JP4938945B2 - Denitration apparatus and denitration method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a denitration apparatus in a system such as a heavy oil / coal fired boiler, a gas fired boiler, a gas turbine, a gas turbine combined cycle, and the like. TECHNICAL FIELD The present invention relates to a denitration apparatus and a denitration method for preventing water. The present invention is also useful for FCC (fluid catalytic cracking device) and RFCC (heavy oil fluid catalytic cracking device) process exhaust gas.
[0002]
[Prior art]
At present, reduction of nitrogen oxides contained in various combustion exhaust gases is essential from the viewpoint of environmental protection, and as a countermeasure against this, harmless N by injecting ammonia in a boiler or the like.₂And H₂After being decomposed into O, it is discharged.
[0003]
FIG. 8 is a schematic configuration diagram showing a denitration facility for a coal fired boiler. The coal-fired boiler 1 includes a boiler 2, an ammonia injection nozzle 4 installed in a duct 3 of the boiler 2, a denitration reactor 5, an air preheater 6, and a forced air blower 7. An unillustrated electrostatic precipitator, desulfurization device, etc. are installed downstream of the denitration reactor 5, and exhaust gas is discharged from the chimney.
[0004]
FIG. 9 is a cross-sectional view showing the denitration reactor shown in FIG. The denitration reactor 5 includes a catalyst layer 52, a rectifying layer 53, and a guide vane 54 provided in a plurality of layers in a reaction vessel 51. The exhaust gas containing nitrogen oxide into which ammonia has been injected undergoes a chemical reaction by passing through the catalyst layer 52, and N₂And H₂Decomposed into O. The catalyst layer 52 is composed of a plurality of catalyst packs 55, and each catalyst pack 55 has a structure in which a plurality of catalysts 56 are accommodated in a frame 57 as shown in FIG. As shown in FIG. 2B, the catalyst 56 has a honeycomb structure mainly composed of titanium oxide. A honeycomb structure made of ceramics such as cordierite or mullite fired at high temperature may be used.
[0005]
By the way, in the denitration reactor 5, unburned components fly to and adhere to the catalyst layer due to abnormal operation of the plant, and are burned by the oxidation action, thereby causing thermal damage to the crystal structure of the catalyst 56. That was a problem. For such a problem, for example, a denitration apparatus described in JP-A-64-39819 has been proposed. In this denitration device, a ceramic filter with a honeycomb structure is installed upstream of the catalyst layer, and tar-like unburned components are attached to the ceramic filter, and thermal damage due to combustion of unburned components is imposed on the ceramic filter. The catalyst layer is protected.
[0006]
[Problems to be solved by the invention]
However, in the above denitration device, the unburned matter is adsorbed only by the ceramic filter, and depending on the operation state of the plant, the unburned matter cannot be completely removed, and unburned matter comes to the catalyst layer and causes heat loss. There was a problem. In addition, since the unburnt part is attached to the ceramic filter so that the ceramic filter is thermally damaged, the ceramic filter has the same material and structure as the catalyst layer. Therefore, there is a problem that running cost is high. The above denitration apparatus is presented for reference, and is not necessarily a so-called public / public technique.
[0007]
Therefore, the present invention has been made in view of the above, and an object thereof is to provide a denitration apparatus and a denitration method that can prevent unburned components from flying into the catalyst layer as much as possible. Another object of the present invention is to provide a denitration apparatus and a denitration method that can reduce running costs for preventing unburned components from flying.
[0008]
[Means for Solving the Problems]
  In order to achieve the above object, a denitration apparatus according to claim 1 is provided upstream of a denitration catalyst layer for denitrating exhaust gas discharged from a combustor and a duct of the denitration catalyst layer, and unburned in the exhaust gas. Adsorbing means for adsorbing and upstream of the adsorbing means~ sideBetween the adsorbing means and the denitration catalyst layer.Provided between the adsorbing means and the ammonia injection nozzle.When the unburned fuel value measured by the unburned fuel measuring device exceeds the predetermined threshold, the bypass means for separating the NOx removal catalyst layer from the bypass line, the switching means for switching between the normal line and the bypass line, and switching And control means for controlling to switch from a normal line to a bypass line by means.
