JP5937560B2 - Dissolved hydrogen concentration measuring device - Google Patents

Description

  The present invention relates to an apparatus and a measuring method for measuring the concentration of dissolved hydrogen contained in a liquid to be measured.

  In recent years, hydrogen water in which hydrogen molecules (hydrogen gas) are dissolved in water has attracted attention in various fields. For example, in the health industry field, attention has been paid to the effect of hydrogen molecules in hydrogen water reducing and removing active oxygen in the body, and hydrogen water is used as drinking water for maintaining health. Also, in the electronic industry field, hydrogen water is used as electronic component cleaning water, paying attention to its cleaning effect. However, since hydrogen molecules in hydrogen water easily escape from the water and the dissolved hydrogen concentration tends to decrease with time, it is required to grasp the dissolved hydrogen concentration in the hydrogen water at the time of use.

  The measurement of the dissolved hydrogen concentration is performed mainly using a diaphragm-type polarographic dissolved hydrogen meter as described in Patent Document 1. In this measuring device, the dissolved hydrogen concentration is measured by dissolving the hydrogen in the solution to be measured into the electrolyte through the hydrogen permeable membrane and measuring the current value due to the oxidation reaction of the hydrogen gas generated in the electrolyte. It is done by.

Japanese Patent No. 4549114

  However, the dissolved hydrogen meter described in Patent Document 1 has a problem that it is difficult to introduce the apparatus because the apparatus becomes relatively large and the price of the apparatus itself is expensive. In addition, the dissolved hydrogen meter described in Patent Document 1 has a problem in that preparation and maintenance are troublesome because it needs to be replaced every time the diaphragm and the electrolytic solution deteriorate.

  The present invention has been devised in view of the above-described points, and an object thereof is to provide a new measuring apparatus and measuring method for dissolved hydrogen concentration.

  Another object of the present invention is to provide a dissolved hydrogen concentration measuring device and a measuring method capable of easily measuring the dissolved hydrogen concentration.

  Still another object of the present invention is to provide a small-sized and inexpensive apparatus for measuring dissolved hydrogen concentration and a measurement method capable of configuring such a measurement apparatus.

  In order to solve the above-mentioned problems, the dissolved hydrogen concentration measuring apparatus of the present invention includes a measured liquid stirring chamber for releasing hydrogen gas contained as dissolved hydrogen in the measured liquid from the measured liquid, and a measured liquid stirring chamber. A fuel cell that generates electric energy by reacting the hydrogen gas with oxygen gas in the air, and a measuring means that is connected to the fuel cell and measures the amount of electric energy generated from the fuel cell. .

  When the measurement liquid is stirred in the measurement liquid stirring chamber, the dissolved hydrogen contained in the measurement liquid is released as hydrogen gas. At this time, the released hydrogen gas is supplied to the hydrogen electrode (fuel electrode, anode) of the fuel cell and oxygen in the air is supplied to the oxygen electrode (air electrode, cathode) of the fuel cell and reacts. Electric energy is generated. By measuring the amount of electric energy using a predetermined measuring means, the concentration of hydrogen gas contained in the liquid to be measured, that is, the dissolved hydrogen concentration is detected.

  Further, the measuring means includes a voltage measuring device connected to the output terminal of the fuel cell, and a low resistance load that is connected in parallel with the voltage measuring device and consumes at least a part of the electric energy generated by the fuel cell. It is also preferable to provide a resistor.

  Further, the measured liquid stirring chamber of the dissolved hydrogen concentration measuring apparatus of the present invention includes an inflow portion and a discharging portion of the measured liquid, a plurality of stirring columns arranged at predetermined intervals in the vertical and horizontal directions, and the plurality of stirring columns. The measured liquid flow path formed in a lattice between the column height A of the stirring column and the width B of the measured liquid flow path are such that the length is A / 2 ≧ B. It is also preferable that there is. By configuring the liquid to be measured flowing into the liquid chamber to be measured to collide with a number of stirring columns, the liquid to be measured is sufficiently stirred, and the dissolved hydrogen contained in the liquid to be measured is released as hydrogen gas. Is done. Further, by setting the column height A of the stirring column and the width B of the flow path to A / 2 ≧ B, the contact area of the liquid to be measured with respect to the stirring column increases, and the liquid to be measured can be efficiently stirred. Therefore, the dissolved hydrogen contained in the liquid to be measured can be reliably released as hydrogen gas, and the amount of electric energy generated based on the amount of hydrogen gas can be measured.

  Moreover, it is also preferable that the measured liquid stirring chamber of the measuring device for the dissolved hydrogen concentration of the present invention is configured as a hydrogen electrode separator of a fuel cell. As a result, the measured liquid stirring chamber can be configured as a fuel cell unit, and it becomes easy to directly supply the hydrogen gas generated in the measured liquid stirring chamber to the hydrogen electrode (fuel electrode), and the entire measuring apparatus. Can be made small. In addition, the separator in this specification does not need to have electroconductivity, can accommodate a battery cell, and can block fuel gas (hydrogen), air, and a liquid to be measured that are not used in each electrode. Anything is possible.

  Furthermore, the outer edge between the hydrogen electrode constituting the fuel cell of the dissolved hydrogen concentration measuring device of the present invention and the electrolyte membrane may be provided with a sealing member for preventing intrusion of the liquid to be measured. preferable. Since the liquid to be measured flows into the hydrogen electrode separator provided with the liquid chamber to be measured, the hydrogen electrode side is immersed in water. However, if the liquid to be measured enters the oxygen electrode side, the oxygen diffusion film becomes wet. As a result, the supply of oxygen is hindered and the electromotive force decreases. Therefore, by providing a sealing member on the outer edge between the hydrogen electrode and the electrolyte membrane, it is possible to prevent the liquid to be measured from entering the oxygen electrode side. Thus, stable power generation is performed in the fuel cell without hindering oxygen supply to the oxygen diffusion membrane, and the dissolved hydrogen concentration in the liquid to be measured can be measured with high accuracy.

