JP2016155102A - Denitration equipment and reductant distribution adjustment method for denitration equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress local concentration increase of unreacted reductant on the outlet side of a denitration reactor.SOLUTION: Denitration equipment comprises: a plurality of reductant injection nozzles; an injection amount adjusting part for adjusting an injection amount of reductant from each reductant injection nozzle; a denitration reactor which is disposed downstream of the reductant injection nozzles and is configured so as to decompose nitrogen oxides by reaction between nitrogen oxides in exhaust gas and the reductant; a distribution measuring part for measuring a second distribution of the reactant in a second surface vertical to a flow direction of the exhaust gas on the outlet side of the denitration reactor; and an instruction producing part for producing an operation instruction for the injection amount adjusting part based on: the injection amount of the reductant of each of the plurality of reductant injection nozzles; a correlation of a first distribution of the reactant in a first surface vertical to a flow direction when the reductant injected with the injection amount arrives at the inlet side of the denitration reactor; and the second distribution measured by the distribution measuring part.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a denitration apparatus and a reducing agent distribution adjustment method for the denitration apparatus.

  Conventionally, a denitration device that removes nitrogen oxides in exhaust gas with a reducing agent is known.

  For example, Patent Document 1 discloses an ammonia injection device of a denitration device provided in an exhaust gas duct. Such an apparatus divides the inside of a duct into a plurality of large sections of two or more sections in an exhaust gas duct, and includes at least two large section distribution control valves capable of controlling distribution of the ammonia supply amount of the large sections. An ammonia pipe capable of distributing and controlling at least two ammonia supply amounts per large-division distribution control valve is connected downstream of the large-division distribution control valve. According to such an apparatus, it is said that the distribution and adjustment of ammonia to be introduced is easy, and ammonia can be injected and dispersed uniformly and accurately.

  Patent Document 2 discloses a reducing agent injection device that is installed in a flue through which exhaust gas flows and injects a reducing agent into the exhaust gas from an injection nozzle, a mixer that mixes the reducing agent and the exhaust gas, and nitrogen oxides. There has been disclosed a denitration apparatus provided with a denitration catalyst that decomposes mainly into water and nitrogen after reacting with a reducing agent. Such a denitration device includes a reducing agent concentration measuring device that sequentially measures the reducing agent concentration by irradiating a sampling gas obtained from a plurality of predetermined positions downstream of the denitration catalyst within a flue and irradiating a laser beam; The nitrogen oxide concentration meter that measures the oxide concentration and the opening of the total flow control valve of the reducing agent main system based on the nitrogen oxide concentration are set, and from the reducing agent main system based on the reducing agent concentration at multiple positions. And an opening degree setting unit for setting the opening degree of the flow control source valve provided in the plurality of reducing agent supply systems.

  Patent Document 3 discloses a reducing agent injection device that is a reducing agent supply means for supplying a reducing agent into combustion exhaust gas from a boiler, and a partitioned denitration catalyst that denitrates nitrogen oxides containing the reducing agent. A provided denitration apparatus is disclosed. Such a denitration apparatus has probe means having a plurality of light-transmitting tubes that are provided on the outlet side and measure the gas component concentration distribution in the exhaust gas in a region corresponding to the denitration catalyst partitioned perpendicular to the gas flow of the denitration apparatus. And a gas component concentration distribution measuring device for measuring the reducing agent concentration by the laser measuring means. Such a gas component concentration distribution measuring apparatus obtains the concentration distribution of the reducing agent in the partitioned area from the measurement result of the reducing agent concentration.

JP-A-10-216475 JP 2013-176733 A JP 2014-94355 A

  However, if the operating state of the denitration device changes due to changes in exhaust gas components or the catalyst in the denitration device deteriorates over time, the distribution of unreacted reducing agent at the outlet side of the denitration reactor becomes uneven. May end up. In this case, in the region where the concentration of the unreacted reducing agent is high, acidic ammonium sulfate adheres to the equipment (for example, the air preheater) located downstream of the denitration reactor, and the equipment deteriorates or malfunctions (for example, the air preheater). Obstruction).

In this regard, Patent Documents 1 to 3 do not describe a specific method for suppressing a local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor. That is, in the apparatus disclosed in Patent Document 1, even if only the control valve corresponding to the concentration of the unreacted reducing agent on the outlet side of the denitration reactor is locally increased, the locally increased concentration is reduced. Can not do it.
Patent Document 2 discloses that the setting of the opening degree of the flow control source valve is performed based on a map of a predetermined reducing agent concentration and the opening degree of each flow control source valve. Specific configurations and methods are not fully disclosed.
Further, in Patent Document 3, when there is a place where the concentration of the reducing agent is high in a part of the reducing agent concentration distribution, the flow rate control is performed so that the reducing agent from the reducing agent injection device corresponding to the place where the reducing agent concentration distribution is high can be injected. Although it is disclosed that the opening degree control of the main valve is performed, it is not sufficiently disclosed how to specify the reducing agent injection device corresponding to the place where the concentration is high.

  An object of at least some embodiments of the present invention is to suppress a local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor.

