KR20210121017A - Corrosion prevention device and corrosion prevention method - Google Patents

Abstract

A first light source unit having a light emitting diode that emits irradiated light in an absorption wavelength band including an absorption spectrum of the first measurement target generated by combustion of a combustion target, and a second measurement target generated by combustion of the fuel combustion target A second light source unit having a light emitting diode that emits irradiated light in an absorption wavelength band having an absorption spectrum and an absorption spectrum different from the absorption spectrum of the first measurement target, and receiving the irradiated light emitted from the first light source unit A first light receiving unit, a second light receiving unit for receiving the irradiated light emitted from the second light source unit, and transmitted light intensity I _{1 of} the irradiated light received by the first light receiving unit and transmitted light intensity I ₂ of the irradiated light received by the second light receiving unit Corrosion prevention device provided with a calculation part for calculating the absorbance and/or transmittance|permeability of the said 1st measurement object in the combustion gas which combusted the said combustion object based on it.

Description

Corrosion prevention device and corrosion prevention method

The present invention relates to a corrosion protection device and a corrosion protection method capable of measuring the concentration of a substance in a mixture comprising two or more substances.

In recent years, in order to secure fuel, the demand for power generation using wood materials other than wood materials and biomass fuels other than wood materials and waste fuels such as waste tires and waste plastics is increasing. In such a power generation mechanism, for example, a combustion furnace which burns a combustion target and generates saturated steam, and the combustion gas generated in the combustion furnace is connected to the combustion furnace and is connected to the saturated steam generated in the combustion furnace. As an example, a technology using a boiler having a superheater for use in power generation by overheating by using the same is exemplified.

On the other hand, due to the depletion of petroleum resources or biomass fuel itself in the future, a situation in which low-quality biomass fuel is used is largely predicted. However, low-quality biomass fuels and waste fuels contain many impurities, such as alkali components, such as Na and K, for example. In this way, when low-grade fuel containing impurities such as alkali components is used, heat exchange efficiency is reduced due to poor flow of circulating material or ash adhesion in devices such as heat exchangers in power generation facilities. , there is a possibility that the inside of the device may be corroded by alkali salts generated by combustion of fuel. As a technique for improving such a problem, for example, a method and an apparatus for measuring the concentration of a toxic gas in flue gas by spectrophotometric light have been proposed (for example, Patent Document 1 below) Reference).

Patent Document 1: Japanese Patent Publication No. 2003-511692

Like the technique described in Patent Document 1, in general ultraviolet absorption spectrophotometry, a high-pressure lamp such as a xenon lamp or a mercury lamp is used as a white light source. However, these high-pressure lamps have a short lifespan, and the high-pressure lamps have a problem in that the stability of luminous intensity is low. For this reason, it is conceivable to use a light emitting diode (LED) having a long light source life and excellent light emission intensity. Here, since the LED has a narrow wavelength width of an emission spectrum and is monochromatic light, a light source having a wavelength according to an absorption spectrum of a measurement target is selected. However, if a substance having the same absorption wavelength band as the absorption wavelength band of the measurement target is mixed, in the technique using a monochromatic LED, light absorption by the measurement target and light absorption by the mixed substance cannot be separated, so the measurement target concentration cannot be accurately measured.

In order to solve the above problems, the present invention provides an anticorrosion device and corrosion protection device capable of measuring the absorbance and/or transmittance of a substance in a mixture containing two or more substances having a long light source life and the same absorption wavelength The purpose is to provide a preventive method.

That is, this invention is as showing below.

<1> A first light source unit including a light emitting diode for emitting light of an absorption wavelength band including an absorption spectrum of a first measurement target generated by combustion of a combustion target;

A second light source unit having a light emitting diode emitting light of an absorption wavelength band that is an absorption spectrum of a second measurement target generated by combustion of the combustion target and includes an absorption spectrum different from the absorption spectrum of the first measurement target; ,

a first light receiving unit for receiving the irradiated light emitted from the first light source unit;

a second light receiving unit for receiving the irradiated light emitted from the second light source unit;

_{Based on the transmitted light intensity I 1 of} the irradiated light received by the first light receiving unit _{and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or Corrosion prevention device having a calculator for calculating the transmittance.

<2> A corrosion inhibitor supply unit for supplying the corrosion inhibitor reacting with the first measurement target to the combustion gas, and a supply quantity control unit for controlling the supply amount of the corrosion inhibitor supplied from the corrosion inhibitor supply unit In <1> Corrosion protection device described.

<3> The corrosion preventing device according to <2>, wherein the supply amount control unit controls the supply amount of the corrosion inhibitor based on the absorbance and/or transmittance of the first measurement target calculated by the calculation unit.

<4> A product having a light emitting diode that emits irradiated light in an absorption wavelength band that is an absorption spectrum of the third measurement target generated from the corrosion inhibitor and includes an absorption spectrum different from the absorption spectrum of the first and second measurement targets A third light source unit, and a third light receiving unit for receiving the irradiation light emitted from the third light source unit,

The calculation unit, based on the transmitted light intensity I _{3 of the irradiated light received by the third light receiving unit and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or transmittance of the third measurement target in the combustion gas to calculate,

The corrosion preventing device according to <2>, wherein the supply amount control unit controls the supply amount of the corrosion inhibitor based on the absorbance and/or transmittance of the first and third measurement objects calculated by the calculation unit.

