JP7764334B2 - fuel cell device - Google Patents

Description

The present invention relates to a fuel cell device.

Fuel cell devices are known that generate electricity using hydrogen-containing fuel gas and oxygen-containing gas (air) and supply the electricity to the outside. Such fuel cell devices are equipped with numerous pipes through which fluids such as fuel and water necessary for power generation flow, and the fuel cell module and multiple auxiliary devices that make up the system are connected to each other via these pipes (see, for example, Patent Document 1).

JP 2018-049783 A

Fuel cell devices have auxiliary equipment that requires periodic replacement to maintain power generation performance. Furthermore, in the event of a malfunction, the auxiliary equipment may need to be removed for repair. During such maintenance, the piping connected to the auxiliary equipment must be removed, but the system was not designed to allow the piping to be easily attached or detached, so improvements were needed to make the replacement process easier.

The present invention aims to solve the above problems by providing a fuel cell device that allows for easy attachment and detachment of piping and is easy to maintain.

The present invention provides a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas,
a fluid flow path through which a fluid used to operate the fuel cell flows;
a plurality of auxiliary devices provided in the fluid flow path, the fluid flow path having a plurality of pipes arranged between the plurality of auxiliary devices,
at least one of the pipes is configured by a single pipe having a first flow path, a second flow path, and a third flow path extending in directions that are mutually different by approximately 90°, the second flow path being provided between the first flow path and the third flow path, and being rotatable about the first flow path;
The rotating pipe connection portion that connects the third flow path and the auxiliary device is a fuel cell device having a connection port that has an opening on the path that is traced by the tip of the rotating third flow path.

The above-described configuration allows for easy attachment and detachment of the piping, resulting in a fuel cell device with excellent maintainability.

1 is a system configuration diagram of a fuel cell device according to an embodiment of the present invention. FIG. 1 is an external perspective view of a fuel cell device. FIG. 2 is a diagram illustrating a portion of a fuel supply device. FIG. 10 is a diagram showing the desulfurizer outflow piping removed from the desulfurizer. FIG. 2 is a top view of the desulfurizer. FIG. 2 is a diagram showing the structure of a vessel lid of a desulfurizer.

We will briefly explain the preferred embodiment of the present invention, illustrating its operation.

The present invention relates to the structure of a fluid flow path through which fluids used in fuel cell operation flow. At least one of the pipes connecting the auxiliary equipment is configured with a first flow path, a second flow path, and a third flow path extending in directions that differ by approximately 90° from each other and is rotatable around the first flow path as an axis. The rotating pipe connection section connecting the third flow path to the auxiliary equipment has a connection port that opens onto the orbit of the rotating third flow path. In other words, because the connection port with the auxiliary equipment is located on the orbit around which the pipe is rotated, the pipe and the auxiliary equipment can be easily connected simply by rotating the first flow path around the axis. This improves maintainability.

In addition, the piping is configured by connecting the first, second, and third flow paths in this order. This allows the auxiliary equipment to be connected using the shortest piping length, thereby reducing manufacturing costs.

The connection port is also designed to be visible from the maintenance surface, which is opened and closed during maintenance. This allows the piping to be removed by rotating it toward the maintenance surface, and the connection position can also be seen, further improving maintainability.

The desulfurizer, an accessory, has a fuel inlet and a fuel outlet on the top surface of the container, with the fuel inlet and fuel outlet having different diameters, and a rotary pipe connection is attached to either the fuel inlet or fuel outlet. This prevents incorrect piping connections during maintenance, even in desulfurizers where both the fuel inlet and fuel outlet are located on the top surface.

One embodiment of the present invention is described below with reference to the drawings.

Figure 1 is a system configuration diagram of a fuel cell device according to this embodiment. The fuel cell device 100 includes a fuel cell module 1, and a number of accessories for operating the fuel cell module 1, such as a first heat exchanger 2, a heat storage tank 3, a condensed water tank 4, a radiator 5, an air supply device 14, a fuel supply device 15, and a reforming water supply device 16, are housed within a housing 50. It is not necessary for all of the above-mentioned devices to be housed within the housing 50; for example, the first heat exchanger 2 and the heat storage tank 3 may be located outside the housing 50. It is also possible to create a fuel cell device that omits some of the above-mentioned devices.

