A reverse vortex type liquid fuel atomizing injector for a gas turbine

Abstract

The purpose of the present invention is to provide a reverse vortex liquid fuel atomizing injector for a gas turbine, comprising a main fuel air swirler, a nozzle outer shell, a first fuel line nozzle, a second fuel line nozzle, a pressing piece with a shell, and an air swirler, wherein the main fuel air swirler is fixed to the end face of the flame tube head, the nozzle outer shell is installed in the inner cylindrical surface of the main fuel air swirler through a mounting surface, the first fuel line nozzle and the pressing piece with a shell are successively nested and installed in the nozzle outer shell, the first fuel line nozzle and the pressing piece with a shell are axially positioned through the inner truncated cone of the nozzle outer shell, the second fuel line nozzle is inserted into the annular gap between the first fuel line nozzle and the pressing piece with a shell, and the air swirler is inserted into the central circular hole of the first fuel line nozzle. The present invention realizes fuel classification and full atomization injection, improves combustion efficiency, reduces pollutants generated by incomplete combustion, improves fuel atomization quality, and reduces carbon deposition at the injector nozzle.

Description

Technical Field

[0001] The present invention relates to an injector, specifically a fuel injector for a gas turbine. Background Art

[0002] The fuel atomizing injector is a key component for organizing combustion in the combustion chamber of a gas turbine. Good atomization performance of the fuel atomizing injector can directly improve the combustion efficiency, reduce the generation of pollutants such as carbon monoxide and unburned hydrocarbons, reduce the carbon deposition rate of the fuel atomizing injector, and avoid backfire at the injection port, which directly affects the overhaul cycle of the entire combustion chamber.

[0003] Currently, most fuel atomizing injectors are single-fuel-path injectors with concentrated fuel injection positions. When the fuel flow rate is large, excessive rich combustion occurs, and the combustion organization is unfavorable, resulting in a decrease in combustion efficiency. Another part is a dual-fuel-path injector, but the two fuel paths interfere with each other, resulting in poor atomization quality and easy carbon deposition. Summary of the Invention

[0004] The purpose of the present invention is to provide a reverse vortex type liquid fuel atomizing injector for a gas turbine that can atomize fuel well in the combustion chamber under high-power and large-fuel-quantity conditions, avoid backfire and carbon deposition, improve the combustion efficiency, reduce pollutant emissions, and ensure the working performance of the combustion chamber.

[0005] The purpose of the present invention is achieved as follows:

[0006] A reverse vortex type liquid fuel atomizing injector for a gas turbine according to the present invention is characterized in that it includes a main combustion air swirler, a nozzle outer housing, a first fuel path nozzle, a second fuel path nozzle, a pressing member with a housing, and an air swirler. The main combustion air swirler is fixed on the end face of the head of the flame tube. The nozzle outer housing is tightly fitted and installed on the inner cylindrical surface of the main combustion air swirler through the mounting surface. The first fuel path nozzle and the pressing member with a housing are successively inserted and sleeved into the nozzle outer housing. The first fuel path nozzle and the pressing member with a housing are axially positioned by the inner conical surface of the nozzle outer housing. The second fuel path nozzle is inserted into the circular ring gap between the first fuel path nozzle and the pressing member with a housing, and the air swirler is inserted into the central circular hole of the first fuel path nozzle.

[0007] The present invention may further include:

[0008] 1. Four round holes are provided on the outer nozzle housing, and air enters through the four round holes of the outer nozzle housing. A part of the air flows out through the gap between the outer nozzle housing and the pressing member with a housing, and swirls through the blade structure on the pressing member with a housing to form the third air path. Another part of the air flowing into the outer nozzle housing flows through the gap between the pressing member with a housing and the second fuel path nozzle into the gap between the first fuel path nozzle and the second fuel path nozzle. A part of it swirls out through the blades outside the first fuel path nozzle to form the second air path. There is a groove outside the second fuel path nozzle, and the air flow through hole is processed in the groove. The air flowing through the through hole of the pressing member with a housing fills the groove of the second fuel path nozzle, and then enters the air through hole of the second fuel path nozzle. The air entering the gap between the first fuel path nozzle and the second fuel path nozzle, in addition to forming the second air path, part of it flows into the center of the air swirler and swirls out to form the first air path. Another part of the air enters the inside of the combustion chamber through the main combustion air swirler to form a high-speed swirling gas.

[0009] 2. The outer nozzle housing is provided with a first fuel path and a second fuel path. The first fuel flows through the central through hole of the outer nozzle housing, the central hole of the first fuel path nozzle, and the small hole of the air swirler into the gap between the first fuel path nozzle and the air swirler, and is atomized by the first air path and the second air path to form a fuel spray cone in the combustion chamber. The second fuel flows through the side hole of the outer nozzle housing, the outer ring through hole of the first fuel path nozzle, and the outer ring through hole of the second fuel path nozzle into the gap between the second fuel path nozzle and the pressing member with a housing, and is atomized by the second air path and the third air path to form a fuel spray cone in the combustion chamber.

