Patent Description:
In recent years, starting with a report of UNFCCC that is an international organism for preventing global warming and Paris Agreement, discussions on carbon-neutrality for reducing the amount of carbon dioxide (CO<NUM>) have been made all over the world. In particular, because power sector occupies about <NUM>% of a total amount of discharged carbon dioxide and the power generation systems are generally driven for a long time of unit of several months, a measure for carbon-neutrality is strongly required.

Accordingly, the gas turbine manufacturers have determined hydrogen (H<NUM>) that does not include carbon and thus does not generate carbon dioxide during combustion as a new measure, and thus have developed technologies using hydrogen from the early <NUM>-th.

However, hydrogen shows a high reactive property, and shows a flame propagation speed of about <NUM> times as high as those of existing fuels, such as methane, propane (C<NUM>H<NUM>) and ethylene (C<NUM>H<NUM>). Accordingly, hydrogen may have a wide operation range without a swirl generator but may tend to cause flashbacks as well.

The flashback means that a propagation speed of flames becomes higher than the flow velocity of supplied reactant mixture due to a high reactive property or strong combustion oscillations of hydrogen flame and thus the flames flow back. Because the flames that flowed back to an upstream side are attached to a site, at which a design for cooling is vulnerable and fuse a system, it is impossible to stably drive a hydrogen gas turbine in an existing burner nozzle structure that has utilized natural gas as a main fuel.

The industrial fields have sought to solve instability of flames of hydrogen by completely changing the shape of the injector. Because hydrogen flames easily incur flashbacks due to a large diameter of nozzles in a multinozzle injector including a swirl generator, most gas turbine manufacturers have employed a multi-tube or micro-mixer type nozzle having a diameter of unit of several millimeters to optimize the shape of the injector. <FIG> is a view conceptually illustrating a cross-section of a conventional multi-tube injector.

However, in a fuel of a high hydrogen fraction, it is still difficult to control flashbacks of flames even though a multi-tube design is utilized. That is, a new shape of an injector that may alleviate flashbacks of hydrogen flames has been required.

Injectors according to the prior art are known from <CIT> and <CIT>.

An aspect of the present disclosure provides an injector that may alleviate flashbacks of hydrogen flames, a burner including the same, and a gas turbine including the same.

Another aspect of the present disclosure provides an injector that may alleviate combustion oscillations, a burner including the same, and a gas turbine including the same.

An injector according to the invention is defined in claim <NUM> and includes an injector body, and a slit formed to pass the injector body along a reference direction, and the slit may include a first slit portion having a shape that extends along a circumferential direction of an imaginary reference circle, a center of which is an imaginary reference axis that extends along the reference direction, and a second slit portion having a shape that extends along a radial direction of the reference circle.

The first slit portion includes a (<NUM>-<NUM>)-th slit having a shape that extends along an imaginary first reference circle, a center of which is the reference axis, and a (<NUM>-<NUM>)-th slit having a shape that extends along a circumferential direction of an imaginary second reference circle, a center of which is the reference axis and a diameter of which is larger than that of the first reference circle.

When it is assumed that an area between the first reference circle and the second reference circle is a first area, the second slit portion includes a (<NUM>-<NUM>)-th slit disposed in the first area and extending in a radial direction of the first reference circle.

When viewed along the reference direction, the (<NUM>-<NUM>)-th slit and the (<NUM>-<NUM>)-th slit may be spaced apart from each other along the radial direction of the first reference circle.

In another example, a plurality of (<NUM>-<NUM>)-th slits may be formed, and wherein the plurality of (<NUM>-<NUM>)-th slits may be spaced apart from each other along a circumferential direction of the first reference circle, and a portion of the first reference circle may have a shape of a first reference arc.

In another example, a plurality of (<NUM>-<NUM>)-th slits may be formed, the plurality of (<NUM>-<NUM>)-th slits may be spaced apart from each other along a circumferential direction of the second reference circle, and a portion of the second reference circle may have a shape of a second reference arc, and a size of a central angle of a first fan shape that defines the first reference arc may be larger than a size of a second fan shape that defines the second reference arc.

