JP2015137870A - Hydrogen concentration measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure the concentration of hydrogen at a high responsiveness in many places.SOLUTION: In order to solve the problem, the hydrogen concentration measurement device includes a measurement cell unit disposed in a measurement object space and measuring means. The measurement cell unit includes: a first cell that is disposed on at least one surface and through which gas can pass, and in which gas in the measurement object space flows after passing a catalyst for converting the hydrogen contained in the passing gas into HO; and a second cell that is disposed adjacently to the first cell and through which gas in the measurement object space flows. The measuring means measures a first measured value as the concentration of the HO contained in the gas flowing through the first cell and a second measured value as the concentration of the HO contained in the gas flowing through the second cell.

Description

  The present invention relates to a hydrogen concentration measuring apparatus that measures the concentration of hydrogen contained in a measurement target gas.

  In some cases, measurement of the concentration of hydrogen contained in the measurement target gas is required for measurement of components of fuel gas and exhaust gas and detection of the presence or absence of hydrogen leakage from a facility storing hydrogen. As a method of measuring the concentration of hydrogen contained in the measurement target gas, there is a method of measuring using laser Raman scattering spectroscopy. In addition, as a method for measuring the concentration of a specific substance contained in a mixed gas (mainly circulating gas) flowing in a pipeline, laser light is passed through a predetermined path of the pipeline, and the specific substance to be measured is measured from its input and output There is a method for measuring the concentration. For example, Patent Document 1 filed by the applicant of the present application discloses a light source that oscillates laser light having an absorption wavelength unique to a gaseous substance to be measured, and at least two oscillation wavelengths of laser light oscillated from the light source. Means for modulating at two different frequencies, means for guiding the laser light modulated by the modulating means to the measurement area where the gaseous substance exists, and light receiving means for receiving the laser light transmitted, reflected or scattered in the measurement area And a plurality of phase sensitive detectors that sequentially demodulate signals modulated from signals received by the light receiving means for each frequency.

  Measurement by laser Raman scattering spectroscopy has a problem that it is difficult to realize measurement accuracy at about 1 vol% at atmospheric pressure. In addition, since the Raman scattering cross section is small, there is also a problem that it is easily affected by stray light due to excitation light, scattered light, and fluorescent lamp noise. Therefore, the environment that can be measured is limited.

In contrast, the applicant of the present invention, the H _{2 O} The hydrogen contained in the measurement target gas is oxidized by the oxidation catalyst, measured of H 2 _O concentration, together, it passes through the oxidation catalyst in the same measurement target gas A method for measuring the hydrogen concentration of the measurement target gas by measuring the H ₂ O of the measurement target gas in a not-contained state and comparing the measurement results to calculate the difference has been proposed (Patent Document 2).

Japanese Patent No. 3342446 JP 2011-257319 A

  Although the apparatus described in Patent Document 2 can measure a substance to be measured with high responsiveness, the apparatus becomes large because the measurement target gas flowing through the pipe is extracted and measured by the measuring apparatus. In addition, there may be restrictions on installation.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a hydrogen concentration measuring apparatus capable of measuring hydrogen concentration with high responsiveness and high accuracy in more places. And

In order to solve the above-described problems and achieve the object, the present invention is a hydrogen concentration measurement device for measuring the concentration of hydrogen in a measurement target space, which is disposed on at least one surface and allows gas to pass therethrough. A first cell through which a gas in the measurement target space flows through a catalyst that converts hydrogen contained in the gas into H ₂ O; and a gas that flows in the measurement target space is disposed adjacent to the first cell. A measurement cell unit disposed in the measurement target space, a first measurement value that is a concentration of H ₂ O contained in a gas flowing through the first cell, and the second cell Measuring means for measuring a second measurement value that is a concentration of H ₂ O contained in the gas flowing through the cell, the measuring means including an absorption wavelength of H ₂ O, and near infrared A laser beam in a wavelength band is incident on the first cell and the second cell. A light-emitting unit, a light-receiving unit that receives the laser light incident from the light-emitting unit and passed through the first cell and the second cell, and the intensity of the laser light output from the light-emitting unit to the first cell And the intensity of the laser beam output from the light emitting unit to the second cell based on the intensity of the laser beam received by the light receiving unit and passing through the first cell; And a control device that calculates the second measurement value based on the intensity of the laser light that has passed through the second cell and received by the light receiving unit.

  Moreover, it is preferable that the said control apparatus measures the density | concentration of the hydrogen of measurement object space from the difference of a said 1st measured value and a said 2nd measured value.

  Moreover, it is preferable that the said measurement cell unit arrange | positions the plate-shaped member which gas does not pass on the surface where the said 1st cell and the said 2nd cell are facing.

  Moreover, it is preferable that the said 1st cell has the said catalyst arrange | positioned on two surfaces orthogonal to the surface which faces the said 2nd cell.

  In the second cell, it is preferable that a member having a flow resistance approximating the catalyst is disposed at a position corresponding to the position where the catalyst of the first cell is disposed.

  The catalyst preferably contains platinum.

