JP7743378B2 - Drainage structure and fuel cell device - Google Patents

Description

The present invention relates to a drainage structure for discharging drainage generated inside the device, and a fuel cell device equipped with this drainage structure.

Fuel cell devices are known that generate electricity using a hydrogen-containing fuel gas and an oxygen-containing gas (air) and supply the electricity to the outside. Since drainage is generated during power generation, such fuel cell devices are equipped with a mechanism for discharging the generated drainage outside the device.

For example, in Patent Document 1, exhaust gas is generated by power generation in a fuel cell module. The exhaust gas is introduced into a heat exchanger and cooled by heat exchange with circulating hot water. The water vapor contained in the exhaust gas condenses to form condensed water, which passes through a condensed water supply pipe and is collected from the water purifier to a reforming water tank. After the condensed water is collected, the exhaust gas passes through an exhaust pipe and is discharged to the outside of the housing through a combustion exhaust gas exhaust port. A drain pipe branches off from the exhaust pipe downstream of the heat exchanger, and the drain pipe is configured to communicate with a water receiving member of the reforming water tank. Drainage from the drain pipe flows into the water receiving member, as well as reforming water that has overflowed from the reforming water tank.

JP 2019-057438 A

In this type of configuration, the drainage collected in the water receiving member is drained to the outside of the housing through a drain pipe. However, if the drain pipe becomes clogged with debris or if the water pipe is deformed, the drainage cannot be discharged to the outside of the housing. If the fuel cell device continues to operate without noticing an abnormality in the drainage, the drainage will overflow from the water receiving member, causing adverse effects such as an abnormal shutdown of the device.

The present invention aims to solve the above-mentioned problems by providing a highly reliable drainage structure that will not cause problems that could lead to equipment failure or shutdown, even if drainage is not performed properly.

The present invention includes a drainage flow path through which drainage generated inside the device flows;
a drain joint attached to a side surface of an exterior case constituting the device and connecting the drain flow path to a pipe outside the device;
The drain joint has an inserting cylindrical portion at one end into which the drain flow path is inserted, and a piping connection portion at the other end to which the piping is connected,
a drain hole is formed in the bottom surface of the inner insertion tube portion closer to the outer case than the end surface of the drain flow path ;
The inner cylindrical portion has a drainage structure in which an air hole is formed on the side surface of the inner cylindrical portion from the end face of the drainage flow path toward the outer case .

The present invention also relates to a fuel cell device equipped with a drainage structure.

By configuring it as described above, even if it becomes difficult to discharge condensate from the piping due to clogging or deformation of the piping, the condensate can be discharged through the drainage joint, preventing situations that could lead to equipment failure or shutdown, resulting in a highly reliable drainage structure.

FIG. 1 is a system configuration diagram of a fuel cell device. FIG. 2 is a cross-sectional view of the drainage structure of the present embodiment. FIG. FIG. 2 is a diagram showing the internal shape of a drainage joint.

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

This invention relates to a drainage structure equipped with a drainage joint that connects a drainage flow path through which drainage generated inside the device flows and a pipe that discharges the drainage outside the device. The drainage joint has an inner cylindrical portion at one end into which the drainage flow path is inserted and a pipe connection portion at the other end to which the pipe is connected, connecting the drainage flow path and the external pipe without direct contact. Furthermore, a drainage hole is formed in the bottom surface of the inner cylindrical portion of the drainage joint, closer to the outer case than the end face of the drainage flow path. Therefore, even if the external pipe becomes clogged with debris or deformed and cannot discharge drainage normally, the drainage can be discharged through the hole in the bottom surface of the joint. This prevents drainage from flowing back into the device, thereby preventing problems related to drainage from adversely affecting the device.

In addition, the drain joint slopes downward from one end to the other, allowing the drain discharged from the drainage flow path to naturally flow out toward the external piping.

The inner insertion tube portion is also provided with a retaining portion that holds the drainage flow path by forming a gap between the drainage flow path and the inner surface of the inner insertion tube portion. If the drainage flow path comes into contact with the inner surface of the drainage fitting, surface tension will come into play, and condensate that flows out of the drainage flow path may flow directly out the drainage hole. Therefore, by providing a retaining portion, the drainage flow path is prevented from coming into contact with the inner surface of the drainage fitting. This prevents condensate from flowing out of the fitting's drainage hole under normal conditions, ensuring that it is reliably discharged through the external piping.

The inner tube section also has a correction section that corrects the direction of the drainage flow path so that it slopes downward. This ensures that the drain that has passed through the drainage flow path is reliably guided to the drainage fitting.

The drain fitting also has a restricting section that restricts the insertion length of the drainage flow path. This prevents the end of the drainage flow path from becoming sealed, ensuring that the drain can flow out reliably.

