JP7344177B2 - Gas turbine combustion control method - Google Patents

Description

The present invention relates to a combustion control method for a gas turbine, and particularly to a combustion control method at times other than rated load.

In diffusion combustion, in which combustion gas is injected into an air atmosphere, the combustion gas and air are not sufficiently mixed and combustion occurs in a highly concentrated state, resulting in high combustion temperatures and NOx (nitrogen oxide) emissions. Concentration increases. Therefore, the NOx concentration can be reduced by injecting steam or water into the combustion region to lower the combustion temperature.
However, a large amount of water is required relative to the amount of fuel supplied, which may reduce the efficiency of the gas turbine plant.

For this reason, diluted premix combustion is employed, which allows low NOx emissions to be emitted without injecting steam or water. In dilute premix combustion, combustion gas is mixed with air and the mixed gas diluted to a low concentration is supplied to the combustion region to cause combustion. Since the combustion temperature of this premixture becomes low, the generation of NOx is suppressed and NOx with a low concentration is discharged.

On the other hand, in order to ensure stable combustion under rated load, the engine is operated so that the fuel equivalence ratio, which is an indicator of the fuel concentration in the air-fuel mixture, is optimized. During high-load rated operation, combustion is stably promoted and NOx emissions are reduced.
While combustion is stable under rated load, when under partial load the amount of air supplied becomes excessive compared to under rated load, leading to lean burn and incomplete combustion.

By the way, for example, facilities such as factories in which gas turbines are installed are operated at full capacity during the day at rated load, but at night and on holidays, they are often operated at partial load. Additionally, when there is a planned power outage in the event of a disaster such as a typhoon or earthquake, the electricity generated by gas turbines is used to transmit power to important facilities such as server centers. Part-load operation at low loads is required. Even during such partial load operation, stable combustion and low NOx emissions are required.

At part load, less fuel is required and the fuel equivalence ratio is lower. If premixed combustion is performed under such conditions, combustion will become unstable, leading to concerns about combustion vibration and misfire, and there is a possibility that normal operation cannot be expected. Note that although stable operation can be expected by performing diffusion combustion, as described above, the amount of NOx emissions will increase.

In order to prevent lean burn during partial loads, Patent Document 1 discloses that the amount of air is adjusted using a variable air flow rate adjusting vane provided in front of the compressed air intake, and an appropriate fuel/air ratio range is achieved. Environmentally friendly gas turbines that aim to reduce exhaust emissions have been proposed.

Further, US Pat. No. 5,001,202 describes a gas turbine engine including at least one compressor with at least one row of adjustable variable vanes for controlling inlet air mass flow, at least one combustor, and at least one turbine is provided and has a control system, the control system being functionally related to at least one measured temperature value measured upstream of the compressor or directly to the compressor. Gas turbine systems have been proposed that control the position of variable blades with respect to measurable quantities.

Japanese Unexamined Patent Publication No. 61-58928 Japanese Patent Application Publication No. 2011-27106

In the environmentally friendly gas turbine described in Patent Document 1, a throttle valve installed in the inlet duct is throttled when there is excess air at low load to reduce the flow rate of air entering the compressor, thereby ensuring proper combustion within the combustor. The air ratio is set to Moreover, the control method for a gas turbine system described in Patent Document 2 controls the position of a variable blade based on a temperature value etc. measured upstream of a compressor.

This invention aims to reduce NOx emissions by controlling combustion using an inlet guide vane (IGV) to enable stable premix combustion even under partial load. .

In order to achieve the above object, a combustion control method for a gas turbine according to the present invention includes a compressor, a combustor using premix combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied. , an inlet guide vane is arranged on the intake side of the compressor, and measures either the turbine inlet gas temperature or the turbine exhaust gas temperature, or both. It is characterized in that the opening area of the inlet guide blade is adjusted with respect to the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature based on the relationship with either or both of the exhaust gas temperatures.

The equivalence ratio of fuel and air at which combustion is stable and the amount of NOx discharged is good is determined in advance, and the relationship between this ratio and one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature is determined. Then, using either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature as a parameter, the actuator etc. are driven to change the opening degree of the inlet guide vane to adjust the air amount and achieve combustion with a stable equivalence ratio. Adjust the value so that it is possible.