<5> Irradiated light in the absorption wavelength band including the absorption spectrum of the first measurement target generated by the combustion of the combustion target, and the absorption spectrum of the second measurement target generated by the combustion of the combustion target, and the first measurement target irradiated light of an absorption wavelength band including an absorption spectrum different from the absorption spectrum of

The irradiated light emitted from the first light source unit and the irradiated light emitted from the second light source unit are received by a first light receiving unit or a second light receiving unit, respectively,

_{Based on the transmitted light intensity I 1 of} the irradiated light received by the first light receiving unit _{and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or transmittance of the first measurement target is calculated by a calculator, Corrosion prevention method.

<6> Controlling the supply amount of the corrosion inhibitor reacting with the first measurement object based on the absorbance and/or transmittance of the first measurement object calculated by the calculator, and supplying the corrosion inhibitor to the combustion gas , The corrosion prevention method according to <5>.

<7> The irradiated light of the absorption wavelength band, which is the absorption spectrum of the third measurement target generated from the corrosion inhibitor and includes absorption spectra different from the absorption spectrum of the first and second measurement targets, is emitted toward the combustion gas Further emitted from the third light source unit having a diode,

receiving the irradiated light emitted from the third light source unit to a third light receiving unit;

_{Based on the transmitted light intensity I 3 of} the irradiated light received by the third light receiving unit _{and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or transmittance of the third measurement target is calculated by the calculation unit,

Controlling the supply amount of the corrosion inhibitor reacting with the first measurement object based on the absorbance and/or transmittance of the first and third measurement objects calculated by the calculator, and supplying the corrosion inhibitor to the combustion gas The method for preventing corrosion according to <6>.

Advantageous Effects of Invention According to the present invention, it is possible to provide an anticorrosive device and a corrosion preventing method capable of measuring the absorbance and/or transmittance of a substance in a mixture containing two or more substances having a long light source life and having the same absorption wavelength. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows 1st Embodiment of this invention.
It is a schematic for demonstrating the structure of the measurement unit in 1st Embodiment.
3 is a schematic diagram showing a second embodiment of the present invention.
Fig. 4 is a schematic diagram showing an aspect of a measurement unit according to the second embodiment.
Fig. 5 is a schematic diagram showing another aspect of the measurement unit in the second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, with reference to the drawings, a mode for carrying out the present invention (hereinafter, simply referred to as “the present embodiment”) will be described in detail. However, the following embodiment is an illustration for demonstrating this invention, and is not the meaning which limits this invention to the following content. The present invention can be implemented with appropriate modifications within the scope of the gist. However, the same reference numerals are assigned to the same elements, and overlapping descriptions are omitted. In addition, the positional relationship such as up, down, left and right shall be based on the positional relationship shown in the drawings, unless otherwise specified. Note that the dimensional ratios in the drawings are not limited to the illustrated ratios.

(First embodiment)

A combustion facility provided with a corrosion protection device according to the first embodiment will be described with reference to FIG. 1 . BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows 1st Embodiment of this invention.

As shown in Fig. 1, the combustion facility 10 includes a combustion furnace 20 in which a combustion target is supplied and combusts the combustion target in a furnace, and each component in the combustion gas in which the combustion target is burned. It includes a measuring unit 30 for measuring and a superheater 40 that is overheated by heat exchange with combustion gas generated in the combustion furnace 20 . In addition, the combustion furnace 20 is provided with a combustion object feeder 22 for supplying a combustion object into the furnace. The measurement unit 30 is provided with a corrosion inhibitor supply device 31 for supplying a corrosion inhibitor to the combustion gas, and in the combustion facility 10, each of the measurement unit 30 and the corrosion inhibitor supply device 31 is provided. An electrically connected control unit 50 is provided. In this embodiment, the measuring unit 30, the corrosion inhibitor supplying device 31, and the control unit 50 serve as corrosion preventing devices. However, in FIG. 1, a thick arrow indicates the flow direction of the combustion gas. In addition, in each of the following drawings, the dashed-dotted line indicates the path of the electric signal.

The combustion facility 10 is not particularly limited, but a so-called boiler used for power generation by overheating steam by heat exchange between the combustion gas generated in the combustion furnace 20 and the superheater 40 may be exemplified. In addition, the combustion facility 10 is not particularly limited, but mainly used for thermal power generation business, in addition to a once-through boiler, a circulation boiler, and a heat recovery boiler, a circulating fluidized bed boiler (CFB) used for industrial purposes, a fluidized bed Any of a boiler (BFB) etc. may be sufficient.

As shown in Fig. 1, the combustion furnace 20 is configured, for example, in a vertical cylinder, and burns the combustion target supplied from the combustion target feeder 22 in the furnace. Although there is no limitation in particular as long as it is a combustible material as a combustion object, For example, biomass fuel containing alkali salts, such as Na and K, and waste fuel containing heavy metals, such as lead and zinc, can be used.

When the combustion target supplied to the combustion furnace 20 from the combustion target feeder 22 is burned, combustion gas is generated in the furnace. In addition, although not illustrated, a water pipe can be provided on the furnace wall of the combustion furnace 20 , and saturated steam can be generated by exposing the water pipe to the combustion gas in the combustion furnace 20 . The combustion gas includes a first measurement object and a second measurement object generated by combustion of a combustion object. The first measurement object and the second measurement object are different substances, and the second measurement object has an absorption spectrum in the same wavelength band as the first measurement object, and has an independent absorption spectrum in a wavelength band different from the first measurement object. For example, the first may be a molten salt having a low melting point, such as ZnCl ₂ generated by the combustion of KCl, NaCl or waste fuel generated by the combustion of the Examples of the measuring object, the biomass fuel. The second measurement target is, for example, solid particles such as carbon burnt ash (fly ash (fly ash), bottom ash (bottom ash)) generated by combustion. can be heard The combustion gas generated in the combustion furnace 20 is sent to the measurement unit 30 in a state including the first measurement object and the second measurement object.

