JP6307409B2 - Gas component measuring device - Google Patents

Description

  The present invention relates to a gas component measuring device, for example, a gas component measuring device suitably used for analyzing combustion exhaust gas of a boiler device.

  Conventionally, there has been proposed a laser type gas analyzer that uses ammonia gas injected as a reducing agent for denitration into exhaust gas from an electric power facility or the like (for example, see Patent Document 1). The gas analyzer includes a light emitting unit provided with a collimating lens and a light receiving unit provided with a condensing lens. In this gas analyzer, it is included in the measurement target gas attached to the surface of the collimating lens of the light emitting unit and the surface of the condensing lens of the light receiving unit by flowing instrument air as a barge gas from the light emitting unit side and the light receiving unit side The lens surface is kept clean by blowing away the dust.

JP 2014-102152 A

  However, in the laser-type gas analysis described in Patent Document 1, a purge gas is used at a constant flow rate (for example, 1 m / s) from each of the light emitting part side and the light receiving part side of the laser light for cleaning the lens surface. Therefore, it may be difficult to secure a utility for instrumentation air due to cost and equipment limitations.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a gas component measuring apparatus capable of reducing purge gas and facilitating securing of utility of instrument air.

  A gas component measuring apparatus according to the present invention is disposed in a laser light emitting unit that emits laser light for analyzing a gas to be measured, a laser light receiving unit that detects light intensity of the laser light, and a flow path of the gas to be measured. A light transmission side light transmitting member that transmits laser light emitted from the laser light emitting unit toward a measurement region provided in the flow path, and a light transmission light transmitting member disposed in the flow path of the gas to be measured. A light-receiving-side light-transmitting member that transmits the laser light transmitted from the side light-transmitting member through the measurement region toward the laser light-receiving unit, the light-transmitting-side light-transmitting member, and the light-receiving-side light-transmitting member And a translucent plate that prevents the gas under measurement from entering the light transmitting side light transmitting member and the light receiving side light transmitting member.

  According to this gas component measuring apparatus, dusts in the combustion exhaust gas into the light transmitting side light transmitting member and the light receiving side light transmitting member are transmitted by the light transmitting plates provided on the light transmitting side light transmitting member and the light receiving side light transmitting member. Intrusion can be prevented. As a result, the gas component measuring device can reduce the supply amount of purge gas from the light transmitting side light transmitting member and the light receiving side light transmitting member toward the measurement region, so that it is easy to ensure the utility of instrument air. It is possible to realize a gas component measuring apparatus that can do this.

  In the gas component measuring apparatus of the present invention, the light transmitting plate is preferably sapphire glass or quartz. This configuration makes it difficult for soot and dust in the combustion gas to adhere to the translucent plate, thus further reducing the amount of purge gas supplied from the inside of the light transmitting side light transmitting member and from the inside of the light receiving side light transmitting member to the measurement region. It becomes possible to do.

  In the gas component measuring apparatus of the present invention, it is preferable that a vent hole is provided between the light transmitting plate, the light transmitting side light transmitting member, and the light receiving side light transmitting member. With this configuration, the purge gas is supplied from the inside of the light transmitting side light transmitting member and the inside of the light receiving side light transmitting member to the measurement region via the vent hole, so that the supply amount of the purge gas can be reduced.

  In the gas component measuring apparatus of the present invention, the gas flowing in the light transmitting side light transmitting member and in the light receiving side light transmitting member on the inner wall of at least one of the light transmitting side light transmitting member and the light receiving side light transmitting member. It is preferable that a rectifying member that guides the light toward the surface of the translucent plate is provided. With this configuration, the purge gas supplied from the light transmitting side light transmitting member and the light receiving side light transmitting member can flow along the surface of the light transmitting plate. It becomes possible to prevent dust from adhering.

  In the gas component measuring apparatus of the present invention, it is preferable that the surface of the translucent plate is antistatic processed. With this configuration, it is possible to prevent adhesion of dust in the flue gas to the surface of the light transmissive plate due to charging of dust, so that it is possible to prevent dust from adhering to the surface of the light transmissive plate even more efficiently.

  In the gas component measuring apparatus of the present invention, it is preferable that the translucent plate has a hydrophobic surface. With this configuration, it is possible to prevent soot from adhering to the surface of the translucent plate via moisture in the combustion exhaust gas, and thus it becomes possible to more effectively prevent soot from adhering to the surface of the translucent plate. .

  In the gas component measuring apparatus of the present invention, it is preferable that a dust collecting electrode for corona discharge is further provided on the surface of the light transmitting plate. With this configuration, ions can be generated by the electrons emitted from the dust collecting electrode to neutralize the static electricity on the surface of the translucent plate, thereby preventing dust from adhering to the surface of the translucent plate more efficiently. It becomes possible.

  In the gas component measuring apparatus of the present invention, it is preferable that the dust collecting electrode is provided on the measurement region side in the light transmitting side light transmitting member and the light receiving side light transmitting member. With this configuration, the dust adhering to the translucent plate can be peeled and dropped by its own weight.

