JP2018185998A - Fuel cell system - Google Patents

Abstract

A fuel cell system that is reduced in size and weight is provided.
A part of a fuel pipe of a fuel cell system having a fuel processing system for desulfurizing a city gas with a desulfurizer and boosting and reforming the desulfurized city gas with a fuel booster blower is constituted by a resin module block 40. . The resin module block 40 receives the fuel flow A discharged from the desulfurizer, and includes a resin module 40a in which a pipe 50 for discharging the fuel B introduced into the fuel booster blower is provided, and a part of the pipe 50 through the main flow path. The bypass type flow meter 61 for measuring the flow rate of the fuel flowing through the pipe 50 is integrated.
[Selection] Figure 2

Description

  Embodiments described herein relate generally to a fuel cell system.

  The fuel cell system generates exhaust heat as electric energy is generated. This is because the heat radiation from the high battery temperature to the ambient temperature is generated as heat.

  If such heat is used, a hybrid operation with electric energy, that is, a cogeneration operation is performed, so that a very economical, energy-efficient and environmentally friendly operation can be realized. In recent years, such a fuel cell system has been developed to be introduced into the home, and has already been put into practical use in Japan. This is because, as a method of preventing global warming, this energy, which emits less carbon dioxide, has attracted attention, and its environmental performance and energy saving are attracting attention.

  The smaller the fuel cell system is and the smaller the installation area, the more places where it can be installed. This increases the market scale and leads to the spread of energy-saving equipment. In addition, the smaller and lighter the system, the easier the movement for installation and the better the merchantability.

JP 2012-146627 A

  Thus, in order to expand the spread of fuel cell systems, it is required not only to improve the basic performance of the power generation efficiency and exhaust heat efficiency system, but also to develop a fuel cell system that is smaller and lighter.

  The problem to be solved by the present invention is to provide a fuel cell system that is reduced in size and weight.

  A fuel cell system according to an embodiment of the present invention includes: a resin module block in which a part of piping through which fuel flows is provided; and a bypass flow meter having the piping provided in the resin module block as a main flow path. It is characterized by providing.

It is a block diagram which shows the structure of the fuel cell system of 1st Embodiment. It is a top view of the resin block module in 1st Embodiment. It is a front view of the resin block module of 1st Embodiment. (A) is a top view of the bypass flow meter mounted with the resin block module of the first embodiment, (b) is a front sectional view of the bypass flow meter, and (c) is a side sectional view of the bypass flow meter. FIG.

[1. First Embodiment]
[1-1. Constitution]
Below, the fuel cell system which concerns on this embodiment is demonstrated, referring FIGS. 1-4.

[overall structure]
FIG. 1 is a block diagram showing the configuration of the fuel cell system of the present embodiment. In the present embodiment, as the fuel cell system 16, a polymer electrolyte fuel cell system having a fuel reformer inside the packaging will be described as an example.

  The fuel cell system 16 mainly includes a fuel processing system (FPS) 1 and a battery body (CSA) 2.

  The fuel processing system 1 includes a fuel 3, a desulfurizer 4, a starting fuel cutoff valve 21, a fuel booster blower 31, a steam generator 5, a reformer 6, a CO shift reactor 7, a CO selective oxidizer 8, and a steam separator. 9, the reforming combustor 10, the reforming water pump 11, the exhaust heat exchanger & tank 12, and the like. On the other hand, the battery body 2 includes an anode electrode 13 and a cathode electrode 14.

  The fuel 3 is a hydrocarbon fuel such as city gas or propane. The fuel 3 flows in the piping and reaches the desulfurizer 4. On the upstream side of the desulfurizer, a fuel cutoff valve 20 for switching cutoff / supply of the fuel 3 flowing in the pipe is arranged.

  The desulfurizer 4 removes the sulfur content of the fuel flowing inside. The desulfurizer 4 includes activated carbon and zeolite inside, and adsorbs the sulfur content of the fuel. On the downstream side of the desulfurizer 4, a bypass flow meter 61 a and a fuel booster 31 are disposed.

  The fuel booster 31 is a blower for pressurizing the fuel 3 in the pipe. On the downstream side of the fuel booster blower 31, the pipe branches. One pipe is connected to the reformer 6 via the starting fuel cutoff valve 21. The other pipe is connected to the CO shift reactor 7 via the main fuel cutoff valve 22.