  In the light emitting unit, it is preferable that a light emitting unit for outputting laser light is fixed to the first cell and the second cell.

  The light receiving unit is fixed to the first cell and receives a laser beam that has passed through the first cell and receives a laser beam that is fixed to the second cell and passed through the second cell. A second light receiving unit that transmits the result detected by the first light receiving unit and the second light receiving unit by wireless communication, and a radio that receives information transmitted from the transmission unit and outputs the information to the control device And a receiving unit.

  The hydrogen concentration measuring apparatus according to the present invention has an effect that the hydrogen concentration can be measured with high responsiveness and high accuracy in more places.

FIG. 1 is a perspective view showing a schematic configuration of an embodiment of a hydrogen concentration measuring apparatus. FIG. 2 is a top view of the hydrogen concentration measuring apparatus shown in FIG. 3 is a cross-sectional view taken along line AA of the hydrogen concentration measuring apparatus shown in FIG. FIG. 4 is a cross-sectional view of the hydrogen concentration measuring apparatus shown in FIG. FIG. 5 is a flowchart for explaining the operation of the hydrogen concentration measuring apparatus. FIG. 6 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. FIG. 7 is a cross-sectional view of the hydrogen concentration measurement apparatus shown in FIG. FIG. 8 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. FIG. 9 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. FIG. 10 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. FIG. 11 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus.

  Hereinafter, an embodiment of a hydrogen concentration measuring apparatus according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. Here, the hydrogen concentration measuring apparatus can measure the concentration of hydrogen contained in various gases in the measurement target space (measurement target space). The measurement target space can be a pipe line through which the measurement target gas flows, a storage section filled with the measurement target gas, or the atmosphere around them. For example, when the concentration of hydrogen contained in a gas can be measured for various gases flowing through a pipeline, a hydrogen concentration measuring device is attached to the pipeline through which the fuel gas flows, and the concentration of hydrogen contained in the fuel gas is measured. May be. Examples of the apparatus having a pipeline through which fuel gas flows include various combustion engines such as vehicles, ships, generators, incinerators and the like. Moreover, as a material which produces | generates gaseous fuel gas, gasoline, light oil, heavy oil, natural gas, biofuel (bioethanol), etc. are illustrated. It can also be used as an apparatus for measuring the hydrogen concentration contained in the gas supplied to the fuel cell. Further, it may be attached to the diesel engine, and the concentration of hydrogen contained in the exhaust gas (circulation gas) discharged from the diesel engine and the distribution gas discharged from the garbage incinerator may be measured. In the present embodiment, hydrogen that is present as a gaseous substance in the flowing gas (measuring gas) flowing in the pipe is the measuring object.

[Embodiment 1]
FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of the hydrogen concentration measuring apparatus of the present invention. FIG. 2 is a top view of the hydrogen concentration measuring apparatus shown in FIG. 3 is a cross-sectional view taken along line AA of the hydrogen concentration measuring apparatus shown in FIG. FIG. 4 is a cross-sectional view of the hydrogen concentration measuring apparatus shown in FIG.

  The hydrogen concentration measuring device 10 collects (samples) a part of the circulating gas flowing in the measurement target space 8 inside the pipe 6 in the measurement target space 8 and measures the concentration of hydrogen contained in the measurement target gas. It is a measuring device. As shown in FIG. 1, the hydrogen concentration measuring device 10 includes a measuring cell unit 20, a light emitting unit 22, a light receiving unit 24, and a control device 26.

  The pipe 6 is a pipe through which a circulation gas that is a measurement target gas flows. In FIG. 1, only a part of the side surface of the pipe 6 is shown, but the pipe 6 has a cylindrical shape. The pipe 6 is surrounded by a cylinder, and the space through which the flowing gas flows becomes the measurement target space 8. In the present embodiment, the measurement target space 8 is set inside the pipe 6 and the measurement target gas flows in a predetermined direction. However, the present invention is not limited to this. The hydrogen concentration measuring device 10 only needs to move the measurement target gas in the measurement target space 8, and may move in any direction. That is, the flow direction of the measurement target gas may be changed.

  The measurement cell unit 20 is arranged in the measurement target space 8. That is, the measurement cell unit 20 is disposed inside the pipe 6 through which the measurement target gas is circulated. The measurement cell unit 20 includes a first cell 30 and a second cell 32.

  The first cell 30 has a rectangular parallelepiped box 34 having a space inside and a catalyst mesh 38 installed in the box 34. The box 34 has a rectangular parallelepiped shape, and openings 52 and 54 are formed on two opposing faces (the face having the largest area in the present embodiment) among the six faces. The box 34 has a light receiving unit 22 in which a part of the light emitting unit 22 on which laser light as measurement light is incident is disposed on one of two surfaces serving as ends in the longitudinal direction of the rectangular parallelepiped, and the other surface receives the laser light. A part of 24 is arranged.

