JP2004185921A - Silencer for fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silencer for a fuel cell system capable of improving layout performance of the fuel cell system by reducing noise and by lowering temperature on its surface part. <P>SOLUTION: This silencer for a fuel cell system is installed on the down stream side of an air passage 17 relative to an air compressor 11 for supplying the air 31 of an oxidizing gas to an air electrode 19 of a fuel cell 16, and composed by forming the air passage 17 through its inside. A cooling fluid passage 26 is formed in the vicinity of the surface part of the silencer 12; and a cooling medium 25 at a temperature lower than that of the air 31 flowing through the air passage 17 housed in the silencer 12 by penetrating it is run in the fluid passage 26. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a silencer for a fuel cell system.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a fuel cell system in which a fuel cell is disposed along an air flow in an air flow path via an air compressor, a silencer, an aftercooler, and the like. Air discharged from the air compressor is reduced in pressure pulsation by a silencer, cooled by an aftercooler, and then flows into a fuel cell. In this case, since the pressure pulsation is reduced by the silencer, the generation of noise due to the resonance of the outer plate of the aftercooler and the subsequent components is reduced.
[0003]
[Patent Document 1]
JP-A-2002-110213
[Problems to be solved by the invention]
However, such a conventional silencer for a fuel cell system has the following problems.
[0005]
Due to the pressure pulsation of the air discharged from the air compressor, the outer panel panel of the silencer itself vibrates, and this vibration may become a sound and become a large noise source. The pressure pulsation component is dominated by the order component of the number of discharges per revolution and a component that is an integral multiple of the order component, and the outer plate has various resonance frequencies depending on the shape and plate thickness. When the resonance frequencies of the two matched, the noise was further increased.
[0006]
In addition, the temperature of the air discharged from the air compressor, particularly in a fuel cell system for a vehicle, becomes high, and under conditions such as continuous rated operation, the suction temperature of the compressor becomes a high temperature of 80 ° C. or more, The discharge temperature becomes extremely high. For this reason, the surface temperature of the silencer closest to the air compressor and upstream of the aftercooler becomes extremely high near the discharge temperature when the load continues, and the silencer is used for electricity, electronic devices, electric wires, etc. that dislike heat. The layout of the fuel cell system was limited because it could not be located nearby. In particular, in-vehicle fuel cell systems in which the layout space is limited, the layout is greatly restricted.
[0007]
In view of the above, the present invention has been made by focusing on such a conventional problem, and reduces the noise of the silencer and improves the layout of the fuel cell system by reducing the temperature at the surface of the silencer. It is aimed at.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a fuel cell, which is disposed downstream of an air flow path from an air compressor that supplies compressed air, which is an oxidizing gas, to an air electrode side of a fuel cell, and has the air therein. A fuel cell system silencer in which a flow path is provided through, wherein a cooling fluid flow path is provided in the vicinity of a surface portion of the silencer, and inside the cooling fluid flow path, the cooling fluid flow path is penetrated inside the silencer. The cooling medium having a lower temperature than the air flowing through the accommodated air flow path is configured to flow.
[0009]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the viscosity of the cooling medium in the cooling fluid flow path provided in the surface part of the silencer becomes resistance of sound conduction, and can reduce the noise of a silencer. In addition, the layout medium of the fuel cell system can be improved by reducing the temperature at the surface of the silencer by the cooling medium in the cooling fluid flow path.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
[First Embodiment]
FIG. 1 is a schematic diagram showing the configuration of the entire fuel cell system according to the first embodiment of the present invention, and FIG. 2 is an enlarged sectional view showing the internal structure of the silencer of FIG.
[0012]
As shown in FIG. 1, the fuel cell system 10 according to the present embodiment includes an air compressor 11, a silencer 12, an aftercooler 13, a filter 14, a humidifier 15, and a fuel cell 16 in this order along the air flow in the air flow path. It is arranged. These components are communicated and connected by a single air pipe 17.
[0013]
In the fuel cell system 10 having this configuration, air is sucked from the suction port 18 provided at the tip of the air pipe 17, compressed and discharged by the air compressor 11, and the air pulsation is reduced by the silencer 12, After the temperature is lowered by the aftercooler 13 and the dust is removed by the filter 14, it is humidified by the humidifier 15 and flows into the air electrode 19 of the fuel cell 16. The fuel electrode 16 of the fuel cell 16 is configured to be supplied with fuel from a fuel port 21.
[0014]
A pipe 22 is connected to the silencer 12, and the pipe 22 is arranged to return to the silencer 12 again via a pump 23 and a heat exchanger 24. Cooling water 25 (see arrow), which is one of the cooling media, flows through the inside of the pipe 22.