  Further, the measuring means of the device for measuring dissolved hydrogen concentration of the present invention is connected to a voltage measuring device, an arithmetic unit for calculating the dissolved hydrogen concentration value from the voltage value measured by the voltage measuring device, It is also preferable to further include a display for displaying the hydrogen concentration value (for example, an LED lamp, a digital level monitor or an analog level monitor for simply displaying the dissolved hydrogen concentration). Thereby, the dissolved hydrogen concentration in the liquid to be measured based on the measured value of the amount of electric energy generated in the fuel battery cell can be easily confirmed.

  The method for measuring the dissolved hydrogen concentration of the present invention includes a step of stirring the liquid to be measured and releasing hydrogen gas contained as dissolved hydrogen in the liquid to be measured from the liquid to be measured, and a liquid to be measured in the fuel cell. A step of supplying the hydrogen gas released from the air and an oxygen gas in the air to generate electric energy, and a step of measuring the amount of electric energy. By stirring the liquid to be measured, the dissolved hydrogen contained in the liquid to be measured is released as hydrogen gas. The released hydrogen gas is supplied to the fuel electrode (hydrogen electrode, cathode) of the fuel cell, and oxygen in the air is supplied to the air electrode (oxygen electrode, cathode) of the fuel cell. Electric energy is generated. By measuring the amount of electric energy, the concentration of hydrogen gas contained in the liquid to be measured, that is, the dissolved hydrogen concentration can be measured.

ADVANTAGE OF THE INVENTION According to this invention, the measuring apparatus and measuring method of the dissolved hydrogen concentration which have the following outstanding effects can be provided.
(1) The dissolved hydrogen concentration contained in the liquid to be measured (hydrogen water or the like) at the time of use can be quickly and easily quantified.
(2) The entire apparatus is small, and a measuring apparatus with a very low cost for the apparatus itself and measurement can be obtained.

It is the schematic of the measuring apparatus of the dissolved hydrogen concentration which concerns on one Embodiment of this invention. It is (a) top view which shows a to-be-measured liquid stirring chamber and hydrogen electrode separator which were comprised as a hydrogen electrode separator, (b) aa sectional view, and (c) front view. It is a disassembled front view which shows the fuel cell of the measuring apparatus which concerns on embodiment of FIG. It is a flowchart which shows schematically the measuring method of the dissolved hydrogen which concerns on embodiment of FIG. In the case of changing the flow rate of the liquid to be measured, (a) a graph showing the relationship between the dissolved hydrogen concentration and the voltage value, and (b) the dissolved hydrogen concentration of 0.7 mg / L in the graph of FIG. It is a graph which shows the approximated curve about the above voltage value. In the case where the temperature of the liquid to be measured is changed, (a) the graph showing the relationship between the dissolved hydrogen concentration and the voltage value, and (b) the dissolved hydrogen concentration in the graph of FIG. 6A is 0.7 mg / L. It is a graph which shows the approximated curve about the above voltage value. It is a graph which shows the relationship between dissolved hydrogen concentration and voltage value at the time of changing the pressure in a to-be-measured liquid stirring chamber. It is a graph which shows the relationship between the dissolved hydrogen concentration and voltage value in the case of changing a measuring method (measurement under low resistance load condition or high resistance load condition). A graph showing the relationship between the dissolved hydrogen concentration and the voltage value when (a) the column height A = 3.5 mm of the stirring column of the measured liquid stirring chamber, and (b) when the column height A = 3.0 mm It is a graph which shows the relationship between the dissolved hydrogen concentration of and a voltage value. It is a graph which shows the relationship between dissolved hydrogen concentration at the time of removing the packing in a fuel cell, and a voltage value.

  The dissolved hydrogen concentration measuring apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the dissolved hydrogen concentration measuring apparatus 1 according to this embodiment mainly includes a measured liquid stirring chamber 30 for releasing hydrogen gas contained in the measured liquid W, and the released hydrogen. A fuel battery cell 4 that generates electric energy by reacting a gas and oxygen gas in the air, and a measuring means 6 that measures the amount of the generated electric energy and calculates the dissolved hydrogen concentration from the value. . In particular, in the present embodiment, as shown in FIG. 3, the measured liquid stirring chamber 30 is formed by sealingly covering the opening side of the recessed portion provided in the hydrogen electrode separator 3 with the fuel cell 4. Has been. The fuel cell 2 is configured by enclosing and holding a fuel cell 4 between a hydrogen electrode separator 3 and an oxygen electrode separator 5.

The test solution stirring chamber 30 of Suisokyoku separator 3, the pump 7, through a cock 8 and the channel L _0, hydrogen water manufacturing apparatus (not shown) is connected, produced in the hydrogen water manufacturing apparatus The liquid W to be measured such as hydrogen water is configured to flow in. Incidentally, the flow path L ₂ is a flow path for supplying to the outside without passing through the measuring device 1 the hydrogen water produced by the hydrogen water manufacturing apparatus. The test solution stirring chamber 30, further, the measured fluid W was measured passage L ₁ is connected to discharge. The measuring means 6 for measuring the electric energy generated by the fuel cell 2 is electrically connected to the positive and negative electrodes of the fuel cell 2.

  The liquid to be measured W, which is a measurement target of the measurement apparatus 1 in the present embodiment, is hydrogen water containing abundant hydrogen gas produced by a hydrogen water production apparatus or the like, but the measurement object of the present invention apparatus is limited to this. Instead, any liquid containing hydrogen gas such as tap water or environmental water may be used.