Further, a combustion control method for a gas turbine according to the present invention includes a compressor, a combustor using premix combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied; An inlet guide vane is arranged in the combustor, a pilot fuel nozzle is arranged in the center of the combustor inner cylinder, a plurality of premixing tubes equipped with main fuel nozzles are arranged around the pilot fuel nozzle, and the turbine Either or both of the inlet gas temperature and the turbine exhaust gas temperature are measured, and based on the relationship between the fuel equivalence ratio measured and set in advance and either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature. , the opening area of the inlet guide blade is adjusted with respect to the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature.

That is, the turbine is equipped with a combustor that performs premix combustion. The premixing tube has a structure in which a plurality of premixing tubes are installed around a pilot fuel nozzle, and each premixing tube is provided with a main fuel nozzle.

Further, a combustion control method for a gas turbine according to the present invention includes a compressor, a combustor using premix combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied; An inlet guide vane is arranged in the combustor, a pilot fuel nozzle is arranged in the center of the combustor inner cylinder, a plurality of premixing tubes equipped with main fuel nozzles are arranged around the pilot fuel nozzle, and the turbine Either or both of the inlet gas temperature and the turbine exhaust gas temperature are measured, and based on the relationship between the pre-measured and set fuel equivalence ratio and either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature. , the number of premixing pipes through which main fuel is injected is adjusted with respect to the measured temperature of the turbine inlet gas temperature or the turbine exhaust gas temperature.

The amount of main fuel injected from the main fuel nozzle is adjusted by increasing or decreasing the number of premixing tubes with respect to the measured temperature of one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature. For example, when six premixing tubes are provided, main fuel is injected from all premixing tubes during rated load operation, and from two premixing tubes during partial load operation. Then, as the load increases, the number of premixing tubes to be injected is increased. Note that the presence or absence of injection is determined by opening and closing a regulating valve disposed in a supply pipe that supplies main fuel to a main fuel nozzle.

Further, a combustion control method for a gas turbine according to the present invention includes a compressor, a combustor using premix combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied; An inlet guide vane is arranged in the combustor, a pilot fuel nozzle is arranged in the center of the combustor inner cylinder, a plurality of premixing tubes equipped with main fuel nozzles are arranged around the pilot fuel nozzle, and the turbine Either or both of the inlet gas temperature and the turbine exhaust gas temperature are measured, and based on the relationship between the fuel equivalence ratio measured and set in advance and either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature. The present invention is characterized by adjusting the opening area of the inlet guide vane and/or adjusting the number of premixing tubes that inject the main fuel with respect to the measured turbine inlet gas temperature or turbine exhaust gas temperature.

Measure one or both of the turbine inlet gas temperature and the turbine exhaust gas temperature, and adjust the opening area of the inlet guide vane and/or the number of injections of the premixing tube according to the load at the time. This allows for stable combustion.

Further, in the combustion control method for a gas turbine described above, the equivalence ratio is such that the turbine blade is in a state where the equivalence ratio is a value that satisfies each reference value of the metal temperature of the turbine blade, combustion vibration, combustion efficiency, and NOx concentration of exhaust gas. It is preferable to determine the relationship with the inlet gas temperature or the turbine exhaust gas temperature and adjust the opening area of the inlet guide vane from the measured temperature based on this relationship.

When finding the optimal equivalence ratio value,
(1) The metal temperature of the turbine blade is below the design upper limit.
(2) Combustion vibration must be below the standard.
(3) Combustion efficiency must be above the standard.
(4) The NOx concentration of exhaust gas is below the regulation value.
The turbine is operated so as to satisfy the conditions (1) to (4), and the equivalence ratio that satisfies these conditions (1) to (4) is found in advance through tests and analysis.

According to the combustion control method for a gas turbine according to the present invention, stable combustion can be performed even during partial load operation, and the amount of NOx emissions can be reduced.

