JPH0893501A - Gas turbine combustor for low calorie gas - Google Patents

Abstract

PURPOSE: To provide a means which supplies nitrogen and continue combustion efficiently. CONSTITUTION: In a gas turbine combustor for low calorie gas which burns low calorie gas fuel, a low calorie gas opening 4, an air opening 5, and a nitrogen opening 6 are provided in a fuel injection nozzle 2 to dilute low calorie gas and air to be supplied with nitrogen so that heating value of gas is reduced, oxygen concentration of air is reduced, temperature of flame at the time of combustion is kept low, and producing amount of NOx is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low calorie gas turbine combustor, and more particularly to a low calorie gas gas turbine combustor having a device for supplying nitrogen gas in addition to ordinary fuel gas.

[0002]

2. Description of the Related Art FIG. 10 is a sectional view of a conventional combustor, and FIG.
FIG. 11 is a sectional view taken along the line AA of FIG. 10. In FIG. 10, the low-calorie gas supplied from the low-calorie gas supply unit 8 is injected from the fuel injection nozzle 2 into the combustor liner 1. On the other hand, part of the air required for combustion is supplied from the air supply unit 13 and injected from the fuel injection nozzle 2 to the combustor liner 1. The remainder is directly injected into the combustor liner 1 through the air holes 12 formed in the combustor liner. The low-calorie gas and air are mixed and burned in the combustion region 11, and the generated combustion gas is discharged as the combustion gas 10 from the combustor liner 1. Since the fuel flow rate is small when the gas turbine is started or when the load is low, it is difficult to burn low-calorie gas having relatively low combustion performance by itself. Therefore, in such a case, liquid fuel such as light oil or kerosene is supplied from the liquid fuel supply unit 7, and the liquid fuel nozzle 3
It is injected from and burned.

Details of the fuel injection nozzle 2 will be described with reference to FIG. The liquid fuel nozzle 3 is located at the center of the combustor liner 1, and low-calorie gas openings 4 having a fan-shaped cross section and air openings 5 having a fan-shaped cross section are alternately arranged in the annular spaces of the liquid fuel nozzles 3. Has been done. As described above, since the low-calorie gas opening 4 and the air supply unit 5 are arranged, the mixing of the low-calorie gas and air is promoted, and uniform combustion in the combustion region is ensured.

[0004]

However, in a power generation system using low-calorie gas, nitrogen gas obtained from an air separation plant has been used in a gas turbine at the same time as low-calorie gas.

FIG. 12 is a flow chart of a recent gasification plant. In FIG. 12, air 111 is sucked into the air separator 101 from the atmosphere. The oxygen 112 separated by the air separator 101 is sent to the gasification furnace 102, and the fuel 1
Used for partial oxidation of 14. The crude low car gas 113 obtained as a result is refined in the desulfurization device 103 and is used as the low car gas 115 in the gas turbine combustor 10 for low calorie gas.
6 (hereinafter referred to as the low-calorie gas combustor 106), the nitrogen separated by the air separator 101 is burned in the low-calorie gas for the purpose of suppressing NOx generation and improving the output of the gas turbine 108. Is supplied to the container 106.

In the gas turbine 108, the compressor 10
The compressed air 117 supplied from No. 5 is supplied to the low calorie gas combustor 106. As a result, in the low-calorie gas combustor 106, the high-temperature combustion gas 11 containing relatively little NOx is generated.
8 is generated and sent to the turbine 107 where it expands and does work. Combustion gas 118 that has finished expanding is exhaust gas 1
It is discharged from the gas turbine as 19.

The work generated in the gas turbine is generated by the generator 1.
It is taken out as electric power at 04.

In such a power generation system, a low-calorie gas combustor 10 capable of efficiently burning three kinds of gases, that is, low-calorie gas 115, nitrogen 116, and air 117.
6 is essential.

In the conventional combustor, the low calorie gas 115
And air 117 can be burned, but nitrogen cannot be supplied to burn them.

The present invention has been made in view of the above circumstances, and provides a low-calorie gas combustor which is equipped with a means for supplying nitrogen and can sustain combustion efficiently.

[0011]

A turbine burner for low-calorie gas according to the present invention is characterized in that a nitrogen gas outlet is provided between a low-calorie gas outlet and an air outlet of a fuel injection nozzle. .