The measurement unit 30 is a device for measuring the concentration of the first measurement target in the combustion gas. _{In the measurement unit 30, transmitted light intensities I 1} and I ₂ corresponding to the first and second measurement objects in the combustion gas are measured. Absorption spectrometry is used for measurement of the concentration of the measurement target in the measurement unit 30, for example, ultraviolet absorptiometry is used. The measurement unit 30 of this embodiment is demonstrated using FIG. Fig. 2 is a schematic diagram for explaining the configuration of the measurement unit in the first embodiment. In Fig. 2, a thin arrow indicates a trajectory of light emitted from the light emitting diode, and a thick arrow indicates a flow direction of the combustion gas.

As shown in FIG. 2 , the measurement unit 30 includes a light emitter 32 and a spectrometer 34 . In addition, the measurement unit 30 is provided with a flow path 39 of the combustion gas sent from the combustion furnace 20, and is configured so that the concentrations of the first and second measurement objects in the combustion gas flowing through the flow path 39 can be measured. has been However, in FIG. 1, it is shown that the combustion gas is sent from the left side to the right side with respect to the measurement unit 30, but in FIG. The measurement unit 30 is shown so that it becomes this.

The light emitter 32 includes a light source unit 32A having a light emitting diode for emitting irradiated light in an absorption wavelength band including the absorption spectrum of the first measurement object, and an absorption spectrum of the second measurement object and of the first measurement object. A light source unit 32B having a light emitting diode that emits irradiated light in an absorption wavelength band including an absorption spectrum different from an absorption spectrum is provided. The measurement unit 30 emits irradiated light having different absorption wavelengths from each light source toward the combustion gas flowing through the flow path 39 .

As described above, light emitting diodes are provided in the light sources 32A and 32B. In the present embodiment, in the measurement of the first and second measurement objects in the combustion gas, a light emitting diode is used instead of a conventional high-pressure lamp such as a xenon lamp or a mercury lamp, so that when a high-pressure lamp is used, In comparison, the light source lifespan is long. In addition, since the light source intensity is excellent in stability, the concentration of the measurement target can be measured more accurately. As the light emitting diode used in the present embodiment, a light emitting diode having a wavelength corresponding to the absorption spectrum of the measurement target can be appropriately selected. However, for example, when other substances other than the first and second measurement targets are included in the combustion gas, the absorption wavelength band of the light 36B emitted from the light source unit 32B is set avoiding the absorption spectrum of the other substances. it is preferable

The spectrometer 34 is provided with a light receiving unit 34A for receiving the irradiated light emitted from the light source unit 32A, and a light receiving unit 34B for receiving the irradiated light emitted from the light source unit 32B. The spectrometer 34 is a device provided with a photodiode that receives light irradiated from the light emitter 32 and transmitted through the combustion gas, and functions as a transmitted light intensity monitor. As shown in Fig. 2, the light 36A and the light 36B emitted from each light source unit pass through the combustion gas in the flow path 39, and are received by the corresponding light receiving unit 34A and light receiving unit 34B, respectively. . For this reason, the spectrometer 34 can measure the transmitted light intensity of the light in the absorption wavelength range for each light source unit.

As shown in FIG. 2, the measurement unit 30 is provided with a beam splitter 37, and a part of the light 36A and the light 36B emitted from the light emitter 32 is configured to be reflected downward. have. The light 37A and light 37B reflected by the beam splitter 37 are received by a photodiode 38 for monitoring light source intensity. The photodiode 38 has a plurality of light receiving units (not shown) so as to receive the light emitted from each light source unit. In the measurement unit 30, the beam splitter 37 is installed so that the light irradiated from the light emitter 32 is reflected before reaching the combustion gas, and each beam provided in the light emitter 32 by the photodiode 38 It is configured to monitor the light source intensity of the light source part. However, the monitoring of the light source intensity of the light emitter 32 is based on the intensity of the light received by the photodiode 38 to measure the instability of the light source intensity or the decrease in intensity due to deterioration of each light source unit, and based on these measured values, The light source intensity corresponding to each set light emitting diode may be configured to be corrected.

As shown in FIG. 2 , the light emitter 32 , the spectrometer 34 , and the photodiode 38 are electrically connected to the control unit 50 . When the light emitted from the light emitter 32 is received by the spectrometer 34, an electric signal is transmitted to the control unit 50, and in the control unit 50, the transmitted light intensity I of the irradiated light received by the light receiving unit 34A _{1 and the transmitted light intensity I 2} of the irradiated light received by the light receiving unit 34B are detected. In addition, as the light emitted from the light emitter 32 is received by the photodiode 38, an electric signal is transmitted to the control unit 50, and each light source intensity I ₀₁ and the light source of the light source unit 32A and the light source unit 32B. Intensity I ₀₂ is detected.

Next, as shown in FIG. 1 , the control unit 50 is a device such as a CPU including a calculation unit 52 and a supply amount control unit 54 . The calculation unit 52 includes the transmitted light intensity or light source intensity measured by the measuring unit 30, that is, the transmitted light intensity I _{1 of} the irradiated light received by the light receiving unit 34A and the transmitted light intensity I of the irradiated light received by the light receiving unit 34B. ₂ , the absorbance and transmittance of the first measurement object and the second measurement object are calculated. In the present embodiment, the concentration of the first measurement target is calculated based on the value. However, in FIG. 1 and the like, although the calculation unit 52 and the supply amount control unit 54 are shown in the control unit 50, they do not need to be independent devices, and can be configured to play respective roles in one CPU. .

