JP2007328968A - Piping system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piping system capable of extending the lifetime of a reformer. <P>SOLUTION: The piping system has a fuel processor 3 including a reformer 31 for generating the hydrogen gas from the fuel gas, a hydrogen gas supply including many buffer tanks 4a and 4b which are connected in parallel with each other for storing the hydrogen gas and supplying the hydrogen gas to fuel cells 9a to 9d; a distributor unit 5 having a controller 302 for supplying the hydrogen gas to the fuel cells 9a to 9d selectively from one of the reformer 31 or buffer tanks 4a and 4b depending on the hydrogen amounts consumed by the fuel cells 9a to 9d, and having a header 51 connected to the buffer tanks 4a and 4b; and many flexible pipings 131a each of which comprises a straight tube 132a and a coating resin 133a, and is connected between the header 51 and fuel cells 9a to 9d mounted on each of exclusively used floors of a building 100. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a piping device for connecting between a hydrogen gas supply pipe and a plurality of fuel cells installed in a multi-story building.

A fuel cell system that has high power generation efficiency and does not emit harmful substances such as NO _X and SO _X has attracted attention as a clean distributed power generation system, and its application to condominiums, apartment houses, office buildings, and the like is being studied. In this fuel cell system, a current generated when water is generated by reforming a fuel gas (for example, city gas) mixed with air or the like and reacting the obtained hydrogen gas with oxygen in the air. While taking out and using as an auxiliary power supply of an electric power system, utilizing the reaction heat is examined. For example, a reformer that generates hydrogen gas from city gas is installed in a common part of an apartment house, and the hydrogen gas is supplied from the common part to the fuel cell installed in each dwelling unit through a hydrogen gas pipe. A fuel cell system has been proposed that uses the generated electric power and the hot water discharged therefrom in each dwelling unit (see Patent Document 1).

  In the fuel cell system, since the transient response characteristic of the reformer is low, for example, a compressed gas is provided between the fuel processor (reformer) and the fuel cell stack in order to start up so as to adapt to an increase in load. It has been proposed to provide a hydrogen storage device such as a cylinder (see Patent Document 2). In addition, in order to quickly supply the hydrogen required by the fuel cell without excess or deficiency, the hydrogen generated by the reformer is stored in the hydrogen storage buffer and provided to the fuel cell downstream of the hydrogen storage buffer. A regulator is provided to keep the hydrogen pressure below the target pressure, and when the amount of hydrogen consumed by the fuel cell is greater than the amount consumed, the hydrogen is stored in a hydrogen storage buffer, and the amount of hydrogen produced by the reformer is It has been proposed to supply hydrogen to a fuel cell using a regulator when the amount of hydrogen consumed by the battery is smaller (see Patent Document 3).

  Moreover, when employ | adopting a fuel cell system for a multilayer building, a piping apparatus as shown, for example in FIG. 10 can be considered. In the figure, reference numeral 100 denotes a multi-story building (four-story building), and each dedicated portion 101a... 101d includes a fuel cell 9 (9a, 9b... 9d) and a hot water storage tank 10 (10a, 10b. ) And a fuel processing unit 3 connected to a city gas supply pipe 11 is installed on the ground, and a main pipe 12 for supplying the generated hydrogen gas to the fuel cell 9 in the fuel processing unit 3. Is connected. The main pipe 12 is connected to a distribution pipe 13 (13a, 13b,... 13d) via a branch joint 60 (60a... 60c), and ends of the distribution pipes 13 are joints 6 (6a, 6b... 6d), respectively. To the fuel cell 9 (9a, 9b... 9d).

  The hydrogen gas pipe for connecting the fuel processing unit 3 and the fuel cell 9 is a steel pipe having high heat resistance and corrosion resistance such as an SGP steel pipe or a stainless steel pipe, and joining the branch parts by welding. It is common. In addition, a gasket is sandwiched between a pair of metal cylinders used in semiconductor manufacturing equipment and the like, and a branching portion is connected by a special mechanical joint that is tightened with a male nut and a female nut. . Therefore, hydrogen gas has a small molecular diameter, enters into a minute gap, and easily leaks from a connecting portion such as a joint. Therefore, it is extremely important to prevent a disaster due to gas leakage in a house or an office building. Therefore, normally, hydrogen gas sensors 7 (7a, 7b... 7g) for detecting leakage of hydrogen gas are installed in each branch joint 60 and joint 6.