[0009]
When the unburned component in the exhaust gas is measured by the unburned component measuring device and the unburned component value, which is the measurement result, exceeds the threshold, the switching means switches from the normal line to the bypass line, and the denitration catalyst layer is unburned. Control so that minutes do not fly. In this way, most of the unburned portion is adsorbed by the adsorbing means, but the unburned portion that has passed through the adsorbing means bypasses the denitration catalyst layer via the bypass line. Carried to the device or outside. Thereby, it is possible to prevent as much as possible unburned components from flying into the denitration catalyst layer.
[0010]
  The denitration apparatus according to claim 2 includes a denitration catalyst layer that denitrates exhaust gas discharged from the combustor, and an adsorption unit that is provided upstream of a duct of the denitration catalyst layer and adsorbs unburned components in the exhaust gas. Between the adsorbing means and the denitration catalyst layer, and an unburned matter measuring device installed downstream of the adsorbing means for measuring the unburned content in the exhaust gas.Provided between the adsorbing means and the ammonia injection nozzle.When the unburned fuel value measured by the unburned fuel measuring device exceeds the predetermined threshold, the bypass means for separating the NOx removal catalyst layer from the bypass line, the switching means for switching between the normal line and the bypass line, and switching And control means for controlling to switch from a normal line to a bypass line by means.
[0011]
In addition, by installing an unburned component measuring device downstream of the adsorbing unit as in the present invention, the unburned component that has passed through the adsorbing unit is measured, and the bypass line switching control is performed based on this. good. If it does in this way, flying to the NOx removal catalyst layer can be prevented as much as possible by measuring the unburned part which actually passed through the adsorption means and bypassing the unburned part which passed through.
[0012]
Further, the adsorbing means may not be used, and the unburned portion may be prevented from flying into the denitration catalyst layer through the denitration catalyst layer bypass line. In this case, periodic maintenance such as replacement of the suction means becomes unnecessary, so that the running cost can be reduced.
[0013]
The denitration apparatus according to claim 4 is characterized in that, in the denitration apparatus, the unburned component measuring device is a device that measures unburned components by a laser method. According to the apparatus that measures by the laser method, the unburned component in the exhaust gas can be measured in a very short time, and therefore, the bypass line can be controlled in real time based on the presence or absence of the unburned component. Thereby, it is possible to prevent unburned components from flying into the denitration catalyst layer as much as possible.
[0016]
  Claims5A denitration apparatus according to the present invention is characterized in that, in the above denitration apparatus, instead of the adsorption means, provided is a combustion means provided upstream of the duct of the denitration catalyst layer to oxidize and burn unburned components in the exhaust gas. To do.
[0017]
The combustion means burns the unburned portion, thereby preventing the unburned portion from flying to the denitration catalyst layer. Further, the use of the combustion means eliminates the need for regular replacement as in the adsorption means, thereby improving maintainability.
[0018]
  A denitration method according to claim 6 is a denitration method for denitrating exhaust gas discharged from a combustor by a denitration catalyst layer,The denitration step of denitrating the exhaust gas by the denitration catalyst layer and the upstream step of the denitration stepAn adsorption process for adsorbing unburned components in the exhaust gas;An unburned matter measurement step for measuring unburned matter in the exhaust gas discharged from the combustor in an upstream step of the adsorption step, and between the adsorption step and the denitration step.An ammonia injection process for injecting ammonia into the exhaust gas after adsorbing unburned matter;By the unburned matter measurement processWhen the measured unburnt value exceeds a predetermined threshold,Between the adsorption step and the ammonia injection stepFromBypass after the denitration processSwitch to the bypass lineThe denitration processBypassA bypass processIt is characterized by that.
  Bypass that measures the unburned content in the exhaust gas by the unburned matter measuring process, and bypasses between the adsorption process and the ammonia injection process after the denitration process when the unburned value that is the measurement result exceeds a threshold value Switch to line and control so that unburned fuel does not fly to the denitration catalyst layer. In this way, most of the unburned portion is adsorbed in the adsorption step, but the unburned portion that has passed through this adsorption step bypasses the denitration catalyst layer via the bypass line, and the subsequent treatment Carried to the device or outside. Thereby, it is possible to prevent as much as possible unburned components from flying into the denitration catalyst layer.
