JP2004158200A - Fuel cell device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To promptly exhaust the hydrogen leaked in the case to house a fuel cell power generation system to the outside of the case. <P>SOLUTION: The fuel cell power generation system 1 consisting of a hydrogen storage tank 5, a pressure control valve 11, and a fuel cell 7 etc. is housed at the upper part inside the case 3. The air exhausted from an air electrode exit of the fuel cell 7 is sent inside the case 3 through outside piping 27a. Air passages 29a, 29b, 29c are formed at the lower part inside the case 3 by arranging passage separation walls 31, 33, 35. The passage separation wall 31 is made as a heat exchange part of metal mesh 36, and the passage separation walls 33, 35 are equipped with heat exchange parts of metal mesh 37, 41. An air exhaust port 49 is provided at the upper part of the case 3 and a condensed water exhaust port 45 is provided at the bottom part of the case 3 respectively. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell device provided with a fuel cell power generation system that generates hydrogen by supplying hydrogen from a hydrogen supply source to the fuel cell.
[0002]
[Prior art]
An example in which a fuel cell power generation system is housed in a case is described in Patent Document 1.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-56864
This is because a branch line is provided in the middle of the pipe connecting the fuel cell and a blower for supplying air to the fuel cell, an on-off valve is installed at the end of the branch line, and the downstream side of the on-off valve is a case. Open to the inside. The on-off valve opens when the hydrogen concentration detected by the hydrogen concentration sensor installed in the case exceeds a predetermined value, and introduces air into the case to prevent an increase in the hydrogen concentration in the case.
[0005]
[Problems to be solved by the invention]
By the way, when hydrogen leakage occurs in the case, it is necessary to quickly discharge the leaked hydrogen to the outside of the case in order to improve the reliability of the fuel cell device.
[0006]
Therefore, an object of the present invention is to quickly discharge hydrogen leaked in a case accommodating a fuel cell power generation system out of the case.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a fuel cell power generation system that supplies hydrogen to a fuel cell from a hydrogen supply source and supplies air to generate electric power in a case, and discharges the fuel cell from the fuel cell. Is supplied into the case and the air in the case is forcibly replaced.
[0008]
【The invention's effect】
According to the present invention, the air discharged from the fuel cell is sent into the case accommodating the fuel cell power generation system, and the air in the case is forcibly replaced, so that hydrogen leakage occurs from the fuel cell power generation system. Even so, the leaked hydrogen can be quickly discharged out of the case without providing a dedicated ventilation facility.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 is a sectional view of a fuel cell device showing one embodiment of the present invention. In this fuel cell device, the fuel cell power generation system 1 is accommodated in an upper part of a case 3. In the fuel cell power generation system 1, a hydrogen storage tank 5 as a hydrogen supply source and a fuel electrode inlet of a fuel cell 7 are connected by a hydrogen pipe 9.
[0011]
The hydrogen piping 9 is provided with a pressure regulating valve 11 for reducing high-pressure hydrogen in the hydrogen storage tank 1, and the hydrogen piping 9 between the pressure regulating valve 11 and the fuel cell 7 is provided with an ejector 13. The ejector 13 is a pump for circulating the hydrogen discharged from the fuel electrode outlet of the fuel cell 7 to the fuel cell 7 through the hydrogen circulation pipe 15.
[0012]
Further, a purge valve 19 is provided in the hydrogen discharge pipe 17 connected to the fuel electrode outlet of the fuel cell 7, and when the impurities in the hydrogen discharged from the fuel electrode outlet increase, the discharged hydrogen is discharged to the hydrogen discharge pipe. It is discharged to the outside of the case 3 through 17.
[0013]
The air electrode inlet of the fuel cell 7 and the compressor 21 arranged in the case 3 are connected by an air supply pipe 23, and the compressor 21 is operated to pass through an air supply pipe 25 drawn out of the case 3. Then, air is supplied to the air electrode of the fuel cell 7.
[0014]
An air discharge pipe 27 is connected to an air electrode outlet of the fuel cell 7. The air discharge pipe 27 includes an external pipe 27 a drawn out of the case 3, and a downstream end of the external pipe 27 a is connected to the case 3. At the lower part of the case 3.
[0015]
Below the fuel cell power generation system 1 in the case 3, there is provided a flow path 29 (29a, 29b, 29c) of the air sent into the case 3 via the external pipe 27a described above. The air flow path 29 is formed by flow path separation walls 31, 33, 35 which are stacked and arranged at predetermined intervals in the vertical direction.
[0016]
The uppermost channel separation wall 31 is located at a position that vertically divides the inside of the case 3 into two parts, and is formed of a metal mesh 36 that is a metal fiber as a heat exchange part.