Japanese Patent Laying-Open No. 2004-95187 (pages 4-5, FIG. 1) Japanese Patent No. 3688271 (pages 18-19, FIG. 9, FIG. 10) Japanese Patent Laying-Open No. 2005-347181 (pages 7 to 10, FIG. 1, FIG. 3, FIG. 4)

  According to the fuel cell systems described in Patent Documents 2 and 3, since hydrogen gas generated in the reformer is stored in the buffer tank, hydrogen gas can be stably supplied. Since the start and stop of the reformer are frequently repeated according to the consumption amount, there is a problem that the durability of the reformer is lowered. In addition, there is a problem that the energy consumed when starting up the reformer increases.

  Also, as shown in FIG. 10, if sensors are provided in all of the portions where leakage is predicted, a large number of sensors are required, resulting in an increase in piping cost, which is not practical.

  Accordingly, an object of the present invention is to provide a piping device capable of extending the life of the reformer.

  Another object of the present invention is to provide a piping device that can supply hydrogen gas at a lower cost and higher safety than the prior art.

In order to achieve the above object, a piping device of the present invention includes a fuel processing unit including a reformer that generates hydrogen gas from fuel gas,
A hydrogen gas supply unit including a plurality of buffer tanks connected in parallel to each other for storing the hydrogen gas and supplying the hydrogen gas to the fuel cell;
And having control means for selectively supplying the hydrogen gas to the fuel cell from one of the reformer or the buffer tank according to the amount of hydrogen consumed by the fuel cell,
A distribution unit having a header connected to the buffer tank;
It comprises an inner pipe and an outer pipe, and is provided with a plurality of distribution pipes connected between the header and a plurality of fuel cells installed on each exclusive floor of the building.

  In the present invention, it is preferable that the distribution unit includes a plurality of small spaces in which portions connected to the distribution pipe are partitioned from each other, and a detection space in which these small spaces communicate with each other. In the present invention, it is more preferable that a single hydrogen gas detection member is installed in the detection space.

  In the present invention, the distribution pipe is preferably a flexible pipe coated with a resin.

  In the present invention, the distribution pipe is connected to the fuel cell through a joint in which a downstream end is inserted and fixed, and hydrogen gas flowing out from a gap between the coating resin and the bellows pipe It is preferable to pass through the inside of the joint and be captured by the hydrogen gas detection member.

  According to the present invention, when a large amount of hydrogen is temporarily consumed and exceeds the supply capacity of the fuel processing unit, hydrogen gas is selectively sent from a plurality of buffer tanks installed on the downstream side of the fuel processing unit. Since the fuel cell can be supplied, a stable supply of hydrogen gas can be guaranteed. Further, since the reformer only needs to be operated for a period during which the buffer tank is filled, the number of times the reformer is started can be reduced. Therefore, the life of the reformer can be extended.

  Furthermore, according to the present invention, a distribution unit is provided on the downstream side of the buffer tank, and the distribution unit and the fuel cell are connected by a plurality of distribution pipes having gaps through which hydrogen gas leaked from the inside can flow out. The number of installed members for detecting hydrogen gas can be minimized. Therefore, it is possible to realize a low-cost and highly safe piping device.

  Details of the present invention will be described below with reference to the accompanying drawings. 1 is a perspective view showing a piping device according to a first embodiment of the present invention, FIG. 2 is a piping system diagram of the piping device of FIG. 1, and FIG. 3 is a block diagram showing a control unit of the piping device of FIG. 4 is a sectional view of the distribution unit, FIG. 5 is a sectional view taken along line XX of FIG. 4, FIG. 6 is a sectional view schematically showing a hydrogen gas pipe, FIG. 7 is a sectional view of a joint, and FIG. FIG. 9 is a schematic diagram showing a piping device according to a second embodiment of the present invention. In each figure, members having the same function are given the same reference numerals (or the same reference numerals in the first one digit or the upper two digits).