(1) A denitration apparatus according to at least one embodiment of the present invention includes:
A denitration device for removing nitrogen oxides in exhaust gas,
A plurality of reducing agent injection nozzles for injecting the reducing agent into the exhaust gas;
An injection amount adjusting unit for adjusting the injection amount of the reducing agent from each of the reducing agent injection nozzles;
A denitration reactor provided on the downstream side of the reducing agent injection nozzle and configured to decompose the nitrogen oxides by a reaction between the nitrogen oxides in the exhaust gas and the reducing agent;
A distribution measuring unit for measuring a second distribution of the reducing agent in a second plane orthogonal to the flow direction of the exhaust gas on the outlet side of the denitration reactor;
The reducing agent injection amount of each of the plurality of reducing agent injection nozzles, and a first direction orthogonal to the flow direction when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. Based on the correlation of the first distribution of the reducing agent in the plane and the second distribution measured by the distribution measuring unit, a command generating unit for generating an operation command for the injection amount adjusting unit; Is provided.

  According to the configuration of (1) above, the injection amount of each reducing agent from the plurality of reducing agent injection nozzles, and the flow direction when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. Based on the correlation of the first distribution of the reducing agent in the first plane orthogonal to the second distribution and the second distribution measured by the distribution measuring unit, an operation command for the injection amount adjusting unit can be generated. Therefore, by operating the injection amount adjusting unit according to the generated operation command, it is possible to suppress a local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor.

(2) In some embodiments, in the configuration of (1) above,
The command generation unit is configured to reduce the injection amount of the reducing agent by at least one nozzle corresponding to the high concentration region of the reducing agent in the second distribution among the plurality of reducing agent injection nozzles. Configured to generate.
According to the configuration of (2), an operation command is generated to reduce the amount of reducing agent injected by at least one nozzle corresponding to the reducing agent high concentration region in the second distribution among the plurality of reducing agent injection nozzles. Therefore, by operating according to the operation command, the concentration of the reducing agent in the high concentration region on the outlet side of the denitration reactor can be reduced.

(3) In some embodiments, in the above configuration (1) or (2),
The command generation unit is configured to determine the deviation on the inlet side of the denitration reactor based on a deviation between the second distribution measured by the distribution measurement unit and the target distribution of the reducing agent in the second surface. The operation command is generated so as to cancel.

  According to the configuration of (3) above, the deviation is canceled on the inlet side of the denitration reactor based on the deviation between the second distribution measured by the distribution measuring unit and the target distribution of the reducing agent in the second plane. Since the operation command is generated, the deviation is canceled on the inlet side of the denitration reactor by operating according to the operation command. Therefore, the local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor can be effectively suppressed.

(4) In some embodiments, in the configuration of (3) above,
The amount of the reducing agent injected from each of the reducing agent injection nozzles, and the distribution of the reducing agent in the first surface when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. And a storage unit in which the map is stored for each of the reducing agent injection nozzles,
The command generation unit generates the operation command to cancel the deviation on the inlet side of the denitration reactor using the map for each reducing agent injection nozzle stored in the storage unit as the correlation. Configured as follows.

  According to the configuration of (4) above, since the map for each reducing agent injection nozzle stored in the storage unit is used as a correlation, an operation command is generated so as to cancel the deviation on the inlet side of the denitration reactor. By operating according to the operation command, the deviation is canceled on the inlet side of the denitration reactor. Therefore, the local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor can be effectively suppressed.

(5) In some embodiments, in any one of the configurations (1) to (4) above,
The portable terminal further includes a portable terminal configured to output the operation command generated by the command generation unit.

  According to the configuration of (5) above, since the operation command generated by the command generation unit is output to the portable terminal, the worker can operate the injection amount adjusting unit while checking the operation command on the portable terminal.

(6) In some embodiments, in any one of the configurations (1) to (4) above,
The apparatus further includes a control unit configured to control the injection amount adjusting unit based on the operation command generated by the command generating unit.

  According to the configuration of (6) above, since the control unit controls the injection amount adjustment unit based on the operation command generated by the command generation unit, the adjustment of the injection amount adjustment unit is automated. Therefore, the injection amount adjusting unit can be controlled without depending on the operator.

(7) In some embodiments, in any one of the configurations (1) to (6) above,
The injection amount adjusting unit includes a plurality of flow rate adjusting valves for adjusting the injection amount of the reducing agent by each of the reducing agent injection nozzles.

  According to the configuration of (7) above, since the amount of reducing agent injected by each reducing agent injection nozzle is adjusted by each flow rate adjustment valve, the amount of reducing agent injected can be finely adjusted.

(8) In some embodiments, in the configuration of (7) above,
Each of the flow rate adjusting valves includes a sensor capable of detecting the opening degree of the flow rate adjusting valve.

  According to the configuration of (8) above, the opening of the flow rate adjustment valve can be detected by the sensor. For this reason, even if the operator manually adjusts the opening degree of the flow rate adjustment valve, it is not necessary to record the opening degree of each flow rate adjustment valve by the operator after the opening degree adjustment. Therefore, the reducing agent distribution adjustment work by the worker can be simplified.

