JPH0783076A - Combustion state grasping method and device to practice this method - Google Patents

Abstract

PURPOSE:To constantly and precisely grasp a combustion state by previously examining a correlation between temperature of a flame holder to hold premixed flame and a combustion state of premixed gas and grasping the combustion state relative to the measured temperature of the flame holder from the correlation. CONSTITUTION:A combustor 10 is furnished with a primary combustion cylinder 13 forming a primary combustion chamber 12 inside of a combustor casing 11 and a secondary combustion cylinder 22 arranged on the downstream side of the primary combustion cylinder 13 and forming a secondary combustion chamber 21. Additionally, at least a premixed burner 23 to inject premixed gas into the secondary combustion chamber 21 and a flame holder 30 to hold premixed flame 29 due to combustion of the premixed gas are furnished. In this case, correlation between temperature of the flame holder 23 and a combustion state of the premixed gas is previously examined. Thereafter, the temperature of the flame holder 30 is measured, for example, by a thermocouple 35. In the meantime, by a control device 100, a combustion state relative to the measured temperature of the flame holder 30 is grasped from the correlation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion state grasping method for a combustor for premixed combustion, an apparatus for executing this grasping method,
And a control device for combustor equipment.

[0002]

2. Description of the Related Art Control of a combustion state in a gas turbine combustor is important in order to reduce exhaust NOx and to make the combustion gas temperature at the combustor outlet uniform so as not to overload the turbine blade. Regarding the technique for controlling the combustion state of the combustor, see, for example, JP-A-60-218535, JP-A-61-135942, JP-A-61-49136, and JP-A-64-29626. Some are listed. These techniques detect the combustion gas temperature at the combustor outlet and control the fuel injection amount according to this temperature, or detect the NOx concentration at the combustor outlet and determine the fuel injection amount according to this concentration. Is to control.

In addition to these techniques, there is also one in which the flame formed in the combustor is imaged and the flame image obtained as a result of the imaging is used to control the fuel injection amount and the like.

[0004]

In recent years, the number of gas turbine combustors performing premixed combustion is increasing in order to reduce the amount of NOx discharged. This premixed combustion is
Although it is superior to diffusion combustion in reducing Ox, it is inferior in flame stability. Therefore, in a combustor that performs premixed combustion, a flame stabilizer is provided at the outlet of the premixed burner, or a swirl flow is formed in the combustion chamber to stabilize the premixed flame.

Basically, it can be said that the combustion gas temperature and NOx concentration at the combustor outlet detected in the prior art have a certain correlation with the combustion state. However, if a flame stabilizer is provided at the exit of the premix burner or a swirl flow is formed in the combustion chamber, the combustion gas temperature and NOx concentration at the exit of the combustor accurately indicate the combustion state on the upstream side. Can't say. In addition, since the combustion cylinder is cooled from the side circumference of the combustion cylinder, air that does not directly affect the combustion is supplied to the combustion chamber, and the combustion gas temperature and NOx concentration at the combustor outlet accurately control the combustion state. It is also one of the reasons for not showing. For this reason, it is possible to directly measure the temperature of the flame itself with a thermometer in order to accurately grasp the combustion state, but since the temperature of the flame is high, there is no thermometer that can withstand this temperature, It cannot directly measure its own temperature. Even if there is a thermometer that can withstand the flame temperature, this thermometer disturbs the flame, which is not preferable in terms of flame stabilization.

In this respect, judging the combustion state from the flame image does not have the above problems because the flame is directly captured. However, as a practical matter, the flame
It is difficult to accurately focus on the flame because it exists in space with a certain extent and the flame itself shakes. In addition, depending on the image capturing direction, the flames may overlap with each other, and it may not be possible to capture the target flame.

That is, the conventional technique has a problem that the combustion state cannot be accurately grasped. The present invention has been made by paying attention to such a conventional problem, and has been grasped by a combustion state grasping method capable of accurately grasping a combustion state, an apparatus for executing this grasping method, and this grasping method. An object of the present invention is to provide a control device that controls combustor equipment according to a combustion state.

[0008]

A combustion state grasping method for achieving the above object is a premixing burner for mixing a fuel and air and ejecting a premixed gas produced by this mixing, and the premixing burner. A combustor having a flame retainer for forming a circulating flow of combustion gas generated by combustion of gas on the downstream side thereof and holding a premixed flame formed by combustion of the premixed gas. In the combustion state grasping method, the temperature of the flame stabilizer and the combustion state of the premixed gas are investigated in advance, the temperature of the flame stabilizer is measured, and the measured temperature of the flame stabilizer is measured. Is grasped from the above correlation.

Here, as the correlation in the combustion state grasping method, specifically, whether the temperature of the flame stabilizer is within a preset temperature range of the flame stabilizer determined with respect to the temperature. Depending on whether the combustion is normal or abnormal, the relationship between the temperature of the flame stabilizer and the air-fuel ratio of the premixed gas, the temperature of the flame stabilizer and the NOx concentration in the combustion gas. And the like, which indicate a relationship with.

