JP2002175824A - Power source system and warming method of solid oxide fuel cell in power generation system using solid oxide fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability of a power source system, using a solid oxide fuel cell(SOFC) and facilitating warming operation of the SOFC. SOLUTION: As a means of producing a reformed gas to the SOFC 3, an internal combustion engine (reciprocal type reformer) 1, which operates by the theoretical air fuel ratio and the air fuel ratio in a state thicker than this in fuel is used. At of the warming operation of the SOFC 3, while the reciprocal type reformer 1 is being operated by he theoretical air fuel ratio, its output is made as the output of the system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power source system and a method for warming up a solid oxide fuel cell in a power generation system using the solid oxide fuel cell, and more particularly, to warming up a solid oxide fuel cell. Operation and replenishment of insufficient power generation of solid oxide fuel cells.

[0002]

2. Description of the Related Art Heretofore, there has been a power source system employing a solid oxide fuel cell (hereinafter, also referred to as "SOFC") as a power source. This SOFC can be used by reforming raw fuels such as natural gas, methanol, gasoline, light oil, and naphtha, and is excellent in fuel diversity. Since the operating temperature of the SOFC is as high as 500 [° C.] or more, internal reforming at the electrode is also possible, but there are restrictions on the material of the electrode and the like.
Generally, a reformer is provided outside the battery to reform the fuel, and then the resulting reformed gas is led to the fuel electrode of the SOFC (see Japanese Patent Application Laid-Open No. 10-214631).

[0003]

However, the power source system combining the conventional external reforming and SOFC has a complicated system configuration and has a problem in reliability. Further, the SOFC cannot perform satisfactory power generation until the temperature of the solid oxide has reached a temperature range having a sufficient ionic conductivity. Therefore, in order to obtain sufficient power from an early stage after the start, a special heat source such as a combustor or an electric heater is required for warming up the SOFC or the reformer. In addition, it is necessary to provide a considerable amount of secondary batteries in order to compensate for the shortage of power generation of the SOFC until the SOFC exhibits a predetermined power generation including at the time of start-up or during transition. If these are added to the system, the cost, volume, weight, etc. increase, and the system configuration becomes more complicated.

[0004] In view of such a situation, the present invention provides a SOF.
The object of the present invention is to provide a simple power source system using C, and to enable the warming-up operation of the SOFC and the supplement of the insufficient power generation of the SOFC without the disadvantages described above.

[0005]

Therefore, the power source system according to the first aspect of the present invention operates on a stoichiometric air-fuel ratio and a fuel-rich state based on the stoichiometric hydrocarbon fuel. And a solid oxide fuel cell that receives the combustion product gas of the first internal combustion engine on the fuel electrode side.

A power source system according to a second aspect of the present invention is characterized in that the first internal combustion engine operates at a stoichiometric air-fuel ratio during a warm-up operation of the solid oxide fuel cell. A power source system according to a third aspect of the invention is characterized in that during the warm-up operation, the first internal combustion engine outputs rotational power.

A power source system according to a fourth aspect of the present invention is characterized in that a steam supply device for supplying steam or water to the first internal combustion engine is provided. Claim 5
The power source system according to the present invention is characterized in that the first internal combustion engine drives an air supply device connected to an air electrode side of the solid oxide fuel cell.

According to a sixth aspect of the present invention, in the power source system, the air supply device is a reciprocating compressor, and a drive shaft thereof is connected to an output shaft of the first internal combustion engine. . A power source system according to a seventh aspect of the present invention is characterized in that the reciprocating compressor includes a second internal combustion engine that can be switched to non-combustion operation.

The power source system according to the present invention is characterized in that an exhaust port of the second internal combustion engine is connected to an air chamber inlet of the solid oxide fuel cell. A power source system according to a ninth aspect of the present invention is characterized in that the second internal combustion engine performs a combustion operation during a warm-up operation of the solid oxide fuel cell. A power source system according to a tenth aspect of the present invention is provided with a third internal combustion engine, the intake port of which is connected to a fuel chamber outlet of the solid oxide fuel cell.