1 is a graph illustrating a control mode in a gas turbine combustion control method according to the present invention. 1 is a schematic cross-sectional view showing the structure of an example of a gas turbine that implements combustion control according to the present invention. 1 is a diagram illustrating a first embodiment of a premixing tube suitable for implementing the combustion control method according to the present invention, and is a perspective view schematically showing the premixing tube. FIG. 4 is a front view of the premixing tube shown in FIG. 3. FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 4. FIG. FIG. 4 is a plan view of the premixing tube shown in FIG. 3; 4 is a sectional view showing the premixing tube shown in FIG. 3 cut along a plane perpendicular to the axis, (A) is a sectional view taken along the line 7A-7A in FIG. 4, (B) is a sectional view taken along the line 7B-7B, and (C ) is a cross-sectional view taken along the line 7C-7C, and (D) is a cross-sectional view taken along the line 7D-7D. 4 is a developed view of the body of the premixing tube of the gas turbine shown in FIG. 3. FIG. FIG. 2 is a diagram illustrating a second embodiment of a premixing tube suitable for carrying out the combustion control method according to the present invention, and is a perspective view schematically showing the premixing tube. 10 is a front view of the premixing tube shown in FIG. 9. FIG. 11 is a cross-sectional view taken along line 11-11 in FIG. 10. FIG. FIG. 2 is a diagram illustrating the state of air intake in a premixing tube, and is a cross-sectional view taken along a plane along an axis. 13 is a diagram showing a premixing tube having a structure in which air is taken in in the axial direction, and is a sectional view corresponding to FIG. 12. FIG.

A combustion control method for a gas turbine according to the present invention will be described based on the illustrated embodiments.
First, with reference to FIG. 2, an outline of an embodiment of a gas turbine to which a combustion control method according to the present invention is implemented will be described.

In the gas turbine 100, air sucked from an air suction port 101 is supplied to a compressor 102 through an inlet guide vane 101a and compressed, and this compressed air is guided to a combustor 103. This combustor 103 has a double structure of a combustor outer cylinder 103a and a combustor inner cylinder 103b, and compressed air is guided to the outside of the combustor inner cylinder 103b.

An appropriate number of premixing tubes 1 are mounted on the upper part of the combustor inner cylinder 103b of the combustor 103 and are arranged at approximately equal intervals on the circumference around the axis of the combustor inner cylinder 103b. The lower part of the premixing tube 1 communicates with the inside of the combustor inner cylinder 103b, and the upper part is provided with a main fuel nozzle 110 to which the main fuel is supplied, so that the main fuel is supplied to the inside of the combustor inner cylinder 103b. Injected. The main fuel is separately supplied to each main fuel nozzle 110 from a fuel supply pipe 110a, and this fuel supply pipe 110a is provided with an adjustment valve 110b for adjusting the amount of main fuel supplied. By opening and closing this regulating valve 110b, it is possible to adjust the supply amount of the main fuel, and to supply and shut off the main fuel. Therefore, the injection amount of the main fuel can be adjusted individually for each of the main fuel nozzles 110. Further, although only one main fuel nozzle 110 is shown in FIG. 2, the main fuel is similarly supplied to each of the plurality of main fuel nozzles 110 through the fuel supply pipe 110a via the regulating valve 110b. Supplied.

A pilot fuel nozzle 111 is arranged at the upper center of the combustor inner cylinder 103b, and pilot fuel is injected into the combustor inner cylinder 103b. The injected pilot fuel is ignited by an ignition device (not shown).
The compressed air guided to the outside of the combustor inner cylinder 103b is guided to the premixing tube 1 and mixed with the combustion gas of the main fuel to generate a mixed gas, which is then combusted from the lower part of the premixing tube 1. It is injected into the interior of the internal cylinder 103b to promote combustion and generate high-temperature, high-pressure working gas.
Working gas generated in the combustor 103 is guided to the turbine 104, which rotates the turbine blades and rotates the main shaft 105. The rotation of the main shaft 105 rotates the compressor 102 and provides desired output rotation. The working gas used to rotate the turbine 104 becomes exhaust gas and is discharged from the exhaust duct 106.

An inlet temperature measuring device 104a is provided at the inlet of the turbine 104 to measure the turbine inlet gas temperature. Further, the exhaust duct 106 is provided with an exhaust temperature measuring device 106a that measures the temperature of the turbine exhaust gas. The turbine inlet gas temperature and turbine exhaust gas temperature measured by the inlet temperature measuring device 104a and the exhaust temperature measuring device 106a, respectively, are provided to the control device 115.

