JP2009264442A - Valve device - Google Patents

Abstract

A valve device capable of smoothly displacing a valve body even in a low-temperature environment is provided.
A primary chamber body 110 provided with a primary chamber 110a into which a fluid is introduced, a secondary chamber body 120 provided with a secondary chamber 120a through which a fluid is led out, a primary chamber 110a and a secondary chamber 120a. And a valve body 130 that is driven by a drive mechanism and includes an introduction path 111 that introduces fluid into the primary chamber 110a, and an orifice 113 provided in the introduction path 111. In the valve device, the introduction path 111 is connected to the bottom wall 112 of the primary chamber body 110 forming the primary chamber 110a, and the orifice 113 is located below the bottom wall 112. To do.
[Selection] Figure 2

Description

  The present invention relates to a valve device.

  In recent years, a polymer electrolyte fuel cell (Polymer Electrolyte Fuel Cell) that generates electricity by supplying hydrogen (fuel gas, reactive gas) to the anode and oxygen-containing air (oxidant gas, reactive gas) to the cathode, respectively. The development of fuel cells such as PEFC is active. In a system using such a fuel cell, a valve device for permitting or controlling the flow of a fluid such as air containing hydrogen or oxygen is used.

By the way, when the fuel cell as described above generates electric power, water vapor (water) is generated at the cathode, and part of the generated water permeates to the anode side through the electrolyte membrane (solid polymer membrane). Further, in order to maintain the wet state of the electrolyte membrane, hydrogen and air toward the fuel cell are humidified by a humidifier equipped with a hollow fiber membrane. Therefore, the anode off-gas discharged from the anode of the fuel cell and the cathode off-gas discharged from the cathode are humid.
However, if water accumulates on the anode side, the supply of fuel gas may be hindered and power generation may become unstable. In addition, since nitrogen in the air supplied to the cathode passes through the electrolyte membrane to the anode side even though a small amount is mixed into the fuel gas, power generation may become unstable if the concentration of nitrogen increases due to recycling of the fuel gas. is there.

  Therefore, a purge valve is provided in the fuel gas circulation passage, and water collected in the anode and nitrogen mixed in the fuel gas are discharged to recover the power generation state (see, for example, Patent Document 1). .

  A purge valve is also considered in which an orifice is provided in the purge valve introduction path so as to restrict the introduction path.

JP 2004-162878 A

  By the way, in the valve device such as the purge valve described above, moisture may remain in the primary chamber into which the fluid is introduced, that is, in the vicinity of the valve body. In particular, when an orifice as described above is provided in the introduction path, a step is formed in the introduction path by restricting the introduction path by the orifice, and moisture may remain on the primary chamber side at the step. It was. If such a moisture residual phenomenon occurs, the operation of the purge valve may be hindered, for example, when the fuel cell system is stopped in a low temperature environment (for example, less than 0 ° C.), the valve body freezes and becomes stuck. There was a risk of coming.

  Then, this invention makes it a subject to provide the valve apparatus which can displace a valve body smoothly also in a low temperature environment.

  In order to achieve the above object, the valve device of the present invention includes a primary chamber body provided with a primary chamber into which a fluid is introduced, a secondary chamber body provided with a secondary chamber from which a fluid is led out, and A valve body that communicates or blocks between the primary chamber and the secondary chamber and is driven by a drive mechanism, and an introduction path that introduces fluid into the primary chamber, and an orifice provided in the introduction path; The introduction path is connected to the bottom wall of the primary chamber body that forms the primary chamber, and the orifice is located below the bottom wall. It is characterized by.

According to this valve device, since the introduction path is connected to the bottom wall of the primary chamber body that forms the primary chamber, the fluid that has flowed into the primary chamber temporarily contains moisture such as water vapor or condensed water. Therefore, even if this condenses in the primary chamber to form water droplets, there is an advantage that it does not easily remain in the primary chamber. That is, after the valve is closed, water droplets remaining in the primary chamber are returned from the bottom wall of the primary chamber body to the introduction path, and moisture hardly remains in the primary chamber.
Moreover, since the orifice is located below the bottom wall, the step formed by arranging the orifice is not formed on the bottom wall of the primary chamber body. Therefore, water such as water droplets remaining in the primary chamber is smoothly returned from the bottom wall of the primary chamber body to the introduction path. This makes it difficult for moisture to remain in the primary chamber.

Therefore, by using such a valve device as a purge valve in, for example, a fuel cell system, the following advantages can be obtained.
That is, even after the anode off gas containing moisture such as water vapor or condensed water is discharged, even if moisture remains in the form of water droplets in the primary chamber, the remaining moisture is returned from the bottom wall of the primary chamber body to the introduction path. It comes to be. This makes it difficult for moisture to remain in the primary chamber and makes it difficult for the valve body to freeze and adhere even in a situation where the inside of the fuel cell freezes when exposed to a low temperature environment (for example, less than 0 ° C.). Can be displaced. As a result, a valve device that contributes to the operation of the fuel cell system with high reliability can be obtained.