Further, a combustion state grasping device for achieving the above object comprises a premixing burner which mixes fuel and air and ejects a premixed gas produced by this mixing, and a premixed burner which burns the premixed gas. Grasp the combustion state of a combustor having a flame stabilizer that forms a circulating flow of the generated combustion gas on its downstream side and holds the premixed flame formed by the combustion of the premixed gas. In the apparatus, the flame stabilizer temperature measuring means for measuring the temperature of the flame stabilizer, and the flame stabilizer temperature measurement from a predetermined correlation between the flame stabilizer temperature and the combustion state of the premixed gas. And a combustion state grasping means for grasping the combustion state with respect to the temperature measured by the means. Here, the combustion state grasping device,
It is preferable to provide a display unit for displaying the combustion state grasped by the combustion state grasping unit.

Further, the control device of the combustor equipment for achieving the above object is grasped by the combustion state grasping device described above and the combustion state grasping means provided in the combustion state grasping device. Depending on the combustion state, the flow rate of the fluid (the fuel or the air) adjusted by the flow rate control valve that controls the flow rate of at least one of the fuel and the air supplied to the premix burner is determined, and the flow rate is determined. Is provided to the flow rate control valve.

[0012]

As described in the prior art, it is possible to predict the combustion state to some extent from the combustion gas temperature at the combustor outlet. However, the combustion gas at the combustor outlet is affected by various effects from the time it is generated by premixed combustion until it reaches the combustor outlet, so the combustion gas temperature at the combustor outlet does not accurately represent the combustion state. I can not say. On the other hand, if the temperature of the premixed flame can be directly measured, it is possible to accurately grasp the combustion state, but because of the fact that there is no thermometer that directly measures the high flame temperature,
It is not possible to understand the combustion state from the temperature of the premixed flame itself.

Therefore, in the present invention, the combustion state is grasped from the temperature of the flame holder for holding the premixed flame. The flame stabilizer forms a circulation flow of the combustion gas generated by premixed combustion on the downstream side of the flame stabilizer to raise the temperature of the downstream side of itself to the ignition point of the premixed gas, thereby premixing the premixed gas. It is intended to stabilize the flame. Therefore, since the combustion gas just generated by the premixed combustion comes into contact with the flame stabilizer, the temperature of the premixed flame is accurately indicated. Therefore, the combustion state can be accurately grasped from the temperature of the flame stabilizer. Moreover, since the temperature of the flame stabilizer is certainly lower than the temperature of the premixed flame, it is also possible to actually measure this temperature with a thermometer.

Further, the present inventors have found that this flame stabilizer temperature and
It was found that there is a certain correlation with the air-fuel ratio, which is one of the indicators showing the combustion state. Therefore, the air-fuel ratio of the premixed gas can be controlled by accurately grasping the air-fuel ratio of the premixed gas using this correlation.

[0015]

EXAMPLES Various examples according to the present invention will be described below.

First, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the gas turbine facility of this embodiment has a compressor 50 that compresses air.
, A plurality of combustors 10, 10, ... Combusting fuel with air compressed by the compressor 50, and these combustors 10,
A gas turbine 60 driven by the combustion gas discharged from 10, and a generator 65 driven by the gas turbine 60.
And a control device 100 for controlling them.

As shown in FIG. 1, the combustor 10 has a cylindrical combustor casing 11, a cylindrical primary combustion cylinder 13 forming a primary combustion chamber 12, and a secondary combustion chamber 21. Secondary combustion cylinder 22 arranged on the downstream side of the cylinder 13.
And a diffusion burner 14 for injecting fuel into the primary combustion chamber 12.
A premixing burner 23 for ejecting the premixed gas into the secondary combustion chamber 21 and a flame stabilizer 30 for holding the premixed flame 29 formed by the combustion of the premixed gas. There is.

The diffusion burner 14 is provided on the central axis of the cylindrical combustor casing 11. Primary combustion cylinder 13
Is provided on the central axis of the cylindrical combustor casing 11 and on the downstream side of the diffusion burner 14. Around the primary combustion cylinder 13, as shown in FIGS. 4 and 5, a plurality of premixing burners 23, 23, ... Are provided in an annular shape. The premix burner 23, as shown in FIG.
And a premixing chamber forming body 25 forming a premixing chamber 24 for mixing the fuel and the air. Premix chamber forming body 25
Has an intake port 26 for taking in the air flowing into the casing 11 at its upstream end, and an injection port 27 for ejecting the premixed gas at its downstream end. Premixing chamber 2
A fuel nozzle 28 is provided on the upstream side within 4.

As shown in FIGS. 1 and 6, the flame stabilizer 30 has a flame stabilizer main body 31 whose cross section is substantially an isosceles triangle shape, and a support leg 32 for supporting the main body 31. Is formed by. Flame stabilizer main body 3 whose cross section is an isosceles triangle
1, the part corresponding to the apex faces the upstream side, the part corresponding to the bottom side faces the downstream side, and the part corresponding to the bottom side is located downstream of the ejection port 27 of the premixing burner 23. It is supported by the support legs 32. As shown in FIG. 5, the flame stabilizer main body 31 has a projected shape in the upstream and downstream directions that corresponds to the plurality of annularly arranged premixing burners 23, 23, ... The premixed gas ejected from the plurality of premixed burners 23, 23, ... Is provided so as to be divided into an outer peripheral side and an inner peripheral side. Flame stabilizer 30
Are fixed in the premix burner 23 to a plurality of flame stabilizer support plates 33, 33, ...
As shown in FIG. 6, inside the flame stabilizer 30, a plurality of thermocouples 35, 35, ... To measure the temperature of the portion corresponding to the bottom side of the flame stabilizer main body 31 having an isosceles triangular cross section. Is embedded. The hole formed for embedding the thermocouple 35 in the flame stabilizer is closed with silver solder or nickel solder 34. The plurality of combustors 10, 10, ... For one gas turbine 60 are usually formed in the same shape, so that each combustor 10, 10 ,. The position of the thermometer (thermocouple) 35 for each combustor is preferably the same. This thermocouple 35,3
5, ... Are connected to a transmitter 36 provided outside the casing via signal lines. The signal from the oscillator 36 is input to the control device 100.