By the way, when the gas turbine 100 is operated, the metal temperature of the turbine blade, combustion vibration, combustion efficiency, and NOx concentration of exhaust gas are measured, and it is determined that the metal temperature is below the design upper limit value and the combustion vibration is below the standard. The equivalence ratio of fuel and air is determined when the combustion efficiency is above the standard and the NOx concentration of the exhaust gas is below the regulation value, and the inlet temperature measuring device 104a measures the equivalence ratio with respect to this equivalence ratio. The relationship between the turbine inlet gas temperature and the turbine exhaust gas temperature measured by the exhaust temperature measuring device 106a is determined in advance, and the relationship is registered in the control device 115.
For example, the optimum fuel equivalence ratio is found through testing or analysis based on the relationship between turbine blade metal temperature, combustion vibration, combustion efficiency, and NOx concentration of exhaust gas.
In FIG. 1, the vertical axis shows the reference value, the horizontal axis shows the opening degree of the inlet guide blade 101a, the solid line shows the turbine blade metal temperature, the broken line shows the combustion efficiency, the one-dot chain line shows the combustion vibration, and the two-dot chain line shows the NOx Concentrations are indicated for each. Further, C, T, and V on the vertical axis respectively indicate the reference values of the equivalence ratio combustion efficiency, the turbine blade metal temperature, and the combustion vibration for stable combustion. Then, the opening adjustment range of the inlet guide blade 101a is such that the turbine blade metal temperature is below the reference value (design upper limit) T, the combustion efficiency is above the reference value C, the combustion vibration is below the reference value V, and the NOx concentration is below the regulation value. Find R. Note that the IGV opening degree corresponding to the reference value V is shown as v, the IGV opening degree corresponding to the reference time T is shown as t, and the IGV opening degree corresponding to the reference value C is shown as c. As shown in FIG. 1, the opening adjustment range R is between the opening degree c and the opening degree t. Then, the relationship between the turbine inlet gas temperature and the turbine exhaust gas temperature at which an equivalence ratio that maintains stable combustion is obtained is determined, and this relationship is registered in the control device 115.
Note that the regulation value of the NOx concentration is a value on the narrower side than the opening degree t in FIG. 1, and in the opening range R, the NOx concentration is below the regulation value.

Further, the output signal of the control device 115 is a drive signal for an actuator that adjusts the opening degree of the inlet guide blade 101a.

Next, combustion control of the gas turbine will be explained.
Measured values of the turbine inlet gas temperature measured by the inlet temperature measuring device 104a and the turbine exhaust gas temperature measured by the exhaust temperature measuring device 106a are input to the control device 115. The control device 115 outputs a drive signal to the actuator of the inlet guide blade 101a so that the opening range R corresponds to the measured values of either or both of the input turbine inlet gas temperature and turbine exhaust gas temperature. As a result, the opening degree of the inlet guide vane 101a is changed, and the amount of air supplied is adjusted to an equivalence ratio that allows good combustion to be maintained. Therefore, even when the load fluctuates and the engine is operated under partial load, stable combustion can be maintained, and the NOx concentration of the exhaust gas can be kept almost constant.
Note that it is preferable to use the turbine exhaust gas temperature as a parameter because a simpler measuring device is required to measure the turbine exhaust gas temperature than to measure the turbine inlet gas temperature, and the measurement is simpler.

Next, the structure of a premixing tube included in a gas turbine using this combustion control method will be described.

3 to 8 show a premixing tube 1 having a structure according to a first embodiment. In this premixing tube 1, the upper part of a cylindrical body part 1a is closed by a bottom plate 1b except for the center part, and a nozzle support pipe 11 for holding a main fuel nozzle 110 is installed in the center part of this bottom plate 1b. , are attached via a seal 11a. Note that the nozzle support tube 11 side of the premixing tube 1 is on the upstream side of the main fuel flow.
Further, the lower part of the body part 1a, that is, the downstream side of the flow of the main fuel, is continuous with a conical body part 1c, which is a cylindrical body whose diameter is gradually reduced so that the lower part has a smaller diameter. Further, an inclined pipe portion 1e continues from the conical body portion 1c so that the opening 1d is oriented in a direction offset from the direction of the axis C of the body portion 1a. Moreover, this opening 1d is circular, as shown in FIG.