(9) In some embodiments, in the above configuration (7) or (8),
The command generator is configured to use each flow rate adjustment valve as the operation command based on a known relationship between the opening degree of each flow rate adjustment valve and the flow rate of the reducing agent passing through the flow rate adjustment valve. It is comprised so that the opening degree command may be output.

According to the configuration of the above (9), based on the known relationship between the opening degree of each flow rate adjustment valve and the flow rate of the reducing agent passing through the flow rate adjustment valve, each flow rate adjustment valve is operated as an operation command. Since the opening degree command is output, the flow rate of the reducing agent passing through the flow rate adjusting valve can be adjusted by performing the adjustment operation of each flow rate adjusting valve in accordance with the opening degree command.
In the configuration of (9) above, each flow rate adjustment valve is provided with a flow meter (for example, an orifice meter) as compared with the case where the operation command output from the command generation unit specifies the flow rate of each flow rate adjustment valve. This is advantageous in that the adjustment operation of the flow rate adjusting valve can be performed without it.

(10) In some embodiments, in any one of the configurations (1) to (9),
The command generation unit issues the operation command to change a supply distribution ratio of the reducing agent to each of the reducing agent injection nozzles while maintaining a total injection amount of the reducing agent by the plurality of reducing agent injection nozzles. Configured to generate.

  According to the configuration of (10) above, an operation command is generated to change the supply distribution ratio of the reducing agent to each reducing agent injection nozzle while maintaining the total amount of reducing agent injected by the plurality of reducing agent injection nozzles. Therefore, the local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor can be suppressed without excessive or insufficient total amount of the reducing agent for decomposing nitrogen oxides in the exhaust gas.

(11) In some embodiments, in the configuration of (10) above,
Further comprising a NOX sensor for measuring a nitrogen oxide concentration in the exhaust gas downstream of the denitration reactor,
The total injection amount of the reducing agent is determined based on the measurement result of the NOX sensor.

  According to the configuration of (10) above, since the total amount of reducing agent injected is determined based on the measurement result of the NOX sensor, it is possible to inject sufficient reducing agent to decompose nitrogen oxides in the exhaust gas.

(12) A reducing agent distribution adjustment method for a denitration apparatus according to at least one embodiment of the present invention includes:
A reducing agent is injected into the exhaust gas from a plurality of reducing agent injection nozzles, and the nitrogen oxide in the exhaust gas reacts with the reducing agent in a denitration reactor downstream of the reducing agent injection nozzle. A reducing agent distribution adjustment method for a denitration apparatus that decomposes
The reducing agent injection amount of each of the plurality of reducing agent injection nozzles and the flow direction of the exhaust gas when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. A correlation obtaining step for obtaining a correlation of the first distribution of the reducing agent in the first plane in advance;
A distribution measuring step for measuring a second distribution of the reducing agent in a second plane orthogonal to the flow direction on the outlet side of the denitration reactor;
An injection amount that adjusts the injection amount of the reducing agent by each of the reducing agent injection nozzles based on the second distribution measured in the distribution measurement step and the correlation acquired in advance in the correlation acquisition step. An adjustment step.

  According to the method of (12) above, first, the amount of reducing agent injected from each of the plurality of reducing agent injection nozzles, and when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. The correlation of the first distribution of the reducing agent in the first plane orthogonal to the flow direction is obtained. Next, on the outlet side of the denitration reactor, the second distribution of the reducing agent in the second plane orthogonal to the flow direction of the exhaust gas is measured. Based on the second distribution and the correlation, the reducing agent injection amount is adjusted for each reducing agent injection nozzle. In this way, a local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor can be suppressed.

  According to at least one embodiment of the present invention, a denitration apparatus and a reducing agent distribution adjustment method for the denitration apparatus that can suppress an increase in the concentration of unreacted reducing agent on the outlet side of the denitration reactor are provided.

It is a figure showing roughly composition of a denitration device concerning one embodiment of the present invention. It is a figure which shows distribution of the reducing agent measured in the distribution measurement part. It is a figure which shows roughly the memory | storage part with which the denitration apparatus which concerns on one Embodiment is provided. It is a figure which shows typically the content of the map memorize | stored in the memory | storage part shown in FIG. It is a figure showing roughly a portable terminal with which a denitration device concerning one embodiment is provided. It is a figure which shows roughly the control part with which the denitration apparatus which concerns on one Embodiment is provided. It is a figure which shows roughly the injection amount adjustment | control part of the denitration apparatus which concerns on one Embodiment. It is a figure which shows roughly the injection amount adjustment | control part of the denitration apparatus which concerns on one Embodiment. It is a flowchart which shows the outline of the reduction | restoration distribution adjustment method of the denitration apparatus which concerns on one Embodiment. It is a flowchart which shows the outline of the reduction | restoration distribution adjustment method of the denitration apparatus which concerns on one Embodiment.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
In addition, for example, expressions representing shapes such as quadrangular shapes and cylindrical shapes not only represent shapes such as quadrangular shapes and cylindrical shapes in a strict geometric sense, but also within the range where the same effect can be obtained. A shape including a chamfered portion or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

FIG. 1 is a diagram schematically showing a configuration of a denitration apparatus 1 according to an embodiment of the present invention.
A denitration apparatus 1 according to at least one embodiment of the present invention removes nitrogen oxide (NOx) in exhaust gas, and includes a plurality of reducing agent injection nozzles 21, an injection amount adjusting unit 3, and a denitration reactor 4. A distribution measuring unit 5 and a command generating unit 6.