  The denitration method according to claim 7 is a denitration method of denitrating exhaust gas discharged from a combustor by a denitration catalyst layer, wherein the denitration step of denitrating the exhaust gas by the denitration catalyst layer, and the denitration step An adsorption step for adsorbing unburned components in the exhaust gas in an upstream step, an unburned component measuring step for measuring unburned components in the exhaust gas discharged from the combustor in a downstream step of the adsorption step, When an ammonia injection step for injecting ammonia into the exhaust gas after adsorbing unburned components between the adsorption step and the denitration step, and an unburned component value measured by the unburned component measuring step exceeds a predetermined threshold, And a bypass step of bypassing the denitration step by switching to a bypass line that bypasses after the denitration step between the unburned component measurement step and the ammonia injection step.
  By installing the unburned component measurement process downstream of the adsorption process, the unburned component in the exhaust gas that has passed through the adsorption process is measured by the unburned component measurement process. When it exceeds, it switches to the bypass line which bypasses after the said denitration process from between the said unburned part measurement process and the said ammonia injection | pouring process, and it controls so that an unburned part does not fly to a denitration catalyst layer. In this way, most of the unburned part is adsorbed in the adsorption process, but the unburned part that actually passed through the adsorption means is measured, and the unburned part that has passed through the adsorption process passes through the bypass line. Thus, the denitration catalyst layer is bypassed, and the denitration catalyst layer is carried to the subsequent processing apparatus or the outside. Thereby, it is possible to prevent as much as possible unburned components from flying into the denitration catalyst layer.
[0019]
  Claims8The denitration method according to the above denitration method,Instead of the adsorption step, a combustion step is provided in the upstream step of the denitration step to oxidize and burn unburned components in the exhaust gas, and the combustion stepUnburned matter in exhaust gasThe acidCombustion and further combustionProcessSupply oxygen toAbovecombustionProcessIt is characterized in that the unburned matter adhering to is burned. By supplying oxygen to the combustion means and burning it, adhesion of unburned matter is prevented and clogging of the combustion means is prevented. Thereby, the replacement frequency of the combustion means can be reduced.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same.
[0021]
(Embodiment 1)
1 is a configuration diagram showing a denitration apparatus according to Embodiment 1 of the present invention. This denitration apparatus 100 is provided with an unburned adsorption layer 101 downstream of the duct 3 of the boiler 2, an ammonia injection nozzle 4 for injecting ammonia downstream of the adsorption layer 101, and further downstream of the ammonia injection nozzle 4. Is a configuration in which a denitration reactor 5 is installed, and a normal processing line A is formed by these. In the denitration reactor 5, a plurality of conventional denitration catalyst layers 52 shown in FIG. Further, a bypass pipe 102 for bypassing the denitration catalyst layer 52 is connected to the duct 3 between the adsorption layer 101 and the ammonia injection nozzle 4 to form a bypass line B branching from the normal line A. . A bypass valve 103 is provided immediately before the ammonia injection nozzle 4. Further, the bypass pipe 102 is also provided with a bypass shutoff valve 104. These valves 103 and 104 are controlled by a control device 105. Note that any known means other than the valves 103 and 104 can be used as long as the means can switch between the normal line A and the bypass line B substantially.
[0022]
For the adsorption layer 101, any one of silica, titania, alumina, zirconia, or a composite oxide composed of at least two kinds, or ZFI-5 having an MFI structure, silicalite, metallosilicate, or the like can be used. An adsorption layer having an MFI structure is advantageous in that it is resistant to heat and has a large adsorption capacity. The adsorption layer 101 has a honeycomb structure like the catalyst layer 52. As shown in FIG. 2, an adsorption material 106 is housed in a frame 107 to form an adsorption pack 108, and a plurality of adsorption packs 108 are formed. They are arranged side by side. The adsorbent 106 is preferably a reprocessed or used product of a used catalyst. The running cost of the denitration apparatus 100 can be reduced by using a reprocessed product or a used product. In particular, when a large amount of unburned matter is generated, a plurality of adsorption layers 101 may be provided. The honeycomb structure is not limited to a rectangular cross section, and a hexagonal or triangular one can be used.
[0023]
More preferably, the adsorbent 106 is made by coating the above-mentioned silica, titania, alumina, zirconia or the like on a high heat-resistant substrate such as mullite or cordierite which has been fired at a high temperature. As shown in FIG. 3, the adsorbent 106 has a base material 106a having the same honeycomb structure as described above, and a coating 106b having a predetermined thickness is applied to the honeycomb inner surface. Further, in consideration of the flow of exhaust gas, clogging of ash, etc., it is preferable that the thickness of the honeycomb after coating is about 1 mm and the pitch is about 6 mm × 6 mm. By coating the ceramic base material 106a with the unburned material adsorbing material 106b, the amount of the adsorbing material can be greatly reduced, so that the manufacturing cost of the adsorbing material 106 can be reduced. In addition, the strength of the adsorbent 106 can be improved due to the structure in which the coating 106b is applied to the ceramic substrate 106a which is a strength member.
