JP5170990B2 - Humidification tank for polymer electrolyte fuel cell - Google Patents

Description

  The present invention relates to a humidification tank of a polymer electrolyte fuel cell suitable as a small power source for home use, for example.

  In recent years, reformers that reform hydrocarbon fuel gases such as natural gas, city gas, methanol, LPG, and butane into hydrogen, CO converters that transform carbon monoxide, and CO removal that removes carbon monoxide , A fuel cell that generates electricity by chemically reacting the thus obtained hydrogen (reformed gas) and an oxidant such as oxygen in the air, and cooling the electrode part of the fuel cell and these reaction gases Proposal of a polymer electrolyte fuel cell power generation device as a compact power source equipped with a humidification tank (water tank) containing water (pure water) treated with a water treatment device such as ion exchange resin to humidify (For example, see Patent Documents 1, 2, and 3).

  The solid polymer electrolyte membrane used in the polymer electrolyte fuel cell power generator functions as a proton conductive electrolyte by containing water. In the polymer electrolyte fuel cell, oxidant gas such as air, fuel gas, etc. A method of operating by supplying water vapor to the reaction gas and supplying it to the electrode section is employed.

  When a fuel gas containing hydrogen is supplied to the fuel electrode and an oxidant gas such as air is supplied to the air electrode, the fuel electrode reacts to decompose hydrogen molecules into hydrogen ions and electrons at the fuel electrode, and oxygen, hydrogen ions, and electrons at the air electrode. Electrochemical reaction to generate water from each is performed, and electric power is supplied to the load by electrons moving in the external circuit from the fuel electrode toward the air electrode, and water is generated on the air electrode side.

FIG. 4 is an exploded cross-sectional view showing a basic configuration of a single cell of a polymer electrolyte fuel cell which is one form of a conventional fuel cell.
Air electrode side catalyst layer 14 and fuel containing precious metal (mainly platinum) on both main surfaces of solid polymer electrolyte membrane 13 such as a polymer ion exchange membrane (for example, a fluororesin ion exchange membrane having a sulfonic acid group). A cell is configured by joining the pole-side catalyst layer 15 together. The air electrode side gas diffusion layer 16 and the fuel electrode side gas diffusion layer 17 are arranged to face the air electrode side catalyst layer 14 and the fuel electrode side catalyst layer 15, respectively.
Thereby, the air electrode 1k and the fuel electrode 1a are comprised, respectively. These gas diffusion layers 16 and 17 serve to transmit an electric current to the outside while allowing the oxidant gas and the fuel gas to pass therethrough, respectively.
A conductive and gas-impermeable material (for example, carbon) having a gas flow path 18 for reaction gas flow facing the cell and a cooling water flow path 19 for cooling water flow on the opposing main surface. A single cell 21 is formed by being sandwiched by a pair of separators 20 made of the same.
The fuel cell 1 is formed by laminating a large number of single cells 21 and sandwiching them by a current collector plate (not shown), an insulating plate for the purpose of electrical insulation and thermal insulation, and a clamping plate for applying a load to maintain the laminated state. And is tightened with a nut.

  FIG. 5 is an explanatory diagram schematically illustrating an example of a humidification tank containing humidification water provided in a conventional fuel cell (PEFC) (polymer electrolite fuel cell).

As shown in FIG. 5, the fuel cell 1 </ b> A includes an oxidant humidification tank 3 containing humidified water 3 </ b> A to be supplied from a supply unit 3 </ b> B via a line 2 </ b> A provided with a pump 2 for supplying air. And a fuel gas humidification tank containing humidified water 4A for supplying the fuel gas supplied through the desulfurizer, reformer, CO converter, and CO remover (not shown) from the supply unit 4B for over humidification 4 is provided.
The oxidant humidification tank 3 is provided with a pipe line 3D that flows the humidified air from the outflow portion 3C to the outside and supplies it to the air electrode 1k of the fuel cell 1A. The fuel gas humidification tank 4 is a fuel after humidification. From the outflow portion 4C to the outside and supply to the fuel electrode 1a of the fuel cell 1A.
The oxidant humidification tank 3 and the fuel gas humidification tank 4 are provided with pipe lines 3N and 4N for draining a required amount of humidified water 3A and humidified water 4A as required.