A method for calculating the concentration of the first measurement target in the calculation unit 52 will be specifically described. First, the calculator 52 calculates Lambert-Beer's law (A=-log ₁₀ (I _x /I _0x )=ECl=εcl[A: absorbance, I _0x : light source intensity of the x- _{th light source unit, I x} : Transmitted light intensity received by the x-th light-receiving unit, E: specific absorbance, C: mass-to-volume percent concentration of a material having an absorption spectrum of light emitted by the x-th light source unit, ε: molar extinction coefficient, x: the amount of light emitted by the x-th light source unit The concentration X1 of the material having the absorption spectrum of the light emitted from the light source unit 32A in the combustion gas is calculated using the molar concentration of the material having the absorption spectrum, l: the length through which light (optical path length)])). Here, in addition to the first measurement object, the second measurement object such as fly ash has an absorption spectrum in the absorption wavelength band of the light emitted from the light source unit 32A. For this reason, the density|concentration of a 2nd measurement object affects the density|concentration X1, and the density|concentration X1 becomes the total density of the 1st measurement object and 2nd measurement object in combustion gas. Next, the concentration X2 of the substance having the absorption spectrum of the light emitted from the light source unit 32B in the combustion gas is calculated. Here, since a substance having an absorption spectrum of light emitted from the light source unit 32B in the combustion gas becomes a second measurement object such as fly ash, the concentration X2 becomes the concentration of the second measurement object in the combustion gas. For this reason, by removing the density|concentration X2 from the density|concentration X1, the influence of the 2nd measurement object is excluded, and the density|concentration of the 1st measurement object can be calculated. However, as described above, as I _0x , the light source intensity I ₀₁ and the light source intensity I ₀₂ monitored by the photodiode 38 are used, and as I _x , the transmitted light intensity I ₁ monitored by the spectrometer 24 and The transmitted light intensity I ₂ is used. However, the method of calculating the concentration in the calculation unit 52 is not limited to the above-described example.

Next, as shown in FIG. 1 , the measurement unit 30 is provided with a corrosion inhibitor supply device 31 for supplying the corrosion inhibitor to the combustion gas. The corrosion inhibitor is a substance that reduces the concentration of the first measurement object by reacting with the first measurement object. The corrosion inhibitor may use a substance having a function of chemically reacting with the first measurement object to convert the first measurement object into another compound by an oxidation-reduction reaction or the like. As such a corrosion inhibitor, for example, when the combustion target is a biomass fuel containing KCl, ammonium sulfate ((NH ₄ )SO ₄ ), aluminum sulfate (Al ₄ (SO ₄ ) ₃ ), sulfur ( Sulfur components, such as 硫黃 (Elemental Sulfur), are mentioned. Moreover, as a corrosion inhibitor, you may use microparticles|fine-particles etc. which can physically adsorb|suck to the 1st measurement object and can reduce the density|concentration of the 1st measurement object itself.

The corrosion inhibitor supply device 31 is electrically coupled to the supply amount control unit 54 in the control unit 50 . The corrosion inhibitor supply device 31 is controlled by the control unit 50 , and the supply timing and supply amount of the corrosion inhibitor are controlled by the supply amount control unit 54 of the control unit 50 . In the present embodiment, the control unit 50 is supplied from the corrosion inhibitor supply device 31 by the supply amount control unit 54 based on the concentration of the first measurement target in the combustion gas calculated by the calculation unit 52 . The supply amount of the corrosion inhibitor to be used is controlled so as to be appropriate for the amount of the first measurement target. Although not particularly limited, the control unit 50 may control the supply amount of the corrosion inhibitor in the combustion gas so that the amount of the corrosion inhibitor is not excessive or insufficient with respect to the amount of the first measurement target.

When the corrosion inhibitor is supplied in the combustion gas in the measurement unit 30, the concentration of the first measurement target in the combustion gas decreases. In this embodiment, it is comprised so that the density|concentration of the 1st measurement target may send the combustion gas in which the density|concentration fell from the measurement unit 30 to the superheater 40. As shown in FIG. A steam tube (not shown) is installed in the superheater 40 . Saturated steam generated by the heat of the combustion furnace 20 circulates in the steam pipe, and the saturated steam is overheated by heat exchange between the combustion gas and the superheater 40 . The combustion gas discharged from the superheater 40 is sent to each facility (downstream device) provided at the lower end of the superheater 40 . The saturated steam superheated by the superheater 40 can be used, for example, to drive a power generation turbine.

As described above, in the present embodiment, the combustion target is burned in the combustion furnace 20, and the irradiation light in the absorption wavelength band including the absorption spectrum of the first measurement target generated by the combustion of the combustion target, and the combustion A light emitting diode is directed to the irradiated light of the absorption wavelength band including the absorption spectrum of the second measurement object generated by the combustion of the object and which is different from the absorption spectrum of the first measurement object toward the combustion gas that has combusted the combustion object, respectively. irradiated from the light source unit 32A and the light source unit 32B provided with ₁ and the transmitted light intensity I ₂ , the absorbance and/or transmittance of the first measurement object and the second measurement object may be calculated by the calculator, and the concentration of the first measurement object may be calculated based on the values. have. As described above, in this embodiment, by using a light emitting diode for a plurality of light source units, the light source life is long and the absorbance, transmittance or concentration of a substance in a mixture containing two or more substances having the same absorption wavelength is measured. It is possible to provide a corrosion-preventing device and a corrosion-preventing method that can be used. In addition, since the light emitting diode is excellent in the stability of the light source intensity, the absorbance, transmittance, and concentration of the first measurement object can be more accurately calculated.