The fuel cell module 1 is constructed by housing, inside a box-shaped storage container 10, a fuel cell 11 that generates electricity using fuel gas and oxygen-containing gas, and a reformer 12 that generates the fuel gas to be supplied to the fuel cell 11.

The configuration of the fuel cell 11 is not particularly limited, but it may have, for example, a cell stack structure in which multiple fuel cell units are arranged. A fuel cell 11 with a cell stack structure is constructed, for example, by fixing the lower end of each fuel cell unit to a manifold using an insulating bonding material such as a glass sealant.

The reformer 12 steam-reforms raw fuel gas, such as natural gas or LP gas, to produce fuel gas that is supplied to the fuel cell 11. The reformer 12 is connected to a fuel supply device 15 that supplies the raw fuel gas and a reforming water supply device 16 that supplies reforming water. The raw fuel gas and reforming water undergo a reforming reaction in the heated reformer 12, producing fuel gas containing hydrogen.

The fuel cell 11 is supplied with fuel gas produced in the reformer 12 and air (oxygen-containing gas) introduced by the air supply device 14. As the fuel gas passes through the fuel cell, it reacts with the oxygen-containing gas to generate electricity. The fuel gas and oxygen-containing gas not used for power generation join together at the top of the fuel cell 11 and are combusted. This combustion of the fuel gas produces high-temperature exhaust gas, which heats the reformer 12. The exhaust gas produced in this way within the fuel cell module 1 is supplied to the first heat exchanger 2.

The first heat exchanger 2 is connected via piping to the heat storage tank 3, heat medium pump P1, and radiator 5, forming the first heat medium circulation line HC1. A heat medium is introduced into this first heat medium circulation line HC1, and in the first heat exchanger 2, heat exchange occurs between this heat medium and the exhaust gas mentioned above, heating the heat medium. Water or other materials can be used as the heat medium, and the heat storage tank 3 stores the heat medium whose temperature has been increased by heat exchange. The heat medium stored in the heat storage tank 3 is sent to the radiator 5 to be cooled, and then exchanges heat with the exhaust gas again in the first heat exchanger 2 before returning to the heat storage tank 3. As a result, high-temperature heat medium is stored in the heat storage tank 3 from the top, creating temperature stratification.

The first heat exchanger 2 is also connected to a condensed water tank 4 via a condensed water recovery path 20. When the exhaust gas generated in the fuel cell module 1 is cooled by heat exchange, the water vapor contained in the exhaust gas is separated into water and gas, and the separated water is collected in the condensed water tank 4 through the condensed water recovery path 20. In the condensed water tank 4, the collected water is purified by removing impurities through an ion exchanger (not shown) or the like. The purified water is supplied to the reformer 12 by the water supply device 16 and used as reforming water. Meanwhile, the gas from which the water has been removed passes through the exhaust path 21 and is then discharged outside the housing 50.

The fuel supply device 15, which supplies raw fuel to the reformer 12, is provided with accessories such as a first solenoid valve 150, pressure sensor 151, desulfurizer 152, gas flow meter 153, fuel pump 154, and second solenoid valve 155 on a raw fuel flow path 22 connected to the fuel supply source. The reforming water supply device 16, which supplies reforming water to the reformer 12, is provided with accessories such as a reforming water pump 160 on a reforming water flow path 23 connected to the condensed water tank 4. The air supply device 14, which supplies oxygen-containing gas to the fuel cell module 1, is provided with accessories such as an air flow meter 140 and blower 141 on an oxygen-containing gas flow path 24. Note that the accessories listed here are merely examples, and other accessories may also be included.

Furthermore, the fuel cell device 100 is equipped with a control device 30 that controls the operation of various devices, as well as a power supply adjustment unit (power conditioner) 40 that converts the DC power generated by the fuel cell module 1 into AC power and adjusts the amount of converted electricity supplied to an external load.