  In addition, the introduction path may have an upward slope shape, and the upper end thereof may be connected to the bottom wall. According to such a valve device, moisture that has flowed into the introduction path from the primary chamber is less likely to stay in the introduction path, and even in a situation where it is exposed to a low temperature environment (for example, less than 0 ° C.), Can be prevented from freezing.

  The valve body is arranged in the primary chamber, and is configured to open by being displaced toward an upper wall of the primary chamber body forming the primary chamber. It is preferable that the surface to be formed has a tapered shape that gradually decreases in diameter toward the upper wall.

  According to such a valve device, even when water adheres in the form of water droplets or the like on the upper part of the valve body, it becomes difficult for the water to stay on the upper part of the valve body, and the primary chamber is formed by the action of gravity. It flows down to the bottom wall of the primary chamber body. Therefore, after the valve is closed, the moisture present in the primary chamber is suitably returned from the bottom wall of the primary chamber body to the introduction path, and the moisture is less likely to remain in the primary chamber. Further, when such a valve device is used in a fuel cell system, a stable operation can be realized over a long period of time, which contributes to the realization of a fuel cell system excellent in durability and reliability.

  The valve seat on which the valve body is seated may be configured to protrude from the bottom wall toward the upper wall.

According to such a valve device, even if water accompanying the fluid condenses in the primary chamber and forms water droplets and accumulates on the bottom wall, the accumulated water adheres between the valve body and the valve seat. Can be suppressed. As a result, the valve body can be suitably prevented from being frozen and fixed to the valve seat, and the displacement of the valve body can be suitably maintained.
Further, when such a valve device is used in a fuel cell system, a stable operation can be realized over a long period of time, which contributes to the realization of a fuel cell system excellent in durability and reliability.

  The valve seat forms the bottom wall around the valve seat, and the portion forming the bottom wall has a side away from the introduction path to the upper wall rather than a side near the introduction path. It is preferable to have a structure that is formed higher toward the end.

According to such a valve device, even if water accompanying the fluid condenses in the primary chamber and becomes water droplets and accumulates on the bottom wall around the valve seat, it is introduced from the side away from the introduction path by the action of gravity. It flows favorably toward the side close to the road, and then returned to the introduction path. Therefore, an advantage that moisture hardly remains in the primary chamber can be obtained.
Further, when such a valve device is used in a fuel cell system, a stable operation can be realized over a long period of time, which contributes to the realization of a fuel cell system excellent in durability and reliability.

The drive mechanism may be configured to drive in the vertical direction.
By adopting such a configuration, compared to the case where the driving direction is vertical and driving in an inclined direction or a horizontal direction, it is less likely to be reduced by sliding, and durability is improved and longer. A valve device capable of realizing stable operation over a period is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the valve apparatus which can displace a valve body smoothly also in a low temperature environment is obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate.
In the present embodiment, the valve device applied to the fuel cell system will be described, but the device to which the valve device is applied is not intended to be limited. Hereinafter, a case where the valve device is used for an anode purge valve of a fuel cell system will be described as an example.

First, the configuration of a fuel cell system to which the valve device of the present embodiment is applied will be described, and the valve device will be described in the following description.
≪Configuration of fuel cell system≫
A fuel cell system 1 according to this embodiment shown in FIG. 1 is mounted on a fuel cell vehicle (moving body) (not shown). The fuel cell system 1 includes a fuel cell stack 10, an anode system that supplies and discharges hydrogen (fuel gas and reaction gas) to and from the anode of the fuel cell stack 10, and air that contains oxygen with respect to the cathode of the fuel cell stack 10. A cathode system that supplies and discharges (oxidant gas, reaction gas) and a scavenging gas system that guides the scavenging gas from the cathode system to the anode system during scavenging.
<Fuel cell stack>
The fuel cell stack 10 is a stack formed by stacking a plurality of (for example, 200 to 400) solid polymer type single cells, and the plurality of single cells are electrically connected in series. The single cell includes an MEA (Membrane Electrode Assembly) and two conductive anode separators and cathode separators sandwiching the MEA.

  The MEA includes an electrolyte membrane (solid polymer membrane) made of a monovalent cation exchange membrane (for example, perfluorosulfonic acid type), and an anode and a cathode sandwiching the electrolyte membrane. The anode and the cathode are mainly composed of a conductive porous material such as carbon paper, and contain a catalyst (Pt, Ru, etc.) for causing an electrode reaction in the anode and the cathode.

The anode separator is formed with a through-hole (called an internal manifold) extending in the stacking direction of the single cells and a groove extending in the surface direction of the single cells in order to supply and discharge hydrogen to the anode of each MEA. These through holes and grooves function as the anode flow path 11 (fuel gas flow path).
The cathode separator is formed with a through-hole (referred to as an internal manifold) extending in the stacking direction of the single cells and a groove extending in the surface direction of the single cells in order to supply and discharge air to and from the cathode of each MEA. These through holes and grooves function as the cathode channel 12 (oxidant gas channel).