A power source system according to an eleventh aspect of the present invention is characterized in that an output shaft of the third internal combustion engine is connected to an output shaft of the first internal combustion engine. Claim 1
The power source system according to the invention described in Item 2, is characterized in that a fuel supply device that supplies the hydrocarbon-based raw fuel to the third internal combustion engine is provided. The power source system according to the invention according to claim 13, wherein the fuel supply device is configured to start up,
The hydrocarbon-based raw fuel is supplied under at least one of a transient state and a high load condition.

A power source system according to a fourteenth aspect of the present invention includes a reformed gas generating means, and a solid oxide fuel cell for receiving the reformed gas generated by the means on the fuel electrode side. Wherein the reformed gas generating means generates reformed gas containing hydrogen and carbon monoxide as main components by combustion under excess fuel, while generating stoichiometric air under predetermined conditions. It is characterized by switching to combustion at the fuel ratio.

The power source system according to the invention of claim 15 is characterized in that the predetermined condition is a warm-up operation of the solid oxide fuel cell. The power source system according to the present invention is characterized in that the reformed gas generation means is a reciprocating reformer, and outputs the rotational power of the reformer during the warm-up operation. And

[0013] A method for warming up a solid oxide fuel cell in a power generation system using the solid oxide fuel cell according to the invention according to claim 17 is a method for warming up hydrogen and carbon monoxide in a normal state by combustion under excess fuel. While generating a reformed gas containing as a main component, and guiding the generated reformed gas to the fuel electrode of the solid oxide fuel cell, and during the warm-up operation of the solid oxide fuel cell, the stoichiometric air-fuel ratio It is characterized by controlling to combustion.

[0014]

According to the first aspect of the invention, by operating the first internal combustion engine in a state where the fuel is richer than the stoichiometric air-fuel ratio, the combustion product gas and the hydrogen (H ₂ ) are reduced by one. A composition suitable for power generation, which contains carbon oxide (CO) as a main component, is provided to the solid oxide fuel cell stably with a combustion product gas having a composition suitable for such power generation. Meanwhile, the first
By operating the internal combustion engine at the stoichiometric air-fuel ratio, the solid oxide fuel cell can be quickly heated by the relatively high-temperature combustion product gas discharged at this time.

According to the second aspect of the invention, the warm-up operation of the solid oxide fuel cell can be performed without adding a special heat source such as an electric heater. According to the third aspect of the invention, the shortage of power generation of the solid oxide fuel cell during the warm-up operation is compensated for by the rotational power of the first internal combustion engine, and the power required during the warm-up operation is transmitted. it can.

According to the fourth aspect of the present invention, carbon (soot) contained in the combustion product gas can be reduced.
According to the fifth aspect of the present invention, since air can be supplied to the solid oxide fuel cell without adding a dedicated power unit, a simpler power source system can be constructed.

According to the invention described in claim 6, a simple power source system can be easily constructed. According to the seventh aspect of the present invention, the second internal combustion engine is caused to function as a compressor by performing non-combustion operation, and air can be supplied to the solid oxide fuel cell. According to the invention described in claim 8, during the combustion operation of the second internal combustion engine, the heating of the solid oxide fuel cell can be promoted by the exhaust heat.

According to the ninth aspect, the heating of the solid oxide fuel cell is promoted by the exhaust heat from the second internal combustion engine, and the power generation of the solid oxide fuel cell during the warm-up operation is insufficient. Can be compensated for by the rotational power of the second internal combustion engine. According to the tenth aspect, at least a part of the energy of the unreacted fuel gas discharged from the solid oxide fuel cell can be recovered as power by the third internal combustion engine.

According to the eleventh aspect, the energy recovered by the third internal combustion engine can be reflected on the efficiency of the system. According to the twelfth aspect, the rotational power of the third internal combustion engine can be easily increased. According to the thirteenth aspect, the timing of supplying the hydrocarbon-based raw fuel is optimized, and the high output from the third internal combustion engine under the condition that it is necessary to particularly compensate for the insufficient power generation of the solid oxide fuel cell Is obtained.

According to the fourteenth aspect of the present invention, since the reformed gas generating means performs combustion at the stoichiometric air-fuel ratio, the solid oxide fuel cell receives a relatively high temperature gas. The oxide fuel cell can be heated quickly. According to the fifteenth aspect, the warm-up operation of the solid oxide fuel cell can be performed without adding a special heat source such as an electric heater.

