DE102005011287A1 - Method for controlling burners in a thermal engine especially in a gas turbine engine has sensors monitoring a range of parameters and with a processor control for optimum burn - Google Patents

Abstract

A method for controlling at least one burner in a thermal engine, especially in a gas turbine engine, e.g. for electricity generation, has sensors (4) in and around the pre-burn chamber (1) and on the fuel and air supply ducts (2. 3) to monitor a range of operating parameters and enabling a process control (5) to run the engine with optimum efficiency and with minimum emission products. The monitored parameters include; burn chamber temperature, flow rates for air and fuel, pressure variations in burn chamber, flame temperature, exhaust gas sampling etc. The control includes safety monitoring, e.g. to prevent flame return and overheating.

Description

Technical area

The The invention relates to a method and a device for operating at least one burner for firing the combustion chamber a heat engine, in particular a gas turbine plant.

burner preferably premix burners are pre-published from a variety Publications known, for example, from EP A1 0 210 462 and EP B1 0 321 809, just to name a few. Premix burners of this type is based on the general principle of action, within a mostly as conical trained swirl generator, the at least two with corresponding mutual overlap compound Teilkegelschalen provides, one from a fuel-air mixture existing swirl flow to produce within a flow direction of the premix burner subsequent combustion chamber to form a spatially possible stable premix flame for ignition is brought.

If in single or multiple burner arrangement, such Vormischbrenner are used for firing combustion chambers for the operation of heat engines preferably used, in particular in gas or steam turbine plants, especially since such premix burners use different fuels to form a largely homogeneous fuel-air mixture allow that ultimately forming an aerodynamically stabilized premix flame to the ignition is brought.

At the operation of heat engines, in particular of gas turbine plants, will be very demanding in terms of their environmental but are subject to the combustion process in the atmosphere released exhaust gases meet strict emission limits. In addition, it applies, heat engines from the point of view of their efficiency with which they are used in the Location for energy conversion into electrical energy are to optimize and if possible in the entire range of their performance range.

Current gas turbine plants be in a conventional manner according to a fixed predetermined operating pattern operated by a limited number of individually specified Environmental conditions depends. For example, such ambient conditions set the ambient temperature, Humidity as well as fuel qualities, just to name a few. By these external influences will significantly affects the performance of a gas turbine plant. So is under consideration this and other environmental conditions before commissioning of the gas turbine plant, for example, a predetermined series of construction, a so-called operating manual or "operating schedule" created according to the one Definition of important controlled variables takes place, by the one possible optimized operation of the gas turbine plant in the entire load range should ensure. The controlled variables relate in particular quantitative as well as qualitative variables, the the fuel and combustion air supply of the burner unit regulate.

issues can However, if already the lowest production engineering Deviations within a gas turbine series are to be observed, which relate in particular to the burner component. Because in the burner used premix burner of the type mentioned an optimized design with regard to flame stability and emission behavior, even the lowest, the aerodynamic flow flow impairing Deviations in the structural design of the premix burners considerable have adverse effects on the combustion result. Becomes in a manner known per se, the combustion process with fixed predetermined Controlled variables performed possibly production-related structural deviations do not occur to take into account capital, so leads this inevitably leads to an unsatisfactory combustion result, which ultimately in the occurrence of overheating in the burner or in the hot gas path downstream of the burner, in so-called thermoacoustic vibrations and deteriorated Emissions. Also bear systemic aging phenomena to the individual Components of gas turbines contribute to the operating behavior the entire gas turbine plant deteriorates with increasing plant age.

aim It should therefore be an active oversight of the entire combustion process and advantageously the combustion process affecting Controlled variables, such as Fuel and air supply, to the possibly resulting changes adapt.

Presentation of the invention

The invention is based on the object of developing a method for operating at least one burner for firing a combustion chamber of a heat engine, in particular a gas turbine plant, in such a way that provision should be made with which it is possible to optimally adjust the combustion process within the burner to the current operating conditions. The necessary procedural as well as equipment technical effort should be as low as possible and beyond in an advantageous manner to already existing burner systems subsequently adaptable. Of particular interest is the operation of multiple burner arrangements, in which it is necessary to run the combustion process stable and with the lowest possible emission levels in terms of the emission of NOx and CO. There is also the desire to protect the operation of a burner in heat engines against malfunction by occurring errors should be detected as soon as possible in order to ultimately take appropriate countermeasures to prevent possible damage caused by the malfunction of the burner assembly.