When hydrogen is supplied to each anode via the anode channel 11, an electrode reaction of the following formula (1) occurs, and when air is supplied to each cathode via the cathode channel 12, An electrode reaction of the following formula (2) occurs, and a potential difference (OCV (Open Circuit Voltage), open circuit voltage) is generated in each single cell. When the fuel cell stack 10 and an external circuit such as a travel motor are electrically connected and current is taken out, the fuel cell stack 10 generates power.
2H ₂ → 4H ⁺ + 4e ⁻ (1)
O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)

  When the fuel cell stack 10 generates power in this way, a part of the water (water vapor) generated at the cathode permeates the electrolyte membrane and moves to the anode. Therefore, both the cathode offgas discharged from the cathode and the anode offgas discharged from the anode are humid.

<Anode system>
The anode system is provided upstream of the fuel cell stack 10, and is provided downstream of the hydrogen tank 21 (fuel gas supply means), the normally closed shut-off valve 22, the ejector 23, and the fuel cell stack 10. A gas-liquid separator 24, a normally closed purge valve 100, and a normally closed scavenging gas discharge valve 27 are provided. Below, the example using the valve apparatus of this embodiment is demonstrated with respect to the purge valve 100 with which this fuel cell stack 10 is provided downstream. Details of the purge valve 100 will be described later.

The hydrogen tank 21 is connected to the inlet side of the anode channel 11 through a pipe 21a, a shutoff valve 22, a pipe 22a, an ejector 23, and a pipe 23a. The piping 22a is provided with a pressure reducing valve (not shown) for reducing hydrogen to a predetermined pressure, and the pressure of air toward the cathode flow path 12 is input to the pressure reducing valve as a signal pressure (pilot pressure). The pressure reducing valve is controlled so that the pressure of the air and the pressure of hydrogen in the anode channel 11 fluctuate correspondingly.
Then, when the ignition of the fuel cell vehicle is turned on, the activation of the fuel cell stack 10 is requested, and the shutoff valve 22 is opened by an ECU (Electronic Control Unit) (not shown), the hydrogen in the hydrogen tank 21 is connected to the pipe 21a. Etc., and is supplied to the anode channel 11.

The outlet of the anode channel 11 is connected to the suction port of the ejector 23 via a pipe 24a, a gas-liquid separator 24, and a pipe 24b. The anode off gas containing unreacted hydrogen discharged from the anode channel 11 (anode) is separated from the liquid water accompanying the anode off gas in the gas-liquid separator 24, and then upstream of the fuel cell stack 10. Is returned to the ejector 23.
The anode off-gas returned to the ejector 23 is mixed with hydrogen from the hydrogen tank 21 and then re-supplied to the anode channel 11. That is, in this embodiment, the hydrogen circulation line which circulates and recycles hydrogen is comprised by the piping 24a and the piping 24b.
In addition, the part close to the gas-liquid separator 24 side of the pipe 24b is arranged in the vertical direction so that when moisture accompanying hydrogen is contained, it is returned to the gas-liquid separator 24 by its own weight. It has become.

  On the other hand, the water separated by the gas-liquid separator 24 is temporarily stored in the gas-liquid separator 24, and then passed through a normally closed drain valve 25 and a pipe 25b that are appropriately opened by the pipe 25a and ECU. It is discharged to the upper side of the diluter 33 described later.

[Purge valve]
The purge valve 100 is a normally-closed electromagnetic valve that discharges impurities (water vapor, nitrogen, etc.) contained in the anode off-gas (hydrogen) circulating through the pipe 24a and the pipe 24b when the fuel cell stack 10 generates power (purge). ) Is a valve that is opened by the ECU. The upstream side of the purge valve 100 is connected to the pipe 24b via the pipe 26a, and the downstream side is connected to the upper side of the diluter 33 described later via the pipe 26b. In the present embodiment, a pipe 26 a connected to an introduction path 111 described later of the purge valve 100 is provided in an upwardly inclined shape toward the introduction path 111. A pipe 26b connected to a lead-out path 121 described later may also be provided so as to be inclined downward toward the diluter 33.
Here, for example, when the voltage (cell voltage) of the single cells constituting the fuel cell stack 10 is equal to or lower than a predetermined cell voltage, the ECU determines that the impurities need to be discharged and opens the purge valve 100. Is set to The cell voltage is detected, for example, via a voltage sensor (cell voltage monitor) that detects the voltage of a single cell, and is input to the ECU.

As shown in FIG. 2, the purge valve 100 is provided with a primary chamber 110a into which an anode off gas is introduced, and is provided adjacent to a primary chamber body 110 and a lower portion of the primary chamber body 110, and the anode off gas is led out. The secondary chamber body 120 is provided with a secondary chamber 120a, and the valve body 130 is driven by a solenoid 150 as a drive mechanism disposed on the lower side of the secondary chamber body 120 (secondary chamber 120a). Thus, the communication state between the primary chamber 110a and the secondary chamber 120a is switched. That is, the purge valve 100 is opened at the time of purging and serves as a valve for discharging the anode off gas sent from the anode flow path 11 of the fuel cell stack 10 to the subsequent diluter 33 as shown in FIG. It is supposed to function. In the present embodiment, the primary chamber 110a on the side where the anode off gas is introduced is disposed on the upper side, the secondary chamber 120a on the side from which the anode off gas is led out is disposed on the lower side, and the valve body 130 is further provided. Is configured to be disposed below the secondary chamber 120a.
An introduction path 111 for introducing the anode off gas into the primary chamber 110 a is connected (opened) to the bottom wall 112 of the primary chamber body 110. The introduction path 111 is provided with an orifice 113, and the orifice 113 is positioned below the bottom wall 112.