  The humidified water 3A, 4A is supplied with pure water by supplying city water to a water treatment device (not shown) made of, for example, an ion exchange resin, and is oxidized through a required amount of pipe 3L and pipe 4L as necessary. It is configured to be supplied to the agent humidification tank 3 and the fuel gas humidification tank 4.

The oxidant humidification tank 3 and the fuel gas humidification tank 4 are provided with a heat exchanger 3E and a heat exchanger 4E that are fixedly installed inside.
The heat exchanger 3E and the heat exchanger 4E include a pipeline 5A that supplies cooling water to the cooling unit 1c of the fuel cell 1A, and a pipeline 5B that circulates and sends the cooling water from the cooling unit 1c. .
After the heat exchange between the cooling water and the humidified water 3A and 4A is indirectly performed in the heat exchanger 3E and the heat exchanger 4E, the cooling water is circulated and sent to the cooling unit 1c of the fuel cell 1A through the pipe line 5A. It is like that.

  3F is a bubbling perforated tube installed in connection with the supply unit 3B of the oxidant humidification tank 3, and 4F is a bubbling perforated tube installed in connection with the supply unit 4B of the fuel gas humidification tank 4.

  The oxidant humidification tank 3 and the fuel gas humidification tank 4 are fixedly provided with partition walls 3K and 4K that partition the gas inflow portions 3G and 4G and the gas outflow portions 3H and 4H, respectively.

The reaction gas flows from the supply units 3B and 4B into the oxidizer humidification tank 3 and the fuel gas humidification tank 4 and is bubbled through the perforated tubes 3F and 4F into the humidified water 3A and 4A to be humidified and humidified. The gas is caused to flow from the gas inflow portions 3G and 4G to the gas outflow portions 3H and 4H through the partition walls 3K and 4K, respectively, and from the respective outflow portions 3C and 4C to the outside.
JP 2003-217620 A JP 2003-217623 A JP 2004-199980 A

  However, when the reaction gas flows from the supply units 3B and 4B into the oxidizer humidification tank 3 and the fuel gas humidification tank 4 and is bubbled into the humidified water 3A and 4A through the porous tubes 3F and 4F, bubbles are generated. The bubbles break, the water surface becomes unstable and the bubbles scatter, and water droplets adhere to the top plate inner walls 3J and 4J of the oxidant humidification tank 3 and the fuel gas humidification tank 4. The adhering water droplets gradually become larger, and the enlarged water droplets move to the outflow portions 3C and 4C respectively, and are accompanied by the humidified reaction gas and flow out to the outside, and the scattered bubbles are humidified. There was a problem of being directly entrained by the reaction gas and flowing out from the outflow portions 3C and 4C.

  When the water droplets and bubbles are accompanied by the humidified reaction gas and flow out to the outside from the outflow portions 3C and 4C, the inner walls of the pipelines 3D and 4D that supply the reaction gas to the air electrode 1k and the fuel electrode 1a of the fuel cell 1A. Or adhering to the inner wall of the gas flow path 18 for circulating the reaction gas, preventing the uniform flow of the reaction gas, causing clogging, and the air electrode 1k and the air electrode of the fuel electrode 1a. The catalyst layer 14, the fuel electrode side catalyst layer 15, the air electrode side gas diffusion layer 16, and the fuel electrode side gas diffusion layer 17 remain unevenly distributed or partially clogged, and the uniform distribution of the reaction gas is impaired. As a result, there is a problem that uniform and stable electrochemical reaction is not performed and stable power generation cannot be performed.

  The object of the present invention is to prevent water droplets from adhering to the inner wall of the top plate of the oxidizer humidification tank and the fuel gas humidification tank to gradually flow out from the outflow part by being accompanied by the humidified reaction gas. In addition, the scattered bubbles are directly entrained by the humidified reaction gas and do not flow out of the outflow part, so that stable electrochemical reaction can be performed and stable power generation can be performed. The present invention provides a humidifying tank for a polymer electrolyte fuel cell.