The compressor 50 and the plurality of combustors 10, 10, ...
As shown in FIG. 2, a compressed air line 51 for introducing the air compressed by the compressor 50 to the combustor 10 is provided between and. The compressed air line 51 is provided with a thermometer 53 that measures the temperature of the compressed air, a pressure gauge 54 that measures the air pressure, and a flow meter 52 that measures the air flow rate. As the air flow meter 52, various flow meters such as a thermal mass flow meter, a Pitot tube flow meter, an orifice flow meter, etc. can be considered. The signals from the thermometer 53, pressure gauge 54, and air flow meter 52 are input to the control device 100.

A fuel line for supplying fuel to the plurality of combustors 10, 10, ... Is a main diffusion fuel line 71 and a branch from the main diffusion fuel line 71, as shown in FIG. 10, 10, ... Diffusion burners 14, 14, ...
A plurality of sub-diffusion fuel lines 74 for supplying fuel to
74, a main premixed fuel line 81, and a plurality of auxiliary premixed fuel lines 84, 8 branched from the main premixed fuel line 81 to distribute the premixed fuel to each of the combustors 10, 10 ,.
4, a plurality of premixing burners 23, 23, ... Branching from the auxiliary premixing fuel line 84 and provided in one combustor 10.
There are multiple premix burner fuel lines that distribute premix fuel to each. However, in FIGS. 1 to 3, the premix burner fuel line is omitted for convenience of the drawings. The fuel flowing through each fuel line is the same fuel, which is a gaseous fuel in this embodiment. The main diffusion fuel line 71, the sub diffusion fuel line 74, the main premixed fuel line 81, and the sub premixed fuel line 84 are respectively fuel flow meters 73, 76, 83, 86 for measuring the flow rate of the fuel passing through each line. When,
Fuel control valves 72, 75, 82, 85 are provided.
The flow rate of each fuel control valve 72, 75, 82, 85 for determining the valve opening is controlled by a signal from the control device 100.

As shown in FIG. 3, the control device 100 includes a plurality of thermocouples 35, 35, 35,
A combustion abnormality determining unit 101, 101, for determining whether the combustion in each combustor 10 is abnormal or normal according to the temperature at each position of the flame stabilizer 30 detected by. Average temperature calculator 1 for obtaining the average of the temperatures at each position of the flame stabilizer 30 detected by the plurality of thermocouples 35, 35, ...
02, 102, ..., Air-fuel ratio calculation units 103, 103, ... For obtaining the air-fuel ratio of each combustor 10 from this average temperature, and Average air-fuel ratio calculation unit 104 for obtaining the average air-fuel ratio for each combustor 10. , Air-fuel ratio deviation calculation units 106, 106, ... Which obtain the deviation between this average air-fuel ratio and the air-fuel ratio of each combustor 10.
And a fuel flow rate flowing through the sub-premix fuel line 84 based on the air-fuel ratio deviation of each combustor 10, and outputs the fuel flow rate to the sub-premix fuel control valve 85.
07, 107, ..., and a main premixed fuel amount calculation unit 108 that obtains a fuel flow rate to be flown to the main premixed fuel line 81 in accordance with a load command from the outside and outputs this fuel flow rate to the main premixed fuel control valve 82. And an exhaust NOx concentration predicting unit 105 that predicts the exhaust NOx concentration from the average air-fuel ratio, and a display unit 109 that displays the combustion abnormality determination result, the air-fuel ratio of each combustor 10, the average air-fuel ratio, the exhaust NOx concentration, and the like. Have In addition to the above, the control device 100 includes the diffusion fuel control valves 72, 7.
There is also provided a diffusion fuel amount calculation unit for obtaining control amounts of 5, 75, ....

By the way, the above is the software configuration of the control device 100. In reality, the control device 100 of the present embodiment is configured by an electronic computer. Therefore, the display unit 109 is composed of a display device, and other various functions are stored in various data and programs.
It is configured to have an OM and a RAM, and a CPU that executes various calculations according to these programs and the like.

Next, the operation of this embodiment will be described.
The air used for combustion is compressed by the compressor 50 and supplied to the combustors 10, 10, ... Through the compressed air line 51. A part of the air supplied into the combustor 10 is directly supplied into the primary combustion chamber 12, and the remaining part is supplied into the premixing chamber 24 of the premixing burner 23. Although part of the air is also used for cooling the primary combustion cylinder 13 and the secondary combustion cylinder 22, it is not shown here. On the other hand, the fuel used for the premixed combustion is the main premixed fuel line 81, the sub-premixed fuel lines 84, 84, ... Provided for each of the plurality of combustors 10, 10 ,. ，
23 ... through the premix burner line provided for each
It is supplied to the fuel nozzle 28 of the premix burner 23. The fuel used for diffusion combustion is the main diffusion fuel line 7
1, the plurality of combustors 10, 10, ... Via the sub diffusion fuel lines 74, 74 ,.
Is supplied to.

