EP3612292A1

EP3612292A1 - Method for operating a flue gas denitrification reactor which catalytically denitrifies flue gas, and flue gas denitrification system having a flue gas denitrification reactor suitable for carrying out the method

Info

Publication number: EP3612292A1
Application number: EP18720559.6A
Authority: EP
Inventors: Justus KRIEB; Reiner HUPFELD; Bernd Vollmer; Ulrich Kersken; Georg Papenheim
Original assignee: Mitsubishi Hitachi Power Systems Europe GmbH
Current assignee: Mitsubishi Power Europe GmbH
Priority date: 2017-04-20
Filing date: 2018-04-20
Publication date: 2020-02-26
Also published as: DE102017108443A1; WO2018193108A1

Abstract

The invention relates to a method for operating a flue gas denitrification reactor (1) which catalytically denitrifies flue gas and in which are formed a plurality of reducing agent injection zones (8), each having at least one associated reducing agent injection system (9), and a plurality of NO_x analysis zones (12), each having at least one associated NO_x analysis device (13). The method allows the flue gas stream from a steam generator of a power plant to be reliably catalytically denitrified even during operation in low load ranges. According to the invention, during operation of the flue gas denitrification reactor (1), a first starting measured NO_x value is measured downstream of the catalyst region (2) in the NO_x analysis zones (12) continuously and online for each NO_x analysis zone (12), the first starting measured NO_x values obtained are assigned in a matrix-like manner to one or more reducing agent injection zone(s) (8) and in each case to at least one value representing a partial reducing agent mass flow (31), and each partial reducing agent mass flow (31) is adjusted by injection zone, wherein each NO_x analysis zone (12) covers a portion of the flow cross-section (10) of a flue gas denitrification reactor section (11) which conducts away the clean flue gas mass flow (27), and all the NO_x analysis zones (12) together form a plane (35) which covers the flow cross-section (10).

Description

Process for the operation of a flue gas catalytically entstickenden

The invention is directed to a method of operating a flue gas catalytically entstickenden flue gas denitrification reactor, which is arranged in the flue gas duct of a carbon-fuel-fired steam generator of a power plant, with respect to the flue gas flow upstream of at least one a catalyst layer comprehensive, traversed by the flue gas catalyst region of the

Rauchgasentstickungsreaktors a to achieve a desired initial ΝΟχ-content in the flowing out of the flue gas denitrification reactor clean gas flue gas mass flow reductant mass flow divided into partial streams several reductant injection zones fed with each associated reductant injection and in each Reduktionsmittel- Eindüsungszone each a Reduktionsmittelteilmassenstrom into an incoming Rohgas- Flue gas mass flow is injected, wherein each reducing agent Eindüsungszone each covers a partial area of a first flow cross section of the inflowing raw gas flue gas mass flow first Rauchgaskanal- or Rauchgasentstickungsreaktorabschnitts and form the plurality of reducing agent Eindüsungszonen in their entirety a first flow cross section of the first flue gas duct or Rauchgasentstickungsreaktorabschnitts overlapping first level ,

Furthermore, the invention is directed to a flue gas denitrification plant, in particular for carrying out the above method, comprising a flue gas catalytically entstickenden flue gas denitrification reactor, which can be arranged in a flowing through the flue gas to be denitrified flue gas channel of a carbon-fuel-fired steam generator of a power plant and comprising at least one catalyst layer, has a catalyst region which can be flowed through by a raw gas flue gas stream flowing to the flue gas denitrification reactor, with respect to the flue gas flow upstream of the catalyst region in FIG a first flow cross-section of a first flue gas channel or flue gas denitrification reactor section, through which the inflowing raw gas flue gas mass flow can flow, a plurality of reductant

Injection zones are each formed and arranged with at least one associated reducing agent injection, which in each case via a fluid-conducting line connection with a the inflow of a

Reducing agent part mass flow regulating regulating valve are in each case, wherein by means of each of the reducing agent injection zones in each case a Reduktionsmittelteilmassenstrom one to achieve a desired starting NOx content in the flowing out of the Rauchgasentstickungsreaktor clean gas flue gas mass flow total required

Reducing agent mass flow in the first flow cross section of the first flue gas or flue gas denitrification reactor section is inflatable, wherein each reducing agent Eindüsungszone each covers a partial surface of the first flow cross section of the first flue gas or Rauchgasentstickungsreaktorabschnitts and the plurality of reducing agent Eindüsungszonen in their entirety form a first flow cross-section covering first level , and wherein the control valves are signal-conducting connected to a control device.

Particularly in the case of fossil incineration plants, including, in particular, steam generators fired by pulverized fuel fired by power plants, efforts have long been underway to reduce the emission of pollutants and thus the emission emission values in the context of environmental protection measures. Likewise, there are currently efforts also to expand the working range of a fossil fuel-fired steam boiler or boiler, in particular with dusty carbonaceous fuel, with respect to its minimal load case, towards smaller load ranges.

As part of these efforts to be respected and further _x for reducing NO values represent a component to be observed. Catalytically entstickende Rauchgasentstickungsanlagen or Rauchgasentstickungsreaktoren are widely today to nitrogen oxide reduction in power plants, which operate according to the so-called SCR (Selective Catalytic Reduction) method. In the SCR process, ammonia (NH ₃ ) is injected into the flue gas stream and chemically converted into catalysts in nitrogen (N ₂ ) and water (H ₂ O). However, in the SCR process flue gas denitrification plants and flue gas denitrification reactors, the conventional control concept reaches its technical limits. This is due to the fact that at the boiler outlet or steam generator outlet, the velocity profiles and also the NO _x concentration profiles of the flue gas emerging there depend strongly on the load conditions in the steam generator or boiler. The previous measures, which include the mixing of the flue gas and also the reducing agent (ammonia, ammonia water, ammonia-containing solution) with the flue gas, have proven to be insufficient to meet the required NO _x values in the clean gas leaving the flue gas denitrification plant or / and Rauchgasentstickungsreaktor or to comply with the so-called NH ₃ -slip. If more reducing agent (ammonia) is provided in a flue gas denitrification plant or a flue gas denitrification reactor than is reacted in the reduction of the nitrogen oxides on the catalyst, the so-called NH ₃ slip occurs. This means that in the flue gas denitrification system or the flue gas denitrification reactor leaving flue gas / exhaust unused reducing agent concentrations, usually ammonia (NH ₃ ) are detected, which should be avoided.