  In the gas component measuring apparatus of the present invention, it is preferable that the surface of the translucent plate is provided with an ultraviolet light irradiation unit that irradiates ultraviolet light, and a photocatalyst layer is provided on the surface of the translucent plate. With this configuration, it is possible to decompose and remove dust contained in the combustion exhaust gas attached to the surface of the light-transmitting plate by an oxidation-reduction reaction via the photocatalyst.

  In the gas component measuring apparatus of the present invention, a control unit that switches between irradiation of ultraviolet light to the light transmitting plate by the ultraviolet light irradiation unit and irradiation of the laser light from the laser light emitting unit to the light transmitting plate. It is preferable to have provided. With this configuration, interference between the laser light and the ultraviolet light can be prevented, so that it is possible to efficiently achieve both the analysis of the gas component and the removal of the dust adhering to the light transmitting plate.

  In the gas component measuring apparatus of the present invention, an exhaust section that exhausts the gas to be measured in the measurement region and makes the measurement region have a negative pressure, the light transmission side light transmission member, and the light reception side light transmission It is preferable that an outside air supply line for supplying outside air is provided in the member. With this configuration, outside air can be supplied into the light transmitting side light transmitting member and the light receiving side light transmitting member to prevent the combustion exhaust gas from entering the light transmitting side light transmitting member and the light receiving side light transmitting member. Therefore, it becomes possible to reduce the supply amount of purge gas.

  In the gas component measuring device of the present invention, it is preferable that a filter for removing moisture and dust contained in the outside air is provided. With this configuration, dust, mist, salt, and the like contained in the outside air can be removed, so that the inside of the light transmitting side light transmitting member and the inside of the light receiving side light transmitting member can be kept clean.

  A gas component measuring apparatus according to the present invention is disposed in a laser light emitting unit that emits laser light for analyzing a gas to be measured, a laser light receiving unit that detects light intensity of the laser light, and a flow path of the gas to be measured. A light transmission side light transmitting member that transmits laser light emitted from the laser light emitting unit toward a measurement region provided in the flow path, and a light transmission light transmitting member disposed in the flow path of the gas to be measured. A light-receiving side light-transmitting member that transmits the laser light transmitted from the side light-transmitting member through the measurement region toward the laser light-receiving unit; and exhausting the gas to be measured in the measurement region and It is characterized by comprising an exhaust section for making negative pressure in the measurement region, and an outside air supply line for supplying outside air into the light transmitting side light transmitting member and the light receiving side light transmitting member.

  According to this gas component measuring device, the inflow of combustion exhaust gas into the light transmitting side light transmitting member and the light receiving side light transmitting member by supplying outside air into the light transmitting side light transmitting member and the light receiving side light transmitting member. Can be prevented. As a result, the gas component measuring device can reduce the supply amount of purge gas from the light transmitting side light transmitting member and the light receiving side light transmitting member toward the measurement region, so that it is easy to ensure the utility of instrument air. It is possible to realize a gas component measuring apparatus that can do this.

  In the gas component measuring device of the present invention, it is preferable that a filter for removing moisture and dust contained in the outside air is provided. With this configuration, dust, mist, salt, and the like contained in the outside air can be removed, so that the inside of the light transmitting side light transmitting member and the inside of the light receiving side light transmitting member can be kept clean.

  ADVANTAGE OF THE INVENTION According to this invention, purge gas can be reduced and the gas component measuring apparatus which can make the utility ensuring of instrumentation air easy can be implement | achieved.

FIG. 1 is a schematic diagram of a boiler apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of the gas component measuring apparatus according to the first embodiment of the present invention. FIG. 3 is a schematic perspective view of the probe of the gas component measuring apparatus according to the first embodiment of the present invention. FIG. 4 is a conceptual diagram of the measurement principle in the gas component measurement device according to the first embodiment of the present invention. FIG. 5 shows an example of the relationship between the transmitted light intensity and the wavelength of transmitted light in the absorption spectroscopic measurement in the gas component measuring apparatus according to the first embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of the light transmission tube of the gas component measurement device according to the first embodiment of the present invention. FIG. 7A is a cross-sectional view taken along line AA in FIG. 7B is a cross-sectional view taken along line B-B in FIG. 6. FIG. 8A is a partially enlarged view of a tip portion of a light transmission side light transmission tube. FIG. 8B is a partially enlarged view of the distal end portion of the light receiving side light transmitting tube. FIG. 9 is a schematic cross-sectional view showing another example of the light transmission tube of the gas component measurement device according to the first embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of the light transmission tube of the gas component measurement device according to the second embodiment of the present invention. FIG. 11A is a partially enlarged view of the distal end portion of the light transmission side light transmission tube according to the third embodiment of the present invention. FIG. 11B is a partially enlarged view of the distal end portion of the light receiving side light transmitting tube according to the third embodiment of the present invention. FIG. 12 is a schematic cross-sectional view of a light transmission tube of a gas component measurement device according to a fourth embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, it is not limited to each following embodiment, It can implement by changing suitably. Also, the following embodiments can be implemented in combination as appropriate. Moreover, the same code | symbol is attached | subjected to the component which is common in each embodiment, and duplication of description is avoided.

