JP2000002420A - Multi-fluid injection combustor - Google Patents

Abstract

(57) Abstract: deterioration of the combustion efficiency due to the water vapor to reduce the nitrogen oxides NO _X in the exhaust gas, is difficult to occur instability and quenching of the combustion flame. SOLUTION: An inner cylinder 2 is provided in a combustion chamber 4 and an inner cylinder 2 and an outer cylinder 1 are provided.
Are formed in an air passage 5, and a multi-fluid injection nozzle in which fuel passages 11, 12 and a vapor passage 15 are formed in a multi-fluid injection combustor in which air, fuel, and steam in the air passage 5 are jetted into a combustion chamber 4. 6, a fuel injection port 14 at the tip of the multi-fluid injection nozzle 6 is opened in the combustion chamber 4, a mixing chamber 18 connecting the vapor passage 15 and the air passage 5 is provided, and a mixture air injection port 20 is formed in the mixing chamber 18. Then, an air-fuel mixture injection port 20 from which a mixture of water vapor and air is jetted is opened in the combustion chamber 4 to open the fuel injection port 14.
And a mixture of steam and air is injected into the combustion flame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-fluid injection combustor mainly used for gas turbines for injecting fuel, air and water vapor and burning.

[0002]

2. Description of the Related Art In a multi-fluid injection combustor used for a gas turbine, an inner cylinder, also called a liner, is coaxially inserted into an outer cylinder, also called a casing, and the inside of the inner cylinder is inserted into a combustion chamber. An air passage is formed between the cylinder and the outer cylinder.

[0003] At the heads of the inner cylinder and the outer cylinder, a fuel nozzle for ejecting fuel into the combustion chamber is provided so as to penetrate therethrough, and an air nozzle for ejecting air in an air passage between the inner cylinder and the outer cylinder to the combustion chamber is provided. provided, also, to reduce the nitrogen oxides NO _X in the exhaust gas by suppressing the temperature rise in the combustion flame in the combustion chamber is provided with a steam nozzle for ejecting water vapor.

[0004] Then, depending on the position from which steam is jetted, 2
Broadly classified into types. One of them is an air passage in which the position of jetting water vapor is between the inner cylinder and the outer cylinder. In the other case, the steam ejection position is the combustion chamber.

In a combustor in which steam is injected into an air passage between an inner cylinder and an outer cylinder, air having a reduced oxygen concentration due to the incorporation of steam flows into a combustion chamber and is used for combustion.
It may cause instability of flame and deterioration of exhaust. Also, since the steam nozzle and the fuel nozzle are provided separately at separate positions,
Production costs and maintenance costs are unlikely to be low.

[0006] In a combustor in which steam is injected into the combustion chamber, the steam is directly injected into the combustion flame in the combustion chamber.
The combustion flame temperature can be reduced with a small amount of water vapor. A small amount of water vapor is consumed. Further, since the steam nozzle and the fuel nozzle are provided at close positions, they can be integrated. Manufacturing and maintenance costs are reduced.

[0007] Combustors for injecting steam into the combustion chamber are classified into two types according to the relative position between the steam ejection position and the combustion ejection position. One is that the steam ejection position is the center of the combustion ejection position. In other cases, the steam ejection position is outside the combustion ejection position.

[0008] The former combustor, which injects steam directly into the center of the combustion flame, has a smaller amount of steam to lower the temperature of the combustion flame to a predetermined temperature than the latter combustor. A small amount of water vapor is consumed.

[0009]

However, water vapor is
The water is cooled before being supplied from the steam boiler and jetted into the combustor, and the supersaturated water may condense and contain water droplets. In the combustor, water vapor containing water droplets of condensed water may be ejected.

[0010] Further, the amount of steam supplied from the steam boiler to the combustor may fluctuate. In the combustor, the amount of steam discharged may fluctuate.

