EP1046861A1 - Process to regulate automatically the combustion of a waste incinerator - Google Patents

Abstract

For automatically setting the furnace in a waste burning system.

Description

TECHNICAL AREA

The invention is a method for automatic adjustment the combustion of a waste incineration plant.

STATE OF THE ART

Müllqualität" entsprechend so anzupassen, dass sie stabil und im Hinblick auf die Emissionen optimiert wird. Die wichtigsten Einflussfaktoren, welche die Feuerung dabei beeinflussen, sind die Zündfähigkeit und das Abbrennverhalten des Mülls. Da die beiden Faktoren nicht messbare Grössen sind, ist eine direkte Messung nicht möglich. Dem Anmelder ist dadurch bis heute keine Messung oder kein Verfahren bekannt, welche(s) die Müllqualität" bezüglich der Zündfähigkeit und des Abbrennverhaltens eindeutig bestimmt. Es wurden lediglich indirekte Messungen betrieben, um die Fahrweise einer Müllverbrennung vorausschauend zu betreiben. Da die beiden genannten Kriterien der Zündfähigkeit und des Abbrennverhaltens entscheidend vom Heizwert und vom Wasseranteil des Mülls beeinflusst werden, wird beispielsweise in der Druckschrift DE 44 45 954 A1 ein Verfahren zur Verbrennung von Abfällen beschrieben, welches den Heizwert des Mülls bereits im Zuteilungsschacht ermittelt. Daraus wird über eine Prozesssteuerungseinheit die Menge der Verbrennungsluft und/oder die Menge des zuzuführenden Abfalls gesteuert. Der Heizwert ergibt sich aus Messungen, welche mit Mikrowellen durchgeführt werden. Ausgesandte Mikrowellen werden reflektiert zurückgesendet und aufgrund dieser Reflexion wird der Wassergehalt des Mülls ermittelt. Dieses Messverfahren hat aber verschiedene Nachteile. Der Aufwand für die Installation der Sensoren ist sehr gross und auch relativ teuer. Zudem ist die Messung nur an diskreten Punkten verfügbar. Auch aus der Druckschrift DE 3537945 A1 ist ein Verfahren zur optimiertenWhen operating a mill-type incinerator, it is important to control the combustion of the

Waste quality "to be adjusted accordingly so that it is stable and optimized with regard to emissions. The most important influencing factors that influence the combustion are the ignitability and the burning behavior of the waste. Since the two factors are not measurable quantities, this is a direct measurement to date, the applicant is therefore not aware of any measurement or method which Waste quality "with regard to the ignitability and the burning behavior was clearly determined. Only indirect measurements were carried out in order to foresee the driving style of a waste incineration. Because the two criteria of ignitability and the burning behavior are decisively influenced by the calorific value and the water content of the waste, for example A process for the incineration of waste is described in the publication DE 44 45 954 A1, which already determines the calorific value of the garbage in the distribution shaft. From this, the amount of combustion air and / or the amount of waste to be supplied is controlled by a process control unit Measurements which are carried out with microwaves, emitted microwaves are sent back in a reflected manner and the water content of the waste is determined on the basis of this reflection, but this measuring method has several disadvantages r sensors is very large and also relatively expensive. In addition, the measurement is only available at discrete points. Document DE 3537945 A1 also describes a method for optimized

Operation of a waste incineration plant known, which regulates the amount of air depending on the calorific value. The combustion air can be set in individual zones. This is done continuously to adjust the amount to a fluctuating calorific value. The calorific value results from the quotient of currently released heat and the waste mass flow. The CO and the O ₂ content of the exhaust gas are included in the air setting. The disadvantage is that the water content of the waste is not taken into account in this process, although it plays a major role in incineration.

