JP2006316840A - Convection preventing valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device having simple construction for opening a valve with a low pressure loss when a fluid is supplied to flow and for closing the valve when the fluid is not supplied. <P>SOLUTION: The valve device 1 provided in a water distribution flow path of a fuel cell system comprises a valve stem 2 provided in a valve box 5 having a valve hole 6 across the flowing direction, a valve element 3 provided on the valve stem 2 in an axially rotatable manner for opening and closing the valve hole 6, a magnetic part 10 formed of a magnetic substance and provided on the valve element 3, and a permanent magnet 11 provided outside the valve hole 6. The valve element 3 is always energized to the valve closing direction with the magnetic effect of the magnetic part 10 on the permanent magnet 11. When water flows, the magnetic element 3 is pushed by fluid pressure to open the valve, and when the water does not flow, it closes the valve by a magnetic energizing force to suppress the convection of gas in the flow path. The valve element energized by the magnetic force can be operated by a relatively small force at the initial stage of opening the valve against the energizing force. When water does not flow in the flow path, the valve element 3 can be restored into a valve closing state by the relatively weak magnetic force. Thus, the weak magnetic force is required to be set, resulting in the lower pressure loss. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a convection prevention valve device provided in a fluid line of a fuel cell system.

  As a valve device provided in a general fluid conduit, for example, there is a rotary blade damper shown in Patent Document 1. The blade damper is provided in the orifice portion of the flow path, and opens and closes the flow path by rotating the damper around the rotation axis, thereby blocking or opening the flow of the fluid or controlling the flow rate.

Moreover, the valve device shown in Patent Document 2 is an electromagnetic rotary valve provided in a reaction gas flow path of a fuel cell system. In the configuration, a valve shaft that crosses the flow path in the pipe diameter direction is provided in the valve box, and a valve body is attached to the valve shaft. The valve body is rotatable around the valve shaft, and can open and close the flow path by the rotation, and is biased around the valve shaft by the coil spring in the valve closing direction.
In the valve box, a solenoid portion is provided at the end of the valve shaft, and the valve body is opened by rotating the valve shaft against the biasing force of the spring by the excitation action of the solenoid portion. It is like that.
JP-A-6-174110 JP 2004-183710 A

  By the way, in the fuel cell system, for example, water from a water tank is supplied in a humidifying portion of each gas supplied to an anode (fuel electrode) and a cathode (air electrode), and the supply flow path is provided. There are places where water flows when the fuel cell is operating, and when the fuel cell stops, the flow of water stops and there is no water in the pipeline. The water stored in the water tank needs to maintain a constant temperature both when the fuel cell is operating and when it is stopped. This is not preferable because the water temperature may fluctuate due to the gas flow. For this reason, when the fuel cell is stopped and water is no longer supplied to the flow path, it is necessary to close the flow path so that the gas in the flow path does not flow.

  Also, for example, when the fuel cell is moving in a flow path that sends air to the air electrode by a pump (or blower), air is sent from the pump to the air electrode, and when the fuel cell stops, the pump also stops. Although the air flow disappears, at this time, moisture diffuses from the fuel electrode into the flow path, and if it is left as it is, moisture may reach the pump and the pump may rust. For this reason, when the fuel cell is stopped and air is no longer supplied to the flow path, it is necessary to close the flow path.

Furthermore, for example, in a fuel cell called DMFC using methanol as fuel, methanol is sent from the tank to the fuel electrode, but not all of the sent fuel has reacted, and unreacted methanol exists. .
At this time, since the unreacted methanol contains carbon dioxide generated by the reaction, it is discharged and returned to the fuel electrode again. This recycled methanol contains carbon dioxide that cannot be exhausted, and it must be avoided that it mixes with the pure methanol in the tank. For this reason, when the fuel cell is stopped and methanol is no longer supplied to the flow path, it is necessary to close the flow path so that methanol containing carbon dioxide does not flow back into the tank.
In addition to the distribution flow channel of the fuel cell system, in the flow channel where the fluid is intermittently supplied, when the supply of the fluid is interrupted, the flow channel is closed and the gas intervening in the flow channel is blocked. You may want to prevent movement.

  However, when the valve device shown in Patent Documents 1 and 2 is used in such a flow path, the valve box has a drive device that rotates the valve shaft in order to open and close the valve hole corresponding to the fluid flow. It is necessary to provide. If the drive device is interposed in the valve box, the structure becomes complicated and the device becomes larger, which is not preferable.