In a combustor in which steam is injected into a combustion chamber, if the mixture of fuel, air, and steam in the combustion chamber contains water droplets of condensed water, the water droplets are not uniform in size and dispersion. The dispersion of the particles may be uneven, and the combustion efficiency may be degraded, or the combustion flame may become unstable due to the rapid evaporation of water droplets by the combustion flame. Also, when the amount of water vapor ejected into the combustion chamber fluctuates,
Fuel dispersion becomes uneven and combustion efficiency deteriorates,
Combustion flame may become unstable or extinguish.

[0012] Fluctuations of water droplets in steam and the amount of steam jetted are greater in a combustor in which the steam jetting position is the center of the combustion jetting position than in a combustor in which the steam jetting position is around the combustion jetting position. Deterioration of combustion efficiency, instability of combustion flame and extinction are likely to occur.

[0013]

According to the present invention, an inner cylinder is inserted into an outer cylinder to form a combustion chamber inside the inner cylinder and an air passage between the inner cylinder and the outer cylinder. A multi-fluid injection combustor configured to eject fuel and water vapor into a combustion chamber, wherein a multi-fluid injection nozzle having a fuel passage and a vapor passage is provided at the heads of an outer cylinder and an inner cylinder, respectively. A fuel injection port formed at the end of the fuel cell is opened to the combustion chamber, and a mixing chamber is provided in which the steam passage and the air passage are connected, and the mixture is injected into the mixing chamber where the steam flowing from the steam passage and the air flowing from the air passage are mixed. A port is formed, and a mixture injection port from which a mixture of steam and air is ejected is opened to the combustion chamber and arranged around the fuel injection port, so that the mixture of steam and air is ejected to the combustion flame.

[0014]

The water vapor flows into the mixing chamber and mixes with the air flowing from the air passage before mixing with the fuel ejected from the fuel injection port. The air in the air passage and the mixing chamber are heated by the heat of the combustion chamber. Therefore, even if the water vapor flowing into the mixing chamber contains water droplets of condensed water, the water vapor flows into the mixing chamber and mixes with the air flowing from the air passage, whereby the water droplets in the water vapor evaporate and decrease. Or disappear.

[0015] Even if the amount of steam supplied to the vapor passage of the multi-fluid injection nozzle fluctuates, the fluctuation is mitigated by flowing into the mixing chamber and mixing with air flowing from the air passage. . The amount of water vapor in the air-fuel mixture ejected from the air-fuel mixture injection port does not fluctuate as much as the supply amount of water vapor.

Further, since the steam ejection position is located outside the combustion ejection position, the influence of fluctuations in water droplets in the steam and the amount of steam ejection is small.

Therefore, the deterioration of combustion efficiency, the instability of combustion flame and the extinction of flame due to the water vapor that reduces nitrogen oxides NO _x in the exhaust gas hardly occur.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment (See FIGS. 1 to 6) [Configuration] The multi-fluid injection combustor of this embodiment has a casing having a circular cross section as shown in FIGS. An inner cylinder 2 having a circular cross section of the liner is inserted concentrically into the outer cylinder 1, and the heads of the outer cylinder 1 and the inner cylinder 2 are fixed by an annular mounting member 3. The inside of the inner cylinder 2 is configured as a combustion chamber 4. As shown in FIG. 5, the combustion chamber 4 includes a small-diameter chamber on the head side of the inner cylinder 2 and a large-diameter chamber concentrically connected to the small-diameter chamber. An air passage 5 is provided between the outer cylinder 1 and the inner cylinder 2.

A multi-fluid injection nozzle 6 is concentrically penetrated through the heads of the outer cylinder 1 and the inner cylinder 2 and the mounting member 3 and is detachably mounted with a plurality of bolts 7. Multi-fluid injection nozzle 6
Can be easily removed for cleaning or replacement.

As shown in FIG. 1, the multi-fluid injection nozzle 6 is provided with an elongated first fuel passage 11 having a circular cross section and a hollow disk-shaped second fuel passage 12 concentrically.
Is connected to the center of the second fuel passage 12.

