Combustion burner for gas turbine

{Technical Field}

0001The present invention relates to gas turbine combustion burners having swirling vanes (swirler vanes) for ejecting fuel from fuel ejection holes into air or a mixture of air and fuel flowing from the upstream side while applying a swirling force to form a swirling mixed airflow.

{Background Art}

0002A known example of this type of gas turbine combustion burner is disclosed in PTL 1.

{Citation List}

{Patent Literature}

0003<ul id="ul0001" list-style="none" compact="compact"><li>{PTL 1} Japanese Unexamined Patent Application, Publication No. <patcit id="pcit0001" dnum="JP2003074855A"><text>2003-74855</text></patcit></li></ul>

{Summary of Invention}

{Technical Problem}

0004However, the combustion burner disclosed in PTL 1 above has a problem in that fuel flowing through gas fuel passages (fuel passages) 8 into gas fuel passage portions (cavities) 16 provided inside swirlers (swirling vanes) 14 forms vortices in the gas fuel passage portions 16, and the vortices create a pressure gradient in the gas fuel passage portions 16, thus leading to varying amounts of fuel ejected from small holes (ejection holes) 15.

0005An object of the present invention, which has been made in light of the above circumstances, is to provide a gas turbine combustion burner capable of uniformly ejecting fuel from ejection holes for reduced NO_x emissions of gas turbine combustors.

{Solution to Problem}

0006To solve the above problem, the present invention employs the following solutions. A gas turbine combustion burner according to a first aspect of the present invention is a gas turbine combustion burner that includes a plurality of swirling vanes for ejecting fuel from fuel ejection holes into air or a mixture of air and fuel flowing from an upstream side while applying a swirling force to form a swirling mixed airflow and a nozzle having the swirling vanes arranged radially on an outer circumferential surface thereof and having a first fuel passage, through which the fuel is guided to the fuel ejection holes, provided therein, a cavity communicating with the fuel ejection holes is provided in each swirling vane, and at least two second fuel passages are provided between the cavity and the first fuel passage along an axial direction.

0007In the gas turbine combustion burner according to the first aspect of the present invention, the fuel guided (supplied) through the first fuel passage toward the swirling vanes is guided through at least two (the plurality of) second fuel passages to the cavities and is ejected (jetted) from the fuel ejection holes. As the fuel passes through the second fuel passages, dynamic pressure generated in the first fuel passage is dispersed so that the fuel flows (is supplied) evenly (uniformly) from the individual second fuel passages into the cavities, thus preventing the formation of vortices in the cavities. This allows uniform ejection of the fuel from the fuel ejection holes, thus contributing to reduced NO_x emissions of gas turbine combustors.

0008A gas turbine combustion burner according to a second aspect of the present invention is a gas turbine combustion burner that includes a plurality of swirling vanes for ejecting fuel from fuel ejection holes into air or a mixture of air and fuel flowing from an upstream side while applying a swirling force to form a swirling mixed airflow and a nozzle having the swirling vanes arranged radially on an outer circumferential surface thereof and having a first fuel passage, through which the fuel is guided to the fuel ejection holes, provided therein, a cavity communicating with the fuel ejection holes is provided in each swirling vane, a slit-like second fuel passage is provided between the cavity and the first fuel passage along an axial direction, and a rectifier grid is disposed at an exit or entrance end of the second fuel passage.

0009In the gas turbine combustion burner according to the second aspect of the present invention, the fuel guided (supplied) through the first fuel passage toward the swirling vanes is guided through the slit-like second fuel passages and the rectifier grids to the cavities and is ejected (jetted) from the fuel ejection holes. As the fuel passes through the second fuel passages and the rectifier grids, dynamic pressure generated in the first fuel passage is dispersed so that the fuel flows (is supplied) evenly (uniformly) from the second fuel passages into the cavities, thus preventing the formation of vortices in the cavities. This allows uniform ejection of the fuel from the fuel ejection holes, thus contributing to reduced NO_x emissions of gas turbine combustors.