An appropriate number of air holes 1a1, 1a2, 1a3, and 1a4 are formed in the body 1a of the premixing tube 1. As shown in the developed view of FIG. 8, these air holes 1a1, 1a2, 1a3, and 1a4 are different in number from the number of air holes 1a1 formed in the circumferential direction on the upstream side of the premixing tube 1 to the circumferential direction on the downstream side. The number is greater than the number of air holes 1a2 to 1a4 formed. In this embodiment, four rows of air holes 1a1, 1a2, 1a3, and 1a4 are arranged in parallel in the direction of the axis C, but the air holes 1a1 on the most upstream side are 16 in number, and the other air holes 1a1 are 16 in number. There are eight air holes 1a2, 1a3, and 1a4 arranged at positions.
The positional relationship of these air holes 1a1, 1a2, 1a3, and 1a4 is shown in FIGS. 7 and 8. FIG. 7(A) is a cross-sectional view taken along line 7A-7A in FIG. 4 at a plane perpendicular to axis C, and 16 air holes 1a1 are arranged in this portion. Moreover, FIG. 7(B) is a cross-sectional view taken along the line 7B-7B in FIG. air holes 1a2 are arranged. These eight air holes 1a2 are arranged at positions that overlap every other one of the 16 air holes 1a1 in the direction of the axis C. In addition, there are eight air holes 1a3 arranged immediately downstream of the air hole 1a2, and as shown in FIGS. 7(B) and 7(C), the positions of the air holes 1a2 and They are arranged at positions shifted at an angle of 22.5° in the circumferential direction. Eight air holes 1a4 arranged at the most downstream side are arranged in the circumferential direction, and as shown in FIG. 7(B) and FIG. 7(D), these air holes 1a4 are It is arranged at the same position as the hole 1a2 in the axis C direction.
Note that by arranging the air holes 1a2, 1a3, and 1a4 at positions shifted by an angle of 15 degrees, all of these air holes 1a2, 1a3, and 1a4 are placed at positions shifted in the direction along the axis C. It doesn't matter what you place.
Furthermore, the air holes 1a1, 1a2, 1a3, and 1a4 may have different diameters. In this case, it is preferable to increase the diameter of the air hole 1a1 arranged on the upstream side. Further, the diameter may be gradually reduced toward the downstream side, or the diameters of the air holes 1a2, 1a3, and 1a4 may be made equal.

As shown in FIG. 2, the premixing tube 1 is arranged with the opening 1d directed toward the center of the combustor inner cylinder 103b. Therefore, the mixed gas is injected toward the flame ignited by the pilot fuel.
Further, as described above, each of the premixing pipes 1 is provided with a main fuel nozzle 110, and main fuel is supplied to this main fuel nozzle 110 from the fuel supply pipe 110a via the regulating valve 110b. Ru. Further, a drive signal is input from the control device 115 to an actuator that opens and closes the regulating valve 110b.

Next, the operation of this premixing tube 1 will be explained below.
In this premixing tube 1, compressed air is introduced from air holes 1a1, 1a2, 1a3, and 1a4 formed in the body part 1a to the combustion gas of the main fuel injected from the main fuel nozzle 110, and the combustion gas is are diluted and mixed inside the premixing tube 1 to produce a mixed gas. The combustion gas is at its highest concentration immediately after being injected by the main fuel nozzle 110. In this premixing tube 1, the number of air holes 1a1 on the most upstream side is larger than the number of air holes 1a2, 1a3, and 1a4 on the downstream side, so a large amount of air is emitted from the air holes 1a1 on the most upstream side. Air is introduced. Therefore, dilution of the highly concentrated combustion gas is promoted.
In addition, since the air holes 1a2, 1a3, and 1a4 are arranged at shifted positions in the circumferential direction, the position where the air hole 1a2 does not face, that is, the position where the middle position between the adjacent air holes 1a2 in the circumferential direction faces. It is difficult for air to be introduced into the combustion gas passing through. However, since the air hole 1a3 arranged downstream of the air hole 1a2 is arranged at a position shifted from the air hole 1a2, the combustion gas that has passed through the part where the air hole 1a2 is not formed is It is diluted by air introduced from the air hole 1a3. Therefore, the supplied combustion gas as a whole is evenly mixed with air, diluted to a desired state, and then combusted to generate high-temperature, high-pressure working gas.
In addition, since the downstream part of the premixing tube 1 is formed with the opening 1d having a smaller diameter than the body part 1a, the flow velocity of the mixed gas injected from the opening 1d increases. Therefore, the flame of the pilot fuel is injected at high speed, so that the flame of the ignited combustion gas does not backfire.

The working gas that has driven the turbine 104 is then exhausted from the exhaust duct 106. The exhaust gas to be discharged has a low combustion gas concentration of the mixed gas diluted by mixing in the premixing tube 1, so the amount of NOx discharged is small.