(First embodiment)
FIG. 1 is a schematic diagram of a boiler apparatus 1 according to a first embodiment of the present invention. As shown in FIG. 1, the boiler apparatus 1 according to the present embodiment supplies ammonia (NH ₃ ) as a reducing agent to the combustion exhaust gas G ₁ from the boiler 11 to desulfurize nitrogen oxides (NOx). A device for discharging from the chimney 12. The boiler device 1 includes an ammonia injection device 14 provided at the rear stage of the boiler 11 in the gas flow direction of the flue 13 through which the combustion exhaust gas G ₁ from the boiler 11 flows, and a denitration provided at the rear stage of the ammonia injection device 14. A device 15, a gas component measuring device 2 provided at the subsequent stage of the denitration device 15, and an air preheater 16 provided at the subsequent stage of the gas component measuring device 2 are provided. The air preheater 16 is provided with a suction ventilator (IDF: Induced Draft Fan) at the outlet portion. Thus, the air preheater 16, so that the exhaust flue gases G ₁ of the flue 13 toward the chimney 12 disposed downstream, the flue 13 has a negative pressure.

The ammonia injection device 14 supplies a reducing agent such as ammonia (NH ₃ ) into the combustion exhaust gas G ₁ . The denitration device 15 includes a partitioned denitration catalyst 151 installed in the flue 13. The through denitration catalyst 151 nitrogen oxides in the combustion exhaust gas G ₁ by the supplied reducing agent to the combustion exhaust gas G ₁ (NOx) is reduced flue gas G ₁ is the denitrification.

The gas component measuring device 2 includes a plurality of light transmission tubes (light transmission members) 21 arranged at the subsequent stage of the denitration catalyst 151. The gas component measuring device 2 measures the gas component (NH ₃ , NOx) concentration distribution in the combustion exhaust gas G ₁ by irradiating the combustion exhaust gas G ₁ with laser light via the light transmission cylinder 21. The measurement result of the gas component concentration distribution by the gas component measuring device 2 is transmitted to the control device 20. The control device 20 is, for example, a computer, a CPU, a ROM (Read Only Memory) for storing a program executed by the CPU, a RAM (Random Access Memory) functioning as a work area when executing each program, a large capacity It includes a hard disk drive (HDD) as a storage device, a communication interface for connecting to a communication network, and an access unit to which an external storage device is mounted. These units are connected via a bus. Furthermore, the control device 20 may be connected to an input unit such as a keyboard and a mouse and a display unit including a liquid crystal display device that displays data. The control device 20 controls the ammonia injection amount from the ammonia injection device 14 based on the measurement result of the gas component concentration distribution.

FIG. 2 is a schematic diagram of the gas component measuring apparatus 2. In FIG. 2 shows a section orthogonal to the flow direction the combustion exhaust gas G ₁ in the flue 13. As shown in FIG. 2, the gas component measuring device 2 is provided outside the flue 13, and is provided outside the flue 13, and a laser light emitting unit 22 that sends the laser light L into the light sending tube 21. And a laser light receiving unit 23 that receives the laser light L transmitted from the laser light emitting unit 22 to the light transmission tube 21. When measuring the ammonia (NH ₃ ) concentration in the combustion exhaust gas G ₁ , the laser emission unit 22 irradiates a semiconductor laser (semiconductor element: InGaAs, wavelength: 1.5 μm, output: about 1 mW) as laser light L. To do. The laser light L emitted from the laser light emitting unit 22 is sequentially reflected by a light transmission reflection unit 241 provided in a light transmission unit 24 that transmits the laser light L into the light transmission cylinder 21, so that nine light transmissions are performed. Light is transmitted into the tube 21. The laser light L transmitted into the light transmission tube 21 is sequentially reflected by the light receiving / reflecting unit 251 in the light receiving unit 25 that receives the laser light L transmitted from the light transmitting tube 21 toward the laser light receiving unit 23. Is transmitted. A purge gas G ₂ is supplied into the light transmitting unit 24 and the light receiving unit 25. By supplying the purge gas G ₂ , it is possible to prevent the combustion exhaust gas G ₁ from entering the light transmission cylinder 21.

