KR102503518B1 - Micromixer and combustor having the same - Google Patents

Abstract

The present invention relates to a micro mixer capable of preventing a flash-back phenomenon occurring inside the micro mixer and a combustor including the same.
In the micro mixer according to an embodiment of the present invention, an inlet through which a first fluid flows is formed at one end and a supply port through which a second fluid is supplied is formed on an inner wall thereof, and the first fluid introduced through the inlet and the supply port are formed. The mixed fluid formed by mixing the second fluid supplied through the fluid flows, and includes a convergence section formed on the inlet side and a divergence section formed on the opposite side based on any one boundary line of the inner wall.

Description

Micromixer and combustor including the same {MICROMIXER AND COMBUSTOR HAVING THE SAME}

The present invention relates to a micro mixer and a combustor including the same. The present invention relates to a gas turbine comprising a combustor. The fuel used in the combustor may include at least one of hydrogen and natural gas.

A gas turbine is a power engine that mixes and burns compressed air compressed by a compressor with fuel, and rotates the turbine with high-temperature gas generated by combustion. Gas turbines are used to drive generators, aircraft, ships and trains.

Gas turbines generally include a compressor, a combustor and a turbine. The compressor draws in outside air, compresses it, and delivers it to the combustor. The air compressed in the compressor becomes a high-pressure and high-temperature state. The combustor mixes the compressed air introduced from the compressor with the fuel and combusts it. Combustion gases generated by combustion are discharged to the turbine. Turbine blades inside the turbine are rotated by the combustion gas, and power is generated through this. The generated power is used in various fields such as power generation and driving of mechanical devices.

US Patent Publication No. 2013-0269351 (Name: Micromixer assembly of a turbine system and method of assembly)

One aspect of the present invention is to provide a micromixer capable of preventing a flash-back phenomenon occurring inside the micromixer and a combustor including the same.

In the micro mixer according to an embodiment of the present invention, an inlet through which a first fluid flows is formed at one end and a supply port through which a second fluid is supplied is formed on an inner wall thereof, and the first fluid introduced through the inlet and the supply port are formed. The mixed fluid formed by mixing the second fluid supplied through the fluid flows, and includes a convergence section formed on the inlet side and a divergence section formed on the opposite side based on any one boundary line of the inner wall.

In the micromixer according to an embodiment of the present invention, the boundary line may be formed in a section where an equivalence ratio, which is a relative ratio between the first fluid and the second fluid for combustion reaction to occur, is 1.3 to 0.7.

In the micromixer according to an embodiment of the present invention, the first fluid may be hydrogen-containing fuel and the second fluid may be air, or the first fluid may be air and the second fluid may be hydrogen-containing fuel.

In the micromixer according to an embodiment of the present invention, an inlet through which a first fluid flows is formed at one end and a supply port through which a second fluid is supplied is formed on an inner wall, and the first fluid introduced through the inlet and the supply port are formed. an inlet flow passage in which the mixed fluid formed by mixing the supplied second fluid flows and includes a convergence section formed on the inlet side and a divergence section formed on the opposite side with respect to any one boundary line of the inner wall; an outlet passage formed at a position spaced apart from a virtual extension of the inlet passage and injecting the mixed fluid into the combustion chamber; and an inclined passage that connects the inlet passage and the outlet passage and is inclined at a predetermined angle to reduce the transfer of radiant heat from the flame generated in the combustion chamber to the inlet passage.

In the micromixer according to an embodiment of the present invention, the boundary line may be formed in a section where an equivalence ratio, which is a relative ratio between the first fluid and the second fluid for combustion reaction to occur, is 1.3 to 0.7.

In the micromixer according to an embodiment of the present invention, the end of the inlet passage has a first cross-sectional area, the outlet passage has a second cross-sectional area larger than the first cross-sectional area, and the inclined passage extends from the end of the inlet passage to the outlet passage. It may have a variable cross-sectional area that gradually increases as time goes on.

In the micromixer according to an embodiment of the present invention, the inclined passage includes a first line forming a first angle with the virtual extension line of the outlet passage, and a second line forming a second angle with the virtual extension line of the outlet passage, The first angle and the second angle may be different from each other.

In the micromixer according to an embodiment of the present invention, the first fluid may be hydrogen-containing fuel and the second fluid may be air, or the first fluid may be air and the second fluid.

A combustor according to an embodiment of the present invention includes a combustion chamber assembly including a combustion chamber in which fuel fluid is combusted; and a micro mixer assembly including a plurality of micro mixers for injecting fuel fluid into the combustion chamber. The micromixer has an inlet through which a first fluid flows into one end and a supply port into which a second fluid is supplied is formed on an inner wall thereof, and the first fluid introduced through the inlet and the second fluid supplied through the supply hole are formed. The mixed fluid formed by mixing flows, and includes a convergence section formed on the inlet side and a divergence section formed on the opposite side based on any one boundary line of the inner wall.

In the combustor according to an embodiment of the present invention, the boundary line may be formed in a section where an equivalence ratio, which is a relative ratio between the first fluid and the second fluid for combustion reaction to occur, is 1.3 to 0.7.