The plurality of reducing agent injection nozzles 21 are for injecting the reducing agent into the exhaust gas.
In the embodiment illustrated in FIG. 1, the reducing agent injected into the exhaust gas is ammonia (NH 3), and the plurality of reducing agent injection nozzles 21 are on the inlet side of the flue 11 connecting the boiler 100 and the denitration reactor 4. Is provided.

  The injection amount adjusting unit 3 is for adjusting the injection amount of the reducing agent from each reducing agent injection nozzle 21.

  The denitration reactor 4 is provided on the downstream side of the reducing agent injection nozzle 21 and is configured to decompose nitrogen oxides by a reaction between nitrogen oxides (NOx) in the exhaust gas and the reducing agent.

The distribution measuring unit 5 is for measuring the second distribution of the reducing agent in the second surface 4B orthogonal to the flow direction of the exhaust gas on the outlet side of the denitration reactor 4.
In the form illustrated in FIG. 1, the distribution measuring unit 5 is configured by a laser exhaust gas sensor or the like.

FIG. 2 is a diagram illustrating the distribution of the reducing agent measured by the distribution measuring unit 5. In FIG. 2, the broken line indicates the distribution of the reducing agent measured by the distribution measuring unit 5, and the solid line is the adjustment amount calculation value.
As shown in FIG. 2, the distribution of the reducing agent measured by the distribution measuring unit 5, that is, the second distribution of the reducing agent in the second surface 4B orthogonal to the flow direction of the exhaust gas on the outlet side of the denitration reactor 4. Is represented by the relationship between the position and the density at the position.

  The command generator 6 is orthogonal to the amount of reducing agent injected from each of the plurality of reducing agent injection nozzles 21 and the flow direction when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor 4. Based on the correlation of the first distribution of the reducing agent in the first surface 4A and the second distribution measured by the distribution measuring unit 5, an operation command for the injection amount adjusting unit 3 is generated. .

  According to the above configuration, the reducing agent injection amount of each of the plurality of reducing agent injection nozzles 21 and the flow direction when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor 4. Based on the correlation of the first distribution of the reducing agent in the orthogonal first surface 4 </ b> A and the second distribution measured by the distribution measuring unit 5, an operation command for the injection amount adjusting unit 3 can be generated. Therefore, by operating the injection amount adjusting unit 3 according to the generated operation command, it is possible to suppress a local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor 4. As a result, adhesion of unreacted reducing agent to the air preheater 200 provided downstream of the denitration apparatus 1 can be suppressed.

  In addition, since an operation command for the injection amount adjusting unit 3 is generated, the injection amount adjusting unit 3 can be appropriately adjusted even when a worker unaccustomed to adjusting the injection amount adjusting unit 3 operates.

  The command generation unit 6 according to some embodiments reduces the injection amount of the reducing agent by at least one nozzle 21 corresponding to the high concentration region of the reducing agent in the second distribution among the plurality of reducing agent injection nozzles 21. It is comprised so that the operation command to make may be produced | generated.

  In the example shown in FIG. 2, at least one of the plurality of reducing agent injection nozzles 21 corresponding to the high concentration region of the reducing agent (ammonia) in the reducing agent distribution (second distribution) measured by the distribution measuring unit 5. The operation command for reducing the injection amount of the reducing agent by the nozzle 21 is generated.

  For example, the operation command is generated in order from the reducing agent injection nozzle 21 having a large adjustment amount. For example, the adjustment amount of the reducing agent injection nozzle 21 having a large adjustment amount is configured to generate an operation command so that the concentration of the high concentration region of the reducing agent in the second distribution is halved.

  According to said structure, the operation command which reduces the injection quantity of the reducing agent by the at least 1 nozzle 21 corresponding to the high concentration area | region of the reducing agent in 2nd distribution among several reducing agent injection | pouring nozzles 21 is produced | generated. Therefore, by operating according to the operation command, the concentration of the reducing agent in the high concentration region on the outlet side of the denitration reactor 4 can be reduced.

  The command generation unit 6 according to some embodiments is based on the deviation between the second distribution measured by the distribution measurement unit 5 and the target distribution of the reducing agent in the second surface 4B. An operation command for canceling the deviation is generated on the inlet side.

  For example, an operation command is generated so that the deviation between the second distribution measured by the distribution measuring unit 5 and the target distribution of the reducing agent in the second surface 4B is halved on the inlet side of the denitration reactor 4. Configured. If the adjustment is repeated according to this operation command, the deviation gradually decreases, and eventually the deviation converges within an allowable range (cancellation).