[0024]
Next, the unburned portion is measured by a laser method. Preferably, a laser induced breakdown spectroscopy (LIBS) proposed by the applicant of the present application in Japanese Patent Laid-Open No. 9-155293 is used. Can be mentioned. The principle of this LIBS method is that the laser beam is concentrated in gas, liquid, and solid to make the measurement field into plasma, the plasma light generated by the laser beam is detected to measure the component concentration of the measurement field, and the coal ash Is detected by detecting the signal intensity of Si, Al, Fe, Ca, and C as the composition components and calculating the intensity ratio with Si as the main component.
[0025]
The LIBS device 108 is provided in a pipe 109 branched from the duct 3 between the boiler 2 and the adsorption layer 101, and measures unburned content in the exhaust gas passing through the duct 3. FIG. 4 is a configuration diagram showing an example of such a LIBS apparatus. The LIBS device 108 includes a pulse laser device 301, a condensing lens 302, a measurement window 304 provided in the pipe 109, a mirror 305 that reflects plasma light, a lens 306 that condenses plasma light, and a spectroscopic device. And a computer 309. The laser beam R 1 output from the pulse laser device 108 is condensed on the measurement field in the pipe 109 via the lens 302 and the measurement window 304. An object to be measured such as pulverized coal or farash is flowing in the pipe 109, and by focusing the laser beam R1, fine particles existing in the measurement field are heated to a high temperature to be converted into plasma, and plasma is generated from the component material converted into plasma. Light R2 is generated.
[0026]
The generated plasma light R2 is output to the outside from the measurement window 304 of the measurement field, reflected by the mirror 305, further collected by the lens 306, and incident on the spectroscope 307. The spectroscope 307 splits the plasma light R2 having a wavelength of 190 nm to 500 nm and inputs the split light component to the CCD camera 308. The CCD camera 308 is capable of high-speed gate detection, detects the spectral plasma light R2 dispersed by the spectroscope 307, and transfers a signal corresponding to the spectral plasma light R2 to the computer 309. Note that the CCD camera 308 is connected to the pulse laser device 301 via a synchronization line 310, whereby the gate control of the CCD camera 308 and the oscillation of the pulse laser device 301 are synchronized.
[0027]
The computer 309 processes a signal having the emission intensity information of each component, and calculates the calorific value, unburnt amount, component composition, and the like of the pulverized coal existing in the measurement field in real time. Thus, since the LIBS apparatus 108 can measure the composition component of the measurement object in real time, it is suitable for real time control.
[0028]
The measurement result of the unburned amount (for example, CO) by the LIBS device 108 is sent to the control device 105, and the control device 105 controls the opening and closing of the valves 103 and 104 when the unburned component value exceeds the threshold value. Specifically, when a large amount of unburned portion is generated due to abnormal combustion of the boiler 2, the unburned portion value is measured by the LIBS device 108, and the control device 105 determines the duct-side valve 103 based on the unburned portion value. Is closed and the valve 104 on the bypass pipe 102 side is opened. As a result, the exhaust gas containing unburned matter is removed by the adsorption layer 101 and is removed through the bypass line B without reaching the catalyst layer 52, and therefore cannot be completely removed by the adsorption layer 101. The unburned component does not adhere to the catalyst layer 52. The threshold value can be set as a value obtained by actually measuring the adsorption capacity of the unburned portion by the adsorption layer 101 and multiplying the adsorption capacity of the adsorption layer 101 by a predetermined safety factor. Specifically, when the adsorption capacity of the adsorption layer 101 is exceeded, the unburned component passes through the adsorption layer 101. The value of, for example, 90% of this adsorption capability is set as a threshold value, and the unburned component may pass. When the value becomes high, the bypass line B is opened. As a result, the catalyst layer 52 is not thermally damaged by the unburned component, and the unburned component discharged to the outside can be minimized.
