Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23M—CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
  • F23M11/00—Safety arrangements
  • F23M11/04—Means for supervising combustion, e.g. windows
  • F23M11/045—Means for supervising combustion, e.g. windows by observing the flame
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N5/00—Systems for controlling combustion
  • F23N5/003—Systems for controlling combustion using detectors sensitive to combustion gas properties
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N5/00—Systems for controlling combustion
  • F23N5/02—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium
  • F23N5/08—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using light-sensitive elements
  • F23N5/082—Systems for controlling combustion using devices responsive to thermal changes or to thermal expansion of a medium using light-sensitive elements using electronic means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2225/00—Measuring
  • F23N2225/08—Measuring temperature
  • F23N2225/16—Measuring temperature burner temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2229/00—Flame sensors
  • F23N2229/20—Camera viewing

Definitions

• the present invention relates to a method and a device for determining the soot loading of a combustion chamber during operation.
• the firing must be optimized using a suitable firing control.
• fluctuations in the calorific value of the fuel or the multi-blend occur because of the different origin of the fuel or the heterogeneous composition of the gauze.
• the ratio of the individual fuels to one another can also fluctuate.
• a known procedure consists in the selective extraction of exhaust gases with soot contents with the aid of an extraction probe. The extraction can take place either in the combustion chamber or in a downstream x-exhaust system. Then the extracted air quantity is checked and the soot load is determined. A complete recording of the soot load is not possible with this procedure, since only a selective extraction takes place. Local fluctuations in the soot load in the combustion chamber or in the exhaust system therefore lead to distortion. In addition, the at the soot oil charge resulting from the combustion is only detected with a certain delay. The intended firing control therefore always works with a comparatively long dead time, which can be up to several 5 minutes in larger power plants.
• Another approach provides for the determination of the soot loading of flames with the help of laser absorption measurements using the Mie theory.
• this measuring method is only suitable for research purposes in the laboratory, since the measurement of the soot loading of a flame is very complex. Use in continuous daily operation is currently not possible.
• this object is achieved in a method of
• At least one parameter characteristic of the combustion which allows a conclusion about the soot loading, is measured by monitoring a flame in the combustion chamber and the soot loading is determined based on the measurement.
• the invention proposes to replace the previously known direct methods for determining the soot loading by an indirect method.
• a spatial distribution of the at least one parameter characteristic of the combustion is measured. This increases the accuracy of the method according to the invention, since the at least one parameter in the area of the flame is generally not constant. By determining the spatial distribution, it is therefore possible to determine the soot loading much more precisely than with a one-dimensional measurement of the at least one parameter characteristic of the combustion.
• Combustion chamber of power plants is always present, the position of the flame during combustion.
• a stationary measurement at individual selected points thus harbors the risk that the flame will not be detected by the measuring device when its position changes.
• this can be prevented by specifying a spatial measuring range.
• a permissible range with a lower limit and / or upper limit can advantageously be specified for the measured values. If a measured value lies outside the specified range, this can be disregarded when determining the soot load.
• the local soot formation rate is determined from the measured spatial distribution of the at least one parameter characteristic of the combustion. This further improves the measuring accuracy.
• the local soot formation rate is based on physical and / or chemical Connections calculated.
• the local soot formation rate can be determined by preliminary fuel or the fuel mixture without previous tests and empirical values.
• the local soot formation rate can be determined by comparing it with predetermined conversion curves. This offense is advisable if conversion curves already exist and / or no physical and / or chemical relationships are known for the fuel or fuel mixture used. If both investigative procedures are used, the double determination gives control. At the same time, the measuring accuracy is increased.
• the determined soot formation rate is advantageously summed up over the measuring range. This reduces the amount of data to be processed. At the same time, there is a total value of the soot formation rate, which can already be used for control and regulation purposes.
• the determined soot formation rate is summed up over a predefinable period. Fluctuations in the flame, particularly due to turbulent combustion, can be reliably detected. At the same time, peak values or minimum values are smoothed. The flame can also be checked by totalizing. If the flame goes out, the soot formation rate drops drastically over a longer period of time. Short-term flak core is smoothed by adding up over the predefinable period, while the flame goes out to one leads to a permanent drop in the soot formation rate, which can be recognized by the method according to the invention. In addition to determining the soot load, it is also possible to monitor the flame.
• the predefinable period is variable.
• this period can be changed as a function of previous measurements.
• the predeterminable period of time can be selected differently than in constant continuous operation.
• the determined soot formation rate is advantageously averaged after the addition. This averaging allows the soot formation rate to be represented in relation to the size of the measuring range, so that several flames or combustion chambers of different sizes can be compared with one another.
• the soot loading rate determined before or after the addition is increased by a
• Calibration factor linked to determine the soot load This calibration factor enables the conclusion of the soot formation rate to the soot loading and is determined on a plant-specific basis.
• the calibration factor can advantageously be changed, in particular
• the temperature is measured as a characteristic parameter for the combustion.
• the temperature can also be detected in a spatial distribution by one or more suitable sensors. The measurement is accurate, non-contact, requires no moving parts and is carried out without delay. Based on the measured spatial temperature distribution, the local soot formation rate is then determined according to the procedure described above. hen determined.
• the carbon monoxide content is measured as a characteristic parameter for the combustion. The carbon monoxide content is measured by detecting the radiation in the radiation range characteristic of carbon monoxide. This radiation area is isolated from the entire spectrum of the flame, for example by a beam plate, and then detected. The spatial distribution of the carbon monoxide in the flame can be measured using a suitable evaluation unit, such as a CCD camera.
• a lower limit of e.g. 800 ° C can be set. Areas where the temperature is below this limit can then be regarded as lying outside the flame and are not taken into account when determining the soot load.
• Both the temperature and the carbon monoxide content are advantageously measured and linked to one another. This procedure enables the soot load to be determined on the basis of two different measured values and thus a check. At the same time, the accuracy is increased.
• a device for carrying out the method has at least one sensor for measuring the at least one parameter characteristic of the combustion and a data processing system for determining the soot formation rate.
• the data processing system comprises, in particular, suitable assemblies or modules for adding up and averaging the soot formation rate and for linking to the calibration factor.
• At least one sensor is advantageously designed as a CCD camera.
• Such “charged-coupéed-dev ⁇ ce” cameras allow a spatial resolution of the measuring range and thus the detection of the at least one parameter of spatial distribution that is characteristic of the combustion.
• the determined soot formation rate can then be processed further by means of a suitable regulation and passed to the burner of the flame.
• Figures 1 and 2 is a schematic representation of the sequence of the inventive method.
• Figure 3 is a schematic representation of a device for performing the inventive method.
• FIG. 1 shows a schematic representation of the sequence of the inventive method.
• a flame 10 m in a combustion chamber 23 is monitored via a detection device I.
• the acquisition device I measures the spatial distribution of at least one parameter which is characteristic of the combustion and which allows a conclusion to be drawn about the soot loading. Either the temperature or the carbon monoxide content or the temperature and carbon monoxide content are recorded together.
• the local soot formation rate, which a soot formation field III provides, is then determined by a calculation or a comparison II.
• the soot formation field III is summed up by an integration IV and, if necessary, averaged. Then there is a link V with a calibration factor.
• the soot loading of the combustion chamber is determined, which is displayed, printed out or saved via a suitable output VI.
• the soot loading can be given to a regulation VII, which acts on the flame 10 and thus on the combustion. In this way a firing control is achieved.
• a temperature field 11 of the flame 10 is detected. Based on local soot loading On the temperature field 11, a conversion curve 12 is used, which has either been determined by experiments or has been calculated on the basis of physical and / or chemical relationships. Such conversion curves 12 are also printed in the VCI warm atlas and m "Technical Combustion", Warnatz, Springer-Verlag.
• the temperature field 11 and the conversion curve 12 are linked in a comparison module 13 and provide a field 14 of the soot formation rate.
• This field 14 of the soot formation rate is transmitted to an integrator 15, which carries out a spatial and / or temporal summation .. If necessary, averaging can also be carried out after the integration Linking module 17.
• the soot loading is calculated, which is then passed on to an output module 18.
• Figure 3 shows schematically a device for performing the inventive method.
• the flame 10 m in the combustion chamber 23 is fed by a burner 21.
• Monitoring is provided by one or more sensors 22 which measure at least one parameter characteristic of the combustion.
• This can be a CCD camera.
• the spatial distribution of temperature and / or carbon monoxide content is advantageously measured.
• the measured value is passed on to the comparison module 13, in which the field 14 of the soot formation rate is determined.
• the comparison module 13 transmits the field 14 of the soot formation rate to the integrator 15, where the summation and optionally averaging takes place.
• the soot loading is then determined in the linking module 17 using the calibration factor 16.
• This soot load is delivered to the output module 18.
• the output module 18 transmits the soot loading to a printer or memory 20.
• the comparison module 13, the integrator 15, the linking module 17 and the output module 18 are combined in a data processing system 19.
• the method according to the invention and the associated device enable the soot loading to be determined quickly, easily and with high precision.