The gas component measurement device 2 includes three probes 21A to 21C arranged in parallel in the flue 13 divided into _nine sections P _{1 to} P ₉ . Each of the three probes 21A to 21C includes three light transmission tubes 21. In this embodiment, the probe 21A is located in a compartment _P 1 to P _3, the probe 21B is arranged in a compartment _P 4 to P _6, probe 21C is disposed in a compartment _P 7 to P _9. The light transmission tube 21 is divided into a light transmission side light transmission tube (light transmission side light transmission member) 211 and a light reception side light transmission tube (light reception side light transmission member) 212 in the flue 13, respectively. The section becomes the measurement region Z. Three light-sending tube 21 of the probe 21A is a gas component of the combustion exhaust gas _{G 1} of the measurement region Z in the compartment _P 1 to P ₃ each analyzed, three light-sending tube 21 of the probe 21B is partitioned _P 4 ~ the gas components of the combustion exhaust gas _{G 1} of the measurement region Z of P ₆ and analyzed respectively, the three light-sending tube 21 of the probe 21C, respectively gaseous components of the combustion exhaust gas _{G 1} of the measurement region Z of the partition _P 7 to P ₉ analyse. In FIG. 2, although there are nine sections, this is not restrictive, and the measurement region Z is set flexibly depending on the exhaust gas properties such as the size, shape, and dust concentration of the duct.

  FIG. 3 is a schematic perspective view of the probe 21A of the gas component measuring device. In FIG. 3, the light transmitting unit 24 and the light receiving unit 25 are omitted. The probe 21B and the probe 21C have the same configuration.

As shown in FIG. 3, the probe 21 </ b> A includes a hollow light transmission tube 21 through which the laser light L passes. The light transmission cylinder 21 is divided into a light transmission side light transmission cylinder 211 and a light reception side light transmission cylinder 212 through the measurement region Z in the flue 13. The laser light L transmitted to the light transmission tube 21 is transmitted from the light transmission side light transmission tube 211 to the light reception side light transmission tube 212 through the measurement region Z. At this time, since the laser light L is transmitted through the measurement region Z through which the combustion exhaust gas G ₁ flows, components such as ammonia in the combustion exhaust gas G ₁ can be measured by the laser light L. This measurement region Z is, for example, a 1 m section where the laser optical path length is 1 m.

Next, the principle of concentration distribution measurement according to this embodiment will be described. FIG. 4 is a conceptual diagram of the measurement principle in the gas component measurement device according to the present embodiment. In the gas component measuring apparatus according to the present embodiment, by spectroscopic analysis using the Lambert-Beer law, which is a relational expression showing the relationship between the light intensity of the laser beam and the concentration of the substance to be measured. , measuring the concentration of such as ammonia as the measurement substance in the combustion exhaust gas G _1. FIG. 5 shows an example of the relationship between the transmitted light intensity and the wavelength of transmitted light in absorption spectroscopy measurement in the gas component measuring apparatus according to the present embodiment.

In the Lambert-Beer law, as shown in FIG. 4, the measurement region Z of the path of the laser light L between the light transmission point P1 on the light transmission unit 24 side and the light reception point P2 on the light reception unit 25 side, and the laser light The relationship of the following formula (1) is established between the irradiation intensity I ₀ of the laser beam, the received light intensity I (L) of the laser beam, and the measurement target (ammonia) concentration C ₀ existing in the distance X.
I (L) = I ₀ exp (−kC ₀ X) (1)
(In formula (1), k is a proportionality coefficient set according to the absorbance of the substance to be measured.)

Further, when the concentration average value C ₁ in the measurement region Z for measuring the concentration of the measurement target substance and the laser path distance X ₁ in the measurement region Z, the above equation (1) is expressed as the following equation (2). be able to. Here, when the laser beam is irradiated for each preset laser path, the laser path distance X ₁ in the measurement region Z, the laser beam irradiation intensity I _0, and the laser beam reception intensity I (L) are known. since, by using the above equation (2) can be calculated the density average value C ₁ of the measuring object in the measurement region.
I (L) = I ₀ exp (−kC ₁ X ₁ ) (2)

Next, the configuration of the light transmission tube 21 of the gas component measurement device 2 according to the present embodiment will be described in detail. FIG. 6 is a schematic cross-sectional view of the light transmission tube 21 of the gas component measurement device 2 according to the present embodiment. As shown in FIG. 6, the light transmission side light transmission tube 211 generally has a cylindrical shape with one end pointed like a bamboo basket, and one end side sharpened like a bamboo basket is inside the flue 13 where the measurement region Z is formed. Placed. Also, sending-side light-sending tube 211, the upper end 211a of the upstream side in the gas flow direction of the combustion exhaust gas G ₁ is arranged to cover the lower end side. This By arranging so, can be prevented from entering into the combustion exhaust gas G ₁ feeding of dust contained in the light side sending cylinder 211.

  The other end side of the light transmission side light transmission cylinder 211 is fixed to the wall surface of the flue 13 via the flange 31. A laser beam window 32 having a substantially cylindrical shape is connected to the flange 31. Inside the laser beam window 32, a sealing optical glass 33 is disposed to block gas in and out between the inside and outside of the laser beam window 32. The light receiving surface of the sealing optical glass 33 may be formed obliquely rather than perpendicular to the optical path of the laser beam in order to prevent reflection of the laser beam.

