JPH0875032A - Operation method for solenoid valve in fuel cell power generation device - Google Patents

Abstract

PURPOSE: To securely change a solenoid valve from a closed condition into an opened condition by applying a drive voltage on a coil of the solenoid valve, repeating operation of lowering it to be under a holding voltage for a specified number of times, and setting it at the holding voltage. CONSTITUTION: For changing a solenoid valve in a closed condition into an opened condition, a drive voltage is applied to a coil 5 of the solenoid valve, operation of lowering the voltage to be under a holding voltage which is almost 1/2 of the drive voltage is repeated twice or more, and it is set at the holding voltage. A plunger 6, that is a main valve 2, thus receives strong force of upward attractive force twice or more by magnetic force generated by the coil 5, so in the case where a seal material on which the main valve 2 is installed is fixed to a seat 7b of a valve body 3, impact load to separate the seal material 1 from the seat 7b of the valve body 3 is applied twice or more repeatedly to separate the fixed parts from each other to change the solenoid valve into the opened condition. The solenoid valve can thus be securely changed from the closed condition into the opened condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve mainly used in a fuel cell power generator, and more particularly to a solenoid valve operating method using a rubber sealing material that opens when a control coil is energized.

[0002]

2. Description of the Related Art A fuel cell power generator is a device in which an electrolyte layer is sandwiched between a fuel electrode and an air electrode, and fuel reforming gas and air are supplied to each electrode to generate electricity by an electrochemical reaction. FIG.
Shows a simplified supply system of these reaction gases. The fuel electrode of the fuel cell body 11 is supplied with the reformed gas having a high hydrogen concentration, which is obtained by feeding the raw fuel gas to the fuel reformer 12 and heating it by the burner 13. The fuel off-gas discharged from the fuel electrode contains residual hydrogen that did not contribute to the electrochemical reaction, and is sent to the burner 13 and used for heating. Further, reaction air is sent to the air electrode of the fuel cell main body 11 and oxygen contained therein contributes to the electrochemical reaction. In addition,
The heat generated by the electrochemical reaction is removed to the outside by supplying cooling water to the cooling plate incorporated in the fuel cell body 11. A reformed gas supply valve 14 is incorporated in the reformed gas supply system, and a nitrogen gas supply system in which a nitrogen purge valve 15 is attached in parallel is incorporated in the supply system. During operation of the fuel cell power generator, the reformed gas supply valve 14 is opened and the nitrogen purge valve 15 is closed to supply the reformed gas to the fuel electrode to cause an electrochemical reaction. On the other hand, when the operation is stopped, the reformed gas supply valve 14 is closed to prevent the supply of harmful gases such as insufficiently reformed gas, insufficiently heated gas, or steam to the fuel cell main body 11, and The nitrogen purge valve 15 is opened and nitrogen gas is supplied to perform nitrogen purge.

FIG. 4 is a basic sectional view of an electromagnetic valve normally used as the reformed gas supply valve 14 described above. This solenoid valve is a so-called normally closed solenoid valve, and when the coil 5 is in the non-energized state, the main valve 2 is driven by the spring 4 as shown in the figure.
Is pushed downward and comes into contact with the seat 7b at the upper end of the valve body 3 through the ring-shaped rubber seal material 1 to be in a closed state. When the coil 5 is energized, a magnetic force that lifts the plunger 6 is generated, the main valve 2 is lifted, and the valve is opened.

When this type of solenoid valve is moved from the closed state to the open state, in order to reduce power consumption, as shown in FIG. A so-called economy drive is generally used in which a high drive voltage is applied only when the valve is moved and the valve is held in an open state after being lowered to a hold voltage of about 1/2 of the drive voltage. .

[0005]

Fluorine rubber is usually used as the seal material 1 of the solenoid valve described above. However, when the rubber is in contact with the load for a long time with a load applied, it has the property of sticking to the metal. In particular, as in the case of the reformed gas supply valve 14 described above, there is a high possibility of sticking if they are in contact with each other under pressure in an atmosphere containing water vapor. Therefore, when shifting such a solenoid valve from the closed state to the open state,
It is necessary to apply a suction force to the main valve 2 that exceeds the adhesion force between the fluororubber and the metal.

As a method of solving this, there is a method of increasing the magnetic force generated by the coil 5, but this method has a drawback that the coil becomes large and power consumption increases. Further, there is a method in which the open / closed state of the solenoid valve is detected as an electric signal, and when the open state is not reached, a drive voltage is applied again to the solenoid valve to bring it into the open state. In the case of (1), since combustible gas is targeted, there is a problem that the structure is complicated and an expensive solenoid valve is required to take out an electric signal indicating the open / closed state.

The present invention has been made under such a background, and an object thereof is to basically change the structure even if the rubber seal material of the solenoid valve and the valve body are fixed to each other. It is an object to provide a method for operating a solenoid valve that can shift from a closed state to an open state at low cost.

[0008]

In order to achieve the above object, according to the present invention, a main valve is pushed down by a spring, and a ring-shaped sealing material installed at the lower end of the main valve is attached to a ring at the upper end of the valve body. In the solenoid valve of the fuel cell power generator, the drive valve is applied to the coil of the solenoid valve in order to move it to the open state by moving the main valve upward by applying a voltage to the coil. Approximately 1/2 of drive voltage
The operation method of shifting from the closed state to the open state by setting the holding voltage after repeating the operation of lowering the holding voltage to 2 or less twice is adopted. Furthermore, the seat of the valve body of the above solenoid valve has a convex cross-section such as a circular cross section or a triangular cross section.