The catalyst mesh 38 is disposed in each of the openings 52 and 54 of the box 34. The catalyst mesh 38 is a mechanism that allows a circulating gas to pass through and converts hydrogen to be measured contained in the passing circulating gas into H ₂ O (gaseous water, water vapor). The catalyst mesh 38 is a combustion catalyst that oxidizes hydrogen contained in the flowing gas passing therethrough, that is, reacts hydrogen and oxygen to convert them into H ₂ O. Various catalysts that oxidize hydrogen can be used as the catalyst mesh 38. The catalyst mesh 38 is preferably a catalyst containing platinum. The catalyst mesh 38 can convert hydrogen into H ₂ O with higher probability by using platinum. Specifically, the catalyst mesh 38 can convert hydrogen into H ₂ O with higher probability even when the measurement target gas is at a low temperature (for example, 50 ° C.) by using platinum.

The first cell 30 has a closed shape in which the openings 52 and 54 of the box 34 are formed. Thereby, the circulating gas flowing into the space inside the box 34 passes through the catalyst mesh 38 of the openings 52 and 54. Therefore, in the first cell 30, the flow gas in which hydrogen is converted to H ₂ O flows into the box 34. Further, in the first cell 30, the openings 52 and 54 are formed on the two opposing surfaces of the box 34, so that the circulating gas flows from the inside of the box 34 to the outside and from the outside to the inside as shown in FIG. 4. It becomes easy. Thereby, it is possible to suppress the circulation gas from staying inside the box 34.

  The second cell 32 includes a rectangular parallelepiped box 36 having a space inside and a non-catalytic mesh 40 installed in the box 36. The second cell 32 has the same configuration as that of the first cell 30 except that a non-catalytic mesh 40 is arranged instead of the catalyst mesh 38. The box 38 has a rectangular parallelepiped shape, and openings 56 and 58 are formed in two opposing faces (the face having the largest area in this embodiment) among the six faces. The box 36 has a light receiving unit 22 in which a part of the light emitting unit 22 on which laser light, which is measurement light, is incident is disposed on one of two surfaces that are ends in the longitudinal direction of the rectangular parallelepiped, and the other surface receives the laser light. A part of 24 is arranged.

The non-catalytic mesh 40 is a member that allows a flow gas to pass through. The non-catalyst mesh 40 is a member having the same shape as the catalyst mesh 38 and has substantially the same flow path resistance as the catalyst mesh 38. The non-catalytic mesh 40 is formed of a material such as SUS that has no function (substantially negligible) that promotes the reaction between hydrogen and oxygen and does not convert it into H ₂ O.

The second cell 32 has a closed shape in which the openings 56 and 58 of the box 36 are formed. Thereby, the circulating gas flowing into the space inside the box 36 passes through the non-catalytic mesh 40 of the openings 56 and 58. Therefore, in the second cell 32, a flow gas in which hydrogen is not converted into H ₂ O flows into the box 36. Further, in the second cell 32, the openings 56 and 58 are formed on the two opposing surfaces of the box 36, so that the circulating gas flows from the inside of the box 36 to the outside and from the outside to the inside as shown in FIG. It becomes easy. Thereby, it is possible to suppress the circulation gas from staying inside the box 36.

  In the measurement cell unit 20, the first cell 30 and the second cell 32 are arranged adjacent to each other. Specifically, one of the two surfaces where the openings 52 and 54 of the box 34 of the first cell 30 are not formed and a part of the light emitting unit 22 and a part of the light receiving unit 24 are not installed. However, the openings 56 and 58 of the box 36 of the second cell 32 are not formed, and contact with one surface of the two surfaces where a part of the light emitting unit 22 and a part of the light receiving unit 24 are not installed. Yes.

The light emitting unit 22 includes a light source 60, a first light incident portion 61a, and a second light incident portion 61b. The light source 60 includes a light emitting element that emits laser light in the near-infrared wavelength region absorbed by H ₂ O. As the light emitting element, for example, a laser diode (LD) can be used. The light source 60 causes the emitted light to enter the first light incident part 61a and the second light incident part 61b. The first light incident portion 61a includes an optical fiber 62a and a fiber support portion 64a. One end of the optical fiber 62 a is connected to the light source 60, and the other end is connected to the surface of the longitudinal end of the box 34 of the first cell 30. The optical fiber 62 a causes the light incident from the light source 60 to enter the inside of the box 34 of the first cell 30. The fiber support 64a is fixed to the box 34 of the first cell 30, and supports the other end of the optical fiber 62a. The second light incident portion 61b includes an optical fiber 62b and a fiber support portion 64b. One end of the optical fiber 62 b is connected to the light source 60, and the other end is connected to the surface of the end of the second cell 32 in the longitudinal direction of the box 36. The optical fiber 62 b causes the laser light incident from the light source 60 to enter the inside of the box 36 of the second cell 32. The fiber support 64b is fixed to the box 36 of the second cell 32, and supports the other end of the optical fiber 62b.

