WO2018056994A1

WO2018056994A1 - Atomizer fuel nozzle for oil operation in a turbine engine

Info

Publication number: WO2018056994A1
Application number: PCT/US2016/053231
Authority: WO
Inventors: Stephen A. Ramier; Krishna C. Miduturi; Khalil Farid ABOU-JAOUDE
Original assignee: Siemens Aktiengesellschaft
Priority date: 2016-09-23
Filing date: 2016-09-23
Publication date: 2018-03-29

Abstract

A turbine engine can have an atomizer having two orifices that form an intersecting spray cone. The turbine engine can also have an atomizer that has three orifices that forms a partially filled spray cone. The intersecting sprays cones or the partially filled spray cone permits operation of the turbine engine without water. The intersecting spray cones or partially filled spray cone can also be used to facilitate ignition and lower NOx emissions.

Description

ATOMIZER FUEL NOZZLE FOR OIL OPERATION IN A TURBINE ENGINE

BACKGROUND

1. Field [0001] Disclosed embodiments are generally related to turbine engines and, more particularly fuel atomizers used in turbine engines.

2. Description of the Related Art

[0002] A turbine engine typically has a compressor section, a combustion section having a number of combustors and a turbine section. Ambient air is compressed in the compressor section and conveyed to the combustors in the combustion section. The combustors combine the compressed air with a fuel and ignite the mixture creating combustion products. The combustion products flow in a turbulent manner and at a high velocity. The combustion products are routed to the turbine section via transition ducts. Within the turbine section are rows of vane assemblies. Rotating blade assemblies are coupled to a turbine rotor. As the combustion product expands through the turbine section, the combustion product causes the blade assemblies and turbine rotor to rotate. The turbine rotor may be linked to an electric generator and used to generate electricity.

[0003] A fuel injection system is employed to introduce fuel into each combustor. The combustion that occurs can result in the formation of oxides of nitrogen (NOx) which is not desirable.

[0004] Water can be employed in the fuel injecting assembly in order to reduce the production of NOx. Water injection is also employed in order to prevent flashback. However, the implementation of water can prove problematic where water costs are an issue.

SUMMARY

[0005] Briefly described, aspects of the present disclosure relate to an atomizer.

[0006] An aspect of the disclosure may be an atomizer. The atomizer may have a first fluid circuit for transporting oil fuel to a first orifice, wherein the first orifice ejects oil fuel. The atomizer may also have a second fluid circuit for transporting water or air to a second orifice and a third orifice, wherein the second orifice ej ects water or air, wherein oil fuel and water ejected from the first orifice, the second orifice and the third orifice forms a partially filled spray cone; and wherein the turbine engine can operate without water.

[0007] Another aspect of the disclosure may be a turbine engine having a fuel lance comprising a first fluid circuit and a second fluid circuit, wherein the first fluid circuit is centrally disposed within the fuel lance and extends along a longitudinal axis of the fuel lance to convey an oil fuel to a downstream end of the fuel lance, wherein the second fluid circuit is annularly disposed about the first fluid circuit to convey water or air to the downstream end of the lance. The turbine engine further has an atomizer disposed at the downstream end of the fuel lance, the atomizer having a first orifice responsive to the first fluid circuit to form a first spray cone, wherein the atomizer has a second orifice responsive to the second fluid circuit to form a second spray cone, wherein the first spray cone and the second spray cone are concentric and intersecting, wherein the first spray cone has a first conical angle greater than 1 15 degrees; wherein the second spray cone has a second conical angle less than 100 degrees; and wherein the turbine engine can operate without water.

[0008] Another aspect of the present invention may be a method for operating an atomizer in a turbine engine comprising: transmitting oil fuel through a first fluid circuit centrally disposed within a lance, wherein the first circuit extends along a longitudinal axis of the lance to convey the oil fuel to a downstream end of the lance to a first orifice, transmitting oil or water through a second fluid circuit located about the first fluid circuit to convey water or air to the downstream end of the lance to a second orifice and third orifice; ejecting oil fuel from the first orifice; ejecting air or water from the second orifice, wherein the turbine engine can operate without water, and forming a partially filled spray cone via the ejection of oil fuel and water from the first orifice, the second orifice and the third orifice.

BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 is a cutaway view of the lance and atomizer. [0010] FIG. 2 is a cutaway view of the atomizer.

[0011] FIG. 3 is a view of an alternative embodiment of the atomizer that can form a partially filled cone.

DETAILED DESCRIPTION [0012] The present inventors have recognized certain drawbacks that affect at least some existing turbine engines. Some turbine engines require water in order to operate when using oil fuel. The water and oil fuel are mixed prior to injection into the combustor. The water is used to prevent flash back and flame holding. The water also reduces NOx emissions.