  The reformer 6 reacts the fuel 3 and water vapor with a catalyst. From the reaction in the reformer 6, hydrogen is generated and CO is also generated. The reforming in the reformer 6 is so-called steam reforming and is an endothermic reaction. Therefore, in order to accelerate the reaction, the reformer 6 includes a combustor for heating. A steam generator 5 is disposed on the downstream side of the reformer 6.

  The steam generator 5 heats the pure supplied from the reforming water pump 11 and generates steam. The generated water vapor merges with the fuel gas. In the polymer electrolyte fuel cell system, CO poisoning in a MEA (Membrane Electrode Assembly) composed of the electrolyte membrane and the catalyst layer of the battery body 2 becomes a problem, and therefore, it is necessary to oxidize CO to CO2. A CO shift reactor 7 and a CO selective oxidizer 8 are disposed on the downstream side of the steam generator 5.

  Air is supplied from the CO selective oxidation air blower 18 to the CO shift reactor 7 and the CO selective oxidizer 8. In the CO shift reactor 7, the shift reaction by H 2 O is performed, and in the CO selective oxidizer 8, the oxidation reaction is advanced by the air supplied from the CO selective oxidation air blower 18 to such an extent that no CO poisoning is generated by the catalyst.

  These catalytic reaction temperatures including the reformer 6 are different from each other. For example, the reaction temperature in the reformer 6 is several hundred degrees, and the reaction temperature in the CO selective oxidizer 8 is one hundred degrees. Thus, it is necessary to take a large temperature difference between the upstream and downstream of the reformed gas discharged from the reformer 6. Therefore, a heat exchanger for lowering the temperature on the downstream side is required.

Next, main process reactions in each catalyst are shown below. For example, in the case of city gas reforming mainly composed of a methane component, the steam reforming reaction is represented by equation (1), the CO shift reaction is represented by equation (2), and the CO selective oxidation reaction is represented by equation (3).
CH4 + 2H2O → CO2 + 4H2 ... (1)
CO + H2O → CO2 + H2 ... (2)
2CO + O2 → 2CO2 ... (3)

  The reformed gas that has passed through the CO selective oxidizer 8 is mainly composed of hydrogen, carbon dioxide gas, excess steam, and the like. The CO selective oxidizer 8 communicates with the anode electrode 13, and the reformed gas discharged from the CO selective oxidizer 8 is sent to the anode electrode 13.

  At the anode 13, the hydrogen gas contained in the reformed gas that has been sent is decomposed into protons H + and electrons. Thereafter, the proton H + moves to the cathode electrode 14 through the MEA catalyst layer. In the cathode 14, water is generated in combination with oxygen and electrons in the air supplied by the cathode air blower 15.

  Therefore, the anode 13 is a minus pole and the cathode 14 is a plus pole, and generates a DC voltage with a potential. If there is an electrical load between these potentials, it will function as a power source. The anode electrode outlet gas remaining without being used for power generation is used as a fuel gas for heating the steam generator 5 and the reformer 6. Further, the water vapor in the cathode electrode outlet and the water vapor in the combustion exhaust gas are collected by the exhaust heat exchanger A12a, and water self-sustained in the system.

  On the other hand, the exhaust heat of the battery body 2 is recovered by the exhaust heat exchanger B12b arranged in the circulation line of the battery cooling water pump 29. The hot water heated by exchanging heat in the exhaust heat exchangers 12a and 12b by the operation of the hot water circulation pump 33 is stored in the hot water storage tank 36 and used as hot water for hot water supply or a bath. In a state where hot water is stored in the lower part of the tank without using the heat of the hot water storage tank 36, the circulating water temperature returning to the fuel cell system 16 rises, so that the operation of the system is stopped until the hot water is used, or Heat is released to the atmosphere through the radiator 37.

  Next, the operation method at the time of starting is shown. When the operation start command is started, the combustion air blower 26 is started with the combustion air switching valve 25 being opened, and the combustion chamber in the reformer 6 is purged with air. In this case, the combustion air is supplied from the combustion air blower 26 not only as premixed air for the starting fuel but also as diffusion air into the combustion chamber.