[0029]
When the measured value of the unburned portion becomes less than a predetermined threshold value, the control device 105 opens the valve 103 on the duct 3 side and closes the valve 104 on the bypass pipe 102 side. Thereby, unburned matter is adsorbed only by the adsorption layer 101, and the unburned matter is prevented from adhering to the catalyst layer 52. The unburned matter adsorbed on the adsorption layer 101 is ignited and burned in the process of increasing the load of the boiler 2. Instead of the LIBS device 108, other laser methods such as laser induced fluorescence (LIF) can be used (hereinafter the same). Further, in the above, the opening / closing control of the bypass line B is performed based on the adsorption capacity of the adsorption layer 101. However, when the unburned portion is measured regardless of the adsorption capacity, the bypass line B is opened. It is also possible to always prevent unburned components from reaching the catalyst layer 52 in both the adsorption layer 101 and the bypass line B.
[0030]
  Next, the above adsorptionlayer101Instead of the oxidation catalyst (common reference numeral 10 in FIG.1) Can also be used. As the oxidation catalyst, a denitration catalyst or a CO catalyst is used. Silica, titania, alumina, zirconia, or a composite oxide composed of at least two of them, or MFI type ZSM-5, silicalite, metallosilicate For example, a structure in which one or more of Pt, Pd, Rh, Ir, and Ru are supported can be used. In addition, it is preferable to use a material obtained by coating a high heat-resistant base material such as mullite or cordierite coated with the oxidation catalyst material, like the adsorbent 106. Thereby, reduction of manufacturing cost and improvement of strength can be achieved.
[0031]
The oxidation catalyst captures the unburned matter and burns the unburned matter by its oxidizing action. Thereby, the unburned portion is prevented from flying and the catalyst layer 52 is protected. Further, the valve 104 of the bypass pipe 102 is opened and the valve 103 on the duct 3 side is closed, and the oxidation catalyst is O₂May be used to wash the oxidation catalyst. O for oxidation catalyst₂, The unburned portion of the oxidation catalyst is completely burned and the exhaust gas can be discharged from the bypass line B. After cleaning, the valve 104 on the bypass line B is closed, the valve 103 on the duct 3 side is opened, and the normal line A is restored. O₂This cleaning may be performed periodically or when the unburned portion is clogged.
[0032]
As described above, according to the denitration apparatus 100, by providing the bypass line B together with the adsorption layer 101, it is possible to completely prevent unburned components from flying into the catalyst layer 52 and causing heat loss. In addition, since the unburned component value is measured by the laser method of the LIBS device 108 and the like, and the opening / closing control of the bypass line B is performed based on the measurement result, real-time control is possible, and heat loss of the catalyst layer 52 can be further prevented. . Furthermore, by arranging the LIBS device 108 upstream of the adsorption layer 101, the control is performed after measuring the unburned portion passing through the adsorption layer 101 (details will be described later in Embodiment 2). The amount of fuel flying to the catalyst layer 52 can be reduced.
[0033]
(Embodiment 2)
FIG. 5 is a block diagram showing a denitration apparatus according to Embodiment 2 of the present invention. This denitration apparatus 150 is characterized in that the LIBS apparatus 108 is installed downstream of the adsorption layer 101, and the other configuration is the same as that of the denitration apparatus 100. Is attached. The denitration device 150 measures the unburned amount that could not be adsorbed by the adsorption layer 101 by the LIBS device 108, and when the unburned amount exceeds a predetermined amount, the valve 104 of the bypass pipe 102 is opened and the valve on the duct 3 side is opened. 103 is controlled to close, and exhaust gas containing unburned matter is discharged through the bypass line B without passing through the catalyst layer 52. In this way, it is possible to reliably prevent unburned components from flying into the catalyst layer 52. Even if the combustion of the boiler 2 is normally performed, a small amount of unburned matter is present, but when the unburned amount is such an amount as to cause heat loss to the catalyst layer 52, the unburned amount is passed through the bypass line B. It is sufficient to bypass the unburned component. If the unburned component is extremely small and does not cause serious heat loss to the catalyst layer 52, the unburned component bypass is not necessary.