[0017]
The left half of the flow passage separating wall 33 in the figure is made of a metal mesh 37 which is a metal fiber serving as a heat exchange part, and the right half thereof is made of a plate-shaped partition wall part 39 which blocks air flow. Then, the flow path separation wall 33 is inclined such that the left metal mesh 37 side in the drawing is lower than the partition wall 39 on the right side.
[0018]
In the lowermost channel separation wall 35, the right half in the figure is constituted by a metal mesh 41 which is a metal fiber as a heat exchange part, and the left half is constituted by a plate-shaped partition part 43 which blocks air flow. . Then, the flow path separation wall 35 is inclined such that the right metal mesh 41 side is lower than the left partition wall 43 in the figure.
[0019]
That is, for the metal meshes 37 and 41 through which the air flows, partition walls 39 and 43 that obstruct the flow of the air are provided along the flow direction of the air, and both of them form the flow path separation walls 33 and 35, respectively. A plurality of the flow path separation walls 33, 35 are arranged at predetermined intervals to form the air flow path 29, and the metal meshes 37, 41 of the flow path separation walls 33, 35 adjacent to each other are alternately arranged. It is arranged so that it becomes.
[0020]
A condensed water discharge port 45 for discharging condensed water of the air introduced into the case 3 is provided on the bottom surface of the case 3 below the right end of the metal mesh 41 of the lowermost channel separation wall 35 in the drawing. The condensed water discharge port 45 is provided with a drain valve 47.
[0021]
On the other hand, an air outlet 49 for discharging air from the case 3 is provided at an upper portion of the case 3 opposite to the external pipe 27 a connected to the air electrode outlet of the fuel cell 7. The density sensor 51 is installed.
[0022]
Next, the operation will be described.
[0023]
Hydrogen is supplied to the fuel cell 7 from the hydrogen storage tank 5 and air is supplied by the compressor 21 to generate power as the fuel cell power generation system 1. At this time, excess hydrogen after the reaction in the fuel cell 7 is circulated to the fuel cell 7 through the hydrogen circulation pipe 15 by the ejector 13.
[0024]
When the impurities in the hydrogen discharged from the fuel electrode outlet increase, the purge valve 19 is opened as appropriate to discharge the hydrogen to the outside of the case 3.
[0025]
On the other hand, excess air after the reaction in the fuel cell 7 flows through the air discharge pipe 27 including the external pipe 27a and is sent to the lower part of the case 3. Here, the temperature of the air discharged from the fuel cell 7 has risen due to the reaction, and the air whose temperature has risen is led to the external pipe 27a, so that the air is cooled and rapidly cooled.
[0026]
The temperature-reduced air flows out to the lowermost air flow path 29a in the case 3 and flows rightward in the drawing, passes through the metal mesh 41 of the lowermost flow path separation wall 35, and flows upward. It flows out to the air passage 29b.
[0027]
The air that has flowed out to the air flow path 29b flows leftward in the drawing, passes through the metal mesh 37 of the flow path separation wall 33 at the center, and flows out to the upper air flow path 29c.
[0028]
The air that has flowed out to the air flow path 29c flows rightward in the drawing, and flows out of the upper part of the case 3 through the flow path separation wall 31, that is, the metal mesh 36 thereabove.
[0029]
The air that has flowed into the case 3 from the external pipe 27a is cooled by heat exchange when passing through the metal meshes 41, 37, and 36, and the air temperature further decreases to the temperature inside the case 3.
[0030]
Further, the air discharged from the air electrode outlet of the fuel cell 7 has a humidity of 100%, and such air is subjected to heat exchange to lower the temperature, thereby generating condensed water. The condensed water falls downward and reaches the bottom of the case 3, and is discharged from the condensed water discharge port 45 to the outside of the case 3 by opening the drain valve 47 as necessary.
[0031]
On the other hand, the air that has flowed to the upper part of the case 3 through the uppermost metal mesh 36 is discharged to the outside of the case 3 from the air discharge port 49. At this time, if hydrogen leaks from the fuel cell power generation system 1, hydrogen lighter than air is discharged to the outside of the case 3 from the air discharge port 49 together with air.
[0032]
Here, the hydrogen concentration sensor 51 detects the hydrogen concentration, and if the detected hydrogen concentration is equal to or higher than a predetermined value, measures such as stopping supply of hydrogen from the hydrogen storage tank 5 are taken.
[0033]
According to the above-described fuel cell power generation system, the following effects can be obtained.
[0034]
(1) The air discharged from the fuel cell 7 is sent into the case 13 containing the fuel cell power generation system 1 and the air in the case 13 is forcibly replaced. Is generated, the leaked hydrogen can be quickly discharged to the outside of the case 13 without providing a dedicated ventilation facility.
[0035]
(2) Since the oxygen concentration of the air discharged from the fuel cell 7 is reduced, the oxygen concentration in the case 3 can be kept lower than, for example, 20%, and the lower combustion limit concentration of hydrogen in the case 3 Can be increased, for example, by more than 4%. That is, even if the hydrogen concentration in the case 3 becomes higher than 4%, combustion can be avoided.