(First embodiment)
As shown in FIG. 1, fuel cells 9a... 9d and hot water storage tanks 10a... 10d for storing hot water generated there are installed on each exclusive floor of a multi-storey building 100 (four floors in the figure). ing. On the ground floor, a fuel processing unit 3 connected via a decompressor 2 to a supply pipe 11 branched from a main pipe 1 through which fuel gas flows is installed, and is generated downstream of the fuel processing unit 3 there. Buffer tanks 4a and 4b for temporarily storing the hydrogen gas are connected in parallel. The distribution unit 5 is connected to the downstream side of the buffer tanks 4a and 4b via a regulator (not shown) and the main pipe 12. The distribution unit 5 is connected to distribution pipes 13a... 13d having hydrogen gas meters 8a... 8d, and connected to fuel cells 9a.

  The configuration of the fuel cell and the fuel processing unit in this piping apparatus will be described with reference to FIG. Although only the fuel cell on the ground floor is shown in FIG. 2, other fuel cells are connected to the distribution unit in the same manner. City gas (G) is indicated by a thick two-dot chain line, air (A) is indicated by a thick broken line, off-gas (exhaust gas) is indicated by a thick one-dot chain line, hydrogen gas is indicated by a thick solid line, and water (W) or water vapor is indicated by a thin solid line. .

  Fuel cells are classified into polymer electrolyte (PEFC), solid oxide (SOFC), phosphoric acid (PAFC), and molten carbonate (MCFC) types, depending on the type of electrolyte used as a carrier ion passage medium. In the present invention, a PEFC that is compact and easy to handle is preferable because it operates at a low temperature and has a high output density. As shown in FIG. 2, this PEFC has a structure in which a fuel electrode 901 and an air electrode 902 (both catalyst layers are supported by a porous layer (current collecting layer)) on both sides of a hydrogen ion conductive electrolyte membrane (not shown). Cell) is formed into a stack. In PEFC, the hydrogen gas generated in the reformer 31 is separated into hydrogen ions and electrons in the fuel electrode 901, and the hydrogen ions move together with water in the electrolyte membrane to the air electrode 902, and the electrons are transferred to an external circuit. The air electrode 902 passes through the air electrode 902, and oxygen, electrons, and hydrogen ions in the air taken in via the blower fan 90 and the blower 91 react to generate water. The DC power E generated in the reaction process is converted into AC by a power converter such as an inverter and can be used in a building or a home. The hot water (W) stored in the hot water storage tanks 10a... 10d can be used as it is for hot water supply in the home. Furthermore, a part (H) of the hydrogen gas flowing out from the distribution pipes 13a... 13d can be taken out and supplied to a gas appliance (not shown).

  When hydrogen gas is supplied to the fuel electrode 901 and the air taken in by the blow pump 90 is supplied to the air electrode 902 through the blower 91, the generated off-gas is supplied to the second cooler 932. . Off-gas generated at the fuel electrode 901 is fed to the reformer 31. The pure water stored in the first tank 941 is fed to the first cooler 931 through the cooling unit 903 by the circulation pump 95 and mixed with the water fed from the feed pump 92 by the first cooler 931. The pure water stored in the first tank 941 is supplied to the reformer 31 via the heat exchanger 38. The water generated in the second cooler 932 and the water generated in the third cooler 933 are collected in the second tank 942. Water is supplied to the second tank 942 by the water supply pump 96, and the exhaust gas flowing into the second tank 942 is exhausted by the exhaust pump 99. The hot water flowing out from the first cooler 931 passes through the second cooler 932 and the third cooler 933, and is supplied to the hot water storage tank 10a by the pump 98. The water in the second tank 942 is recovered by the recovery pump 97 and then supplied to the first tank 941 through a cooler and a filter (both not shown).

The fuel processing unit 3 includes a steam reformer 31 that generates hydrogen gas (hereinafter simply referred to as a reformer 31), and a reforming unit 30 that includes a CO modification 32 and a CO removal 33 that purify the hydrogen gas. The reformer 31 includes a reaction chamber 312 in which a catalyst 311 is incorporated and supplied with city gas and water vapor, and combustion in which air is mixed with reformed gas that has not been consumed by the fuel cell to heat the catalyst 311. A chamber 313 is provided. In the reforming unit 30, when the city gas from which the sulfur compound (odorant) is removed by the desulfurizer 34 is supplied to the catalyst 311 of the reformer 31 through the decompressor 2, it is a main component of the city gas. Hydrocarbon compound (methane) reacts on a catalyst kept at about 700 ° C. to form hydrogen as a main component (hydrogen: 70%, carbon dioxide: 20%, others: 10%) reformed gas (hydrogen gas) ) Is generated, and the CO modification 32 reduces the concentration of carbon monoxide to about 5000 ppm by a shift reaction (CO + H ₂ O → CO ₂ + H ₂ ), and then the CO selective oxidation reaction (CO + 1 / 2O ₂ → The carbon monoxide concentration is purified to be 10 PPM or less by CO ₂ ).