The invention is therefore based on the object to provide a solution which makes it possible to reliably de-stiffen the flue gas flow of a steam generator of a power plant even when operating in low load ranges.

In a method of the type described in more detail, this object is achieved in that during operation of the flue gas denitrification reactor downstream of the catalyst area in a second level in NO _x -Analysezonen each with at least one associated

ΝΟχ-Absaugungs- and / or NO _x -Analyse¬ permanently per NO _x - analysis zone a respective first output NO _x content is measured as an analysis-related first output NO _x -measured value of the outflowing pure gas flue gas mass flow, the analyzer zone based obtained first starting NO _x - Measured values are assigned to one or more reductant injection zone (s) in a matrix-like manner and in each case at least one value representative of the desired starting NO _x content in the outflowing pure gas flue gas mass flow and thus the distribution of the reducing agent mass flow to the individual reducing agent partial mass flows It is thereby automatically adjusted and / or readjusted so that each of the reducing agent partial mass flows to be fed to a reducing agent injection is adjusted to the actual required value in the clean gas flue gas mass flow, in particular in the respective matrix-like NO _x analysis zone in order to achieve the desired starting ΝΟχ content and regulated, wherein each NO _x -Analysezone each a partial area of a second flow cross-section of the clean gas flue gas mass flow laxative n second flue gas or flue gas denitrification reactor section covered and the NO _x -Analysezonen in their entirety forming the flow cross section of the second flue gas or Rauchgasentstickungsreaktorabschnitts second level.

Likewise, the above object is achieved in a flue gas denitrification of the type described above, characterized in that downstream of the catalyst region in a second plane permanently and preferably stationary multiple NO _x -Analysezonen each with at least one associated NO _x - exhaust and / or NO _x -Analysevorrichtung in a second flue gas channel or flue gas denitrification reactor section discharging a clean gas flue gas mass flow are formed and arranged, wherein a first starting NO _{x is} permanently online by means of the NO _x exhaust and / or NO _x analysis device during operation of the flue gas denitrification reactor. Content as an analysis-related first output NO _x value of the second flow cross-section flowing through pure gas flue gas mass flow is measurable, each NO _x -Analysezone each have a partial area of the second flow cross-section of the abst Roman clean gas flue gas mass flow through the second Rauchgaskanal- or Rauchgasentstickungsreaktorabschnitts covered and the NO _x analysis zones in their entirety form the second plane covering the second flow cross section of the second flue gas or flue gas denitrification reactor section. Advantageous embodiments and expedient developments of the invention are the subject of the respective subclaims.

By means of the measure according to the invention, in addition to reducing agent injection zones, which are arranged upstream of or in relation to the flue gas flow upstream of a catalytic converter region of the flue gas denitrification reactor operating according to the SCR method, NO _x analysis zones permanently and firmly on the output side or in relation to the flue gas flow direction downstream of the catalyst region of the flue gas denitration reactor installed and to connect them in a controller comprising a control circuit with the reducing agent injection zones and during operation of the flue gas denitrification reactor online detected NO _x values for the automatic controlled injection of reducing agent, in particular ammonia, to use the desired NO _x - In particular, setpoint values can be achieved well even with a steam generator operated in low load ranges and the reduction agent or ammonia slip can be avoided. In this case, the NO _x values are detected zone by zone by means of a so-called NO _x measuring grid which has a plurality of zones and is permanently and stationarily arranged on the output side of the catalyst region of the flue gas denitrification reactor. Similarly, on the input side zonenformig split injection grille with individual Reduktionsmitteleindüsungspunkten or

Reductant injections formed. The number of zones and thus the geometric design of the measuring grid and the injection grid do not have to match. An allocation of NO _x -Analysezonen and Reduktionsmitteleindüsungszonen by means of a matrix, which they each assign each other and which is stored in the control device and / or control device of a control and / or regulating circuit. To a dynamic, fast and to the respective load situation and the respective operating state or the respective operating situation of the flue gas denitration reactor To be able to realize automatically adaptable admission of the flow cross-section equipped with the reducing agent injections, the individual reducing agent injections have assigned to them automatically adjustable control valves, which are integrated in the control and / or regulating circuit with the regulating device. By extending the usual in SCR process control loop to a _NOx - analysis zones-forming _NOx -Messgitter outlet side of the catalyst portion of the Rauchgasentstickungsreaktors and remotely adjustable control valves with line connection to the Reduktionsmitteleindüsungen can about the matrix-like assignment of NO _x - analysis zones and Reduktionsmitteleindüsungszonen in which the control device comprehensive control circuit, the distribution of the reducing agent, in particular ammonia, automatically to the inlet side of the flue gas denitration reactor prevailing conditions, in particular flow conditions of the flue gas and NO _x -Beladung the flue gas to be adjusted. In particular, by means of the NO _x analysis zones on the output side of the catalyst region and thus on the clean gas side of the flue gas denitration reactor zone-wise deviations of the resulting NO _x -Regas value to the mean value over the entire flue gas mass flow can be determined automatically continuously or periodically in short or short time intervals and, if necessary, by targeted Controlling a Reduktionsmittelindüsung a matrix-like associated

Regulate reducing agent injection zone. This makes it possible to avoid the reduction agent, in particular ammonia, slippage.

In an advantageous embodiment of the invention, it is provided that the reducing agent partial mass flow fed to each reducing agent injection during operation of the flue gas denitrification reactor has a permanent injection zone zone for setting a NO _x analysis zone (s) and / or the clean gas

Flue gas mass flow to be reached NO _x setpoint currently required value is readjusted. It is expedient and advantageous, according to a further embodiment of the invention, during the operation of the flue gas denitrification reactor, that the downstream clean gas flue gas mass flow downstream of the catalyst region is permanently measured online and used to determine the actual clean gas output in the flue gas denitration reactor to achieve the desired starting NO _x content. Flue gas mass flow required

Reducing agent mass flow is used.