The humidification tank of the polymer electrolyte fuel cell according to claim 1 of the present invention for solving the above-mentioned problem is that the air electrode and the fuel electrode are formed on both surfaces of the solid polymer electrolyte membrane, and the air electrode and the fuel are provided. A humidification tank containing humidified water for humidifying the reaction gas provided in a fuel cell for generating electricity by supplying reaction gas to each of the electrodes,
The reaction gas is provided with a gas inflow part, a gas outflow part of the reaction gas, a partition partitioning the gas inflow part and the gas outflow part, and the reaction gas is supplied and bubbled into the humidified water to be humidified. The humidified water is provided at the tip of the partition as a bubble scattering prevention means for preventing the bubble from scattering by the bubbling to the outflow path for allowing the humidified reaction gas to flow out from the gas outflow portion beyond the partition. A foam scattering prevention plate inclined at a predetermined angle θ and having a predetermined length L is fixedly installed on the side, and water droplets adhering to the inner wall of the top plate of the humidifying tank are accompanied by the humidified reaction gas to the outside. As a means for preventing water droplet entrainment from flowing out, a water droplet entrainment prevention plate is fixed in parallel to the inner wall of the top plate of the humidifying tank with a predetermined interval W with respect to the foam scattering prevention plate. The foam It was dispersed prevention plate configured to have a flow path of humidified the reaction gas between the water droplet entrainment baffle plate and said.

(Delete)

Humidification tank of the polymer electrolyte fuel cell according to claim 2 of the present invention, in a humidified tank of the polymer electrolyte fuel cell according to claim 1 Symbol placement,
A heat exchanger for indirectly exchanging heat between the cooling water for cooling the fuel cell and the humidified water is fixed and installed inside.

The humidification tank of the polymer electrolyte fuel cell according to claim 1 of the present invention comprises an air electrode and a fuel electrode on both surfaces of the solid polymer electrolyte membrane, and a reaction gas is supplied to each of the air electrode and the fuel electrode. A humidifying tank containing humidified water for humidifying the reaction gas provided in a fuel cell that supplies and reacts to generate electricity,
The reaction gas is provided with a gas inflow part, a gas outflow part of the reaction gas, a partition partitioning the gas inflow part and the gas outflow part, and the reaction gas is supplied and bubbled into the humidified water to be humidified. The humidified water is provided at the tip of the partition as a bubble scattering prevention means for preventing the bubble from scattering by the bubbling to the outflow path for allowing the humidified reaction gas to flow out from the gas outflow portion beyond the partition. A foam scattering prevention plate inclined at a predetermined angle θ and having a predetermined length L is fixedly installed on the side, and water droplets adhering to the inner wall of the top plate of the humidifying tank are accompanied by the humidified reaction gas to the outside. As a means for preventing water droplet entrainment from flowing out, a water droplet entrainment prevention plate is fixed in parallel to the inner wall of the top plate of the humidifying tank with a predetermined interval W with respect to the foam scattering prevention plate. The foam Since the diffuser preventing plate configured to have a flow path of humidified the reaction gas between the water droplet entrainment prevention plate,
Even if water droplets adhere to the top wall of the top plate of the oxidizer humidification tank and fuel gas humidification tank and gradually increase in size, the water droplets accompanying the humidified reaction gas will not flow out to the outside due to the action of the water droplet entrainment prevention plate, The action of the water droplet entrainment prevention plate has the effect of returning water droplets to the humidified water in each humidification tank, and the scattered bubbles are directly entrained by the reaction gas humidified by the action of the foam splash prevention plate and do not flow outside. In addition, since the foam has the effect of returning to the humidified water in each humidifying tank due to the action of the foam scattering prevention plate, it is possible to perform more stable electrochemical reaction and more stable power generation. Has a remarkable effect.

(Delete)

Humidification tank of the polymer electrolyte fuel cell according to claim 2 Symbol placement of the present invention, in a humidified tank of the polymer electrolyte fuel cell according to claim 1 Symbol placement,
Since the heat exchanger for indirectly exchanging heat between the cooling water for cooling the fuel cell and the humidified water is fixed and installed inside,
Humidified water in the oxidizer humidification tank and fuel gas humidification tank is controlled to an appropriate temperature, and humidified reaction gas controlled to an appropriate temperature can be supplied to the air electrode and the fuel electrode, respectively. Since the temperature in the fuel cell is controlled by the cooling water so as to be maintained at a temperature suitable for power generation, there is a further remarkable effect that stable electrochemical reaction can be performed and more stable power generation can be performed.

Next, the present invention will be described in detail based on embodiments with reference to the drawings.
FIG. 1 is an explanatory view schematically illustrating an example of a humidifying tank of a polymer electrolyte fuel cell of the present invention.
FIG. 2 is an explanatory view for schematically explaining the main part of the humidifying tank shown in FIG.
FIG. 3 is an explanatory view for explaining one embodiment of the humidifying tank of the polymer electrolyte fuel cell of the present invention.
1-3, the parts having the same reference numerals as those in FIG. 5 are parts having the same functions.