According to the sixteenth aspect of the invention, the insufficient power generation of the solid oxide fuel cell during the warm-up operation is compensated for by the rotational power of the reciprocating reformer, and the power required during the warm-up operation is reduced. Can tell. According to the seventeenth aspect, it is possible to construct a power generation system that does not require a special heat source for a warm-up operation of the solid oxide fuel cell.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 to 9, the moving path of the fluid (that is, the piping system) is indicated by a solid line, the transmission path of mechanical power is indicated by a one-dot chain line, and the electrical connection path including the signal transmission path is indicated by two points. This is indicated by a chain line.

First, a first embodiment will be described.
FIG. 1 schematically shows an overall configuration of a power source system S1 according to the present embodiment.
Internal combustion engine (as will be described later, it functions as a hydrocarbon-based raw fuel reformer, and is therefore represented by F / R in the figure).
1 and an SOFC (Solid Oxide Fuel Cell) 3 as main components.

The internal combustion engine 1 has an air intake path C on the upstream side.
f1 is connected, and a fuel mixing chamber 5 is formed on the way. Further, a fuel supply path Cf2 is connected to the fuel mixing chamber 5. On the other hand, a combustion product gas flow path Cf3 is connected to the downstream side of the internal combustion engine 1, and the internal combustion engine 1 and the SOFC 3
Connected to the fuel chamber. Combustion gas flow path Cf
A heat exchanger 6 is provided in the middle of 3. A water vapor supply path Cf4 is connected to the heat exchanger 6, and water is supplied from an upstream side of the heat exchanger 6, and steam vaporized (evaporated) by heat exchange with a combustion product gas flows downstream. The air is led to the air suction path Cf1. Also,
An exhaust passage Cf5 is connected to a fuel chamber outlet of the SOFC 3.

The air chamber of the SOFC 3 has an air flow path C
f6 is connected, and air is pressurized by the compressor 7 and sent to the air chamber. A power transmission path Ce is formed in the SOFC 3 between the SOFC 3 and the electric motor 8, and the power generated by the SOFC 3 is supplied to the electric motor 8 and converted into rotational power in the electric motor 8.

The output of the electric motor 8 is a power transmission path Cd
(Eg, driving wheels in a vehicle) 9
Conveyed to. A gearbox 10 is provided in the middle of the power transmission path Cd, and a power transmission path Cr1 is formed between the gearbox 10 and the internal combustion engine 1 so that the output of the internal combustion engine 1 The driving object 9 is transmitted to the driving object 9 via the control unit 9.

Next, the system S1 will be described based on a specific structure. First, the internal combustion engine 1 will be described with reference to FIG. FIG. 2 shows a cross-sectional view of the internal combustion engine 1 and also shows a connection state with peripheral elements thereof. The internal combustion engine 1 can take out the combustion expansion force of the fuel as the rotational force of the crankshaft 12 (indicated by a dashed line in the figure) via the reciprocating motion of the piston 11.
This is a so-called reciprocating internal combustion engine.

Here, the internal combustion engine 1 is not a power generating device, but rather is a reforming process in which hydrogen (H ₂ ) and carbon monoxide (CO) are the main components by operating under an excessive supply of fuel. The main purpose is to generate gas (for this reason, in the following description, the internal combustion engine 1 is referred to as a "reciprocating reformer"). The internal combustion engine 1 constitutes a reformed gas generation unit according to the present invention.

The principle of operation of the reciprocating reformer 1 is the same as that of the system S1 in the case where it is generally used as a power generator, but will be briefly described here. The hydrocarbon-based raw fuel to be supplied to the reciprocating reformer 1 is stored in a fuel tank (not shown).
The fuel supply path Cf2 is pressure-fed by the fuel pump 13, and fuel is mixed from a nozzle 14 at the end of the path (a valve device based on an electric operation principle is provided and can be opened at an arbitrary timing). It is supplied to the chamber 5. The supplied fuel mixes with the air passing therethrough to form a rich mixture of fuel.