Moreover, in this embodiment, the supply amount of a corrosion inhibitor is controlled based on the density|concentration of the 1st measurement target calculated by the calculation part 52, and a corrosion inhibitor is supplied to combustion gas. For this reason, since an appropriate amount of the corrosion inhibitor can be supplied with respect to the amount of the first measurement object present in the combustion gas, the concentration of the first measurement object is effectively reduced, and the angle in the combustion facility 10 by the first measurement object is effectively reduced. Corrosion in the device can be effectively suppressed.

However, in this embodiment, the absorbance and/or transmittance of the first measurement object and the second measurement object are calculated and the mode of calculating the concentration of the first measurement object from the values has been described. However, the present invention relates to this aspect is not limited to, the embodiment in which only the absorbance and/or transmittance of the first measurement object is calculated in the calculation unit 52 without calculating the concentration of the first measurement object, and subsequent steps are performed based on the values may be

(Second embodiment)

A combustion facility provided with a corrosion prevention device according to a second embodiment will be described with reference to FIG. 3 . 3 is a schematic diagram showing a second embodiment of the present invention. In this embodiment, a biomass fuel containing KCl is used as a first measurement object as a combustion object, a sulfur component is used as a corrosion inhibitor, and a circulating fluidized bed boiler (CFB) is used as a combustion furnace. A combustion facility will be described as an example.

As shown in FIG. 3 , the combustion facility 100 separates the solid content from the combustion furnace 120 in which the biomass fuel is supplied and burns the biomass fuel in the furnace, and the combustion gas in which the biomass fuel is burned. A cyclone 130, a measurement unit 140 for measuring each component in the combustion gas, and a superheater 150 that is overheated by heat exchange with the combustion gas is provided. In addition, the combustion furnace 120 is provided with a fuel supply unit 122 for supplying biomass fuel into the furnace. The measurement unit 140 is provided with a corrosion inhibitor supply device 148 for supplying a sulfur component to the combustion gas, and in the combustion facility 100, each of the measurement unit 140 and the corrosion inhibitor supply device 148 is provided. An electrically connected control unit 50 is further provided. In the present embodiment, the measuring unit 140 and the control unit 50 serve as corrosion preventing devices.

The combustion furnace 120 is composed of a vertically long cylinder, and burns the biomass fuel supplied from the fuel supply unit 122 in the furnace. The combustion furnace 120 is a fluidized bed furnace that burns biomass fuel while flowing it in a fluidized bed. In addition, the combustion furnace 120 is a circulating fluidized bed furnace to which the solid content of a predetermined particle diameter or more is returned by the cyclone 130 as mentioned later. Although the temperature in the combustion furnace 120 is not specifically limited, the temperature of combustion gas can be set so that it may become about 800-1000 degreeC.

When the biomass fuel supplied from the fuel supply unit 122 to the combustion furnace 120 is burned, combustion gas is generated. In addition, although not shown, a water pipe can be installed on the furnace wall of the combustion furnace 120 , and saturated steam can be generated by exposing the water pipe to the combustion gas in the combustion furnace 120 . Moreover, by combustion of biomass fuel, while KCl which is a 1st measurement object is contained in combustion gas, fly ash (fly ash) produced|generated by the said combustion is contained. In the present embodiment, fly ash is the second measurement object. Further, in the present embodiment, in the combustion gas, in addition to KCl and flash ash, NaCl and SO ₂ contained in a sulfur component to be described later are contained. The combustion gas generated in the combustion furnace 120 is sent to the cyclone 130 in a state containing these components such as KCl and fly ash.

The cyclone 130 is a meat separation device that separates the solids having a particle size or larger discharged from the combustion furnace 120 from the combustion gas and returns them to the combustion furnace 120 . The cyclone 130 separates the solids having a particle size or larger from the combustion gas and returns them to the combustion furnace 120 , and sends the combustion gas from which these solids are separated to the measurement unit 140 at the rear stage. Although the particle size of the solid content selected by the cyclone 130 is not particularly limited, for example, it can be set to about 20 µm.

The measuring unit 140 is a device for calculating the absorbance and transmittance of KCl in the combustion gas, and measuring the concentration based on the values. _{In the measurement unit 140, transmitted light intensities I 1} and I ₂ corresponding to KCl (first measurement object) and fly ash (second measurement object) in the combustion gas are measured. In the present embodiment, the measurement of the concentration of the measurement target in the measurement unit 140 uses an ultraviolet absorption spectrophotometry. The measurement unit 140 of the present embodiment will be described with reference to FIG. 4 . Fig. 4 is a schematic diagram showing an aspect of a measurement unit according to the second embodiment.

As shown in FIG. 4 , the measurement unit 140 is provided with a main pipe 141 through which the combustion gas supplied from the cyclone 130 circulates and an external measuring unit 142 , and the combustion gas flowing through the main pipe 141 . A part of it is configured to flow to the external measurement unit 142 through the gas pipe 141A. A light emitter 144 and a spectrometer 146 are provided in the external measuring unit 142 , and combustion gas flows between the light emitter 144 and the spectrometer 146 from the left to the right in the paper. The combustion gas discharged from the external measuring part 142 is returned to the main pipe 141 through the gas pipe 141B.