[0015]
That is, the cooling water 25 flows through the inside of the silencer 12, is discharged therefrom, is pressurized by the pump 23, is cooled by the heat exchanger 24, and flows again into the silencer 12.
[0016]
As shown in FIG. 2, a cooling fluid channel 26 is formed on the surface of the silencer 12. The cooling fluid flow path 26 can be formed by arranging, for example, a pipe through which the cooling water 25 flows inside the outer plate member 27. That is, the surface of the silencer 12 is covered with the outer plate member 27, and a cooling fluid flow path 26 is formed inside the outer plate member 27 along the outer plate member 27. An inlet pipe 28 and an outlet pipe 29 are provided at the ends of the cooling fluid flow path 26, respectively. The inside of the cooling fluid passage 26 is formed in a sound absorbing portion 30 filled with a sound absorbing material, and an air pipe 17 is routed through the inside of the sound absorbing portion 30 in a lateral direction. In addition, in order to make the air flow inside the air pipe 17 clear, it is partially cut away. In the silencer 12 shown in FIG. 2, the cooling water 25 flows into the cooling fluid flow path 26 from the inlet pipe 28, flows through the cooling fluid flow path 26, and is discharged from the outlet pipe 29. It is configured to:
[0017]
The operation of the silencer 12 having the above configuration will be described.
[0018]
The discharge air from the air compressor 11 flows into the silencer 12 via the air pipe 17 with a very large pressure pulsation. The pressure pulsation of the discharged air is transmitted from the air pipe 17 to the sound absorbing section 30 of the silencer 12, and then transmitted to the cooling fluid flow path 26. Since the cooling water 25 flows through the cooling fluid flow path 26, the viscosity of the cooling water 25 becomes a resistance of sound conduction, and the vibration of the outer plate member 27 provided outside the cooling fluid flow path 26 is caused. Is greatly attenuated. Thus, the vibration of the outer plate member 27 is greatly attenuated, so that the amplitude of the vibration of the outer plate member 27 is reduced, and the sound radiation from the surface of the outer plate member 27 is significantly reduced.
[0019]
Further, since the cooling water 25 before flowing into the silencer 12 is cooled by the heat exchanger 24, the temperature of the cooling fluid flow path 26 provided on the surface portion of the silencer 12 is determined by connecting the air pipe 17 to the silencer 12. It becomes lower than the temperature of the air 31 flowing through. Here, the temperature of the air 31 flowing into the silencer 12 depends on the pressure of the discharge air of the air compressor 11, the temperature of the intake air, the efficiency of the air compressor 11, and the like, but generally becomes considerably high. However, the surface portion of the silencer 12 is cooled by the cooling water 25 and does not become very hot. Accordingly, it becomes possible to arrange heat-sensitive electrical, electronic devices, and electrical wirings in the vicinity of the surface of the silencer 12, thereby improving the layout flexibility of the fuel cell system 10.
[0020]
Further, since the temperature of the compressed air exiting the silencer 12 is reduced by the cooling effect of the cooling water 25 as compared with a case where the air is not cooled, the cooling performance of the aftercooler 13 can be further reduced, and the size of the aftercooler 13 can be reduced. become. The downsizing of the aftercooler 13 and the improvement in the degree of freedom in the layout of the fuel cell system 10 allow the fuel cell system 10 to be dramatically downsized. This effect of miniaturization is very useful in the vehicle fuel cell system 10 which has a smaller space than the stationary type.
[0021]
[Second embodiment]
Next, a silencer for a fuel cell system according to a second embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0022]
FIG. 3 is an enlarged sectional view showing an outer surface portion of a silencer 40 according to the second embodiment.
[0023]
In the present embodiment, the closed cross-section formed by the outer plate member 41 and the inner plate member 42 is used as the cooling fluid flow path 43. As shown in FIG. 3, the surface of the silencer 40 is covered with an outer plate member 41, and an inner plate member 42 is provided inside the outer plate member 41. The member 42 is joined at its ends 44. Thus, the space between the outer plate member 41 and the inner plate member 42 has a closed cross-sectional structure, and the cooling fluid flow path 43 is configured.
[0024]
Since the cooling structure of the silencer 40 according to the present embodiment can be made of sheet metal, a thin material can be used, and the weight can be further reduced.
[0025]
[Third Embodiment]
Then, the silencer according to the third embodiment will be described, but the same parts as those in the above-described embodiment will be denoted by the same reference numerals, and description thereof will be omitted.