  According to the above configuration, the deviation is canceled on the inlet side of the denitration reactor 4 based on the deviation between the second distribution measured by the distribution measuring unit 5 and the target distribution of the reducing agent in the second surface 4B. Since the operation command is generated, the deviation is canceled on the inlet side of the denitration reactor 4 by operating according to the operation command. Therefore, the local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor 4 can be effectively suppressed.

  FIG. 3 is a diagram schematically illustrating the storage unit 7 included in the denitration apparatus 1 according to the embodiment. FIG. 4 is a diagram schematically showing the contents of maps D11, D12... Dij stored in storage unit 7 shown in FIG.

As shown in FIG. 3, some embodiments further include a storage unit 7.
The storage unit 7 stores the reducing agent injection amount of each reducing agent injection nozzle 21 and the reducing agent in the first surface 4A when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor 4. Are stored for each reducing agent injection nozzle 21.

  In the form illustrated in FIG. 3, maps D11, D12... Dij are stored for each of the reducing agent injection nozzles N11, N12. Has been.

  Specifically, as shown in FIG. 4, when the reducing agent (ammonia) injected with the reducing agent injection nozzle 21 fully opened reaches the inlet side of the denitration reactor 4, The distribution is stored for each reducing agent injection nozzle 21.

  The command generation unit 6 described above uses the map for each reducing agent injection nozzle 21 stored in the storage unit 7 as a correlation, and generates an operation command that cancels the deviation on the inlet side of the denitration reactor 4. Configured.

  In the form illustrated in FIG. 3, the reducing agent injection amount of each reducing agent injection nozzle 21 and the inside of the first surface 4 </ b> A when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor 4. The operation command that cancels the deviation is generated on the inlet side of the denitration reactor 4 by using the superposed distribution of the reducing agent as a correlation.

  Specifically, an operation command is issued so that the deviation between the second distribution measured by the distribution measuring unit 5 and the target distribution of the reducing agent in the second surface 4B is halved on the inlet side of the denitration reactor 4. Configured to generate. If the adjustment is repeated according to this operation command, the deviation gradually decreases, and eventually the deviation converges within an allowable range (cancellation).

  According to the above configuration, since the map for each reducing agent injection nozzle 21 stored in the storage unit 7 is used as a correlation, an operation command for canceling the deviation on the inlet side of the denitration reactor 4 is generated. By operating according to the operation command, the deviation is canceled on the inlet side of the denitration reactor 4. Therefore, the local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor 4 can be effectively suppressed.

FIG. 5 is a diagram schematically showing the portable terminal 8 provided in the denitration apparatus 1 according to the embodiment.
As shown in FIG. 5, some embodiments further comprise a portable terminal 8.
The portable terminal 8 is configured to output an operation command generated by the command generation unit 6.

  In the form illustrated in FIG. 5, the portable terminal 8 is configured to receive an operation command from the command generation unit 6 and output the operation command to the screen. The portable terminal 8 is preferably easy to carry. For example, a tablet terminal that can output an operation command to the screen and can be input from the screen is employed.

  According to the above configuration, since the operation command generated by the command generation unit 6 is output to the portable terminal 8, the worker can operate the injection amount adjusting unit 3 while confirming the operation command on the portable terminal 8.

FIG. 6 is a diagram schematically illustrating the control unit 32 included in the denitration apparatus 1 according to an embodiment.
As shown in FIG. 6, some embodiments further include a control unit 32.
The control unit 32 is configured to control the injection amount adjustment unit 3 based on the operation command generated by the command generation unit 6 described above.

  In the form illustrated in FIG. 6, the control unit 32 is connected to the command generation unit 6 by wire or wirelessly, and is configured to control the flow rate adjustment valve 31 based on the operation command generated by the command generation unit 6. .

  According to the above configuration, since the control unit 32 controls the injection amount adjustment unit 3 based on the operation command generated by the command generation unit 6, the adjustment of the injection amount adjustment unit 3 is automated. Therefore, the injection amount adjusting unit 3 can be controlled without depending on the operator.

FIG. 7 is a diagram schematically showing the injection amount adjusting unit 3 of the denitration apparatus 1 according to one embodiment.
As shown in FIG. 7, the injection amount adjustment unit 3 according to some embodiments includes a plurality of flow rate adjustment valves 31.
The plurality of flow rate adjusting valves 31 are for adjusting the amount of reducing agent injected by each reducing agent injection nozzle 21.

  In the form illustrated in FIG. 7, the injection amount adjustment unit 3 is provided in the reducing agent injection unit 2. The reducing agent injection unit 2 includes a mixer 22, a header pipe 23, and a plurality of injection pipes 24.

  The mixer 22 is for diluting and mixing the reducing agent, and is supplied with the reducing agent and the diluent gas. The reducing agent is, for example, ammonia (NH 3), and the diluent gas is, for example, air. The reducing agent diluted and mixed in the mixer 22 (hereinafter simply referred to as “reducing agent”) is supplied to the header pipe 23.