In this case, it may furthermore be expedient if, during operation of the flue gas denitrification reactor, the inflowing raw gas flue gas mass flow upstream and / or the outflowing clean gas flue gas mass flow downstream of the catalyst region and at an input NO _x measuring point of the incoming NO _x content of the inflowing crude gas Flue gas mass flow upstream of the first level formed by the reducing agent Eindüsungszonen be measured permanently online and from the input NO _x content and the raw gas flue gas mass flow and / or the clean gas flue gas mass flow currently to achieve the desired output NOx content from the Rauchgasentstickungsreaktor flowing clean gas flue gas mass flow required reductant mass flow is calculated.

Furthermore, in an advantageous embodiment of the method, it is also possible that during operation of the flue gas denitrification reactor at an initial NO _x measuring point, the desired starting NO _x content of the outflowing clean gas flue gas mass flow is measured continuously online downstream of the plane formed by the NO _x analysis zones becomes.

For the control of the method, it is also advantageous that during the operation of the flue gas denitrification online permanently determined measurements of input NO _x content, first output NO _x content, desired output NO _x content and raw gas flue gas mass flow and / or clean gas flue gas mass flow and a NO _x setpoint are fed to a control loop, the currently required Determined reductant mass flow and / or its distribution to the individual reducing agent part mass flows and regulated regulating.

The regulation of the injection of the reduction medium part mass flows is advantageously carried out in that the determined measured values of the first output NOx contents are fed analytically to a control device integrated into the control loop and assigned to one or more reducing agent injection zones in a matrix-like manner in the control device, wherein the control device of matrix-like assignment of the measured values of the first output NOx contents to the reducing agent injection zones corresponding control signals to each of the inflow of reducing agent part mass flow to a reducing agent injection regulating, automatically adjustable control valves output and the reducing agent injections zone by zone to set a in the or each associated NO _x -Analysezone (s) and / or in the outflowing clean gas flue gas medium flow to be reached NO _x Sollwertes einge for a required reducing agent mass flow lt and / or readjusted.

Advantageously, the flue gas denitrification reactor is arranged downstream of a flue gas dedusting with respect to the flow direction of the flue gas leaving the steam generator or boiler, so that a so-called low-dust circuit is present. In a further development, the method according to the invention is characterized in that it is catalytically de-nitrogening during operation of a downstream dedusting and / or desulfurization of the flue gas mass flow

Flue gas denitration reactor is performed.

The influence of a particular reducing agent injection in a respective reducing agent injection zone on the individual NO _x analysis zones is determined empirically during the commissioning of the flue gas denitrification reactor and stored in one or more of the association ratios mapping matrix / matrices in the form of numerical values in the control device. In this regard, the invention is characterized in a further development in that a matrix-like assignment or matrix-like assignments of one of the plurality of NO _x -Analysezonen to one or more reducing agent injection zones and first output NO _x readings to be adjusted flue gas middle mass flow during commissioning of the flue gas denitrification reactor empirically determined and, in particular in the control device, deposited / will.

The matrix determined during commissioning is expediently maintained during operation of the flue gas denitrification reactor, so that the invention also provides that the determined and deposited matrix-like assignment or the determined and stored matrix-like assignments are / remains unchanged during operation of the flue gas denitration reactor. Incidentally, this approach of empirically determining the matrix-like relationships does not require the number of NOx analysis zones to match the number of reductant injection zones.

The matrix-type assignment can differ depending on the amount of smoke gas, so that it is also possible to deposit more than one matrix. In this regard, the method according to the invention is characterized in that the matrix-type assignment or the matrix-like assignments of reducing agent injection zones and NO _x analysis zones is / are formed differently depending on the quantity of flue gas.

The measurement intervals may be different, so that the invention further provides in development of the method that the online permanently determined measurements of first output NO _x content, desired starting NO _x content, input NO _x content, inflowing raw gas flue gas mass flow and / or flowing clean gas flue gas mass flow continuously or periodically measured at short intervals.

Preferred reducing agents are ammonia and urea, so that advantageously further provided that as a reducing agent gaseous or liquid ammonia (NH ₃ ), an ammonia-containing solution, in particular ammonia water, an ammonium chloride solution or urea as Reductant mass flow supplied and injected as reducing agent mass sub-stream in the raw gas flue gas mass flow.

The flue gas denitrification plant is characterized for carrying out a particularly advantageous method in a further development in that the NO _x - exhaust and / or NO _x -Analysevorrichtungen are each in a first signal-conducting line connection with the control device, which determined this first output NO _x - Analyzer-related, which allocates them by means of a matrix deposited in the control device matrix one or more reducing agent injection zones, and wherein the control device via each a second signal-conducting line connection with each of a respective reducing agent mass flow to a respective connected reducing agent injection regulating, automatically adjustable control valves is and corresponding to the control valves of the matrix-like assignment of the reducing agent injection zones to the analysis zone-related first output NO _x measurements, the respective Reduktionsmi In order to set a desired starting NO _x content to be achieved in the or each matrix-associated NO _x analysis zones in the clean gas flue gas medium flow, the reductant partial mass flow required in each of the reductant injection zones is in each of the reductant injection zones the first flow cross section of the first flue gas or flue gas denitrification reactor section is injected. It is furthermore advantageous if each NO _x exhaustion and / or NO _x -

Analyzing apparatus is connected via a or the first signal conducting line connection with the control means in line connection, via which the respectively each NO _x -Analysezone measured first Au sgangs-NO _x -M esswert a first output NO _x content of the second flow cross section by flowing clean gas flue gas mass flow the control device is supplied to the respective output NO _x -Messwert matrix-like one or more reducing agent injection zone (s) and each one in the or each associated reducing agent injection zone (s) to achieve the desired output NO _x content each currently einzudüsenden Assigning reducing agent mass fraction representing value and wherein the control means each of the respective one or more Reduktionsmittel- Eindüsungszonen associated values via one of the second signal-conducting line connections each one of a Reduktionsmittel- injection associated with a reduction agent injection and the distribution of the reducing agent mass flow to each reducing agent partial flow causing control valve as a control signal, the automatically adjusts the reduction medium partial flow to be supplied in each case to reduction agent injection in an injection zone manner to the value currently required in each case to achieve the desired starting NO _x content in the clean gas flue gas mass flow and / or readjusted.