In the combustor according to an embodiment of the present invention, the first fluid may be fuel containing hydrogen and the second fluid may be air, or the first fluid may be air and the second fluid may be fuel containing hydrogen.

A combustor according to an embodiment of the present invention includes a combustion chamber assembly including a combustion chamber in which fuel fluid is combusted; and a micro mixer assembly including a plurality of micro mixers for injecting fuel fluid into the combustion chamber. The micro mixer has an inlet through which the first fluid flows in and a supply port through which the second fluid is supplied is formed on an inner wall, and the first fluid introduced through the inlet and the second fluid supplied through the supply are mixed. an inlet passage through which the formed mixed fluid flows and includes a convergence section formed on the inlet side and a divergence section formed on the opposite side with respect to any boundary line of the inner wall; an outlet passage formed at a position spaced apart from a virtual extension of the inlet passage and injecting the mixed fluid into the combustion chamber; and an inclined passage that connects the inlet passage and the outlet passage and is inclined at a predetermined angle to reduce the transfer of radiant heat from the flame generated in the combustion chamber to the inlet passage.

In the combustor according to an embodiment of the present invention, the boundary line may be formed in a section where an equivalence ratio, which is a relative ratio between the first fluid and the second fluid for combustion reaction to occur, is 1.3 to 0.7.

In the combustor according to an embodiment of the present invention, the end of the inlet passage has a first cross-sectional area, the outlet passage has a second cross-sectional area larger than the first cross-sectional area, and the inclined passage is gradually moving from the end of the inlet passage toward the outlet passage. It may have a variable cross-sectional area that gradually increases.

In the combustor according to an embodiment of the present invention, the inclined passage includes a first line forming a first angle with a virtual extension line of the outlet passage and a second line forming a second angle with a virtual extension line of the outlet passage, The first angle and the second angle may be different from each other.

In the combustor according to an embodiment of the present invention, the first fluid may be fuel including hydrogen and the second fluid may be air, or the first fluid may be air and the second fluid.

Other specific details of implementations according to various aspects of the present invention are included in the detailed description below.

According to an embodiment of the present invention, a flashback phenomenon occurring inside a micromixer can be prevented.

1 is a view showing the inside of a gas turbine according to an embodiment of the present invention.
2 is a diagram illustrating one burner module constituting a combustor according to an embodiment of the present invention.
3 is a side cross-sectional view of a micromixer bundle according to a first embodiment of the present invention.
4 is a side cross-sectional view of a micro mixer according to a first embodiment of the present invention.
5 is a diagram for explaining a phenomenon in which flashback is prevented in the micromixer according to the first embodiment of the present invention.
6 is a side cross-sectional view showing a micro mixer bundle according to a second embodiment of the present invention.
7 and 8 are side cross-sectional views of a micro mixer according to a second embodiment of the present invention.
9 is a view showing one burner module constituting a combustor according to another embodiment of the present invention.
10 is a side cross-sectional view of a micromixer bundle according to a third embodiment of the present invention.
11 is a side cross-sectional view of a micro mixer according to a third embodiment of the present invention.
12 is a diagram for explaining a phenomenon in which flashback is prevented in the micromixer according to the third embodiment of the present invention.
13 is a side cross-sectional view of a micromixer bundle according to a fourth embodiment of the present invention.
14 and 15 are side cross-sectional views of a micromixer according to a fourth embodiment of the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be exemplified and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as 'include' or 'having' are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded. Hereinafter, a micromixer and a combustor including the same according to an embodiment of the present invention will be described with reference to the drawings.

1 is a view showing the inside of a gas turbine according to an embodiment of the present invention, and FIG. 2 is a view showing any one burner module constituting a combustor according to an embodiment of the present invention.

Referring to FIGS. 1 and 2, a gas turbine 1000 according to an embodiment of the present invention includes a compressor 1100 that compresses incoming air at a high pressure, and a combustor that mixes compressed air compressed from the compressor with fuel and combusts ( 1200) and a turbine 1300 generating rotational force with combustion gas generated from the combustor. In this specification, upstream and downstream are defined based on the order of fuel or air flow.

The thermodynamic cycle of a gas turbine ideally follows a Brayton cycle. The Brayton cycle consists of four processes: isentropic compression (adiabatic compression), constant pressure rapid heating, isentropic expansion (adiabatic expansion), and constant pressure dissipation. That is, after atmospheric air is sucked in and compressed to high pressure, the fuel is burned in a constant pressure environment to release thermal energy, and the high-temperature combustion gas is expanded to convert it into kinetic energy, and then the exhaust gas containing the remaining energy is released into the atmosphere. . In other words, the cycle consists of four processes: compression, heating, expansion, and heat dissipation. The description of the present invention can also be widely applied to a turbine engine having an equivalent configuration to the gas turbine 1000 exemplarily shown in FIG. 1 .