[0012]

In the combustion of the present invention having the above structure, since the nitrogen outlet is provided between the low-calorie gas outlet and the air outlet of the fuel injection nozzle, these gases are injected into the combustor liner. Then, the low-calorie gas and nitrogen, the air and the nitrogen are mixed with each other, and each is diluted with nitrogen. This dilution further reduces the calorific value of the low-calorie gas. In addition, the concentration of oxygen is reduced by mixing air with nitrogen. Combustion with low-calorie gas, which has a very low calorific value, and air, which has a low oxygen concentration, has a low flame temperature and a low NOx generation amount. Further, by increasing the number of divisions of the injection port, mixing is uniformly performed and stable combustion is obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 in which the same parts as those in FIGS.
The typical side view of the 1st Example of this invention, FIG.
FIG. Combustion liner 1 inside combustor liner 1
Within 1, a combustion reaction occurs. The side surface of the combustor liner 1 is provided with an air hole 12 that introduces air required for combustion into the inside. On the other hand, inside the combustor liner 1, a fuel injection nozzle 2 and a liquid fuel nozzle 3 are provided. The fuel injection nozzle 2 is provided with a low-calorie gas supply unit 8, a nitrogen supply unit 9, and an air supply unit 13, from which low-calorie gas, nitrogen, and air are supplied to different compartments inside the fuel injection nozzle 2. It Liquid fuel is supplied from the liquid fuel supply unit 7 to the liquid fuel nozzle 3.

In FIG. 2, the fuel injection nozzle 2 has a low-calorie gas opening 4, an air opening 5, and a nitrogen opening 6 each having a fan-shaped cross section, and between the low-calorie gas opening 4 and the air opening 5. Is provided with a nitrogen opening 6. That is, in the fuel injection nozzle 2, the low-calorie gas opening 4, the nitrogen opening 6, the low-calorie gas opening 4, and the air opening 5 are arranged in this order. Like nitrogen opening 6 ', low calorie gas opening 4', nitrogen opening 6 ', air opening 5',
The same arrangement as above is repeated to form the injection portion of the fuel injection nozzle. The liquid fuel nozzle 3 is arranged at the center of the fuel injection nozzle 2.

The low-calorie gas supplied from the low-low-calorie gas supply unit 8 is injected from the fuel injection nozzle 2 into the combustor liner 1. On the other hand, part of the air required for combustion is supplied from the air supply unit 13 and injected from the fuel injection nozzle to the combustor liner 1. The remainder is injected into the combustor liner 1 through the air holes 12 on the side surface of the combustor liner 1. Nitrogen is supplied from the nitrogen supply unit 9 to the fuel injection nozzle 2 and is injected into the combustor liner 1 from the nitrogen opening 6.

Since nitrogen gas is also injected on both sides of the low-calorie gas injected into the combustor liner 1, the low-calorie gas and the nitrogen gas are mixed immediately after the injection, and the low-calorie gas is diluted to generate heat. The amount will be lower. Also,
Since the nitrogen gas is also injected to both sides of the air injected into the combustor liner 1, the air is also mixed with the nitrogen gas immediately after the injection, and the oxygen concentration is relatively reduced.

By this mixing, a low calorific gas having an extremely low calorific value and air having a low oxygen concentration can be obtained. Then, they burn in the combustion region 11. In such combustion, the flame temperature is low and the NOx generation amount is suppressed low.

Further, since the nitrogen opening 6, the low-calorie gas opening 4, and the air opening 5 are subdivided, the injected gas can be mixed uniformly and in a short time, and the flame stability can be improved. Can be secured.

The combustion gas 10 generated in the combustion region 11 is discharged from the combustor liner 1.

Since the fuel flow rate is small when the gas turbine is started or when the load is low, it is difficult to maintain combustion with the low-calorie gas alone. Therefore, the liquid fuel is supplied from the liquid fuel supply unit 7 and the liquid fuel is supplied. It is injected from the nozzle 2 and burned.

The low calorie gas combustor of the present invention has means for injecting nitrogen directly into the combustor liner 1. Combustion with a low calorific gas having an extremely low calorific value and air having a low oxygen concentration realizes a low flame temperature and suppresses the NOx generation amount to a low level.

Further, as a result of subdividing the nitrogen opening 6, the low-calorie gas opening 4, and the air opening 5, the injected gas can be mixed uniformly and in a short time, and a stable flame can be maintained. Is possible.

FIG. 3 shows a second embodiment of the present invention and corresponds to FIG. In this figure, the openings of the injection nozzle 2 are provided in order of the low-calorie gas opening 4, the nitrogen opening 6, the low-calorie gas opening 4, and the air opening 5. Similar to the first embodiment, the openings are sequentially arranged in the circumferential direction.