Hereinafter, each part will be described in detail.
As described above, the primary chamber body 110 is connected to the bottom wall 112 through the introduction path 111 for introducing the anode off gas. In this example, the introduction path 111 has an upwardly inclined shape, and its upper end is connected to the bottom wall 112 so as to be open for communication. In other words, the introduction path 111 is provided at a lower position below the bottom wall 112, and this causes moisture to accumulate in the primary chamber 110 a when moisture accompanying the anode off-gas is included. However, the moisture flows into the introduction path 111 through the opening 111a of the introduction path 111 and is discharged to the upstream gas-liquid separator 24 (see FIG. 1) by its own weight.

  The introduction passage 111 is provided with the orifice 113 as described above, and this orifice 113 serves to limit the flow rate of the anode off gas flowing from the introduction passage 111 toward the primary chamber 110a. That is, the orifice 113 functions to reduce the pressure of the anode off gas introduced into the primary chamber 110a, and reduces the load applied to the diaphragm 160 described later disposed in the secondary chamber 120a. Thereby, the deformation | transformation beyond the tolerance | permissible_range of the diaphragm 160 can be prevented, and durability of the diaphragm 160 can be improved.

  Further, the water accompanying the anode off gas condenses when passing through the orifice 113 and adheres as a water droplet around the orifice 113. This suppresses introduction of excess moisture into the primary chamber 110a.

A valve body 130 is disposed in the primary chamber 110a so as to be displaceable in the vertical direction (valve opening / closing direction), and a valve seat 116 is provided on the bottom surface side of the valve body 130.
The valve body 130 is configured to open by being displaced toward the upper wall 114 of the primary chamber body 110 that forms the primary chamber 110 a, and the surface that forms the top of the valve body 130 is in relation to the upper wall 114. Inclined. That is, the top of the valve body 130 is pointed without a flat surface. In the present embodiment, the valve body 130 has a tapered section 130a having a mountain-shaped cross section that gradually decreases in diameter toward the upper wall 114 side. It is formed including.
In addition, you may give a fluorine coating to the surface of the taper-shaped part 130a. Since the fluorine coating has a water repellent effect of repelling moisture, it becomes difficult for moisture to stay at the top or upper portion of the valve body 130, and drainage can be improved.

  The valve seat 116 is provided integrally with a partition wall 115 that partitions the primary chamber 110a and the secondary chamber 120a, and protrudes from the partition wall 115 (the bottom of the primary chamber body 110) toward the upper wall 114. The valve seat 116 has a cylindrical shape and is formed so as to be reduced in diameter toward the upper end. An annular valve seat portion 117 on which the valve body 130 is seated is provided at the distal end portion of the valve seat 116. The valve seat 117 is formed flat so as to be in close contact with the flat bottom surface 132 formed on the valve body 130. Further, the valve seat portion 117 may be formed in a round shape, for example, in order to improve the adhesion.

The upper wall 114 of the primary chamber 110a is provided with a recess 114a, and the upper end of a return spring 135 that biases the valve body 130 toward the valve seat 117 is held in the recess 114a. The return spring 135 is contracted between the valve body 130 and the recess 114a, and the bottom surface 132 of the flange portion 134 of the valve body 130 is the valve seat portion in a state where the valve body 130 is closed as will be described later. It is urged to sit on 117 with good airtightness. By such an urging of the return spring 135, the primary chamber 110a and the secondary chamber 120a are blocked from being able to communicate with each other.
A predetermined clearance is formed between the recess 114a and the valve body 130 when the valve body 130 is driven and displaced upward.
Further, the left side portion of the primary chamber 110a is closed by a closing member 118.

  The secondary chamber 120a is continuously provided in the lower part of the primary chamber 110a via a partition wall 115, and a pipe 26b (see FIG. 1, the same applies hereinafter) leading to a diluter 33 (see FIG. 1, the same applies hereinafter) described later. ) Can be connected to the lead-out path 121. That is, as will be described later, when the valve body 130 is driven to open, and when the anode off gas flows from the primary chamber 110a to the secondary chamber 120a via the valve body 130, the anode off gas flowing into the secondary chamber 120a is It is sent from the outlet path 121 to the diluter 33 through the pipe 26b. In the present embodiment, the lead-out path 121 is provided on the side opposite to the introduction path 111 described above, that is, on the side where the pipe 26b leading to the diluter 33 can be connected.

A seal member (not shown) is attached to a connection portion between the introduction path 111 and the pipe 26a and a connection portion between the lead-out path 121 and the pipe 26b, and the airtightness of the flowing anode off gas is maintained.
Further, fluorine coating may be applied to the inside of the primary chamber 110a and the secondary chamber 120a. Since the fluorine coating has a water repellent effect of repelling moisture, it is difficult for moisture to stay inside the primary chamber 110a and the secondary chamber 120a, and drainage can be improved.
In particular, in the primary chamber 110a, water such as water droplets remaining in the primary chamber 110a is returned from the bottom wall 112 of the primary chamber body 110 to the introduction path 111, so that it is difficult for water to remain in the primary chamber 110a. .