A valve device 15 is provided at a connection between the air intake passage Cf1 and the water vapor supply passage Cf4, and is opened and closed in response to a signal from an electronic control unit (not shown) to supply a fuel-air mixture. Steam can be added. By performing the addition of steam in accordance with the air-fuel ratio, a steam reforming reaction described below is caused, and the generation of carbon during combustion can be suppressed. Although an example in which steam is port-injected is described here, the steam supply path Cf4 may be connected to the fuel mixing chamber 5.

The mixture of fuel and air (and, in some cases, water vapor) flows into a combustion chamber (hereinafter referred to as a “reforming chamber”) 17 under the control of a suction-side valve device 16.
The fuel is ignited in a predetermined compression state accompanying the rise of the piston 11, and a fuel reforming reaction occurs. Further, when the piston 12 rises again after the expansion, the discharge-side valve device 18 opens,
The combustion product gas (that is, the reformed gas) is sent out to the combustion product gas circulation path Cf3. Combustion gas distribution path C
The combustion product gas flowing through f3 joins in the midway manifold section and passes through the heat exchanger 6.

Here, the principle of fuel reforming will be briefly described. This principle can be largely explained by the following general formula (1).

[0033]

(Equation 1)

[0034] This reforming reaction is particularly called “partial oxidation reaction”.
Called and caused by proper adjustment of fuel and air flow
Things. In addition, the valve device 15 is operated to operate the reforming chamber 17.
The next steam reforming reaction is caused by the presence of steam in the
Can also be caused.

[0035]

(Equation 2)

[0036] Simultaneously with the reforming reaction represented by the above equation,
The reaction represented by the following two equations is also partially performed.

[0037]

(Equation 3)

[0038] It is explained from the above general formulas (1) to (4).
Based on the principle of reciprocating reformer 1
The combustion product gas obtained by the operation of_Two, CO,
CH _FourIs a mixed gas mainly composed of Here,
Is an example of a spark ignition type internal combustion engine as the reciprocating reformer 1.
However, the same applies to compression ignition type internal combustion engines.
Purpose can be achieved.

Next, the SOFC 3 will be described with reference to FIG. FIG. 3 is a cross-sectional view schematically showing the internal structure of the SOFC 3. Inside the SOFC 3, a fuel chamber 32 is formed on one side and an air chamber 33 is formed on the other side with the solid oxide 31 interposed therebetween. The fuel chamber 32 has a fuel chamber inlet passage 34 which forms the end of the combustion product gas flow path Cf3.
And the fuel chamber outlet passage 3 forming the end of the exhaust passage Cf5
5 are connected. On the other hand, in the air chamber 33, an air chamber inlet passage 36 forming an end on the air chamber inlet side of the air circulation path Cf6, and an air chamber outlet passage 37 forming an end on the air chamber outlet side of the air circulation path Cf6. Connected.

When the SOFC 3 is in the operating condition
In other words, during normal times, the combustion product gas is supplied to the fuel chamber 32.
When the air flows into the air chamber 33, the fuel electrode
Between the solid oxide 31 and the air electrode 312
By the action, power generation is performed according to the amount of combustion product gas that has flowed in.
Done. On the other hand, when the SOFC 3 is not operated, that is,
When the SOFC 3 at the time of starting or the like is in a predetermined temperature range (approximately 500
[° C.] or more), the solid oxide 31
No on-conductivity or a sufficiently high level
Since it has not reached, satisfactory power generation cannot be obtained.

[0041] The system S1 operates under such conditions.
Switches the reciprocating reformer 1 to operation at the stoichiometric air-fuel ratio
You. In the reciprocating reformer 1, the relatively high temperature
A combustion product gas is generated, and this is supplied to the heat exchanger 6 and the fuel chamber.
32, the SOFC 3 and the heat exchanger 6
Heat etc. Therefore, the reciprocating reformer 1 is
Not only function as gas generation means, but also warm-up of system
It also has a function as a means.

By operating the reciprocating reformer 1 at the stoichiometric air-fuel ratio, the SOFC 3 is sufficiently warmed and the solid oxide 31
After reaching the temperature range with sufficient ionic conductivity,
Switching the reciprocating reformer 1 to operation under excess fuel,
Power generation by SOFC3 is performed. In this specification, such an operation of heating the SOFC 3 from a low temperature state to a predetermined temperature range is referred to as a “warm-up operation” of the SOFC 3.