0010A gas turbine combustion burner according to a third aspect of the present invention is a gas turbine combustion burner that includes a plurality of swirling vanes for ejecting fuel from fuel ejection holes into air or a mixture of air and fuel flowing from an upstream side while applying a swirling force to form a swirling mixed airflow and a nozzle having the swirling vanes arranged radially on an outer circumferential surface thereof and having a first fuel passage, through which the fuel is guided to the fuel ejection holes, provided therein, a cavity communicating with the fuel ejection holes is provided in each swirling vane, a slit-like second fuel passage is provided between the cavity and the first fuel passage along an axial direction, and a pressure loss member is disposed in the first fuel passage near the upstream side of the second fuel passage.

0011In the gas turbine combustion burner according to the third aspect of the present invention, the fuel guided (supplied) through the first fuel passage toward the swirling vanes is guided through the slit-like second fuel passages and the pressure loss member to the cavities and is ejected (jetted) from the fuel ejection holes. As the fuel passes through the second fuel passages and the pressure loss member, dynamic pressure generated in the first fuel passage is dispersed so that the fuel flows (is supplied) evenly (uniformly) from the second fuel passages into the cavities, thus preventing the formation of vortices in the cavities. This allows uniform ejection of the fuel from the fuel ejection holes, thus contributing to reduced NO_x emissions of gas turbine combustors.

0012A gas turbine combustor according to a fourth aspect of the present invention includes any one of the above gas turbine combustion burners.

0013The gas turbine combustor according to the fourth aspect of the present invention includes a gas turbine combustion burner capable of uniformly ejecting fuel from ejection holes, thus contributing to reduced NO_x emissions of the gas turbine combustor.

{Advantageous Effects of Invention}

0014The gas turbine combustion burners according to the present invention provide the advantage of uniformly ejecting fuel from the ejection holes, thus contributing to reduced NO_x emissions of gas turbine combustors.

{Brief Description of Drawings}

0015<ul id="ul0002" list-style="none" compact="compact"><li>{<figref idref="f0001">Fig. 1</figref>} <figref idref="f0001">Fig. 1</figref> is a schematic structural diagram showing a gas turbine combustor including gas turbine combustion burners according to the present invention.</li><li>{<figref idref="f0002">Fig. 2</figref>} <figref idref="f0002">Fig. 2</figref> is a perspective view showing the gas turbine combustor shown in <figref idref="f0001">Fig. 1</figref>, showing fuel nozzles, an inner cylinder, and a tailpipe in an exploded view.</li><li>{<figref idref="f0003">Fig. 3</figref>} <figref idref="f0003">Fig. 3</figref> is a sectional view showing, in magnified view, a relevant part of a gas turbine combustion burner according to a first embodiment of the present invention.</li><li>{<figref idref="f0003">Fig. 4</figref>} <figref idref="f0003">Fig. 4</figref> is a sectional view as viewed along arrow IV-IV in <figref idref="f0003">Fig. 3</figref>.</li><li>{<figref idref="f0004">Fig. 5</figref>} <figref idref="f0004">Fig. 5</figref> is a sectional view as viewed along arrow V-V in <figref idref="f0003">Fig. 3</figref>.</li><li>{<figref idref="f0004">Fig. 6</figref>} <figref idref="f0004">Fig. 6</figref> is a sectional view showing, in magnified view, a relevant part of a gas turbine combustion burner according to a second embodiment of the present invention.</li><li>{<figref idref="f0005">Fig. 7</figref>} <figref idref="f0005">Fig. 7</figref> is a sectional view as viewed along arrow VII-VII in <figref idref="f0004">Fig. 6</figref>.</li><li>{<figref idref="f0005">Fig. 8</figref>} <figref idref="f0005">Fig. 8</figref> is a sectional view showing, in magnified view, a relevant part of a gas turbine combustion burner according to a third embodiment of the present invention.</li><li>{<figref idref="f0006">Fig. 9</figref>} <figref idref="f0006">Fig. 9</figref> is a sectional view showing, in magnified view, a relevant part of a gas turbine combustion burner according to another embodiment of the present invention.</li><li>{<figref idref="f0007">Fig. 10</figref>} <figref idref="f0007">Fig. 10</figref> is a sectional view as viewed along arrow X-X in <figref idref="f0006">Fig. 9</figref>.</li><li>{<figref idref="f0007">Fig. 11A</figref>} <figref idref="f0007">Fig. 11A</figref> is a sectional view as viewed along arrow XI-XI in <figref idref="f0006">Fig. 9</figref>.</li><li>{<figref idref="f0007">Fig. 11B</figref>} <figref idref="f0007">Fig. 11B</figref> is a sectional view as viewed along arrow XI-XI in <figref idref="f0006">Fig. 9</figref>.</li></ul>