[0010] 3. The first air path and the third air path have the same swirling direction, the second air path and the main combustion air swirler have the same swirling direction, and the adjacent two air paths are in reverse swirl.

[0011] The advantages of the present invention are as follows: Compared with other domestic fuel atomizing injectors, the present invention arranges two fuel paths, three atomizing air paths and one main combustion air path, realizes fuel staging and full atomizing injection in a limited space, improves the combustion efficiency, and reduces the pollutants generated by incomplete combustion. By adjusting the swirling direction and controlling the air volume of the three swirling air paths, the fuel atomization quality is improved, and the carbon deposition at the injector nozzle is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural diagram of the present invention;

[0013] Figure 2 is a view taken along line A-A;

[0014] Figure 3 is a view taken along line B-B;

[0015] Figure 4It is a schematic diagram of the fuel and air paths. Specific embodiments

[0016] The present invention will be described in more detail with reference to the accompanying drawings as follows:

[0017] Combined with Figures 1-4 , a reverse vortex type liquid fuel atomizing injector for a gas turbine of the present invention mainly includes a nozzle outer housing 1, an I fuel path nozzle 2, a pressing member 3 with a housing, an II fuel path nozzle 4, an I air swirler 5, and a main combustion air swirler 6. The flame tube 7 is used in cooperation with the fuel injector, and the type of the flame tube is not unique, and only schematically marked. The atomizing injector includes two fuel paths, three atomizing air paths, and one main combustion air path. The three atomizing air paths and one main combustion air path are all swirling air. The two fuel paths are sandwiched between the three atomizing air paths. The swirling directions of the adjacent two of the three atomizing air paths are opposite, which can increase the relative velocity between the fuel and the atomizing air, improve the fuel atomization quality, and thus improve the combustion efficiency and reduce the pollutants generated by incomplete combustion. The three atomizing air paths can fully wrap the nozzle end of the injector, cool the hot end components, and reduce fuel carbon deposition. The injection angle of the I fuel path near the center of the two fuel paths is large, and the combustion zones of the I fuel path and the II fuel path overlap, ensuring that the flame of the I fuel path can ignite the II fuel path and improving the working stability of the combustion chamber under various conditions.

[0018] The injector has two fuel paths, three atomizing air paths, and one main combustion air path. The three atomizing air paths are all swirling air, and the swirling directions of the adjacent two are opposite; the two fuel paths are independent fuel supply paths; a swirler is provided outside the injector to introduce the main combustion air. The swirling directions of the atomizing air of the two fuel paths of the injector are opposite, increasing the relative velocity between the air and the fuel, and thus improving the air atomization quality. The three atomizing air paths of the injector can fully purge the fuel paths to prevent carbon deposition during the operation of the injector. A main combustion air swirler is provided outside the injector to provide sufficient air for the fuel to burn, and the high-speed swirling air forms a negative pressure zone for stable combustion. The injection angle of the central I fuel path is relatively large, so that there is an overlapping area in the space between the combustion zones of the I fuel path and the II fuel path, and the combustion flame of the I fuel path can ignite the II fuel path.

[0019] The fuel injector is nested and installed with the flame tube 7, and the main combustion air swirler 6 is fixed to the head end face of the flame tube 7 by welding. The nozzle outer housing 1 is tightly fitted and installed in the inner cylindrical surface of the main combustion air swirler 6 through a high-precision mounting surface. The I fuel path nozzle 2 and the pressing member 3 with a housing are successively inserted and installed in the nozzle outer housing 1, and the I fuel path nozzle 2 and the pressing member 3 with a housing are axially positioned by the inner circular table of the nozzle outer housing 1. The II fuel path nozzle 4 is inserted into the circular ring gap between the I fuel path nozzle 2 and the pressing member 3 with a housing. The I air swirler 5 is inserted into the central circular hole of the I fuel path nozzle 2.

[0020] The air path of the fuel injector is shown inFigure 2 , Figure 3 and Figure 4 . Air enters the fuel injector assembly through four round holes in the nozzle outer housing 1. A part of the air flows out of the fuel injector assembly through the gap between the nozzle outer housing 1 and the pressing member 3 with a housing, and swirls through the blade structure on the pressing member 3 with a housing to form the third air path. Another part of the air flowing in through the nozzle outer housing 1 flows through the gap between the pressing member 3 with a housing and the II fuel path nozzle 4 into the gap between the I fuel path nozzle 2 and the II fuel path nozzle 4. A part of it swirls out of the fuel injector through the blades outside the I fuel path nozzle 2 to form the second air path. Among them, considering the processing and installation technology, there are grooves outside the fuel path nozzle 4, and the air circulation through holes are processed in the grooves. The air flowing through the through hole of the pressing member 3 with a housing can fill the grooves of the fuel path nozzle 4, and then enter the air through hole of the fuel path nozzle 4. The air circulation holes of the pressing member 3 with a housing and the fuel path nozzle 4 do not need to be centered, and it can also ensure that the air smoothly enters the gap between the I fuel path nozzle 2 and the II fuel path nozzle 4. Using a similar structure, the air entering the gap between the I fuel path nozzle 2 and the II fuel path nozzle 4, in addition to forming the second air path, part of it flows into the center of the I air swirler 5 and swirls out of the fuel injector to form the first air path. In addition, there is air entering the inside of the combustion chamber 7 through the main combustion air swirler 6 to form a high-speed swirling gas, which is fully mixed and burned with the fuel.

