BURNER AND METHOD FOR OPERATING A BURNER

Abstract

Burner comprising an inner fluid supply unit and an outer fluid supply unit, wherein the inner fluid supply unit comprises a first inner fluid ejection element, a second inner fluid ejection element encompassing the first inner fluid ejection element and a third inner fluid ejection element encompassing the second inner fluid ejection element and wherein the inner fluid supply unit is configured for ejecting a first oxidant, a second oxidant and a fuel. The outer fluid supply unit comprises at least two outer fluid ejection elements, arranged at a specific radial distance from the inner fluid supply unit, wherein each individual outer fluid ejection element is configured for ejecting the first oxidant and the second oxidant by means of a central fluid ejection element and an encompassing fluid ejection element encompassing the central fluid ejection element.

Claims

1. A burner for combustion of fluids comprising an inner fluid supply unit with fluid ejection elements and an outer fluid supply unit, wherein the inner fluid supply unit comprises a first inner fluid ejection element, particularly a first pipe, and a second inner fluid ejection element, particularly a second pipe, encompassing at least an axial portion of the first inner fluid ejection element and a third inner fluid ejection element, particularly a third pipe, encompassing at least an axial portion of the second inner fluid ejection element and wherein the inner fluid supply unit is configured for ejecting a first oxidant, a second oxidant and a fuel by means of the fluid ejection elements of the inner fluid supply unit, wherein the outer fluid supply unit comprises at least two outer fluid ejection elements, arranged at a specific radial distance from the inner fluid supply unit, particularly from a centre of the inner fluid supply unit, particularly from a centre of the first inner fluid ejection element, wherein each individual outer fluid ejection element is configured for ejecting the first oxidant and the second oxidant by means of a central fluid ejection element, particularly a central pipe, and an encompassing fluid ejection element, particularly an encompassing pipe, encompassing at least an axial portion of the central fluid ejection element.

2. The burner according to claim 1 configured for controlling at least one ratio between amounts of the ejected first oxidant and/or the ejected second oxidant and/or the ejected fuel such that at least one process parameter is optimised.

3. The burner according to claim 2 configured for controlling a first ratio between an amount of the first oxidant and an amount of the second oxidant ejected by means of both the inner fluid supply unit and the outer fluid supply unit; controlling a second ratio between an amount of the first oxidant and/or the second oxidant ejected by means of the inner fluid supply unit and an amount of the first oxidant and/or the second oxidant ejected by means of the outer fluid supply unit; and controlling the first ratio and the second ratio such that the at least one process parameter is optimized.

4. The burner according to claim 1, wherein the outer fluid supply unit comprises at least two outer fluid ejection elements arranged circumferentially around the inner fluid supply unit, particularly such that the at least two outer fluid ejection elements have the same radial distance from the inner fluid supply unit, particularly from the centre of the inner fluid supply unit.

5. The burner according to claim 1, wherein at least one pressure reducing element is attached to an inner wall and/or outer wall of at least one of the fluid ejection elements of the inner fluid supply unit.

6. The burner according to claim 5, wherein at least one pressure reducing element is provided for an individual fluid ejection element of the inner fluid supply unit, wherein a fluid, which is to be ejected by means of this individual fluid ejection element, is further to be ejected by means of at least one outer fluid ejection element of the outer fluid supply unit.

7. A method for operating a burner according to claim 1, comprising the steps of: ejecting a first oxidant, a second oxidant and a fuel by means of individual fluid ejection elements of the inner fluid supply unit and the outer fluid supply unit; and controlling at least one ratio between amounts of the ejected first oxidant and/or the ejected second oxidant and/or the ejected fuel such that at least one process parameter is optimised.

8. The method according to claim 7, comprising the steps of: controlling a first ratio between an amount of the first oxidant and the second oxidant ejected by means of both the inner fluid supply unit and the outer fluid supply unit; controlling a second ratio between an amount of the first oxidant and/or the second oxidant ejected by means of the inner fluid supply unit and an amount of the first oxidant and/or the second oxidant ejected by means of the outer fluid supply unit; and controlling the first ratio and the second ratio such that the at least one process parameter is optimised.

9. The method according to claim 7 wherein the first oxidant comprises more than 80%, more than 90% or more than 95% by volume oxygen and wherein the second oxidant is air.

10. Method according to claim 7 comprising the steps of: ejecting the first oxidant, particularly oxygen, by means of the first inner fluid ejection element; ejecting the fuel, particularly methane or natural gas, by means of the second inner fluid ejection element; and ejecting the second oxidant, particularly air, by means of the third inner fluid ejection element.