Also from Development of a camera-guided combustion control system for improving the combustion, burnout and emission behavior of a waste incineration plant ", GB Kraftwerkstechnik 73 (1993), No. 7, a combustion control system for waste incineration is known. In this process, the O ₂ - Concentration in the exhaust gas and the amount of steam generated are determined from these values, the waste loading and the primary and secondary air supply, while minimizing the CO content. The air supply can be adjusted on the grate in different zones. This method works with a Camera monitoring, with which the temperature distribution in the boiler is determined by means of infrared images. However, this system is relatively complex and expensive due to camera monitoring. This method for controlling the firing performance of incinerators with zone-wise different primary air supply on Combustion grate is also described in EP 352 620A2.

A method for controlling the combustion of fuel with a strongly fluctuating calorific value is known from EP 317 731 B1. The water content of the fuel and / or the CO ₂ content of the combustion gases is measured by the intensity of the radiation in the area of the feed point and the evaporation and degassing zone of the furnace. Among other things, the calorific value of the waste is determined from these values and the air supply is controlled as a function thereof. The disadvantage of this prior art, however, is that, in the case of very moist waste, the water content and the CO ₂ content in the flue gas also decrease due to a considerably poorer combustion. With automatic firing control, however, this can mean that, contrary to reality, the waste appears to be much drier. In addition, expensive opto-electrical sensors are required to detect the water content or the CO ₂ content.

PRESENTATION OF THE INVENTION

The invention overcomes the disadvantages mentioned. It solves the task of creating a method for determining the waste quality that works simply and reliably. If a flue gas scrubber is available, the method should only use temperature, pressure and differential measurements (e.g. volume flow). It should also be easy to integrate into an existing waste incineration plant and be inexpensive.
According to the invention, this is achieved in a method according to the preamble of the independent claim in that a fictitious process variable for setting the combustion parameters, such as combustion air distribution, waste layer thickness and rust rate Waste quality "is determined from the calorific value of the waste (Hu) and the water content of the waste (H ₂ O _waste ).
If a flue gas scrubber is available, the method according to the invention makes direct measurement of the water content superfluous. Furthermore, the water produced during the combustion can advantageously be determined via a statistical relationship between the heat of combustion and the mass flow of carbon. In addition, the process can be easily and inexpensively integrated into an existing waste incineration plant, since all the necessary devices are usually already available. Despite the simplicity, it is a very reliable process.

The other design options are the subject of the dependent Expectations.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.1

eine schematische Darstellung des erfindungsgemässen Verfahrens,

Fig.2

ein Diagramm Müllqualität" über Heizwert und Wasseranteils des Mülls,

Fig.3

eine schematische Darstellung zur Ermittlung des Mülldurchsatzes,

Fig.4

eine schematische Darstellung zur Ermittlung des Mülldurchsatzes,

Fig.5

eine schematische Darstellung zur Ermittlung des Wassergehalts im Rauchgas,

Fig.6

eine schematische Darstellung zur Ermittlung des Wassergehalts im Rauchgas mit einer Temperaturmessung vor und im Rauchgaswäscher,

Fig.7

das Diagramm zur Ermittlung des Wassergehalts im Rauchgas aus Rauchgaseintrittstemperatur und Sättigungstemperatur der Rauchgase im Wäscher,

Fig.8

eine statistische Beziehung zwischen entbundener Wärme und Massenstrom an Kohlenstoff und

Fig.9

ein Diagramm über die Fehleranfälligkeit des erfindungsgemässen Verfahrens.

Show it:

Fig. 1

2 shows a schematic representation of the method according to the invention,

Fig. 2

a diagram Waste quality "about the calorific value and water content of the waste,

Fig. 3

a schematic representation for determining the waste throughput,

Fig. 4

a schematic representation for determining the waste throughput,

Fig. 5

a schematic representation for determining the water content in the flue gas,

Fig. 6

1 shows a schematic representation for determining the water content in the flue gas with a temperature measurement before and in the flue gas scrubber,

Fig. 7

the diagram for determining the water content in the flue gas from the flue gas inlet temperature and the saturation temperature of the flue gases in the scrubber,

Fig. 8

a statistical relationship between released heat and mass flow of carbon and

Fig. 9

a diagram of the susceptibility to errors of the inventive method.