Furthermore, the fuel cell device 100 may be equipped with a second heat exchanger 6, a heat pump P2 that circulates the heat medium from the heat storage tank 3, and a second heat medium circulation line HC2 that includes piping connecting these. In the second heat medium circulation line HC2, tap water supplied from the outside via the supply flow path 25 is heated in the second heat exchanger 6 using the high-temperature heat medium stored in the heat storage tank 3. The heated water can be supplied via the supply flow path 26 to an external reheating device such as a water heater. The fuel cell device 100 may be a so-called monogeneration system that does not supply hot water to the outside.

As such, the fuel cell device 100 has fluid flow paths through which fluids used to operate the fuel cell 11 flow. Fluids include raw fuel, water, and air. In this embodiment, the raw fuel flow path 22, condensed water recovery flow path 20, reforming water flow path 23, and oxygen-containing gas flow path 24 are examples of fluid flow paths.

Figure 2 is an external perspective view of the fuel cell device. The exterior case 50 of the fuel cell device 100 is rectangular and includes a bottom plate 51, a top panel 52, and multiple side panels 53-56. The side panels include a left side panel 53, a right side panel 54, a front panel 55, and a rear panel 56. The fuel cell device 100 also has a pre-defined maintenance surface for maintenance, with the top panel 52 and some of the multiple side panels 53-56 being maintenance panels that are removed during maintenance. In this embodiment, the right side panel 54 and the front panel 55 serve as maintenance panels.

The right side panel 54 is composed of an upper panel 541 and a lower panel 542. The upper panel 541 has an openable cover 541a, and removing this cover 541a allows the power switch and breaker switch of the fuel cell device 100 to be operated. Furthermore, during maintenance, the upper panel 541 can be removed while the lower panel 542 remains attached. The lower panel 542 is also connected to flow paths for raw fuel, water, etc. via fittings. Examples of fittings include a raw fuel fitting 60 connected to the raw fuel flow path 22, a water supply fitting 61 connected to the water supply flow path 27, a water supply fitting 62 connected to the water supply flow path 28, and a drain fitting 63 connected to the drain flow path 25.

Next, the structure for connecting the fluid flow paths and the auxiliary equipment in the fuel cell device of this embodiment will be described with reference to Figures 3 to 5. Below, the raw fuel flow path 22 will be used as an example of the fluid flow path.

Figure 3 shows an excerpt from a fuel supply device. The raw fuel flow path 22, which is an example of a fluid flow path, constitutes the fuel supply device 16. From upstream, the fuel supply device 16 is equipped with a first solenoid valve 150, a pressure sensor 151, a desulfurizer 152, and a gas flow meter 153, as well as pipes that connect these to form the flow path: a solenoid valve supply pipe 70, a desulfurizer supply pipe 71, and a flow meter supply pipe 72. The pipes are copper pipes with high thermal conductivity, and are appropriately bent.

As shown in FIG. 1, the first solenoid valve 150 is configured with two solenoid valves 150a, 150b connected in a casing. Opening and closing these solenoid valves 150a, 150b switches the raw fuel flow path 22 between an open and closed state, thereby controlling the supply and cut-off of raw fuel to the fuel cell device 100. The first solenoid valve 150 is connected to a solenoid valve feed pipe 70 and a desulfurizer feed pipe 71. The solenoid valve feed pipe 70 is connected to a fuel supply source external to the fuel cell device 100 via a raw fuel coupling 60, and the desulfurizer feed pipe 71 is connected to a desulfurizer 152 for removing sulfur contained in the raw fuel.

The desulfurizer 152 comprises a cylindrical container body 80 filled with a desulfurizing agent and a container lid 81 attached to the top of the container body 80. The container lid 81 is equipped with a fuel inlet 82 through which the raw fuel flows and a fuel outlet 83 through which the raw fuel flows after passing through the desulfurizing agent to remove sulfur. The raw fuel that flows into the desulfurizer 152 from the fuel inlet 82 flows downward within the container body 80, turns around at the bottom end of the container body 80, and flows upward. As it flows within the container body 80, sulfur is adsorbed by the desulfurizing agent. An inlet joint 84 is attached to the fuel inlet 82, and the desulfurizer supply pipe 71 is connected via the inlet joint 84. Similarly, an outlet joint 85 is attached to the fuel outlet 83, and the flow meter supply pipe 72 is connected via the outlet joint 85.