In addition, a method of urging the valve body in the valve closing direction by an elastic body such as a spring and pushing the valve body by the fluid pressure when the fluid flows can be considered. Employing the body can cause significant pressure loss in the fluid passing through the valve. This is because, generally, when the valve body is urged in the valve closing direction by a spring, the amount of deformation of the spring gradually increases as the valve is opened, and the urging force increases in accordance with the increase.
For this reason, it is not preferable to use this type of valve device because the fluid is not supplied smoothly.

  Furthermore, when the valve device described in Patent Document 2 is used, when the flow of fluid in the flow path stops, it is necessary to stop energization of the solenoid portion and close the valve. For this reason, a device for detecting the change in the flow is required. Providing the detection device in the flow path is not preferable because the structure is complicated and the device is enlarged.

  Accordingly, an object of the present invention is to make the valve device a simple structure so that when the fluid is supplied and flowing, the valve device is opened with a low pressure loss, and when the fluid supply is cut off, the valve device is closed. To do.

  In order to solve the above problems, the present invention provides a valve box in a flow path to which a fluid medium is intermittently supplied, forms a valve hole in the flow path in the valve box, and swings the valve hole. A valve body that opens and closes the valve hole by movement or rotation is provided, and the valve body is urged in the valve closing direction by the action of magnetic force, and the urging causes the valve body to supply fluid into the flow path. When the valve is cut off, the valve hole is closed to prevent movement of the fluid medium remaining in the flow path and not receiving supply pressure, or other gas in the flow path P.

In this way, when the fluid is supplied to the flow path, the valve body is pushed by the fluid pressure to open, and when the supply of fluid is cut off, the valve body is biased by the magnetic force. Thus, the valve can be closed to prevent movement of the gas interposed in the flow path.
At this time, since the valve body is urged by magnetic force, it is not necessary for the urging means to directly touch the respective members such as the valve body and the valve shaft that supports the valve body. For this reason, the frictional resistance when operating the valve body is reduced, and the pressure loss can be reduced. In addition, when no fluid is supplied to the flow path, gas other than the supply fluid (pressure medium) is present in the flow path, but the supply pressure of the supplied fluid does not act on the valve body. The valve body can return to the closed state by a weak magnetic force. For this reason, a weak magnetic force is sufficient. Therefore, the pressure loss generated when the fluid opens the valve body against the urging force by the magnetic force can be reduced.

  In the above configuration, if the valve body is a check valve that opens the valve hole only with respect to the flow of the supply fluid in the supply direction, when the supply of fluid is cut off, It is possible to prevent the gas from flowing backward in the flow path and reaching the fluid supply source.

  Moreover, the said valve apparatus is employable as the water distribution flow path of a fuel cell system. The water distribution flow path of the fuel cell system is in a state where there is no water in the flow path when water is not supplied to the flow path, and air is interposed in the flow path at that time. For this reason, if the valve element closes the valve hole only when there is no water in the flow path, the movement of air in the flow path can be suppressed when the fluid is not supplied to the flow path. For this reason, fluctuations in the water temperature can be prevented in the water supply source.

  Further, as a specific mode for urging the valve body by the action of magnetic force, a magnetic body portion formed of a magnetic body is provided on the valve body, and the valve body is provided outside the valve hole by the action of magnetic force. A magnetic body portion that attracts the magnetic body portion may be provided, and the valve body may be configured to be biased by the action of magnetic force between the two magnetic body portions.

  In this way, since the biasing force due to the magnetic force is inversely proportional to the distance between the two corresponding magnetic bodies, the magnetic force generated between the magnetic bodies gradually decreases as the valve is opened, and the biasing force also decreases according to the decrease. Get smaller. For this reason, the pressure loss generated in the fluid passing through the valve can be reduced. Moreover, since it is sufficient to provide the magnetic body portions on the valve body and the outside of the valve hole, it is easy to dispose both.

  Further, in the above configuration, the magnetic body portion is a plate-like member formed of a magnetic body, the sheet-like member is fixed to the periphery of the plate-like member to constitute the valve body, and the edge of the sheet-like member is It is possible to adopt a configuration in which the valve body swings by being fixed around the valve hole and bending the sheet-like member. In this way, since it is not necessary to provide a valve shaft, the configuration of the valve device is simplified.