In another example, a plurality of (<NUM>-<NUM>)-th slits may be formed, and the plurality of (<NUM>-<NUM>)-th slits may be spaced apart from each other along the circumferential direction of the first reference circle.

In another example, a plurality of (<NUM>-<NUM>)-th slits may be formed, the plurality of (<NUM>-<NUM>)-th slits may be spaced apart from each other along the circumferential direction of the first reference circle, and when it is assumed that a space between a pair of (<NUM>-<NUM>)-th slits that are adjacent to each other is a (<NUM>-<NUM>)-th spacing space, the (<NUM>-<NUM>)-th slit may include a spacing space overlapping slit that overlaps the (<NUM>-<NUM>)-th spacing space when viewed along the radial direction.

In another example, a plurality of (<NUM>-<NUM>)-th slits and a plurality of (<NUM>-<NUM>)-th slots may be formed, and the number of the (<NUM>-<NUM>)-th slits may be smaller than the number of the (<NUM>-<NUM>)-th slits.

In another example, the first slit portion may further include a (<NUM>-<NUM>)-th slit having a shape that extends along a circumferential direction of an imaginary third reference circle, a center of which is the reference axis and a diameter of which is larger than that of the second reference circle, and when it is assumed that an area between the second reference circle and the third reference circle is a second area, the second slit portion may further include a (<NUM>-<NUM>)-th slit disposed in the second area and extending in a radial direction of the second reference circle.

In another example, a plurality of (<NUM>-<NUM>)-th slits and a plurality of (<NUM>-<NUM>)-th slots may be formed, and the (<NUM>-<NUM>)-th slit may include an overlapping slit that overlaps any one of the (<NUM>-<NUM>)-th slits when viewed along the radial direction.

In another example, a plurality of (<NUM>-<NUM>)-th slits and a plurality of (<NUM>-<NUM>)-th slots may be formed, and when it is assumed that one direction that is perpendicular to the reference direction is a first direction and one direction that is perpendicular to the reference direction and the first direction is a second direction, the number of the (<NUM>-<NUM>)-th slits located in a first reference area defined by a first line extending from the reference axis along the first direction and a second line extending from the reference axis along the second direction, when viewed along the reference direction, may be the same as the number of the (<NUM>-<NUM>)-th slits located in the first reference area and the number of the (<NUM>-<NUM>)-th slits located in a second reference area defined by the first line and a third line extending from the reference axis along an opposite direction to the second direction may be smaller than the number of the (<NUM>-<NUM>)-th slits located in the second reference area.

In another example, the numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in the first reference area may be the same as the numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in a third reference area defined by a fourth line extending from the reference axis along an opposite direction to the first direction and the third line, and the numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in the second reference area may be the same as the numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in a fourth reference area defined by the second line and the fourth line, respectively.

In another example, the plurality of second slit portions may be provided, and the numbers of the second slit portions disposed on opposite sides of a reference plane that is an imaginary plane including the reference axis when the injector body is divided by the reference plane may be different.

A burner according to an aspect of the present disclosure may include a supply pipe that supplies a fuel and air, an injector coupled to the supply pipe and that injects the fuel and the air, which are introduced thereinto, and a combustion chamber configured such that the fuel and the air injected by the injector are introduced thereinto, the injector may include a slit extending along a reference direction, and the slit may include a first slit portion having a shape that extends along a circumference direction of an imaginary reference circle, and a second slit portion having a shape that extends along a radial direction of the reference circle.

A gas turbine according to an aspect of the present disclosure may include a compressor that compresses and discharge air, a burner that mixes a fuel and the air compressed and discharged by the compressor, and then generate a combustion gas by burning a mixture of the fuel and the air, and turbine blades that is rotated by the combustion gas delivered from the burner, the burner may include an injector that injects the fuel and the air compressed and discharged by the compressor, which are mixed, and the injector may include a slit including a first slit portion having a shape that extends along a circumferential direction of the imaginary reference circle and a second slit portion having a shape that extends along a radial direction of the reference circle.

According to the present disclosure, because slits having smaller widths than those of an existing multi-tube injector are included, a flashback phenomenon may be alleviated.