As shown in FIG. 1, the fuel cell 1 includes an oxidant humidifier containing humidified water 3 </ b> A for supplying air from a supply unit 3 </ b> B via a line 2 </ b> A provided with a pump 2 for supplying air. A tank 3 is provided, and a fuel gas humidifying tank 4 containing humidified water 4A for supplying the fuel gas from the supply unit 4B and overhumidifying is provided.
The oxidant humidification tank 3 is provided with a pipe line 3D that flows the humidified air from the outflow portion 3C to the outside and supplies it to the air electrode 1k of the fuel cell 1, and the fuel gas humidification tank 4 is a fuel after humidification. Is provided to the outside from the outflow portion 4C to be supplied to the fuel electrode 1a of the fuel cell 1.
The oxidant humidification tank 3 and the fuel gas humidification tank 4 are provided with pipe lines 3N and 4N for draining a required amount of humidified water 3A and humidified water 4A as required.

  The humidified water 3A, 4A is supplied with pure water by supplying city water to a water treatment device (not shown) made of, for example, an ion exchange resin, and is oxidized through a required amount of pipe 3L and pipe 4L as necessary. It is configured to be supplied to the agent humidification tank 3 and the fuel gas humidification tank 4.

The oxidant humidification tank 3 and the fuel gas humidification tank 4 are provided with a heat exchanger 3E and a heat exchanger 4E that are fixedly installed inside.
The heat exchanger 3E and the heat exchanger 4E include a pipeline 5A that supplies cooling water to the cooling unit 1c of the fuel cell 1A, and a pipeline 5B that circulates and sends the cooling water from the cooling unit 1c.
After the heat exchange between the cooling water and the humidified water 3A and 4A is indirectly performed in the heat exchanger 3E and the heat exchanger 4E, the cooling water is circulated and sent to the cooling unit 1c of the fuel cell 1A through the pipe line 5A. It is like that.

  3F is a bubbling perforated tube installed in connection with the supply unit 3B of the oxidant humidification tank 3, and 4F is a bubbling perforated tube installed in connection with the supply unit 4B of the fuel gas humidification tank 4.

  The oxidant humidification tank 3 and the fuel gas humidification tank 4 are fixedly provided with gas inflow portions 3G, gas inflow portions 4G and gas outflow portions 3H, and partition walls 3K and 4K that partition the gas outflow portions 4H, respectively. .

  The reaction gas flows from the supply units 3B and 4B into the oxidant humidification tank 3 and the fuel gas humidification tank 4, respectively, and is humidified by bubbling into the humidified water 3A and 4A through the porous tubes 3F and 4F. The reaction gas flows from the gas inflow portions 3G and 4G to the gas outflow portions 3H and 4H through the partition walls 3K and 4K, respectively, and flows out from the outflow portions 3C and 4C to the outside.

  Hereinafter, although the structure and effect of the fuel gas humidifying tank 4 will be described, the oxidant humidifying tank 3 is the same as the fuel gas humidifying tank 4, and thus the description thereof is omitted.

As shown in FIG. 2, in the present invention, a foam scattering prevention plate 6 having a predetermined length L on the humidified water 4A side and inclined at a predetermined angle θ is fixed to the tip of the partition wall 4K of the humidifying tank 4. together with installation by, for installation in parallel to fix the water droplet entrainment prevention plate 7 at a predetermined distance W to foam shatterproof plate 6 to the top plate inner wall 4J humidification tank 4.
That is, the fuel gas humidification tank 4 has a bubble scattering prevention plate 6 fixed at a tip end of the partition wall 4K having a predetermined length L on the humidified water 4A side and inclined at a predetermined angle θ. In addition, a water droplet entrainment prevention plate 7 is fixed on the top wall 4J of the fuel gas humidification tank 4 with a predetermined interval W in parallel to the bubble scattering prevention plate 6 and is installed in parallel with the bubble scattering prevention plate 6 and water droplets. A humidified fuel gas flow path 8 is formed between the entrainment prevention plate 7.
Reference numeral 6-1 denotes a fixing part of the foam scattering prevention plate 6 to the tip of the partition wall 4K, and 7-1 denotes a fixing part of the water droplet entrainment prevention plate 7 to the top plate inner wall 4J.