Landscapes

• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Control Of Combustion (AREA)
• Radiation Pyrometers (AREA)
• Combustion Of Fluid Fuel (AREA)
• Incineration Of Waste (AREA)
• Investigating Or Analyzing Materials Using Thermal Means (AREA)
• Feeding And Controlling Fuel (AREA)
• Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
• Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)

Applications Claiming Priority (3)

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• 1998
  • 1998-09-11 DE DE19841877A patent/DE19841877A1/de not_active Withdrawn
• 1999
  • 1999-09-08 WO PCT/DE1999/002839 patent/WO2000016010A1/fr active IP Right Grant
  • 1999-09-08 JP JP2000570504A patent/JP4365036B2/ja not_active Expired - Fee Related
  • 1999-09-08 DK DK99955673T patent/DK1114280T3/da active
  • 1999-09-08 EP EP99955673A patent/EP1114280B1/fr not_active Expired - Lifetime
  • 1999-09-08 ES ES99955673T patent/ES2213396T3/es not_active Expired - Lifetime
  • 1999-09-08 DE DE59908129T patent/DE59908129D1/de not_active Expired - Lifetime
  • 1999-09-08 AT AT99955673T patent/ATE256843T1/de active
• 2001
  • 2001-03-12 US US09/803,764 patent/US6551094B2/en not_active Expired - Lifetime

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