{Description of Embodiments}

0016A gas turbine combustion burner according to a first embodiment of the present invention will be described below with reference to <figref idref="f0001 f0002 f0003 f0004">Figs. 1 to 5</figref>. <figref idref="f0001">Fig. 1</figref> is a schematic structural diagram showing a gas turbine combustor including gas turbine combustion burners according to the present invention; <figref idref="f0002">Fig. 2</figref> is a perspective view showing the gas turbine combustor shown in <figref idref="f0001">Fig. 1</figref>, showing fuel nozzles, an inner cylinder, and a tailpipe in an exploded view; <figref idref="f0003">Fig. 3</figref> is a sectional view showing, in magnified view, a relevant part of a gas turbine combustion burner according to this embodiment; <figref idref="f0003">Fig. 4</figref> is a sectional view as viewed along arrow IV-IV in <figref idref="f0003">Fig. 3</figref>; and <figref idref="f0004">Fig. 5</figref> is a sectional view as viewed along arrow V-V in <figref idref="f0003">Fig. 3</figref>.

0017A gas turbine 1 (see <figref idref="f0001">Fig. 1</figref>) including gas turbine combustors (hereinafter referred to as "combustors") 10 shown in <figref idref="f0001">Figs. 1</figref> and <figref idref="f0002">2</figref> includes a compressor (not shown) and a turbine (not shown) in addition to the combustors 10. Most gas turbines include a plurality of combustors 10; they mix air compressed by the compressor (compressed air) with fuel supplied to the combustors 10 and combust it in the individual combustors 10, thereby producing high-temperature combustion gas. This high-temperature combustion gas is supplied to the turbine to rotate and drive the turbine.

0018As shown in <figref idref="f0001">Fig. 1</figref>, the plurality of combustors 10 are arranged in a circle in a combustor casing 11 (only one of them is shown in <figref idref="f0001">Fig. 1</figref>). The combustor casing 11 and a gas turbine casing 12 are filled with compressed air, forming a chamber 13. The air compressed by the compressor is introduced into the chamber 13. The introduced compressed air enters the combustor 10 through an air inlet 14 provided in an upstream portion of the combustor 10. In an inner cylinder 15 of the combustor 10, fuel supplied from a combustion burner 16 is mixed with the compressed air and is combusted. Combustion gas produced by combustion is supplied through a tailpipe 17 to a turbine chamber to rotate a turbine rotor (not shown).

0019<figref idref="f0002">Fig. 2</figref> is a perspective view showing the combustion burner 16, the inner cylinder 15, and the tailpipe 17 in an exploded view. As shown in <figref idref="f0002">Fig. 2</figref>, the combustion burner 16 includes a plurality of main combustion burners (gas turbine combustion burners) 18 and a single pilot combustion burner (gas turbine combustion burner) 19. As shown in <figref idref="f0002">Fig. 2</figref>, the plurality of main combustion burners 18 are disposed in the inner cylinder 15 so as to surround the pilot combustion burner 19. Fuel ejected from the main combustion burners 18 is premixed with a swirling flow of air through swirling vanes (swirler vanes) 20 of the main combustion burners 18 and is combusted in the inner cylinder 15.