[0043] Next, a second embodiment will be described.
FIG. 4 is an overall view of a power source system S2 according to the present embodiment.
It shows the outline of the configuration, and the power source explained earlier
For components having the same functions as the system S1,
The same reference numerals are given. Characteristic configuration of the present system S2
Goes to the reciprocating reformer 1 and the air chamber 33 of the SOFC 3.
Power transmission path C between the compressor 7 for supplying air
r2 is formed, and the compressor 7 is operated by the reciprocating reformer 1.
That is, it is driven.

Here, the drive shaft of the compressor 7 is connected to the crankshaft 12 of the reciprocating reformer 1, and the output of the reciprocating reformer 1 is transmitted to the compressor 7. . In addition, as a connection form of both, the crankshaft 12 and the drive shaft of the compressor 7 are made coaxial, the compressor 7 is connected to the end of the crankshaft, or a power transmission mechanism such as a belt, a chain, a gear, etc. ) May be used.

The reciprocating reformer 1 has an intake / exhaust
Valves and connect these valves to the crankshaft 12
When using a type driven by a valve train shaft
Obtains power for driving the compressor 7 from the valve shaft.
You can also. Next, a third embodiment will be described.
You. FIG. 5 shows a power source system S3 according to this embodiment.
The cross-sectional view of the reciprocating reformer 1 and the compressor 7 shown in FIG.
In both cases, the connection state with the peripheral element is also described.

The overall basic configuration of the system S3 is as follows.
Power source system S2 (FIG. 4),
In particular, the compressor 7 is a reciprocating type,
Its drive shaft is the crankshaft 1 of the reciprocating reformer 1.
2 and the reciprocating reformer 1 and the compressor 7
Is formed in the body cylinder. Note that FIG.
And reference numeral 71 allows the flow toward the compression chamber 72,
A check valve for regulating the flow in the opposite direction;
Allow the flow out of the compression chamber 72 and its opposite direction
3 shows a check valve for regulating flow.

[0047] Next, a fourth embodiment will be described.
FIG. 6 is an overall view of a power source system S4 according to the present embodiment.
It shows the outline of the configuration, and the power source explained earlier
For components having the same functions as the system S1,
The same reference numerals are given. Characteristic configuration of the present system S4
Is in the middle of the air flow path Cf6 on the upstream side of the SOFC3.
A fuel engine 100 is provided, and the reciprocating reformer 1
A power transmission path Cr3 was formed between Abox 10
That is. As a result, the output of the engine type reformer 1 becomes
Transmitted to the internal combustion engine 100, and conversely,
The output is also transmitted to the reciprocating reformer 1.
You. These outputs are transmitted via the power transmission path Cr3.
To the gearbox 10 and, consequently, the driven object 9
It is. Further, the air flow path Cf on the upstream side of the internal combustion engine 100
6 is connected to a fuel supply path Cf7.

FIG. 7 shows a cross-sectional view of the reciprocating reformer 1 and the internal combustion engine 100 in the present system S4, and also shows a connection state with peripheral elements thereof. Although the reciprocating reformer 1 and the internal combustion engine 100 may be separate bodies, the piston 111 of the internal combustion engine 100 is connected to the crankshaft 12 of the reciprocating reformer 1, and the reciprocating reformer 1 and the internal combustion engine 100 are connected. By forming 100 and 100 in an integral cylinder, the system is simplified and the warm-up efficiency is improved.

In the present system S4, an electronic control unit (hereinafter referred to as “ECU”) 200 inputs a detection signal from a temperature sensor 210 installed inside the SOFC 3 (for example, on the surface of the fuel electrode 311), and It is determined whether the warm-up operation should be performed. The ECU 200 is provided on the fuel supply valve device 21, the water vapor supply valve device 15, the gear box 10, and the connection portion between the air flow path Cf6 and the fuel supply path Cf7 based on the operating conditions including the determination result. A command signal is issued to the fuel supply valve device 110.

When the ECU 200 determines that the SOFC 3 is in the warm-up operation, the opening period of the valve device 21 is set so that the air-fuel mixture to the reciprocating reformer 1 has the stoichiometric air-fuel ratio. In operation, fuel is supplied to the internal combustion engine 100. Accordingly, from the reciprocating reformer 1, the combustion product gas at a relatively high temperature is supplied to the SOFC 3 through the heat exchanger 6.
And the exhaust gas from the internal combustion engine 100 is also sent to the air chamber 33 of the SOFC 3, so that the heating of the SOFC 3 is promoted.