[0021] The fuel path of the fuel injector is shown in Figure 2 , Figure 3 and Figure 4 . Fuel enters the fuel injector through two fuel inlets of the nozzle outer housing 1. The I-path fuel flows through the central through hole of the nozzle outer housing 1 (see Figure 4 ), the central hole of the I fuel path nozzle 2 (see Figure 4 ), and two small holes of the I air swirler 5 (see Figure 3 ) into the gap between the I fuel path nozzle 2 and the I air swirler 5, and is atomized by the first and second air paths to form a fuel spray cone in the combustion chamber 7. The II-path fuel flows through the side hole of the nozzle outer housing 1 (see Figure 4 ), the outer ring through hole of the I fuel path nozzle 2 (see Figure 4 ), and the outer ring through hole of the II fuel path nozzle 4 (see Figure 3 ) into the gap between the II fuel path nozzle 4 and the pressing member 3 with a housing, and is atomized by the second and third air paths to form a fuel spray cone in the combustion chamber 7. The central I-path fuel injection angle is relatively large, which can make the space of the I-path fuel combustion area and the II-path fuel combustion area overlap. The I-path combustion flame can ignite the II-path fuel (see Figure 4 ).

[0022] The swirling directions of the first air path and the third air path are the same, and the swirling directions of the second air path and the main combustion air are the same. The adjacent two air paths have reverse swirls, which can increase the relative velocity between the atomizing air and the fuel oil film, increase the relative momentum, strengthen the rupture of the oil film, and improve the atomization quality.

Claims

1. A reverse vortex type liquid fuel atomizing injector for a gas turbine, characterized in that: it includes a main combustion air swirler, a nozzle outer housing, a first fuel path nozzle, a second fuel path nozzle, a pressing member with a housing, and an air swirler. The main combustion air swirler is fixed on the end face of the head of the combustion chamber liner. The nozzle outer housing is tightly and fittingly installed on the inner cylindrical surface of the main combustion air swirler through a mounting surface. The first fuel path nozzle and the pressing member with a housing are successively inserted and sleeved into the nozzle outer housing. The first fuel path nozzle and the pressing member with a housing are axially positioned by the inner conical surface of the nozzle outer housing. The second fuel path nozzle is inserted into the circular ring gap between the first fuel path nozzle and the pressing member with a housing. The air swirler is inserted into the central circular hole of the first fuel path nozzle; 4 circular holes are provided on the nozzle outer housing. Air enters through the 4 circular holes of the nozzle outer housing. A part of the air flows out through the gap between the nozzle outer housing and the pressing member with a housing and is swirled by the blade structure on the pressing member with a housing to form the third air path; Another part of the air flowing in through the nozzle outer housing flows into the gap between the first fuel path nozzle and the second fuel path nozzle through the pressing member with a housing and the second fuel path nozzle. A part of it swirls and flows out through the blades on the outside of the first fuel path nozzle to form the second air path. There are grooves on the outside of the second fuel path nozzle. Air circulation through holes are processed in the grooves. The air flowing through the through holes of the pressing member with a housing fills the grooves of the second fuel path nozzle and then enters the air through holes of the second fuel path nozzle. The air entering the gap between the first fuel path nozzle and the second fuel path nozzle, in addition to forming the second air path, partially flows into the center of the air swirler and swirls out to form the first air path. Another part of the air enters the inside of the combustion chamber liner through the main combustion air swirler to form a high-speed swirling gas.

2. The reverse vortex type liquid fuel atomizing injector for a gas turbine according to claim 1, characterized in that: the nozzle outer housing is provided with a first fuel path and a second fuel path. The first fuel flows through the central through hole of the nozzle outer housing, the central hole of the first fuel path nozzle, and the small holes of the air swirler into the gap between the first fuel path nozzle and the air swirler, and is atomized by the first air path and the second air path to form a fuel spray cone in the combustion chamber liner; the second fuel flows through the side hole of the nozzle outer housing, the outer ring through hole of the first fuel path nozzle, and the outer ring through hole of the second fuel path nozzle into the gap between the second fuel path nozzle and the pressing member with a housing, and is atomized by the second air path and the third air path to form a fuel spray cone in the combustion chamber liner.

3. The reverse vortex type liquid fuel atomizing injector for a gas turbine according to claim 1, characterized in that: the first air path and the third air path have the same swirling direction, the second air path and the main combustion air swirler have the same swirling direction, and adjacent two air paths are in reverse swirl.

Images