The air and fuel supplied into the primary combustion chamber 12 are diffused and burned here. The high-temperature combustion gas generated by diffusion combustion flows into the primary combustion chamber 12 and contributes to the stabilization of the premixed flame 29 formed here.

The fuel injected from the fuel nozzle 28 of the premix burner 23 mixes with the air supplied thereto. The premixed gas formed by mixing the fuel and the air is ejected from the ejection port 27 of the burner 23 into the secondary combustion chamber 21, where the premixed combustion is performed. The combustion gas generated by this combustion enters into the circulation flow formed on the downstream side of the flame stabilizer 30, and raises the temperature of the downstream portion of the flame stabilizer 30. As a result, the premixed flame 29 is stably formed on the downstream side of the flame stabilizer 30.

The combustion gas generated by the combustion in each combustor 10 is supplied to the gas turbine 60, and the gas turbine 60
To drive. By driving the gas turbine 60, the generator 65 is driven. The temperature of the flame stabilizer 30 measured by the thermocouple 35 is output to the control device 100 via the transmitter 36 and used for controlling the premixed fuel.

Here, the control of the premixed fuel based on the temperature of the flame stabilizer 30 will be described. Generally, the combustion state in the combustor 10 can be represented by an air-fuel ratio. The present inventors have found that the air-fuel ratio and the temperature of the flame stabilizer 30 are approximately in the following equation. Therefore, as a result of being able to derive the air-fuel ratio from the temperature of the flame stabilizer 30, the combustion state can be grasped from the temperature of the flame stabilizer 30. Tf = T0 + k1 · Ta−k2 · ln (λ) ···· (Equation 1) where Tf: Flame stabilizer temperature ( ℃), T0: Constant (℃), T
a: air temperature (° C.) flowing into the combustor 10, k1: constant (−), k2: constant (° C.), λ: air-fuel ratio (−).

By the way, since the above constants differ depending on the operating conditions and structure of the combustor 10, it is difficult to increase the concrete value of the temperature Tf of the flame stabilizer 30 and the air-fuel ratio λ in relation to this. , As an example, the air-fuel ratio λ
When (λ = 17.4 is the stoichiometric air-fuel ratio, the fuel is methane in this case) from 29.6 to 33.1, the temperature Tf of the flame stabilizer 30 decreases by about 30 ° C.

Further, the relationship between the air-fuel ratio λ and the exhausted NOx concentration is roughly expressed by the following equation if it is limited to the premixed combustion section. NOx = k3−k4 · ln (λ) (Equation 2) where NOx: Emission NOx concentration (ppm), k3: constant (ppm), k4: constant (ppm). Note that (Equation 2) shows the relationship between the NOx concentration and the air-fuel ratio λ, but by combining (Equation 1), it can be transformed into an expression that defines the relationship between the NOx concentration and the flame stabilizer temperature. Needless to say.

The control device 100 grasps the combustion state of each combustor 10 using the above (Equation 1) and (Equation 2), and controls the premixed fuel.

Specifically, signals from a plurality of thermocouples 35, 35, ...
00, the combustion abnormality determination unit 101 provided corresponding to each combustor 10 determines whether the combustion state is abnormal or normal based on this signal. Whether or not the combustion state is abnormal is determined by whether or not the temperature of the flame stabilizer 30 is within a set temperature range defined by preset upper and lower limits. The upper limit value is set to an allowable temperature of the material forming the flame stabilizer 30, for example, 800 ° C. Also, as the lower limit value, a predetermined value from the flame stabilizer 30 temperature calculated from the air-fuel ratio corresponding to the set load, for example, 100 ° C.
Set to the value minus.

When the temperature of the flame stabilizer 30 exceeds the upper limit value, the possibility that the flame stabilizer 30 begins to melt increases, and
In the worst case, there is a risk of flashback. Further, when the temperature of the flame stabilizer 30 is below the lower limit value, misfire is expected. Therefore, a plurality of thermocouples 35, 3 in one combustor 10 are used.
If at least one of the signals from 5, ... goes out of the set temperature range, the main premixed fuel amount calculation unit indicates that there is an abnormality in order to stop the fuel supply to all combustors 10, 10 ,. 108
To fully close the main premixed fuel control valve 82. The main premixed fuel amount calculation unit 108 normally obtains a fuel amount according to a load command signal from the outside, and outputs this fuel amount to the main premixed fuel control valve 82 to determine the main premixed fuel amount. Have control. In this way, the main premixed fuel amount (total premixed fuel amount) is controlled separately from the control of the fuel flow rate to each combustor 10, so that the fuel flow rate to each combustor 10 can be controlled. Even if a time delay or an error occurs, it is possible to prevent the power generation amount from changing.