The solution the object underlying the invention is specified in claim 1. An inventively designed Burner assembly is the subject of claim 14. The concept of the invention advantageous further-forming features are the subject of the dependent claims and the further description, in particular with reference to the Embodiment, refer to.

The inventive method concept for Operating at least one burner for firing a combustion chamber a heat engine, in particular a gas turbine plant, on the one hand sees a sensorial Detecting a number of operating parameters before the combustion process determine qualitatively within the burner. This concerns in an advantageous manner Make the detection of the temperature on and / or in the burner housing with the help a suitable thermal sensor element, preferably in a Recess is housed within the burner housing. Further the mass flow of the combustion air supplied to the burner is detected, as well as the mass flow of at least one type of fuel, the burner for the formation of an ignitable fuel mixture, in the form of a fuel air mixture is supplied. Both the burner timed Amount of combustion air supply and also the supplied fuel are in an advantageous Way with a differential pressure measuring probe, which introduced in the respective mass flows is, captured exactly. Is the fuel supplied to the burner reversing? Liquid fuel, so are known per se, introduced into the liquid mass flow Flow sensors. In the case of the supply of gaseous Fuels is the use of the above differential pressure measuring sensors.

Further Pressure fluctuations that are caused within the burner housing occur by the formation of thermoacoustic vibrations by means of sound-acoustic sensors, for example with the aid of a microphone detected. Also, optical sensors are suitable for detecting the integral as well as spatially resolved heat release the flame forming inside the burner. Ultimately, can with Help appropriate gas sensors by chemical reaction or work by means of optical absorption or transmission measurements, the gas composition of forming by the combustion process hot gases be recorded.

The in not final Number of above-mentioned operating parameters that provide information about the quality be able to deliver the combustion process within the burner according to the invention for purposes Evaluated evaluation of the combustion process to ultimately a complete information about to get the current combustion state.

Around a qualitative statement about be able to make the current state of combustion, at least some the sensor-recorded operating parameters are preferably compared with desired values, with one possible good match or at least a broad approximation aiming for the acquired operating parameters with the predetermined setpoint values is to ultimately one as possible To achieve optimized and stable combustion, whose quality is preferably reflected in the following operating variables: flame temperature distribution, Hot gas temperature at the turbine inlet, concentration of nitrogen oxides and carbon monoxide in the exhaust gases, pressure fluctuations within the Brenners, by which made a statement about the flame stability and finally information about flame stability, from which the occurrence of a flashback of Back sides of the combustion chamber in the burner.

ever according to the size of the deviation between the sensory operating parameters, the so-called Actual values and suitable preset nominal values can be burner disruptions in time detect even before irreversible damage to the burner itself in appearance can occur. Exceed the detected deviations given tolerance limits, so can be advantageously converted into a safety mode, the burner in the burner damage can be excluded and in which the burner is operated until a regular burner inspection carried out becomes. Alternatively to the operation of the burner in a safety mode the corresponding burner can be completely switched off to immediately investigate the damage that has occurred and correct it accordingly to be able to.

The transfer of a Brenners in a required safety mode in which the burner with operated reduced or greatly reduced burner power, is done by activating at least one actuating means, the Influx of fuel can influence. In a simple embodiment is the actuating means as introduced in a fuel line Throttle valve formed by the fuel supply infinitely throttled and completely can be prevented.

The Actuation of the actuating means takes place with the aid of a control signal, that in dependence the above-described evaluation of the sensory detected Operating parameters of the burner is generated. In particularly advantageous Way, it is conceivable, the evaluation of the sensory detected Operating parameters of the burner within a closed loop to perform, wherein the generated control signal in the form of a control signal at the adjusting means a change the mass flow of the fuel supplied to the burner causes which in turn directly affects the operating parameters of the burner to be influenced. In the context of such a closed loop Is it possible, the burner continuously in an optimized combustion state dependent on that of the heat engine requested performance.