  Since the present invention has been described above, the valve device has a simple structure, and when the fluid is supplied and flows, the valve device is opened with a low pressure loss and is closed when the fluid supply is cut off. be able to.

  One embodiment is shown in FIGS. The valve device of this embodiment is a convection prevention valve device 1 provided in a flow path P provided for supplying constant temperature water from a water tank in a fuel cell system. Water from the water tank is appropriately supplied to the flow path P. When the fuel cell is operating, the water flows through the supply flow path P, and the fuel cell stops. The water flow is stopped and the water in the pipeline is empty, that is, the air is interposed.

  In the configuration of the valve device 1, as shown in FIG. 1A, a valve body 3 is attached via a valve shaft 2 to a valve box 5 having a flow path P having a circular cross section. As shown in FIG. 3A, the valve body 3 has a plate shape with a circular cross section, and the valve shaft 2 is provided on the same shaft at both ends thereof. The valve body 3 is arranged so that the valve shaft 2 is orthogonal to the flow direction indicated by the arrow in FIG. 1A, and the axial direction of the valve shaft 2 crosses the center of the flow path P. 2 (a) and 2 (b), both ends of 2 are fitted into shaft support portions 8 and 8 of the valve box 5, and the valve body 3 is inserted into the valve box 5 via the valve shaft 2. It is supported and can rotate 360 degrees around the axis of the valve shaft 2.

  The valve body 3 is rotatable in both directions around the axis of the valve shaft 2 with the valve hole 6 closed, that is, with the valve closing position shown in FIG. 1 (a) interposed therebetween. By rotating in either direction around the valve shaft 2, the valve hole 6 formed in the flow path P can be opened and closed as shown in FIGS. Further, in the valve closed state, a gap extends between the outer peripheral edge 3a of the valve body 3 and the inner peripheral edge of the valve hole 6 of the flow path P as shown in FIG. Is provided.

  The valve body 3 is made of a magnetic material such as nickel or ferrite stainless steel, and the valve body 3 as a whole forms the magnetic body portion 10. The valve shaft 2 is fixed by fitting a resin molded product formed in a rod shape into the valve body 3.

  As shown in FIG. 1, a permanent magnet (magnetic body portion) 11 is attached to the valve box 5 outside the valve hole 6, and by the action of magnetic force between the magnetic body portion 10 and the permanent magnet 11, The magnetic body portion 10 (valve body 3) is attracted, and the valve body 3 is always urged in the valve closing direction.

  The operation of the valve device 1 will be described. When water does not flow in the flow path P, there is no water in the flow path P as described above. Is not added. For this reason, the valve body 3 is attracted | sucked by the effect | action of magnetic force, and exists in the position of the valve closing state shown to Fig.1 (a).

  In the closed state, when water flows in the direction of arrow A shown in FIG. 1 (a), the valve body 3 rotates around the valve shaft 2 and rotates as shown by arrow B in FIG. 1 (b). To open the valve. Thereafter, when the water flow is stabilized, the valve body 3 rotates to a position substantially parallel to the water flow direction and is maintained at that position. When the flow of water in the flow path P stops and there is no water in the flow path, the valve element 3 returns to the closed state shown in FIG.

  At this time, the permanent magnet 11 forms a magnetic line of force with the magnetic body portion 10, and the magnetic force is generated when a gas such as air in the flow path P tries to naturally convect in the valve-closed state. Prevents the valve body 3 from opening and applies a biasing force, which is weaker than the water pressure acting on the valve body 3 to the magnetic body portion 10 of the valve body 3, when water flows. For this reason, when water flows in the flow path P, it opens, and when water runs out, it closes, and the convection of the gas in the flow path P can be prevented.

  In addition to the embodiment shown in FIG. 3A, the valve body 3 is formed by integrally forming the valve shaft 2 and the valve body 3 with a magnetic material such as metal as shown in FIG. 3B. Alternatively, as shown in FIG. 3C, the valve body 3 made of a magnetic material such as metal and the valve shaft 2 made of a magnetic material or other material may be fixed. When both the valve body 3 and the valve shaft 2 are made of metal, a fixing method by spot welding or the like can be adopted.