Here, the desulfurizer-bound piping 71 has a first flow path 711, a second flow path 712, and a third flow path 713 that extend in different directions at approximately 90° angles from each other. In other words, the second flow path 712 is formed by bending the piping so that it forms an angle of approximately 90° with the first flow path 711, and the third flow path 713 is formed by bending the piping so that it forms an angle of approximately 90° with the second flow path, and the third flow path 713 also forms an angle of approximately 90° with the first flow path 711.

The first flow path 711 is connected to the first solenoid valve 151, an accessory located upstream of the piping, and is rotatable around the connection with the first solenoid valve 151. Therefore, when the desulfurizer-supply piping 71 rotates around the first flow path 711, the second flow path 712 corresponds to the radius of the rotation circle, and the third flow path 713 corresponds to the tangent to a circle with the second flow path 712 as its radius. Furthermore, the third flow path 713 is connected to the desulfurizer 152, an accessory located downstream of the piping. In this configuration, the third flow path 713 is connected to the fuel inlet 82 of the desulfurizer 152 via the inlet joint 84, and the inlet joint 84 serves as the rotating pipe connection.

Figure 4 shows the desulfurizer with the desulfurizer supply piping removed from the desulfurizer, and Figure 5 shows the desulfurizer from above. In Figure 5, the trajectory of the third flow path 713 when the desulfurizer supply piping 71 is rotated around the first flow path 711 is indicated by a dashed line. The inlet joint 84 is L-shaped and has a connection port 86 to which the third flow path 713 is connected, and this connection port 86 opens onto the trajectory of the third flow path 713 indicated by the dashed line. This allows the desulfurizer supply piping 71 to be easily attached and detached to the connection port 86 simply by rotating it around the first flow path 711.

The desulfurizer 152 removes sulfur contained in the raw fuel by utilizing the adsorption properties of a desulfurizing agent. Because the amount of sulfur components that a desulfurizing agent can adsorb is limited, continued use of the fuel cell device 100 gradually reduces its sulfur removal performance. Therefore, the desulfurizer 152 is periodically replaced with a new one before the desulfurizing agent reaches the end of its life. To replace the desulfurizer 152, remove the maintenance panel and disconnect the fuel inlet 82 from the desulfurizer supply pipe 71 and the fuel outlet 83 from the flowmeter supply pipe 72. The desulfurizer supply pipe 71 can be easily removed from the desulfurizer 152 by rotating it around the first flow path 711, as described above. After replacing the desulfurizer 152 with a new one, simply rotate the desulfurizer supply pipe 71 in the opposite direction. In this way, the desulfurizer supply pipe 71 can be easily attached and detached simply by rotating the first flow path 711 around the axis.

In this embodiment, when replacing the desulfurizer 152, the desulfurizer supply pipe 71 is described as a rotatable pipe, but the flow meter supply pipe 72 may also be made rotatable.

In addition to the desulfurizer 152, the fuel cell system 100 also has other auxiliary equipment that requires periodic replacement and maintenance. For example, ion exchange resins that remove impurities from condensed water to purify it, and air filters that remove dust particles from the air, are examples of auxiliary equipment that require maintenance. Therefore, by applying the above-described connection structure not only to the piping for raw fuel, but also to the piping that forms the flow path for water and air, it is possible to improve maintainability. Furthermore, it may also be applied to the connection of auxiliary equipment other than those exemplified, assuming replacement in the event of a malfunction.

The right side panel 54 of the fuel cell device 100 is configured as a maintenance panel. By making the connection port 86 of the inlet joint 84 visible from the maintenance side, the first flow path 711 rotates when the piping is pulled toward you to remove it, making it easy to remove. Conversely, when connecting the piping, the connection can be made securely.