9 to 11 show a premixing tube 2 having a structure according to a second embodiment. The same parts of the premixing tube 2 according to this embodiment as the premixing tube 1 according to the first embodiment shown in FIGS. 3 to 8 are given the same reference numerals.
At the upper part of the body 2a of the premixing tube 2, there is provided a lid 2b which is formed separately from the body 2a and has a nozzle support tube 11 attached to the center thereof via a seal 11a.
At the lower part of the body part 2a, there is a connection body part 2c in which the upper end part on the upstream side is circular and continuous with the body part 2a and gradually reduces in diameter toward the downstream side, and the lower end part on the downstream side is formed in a square shape. are continuous.
The upper end of a rectangular inclined tube section 2e that is continuous with the connecting body section 2c is connected to the lower end of this connecting body section 2c, and the opening of the lower end of this inclined tube section 2e is oriented in the direction of the axis C. It is designed to point in a biased direction. That is, the opening 2d is square, as shown in FIG.

The body 2a of the premixing tube 2 is provided with an appropriate number of air holes 2a1, 2a2, 2a3, and 2a4, similar to the body 1a of the premixing tube 1 according to the first embodiment. These air holes 2a1, 2a2, 2a3, and 2a4 are arranged in the same number and in the same position as the air holes 1a1, 1a2, 1a3, and 1a4 formed in the body portion 1a of the premixing tube 1. Therefore, regarding the air holes 2a1, 2a2, 2a3, and 2a4 formed in the body 2a, FIGS. ) has the same cross-sectional shape.

As in the case of the premixing tube 1, this premixing tube 2 is also arranged with the opening 2d facing the center of the combustor inner cylinder 103b, as shown in FIG. 2, and the pilot fuel is ignited. The mixed gas is injected towards the flame. Furthermore, since the opening area of the opening 2d is smaller than the cross-sectional area of the body portion 2a, the flow velocity of the mixed gas increases and flashback is prevented.

A plurality of premixing tubes 1 and 2 are arranged circumferentially in the upper part of the combustor inner cylinder 103b, and each provided main fuel nozzle 110 has a fuel supply tube 110a for supplying main fuel. A regulating valve 110b is interposed therein. A drive signal is input from the control device 115 to the actuator responsible for opening and closing the regulating valve 110b.
When the load on the turbine changes, the regulating valve 110b is opened or closed based on a drive signal from the control device 115, and the number of main fuel nozzles 110 that inject the main fuel is changed. That is, during partial load operation, the number of main fuel nozzles 110 to be injected is reduced to reduce the injection amount of main fuel, and as the load increases, the injection amount is increased.
For example, six premixing tubes 1 and 2 are arranged, and during partial load operation, the main fuel is injected from the main fuel nozzles 110 of the two premixing tubes 1 and 2, and during rated load operation, the main fuel is injected from the main fuel nozzles 110 of the two premixing tubes 1 and 2. The fuel is injected from the fuel nozzle 110.
Therefore, by reducing the amount of main fuel in accordance with the increase or decrease in load, the equivalence ratio is adjusted and good combustion can be maintained.

In addition to increasing or decreasing the number of injections from the main fuel nozzles 110, combustion control of the turbine can also be performed by changing the opening degree of the inlet guide vanes 101a.
More stable combustion can be maintained by controlling combustion of the turbine by combining an increase or decrease in the number of injections of the main fuel nozzles 110 and a change in the opening degree of the inlet guide vanes 101a.

In the premixing tubes 1 and 2 described above, as shown in FIG. 12, premixing air for diluting the combustion gas is supplied from the sides of the body parts 1a and 2a.
On the other hand, FIG. 13 shows a structure in which air is taken in from the upper opening 4a of the premixing tube 4. Since this premixing tube 4 has a structure in which air is taken in from above, it is necessary to increase the distance between the canopy 112 of the gas turbine 100 and the upper opening 4a of the premixing tube 4.
On the other hand, in the premixing tubes 1 and 2 having the structure according to the present invention, air is taken in from the side, so that there is a gap between the upper part of the premixing tubes 1 and 2 and the canopy 112, as shown in FIG. The distance can be made small.
Therefore, the height of the gas turbine 100 can be reduced and the size of the gas turbine 100 can be reduced.