  The light emitting unit 22 emits laser light from the light source 60, and guides the emitted laser light by the first light incident part 61a and the second light incident part 61b, so that each of the first cell 30 and the second cell 32 is provided. A laser beam is incident. In the light emitting unit 22, the light source 60 is disposed outside the measurement target space 8, that is, outside the pipe 6. As a result, the optical fibers 62 a and 62 b are inserted into openings formed in the wall surface of the pipe 6, one end is connected to the light source 60, and the other end is connected to the measurement cell unit 20. A seal mechanism 80 is provided between the pipe 6 and the optical fibers 62a and 62b. The sealing mechanism 80 seals between the pipe 6 and the optical fibers 62 a and 62 b, the circulating gas in the measurement target space 8 leaks to the outside of the pipe 6, and the air outside the pipe 6 is in the measurement target space 8. Inflow into the.

  The light receiving unit 24 includes a first light receiving unit 70 and a second light receiving unit 72. The 1st light-receiving part 70 is arrange | positioned at the surface facing the surface in which the optical fiber 62a of the 1st cell 30 is installed. The first light receiving unit 70 receives the laser light that has passed through the inside of the first cell 30. The first light receiving unit 70 includes, for example, a photodetector such as a photodiode (PD), receives the laser beam by the photodetector, and detects the intensity of the light. The first light receiving unit 70 is connected to the control device 26 by wiring, and sends the intensity of the received laser light to the control device 26 as a light reception signal. The second light receiving unit 72 is disposed on the surface facing the surface on which the optical fiber 62b of the second cell 32 is installed. The second light receiving unit 72 receives the laser light that has passed through the inside of the second cell 32. The second light receiving unit 72 includes, for example, a photodetector such as a photodiode (PD), receives the laser beam by the photodetector, and detects the intensity of the light. The second light receiving unit 72 is connected to the control device 26 by wiring, and sends the intensity of the received laser light to the control device 26 as a light reception signal. Here, in the control device 26, the light source 60 is disposed outside the measurement target space 8, that is, outside the pipe 6. Thereby, the wiring which connects the 1st light-receiving part 70, the 2nd light-receiving part 72, and the control apparatus 26 is inserted in the opening formed in the wall surface of the piping 6, and one edge part connects with the control apparatus 26, The other end is connected to the first light receiving unit 70 and the second light receiving unit 72. A seal mechanism 80 is provided between the pipe 6 and the wiring. The seal mechanism 80 seals the space between the pipe 6 and the wiring so that the circulating gas in the measurement target space 8 leaks to the outside of the pipe 6 and the air outside the pipe 6 flows into the measurement target space 8. Suppress.

The control device 26 controls the operation of the light emitting unit 22 and the light receiving unit 24, acquires detection values, and executes various processes to detect the hydrogen concentration in the measurement target space 8. Specifically, the control device 26 drives the light source 60 and the signal of the intensity of the laser beam received by the first light receiving unit 70 and the second light receiving unit 72 and enters the first cell 30 and the second cell 32. The intensities of the laser beams are compared, and the concentration of the measurement target substance (substance converted from H ₂ O and H ₂ ) contained in the flowing gas flowing through the measurement target space 8 is calculated.

In the hydrogen concentration measuring apparatus 10, the near-infrared wavelength laser beam output from the light source 60 enters the first cell 30 from the optical fiber 62 a, passes through the inside of the first cell 30, and passes through the first light receiving unit. Reach 70. At this time, if the flowing gas in the first cell 30 contains H ₂ O, the laser light passing through the first cell 30 is absorbed. Therefore, the output of the laser light that reaches the first light receiving unit 70 varies depending on the concentration of H ₂ O in the flowing gas. The first light receiving unit 70 converts the received laser light into a light reception signal and outputs it to the control device 26. The light source 60 outputs the intensity of the laser beam output to the optical fiber 62a to the control device 26. The control device 26 compares the intensity of the light output from the light source 60 with the intensity calculated from the received light signal, and calculates the concentration of H ₂ O of the flowing gas flowing in the first cell 30 from the decrease rate. Of H _{2 O} concentration in the flowing gas flowing through the first cell 30 is, H ₂ and H _{2 O} (coexisting gas) contained before entering the first cell 30, the hydrogen at the time of passage of catalyst mesh 38 is converted Including both O.

Further, the hydrogen concentration measuring apparatus 10 calculates the concentration of H ₂ O of the flowing gas flowing through the second cell 32 by the same method as that for the first cell 30. In the hydrogen concentration measuring apparatus 10, the near-infrared wavelength laser beam output from the light source 60 enters the second cell 32 from the optical fiber 62b, passes through the inside of the second cell 32, and passes through the second light receiving unit. 72 is reached. At this time, if the flowing gas in the second cell 32 contains H ₂ O, the laser light passing through the second cell 32 is absorbed. Therefore, the output of the laser light that reaches the second light receiving unit 72 varies depending on the concentration of H ₂ O in the flowing gas. The second light receiving unit 72 converts the received laser light into a light reception signal and outputs it to the control device 26. The light source 60 outputs the intensity of the laser beam output to the optical fiber 62b to the control device 26. The control device 26 compares the intensity of the light output from the light source 60 with the intensity calculated from the received light signal, and calculates the concentration of H ₂ O of the flowing gas flowing in the second cell 32 from the decrease rate. The concentration of H ₂ O in the flowing gas flowing in the second cell 32 includes H ₂ O (coexistence gas) contained before flowing into the second cell 32.