  Next, the configuration and operation of the measured liquid stirring chamber 30 will be described in detail. As shown in FIGS. 2A and 3, the measured liquid stirring chamber 30 includes a measured liquid inflow portion 31 into which the measured liquid W flows and a measured liquid W that has flowed into the measured liquid stirring chamber 30. Are roughly constituted by a plurality of agitation columns 33 for agitating them and a liquid to be measured discharge unit 32 from which the liquid to be measured W is discharged. The measured liquid inflow portion 31 includes an inflow port 31a that opens to the measured liquid stirring chamber 30, and a cylindrical portion 31b that communicates with the inflow port 31a. In addition, the measured liquid discharge part 32 includes a discharge port 32a that opens to the measured liquid stirring chamber 30, and a cylindrical part 32b that communicates with the discharge port 32a.

  The plurality of stirring columns 33 are arranged in a matrix at predetermined intervals in portions other than the locations where the inlet 31a and the outlet 32a are arranged in the measured liquid stirring chamber 30. Therefore, between the stirring columns 33 adjacent to each other, a measured liquid channel 34 formed of a lattice-like groove is formed. The measured liquid W flows into the measured liquid stirring chamber 30 through the inlet 31a of the measured liquid inflow part 31, and then passes through the measured liquid flow path 34 while colliding with the stirring column 33. It goes to the discharge port 32a of the discharge part 32. At that time, the gas collides with a large number of stirring columns 33 and becomes turbulent and stirred, so that hydrogen gas contained in the liquid W to be measured is released. The shape of each stirring column 33 is not particularly limited, and examples thereof include a polygonal column shape, a columnar shape, a truncated pyramid shape, a truncated cone shape, a star shape, and the like. From the viewpoint of release, a polygonal column shape such as a rectangular parallelepiped is preferable. Further, as shown in FIG. 3, as the column height A of the stirring column (groove depth of the measured liquid channel 34), the contact area of the measured liquid W with respect to the stirring column 33 increases, and the measured liquid W is reduced. From the viewpoint of efficient stirring, it is preferable to satisfy A / 2 ≧ B, more preferably A / 3 ≧ B, and A / 3> B with respect to the width B of the measured liquid channel. It is particularly preferred. As an example only, each stirring column 33 has a bottom surface of about a square of about 1.4 mm × about 1.4 mm, a height A of about 3.5 mm, and a measured liquid channel 34 having a width B of about 1 mm. Designed to be By being stirred by the plurality of stirring columns 33 configured as described above, the hydrogen gas released from the liquid to be measured W is supplied to the hydrogen electrode 40 of the fuel battery cell 4 to be described later.

  In the present embodiment, the measured liquid stirring chamber 30 is formed in the hydrogen electrode separator 3 which is a member of the fuel cell 2, but the dissolved hydrogen contained in the measured liquid W is sufficiently released. Any configuration is possible as long as the released hydrogen gas can be supplied to the hydrogen electrode of the fuel cell. For example, the configuration of the measured liquid stirring chamber 30 is such that hydrogen gas is released by bubbling the measured liquid W, and the released hydrogen gas is supplied to the hydrogen electrode of the fuel cell via a conduit or the like. It can also be configured.

  Next, the configuration and operation of the fuel battery cell 4 will be described with reference to FIG. The fuel cell 4 in this embodiment is configured by sequentially stacking a hydrogen electrode 40, a hydrogen diffusion film 41, a catalyst film 43, a polymer electrolyte film 44, an oxygen diffusion film 45, and an oxygen electrode 46 in this order. The fuel cell 4 is accommodated in a recess provided in the hydrogen electrode separator 3, and is mounted so as to cover the opening side of the recess in a hermetically sealed manner. Thereby, the space surrounded by the recess and the fuel battery cell 4 becomes the measured liquid stirring chamber 30, and the hydrogen electrode 40 of the fuel battery cell 4 is disposed adjacent to the measured liquid stirring chamber 30. Become. The configuration of the fuel cell 4 is not limited to that described in the present embodiment, and a configuration generally used as a fuel cell can be widely used. For example, it is possible to use one in which the catalyst film 43 and the polymer electrolyte membrane 44 are integrated, or one in which the electrode and the diffusion film are integrated. It is also possible to use a catalyst film 43 disposed between the oxygen diffusion film 45 and the polymer electrolyte film 44 or a film in which other functional films are disposed.

  Hereinafter, the configuration and operation of each membrane constituting the fuel cell 4 will be briefly described. The hydrogen electrode 40 in this embodiment is formed by sintering carbon on a stainless steel (SUS) material. A large number of holes 40 a are formed in the hydrogen electrode 40 in a matrix, and the hydrogen gas discharged from the measured liquid stirring chamber 30 through these holes 40 a and a part of the measured liquid W are formed in the hydrogen diffusion film 41. Supplied. Further, the hole 40 a formed in the hydrogen electrode 40 is disposed at a position facing the measured liquid flow path 34 of the measured liquid stirring chamber 30 so as not to be covered with the column top 33 a of the stirring column 33. Is formed. Therefore, the hydrogen gas released from the liquid W to be measured is designed to be efficiently supplied to the hydrogen diffusion film 41 side through the hole 40a.

  Next, the hydrogen diffusion film 41 to which the hydrogen gas reaches is formed of carbon fiber. The hydrogen diffusion film 41 has a function of holding the liquid to be measured W and the hydrogen gas supplied through the holes 40 a of the hydrogen electrode 40 and allowing the hydrogen gas to uniformly reach the catalyst film 43. The hydrogen diffusion film 41 also has a function of preventing the platinum component constituting the catalyst film 43 from falling off.

  Next, the catalyst film 43 to which hydrogen gas reaches is formed of carbon fibers containing a platinum catalyst. In the catalyst film 43, a reaction for separating the hydrogen gas that has reached through the hydrogen diffusion film 41 into hydrogen ions is performed. Electrons generated simultaneously with the hydrogen ions move to the oxygen electrode 46 through the carbon fiber of the hydrogen diffusion film 41, the hydrogen electrode 40, and the conductive wire.

  In this embodiment, the polymer electrolyte membrane 44 to which the hydrogen ions reach is formed of a fluororesin cation exchange membrane. In the polymer electrolyte membrane 44, a reaction in which hydrogen ions pass through the polymer electrolyte membrane 44 and move from the hydrogen electrode side to the oxygen electrode side is performed.