The low-calorie gas opening 4 is in contact with the air opening 5 on one side and the nitrogen opening 6 on the opposite side. When the low-calorie gas is injected into the combustor liner 1, the low-calorie gas and the nitrogen are mixed in a portion where the low-calorie gas and the nitrogen are in contact with each other, and the low-calorie gas is diluted with the nitrogen gas. The calorific value of the low-calorie gas is further reduced by this dilution. The flame temperature when a gas with a very low calorific value burns is low, and the generation of NOx is suppressed. On the other hand, on the side where the low-calorie gas is in direct contact with the air, the low-calorie gas and the air are mixed and combustion is started.
Since the calorific value of low-calorie gas is low originally, the flame temperature is low, but compared with the gas diluted with nitrogen on the other side,
The flame temperature becomes slightly higher, and accordingly the amount of NOx generated becomes slightly higher. However, flame stability is increased due to the relatively high flame temperature.

As described above, since a part of the low-calorie gas is diluted with nitrogen, the flame temperature when burning this part is kept low and the amount of NOx produced is suppressed. On the other hand, since the flame temperature of the gas that is not diluted with nitrogen is slightly high, a large amount of NOx is generated during combustion, but a stable flame can be maintained.

FIG. 4 shows a third embodiment of the present invention and is similar to FIG. In this figure, the openings of the fuel injection nozzle 2 are arranged in the order of the low-calorie gas opening 4, the air opening 5, the nitrogen opening 6, and the air opening 5.

The low-calorie gas opening 4 is provided with air openings 5 on both sides. When the low-calorie gas is injected into the combustor liner 1, the low-calorie gas and air are mixed and combustion is started. Since the calorific value of the low-calorie gas is low originally, the flame temperature is low, but the flame temperature is slightly higher than that of the gas diluted with nitrogen, and accordingly, the amount of NOx generated is slightly higher. However, since the flame temperature is slightly high, the stability of the flame is increased.

In the third embodiment, since the low-calorie gas is not diluted with nitrogen, the flame temperature is slightly high and a large amount of NOx is generated, but it is easy to maintain a stable flame.

FIG. 5 shows a fourth embodiment of the present invention and is similar to FIG. In this figure, the low-calorie gas opening 4, the nitrogen opening 6, and the air opening 5 are concentrically arranged in order from the inside.

The low-calorie gas opening 4 is surrounded by the nitrogen opening 6 on the outer circumference thereof. When the low-calorie gas is injected into the combustor liner 1, the low-calorie gas and nitrogen are first mixed in a portion where the low-calorie gas and nitrogen are in contact with each other, and the low-calorie gas is diluted with nitrogen. This mixing further reduces the calorific value of the low-calorie gas. on the other hand,
Nitrogen is surrounded by air on its outer periphery, and on the side in contact with air, nitrogen and air are mixed, and the oxygen concentration in the air is reduced. As a result, a very low calorific value gas will combust with low oxygen concentration air. In this case, the flame temperature is low and the amount of NOx generated is greatly suppressed.

As mentioned above, in this embodiment the low car gas is diluted with nitrogen. Further, since the air is also diluted with nitrogen, the flame temperature during combustion is kept low and the generation of NOx is significantly suppressed. If the arrangement of the low-calorie gas opening 4, the air opening 5, and the nitrogen opening 6 is changed, the second,
The same effect as that of the third embodiment can be obtained.

6 in which the same parts as those in FIG. 1 are designated by the same reference numerals.
FIG. 7 shows a fifth embodiment of the present invention and is a view similar to FIG. In this figure, a side portion of the combustor liner 1 is provided at several locations on the circumference of the premix duct 21 cancer. A low-calorie gas injection nozzle 22 and a nitrogen injection nozzle 23 are installed toward the inside of the premixing duct 21. The low-calorie gas injection nozzle 22 is supplied with low-calorie gas from the low-calorie gas supply unit 9.
Further, nitrogen gas is supplied from the nitrogen gas supply unit 9 to the nitrogen injection nozzle 23.

Air is supplied from the air supply unit 13 into the premixing duct 21. The low-calorie gas and nitrogen are supplied to the low-calorie gas injection nozzle 22 and the nitrogen gas injection nozzle 23 from the low-calorie gas supply unit 8 and the nitrogen gas supply unit 9, respectively, and into the premixing duct from the respective injection nozzles. It is injected and mixed thoroughly with air.
The premixed gas obtained as described above is injected into the combustion region 11 of the combustor liner 1 and burns there.

As described above, in this embodiment, nitrogen gas can be supplied to the inside of the gas turbine. Further, since the low-calorie gas, nitrogen, and air can be completely mixed in the premixing duct 21 before combustion, there is no local high temperature part that generates NOx during combustion. Therefore, NOx can be suppressed to a minimum, and a very uniform premixed gas can be produced, so that combustion stability is good.