The compressor 1100 of the gas turbine is a part that serves to inhale and compress air, and serves to supply air for combustion to the combustor 1200 while supplying air for cooling to a high-temperature region requiring cooling in the gas turbine. . Since the intake air undergoes an adiabatic compression process in the compressor 1100, the pressure and temperature of the air passing through the compressor 1100 increase.

The compressor 1100 constituting the gas turbine can usually be designed as centrifugal compressors or axial compressors. In small gas turbines, centrifugal compressors are applied, whereas in large gas turbines, a large amount of air is compressed. As shown in FIG. 1, it is common to apply a multi-stage axial compressor.

The compressor 1100 is driven using some of the power output from the turbine 1300. To this end, as shown in FIG. 1 , the rotation axis of the compressor 1100 and the rotation axis of the turbine 1300 are directly connected.

The combustor 1200 mixes the compressed air supplied from the outlet of the compressor 1100 with fuel and performs constant pressure combustion to produce high-energy combustion gas. The combustor 1200 is disposed downstream of the compressor 1100 and includes a plurality of burner modules 1210 arranged in an annular shape around a rotation axis.

As shown in FIG. 2, the burner module 1210 includes a combustion chamber assembly 1220 including a combustion chamber 1240 in which fuel fluid is combusted, and a plurality of micro mixers 100 for injecting fuel fluid into the combustion chamber 1240. It may include a micro mixer assembly 1230 including a. The fuel fluid may be supplied from a fuel tank in which fuel (eg, hydrogen) is stored.

The gas turbine may use gas fuel and liquid fuel including hydrogen and natural gas, or a combination fuel in which they are combined, and the fuel fluid in the present invention means these. It is important to create a combustion environment to reduce the amount of exhaust gases such as carbon monoxide and nitrogen oxides, which are subject to legal regulation. Although combustion control is relatively difficult, it has the advantage of reducing exhaust gases by lowering the combustion temperature and creating uniform combustion. Premixed combustion is widely applied.

In the case of pre-mixed combustion, in the micro mixer assembly 1230, compressed air introduced from the compressor 1100 is mixed with fuel and then enters the combustion chamber 1240. Initial ignition of the premixed gas is performed using an igniter, and then, when combustion is stable, combustion is maintained by supplying fuel and air.

The micro mixer assembly 1230 includes a plurality of micro mixer bundles (MB) in which a plurality of micro mixers for injecting mixed fuel fluid are disposed. The micromixer mixes the fuel with air in the proper proportions to make it suitable for combustion. In the plurality of micro mixer bundles MB, a plurality of external micro mixer bundles may be radially arranged around one internal micro mixer bundle. A detailed description of the micromixer will be described later.

The combustion chamber assembly 1220 includes a combustion chamber 1240, which is a space in which combustion takes place, and includes a liner 1250 and a transition piece 1260.

The liner 1250 is disposed downstream of the micro mixer assembly 1230 and may have a dual structure of an inner liner 1251 and an outer liner 1252 . That is, it may have a double structure in which the inner liner 1251 is surrounded by the outer liner 1252 . At this time, the inner liner 1251 is a hollow tubular member, and the inside of the inner liner 1251 forms the combustion chamber 1240 . The compressed air may cool the inner liner 1251 by penetrating into the annular space inside the outer liner 1252 through the compressed air introduction hole H.

Meanwhile, a transition piece 1260 is positioned downstream of the liner 1250, and the transition piece 1260 can send combustion gas generated in the combustion chamber 1240 to the turbine 1300 at high speed. The transition piece 1260 may have a dual structure of an inner transition piece 1261 and an outer transition piece 1262 . That is, it may have a double structure in which the outer transition piece 1262 surrounds the inner transition piece 1261 . Like the inner liner 1251, the inner transition piece 1261 is also formed as a hollow tubular member, and may have a shape in which the diameter gradually decreases from the liner 1250 toward the turbine 1300. In this case, the inner liner 1251 and the inner transition piece 1261 may be coupled to each other by a plate spring seal (not shown). Since each end of the inner liner 1251 and the inner transition piece 1261 is fixed to the side of the combustor 1200 and the turbine 1300, respectively, the plate spring seal has a structure capable of accommodating the extension of the length and diameter due to thermal expansion As a result, the inner liner 1251 and the inner transition piece 1261 may be supported.

The outer liner 1252 and the outer transition piece 1262 surround the inner liner 1251 and the inner transition piece 1261, and the inner liner 1251 and the outer liner ( 1252) and into the annular space between the inner transition piece 1261 and the outer transition piece 1262, compressed air may penetrate. Compressed air penetrating the annular space may cool the inner liner 1251 and the inner transition piece 1261 .

Meanwhile, the high-temperature, high-pressure combustion gas produced in the combustor 1200 is supplied to the turbine 1300 through the liner 1250 and the transition piece 1260 . In the turbine 1300, while the combustion gas expands adiabatically, it collides with a plurality of blades arranged radially on the rotation shaft of the turbine 1300 to give a reaction force, so that the thermal energy of the combustion gas is converted into mechanical energy for rotating the rotation shaft. A portion of the mechanical energy obtained from the turbine 1300 is supplied as energy required to compress air in the compressor, and the remainder is used as effective energy such as generating power by driving a generator.