  Next, the oxygen electrode separator 5 will be described. The oxygen electrode separator 5 is configured so as to be able to sandwich and accommodate the fuel cell 4 by being combined with the hydrogen electrode separator 3. The oxygen electrode separator 5 is formed with a plurality of oxygen supply holes 50 penetrating the separator surface so that oxygen in the air can be supplied from the holes and water (water vapor) generated by the electrodes can be discharged and evaporated. It is configured.

  In the oxygen electrode separator 5, oxygen in the air is supplied to the oxygen diffusion film 45 through the oxygen supply hole 50 formed in the oxygen electrode separator 5 and the hole 46 a formed in the oxygen electrode 46. Here, the hydrogen ions that have moved to the oxygen electrode 46 side, the electrons that have moved through the conducting wire, and the supplied oxygen react to generate water (water vapor). On the oxygen electrode side, the position of the oxygen supply hole 50 of the oxygen electrode separator 5 and the position of the hole 46a of the oxygen electrode 46 correspond to each other, so that oxygen can be sufficiently taken in and water generated by the chemical reaction is evaporated and released. It is configured to be able to. Similar to the hydrogen electrode 40, the oxygen electrode 46 is formed by sintering carbon on a stainless steel (SUS) material. The oxygen diffusion film 45 is mainly formed of carbon fiber, and by imparting water repellency with a fluororesin or the like, it prevents water wetting and promotes evaporation and release of water (water vapor) generated by the reaction. The oxygen supply can be efficiently performed. Since the hydrogen diffusion film 41 needs to hold a liquid to be measured to a certain degree, the hydrogen diffusion film 41 is configured to give a certain hydrophilicity without applying water repellency.

  In this embodiment, since the fuel battery cell 4 and the measured liquid stirring chamber 30 are adjacent to each other, the measured liquid W filled in the measured liquid stirring chamber 30 is contained in the fuel battery cell 4. There is a possibility of infiltration in large quantities. It is said that the function of the fuel battery cell 4 does not occur at a normal humidity level, but rather the movement of hydrogen ions is facilitated by the presence of moisture in the polymer electrolyte membrane 44. However, in the present invention, since the liquid to be measured W containing hydrogen gas is supplied into the fuel cell 2 instead of hydrogen gas as in a normal fuel cell, the constituent members of the fuel cell 4 are provided. There is a possibility that the function of each film may deteriorate due to water wetting. For example, when the oxygen diffusion film 45 is wetted with water, the supply of oxygen gas is impaired, and the electromotive force is significantly reduced. Further, in the catalyst film 43, a reaction for separating the hydrogen gas into hydrogen ions occurs. However, when the catalyst film 43 gets wet with a large amount of water, the uniform supply of the hydrogen gas to the catalyst film 43 is impaired, so that the electromotive force decreases. To do. Therefore, it is preferable to provide a packing 36 for sealing the peripheral edge between the measured liquid stirring chamber 30 and the hydrogen electrode 40 of the fuel cell 4. In this embodiment, the packing 36 is fitted in a packing groove 35 provided in the measured liquid stirring chamber 30 and is in contact with the peripheral edge of the hydrogen electrode 40. Furthermore, it is preferable to provide a packing 42 for sealing the peripheral edge between the polymer electrolyte membrane 44 and the hydrogen electrode 40. In the present embodiment, as shown in FIG. 3, the packing 42 is in contact with the periphery of the polymer electrolyte membrane 44 and the hydrogen electrode 40 so as to sandwich the hydrogen diffusion membrane 41 and the catalyst membrane 43. Water permeation into the oxygen diffusion film 45 from the periphery between the polymer electrolyte film 44 is prevented. Furthermore, the liquid W to be measured is prevented from entering the hydrogen diffusion film 41 and the catalyst film 43 from other than the holes 40a. In the present embodiment, both the hydrogen diffusion film 41 and the catalyst film 43 are formed to be slightly smaller than the polymer electrolyte film 44 and the hydrogen electrode 40, and the hydrogen diffusion film 41 and the catalyst film 43 are laminated. The peripheral ends of these films are configured to come into contact with the packing 42 when sealed. In the present embodiment, the packing 42 is configured to seal the peripheral portion with a plurality of components interposed therebetween. However, as another embodiment, for example, between the catalyst film 43 and the hydrogen diffusion film 41. It is good also as a structure which seals only a peripheral part. By providing the packing in this way, the liquid W to be measured is prevented from entering the fuel cell 4 in a large amount, and the catalyst film 43 in which the reaction for separating the hydrogen gas into hydrogen ions occurs is caused from excessive water wetting. It is possible to reliably prevent the oxygen diffusion film 45 from being wetted with water.

  The packings 36 and 42 described above may have any configuration as long as water can be prevented from entering, but specifically, those formed of silicon, rubber, or the like are preferably used. Further, instead of these packings, it is possible to use a packing adhered to the peripheral portion of the membrane constituting the fuel battery cell 4 or a configuration in which the peripheral portion of the membrane itself has a sealing function. Specifically, as an example, a configuration in which the packing 42, the polymer electrolyte membrane 44, the catalyst membrane 43, and the hydrogen diffusion membrane 41 are stacked and incorporated is included.

  Further, as described above, in order to avoid excessive water wetting such that the electromotive force of the catalyst film 43 and the oxygen diffusion film 45 is reduced, the water pressure resistance of each film constituting the fuel cell 4 is as follows. Preferably there is. For the hydrogen diffusion film 41, for example, when the internal pressure due to the flow of the measured liquid W in the measured liquid stirring chamber 30 is 0.02 MPa, the water pressure resistance of the hydrogen diffusion film 41 is 0.02 MPa or less. It is preferable that the pressure is 0.0005 MPa to 0.003 MPa. Further, the water pressure resistance on the hydrogen electrode side of the catalyst film 43 is preferably higher than that of the hydrogen diffusion film 41. For example, when the water pressure resistance of the hydrogen electrode side diffusion film 41 is 0.0005 MPa to 0.003 MPa, It is preferably 0.002 MPa to 0.005 MPa.

