CN103807873A - Active control method for burning instability of combustion gas turbine combustor - Google Patents

Abstract

The invention provides an active control method for burning instability of a combustion gas turbine combustor. The method comprises the steps that an end cover or the wall surface of a flame tube of the combustion gas turbine combustor is provided with a dynamic pressure sensor; dynamic pressure original signals of the interior of the combustor are collected by the dynamic pressure sensor and sent to a signal processing unit; de-noising processing is conducted on the dynamic pressure original signals through a preprocessor, Fourier series expansion is conducted on the processed dynamic pressure signals through the signal processing unit, and superposed signals of direct-current signals and harmonic signals with different frequency components are obtained; harmonic signal components with the amplitude exceeding a set amplitude threshold valve in the harmonic signals are kept, and frequency, the amplitude and phase information of the kept harmonic signals are sent to a controller; a controller drives a rapid response valve according to input information to input common-frequency stimulation with a 180-degree phase difference with the corresponding frequency harmonic signals for fuel flow, so that high-amplitude pressure pulsation in the combustor is restrained, and therefore active control over burning instability is achieved.

Description

A kind of Active Control Method of gas-turbine combustion chamber combustion instability

Technical field

The present invention relates to a kind of method for controlling combustion of industry gas turbine, relate in particular to a kind of Active Control Method of combustion instability.

Background technology

In order to reduce discharge, obtain higher efficiency of combustion, modern industry gas-turbine combustion chamber adopts the combustion system of fuel-air pre-mixing more and more.The non-premixing system that the discharge performance of lean premixed combustion system is more traditional is good, but its development is subject to the restriction of combustion instability; Its flameholding narrow range, can not adapt to the requirement that gas turbine in very large range changes; Unsettled combustion process produces the pressure vibration of low-frequency high-amplitude, and it not only affects the combustibility of combustion chamber, and likely destroys the structure of combustion chamber when serious.

Destruction for fear of combustion instability to combustion system and gas turbine, Ge great research institution has dropped into a large amount of human and material resources and financial resources are carried out this research, and has proposed the control measure that much have Practical Project to be worth.As the people such as Yedidia Neumeier have proposed a kind of Active Control Method of combustion instability, but the combustion instability Active Control Method that they invent is mainly used in rocket, and the unsettled combustion system of high frequency easily appears in guided missile etc.The people such as Michael D.CornWell have also proposed a kind of Active Control Method of combustion instability, the Active Control Method that they invent mainly judges in burning by the degree of coupling of analytic combustion room pressure fluctuating signal and flame intensity signal whether combustion instability occurs, and then regulates nozzle fuel amount on duty to realize the ACTIVE CONTROL of combustion instability by controller control valve group.In US7728736 patent documentation, the unstable combustion locking control method proposing is mainly to adopt flame sensor to measure not flame intensity in the same time, then the flame intensity of asking for two adjacent moment is poor, and by poor this flame intensity and setting threshold comparison, if the poor setting threshold that is greater than of flame intensity, takes measures to suppress combustion instability by controller to combustion chamber.And in US6059560 patent documentation, proposed a kind of method by periodic adjustment equivalent proportion and realize the ACTIVE CONTROL of combustion instability, but the adjustment process more complicated of the method is applied difficulty larger in Practical Project.

Summary of the invention

The object of the invention is for shortcomings and deficiencies of the prior art, propose a kind of Active Control Method for gas-turbine combustion chamber combustion instability.

The technical solution adopted in the present invention is as follows:

An Active Control Method for gas-turbine combustion chamber combustion instability, is characterized in that described method comprises:

1) on gas-turbine combustion chamber end cap parts or burner inner liner wall, dynamic pressure transducer is installed, dynamic pressure transducer is measured the dynamic pressure signal of setting-up time step-length t;

2) the dynamic pressure primary signal in the combustion chamber of dynamic pressure transducer collection is sent to signal processing unit, and this primary signal is designated as to P (t), t ∈ [τ ₁, τ ₂]; τ ₁for starting the moment of record data, τ ₂for the moment of end record data;

3) by the preprocessor being embedded in signal processing unit, dynamic pressure primary signal is carried out to denoising, the noise signal in primary signal and dynamic pressure signal after treatment are designated as respectively to P _noise(t) and P ' (t);

P′(t)=P(t)-P _niose(t) （1）

4) by signal processing unit, dynamic pressure signal P ' after treatment (t) is carried out to Fourier expansion, obtain direct current signal

superposed signal with the harmonic signal of K different frequency composition, is designated as respectively C by the amplitude of each frequency harmonics signal, frequency and phase place _n, f _n, φ _n, n ∈ (1,2,3 ... K);

for the average pressure in combustion chamber;