When there is no combustion abnormality, the temperature of the flame stabilizer 30 is output as it is to the average temperature calculation unit 102, and the average value of the temperature at each position of the flame stabilizer 30 is obtained there. In the air-fuel ratio calculation unit 103, from the flame stabilizer average temperature,
The air-fuel ratio for each combustor is calculated using (Equation 1). In addition,
In calculating the air-fuel ratio using (Equation 1), the combustor 10
The temperature Ta of the air flowing in is required, but the value measured by the thermometer 53 provided in the compressed air line 51 is used. The average air-fuel ratio calculation unit 104 calculates the average value of the air-fuel ratios of all the combustors 10, 10, .... This average air-fuel ratio is output to the air-fuel ratio deviation calculation unit 106, and the deviation from the air-fuel ratio for each combustor is obtained. This air-fuel ratio deviation is output to the sub-premixed fuel amount calculation unit 107, and the sub-premixed fuel amount for each combustor that eliminates this deviation is calculated. However, the sum of the sub-premixed fuel amounts for each combustor 10 becomes the main premixed fuel amount (total premixed fuel amount), and the sum of the main premixed fuel amount and the main diffusion fuel amount is The total fuel quantity must be reached. The sub-premixed fuel amount for each combustor is output to the sub-premixed fuel control valve 85 provided for each combustor, and the flow rate of the fuel flowing through the sub-premixed fuel line 84 is adjusted to this fuel amount. Adjusted.

The average air-fuel ratio is also output to the exhausted NOx concentration predicting section 105, and the exhausted NOx concentration is predicted from this average air-fuel ratio using (Equation 2). If the predicted result exceeds the preset upper limit value, the emission NO
To reduce the x concentration, the average air-fuel ratio corresponding to the amount exceeding the upper limit value is output to each air-fuel ratio deviation calculation unit 106. The newly calculated average air-fuel ratio is a value larger than the air-fuel ratio calculated by the average air-fuel ratio calculation unit 104 (the air amount is larger than the fuel amount). Each air-fuel ratio deviation calculation unit 106
Then, the deviation between the newly obtained average air-fuel ratio and the air-fuel ratio of each combustor is obtained.

Any of the combustion abnormality determining units 101, 10
When it is determined that the combustion is abnormal, the combustor 10, 10, ...
Is displayed in. In addition to this, the display unit 109 also displays the air-fuel ratio of each combustor, the average air-fuel ratio of all combustors 10, 10, ..., And the exhausted NOx concentration.

As described above, in this embodiment, the flame stabilizer 30 is used.
Since the combustion state is grasped from the temperature of, the temperature of the premixed flame 29 formed on the downstream side of the flame stabilizer 30 is substantially directly measured, and the premixed combustion state is grasped accurately. be able to.

Normally, when a plurality of combustors 10 having the same specifications are provided for one gas turbine 60 as in this embodiment, even if each combustor 10 has the same specifications, in reality, Manufacturing accuracy error for each combustor, difference in pipe length,
Due to the difference in the length of the gas flow path, the combustion characteristics of the combustor 10
Each is different. When the combustion characteristics differ from one combustor 10 to another, naturally, the characteristics of the combustion gas discharged from each combustor 10 (specifically, the gas temperature and NOx concentration) also differ. As a result, the load on the blades of the gas turbine 60 becomes uneven, the life of the gas turbine 60 is shortened, and the amount of NOx exhausted from some combustors 10 increases. , And the like, the average value of the amount of NOx discharged from the vehicle increases, and other problems occur. In this embodiment, the air-fuel ratio of each combustor is obtained, and the air-fuel ratio of each combustor is controlled to be the average air-fuel ratio of all combustors 10, 10 ,. The load is leveled,
The above problems can be avoided.

When the exhausted NOx concentration exceeds the upper limit value, the average air-fuel ratio is increased and the air-fuel ratio of each combustor 10 is controlled to this average air-fuel ratio. Can be reduced.

In this embodiment, one combustor 1
For one flame stabilizer 30 at 0, a plurality of thermocouples 3
, 35, ... are provided for the purpose of accurately grasping the combustion state in one combustor 10, and when it is not necessary, a thermocouple for one flame stabilizer 30 is provided. Only one 35 may be provided. In such a case, it goes without saying that the average temperature calculation unit 102 of the control device 100 in the present embodiment is unnecessary.

Further, in the present embodiment, these values are obtained in order to display the air-fuel ratio of each combustor and the average air-fuel ratio of all combustors 10, 10 ,. Since it itself indicates the combustion state, all the combustors 10, 1 are calculated from the average temperature of the flame stabilizer for each combustor without obtaining the air-fuel ratio.
The flame stabilizer average temperature of 0, ... Is obtained, and the sub-premixed fuel is controlled according to the deviation between the flame stabilizer average temperature of each combustor and the flame stabilizer average temperature of all combustors 10, 10. You may

Next, a second embodiment according to the present invention will be described with reference to FIG. In this embodiment, one combustor 10 is used.
It controls the combustion state in each part inside. First
A plurality of premix burners 2 such as the combustor 10 of the embodiment of
In the combustor 10 provided with 3, 23, ..., Premixed burner fuel lines (not shown in FIG. 3 showing the first embodiment) 87, 87, ... Are provided for each burner. Therefore, in this embodiment, as in the first embodiment, each combustor 10 is
, Rather than controlling the amount of sub-premixed fuel supplied to the pre-mixed burners 23, 23 ,. The premix burner fuel line 87 is provided with a premix burner fuel control valve 88.