  The buffer tanks 4a and 4b are connected in parallel to the downstream side of the fuel processing unit 3 via the first valve 41a and the second valve 41b, and the outlet side of the buffer tanks 4a and 4b is the third valve 41c and the fourth valve 41d. To the distribution unit 5. These buffer tanks can have a structure in which a carbon fiber reinforced layer is provided on the surface of a cylinder made of an aluminum alloy or plastic, and a resin coating layer is further provided on the surface.

  In the above piping apparatus, the circuit for controlling the operation of the reformer 31 and the opening and closing of the buffer tanks 4a and 4b is shown in FIG. 3 in order to stably supply hydrogen gas and reduce the number of times the reformer is started. It is configured. That is, the control unit 302 is based on a signal processing circuit 301 that processes a signal corresponding to the pressure in the buffer tanks 4 a and 4 b detected by a pressure detection sensor (not shown), and a signal output from the signal processing circuit 301. A drive circuit 303 is provided that outputs a signal for starting or stopping the reformer 31 and a drive signal for opening and closing the first valve 41a, the second valve 41b, the third valve 41c, and the fourth valve 41d.

The structure of a piping member among said piping apparatuses is demonstrated with FIGS.
As shown in FIGS. 4 and 5, a main pipe 12 for supplying hydrogen gas to the fuel cell 9 is connected to the buffer tanks 4a and 4b, and the main pipe 12 is installed inside the distribution unit 5 via a joint 6e. Connected to the header 51. A plurality of distribution pipes 13a, 13b, 13c, and 13d are connected to the header 51, and the end portions of the distribution pipes are connected to the fuel cells 9a to 9d on each exclusive floor via joints 6a to 6d (see FIG. 1). It is connected to the. In addition, a hydrogen gas sensor 7e is attached to the distribution unit 5, and hydrogen gas sensors 7a... 7d (see FIG. 1) are also attached to the joints 6a.

  The distribution unit 5 has a sealed rectangular parallelepiped hollow container 50 and a header 51 accommodated therein, and the header 51 is connected to the distribution pipes 13a... 13d via a plurality of branch portions 52a. Has been. The hollow container 50 is partitioned into a branch space 54 and a detection space 56 by a partition plate 53e extending in a long side direction when viewed from the plane and a partition plate 53a fixed to an end portion (the branch portion 52a side). 54 is divided into four small spaces 54a... 54d by partition plates 53b... 53d (see FIG. 5). Since the partition plate 53e is provided with communication holes 57a ... 57d for each small space 54a ... 54d, each small space 54a ... 54d is configured to communicate with the detection space 56. A single hydrogen gas sensor 7e is installed at one place in the detection space 56.

  As shown in FIG. 6A, the distribution pipe 13 (13a... 13d) has a flexible pipe 131 (131a) made of a corrugate pipe and a coating resin 133 (133a) deposited on the outer peripheral surface thereof. When a defect such as a crack 134 (134a) occurs in the flexible tube 131 (131a), hydrogen gas can flow through a gap formed between them. In the present invention, the distribution pipe 13 (13a... 13d) only needs to have an inner pipe and an outer pipe. For example, as shown in FIG. A resin-coated tube having a straight tube 132 (132a) and a coating resin 133 (133a) is also possible, and when a defect such as a crack 134 (134a) occurs in the straight tube 132 (132a), between the two It may be configured so that hydrogen gas can flow through the gap formed in the above. The flexible pipe 131 (131a) or the straight pipe 132 (132a) is formed of a corrosion-resistant metal material (for example, austenitic stainless steel) in order to prevent leakage due to generation of cracks due to corrosion. 6 shows the distribution pipe 13a as a representative example, the same applies to the distribution pipes 13b, 13c, and 13d.