It is expedient and advantageous, according to a further embodiment of the invention, if the flue gas denitrification downstream of the catalyst region has a second flue gas mass flow measuring the exhaust gas pure flue gas mass flow which is signal conductively connected to the control unit and set to be permanently online during operation of the flue gas denitration reactor and during online the operation of the flue gas denitrification reactor the downstream clean gas flue gas mass flow downstream of the catalyst area and the control device for determining the currently required to achieve the desired output NO _x content in flowing out of the flue gas denitrification reactor clean gas flue gas mass flow reducing agent mass flow a current clean gas flue gas mass flow representing Supply measuring signal.

In this case, the flue gas denitrification plant is further distinguished by the fact that upstream of the catalyst region, it is a first flue gas mass flow measuring device which measures the inflowing raw gas flue gas mass flow and / or downstream of the catalyst region, which separates the outgoing clean gas.

Flue gas mass flow measuring second flue gas mass flow measuring point, upstream of the first plane formed by the reducing agent Eindüsungszonen a the input NO _x content of the incoming raw gas flue gas mass flow measuring input NO _x measuring point and downstream the second level formed by the NO _x -Analysezonen has a desired output NO _x content of the outflowing pure gas flue gas mass flow measuring output NO _x measuring point, which are permanently operated online during operation of the flue gas denitrification reactor.

It is expedient according to a further development of the invention that the flue gas denitrification system comprises a control circuit in the third signal-conducting line connection with the control device, in the fourth signal-conducting line connection with an input NO _x measuring point, in the fifth signal-conducting line connection with the outgoing clean gas flue gas mass flow measuring second Rauchgasmassenstrommessstelle and in sixth signal-conducting line connection with the output NOx measuring point, which determine online during the operation of the flue gas denitrification reactor permanently measured values and the control loop, the processing of a NO _x setpoint the currently required reductant mass flow and / or its distribution the individual reducing agent partial mass flows are determined and regulated in a regulated manner.

The flue gas denitrification plant according to the invention is characterized in a further embodiment in that the control valves are designed as PID (Proportional Integral Derivative) control valves. As a result, the ammonia mass flow can be regulated well. However, other embodiments of control valves are possible. Furthermore, the flue gas denitrification plant is characterized in an embodiment in that the control circuit and / or the control device depending on the operating situation in einzudüsende in the inflowing raw gas flue gas mass flow first flow cross section reductant mass flow as a function of the load requested by the associated steam generator and / or in dependence on the Rauchgasentstickungsreaktor inflowing crude gas flue gas mass flow or determined from the flue gas denitrification reactor clean gas flue gas mass flow determines and regulates. Depending on load different flue gas volumes, NO _x profiles and Flue gas velocities are present at the beginning of the flue gas denitration reactor, load-dependent and different amounts of reducing agent, in particular ammonia, for the desired NO _x reduction is required, which is taken into account in the formation of the flue gas denitrification plant according to the invention.

Finally, the flue gas denitrification system is characterized in an embodiment in that the reducing agent injection zones and the NOx analysis zones each cover the entire first or second flow cross-section without gaps in the first or second plane formed by them.

The invention is explained below with reference to a single figure.

The single FIGURE shows a schematic representation of a flue gas denitrification reactor 1, the catalyst region 2 of which comprises three catalyst layers 3. The catalyst region 2 can be supplied via a flue gas duct 4 via a raw gas flue gas mass flow 30 flowing in from a fossil-fueled steam generator of a power plant, that is to say a raw gas flue gas quantity. The flue gas denitration reactor 1 operates according to a flue gas catalytically entstickenden process, the so-called SCR process, including the input side of the catalyst layers 3 having catalyst region 2 reducing agent, in particular an ammonia (NH ₃ ) or urea-containing agent is injected into an incoming crude gas flue gas mass flow 30 which raw gas flue gas mass flow 30 then flows through the catalyst region 2 and on the output side as de-dense pure gas flue gas mass flow 27, ie a clean gas flue gas quantity, into a chimney of the power plant leading exhaust pipe 5 opens. The injection of reducing agent takes place on the inlet side and upstream of the catalyst region 2 in a flow-through from the incoming crude gas flue gas mass flow 30 first flow cross-section 6, which is formed in a first flue gas or flue gas denitrification reactor section 7. In this first flow cross-section 6 are several, nine in the embodiment Reductant injection zones 8 are formed, each having a reducing agent injection 9. Due to their relative position to the catalyst region 2 of the flue gas denitrification reactor 1, the reducing agent injection zones 8 are connected upstream of the catalyst region 2 of the flue gas denitrification reactor 1. Each reducing agent injection zone 8 covers in each case a partial area or a partial area of the catalyst zone 2 the inflowing raw gas flue gas mass flow 30 supplying first flow cross section 6, wherein the reducing agent injection zones 8 in total, ie in their entirety, the total formation of a first plane 32 the Cover entire entire flow cross-section 6.

On the output side, the catalyst region 2 of the flue gas denitrification reactor 1 is followed by a plurality of, in the exemplary embodiment, eight, NO _x analysis zones 12, arranged and arranged, in a second flow cross section 10 of a second flue gas denitrification reactor section 1 1 discharging the clean gas flue gas mass flow 27 out of the catalyst region 2. Each NO _x analysis zone 12 includes a NO _x exhaust and / or NO _x analysis device 13. Each NO _x -Analysezone 12 each covers a partial surface of the outflowing clean gas flue gas mass flow 27 from the

Catalyst region 2 discharging second flow cross-section 10 of the second flue gas or flue gas denitration reactor section 1 1, wherein all the NOx analysis zones 12 together total, i. in their entirety, cover the entire second flow cross-section 10.