[0036]
(3) Since the humidity of the air discharged from the fuel cell 7 is 100%, the humidity of the air in the case 3 can be maintained at about 100%, and the air in the flammable region generated when hydrogen leaks out. The heat capacity of the air-mixed hydrogen can be increased, and ignition and combustion can be suppressed.
[0037]
(4) The air discharged from the fuel cell 7 is condensed by lowering the temperature to the temperature inside the case 3 in the air flow path 29 in the case 3, the condensed water is captured, and the case 3 is discharged from the condensed water discharge port 45. To the outside of the For this reason, dew condensation in the case 3 can be prevented, and corrosion and leakage of components of the fuel cell power generation system 1 can be prevented.
[0038]
(5) Since the metal meshes 36, 37, and 41, which are the heat exchange units, are arranged below the fuel cell power generation system 1 in the case 3, the condensed water condensed in the heat exchange unit is located below the case 3. And is discharged to the outside of the case 3. For this reason, condensed water does not come into contact with the fuel cell power generation system 1 in the process, and the components of the fuel cell power generation system 1 can prevent adhesion of water droplets and can reliably avoid corrosion and electric leakage. Further, the air sent into the case 3 flows from the lower part to the upper part of the case 3 and is discharged to the outside of the case 3 from the air exhaust port 49, so that hydrogen (leakage) lighter than air is discharged from the air exhaust port 49. Can be easily discharged from
[0039]
(6) The air discharged from the fuel cell 7 once flows into the external pipe 27 outside the case 3 and is rapidly cooled, so that it is cooled by the heat exchange portions (metal meshes 36, 37, and 41) in the case 3. Thus, the air can be quickly cooled down to the temperature in the case 3.
[0040]
(7) Since the heat exchange portions (metal meshes 36, 37, 41) are made of metal fibers having a large heat capacity and a large surface area, the air passing through the heat exchange portion can be quickly cooled to the temperature in the case 3. It is possible to reliably discharge excess water.
[0041]
(8) Since the air flow path 29 is formed as the meandering air flow paths 29a, 29b, and 29c by the flow path separation walls 33 and 35 provided with the partition walls 39 and 43, when the partition walls 39 and 43 are not provided. In comparison, the air flow path length is longer, and the air can be reliably cooled to the temperature inside the case 3 before reaching the upper fuel cell power generation system 1.
[0042]
(9) Since the flow path separation walls 33 and 35 are inclined by disposing the metal meshes 37 and 41 below the partition walls 39 and 43, respectively, the flow path separation walls 33 and 35 condense on the metal meshes 36, 37 and 41 and move downward. The water that has dropped can smoothly flow downward due to the above inclination, drop quickly to the bottom surface of the case 3, and be discharged to the outside of the case 3.
[Brief description of the drawings]
FIG. 1 is a sectional view of a fuel cell device showing one embodiment of the present invention.
[Explanation of symbols]
1 fuel cell power generation system 3 case 5 hydrogen storage tank (hydrogen supply source)
7 Fuel cell 27a External piping 29 (29a, 29b, 29c) Air flow paths 31, 33, 35 Flow path separation walls 36, 37, 41 Metal mesh (metal fiber, heat exchange section)
39, 43 Partition wall 45 Condensed water outlet 49 Air outlet

Claims (7)

To the fuel cell, while supplying hydrogen from a hydrogen supply source, a fuel cell power generation system that supplies air to generate power is housed in a case, and air discharged from the fuel cell is sent into the case, and the case is A fuel cell device for forcibly replacing air in a fuel cell. In the case, a heat exchange unit that reduces the temperature of the air sent into the case, and a condensed water discharge port that discharges condensed water generated from the air whose temperature has been reduced in the heat exchange unit to the outside of the case. 2. The fuel cell device according to claim 1, wherein 3. The fuel cell device according to claim 2, wherein the heat exchange unit is disposed below the fuel cell power generation system, and an air outlet is provided in an upper part of the case. 4. The fuel cell device according to claim 1, further comprising an external pipe for guiding air discharged from the fuel cell from the inside of the case to the outside of the case, and then sending the air into the case. The fuel cell device according to any one of claims 1 to 4, wherein the heat exchanging part is made of a metal fiber. For the heat exchange section through which air flows, a partition section that obstructs the flow of air is provided along the flow direction of the air, and both of them form a flow path separation wall. 6. An air flow path is formed by arranging a plurality of air flow paths, and heat exchange portions of the flow path separation walls adjacent to each other are disposed alternately. Fuel cell device. A plurality of the plurality of flow path separation walls are stacked and arranged along a vertical direction, and the flow path separation walls are arranged so as to be inclined such that the heat exchange section is located below the partition section. The fuel cell device according to claim 6, wherein

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