The hydrogen concentration measuring apparatus 10 uses a so-called TDLAS method (Tunable Diode Laser Absorption Spectroscopy), and the first cell 30 is based on the intensity of the output laser light and the received light signal detected by the light receiving unit. Among them, the concentration of H ₂ O in the circulating gas passing through a predetermined position in the second cell 32, that is, the measurement position is calculated and / or measured. Further, the hydrogen concentration measuring device 10 can continuously calculate and / or measure the concentration of H ₂ O.

  The hydrogen concentration measuring device 10 measures the concentration of hydrogen in the measurement target space 8 based on the measurement result of the first cell 30 and the measurement result of the second cell 32.

  Next, the operation of the hydrogen concentration measuring apparatus 10 will be described. Here, FIG. 5 is a flowchart for explaining the operation of the hydrogen concentration measuring apparatus. Note that the processing shown in FIG. 5 can be realized by the control device 26 controlling the operation of each unit. First, the hydrogen concentration measuring apparatus 10 arranges the measurement cell unit 20 and a portion connected to the measurement cell unit 20 in the measurement target space 8. Thereafter, the optical fibers 62a and 62b and wiring are inserted into the pipe 6, and the seal mechanism 80 is provided at the insertion portion. Thus, if the measurement cell unit 20 is arrange | positioned in the measurement object space 8, measurement will be started.

The control device 26 of the hydrogen concentration measuring device 10 acquires the output of the laser beam output to the first cell 30 as described above (step S12), and acquires the measurement result at the first light receiving unit 70 (step S14). Based on the information acquired in step S12 and step S14, preset conditions, and the like, the concentration (first measured value) of H ₂ O in the first cell 30 is calculated (step S16).

The control device 26 of the hydrogen concentration measuring apparatus 10 acquires the output of the laser beam output to the second cell 32 in parallel with the processing from step S12 to step S16 (step S22), and performs measurement by the second light receiving unit 72. A result is acquired (step S24), and the concentration (second measured value) of H ₂ O in the second cell 32 is calculated based on the information acquired in steps S22 and S24, preset conditions, and the like (step S24). S26).

Controller of the hydrogen concentration measuring device 10 26 comprises a of _{H 2} O concentration in the first cell 30 (first measure), based on the difference between of _{H 2} O concentration in the second cell 32 (second measure) Thus, the hydrogen concentration in the measurement target space 8 is calculated (step S30). Based on the difference between the first measurement value measured in step S16 and the second measurement value measured in step S26, the measurement value of hydrogen contained in the flowing gas is calculated. That is, by subtracting the concentration of the coexisting gas from the total concentration of H ₂ O derived from the measurement target hydrogen contained in the flow gas and the coexistence gas, the H ₂ O derived from the hydrogen contained in the flow gas The concentration can be calculated.

As described above, the hydrogen concentration measuring apparatus 10 measures the concentration of H ₂ O contained in the flow gas flowing through the first cell 30 and oxidizing the hydrogen to be measured by the catalyst mesh 38, and the second cell 32. The concentration of hydrogen to be measured can be calculated by measuring the concentration of H ₂ O contained in the flowing gas that does not oxidize the hydrogen to be measured flowing through the gas and taking the difference.

  Further, the hydrogen concentration measuring apparatus 10 can install a mechanism for measuring the hydrogen concentration in the measurement target space 8 by using the measurement cell unit 20 having the first cell 30 and the second cell 32. Thereby, it is not necessary to extract the circulating gas from the measurement target space 8 with a sampling pipe or the like, and it can be installed in various places. In addition, by using the flow of the circulating gas, that is, by natural convection, the gas to be measured is caused to flow in the measurement cell unit 20, thereby simplifying the apparatus configuration. Moreover, it can suppress that the mechanism which generate | occur | produces a convection has a bad influence on hydrogen.

In addition, the measurement cell unit 20 allows the first cell 30 and the second cell 32 to be adjacent to each other, so that even if there is a variation in gas components in the measurement target space 8, it can be compared in the vicinity, so that the measurement accuracy can be improved. Can be high. In addition, the measurement cell unit 20 has a structure in which the first cell 30 and the second cell 32 are adjacent to each other and a plate is disposed on the adjacent surface so that H ₂ O does not pass through the first cell 30. It is possible to prevent the gas that has passed through from flowing into the second cell 32 or vice versa. Thereby, measurement accuracy can be made high.

  In addition, the measurement cell unit 20 provides the non-catalytic mesh 40 in the second cell 32, so that the difference between the amount of flowing gas flowing into the second cell 32 and the amount of flowing gas flowing into the first cell 30 is calculated. Can be small. Thereby, the circulation gas of the same state can be flowed in and out, and measurement accuracy can be improved.

Moreover, the hydrogen concentration measuring apparatus 10 irradiates laser light in the near-infrared wavelength region of the absorption wavelength region of the oxide of hydrogen to be measured (H ₂ O converted from hydrogen) and is absorbed by the H ₂ O. By detecting the intensity, the hydrogen concentration can be measured in a short time and with high accuracy.