The total denoted by 14 flue gas denitrification plant comprises a control and / or regulating circuit 15, the component of which is a control device 16. The controller 16 is connected via a respective first signal conducting line connections 17 with one of the NO _x - extraction and / or NO _x -Analysevorrichtungen 13 in line connection, via which determined on a respective NO _x -Absaugungs- and / or NO _x -Analysevorrichtung 13 first output NO _x measured values based on analysis zones, ie determined separately per NO _x analysis zone 12, can be fed to the regulating device 16. Likewise, the control device 16 via second signal-conducting Line connections 18 are connected to PID control valves 19, which in turn are in a fluid-conducting and fluid-carrying line connection 24 each with a reducing agent injection 9 and each of the inflow of Reduktionsmittelteilmassenstroms 31 of the flue gas denitration reactor 1 and supplied and supplied in several, the number of Reduktionsmitteleindüsungen 9 corresponding partial mass flows 31 divided reducing agent mass flow 29 to a respective reducing agent injection 9 and thus a reducing agent injection zone 8 regulate. Here, the control device 16 is further designed so that it automatically assigns by adjusting the control valves 19 according to a stored in her matrix, which assigns each NO _x -Analysezone 12 one or more reducing agent injection zone (s) 8 during operation of the flue gas denitrification system 14 from a reducing agent injection 9 each reductant partial mass flow 31 to be delivered in response to the first output NO _x measured value determined in a respectively assigned NO _x -Analysezone 12 controls and outputs. This takes place in that the control device 16 outputs corresponding control signals to the respectively connected and controlled control valves 19 via the second line connections 18 corresponding to the number of control valves 19 connected to the control device 16. In this case, the respective reducing agent partial mass flow 31 is in each case regulated in such a way that precisely the amount of reducing agent required in the respective reducing agent injection zone 8 for setting a first starting NO _x setpoint value to be achieved in the or each NO _x analysis zones assigned in a matrix-like manner first flow cross-section 6 is injected into the incoming crude gas flue gas mass flow 30. About one

Control valve 22, the total reducing agent mass flow 29 can be adjusted automatically and control valves 19, the distribution to the reducing agent injections 9 is automatically set with each other. It is also possible for the control valve 22 to be omitted and the reducing agent partial mass flows 31 to the respective reducing agent

Injection zones 8 with associated reductant injection 9 are each automatically set directly via the control valves 19. The ΝΟχ-suction and / or NO _x -Analysevorrichtungen 13 are permanently and fixed in the in the the outgoing pure flue gas mass flow from the catalyst region 2 laxative second flow section 10 of the second flue gas or flue gas denitration reactor section 1 1 of the flue gas denitration reactor 1 arranged NO _x -Analysezonen 12 formed. The NO _x -Absaugungs- and / or NO _x -Analysevorrichtungen13 form of a measuring grid or NO _x -Messgitter, the forming by the in its entirety a second plane 35 NO _x -Analysezonen 12 is formed and with which during operation of the Rauchgasentstickungsreaktors 1 permanently online continuously or periodically at short intervals per NO _x -Analysezone 12 of the first output NO _x content 37 of the flowing in the clean gas flue gas mass flow 27 second flow cross section 10 flowing flue gas can be determined. The determination of the individual NO _x zone values can be carried out continuously or periodically in short or short time intervals, wherein the period of the periodic query is chosen so short that the temporal changes of the NOx concentration profiles are detected in the second level 35 formed as a measurement plane.

The control device 16 is designed and set up so that it can be injected into the incoming raw gas flue gas mass flow 30 as a function of the load demanded from the associated steam generator and / or as a function of the flue gas denitrification reactor 1 or the operating gas being fed into the first flow cross section 6 determined from the flue gas denitrification reactor 1 discharged flue gas mass flow and controls. In this respect, the control device 16 also forms a control device.

The above-described regulation of the reducing agent addition is part of the overall control and / or regulating circuit 15, which is also a

Control of the addition of reducing agent by means of the einzudüsenden flue gas mass flow 29 via the determination of the output NO _x content 28 in the flue gas denitrification reactor 1 via the exhaust pipe 5 leaving the clean gas flue gas mass flow 27 includes a supply of at one Output NOx measuring point 36 determined desired NO _x output content 28 via a sixth signal-conducting line connection 20 to the control circuit 15, the detection of the input NO _x content 33 of the incoming raw gas flue gas stream 27 at an input NOx measuring point 26th and the supply of the measured value ascertained here via a fourth signal-conducting line connection 21 to the control circuit 15 and the control of a control valve 22 derived from at least these two values and the comparison with a NO _x setpoint 34 by means of a control signal supplied via a seventh signal-conducting line connection 23 wherein the control valve 22 regulates the reducing agent mass flow 29 flowing to all or individual reducing agent injections 9. Depending on the dynamic mode of combustion in the associated steam generator and thus in dependence on the generated flue gas mass flow can be done via the control of the control valve 22, a central control and injection of reducing agent by the reducing agent mass flow 29 of denitrification 14 fed centrally and then divided into flue gas partial streams 31 the individual Control valves 19 is supplied. It can be done with the flue gas denitrification 14 of the invention but also a decentralized control in which the control valves 19 each directly a reducing agent mass flow 31 is supplied and each currently required Reduktionsmittelteilmassenstrom 31 respectively by opening or closing the individual, each one reducing agent injection 9 and is adjusted, adjusted or readjusted with this in fluidly connected control valves 19.

In the case of a central control, the individual control valves 19 are controlled in particular such that the total reducing agent mass flow 29 set by the control valve 22 is distributed to the individual reducing agent injection zones 8. The control valves 19 may assume a position between closed and fully open.

In a decentralized control, the control valve 22 is fully opened or deleted altogether. The individual control valves 19 are controlled so that the individual reducing agent injection zones 8 directly directly desired reduction mass fraction 31 and thus the desired amount of reducing agent.