  The header pipe 23 is for distributing the reducing agent to the plurality of injection pipes 24, and the plurality of injection pipes 24 described above are branched. In each of the injection pipes 24, the reducing agent injection nozzles 21 described above are arranged in a grid pattern.

  In the form illustrated in FIG. 7, the injection amount adjustment unit 3 includes a plurality of flow rate adjustment valves 31. A plurality of flow rate adjustment valves 31 are provided for each injection pipe 24, and an orifice 34 is provided upstream thereof, and a check valve 35 is provided downstream thereof.

  According to the above configuration, the amount of reducing agent injected by each of the reducing agent injection nozzles 21 is adjusted by each flow rate adjusting valve 31, so that the amount of reducing agent injected can be finely adjusted.

FIG. 8 is a diagram schematically showing the injection amount adjusting unit 3 of the denitration apparatus 1 according to one embodiment.
As shown in FIG. 8, in some embodiments, each flow rate adjustment valve 31 includes a sensor 33 that can detect the opening degree of the flow rate adjustment valve 31.

  In the form illustrated in FIG. 8, the sensor 33 is connected to the command generation unit 6 by wire or wirelessly, and the opening degree of the flow rate adjustment valve 31 detected by the sensor 33 is output to the command generation unit 6.

  According to the above configuration, the opening degree of the flow rate adjustment valve 31 can be detected by the sensor 33. For this reason, even if the operator manually adjusts the opening degree of the flow rate adjustment valve 31, it is not necessary to record the opening degree of each flow rate adjustment valve 31 by the operator after the opening degree adjustment. Therefore, the reducing agent distribution adjustment work by the worker can be simplified.

  As shown in FIG. 8, the command generator 6 according to some embodiments has a known relationship between the opening degree of each flow rate adjustment valve 31 and the flow rate of the reducing agent passing through the flow rate adjustment valve 31. Based on this, it is configured to output an opening command of each flow rate adjustment valve 31 as an operation command.

  For example, the known relationship is a function of the correlation between the opening degree of the flow rate adjustment valve 31 and the pressure loss coefficient of the reducing agent injection nozzle 21 including the flow rate adjustment valve 31, and the opening degree of the flow rate adjustment valve 31 and the flow rate of the reducing agent. The correlation between the opening degree of the flow rate adjustment valve 31 and the pressure loss coefficient of the reducing agent injection nozzle 21 including the flow rate adjustment valve 31 is obtained by, for example, Equation 1.

According to the above configuration, based on a known relationship between the opening degree of each flow rate adjustment valve 31 and the flow rate of the reducing agent that passes through the flow rate adjustment valve 31, each flow rate adjustment valve 31 is opened as an operation command. Since the degree command is output, the flow rate of the reducing agent passing through the flow rate adjustment valve 31 can be adjusted by performing the adjustment operation of each flow rate adjustment valve 31 according to the opening degree command.
In the above configuration, each flow rate adjustment valve 31 is not provided with a flow meter (for example, an orifice meter) as compared with the case where the operation command output from the command generation unit 6 specifies the flow rate of each flow rate adjustment valve 31. However, it is advantageous in that the adjustment operation of the flow rate adjustment valve 31 can be performed.

  The command generator 6 according to some embodiments changes the supply distribution ratio of the reducing agent to each reducing agent injection nozzle 21 while maintaining the total amount of reducing agent injected by the plurality of reducing agent injection nozzles 21. Configured to generate an operation command.

  For example, the total amount of reducing agent injected is set based on the concentration of nitrogen oxides in the exhaust gas. Therefore, the concentration of nitrogen oxides in the exhaust gas, for example, in the coal-fired boiler, the concentration of nitrogen oxides in the exhaust gas is not changed unless the coal type is changed, and the total amount of reducing agent injected is maintained.

  According to the above configuration, the operation command is generated so as to change the supply distribution ratio of the reducing agent to each reducing agent injection nozzle 21 while maintaining the total amount of reducing agent injected by the plurality of reducing agent injection nozzles 21. The local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor 4 can be suppressed without excessive or insufficient total amount of the reducing agent for decomposing nitrogen oxides in the exhaust gas.

As shown in FIG. 1, some embodiments further include a NOX sensor 9.
The NOX sensor 9 is for measuring the nitrogen oxide concentration in the exhaust gas on the downstream side of the denitration reactor 4, and the total amount of reducing agent injected is determined based on the measurement result of the NOX sensor 9. .

  In the form illustrated in FIG. 1, the NOX sensor 9 is connected to the command generation unit 6 by wire or wirelessly, and the nitrogen oxide concentration in the exhaust gas measured by the NOX sensor 9 is output to the command generation unit 6.

  According to the above configuration, since the total amount of reducing agent injected is determined based on the measurement result of the NOX sensor 9, it is possible to inject sufficient reducing agent to decompose nitrogen oxides in the exhaust gas.