Referring back to FIG. 2 , the casing 1270 and the end cover 1231 are coupled to receive the compressed air A flowing into the burner module 1210 . The compressed air (A) is introduced into the annular space inside the liner 1250 or the transition piece 1260 through the compressed air inlet hole (H) and flows, and then the flow direction is changed by the end cover 1231 to form a micro mixer ( 100, 200, see FIGS. 3 and 6). The fuel F is introduced into the fuel plenum 1234 through the fuel passage 1232 and the plenum inlet 1234a (see FIG. 3), and then enters the micro mixer 100 through the supply port 112 (see FIG. 4). and can be mixed with compressed air. The micro mixer bundle (MB) includes a plurality of micro mixers (100, 200).

Next, the micro mixer 100 according to the first embodiment of the present invention will be described with reference to FIGS. 3 and 4 . 3 is a side cross-sectional view of a micromixer bundle according to the first embodiment of the present invention, and FIG. 4 is a side cross-sectional view of the micromixer according to the first embodiment of the present invention.

Referring to FIGS. 3 and 4 , the micro mixer bundle MB includes a plurality of micro mixers 100 and extends radially around the fuel passage 1232 . The micro mixer 100 extends in the flow direction of fluid (fuel or air).

The micro mixer 100 has an inlet 111 through which air A is introduced at one end, and a supply port 112 through which fuel F is supplied is formed on an inner wall thereof. The air (A) introduced through the inlet 111 and the fuel (F) supplied through the supply port 112 are mixed inside the micro mixer 100 to form a mixed fluid (FA) and injected into the combustion chamber 1240. do.

On the other hand, when the fuel F includes hydrogen, since hydrogen is a fuel with a high combustion rate, there is a high risk of flashback phenomenon as the flame generated in the combustion chamber 1240 flows backward into the micromixer. To prevent this, the flow rate of the fuel must be increased. Flashback can be prevented if the flow rate of the fuel is greater than the combustion rate. However, in order to increase the flow rate of the fuel, the cross-sectional area of the passage through which the fuel flows is reduced, which inevitably causes a large pressure loss. Therefore, there is a need for a flow path structure capable of reducing pressure loss while increasing the flow rate.

Accordingly, in the first embodiment of the present invention, the micro mixer 100 may include a convergence section 101 and a divergence section 102. A plurality of supply ports 112 may be formed in the convergence section 101 and the divergence section 102 . The convergence section 101 is formed on the side of the inlet 111 based on the boundary line T between the convergence section 101 and the divergence section 102, and the divergence section 102 is formed on the opposite side. The boundary line T may be a closed curve formed along the cross-sectional shape of the micro mixer 100 .

The equivalence ratio means the relative ratio of air (A) and fuel (F) for the combustion reaction to occur, and can also be expressed as an air-fuel ratio (air-fuel ratio) and an air-fuel ratio (fuel-air ratio). The air-fuel ratio indicates the relative amount of air to the mass of fuel, and the air-fuel ratio means the reciprocal. The equivalence ratio (Φ) is the same as theory and practice, that is, the closer to Φ = 1, the better. In particular, in the condition of Φ > 1 (rich fuel, lack of air, rich-burn), incomplete combustion of fuel occurs, so the higher the equivalence ratio, the better the combustion. Efficiency decreases.

In the section where the equivalence ratio is 1.3 to 0.7, the combustion efficiency is high and the combustion speed is greater than the flow speed of the fluid, so flashback is likely to occur in the section. In particular, the point where the equivalence ratio is 1 has the highest combustion efficiency, so the flashback is most likely to occur at that point.

Therefore, in the first embodiment of the present invention, the boundary line T dividing the convergence section 101 and the divergence section 102 is preferably formed at any one point among the sections having an equivalence ratio of 1.3 to 0.7. In particular, it is most preferable that the boundary line T is formed at a point where the equivalence ratio becomes 1. When the equivalence ratio is out of the range of 1.3 to 0.7, the combustion efficiency is relatively low, so the fuel flow rate is faster than the combustion rate, so there is little concern about flashback.

The range in which the equivalence ratio is 1.3 to 0.7 sets the power range (high power or low power) of the turbine in which flashback can occur during design, and can be set through repeated experiments or simulations.

5 is a diagram for explaining a phenomenon in which flashback is prevented in the micromixer according to the first embodiment of the present invention.

In FIG. 5, (a) is a case of a conventional micro mixer, and (b) is a case of a micro mixer according to the first embodiment of the present invention. In (a) and (b) of FIG. 5, the horizontal axis X is the position in the longitudinal direction inside the micromixer, Y1 is the equivalent ratio, and Y2 is the speed. V1 is the flow velocity of the fluid, and V2 is the combustion velocity of the fluid. The flow rate of the fluid may be determined by several factors, but one factor may be determined by the internal structure of the micromixer.