$P^{\′}\left(t\right)=\stackrel{\‾}{P}+\underset{n=1}{\overset{K}{\mathrm{\Σ}}}{C}_n\sin (2\mathrm{\π}\·f_n\·t+{\mathrm{\φ}}_n)---\left(2\right)$

5) set the amplitude threshold of each frequency harmonics signal, and be designated as C _{n, set}(n=1,2,3 ... K); For 1Hz≤f _nthe low-frequency range of <50Hz,

for 50Hz≤f _nthe Mid Frequency of <500Hz, for 500Hz≤f _n<5000Hz high band,

6) retain amplitude in harmonic signal and exceed the harmonic signal composition of set amplitude threshold value, and be designated as X (t), frequency, amplitude and the phase information of the harmonic signal then these being remained are sent to controller; Work as C _n>C _{n, set}time, C _nremain unchanged; Work as C _n≤ C _{n, set}time, C _n=0;

$X\left(t\right)=\underset{n=1}{\overset{K}{\mathrm{\&Sigma;}}}{C}_n\sin (2\mathrm{\&pi;}\&CenterDot;f_n\&CenterDot;t+{\mathrm{\&phi;}}_n)---\left(3\right)$

7) controller drives the same frequency that quick responsive valves is 180 degree to one of fuel flow rate input with respective frequencies harmonic signal phase difference to encourage according to input message, is designated as Y (t), thereby the high amplitude pressure fluctuation in inhibition combustion chamber; Reach the ACTIVE CONTROL of combustion instability.

The present invention has the following advantages with respect to prior art and the technique effect of high-lighting: control logic is clear simple, easily realizes the unsettled ACTIVE CONTROL of combustion chambers burn; Need not additionally increase monitoring instrument, the dynamic pressure transducer while only utilizing gas turbine normally to move can complete ACTIVE CONTROL; Adopt combustion instability Active Control Method of the present invention can effectively suppress or eliminate the combustion instability problem of gas-turbine combustion chamber, to guarantee the safe operation of equipment.

Accompanying drawing explanation

Fig. 1 is combustion instability ACTIVE CONTROL flow chart.

Fig. 2 is the schematic diagram of combustion instability ACTIVE CONTROL specific embodiment.

The specific embodiment

Below in conjunction with the drawings and specific embodiments, specific embodiment of the invention is described further.

The Active Control Method of a kind of gas-turbine combustion chamber combustion instability provided by the invention, as shown in Figure 1, concrete grammar comprises its control flow:

1) on gas-turbine combustion chamber end cap parts or burner inner liner wall, dynamic pressure transducer is installed, dynamic pressure transducer is measured the dynamic pressure signal of setting-up time step-length t;

2) the dynamic pressure primary signal in the combustion chamber of dynamic pressure transducer collection is sent to signal processing unit, and this primary signal is designated as to P (t), t ∈ [τ ₁, τ ₂]; τ ₁for starting the moment of record data, τ ₂for the moment of end record data;

3) by the preprocessor being embedded in signal processing unit, dynamic pressure primary signal is carried out to denoising, the noise signal in primary signal and dynamic pressure signal after treatment are designated as respectively to P _noise(t) and P ' (t);

P′(t)=P(t)-P _niose(t) （1）

4) by signal processing unit, dynamic pressure signal P ' after treatment (t) is carried out to Fourier expansion, obtain direct current signal

superposed signal with the harmonic signal of K different frequency composition, is designated as respectively C by the amplitude of each frequency harmonics signal, frequency and phase place _n, f _n, φ _n, n ∈ (1,2,3 ... K);

for the average pressure in combustion chamber;

$P^{\&prime;}\left(t\right)=\stackrel{\&OverBar;}{P}+\underset{n=1}{\overset{K}{\mathrm{\&Sigma;}}}{C}_n\sin (2\mathrm{\&pi;}\&CenterDot;f_n\&CenterDot;t+{\mathrm{\&phi;}}_n)---\left(2\right)$

5) set the amplitude threshold of each frequency harmonics signal, and be designated as C _{n, set}(n=1,2,3 ... K); For 1Hz≤f _nthe low-frequency range of <50Hz,

for 50Hz≤f _nthe Mid Frequency of <500Hz, for 500Hz≤f _n<5000Hz high band,

6) retain amplitude in harmonic signal and exceed the harmonic signal composition of set amplitude threshold value, and be designated as X (t), frequency, amplitude and the phase information of the harmonic signal then these being remained are sent to controller; Work as C _n>C _{n, set}time, C _nremain unchanged; Work as C _n≤ C _{n, set}time, C _n=0;