The above-described intelligent burner monitoring by a burner's own measured value acquisition, in their context first the operating parameters characterizing the combustion process of the burner thus comprises in a second step a qualitative assessment of the burner state, which on the one hand possible is the reliability of the burner to increase significantly and On the other hand, the quality of the Decisively improve the combustion process.

From of particular value is the burner control according to the invention in multi-burner arrangements, in which a large number of individual burners for firing a large-scale Serving combustion chamber, as for example in the case of ring or Topfbrennkammern is the case.

Especially in multiple burner arrangements, the individual burners are u.a. for reasons a flame forming stable in the combustion chamber and reduced Emission levels graded with fuel. The fuel grading takes place in a conventional manner either by a classification of the burner in burner groups, with each individual burner group separated via a fuel feed line fueled - one This type of grading is usually called outer grading - or the individual Burners of the multiple burner arrangement are each over at least two supplied fuel to separate fuel lines. The latter Grading type is also referred to as internal grading. Also is one Combination of both grading types conceivable.

So it is basically possible, in multi-burner arrangements, monitoring of each one Burner separately from each other, as described above, being a possible Burner control as part of a control or regulation for each individual burner separate and independent of the other burners takes place in the multiple burner arrangement. Also, the monitoring and a related Regulating whole burner groups that are part of a fuel staging be supplied with fuel accordingly. Basically the possibilities for the burner monitoring No technical limits.

In a preferred embodiment However, those for each individual burner sensory recorded operating parameters burner specific directly or as a previously evaluated information unit of a higher-level monitoring unit fed. By the inventive merger of the sensorial recorded operating parameters all in a multiple burner arrangement provided burner, it is basically possible, the entire combustion process uniformly monitor the multiple burner assembly. Thus, the parent could Control unit in a first stage only as a parent Data Acquisition serve, based on the current combustion state of the multiple burner assembly only "readable" is.

In an extended embodiment takes the parent monitoring unit a surveillance the current combustion process in such a way that the current combustion states the individual burner with a superordinate burner policy implemented in the monitoring unit adjusted and, if deviations occur, appropriate control or control signals are generated, which are used to activate the actuating means serve within each burner. The higher-level monitoring unit can thus be understood as a kind of control center, in which a multiple burner arrangement given a predetermined predetermined multi-burner operation, the so-called burner policy, is monitored and regulated.

For the active control of the multiple burner arrangement, certain operating variables of the multiple burner arrangement are detected and, for purposes of optimizing the higher-level monitoring unit, additionally the burner-specific one Operating parameters supplied. Details of this can be found in the embodiment described below.

Under proviso a predetermined burner policy and for the purposes of their optimization recorded and the monitoring unit supplied operating parameters the multiple burner arrangement generates control commands, which affect the fuel supply of the individual burners Transfer actuating means become. Likewise, in the case of the reliability of the multiple burner arrangement in danger burning combustion situation a protective signal from sides the higher-level monitoring unit be discontinued, for example, by the fuel supply for the entire Multiple burner arrangement or only for certain burner groups or single burner is interrupted abruptly.

The inventive method for operating a burner assembly, in an advantageous manner used for firing a gas turbine plant, thus offering the possibility both the mere surveillance as well as the active control of the combustion process.

in the The simplest case is the acquisition of the sensorially recorded operating parameters the mere assessment the combustion process of a single burner. In a first Enlargement stage is the sensorially recorded operating parameters Evaluated for the purpose of optimizing the combustion result, to ultimately generate control or control signals through Targeted control or regulation of the fuel flow the combustion process of the single burner.

A advanced monitoring level concerns multiple burner arrangements and the merging of all sensory operating parameters of a plurality of individual burners, through the improved monitoring the combustion process with respect the entire multi-burner arrangement is possible.

A so far the last training level for controlled surveillance a multiple burner arrangement provides the targeted generation of Control or regulating signals, which for purposes of optimizing the Total combustion result the fuel supply to a variety of individual burners by targeted activation of suitable adjusting agents influence.