  Next, the configuration and operation of the measuring means 6 will be described with reference to FIG. In this embodiment, the measuring means 6 includes a voltage measuring device 60 connected in parallel between the positive and negative electrodes of the fuel cell 2 and a load having a low resistance value (for example, several tens to several tens Ω) constituting a steady load. It is mainly composed of a series circuit of a resistor 61 and a normally closed contact switch 62 and an arithmetic unit 63 which is connected to a voltage measuring device 60 and calculates a measurement result representing a dissolved hydrogen concentration from its output voltage value. Yes. You may provide the indicator (not shown) which displays the calculation result of the calculating unit 63. FIG. As the display, for example, an LED lamp, a digital level monitor, an analog level monitor, or the like can be used. By using such an indicator, the measured dissolved hydrogen concentration is simply displayed, so that the dissolved hydrogen concentration can be easily confirmed.

  As described above, electric energy is generated by moving the conductive wire connected to the negative electrode connected to the hydrogen electrode 40 and the positive electrode connected to the oxygen electrode 46 by the electrons generated in the fuel cell 4. By arranging the load resistor 61 and the voltage measuring device 60 between the conductors and measuring the voltage, the electric energy generated in the fuel cell 4 can be measured, and this electric energy corresponds to the dissolved hydrogen concentration. Therefore, the dissolved hydrogen concentration of the liquid W to be measured can be obtained by calculating the measured voltage with the calculator 63.

Since the positive and negative electrodes of the fuel cell 2 are connected by a low-resistance load resistor 61 and are always in a state of low resistance and close to a short circuit, the electric energy generated by the fuel cell 4 is always consumed by the load resistor 61. It is possible to leave it. The value of the low resistance load is not particularly limited as long as it can be adjusted so that at least a part of the electric energy generated by the fuel battery cell 4 is consumed and an output voltage in a suitable range can be obtained. When a fuel battery cell of about 0.04 dm ² is used, 3 to 100Ω is preferable, 7 to 70Ω is more preferable, and 10 to 50Ω is more preferable.

  The voltage measuring device 60 actually measures the voltage across the load resistor 61 connected in parallel to the voltage measuring device 60, but the response speed at which the measured voltage is saturated with respect to the change in the dissolved hydrogen concentration is slow. The switch 62 is opened once and the connection of the load resistor 61 is released. For example, after accumulating electromotive force (electric energy) for about 10 seconds, the switch 62 is closed again and voltage measurement is performed. It is possible to increase the speed.

  Although the load resistor 61 is formed of a fixed resistor in the present embodiment, it can be a variable resistor. By adjusting this variable resistor, it is possible to obtain a voltage value in a suitable measurement range.

  Next, a method for measuring the dissolved hydrogen concentration and a method for using the measuring device for the dissolved hydrogen concentration according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 4, the method for measuring the dissolved hydrogen concentration according to the present embodiment is supplied with a preparatory step S0 for preparing the measurement liquid W, a step S1 for releasing the hydrogen gas contained in the measurement liquid W, Step S2 for generating an electromotive force by the fuel cell using hydrogen gas and oxygen in the air, Step S3 for measuring the amount of electric energy (voltage value) obtained by the generation of the electromotive force, and dissolution from the measured voltage value It consists of process S4 which calculates | requires hydrogen concentration.

(Preparation process)
First, the preparation step S0 shown in FIG. 4 will be described. In this pre-preparation step S0, the liquid to be measured W is prepared. As shown in FIG. 1, the measurement apparatus 1 is connected to, for example, a hydrogen water production apparatus via a pump 7, a cock 8, and a flow path L ₀ , and a measurement target liquid W is prepared to be supplied to the measurement apparatus 1. The liquid W to be measured may be produced each time by a hydrogen water production apparatus or the like as in this embodiment, or is contained in a container such as a cylinder, can or bottle. Also good.

(Measurement liquid stirring process)
Next, the measured liquid stirring step S1 will be described. The prepared measured liquid W is caused to flow from the measured liquid inflow portion 31 of the measuring apparatus 1 into the measured liquid stirring chamber 30 via the pump 7, the cock 8 and the flow path L ₀ shown in FIG. As a result, the measured liquid W collides with the stirring column 33 in the measured liquid stirring chamber 30 to generate a turbulent flow, and hydrogen gas is released. At this time, since the amount of hydrogen gas released in the measured liquid stirring chamber 30 depends on the flow rate and the liquid temperature of the measured liquid W, the measured liquid flow rate and the liquid temperature at the time of measurement are a constant amount and a constant temperature. It is preferable to do. For example, when the flow rate of the liquid to be measured W is increased, the amount of hydrogen gas released by colliding with the stirring column 33 in the liquid to be measured stirring chamber 30 also increases, and as a result, the amount of power generated by the fuel cell 4 is high. Become. Similarly, when the liquid temperature of the liquid W to be measured is high, the amount of released hydrogen gas increases and the activity of hydrogen ions and oxygen ions becomes active and the reaction rate is improved. The amount of power generation increases. Further, when the flow of the measured liquid W is stopped, the hydrogen gas is not released and the amount of power generated by the fuel cell 4 becomes zero. Therefore, the measured liquid W is kept constant until the measurement of the voltage value in the process described later is completed. It is preferable to flow in at a flow rate.

(Electromotive force generation process)
Next, step S2 for generating an electromotive force by the fuel cell 2 using the released hydrogen gas and oxygen in the air will be described. The released hydrogen gas is supplied to the adjacent hydrogen electrode 40 in the fuel cell 4. On the other hand, oxygen in the air is supplied to the oxygen electrode 46 through the oxygen supply hole 50 of the oxygen electrode separator 5. These hydrogen and oxygen react in the fuel cell 4 to generate electric energy. As described above, the electromotive force increases as the amount of released hydrogen gas increases.