0020The main combustion burners 18 are each composed mainly of a main fuel nozzle (hereinafter referred to as "main nozzle") 21, a main burner cylinder 22, and swirling vanes 20. The main burner cylinder 22 is disposed concentrically with the main nozzle 21 so as to surround the main nozzle 21. Thus, the outer circumferential surface of the main nozzle 21 and the inner circumferential surface of the main burner cylinder 22 form an annular air passage (not shown) through which the compressed air (not shown) flows from the upstream side to the downstream side.

0021A plurality of (in this embodiment, six) swirling vanes 20 are arranged radially from the outer circumferential surface of the main nozzle 21 along the axial direction of the main nozzle 21. As shown in <figref idref="f0003">Figs. 4</figref> and <figref idref="f0004">5</figref>, the swirling vanes 20 are streamlined members having a wing shape in plan view; they apply a swirling force to the compressed air flowing through the air passage formed between the outer circumferential surface of the main nozzle 21 and the inner circumferential surface of the main burner cylinder 22, thereby changing the compressed air to a swirling airflow.

0022As shown in <figref idref="f0003">Fig. 4</figref>, a plurality of (in this embodiment, two) (fuel) ejection holes 23 are formed through a dorsal surface 20a of each swirling vane 20 in the thickness direction, and a plurality of (in this embodiment, two) (fuel) ejection holes 24 are formed through a ventral surface 20b of each swirling vane 20 in the thickness direction. A cavity 25 communicating with the ejection holes 23 and 24 is provided in each swirling vane 20, and a (first) fuel passage 26 (see <figref idref="f0003">Fig. 3</figref>) is provided in the main nozzle 21. The cavity 25 communicates with the fuel passage 26 through a plurality of (in this embodiment, three) (second) fuel passages 27 (see <figref idref="f0003">Figs. 3</figref> and <figref idref="f0004">5</figref>) such that fuel is supplied through the fuel passages 26 and 27 and the cavities 25 to the ejection holes 23 and 24. The fuel ejected from the ejection holes 23 and 24 is mixed with the compressed air, and the fuel gas is supplied to the inner space of the inner cylinder 15 and is combusted.

0023In the main combustion burner 18 according to this embodiment, the fuel guided (supplied) through the fuel passage 26 toward the swirling vanes 20 is guided through the plurality of fuel passages 27 to the cavities 25 and is ejected (jetted) from the ejection holes 23 and 24. As the fuel passes through the fuel passages 27, dynamic pressure generated in the fuel passage 26 is dispersed so that the fuel flows (is supplied) evenly (uniformly) from the individual fuel passages 27 into the cavities 25, thus preventing the formation of vortices in the cavities 25. This allows uniform ejection of the fuel from the ejection holes 23 and 24, thus contributing to reduced NO_x emissions of the combustor 10.

0024A second embodiment of a gas turbine combustion burner according to the present invention will now be described with reference to <figref idref="f0004">Figs. 6</figref> and <figref idref="f0005">7</figref>. <figref idref="f0004">Fig. 6</figref> is a sectional view showing, in magnified view, a relevant part of the gas turbine combustion burner according to this embodiment, and <figref idref="f0005">Fig. 7</figref> is a sectional view as viewed along arrow VII-VII in <figref idref="f0004">Fig. 6</figref>. The main combustion burner 18 (gas turbine combustion burner) according to this embodiment differs from that of the first embodiment described above in that it includes a main nozzle 31 having a single (second) fuel passage 30 instead of the plurality of fuel passages 27 shown in <figref idref="f0003">Figs. 3</figref> and <figref idref="f0004">5</figref>. The other elements are the same as those of the first embodiment described above; a description of these elements will be omitted here. The same members as those of the first embodiment described above are designated by the same reference signs.