The first fuel passage 11, as shown in FIG.
A fuel supply port 13 is provided concentrically at the base end. As shown in FIGS. 1 and 2, the second fuel passage 12 penetrates a large number of fuel injection ports 14 having a circular cross section at circumferentially equal intervals in a conical cylindrical chamfered wall between the front end wall and the outer peripheral wall. ing. Each fuel injection port 14 is open in a direction orthogonal to the chamfered wall at the penetrating position.

That is, the multi-fluid injection nozzle 6 has a large number of fuel injection ports 14 arranged at equal intervals in a circle at the tip, and each fuel injection port 14 is open to the combustion chamber 4.

At the outer position of the first fuel passage 11, FIG.
As shown in FIG. 2, an elongated steam passage 15 having a circular cross section is provided concentrically. In the steam passage 15, a steam supply port 16 is provided in the outer peripheral wall at the base end in the radial direction, and a plurality of steam outlets 17 pass through the outer peripheral wall at the distal end at equal circumferential positions. As shown in FIG. 3, each of the steam outlets 17 is open in a tangential direction to the inner surface of the outer peripheral wall at the penetrating position.

The outer peripheral surface of the multi-fluid injection nozzle 6 and the mounting member 3
As shown in FIG. 1, an annular space 18 is provided between the inner peripheral surfaces of the two. That is, an annular mixing chamber 18 is provided concentrically at an outer circumferential position at the tip of the steam passage 15.

The mixing chamber 18 is provided with each of the steam outlets 1 at the center of the inner circumference.
7 are connected, and a plurality of air inlets 19 are penetrated at equal circumferential positions on the distal end side of the outer peripheral wall. Each air inlet 19
As shown in FIG. 4, an opening is provided in the tangential direction of the inner surface of the outer peripheral wall at the penetrating position.

An air inlet 19 through which air in the air passage 5 flows into the mixing chamber 18 has a total cross-sectional area of water vapor.
Or less than the steam outlet 17 that flows into Mixing chamber 18 in which a mixture of steam and air swirls and flows
Has a sectional area equal to or smaller than the sum of the total sectional area of the air inlet 19 and the total sectional area of the steam outlet 17.

As shown in FIGS. 1 and 2, the mixing chamber 18 has a concentric air-fuel mixture injection port 20 having a circular cross section on the inner peripheral side of the end wall. The air-fuel mixture injection port 20 is disposed near the fuel injection ports 14 arranged on a circle concentric with the fuel-air mixture injection port 20 and on the outer periphery thereof on the base end side.

As shown in FIG. 5, the fuel supply device connects a city gas pipe 41 to a gas compressor 42 and an electromagnetic on-off valve 4.
3. It is connected to the fuel supply port 13 of the multi-fluid injection nozzle 6 via an electromagnetic opening / closing valve 44 and a flow control valve 45. A gas passage between the electromagnetic on-off valve 43 and the electromagnetic on-off valve 44 is open to the atmosphere via an electromagnetic on-off valve 46 for gas purging.

As shown in FIG. 5, the steam supply device comprises a steam boiler 51 having a pressure reducing valve 52, an on-off valve 53, a fixed throttle 54,
Multi-fluid injection nozzle 6 through electromagnetic on-off valve 55 and check valve 56
Is connected to the steam supply port 16 of the air conditioner. The steam passage between the on-off valve 53 and the fixed throttle 54 is open to the atmosphere via a solenoid on-off valve 57 for drain discharge.

As shown in FIG. 5, the combustion chamber 4 has a spark plug 61 protruding from an upstream end and a downstream end connected to a gas inlet of a gas turbine 62. The air passage 5 is connected to the air outlet of an air compressor 63 connected to the gas turbine 62. The multi-fluid injection combustor of this example is used in a gas turbine plant.

[Operation] When the multi-fluid injection combustor of this embodiment is operated, the gas compressor 42 is started to increase the pressure of the city gas called 13A to about 9 atm. The gas turbine 62 is started by a starter motor. Air compressor 6
3 is also driven to rotate. The ignition plug 61 is energized. The electromagnetic switching valves 43 and 44 are opened.