(Voltage measurement process)
Next, step S3 for measuring the amount of electric energy (voltage) generated in the fuel cell 4 will be described. As shown in FIG. 1, the measurement in this embodiment is performed by measuring the voltage across the load resistor 61 connected in parallel by the voltage measuring device 60 of the measuring means 6. The switch 62 is normally closed. When the response speed until the measured voltage settles to a constant value is slow, the switch 62 is opened once, the connection of the load resistor 61 is released, the electromotive force is accumulated in the fuel cell 4, and then again. Voltage is measured with the switch 62 closed. Thereby, the response speed can be increased.

(Calculation of dissolved hydrogen concentration)
Next, step S4 related to the calculation of the dissolved hydrogen concentration will be described. The arithmetic unit 63 of the measuring means 6 performs a calculation for applying the voltage value obtained in the voltage measurement step S3 described above to a calibration curve obtained by a test under the same conditions, thereby obtaining a dissolved hydrogen concentration. Further, the calculated dissolved hydrogen concentration may be simply displayed by an LED lamp, a digital level monitor, an analog level monitor, or the like.

  Hereinafter, the present invention will be described in detail with reference to examples.

1. Examination of flow rate of liquid to be measured Voltage when hydrogen water adjusted to various dissolved hydrogen concentrations is used as liquid to be measured (sample liquid) W using the apparatus described in the embodiment of the present invention shown in FIGS. Was measured. Specifically, the fuel cell 4 and the oxygen electrode separator 5 are Horizon Fuel Cell's small PEM fuel cells (product reference number: FCSU-012), and are equipped with a measurement liquid stirring chamber 30 shown in FIG. The pole separator 3 was used. The column height A of the stirring column 33 in the measured liquid stirring chamber 30 was 3.0 mm, and the width B of the measured liquid channel 34 was 1.0 mm. Of the membranes constituting the fuel cell 4, the hydrogen diffusion membrane 41 is made of only carbon fibers and not water-repellent. Further, a packing 36 was inserted between the hydrogen electrode separator 3 and the fuel battery cell 4, and a packing 42 was also inserted between the polymer electrolyte membrane 44 and the hydrogen electrode 40 to prevent the liquid W to be measured from entering. As the measuring means 6, a commercially available voltmeter (model: 732-03, Yokogawa Meter & Instruments Co., Ltd. product) was used as the voltage measuring device 60, and a load resistor 61 of 33.8Ω was used. Measurement conditions were such that the switch 62 was kept closed and only the load resistor 61 was connected between the electrodes of the fuel cell 4. The resistance of the voltage measuring device 60 was considered to be close to infinity. The water temperature of the measured liquid W was 29 ° C., the flow rate of the measured liquid W to the measured liquid stirring chamber 30 was 1050 mL / min, and the pressure in the measured liquid stirring chamber 30 was 0.03 MPa. In addition, about the dissolved hydrogen density | concentration of the to-be-measured liquid (sample liquid) W, it measured simultaneously using the commercially available dissolved hydrogen regulator (model | form; BIH-50D, Bionics apparatus company product).

  Next, the test was performed under the same conditions as described above except that the flow rate of the liquid W to be measured was set to 1680 mL / min or 2100 mL / min.

  The results are shown in FIG. The vertical axis represents the measured output voltage (mV), and the horizontal axis represents the dissolved hydrogen concentration (mg / L) of the measurement liquid W supplied to the measurement liquid stirring chamber 30. Thus, it has been found that the amount of electric energy generated from the fuel cell varies depending on the flow rate of the liquid to be measured, and a larger voltage can be obtained as the flow rate of the liquid to be measured increases. Further, since the dissolved hydrogen concentration and the measured voltage have a substantially linear relationship at any measured liquid flow rate, the dissolved liquid concentration corresponding to the voltage measured from the calibration curve can be obtained if the measured liquid flow rate is constant. It was shown that the hydrogen concentration can be determined. In the low concentration region where the dissolved hydrogen concentration is less than 0.7 mg / L, the linearity of the graph is somewhat disturbed. In the measurement of such a low concentration region, the load resistor 61 is less than 33.8Ω. It is considered preferable to select a calibration curve obtained with a high resistance of about 100Ω and a dissolved hydrogen concentration in a low concentration range. Alternatively, it is considered that the measurement can be performed by setting the flow rate of the liquid to be measured to about 1000 mL / min and selecting a calibration curve having a small slope.

  Moreover, the graph which calculated | required the approximate curve about FIG.5 (b) about the data whose dissolved hydrogen concentration is 0.7 mg / L or more is shown. Thus, the voltage measured at various measured liquid flow rates and the dissolved hydrogen concentration in the measured liquid show a linear relationship. Therefore, it has been found that the apparatus of the present invention can be put into practical use as a dissolved hydrogen concentration measuring apparatus by making the measured liquid flow rate constant during measurement.

2. Examination of measured liquid temperature The same conditions as in Example 1 except that the temperature of the measured liquid, the measured liquid flow rate, and the pressure in the measured liquid stirring chamber 30 were changed using the apparatus described in Example 1. The voltage when hydrogen water adjusted to various dissolved hydrogen concentrations was used as the liquid W to be measured was measured. The measured liquid flow rate was set to 1110 mL / min, and the measured liquid stirring chamber 30 pressure was set to 0.011 MPa. About the liquid temperature of to-be-measured liquid, it tested using what adjusted to 16 degreeC, 23 degreeC, and 33 degreeC, respectively.