A light emitter 144 is installed above the ground of the external measurement unit 142 . Although not shown, in the light emitter 144, the first light source unit having a light emitting diode for emitting the irradiated light of the absorption wavelength band including the absorption spectrum of KCl, the absorption spectrum of fly ash, and the absorption spectrum of KCl A second light source unit having a light emitting diode that emits irradiated light in an absorption wavelength band including a different absorption spectrum is provided. Here, the peaks of the absorption spectrum of each component included in the combustion gas are around 250 nm for KCl, around 240 nm for NaCl, and around 220 nm and 290 nm for _{SO 2 .} On the other hand, fly ash has a broad wavelength band of an absorption spectrum, and has absorption in a wavelength band of an absorption spectrum such as KCl. For this reason, in the present embodiment, a light emitting diode having a wavelength of about 250 nm corresponding to the absorption spectrum of KCl is used for the first light source unit, and a light emitting diode having a wavelength of about 400 nm is used for the second light source unit. . In this way, by setting the wavelength of the light emitting diode of the second light source unit to around 400 nm, which is not easily affected by components other than fly ash, which is the second measurement target, the absorbance, transmittance, and concentration of flash ash in the combustion gas can be calculated more accurately. can

A spectrometer 146 is installed below the ground of the external measurement unit 142 . Although not shown, the spectrometer 146 is provided with a first light receiving unit that receives the irradiated light with a wavelength of 250 nm emitted from the first light source unit, and a light receiving unit that receives the irradiated light with a wavelength of 400 nm emitted from the second light source unit. Similar to the first embodiment, the irradiated light emitted from each light source unit passes through the combustion gas and is received by the corresponding light receiving unit.

In addition, although not shown, a beam splitter is provided in the external measurement unit 142 so that the light emitted from the light emitter 144 is reflected before reaching the combustion gas, and a part of the emitted light emitted from the light emitter 144 is reflected. It is configured to receive light by a photodiode for monitoring light source intensity. In this embodiment, similarly to the first embodiment, the light source intensity of the light emitter 144 is detected by the photodiode.

As shown in FIG. 3 , the external measuring unit 142 is electrically connected to the control unit 50 . When the light emitted from the light emitter 144 is received by the spectrometer 146, an electric signal is transmitted to the control unit 50, and in the control unit 50, the transmitted light of the irradiated light having a wavelength of 250 nm received by the first light receiving unit The intensity I _{1 and the transmitted light intensity I 2} of the irradiated light having a wavelength of 400 nm received by the second light receiving unit are detected. In addition, as the light emitted from the light emitter 144 is received by the photodiode, an electrical signal is transmitted to the control unit 50, and each light source intensity I ₀₁ and light source intensity I ₀₂ of the first and second light source units are detected. .

However, in this embodiment, the external measuring part 142 is installed in the main pipe 141 located at the front end of the superheater 150, and the method of measuring the concentration of components in the combustion gas is adopted. , the installation location of the external measuring part 142 is not limited to this, for example, the combustion furnace 120 and the like can be appropriately selected according to the purpose. As shown by Lambert-Beer's law, as the optical path length increases, the transmittance decreases accordingly. For this reason, when the external measuring unit 142 is used as in the present embodiment, the optical path length (the distance between the light emitter 144 and the spectrometer 146) can be made constant according to the size of the external measuring unit 142. It is possible to detect _{transmitted light intensity I 1} or transmitted light intensity I ₂ under the same conditions without being affected by the size of the furnace or tube in which the measuring unit is installed.

In the present embodiment, the control unit 50 includes a calculation unit 52 and a supply amount control unit 54, and the transmitted light intensity I ₁ measured by the measurement unit 140 and The absorbance and transmittance of KCl, the first measurement target, are calculated based on the transmitted light intensity I _{2 , and the concentration thereof is calculated based on the values.}

The measurement unit 140 is provided with a corrosion inhibitor supply device 148 for supplying a sulfur component to the combustion gas. The sulfur component includes, for example, _{at least one selected from ammonium sulfate ((NH 4} )SO ₄ ), aluminum sulfate (Al ₄ (SO ₄ ) ₃ ), and sulfur (Elemental Sulfur). As shown in the following formula, the sulfur component reacts with KCl _{to generate harmless K 2} SO ₄ , and can reduce the concentration of KCl.

2KCl+SO ₂ +H ₂ O+1/2O ₂ → K ₂ SO ₄ +2HCl

2KCl+SO ₃ +H ₂ O → K ₂ SO ₄ +2HCl

As shown in FIG. 3 , the corrosion inhibitor supply device 148 is electrically coupled to the supply amount control unit 54 in the control unit 50 . The corrosion inhibitor supply device 148 is controlled by the control unit 50 , and the supply amount of the sulfur component supplied from the corrosion inhibitor supply device 148 is controlled by the supply amount control unit 54 . The control unit 50 determines that, based on the concentration of KCl in the combustion gas calculated by the calculation unit 52 , the supply amount of the sulfur component supplied from the corrosion inhibitor supply device 148 by the supply amount control unit 54 is KCl. Control to be appropriate for the abundance. Although not particularly limited, the control unit 50 may control the supply amount of the sulfur component in the combustion gas so that the amount of the sulfur component is not excessive or insufficient with respect to the amount of KCl.