Then, the gas fuel of the city gas is supplied to the multi-fluid injection nozzle 6 at a flow rate set by the flow control valve 45, and is injected from the fuel injection port 14 into the combustion chamber 4. Further, the air in the air passage 5 passes through the mixing chamber 18,
From the combustion chamber 4. The mixture of fuel and air formed in the combustion chamber 4 is ignited by the ignition plug 61 and performs diffusion combustion or premix combustion.

On the other hand, when the steam boiler 51 is started and the pressure becomes 1
At about 0 atm, steam at a temperature of about 180 ° C. is generated.
The on-off valve 53 and the electromagnetic on-off valve 57 are opened. The drain is discharged, and the temperature of the steam passage is raised. Gas turbine 6
2 reaches a predetermined rotational speed, the solenoid on-off valve 57
Is closed and the electromagnetic on-off valve 55 is opened.

Then, the steam is supplied to the multi-fluid injection nozzle 6 at the pressure set by the pressure reducing valve 52 and the flow rate set by the fixed throttle 54, and passes through the mixing chamber 18, and the mixture injection port 20.
From the combustion chamber 4.

The gas fuel supplied to the multi-fluid injection nozzle 6 becomes a jet at the tip of the first fuel passage 11, collides with the tip wall of the second fuel passage 12, and flows radially through the second fuel passage 12. Then, the fuel is ejected from the fuel injection port 14 in the shape of a conical cylinder that is widened. The outer surface of the end wall of the second fuel passage 2 is heated by the combustion flame of the combustion chamber 4, but is cooled by the collision of gas fuel having a temperature of about 60 ° C. with the inner surface.

The air in the air passage 5 is heated by the heat of the combustion chamber 4 and reaches a temperature of about 300 ° C., flows into the mixing chamber 18 from the air inlet 19 and swirls through the mixing chamber 18. The mounting member 3 forming the mixing chamber 18 is heated by the heat of the combustion chamber 4, and the temperature of the outer peripheral surface and the front end side of the mixing chamber 18 is 300 to
It will be around 400 ° C.

The water vapor supplied to the multi-fluid injection nozzle 6 is cooled while passing through the vapor passage 15, but its temperature is reduced by flowing outside the first fuel passage 11 through which gas fuel having a temperature of about 60 ° C. flows. Is suppressed.

The steam flowing through the steam passage 15 flows into the mixing chamber 18 from the steam outlet 17 and swirls through the mixing chamber 18 to flow. The swirling of the steam in the mixing chamber 18 is in the same direction as the swirling of the air in the mixing chamber 18. In the mixing chamber 18, steam and air flow and mix.

The steam generated by the steam boiler 51 is cooled in the middle of the supply pipe, and when it flows into the steam passage 15 of the multi-fluid injection nozzle 6, the temperature drops to about 150 ° C. and may contain water droplets of condensed water. is there.

Even if the water vapor flowing into the mixing chamber 18 contains water droplets of condensed water, the water vapor is mixed with the air having a temperature of about 300 ° C. flowing into the mixing chamber 18 from the air passage 5 to reduce the saturation. As a result, the water droplets in the water vapor evaporate and disappear or decrease. Further, the water droplets in the steam are generated by the centrifugal force generated by the swirling of the mixture of the steam and the air.
It adheres to the outer peripheral surface and the front end surface at a temperature of about 0 to 400 ° C. and evaporates.

Therefore, the mixture of steam and air ejected from the mixture injection port 20 contains no or almost no water droplets.

The amount of steam supplied from the steam boiler 51 to the multi-fluid injection nozzle 6 may fluctuate. Even if the supply amount of water vapor fluctuates, water vapor is supplied to the mixing chamber 1
8 and mixed with the air flowing from the air passage 5, the fluctuation is reduced. The amount of water vapor in the air-fuel mixture ejected from the air-fuel mixture injection port 20 does not fluctuate as much as the supply amount of water vapor.