  The results are shown in FIG. The vertical axis represents the measured output voltage (mV), and the horizontal axis represents the dissolved hydrogen concentration (mg / L) of the measured liquid W supplied to the measured liquid stirring chamber 30. As a result, it was found that the amount of electric energy generated from the fuel battery cell 4 differs depending on the temperature of the liquid to be measured, but a larger voltage is obtained as the temperature of the liquid to be measured increases, although not as much as the flow rate of the liquid to be measured. In addition, since the dissolved hydrogen concentration and the measured voltage are in a substantially linear relationship at any measured solution temperature, the dissolved solution corresponding to the voltage measured from the calibration curve can be obtained if the measured solution temperature is constant. It was shown that the hydrogen concentration can be determined.

  Moreover, the graph which calculated | required the approximate curve about FIG.6 (b) about the data whose dissolved hydrogen concentration is 0.7 mg / L or more is shown. Thus, the voltage measured at various measured liquid temperatures and the dissolved hydrogen concentration in the measured liquid show a linear relationship. Therefore, it was shown that the device of the present invention can be practically used as a dissolved hydrogen concentration measuring device by keeping the temperature of the liquid to be measured at the time of measurement constant and keeping the flow rate of the liquid to be measured constant as shown in Example 1 described above. .

3. Examination of the pressure in the measured liquid stirring chamber Various dissolved hydrogens under the same conditions as in the first embodiment, except that the flow rate of the measured liquid and the pressure in the measured liquid stirring chamber 30 were changed using the apparatus described in the first embodiment. The voltage when hydrogen water adjusted to the concentration was used as the measurement liquid W was measured. The test was performed with the measured liquid flow rate set to 1350 mL / min and the pressure in the measured liquid stirring chamber 30 set to 0.05 MPa, 0.025 MPa, and 0.012 MPa, respectively.

  The results are shown in FIG. The vertical axis represents the measured output voltage (mV), and the horizontal axis represents the dissolved hydrogen concentration (mg / L) of the measurement liquid W supplied to the measurement liquid stirring chamber 30. As a result, it was shown that the dissolved hydrogen concentration and the measured voltage were in a substantially linear relationship at any water pressure, and the obtained voltage value was not affected by the water pressure value in the measured liquid stirring chamber. . Thereby, it was confirmed that the water pressure of the liquid W to be measured does not affect the electromotive force of the fuel cell, and the liquid volume to be measured and the liquid temperature shown in Examples 1 and 2 have an effect.

4). Examination of measurement method In the apparatus described in Example 1, the resistance value of the low resistance load resistor 61 is set to 10Ω, and a high resistance load resistor of 10 kΩ is connected in parallel to the voltage measuring device 60, and the flow rate of the liquid to be measured The hydrogen was adjusted to dissolved hydrogen concentrations of 1.02, 1.28, 1.61 and 1.90 mg / L under the same conditions as in Example 1 (switch 62 in the closed state) except that was changed to 2100 mL / min. The voltage when water was used as the liquid to be measured W was measured. Also, by using this device, the switch 62 is opened to open the low-resistance load resistor 61, so that only the high-resistance load resistor is used, for 5 seconds, 10 seconds, 15 seconds, 25 seconds, and 30. The output voltage was measured when 2 seconds passed.

  The results are shown in FIG. The vertical axis represents the measured output voltage (mV), and the horizontal axis represents the dissolved hydrogen concentration (mg / L) of the measurement liquid W supplied to the measurement liquid stirring chamber 30. Thereby, it turned out that the voltage value obtained changes with voltage measuring methods. In the fuel cell used in this example, since it is saturated at about 850 mV, when measuring the dissolved hydrogen concentration by the output voltage after opening the switch 62 and using only the high resistance load resistor, It was found that it was necessary to adjust the measurement conditions so that the measured voltage value was 850 mV or less. The measurement conditions can be adjusted by the flow rate and temperature of the liquid to be measured, the short-circuit load amount, the steady load amount, the measurement time, and the like. On the other hand, in the voltage measurement based on the output voltage when the switch 62 is kept closed and the low resistance load resistor 61 is connected, the voltage and the dissolved hydrogen concentration showed a clean linear relationship. In the fuel cell used in this example, it is preferable to control the measured standby voltage to 500 mV or less. For this purpose, it is appropriate to use a load resistor 61 having a low resistance of about 50Ω. It is believed that there is. Thus, it has been found that the apparatus of the present invention is adapted to various voltage measuring methods and can be used as a highly accurate dissolved hydrogen concentration measuring apparatus by adjusting the measurement conditions.

5. Examination of the column height of the stirring column of the measured liquid stirring chamber Using the apparatus described in the embodiment of the present invention shown in FIGS. 1 to 3, hydrogen water adjusted to various dissolved hydrogen concentrations was used as the measured liquid W. The voltage at the time was measured. Specifically, as the fuel cell 4 and the oxygen electrode separator 5, a small PEM fuel cell (product reference number: FCSU-012) manufactured by Horizon Fuel Cell is used, and the liquid stirring chamber 30 shown in FIG. Used as. The column height A of the stirring column 33 in the measured liquid stirring chamber 30 was 3.5 mm, and the width B of the measured liquid channel was 1.0 mm. Of the membranes constituting the fuel cell 4, the hydrogen diffusion membrane 41 was made of only carbon fibers and not water repellent. Further, a packing 36 was inserted between the hydrogen electrode separator 3 and the fuel battery cell 4, and a packing 42 was also inserted between the polymer electrolyte membrane 44 and the hydrogen electrode 40 to prevent the liquid W to be measured from entering. As the measuring means 6, a commercially available voltmeter (model; 732-03, Yokogawa Meter & Instruments Co., Ltd. product) was used as the voltage measuring device 60. As measurement conditions, the switch 62 was kept closed, a low resistance load resistor 61 was connected, and the resistance value was 62.9Ω. In addition, the variable resistor was adjusted so that the output voltage value was 1500 mV when the dissolved hydrogen concentration was 2.0 mg / L. The water temperature of the measured liquid was 28 ° C., the flow rate of the measured liquid W to the measured liquid stirring chamber 30 was 1620 mL / min, and the pressure in the measured liquid stirring chamber 30 was 0.02 MPa.