[0009]

As described above, when the solenoid valve in the closed state is moved to the open state, the operation of applying the drive voltage to the coil of the solenoid valve and then lowering it to the holding voltage or lower is repeated twice or more and then becomes the holding voltage. If the operation method is taken, the magnetic force generated by the coil will cause the plunger, and hence the main valve, to be repeatedly attracted upward with a strong force by repeating it twice or more times. If the material adheres to the valve seat, the impact load that separates the seal material from the valve seat is applied twice or more repeatedly, causing the adhered part to separate and opening the solenoid valve. It will shift to the state. Also, since the fixing force of the fixed portion is strong in the direction perpendicular to the fixed surface and weak in the horizontal direction to the fixed surface, the seat of the valve body of the solenoid valve should have a convex cross-sectional shape such as a circular cross section or a triangular cross section. The force that is sucked upward by the coil exerts a force in the parallel direction on the fixing surface between the seal member and the seat of the valve body, and can be released more easily.

[0010]

EXAMPLES The present invention will be described below based on examples. FIG. 1 shows a change in voltage applied to a coil when an open state is used, which is used in a method of operating a solenoid valve of a fuel cell power generator according to the present invention. In this embodiment, an operation method of applying a drive voltage to the coil of the solenoid valve, lowering it to the holding voltage, and further interrupting the applied voltage twice, and then applying the drive voltage again and holding the holding voltage. It corresponds to the case where the operation of applying the drive voltage and then lowering it to the holding voltage or lower is repeated three times. According to this method, an impact load is applied three times to the fixed portion between the seal member and the seat of the valve body, the fixed portion is released, and the solenoid valve shifts to the open state.

FIG. 2 is a sectional view showing the basic structure of an electromagnetic valve used in the method for operating an electromagnetic valve of a fuel cell power generator according to the present invention. Components having the same functions as those of the conventional example are designated by the same reference numerals. And the description is omitted. The difference between this embodiment and the conventional example is that the seat 7a at the upper end of the valve body 3 is formed in a circular cross section instead of the conventional flat plate shape.
When the seat 7a is formed in a circular cross-section in this way, the fixing surface with the sealing material has not only a horizontal component but also a vertical component in which the main valve 2 is sucked. It will be released more easily than in comparison.

Although the seat 7a is formed in a circular cross section in this example, the contact surface is not limited to a circular cross section but a triangular cross section or the like has a convex cross section having a vertical component. Obviously, the same effect can be obtained by doing so.

[0013]

According to the present invention, the main valve is pushed down by the spring, and the ring-shaped sealing material installed at the lower end of the main valve is pressed against the ring-shaped seat at the upper end of the valve body to close it, and the coil is energized. In a solenoid valve of a fuel cell power generator that moves the main valve upwards by applying to obtain an open state, after applying a drive voltage to a coil of the solenoid valve, the voltage is reduced to a holding voltage of about a half or less of the drive voltage. Even if the rubber seal material of the solenoid valve and the valve body may stick to each other, the operation method of changing from the closed state to the open state by setting the holding voltage after repeating the lowering operation twice or more is adopted. , It has become possible to reliably shift from the closed state to the open state without changing its structure basically and without adding a special detection function.

Furthermore, by making the seat of the valve body of the solenoid valve to have a convex cross section such as a circular cross section or a triangular cross section, the rubber seal material and the valve body can more easily separate the fixed portion. As a result, it is possible to more reliably shift from the closed state to the open state.

[Brief description of drawings]

FIG. 1 is a change diagram of a voltage applied to a coil during an open state transition used in a method of operating a solenoid valve of a fuel cell power generator according to the present invention.

FIG. 2 is a sectional view showing a basic structure of a solenoid valve used in a method of operating a solenoid valve of a fuel cell power generator according to the present invention.

FIG. 3 is an explanatory view showing a simplified reaction gas supply system of the fuel cell power generator.

FIG. 4 is a cross-sectional view showing a basic structure of a solenoid valve used in a method for operating a solenoid valve of a conventional fuel cell power generator.

FIG. 5 is a change diagram of a voltage applied to a coil at the time of transition to an open state, which is used in a method of operating a solenoid valve of a conventional fuel cell power generator of this type.

[Explanation of symbols]

 1 Sealing Material 2 Main Valve 3 Valve Body 4 Spring 5 Coil 6 Plunger 7a Seat 11 Fuel Cell Main Body 12 Fuel Reformer 14 Solenoid Valve

Front page continuation (72) Inventor Motoichi Ikeda 2-6 B9, Kuki, Zushi City, Kanagawa Prefecture (72) Nobuhiro Iwasa 910-55, Katsuragi Town, Kishiwada City, Osaka Prefecture (72) Hiromasa Yoshida Nagoya, Aichi Prefecture 1-9-6 Oshikiri, Nishi-ku, Japan (72) Inventor Takehiro Enomoto 1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd.

Claims (2)

[Claims] 1. A main valve is pushed down by a spring, a ring-shaped sealing material installed at the lower end of the main valve is pressed against a ring-shaped seat at the upper end of the valve body to close it, and a voltage is applied to the coil. In a solenoid valve of a fuel cell power generator that moves the main valve upward to obtain an open state, an operation of applying a drive voltage to the coil of the solenoid valve and then lowering it to a holding voltage of about a half or less of the drive voltage is performed. A method for operating a solenoid valve of a fuel cell power generation device, which comprises repeating the operation twice or more and then changing the holding voltage from the closed state to the open state. 2. The method for operating a solenoid valve of a fuel cell power generator according to claim 1, wherein the seat of the solenoid valve is formed in a convex cross-section of a circular cross section or a triangular cross section. For operating a solenoid valve of a fuel cell power generator.