The controller 100a determines whether the combustion inside the combustor 10 is abnormal according to the temperature of the flame stabilizer 30 detected by the plurality of thermocouples 35, 35, ... A combustion abnormality determination unit 101 that determines whether the temperature is normal, and a temperature that determines the air-fuel ratio of the fuel region corresponding to the temperature detection position from the temperature at each location of the flame stabilizer 30 detected by the plurality of thermocouples 35, 35 ,. ..., an average air-fuel ratio calculation unit 104a that obtains the average of the air-fuel ratios calculated by the air-fuel ratio calculation unit 103a, and an air-fuel ratio of the fuel region corresponding to the average air-fuel ratio and the temperature detection position. , And a premixed burner fuel amount calculation for obtaining a premixed fuel amount for each premixed burner based on the air-fuel ratio deviation for each fuel region corresponding to the temperature detection position. Parts 107a, 10 a, ... a, Shu予 mixed fuel calculation unit 108 for obtaining the Shu予 mixed fuel amount corresponding to the load command from the outside
And a display unit 109 that displays the combustion abnormality determination result, the air-fuel ratio and the average air-fuel ratio of the fuel region corresponding to the temperature detection position, and the like.
And have. These various functions of the control device 100a are
Except for the display unit 109 and the main premixed fuel amount calculation unit 108, all are provided corresponding to each combustor. The present embodiment has the same hardware configuration as the first embodiment except that the premix burner fuel control valve 88 is provided in the premix burner fuel line 87.

Next, the operation of this embodiment will be described.
The signals from the plurality of thermocouples 35, 35, ...
When 0 is input, the combustion abnormality determination unit 10 determines whether the fuel area corresponding to the temperature detection position of the flame stabilizer 30 is abnormal or normal.
1 does. Similar to the first embodiment, the determination as to whether or not the combustion is abnormal is made based on whether or not the temperature of the flame stabilizer 30 is within the set temperature range defined by the preset upper and lower limits. To be done. Multiple thermocouples 3 in one combustor 10
If at least one of the signals from 5, 35, ... Is out of the set temperature range, it is determined that there is an abnormality in order to stop the fuel supply to all combustors 10, 10 ,. Output to the calculation unit 108 to fully close the main premixed fuel control valve 82.

When there is no combustion abnormality, each air-fuel ratio calculation unit 103a, 103a, ... Calculates the air-fuel ratio of each fuel region corresponding to each temperature detection position of the flame stabilizer 30 by (Equation 1). The average air-fuel ratio calculation unit 104a obtains the average value of the air-fuel ratio of each fuel region corresponding to each temperature detection position of the flame stabilizer 30. This average air-fuel ratio is calculated by the air-fuel ratio deviation calculation unit 10
6a, 106a, ..., And the deviation from the air-fuel ratio of each fuel region corresponding to each temperature detection position is obtained. This air-fuel ratio deviation is calculated by the premix burner fuel amount calculation units 107a, 10a.
Are output to 7a, ... And the premixed fuel amount for each premixing burner that eliminates this deviation is calculated. The premixed fuel amount for each premixed burner is output to the premixed burner fuel control valve 88, and the flow rate of the premixed fuel flowing through the premixed burner fuel line 87 is adjusted so as to reach this fuel amount.

As described above, also in this embodiment, the first
Since the combustion state is grasped from the temperature of the flame stabilizer 30, as in the above embodiment, the premixed combustion state can be grasped accurately. Further, since the fuel flow rate for each premix burner is controlled, the unbalanced combustion state in one combustor 10 can be leveled.

In FIG. 7, the number of premix burner fuel control valves 88, 88, ... (= the number of premix burners 23) is the same as the number of thermocouples 35, 35 ,.
This is merely for notational convenience. For example, in one combustor 10, four thermocouples 35, 35, ... For 32 premixed burner fuel control valves 88, 88 ,.
May be In this case, the premixed fuel control for the temperature measurement result with one thermocouple 35 is 8 (= 32 ÷
4) The premixed fuel control valves 88, 88, ... Are executed.

Further, in the present embodiment, the fuel flow rate control for each of the premix burners 23, 23, ... In one combustor 10 is performed, but as in the first embodiment, further In order to adjust the premixed fuel flow rate for each of the combustors 10, 10 ,.
Combustor air-fuel ratio calculation unit 103 for obtaining the air-fuel ratio for each combustor
, An all-combustor average air-fuel ratio calculation unit 104 for obtaining an average air-fuel ratio of all combustors 10, 10, ..., An air-fuel ratio for each combustor and an average air-fuel ratio of all combustors 10, 10 ,. The deviation calculation unit 106 and the sub-premixed fuel amount calculation unit 10 for obtaining the amount of fuel flowing in the sub-premixed fuel line 84 from the air-fuel ratio deviation
7 may be added to the control device 100a.

Next, a third embodiment according to the present invention will be described with reference to FIGS. In this embodiment, the flow rate of air supplied to each combustor 10b is controlled based on the temperature of the flame stabilizer 30.