Furthermore, according to the present disclosure, because the slits having widths that are similar to the thicknesses of the flames are included as compared with the conventional multi-tube circular injector to restrain a change of the surfaces of the flames, the instability of combustion may be alleviated and combustion oscillations may be alleviated.

This application claims the benefit of priority to Korean <CIT>, Korean <CIT>, and Korean <CIT>.

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the exemplary drawings. In providing reference numerals to the constituent elements of the drawings, the same elements may have the same reference numerals even if they are displayed on different drawings. Further, in the following description of the present disclosure, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear.

An injector according to the present disclosure may be an injector that is applied to a burner of a gas turbine. <FIG> is a cutaway perspective view conceptually illustrating a gas turbine, to which an injector according to the present disclosure may be applied. <FIG> is a view conceptually illustrating a cross-section of a burner, to which an injector according to the present disclosure may be applied. <FIG> may be understood as a conceptual illustration of area "B" of <FIG>.

Hereinafter, embodiments of injectors will be described in detail.

<FIG> is a view conceptually illustrating an appearance of an injector according to a first embodiment of the present disclosure, when viewed from a reference direction. <FIG> is a view conceptually illustrating the injector according to a first embodiment of the present disclosure. <FIG> is a view conceptually illustrating a cross-section of any one of slits of the injector according to a first embodiment of the present disclosure.

The injector may include an injector body <NUM> and slits <NUM>. The slits <NUM> may be formed to pass through the injector body <NUM> along a reference direction "D". The injector body <NUM> may be formed of a metallic material. The injector body <NUM> may extend along the reference direction "D".

The slits <NUM> may include first slit portions <NUM> and second slit portions <NUM>. The first slit portions <NUM> may have shapes that extend along a circumferential direction of an imaginary reference circle. The reference circle may be a circle, a center of which is an imaginary reference axis that extends along the reference direction "D".

A first width of the first slit portions <NUM> may be <NUM> to <NUM>. Preferably, the first width may be <NUM>. The first width may be a length of the first slit portions <NUM> along a direction that is perpendicular to an extension direction of the first slit portions <NUM>. The first width may be similar to a thickness which hydrogen frames may theoretically have.

The second slit portions <NUM> may have shapes that extend along a radial direction of the reference circle. A second width of the second slit portions <NUM> may be <NUM> to <NUM>. Preferably, the second width may be <NUM>. The second width may be a length of the second slit portions <NUM> along a direction that is perpendicular to an extension direction of the second slit portions <NUM>. The second width may be similar to a thickness which hydrogen frames may theoretically have.

The first slit portions <NUM> may include a (<NUM>-<NUM>)-th slit 21a and a (<NUM>-<NUM>)-th slit 21b. The (<NUM>-<NUM>)-th slit 21a may have a shape that extends along an imaginary first reference circle, a center of which is the reference axis. Furthermore, the (<NUM>-<NUM>)-th slit 21b may have a shape that extends along an imaginary second reference circle, a center of which is the reference axis. A diameter of the second reference circle may be larger than that of the first reference circle.

A plurality of slits 21a may be formed. The plurality of (<NUM>-<NUM>)-th slits 21a may be spaced apart from each other along a circumferential direction of the first reference circle, and may have shapes of a first reference arc that is a portion of the first reference circle. A (<NUM>-<NUM>)-th spacing space S1 may be formed between a pair of (<NUM>-<NUM>)-th slits 21a that are adjacent to each other.

A plurality of slits 21b may be formed. The plurality of (<NUM>-<NUM>)-th slits 21b may be spaced apart from each other along a circumferential direction of the second reference circle, and may have shapes of a second reference arc that is a portion of the second reference circle.

A size of a central angle of a first fan shape that defines the first reference arc may be larger than a size of a central angle of a second fan shape that defines the second reference arc. This mean that the number of the (<NUM>-<NUM>)-th slits 21a is smaller than the number of the (<NUM>-<NUM>)-th slits 21b.

The slit portions <NUM> may include (<NUM>-<NUM>)-th slits 22a. The (<NUM>-<NUM>)-th slits 22a may be disposed in a first area AR1, and may extend in a radial direction of the first reference circle. The first area AR1 may mean an area between the first reference circle and the second reference circle.