  As another embodiment, there is a valve device 1 shown in FIG. The valve device 1 shown in FIG. 4 is provided with a valve seat 7 having a surface orthogonal to the flow direction in the valve hole 6 of the flow path P so that the valve body 3 comes into contact with the valve seat 7 in the closed state. It is a thing. The valve seat 7 is provided on both sides of the axis of the valve shaft 2 and is formed in a semicircular arc shape along the inner circumference of the flow path P. Moreover, both valve seats 7 and 7 are formed in the opposite direction with respect to the flow direction of the flow path P, as shown in the figure.

  As shown in FIG. 4B, with respect to the flow of water from the direction of the arrow A ', the valve body 3 rotates in the direction of the arrow B' shown to open. Moreover, as shown in FIG.4 (c), with respect to the flow of the water from the direction of arrow C, the valve body 3 maintains a valve closing state and functions as a check valve.

This is because the fluid pressure acting on the “b” portion of the valve body 3 shown in FIG. 4A is the “a” portion with respect to the flow of water from the direction of the arrow A ′. This is because it is set so as to largely contribute as a moment acting around the valve shaft 2 of the valve body 3 rather than the fluid pressure acting on the valve body 3. For the flow of water from the direction of arrow C, the fluid pressure acting on the “d” portion of the valve body 3 shown in FIG. 4C is more than the fluid pressure acting on the “c” portion. This is because it is set so as to greatly contribute as a moment acting around the valve shaft 2 of the valve body 3.
The setting is based on the distance from the valve shaft 2 between the “a” portion and the “b” portion or the “c” portion and the “d” portion to be compared (the length of the arm from the center of rotation to the point of action of the force). And the difference in pressure receiving area.
As long as the fluid pressure acting on the “b” portion is set so as to contribute more as a moment acting around the valve shaft 2 of the valve body 3 than the fluid pressure acting on the “a” portion. A difference may be set in the weight balance between the valve bodies 3 on both sides of the valve shaft 2, that is, the weights of the “a” portion and the “d” portion. As for the difference, it is desirable to set the weight of the portion “a” to be heavier than “d”.
Further, even if the weights of the “a” and “d” portions are the same, the weight center of gravity of the “d” portion is set so as to be as far away from the valve shaft 2 as possible. The center of gravity of the portion “a” may be set as close to the valve shaft 2 as possible.

  Furthermore, there exists the valve body 3 shown in FIG. 5 as other embodiment. The valve body 3 is made by injection molding or the like with a valve body body made of resin, and a magnetic body portion 10 formed of a magnetic body is provided on a part thereof. Usually, when the valve body 3 and the valve shaft 2 are to be molded from metal, it takes time to process the shaft portion and the like in order to secure a predetermined rotational performance. The magnetic body 10 can be easily formed by a known method such as adhesion or embedding of the magnetic body. Further, the weight balance of the valve body 3 can be easily set by adjusting the weight of the magnetic body constituting the magnetic body portion 10.

  In addition, as long as it has the effect | action of the said valve apparatus, the position of the valve axis | shaft 2 may be the aspect which crosses the flow path P in the center part, or the position eccentric to either one from the center part, The shaft 2 may be provided at the radial end of the flow path P, and the valve body 3 may be cantilevered.

  As an embodiment in which the valve body 3 is supported in a cantilever manner, a valve device shown in FIG. 6 can be considered. In this embodiment, the valve shaft 2 is disposed at the radial end of the flow path P, and a rectangular valve body 3 corresponding to the cross-sectional shape of the flow path P is fixed to the valve shaft 2 (see FIG. 6 (b)). The configuration of the magnetic body 10 may be the same as that in each of the above embodiments.

  Furthermore, the valve apparatus shown in FIG. 7 can be considered as another embodiment. In this embodiment, the magnetic body portion 10 is a metallic plate-like member that is a magnetic body, and the plate-like member is held by sheet-like members 13 and 13 made of a resin film. The periphery of the sheet-like members 13 and 13 is fused on the outer periphery of the plate-like member so that the plate-like member is not exposed. A magnetic body portion 11 made of a permanent magnet is provided outside the valve box 5. And the edge part of the said sheet-like member 13 is fixed to the valve box 5 with pin 2 'in a figure, and when the sheet-like member 13 bends, the valve body 3 will rock | fluctuate and the valve hole 6 will be opened and closed It is what you do. The sheet-like member 13 may be fixed to the valve box 5 with a pin 2 'as shown in the figure, or may be bonded.