As shown in FIG. 8, the combustor 10b of this embodiment measures the flow rate of air for premixed combustion which flows into the air inlet 26 of each premixed burner 23 from here and into the premixed chamber 24. The combustor 10 of the first embodiment is the same as that of the combustor 10 of the first embodiment except that an air flow meter 41 for controlling the air flow rate and a premix air control valve 40 for adjusting the air flow rate are provided.

Further, since the control device 100b of the present embodiment controls the air-fuel ratio in each combustor 10b based on the temperature of the flame stabilizer 30, it is basically the same as that of the first embodiment. It is the same. However, in this embodiment, each combustor 10
In controlling the air-fuel ratio of b, since the flow rate of the air supplied to each combustor 10b is controlled, the air supplied to the premix burner 23 based on the air-fuel ratio calculated by the air-fuel ratio deviation calculation unit 106. The amount of the premixed air amount calculation unit 107b
Then, this air amount is output to the premix air control valve 40.

In this embodiment, although the amount of air supplied to each combustor 10 is controlled, the air-fuel ratio of each combustor 10 can be made substantially constant as a result of the operation, so the first
It is possible to obtain the same effect as that of the embodiment. In this embodiment, the amount of air supplied to each combustor 10 is controlled, but since the premix air control valve 40 is provided for each premix burner 23, it is different from the second embodiment. Similarly, the amount of air supplied to each premix burner 23 may be controlled.

Next, a fourth embodiment according to the present invention will be described with reference to FIG. This embodiment is a combination of the controls in the above embodiments.

That is, in this embodiment, the valve opening degrees of the sub premix fuel control valve, the premix burner fuel control valve, and the premix air control valve are controlled based on the flame stabilizer temperature in each combustor. , The air-fuel ratio of each combustor, and the air-fuel ratio in one combustor. Therefore, the control device can combine the functions of the above embodiments. According to this embodiment, it is possible to prevent the imbalance of the air-fuel ratio of each combustor and the imbalance of the air-fuel ratio in one combustor.
However, in the present embodiment, the number of various control valves is very large, and thus it is undeniable that the present embodiment is more disadvantageous in terms of manufacturing cost and failure than the above embodiments.

Although the thermocouple 35 is used to measure the temperature of the flame stabilizer 30 in the above embodiments, any thermocouple 35 that can measure the temperature in the vicinity of the allowable temperature of the flame stabilizer 30 may be used. Other than the thermocouple, for example, a resistance temperature detector or the like may be used.

Further, the flame stabilizer 30 in the above embodiment
Is a so-called bluff body flame stabilizer 30 which divides the premixed gas ejected from the premix burner 23 into two, but the present invention is not limited to this, and for example, FIG.
As shown in, the present invention may be provided for a so-called recess type flame stabilizer 30a that forms a circulation flow of combustion gas on the downstream side of itself without dividing the premixed gas into two. Further, as shown in FIG. 12, the jet port 27b of the premix burner 23b is also provided.
The flame stabilizer 30b that forms a circulation flow of the combustion gas around the nozzle and downstream of the ejection port 27b may be used. When employing these flame stabilizers 30a and 30b, it is preferable to measure the temperature of the corners of the flame stabilizers 30a and 30b, which are the ignition points of the premixed flame 29. In FIGS. 11 and 12, reference numeral 45 denotes a swirl vane.

[0057]

The flame stabilizer is intended to stabilize the premixed flame by forming a circulation flow of the combustion gas generated by the premixed combustion on the downstream side of the flame stabilizer. However, the combustion gas just generated by the premixed combustion comes into contact. Therefore, according to the present invention, since the temperature of the combustion gas just generated by the premixed combustion can be measured, the combustion state can be accurately grasped.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a combustor and a structure around the combustor according to a first embodiment of the present invention.

FIG. 2 is a system diagram of a gas turbine facility according to the first embodiment of the present invention.

FIG. 3 is a functional block diagram of a control device according to the first embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5 is a sectional view taken along line VV in FIG.

FIG. 6 is a perspective view of the flame stabilizer according to the first embodiment of the present invention.

FIG. 7 is a functional block diagram of a control device according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a combustor and a structure around the combustor according to a third embodiment of the present invention.

FIG. 9 is a functional block diagram of a control device according to a third embodiment of the present invention.

FIG. 10 is an explanatory diagram of a combustor and its surroundings according to a fourth embodiment of the present invention.

FIG. 11 is a sectional view of a premix burner and a flame stabilizer according to another embodiment of the present invention.

FIG. 12 is a sectional view of a premix burner and a flame stabilizer according to still another embodiment of the present invention.

[Explanation of symbols]