The mixture of steam and air swirling through the mixing chamber 18 is injected into the cylindrical shape from the air-fuel injection port 20, and concentrically with the fuel injected from the fuel injection port 14 into the converging conical cylinder shape. It collides with the outer peripheral surface of the root and mixes with fuel. The mixture of water vapor and air blows out around the combustion flame.

The deterioration of combustion efficiency, the instability of the combustion flame and the extinction of the flame due to fluctuations in the supply amount of water droplets and water vapor in the steam are unlikely to occur. Temperature rise in the combustion flame suppressed to be generated nitrogen oxides NO _X is suppressed.

[Experiment] In the multi-fluid injection type combustor of this example, nitrogen oxide NO
A reduced rate, the percentage of nitrogen oxides concentration of NO _X exhaust when the ejected steam was reduced with respect to _{the X} concentration was determined a relationship between the driver equivalence ratio indicating a ratio of an actual air-fuel ratio to the theoretical air-fuel ratio.

When the weight ratio of the steam supply flow rate to the gas fuel supply flow rate is about 0.6, as shown by a solid line in FIG. things NO _X concentration reduction rate is nearly half.
By setting the weight ratio of the supply flow rate of water vapor to the supply flow rate of the gas fuel to 1 or less, the nitrogen oxides NO _x
Combustion with a sufficiently low concentration can be realized.

For comparison, in the multi-fluid injection combustor of the present embodiment, gas fuel is supplied to the vapor supply port 16 of the multi-fluid injection nozzle 6 and steam is supplied to the fuel supply port 13, and the steam is supplied to the center of the combustion flame. It erupted, nitrogen oxides of the exhaust NO _X
The relationship between the concentration reduction rate and the operating equivalent ratio was similarly obtained.

Then, as shown by the broken line in FIG. 6, the concentration of nitrogen oxides NO _X in the exhaust gas becomes extremely low. However, when water vapor is included in the water vapor, condensed water collected in a local area is ejected as a lump. As soon as the combustion flame blows out. Practical application is difficult.

When the steam ejection position is at the center of the combustion ejection position, the influence of fluctuations in water droplets in steam and the amount of steam ejection is greater than when the steam ejection position is outside the combustion ejection position.

<Second Example (See FIGS. 7 to 9)> The multi-fluid injection type combustor of this example is only slightly different from that of the first example.

As shown in FIGS. 7 and 8, the number of the steam outlets 17 is large, and the opening direction is the radial direction of the steam passage 15 and the mixing chamber 18. As shown in FIGS. 7 and 9, the number of the air inlets 19 is large.

The combustion chamber 4 comprises one chamber. As shown in FIG. 7, an air inlet 71 having a ring-shaped airflow swirler is provided between the mounting member 3 and the inner cylinder 2, and swirls the air in the air passage 5 to make the upstream end of the combustion chamber 4. To the configuration.

The other points are almost the same as those in the first example.

<Third example (see FIGS. 10 and 11)> The multi-fluid injection combustor of this embodiment uses liquid fuel instead of gaseous fuel in the first and second examples. It is.

As shown in FIG. 10, the multi-fluid injection nozzle 6 is provided with a fuel passage 11 having a circular cross section concentrically, a fuel supply port 13 at a base end of the fuel passage 11, and a fuel supply port 13 at the tip of the fuel passage 11. A fuel injection opening is provided in the combustion chamber 4 so as to open. The combustion chamber 4 comprises one chamber. The liquid fuel supplied to the fuel passage 11 is ejected from the fuel injection port into the combustion chamber 4.

As shown in FIG. 10, a steam passage 15 having a circular cross section is provided concentrically at an outer position of the fuel passage 11.
A steam supply port 16 is provided at the base end of the steam passage 15. An annular mixing chamber 18 is provided concentrically around the fuel passage 11, and a vapor passage 15 is provided at the rear end of the mixing chamber 18.
Is connected to the steam outlet at the end. The steam supplied to the steam passage 15 flows into the mixing chamber 18.