[0013] The present inventors have also recognized that some turbines use many points of oil fuel injection. These multiple points of oil fuel injection add to overall costs and can lead to complexity issues in the field.

[0014] In view of these recognitions, the present inventors propose an innovative fuel injector that is expected to avoid or least reduce the foregoing drawbacks.

Without limitation, disclosed embodiments of the fuel injector may be made with a dual orifice atomizer in order to produce to intersecting conical sprays. The dual orifice atomizer is able to operate with reduced water and/or no water without suffering issues such as flash back while still being able to achieve reduced NOx emissions.

[0015] It should be understood that additional benefits may be achieved by the features disclosed here and not limited to those discussed above.

[0016] To facilitate an understanding of embodiments, principles, and features of the present disclosure, they are explained hereinafter with reference to

implementation in illustrative embodiments. Embodiments of the present disclosure, however, are not limited to use in the described systems or methods.

[0017] The components and materials described hereinafter as making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components and materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of embodiments of the present disclosure. [0018] Fig. 1 shows a cut away view of an atomizer 10 and lance 12. The lance 12 has a first fluid circuit 14 and a second fluid circuit 16. The lance 12 further has a first inlet 7 and a second inlet 8. The first inlet 7 opens into the first fluid circuit 14. The second inlet 8 opens into the second fluid circuit 16. The first inlet 7 receives a first fluid 20 that is transmitted through the first fluid circuit 14. The second inlet 8 receives a second fluid 24 that is transmitted through the second fluid circuit 16.

[0019] Lance 12 is an annular fuel- injecting lance 12 including the first fluid circuit 14 and the second fluid circuit 16. First fluid circuit 14 is centrally disposed within fuel-injecting lance 12. First fluid circuit 14 extends along the longitudinal axis A of the lance 12 to convey the first fluid 20 to the downstream end 22 of the lance 12.

[0020] Shown in Fig. 2 is a cutaway view of the atomizer 10 that injects the first fluid 20 and the second fluid 24 into the combustion chamber (not shown). The atomizer 10 has a first orifice 15 and a second orifice 25. The first orifice 15 is the only point of fuel injection into the combustion chamber. By having only one point of fuel inj ection simplification of the overall system occurs, which reduces the potential for complications and further reduces the need for maintenance. When the first fluid 20 is ejected from the first orifice 15 the first fluid 20 may form a spray cone. The second orifice 25 may be an annular ring that surrounds the first orifice 15. The second fluid 24 is ejected from the second orifice 25 and may also form a spray cone. The first fluid 20 and the second fluid 24 intersect during operation.

[0021] The atomizer 10 is designed to be used with a first fluid 20 that is oil fuel. The atomizer 10 also operates with a second fluid 24, the second fluid 24 may be air and/or water. The atomizer 10 is designed and is able to operate with little to no water so as to be effective in those areas where water is scarce. When operating with air the atomizer 10 is improving ignition capabilities. When operating with water the atomizer 10 is reducing the NOx emissions. A water to oil fuel ratio of approximately 1.25 is preferred for NOx reduction and combustion performance.

[0022] The first orifice 15 and the second orifice 25 are oriented in such a manner that the spray cones are emitted from first orifice 15 and the second orifice 25 at different angles. Furthermore, the orientation of the first orifice 15 and the second orifice 25 create spray cones that intersect. In addition to having spray cones at different angles and intersecting, the spray cones may also be concentric. [0023] Utilization of the intersecting spray cones may permit the atomizer 10 to operate in low to no water conditions. The turbine is able to operate on a first fluid 20, such as oil fuel, or other liquid fuels, with no water injection if needed. Furthermore, the atomizer 10 is also able to operate with second fluid 24, such as water or air, in some instances in order to reduce emissions or to enhance ignition capabilities. Other benefits to the atomizer 10 are excellent ignition capability, no combustion performance issues, such as flash back, improved acoustic dynamics and reduced metal temperatures.

[0024] Second fluid circuit 16 is annularly disposed about first fluid circuit 14 so as provide the second fluid 24 to the downstream end 22 of the lance 12. The second fluid circuit 16 and the first fluid circuit 14 are concentric. The second fluid 24 is inserted into the second fluid circuit 16 an ejected from the second orifice 25. The second fluid 24 may be selectable. While other fluids may be utilized with the atomizer 10 discussed herein, it is the implementation of the oil fuel, water and air discussed herein that helps achieve the operation of the turbine in those environments where water is a scarce commodity.