Referring to (a) of FIG. 5, since a conventional micromixer is formed in the form of a straight tube, the flow rate (V1) of the mixed fluid (FA) of fuel (F) and air (A) is linear. It can be seen that increases with Meanwhile, the combustion rate V2 of the mixed fluid FA may be determined by an equivalence ratio. The burning rate (V2) is formed in the form of a curve where the point where the equivalence ratio is 1 becomes the maximum.

In (a), it can be confirmed that the combustion speed V2 is greater than the flow speed V1 in the left and right predetermined regions (region B) based on the point where the equivalence ratio is 1. Therefore, it can be seen that there is a high possibility of flashback occurring in this area B.

Referring to (b) of FIG. 5, since the micromixer 100 according to the first embodiment of the present invention includes a convergence section 101 and a divergence section 102 based on the boundary line T, It can be seen that the flow velocity V1 increases nonlinearly in the convergence section 101 and decreases nonlinearly in the divergence section 102. On the other hand, since the ratio of fuel (F) to air (A) is the same as in (a), the combustion rate (V2) is the same as in (a).

From the convergence section 101 to the equivalence ratio of 1, the flow speed V1 of the fluid increases nonlinearly, and it can be confirmed that the flow speed V1 is always greater than the combustion speed V2. In addition, in the divergence section 102, the flow rate V1 decreases nonlinearly, but the combustion rate V2 also decreases, so it can be confirmed that the flow rate V1 is always greater than the combustion rate V2. As a result, it can be confirmed that the flow rate V1 is always greater than the combustion rate V2 in the entire section in the micro mixer 100.

This suggests that the micro mixer 100 according to the first embodiment of the present invention can prevent a flash-back phenomenon occurring inside.

Next, a micro mixer 200 according to a second embodiment of the present invention will be described with reference to FIGS. 6 to 8 . 6 is a side cross-sectional view of a micromixer bundle according to a second embodiment of the present invention, and FIGS. 7 and 8 are side cross-sectional views of a micromixer according to a second embodiment of the present invention.

Referring to FIGS. 6 to 8 , the micro mixer bundle MB includes a plurality of micro mixers 200 and extends radially around the fuel passage 1232 . The micro mixer 200 extends in the flow direction of fluid (fuel or air).

The micromixer 200 is not in the form of a normal straight tube, but is formed in the form of a tube whose cross-sectional area gradually expands as the middle part is inclined, so that the radiant heat generated by the flame generated in the combustion chamber 1240 is a micromixer ( 200) to prevent spontaneous ignition and flashback occurring inside the micro mixer 200 by reducing transmission to the inside. In addition, the micromixer 200 has a convergence section 210a and a divergence section 210b, so that the flow speed V1 of the fluid is always greater than the combustion speed V2, so that the flashback phenomenon can be further prevented do.

Specifically, the micromixer 200 includes an inlet passage 210, an inclined passage 220, and an outlet passage 230.

An inlet 211 through which air A is introduced is formed at one end of the inlet passage 210, and a supply port 212 through which fuel F is supplied is formed on an inner wall thereof. The air (A) introduced through the inlet 211 and the fuel (F) supplied through the supply port 212 are mixed in the inlet passage 210 to form a mixed fluid FA and flow into the inclined passage 220. .

Also, the inlet passage 210 may include a converging section 210a and a diverging section 210b. The convergence section 210a is formed on the side of the inlet 211 based on the boundary line T between the convergence section 210a and the divergence section 210b, and the divergence section 210b is formed on the side of the gradient passage 120.

The boundary line T dividing the convergence section 210a and the divergence section 210b may be formed at any one point among sections having an equivalence ratio of 1.3 to 0.7. In particular, it is most preferable that the boundary line T is formed at a point where the equivalence ratio becomes 1.

The inclined passage 220 connected to the other end of the inlet passage 210 is inclined at a predetermined angle. The mixed fluid FA flows along the inclined passage 220 and the outlet passage 230 and then is injected into the combustion chamber 1240 .

The outlet passage 230 is formed at a position spaced apart from the imaginary extension of the inlet passage 210 . That is, the flow axis (X1, center of the flow direction of the mixed fluid) of the mixed fluid FA flowing through the inlet passage 210 and the mixed fluid FA flowing through the outlet passage 230 by the inclined passage 220 The flow axes (X2) of the do not coincide and are spaced apart at a predetermined distance to form parallel. The virtual extension line may be a flow axis of the mixed fluid FA.

The inclined passage 220 connects the inlet passage 210 and the outlet passage 230 and is inclined at a predetermined angle. The inclined passage 220 connects the inlet passage 210 and the outlet passage 230 spaced apart by a predetermined distance, but has a tube shape whose cross-sectional area gradually increases from the inlet passage 210 to the outlet passage 230. It is formed.

As a result, the cross-sectional area of the inlet passage 210 may be formed to be the smallest, and the cross-sectional area of the outlet passage 230 may be formed to be the largest. That is, the end of the inlet passage 210 (the end on the side of the inclined passage 220) has a first cross-sectional area, the outlet passage 230 has a second cross-sectional area larger than the first cross-sectional area, and the inclined passage 220 has a It may have a variable cross-sectional area that gradually increases from the inlet passage 210 toward the outlet passage 230.