If the length L of the bubble scatter prevention plate 6 is too long, the area above the humidified water 4A is covered with a large area, so the effect of preventing the bubble scatter is great. However, the tip of the bubble scatter prevention plate 6 is too close to the top plate inner wall 4J. The fuel gas flow path 8 becomes narrow, the fuel gas supply pressure increases, and there is a possibility that a predetermined amount of fuel gas cannot be supplied to the fuel electrode 1a of the fuel cell 1A.
Conversely, if the length L of the bubble scatter prevention plate 6 is too short, the effect of preventing the bubble scatter is reduced because the area above the humidified water 4A can be covered only by a small area, and bubbles and water droplets are directly accompanied by the humidified fuel gas. May flow out to the outside, and the scattered bubbles may adhere to the foam scattering prevention plate 6 and become water droplets, making it difficult to return to the humidified water 4A in the fuel gas humidifying tank 4.

On the other hand, if the angle θ between the bubble scatter prevention plate 6 and the partition wall 4K is too large, the scattered bubbles adhere to the bubble scatter prevention plate 6 and are easily returned to the humidified water in the fuel gas humidification tank 4 as water droplets. However, the tip of the bubble scattering prevention plate 6 is too close to the top plate inner wall 4J, the fuel gas flow path 8 is narrowed, the fuel gas supply pressure is increased, and a predetermined amount of fuel gas is supplied to the fuel electrode of the fuel cell 1A. There is a possibility that it cannot be supplied to 1a, and since the area covering the humidified water 4A is small, the effect of preventing foam scattering may be small.
Conversely, if the angle θ of the bubble scatter preventing plate 6 is too small, the effect of preventing the bubble scatter is great because the area above the humidified water 4A is covered with a large area, but the interval W between the water droplet entrainment preventing plate 7 and the bubble scatter preventing plate 6 is large. Since it becomes larger, there is a possibility that bubbles and water droplets are directly entrained in the humidified fuel gas and flow out to the outside, and the bubbles adhering to the bubble scattering prevention plate 6 become water droplets and become humidified water 4A in the fuel gas humidifying tank 4 There is a risk that it will be difficult to return.

The water droplet entrainment prevention plate 7 is fixed to the top plate inner wall 4J in parallel to the bubble scattering prevention plate 6 with a predetermined interval W therebetween.
If the interval W is too narrow, the fuel gas supply pressure increases, and a predetermined amount of fuel gas may not be supplied to the fuel electrode 1a of the fuel cell 1A. If the interval W is too wide, the flow path resistance is small. However, water droplets and bubbles may be directly entrained with the humidified fuel gas and flow out to the outside.

If the water droplet entrainment prevention plate 7 is not parallel to the bubble scattering prevention plate 6 and the tip of the water droplet entrainment prevention plate 7 opposite to the fixing portion 7-1 is too close to the bubble scattering prevention plate 6, the fuel gas supply pressure , And a predetermined amount of fuel gas cannot be supplied to the fuel electrode 1a of the fuel cell 1A. On the contrary, the tip of the water droplet entrainment prevention plate 7 on the opposite side of the fixed portion 7-1 prevents bubbles from scattering. If it is too far from the plate 6, the flow path resistance becomes small, but there is a possibility that the water droplets adhering to the water droplet entrainment prevention plate 7 are difficult to be returned to the humidified water in the fuel gas humidifying tank 4.
If the length of the water droplet entrainment prevention plate 7 is too long than L, the distance a between the tip of the water droplet entrainment prevention plate 7 opposite to the fixed portion 7-1 and the side wall of the fuel gas humidification tank 4 becomes too small. The fuel gas supply pressure becomes high, and there is a possibility that a predetermined amount of fuel gas cannot be supplied to the fuel electrode 1a of the fuel cell 1A.
If the length of the water droplet entrainment prevention plate 7 is too short than L, the flow path resistance becomes small, but there is a possibility that water droplets and bubbles are directly entrained with the humidified fuel gas and flow out to the outside.