The laser beam window 32 is provided with a pair of vent holes 34 with a sealing optical glass 33 interposed therebetween. By blowing from the pair of vent holes 34 into the purge gas G ₂ is sending-side sending tube 211, can prevent adhesion of materials such as dust in the combustion exhaust gas G in ₁ to sealing optical glass 33. In addition, by purge gas G ₂ to the light-sending side sending cylinder 211 is filled, it is possible to prevent the inflow of the combustion exhaust gas G ₁ to the sending-side sending cylinder 211 from the measurement region Z. The vent hole 34 is not necessarily provided with the optical glass 33 for sealing interposed therebetween, and may be provided on the measurement region Z side with respect to the optical glass 33 for sealing.

At one end of the sending-side sending tube 211, the transparent plate 26 to prevent the intrusion combustion exhaust gas G ₁ to the interior light side sending tube 211 feeding from the measurement region Z is placed. Transparent plate 26, with a light-transmitting transmits the laser beam L, not particularly limited as long as it is a member having a resistance to the combustion exhaust gas G _1, and various glass member can be used. Among these glass member, from the standpoint of preventing scratches and adhesion of dust in the combustion exhaust gas G ₁ to the surface, it is preferable to use a sapphire glass or quartz, it is more preferable to use a sapphire glass.

The translucent plate 26 is fixed in the light transmission side light transmission tube 211 via the support member 27. At one end of the measurement region Z side of the support member 27, the rectifying member for flowing a purge gas G ₂ flows toward the measurement region Z side from the sending-side sending tube within 211 guided toward the surface of the transparent plate 26 28 is provided.

The light-receiving side light-receiving tube 212 has a cylindrical shape with one end generally pointed in a bamboo basket shape, and one end side sharpened in a bamboo basket shape is arranged toward the flue 13 serving as the measurement region Z. The light-receiving side light-sending tube 212 has an upper end 212b side is disposed so as to cover the lower side is the upstream side in the gas flow direction of the combustion exhaust gas G _1. With this arrangement, it is possible to prevent from entering the light-receiving side light-sending tube 212 of the dust contained in the combustion exhaust gas G _1.

  The other end of the light-receiving side light transmission tube 212 is fixed to the wall surface of the flue 13 via the flange 31. A laser beam window 32 having a substantially cylindrical shape is connected to the flange 31. Inside the laser beam window 32, a sealing optical glass 33 is disposed to block gas in and out between the inside and outside of the laser beam window 32. The light receiving surface of the sealing optical glass 33 may be formed obliquely rather than perpendicular to the optical path of the laser beam in order to prevent reflection of the laser beam.

The laser beam window 32 is provided with a pair of vent holes 34 with a sealing optical glass 33 interposed therebetween. By blowing from the pair of vent holes 34 into the purge gas G ₂ is the light-receiving side light-sending pipe 212, thereby preventing the adhesion of materials such as dust in the combustion exhaust gas G in ₁ to sealing optical glass 33. Further, the purge gas G ₂ is filled in the light receiving side light transmitting cylinder 212, so that the inflow of the combustion exhaust gas G ₁ from the measurement region Z into the light receiving side light transmitting cylinder 212 can be prevented. The vent hole 34 is not necessarily provided with the optical glass 33 for sealing interposed therebetween, and may be provided on the measurement region Z side with respect to the optical glass 33 for sealing.

At one end of the light-receiving side light-sending pipe 212, the transparent plate 26 is disposed to prevent the intrusion combustion exhaust gas G ₁ to the internal light-receiving side light-sending pipe 212 from the measurement region Z. Transparent plate 26, with a light-transmitting transmits the laser beam L, not particularly limited as long as it is a member having a resistance to the combustion exhaust gas G _1, and various glass member can be used. Among these glass member, from the viewpoint of preventing adhesion of dust scratches and combustion gas G in ₁ to the surface, it is preferable to use a sapphire glass.

The light transmitting plate 26 is fixed in the light receiving side light transmitting tube 212 via the support member 27. At one end of the support member 27 on the measurement region Z side, a rectifying member 28 is provided for flowing the purge gas G ₂ flowing from the light receiving side light transmission tube 212 toward the measurement region Z side toward the surface of the light transmitting plate 26. It has been.

7A is a cross-sectional view taken along line AA in FIG. 6, and FIG. 7B is a cross-sectional view taken along line BB in FIG. 6. As shown in FIGS. 7A and 7B, the translucent plate 26 disposed in the light transmitting side light transmitting tube 211 and the light receiving side light transmitting tube 212 has a substantially circular shape in a plan view and has a diameter. It is smaller than the inner diameters of the light transmission side light transmission cylinder 211 and the light reception side light transmission cylinder 212. The translucent plate 26 is fixed in the light transmitting side light transmitting tube 211 and the light receiving side light transmitting tube 212 by a support member 27 at two positions on the outer edges of the orthogonal straight lines passing through the center of each other, for a total of four positions. Has been. Thus, a predetermined space (slit) S is provided between the outer edge portion of the light transmitting plate 26 and the inner walls of the light transmission side light transmission tube 211 and the light reception side light transmission tube 212. This space S becomes a vent hole for the purge gas G ₂ from the light transmission side light transmission cylinder 211 and the light reception side light transmission cylinder 212.

