow into the peripheral and central flows, the gas nozzles of the central manifold are made rotatable by 360°, which allows you to adjust the direction of gas outflow from the nozzles of the nozzles into the central or peripheral air flow.

The design of a double-flow burner is shown in Fig. 1 where:

1 - peripheral air intake with tangential fixed blades, 2 - movable bottom of the peripheral air intake, 3 - central air intake with tangential fixed blades, 4 - movable bottom of the central air intake, 5 - peripheral gas manifold with gas holes, 6 - central gas manifold, 7 - rotary gas nozzles of the central manifold, 8 - gas nozzles of rotary nozzles,
9 and 10 - valves for distributing gas flow between the peripheral and central gas manifolds, 11 - steam-mechanical nozzle for liquid fuel.

The combination of pollutants and movable bottoms makes up the air guide device of the burner.

A double-flow oil-gas burner works as follows:

In the process of testing the burner on the boiler, an experimental selection of the optimal degree of air twist is carried out both in the peripheral and in the central flow by moving the corresponding pollutant and its movable bottom.

In FIG. 2 shows a variant of an increased degree of twisting of the central and peripheral air flows, which is achieved by partially overlapping the outlet section of the tangential blades of the air intake 1 and 3 with movable bottoms 2 and 4.

In FIG. 3 shows the supply of the central air flow without twist (forward flow) by moving the air intake 3 and opening the movable bottom 4, which also performs the function of setting the proportion of air flow into the central flow.

In FIG. 4 shows a decrease in the twist of the central air flow by opening the bottom 4 without moving the air intake 3.

In FIG. 5 shows the supply of peripheral air flow without twist (forward flow) by moving air intake 1 and adjusting the share of air flow in the peripheral flow with bottom 2.

In FIG. 6 shows a decrease in the twist of the peripheral air flow by opening the bottom 2 to the maximum with the partial opening of the air intake 1.

Simultaneously with the setting of the air guide described above, the optimal distribution of gas flow between the peripheral and central flows is selected by closing one of the valves - 9 or 10, and the direction of gas outflow from nozzles 8 of rotary gas nozzles 7 is selected, the main positions of which are shown in Fig. 7.

The selection criteria are: matching the shape of the torch to the shape of the combustion chamber, the minimum NOx emission in the absence of chemical underburning (CO content in the flue gases is within the normal range).

A burner set for gas fuel is tested for oil operation, with separate adjustment of the fuel-air ratios for gas and oil. During operation, it is not required to change the optimal positions of the elements of the air guide of the burner and the distribution of gas flow between the peripheral and central flows.

The proposed design provides extended options for combustion adjustment with minimal NOx emissions in furnaces of various shapes.

Claims (2)

1. A double-flow gas-oil burner containing an air guide with two air swirlers - central and peripheral, two gas manifolds - central and peripheral, as well as a steam-mechanical liquid fuel nozzle, characterized in that the central gas manifold is equipped with gas tips, the central and peripheral air swirlers have tangential non-rotating blades, made moving and have movable bottoms, providing an increase or decrease in the degree of twist of the air flows. 2. Double-flow oil-gas burner according to claim 1, characterized in that the gas nozzles of the central manifold are rotatable through 360° and have nozzles directed perpendicular to the burner axis.

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