Here, one end of the fuel supply path Cf7 for sending the fuel supplied to the internal combustion engine 100 is connected to the fuel supply path Cf2 on the downstream side of the fuel pump 13; , The same as the fuel of the reciprocating reformer 1, that is, the raw hydrocarbon-based fuel before reforming is supplied. When the SOFC 3 is sufficiently warmed and the ECU 200 determines that the warm-up operation of the SOFC 3 is completed, the valve device 2
The open period of 1 is set so that the air-fuel mixture to the reciprocating reformer 1 becomes rich in fuel (that is, the open period is extended), and the valve device 110 is stopped. .

Therefore, after the SOFC 3 is warmed up,
H from the reformer 1 to the SOFC 3 _TwoAnd CO as main components
Is sent. On the other hand, the internal combustion engine 100
Is a reciprocating compressor with adjusted valve timing
Functions and sends air to SOFC3. Therefore, SO
FC3 can perform normal power generation. Next, the fifth
An embodiment will be described. FIG. 8 relates to the present embodiment.
Schematically shows the overall configuration of the power source system S5.
And has the same function as the power source system S1 described above.
The same reference numerals are given to the components having.

The characteristic structure of the present system S5 is that the SOF
The internal combustion engine 150 is disposed on the fuel chamber outlet side of C3, and a path Cf is provided between the intake path Cf8 and the fuel chamber outlet passage 37.
9 is connected. Further, the internal combustion engine 150, the reciprocating reformer 1, the gearbox 10, and the SOF
A power transmission path Cr3 is formed between the compressor 7 for supplying air to the air chamber 33 of C3. A fuel supply path Cf7 is connected to the intake path Cf8, and a reference symbol Cf10 in the figure indicates an exhaust path from the internal combustion engine 150.

FIG. 9 shows a cross-sectional view of the reciprocating reformer 1 and the internal combustion engine 150 in the present system S5, and also shows a connection state with peripheral elements. Although the reciprocating reformer 1 and the internal combustion engine 150 may be separate bodies, the crankshafts are made coaxial as in the case of the reciprocating reformer 1 and the internal combustion engine 100 in the power source system S4. , Formed in an integral cylinder. Reference numeral 161 denotes a piston of the internal combustion engine 150 connected to the crankshaft via a connecting rod.

When the ECU 200 determines that the SOFC 3 is in the warm-up operation based on the detection signal from the temperature sensor 210 installed in the SOFC 3, the ECU 200 supplies the open period of the fuel supply valve device 21 to the reciprocating reformer 1. Is set so that the air-fuel mixture to be obtained has the stoichiometric air-fuel ratio. At this time, the combustion product gas discharged from the reciprocating reformer 1 is used exclusively for heating the SOFC 3 and the heat exchanger 6.

Then, the exhaust gas from the fuel chamber 32 of the SOFC 3 (which contains a large amount of unreacted fuel gas which has been reformed) joins the intake path Cf8 of the internal combustion engine 150 via the path Cf9. . The internal combustion engine 150 is mainly composed of SO
At times other than the warm-up operation of FC3, the unreacted fuel gas contained in the exhaust gas is driven as fuel. Here, the air-fuel ratio of the gas supplied to the internal combustion engine 150 depends on the exhaust path C
It is preferable that the nitrogen oxide (NO _x ) contained in the exhaust gas to f10 is lean enough to be less than or equal to a predetermined value.
U200 controls a valve device (not shown) provided in intake path Cf8 to adjust the intake air amount.

Further, a condition that the air contained in the exhaust gas from the fuel chamber 32 of the SOFC 3 does not satisfy the amount required for combustion of the internal combustion engine 150 (such a condition tends to be satisfied during normal power generation) )), A combustible air-fuel mixture is formed by controlling the valve device of the intake path Cf8 to take in air. As described above, according to the present system S5, the energy of the unreacted fuel gas discharged from the SOFC 3 can be recovered, and the efficiency of the system can be improved.