A plurality of slits 22a may be formed. The plurality of (<NUM>-<NUM>)-th slits 22a may be spaced apart from each other along a circumferential direction of the first reference circle.

The (<NUM>-<NUM>)-th slits 22a may include spacing space overlapping slits 22a'. The spacing space overlapping slits 22a' may mean the (<NUM>-<NUM>)-th slits that overlap the (<NUM>-<NUM>)-th spacing space S1 when viewed along radial directions of the plurality of (<NUM>-<NUM>)-th slits 22a. This may mean that the plurality of (<NUM>-<NUM>)-th slits 22a may include (<NUM>-<NUM>)-th slits that overlap the (<NUM>-<NUM>)-th spacing space S1 and (<NUM>-<NUM>)-th slits that do not overlap it, when viewed along the radial directions.

The first slit portions <NUM> may further include (<NUM>-<NUM>)-th slits 21c. The (<NUM>-<NUM>)-th slit 21c may have shapes that extend along a circumferential direction of a third reference circle. The third reference circle may be an imaginary circle, a center of which is the reference axis and a diameter of which is larger than that of the second reference circle.

A plurality of (<NUM>-<NUM>)-th slits 21c may be formed. The plurality of (<NUM>-<NUM>)-th slits 21c may be spaced apart from each other along the circumferential direction of the third reference circle, and may have shapes of a third reference arc that is a portion of the third reference circle.

The slit portions <NUM> may further include the (<NUM>-<NUM>)-th slits 22b. The (<NUM>-<NUM>)-th slits 22b may be disposed in a second area AR2, and may extend in a radial direction of the second reference circle. The second area AR2 may mean an area between the second reference circle and the third reference circle.

A plurality of (<NUM>-<NUM>)-th slits 22b may be formed. The plurality of (<NUM>-<NUM>)-th slits 22b may be spaced apart from each other along a circumferential direction of the second reference circle.

The (<NUM>-<NUM>)-th slits 22b may include overlapping slits 22b'. The overlapping slits 22b' may mean the (<NUM>-<NUM>)-th slits that overlap any one of the (<NUM>-<NUM>)-th slits 22a' when viewed along radial directions of the (<NUM>-<NUM>)-th slits 22b.

This may mean that the plurality of (<NUM>-<NUM>)-th slits 22b may include (<NUM>-<NUM>)-th slits that overlap any one of the (<NUM>-<NUM>)-th slits 22a, and (<NUM>-<NUM>)-th slits that do not overlap it.

The injector according to the first embodiment of the present disclosure may be an injector, in which a flashback phenomenon may be alleviated. <FIG> is a view conceptually illustrating a cross-section of any one of slits of the injector according to a first embodiment of the present disclosure. A premixed fuel/air mixture may be supplied to the slits <NUM> along the reference direction "D".

<FIG> is a view conceptually illustrating a flashback phenomenon. As illustrated in <FIG>, flames <NUM> that undergo flashback may flow in an opposite direction D' to the reference direction "D". The injector according to the first embodiment of the present disclosure includes the slits <NUM>, cross-sectional areas of which are larger than those of a conventional multi-tube nozzle with reference to volumes thereof. The slits <NUM> having the larger cross-sectional area with reference to volumes may decrease a flashback phenomenon as compared with the conventional multi-tube nozzle due to two following reasons.

First, the flames that undergo flashback may induce heat loss through the metallic injector body <NUM> while they pass through the slits <NUM>. When the heat loss becomes higher than the heat generated by the combustion reaction, the combustion reaction may be suppressed. Because the present disclosure includes the slits <NUM> having the larger cross-sectional area than that of the multi-tube nozzle with reference to volumes, an area, in which the flames that flow back may contact an inner surface of the injector body <NUM>, may be increased. Accordingly, heat loss may be increased as compared with the conventional multi-tube nozzle, which may decrease the flashback phenomenon.

