Patent Application
20240102579
The invention relates to an electromagnetic valve for an anode supply of a fuel cell system which is configured as a purge valve or drain valve and a fuel cell system with the valve.
Fuel cell systems with an anode supply and a cathode supply are known in the art. Fuel cell systems utilize a chemical transformation of a fuel with oxygen into water in order to generate electrical energy. In order to supply a fuel cell stack of the fuel cell system with operating agents an anode supply is provided for feeding and exhausting the anode operating agent, e.g. hydrogen, a cathode supply for feeding and exhausting a cathode operating agent, e.g. air and a coolant cycle. The anode supply and the cathode supply respectively include a feed conduit for feeding the operating agent and an exhaust conduit. The anode supply additionally includes a recirculation conduit configured to feed hydrogen included in the anode side exhaust gas of the fuel cell stack back into the fuel cell stack.
The anode exhaust gas conduit typically includes a water precipitator including a downstream drain valve configured to drain product water generated by the fuel cell reaction and a purge valve configured to drain the anode gasses, mostly nitrogen.
At low ambient temperatures there is a risk of water arranged in the valve channels freezing so that valve devices of the valve freeze. This can cause malfunctions and damages of the fuel cell system.
Therefore, it is known in the art to use the magnet coil of the valve as a heating coil and to apply a non-switching heating current to the magnet coil in addition to a switching current. However, the valve device is only heated indirectly by heating the magnet coil which is perceived as a disadvantage.
Quickly heating the valve device is desirable. Thus, it is an object of the invention to provide an electromagnetic valve configured as a purge valve or drain valve of a fuel cell system which facilitates heating the valve device more quickly compared to known magnet valves. It is another object of the invention to provide a fuel cell system with valves that are heatable rather quickly.
The object is achieved by An electromagnetic valve for an anode supply of a fuel cell system, the electromagnetic valve configured as a purge or drain valve including an actuator including a magnet coil configured to electromagnetically actuate an armature, and a valve plunger operatively connected with the armature; a valve seat openable and closable as a function of an actuation of the valve plunger so that a media connection between an inlet and an outlet is controlled through a valve chamber, wherein the valve seat and the inlet are configured at a connection spout connected with the actuator, and wherein an additional magnet coil is provided as a heating coil.
The electromagnetic valve according to the invention for an anode supply of a fuel cell system is configured as a purge valve or drain valve and includes an actuator including a magnet coil configured to electromagnetically actuate an armature and a valve plunger operatively connected with the armature, a valve seat which is openable and closeable as a function of an actuation of the valve plunger so that a media connection between an inlet and an outlet is controlled through a valve chamber. The valve seat and the inlet are configured at a connection spout connected with the actuator. According to the invention an additional magnet coil is provided as a heating coil. The configuration according to the invention facilitates quick heating of the valve system at low ambient temperatures and thus assures a functioning of the fuel cell system at low ambient temperatures.
Advantageously the connection spout is one piece, containing at least the inlet and the outlet.
According to an advantageous embodiment the heating coil is arranged between the actuator and the connection spout and the heating coil envelops the valve seat in a radial direction.
Advantageously the connection spout is an injection molded part and the heating coil is integrated in the connection spout near the valve seat.
According to an advantageous embodiment the heating coil is attached at the actuator by the connection spout.
According to an advantageous embodiment of the invention the heating coil can include an additional contact.
The object is also achieved by a fuel cell system including at least one fuel cell stack, a cathode supply and an anode supply and a valve according to the invention arranged in the anode supply.
The subsequent detailed description of the invention and the patent claims define additional advantageous embodiments and features combinations of the invention.
The invention is now described based on two advantageous embodiments with reference to drawing figures, wherein:
The fuel cell system 1 includes a fuel cell stack 2 that is typically configured as a stack of proton exchange membrane (PEM) fuel cells. A common cathode cavity 3 is associated with a cathode supply 30 configured to feed an exhaust a cathode operating agent, e.g. air and a common anode cavity 4 is associated with an anode supply 40 configured to feed and exhaust an anode operating agent, e.g. hydrogen.
The cathode supply 30 includes a cathode supply conduit 31 that feeds air pulled from ambient into the common cathode cavity 3 of the fuel cell stack 2. A cathode exhaust conduit 32 exhausts cathode exhaust gas from the common cathode cavity 3. The cathode exhaust gas may be fed to an exhaust gas arrangement as needed.
The anode supply 40 includes an anode supply conduit 41 which provides the anode operating agent, in particular hydrogen from a hydrogen tank 43 to the common anode cavity 4. The anode supply conduit 41 typically includes additional components including a tank valve, a dosing valve and a cut off valve. An anode exhaust gas conduit 42 exhausts anode exhaust gas from the common anode cavity 4. The anode supply 40 additionally includes a recirculation conduit 44 configured to feed hydrogen included in the anode side exhaust gas of the fuel cell stack 2 back to the fuel cell stack 2 through a recirculation device 45, e.g. a recirculation blower.
The anode exhaust gas conduit 41 furthermore includes a water precipitator 46 with a downstream drain valve 47 configured to drain product water generated by the fuel cell reaction and a purge valve 48 configured to vent anode gasses, mostly nitrogen.
The drain valve 47 and the purge valve 48 are configured as electromagnetic valves and respectively include a magnet coil 50 configured to electromagnetically actuate the valve.
The valve 51 includes an electromagnetic actuator 52 which includes the magnet coil 50 configured to electromagnetically actuate an armature 53 and a valve plunger 54 operatively connected therewith. A connection spout 55 of the valve 51 including an inlet 56 configured as a pass-through opening and a valve seat 57 is connected with the actuator 52 in a sealing manner. A valve chamber 58 is configured between the connection spout 55 and the valve plunger 54 wherein the valve chamber facilitates a media connection between the inlet 56 and an outlet 59 when the valve seat 57 is open as illustrated. In the illustrated embodiment, the outlet 59 is also provided in the connection spout 55.
When the valve plunger 54 is moved by the armature 53 against a compression spring or plural compression springs 60 in a direction towards the armature 53 the valve seat 57 opens and the media connection is established. When no current is supplied to the armature 53 the valve seat 57 remains closed by the spring force of the compression spring 60.
An additional magnet coil is provided configured as a heating coil 70 in order to assure a quick heating of the valve system at low ambient temperatures and thus a functioning of the fuel cell system.
As evident from
The heating coil 70 can be attached at the actuator 52 in a simple manner through the connection spout 55. Therefore, the connection spout 55 envelops the heating coil 70 at least partially, wherein the heating coil 70 includes an additional contact 71. The connection spout 55 could be one piece, containing multiple components, e.g. inlet 56 and outlet 59.
As it can be seen from
Furthermore, the connection spout 55 and the heating coil 70 with the terminal blades are placed in a tool and overmolded with plastic to cover the windings. Additionally, material for the outlet 59 can be added, so that it is formed integrally with the connection spout 55. In an advantageous embodiment, contact 71, which holds the two terminal blades and forms the connection geometry, could also be added integrally to connection spout 55.
All features described and shown with respect to individual embodiments of the invention can be combined in various combinations according to the invention in order to achieve the advantageous effects of the invention. The patent scope is defined exclusively by the appended claims and is not limited by the features described in the specification or shown in the drawing figures.