  As shown in FIG. 7, the joint 6 (6a... 6d) has a female thread portion on the inner peripheral surface on one end side (side into which the distribution pipe 13 is inserted) and a male thread portion on the outer peripheral surface on the other end side. It has the coupling main body 60 which consists of a metal material which has, and the nut 61 screwed into a female thread part. Inside the joint body 60, a disc-shaped gasket 62 and a ring-shaped fireproof packing 63 are mounted in this order from the back, and a retainer 64 is pressed by the nut 61 to fix the distribution pipe 13. . The retainer 64 has a cone shape, and a fastening ring 65 formed so that an end portion on the side facing the gasket 62 is bent toward an inner diameter side and comes into contact with a trough portion at the tip of the flexible tube 131 and an inner peripheral surface thereof. And a guide ring 66 to be fitted into the. A gap between the end of the joint body 60 and the nut 61 is sealed with an O-ring 67. A through-hole 611 that connects the inner peripheral surface and the outer peripheral surface is formed inside the nut 61, and a selectively permeable member 68 that transmits only a gas containing hydrogen gas is enclosed therein. An end portion of the nut 61 is sealed with a packing 69 having a lip portion that comes into contact with the outer peripheral surface of the coating resin 133. The permselective member 68 has, for example, a three-dimensional continuous network structure made of a high molecular polymer such as a fluororesin (for example, PTFE), a polyolefin (PE, PP, etc.), and an acrylic resin (for example, PMA). And a porous body having a pore size of about 1 to 50 μm.

  According to the joint 6 described above, the distribution pipe 13 and the fuel cells 9a... 9d can be connected by the following procedure. The gasket 62 and the fireproof packing 63 are inserted into the joint body 60, the selectively permeable member 68 and the packing 69 are inserted into the nut 61, and both the O-ring 67 is sandwiched between the joint body 60 and the nut 61. The member is screwed to leave a predetermined tightening amount (for example, about one pile of the flexible pipe 131), and then the joint body 60 is screwed into the fuel cell 9a... 9d and the header 51 (both not shown in FIG. 6). . After the end of the distribution pipe 13 is inserted to the depth of the joint body 60, the nut 61 is tightened, whereby the state shown in FIG.

  According to the joint 6 described above, hydrogen gas can be detected by mounting a hydrogen gas detection member (not shown in FIG. 7) in the through hole 611 of the nut 61. That is, the hydrogen gas leaked from the flexible tube 131 follows the path indicated by the arrow, flows inside the joint 6, passes through the selectively permeable member 68, and is captured by the hydrogen gas detection member.

  As the hydrogen gas detection members 7a to 7e for detecting leakage of hydrogen gas from the distribution unit 5 and the joint 6, a known sensor for detecting combustible gas can be used. For example, a semiconductor resistance change sensor or a combustible sensor that adsorbs gas molecules on the surface of a semiconductor oxide (such as tin oxide) that is a sensor material or detects a change in resistance of the sensor material due to catalytic combustion on the surface of the gas molecules. It is possible to use a thermoelectric conversion sensor or the like that converts heat generated by the catalytic reaction between the reactive gas and the catalyst material into a voltage signal by a thermoelectric conversion effect and uses the voltage signal as a detection signal.

  According to the above piping device, hydrogen gas can be supplied to the fuel cell as follows. When fuel gas (for example, city gas) is supplied from the main pipe 12 to the fuel processing units 3a and 3b, the hydrogen gas generated therein is stored in the buffer tanks 4a and 4b and is supplied to the distribution unit 5 through the main pipe 12. Is done. Here, when a large amount of hydrogen is temporarily consumed and exceeds the supply capacity of the fuel processing unit 3, hydrogen gas is supplied from the buffer tanks 4a and 4b according to the procedure shown in FIG. Here, in the initial state, the pressures (Pa, Pb) of the buffer tanks 4a, 4b are the upper limit values (P2) (for example, 100 kPa) and (P4) (for example, 100 kPa). In the initial state, the first valve 41a is closed, the third valve 41c is opened, and the hydrogen gas stored in the buffer tank 4a is decompressed by a regulator (not shown) and supplied to the fuel cell (S1). ). When the hydrogen gas stored in the buffer tank 4a is used and the pressure (Pa) of the buffer tank 4a reaches the lower limit (P1) (for example, 3 kPa) (S2) (S2), the fourth valve 41d is opened and the third valve is opened. The hydrogen gas stored in the buffer tank 4b is closed and 41c is supplied to the fuel cell (S3).