The assignment of the individual NO _x analysis zones 12 to one or more reducing agent injection zones 8 and reducing agent injections 9 takes place by setting up a matrix, wherein a plurality of matrices are formed depending on the respective raw gas flue gas mass flow 30 to be treated and stored in the control device 16 can be. The matrix-like assignment of reducing agent injection zones 8 and NO _x analysis zones 12 is determined empirically during commissioning of the flue gas denitrification reactor 1 and then deposited in the control device 16, the determined and deposited matrix-like assignment or the determined and deposited matrix-like assignments during operation of the flue gas denitration reactor 1 is / are maintained unchanged.

In the empirical determination of the assignment of NO _x analysis zones 12 to reducing agent injection zones 8 and thus to reducing agent injections 9, the entirety of reducing agent injection zones 8 is laid over the entirety of the reducing agent analysis zones 12 in a manner of templates, so that they overlap individual reducing agent analysis zones 12 and reducing agent injection zones 8 comes. The influence of each reducing agent injection zone 8, and thus of the reductant injection 9 associated therewith, to form a NO _x analysis zone 12 is expressed in percentages and determined in a matrix-like manner. For example, this can lead to the NO _x analysis zone 12A and thus the first determined here

Output NO _x value of the purified pure flue gas mass flow 27 to 55% of the reducing agent injection zone 8 B and thus the injected here in the unpurified raw flue gas mass flow 30

Reduktionsmittelteilmassenstrom, to 20% of the reducing agent injection zone 8C and thus the injected here

Reductant partial mass flow, to 15% of the reducing agent injection zone 8D and thus the reductant medium mass flow injected here and 10% of the reducing agent injection zone 8E and the reducing agent partial mass flow injected here being affected. These relationships are represented as a matrix, determined for all NO _x analysis zones 12 and stored in the form of a matrix or multiple matrices in the control device 16. In addition, in the exhaust pipe 5 at a second flue gas mass flow measuring point 39 or second flue gas metering point the outflowing clean gas flue gas mass flow 27, so the outflowing clean gas flue gas quantity measured, the determined measured value via a fifth signal-conducting line connection 25 input to the control and / or control circuit 15th and the control device 16 finds. Alternatively or additionally, it is also possible to determine the inflowing raw gas flue gas mass flow 30, ie the inflowing raw gas flue gas quantity, at a first flue gas mass flow measuring point or first flue gas flow measuring point, which is arranged upstream of the catalyst region 2 and in particular the first plane 32 designed as an injection plane.

Claims

A method for operating a flue gas catalytically entstickenden flue gas denitrification reactor (1) which is arranged in the flue gas duct (4) of a fuel-fired steam generator of a power plant, wherein with respect to the flue gas flow upstream of at least one catalyst layer (3) comprehensive, flowed through by the flue gas catalyst area (2) of the flue gas denitrification reactor (1) a reductant flue gas mass flow (29) required to achieve a desired starting NOx content (28) in the clean gas flue gas mass flow (27) flowing from the flue gas denitrification reactor (1) divided into substreams a plurality of reductant injection zones (8 ) is fed in each reducing agent injection zone (8) and in each reducing agent Eindüsungszone (8) each a reducing agent mass fraction (31) is injected into an incoming crude gas flue gas mass flow (30), wherein each reducing agent Eindü In each case, a partial area of a first flow cross-section (6) of a first flue gas dense or flue gas denitrification reactor section (7) which feeds the incoming raw gas flue gas mass flow (30) covers and the plurality of reductant injection zones (8) in their entirety comprise a first flow cross section (6) of the forming the first flue-gas channel or flue gas denitrification reactor section (7) covering the first plane (32),

characterized,

in that during operation of the flue gas denitrification reactor (1) downstream of the catalyst region (2) in a second plane (35) in NO _x analysis zones (12) each having at least one associated NO _x exhaust and / or NO _x analysis device (13) permanently per NO _x -Analysezone (12) a respective first output NO _x content (37) is measured as the analysis zone-related first output NO _x value of the outflowing clean gas flue gas mass flow (27), the analysis zone obtained first output NO _x -Measurements matrix-like one or more reducing agent injection zone (s) (8) and in each case at least one value representing the reductant partial mass flow (31) currently to be injected therein to achieve the desired starting NO _x content (28) in the outflowing flue gas mass flow (27) is assigned, and thus the distribution of the reducing agent mass flow (29) to the individual Reduktionsmittelteilmassenströme (31) is thereby automatically adjusted and / or readjusted that each of the reductant injection (9) to be supplied

Reduktionsmittelteilmassenströme (31) injection zone on the particular in the respective matrix-associated NO _x -Analysezone (12) to achieve the desired output NO _x content (28) in the clean gas flue gas mass flow (27) each currently required value is set and adjusted, each NO _x -Analysezone (12) each cover a partial surface of a second flow cross section (10) of the clean gas flue gas mass flow (27) discharging second flue gas denitrification reactor section (1 1) and the NO _x - analysis zones (12) in their entirety forming the second flow cross section (10) of the second flue gas or flue gas denitrification reactor section (1 1) overlapping second plane (35).

A method according to claim 1, characterized in that the one each reducing agent injection (9) supplied

Reduktionsmittelteilmassenstrom (31) during operation of the flue gas denitrification reactor (1) permanently injection zone on a for setting in the or each of the matrix-associated NO _x -Analysezone (s) (12) and / or the clean gas flue gas mass flow (27) to be reached NO _x Setpoint (34) currently required value is readjusted.

A method according to claim 1 or 2, characterized in that during the operation of the flue gas denitrification reactor (1) of the flowing clean gas flue gas mass flow (27) downstream of the

Catalyst area (2) online permanently measured and for investigation the currently required to achieve the desired output NO _x content (28) in the from the flue gas denitrification reactor (1) flowing clean gas flue gas mass flow (27) required reductant mass flow (29) is used.