$X\left(t\right)=\underset{n=1}{\overset{K}{\mathrm{\&Sigma;}}}{C}_n\sin (2\mathrm{\&pi;}\&CenterDot;f_n\&CenterDot;t+{\mathrm{\&phi;}}_n)---\left(3\right)$

7) controller drives the same frequency that quick responsive valves is 180 degree to one of fuel flow rate input with respective frequencies harmonic signal phase difference to encourage according to input message, is designated as Y (t), thereby the high amplitude pressure fluctuation in inhibition combustion chamber; Reach the ACTIVE CONTROL of combustion instability.

Below by a specific embodiment, the present invention is further detailed.

Fig. 2 is the schematic diagram of the unstable ACTIVE CONTROL specific embodiment of gas turbine combustion, and concrete grammar is:

1) on gas-turbine combustion chamber burner inner liner wall, dynamic pressure transducer is installed, dynamic pressure transducer is measured the dynamic pressure signal of setting-up time step-length t;

2) the dynamic pressure primary signal in the combustion chamber of dynamic pressure transducer collection is sent to signal processing unit, and this primary signal is designated as to P (t), t ∈ [0,1]; In Fig. 2, (a) curve has shown the dynamic pressure primary signal in the combustion chamber in the setting-up time step-length t gathering by dynamic pressure transducer; 0 for starting moment of record data, and 1 is end record data moment;

3) by the preprocessor being embedded in signal processing unit, dynamic pressure primary signal is carried out to denoising, the noise signal in primary signal and dynamic pressure signal after treatment are designated as respectively to P _noise(t) and P ' (t);

P′(t)=P(t)-P _niose(t) （1）

In the present embodiment, noise signal is common white noise signal, and the dynamic pressure signal after denoising is as shown in (b) curve in Fig. 2;

4) by signal processing unit, dynamic pressure signal P ' after treatment (t) is carried out to Fourier expansion, obtain direct current signal

superposed signal with the harmonic signal of K different frequency composition, is designated as respectively C by the amplitude of each frequency harmonics signal, frequency and phase place _n, f _n, φ _n, n ∈ (1,2,3 ... K);

for the average pressure in combustion chamber;

In the present embodiment, by signal processing unit, dynamic pressure signal after treatment is carried out the stack of resolving into the harmonic signal of direct current signal and 7 different frequency compositions after Fourier expansion, expression formula specific as follows:

$P^{\&prime;}\left(t\right)=1.7+1.7\&times;\left(\begin{array}{c}0.06\%\&times;\sin (2\mathrm{\&pi;}\&CenterDot;25\&CenterDot;t+{30}^0)+0.04\%\&times;\sin (2\mathrm{\&pi;}\&CenterDot;50\&CenterDot;t+{40}^0)\\ +0.8\%\&times;\sin (2\mathrm{\&pi;}\&CenterDot;150\&CenterDot;t+{50}^0)+1.2\%\&times;\sin (2\mathrm{\&pi;}\&CenterDot;200\&CenterDot;t+{60}^0)\\ +0.06\%\&times;\sin (2\mathrm{\&pi;}\&CenterDot;500\&CenterDot;t+{70}^0)+0.03\%\&times;\sin (2\mathrm{\&pi;}\&CenterDot;1000\&CenterDot;t+{75}^0)\\ +0.02\%\&times;\sin (2\mathrm{\&pi;}\&CenterDot;2000\&CenterDot;t+{850}^0)\end{array}\right)---\left(2\right)$

In this expression formula, direct current signal

f ₁=25Hz, φ ₁=30 ⁰;

f ₂=50Hz, φ ₂=40 ⁰; f ₃=150Hz, φ ₃=50 ⁰;

f ₄=200Hz, φ ₄=60 ⁰;

f ₅=500Hz, φ ₅=70 ⁰;

f ₆=1000Hz, φ ₆=75 ⁰;

f ₇=2000Hz, φ ₇=85 ⁰;