  In addition, by oxidizing the measurement target hydrogen and measuring it as an oxide, the concentration of hydrogen having no absorption wavelength in the near-infrared wavelength region can be measured using semiconductor laser absorption spectroscopy. In addition, as in the present embodiment, measurement using light in the near-infrared wavelength region of a substance to be measured can be performed, so that measurement with high accuracy can be performed.

  Furthermore, in the measurement using laser light in the near-infrared wavelength region, the concentration of the oxide to be measured can be appropriately measured even when components other than the oxide to be measured are mixed. That is, components other than the oxide to be measured can be made less likely to be noise. Thereby, a filter and a dehumidification process can be eliminated or reduced, and the time from when the flow gas is sucked from the pipe 6 until measurement is performed and the measurement result is calculated can be shortened. That is, the measurement time delay can be reduced. Thereby, responsiveness can be made high.

Further, the hydrogen concentration measuring apparatus 10 can also measure the coexisting gas contained in the flow gas, that is, the concentration of H ₂ O originally contained in the flow gas. Thereby, the ratio of hydrogen contained in the circulation gas and H ₂ O can also be calculated.

Here, it is preferable that the hydrogen concentration measuring apparatus 10 is provided with a temperature detection unit that detects the temperature in the measurement cell unit 20. The control device 26 preferably measures the hydrogen concentration in consideration of the temperature detected by the temperature detection unit. When the temperature of the circulating gas is high, the catalyst mesh 38 also converts hydrocarbons other than hydrogen into H ₂ O. Therefore, the hydrogen concentration measuring device 10 can measure the hydrogen concentration with high accuracy by adjusting the measurement result according to the temperature. Note that the hydrogen concentration measuring device 10 may stop measuring the hydrogen concentration when the temperature is high.

  Here, the hydrogen concentration measuring device is not limited to the above-described embodiment, and can be various embodiments. Hereinafter, another embodiment will be described with reference to FIGS.

[Embodiment 2]
FIG. 6 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. FIG. 7 is a cross-sectional view of the hydrogen concentration measurement apparatus shown in FIG. The hydrogen concentration measuring device 10a is basically the same as the hydrogen concentration measuring device 10 except that the light receiving unit of the light receiving unit 24a is provided outside the pipe 6 and the received light is guided by an optical fiber. It is. Therefore, the same components as those of the hydrogen concentration measuring device 10 are denoted by the same reference numerals, and the description thereof will be omitted, and points unique to the hydrogen concentration measuring device 10a will be described. The hydrogen concentration measuring apparatus 10a shown in FIGS. 6 and 7 includes a measurement cell unit 20, a light emitting unit 22, and a light receiving unit 24a.

  The light receiving unit 24a includes optical fibers 90a and 90b, fiber support portions 92a and 92b, and a light receiving portion 94. In the light receiving unit 24a, a combination of the optical fiber 90a, the fiber support portion 92a, and the light receiving portion 94 becomes a first light receiving portion, and a combination of the optical fiber 90b, the fiber support portion 92b, and the light receiving portion 94 becomes a second light receiving portion. One end of the optical fiber 90 a is disposed on a surface facing the surface on which the optical fiber 62 a of the first light incident portion 61 a of the first cell 30 is disposed, and the other surface is coupled to the light receiving portion 94. Yes. The fiber support portion 92 a is fixed to the first cell 30, and the end portion of the optical fiber 92 a is fixed to a predetermined position of the first cell 30. One end of the optical fiber 90b is disposed on the surface facing the surface on which the optical fiber 62b of the second light incident portion 61b of the second cell 32 is disposed, and the other surface is coupled to the light receiving portion 94. Yes. The fiber support portion 92 b is fixed to the second cell 32, and the end portion of the optical fiber 90 b is fixed to a predetermined position of the second cell 32.

  The light receiving unit 94 is disposed outside the pipe 6, receives the laser light guided by the optical fibers 90a and 90b, and detects the intensity of the laser light. The light receiving unit 94 outputs a signal indicating the intensity of the laser beam to the control device 26a. In the light receiving unit 24, the light receiving portion 94 is installed outside the pipe 6, and the optical fibers 90 a and 90 b are respectively inserted into holes of the pipe 6 provided with the seal mechanism 80.

  Thus, the hydrogen concentration measuring apparatus 10a arranges the light receiving unit 94 outside the pipe 6, and guides the received light through the optical fibers 90a and 90b, thereby arranging the measurement cell unit 20 in the measurement target space 8. The device configuration in the vicinity of can be reduced in size. Thereby, it becomes easier to arrange in the measurement target space 8.

[Embodiment 3]
FIG. 8 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. The hydrogen concentration measuring device 10b is basically the same as the hydrogen concentration measuring device 10 except that the reception signal detected by the light receiving unit 24b is output by wireless communication. Therefore, the same components as those in the hydrogen concentration measuring apparatus 10 are denoted by the same reference numerals, and the description thereof will be omitted, and points unique to the hydrogen concentration measuring apparatus 10b will be described. A hydrogen concentration measuring apparatus 10b shown in FIG. 8 includes a measuring cell unit 20, a light emitting unit 22, and a light receiving unit 24b.