The mixing chamber 18 has a plurality of air inlets 19 penetrating the outer peripheral wall at equal circumferential positions. As shown in FIG. 11, each air inlet 19 opens in a tangential direction to the inner surface of the outer peripheral wall at the penetrating position.

As shown in FIG. 10, the mixing chamber 18 is provided with an annular airflow swirler 81 concentrically at the front end and a mixed air injection port 20 having a circular cross section at the front end. And are provided concentrically. The air-fuel mixture injection port 20 is disposed close to and around the fuel injection port concentric with the fuel injection port.

Outer peripheral surface of multi-fluid injection nozzle 6 and mounting member 3
As shown in FIGS. 10 and 11, an annular space 82 is provided between the inner peripheral surfaces of the mounting member 3, and an air inflow passage 83 is provided between the inner peripheral surface and the outer peripheral surface of the mounting member 3 at equal intervals in the circumferential direction. Penetrates radially in position. The air in the air passage 5 is supplied to the air inflow passage 83,
It flows into the mixing chamber 18 through the space 82 and the air inlet 19 and turns.

The steam and air flowing into the mixing chamber 18 mix and swirl, pass through the airflow swirler 81 to increase the swirling speed, and spout out while swirling from the air-fuel mixture injection port 20 to swirl the steam and air. Liquid fuel is ejected from the fuel injection port to the center of the air-fuel mixture, and a mixture of water vapor and air collides with the liquid fuel, and the liquid fuel is atomized and mixed with the air-fuel mixture of water vapor.

A mixture of liquid fuel particles, air and water vapor is ejected in the shape of a convergent conical cylinder, ignited by a spark plug 61 and burned.

The other points are almost the same as in the first example.

[Brief description of the drawings]

FIG. 1 is a vertical side view of a head of a multi-fluid injection combustor according to a first example of an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows AA in FIG. 1;

FIG. 3 is an end view taken along line BB of FIG. 1;

FIG. 4 is an end view taken along line CC of FIG. 1;

FIG. 5 is a schematic diagram of a gas turbine plant using the multi-fluid injection combustor.

FIG. 6 is a diagram showing the relationship between the NO _X concentration reduction rate and the operating equivalent ratio in the multi-fluid injection combustor.

FIG. 7 is a vertical sectional side view of a head of a multi-fluid injection combustor according to a second example of the embodiment.

8 is an end view taken along line DD of FIG. 7;

FIG. 9 is an end view taken along line EE of FIG. 7;

FIG. 10 is a vertical side view of a head of a multi-fluid injection combustor according to a third example of the embodiment.

FIG. 11 is an end view taken along line FF of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer cylinder 2 Inner cylinder 4 Combustion chamber 5 Air passage 6 Multi-fluid injection nozzle 11, 12 Fuel passage 14 Fuel injection port 15 Steam passage 18 Mixing chamber 20 Mixture air injection port

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoichiro Okubo 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Kenji Amano 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation ( 72) Inventor Sueyoshi Sugiyama 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tsuneo Tsutsui 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (1)

[Claims] 1. An inner cylinder is inserted into an outer cylinder, an inner cylinder is formed as a combustion chamber, and a space between the inner cylinder and the outer cylinder is formed as an air passage, and air, fuel and steam in the air passage are formed in the combustion chamber. In a multi-fluid injection combustor configured to eject, a multi-fluid injection nozzle having a fuel passage and a vapor passage is provided at the head of the outer cylinder and the inner cylinder, and a fuel injection port formed at the tip of the multi-fluid injection nozzle Is provided in the combustion chamber, and a mixing chamber is provided in which the steam passage and the air passage are connected to each other, and a mixture injection port is formed in the mixing chamber in which the steam flowing from the steam passage and the air flowing from the air passage are mixed. Multi-fluid injection type, characterized in that the air-fuel mixture injection port for discharging the air-fuel mixture is opened to the combustion chamber and arranged around the fuel injection port, and the air-fuel mixture of steam and air is injected into the combustion flame Combustor.