  If the water drop entrainment prevention plate 7 is not parallel to the bubble splash prevention plate 6 and the tip of the opposite side of the fixing portion 6-1 of the bubble splash prevention plate 6 is too close to the water drop entrainment prevention plate 7, the fuel gas supply pressure , And a predetermined amount of fuel gas may not be supplied to the fuel electrode 1a of the fuel cell 1A. Conversely, the tip on the opposite side of the fixed portion 6-1 of the bubble scattering prevention plate 6 is prevented from being accompanied by water droplets. If it is too far from the plate 7, the flow resistance becomes small, but bubbles or water droplets may be directly entrained in the humidified fuel gas and flow out to the outside, and the water droplets adhering to the bubble scattering prevention plate 6 are humidified by the fuel gas. There is a risk that it will be difficult to return to the humidified water in the tank 4.

  The material of the water drop entrainment prevention plate 7 and the bubble scattering prevention plate 6 is not particularly limited. However, it is preferable to form the same material as the fuel gas humidification tank 4, the partition wall 4K, and the top plate inner wall 4J because corrosion hardly occurs in the connection parts 6-1 and 7-1.

As shown in FIG. 2, even if water droplets adhere to the top plate inner wall 4J surface of the fuel gas humidifying tank 4 and gradually increase in size, the water droplets accompanying the humidified fuel gas is externally moved by the action of the water droplet entrainment prevention plate 7. Water droplets that do not flow out to the top plate inner wall 4J surface and are gradually moved to the water droplet entrainment prevention plate 7 side by the humidified fuel gas, and water droplets adhering to the water droplet entrainment prevention plate 7 It flows downward along the prevention plate 7 and returns to the humidified water 4 </ b> A in the fuel gas humidifying tank 4.
Further, the scattered bubbles are directly accompanied by the fuel gas humidified by the action of the bubble scattering prevention plate 6 and do not flow to the outside, and the bubbles are attached to the bubble scattering prevention plate 6 by the action of the bubble scattering prevention plate 6 and partly It becomes water droplets, flows downward along the bubble scattering prevention plate 6, and returns to the humidified water 4 </ b> A in the fuel gas humidifying tank 4.
As a result, more stable electrochemical reaction can be performed, and more stable power generation can be performed.

Further, since the fuel gas humidification tank 4 is configured to include the heat exchanger 4E, the humidified water 4A of the fuel gas humidification tank 4 indirectly exchanges heat with the cooling water of the fuel cell 1 in the heat exchanger 4E. To an appropriate temperature (for example, 73 to 76 ° C.).
The fuel gas bubbled in the humidified water 4A becomes a humidified fuel gas controlled to an appropriate temperature, and in this way, after the moisture is given so that the reaction in the fuel cell 1 is appropriately maintained. Since the fuel gas flows out from the outflow portion 4C of the fuel gas humidification tank 4 and is supplied to the fuel electrode 1a of the fuel cell 1 through the conduit 4D, a more stable electrochemical reaction can be performed. More stable power generation can be performed.

Similarly, since the oxidant humidification tank 3 includes a heat exchanger 3E, the humidified water 3A in the oxidant humidification tank 3 indirectly exchanges heat with the cooling water of the fuel cell 1 in the heat exchanger 3E. To an appropriate temperature (for example, 75 to 78 ° C.).
The oxidant gas bubbled in the humidified water 3A became a humidified oxidant gas controlled to an appropriate temperature, and thus was given moisture so that the reaction in the fuel cell 1 was maintained moderately. Since the subsequent oxidant gas flows out from the outflow part 3C of the oxidant humidification tank 3 and is supplied to the air electrode 1k of the fuel cell 1 through the conduit 3D, a more stable electrochemical reaction It is possible to perform more stable power generation.

In the fuel cell 1, power generation is performed by an electrochemical reaction between hydrogen in the reformed gas supplied to the fuel electrode 1a and oxygen in the air supplied to the air electrode 1k.
The cooling unit 1c of the fuel cell 1 circulates and uses cooling water so that the fuel cell 1 does not overheat due to the reaction heat of the electrochemical reaction, and the temperature inside the fuel cell 1 is suitable for power generation (for example, 78 (About ˜80 ° C.). In this way, the fuel cell 1 continues the predetermined chemical reaction and power generation.