Only the elements essential to the invention are shown. Same Elements are provided with the same reference symbols in different figures.

WAY OF CARRYING OUT THE INVENTION

The method according to the invention is suitable for determining the water content of the waste H ₂ O _waste and
Calorific value of garbage Hu
a fictional size in a waste incineration plant Waste quality "and thereby perform an automatic firing setting, for example in relation to essential variables such as the combustion air distribution, the thickness of the waste layer or the rust speed.

• Müllkrananlage mit Wägeeinrichtung der einzelnen, beschickten Müllchargen
• Kessel
• Frischdampfmengenmessung
• Temperatur und Druck von Frischdampf und Speisewasser
• Verbrennungsluft Volumenstrom
• Entweder Wäscher mit Temperaturmessung der Rauchgase vor Eintritt und im Wäscher,
  oder H₂O Messung im Rauchgas am Kesselende

FIG. 1 shows schematically the process for reaching the values of calorific value (Hu) and waste moisture (A). First, the waste mass flow (F waste) is determined by the individual waste crane batches. The calorific value of the waste (Hu) is then calculated using the waste mass flow and the amount of live steam produced using the amount of heat transferred. Temperature measurements can be used to determine the flue gas moisture (A) via physical relationships and the water content (A) of the waste from the statistical relationship. A waste quality is determined from the calorific value of the waste and the waste moisture, which is used for the automatic setting of the furnace. The following measurements or components, which are usually present in every waste incineration plant, are required to determine the values mentioned:

• Garbage crane system with weighing device for the individual, loaded waste batches
• boiler
• Live steam quantity measurement
• Temperature and pressure of live steam and feed water
• Combustion air volume flow
• Either scrubber with temperature measurement of the flue gases before entering and in the scrubber,
  or H ₂ O measurement in the flue gas at the end of the boiler

In Figure 2, the Garbage quality "is shown in a 3-dimensional diagram with the two basic parameters calorific value and water content in the garbage Garbage quality "is the greater, the higher the calorific value and the lower the water content in the garbage. The sloping level in this diagram, from which the garbage quality results, was chosen based on many years of trials and experience.

The following steps are to be carried out in the method according to the invention:

1. Calculation of the waste throughput / waste mass flow with _waste

FIGS. 3 and 4 schematically show the first method step in a waste incineration plant 10 with a furnace 40. In order to enable a rapid calculation of the waste throughput m ˙ _waste , the throughput is calculated on the basis of the pause time between the feedings and the loading quantity of the waste in a hopper 20. It is assumed that the volume fed is constant (= gripper content 1-12) and only the specific weight changes. You also know the number of grippers that are necessary to fill the garbage shaft 50 (determine once). 3 and 4, the grippers are numbered from 1 to 12. This type of garbage throughput calculation also means that more or less always the same label 30 is loaded in the garbage shaft 50 (e.g. a weld seam, the deflection edge or the field of view of the camera). This means that the volume decrease between 2 loads corresponds to one gripper content.

• der Müllschacht 50 ist z.B. mit 8 Greifern (Nr 3-10) bis zur Marke 30 gefüllt,
• von jedem der beschickten Greifer kennt man das Gewicht (gespeichert im Prozessleitsystem)
• der Kranführer legt einen 11. Greifer in den Trichter 20
• durch den Müllnachschub für die Verbrennung rutscht der Müll im Müllschacht 50 langsam nach unten, bis die Marke 30 erreicht ist.
• in diesem Moment wird ein neuer Greifer beschickt (Nr. 12)
• man misst die Zeit t_11-12 die der 11. Greifer gebraucht hat, um die Marke 30 zu erreichen (entspricht der Volumenabnahme)
• während dieser Zeit müssen die w₃ kg des Greifers 3 in die Feuerung transportiert worden sein
• Durch den Müllnachschub für die Verbrennung rutscht der Müll im Müllschacht 50 langsam nach unten, bis die Marke 30 wiederum erreicht ist.
• ein neuer Greifer wird beschickt (Nr. 13)
• man misst die Zeit t_12-13 die der 12. Greifer gebraucht hat, um die Marke 30 zu erreichen (entspricht der Volumenabnahme)
• während dieser Zeit müssen die w₄ kg des Greifers 4 in die Feuerung transportiert worden sein