[0025] Atomizer 10 may also employ a heat shield 17 that is able to receive cooling air. The shield 17 further assists in keeping the wear of the components minimized. The shield 17 also keeps the temperature of the components at a lower temperature thereby allowing continued operation.

[0026] The first orifice 15 of the atomizer 10 is formed so as to eject a first spray cone 35 having an angle θι. The second orifice 25 of the atomizer 10 is formed so as to eject a second spray cone 45 having an angle Θ2. The selected angles allow water to cool the hot regions of the flame. The first orifice 15 and the second orifice 25 may be configured so that the first spray cone 35 and the second spray cone 45 form concentric patterns that intersect with one another over a predefined angular range. Without limitation, such patterns may comprise solid cones, semi-solid cones, hollow cones, fine spray cones, sheets of air, or individual droplets.

[0027] The angular range of angle θι of the first spray cone 35 is preferably greater than 1 15 degrees. Further, the angular range of angle θι is preferably less than 120 degrees. However, the angular range of angle θι may be between 100 degrees and 125 degrees. For example the angle θι of the first spray cone 35 may be 1 17 degrees. [0028] The angular range of angle Θ2 of the second spray cone 45 is preferably less than 100 degrees. Further, the angular range of angle Θ2 is preferably greater than 80degrees. However, the angular range of angle Θ2 may be between 75 degrees and 105 degrees. For example the angle Θ2 of the second spray cone 45 may be 97 degrees.

[0029] The angle θι of the first spray cone 35 and the angle Θ2 of the second spray cone 45 are able to provide enhanced atomization during an ignition event of the first fluid 20. For example, when the first fluid 20 is oil fuel emitted from the first orifice 15 and the second fluid 24 is air ejected from the second orifice 25, the second spray cone 45 intersects with the first spray cone 35. The interaction of the second spray cone 45 and the first spray cone 35 enhances atomization of the oil fuel and facilitates ignition.

[0030] Furthermore, the angle θι of the first spray cone 35 and the angle Θ2 of the second spray cone 45 are able to provide enhanced NOx reduction capability during operation of the turbine. When the second fluid 24 is water, it is ej ected from the second orifice 25 to form second spray cone 45. The second spray cone 45 intersects with the first spray cone 35 that is formed by the first fluid 20, which is comprised of oil fuel. The interaction of the second spray cone 45 and the first spray cone 35 allows cooling of the hottest region of the flame. This in turn reduces NOx emissions. However, it should be understood that it is also possible to operate the turbine engine without water at all.

[0031] In addition to the respective angles of the first spray cone 35 and the second spray cone 45, the flows of the first fluid 20 and the second fluid 24 also impact the performance of the turbine engine. The flow of the first spray cone 35 may produce an atomized spray with an effective area of between 15 to 20 mm², preferably between 16-19 mm², and most preferably around 18 mm². The flow from the second spray cone 45 may produce an atomized spray with an effective area between 5 and 10 mm², preferably between 6-9 mm², and most preferably around 7-8 mm². These effective areas help achieve the operation of the turbine in those environments where water is a scarce commodity.

[0032] Now turning to Fig. 3, shown is atomizer 11 , which is an alternative embodiment. The atomizer 1 1 in Fig. 4 has an additional channel 31 that is part of the second fluid circuit 16. The channel 31 leads to a third orifice 36. The channel 31 is located radially further away from the longitudinal axis than the second orifice 25. The third orifice 36 can eject the second fluid 24 in a direction that is parallel to the longitudinal axis A. This forms a cylindrical ejection 37 of the second fluid 24.

[0033] The addition of the channel 31 to the second fluid circuit 16 provides improved results when using water to reduce NOx. During operation, when water is used as the second fluid 24, the second fluid 24 is provided through the second fluid circuit 16 and water is emitted from both the second orifice 25 and the third orifice 36. Unlike the hollow first spray cone 35 and second spray cone 45 discussed above the third orifice 36 helps create a cylindrical ejection 37 that further forms into a partially filled spray cone 38 when interacting with the first fluid 20. The partially filled portion of the partially filled spray cone 38 is still hollow in the portion formed by the cylindrical ejection 36.

[0034] The partially filled spray cone 38 may have an angle Θ3. The angular range of angle Θ3 of the partially filled spray cone 38 is preferably less than 100 degrees and is preferably between 60 and 90 degrees and more preferably is between 70 and 80 degrees. For example the angle Θ3 of the partially filled spray cone 38 may be 76 degrees. In part the angle of the partially filled spray cone 38 if formed by the interaction of the angle of the spray cone 35 that would be formed by the oil fuel ejected from the first orifice 15 without the ejection of water from the third orifice 31 with the water ejected from the third orifice 31. This angle is the same as those discussed above in reference to angle θι.