Second, in the combustion process, radical ions are repeatedly generated and re-bonded. In the injector according to the first embodiment of the present disclosure, hydrogen radicals are diffused via a wall surface of the metallic injector body <NUM>, and the diffusion of the hydrogen radicals on the wall surface may suppress the combustion reaction. The hydrogen radicals are intermediate products that are necessary for a combustion reaction mechanism, and the combustion reaction may be halted when the hydrogen radicals disappear due to the diffusion on the wall surface. Because the present disclosure includes the slits <NUM> having a larger cross-sectional area than that of the conventional multi-tube nozzle with reference to volumes, an area, in which the hydrogen radicals may disappear due to the diffusion on the wall surface, may be provided, and thus the flashback phenomenon may be alleviated.

Furthermore, the injector according to the first embodiment of the present disclosure may be an injector, in which combustion oscillations may be alleviated. The combustion oscillations are related to combustion instability. Because the combustion instability is dominantly influenced by a change in the shape of the flames, the change in the shape of the flames has to be minimized for the control. To minimize the change in the shape of the flames, the shape of the flames has to have a shape having a relatively large surface area.

In the conventional multi-tube nozzle, because the shape of the flames may be viewed conically due to the tubular shape, the conical flames may be contracted and expanded due to external perturbations. Accordingly, a possibility of, the shapes of the flames, being changed may be high.

The injector according to the first embodiment of the present disclosure includes the slits having a larger cross-sectional area with reference to volumes, a possibility of the change in the thin flame surface is relatively low, and thus, a heat release rate of the flames may become lower and an instability of combustion may be decreased, whereby combustion vibrations may be restrained.

<FIG> is a view conceptually illustrating equipment for a hydrogen combustion test. <FIG> is a view illustrating a comparison result of hydrogen combustion tests of the multi-tube injector of <FIG> and the injector of <FIG>.

The equipment for a hydrogen combustion test may include a fuel/air mixing part <NUM>, a quartz tube <NUM>, a metal tube <NUM>, and a dynamic pressure sensor <NUM>. The metal tube <NUM> may include a cooling air introducing pipe <NUM> and a piston <NUM>. The injector body <NUM> may be disposed between the fuel/air mixing part <NUM> and the quartz tube <NUM>. The dynamic pressure sensor <NUM> may be configured to measure a magnitude of acoustic vibrations due to the combustion vibrations.

For the hydrogen combustion test, the hydrogen/air mixture that passed through the fuel/air mixing part <NUM> was ignited in the injector body <NUM>, and the magnitude of the acoustic vibrations due to the combustion vibrations was measured by the dynamic pressure sensor <NUM> after the planned flow velocity and equivalence ratio condition is reached.

In <FIG>, results of hydrogen combustion tests of the multi-tube injector and the injector according to the first embodiment of the present disclosure in a condition, in which the flow velocity of the fuel/air mixture that passed through the slits <NUM> was <NUM>/s and equivalence ratios (φ) were <NUM>, <NUM>, and <NUM>, respectively, are compared. Then, the equivalence ratio condition of the experiment corresponds to a level that is similar to or higher than a temperature utilized in management of an actual turbine in a condition, in which adiabatic flame temperatures were <NUM>, <NUM>, and <NUM>.

The X axis may mean frequencies. The PSD of the Y axis is a power spectral density, and is a value that shows the magnitude of acoustic vibrations due to the combustion vibrations. As illustrated in <FIG>, it may be identified that the acoustic vibrations of the injector (a dotted line) according to the embodiment of the present disclosure were alleviated as compared with the conventional multi-tube injector (a solid line) in all equivalence ratio conditions.

<FIG> is a view illustrating a result of a hydrogen combustion test when a flow velocity of a mixture of a fuel and air, which passes through a slit, is <NUM>/s. In more detail, in <FIG>, a result of a hydrogen combustion test of the injector according to the first embodiment of the present disclosure in a condition, in which the flow velocity of the fuel/air mixture that passed through the slits <NUM> was <NUM>/s and equivalence ratios (φ) were <NUM>, <NUM>, and <NUM>, respectively, was measured. It may be seen in <FIG> that an experimental result was secured in a situation that is similar to a management condition of an actual gas turbine. Referring to <FIG>, it may be identified that the acoustic vibrations show an aspect that is stabilized as a whole similarly to the experimental result of <FIG>.