  When the air purge is completed, a spark from, for example, a spark plug for starting fuel ignition is generated in the combustion chamber. If the fuel cutoff valve 20 and the startup fuel cutoff valve 21 are opened with the main fuel cutoff valve 22 closed and the deaeration cutoff valve 23 open, the startup that has passed through the fuel cutoff valve 20 and the startup fuel cutoff valve 21 The fuel is boosted by the fuel booster blower 31 and ignited in the combustion chamber to form a flame.

  The burner used in the combustion chamber is an integrated burner that serves both for start-up and power generation, and methane-based starter fuel is slower in combustion speed than hydrogen-based fuel, which is off-gas fuel during power generation, and easily blows off. The premixed combustion improves the combustibility. Combustion continues, the reformer 6 is heated by the combustion gas, and the CO shift reactor 7, the CO selective oxidizer 8, the steam separator 9, and the like heated by an electric heater (not shown), etc. When the temperature reaches, the reformed water supplied to the steam separator 9 by the reforming water pump 11 becomes steam therein, and the steam flow rate adjusting valve 27 is opened and supplied to the fuel reforming line. Is supplied into the FPS 1 together with the fuel 3 which is supplied while being opened, and the reforming reaction starts. At this timing, the starting fuel cutoff valve 21, the deaeration cutoff valve 23, and the combustion air switching valve 25 are closed.

  After the reforming reaction is started, the reformed gas that is oxidized by the air of the CO selective oxidation air blower 18 and exits from the outlet of the CO selective oxidizer 8 is mainly composed of components such as hydrogen, carbon dioxide gas, and water vapor. 2 to the anode electrode 13. The off gas that exits from the outlet of the anode 13 passes through the off gas check valve 24 and is then supplied to the reforming combustor 10.

  The off-gas fuel supplied to the reforming combustor 10 ignites, and starts stable diffusion combustion with the main fuel air. Thereafter, air is supplied from the cathode air blower 15 to the cathode 14 of the battery body 2 and when the inverter is activated, the fuel cell system 16 starts generating electricity. The off gas that exits from the outlet of the anode electrode 13 that remains without contributing to power generation continues to be supplied to the reforming combustor 10.

[Configuration of Resin Module Block 40]
2 and 3 show the resin module block 40 mounted on the fuel cell system 16 of the present embodiment. 2 is a plan view of the resin module block 40 (a front view at the time of installation), and FIG. 3 is a front view. The resin module block 40 is obtained by integrally molding the piping at the broken line in FIG. 1 with resin. Moreover, the arrows A to E showing the flow of the fuel 3 in FIG. 1 correspond to the arrows A to E in FIGS.

  Two pipes are formed in the resin module block 40. The first pipe is a pipe (arrow A to arrow B) between the desulfurizer 4 and the fuel booster blower 31 in FIG. The piping continuing from the desulfurizer 4 is connected to the resin module block 40 at the portion indicated by the arrow A, and connected to the piping on the upstream side of the fuel booster blower 31 at the portion indicated by the arrow B. Further, the second pipe branches in two directions inside the resin module block 40. In FIG. 1, a pipe between the fuel booster blower 31 and the reformer 6 (arrow C to arrow E) and a pipe between the fuel booster blower 31 and the CO shift reactor 7 (arrow C to arrow D) are provided.

  The resin module block 40 is formed by combining a plurality of members that form internal piping. The resin module block 40 includes a resin module 40 a, a bypass flow meter 61 a, a bypass flow meter mounting child part 62, a starting fuel cutoff valve 21, and a main fuel cutoff valve 22. In other words, the resin module block 40 includes the resin module 40a on which the bypass flow meter 61a, the bypass flow meter mounting child component 62, the starting fuel cutoff valve 21, and the main fuel cutoff valve 22 are mounted.

  A bypass type flow meter 61 a is installed in the pipe from the arrow A to the arrow B of the resin module block 40. The pipes in the bypass flow meter mounting sub-part 62 are the main flow path of the bypass flow meter 61a and a pipe that becomes a part of the bypass flow path. The piping in the bypass flow meter mounting sub-part 62 branches inside and flows into the main flow path of the bypass flow meter 61a, the inlet to the bypass flow meter 61a branched from the main flow path, and the main flow path. It becomes an outlet from the bypass flow meter 61a. Here, a module in which the bypass flow meter 61a is provided is referred to as a first module, and a module in which the bypass flow meter mounting subcomponent 62 is provided is referred to as a second module. In addition, the buffer tank portion 51 is provided in the resin module 40a of the piping from the arrow A to the arrow B.