In advantageous way the process of the invention individually to the control requirements but especially to the complexity adjust the respective burner assembly. Basically, it is the monitoring and possibly the control of a burner arrangement the more comprehensive and more complex the more extensive and complex the burner assembly is. In addition are more extensive surveillance and controls on burner systems advantageous the closer the burner operation is based on strongly reduced emission values, especially with regard to greatly reduced NOx emissions. Also in cases, in which the burner with different types of fuel or -qualities is operated, the inventive method helps an all-encompassing Statement about state the current operating behavior and ultimately a safe one and ensure combustion-optimized operation.

to technical implementation of the method according to the invention requires one Burner arrangement with at least one burner for firing a Heat engine in particular a gas turbine plant, in the burner for training an ignitable fuel / air mixture at least one type of fuel through at least one fuel line supplied is, with sensors are provided on the burner, through each detects the combustion process characterizing operating parameters can be. To evaluate the measurement signals detected by the sensors, the ultimately represent the operating parameters, an evaluation unit, which is assigned to the burner and the sensory detected Operating parameters for purposes of evaluating the combustion process at least for presentation brings. In extension is preferred a burner control unit is provided, preferably with the Evaluation unit is combinable and in the on the basis of in the evaluation unit evaluated operating parameters at least a control or regulating signal is generated, the at least one Setting means activated, the mass flow of at least one Fuel type by at least one, preferably all on the burner affected fuel lines influenced. By the adjusting means, that in a simplest embodiment is designed as a valve within a fuel line can the combustion process can be directly influenced.

In the case of a multitude of individual burners which are present in the context of a multiple burner arrangement, each burner provides its burner-own evaluation and control unit, which are respectively connected via corresponding signal lines to a higher-level monitoring unit. As already mentioned above, the higher-level monitoring unit allows both an overall detection of the sensor-sensed operating parameters of all burners and, depending on the training level, a corresponding active control of the individual burners involved in the combustion process, as detailed in the exemplary embodiment shown in the following men is.

Short description of invention

The Invention will be described below without limiting the general inventive concept an embodiment described by way of example with reference to the drawing. It shows:

1 Schematic representation of a longitudinal section through a single burner assembly with schematized monitoring and control units

Ways to execute the Invention, industrial applicability

• – Der Massenfluss der Verbrennungszuluft, die dem Brenner 1 zugeführt wird, wird im Wege einer Partialdruckmessung δp_air erfasst.
• – Im Wege einer Temperaturmessung wird die Gehäusetemperatur T_Burner,Shell des Brenners erfasst.
• – Im Wege einer Druckmessung, vorzugsweise mittels eines Mikrofonsensors, können Druckschwankungen (P_rms,mikro) erfasst werden, die als Maß für sich im Brenner ausbildende thermoakustische Schwingungen dienen.
• – Mit Hilfe eines optischen Sensors ist es möglich ein Flammensignal (Signal_Flame-Sensor) zu erfassen, um eine Aussage darüber treffen zu können, ob eine Flamme innerhalb des Brenners vorhanden ist oder bereits erloschen ist.
• – Ferner wird der Brennstoffzufluß längs der Brennstoffleitungen 2, 3, ebenfalls im Wege einer Partialdruckmessung erfasst (P_{1st STAGE GAS}, P_{2nd STAGE GAS})

The single figure shows a schematic longitudinal section through a single premix burner assembly, with a conical premix burner 1 with supply lines 2 . 3 that serve a dual-tiered fuel feeder. On the other detail components of the burner assembly shown in the single figure should not be gone further at this point. Only it should be noted that on the housing of the premix burner 1 a burner-own sensor unit 4 is provided, via which a plurality of individual operating parameters can be detected by sensors. The sensor unit 4 enables in detail the acquisition of the following operating parameters:

• - The mass flow of the combustion air supplied to the burner 1 is supplied, is detected by means of a partial pressure measurement δp _air .
• - By measuring the temperature, the housing temperature T _{Burner, Shell of} the burner is detected.
• - By pressure measurement, preferably by means of a microphone _sensor, pressure fluctuations (P _{rms, micro} ) can be detected, which serve as a measure of forming in the burner thermoacoustic oscillations.
• - With the help of an optical sensor, it is possible to detect a flame signal (signal _{flame sensor} ) in order to be able to make a statement as to whether a flame is present within the burner or has already gone out.
• - Furthermore, the fuel flow along the fuel lines 2 . 3 also detected by means of a partial pressure measurement (P _{1st STAGE GAS} , P _{2nd STAGE GAS} )