8A is a partially enlarged view of the distal end portion of the light transmitting side light transmitting cylinder 211, and FIG. 8B is a partially enlarged view of the distal end portion of the light receiving side light transmitting cylinder 212. As shown in FIGS. 8A and 8B, a predetermined distance D is provided between the front end portions of the light transmitting side light transmitting tube 211 and the light receiving side light transmitting tube 212 and the surface of the translucent plate 26 on the measurement region Z side. The rectifying member 28 is arranged. By disposing such a rectifying member 28, purge gas G ₂ which is supplied from the sending side sending tube 211 and the light receiving side sending tube inside 212, the transparent plate 26 and the sending-side light-sending tube 211 and the light The light passes through the translucent plate 26 via the space S between the side light transmission tube 212 and flows along the surface of the translucent plate 26 by the rectifying member 28. Thereby, even if the dust in the combustion exhaust gas G ₁ adheres to the surface of the translucent plate 26 on the measurement region Z side, the translucent plate 26 is caused by the purge gas G ₂ flowing along the surface of the translucent plate 26. Can keep the surface clean.

As described above, according to the gas component measuring apparatus 2 according to the present embodiment, the light transmission side light transmission tube 211 is provided by the light transmitting plate 26 provided on the light transmission side light transmission tube 211 and the light reception side light transmission tube 212. it is possible to prevent the inner and dust from entering in the combustion exhaust gas G ₁ to the light receiving side light-sending tube 212. Thus, the gas component measuring apparatus 2, it is possible to reduce the supply amount of the purge gas G ₂ toward the measurement region Z from the sending-side light-sending tube 211 and the light receiving side sending tube within 212, instrument air It is possible to realize the gas component measuring apparatus 2 that can easily secure the utility.

In the above-described embodiment, the example in which the light transmission side light transmission tube 211 and the light reception side light transmission tube 212 of the light transmission tube 21 are provided apart from each other has been described. However, the configuration of the light transmission tube 21 is as follows. The configuration is not limited to this. As shown in FIG. 9, the light transmission tube 21 may be arranged such that the upper end 211 a on one end side of the light transmission side light transmission tube 211 and the upper end 212 b of the light reception side light transmission tube 212 are in contact with each other. With this arrangement, it is possible by the upper end 212b of the upper end 211a and the light receiving side light-sending pipe 212 of the sending-side sending tube 211 covers the downstream side of the gas flow direction the combustion exhaust gas G _1, feeding more it is possible to prevent dust from entering in the combustion exhaust gas G ₁ to the light side sending cylinder and the receiving side sending barrel 212 211. Further, the configuration of the light transmission cylinder 21 is measured by providing a light transmission side light transmission cylinder 211 and a light reception side light transmission cylinder 212 as a single unit, and cutting out the lower side of the desired part of the light transmission cylinder 21 in the gas flow direction. It is good also as a structure which provided the area | region Z.

  In the above-described embodiment, an example in which the light transmission tube 21, the light transmission side light transmission tube 211, and the light reception side light transmission tube 212 are cylindrical members has been described. The light tube 211 and the light-receiving side light-transmitting tube 212 are not limited to cylindrical members, and the shapes can be appropriately changed as long as the laser light L can be transmitted.

  Further, in the above-described embodiment, the surface of the translucent plate 26 may be subjected to antistatic processing. Thereby, since the electric charge of the dust adhering to the surface of the light transmission board 26 can be removed, the adhesion of the dust to the surface of the light transmission board 26 can be prevented further. Moreover, the surface of the translucent plate 26 may be subjected to hydrophobic processing. Thereby, it is possible to prevent dust from adhering to the translucent plate 26 through moisture.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following, differences from the first embodiment described above will be mainly described to avoid duplication of description.

  FIG. 10 is a schematic cross-sectional view of the light transmission tube 21 of the gas component measurement device 2 according to the second embodiment of the present invention. The gas component measurement device 2 according to the present embodiment is provided in the light transmission side light transmission tube 211 and the light reception side light transmission tube 212 in addition to the configuration of the gas component measurement device 2 according to the first embodiment described above. The dust collecting electrode 29 is provided. The dust collection electrode 29 generates corona discharge on the surface of the translucent plate 26 and peels and drops the dust attached to the surface of the translucent plate 26. The other configuration is the same as that of the light transmission tube 21 shown in FIG.

  In the present embodiment, the dust collecting electrode 29 is provided on the inner wall side of the upper ends 211 a and 212 b at the distal end portions of the light transmitting side light transmitting tube 211 and the light receiving side light transmitting tube 212. By arranging in this way, the dust that has been charged by corona discharge from the upstream side in the gas flow direction with respect to the translucent plate 26 can be efficiently collected, so that the dust that has adhered to the surface of the translucent plate 26 can be efficiently collected. It is possible to peel and drop well. Since other configurations are the same as those of the gas component measuring apparatus 1 according to the first embodiment described above, description thereof is omitted.