  The light receiving unit 24b includes a first light receiving unit 70, a second light receiving unit 72, a signal transmission device 110, and a signal reception device 114. The signal transmission device 110 is disposed adjacent to the first light receiving unit 70 and the second light receiving unit 72, and transmits signals detected by the first light receiving unit 70 and the second light receiving unit 72 by wireless communication. The signal receiving device 114 is disposed outside the pipe 6 and receives a radio signal output from the signal transmission device 110. The signal receiving device 114 outputs a signal indicating the intensity of the received laser beam to the control device 26b.

  The hydrogen concentration measuring device 10b outputs the signal of the intensity of the laser beam received by the first light receiving unit 70 and the second light receiving unit 72 by wireless communication, thereby receiving the signal of the intensity of the laser beam received without using the wiring. It can output to the control apparatus 26b. Thereby, the seal mechanism 80 provided in the piping 8 can be reduced by reducing the number of holes provided in the piping 8. Further, by reducing the number of sealing mechanisms 80, the risk of flowing out gas that may contain hydrogen can be reduced. Moreover, the safety device for providing the hydrogen concentration measuring device 10b can be reduced.

[Embodiment 4]
FIG. 9 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. The hydrogen concentration measuring device 10c is basically provided with a plurality of measuring cell units 20, and except for the point that the light emitting unit 22c and the light receiving unit 24c are provided in accordance with the measuring cell unit 20, the hydrogen concentration measuring device 10b basically It is the same. Therefore, the same components as those of the hydrogen concentration measuring device 10b are denoted by the same reference numerals, description thereof is omitted, and points unique to the hydrogen concentration measuring device 10c will be described. The hydrogen concentration measuring apparatus 10c shown in FIG. 9 includes a plurality of measurement cell units 20, a plurality of light emitting units 22c, and a light receiving unit 24b. In the hydrogen concentration measuring device 10c, the control device 26c, the light source 130, and the signal receiving device 140 are provided as a common device for the plurality of light emitting units 22c and the plurality of light receiving units 24b.

  The light emitting unit 22c includes a light source 130, an optical fiber 132, a branching portion 134, optical fibers 62a and 62b, and fiber support portions 64a and 64b. The light source 130, the optical fiber 132, and the branching unit 134 are common to the plurality of light emitting units 22c. The optical fibers 62a and 62b and the fiber support portions 64a and 64b are the same as the respective portions of the light emitting unit 22c.

  The optical fiber 132 guides the laser beam output from the light source 130 to the branching unit 134. Here, in the light emitting unit 22 c, the light source 130 is disposed outside the pipe 6, and the branch portion 134 is disposed in the pipe 6. The optical fiber 132 is inserted into the pipe 6 and the insertion portion is sealed by a sealing mechanism. The branching unit 134 is connected to the optical fiber 132 and the optical fibers 62a and 62b of the plurality of light emitting units 22c. The branching unit 134 branches and outputs the laser light output from the optical fiber 132 to each of the optical fibers 62a and 62b.

  The hydrogen concentration measuring device 10c can simultaneously measure the hydrogen concentration at a plurality of locations in the measurement target space 8 by providing a plurality of measurement cell units 20. In addition, by providing the branch portion 134 in the pipe 6, the number of optical fibers inserted into the pipe 6 can be reduced. Thereby, the apparatus can be made safer and can be easily installed.

[Embodiment 5]
FIG. 10 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. The hydrogen concentration measurement device 10d is basically the same as the hydrogen concentration measurement device 10b except that the measurement cell unit 20 is provided with a device that emits laser light from the light emitting unit 22d. Therefore, the same components as those of the hydrogen concentration measuring device 10b are denoted by the same reference numerals, and the description thereof will be omitted, and points unique to the hydrogen concentration measuring device 10d will be described. A hydrogen concentration measuring apparatus 10d shown in FIG. 10 includes a measuring cell unit 20, a light emitting unit 22d, and a light receiving unit 24b.

The light emitting unit 22d includes a first light emitting unit 152, a second light emitting unit 154, and a light emitting unit control device 156. The first light emitting unit 152 is fixed to the first cell 30 and outputs laser light used for measuring H ₂ O to the first cell 30. The second light emitting unit 154 is provided in the second cell 32 and outputs laser light used for measuring H ₂ O to the second cell 32. In addition, the 1st light emission part 152 and the 2nd light emission part 154 are provided with the power supply, and are driven with the electric power currently charged by the power supply. The light emitting unit control device 156 performs wireless communication with the first light emitting unit 152 and the second light emitting unit 154 and controls operations of the first light emitting unit 152 and the second light emitting unit 154. The light emitting unit control device 156 outputs information on the intensity of the laser light output from the first light emitting unit 152 and the second light emitting unit 154 to the first cell 30 and the second cell 32 to the control device 26d.

  The hydrogen concentration measurement device 10d can separate the mechanism around the measurement cell unit 20 and the control device 26d by providing a device that outputs laser light integrally with the measurement cell unit 20. Thereby, when installing the measurement cell unit 20, it is not necessary to make a hole in the pipe 6, and the installation can be performed more safely.