[0035] The filled portion of partially the partially filled spray cone 38 is represented by angle Θ4, which is taken from the perimeter of the cylindrical ejection 36 to the perimeter of the partially filled spray cone 38. The range of angle Θ4 may be between 5 and 45 degrees, more preferably between 10 and 40 degrees and most preferably between 15 and 35 degrees.

[0036] Atomizer 11 is able to provide air as the second fluid 24 during ignition situations and use water as the second fluid 24 during those situations when the turbine engine is going be run with water in order to reduce NOx emissions. The partially filled spray cone 38 formed by atomizer 11 is able to obtain a reduction in NOx emissions that is better than typical atomizers. Furthermore, by using the atomizer 11 the turbine engine is able to run without water.

[0037] While embodiments of the present disclosure have been disclosed in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention and its equivalents, as set forth in the following claims.

Claims

What is claimed is:

1. An atomizer for use in a turbine engine comprises:

a first fluid circuit for transporting oil fuel to a first orifice, wherein the first orifice ejects oil fuel

a second fluid circuit for transporting water or air to a second orifice and a third orifice, wherein the second orifice ejects water or air,

wherein oil fuel and water ejected from the first orifice, the second orifice and the third orifice forms a partially filled spray cone; and

wherein the turbine engine can operate without water.

2. The atomizer of claim 1, wherein water ejected from the third orifice forms a cylindrical ejection located closer to the first orifice than the partially filled spray cone.

3. The atomizer of claim 2, wherein the partially filled spray cone an angle that is less than 100 degrees.

4. The atomizer of claim 3, wherein the partially filled spray cone has an angle that is between 60 and 90 degrees.

5. The atomizer of claim 4 wherein the partially filled spray cone has an angle that is between 70 and 80 degrees.

6. The atomizer of claim 1 , wherein the second orifice ejects air.

7. The atomizer of claim 1 , wherein a filled portion of the partially filled spray cone has an angle that is between 15 and 35 degrees.

8. The atomizer of claim 1 , wherein the first orifice is an only point of fuel inj ection.

9. A turbine engine comprising the atomizer as claimed in claim 1.

10. A turbine engine having a fuel nozzle, comprising:

an annular fuel inj ecting lance comprising a first fluid circuit and a second fluid circuit,

wherein the first fluid circuit is centrally disposed within the lance and extends along a longitudinal axis of the lance to convey an oil fuel to a downstream end of the lance,

wherein the second fluid circuit is annularly disposed about the first fluid circuit to convey water or air to the downstream end of the lance,

an atomizer disposed at the downstream end of the lance, the atomizer having a first orifice responsive to the first fluid circuit to form a first spray cone, wherein the atomizer has a second orifice responsive to the second fluid circuit to form a second spray cone, wherein the first spray cone and the second spray cone are concentric and intersecting,

wherein the first spray cone has a first conical angle greater than 1 15 degrees; wherein the second spray cone has a second conical angle less than 100 degrees; and

wherein the turbine engine can operate without water.

1 1. The turbine engine of claim 10, wherein the first conical angle is less than 120 degrees.

12. The turbine engine of claim 11 , wherein the second conical angle is greater than 90 degrees.

13. The turbine engine of claim 10, wherein the second orifice ejects air.

14. The turbine engine of claim 10, wherein the first orifice is an only point of fuel injection.

15. A method for operating an atomizer in a turbine engine comprising:

transmitting oil fuel through a first fluid circuit centrally disposed within a lance, wherein the first circuit extends along a longitudinal axis of the lance to convey the oil fuel to a downstream end of the lance to a first orifice, transmitting oil or water through a second fluid circuit located about the first fluid circuit to convey water or air to the downstream end of the lance to a second orifice and third orifice;

ejecting oil fuel from the first orifice;

ejecting air or water from the second orifice, wherein the turbine engine can operate without water; and

forming a partially filled spray cone via the ejection of oil fuel and water from the first orifice, the second orifice and the third orifice.

16. The method of claim 15, wherein water ejected from the third orifice forms a cylindrical ejection located closer to the first orifice than the partially filled spray cone.

17. The method of claim 16, wherein the partially filled spray cone an angle that is less than 100 degrees.

18. The method of claim 17, wherein the partially filled spray cone has an angle that is between 60 and 90 degrees.

19. The method of claim 15, wherein the partially filled spray cone has an angle that is between 70 and 80 degrees.

20. The method of claim 15, wherein a filled portion of the partially filled spray cone has an angle that is between 15 and 35 degrees.