The above sensorially detected operating parameters of the burner 1 Individually or holistically, a burner-own evaluation unit 5 fed. The evaluation unit 5 is primarily used for merging and evaluating all operating parameters detected by the burner. In extension of the evaluation unit 5 the sensory operating parameters are evaluated. In the simplest case, the sensorially recorded operating parameters are in the evaluation unit supplemented by a control function 5 compared with fixed reference values, which can be removed for example from manuals or operating tables. In the case of intolerable deviations, control or regulating signals S1, S2 are generated, by means of which adjusting means (not shown) can be activated, which are within the fuel supply lines 2 . 3 are provided and determine the mass flow of the fuel and thus directly influence the combustion behavior.

If it is a multiple burner arrangement, as in 1 by the multiple representation of successively arranged evaluation units 5 is indicated, the operating parameters of each burner are detected separately in the manner described above and in each case the burner's own evaluation 5 fed. The burner-specific operating parameters are sent directly or in edited form to a higher-level monitoring unit 6 forwarded, which serves in a simplest embodiment only as a measured value detection unit and offers the possibility of a summarized representation of the combustion states of all contained in the multiple burner assembly burners.

In extension of the function of the monitoring unit 6 in the sense of a control unit, further input signals, which represent the combustion result of the multiple burner arrangement, of the monitoring unit 6 made available. This applies in particular to the temperature Tk2 and the pressure pk2 of the combustion air supplied to the burners, the burner load load, the nitrogen oxide concentration and carbon monoxide concentration in the exhaust gases and the temperature distribution TAT at the turbine outlet.

On the basis of these additional input variables, the higher-level monitoring unit is used 6 an evaluation of all sensory recorded operating parameters of all individual burners, which ultimately control commands B1, B2, etc. are generated and sold, which have a direct impact on the performance and thus on the fuel supply of the respective burner.

The burner monitoring according to the invention can be modular due to its multilevel upgradeability existing burner systems, in particular multiple burner arrangements be adapted.

Through the combined monitoring of a large number of individual burners in a multiple burner arrangement, the inventive method provides the ability to summarize certain individual burners to burner groups, which are controlled or controlled jointly for the purpose of optimizing the overall combustion result.

ever offers burner arrangement, purpose and performance the inventive method individual optimization strategies that determine the combustion result improve and ultimately the reliability of single as well as multiple burner arrangements increase significantly.

1

premix

2, 3

fuel supply line

4

sensor unit

5

evaluation and control unit

6

higher-level monitoring unit

Claims (20)