10, 10b ... Combustor, 11 ... Casing, 12 ... Primary combustion chamber, 13 ... Primary combustion cylinder, 14 ... Diffusion burner, 21 ...
Secondary combustion chamber, 22 ... Secondary combustion cylinder, 23, 23a, 23b
... premix burner, 24 ... premix chamber, 26 ... air intake,
27 ... Jet port, 28 ... Combustion nozzle, 29 ... Premixed flame,
30, 30a, 30b ... Flame stabilizer, 35 ... Thermocouple, 40 ...
Premix air control valve, 41 ... Premix air flow meter, 45 ... Swivel blade, 50 ... Compressor, 60 ... Gas turbine, 65 ... Generator, 71 ... Main diffusion fuel line, 72 ... Main diffusion fuel control valve, 73 ... Main diffusion fuel flowmeters 73, 74 ... Sub diffusion fuel line, 75 ... Sub diffusion fuel control valve, 76 ... Sub diffusion fuel flow meter, 81 ... Main premix fuel line, 82 ... Main premix fuel control valve, 83 ... Main premix fuel flow meter, 84 ... Sub mix fuel line, 85 ... Sub premix fuel control valve, 86 ... Sub premix fuel flow meter, 87 ... Premix burner fuel line, 88 ... Premix burner fuel control valve, 89 ... Premix burner fuel flow meter, 1
00, 100a, 100b, 100c ... Control device, 10
1 ... Combustion abnormality determination unit, 102 ... Average temperature calculation unit, 10
3, 103a ... Air-fuel ratio calculation unit, 104, 104a ... Average air-fuel ratio calculation unit, 105 ... Emission NOx prediction unit, 106, 1
06a ... Air-fuel ratio deviation calculation unit, 107 ... Sub-premixed fuel amount calculation unit, 107b ... Premixed air amount calculation unit, 108 ... Main premixed fuel amount calculation unit, 109 ... Display unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Kuroda 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd., Hitachi Works

Claims (9)

[Claims] 1. A premixing burner which mixes fuel and air and ejects a premixed gas generated by this mixing, and a circulation flow of combustion gas generated by combustion of the premixed gas, which is located downstream of itself. A flame stabilizer for holding a premixed flame formed by combustion of the premixed gas, the temperature of the flame stabilizer and the premixing Combustion state characterized by previously checking the correlation with the combustion state of gas, measuring the temperature of the flame stabilizer, and grasping the combustion state for the measured temperature of the flame stabilizer from the correlation How to grasp. 2. The correlation is indicative of normal combustion or abnormal combustion depending on whether or not the temperature of the flame stabilizer is within a predetermined flame stabilizer set temperature range with respect to the temperature. The method for ascertaining the combustion state of a combustor according to claim 1, wherein 3. The method according to claim 1, wherein the correlation indicates a relationship between the temperature of the flame stabilizer and the air-fuel ratio of the premixed gas. 4. The combustion state grasping method according to claim 1, wherein the correlation indicates a relationship between the temperature of the flame stabilizer and the NOx concentration in the combustion gas. 5. A premixing burner that mixes fuel and air and injects a premixed gas generated by this mixing, and a circulating flow of combustion gas generated by combustion of the premixed gas on the downstream side thereof. And a flame stabilizer for holding a premixed flame formed by combustion of the premixed gas, the combustion state grasping device for the combustor comprising: Combustion for grasping the combustion state with respect to the temperature measured by the flame stabilizer temperature measuring means and the predetermined combustion temperature of the flame stabilizer and the combustion state of the premixed gas A combustion state grasping device characterized by comprising a state grasping means. 6. The combustion state grasping apparatus according to claim 5, further comprising display means for displaying the combustion state grasped by the combustion state grasping means. 7. A premixing burner which mixes fuel and air and ejects a premixed gas produced by this mixing, and a circulating flow of combustion gas produced by combustion of the premixed gas, which is located downstream of itself. A combustor having a flame stabilizer for holding a premixed flame formed by combustion of the premixed gas, and fuel and air supplied to the premixed burner,
In a control device for a combustor facility, which comprises at least one flow rate control valve for controlling a flow rate, a flame stabilizer temperature measuring means for measuring a temperature of the flame stabilizer, and a predetermined temperature of the flame stabilizer. From the correlation between the combustion state of the premixed gas and the combustion state grasping means for grasping the combustion state for the temperature measured by the flame stabilizer temperature measuring means, and the combustion state grasped by the combustion state grasping means According to the above, a flow rate calculating means for obtaining a flow rate of the fluid (the fuel or the air) to be adjusted by the flow rate adjusting valve and outputting the flow rate to the flow rate adjusting valve is provided. Equipment control device. 8. The combustor facility comprises a plurality of the combustors, and a plurality of flow rate control valves corresponding to the plurality of the combustors, wherein the flame stabilizer temperature measuring means comprises a plurality of the combustion chambers. Measuring the temperature of the flame stabilizer for each combustor, the combustion state grasping means grasps the combustion state of each combustor from the temperature of the flame retainer of each of the plurality of combustors, and the flow rate calculating means. The controller for combustor equipment according to claim 7, wherein the flow rate of the fluid adjusted by the plurality of flow rate adjusting valves is obtained, and each flow rate is output to the plurality of flow rate adjusting valves. 9. The combustor includes a plurality of the premix burners,
And a plurality of flow control valves corresponding to a plurality of premix burners, the flame stabilizer is provided so as to be able to hold the premix flame by a plurality of premix burners, the flame stabilizer temperature measurement Means measures the temperature at a plurality of points of the flame stabilizer, the combustion state grasping means, from the temperature at a plurality of points of the flame stabilizer combustion state of each combustion region corresponding to the temperature measurement point of the flame stabilizer Respectively, the flow rate calculating means obtains the flow rate of the fluid to be adjusted by the flow rate adjusting valve corresponding to the premixing burner that affects the combustion state of each combustion region, and the flow rate corresponding to each flow rate is calculated. The control device for the combustor facility according to claim 7, wherein the control device outputs the flow rate control valve.