[0034]
(Embodiment 3)
FIG. 6 is a configuration diagram showing a denitration apparatus according to Embodiment 3 of the present invention. This denitration apparatus 200 is characterized in that the adsorption layer 101 of the denitration apparatus 100 shown in the first embodiment is omitted and the unburned portion is prevented from flying only by the bypass line B. Since the other configuration is the same as that of the denitration apparatus 100, the description thereof is omitted and the same components are denoted by the same reference numerals. Since the adsorption layer 101 is omitted in the denitration device 100, the control device 105 opens the valve 104 of the bypass pipe 102 along with the occurrence of unburned content based on the measurement result of the unburned content value by the LIBS device 108, and the duct. By closing the 3-side valve 103, the exhaust gas containing unburned components is discharged to the outside. When it is determined by the LIBS device 108 that no unburned matter is generated, the valve 104 on the bypass line B side is closed and the valve 103 on the duct 3 side is opened to return to the normal line. In such a configuration, the opening / closing control of the bypass line B is performed on the basis of the generation of the unburned portion. However, the unburned portion may be bypassed to the extent that no heat loss occurs with respect to the catalyst layer 52.
[0035]
That is, even if unburned components are present, if the other conditions are not satisfied, the catalyst layer 52 may not be thermally damaged. Under these conditions, exhaust gas containing unburned components may be bypassed. good. FIG. 7 is a flowchart showing an example (oil-fired boiler) of a heat loss generation process due to generation of unburned fuel. As shown in the figure, assuming that sufficient oxygen is present (step S1), unburned dust is present (step S2), and the temperature of the exhaust gas is higher than a specified temperature (step S3). A predetermined sufficient time (step S4) and the temperature rise / ignition of the unburned portion (step S5) cause heat loss. Alternatively, oil mist is present (step S6) and the exhaust gas temperature is higher than the specified temperature (step S7), and a predetermined sufficient time (step S4), and the unburned portion is heated and ignited. (Step S5) also causes heat loss.
[0036]
The controller 105 may perform opening / closing control of the bypass pipe 102 when the above conditions are satisfied. The exhaust gas temperature is measured by a thermometer provided in the duct 3. The presence or absence of unburned dust and oil mist is measured by the LIBS device 108. According to this denitration apparatus 200, since the opening and closing of the bypass pipe 102 is controlled in real time based on the measurement result by the laser method, it is possible to effectively suppress the unburned portion from flying to the catalyst layer 52, and the heat of the catalyst layer 52 Loss can be prevented. Further, since no adsorbent is required, the running cost can be reduced.
[0037]
【The invention's effect】
  As described above, in the denitration apparatus of the present invention (Claim 1), the denitration catalyst layer for denitrating exhaust gas discharged from the combustor and the denitration catalyst layer are provided upstream of the duct of the denitration catalyst layer, and unburned in the exhaust gas. Adsorbing means for adsorbing and upstream of the adsorbing means~ sideBetween the adsorbing means and the denitration catalyst layer.Provided between the adsorbing means and the ammonia injection nozzle.When the unburned fuel value measured by the unburned fuel measuring device exceeds the predetermined threshold, the bypass means for separating the NOx removal catalyst layer from the bypass line, the switching means for switching between the normal line and the bypass line, and switching Control means for controlling so as to switch from the normal line to the bypass line by means, so that the unburned matter that has passed through the adsorption means bypasses the denitration catalyst layer via the bypass line, It is possible to prevent the fuel from flying as much as possible.
[0038]
  Further, in the denitration apparatus of the present invention (Claim 2), the denitration catalyst layer for denitrating the exhaust gas discharged from the combustor and the denitration catalyst layer are provided upstream of the duct of the denitration catalyst layer and adsorb the unburned components in the exhaust gas. Between the adsorbing means, the unburned matter measuring device that is installed downstream of the adsorbing means and measures the unburned content in the exhaust gas, and the adsorbing means and the denitration catalyst layerProvided between the adsorbing means and the ammonia injection nozzle.When the unburned fuel value measured by the unburned fuel measuring device exceeds the predetermined threshold, the bypass means for separating the NOx removal catalyst layer from the bypass line, the switching means for switching between the normal line and the bypass line, and switching The control means for controlling to switch from the normal line to the bypass line by the means is provided, so that the unburned portion that has actually passed through the adsorption means can be bypassed to prevent flying to the denitration catalyst layer as much as possible.