The procedure for determining the garbage throughput m ˙ _garbage is as follows:

• the garbage shaft 50 is filled, for example, with 8 grippers (No. 3-10) up to the mark 30,
• the weight of each of the loaded grippers is known (stored in the process control system)
• the crane operator places an 11th gripper in the hopper 20
• due to the refill of refuse for the combustion, the refuse in the refuse shaft 50 slowly slides down until the mark 30 is reached.
• at this moment a new gripper is being loaded (No. 12)
• one measures the time t _11-12 that the 11th gripper took to reach the mark 30 (corresponds to the decrease in volume)
• during this time the w ₃ kg of the gripper 3 must have been transported into the furnace
• Due to the refill of refuse for the combustion, the refuse slowly slides down in the refuse shaft 50 until the mark 30 is reached again.
• a new gripper is loaded (No. 13)
• measure the time t _12-13 that the 12th gripper took to reach mark 30 (corresponds to the decrease in volume)
• during this time the w ₄ kg of the gripper 4 must have been transported into the furnace

The garbage throughput with _garbage during this time was over 2 grippers m rubbish = 1 H ( t 11-12 + t 12-13 ) * ( w 3rd + w 4th )

The influences of the errors regarding the assumptions (uniform loading, constant volume, etc.) will minimize this calculation using a few grippers averaged (depending on the volume of the gripper, size of the system and driving style of the Crane operator).

2. Calculation of the waste heating value Hu

If the garbage throughput m ˙ _{garbage is} known, the _garbage calorific value Hu can be calculated using the boiler efficiency ζ _boiler , the enthalpy of feed water h _SPW and live steam h _FD as well as the fresh steam quantity m ˙ _FD .

Waste incineration heat input: QB = m FD · ( H FD - H SPW ) ζ boiler - Q Additional burner where the following applies (from water vapor table): Fresh steam enthalpy (FD): H FD = f (T FD , P FD ) Feed water enthalpy (SPW): H SPW = f ( T SPW , P SPW )

Applied heat output when using an additional burner (e.g. auxiliary firing for 17th BlmSchV): Q Additional burner = m oil Hu oil

The following results for the waste heating value, including (1) and (2): Hu rubbish = QB m rubbish

3. Determination of the flue gas moisture H ₂ O _{flue gas}

The flue gas moisture serves as the basis for determining the water content in the waste. The proportion of water in the garbage cannot be detected directly due to the lack of suitable measuring systems. The higher the water content in the garbage, the more water has to evaporate before or in the furnace. The flue gas moisture must therefore also rise. This process is shown in FIG. 5.
The flue gas moisture H ₂ O _{flue gas} can be calculated for an existing scrubber from the flue gas temperature upstream of the scrubber and the saturation temperature in the scrubber. FIG. 6 shows this process with the two temperature measurements. The flue gas moisture H ₂ O _{flue gas} can be determined from these measurements using a diagram which is shown in FIG. H 2nd O Flue gas = f ( T Gas_vor_wascher , T Gas_in_washers )

The following applies: the drier the flue gas, the more water it can absorb and the lower the saturation temperature will be in the scrubber. If there is no scrubber, the flue gas H ₂ O _{flue gas is} determined directly, for example, using a measurement based on laser absorption (at the corresponding frequency).