  Next, the measured liquid stirring chamber 30 was tested under the same conditions as described above except that the column height A of the stirring column 33 was 3.0 mm and the width B of the measured liquid flow path was 1.0 mm. Went.

  The measurement test was carried out under the same conditions for almost half a month, changing the implementation date, 14 times for the test section where the column height A of the stirring column 33 is 3.5 mm, and 11 for the test section where the column height A is 3.0 mm. A round test was performed and the average value of each was calculated. The results are shown in FIG. The vertical axis represents the measured output voltage (mV), and the horizontal axis represents the dissolved hydrogen concentration (mg / L) of the measurement liquid W supplied to the measurement liquid stirring chamber 30. In any test section, it was found that the dissolved hydrogen concentration and the measured voltage had a substantially linear relationship, and the dissolved hydrogen concentration corresponding to the voltage measured from this calibration curve was obtained. Moreover, when the column height A of the stirring column 33 of the measured liquid stirring chamber 30 is 3.5 mm (FIG. 9A) and 3.0 mm (FIG. 9B), the dissolved hydrogen concentration is compared. When a stirring column having a high column height A was used in a relatively low concentration range of 0.5 mg / L or less, a tendency toward stable linearity of the graph was observed. This is presumably because the contact area between the liquid to be measured W and the stirring column is increased by increasing the column height A, which affects the stirring efficiency of hydrogen water.

6). Examination of Packing Using the apparatus described in Example 1, the packing 42 between the polymer electrolyte membrane 44 and the hydrogen electrode 40 is removed, the measured liquid flow rate is 1170 mL / min, and the measured liquid stirring chamber 30 pressure Was changed to 0.022 MPa, and the voltage when hydrogen water adjusted to various dissolved hydrogen concentrations under the same conditions as in Example 1 was used as the measurement liquid W was measured. The measurement test was performed five times under the same conditions, changing the day, and each voltage value was measured.

  The results are shown in FIG. The vertical axis represents the measured output voltage (mV), and the horizontal axis represents the dissolved hydrogen concentration (mg / L) of the measurement liquid W supplied to the measurement liquid stirring chamber 30. Thus, it has been found that when there is no packing 42 between the polymer electrolyte membrane 44 and the hydrogen electrode 40, the voltage and the dissolved hydrogen concentration are not in a linear relationship and may be disturbed. When the fuel cells on the test day that did not show a linear relationship were disassembled and examined, the measured liquid W reached the catalyst film 43 and the oxygen diffusion film 45 along the peripheral edge of the film, and the catalyst film 43 and It was found that the oxygen diffusion film 45 was excessively wetted. Thereby, it is considered that the uniform supply of hydrogen gas to the catalyst film 43 and the supply of oxygen gas to the oxygen diffusion film 45 are impaired, and a stable electromotive force cannot be obtained. Therefore, it is preferable to arrange the packing 42 between the polymer electrolyte membrane 44 and the hydrogen electrode 40 in order to stably measure the dissolved hydrogen concentration.

  The present invention is not limited to the above-described embodiments or examples, and various design changes within the scope not departing from the gist of the invention described in the claims are also included in the technical scope. .

DESCRIPTION OF SYMBOLS 1 Measuring apparatus of dissolved hydrogen concentration 2 Fuel cell 3 Hydrogen electrode separator 30 Measuring liquid stirring chamber 31 Measuring liquid inflow part 31a Inlet 31b Tube part 32 Measuring liquid discharge part 32a Outlet 32b Tube part 33 Stirring pillar 33a Column top 34 Liquid channel for measurement 35 Groove for packing 36 Packing A Column height of stirring column B Width of liquid channel for measurement 4 Fuel cell 40 Hydrogen electrode 40a Hole 41 Hydrogen diffusion membrane 42 Packing 43 Catalyst membrane 44 Polymer electrolyte membrane 45 Oxygen diffusion film 46 Oxygen electrode 46a Hole 5 Oxygen electrode separator 50 Oxygen supply hole 6 Measuring means 60 Voltage measuring device 61 Load resistor 62 Switch 63 Calculator 7 Pump 8 Cock L _{0 to} L ₂ Flow path W Liquid to be measured

Claims (5)

A measurement liquid stirring chamber for releasing hydrogen gas contained as dissolved hydrogen in the measurement liquid from the measurement liquid;
A fuel battery cell that generates electric energy by reacting hydrogen gas released from the liquid to be measured with oxygen gas in the air;
Measuring means connected to the fuel cell and measuring the amount of electric energy generated from the fuel cell ,
The test solution stirring chamber, apparatus for measuring dissolved hydrogen concentration which is characterized that you have been configured as a hydrogen electrode separator of the fuel cell.   The measuring means is connected to the voltage measuring device connected to the output terminal of the fuel cell, and is connected in parallel with the voltage measuring device, and consumes at least a part of the electric energy generated by the fuel cell. The dissolved hydrogen concentration measuring device according to claim 1, further comprising a resistive load resistor. The measuring means is connected to the voltage measuring device and calculates a dissolved hydrogen concentration value from the voltage value measured by the voltage measuring device, and a display for displaying the dissolved hydrogen concentration value calculated by the calculating device. The apparatus for measuring a dissolved hydrogen concentration according to claim 2 , further comprising: The measurement liquid stirring chamber includes an inflow portion and a discharge portion of the measurement liquid, a plurality of stirring columns arranged at predetermined intervals in the vertical and horizontal directions, and a target formed in a lattice shape between the plurality of stirring columns. A measurement liquid flow path,
Wherein the column height A of the stirring pole and the width B of the measured liquid flow path, according to any one of claims 1 to 3, their length is characterized by a A / 2 ≧ B Measuring device for dissolved hydrogen concentration. 5. The sealing member for preventing intrusion of the liquid to be measured is provided at an outer edge between the hydrogen electrode constituting the fuel battery cell and the electrolyte membrane . The apparatus for measuring a dissolved hydrogen concentration according to Item 1 .