[0026]
As shown in FIG. 4, in the present embodiment, a pipe 50 from the air compressor 11 is connected to a pipe 22 provided for the silencer 12 according to the first embodiment. That is, the common pump 23 and the heat exchanger 24 are used for the silencer 12 and the air compressor 11, and the common cooling water 25 is used.
[0027]
Usually, an air compressor for a fuel cell system is often cooled by cooling water. Therefore, according to this embodiment, the liquid cooling system of the silencer 12 can be greatly simplified by using a common cooling system.
[0028]
[Fourth embodiment]
The silencer according to the fourth embodiment will be described, and the same parts as those in the above-described embodiment will be denoted by the same reference numerals and description thereof will be omitted.
[0029]
As shown in FIG. 5, the air compressor 60 is directly connected to a silencer 62 via a communication channel 61, and a pipe 63 is routed from the silencer 62, and the pipe 63 is connected to the pump 23 and the heat exchanger 24. ing.
[0030]
FIG. 6 shows an air compressor 60 and a silencer 62 having a cooling water flow path having a structure different from that of FIG. As shown in FIG. 6, a water jacket 64 is provided on the surface of the air compressor 60, and the water jacket 64 is connected to a cooling fluid flow path 65 provided in the silencer 62. According to this, after the cooling water 25 flows into the water jacket 64 from the supply port 67 of the air compressor 60, the cooling water 25 is allowed to flow through the communication flow path 68 to the cooling fluid flow path 65 of the silencer 62, and the outlet pipe is provided. Flow out from 65. The communication channel 68 is formed inside an inlet pipe 69.
[0031]
According to the present embodiment, the arrangement of the cooling water passages in series simplifies the cooling structure. Further, since only one inlet pipe 69 and one outlet pipe 66 are required, the size of the cooling device can be reduced. Since the cooling water 25 flows from the air compressor 60 to the silencer 62, the temperature of the cooling water 25 of the air compressor 60 is lower than that of the cooling water 25 flowing from the silencer 62 to the air compressor 60. Since the efficiency of the air compressor 60 increases as the temperature of the cooling water 25 decreases, the efficiency of the air compressor 60 increases when the air compressor 60 is cooled first.
[0032]
[Fifth Embodiment]
Then, a silencer according to the fifth embodiment will be described, and the same parts as those in the above-described embodiment will be denoted by the same reference numerals and description thereof will be omitted.
[0033]
The silencer according to the present embodiment uses oil as a cooling medium flowing in the cooling fluid flow path. As the oil, lubricating oil for an air compressor can be suitably used.
[0034]
As shown in FIGS. 7 and 8, an outlet pipe 71 is provided in the silencer 70 according to the present embodiment, and the outlet pipe 71 is connected to an inlet pipe 74 of an air compressor 73 via an oil cooler 72. An oil chamber 75 is provided inside the air compressor 73, and a lubricating oil 76 is stored in the oil chamber 75. An outlet pipe 77 of the air compressor 73 is connected to an inlet pipe 78 of the silencer 70 via the oil pump 23, and the inlet pipe 78 communicates with a cooling fluid flow path 79 provided inside the silencer 70. ing.
[0035]
According to the silencer 70 having this configuration, the lubricating oil 76 is sent from the outlet pipe 71 of the silencer 70 to the oil cooler 72 via the pipe 80, and is cooled by the oil cooler 72. After being lubricated and cooled, the oil is pressurized by the oil pump 23 and flows into the cooling fluid passage 79 of the silencer 70 from the inlet pipe 78. Thus, the configuration of the system can be simplified by using the oil circulation system used for the air compressor 73.
[0036]
When lubricating oil 76, which is oil having a higher viscosity than cooling water 25, flows through cooling fluid passage 79 of silencer 70, a higher vibration damping effect is obtained, and noise radiated from the surface of silencer 70 is reduced. Reduce.
[0037]
[Sixth Embodiment]
Furthermore, a silencer according to the sixth embodiment will be described, and the same parts as those in the above-described embodiment will be denoted by the same reference numerals and description thereof will be omitted.
[0038]
As shown in FIG. 9, the silencer 81 according to the sixth embodiment is provided below the air compressor 82. An oil chamber 83 is formed inside the air compressor 82, and stores the lubricating oil 76 of the air compressor 82. The oil chamber 83 communicates with a cooling fluid flow path 86 in the silencer 81 via an inlet pipe 84 and an outlet pipe 85.