  The resin module 40a formed separately from each other and the bypass flow meter mounting subpart 62 are connected by welding. On the other hand, the fixing of the bypass flow meter mounting child part 62 and the bypass flow meter 61a is screwed. An annular packing is disposed and sealed at the connecting portion between the bypass flow meter mounting sub-part 62 and the bypass flow meter 61a. The annular packing is a so-called O-ring.

  A main fuel cutoff valve 22 is installed in the piping from the arrow C to the arrow D of the resin module block 40. The main fuel cutoff valve 22 becomes a part of the pipe from the arrow C to the arrow D. The main fuel cutoff valve 22 is fixed to the resin module 40a with screws. An annular packing is disposed on the connecting portion and sealed.

  An activation fuel cutoff valve 21 is installed in the piping from the arrow C to the arrow E of the resin module block 40. The starting fuel cutoff valve 21 is a part of the piping from the arrow C to the arrow E. The starting fuel cutoff valve 21 is fixed to the resin module 40a with screws. An annular packing is disposed on the connecting portion and sealed.

[Flow of fuel in resin module block 40]
Hereinafter, the flow of the fuel 3 flowing through the resin module block 40 in the fuel cell system 16 according to the present embodiment will be described.

  The fuel cutoff valve 20 is opened and the fuel 3 that has passed through the desulfurizer 4 is supplied to the resin module block 40 from the fuel flow meter inlet connection 48. After passing through the bypass flow meter 61a, the fuel 3 enters the resin pipe part a50, passes through the buffer tank part 51 having a larger cross-sectional area than the pipe part, and temporarily passes through the buffer tank outlet connection part 52 to the resin module block 40. Go outside.

  The fuel 3 is supplied again to the resin module block 40 from the fuel cutoff valve inlet connection portion 53 via the fuel booster 31. Each fuel branches at the resin piping part b54 and then enters the starting fuel cutoff valve 21 and the main fuel cutoff valve 22, and the flow is determined by opening / closing control of each cutoff valve. At startup, the startup fuel cutoff valve outlet connection 55 During normal operation, the main fuel cutoff valve outlet connection portion 56 leads to a connection pipe (not shown) outside the resin module block 40.

  Here, the mounting method of the bypass type flow meter 61a for fuel according to the first embodiment on the resin module block 40 and the flow path structure related to the flow rate measurement will be described. FIG. 4A is a plan view of the bypass flow meter 61a mounted on the bypass flow meter mounting sub-component 62 of the resin module block 40, FIG. 4B is a front sectional view (AA section), and FIG. A side view (BB section) is shown in FIG.

  The bypass flow meter 61 a shown in FIG. 4A is fixed to the bypass flow meter mounting child part 62 by two screw portions 64 and sealed by two O-rings 63. The bypass type flow meter 61a is fixed by the screw part 64 in consideration of maintainability because a failure after the system operation is considered.

  On the other hand, the bypass flow meter mounting subpart 62 is welded and sealed to the resin module block 40 by, for example, vibration welding. As shown in FIGS. 4B and 4C, the bypass flow meter 61a bypasses a part of the fluid (here, fuel 3) whose flow direction is indicated by an arrow to the bypass passage 65, The flow rate can be detected and the flow rate of the main flow channel 66 can be calculated.

  The characteristic of the bypass flow meter 61a is that the bypass flow ratio of the fluid flowing through the bypass flow path 65 and the main flow path 66 is appropriately set, and the setting includes the main flow path orifice section 67, the main flow path 66, and the bypass flow. It is mainly determined by each diameter and structure of the path 65.

[1-2. Effect]
As described above, in the fuel cell system, a part of the piping through which the fuel flows is provided inside the resin module block. In addition, a bypass flow meter having a main flow path as a pipe provided in the resin module block is provided. As a result, the bypass flow meter 61a can be reduced in size and weight.

  A part of the bypass flow path of the bypass flow meter may be provided inside the resin module block. Thereby, compared with the case where piping of a bypass channel is separately connected to a resin module block, it becomes possible to make formation of a bypass channel easier.