  The dust collecting electrode 29 does not need to be provided on the inner walls of the upper ends 211 a and 212 b at the distal end portions of the light transmitting side light transmitting tube 211 and the light receiving side light transmitting tube 212. The light transmission side light transmission tube 211 and the light reception side light transmission tube 212 may be disposed.

  As described above, according to the present embodiment, ions can be generated by the electrons emitted from the dust collecting electrode 29 to neutralize the static electricity on the surface of the translucent plate 26, so that the translucent light can be more efficiently transmitted. It is possible to prevent dust from adhering to the surface of the plate 26.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the following, differences from the first embodiment described above will be mainly described to avoid duplication of description.

  FIG. 11A is a partially enlarged view of the distal end portion of the light transmission side light transmission tube 211 according to the third embodiment of the present invention, and FIG. 11B is a light reception side transmission according to the third embodiment of the present invention. FIG. 4 is a partially enlarged view of a tip portion of a light tube 212. As shown in FIGS. 11A and 11B, the gas component measuring apparatus 2 according to the present embodiment includes a measurement region of the translucent plate 26 in addition to the configuration of the light transmission cylinder 21 according to the first embodiment described above. The photocatalyst layer 30 provided on the surface on the Z side, and the ultraviolet light irradiation unit 41 disposed at the upper ends 211a and 212b at the tip portions of the light transmission side light transmission tube 211 and the light reception side light transmission tube 212 are provided. The other configurations are the same as those of the light transmission side light transmission tube 211 and the light reception side light transmission tube 212 shown in FIGS.

The photocatalyst layer 30 contains a photocatalyst such as titanium oxide (TiO ₂ ). The ultraviolet light irradiation unit 41 irradiates the light transmitting plate 26 with ultraviolet light. The ultraviolet light irradiation unit 41 starts irradiation of ultraviolet rays toward the light transmitting plate 26 when the light emitting unit 24 is not emitting the laser light L for gas component analysis, and the light emitting unit 24 is used for gas component analysis. When the laser beam L is emitted, the irradiation of ultraviolet rays toward the light transmitting plate 26 is stopped. Thereby, it is possible to prevent the dust from adhering to the light transmitting plate 26 due to the oxidation-reduction reaction by the photocatalyst included in the photocatalyst layer 30, and even if the dust adheres to the light transmitting plate 26, Soot and dust such as adhering hydrocarbon components can be efficiently removed.

Thus, according to this embodiment, it is possible to the dust contained in the combustion exhaust gas G ₁ attached to the surface of the transparent plate 26, is removed by decomposition by an oxidation-reduction reaction through the photocatalytic .

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. In the following, differences from the first embodiment described above will be mainly described to avoid duplication of description.

FIG. 12 is a schematic cross-sectional view of the light transmission tube 21 of the gas component measurement device 2 according to the fourth embodiment of the present invention. As shown in FIG. 12, the gas component measuring apparatus 2 according to the present embodiment has an outside air supply line that supplies outside air G ₃ to the vent holes 34 of the light transmitting side light transmitting tube 211 and the light receiving side light transmitting tube 212. equipped with a L _1. The fresh air supply line L _1, the moisture contained in the outside air G ₃ flowing outside air supply line L _1, mist, salt, dust, a filter 42 for dust removal a dust flow rate of the outside air G ₃ flowing outside air supply line L ₁ And a flow rate adjusting valve V for adjusting. The filter 42 is not particularly limited as long as it can remove the dust in the outside air G _3, for example, it can be used as the HEPA filter. The other configuration is the same as that of the light transmission tube 21 shown in FIG.

In the boiler device 1, the denitration device 15 is configured such that the inside of the flue 13 has a negative pressure (for example, 0. 0 mm) by an intake draft fan (IDF) provided at an outlet of an air preheater 16 provided at a subsequent stage. 1 kPa to 0.2 kPa). Therefore, in this embodiment, by supplying air from the outside by connecting the fresh air supply line L ₁ to the ventilation hole 34, permeable by the outside air G ₃ to be introduced from the ventilation hole 34 without using the purge gas G ₂ It is possible to prevent dust from adhering to the light plate 26. Note that in this embodiment, ozone may be supplied in addition to the outside air. Further, the light transmitting plate 26 is not necessarily provided.

As described above, according to the present embodiment, the outside air G ₃ is supplied into the light transmission side light transmission tube 211 and the light reception side light transmission tube 212, and the light transmission side light transmission tube 211 and the light reception side light transmission tube are supplied. it is possible to prevent the intrusion combustion exhaust gas G ₁ into the 212, it is possible to reduce the supply amount of the purge gas G _2, even when securing instrumentation air itself is difficult to analyze the gas components It becomes possible.

