DEVICE FOR COMBUSTING AMMONIA

Abstract

A device for decomposing ammonia into a nitrogen-hydrogen mixture. The device comprising a cylindrical combustion chamber, a device for supplying air-ammonia mixture, at least one main channel for its supply, a tangential swirler, a spark plug installed in the combustion chamber, and a channel for supplying auxiliary fuel with increased flammability. A cylindrical body is introduced, inside of which a cylindrical combustion chamber is located coaxially with the formation between them, the entrance of the main channel and the tangential swirler, an additional annular channel for supplying and heating the air-ammonia mixture, wherein the cylindrical side surfaces of the body and the combustion chamber have at least one through hole for installation of the spark plug, a flame sensor, a device for secondary air supply and a flame stabilizer are introduced, wherein the combustion chamber is a cooling chamber, at the outlet of which a catalytic unit is installed.

Claims

1. A device for combusting ammonia, comprising: a cylindrical combustion chamber, a device for supplying air-ammonia mixture, including at least one main channel for its supply, at the outlet of which is installed tangential swirler, spark plug installed in the combustion chamber, a channel for supplying auxiliary fuel with increased flammability, characterized in that a cylindrical body is additionally introduced, inside of which a cylindrical combustion chamber is located coaxially with the formation between them, the entrance of the main channel and the tangential swirler, an additional annular channel for supplying and heating the air-ammonia mixture, wherein the cylindrical side surfaces of the body and the combustion chamber have at least one through hole for installation of the spark plug, a flame sensor, a device for secondary air supply and a flame stabilizer are introduced, wherein the combustion chamber is a cooling chamber, at the outlet of which a catalytic unit is installed.

2. The device according to claim 1, characterized in that the flame sensor is made in the form of a thermocouple.

3. The device according to claim 1, characterized in that the flame sensor is installed along the axis of the device in the secondary air supply channel.

4. The device according to claim 1, characterized in that the secondary air channel is formed in the annular gap between the flame sensors and the auxiliary fuel gas supply channel.

5. The device according to claim 1, characterized in that the axial swirler is installed at the outlet of the secondary air channel.

6. The device according to claim 1, characterized in that the secondary fuel supply channel is made in the form of an annular gap between the outer casing and the inner shell of the secondary air supply channel.

7. The device according to claim 1, characterized in that the outlet of the additional fuel channel has axial nozzles.

8. The device according to claim 1, characterized in that the additional fuel may be H.sub.2, CH.sub.4, C.sub.3H.sub.8.

9. The device according to claim 1, characterized in that the catalytic unit contains a fire barrier plate combined with a mesh catalyst.

10. The device according to claim 9, characterized in that the catalytic unit contains (Pt, Pd) as the active substance.

11. The device according to claim 1, characterized in that the heat exchanger is made as a pipe in a pipe, in the annular gap of which passes ammonia-air mixture containing intensifiers to improve heat exchange.

12. The device according to claim 1, characterized in that the spark plug is cooled by an ammonia-air mixture.

13. The device according to claim 1, characterized in that the secondary air is supplied to the device in a volume of no more than 50% of the primary air volume.

14. The device according to claim 1, characterized in that the additional fuel is supplied in the volume of 5-15% of the ammonia volume.

Description

LIST OF FIGURES, DRAWINGS AND OTHER MATERIALS

[0014] FIG. 1 shows the design of the claimed device, longitudinal section;

[0015] FIG. 2 shows a cross section along the plane A-A.

DETAILS CONFIRMING THE FEASIBILITY OF EMBODIMENT OF THE INVENTION

[0016] A device for combusting ammonia (FIG. 1) comprises a cooled combustion chamber 1 of cylindrical shape with a burner device 3 located in it with tangential input of working reagentsammonia with primary air, one or more spark plugs 2 located on the cylindrical surface, flame sensors 4 located along the axis of the burner device 3, channels for supplying secondary air 6 and secondary fuel 5, a flame stabilizer 7, a mesh unit 8 with catalysts. An axial swirler 12 is installed at the outlet of the secondary air channel 6, and axial nozzles 13 are installed at the outlet of the secondary fuel channel 5. The gas mixture of ammonia and primary air is supplied through the connection 11 into the annular type intertube space formed by inner 14 and outer 15 cylinders. Secondary air is supplied in the connection 10 to the intertube space formed by cylinders 17 and 18, and secondary fuel is supplied in the connection 9 to the intertube space formed by cylinders 16 and 17.

[0017] The device operates as follows.

[0018] At startup, the ammonia-air mixture is supplied through the connection 11 into the intertube space 18 and exits into the combustion chamber 1, at the same time the plugs 2 are energized. When necessary or required, secondary fuel is supplied to the combustion chamber 1 through the connection 9, which enters the combustion chamber 1 through the axial nozzles 13. The flame sensor 4 mounted in the axis of the device detects the presence of ignition in the device. By regulating the supply of ammonia-air mixture, secondary fuel and air, ignition and regulation of the operation modes of the ammonia combustion device are provided.

[0019] Gas ammonia-air mixture before entering the tangential swirler passes through the gas-cooled jacket, where it is additionally mixed and heated, which contributes to the increase of ammonia combustion rate and completeness of combustion and leads to the reduction of NOx and NH.sub.3 emissions. At the same time, the inner cylinder and the spark plug body are cooled, which ensures longer operational life. On the inner cylinder of the device there is a stabilizing device in the form of a washer, which creates a zone of recirculation of combustion products and contributes to an increase in the time of combustion of fuel and, as a consequence, to an increase in the completeness of combustion. Unlike devices for combustion of raw hydrocarbons, where spark plugs are located mainly near the supply of the fuel-air mixture on the end surface, in the claimed device at least one spark plug is located on the side surface, which ensures more stable ignition and the ability to install the spark plug or multiple spark plugs at different heights. In the absence of ammonia-air mixtures of soot in the combustion products, this solution allows for long-lasting plug operation. The large area of the inner cylinder allows, if necessary, to install several plugs, both on the cylinder circumference and height, which also contributes to the reliability of ignition of ammonia-air mixtures.

[0020] Ensuring qualitative and complete combustion of ammonia-air mixtures requires, in addition to complete and uniform mixing of ammonia with air and its ignition, also a long combustion process. To meet this requirement, a stabilizing membrane in the form of a washer is installed inside the cylinder, which ensures that the combustion products are swirled and increases the residence time of the combustion products in the combustion chamber. The products of complete combustion of ammonia-air mixtures are N.sub.2 and H.sub.2O, while those of incomplete combustion are NOx and NH.sub.3 residues. NOx and NH.sub.3 in the combustion products must be minimized in order to completely eliminate the combustion products. To fulfill this requirement, it is proposed to install at the outlet of combustion products a mesh unit containing both screens of heat-resistant material in the form of stainless steel or nichrome and an afterburning catalyst placed on the screen. The invention proposed by the inventors is a technical solution aimed at solving the problem of qualitative combustion of ammonia. The invention provides stable, reliable environmentally friendly combustion of ammonia, increasing the operating life of the device and safety.