[0039]
A water jacket 87 is formed on the surface of the air compressor 82. The water jacket 87 is provided with an inlet pipe 88 and an outlet pipe 89. The cooling water 25 flows from the inlet pipe 88, flows through the water jacket 87, and is discharged from the outlet pipe 89. ing.
[0040]
According to the present embodiment, since the cooling water 25 also cools the lubricating oil 76 by cooling the air compressor 82 with water, the oil cooler 72 according to the fifth embodiment is not required, and the oil chamber of the air compressor 82 is not required. The temperature of the lubricating oil 76 inside 83 becomes lower than the temperature of the lubricating oil 76 inside the cooling fluid passage 86 of the silencer 81. Further, since the silencer 81 is located at a position lower than the air compressor 82, the high-temperature lubricating oil 76 flows toward the oil chamber 83 of the air compressor 82 located at a higher position due to natural convection. It circulates between the cooling fluid flow path 86 of the silencer 81 and the oil chamber 83 of the air compressor 82, thereby simplifying the structure and eliminating the need for power.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an entire fuel cell system according to a first embodiment.
FIG. 2 is an enlarged sectional view showing an internal structure of the silencer of FIG.
FIG. 3 is an enlarged sectional view showing an outer surface portion of a silencer according to a second embodiment.
FIG. 4 is a schematic diagram showing an entire fuel cell system according to a third embodiment.
FIG. 5 is a schematic diagram showing an entire fuel cell system according to a fourth embodiment.
FIG. 6 is an enlarged sectional view showing an internal structure of another air compressor and a silencer according to a fourth embodiment.
FIG. 7 is a schematic diagram showing an entire fuel cell system according to a fifth embodiment.
FIG. 8 is an enlarged sectional view showing the internal structure of the air compressor and the silencer of FIG. 7;
FIG. 9 is an enlarged sectional view showing the internal structure of an air compressor and a silencer according to a sixth embodiment.
[Explanation of symbols]
Reference Signs List 10 fuel cell system 11, 60, 73, 82 air compressor 12, 40, 62, 70, 81 silencer 13 aftercooler 16 fuel cell 17 air pipe (air flow path)
25 Cooling water (cooling medium)
26, 43, 65, 79, 86 Cooling fluid flow paths 27, 41 Outer plate member 42 Inner plate member 64, 87 Water jacket

Claims (9)

A silencer for a fuel cell system, which is provided on a downstream side of an air flow path of an air compressor that supplies air to a fuel cell, and in which the air flow path is provided internally,
A cooling fluid flow path is provided in a surface portion of the silencer, and the cooling fluid flow path is configured to flow a cooling medium having a lower temperature than air flowing in an air flow path facing the inside of the silencer. Features Silencers for fuel cell systems. The cooling fluid flow path is a closed cross-section formed by an outer plate member provided on a surface of the silencer and an inner plate member provided inside the outer plate member. Item 7. A silencer for a fuel cell system according to Item 1. A fluid flow path for cooling the air compressor is provided inside the air compressor, and after the cooling medium discharged from the cooling fluid flow path of the silencer flows into the fluid flow path, the cooling medium for cooling the silencer is provided. The silencer for a fuel cell system according to claim 1, wherein the silencer is configured to return to the fluid flow path. A water jacket is formed inside the air compressor, and the water jacket is communicated with the cooling fluid flow path of the silencer, whereby cooling water as the cooling medium flows from the water jacket to the fluid flow path of the silencer. The silencer for a fuel cell system according to claim 1, wherein the silencer is configured to return to the water jacket after the return. The communication between the water jacket and the cooling fluid flow path of the silencer is performed by connecting the water jacket to the cooling fluid flow path via the communication flow path,
5. The silencer for a fuel cell system according to claim 4, wherein the cooling water is configured to flow from a water jacket to a cooling fluid flow path and then discharged to the outside. The silencer for a fuel cell system according to any one of claims 1 to 3, wherein the cooling medium is oil. An oil chamber for containing lubricating oil for the air compressor is provided inside the air compressor, and the oil chamber is communicated with a cooling fluid flow path for the silencer. The silencer for a fuel cell system according to claim 6, wherein the silencer is configured to be circulated to the fuel cell system. A water jacket is provided in the air compressor, while cooling lubricating oil contained in the oil chamber with cooling water flowing through the water jacket,
6. The silencer for a fuel cell system according to claim 4, wherein the silencer is disposed at a position lower than an air compressor. The said silencer was arrange | positioned between the said air compressor and the aftercooler provided in the downstream of the air flow path of this air compressor, and cooling the compressed air, The Claims 1-8 characterized by the above-mentioned. A silencer for a fuel cell system according to item 1.

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