7 and 8, in which the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, show a sixth embodiment of the present invention.
FIG. 3 is a view similar to FIGS. 1 and 2. In these drawings, a fuel / nitrogen mixing chamber 14 is provided inside the fuel injection nozzle 2,
Nitrogen is supplied from the nitrogen supply unit 9 and low-calorie gas is supplied from the low-calorie gas supply unit 8. The combustion air is supplied from the air supply unit 13 to the air chamber 15.

The low-calorie gas is mixed with nitrogen in the fuel / air mixing chamber 14 and then injected into the combustor liner 1 through the low-calorie gas opening 4. On the other hand, air is injected from the air opening 5 into the combustor liner. The low-calorie gas is thoroughly mixed and diluted with nitrogen before burning, and the calorific value is reduced.

As described above, in this embodiment, the total amount of the low-calorie gas is diluted with nitrogen, so that the flame temperature during combustion is kept low and the generation of NOx is suppressed.

FIG. 9 is a schematic perspective view of the seventh embodiment of the present invention. In this figure, the fuel injection nozzle 30 has the liquid fuel injection nozzle 3 arranged on its head, and the liquid fuel supply unit 7
Is supplied with liquid fuel. Inside the fuel injection nozzle 30, there is provided an air swirler 34 for swirling the air supplied from the air supply unit 13 and flowing it into the central portion. The air swirls as a swirling air flow 32 as a premixing zone 35.
Is injected into. The low-calorie gas and nitrogen are supplied to the low-calorie gas and nitrogen mixer 33 from the low-calorie gas supply unit 8 and the nitrogen supply unit 9, respectively, and are mixed therein. The low-calorie gas / nitrogen mixed air flow 31 is injected into the swirling air flow 32 and mixed therewith, and is injected as a fuel / nitrogen / air premixture 36 into a combustor liner (not shown) for combustion.

Since the low-calorie gas is constituted as described above, the low-calorie gas is mixed with nitrogen in the low-calorie gas and the nitrogen mixer 33 before combustion, and then jetted into the swirling airflow as the low-calorie gas nitrogen mixed airflow 31. . As a result, the low-calorie gas is diluted by being completely mixed with nitrogen before combustion, and the initial heat amount is reduced.

Also in this embodiment, since the total amount of the low-calorie gas is diluted with nitrogen, the flame temperature during combustion is kept low and the generation of NOx is suppressed.

[0041]

As is apparent from the above, the low-calorie gas combustor of the present invention has a means for supplying nitrogen to the combustor and is capable of obtaining high combustion stability while suppressing the generation of NOx. it can.

[Brief description of drawings]

FIG. 1 is a schematic side view of a first embodiment of the present invention.

FIG. 2 is a view on arrow AA.

FIG. 3 is a diagram corresponding to FIG. 2 of the second embodiment of the present invention.

FIG. 4 is a diagram corresponding to FIG. 2 of the third embodiment of the present invention.

FIG. 5 is a diagram corresponding to FIG. 2 of the fourth embodiment of the present invention.

FIG. 6 is a diagram corresponding to FIG. 1 of a fifth embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 1 of a sixth embodiment of the present invention.

FIG. 8 is a diagram corresponding to FIG. 2 of the sixth embodiment of the present invention.

FIG. 9 is a schematic perspective view of a seventh embodiment of the present invention.

FIG. 10 is a sectional view of a conventional combustor.

11 is a cross-sectional view taken along the line AA of FIG.

FIG. 12 is a flow chart of a recent gasification plant.

[Explanation of symbols]

 1 ... Combustor liner 2 Fuel injection nozzle 3 Liquid fuel nozzle 4 Low calorie gas opening 5 Air opening 6 Nitrogen opening 7 Liquid fuel Supply unit 8 ... Low calorie gas supply unit 9 ... Nitrogen supply unit 10 ... Combustion gas 11 ... Combustion region 12 ... Air holes 13 ... Air supply unit 21 ... Premix duct 22 ………… Low-calorie gas injection nozzle 23 ………… Nitrogen injection nozzle

Claims (4)

[Claims] 1. A low-calorie gas turbine combustor for burning low-calorie gas fuel, comprising a nitrogen gas supply means. 2. A gas turbine combustion system for low-calorie gas according to claim 1, further comprising a phosphorus injection nozzle having an opening for injecting low-calorie gas, nitrogen, and air into the combustor liner. vessel. 3. The gas turbine combustor for low-calorie gas according to claim 1, further comprising a premixing duct for premixing the low-calorie gas, nitrogen and air. 4. The fuel injection nozzle of claim 1 including a fuel injection nozzle having means for premixing the low calorie gases, nitrogen and air prior to injection into the combustor liner. Turbine combustor for calorie gas.