4. Calculation of the flue gas volume flow V ˙ _{flue gas}

wobei gilt:

gemessene Grössen: V ˙_PL , V ˙_SL

konstante Grössen: V ˙_Falschluft = 5000Nm ³ / h

Anteil_Asche = 25%

ρ _Rauchgas = 1,277kg /Nm ³

berechnete Grössen (aus (1)): m ˙_Müll

The flue gas volume flow can be calculated using a mass balance, taking into account the respective densities:

where:

Measured sizes: V ˙ _PL , V ˙ _SL

constant sizes: V ˙ _{false air} = 5000 Nm ³ / h

_Ash content = 25%

ρ _{flue gas} = 1.277 kg / Nm ³

calculated sizes (from (1)): m ˙ _garbage

From acceptance tests and performance measurements it is known from various plants that 20..30% of the garbage mass flow garbage _accumulates as ash _{mass flow} ( _fly and grate ash) and is fairly constant on average.
The flue gas density ρ _{flue gas} depends on the composition. The density ρ _{flue gas} = 1.277kg / Nm ³ applies to the following (average) flue gas composition (volume percent): 14.5% H ₂ O, 11% CO ₂ , 7.5% O ₂ , balance N ₂

5. Calculation of the water mass flows m ˙ _{H2O_ smoke gas}

The total water mass _flow m ˙ _{H2O_ smoke gas} at the end of the boiler is calculated taking into account (7) and (8): m H 2nd O_ smoke gas = V Rauchgas_Kesselende · H 2nd O Flue gas · ρ H 2nd O_ steam

• H-Verbrennung Müllfeuerung
• H-Verbrennung Zusatzfeuerung (Öl)
• H₂O aus der Verbrennungsluft
• H₂O aus dem Müll

daraus folgt: m H2O_Rauchgas = m H 2 O_Müllverbrennung + m H2O_Öl + m H 2 O_Müll + m H 2 O_Verbrennungsluft daraus folgt: m H 2 O_Müll = m H 2 O_Rauchgas - m H 2 O_Müllverbrennung - m H 2 O_Öl - m H 2 O_Verbrennungsluft The water found in the flue gas has 4 different sources:

• H-combustion waste incineration
• H-combustion additional combustion (oil)
• H ₂ O from the combustion air
• H ₂ O from the trash

it follows: m H 2nd O_ smoke gas = m H 2nd O_waste incineration + m H 2nd O_oil + m H 2nd O_waste + m H 2nd O _ Combustion air it follows: m H 2nd O_waste = m H 2nd O_ smoke gas - m H 2nd O_waste incineration - m H 2nd O_oil - m H 2nd O_combustion air

From acceptance tests and performance measurements with an installed CO ₂ measurement in the flue gas, a statistical analysis of the measurement data resulted in a linear relationship m CO 2nd = k CO 2nd · QB detected. This equation results from the diagram which is shown in FIG. 8. The C mass flow from the combustion is calculated from this. m C. = k CO 2nd · QB 3,667

If you use a constant C / H ratio in the waste, you can also calculate the H ₂ O mass flow from the waste incineration using the above-mentioned relationship. The C / H ratio is usually 7 to 8. With a constant value of 7.5 for the C / H ratio, the following relationship occurs:

The following applies to the additional firing with heating oil: m H 2nd O_oil = m oil · proportion of H 9,000 where share _{H is known} for different types of heating oil (heating oil EL = 13%)

The following applies to the water introduced via the combustion air: m H 2nd O_combustion air = ( V PL + V SL + V False air ) · H 2nd O Combustion air where H ₂ O _{combustion air is} between 7..12g / Nm ³ and is assumed to be constant in this range.

6. Calculation of the water content in the waste H ₂ O _waste

If one sets the water mass _flow m ˙ _{H2O_waste} from the garbage (11) in relation to the garbage throughput m ˙ _garbage (2), the water content in the garbage is obtained: H 2nd O rubbish = m H 2nd O_waste m rubbish

Ein (kleiner) Fehler in der Berechnung des Müllmassenstromes m ˙_Müll wirkt sich nun folgendermassen aus:

Ausgangslage: Hu = 10000kJ/kg und Wasseranteil Müll H₂O_Müll = 30% ergibt eine Müllqualität von 29,2%. Ist der berechnete Müllmassenstrom m ˙_Müll ca. 10% grösser als effektiv, werden der Heizwert Hu und der Wasseranteil im Müll H₂O_Müll um diese 10% kleiner sein.