11. The method according to claim 10, further comprising the step of: ejecting the first oxidant and/or the second oxidant by means of the at least one outer fluid ejection element.

12. The method according to claim 7, further comprising the steps of: ejecting the first oxidant, particularly oxygen, by means of the central fluid ejection element of the at least one of the outer fluid ejection elements and ejecting the second oxidant, particularly air, by means of the encompassing fluid ejection element of the at least one of the outer fluid ejection elements.

13. The method according to claim 7, wherein the first oxidant is independently supplied to the inner fluid supply unit and to the outer fluid supply unit.

14. The method according to claim 7, wherein the second oxidant is independently supplied to the inner fluid supply unit and to the outer fluid supply unit.

Description

[0062] The present invention will now be described further, by way of example, with reference to the accompanying drawings, in which

[0063] FIG. 1 schematically shows a preferred embodiment of a burner according to the present invention in a front view and in a sectional side view.

DETAILED DESCRIPTION

[0064] FIG. 1 schematically shows a preferred embodiment of a burner according to the present invention. FIG. 1a shows the burner 100 in a schematic front view. FIG. 1b shows the burner 100 in a sectional side view along the line A-A of FIG. 1a.

[0065] The burner 100 comprises an inner fluid supply unit 110 and an outer fluid supply unit 120 arranged in a common housing 101.

[0066] The inner fluid supply unit 110 comprises a first inner fluid ejection element 111, particularly a first pipe, a second inner fluid ejection element 112, particularly a second pipe, and a third inner fluid ejection element 113, particularly a third pipe. The first, second and third inner fluid ejection elements 111, 112, 113 are arranged coaxially and concentrically.

[0067] The second inner fluid ejection element 112 encompasses, i.e. circumferentially surrounds an axial portion of the first inner fluid ejection element 111 and the third inner fluid ejection element 113 encompasses, i.e. circumferentially surrounds an axial portion of the second inner fluid ejection element 112. Thus, by means of the second inner fluid ejection element 112 a first annular channel is provided around the first inner fluid ejection element 111. Accordingly, by means of the third inner fluid ejection element 113 a second annular channel is provided around the second inner fluid ejection element 112.

[0068] A port 111a of the first inner fluid ejection element 111 can be connected with a first fluid supply 131, e.g. comprising a fluid storing vessel and a pump, such that a first fluid can be led from the first fluid supply 131 through the first fluid ejection element 111 and can be ejected throughout an axial end 111b of the first fluid ejection element 111.

[0069] Accordingly, a port 112a of the second inner fluid ejection element 112 can be connected with a second fluid supply 132 such that a second fluid can be ejected throughout an axial end 112b of the second fluid ejection element 112.

[0070] Further, a port 113a of the third inner fluid ejection element 113 can be connected with a third fluid supply 133 such that a third fluid can be ejected throughout an axial end 113b of the third fluid ejection element 113.

[0071] The first inner fluid ejection element 111 comprises a first pressure reducing element 102 in the form of a perforated plate arranged at an inner wall of the first inner fluid ejection element 111. By means of this first pressure reducing element 102 a velocity of the first fluid flowing through the first inner fluid ejection element 111 can be reduced. A second pressure reducing element 103 in the form of a perforated plate is arranged at an inner wall of the third inner fluid ejection element 113 for reducing a velocity of the third fluid flowing through the third inner fluid ejection element 113.

[0072] The outer fluid supply unit 120 comprises a multitude of outer fluid ejection elements 121. These outer fluid ejection elements 121 are each arranged at a specific radial distance from the inner fluid supply unit 110, particularly from a centre of the inner fluid supply unit 110, particularly from a centre of the first inner fluid ejection element 111. These radial distances of the outer fluid ejection elements 121 are particularly to be understood as the radial distance between the centre of the corresponding outer fluid ejection element 121 and the centre of the first inner fluid ejection element 111 at the axial end 111b of the first fluid ejection element 111. For example, these radial distances can each be in the range between the radius of the third inner fluid ejection element 113 and 1.5 times the radius of the third inner fluid ejection element 113.

[0073] In particular, four outer fluid ejection elements 121 are arranged circumferentially around the inner fluid supply unit 110, especially symmetrically and in equidistant circumferential distances to each other. Particularly, each outer fluid ejection element 121 has the same radial distance to the centre of the first inner fluid ejection element 111.