9 and 10 are flowcharts showing an outline of the reduction distribution adjustment method of the denitration apparatus 1 according to one embodiment.
As shown in FIGS. 9 and 10, the reducing agent distribution adjusting method of the denitration apparatus 1 according to at least one embodiment of the present invention injects the reducing agent into the exhaust gas from the plurality of reducing agent injection nozzles 21 and injects the reducing agent. In the denitration reactor 4 on the downstream side of the nozzle 21, the nitrogen oxide in the exhaust gas is reacted with the reducing agent to decompose the nitrogen oxide.
As shown in FIGS. 9 and 10, the reducing agent distribution adjustment method of the denitration apparatus 1 according to some embodiments includes a correlation acquisition step (step S10), a distribution measurement step (step S12), and an injection amount adjustment. Step (step S16).

  The correlation acquisition step (step S10) is performed when the reducing agent injection amount of each of the plurality of reducing agent injection nozzles 21 and when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor 4. The correlation of the first distribution of the reducing agent in the first surface 4A orthogonal to the flow direction of the exhaust gas is obtained in advance.

  For example, the correlation of the first distribution of the reducing agent in the first surface 4A is obtained by using CFD (Computational Fluid Dynamics) analysis in a typical operation state of the plant in which the denitration apparatus 1 is incorporated, actual machine measurement data, or the like. It is done. Specifically, the first distribution (map) of the reducing agent in the first surface 4A is obtained by CFD analysis, actual machine measurement data, and the like, and superposed. In addition, when the flow path changes, the entire distribution is obtained by switching the first distribution (map) obtained by CFD analysis or actual machine measurement data for each flow path.

  The distribution measurement step (step S12) measures the second distribution of the reducing agent in the second surface 4B orthogonal to the flow direction on the outlet side of the denitration reactor 4.

  In the form illustrated in FIG. 1, the distribution measuring unit 5 is installed on the outlet side of the denitration reactor 4 to measure the second distribution of the reducing agent in the second surface 4B orthogonal to the flow direction of the exhaust gas. In addition, the distribution measurement part 5 is comprised with a laser exhaust gas sensor etc., for example.

  The injection amount adjustment step (step S16) is performed based on the second distribution measured in the distribution measurement step (step S12) and the correlation acquired in advance in the correlation acquisition step (step S10). The amount of the reducing agent injected by the nozzle 21 is adjusted.

  For example, in the injection amount adjusting step (step S16), as will be described later, the operator may operate the injection amount adjusting unit 3 based on the operation command generated based on the second distribution and the correlation. The control unit 32 may control the injection amount adjustment unit 3 based on the command.

  According to the above method, first, the amount of reducing agent injected from each of the plurality of reducing agent injection nozzles 21 and the flow direction when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor 4. The correlation of the first distribution of the reducing agent in the first surface 4A orthogonal to is obtained. Next, on the outlet side of the denitration reactor 4, the second distribution of the reducing agent in the second surface 4B perpendicular to the flow direction of the exhaust gas is measured. Based on the second distribution and the correlation, the reducing agent injection amount is adjusted for each reducing agent injection nozzle 21. In this way, a local concentration increase of the unreacted reducing agent on the outlet side of the denitration reactor 4 can be suppressed.

  9 and 10 further includes a command generation step (step S14). The command generation step (step S14) is performed on the injection amount adjustment unit 3 based on the second distribution measured in the distribution measurement step (step S12) and the correlation acquired in advance in the correlation acquisition step (step S10). An operation command is generated.

  Specifically, among the plurality of reducing agent injection nozzles 21, an operation command for reducing the amount of reducing agent injected by at least one nozzle 21 corresponding to the high concentration region of the reducing agent in the second distribution is generated.

  The form illustrated in FIG. 10 further includes an adjusted opening degree input step (step S18). In the post-adjustment opening degree input step (step S18), the adjustment amount of the injection amount adjustment unit 3 adjusted in the injection amount adjustment step (step S16) is input.

  Specifically, the opening degree of the flow rate adjustment valve 31 adjusted in the injection amount adjustment step (step S16) is input.

  The opening of the flow rate adjustment valve 31 may be input by an operator operating the portable terminal 8 or may be input by the opening detected by the sensor 33.

  When the opening detected by the sensor 33 is input, even if the operator manually adjusts the opening of the flow rate adjustment valve 31, each flow rate adjustment valve by the operator after opening adjustment is performed. It is not necessary to record the opening of 31. Therefore, the reducing agent distribution adjustment work by the worker can be simplified.

Further, the embodiment illustrated in FIG. 10 further includes an adjustment completion determination step (step S20).
The adjustment completion determination step (step S20) is for determining whether to continue the adjustment or to complete the adjustment.
For example, the adjustment is completed when the concentration distribution of the unreacted reducing agent at the outlet side of the denitration reactor 4 has converged within the allowable range, and the concentration distribution of the unreacted reducing agent has not converged within the allowable range. Continue to adjust (readjustment).

The present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.
For example, some of the denitration apparatuses 1 described above are used in a denitration apparatus for a coal fired boiler, but are not limited to a denitration apparatus for a coal fired boiler.
Moreover, in embodiment mentioned above, although the execution timing of the reducing agent distribution adjustment of the denitration apparatus 1 is not mentioned, it can implement at arbitrary timings.
For example, it may be determined whether or not adjustment is necessary from the second distribution measured by the distribution measuring unit 5, and the reducing agent distribution adjustment may be performed.