5) set the amplitude threshold of each frequency harmonics signal, and be designated as C _{n, set}(n=1,2,3 ... 7); For 1Hz≤f _nthe low-frequency range of <50Hz,

for 50Hz≤f _nthe Mid Frequency of <500Hz,

for 500Hz≤f _n<5000Hz high band,

for average pressure in combustion chamber,

6) retain amplitude in harmonic signal and exceed the harmonic signal composition of set amplitude threshold value, and be designated as X (t), frequency, amplitude and the phase information of the harmonic signal then these being remained are sent to controller; Work as C _n>C _{n, set}time, C _nremain unchanged; Work as C _n≤ C _{n, set}time, C _n=0;

In this embodiment, C ₃>C _{3, set}, C ₄>C _{4, set}, C ₃remain unchanged, C ₄remain unchanged, C ₁≤ C _{1, set}, C ₂≤ C _{2, set}, C ₅≤ C _{5, set}, C ₆≤ C _{6, set}, C ₇≤ C _{7, set}therefore, C ₁=C ₂=C ₅=C ₆=C ₇=0.So retain the frequency of these two harmonic signals, amplitude and phase place, expression formula specific as follows:

X(t)=1.7×[0.8%×sin(2π·150·t+50 ⁰)+1.2%×sin(2π·200·t+60 ⁰)] （3）

7) controller drives the same frequency that quick responsive valves is 180 degree to one of fuel flow rate input with respective frequencies harmonic signal phase difference to encourage according to input message, is designated as Y (t);

In this embodiment, with being frequently actuated to following expression:

Y(t)=1.7×[0.8%×sin(2π·150·t+50 ⁰+π)+1.2%×sin(2π·200·t+60 ⁰+π)]

Finally complete the ACTIVE CONTROL to combustion chamber in embodiment by above-mentioned steps, in Fig. 2, (c) curve has shown through the dynamic pressure signal in above-mentioned ACTIVE CONTROL after-burner.

Claims (1)

1. an Active Control Method for gas-turbine combustion chamber combustion instability, is characterized in that described method comprises:

1) on gas-turbine combustion chamber end cap parts or burner inner liner wall, dynamic pressure transducer is installed; Dynamic pressure transducer is measured the dynamic pressure signal of setting-up time step-length t;

2) the dynamic pressure primary signal in the combustion chamber of dynamic pressure transducer collection is sent to signal processing unit, and this primary signal is designated as to P (t), t ∈ [τ ₁, τ ₂]; τ ₁for starting the moment of record data, τ ₂for the moment of end record data;

3) by the preprocessor being embedded in signal processing unit, dynamic pressure primary signal is carried out to denoising, the noise signal in primary signal and dynamic pressure signal after treatment are designated as respectively to P _noise(t) and P ' (t);

P′(t)=P(t)-P _niose(t) （1）

4) by signal processing unit, dynamic pressure signal P ' after treatment (t) is carried out to Fourier expansion, obtain direct current signal

superposed signal with the harmonic signal of K different frequency composition, is designated as respectively C by the amplitude of each frequency harmonics signal, frequency and phase place _n, f _n, φ _n, n ∈ (1,2,3 ... K);

for the average pressure in combustion chamber;

$P^{\&prime;}\left(t\right)=\stackrel{\&OverBar;}{P}+\underset{n=1}{\overset{K}{\mathrm{\&Sigma;}}}{C}_n\sin (2\mathrm{\&pi;}\&CenterDot;f_n\&CenterDot;t+{\mathrm{\&phi;}}_n)---\left(2\right)$

5) set the amplitude threshold of each frequency harmonics signal, and be designated as C _{n, set}(n=1,2,3 ... K); For 1Hz≤f _nthe low-frequency range of <50Hz,

for 50Hz≤f _nthe Mid Frequency of <500Hz,

for 500Hz≤f _n<5000Hz high band,

6) retain amplitude in harmonic signal and exceed the harmonic signal composition of set amplitude threshold value, and be designated as X (t), frequency, amplitude and the phase information of the harmonic signal then these being remained are sent to controller; Work as C _n>C _{n, set}time, C _nremain unchanged; Work as C _n≤ C _{n, set}time, C _n=0;

$X\left(t\right)=\underset{n=1}{\overset{K}{\mathrm{\&Sigma;}}}{C}_n\sin (2\mathrm{\&pi;}\&CenterDot;f_n\&CenterDot;t+{\mathrm{\&phi;}}_n)---\left(3\right)$

7) controller drives the same frequency that quick responsive valves is 180 degree to one of fuel flow rate input with respective frequencies harmonic signal phase difference to encourage according to input message, is designated as Y (t),

thereby the high amplitude pressure fluctuation in inhibition combustion chamber; Reach the ACTIVE CONTROL of combustion instability.

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