In addition, the inclined passage 220 includes a lower first line 221 and an upper second line 222 . The first line 221 forms a first angle θ1 with the virtual extension line X2 of the outlet passage 230, and the second line 222 forms a second angle with the virtual extension line X2 of the outlet passage 230. (θ2). Since the inclined passage 220 has a variable cross-sectional area, the first angle θ1 and the second angle θ2 may be formed at different angles.

As shown in FIG. 7 , when the inclined passage 220 is inclined downward, the first angle θ1 may be greater than the second angle θ2. Alternatively, as in the micro mixer 200 formed in the upper fuel plenum 1234 in FIG. 6, when the inclined passage 220 is formed to be inclined upward, the second angle θ2 is greater than the first angle θ1. can be formed

Cross sections of the inlet passage 210 , the inclined passage 220 , and the outlet passage 230 may be formed in a polygonal shape.

According to the micromixer 100 according to an embodiment of the present invention configured as described above, as shown in FIG. 8, the micromixer passes through the outlet passage 230 among radial radiant heat from the flame generated in the combustion chamber 1240. The radiant heat R1 transferred to the inside of the 200 is repeatedly reflected on the inner wall of the gradually narrowing passage of the inclined passage 220, and does not reach the region of the inlet passage 210 where the fuel F and air A are mixed. However, it is discharged (R2) to the combustion chamber 1240 through the outlet passage 230 again. Accordingly, spontaneous ignition and flashback phenomena occurring as the radiant heat R1 is transferred to the region where the fuel F and the air A are mixed can be prevented. In addition, the micromixer 200 has a convergence section 210a and a divergence section 210b, so that the flow speed V1 of the fluid is always greater than the combustion speed V2, so that the flashback phenomenon can be further prevented do.

On the other hand, according to the above-described embodiment, the fuel (F) is supplied through the supply ports 112 and 212 in a state in which air A flows inside the micro mixers 100 and 200 to generate a mixed fluid FA However, in this case, since the low-speed fuel F is injected while the air A flows at a relatively high speed, there is a problem in that the fuel and air are not sufficiently mixed.

Accordingly, another embodiment of the present invention proposes a way to improve mixing efficiency by supplying high-speed air (A) while relatively low-speed fuel (F) flows inside the micromixer.

9 is a view showing one burner module constituting a combustor according to another embodiment of the present invention, and FIG. 10 is a side cross-sectional view showing a micromixer bundle according to a third embodiment of the present invention.

Referring to FIGS. 9 and 10 , in a burner module 2210 according to another embodiment of the present invention, air A may be mixed while fuel F flows inside the micro mixer 300 . The fuel F supplied from the fuel tank FT flows into the micro mixer 300 via the end cover 2231 and the fuel passage 2232 .

The compressed air (A) flows into the annular space inside the liner 2250 or the transition piece 2260 through the compressed air inlet hole H, and then the flow direction is changed by the end cover 2231 to form an air flow space. After flowing along the plenum inlet 2234a, it flows into the air plenum 2234 through the plenum inlet 2234a, and then flows into the micro mixer 300 through the supply port to mix with the fuel F. there is. Reference numeral 2220 is a combustion chamber assembly, 2230 is a micromixer assembly, and 2235 is a shroud.

Next, a micro mixer 300 according to a third embodiment of the present invention will be described with reference to FIGS. 10 and 11 . 10 is a side cross-sectional view showing a micro mixer bundle according to a third embodiment of the present invention, and FIG. 11 is a side cross-sectional view showing a micro mixer according to a third embodiment of the present invention.

Referring to FIGS. 10 and 11 , the micromixer bundle includes a plurality of micromixers 300 and extends in a radial direction around an imaginary central axis of an air flow space 2233 . The micro mixer 300 extends in the flow direction of fluid (fuel or air).

The micro mixer 300 has an inlet 311 through which fuel F is introduced at one end, and a supply port 312 through which air A is supplied is formed on an inner wall thereof. The fuel F introduced through the inlet 311 and the air A supplied through the supply port 312 are mixed inside the micro mixer 300 to form a mixed fluid FA and injected into the combustion chamber 2240. do.

The micro mixer 300 may include a convergence section 301 and a divergence section 302. A plurality of supply ports 312 may be formed in the convergence section 301 and the divergence section 302 . The convergence section 301 is formed on the side of the inlet 311 based on the boundary line T between the convergence section 301 and the divergence section 302, and the divergence section 302 is formed on the opposite side.

The boundary line T dividing the convergence section 301 and the divergence section 302 may be formed at any one point among sections having an equivalence ratio of 1.3 to 0.7. In particular, it is most preferable that the boundary line T is formed at a point where the equivalence ratio becomes 1.

12 is a diagram for explaining a phenomenon in which flashback is prevented in the micromixer according to the third embodiment of the present invention. 12 is substantially the same in content related to the flow of the mixed fluid FA as compared to FIG. do.