  The resin module block may be formed from a plurality of modules. In the present embodiment, the bypass flow meter 61a, the bypass flow meter mounting child part 62, the starting fuel cutoff valve 21, and the main fuel cutoff valve 22 are mounted on the resin module 40a. As a result, the piping portion can be made compact, and the fuel cell system can be reduced in size, weight and space.

  The plurality of modules may be a first module including a bypass flow meter 61a and a second module serving as a bypass flow meter mounting child component 62. As a result, a lightweight and space-saving bypass flow meter can be mounted on the fuel cell system.

  The bypass flow meter mounting subpart 62 is welded to the resin module block. A main flow path of the bypass flow meter is formed in the bypass flow meter mounting child part 62. The main flow path can be easily processed by previously forming the main flow path in the bypass flow meter mounting sub-part 62 and bonding the bypass flow meter mounting sub-part 62 to the resin module. . Thereby, the processing accuracy of the main channel can be improved.

  The bypass flow meter mounting subpart 62 is provided with a main flow path of the bypass flow meter. The main channel is provided with an orifice, and the orifice is disposed between the inlet of the bypass channel and the outlet of the bypass channel. Thereby, the flow volume which flows into the bypass flow path 65 can be decreased. That is, the flow rate of the bypass flow meter 61a is calculated based on the pressure difference between the bypass flow channel 65 and the main flow channel 66, and therefore the flow resistance on the main flow channel 66 side is compared with the flow resistance of the bypass flow channel 65. And made it smaller.

  In order to sufficiently reduce the size and weight of the bypass flow meter 61a, the flow rate of the bypass flow channel 65 is desirably 1/10 or less of the flow rate of the main flow channel 66. In order to ensure the flow rate measurement accuracy of the bypass flow meter 61a, it is important to manage the bypass flow rate ratio, and in order to manage the bypass flow rate ratio, the main flow path orifice section 67, the main flow path 66, and the bypass flow path 65 must be controlled. Strict dimensional control is required.

Assuming that the bypass flow rate ratio is (bypass flow rate 65 flow rate) / (main flow rate 66 flow rate + bypass flow rate 65 flow rate), the smaller the bypass flow rate ratio, the more strict the dimensional accuracy becomes. By integrating into the meter mounting child part 62 and making it into a separate module, it becomes possible to manage the dimensions separately from the entire resin module block 40.
According to at least one embodiment described above, the size and weight can be reduced.

  In the present specification, a plurality of embodiments according to the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. Specifically, various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

DESCRIPTION OF SYMBOLS 1 ... Fuel processing system, 2 ... Battery main body, 16 ... Fuel cell system, 36 ... Hot water storage tank, 40 ... Resin module block, 40a ... Resin module, 50 ... Resin piping part a, 54 ... Resin piping part b, 61a ... Bypass Type flow meter, 62... Bypass type flow meter mounting component, 63... O-ring, 65 .. bypass channel, 66 .. main channel, 67.

Claims (8)

A resin module block in which a part of piping through which fuel flows is provided;
A bypass type flow meter having the pipe provided inside the resin module block as a main flow path;
A fuel cell system comprising:   The fuel cell system according to claim 1, wherein a part of a bypass flow path of the bypass flow meter is provided inside the resin module block.   The fuel cell system according to claim 1, wherein the resin module block is formed from a plurality of modules. The plurality of modules includes a first module including the bypass flow meter;
A second module disposed between the first module and the resin module block;
The fuel cell system according to claim 1, further comprising: The second module is:
The fuel cell system according to claim 4, wherein the fuel cell system is welded to the resin module block. The second module includes
A main flow path of the bypass flow meter;
An inlet of a bypass channel branched from the main channel;
An outlet of a bypass channel that merges with the main channel;
Is provided,
The main flow path is provided with an orifice part,
6. The fuel cell system according to claim 4, wherein the orifice portion is disposed between an inlet of the bypass channel and an outlet of the bypass channel.   The fuel cell system according to claim 6, wherein a diameter of the orifice portion is larger than a diameter of the bypass flow path. The first module is configured to be detachable from the second module,
The annular packing is disposed at a connection portion between the bypass flow path provided in the first module and the bypass flow path of the second module, according to any one of claims 4 to 7. The fuel cell system described.

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