When the sulfur component is supplied in the combustion gas by the corrosion inhibitor supply device 148, the concentration of KCl in the combustion gas can be reduced. In this embodiment, it is comprised so that the combustion gas in which the density|concentration of KCl decreased may be sent from the measurement unit 140 to the superheater 150. As shown in FIG. In the superheater 150, similarly to the first embodiment, a pipe (not shown) is installed, and saturated steam generated by the heat of the combustion furnace 120 is circulated in the pipe, so that the combustion gas and the superheater 150 are ), the saturated steam is overheated by heat exchange. The combustion gas discharged from the superheater 150 is sent to each facility (downstream device) installed downstream of the superheater 150 . In addition, the saturated steam superheated by the superheater 150 can be used, for example, to drive a power generation turbine.

Here, since KCl has a melting point of about 780° C., during heat exchange between the superheater 150 and the combustion gas, KCl itself adheres to the inner wall of the superheater 150, etc., causing corrosion of these devices. In addition, adhesion of KCl gas promotes adhesion of fly ash. The adhesion of fly ash causes a decrease in heat exchange efficiency in the superheater 150 . The combustion facility 100 reduces the concentration of KCl in the combustion gas by supplying the sulfur component in order to reduce the influence of the components contained in such low-grade biomass fuel. As a result, the superheater 150, etc. located at the rear end of the corrosion inhibitor supply device 148 is corroded by KCl, or fly ash is attached in the superheater 150 due to the presence of KCl, thereby reducing the heat exchange efficiency. can In particular, in the superheater 150, since the temperature of the combustion gas is lowered by heat exchange, since KCl tends to aggregate, it is preferable to supply the corrosion inhibitor at a stage between the cyclone 130 and the superheater 150.

As described above, in this embodiment, the biomass fuel containing KCl is burned in the combustion furnace 120, the irradiation light of the absorption wavelength band containing the absorption spectrum of KCl, and the combustion of the biomass fuel The irradiated light of the absorption wavelength band including the absorption spectrum of the generated fly ash and an absorption spectrum different from that of KCl is irradiated from a light source unit equipped with a light emitting diode, respectively, toward the combustion gas in which the biomass fuel is burned, The irradiated light emitted from the light source unit is received by the light receiving unit, respectively, _{and based on the transmitted light intensity I 1} and the transmitted light intensity I ₂ of the irradiated light received by each of these light receiving units, the absorbance and transmittance of KCl are calculated, and based on the values, the The concentration can be calculated by the calculator. As described above, in the present embodiment, by using a light emitting diode for a plurality of light source units, the light source has a long lifespan, and it is possible to measure the concentration of substances in a mixture containing two or more substances having the same absorption wavelength. A device and a method for preventing corrosion may be provided. Moreover, since the light emitting diode is excellent in the stability of the light source intensity, the absorbance, transmittance, and concentration of KCl can be more accurately calculated.

Moreover, in this embodiment, the supply amount of a sulfur component is controlled based on the density|concentration of KCl calculated by the calculation part 52, and a sulfur component is supplied to combustion gas. For this reason, since an appropriate amount of sulfur component can be supplied with respect to the amount of KCl present in the combustion gas, the concentration of KCl can be effectively reduced, and corrosion in each device in the combustion facility 100 caused by KCl can be effectively suppressed. .

However, also in this embodiment, the absorbance and/or transmittance of KCl and fly ash were calculated, and the aspect of calculating the concentration of KCl from the value was described, but the present invention is not limited to the aspect, and the KCl An aspect in which only the absorbance and/or transmittance of KCl is calculated in the calculation unit 52 without calculating the concentration, and the subsequent steps are performed based on the values may be employed.

(Other aspects)

In the second embodiment, the aspect using the measurement unit 140 provided with the external measurement unit 142 has been described, but as the measurement unit, the measurement unit 160 having a structure as shown in FIG. 5 may be used. . Fig. 5 is a schematic diagram showing another aspect of the measurement unit in the second embodiment.

As shown in FIG. 5 , the measurement unit 160 includes a main tube 141 through which the combustion gas supplied from the cyclone 130 circulates, and a light emitter 162 and a spectrometer 164 are installed in the main tube 141 . has been In the main building 141, combustion gas flows from the left side toward the right side of the paper. In addition, in the pipe of the main pipe 141, the flow path of the combustion gas is narrowed by the light emitter 162 and the spectrometer 164. As shown in FIG. By narrowing the distance between the light emitter 162 and the spectrometer 164 in this way, the optical path length (the distance between the light emitter 144 and the spectrometer 146 ) in the measurement unit 160 can be shortened with a simple configuration. In this way, by appropriately adjusting the optical path length in the measurement unit 160 to a length suitable for the type and concentration of the gas in the boiler to be measured, the measurement accuracy of the concentration of each component in the combustion gas can be increased.

Further, in each of the above-described embodiments, the first and second light source units were used to supply the corrosion inhibitor based on the concentration of the first measurement target calculated by the calculation unit, but the present invention is not limited to these aspects. It is not limited, For example, it is also possible to use 3 types of light source parts. For example, in addition to the first and second light sources, etc., irradiation light in an absorption wavelength band including an absorption spectrum of the third measurement object generated from the corrosion inhibitor and different from the absorption spectrum of the first and second measurement objects A third light source unit having a light emitting diode for emitting light and a third light receiving unit for receiving irradiation light emitted from the third light source unit may be further installed. In such an aspect, the calculation unit calculates the absorbance and transmittance of the third measurement target in the combustion gas based on the _{transmitted light intensity I 3 of} the irradiated light received by the third light receiving unit _{and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit. and calculates the concentration based on the value, and the supply amount control unit calculates the absorbance or transmittance of the first and third measurement objects calculated by the calculation unit, or the corrosion based on the concentration calculated based on the value. It can be configured to control the feed amount of the inhibitor.