An air hole is also formed on the side of the inner tube, closer to the outer case than the end face of the drainage channel. A drainage hole is provided at the bottom of the drainage fitting, and there is a risk of air being blown in through this drainage hole. However, the air blown in through the drainage hole escapes through this air hole, preventing drainage from returning to the device due to the pressure of the blown in air.

In addition, by using a drainage structure in a fuel cell device, generated drainage can be efficiently discharged outside the device, improving the reliability of the fuel cell device.

An embodiment of the present invention will be described below with reference to the drawings. The drainage structure of the present disclosure can be applied to any device that generates drainage inside. The following description will use a fuel cell device as an example of a device equipped with a drainage structure.

Figure 1 is a system configuration diagram of a fuel cell device. The fuel cell device 100 includes a fuel cell module 1, and multiple accessories for operating the fuel cell module 1, such as a first heat exchanger 2, a heat storage tank 3, a condensate 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 an outer case 50. It is not necessary for all of the above-mentioned devices to be housed within the outer case 50; for example, the first heat exchanger 2 and the heat storage tank 3 may be located outside the outer case 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 drainage water and gas, and the separated drainage water is collected in the condensed water tank 4 through the condensed water recovery path 20. In the condensed water tank 4, the collected drainage water is purified by removing impurities through an ion exchanger (not shown) and other devices. The purified drainage water is supplied to the reformer 12 by the water supply device 16 and used as reforming water. Meanwhile, the gas from which the moisture has been removed passes through the exhaust path 21 and is then discharged outside the exterior case 50.

A drainage flow path 25 is connected to the condensate tank 4. Drainage that overflows from the condensate tank 4 is discharged through the drainage flow path 25 to the outside of the outer case 50. A drainage joint 60 is attached to the side of the outer case 50, and this drainage joint 60 connects the drainage flow path 25 to piping 70 outside the fuel cell device 100. The piping 70 is connected to the house's sewage manhole, and the drainage is discharged through the piping 70 into the sewage manhole.

The fuel supply device 15, which supplies raw fuel to the reformer 12, is provided with accessories such as a first solenoid valve V1, pressure sensor PS, desulfurizer DS, gas flow meter FM1, fuel pump B1, and second solenoid valve V2 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 P3 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 FM2 and blower B2 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.

Fuel cell device 100 may also 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 supply flow path 26 is heated in second heat exchanger 6 using the high-temperature heat medium stored in the heat storage tank 3. The heated water can be supplied via supply flow path 27 to an external reheating device such as a water heater. Fuel cell device 100 may be a so-called monogeneration system that does not supply hot water to the outside.

Figure 2 is a cross-sectional view of the drainage structure of this embodiment, Figure 3 is an external perspective view of the drainage joint, and Figure 4 is a diagram showing the internal shape of the drainage joint. The drainage joint 60 is attached to the side of the outer case 50 with screws or the like, and connects the drainage flow path 25 extending from the inside of the fuel cell device 100 to piping 70 outside the fuel cell device 100. The drainage flow path 25 is fixed to the outer case 50 with a resin fixing member 51.

The drainage flow path 25 is connected to one end 60a of the drainage fitting 60, and the piping 70 is connected to the other end 60b. In this embodiment, the drainage fitting 60 is molded into a shape consisting of multiple cylindrical sections with different outer diameters connected together, and has a large-diameter inner cylindrical section 61 and a small-diameter pipe connection section 62. The drainage flow path 25 is inserted inside the inner cylindrical section 61, and the piping 70 is connected to the outside of the pipe connection section 62. The pipe connection section 62 has a male thread with a thread formed on the outer periphery of the cylindrical section, and can be connected to a female thread on the piping. Note that the drainage fitting 60 is only required to be configured so that the drainage flow path 25 and the piping 70 do not come into direct contact; the diameter of the pipe connection section 62 may be increased so that the piping 70 can be inserted inside.

The drain joint 60 slopes downward from one end 60a to the other end 60b. Drainage that flows through the drainage flow path 25 drips into the drain joint 60, flows into the pipe 70 via the pipe connection part 62, and is then drained to the outside.

A drain hole 63 is provided on the bottom surface of the inner tube portion 61. As shown in Figure 2, this drain hole 63 is located closer to the outer case 50 than the end face 25a of the drainage flow path 25. If the piping 70 becomes clogged with debris or deformed and is unable to discharge condensate normally, the condensate can be discharged through this drain hole 63. This prevents condensate from flowing back into the device, thereby preventing problems with condensate discharge from adversely affecting the device. Furthermore, if condensate is found flowing from the drain hole 63, the piping 70 can be checked for any abnormalities and the cause of the abnormality can be removed to restore the device to normal.