According to the combustion control method for a gas turbine according to the present invention, stable combustion can be maintained even when there are load fluctuations, and in particular, combustion can be stabilized during partial load operation such as at night, and the gas turbine contributes to highly efficient operation.

1 Premixing tube 1a Body 1b Bottom plate 1c Conical body 1d Opening 1e Inclined tube 1a1, 1a2, 1a3, 1a4 Air hole 11 Nozzle support tube 11a Seal 2 Premixing tube 2a Body 2b Lid 2c Connection body 2d Opening 2e Inclined pipe portion 2a1, 2a2, 2a3, 2a4 Air hole 100 Gas turbine 101 Air suction port 101a Inlet guide vane 102 Compressor 103 Combustor 103a Combustor outer cylinder 103b Combustor inner cylinder 104 Turbine 104a Inlet temperature measuring device 105 Main shaft 106 Exhaust duct 106a Exhaust temperature measuring device 110 Main fuel nozzle 110a Fuel supply pipe 110b Adjustment valve 111 Pilot fuel nozzle 112 Canopy 115 Control device C Axis R Opening range

Claims (4)

Comprising a compressor, a combustor using premix combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied,
An inlet guide vane is placed on the intake side of the compressor.
A pilot fuel nozzle is located in the center of the combustor inner cylinder,
A main fuel nozzle is provided around the pilot fuel nozzle, and a plurality of premixing tubes each having a plurality of air holes formed in a cylindrical body are disposed,
The plurality of air holes are formed in a plurality of rows in the axial direction of the body, and the number of air holes in the row arranged on the upstream side in the flow direction of combustion gas is equal to the number of air holes in the row arranged on the downstream side. formed in greater numbers than
Measuring either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
Based on the relationship between the fuel equivalence ratio measured and set in advance and either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
A combustion control method for a gas turbine, the method comprising adjusting an opening area of an inlet guide blade with respect to a measured turbine inlet gas temperature or a turbine exhaust gas temperature. Comprising a compressor, a combustor using premix combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied,
An inlet guide vane is placed on the intake side of the compressor.
A pilot fuel nozzle is located in the center of the combustor inner cylinder,
A main fuel nozzle is provided around the pilot fuel nozzle, and a plurality of premixing tubes each having a plurality of air holes formed in a cylindrical body are disposed,
The plurality of air holes are formed in a plurality of rows in the axial direction of the body, and the number of air holes in the row arranged on the upstream side in the flow direction of combustion gas is equal to the number of air holes in the row arranged on the downstream side. formed in greater numbers than
Measuring either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
Based on the relationship between the fuel equivalence ratio measured and set in advance and either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
A combustion control method for a gas turbine, the method comprising adjusting the number of premixing tubes through which main fuel is injected with respect to a measured turbine inlet gas temperature or a turbine exhaust gas temperature. Comprising a compressor, a combustor using premix combustion to which compressed air is supplied, and a turbine to which combustion gas is supplied,
An inlet guide vane is placed on the intake side of the compressor.
A pilot fuel nozzle is located in the center of the combustor inner cylinder,
A main fuel nozzle is provided around the pilot fuel nozzle, and a plurality of premixing tubes each having a plurality of air holes formed in a cylindrical body are disposed,
The plurality of air holes are formed in a plurality of rows in the axial direction of the body, and the number of air holes in the row arranged on the upstream side in the flow direction of combustion gas is equal to the number of air holes in the row arranged on the downstream side. formed in greater numbers than
Measuring either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
Based on the relationship between the fuel equivalence ratio measured and set in advance and either or both of the turbine inlet gas temperature and the turbine exhaust gas temperature,
For the measured temperature of turbine inlet gas temperature or turbine exhaust gas temperature,
adjusting the opening area of the inlet guide vanes;
or/and adjusting the number of premixing tubes injecting the main fuel;
A combustion control method for a gas turbine characterized by: A combustion control method for a gas turbine according to any one of claims 1 to 3, comprising:
The equivalence ratio is determined by determining the relationship between the turbine blade metal temperature and the turbine inlet gas temperature or turbine exhaust gas temperature that satisfies the respective reference values of combustion vibration, combustion efficiency, and NOx concentration of exhaust gas. , a combustion control method for a gas turbine, characterized in that the opening area of the inlet guide blade is adjusted from the measured temperature based on this relationship.

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