Method according to one of the preceding claims, characterized in that during the operation of the flue gas denitrification reactor (1) the incoming raw gas flue gas mass flow (30) upstream and / or the outgoing clean gas flue gas mass flow (27) downstream of the

Catalyst range (2) and at an input NO _x measuring point (26) the input NOx content (33) of the incoming raw gas flue gas mass flow (30) upstream of the first plane (32) formed by the reducing agent Eindüsungszonen (8) online be permanently measured and from the input NO _x content (33) and the raw gas flue gas mass flow (30) and / or the clean gas flue gas mass flow (27) currently to achieve the desired output NO _x content (28) in the flue gas denitrification reactor (1) flowing clean gas flue gas mass flow (27) required reductant mass flow (29) is calculated.

Method according to one of the preceding claims, characterized in that during operation of the flue gas denitrification reactor (1) at an output NO _x measuring point (36) of the desired output NO _x content (28) of the downstream clean gas flue gas mass flow (27) downstream the level (35) formed by the NO _x analysis zones (12) is permanently measured online.

A method according to claim 4 and 5, characterized in that during operation of the flue gas denitration reactor (1) online permanently determined measured values of input NO _x content (33), first output NO _x content (37), desired output NO _x content (28) and raw gas flue gas mass flow (30) and / or clean gas Flue gas mass flow (27) and a NO _x setpoint (34) are fed to a control circuit (15) which determines the respective currently required reducing agent mass flow (29) and / or its distribution to the individual reducing agent part mass flows (31) and regulate readjusting.

A method according to claim 6, characterized in that the determined measured values of the first output NO _x contents (37) are supplied to one control system (16) integrated into the control loop (15) and in the control device (16) one or more reductant-like Injection zones (8) are assigned, wherein by the control device (16) of the matrix-like assignment of the measured values of the first output NO _x contents (37) to the reducing agent injection zones (8) corresponding control signals (18) to each of the inflow of a reducing agent partial mass flow ( 31) to a reducing agent injection (9) regulating, automatically adjustable control valves (19) output and the reducing agent injections (9) zone by zone for setting in the or each associated NO _x -Analysezone (s) (12) and / or in the outflowing clean gas flue gas flow (27) to be reached NO _x target value (34) to a required reducing agent mass flow (31) regulated and / or readjusted.

Method according to one of the preceding claims, characterized in that it is carried out during the operation of a downstream of a dedusting and / or desulfurization of the flue gas mass flow (30) arranged catalytically denitrifying flue gas denitration reactor (1).

Method according to one of the preceding claims, characterized in that a matrix-like mapping or matrix-like assignments of one of the plurality of NO _x -Analysezonen (12) to be set to one or more reducing agent Eindüsungszonen (8) and of the first output NO _x metrics family to a Rauchgasmittelteilmassenstrom (31) during commissioning of the flue gas denitrification reactor (1) determined empirically and, in particular in the control device (16), deposited / will.

A method according to claim 9, characterized in that the determined and deposited matrix-like assignment or the determined and stored matrix-like assignments in the operation of the

Flue gas denitration reactor (1) is maintained unchanged.

1 1. Method according to one of the preceding claims, characterized in that the matrix-like assignment or matrix-like assignments of reducing agent injection zones (8) and NO _x analysis zones (12) are designed differently depending on the amount of flue gas.

12. The method according to any one of the preceding claims, characterized in that the online permanently determined measured values of the first output NO _x content (37), desired output NO _x content (28), input NO _x content (33), inflowing raw gas flue gas mass flow (30) and / or outgoing clean gas

Flue gas mass flow (27) are measured continuously or periodically at short intervals.

13. The method according to any one of the preceding claims, characterized in that as a reducing agent gaseous or liquid

Ammonia (NH ₃ ), an ammonia-containing solution, in particular ammonia water, an ammonium chloride solution or urea as reducing agent mass flow (29) is supplied and injected as reducing agent mass sub-stream (31) in the raw gas flue gas mass flow (30).

14. flue gas denitrification system (14), in particular for carrying out the method according to one of claims 1 - 13, comprising a flue gas catalytically de-nitrogening flue gas denitrification reactor (1) which can be arranged in a flue gas duct (4) of a power plant fired with carbonaceous fuel and comprises at least one catalyst ply (3) of a crude gas stream flowing to the flue gas denitrification reactor (1). Flue gas medium flow (30) throughflowable catalyst region (2), wherein with respect to the flue gas flow upstream of the catalyst region (2) in a first flow cross-section (6) of a first, of the inflowing raw gas flue gas mass flow (30) through flue flue or denitrification reactor section (7) a plurality of reducing agent injection zones (8) each having at least one associated reducing agent injection (9) are formed and arranged, in each case via a fluid-conducting line connection (24) with an influx of a reducing agent Teilmassenstroms (31) r egelnden control valve (19) are, wherein by means of each of the reducing agent Eindüsungszonen (8) each a Reduktionsmittelteilmassenstrom (31) to achieve a desired output NO _x content (28) in the flue gas denitration reactor (1) flowing clean gas flue gas mass flow ( 27) required in total

Reducing agent mass flow (29) in the first flow cross-section (6) of the first flue gas or flue gas denitrification reactor section (7) is inflatable, wherein each reducing agent Eindüsungszone (8) each have a partial surface of the first flow cross section (6) of the first flue gas or Rauchgasentstickungsreaktorabschnitts (7) covered and the plurality of reducing agent injection zones (8) in their entirety form a first plane (32) covering the first flow cross section (6), and wherein the control valves (19) are signal-connected to a control device (16),

characterized,

that downstream of the catalyst region (2) in a second plane (35) permanently and preferably stationary multiple NO _x -Analysezonen (12) each having at least one associated NO _x -Absaugungs- and / or NO _x -Analysevorrichtung (13) in a one flowing out clean gas Flue gas mass flow (27) laxative second flow cross-section (10) of a second flue gas duct or

Rauchgasentstickungsreaktorabschnitts (1 1) are formed and arranged, wherein by means of the NO _x exhaust and / or NO _x -Analysevorrichtung (13) during operation of the flue gas denitrification reactor (1) permanently online each have a first output NO _x content (37) as an analysis-related first output NO _x measured value of the clean gas flowing through the second flow cross section (10)

Flue gas mass flow (27) is measurable, wherein each NO _x - analysis zone (12) each cover a partial surface of the second flow cross-section (10) of the flowing from the clean gas flue gas mass flow (27) through the second flue gas or flue gas denitrification reactor section (1 1) and the NO _x - Analysis zones (12) in their entirety, the second plane (35) covering the second flow cross section (10) of the second flue gas or flue gas denitrification reactor section (1 1) form.