0025As shown in <figref idref="f0004">Figs. 6</figref> and <figref idref="f0005">7</figref>, each cavity 25 communicates with the fuel passage 26 through, for example, a slit-like fuel passage 30 having the same passage cross-section as the cavity 25, and a rectifier grid 32 is disposed at an exit end (or entrance end) of the fuel passage 30.

0026In the main combustion burner 18 according to this embodiment, the fuel guided (supplied) through the fuel passage 26 toward the swirling vanes 20 is guided through the fuel passages 30 and the rectifier grids 32 to the cavities 25 and is ejected (jetted) from the ejection holes 23 and 24. As the fuel passes through the fuel passages 30 and the rectifier grids 32, dynamic pressure generated in the fuel passage 26 is dispersed so that the fuel flows (is supplied) evenly (uniformly) from the fuel passages 30 into the cavities 25, thus preventing the formation of vortices in the cavities 25. This allows uniform ejection of the fuel from the ejection holes 23 and 24, thus contributing to reduced NO_x emissions of the combustor 10.

0027A third embodiment of a gas turbine combustion burner according to the present invention will now be described with reference to <figref idref="f0005">Fig. 8. Fig. 8</figref> is a sectional view showing, in magnified view, a relevant part of the gas turbine combustion burner according to this embodiment. The main combustion burner (gas turbine combustion burner) 18 according to this embodiment differs from that of the second embodiment described above in that it includes a main nozzle 41 having a pressure loss member 40 instead of the rectifier grids 32 shown in <figref idref="f0004">Fig. 6</figref>. The other elements are the same as those of the second embodiment described above; a description of these elements will be omitted here. The same members as those of the second embodiment described above are designated by the same reference signs.

0028As shown in <figref idref="f0005">Fig. 8</figref>, for example, a pressure loss member 40 formed of a porous material is disposed at the end (downstream end) of the fuel passage 26 such that the fuel flowing from the upstream side of the fuel passage 26 is supplied through the pressure loss member 40 and the fuel passages 30 to the cavities 25.

0029In the main combustion burner 18 according to this embodiment, the fuel guided (supplied) through the fuel passage 26 toward the swirling vanes 20 is guided through the fuel passages 30 and the pressure loss member 40 to the cavities 25 and is ejected (jetted) from the ejection holes 23 and 24. As the fuel passes through the fuel passages 30 and the pressure loss member 40, dynamic pressure generated in the fuel passage 26 is dispersed so that the fuel flows (is supplied) evenly (uniformly) from the fuel passages 30 into the cavities 25, thus preventing the formation of vortices in the cavities 25. This allows uniform ejection of the fuel from the ejection holes 23 and 24, thus contributing to reduced NO_x emissions of the combustor 10.

0030The present invention is not limited to the above embodiments and can also be applied to the pilot combustion burner 19. As shown in <figref idref="f0002">Fig. 2</figref> or <figref idref="f0006">9</figref>, the pilot combustion burner 19 is composed mainly of a pilot combustion nozzle (hereinafter referred to as "pilot nozzle") 51, a pilot burner cylinder 52, and swirling vanes (swirler vanes) 53. The pilot burner cylinder 52 is disposed concentrically with the pilot nozzle 51 such that its base end (left end in <figref idref="f0006">Fig. 9</figref>) surrounds the leading end (right end in <figref idref="f0006">Fig. 9</figref>) of the pilot nozzle 51. Thus, the outer circumferential surface 51a of the leading end of the pilot nozzle 51 and the inner circumferential surface 52a of the base end of the pilot burner cylinder 52 form an annular air passage 54 through which the compressed air (not shown) flows from upstream (to the left in <figref idref="f0006">Fig. 9</figref>) to downstream (to the right in <figref idref="f0006">Fig. 9</figref>). Here, for simplicity of illustration, the swirling vanes 53 are not shown in <figref idref="f0002">Fig. 2</figref>.