[Embodiment 6]
FIG. 11 is a schematic diagram showing a schematic configuration of another embodiment of the hydrogen concentration measuring apparatus. The hydrogen concentration measuring device 10e is basically the same as the hydrogen concentration measuring device 10d except that the light emitting unit 22e emits laser light as one device for two cells. is there. Therefore, the same components as those in the hydrogen concentration measuring device 10d are denoted by the same reference numerals and description thereof will be omitted, and points unique to the hydrogen concentration measuring device 10e will be described. A hydrogen concentration measuring device 10e shown in FIG. 11 includes a measuring cell unit 20, a light emitting unit 22e, and a light receiving unit 24b.

The light emitting unit 22e includes a light source 170, a light distributor 172, and a light emitting unit controller 174. The light source 170 is fixed to the measurement cell unit 20 together with the light distributor 172. The light source 170 outputs laser light used for measuring H ₂ O. Note that the light source 170 includes a power source and is driven by power charged in the power source. The optical distributor 172 is fixed to the first cell 30 and the second cell 32, and the laser beam used for measuring H ₂ O output from the light source 170 is incident on each of the first cell 30 and the second cell 32. Let The light emitting unit control device 174 performs wireless communication with the light source 170 and controls the operation of the light source 170. The light emitting unit control device 174 outputs information on the intensity of the laser light output from the light source 179 to the first cell 30 and the second cell 32 to the control device 26e.

  The hydrogen concentration measuring device 10e can separate the mechanism around the measurement cell unit 20 and the control device 26e by providing a device for outputting laser light integrally with the measurement cell unit 20. Thereby, when installing the measurement cell unit 20, it is not necessary to make a hole in the pipe 6, and the installation can be performed more safely. Further, by sharing a light source that outputs laser light, the apparatus can be further simplified.

  Here, the present invention is not limited to the above embodiment, and various forms can be adopted. For example, you may combine each embodiment.

6 piping 8 measurement object space 10 hydrogen concentration measuring device 20 measuring cell unit 22 light emitting unit 24 light receiving unit 26 control device 30 first cell 32 second cell 34, 36 box 38 catalyst mesh 40 non-catalyst mesh 52, 54, 56, 58 Aperture 60 Light source 61a First light incident portion 61b Second light incident portions 62a and 62b Optical fibers 64a and 64b Fiber support portion 70 First light receiving portion 72 Second light receiving portion 80 Sealing mechanism

Claims (8)

A hydrogen concentration measuring device that measures the concentration of hydrogen in a measurement target space,
A first cell that is disposed on at least one surface and through which a gas that can pass through and converts hydrogen contained in the passing gas into H ₂ O passes through the catalyst; A measurement cell unit arranged adjacent to the second cell into which the gas in the measurement target space flows, and arranged in the measurement target space;
A first measurement value that is a concentration of H ₂ O contained in a gas flowing through the first cell and a second measurement value that is a concentration of H ₂ O contained in a gas flowing through the second cell are measured. Measuring means,
The measuring means includes
A light emitting unit that includes an absorption wavelength of H ₂ O and makes laser light in a near-infrared wavelength region incident on the first cell and the second cell;
A light receiving unit that receives each laser beam incident from the light emitting unit and passed through the first cell and the second cell;
Based on the intensity of the laser light output from the light emitting unit to the first cell and the intensity of the laser light received by the light receiving unit and passing through the first cell, the first measurement value is calculated, and the light emission A control device for calculating the second measurement value based on the intensity of the laser light output from the unit to the second cell and the intensity of the laser light received by the light receiving unit and passed through the second cell; A hydrogen concentration measuring apparatus comprising:   The hydrogen concentration measurement apparatus according to claim 1, wherein the control device measures a hydrogen concentration in a measurement target space from a difference between the first measurement value and the second measurement value.   3. The measurement cell unit according to claim 1, wherein a plate-like member that does not allow gas to pass is disposed on a surface where the first cell and the second cell face each other. Hydrogen concentration measuring device.   The hydrogen concentration measuring device according to claim 3, wherein the first cell has the catalyst disposed on two surfaces orthogonal to a surface facing the second cell.   The second cell is characterized in that a member having a flow path resistance similar to the catalyst is disposed at a position corresponding to a position where the catalyst of the first cell is disposed. The hydrogen concentration measuring device according to any one of the above.   The hydrogen concentration measuring apparatus according to claim 1, wherein the catalyst contains platinum.   6. The hydrogen concentration measuring apparatus according to claim 1, wherein the light emitting unit has a light emitting unit that outputs a laser beam fixed to the first cell and the second cell. 7.   The light receiving unit is fixed to the first cell and receives a laser beam that has passed through the first cell and receives a laser beam that is fixed to the second cell and passed through the second cell. A second light receiving unit that transmits the result detected by the first light receiving unit and the second light receiving unit by wireless communication, and a radio that receives information transmitted from the transmission unit and outputs the information to the control device The hydrogen concentration measuring device according to claim 1, further comprising a receiving unit.

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