[0074] Further, the longitudinal axis of each outer fluid ejection element 121 is at least essentially parallel to the longitudinal axes of the first, second and third inner fluid ejection elements 111, 112, 113. Further, the outer fluid ejection elements 121 are arranged at a side of a wall of the second inner fluid ejection element 112 and of a wall of the third inner fluid ejection element 113 facing away from a wall of the first inner fluid ejection element 111.

[0075] In this preferred embodiment, each outer fluid ejection element 121 comprise a central fluid ejection element 122, particularly a central pipe, and an encompassing fluid ejection element 123, particularly an encompassing pipe, encompassing an axial portion of the central fluid ejection element 122. It is, however, also possible, that some or all of the outer fluid ejection elements 121 each comprise only one single fluid ejection element, particularly one single pipe.

[0076] A port 122a of each central fluid ejection element 122 can be connected with the first, the second or the third fluid supply 131, 132, 133 such that the corresponding fluid can be ejected throughout an axial end 122b of the central fluid ejection element 122. In the present example, the ports 122a are connected to the first fluid supply 131.

[0077] Accordingly, a port 123a of each encompassing fluid ejection element 123 can be connected to the first, the second or the third fluid supply 131, 132, 133 in order to eject the corresponding fluid throughout an axial end 123b of the encompassing fluid ejection element 123. In the present example, the ports 123a are connected to the third fluid supply 133.

[0078] According to a particularly advantageous embodiment, the first fluid supply 131 is an oxygen supply, the second fluid supply 132 is fuel supply, e.g. for natural gas, and the third fluid supply 133 is an air supply.

[0079] Thus, by means of the first, second and third inner fluid ejection elements 111, 112, 113, a central high velocity oxygen jet, an annular high velocity gaseous fuel jet around the oxygen jet and a second annular high velocity air jet around the gaseous fuel jet can be created. For example, the oxygen speed can be larger than the fuel speed at full oxygen operation and the fuel speed can be larger than the air speed at full air operation. Further, by each of the outer fluid ejection elements 121, a high velocity, especially a sonic or supersonic oxygen jet surrounded by a high velocity annular air stream is created. Expediently, a portion of the total air and total oxygen can be delivered to the inner supply unit 110, e.g. 20%, with the balance delivered to the outer supply unit 120.

[0080] Since the first inner fluid ejection element 111 and the central fluid ejection elements 122 are connected to the same fluid supply 131 and are therefore provided for ejecting the same fluid, i.e. oxygen, the first inner fluid ejection element 111 is provided with the pressure reducing elements 102. Thus, the same supply pressure is used for the first inner fluid ejection element 111 and the central fluid ejection elements 122. By means of the pressure reducing elements 102 the amount of oxygen that flows to the inner fluid supply unit 110 can be reduced while achieving a lower injection velocity compared to the outer fluid supply unit 120.

[0081] Accordingly, the third inner fluid ejection element 113 is provided with the pressure reducing elements 103, since the third inner fluid ejection element 113 and the encompassing fluid ejection elements 123 are connected to the same fluid supply 133 and are provided for ejecting the same fluid, e.g. air. The same supply pressure is therefore used for the third inner fluid ejection element 113 and the encompassing fluid ejection elements 123. By means of the pressure reducing elements 103 the amount of air flowing to the inner fluid supply unit 110 can be reduced while achieving a lower injection velocity compared to the outer fluid supply unit 120.

REFERENCE LIST

[0082] 100 burner [0083] 101 housing [0084] 102 pressure reducing element, perforated plate [0085] 103 pressure reducing element, perforated plate [0086] 110 inner fluid supply unit [0087] 111 first inner fluid ejection element [0088] 111a port of the first fluid ejection element [0089] 111b axial end of the first fluid ejection element [0090] 112 second inner fluid ejection element [0091] 112a port of the second fluid ejection element [0092] 112b axial end of the second fluid ejection element [0093] 113 third inner fluid ejection element [0094] 113a port of the third fluid ejection element [0095] 113b axial end of the third fluid ejection element [0096] 120 outer fluid supply unit [0097] 121 outer fluid ejection element [0098] 122 central fluid ejection element [0099] 122a port of the central fluid ejection element [0100] 122b axial end of the central fluid ejection element [0101] 123 encompassing fluid ejection element [0102] 123a port of the encompassing fluid ejection element [0103] 123b axial end of the encompassing fluid ejection element [0104] 131 first fluid supply, oxygen supply [0105] 132 second fluid supply, fuel supply [0106] 133 third fluid supply, air supply