DESCRIPTION OF SYMBOLS 1 Denitration apparatus 11 Flue 2 Reductant injection | pouring part 21 Reductant injection | pouring nozzle 22 Mixer 23 Header pipe 24 Injection pipe 3 Injection amount adjustment part 31 Flow control valve 32 Control part 33 Sensor 34 Orifice 35 Check valve 4 Denitration reactor 5 Distribution measurement unit 6 Command generation unit 7 Storage unit 8 Portable terminal 9 NOX sensor 100 Boiler 200 Air preheater

Claims (12)

A denitration device for removing nitrogen oxides in exhaust gas,
A plurality of reducing agent injection nozzles for injecting the reducing agent into the exhaust gas;
An injection amount adjusting unit for adjusting the injection amount of the reducing agent from each of the reducing agent injection nozzles;
A denitration reactor provided on the downstream side of the reducing agent injection nozzle and configured to decompose the nitrogen oxides by a reaction between the nitrogen oxides in the exhaust gas and the reducing agent;
A distribution measuring unit for measuring a second distribution of the reducing agent in a second plane orthogonal to the flow direction of the exhaust gas on the outlet side of the denitration reactor;
The reducing agent injection amount of each of the plurality of reducing agent injection nozzles, and a first direction orthogonal to the flow direction when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. Based on the correlation of the first distribution of the reducing agent in the plane and the second distribution measured by the distribution measuring unit, a command generating unit for generating an operation command for the injection amount adjusting unit; A denitration apparatus comprising:   The command generation unit is configured to reduce the injection amount of the reducing agent by at least one nozzle corresponding to the high concentration region of the reducing agent in the second distribution among the plurality of reducing agent injection nozzles. The denitration apparatus according to claim 1, wherein the denitration apparatus is configured to generate the denitration apparatus.   The command generation unit is configured to determine the deviation on the inlet side of the denitration reactor based on a deviation between the second distribution measured by the distribution measurement unit and the target distribution of the reducing agent in the second surface. The denitration apparatus according to claim 1, wherein the operation command is generated so as to cancel the operation. The amount of the reducing agent injected from each of the reducing agent injection nozzles, and the distribution of the reducing agent in the first surface when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. And a storage unit in which the map is stored for each of the reducing agent injection nozzles,
The command generation unit generates the operation command to cancel the deviation on the inlet side of the denitration reactor using the map for each reducing agent injection nozzle stored in the storage unit as the correlation. The denitration apparatus according to claim 3, wherein the denitration apparatus is configured as described above.   The denitration apparatus according to any one of claims 1 to 4, further comprising a portable terminal configured to output the operation command generated by the command generation unit.   5. The control unit according to claim 1, further comprising a control unit configured to control the injection amount adjustment unit based on the operation command generated by the command generation unit. Denitration equipment.   The said injection amount adjustment | control part contains the some flow volume adjustment valve for adjusting the injection amount of the said reducing agent by each said reducing agent injection | pouring nozzle, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. NOx removal equipment.   The denitration device according to claim 7, wherein each of the flow rate adjustment valves includes a sensor capable of detecting an opening degree of the flow rate adjustment valve.   The command generator is configured to use each flow rate adjustment valve as the operation command based on a known relationship between the opening degree of each flow rate adjustment valve and the flow rate of the reducing agent passing through the flow rate adjustment valve. The denitration device according to claim 7, wherein the denitration device is configured to output a degree of opening command.   The command generation unit issues the operation command to change a supply distribution ratio of the reducing agent to each of the reducing agent injection nozzles while maintaining a total injection amount of the reducing agent by the plurality of reducing agent injection nozzles. The denitration device according to any one of claims 1 to 9, wherein the denitration device is configured to generate the denitration device. Further comprising a NOX sensor for measuring a nitrogen oxide concentration in the exhaust gas downstream of the denitration reactor,
The denitration apparatus according to claim 10, wherein the total injection amount of the reducing agent is determined based on a measurement result of the NOX sensor. A reducing agent is injected into the exhaust gas from a plurality of reducing agent injection nozzles, and the nitrogen oxide in the exhaust gas reacts with the reducing agent in a denitration reactor downstream of the reducing agent injection nozzle. A reducing agent distribution adjustment method for a denitration apparatus that decomposes
The reducing agent injection amount of each of the plurality of reducing agent injection nozzles and the flow direction of the exhaust gas when the reducing agent injected at the injection amount reaches the inlet side of the denitration reactor. A correlation obtaining step for obtaining a correlation of the first distribution of the reducing agent in the first plane in advance;
A distribution measuring step for measuring a second distribution of the reducing agent in a second plane orthogonal to the flow direction on the outlet side of the denitration reactor;
An injection amount that adjusts the injection amount of the reducing agent by each of the reducing agent injection nozzles based on the second distribution measured in the distribution measurement step and the correlation acquired in advance in the correlation acquisition step. And a reducing agent distribution adjusting method for the denitration apparatus.

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