Hereinafter, a burner including the injector according to the first embodiment of the present disclosure will be described in detail with reference to the above-described contents. The contents on the injector have been described above, and a detailed description thereof will be omitted. <FIG> may be referenced for understanding.

As illustrated in <FIG>, a burner "B" may include a supply pipe <NUM>, the injector, and a combustion chamber <NUM>. The supply pipe <NUM> may be configured to supply a fuel and air. The injector may be coupled to the supply pipe <NUM> and may be configured to inject the fuel and the air, which are introduced. The combustion chamber <NUM> may be configured such that the fuel and the air, which are injected, may be introduced thereinto. Furthermore, in the combustion chamber <NUM>, the fuel and the air, which are injected, may be mixed. A combustion reaction may occur in the combustion chamber <NUM>.

Hereinafter, a gas turbine including the injector according to the first embodiment of the present disclosure will be described in detail with reference to the above-described contents. The contents on the injector have been described above, and a detailed description thereof will be omitted.

The gas turbine may include the burner "B" and turbine blades. The compressor may be configured to compress and discharge the air. The burner "B" may be configured to mix the fuel and the air compressed and discharged by the compressor, and then to generate a combustion gas by burning a mixture of the fuel and the air. The turbine blades may be configured to be rotated by the combustion gas delivered from the burner "B".

The burner "B" may include the injector that injects the fuel and the air compressed and discharged by the compressor, which are mixed.

<FIG> is a view conceptually illustrating an appearance of an injector according to a second embodiment of the present disclosure, when viewed from a reference direction. Hereinafter, referring to <FIG>, the injector according to the second embodiment of the present disclosure will be described. The injector according to the second embodiment is different from the injector according to the first embodiment in disposition of the second slit portions. The same or corresponding reference numerals are given to configurations that are the same as or correspond to those of the injector according to the first embodiment, and a detailed description thereof will be omitted.

Hereinafter, one direction that is perpendicular to the reference direction "D" will be referred to a first direction D1, and one direction that is perpendicular to the reference direction "D" and the first direction D1 will be referred to as a second direction D2.

Furthermore, first to fourth lines L1, L2, L3, and L4 and first to fourth reference areas RA1, RA2, RA3, and RA4 will be defined for convenience of description. The first line L1 may mean a line that extends from the reference axis "A" along the first direction D1. The second line L2 may mean a line that extends from the reference axis "A" along the second direction D2. The third line L3 may mean a line that extends from the reference axis "A" along an opposite direction to the second direction D2. The fourth line L4 may mean a line that extends from the reference axis "A" along an opposite direction to the first direction D1.

The first reference area RA1 may mean an area that is defined by the first line L1 and the second line L2 when viewed along the reference direction "D". The second reference area RA2 may mean an area that is defined by the first line L1 and the third line L3. The third reference area RA3 may mean an area that is defined by the third line L3 and the fourth line L4. The fourth reference area RA4 may mean an area that is defined by the second line L2 and the fourth line L4. The first to fourth reference areas RA1, RA2, RA3, and RA4 may be disposed in a sequence thereof along a counterclockwise direction.

The number of the (<NUM>-<NUM>)-th slits located in the first reference area RA1 may be the same as the number of the (<NUM>-<NUM>)-th slits located in the first reference area RA1. Similarly, the number of the (<NUM>-<NUM>)-th slits located in the first reference area RA1 may be the same as the number of the (<NUM>-<NUM>)-th slits located in the first reference area RA1. As an example, each of the numbers of the (<NUM>-<NUM>)-th slits, the (<NUM>-<NUM>)-th slits, and the (<NUM>-<NUM>)-th slits located in the first reference area RA1 may be two.

The number of the (<NUM>-<NUM>)-th slits located in the second reference area RA2 may be smaller than the number of the (<NUM>-<NUM>)-th slits located in the second reference area RA2. Similarly, the number of the (<NUM>-<NUM>)-th slits located in the second reference area RA2 may be smaller than the number of the (<NUM>-<NUM>)-th slits located in the second reference area RA2. As an example, the number of the (<NUM>-<NUM>)-th slits located in the second reference area RA2 may be one, the number of the (<NUM>-<NUM>)-th slits may be three, and the number of the (<NUM>-<NUM>)-th slits may be five.