  A shaft 140 that is driven by a solenoid 150 and whose tip is fixed to the mounting hole 133 of the valve body 130 passes through the secondary chamber 120a, and a shaft is interposed between the secondary chamber 120a and the shaft 140. A diaphragm 160 made of an elastic member (for example, a material such as rubber) that is locked to 140 and bends following the displacement operation of the shaft 140 is provided.

  The diaphragm 160 is an annular member that surrounds the periphery of the shaft 140, and has an inner peripheral edge 161 attached to the flange portion 141 of the shaft 140, and a thin-walled shape that extends radially outward from the inner peripheral edge 161. It consists of a skirt portion 162 (curved convex portion) and an outer peripheral edge portion 163 formed on the outer peripheral portion of the skirt portion 162.

The inner peripheral edge 161 is locked to the shaft 140 by being sandwiched between the flange 141 and the bottomed cylindrical pressing member 142 attached to the shaft 140.
The skirt portion 162 can be bent following the displacement operation of the shaft 140.
The outer peripheral edge 163 is sandwiched between the bottom wall 122 of the secondary chamber 120a and a fixed core 151 of the solenoid 150 described later.

  By providing such a diaphragm 160, the space between the secondary chamber 120a and the shaft 140 is sealed, and the airtightness inside the secondary chamber 120a is suitably maintained.

  The solenoid 150 is disposed inside the casing 154, and a bobbin 155 around which the coil 155a is wound, a fixed core 151 disposed so as to close the upper end portion of the casing 154, and an exciting action of the coil 155a. A cylindrical movable core 156 that is displaced in the axial direction of the shaft 140 and a cap portion 157 that covers an opening provided in the lower end portion of the casing 154 are configured.

The movable core 156 is a cylindrical member made of a magnetic metal material, and is disposed so as to be freely inserted along the inner wall surface of the bobbin 155. The movable core 156 is movable in the axial direction of the shaft 140 by the exciting action of the coil 155a. . That is, the movable core 156 is attracted to the fixed core 151 when the coil 155a is excited, and moves upward against the urging force of the return spring 135. Thereby, the valve body 130 is pushed upward.
A through hole 156a is formed in the substantially central portion of the movable core 156 along the axial direction, and the lower end 140a of the shaft 140 is inserted into and fixed to the through hole 156a.

  The shaft 140 has a lower end 140 a side fitted and fixed in a hollow portion of the movable core 156, and an upper end 140 b side inserted and fixed in an attachment hole 133 that opens at a lower portion of the valve body 130. A flange portion 141 for fixing the inner peripheral edge portion 161 of the diaphragm 160 to the pressing member 142 is formed at a substantially central portion in the axial direction of the shaft 140.

  In addition, you may comprise so that the sliding resistance at the time of the shaft 140 being displaced may be reduced by giving a fluorine coating etc. to the outer peripheral surface of the shaft 140. By doing in this way, abrasion of the shaft 140 can be reduced and durability can be improved. At the same time, it is possible to suppress the generation of wear powder when the shaft 140 is displaced. Since the fluorine coating has a water repellent effect of repelling moisture, moisture does not adhere to the outer peripheral surface of the shaft 140, rusting of the shaft 140 can be prevented, and durability of the shaft 140 can be improved.

  The cap portion 157 is attached so as to cover a through hole 158 that communicates with the movable core 156, and a moisture permeable waterproof material 157a that prevents the entry and exit of water while allowing the entry and exit of air is mounted inside. . The moisture permeable waterproof material 157a is made of, for example, the well-known Gore-Tex (registered trademark). By disposing such a moisture permeable waterproof material 157a, it is possible to prevent water and dust from entering the solenoid 150.

[Scavenging gas discharge valve]
Returning to FIG. 1, the scavenging gas discharge valve 27 is a normally closed electromagnetic valve, and is a valve that is opened when scavenging the fuel cell stack 10. Specifically, the scavenging gas discharge valve 27 is opened by a command from the ECU in a state where the compressor 31 is operated when scavenging the anode flow path 11 of the fuel cell stack 10. The scavenging gas discharge valve 27 is set to be opened together with the scavenging gas introduction valve 41 described later.

More specifically, when scavenging the fuel cell stack 10, for example, when the system is stopped, the system temperature detected by a temperature sensor (not shown) is lower than a predetermined temperature, and then the fuel cell stack 10 is frozen. It is a time of concern.
When it is determined that the fuel cell stack 10 may be frozen, the ECU operates the compressor 31 and opens the scavenging gas introduction valve 41 and the scavenging gas discharge valve 27 so that the scavenging gas (air) from the compressor 31 is opened. ) Is pushed into the anode channel 11 and the cathode channel 12. As a result, moisture (steam, condensed water, etc.) in the anode flow path 11 is pushed out, and the fuel cell stack 10 is scavenged.