  Next, the first valve 41a is opened (the second valve 41b is closed) (S4) and the reformer 31 is started (S5), so that the hydrogen gas reformed by the reformer 31 is buffered. It is stored in the tank 4a (S6). If the pressure (Pa) of the buffer tank 4a reaches the upper limit (P2) before the pressure (Pb) of the buffer tank 4b reaches the lower limit (P3) (for example, 3 kPa), Proceed to step (S8). On the other hand, when the pressure (Pb) of the buffer tank 4b reaches the lower limit (P3) before the pressure (Pa) of the buffer tank 4a reaches the upper limit (P2), the pressure of the buffer tank 4b is measured ( S7) When Pb = P3, the process proceeds to the next step (S8). The pressures Pa and Pb of the buffer tanks 4a and 4b are compared with the upper limit values P2 and P4 (S8). If both Pa and Pb are upper limit values, the reformer 31 is stopped (S9). Proceed to step (S10).

  Next, the third valve 41c is opened, the fourth valve 41d is closed, and hydrogen is supplied from the buffer tank 4a to the fuel cell (S10). Next, the first valve 41a is closed (S11), the second valve 41b is opened, and the hydrogen gas reformed by the reformer 31 is stored in the buffer tank 4b (S12). If the pressure (Pa) of the buffer tank 4b reaches the upper limit value (P4) before the pressure (Pa) of the buffer tank 4a reaches the lower limit value (P1) (for example, 3 kPa), the next operation is performed when Pb = P4. Proceed to step (S12). On the other hand, when the pressure (Pa) of the buffer tank 4a reaches the lower limit (P1) before the pressure (Pb) of the buffer tank 4b reaches the upper limit (P4), the pressure of the buffer tank 4a is measured ( S13) When Pa = P1, the process proceeds to the next step (S16). The pressures Pa and Pb of the buffer tanks 4a and 4b are compared with the upper limit values P2 and P4 (S14). If both Pa and Pb are upper limit values, the reformer 31 is stopped (S15). Proceed to step (S16).

  Next, the third valve 41c is closed, the fourth valve 41d is opened, and hydrogen is supplied from the buffer tank 4b to the fuel cell (S16). Next, the first valve 41a is opened, the second valve is closed (S17), and the process proceeds to (S6) to loop from (S6) to (S17). Thus, according to said piping apparatus, since hydrogen gas is stored or supplied to a fuel cell by switching buffer tank 4a, 4b according to consumption of hydrogen gas, stable supply of hydrogen gas can be performed. Further, since the number of times of starting the reformer 31 is reduced, the reformer can be continuously operated in a state where the reforming amount is kept constant, so that the life of the reformer can be extended.

  If the fuel cell is operated for a long period of time, the flexible pipe 131 or the straight pipe 132 constituting the distribution pipes 13a... 13d may corrode and cracks 134 may be generated. Passes through the gap between the flexible pipe 131 (or straight pipe 132) and the coating resin 133 (see FIG. 6), and returns to the distribution unit 5. This hydrogen gas leaks into the small space 54a... 54d formed inside the hollow container 50 from the gap between the connecting portions of the distribution pipes 13a... 13d and the branch portions 52a. To do. The hydrogen gas that has flowed into the detection space 56 is detected by the hydrogen gas detection member 7e attached thereto, and an output signal thereof is sent to an alarm device (not shown), and the alarm device operates to cause gas leakage. Can be detected. Further, when the leaked hydrogen gas flows into the joints 6a... 6d, it is detected by the hydrogen gas detection members 7a.

  As described above, according to the piping apparatus shown in FIG. 1, the distribution unit 5 is provided on the downstream side of the reformer 31 except that the hydrogen gas detection members 7 a... 7 d are provided on the inlet side of the fuel cells 1 a. By simply connecting and providing a single hydrogen gas detection member there, the hydrogen gas leaked from the distribution pipes 13a... 13d can be reliably detected. Therefore, the piping cost can be reduced as compared with the prior art.