Therefore, the description of FIG. 12 is similar to the description of FIG. 5, and in summary, the flow speed V1 of the fluid increases nonlinearly from the convergence section 301 to the equivalence ratio 1, and the flow speed ( It can be confirmed that V1) is greater than the combustion rate V2. In addition, in the divergence section 302, the flow rate V1 decreases nonlinearly, but the combustion rate V2 also decreases, so it can be confirmed that the flow rate V1 is always greater than the combustion rate V2. As a result, it can be confirmed that the flow rate (V1) is always greater than the combustion rate (V2) in the entire section in the micro mixer 300.

This suggests that the micro mixer 300 according to the third embodiment of the present invention can prevent a flash-back phenomenon occurring inside. In addition, mixing efficiency can be improved by supplying high-speed air (A) while relatively low-speed fuel (F) flows inside the micromixer.

Next, a micro mixer 400 according to a fourth embodiment of the present invention will be described with reference to FIGS. 13 to 15 . 13 is a side cross-sectional view showing a micromixer bundle according to a fourth embodiment of the present invention, and FIGS. 14 and 15 are side cross-sectional views showing a micromixer according to a fourth embodiment of the present invention.

13 to 15, the micro mixer bundle MB includes a plurality of micro mixers 400, and the micro mixers 400 extend in a flow direction of a fluid (fuel or air).

The micromixer 400 is not in the form of a normal straight tube, but is formed in the form of a tube whose cross-sectional area gradually expands as the middle part is inclined, so that the radiant heat generated by the flame generated in the combustion chamber 2240 is a micromixer ( 400) to prevent spontaneous ignition and flashback occurring inside the micro mixer 400 by reducing transmission to the inside.

Specifically, the micromixer 400 includes an inlet passage 410, an inclined passage 420, and an outlet passage 430.

The inlet passage 410 is connected to the fuel passage 2232, has an inlet 411 through which fuel F is introduced, and a supply port 412 through which air A is supplied is formed on an inner wall thereof. do. The fuel F introduced through the inlet 411 and the air A supplied through the supply port 412 are mixed in the inlet passage 410 to form a mixed fluid FA and flow into the inclined passage 420. .

Also, the inlet passage 410 may include a converging section 410a and a diverging section 410b. A convergence section 410a is formed on the side of the inlet 411 based on the boundary line T between the convergence section 410a and the divergence section 410b, and the divergence section 410b is formed on the side of the gradient passage 120.

The boundary line T dividing the convergence section 410a and the divergence section 410b may be formed at any one point among sections having an equivalence ratio of 1.3 to 0.7. In particular, it is most preferable that the boundary line T is formed at a point where the equivalence ratio becomes 1.

The inclined passage 420 connected to the other end of the inlet passage 410 is inclined at a predetermined angle. The mixed fluid FA flows along the inclined passage 420 and the outlet passage 430 and then is injected into the combustion chamber 2240 .

The outlet passage 430 is formed at a position spaced apart from the imaginary extension of the inlet passage 410 . That is, the flow axis (X1, center of the flow direction of the mixed fluid) of the mixed fluid FA flowing through the inlet passage 410 and the mixed fluid FA flowing through the outlet passage 430 by the inclined passage 420 The flow axes (X2) of the do not coincide and are spaced apart at a predetermined distance to form parallel. The virtual extension line may be a flow axis of the mixed fluid FA.

The inclined passage 420 connects the inlet passage 410 and the outlet passage 430 and is inclined at a predetermined angle. The inclined passage 420 connects the inlet passage 410 and the outlet passage 430 spaced apart by a predetermined distance, but is formed in a tube shape whose cross-sectional area gradually increases from the inlet passage 410 to the outlet passage 430.

As a result, the cross-sectional area of the inlet channel 410 is the smallest and the cross-sectional area of the outlet channel 430 is the largest. That is, the end of the inlet passage 410 (the end on the side of the inclined passage 420) has a first cross-sectional area, the outlet passage 430 has a second cross-sectional area larger than the first cross-sectional area, and the inclined passage 420 has a It may have a variable cross-sectional area that gradually increases from the inlet passage 410 toward the outlet passage 430.

In addition, the inclined passage 420 includes a lower first line 421 and an upper second line 422 . The first line 421 forms a first angle θ1 with the virtual extension line X2 of the outlet passage 430, and the second line 422 forms a second angle with the virtual extension line X2 of the outlet passage 430. (θ2). Since the inclined passage 420 has a variable cross-sectional area, the first angle θ1 and the second angle θ2 may be formed at different angles.

As shown in FIG. 14 , when the inclined passage 420 is inclined downward, the first angle θ1 may be greater than the second angle θ2 . Alternatively, as in the micro mixer 400 formed in the upper air plenum 2234 in FIG. 13, when the inclined passage 420 is formed to be inclined upward, the second angle θ2 is greater than the first angle θ1. can be formed

Cross sections of the inlet passage 410 , the inclined passage 420 , and the outlet passage 430 may be formed in a polygonal shape.