  In this case, the water pushed out from the anode flow path 11 is connected to the cathode flow path 12 through the piping 24a, the gas-liquid separator 24, the piping 24b, the piping 27a, the scavenging gas discharge valve 27, and the piping 27b together with the scavenging gas. The scavenging gas (cathode off gas) discharged from the exhaust gas is discharged to the pipe 32c, and then discharged to the outside of the vehicle through the pipe 33b and the pipe 33d. On the other hand, the water pushed out from the cathode channel 12 is discharged to the outside of the vehicle together with the scavenging gas via a pipe 32b, a pipe 32c, a pipe 33b, and a pipe 33d described later.

<Cathode system>
Returning to FIG. 1, the description will be continued.
The cathode system includes a compressor 31 (oxidant gas supply means, scavenging means), a humidifier 32, and a diluter 33 (gas treatment device).

The compressor 31 is connected to the inlet of the cathode channel 12 through a pipe 31a, a humidifier 32, and a pipe 32a. When operated according to a command from the ECU, the compressor 31 takes in oxygen-containing air and supplies the air to the cathode channel 12. The compressor 31 functions as a scavenging means for scavenging the fuel cell stack 10 when scavenging.
The compressor 31 operates using a fuel cell stack 10 and / or a high-voltage battery (not shown) that charges and discharges the power generated by the fuel cell stack 10 as a power source.

  The outlet of the cathode channel 12 is connected to the diluter 33 via a pipe 32b, a humidifier 32, and a pipe 32c. The humid cathode off gas discharged from the cathode channel 12 (cathode) is supplied to the diluter 33 through the pipe 32b and the like. The pipe 32c is provided with a back pressure valve (not shown) (not shown) that controls the pressure of air in the cathode channel 12.

<Humidifier>
The humidifier 32 includes a hollow fiber membrane 32d for exchanging moisture between the air traveling from the compressor 31 toward the cathode flow path 12 and the air flowing toward the cathode flow path 12 and the humid cathode offgas.

<Diluter>
The diluter 33 is a container that mixes the anode off-gas introduced from the purge valve 100 and the cathode off-gas (dilution gas) introduced from the pipe 32c, and dilutes hydrogen in the anode off-gas with the cathode off-gas. A dilution space 33a is provided therein. Specifically, the diluter 33 has a pipe 33b through which the cathode off gas flows vertically below the dilution space 33a. The pipe 33b has a communication hole 33c that communicates the inside with the dilution space 33a. Has been.

  A part of the cathode offgas flows out to the dilution space 33a through the communication hole 33c, and mixes with the anode offgas to generate a mixed gas, dilute the hydrogen in the anode offgas, and reduce the hydrogen concentration. It has become. The generated mixed gas is sucked into the pipe 33b through the communication hole 33c by the cathode off gas flowing through the pipe 33b, and is further diluted, and is discharged outside the vehicle through the pipe 33d. .

  That is, in the present embodiment, the cathode offgas piping through which the cathode offgas discharged from the cathode flow path 12 (cathode) of the fuel cell stack 10 flows is configured by the piping 32b, the piping 32c, the piping 33b, and the piping 33d. ing. The diluter 33 is provided in a cathode offgas pipe composed of the pipe 32b and the like.

<Scavenging system>
The scavenging system is a system that guides the scavenging gas (non-humidified air) from the compressor 31 to the anode system when scavenging the fuel cell stack 10, and includes a normally closed scavenging gas introduction valve 41. The upstream side of the scavenging gas introduction valve 41 is connected to the pipe 31a via the pipe 41a, and the downstream side of the scavenging gas introduction valve 41 is connected to the pipe 23a via the pipe 41b.
The scavenging gas introduction valve 41 is set to be opened together with the scavenging gas discharge valve 27 described above.

Next, the operation of the purge valve 100 to which the valve device of this embodiment is applied will be described.
When the voltage (cell voltage) of a single cell constituting the fuel cell stack 10 becomes equal to or lower than a predetermined cell voltage, the ECU determines that it is necessary to discharge impurities, and the purge valve 100 is opened by an instruction from the ECU.

  When the purge valve 100 is opened, the anode off-gas that is derived from the anode flow path 11 and contains impurities passes through the pipe 24 a, the gas-liquid separator 24, the pipe 24 b, the pipe 26 a, and the introduction path 111, and the primary chamber 110 a of the purge valve 100. To be introduced. At this time, the anode off-gas introduced into the introduction passage 111 is reduced in pressure by being throttled to a predetermined flow rate by the orifice 113, and then passes from the primary chamber 110a to the secondary chamber 120a through the valve body 130 and the valve seat portion 117. It flows in and is led out from the secondary chamber 120a to the lead-out path 121. The anode off gas led out from the lead-out path 121 is sent to the diluter 33 through the pipe 26b.

  At the end of the purge, if the ECU 150 turns off the energization of the coil 155a of the solenoid 150, the coil 155a is de-energized and the movable core 156 is displaced downward along the axial direction. At substantially the same time, the valve body 130 is pressed downward by the elastic force of the return spring 135, and the valve body 130 is seated on the valve seat portion 117 by the elastic force of the return spring 135. Thereby, the communication between the primary chamber 110a and the secondary chamber 120a is blocked, and the communication between the introduction path 111 and the outlet path 121 is blocked.