In any of the embodiments, the magnetic body portion 10 provided in the valve body 3 is a permanent magnet, and the magnetic body portion 11 provided outside the valve hole 6 of the valve box 5 is attracted to the permanent magnet such as a metal. It is good.
Moreover, in the said embodiment, although the valve apparatus was provided in the water distribution flow path of the fuel cell system, when the medium supplied to the flow path is other than water, for example, in the case of methanol, air, city gas, LPG, etc. Can exert the same effect.

When the case where the said medium is air is illustrated, the said valve apparatus 1 will be arrange | positioned in the flow path P which sends air to a pole with a pump (or blower). When the fuel cell is moving through the flow path P, air is sent from the pump to the air electrode. When the fuel cell is stopped, the pump is stopped (the supply pressure is lost), and the air flow is stopped. In this way, when air is no longer supplied to the flow path P, the valve element 3 closes the valve hole 6 so that the air remaining in the flow path P does not receive supply pressure, or in the flow path P. Prevent the movement of other intervening gases.
By preventing this movement, it is possible to prevent moisture from diffusing into the flow path P from the fuel electrode side and reaching the pump to cause rust and the like.

Further, when the case where the medium is methanol is exemplified, for example, in a fuel cell called DMFC using methanol as a fuel, methanol is supplied from the tank to the fuel electrode via the flow path P. The valve device 1 is disposed.
At this time, not all of the supplied fuel has reacted, but unreacted methanol exists. In addition, this unreacted methanol contains carbon dioxide produced by the reaction, so it is discharged and returned to the fuel electrode again, but this recirculated methanol cannot be completely discharged. Contains carbon.
Therefore, when the fuel cell is stopped and methanol is no longer supplied to the flow path P (the supply pressure is lost), the valve body 3 closes the valve hole 6 and remains in the flow path P. The movement of the medium that is not subjected to the supply pressure, that is, methanol containing carbon dioxide, is prevented.
By preventing this movement, methanol containing carbon dioxide can be prevented from flowing back into the tank and mixed with pure methanol in the tank.

  In addition to the flow path of the fuel cell system, in the flow path where the fluid is intermittently supplied, the flow path is closed when the supply of the fluid is interrupted to prevent the movement of gas intervening in the flow path. This valve device can be used when desired.

In the operation diagram of one embodiment, (a) shows a valve closing state, and (b) shows a valve opening state. 1A is a right side view of FIG. 1A, and FIG. 1B is a plan view of FIG. Detailed view of valve body of one embodiment Other embodiments are shown, in which (a) is a valve-closed state, (b) is a valve-opened state, (c) is a state where a fluid flows from the opposite direction, and (d) is a cross section near the valve hole. Sectional drawing of the valve body of other embodiment Other embodiment is shown, (a) is a valve closing state, (b) shows the detail of a valve body. The valve closing state of other embodiment is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve apparatus 2 Valve shaft 3 Valve body 3a Outer periphery 5 Valve box 6 Valve hole 7 Valve seat 8 Shaft support part 10 Magnetic body part 11 Permanent magnet (magnetic body part)
13 Sheet-like member P Flow path

Claims (5)

  A valve hole 6 is formed in a flow path P to which a fluid medium is intermittently supplied, and a valve body 3 that opens and closes the valve hole 6 by swinging or rotating is provided in the valve hole 6. When the supply of the fluid into the flow path P is cut off, the valve body 3 closes the valve hole 6 by the biasing by the action of A valve device that prevents movement of the fluid medium remaining in P and not receiving supply pressure, or other gas in the flow path P.   The valve device according to claim 1, wherein the valve body (3) is a check valve that opens the valve hole (6) only for the flow of the supply fluid in the supply direction.   The flow path P is a water distribution flow path of the fuel cell system, and the valve body 3 closes the valve hole 6 only when there is no water in the flow path P. The valve device described.   The valve body 3 is provided with a magnetic body portion 10 formed of a magnetic body, and a magnetic body portion 11 for attracting the magnetic body portion 10 of the valve body 3 by the action of magnetic force is provided outside the valve hole 6. The valve device according to any one of claims 1 to 3, wherein the body (3) is biased by the action of magnetic force between the magnetic body portions (10, 11).   The magnetic body portion 10 is a plate-like member formed of a magnetic body. The sheet-like member 13 is fixed to the periphery of the plate-like member to constitute the valve body 3, and the edge of the sheet-like member 13 is connected to the valve. The valve device according to claim 4, wherein the valve body 3 is rocked by being fixed to the hole 6 and bending the sheet-like member 13.

Images