Meanwhile, the numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in the first reference area RA1 and the numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in the third reference area RA3 may be the same, respectively. Similarly, the number of the (<NUM>-<NUM>)-th slits located in the first reference area RA1 may be the same as the number of the (<NUM>-<NUM>)-th slits located in the third reference area RA3. That is, the first reference area RA1 and the third reference area RA3 may be formed to be symmetrical to each other.

The numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in the second reference area RA2 and the numbers of the (<NUM>-<NUM>)-th slits and the (<NUM>-<NUM>)-th slits located in the fourth reference area RA4 may be the same, respectively. Similarly, the number of the (<NUM>-<NUM>)-th slits located in the second reference area RA2 may be the same as the number of the (<NUM>-<NUM>)-th slits located in the fourth reference area RA4. That is, the second reference area RA2 and the fourth reference area RA4 may be formed to be symmetrical to each other.

The first slit portions <NUM> may be a configuration for dispersing distribution of frames in the radial direction and expanding an area of a nozzle. The second slit portions <NUM> may be a configuration for collapsing symmetry of distribution of flames in the circumferential direction through disposition or arrangement thereof. In more detail, when the disposition of the second slit portions <NUM> is changed to asymmetric disposition, the symmetry of the distribution of the flames may be collapsed. Because the high symmetry of the distribution of the flames may mean that big constructive interferences may occur, it may be regarded as high combustion instability.

That is, as described above, because the combustion instability is dominantly influenced by the change in the shape of the flames, the instability of combustion may become higher as the disposition of the second slit portions <NUM> becomes more symmetrical. This may mean that the instability of combustion may be alleviated as the disposition of the second slit portions <NUM> becomes more asymmetrical.

Because the asymmetry of the second slit portions <NUM> is higher than that of the injector according to the first embodiment in the case of the injector according to the second embodiment, the instability of combustion may be alleviated as compared with the injector according to the first embodiment.

<FIG> is a view conceptually illustrating an appearance of an injector according to a third embodiment of the present disclosure, when viewed from a reference direction. Hereinafter, referring to <FIG>, the injector according to the third embodiment of the present disclosure will be described. The injector according to the third embodiment is different from the injector according to the first embodiment in disposition of the second slit portions. The same or corresponding reference numerals are given to configurations that are the same as or correspond to those of the injector according to the first embodiment, and a detailed description thereof will be omitted.

In the injector according to the third embodiment, the numbers of the second slit portions <NUM> disposed on opposite sides of a reference plane RS that is an imaginary plane including the reference axis "A" when the injector body <NUM> is divided by the reference plane RS. That is, the injector according to the third embodiment may be understood as being a form, in which the symmetry of the disposition of the second slit portions <NUM> is collapsed.

Claim 1:
An injector for a combustor of a gas turbine, the injector comprising:
an injector body (<NUM>); and
a slit (<NUM>) formed to pass the injector body (<NUM>) along a reference direction,
wherein the slit (<NUM>) includes:
a first slit portion (<NUM>) having a shape that extends along a circumferential direction of an imaginary reference circle, a center of which is an imaginary reference axis that extends along the reference direction; and
a second slit portion (<NUM>) having a shape that extends along a radial direction of the reference circle,
wherein the first slit portion (<NUM>) includes:
a (<NUM>-<NUM>)-th slit (21a) having a shape that extends along an imaginary first reference circle, a center of which is the reference axis; and
a (<NUM>-<NUM>)-th slit (21b) having a shape that extends along a circumferential direction of an imaginary second reference circle, a center of which is the reference axis and a diameter of which is larger than that of the first reference circle
characterized in that
when it is assumed that an area between the first reference circle and the second reference circle is a first area,
the second slit portion (<NUM>) includes:
a (<NUM>-<NUM>)-th slit (22a) disposed in the first area and extending
in a radial direction of the first reference circle.