Method for operating at least one burner ( 1 ) for firing a combustion chamber of a heat engine, in particular a gas turbine plant, characterized in that a number of operating parameters is sensed, which determines the combustion process in each case within the at least one burner ( 1 ) and that the number of operating parameters is evaluated for purposes of evaluating the combustion process within the combustion chamber. A method according to claim 1, characterized in that at least one of the following operating parameters is detected by sensors: - temperature on and / or in the burner housing, - mass flow of the burner ( 1 ) supplied mass of combustion air, - mass flow of at least one type of fuel, the burner ( 1 ) is supplied to form an ignitable fuel mixture, - pressure fluctuations within the burner ( 1 ) due to the formation of thermoacoustic vibrations, - heat release in the burner ( 1 ) forming flame, - flame temperature in the burner ( 1 ) forming flame, - gas composition of forming by the combustion process hot gases. Method according to claim 2, characterized in that that the mass flow of both the combustion air supply and the at least one fuel type by way of a differential pressure measurement is determined. Method according to one of claims 1 to 3, characterized that the at least one burner in the way of a so-called inner stepped fuel supply is operated, the at least a burner over at least two separate Brennstoffzuführleitungen the at least one Fuel type supplied becomes. Method according to one of claims 1 to 4, characterized in that a plurality of burners ( 1 ) is provided for firing a combustion chamber, which is supplied by at least one type of fuel by way of an external staging, that a first group of burners via at least a first fuel supply line and at least a second group of burners via at least one second fuel line with the at least one fuel be supplied. Method according to claim 4 or 5, characterized that the mass flow of the at least one type of fuel through each single fuel supply line is determined separately. A method according to claim 5, characterized in that a ratio is determined from the mass flows through the at least two fuel supply lines ( 2 . 3 ) the at least one burner ( 1 ) supplied at least one type of fuel. Method according to one of claims 1 to 7, characterized in that by the in the burner ( 1 ) is detected calorically, and that the heat release is given as an integral value over the entire flame or by a spatially resolved temperature field representing at least a portion of the flame. Method according to one of claims 1 to 8, characterized in that on the basis of the evaluation of the sensor-detected operating parameters at least one control or regulating signal (S1, S2) is generated with the at least one actuating means is activated by the combustion process of at least a burner ( 1 ) being affected. A method according to claim 9, characterized in that by the control or regulating signal (S1, S2) of the mass flow of the at least one type of fuel through at least one, preferably all of the burner ( 1 ) fuel lines ( 2 . 3 ) is controlled or regulated. A method according to claim 9 or 8, characterized in that the influencing of the combustion process by targeted activation of the at least one actuating means optimizes at least one of the following combustion properties - Hot gas temperature at the turbine inlet (TIT) and homogenization of the temperature distribution within the combustion chamber, - Reduction of the emission values of NOx and CO in the exhaust gases of the internal combustion engine, - Increase of the flame stability and reduction in the burner ( 1 ) forming thermoacoustic vibrations and - reducing the risk of flashback and overheating. Method according to one of claims 1 to 11, characterized in that in the case of a plurality of individual burners ( 1 ), which are arranged in the context of a multiple burner arrangement, in particular a ring or pot combustion chamber, the operating parameters of each burner ( 1 ) are recorded and evaluated separately. Method according to claim 12, characterized in that the per burner ( 1 ) or based on the operating parameters per burner ( 1 ) information of a higher-level monitoring unit ( 6 ) are supplied for monitoring and control of the multi-burner arrangement. Method according to Claim 13, characterized in that, based on a burner policy determining the mode of operation of the multiple burner arrangement, the monitoring unit ( 6 ) Control or regulating signals (B1, B2) for controlling or regulating individual burners ( 1 ) or burner groups. A method according to claim 14, characterized in that by the control or regulating signals (B1, B2) of the mass flow of the at least one type of fuel per burner ( 1 ) is controlled or regulated. Burner arrangement with at least one burner ( 1 ) for firing a heat engine, in particular a gas turbine plant, the formation of an ignitable fuel / air mixture at least one fuel type by at least one fuel line ( 2 . 3 ), characterized in that a number of sensors ( 4 ) on the burner ( 1 ) is provided, each detecting the combustion process characterizing operating parameters, and that the burner ( 1 ) assignable evaluation unit ( 5 ), which evaluates the number of sensory operating parameters for purposes of evaluating the combustion process. Burner arrangement according to claim 16, characterized in that the number of sensors ( 4 ) comprises at least one of the following sensors: - temperature sensor for detecting the temperature at the burner housing, - mass flow sensor for detecting the combustion air supplied to the burner, - mass flow sensor for detecting the at least one fuel type, - pressure sensor for detecting pressure fluctuations within the burner due to the formation of thermoacoustic Vibrations, - thermal sensor for detecting the heat release of the flame forming in the burner, - thermal sensor for detecting the flame temperature of the flame forming in the burner, - gas sensor for detecting the gas composition of the hot gases forming during the combustion process. Burner arrangement according to claim 16 or 17, characterized in that a burner control unit is provided, in which on the basis of the in the evaluation unit ( 5 ) at least one control or regulating signal (S1, S2) can be generated, which activates at least one actuating means which controls the mass flow of the at least one type of fuel through at least one, preferably all, burner. 1 ) fuel lines ( 2 . 3 ). Burner arrangement according to claim 18, characterized in that the actuating means as a in the fuel line ( 2 . 3 ) provided valve is formed. Burner arrangement according to one of claims 16 to 19, characterized in that a plurality of individual burners ( 1 ) is arranged in the context of a multiple burner arrangement that a higher-level monitoring unit ( 6 ), which is the per burner ( 1 ) or based on the operating parameters per burner ( 1 ) information can be supplied, and that the higher-level monitoring unit ( 6 ) based on a desired combustion behavior with respect to the multiple burner arrangement generates control or control variables, each of which determines the actual combustion state of the individual burners ( 1 ) influence.