As such an example, for example, using biomass fuel as a combustion object, the first measurement object is KCl, the second measurement object is fly ash, and the third measurement object is SO ₂ generated from a sulfur component, and the first In the light source unit, a light emitting diode having a wavelength of about 250 nm corresponding to the absorption spectrum of KCl is used, and in the second light source unit, a light emitting diode having a wavelength of about 400 nm is used, and in the third light source unit, an absorption spectrum of _{SO 2} An embodiment using a light emitting diode having a wavelength of about 290 nm corresponding to . _{According to this aspect, the absorbance and transmittance of SO 2} generated from the sulfur component supplied as a corrosion inhibitor can be calculated, and the concentration can be calculated based on the values, so based on the concentration of SO ₂ in the supply amount control unit When it is determined that the sulfur component is excessively supplied, the supply amount of the sulfur component is reduced to provide a more appropriate amount of the corrosion inhibitor.

The embodiments described through the embodiments of the invention described above can be used in appropriate combinations or by adding changes or improvements depending on the use. In addition, this invention is not limited to description of embodiment mentioned above.

10, 100… combustion equipment
20, 120… combustion furnace
22… Combustion object feeder
30, 140… measuring unit
31, 148… Corrosion inhibitor supply device
32, 144, 162… emitter
32A, 32B... light source
34, 146, 164... spectrometer
34A, 34B... light receiver
37… beam splitter
38… photodiode
40, 150… superheater
50… control unit
52… output unit
54… supply control unit
122… fuel supply
130… cyclone
141… Main building
142… external measurement

Claims (7)

A first light source unit having a light emitting diode that emits irradiated light in an absorption wavelength band including an absorption spectrum of a first measurement target generated by combustion of a combustion target;
A second light source unit having a light emitting diode emitting light of an absorption wavelength band that is an absorption spectrum of a second measurement target generated by combustion of the combustion target and includes an absorption spectrum different from the absorption spectrum of the first measurement target; ,
a first light receiving unit for receiving the irradiated light emitted from the first light source unit;
a second light receiving unit for receiving the irradiated light emitted from the second light source unit;
_{Based on the transmitted light intensity I 1 of} the irradiated light received by the first light receiving unit _{and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or Corrosion prevention device having a calculator for calculating the transmittance. According to claim 1,
Corrosion prevention device having a corrosion inhibitor supply unit for supplying a corrosion inhibitor reacting with the first measurement target to the combustion gas, and a supply quantity control unit for controlling the supply amount of the corrosion inhibitor supplied from the corrosion inhibitor supply unit. 3. The method of claim 2,
The supply amount control unit, a corrosion preventing device for controlling the supply amount of the corrosion inhibitor based on the absorbance and / or transmittance of the first measurement target calculated by the calculator. 3. The method of claim 2,
A third light source unit having a light emitting diode that emits irradiated light in an absorption wavelength band that is an absorption spectrum of the third measurement target generated from the corrosion inhibitor and includes an absorption spectrum different from the absorption spectrum of the first and second measurement targets; , Further comprising a third light receiving unit for receiving the irradiation light emitted from the third light source unit,
The calculation unit, based on the transmitted light intensity I _{3 of the irradiated light received by the third light receiving unit and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or transmittance of the third measurement target in the combustion gas to calculate,
The supply amount control unit, a corrosion preventing device for controlling the supply amount of the corrosion inhibitor based on the absorbance and / or transmittance of the first and third measurement objects calculated by the calculator. The irradiated light in the absorption wavelength band including the absorption spectrum of the first measurement target generated by the combustion of the combustion target, and the absorption spectrum of the second measurement target generated by the combustion of the combustion target, and the absorption spectrum of the first measurement target Irradiated light of an absorption wavelength band including an absorption spectrum different from that is irradiated from a first light source unit or a second light source unit each having a light emitting diode toward the combustion gas that has combusted the combustion target,
The irradiated light emitted from the first light source unit and the irradiated light emitted from the second light source unit are received by a first light receiving unit or a second light receiving unit, respectively,
_{Based on the transmitted light intensity I 1 of} the irradiated light received by the first light receiving unit _{and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or transmittance of the first measurement target is calculated by a calculator, Corrosion prevention method. 6. The method of claim 5,
Controlling the supply amount of the corrosion inhibitor reacting with the first measurement object based on the absorbance and/or transmittance of the first measurement object calculated by the calculator, and supplying the corrosion inhibitor to the combustion gas, corrosion prevention Way. 7. The method of claim 6,
A light emitting diode is provided for irradiated light of an absorption wavelength band that is an absorption spectrum of the third measurement target generated from the corrosion inhibitor and includes an absorption spectrum different from the absorption spectrum of the first and second measurement targets, toward the combustion gas. Further emitted from a third light source,
receiving the irradiated light emitted from the third light source unit to a third light receiving unit;
_{Based on the transmitted light intensity I 3 of} the irradiated light received by the third light receiving unit _{and the transmitted light intensity I 2} of the irradiated light received by the second light receiving unit, the absorbance and/or transmittance of the third measurement target is calculated by the calculation unit,
Controlling the supply amount of the corrosion inhibitor reacting with the first measurement object based on the absorbance and/or transmittance of the first and third measurement objects calculated by the calculator, and supplying the corrosion inhibitor to the combustion gas Corrosion prevention method.

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