The drain hole 63 is rectangular and extends to one end 60a of the drain joint 60. Various hole shapes, such as circular or oval, can be used. Multiple holes may also be provided.

The drain joint 60 also has a side wall 64 that extends downward from the drain hole 63. The side wall 64 has a rounded portion 64a, which is positioned so that the rounded portion 64a is at its lowest point, allowing the drain that flows out of the drain hole 63 to drip down the tip of the rounded portion 64a along the side wall 64. This prevents the drain from soiling the outer case 50. The side wall 64 also acts as a windbreak that prevents wind from blowing in through the drain hole 63.

As shown in Figures 2 and 4, the inside of the drain joint 60 is formed with multiple ribs 651, 652, and 653 that protrude from the inner circumferential surface.

The rib 651 is a retaining portion that holds the drainage flow path 25 so that it does not come into contact with the inner surface of the drainage joint 60. If the bottom of the drainage flow path 25 comes into contact with the inner surface of the drainage joint 60, surface tension may come into play, causing drainage to flow out of the drain hole 63 even if there is no abnormality in the piping 70. Therefore, to prevent this, the retaining portion 651 is provided to prevent the drainage flow path 25 from coming into contact with the inner surface of the drainage joint 60. The retaining portion 651 is provided below the drainage flow path 25 in the inner insertion tube portion 61, and this retaining portion 651 forms a gap between the drainage flow path 25 and the inner surface of the inner insertion tube portion 61.

The rib 652 is a correction portion that corrects the orientation of the drainage flow path 25 so that it slopes downward. The correction portion 652 is provided at the top of the drainage flow path 25 in the inner insertion tube portion 61. When the drainage flow path 25 is inserted into the inner insertion tube portion 61, its end is directed downward by abutting against the correction portion 652. This ensures that the drain that has passed through the drainage flow path 25 is reliably guided to the drainage fitting 60.

The rib 653 is a restricting portion that restricts the insertion length of the drainage flow path 25. The restricting portion 653 is provided on the pipe connection portion 62. It prevents the end face 25a of the drainage flow path 25 inserted into the inner tube portion 61 from being sealed, ensuring that the drain can flow out reliably. In this embodiment, the restricting portion 653 is provided on the pipe connection portion 62, but it may also be provided on the inner tube portion 61.

An air hole 66 is formed on the side of the inner tube portion 61. A drain hole 63 is provided at the bottom of the drain fitting 60, and if air blows in through this drain hole 63, the wind pressure may push the drain back into the device. The air hole 66 is provided to avoid this. In other words, the wind blowing in through the drain hole 63 can escape through this air hole 66, preventing the drain from being pushed back into the device by wind pressure. It is also preferable to provide the air hole 66 closer to the outer case 50 than the end face 25a of the drain flow path 25. This prevents the air blown in through the drain hole 63 from interfering with the drain's discharge when it passes through the air hole 66 on the side.

Furthermore, flat surfaces 67 consisting of lattice-like ribs are provided on both sides of the drain fitting 60. When clamping and holding the drain fitting 60 with a tool, clamping these flat surfaces 67 with the tool makes it easy to install the piping 70.

REFERENCE SIGNS LIST 1 fuel cell module 11 fuel cell 25 drainage flow path 50 exterior case 60 drainage joint 61 inner tube portion 62 piping connection portion 63 drainage hole 651 holding portion 652 correction portion 653 restriction portion 66 air hole 70 piping

Claims (6)

a drainage flow path through which drainage generated inside the device flows;
a drain joint attached to a side surface of an exterior case constituting the device and connecting the drain flow path to a pipe outside the device;
The drain joint has an inserting cylindrical portion at one end into which the drain flow path is inserted, and a piping connection portion at the other end to which the piping is connected,
a drain hole is formed in the bottom surface of the inner insertion tube portion closer to the outer case than the end surface of the drain flow path ;
A drainage structure in which an air hole is formed on the side surface of the inner insertion tube portion closer to the outer case than the end face of the drainage flow path . The drainage structure of claim 1, wherein the drain joint slopes downward from the one end to the other end. The drainage structure according to claim 2, wherein the inner cylindrical portion is provided with a holding portion that holds the drainage flow path by forming a gap between the drainage flow path and the inner surface of the inner cylindrical portion. The drainage structure of claim 3, wherein the inner tube portion is provided with a correction portion that corrects the orientation of the drainage flow path so that it slopes downward. The drainage structure of claim 4, wherein the drainage joint is provided with a restriction portion that restricts the insertion length of the drainage flow path. a fuel cell module including a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas;
A fuel cell device comprising the drainage structure for a drain according to any one of claims 1 to 5 .