Ausgangslage Fehler: Hu = 11000 kJ/kg und Wasseranteil Müll H₂O_Müll = 33% ergibt eine Müllqualität von 31,2% (vorher 29,2%)

Ändert sich der Wassermassenstrom m ˙_Müll aus dem Müll um +10%, so ergibt dies bei einem Hu von 10000kJ/kg eine Müllqualität von ca. 24,6% (vorher 29.2%). Der Müll ist also schlechter geworden.

Ändert sich Heizwert des Mülls um +10%, so ergibt dies bei einem Wasseranteil im Müll von 30% eine Müllqualität von 36% (vorher 29,2%). Der Müll ist also offensichtlich besser geworden.

Die Figur 9 zeigt in einem Diagramm einige Beispiele, wie ein Fehler von Müllmassenstrom m ˙_Müll, Heizwert Hu und Wassermassenstrom m ˙_{H2O_müll} in bezug auf die Müllqualität ändert. Durch eine geeignete Wahl der Funktion Müllqualität = f(HuMüll ,H 2 OMüll ) lässt sich der Fehler aus der Berechnung des Müllmassenstromes m ˙_Müll gänzlich ausblenden oder zumindest klein halten.
Allen Berechnungen liegen ausschliesslich (bei Einsatz eines Wäscher in der Rauchgasreinigung)

• Temperatur-
• Druck-
• Differenzdruck (Durchfluss, Volumenstrom)-

All calculations are based on constants or assumptions. They falsify the result in relation to the effective, physical value. The fictitious quantity "waste quality" as the basis for the combustion setting is based on these calculated values. In terms of waste incineration, however, the absolute values do not play a major role. However, it is critical when the absolute value changes. Only a change in the value finally causes a change in the firing setting via the fictitious size "waste quality". Systematic errors (due to incorrect assumptions or incorrect constants) that mainly affect the absolute value can therefore have no influence on the firing process. The greatest influence on the ultimately decisive size "waste quality", however, is the waste mass flow with _waste . The presented method is structured in such a way that this influence can be neglected in an elegant way:

A (small) error in the calculation of the garbage mass flow m ˙ _garbage now has the following effects:

Starting position: Hu = 10000kJ / kg and water content waste H ₂ O _waste = 30% results in a waste quality of 29.2%. If the calculated garbage mass flow m ˙ _{garbage is} approx. 10% larger than effective, the calorific value Hu and the water content in the garbage H ₂ O _{garbage will} be 10% smaller.

Starting point error: Hu = 11000 kJ / kg and water content waste H ₂ O _waste = 33% results in a waste quality of 31.2% (previously 29.2%)

If the water mass flow m ˙ _garbage from the garbage changes by + 10%, this results in a garbage quality of approx. 24.6% (previously 29.2%) with a Hu of 10000kJ / kg. So the garbage has gotten worse.

If the calorific value of the garbage changes by + 10%, this results in a garbage quality of 36% (previously 29.2%) with a water content in the garbage of 30%. So the garbage has obviously gotten better.

FIG. 9 shows some examples in a diagram of how an error of waste mass flow m ˙ _waste , calorific value Hu and water mass _flow m ˙ _{H2O_müll changes} in relation to the waste quality. By a suitable choice of function Waste quality = f ( Hu rubbish , H 2nd O rubbish ) the error from the calculation of the garbage mass flow m ˙ _{garbage can be} completely hidden or at least kept small.
All calculations are exclusive (when using a scrubber in flue gas cleaning)

• Temperature-
• Print-
• Differential pressure (flow, volume flow) -

Measurements. These measurements are also considered highly available in the waste incineration area. The availability of the fictitious process variable "waste quality" must therefore be highly available.
Small errors are made in all calculations, which either cancel or reinforce each other. The present method for determining the "waste quality", which must serve as the basis for the furnace setting, has proven to be very reliable in various plants, regardless of these errors. The fictitious process size "waste quality" corresponds in 95% of all operating cases with the combustion conditions observed in the combustion chamber. The signal is therefore ideally suited for deriving a combustion setting from its value via functions and tables (combustion air distribution, garbage layer thickness, rust speeds, etc.).