(Second Embodiment)
The piping apparatus shown in FIG. 9 has the same structure as described above except that the reformer 3, the buffer tanks 4a and 4b, and the distribution unit 5 are installed on the roof of the building 100, and thus detailed description thereof is omitted. According to this piping apparatus, since the hydrogen gas generation part is installed on the rooftop, the ground floor of the building can be used effectively.

It is a perspective view of the piping apparatus which concerns on the 1st Embodiment of this invention. It is a piping system diagram showing an example of a hydrogen gas supply system. It is a block diagram which shows an example of the control circuit of the supply control part of hydrogen gas. It is sectional drawing of a distribution unit. FIG. 3 is a sectional view taken along line XX in FIG. 2. (A) is a longitudinal cross-sectional view which shows typically an example of distribution piping, (b) is a longitudinal cross-sectional view which shows the other example of distribution piping typically. It is sectional drawing of a coupling. It is a flowchart figure which shows the supply method of hydrogen gas. It is the schematic which shows the piping apparatus which concerns on the 2nd Embodiment of this invention. It is the schematic of the conventional piping apparatus.

Explanation of symbols

1: main pipe, 2: decompressor,
3, 3a, 3b: fuel processing section, 30: reforming section,
31: reformer, 311: catalyst, 312: reaction chamber, 313: heating chamber, 32: CO modifier, 33: CO remover, 34: desulfurizer, 35: steam generator, 36: intake pump, 37: Blower, 38: Heat exchanger,
302: Control unit, 301: Signal processing circuit, 303: Drive circuit,
4a, 4b: buffer tank, 41a: first valve, 41b: second valve, 41c: third valve, 41d: fourth valve,
5: Distribution unit, 50: Case, 51: Header, 52a, 52b, 52c, 52d: Branch part, 53a, 53b, 53c, 53d: Partition plate window, 54: Branch space, 54a, 54b, 54c, 54d: Small Space 56: detection space 57a, 57b, 57c, 57d: communication holes 6a, 6b, 6c, 6d, 6e: joints,
7a, 7b, 7c, 7d, 7e: hydrogen gas sensor,
8a, 8b, 8c, 8d: hydrogen gas meter,
9a, 9b, 9c, 9d: fuel cell,
901: Fuel electrode, 902: Air electrode, 903: Cooling unit, 90: Intake pump, 91: Blower, 92: Feed water pump, 931: First cooler, 932: Second cooler, 933: Third cooler, 941: first tank, 942: second tank, 95: circulation pump, 96: supply pump, 97: recovery pump, 98: hot water supply pump, 99: exhaust pumps 10a, 10b, 10c, 10d: hot water storage tank, 11: supply Pipe, 12: main pipe,
13a, 13b, 13c, 13d: distribution pipes,
131, 131a: flexible pipe, 132, 132a: straight pipe, 133, 133a: coating resin, 134, 134a: cracks 14a, 14b, 14c, 14d: connecting pipe,
100: Building, 101a, 101b, 101c, 101d: Exclusive floor

Claims (5)

A fuel processing unit including a reformer that generates hydrogen gas from the fuel gas;
A hydrogen gas supply unit including a plurality of buffer tanks connected in parallel to each other for storing the hydrogen gas and supplying the hydrogen gas to the fuel cell;
A control means for selectively supplying the hydrogen gas to the fuel cell from one of the reformer or the buffer tank according to the amount of hydrogen consumed in the fuel cell;
A distribution unit having a header connected to the buffer tank;
A piping device comprising a plurality of distribution pipes, each of which is constituted by an inner pipe and an outer pipe, and is connected between the header and a plurality of fuel cells installed on each exclusive floor of the building. The piping device according to claim 1, wherein the distribution unit includes a plurality of small spaces in which portions connected to the distribution pipe are partitioned from each other, and a detection space in which the small spaces communicate with each other. The piping device according to claim 2, wherein a single hydrogen gas detection member is installed in the detection space. 4. The piping device according to claim 1, wherein the distribution pipe is a flexible pipe coated with a resin. The distribution pipe is connected to the fuel cell via a joint where the downstream end is inserted and fixed, and hydrogen gas flowing out from the gap between the coating resin and the bellows pipe passes through the joint. The piping device according to claim 4, wherein the piping device passes and is captured by the hydrogen gas detection member.

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