  Then, by humidifying using the oxidant humidification tank 3 and the fuel gas humidification tank 4 having appropriate heat capacities, the reaction gas can be mixed with the water temperature of the oxidant humidification tank 3 and the fuel gas humidification tank 4 even if disturbance such as load fluctuation occurs. The dew point can be maintained, and even when the temperature of the fuel cell 1 fluctuates, the dew point fluctuates accordingly, so that stable dew point control is possible, and the reaction in the fuel cell 1 is appropriately maintained. Thus, the reaction gas after being given moisture can be supplied to the fuel cell 1, and the heat exchangers 3E and 4E indirectly exchange heat with the cooling water of the fuel cell 1 to control the temperature appropriately. High oxidant dew point and fuel gas dew point can be secured by directly bubbling oxidant such as air and fuel gas in each of the humidified water 3A and 4A.

  The description of the above embodiment is for explaining the present invention, and does not limit the invention described in the claims or reduce the scope. Moreover, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

Humidification tank of the polymer electrolyte fuel cell of the present invention uses a water droplet entrainment prevention plate as water droplets entrained prevention means, since the use foam shatterproof plate as a foam scattering prevention means, water droplets adhered to the top plate inner wall surface However, even if it gradually increases, the water droplets accompanying the humidified reaction gas by the action of the water droplet entrainment prevention plate does not flow out to the outside, and the water droplets are prevented from flowing into the humidified water in each humidifying tank by the action of the water drop entrainment prevention plate. In addition to the effect of returning bubbles, the scattered bubbles are directly entrained by the reaction gas moistened by the action of the foam scatter prevention plate and do not flow outside, and the foam becomes water droplets by the action of the foam scatter prevention plate. since there is an effect to be returned to the humidification water in, performing the more stable electrochemical reaction, so a marked effect called can be performed more stable power generation and high industrial value .

It is explanatory drawing which illustrates typically an example of the humidification tank of the polymer electrolyte fuel cell of this invention. It is explanatory drawing which illustrates typically the principal part of the humidification tank shown in FIG. It is explanatory drawing explaining 1 Example of the humidification tank of the polymer electrolyte fuel cell of this invention. It is an exploded sectional view showing the basic composition of the single cell of the polymer electrolyte fuel cell which is one form of the conventional fuel cell. It is explanatory drawing which illustrates typically an example of the humidification tank containing the humidification water with which the conventional fuel cell (PEFC) was equipped.

DESCRIPTION OF SYMBOLS 1, 1A Fuel cell 1a Fuel electrode 1k Air electrode 1c Cooling part 2 Pump 3 Oxidant humidification tank 4 Fuel gas humidification tank 3A, 4A Humidification water 3B, 4B Supply part 3C, 4C Outflow part 3D, 4D, 3N, 4N, 3L 4L, 5A, 5B, pipeline 3E, 4E heat exchanger 3F, 4F porous tube 3G, 4G gas inflow part 3H, 4H gas outflow part 3K, 4K partition 13 solid polymer electrolyte membrane 18 gas flow path 19 cooling water flow path θ Angle L Length W Interval a Distance

Claims (2)

An air electrode and a fuel electrode are formed on both surfaces of the solid polymer electrolyte membrane, and the reaction gas provided in the fuel cell for generating electric power by supplying a reaction gas to the air electrode and the fuel electrode for reaction is humidified. A humidifying tank containing humidifying water for
The reaction gas is provided with a gas inflow part, a gas outflow part of the reaction gas, a partition partitioning the gas inflow part and the gas outflow part, and the reaction gas is supplied and bubbled into the humidified water to be humidified. The humidified water is provided at the tip of the partition as a bubble scattering prevention means for preventing the bubble from scattering by the bubbling to the outflow path for allowing the humidified reaction gas to flow out from the gas outflow portion beyond the partition. A foam scattering prevention plate inclined at a predetermined angle θ and having a predetermined length L is fixedly installed on the side, and water droplets adhering to the inner wall of the top plate of the humidifying tank are accompanied by the humidified reaction gas to the outside. As a means for preventing water droplet entrainment from flowing out, a water droplet entrainment prevention plate is fixed in parallel to the inner wall of the top plate of the humidifying tank with a predetermined interval W with respect to the foam scattering prevention plate. The foam Polymer electrolyte fuel cell humidification tank, characterized in that the humidified configuration in which a flow path of the reaction gas between the diffuser preventing plate wherein the water droplet entrainment prevention plate. 2. The polymer electrolyte fuel cell according to claim 1 , wherein a heat exchanger for indirectly exchanging heat between the cooling water for cooling the fuel cell and the humidified water is fixed and installed inside. Humidification tank.

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