  In such a process, the moisture W accompanying the anode off-gas may condense in the primary chamber 110a to form water droplets, and may accumulate on the bottom wall 112 as shown in FIG. In this case, the accumulated water W flows from the bottom wall 112 into the introduction path 111 through the opening 111a as shown in FIG. That is, the moisture W remaining in the primary chamber 110a is returned to the introduction path 111.

According to the valve device of the present embodiment described above, the introduction path 111 is connected to the bottom wall 112 of the primary chamber body 110 forming the primary chamber 110a, so that the anode off-gas flowing into the primary chamber 110a is detected. Even if water such as water vapor or dew condensation water is contained, and this condenses in the primary chamber 110a to form water droplets, there is an advantage that it is difficult to remain in the primary chamber 110a. That is, after the valve is closed, water droplets remaining in the primary chamber 110a are returned from the bottom wall 112 of the primary chamber body 110 to the introduction path 111, and moisture hardly remains in the primary chamber 110a.
In addition, since the orifice 113 is located below the bottom wall 112, a step formed by disposing the orifice 113 is not formed on the bottom wall 112. Therefore, moisture such as water droplets remaining in the primary chamber 110 a is smoothly returned from the bottom wall 112 to the introduction path 111. This makes it difficult for moisture to remain in the primary chamber 110a.

  Even if water droplets do not adhere to the inside of the primary chamber 110a during the operation of the fuel cell system 1, the water that was contained in the anode off gas due to a temperature drop during the stop of the fuel cell system 1 is retained. Even when the water condenses inside and adheres as water droplets, it returns to the introduction path 111 from the bottom wall 112 of the primary chamber body 110, and moisture hardly remains in the primary chamber 110a.

  Therefore, even in a situation where the inside of the fuel cell system 1 is frozen under exposure to a low temperature environment (for example, less than 0 ° C.), the valve body 130 becomes difficult to freeze and adhere, and the valve body 130 can be smoothly displaced. As a result, a valve device that contributes to the operation of the fuel cell system with high reliability can be obtained.

  In addition, the introduction path 111 is preferably inclined upward toward the primary chamber 110 a and the upper end thereof is connected to the bottom wall 112. According to such a purge valve 100, moisture such as water droplets remaining in the primary chamber 110a can be successfully returned to the upstream gas-liquid separator 24 using the inclined introduction path 111. Therefore, it becomes difficult for moisture to stay in the introduction path 111, and the inside of the introduction path 111 can be reliably prevented from freezing even in a situation where it is exposed to a low temperature environment (for example, less than 0 ° C.).

  In addition, since the solenoid 150 is driven in the vertical direction, compared with the case of driving in the tilt direction or the horizontal direction, it is less likely to be reduced by sliding, and durability is improved and stable over a long period of time. A purge valve 100 capable of realizing the operation is obtained.

  Further, the valve body 130 is disposed in the primary chamber 110a, and at least the side facing the upper wall 114 is formed to include a tapered portion 130a whose diameter gradually decreases toward the upper wall 114 side. Even when water adheres to the upper part of the body 130 as water droplets or the like, the water hardly stays on the upper part of the valve body 130 and flows down to the bottom wall 112 forming the primary chamber 110a by the action of gravity. Therefore, after the valve is closed, the moisture present in the primary chamber 110a is preferably returned from the bottom wall 112 to the introduction path 111, and the moisture is less likely to remain in the primary chamber 110a. This contributes to the realization of the stable operation of the fuel cell system 1 over a long period of time, and the fuel cell system 1 excellent in durability and reliability can be obtained.

  Since the valve seat 116 protrudes from the bottom wall 112 toward the upper wall 114, even if moisture accompanying the anode off gas condenses in the primary chamber 110a and accumulates as water droplets on the bottom surface (on the bottom wall), It is possible to suppress the accumulated water from adhering between the valve body 130 and the valve seat 116. Accordingly, it is possible to suitably prevent the valve body 130 from being frozen and fixed to the valve seat 116, and it is possible to suitably maintain the displacement of the valve body 130.

In the above-described embodiment, the example in which the bottom wall 112 of the primary chamber 110a is formed flat has been shown. However, the present invention is not limited to this, for example, the bottom wall 112 is directed toward the opening 111a of the introduction path 111. You may form so that 112 may become a downward inclination. Further, a drain groove may be provided so that moisture in the primary chamber 110a flows toward the opening 111a of the introduction path 111. In this case, the drainage groove may be formed in an annular shape surrounding the periphery of the valve seat 116.
By configuring as described above, when moisture remains in the primary chamber 110a, the purge valve 100 can flow toward the introduction path 111 and can more appropriately prevent freezing. can get.

  FIG. 4 is a cross-sectional view showing a modified example of the valve device of the present embodiment, in which the valve seat 116 forms a part of the bottom wall around the valve seat 116 and forms the bottom wall. The parts 116a and 116b have a height difference. In this example, the bottom wall portion 116 b on the side farther from the introduction path 111 is formed to be higher toward the upper wall 114 than the bottom wall portion 116 a on the side closer to the introduction path 111.