[0039]
  Further, in the denitration device of the present invention (Claim 3), a denitration catalyst layer that performs denitration of exhaust gas discharged from the combustor, an unburned component measuring device that measures unburned component in the exhaust gas,An ammonia injection nozzle that is provided upstream of the denitration catalyst layer and injects ammonia, and between the unburned fuel measuring device and the ammonia injection nozzle.When the unburned fuel value measured by the unburned fuel measuring device exceeds the predetermined threshold, the bypass means for separating the NOx removal catalyst layer from the bypass line, the switching means for switching between the normal line and the bypass line, and switching And a control means for controlling to switch from the normal line to the bypass line by the means, so that the unburned portion can be prevented from flying into the denitration catalyst layer as much as possible. Moreover, since regular maintenance such as replacement of the suction means is unnecessary, the running cost can be reduced.
[0040]
Further, in the denitration apparatus of the present invention (Claim 4), since the apparatus for measuring unburned components by the laser method is used as the unburned component measuring apparatus, it is possible to perform bypass line switching control in real time. Thus, the unburned portion will be prevented from flying as much as possible.
[0042]
  Further, the denitration apparatus of the present invention (claims)5), In place of the adsorption means, a combustion means is provided upstream of the denitration catalyst layer duct to oxidize and burn the unburned components in the exhaust gas. Can be prevented and maintainability can be improved.
[0043]
  The denitration method of the present invention (Claim 6) is a denitration method of denitrating exhaust gas discharged from a combustor by a denitration catalyst layer,The denitration step of denitrating the exhaust gas by the denitration catalyst layer and the upstream step of the denitration stepAn adsorption process for adsorbing unburned components in the exhaust gas;An unburned matter measurement step for measuring unburned matter in the exhaust gas discharged from the combustor in an upstream step of the adsorption step, and between the adsorption step and the denitration step.An ammonia injection process for injecting ammonia into the exhaust gas after adsorbing unburned matter;By the unburned matter measurement processWhen the measured unburnt value exceeds a predetermined threshold,Between the adsorption step and the ammonia injection stepFromBypass after the denitration processSwitch to the bypass lineThe denitration processBypassA bypass process.Therefore, it is possible to prevent as much as possible unburned fuel from flying into the denitration catalyst layer.
  The denitration method of the present invention (Claim 7) is a denitration method for denitrating exhaust gas discharged from a combustor by a denitration catalyst layer,The denitration step of denitrating the exhaust gas by the denitration catalyst layer and the upstream step of the denitration stepAn adsorption process for adsorbing unburned components in the exhaust gas;The exhaust discharged from the combustor in a downstream process of the adsorption processAn unburned component measuring step for measuring unburned component in exhaust gas;Between the adsorption process and the denitration processAn ammonia injection step of injecting ammonia into the exhaust gas after adsorbing the unburned matter,By the unburned matter measurement stepWhen the measured unburnt value exceeds a predetermined threshold,Between the unburned matter measurement step and the ammonia injection stepFromBypass after the denitration processSwitch to the bypass lineThe denitration processBypassA bypass process.Therefore, it is possible to prevent as much as possible unburned fuel from flying into the denitration catalyst layer.
[0044]
  In the denitration method of the present invention (Claim 8),Instead of the adsorption step, a combustion step is provided in the upstream step of the denitration step to oxidize and burn unburned components in the exhaust gas, and the combustion stepUnburned matter in exhaust gasThe acidCombustion and further combustionProcessSupply oxygen toAbovecombustionProcessSince the unburned matter adhering to the fuel is burned, the replacement frequency of the combustion means is reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a denitration apparatus according to Embodiment 1 of the present invention.
FIG. 2 is an explanatory view showing an adsorption layer.
FIG. 3 is an explanatory view showing an adsorbent.
FIG. 4 is a configuration diagram illustrating an example of a LIBS apparatus.
FIG. 5 is a configuration diagram showing a denitration apparatus according to Embodiment 2 of the present invention.
FIG. 6 is a configuration diagram showing a denitration apparatus according to Embodiment 3 of the present invention.
FIG. 7 is a flowchart showing an example of a process of generating heat loss due to generation of unburned components.
FIG. 8 is a schematic configuration diagram showing a denitration facility for a coal fired boiler.
9 is a cross-sectional view showing the denitration reactor shown in FIG.
FIG. 10 is a configuration diagram showing a catalyst pack.