In this embodiment, the desulfurizer-supply piping 71 includes the first flow path 711, the second flow path 712, and the third flow path 713, arranged in this order. However, this configuration is not limited to this. For example, a flow path extending in the same direction as the third flow path 713 can be formed between the first flow path 711 and the second flow path 712, or a flow path extending in the same direction as the first flow path 711 can be added between the second flow path 712 and the third flow path 713. Furthermore, flow paths other than the first flow path 711, the second flow path 712, and the third flow path 713 do not need to form a 90° angle with the other flow paths. In other words, as long as the first flow path 711, the second flow path 712, and the third flow path 713 extend in directions that are 90° apart from each other, the first flow path 711 serves as the axis of rotation, and the third flow path 713 is configured to be connected to auxiliary equipment, the piping can be rotated for attachment and detachment.

However, if the first flow path 711, second flow path 712, and third flow path 713 are arranged consecutively in this order, the amount of work required to bend the piping is minimized, and the first solenoid valve 150 and desulfurizer 152 can be connected using the shortest piping length. However, since numerous auxiliary devices are installed inside the fuel cell device 100, if the piping is arranged in a complex manner, it may be difficult to ensure sufficient space for rotation. Therefore, to avoid other auxiliary devices and piping, other piping may be sandwiched between the first flow path 711, second flow path 712, and third flow path 713, as necessary.

Figure 6 shows the container lid of a desulfurizer. The container lid 81 of the desulfurizer 152 is provided with a cylindrical fuel inlet 82 and a fuel outlet 83, and the diameters of the fuel inlet 82 and the fuel outlet 83 are designed to be different sizes (φa < φb). If the fuel inlet 82 and the fuel outlet 83 are provided close to each other, there is a risk of connecting the pipes incorrectly. However, by making the diameters different, it is possible to prevent incorrect pipe connection.

Furthermore, the fuel inlet section 82 and the fuel outlet section 83 are designed to be at different heights from the top surface of the container lid 81 (Ha > Hb). An inlet section fitting 84 and an outlet section fitting 85 are attached to the fuel inlet section 82 and the fuel outlet section 83, respectively, and these fittings may be secured with a fixing member (not shown) to prevent them from coming loose. Quick fasteners or the like are used as fixing members. By making the fuel inlet section 82 and the fuel outlet section 83 at different heights, interference between the quick fasteners can be prevented, allowing the fuel inlet section 82 and the fuel outlet section 83 to be located close to each other, improving design flexibility.

REFERENCE SIGNS LIST 11 fuel cell 152 desulfurizer 20 condensed water recovery flow path 22 raw fuel flow path 23 reforming water flow path 24 oxygen-containing gas flow path 70 solenoid valve forward piping 71 desulfurizer forward piping 711 first flow path 712 second flow path 713 third flow path 72 flow meter forward piping 82 fuel inlet 83 fuel outlet 84 inlet joint 86 connection port

Claims (4)

a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas;
a fluid flow path through which a fluid used to operate the fuel cell flows;
a plurality of auxiliary devices provided in the fluid flow path, the fluid flow path having a plurality of pipes arranged between the plurality of auxiliary devices,
at least one of the pipes is configured by a single pipe having a first flow path, a second flow path, and a third flow path extending in directions that are mutually different by approximately 90°, the second flow path being provided between the first flow path and the third flow path, and being rotatable about the first flow path;
A fuel cell device, wherein a rotating pipe connection portion that connects the third flow path and the auxiliary device has a connection port that has an opening on the path that is traced by the tip of the rotating third flow path. The fuel cell device of claim 1, wherein the first flow path, the second flow path, and the third flow path are continuous in this order. A fuel cell device according to claim 1 or 2, wherein the connection port is arranged so as to be visible from a maintenance surface that is opened and closed during maintenance. As one of the auxiliary machines, a desulfurizer is provided to remove sulfur from the raw fuel,
The desulfurizer has a fuel inlet and a fuel outlet on the top surface of a container filled with a desulfurizing agent,
The fuel inlet and the fuel outlet have different diameters,
2. The fuel cell device according to claim 1, wherein the rotary pipe connection portion is attached to either the fuel inlet portion or the fuel outlet portion.