15. flue gas denitrification system (14) according to claim 14, characterized in that the NO _x -Absaugungs- and / or NO _x - analysis devices (13) each in a first signal-conducting line connection (17) with the control device (16), which determined this supply the first output NO _x measured values in an analytical zone-related manner, which assigns them matrix-like to one or more reducing agent injection zones (8) by means of a matrix stored in the control device (16), and wherein the control device (16) in each case has a second signal-conducting line connection (18). with each of the one Reduktionsmittelteilmassenstrom (31) to each connected reducing agent injection (9) regulating, automatically adjustable control valves (19) and to the control valves (19) of the matrix-like allocation of the reducing agent injection zones (8) to the analysenzonenbezogene first output -NO _x measurements corresponding, the respective reducing agent Partial current (31) to a reducing agent injection (9) regulating control signals such that in each of the reducing agent Eindüsungszonen (8) in each case for setting a in the or each matrix-like NO _x -Analysezonen (12) to be reached desired starting NOx content (28) in the clean gas flue gas stream (27) required Reduktionsmittelteilmassenstrom (31) in the first flow cross-section (6) of the first Rauchgaskanal- or

Rauchgasentstickungsreaktorabschnitts (7) is injected.

16. flue gas denitrification system (14) according to claim 14 or 15, characterized in that each NO _x -Absaugungs- and / or NO _x - analysis device (13) via one or the first signal-conducting line connection (17) with the control device (16) in line connection is, via which of the respective NO _x -Analysezone (12) measured first output NO _x measured value of a first output NO _x content (37) of the second flow cross-section (10) flowing through the clean gas flue gas mass flow (27) of the control device ( 16) is supplied to the respective output NO _x measured value matrix-like one or more reducing agent Eindüsungszone (s) (8) and each one in the or the respectively associated reducing agent Eindüsungszone (s) (8) to achieve the desired Starting NO _x - content (28) currently einzudüsenden

Assigning reductant part mass flow (31) representing value and wherein the control means (16) each of the respective one or more reducing agent injection zones (8) associated values via one of the second signal-conducting line connections (18) each one of a reducing agent injection (9) and assigned Distribution of the reducing agent mass flow (29) in each case on a reducing agent partial flow (31) causing control valve (19) as a control signal automatically to each of the reductant injection (9) to be supplied

Reduktionsmittelteilmassenstrom (31) injection zone on the set to achieve the desired output NO _x content (28) in the clean gas flue gas mass flow (27) each currently required value and / or readjusted.

17 flue gas denitrification system (14) according to one of claims 14 to 16, characterized in that it downstream of the catalyst region (2) has a the downstream clean gas flue gas mass flow (27) measuring second flue gas mass flow measuring point (39), the signal-conducting with the control unit (16) is connected and set up to be able to be operated permanently online during operation of the flue gas denitration reactor (1) and to permanently measure the outflowing clean flue gas mass flow (27) downstream of the catalyst region (2) during operation of the flue gas denitration reactor (1) and the control device (16 ) for determining the currently required to achieve the desired output NO _x - content (28) in the flue gas denitration reactor (1) flowing clean gas flue gas mass flow (27) required reducing agent mass flow (29) to supply the current clean gas flue gas mass flow (2) representing measurement signal.

18, flue gas denitrification system (14) according to one of claims 14 to 17, characterized in that it upstream of the catalyst region (2) an inflowing raw gas flue gas mass flow (30) measuring the first flue gas mass flow measuring point and / or downstream of the catalyst region (2) the the outflowing clean gas - Flue gas mass flow (27) measuring the second flue gas mass flow measuring point (39) upstream of the reductant Eindüsungszonen (8) formed first level (32) an input NOx content (33) of the incoming Rohgas- flue gas mass flow (30) measuring input NO _x- measuring point (26) and downstream of the NO _x -Analysezonen (12) formed second level (35) has a desired output NO _x content (28) of the outgoing clean gas flue gas mass flow (27) measuring output NOx measuring point (36) which are permanently operable online during operation of the flue gas denitrification reactor (1). Flue gas denitrification system (14) according to claim 18, characterized in that it comprises a control circuit (15) in the third signal-conducting line connection (38) with the control device (16) in the fourth signal-conducting line connection (21) with an input NO _x - measuring point (26), in the fifth signal-conducting line connection (25) with the outgoing clean gas flue gas mass flow (27) measuring second flue gas mass flow measuring point (39) and in the sixth signal-conducting line connection (20) with the output NO _x measuring point (36) during the operation of the flue gas denitration reactor (1) online permanently determine measured values and the control circuit (15), the processing (27) of a NO _x setpoint (34) the currently required reductant mass flow (29) and / or its distribution to the individual Reduktionsmittelteilmassenströme (31) determined and regulated readjusted.

20. flue gas denitrification system (14) according to any one of claims 14 to 19, characterized in that the control valves (19) are designed as PID control valves.

Rauchgasentstickungsanlage (14) according to one of claims 18 to 20, characterized in that the control circuit (15) and / or the control device (16) the operating situation dependent einzudüsende in by the inflowing raw gas flue gas mass flow (30) through which flowable first flow cross-section (6)

Reducing agent mass flow (29) as a function of the demanded by the associated steam generator load and / or depending on the flue gas denitrification reactor (1) inflowing raw gas flue gas mass flow (30) or from the flue gas denitration reactor (1) flowing clean gas flue gas mass flow (27) determines and controls ,

Flue gas denitrification plant (14) according to one of claims 14 to 21, characterized in that the reducing agent injection zones (8) and the NOx analysis zones (12) each have a gap in each of them formed first or second level (32, 35) cover the entire first or second flow cross-section (6, 10).