0031A plurality of (in this embodiment, eight) swirling vanes 53 are arranged radially from the outer circumferential surface 51a of the leading end of the pilot nozzle 51 along the axial direction of the pilot nozzle 51. As shown in <figref idref="f0007">Fig. 10</figref>, the swirling vanes 53 are streamlined members having a wing shape in plan view; they apply a swirling force to the compressed air flowing through the air passage 54 formed between the outer circumferential surface 51a of the leading end of the pilot nozzle 51 and the inner circumferential surface 52a of the base end of the pilot burner cylinder 52, thereby changing the compressed air to a swirling airflow.

0032As shown in <figref idref="f0006">Fig. 9</figref> or <figref idref="f0007">10</figref>, a plurality of (for example, two) (fuel) ejection holes 55 are formed through a dorsal surface 53a of each swirling vane 53 in the thickness direction, and a plurality of (for example, two) (fuel) ejection holes 56 are formed through a ventral surface 53b of each swirling vane 53 in the thickness direction. A cavity 25 communicating with the ejection holes 55 and 56 is provided in each swirling vane 53, and a single fuel passage 57 (for premixed combustion) having an annular shape in sectional view, as shown in <figref idref="f0007">Fig. 11A</figref>, or a plurality of (in this embodiment, eight) fuel passages 57 (for premixed combustion) having a circular shape in sectional view, as shown in <figref idref="f0007">Fig. 11B</figref>, are provided in the pilot nozzle 51. The cavity 25 communicates with the (first) fuel passage 57 through the fuel passages 27, described in the first embodiment, such that fuel is supplied through the fuel passages 57 and 27 and the cavities 25 to the ejection holes 55 and 56. The fuel ejected from the ejection holes 55 and 56 is mixed with the compressed air, and the fuel gas is supplied to the inner space of the inner cylinder 15 and is combusted.

0033A fuel passage 58 (for premixed combustion) separate from the fuel passage 57 is provided in the center of the pilot nozzle 51 located radially inside the fuel passage 57 such that the fuel supplied through the (third) fuel passage 58 is ejected from a plurality of (fuel) ejection holes 59 provided at the end of the pilot nozzle 51, is supplied to the inner space of the inner cylinder 15, and is combusted.

{Reference Signs List}

0034<dl id="dl0001" compact="compact"><dt>10</dt><dd>combustor (gas turbine combustor)</dd><dt>18</dt><dd>main combustion burner (gas turbine combustion burner)</dd><dt>19</dt><dd>pilot combustion burner (gas turbine combustion burner)</dd><dt>20</dt><dd>swirling vane</dd><dt>21</dt><dd>main nozzle (nozzle)</dd><dt>23</dt><dd>ejection hole (fuel ejection hole)</dd><dt>24</dt><dd>ejection hole (fuel ejection hole)</dd><dt>25</dt><dd>cavity</dd><dt>26</dt><dd>fuel passage (first fuel passage)</dd><dt>27</dt><dd>fuel passage (second fuel passage)</dd><dt>30</dt><dd>fuel passage (third fuel passage)</dd><dt>31</dt><dd>main nozzle (nozzle)</dd><dt>32</dt><dd>rectifier grid</dd><dt>40</dt><dd>pressure loss member</dd><dt>41</dt><dd>main nozzle (nozzle)</dd><dt>51</dt><dd>pilot nozzle (nozzle)</dd><dt>53</dt><dd>swirling vane</dd><dt>55</dt><dd>ejection hole (fuel ejection hole)</dd><dt>56</dt><dd>ejection hole (fuel ejection hole)</dd><dt>57</dt><dd>fuel passage (first fuel passage)</dd></dl>