The process is designed so that it can be used in any commercially available control system can be installed. It is based on no additional, special hardware or software reliant.

Below is an example of a calculation (snapshot) from a Waste incineration plant listed. The control system calculates all the values online 250ms new.

1. Garbage throughput

The grabs 3-10 with the weights w3-w10 are in the garbage shaft: w3 2950kg w4 3120kg w5 2760kg w6 2370kg w7 2590kg w8 3280kg 08:48 w9 2880kg 09:00 w10 3010kg

The gripper 10 has reached the mark after 10 minutes and a gripper w11 and later (w11 for the mark) a gripper w12 is added: 09:10 w11 2810kg 09:25 w12 2930kg at 09:25 the waste throughput is calculated m rubbish = 1 H ( t 11-12 + t 12-13 * ( w 3rd + w 4th ) = 14568 kg / h = 4.0467 kg / s

2. Garbage calorific value

h _FD = f ( T _FD , P _FD ) from water-steam table

T _FD = 400 ° C

P _FD = 39 bar

h _FD = 3217.4 kJ / kg

h _SPW = f ( T _SPW , P _SPW ) from water-steam table

T _SPW = 130 ° C

P _SPW = 56 bar

h _SPW = 549.9 kJ / kg QB = m FD · ( H FD -H SPW ) ζ boiler - Q Additional burner

m _FD = 55000 kg / h = 15.2778 kg / s

ζ _boiler = 0.855

Q _{additional burner} = 0 kW

⇒ QB = 47665 kW Hu rubbish = QB m rubbish = 11779 kJ / kg

3. Flue gas moisture

H 2nd O Flue gas  = f ( T Gas_vor_wascher , T Gas_in_washers ):

T _{RG before scrubber} = 180 ° C

Saturation temperature of the flue gases in the scrubber = 62 ° C

⇒ H ₂ O _{flue gas} = 15.60 vol%

4. Flue gas flow

V_PL = 56500 Nm³/h

V_SL = 11600 Nm³/h

V_Falschluft = 5000 Nm³/h

m_Müll = 14568 kg/h (siehe oben)

Anteil_Asche = 25%

ρ_Rauchgas = 1.277 kg/Nm³

V _PL = 56500 Nm ³ / h

V _SL = 11600 Nm ³ / h

V _{false air} = 5000 Nm ³ / h

m _garbage = 14568 kg / h (see above)

_Ash content = 25%

ρ _{flue gas} = 1,277 kg / Nm ³

5. Water mass flows

V _{flue gas volume flow} = 82572 Nm ³ / h (see above)

H ₂ O _Rachgas = 15.60 vol%

ρ _{flue gas} = 0.80 kg / Nm ³ m H 2nd O_ smoke gas = V Rauchgas_Kesselende · H 2nd O Flue gas · Ρ H 2nd O_ steam = 10305 kg / h

m _{H2O oil} = 0 kg / h

H ₂ O combustion air 10g / Nm ³ m H 2nd O_combustion air = ( V PL + V SL + V False air ) · H 2nd O Combustion air = 686 kg / h

k _CO2 = 0.3770 kg / kWh QB = 47655 kW (see above)

⇒ m H 2nd O_waste = m H 2nd O_ raw gas - m H 2nd O_waste incineration - m H 2nd O_Oel - m H 2nd O_combustion air = 3739 kg / h

6. Water content in the garbage

m _garbage = 14568 kg / h (see above)

m _{H2O waste} = 3739 kg / h ⇒ H 2nd O rubbish = m H 2nd O_waste m rubbish = 25.66%

7. Garbage quality

H ₂ O _garbage = 25.66%

Hu _garbage = 11779 kJ / kg

Water content in the garbage Garbage calorific value 15 20th 25th 30th 35 40 45 6000 21 14 8th 3rd 0 0 0 8000 33 25th 18th 12th 7 3rd 0 10,000 52 44 36 28 20th 11 2nd 12,000 75 67 59 51 41 28 10th 14000 93 86 79 70 58 41 20th 16000 100 94 87 79 67 52 30th Q _garbage = 55.40%