According to the micromixer 400 according to the fourth embodiment of the present invention configured as described above, as shown in FIG. 15, the radiant heat from the flame generated in the combustion chamber 2240 in the radial direction passes through the outlet passage 430 to the micromixer 400. The radiant heat (R1) transmitted into the mixer 400 is repeatedly reflected on the inner wall of the gradually narrowing passage of the inclined passage 420, and reaches the region of the inlet passage 410 where the fuel F and air A are mixed. It does not reach, and is discharged (R2) to the combustion chamber 2240 through the outlet passage 430 again. Accordingly, spontaneous ignition and flashback phenomena occurring as the radiant heat R1 is transferred to the region where the fuel F and the air A are mixed can be prevented. In addition, the micromixer 400 has a convergence section 410a and a divergence section 410b, so that the flow speed V1 of the fluid is always greater than the combustion speed V2, so that the flashback phenomenon can be further prevented do.

In addition, mixing efficiency can be improved by supplying high-speed air (A) while relatively low-speed fuel (F) flows inside the micromixer.

Although one embodiment of the present invention has been described above, those skilled in the art can add, change, delete, or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention can be variously modified and changed by the like, and this will also be said to be included within the scope of the present invention.

1100: compressor 1200: combustor
1210, 2210: burner module 1220, 2220: combustion chamber assembly
1230, 2230: micro mixer assembly 1300: turbine
100, 200, 300, 400: Micro mixer
101, 210a, 301, 410a: convergence section
102, 210b, 302, 410b: divergence section
210, 410: inlet passage
220, 420: inclined passage
230, 430: Exit Euro

Claims (10)

An inlet through which the first fluid is introduced is formed at one end and a supply port through which the second fluid is supplied is formed on the inner wall, and the first fluid introduced through the inlet and the second fluid supplied through the supply are mixed. an inlet passage through which the mixed fluid flows and including a convergence section formed on the inlet side and a divergence section formed on the opposite side based on any boundary line of an inner wall;
an outlet passage formed at a position spaced apart from a virtual extension of the inlet passage and injecting the mixed fluid into a combustion chamber;
an inclined passage connecting the inlet passage and the outlet passage and being inclined at a predetermined angle to reduce the transfer of radiant heat from the flame generated in the combustion chamber to the inlet passage;
A micro mixer comprising a.
The method according to claim 1, wherein the boundary line,
A micromixer formed in a section where the equivalent ratio, which is the relative ratio of the first fluid and the second fluid for the combustion reaction to occur, is 1.3 to 0.7.
The method of claim 1,
An end of the inlet passage has a first cross-sectional area, the outlet passage has a second cross-sectional area larger than the first cross-sectional area, and the inclined passage has a variable cross-sectional area gradually increasing from the end of the inlet passage to the outlet passage. A micro mixer comprising a.
The method according to claim 1, wherein the inclined passage,
A micro mixer including a first line forming a first angle with a virtual extension line of the outlet passage and a second line forming a second angle with a virtual extension line of the outlet passage, wherein the first angle and the second angle are different from each other. .
The method of claim 1,
the first fluid is a fuel comprising hydrogen and the second fluid is air, or
Wherein the first fluid is air and the second fluid is a fuel containing hydrogen.
a combustion chamber assembly including a combustion chamber in which fuel fluid is combusted;
A micro mixer assembly including a plurality of micro mixers for injecting the fuel fluid into the combustion chamber; includes,
The micro mixer,
An inlet through which the first fluid is introduced is formed at one end and a supply port through which the second fluid is supplied is formed on the inner wall, and the first fluid introduced through the inlet and the second fluid supplied through the supply are mixed. an inlet passage through which the mixed fluid flows and including a convergence section formed on the inlet side and a divergence section formed on the opposite side based on any boundary line of an inner wall;
an outlet passage formed at a position spaced apart from a virtual extension of the inlet passage and injecting the mixed fluid into a combustion chamber;
an inclined passage connecting the inlet passage and the outlet passage and being inclined at a predetermined angle to reduce the transfer of radiant heat from the flame generated in the combustion chamber to the inlet passage;
Combustor comprising a.
The method according to claim 6, The boundary line,
A combustor formed in a section in which an equivalence ratio, which is a relative ratio of the first fluid and the second fluid for a combustion reaction to occur, is 1.3 to 0.7.
The method of claim 6,
An end of the inlet passage has a first cross-sectional area, the outlet passage has a second cross-sectional area larger than the first cross-sectional area, and the inclined passage has a variable cross-sectional area gradually increasing from the end of the inlet passage to the outlet passage. Combustor having a.
The method according to claim 6, The inclined passage,
A combustor comprising a first line forming a first angle with a virtual extension line of the outlet passage and a second line forming a second angle with a virtual extension line of the outlet passage, wherein the first angle and the second angle are different from each other.
The method of claim 6,
the first fluid is a fuel comprising hydrogen and the second fluid is air, or
wherein the first fluid is air and the second fluid is a hydrogen-containing fuel.

Images