DESCRIPTION OF SYMBOLS 1 Boiler apparatus 11 Boiler 12 Chimney 13 Chimney 14 Ammonia injection apparatus 15 Denitration apparatus 151 Denitration catalyst 16 Air preheater 2 Gas component measuring apparatus 20 Control apparatus 21 Light transmission cylinder (light transmission member)
21A, 21B, 21C Probe 211 Light transmission side light transmission tube (light transmission side light transmission member)
212 Light Receiving Side Light Transmitting Tube (Light Receiving Side Light Transmitting Member)
DESCRIPTION OF SYMBOLS 22 Laser light emission part 23 Laser light-receiving part 24 Light transmission unit 241 Light transmission reflection part 25 Light reception unit 251 Light reception reflection part 26 Light transmission board 27 Support member 28 Rectification member 29 Dust collection electrode 30 Photocatalyst layer 31 Flange 32 Laser beam window 33 For sealing Optical glass 34 Ventilation hole G ₁ Combustion exhaust gas (exhaust gas)
G ₂ purge gas G ₃ outside air L laser light L ₁ outside air supply line S space (vent hole)
V Flow control valve Z Measurement area

Claims (12)

A laser emitting section for emitting laser light for analyzing the gas to be measured;
A laser receiving unit for detecting the light intensity of the laser beam;
A light transmitting side light transmitting member that is disposed in the flow path of the gas to be measured and transmits the laser light emitted from the laser light emitting unit toward a measurement region provided in the flow path;
A light-receiving-side light-transmitting member that is disposed in the flow path of the gas to be measured and transmits the laser light transmitted from the light-transmitting-side light-transmitting member through the measurement region toward the laser light-receiving unit; ,
A translucent plate that is provided on at least one of the light transmission side light transmission member and the light reception side light transmission member and prevents the measurement gas from entering the light transmission side light transmission member and the light reception side light transmission member; equipped with,
A gas component measuring apparatus, wherein a vent hole is provided between the light transmitting plate, the light transmitting side light transmitting member, and the light receiving side light transmitting member .   The gas component measuring apparatus according to claim 1, wherein the translucent plate is sapphire glass or quartz glass. On the inner wall of at least one of the light transmission side light transmission member and the light reception side light transmission member, the gas flowing in the light transmission side light transmission member and the light reception side light transmission member is directed toward the surface of the light transmitting plate. The gas component measuring device according to claim 1, wherein a rectifying member for guiding is provided. A laser emitting section for emitting laser light for analyzing the gas to be measured;
A laser receiving unit for detecting the light intensity of the laser beam;
A light transmitting side light transmitting member that is disposed in the flow path of the gas to be measured and transmits the laser light emitted from the laser light emitting unit toward a measurement region provided in the flow path;
A light-receiving-side light-transmitting member that is disposed in the flow path of the gas to be measured and transmits the laser light transmitted from the light-transmitting-side light-transmitting member through the measurement region toward the laser light-receiving unit; ,
A translucent plate that is provided on at least one of the light transmission side light transmission member and the light reception side light transmission member and prevents the measurement gas from entering the light transmission side light transmission member and the light reception side light transmission member; Comprising
On the inner wall of at least one of the light transmission side light transmission member and the light reception side light transmission member, the gas flowing in the light transmission side light transmission member and the light reception side light transmission member is directed toward the surface of the light transmitting plate. A gas component measuring device , characterized in that a rectifying member is provided .   The gas component measuring device according to any one of claims 1 to 4, wherein a surface of the translucent plate is antistatic processed.   The gas component measuring device according to any one of claims 1 to 5, wherein the translucent plate has a hydrophobic surface.   Furthermore, the gas component measuring device of any one of Claim 1 to 6 provided with the dust collection electrode which corona discharges on the surface of the said translucent board.   The gas component measuring device according to claim 7, wherein the dust collection electrode is provided on the measurement region side in the light transmission side light transmission member and the light reception side light transmission member. An ultraviolet light irradiation unit that irradiates the surface of the translucent plate with ultraviolet light,
The gas component measuring device according to any one of claims 1 to 8, wherein a photocatalyst layer is provided on a surface of the translucent plate.   10. The control unit according to claim 9, further comprising: a control unit that switches between irradiation of the ultraviolet light to the light transmitting plate by the ultraviolet light irradiation unit and irradiation of the laser light from the laser light emitting unit to the light transmitting plate. Gas component measuring device. A laser emitting section for emitting laser light for analyzing the gas to be measured;
A laser receiving unit for detecting the light intensity of the laser beam;
A light transmitting side light transmitting member that is disposed in the flow path of the gas to be measured and transmits the laser light emitted from the laser light emitting unit toward a measurement region provided in the flow path;
A light-receiving-side light-transmitting member that is disposed in the flow path of the gas to be measured and transmits the laser light transmitted from the light-transmitting-side light-transmitting member through the measurement region toward the laser light-receiving unit; ,
A translucent plate that is provided on at least one of the light transmission side light transmission member and the light reception side light transmission member and prevents the measurement gas from entering the light transmission side light transmission member and the light reception side light transmission member; Comprising
An exhaust section for exhausting the gas to be measured in the measurement region to make the measurement region have a negative pressure; and an outside air supply line for supplying outside air into the light transmitting side light transmitting member and the light receiving side light transmitting member characterized in that is provided, the gas component measuring apparatus.   The gas component measuring apparatus according to claim 11, further comprising a filter that removes moisture and dust contained in the outside air.

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