REFERENCE SIGN LIST

1-12

Gripper content

20th

funnel

30th

brand

40

Firing

50

Garbage chute

60

Incinerator

h _FD

Enthalpy of live steam

h _SPW

Enthalpy of the feed water

H ₂ O

water

Hu

calorific value

k

Proportionality factor

m ˙

Mass flow

m ˙ _garbage

Mass flow of garbage

P _FD

Live steam pressure

P _SPW

Feed water pressure

PL

Primary air

Q

Heat output

QB

Thermal output of the furnace

SL

Secondary air

T

temperature

T _FD

Live steam temperature

T _SPW

Feed water temperature

t

time

V

volume

V ˙ _{flue gas}

Volume flow of the flue gas

w ₃

Mass of the 3rd gripper

w ₄

Mass of the 4th gripper

ρ

density

ζ _boiler

Efficiency of the boiler

Claims (4)

Process for automatically setting the combustion of a waste incineration plant, in which the calorific value of the waste (Hu) is continuously determined from the heat currently released in the combustion chamber (QB) and the registered waste mass flow (m ˙ _waste ),
characterized in that
a fictitious process variable for setting the combustion parameters such as combustion air distribution, waste layer thickness and rust speed

Waste quality "is determined from the calorific value of the waste (Hu) and the water content of the waste (H ₂ O _waste ), the water content of the waste (H ₂ O _waste ) according to the equation H 2nd O rubbish = m H 2nd O_waste m rubbish is determined
with m ˙ _{H2O_Müll} water mass _flow of waste,
and the water mass _flow of the garbage m ˙ _{H2O_garbage} m H 2nd O_waste = m H 2nd O_ smoke gas - m H 2nd O_waste incineration - m H 2nd O_oil - m H 2nd O_combustion air put together,
With m ˙ _{H2O_Fauchgas} Water mass _flow in the flue gas m ˙ _{H2O_Waste} incineration water mass _{flow generated} during combustion m ˙ _{H2O_Oil} water mass _{flow created} by additional oil firing m ˙ _{H2O_combustion} air contained in the supplied combustion air Water mass flow, where: m H 2nd O_ smoke gas = V Rauchgas_Kesselende · H 2nd O Flue gas · Ρ H 2nd O_ steam With V ˙ _{Rauchgas_Kessolende} Volume flow of the flue gas at the end of the boiler H ₂ O _{Flue gas} humidity in the flue gas ρ _{H2O_Dampf} Density of water in vapor form m H 2nd O_waste incineration = k H 2nd O · QB With k _H2O proportionality factor QB heat released during firing m H 2nd O_oil = m oil · proportion of H 9,000 With m ˙ _oil mass flow of oil Share _H Share of hydrogen in the oil m H 2nd O_combustion air = ( V PL + V SL + V False air ) · H 2nd O Combustion air With V ˙ _PL Volume flow of the primary air V ˙ _SL volume flow of the secondary V ˙ _{false air} Volume flow of the false air H ₂ O _Combustion air Water contained in the air supplied to the combustion Method according to claim 1,
characterized in that
the humidity in the flue gas (H ₂ O _{flue gas} ) is measured directly at the end of the furnace. Method according to claim 1,
characterized in that
the humidity in the flue gas (H ₂ O _{flue gas} ) is determined via the temperature before the flue gas enters a flue gas scrubber downstream of the waste incineration plant and via the saturation temperature of the flue gases in the flue gas scrubber. Method according to one of claims 2 or 3,
characterized in that
the proportionality constant k _H2O over a statistical relationship carbon mass flow m CO2 = k CO2 * QB and the carbon to hydrogen ratio (C / H) in the waste is determined, where k _{CO2 is} a proportionality constant between the released heat (QB) and the carbon dioxide mass flow (m ˙ _CO2 ).

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