[Explanation of symbols]
100 Denitration equipment
2 Boiler
3 Duct
4 Ammonia injection nozzle
5 Denitration reactor
51 reaction vessel
52 Catalyst layer
101 Adsorption layer
102 Bypass pipe
103 valves
104 valves
105 Control device
108 LIBS equipment
109 piping

Claims (8)

A denitration catalyst layer for denitrating exhaust gas discharged from the combustor;
An adsorption means provided upstream of the duct of the denitration catalyst layer and adsorbs unburned components in the exhaust gas;
An unburned fuel measuring device installed upstream of the adsorbing means for measuring unburned fuel in exhaust gas;
An ammonia injection nozzle that is provided between the adsorption means and the denitration catalyst layer and injects ammonia;
A bypass line that separates from the duct between the adsorption means and the ammonia injection nozzle and bypasses the denitration catalyst layer;
Switching means for switching between a normal line and a bypass line;
Control means for controlling the switching from the normal line to the bypass line when the unburned part value measured by the unburned part measurement device exceeds a predetermined threshold;
A denitration apparatus comprising: A denitration catalyst layer for denitrating exhaust gas discharged from the combustor;
An adsorption means provided upstream of the duct of the denitration catalyst layer and adsorbs unburned components in the exhaust gas;
An unburned fuel measuring device installed downstream of the adsorbing means and measuring unburned fuel in the exhaust gas;
An ammonia injection nozzle that is provided between the adsorption means and the denitration catalyst layer and injects ammonia;
A bypass line that separates from the duct between the adsorption means and the ammonia injection nozzle and bypasses the denitration catalyst layer;
Switching means for switching between a normal line and a bypass line;
Control means for controlling the switching from the normal line to the bypass line when the unburned part value measured by the unburned part measurement device exceeds a predetermined threshold;
A denitration apparatus comprising: A denitration catalyst layer for denitrating exhaust gas discharged from the combustor;
An unburned component measuring device for measuring unburned component in exhaust gas;
An ammonia injection nozzle that is provided upstream of the denitration catalyst layer and injects ammonia;
A bypass line that separates from the duct between the unburned fuel measuring device and the ammonia injection nozzle and bypasses the denitration catalyst layer;
Switching means for switching between a normal line and a bypass line;
Control means for controlling the switching from the normal line to the bypass line when the unburned part value measured by the unburned part measurement device exceeds a predetermined threshold;
A denitration apparatus comprising: The denitration apparatus according to any one of claims 1 to 3, wherein the unburned component measuring device is a device that measures unburned components by a laser method. 5. The combustion apparatus according to claim 1, further comprising a combustion means provided upstream of the denitration catalyst layer duct for oxidizing and burning unburned components in the exhaust gas instead of the adsorption means. The denitration apparatus according to one. A denitration method for denitrating exhaust gas discharged from a combustor by a denitration catalyst layer,
A denitration step of denitrating the exhaust gas by the denitration catalyst layer;
An adsorption process for adsorbing unburned components in the exhaust gas in an upstream process of the denitration process ;
An unburned component measuring step of measuring unburned component in the exhaust gas discharged from the combustor in an upstream step of the adsorption step;
An ammonia injection step of injecting ammonia into the exhaust gas after adsorbing unburned components between the adsorption step and the denitration step ;
When the unburned component value measured in the unburned component measurement step exceeds a predetermined threshold, the denitration step is bypassed by switching to a bypass line that bypasses after the denitration step between the adsorption step and the ammonia injection step . A denitration method comprising a bypass step . A denitration method for denitrating exhaust gas discharged from a combustor by a denitration catalyst layer,
A denitration step of denitrating the exhaust gas by the denitration catalyst layer;
An adsorption process for adsorbing unburned components in the exhaust gas in an upstream process of the denitration process ;
An unburned component measuring step of measuring unburned components in the exhaust gas discharged from the combustor in a downstream step of the adsorption step ;
An ammonia injection step of injecting ammonia into the exhaust gas after adsorbing unburned components between the adsorption step and the denitration step ;
When the unburned component value measured by the unburned component measurement step exceeds a predetermined threshold, the denitration step is switched to a bypass line that bypasses after the denitration step from between the unburned component measurement step and the ammonia injection step. A denitration method comprising: a bypass step for bypassing the gas. In place of the adsorption step, a combustion step is provided in the upstream step of the denitration step to oxidize and burn the unburned component in the exhaust gas,
Claim 6 or 7, characterized in that said with burning oxidation unburned in the exhaust gas by the combustion process, the combustion of the unburned combustibles was further adhered to the combustion process the combustion process by supplying oxygen to the 2. A denitration method as described in 1.

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