  In other words, in this example, even if water accompanying the fluid condenses in the primary chamber 110a and becomes water droplets W2 and accumulates on the bottom wall portion 116b around the valve seat 116, it becomes the lower side due to the action of gravity. It will flow suitably toward the bottom wall 116a side, and then returned to the introduction path 111. Therefore, there is an advantage that moisture hardly remains in the primary chamber 110a.

  As another example, although not shown, the bottom wall 122 and the lead-out path 121 of the secondary chamber 120a may be formed in a downward inclined shape toward the pipe 26b. By configuring in this way, when water stays in the secondary chamber 120a, it is possible to flow the moisture from the outlet path 121 to the pipe 26b, and a purge that can more appropriately prevent freezing. A valve 100 is obtained.

  In the above-described embodiment, the example in which the valve device is used for the purge valve 100 has been described. However, the present invention is not limited to this and may be used for the drain valve 25 and the scavenging gas discharge valve 27.

  In addition, although the orifice 113 is configured by a member different from the introduction path 111, the inner wall shape of the introduction path 111 may be processed into an orifice shape, and the orifice 113 may be integrally provided in the introduction path 111.

In the above-described embodiment, the example in which the shaft 140 slides in the vertical direction by the solenoid 150 has been described. However, the present invention is not limited to this, and the shaft 140 slides in a state inclined by a predetermined angle from the vertical direction. You may comprise as follows. Also in this case, the orifice 113 only needs to be disposed below the portion that forms the bottom wall of the primary chamber 110a.
Further, the purge valve 100 may be installed so as to be upside down. That is, when the top and bottom are reversed, the upper wall 114 of the primary chamber body 110 functions as a bottom wall located on the bottom side of the primary chamber 110a, and the upper end of the introduction path 111 is connected to the bottom wall. In addition, the orifice 113 is provided in the introduction path 111 below the bottom wall. Even when configured in this manner, moisture can be suitably returned to the introduction path 111, and freezing of the valve body 130 can be suitably prevented.

  In the above-described embodiment, the valve body 130 has a mountain-shaped cross section, but is not limited to this, and may have a semicircular cross section. In other words, the valve body 130 does not have a flat surface at the top, and has a shape in which water drops do not stay and flow easily (for example, the surface forming the top is inclined with respect to the upper wall 114. Various shapes can be adopted.

  In addition, the solenoid 150 is exemplified as the drive mechanism, but the present invention is not limited to this, and other drive mechanisms, for example, a coil member is disposed between the magnetic pole surfaces of the permanent magnets that are spaced apart from each other and energized. Thus, it is possible to employ a voice coil type driving means that drives the shaft 140 in the axial direction using electromagnetic force.

  Furthermore, in the above-described embodiment, the case where the fuel cell system 1 is mounted on a fuel cell vehicle has been illustrated. However, for example, a fuel cell system mounted on a motorcycle, a train, or a ship may be used. Further, it may be a fuel cell system for use in stores, offices and the like.

It is a figure which shows the function of the fuel cell system using the purge valve as a valve apparatus which concerns on one Embodiment of this invention. It is sectional drawing of a purge valve. (A) is sectional drawing which shows the mode in the primary chamber of a valve opening state, (b) is sectional drawing which shows the mode of the primary chamber when a valve is opened. It is sectional drawing which shows the modification of the valve apparatus of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell system 10 Fuel cell stack 25 Drain valve 26 Purge valve 27 Scavenging gas discharge valve 100 Purge valve 110 Primary chamber body 110a Primary chamber 111 Introductory path 111a Opening 112 Bottom wall 113 Orifice 114 Top wall 116 Valve seat 116a, 116b Bottom wall Part 117 valve seat part 120 secondary chamber body 120a secondary chamber 121 lead-out path 130 valve element 130a taper part 150 solenoid (drive mechanism)
W moisture

Claims (6)

A primary chamber body provided with a primary chamber into which fluid is introduced;
A secondary chamber body provided with a secondary chamber through which fluid is derived;
A valve body that communicates or blocks between the primary chamber and the secondary chamber and is driven by a drive mechanism;
An introduction path for introducing a fluid into the primary chamber;
An orifice provided in the introduction path, and a valve device comprising:
The valve device is characterized in that the introduction path is connected to a bottom wall of the primary chamber body forming the primary chamber, and the orifice is positioned below the bottom wall.   2. The valve device according to claim 1, wherein the introduction path has an upwardly inclined shape, and an upper end thereof is connected to the bottom wall. The valve body is arranged in the primary chamber, and is configured to open by being displaced toward the upper wall of the primary chamber body forming the primary chamber,
3. The valve device according to claim 1, wherein a surface forming a top portion of the valve body has a tapered shape that gradually decreases in diameter toward the upper wall.   The valve device according to any one of claims 1 to 3, wherein the valve seat on which the valve body is seated projects from the bottom wall toward the upper wall.   The valve seat forms the bottom wall around the valve seat, and the portion forming the bottom wall has a side away from the introduction path to the upper wall rather than a side near the introduction path. The valve device according to claim 4, wherein the valve device is formed higher toward the end.   The valve device according to any one of claims 1 to 5, wherein the drive mechanism is driven in a vertical direction.

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