At the time of starting the system, at the time of transition, and at the time of high load, the fuel supply valve device 110 provided at the connection between the fuel supply path Cf7 and the intake path Cf8 is operated.
By also supplying raw fuel to the internal combustion engine 150, SO
The shortage of power generation of FC3 can be compensated for by increasing the output of internal combustion engine 150. In the above description, steam is obtained by heat exchange between the combustion product gas and water. However, as another method, water is generated by heat obtained by burning unreacted fuel gas discharged from the fuel chamber of the SOFC 3. May be vaporized.

In this specification, the term “stoichiometric air-fuel ratio”
The term “not only includes the strict stoichiometric air-fuel ratio, but also includes an air-fuel ratio close to the stoichiometric air-fuel ratio as long as the object of the present invention can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a power source system according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a reciprocating reformer in the power source system.

FIG. 3 is a configuration diagram of an SOFC (Solid Oxide Fuel Cell)

FIG. 4 is a configuration diagram of a power source system according to a second embodiment of the present invention.

FIG. 5 is a specific configuration diagram of a reciprocating reformer and an air supply compressor in a power source system according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a power source system according to a fourth embodiment of the present invention.

FIG. 7 is a specific configuration diagram of a reciprocating reformer in the power source system and an internal combustion engine coaxial therewith;

FIG. 8 is a configuration diagram of a power source system according to a fifth embodiment of the present invention.

FIG. 9 is a specific configuration diagram of a reciprocating reformer in the power source system and an internal combustion engine coaxial therewith;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 reciprocating reformer 3 SOFC (solid oxide fuel cell) 5 fuel mixing chamber 6 heat exchanger 7 compressor 8 electric motor 9 object to be driven 10 gearbox 100 internal combustion engine 150 Internal combustion engine Cf1 Air intake path Cf2 Fuel supply path Cf3 Combustion gas distribution path Cf4 Water vapor supply path Cf5 Exhaust path Cf6 Air distribution path Cf7 Fuel supply path Cf8 Intake path Cf10 Exhaust path Ce Power transmission Path Cd: Power transmission path Cr: Power transmission path

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Komatsu Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Wabiko 2nd Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture F Nissan Motor Co., Ltd. Terms (reference) 5H026 AA06 5H027 AA06 BA01 BA09 BA20 BC20

Claims (17)

[Claims] 1. A first internal combustion engine that uses a hydrocarbon-based raw fuel as a fuel and switches between a stoichiometric air-fuel ratio and an operation in which the fuel is richer than the stoichiometric air-fuel ratio, and a combustion product gas of the first internal combustion engine And a solid oxide fuel cell that receives fuel on the fuel electrode side. 2. The power source system according to claim 1, wherein the first internal combustion engine operates at a stoichiometric air-fuel ratio during a warm-up operation of the solid oxide fuel cell. 3. The power source system according to claim 2, wherein during the warming-up operation, the rotational power by the first internal combustion engine is output. 4. The power source system according to claim 1, further comprising a steam supply device for supplying steam or water to said first internal combustion engine. 5. The solid oxide fuel cell according to claim 1, wherein the first internal combustion engine drives an air supply device connected to an air electrode of the solid oxide fuel cell. Power source system. 6. The air supply device is a reciprocating compressor,
The power source system according to claim 5, wherein the drive shaft is connected to an output shaft of the first internal combustion engine. 7. The power source system according to claim 6, wherein the reciprocating compressor includes a second internal combustion engine switchable to non-combustion operation. 8. The power source system according to claim 7, wherein an exhaust port of the second internal combustion engine is connected to an air chamber inlet of the solid oxide fuel cell. 9. The power source system according to claim 8, wherein the second internal combustion engine performs a combustion operation during a warm-up operation of the solid oxide fuel cell. 10. The power source according to claim 1, wherein a third internal combustion engine is provided, and an intake port thereof is connected to a fuel chamber outlet of the solid oxide fuel cell. system. 11. The power source system according to claim 10, wherein an output shaft of said third internal combustion engine is connected to an output shaft of said first internal combustion engine. 12. The power source system according to claim 10, wherein a fuel supply device for supplying the hydrocarbon-based raw fuel to the third internal combustion engine is provided. 13. The fuel supply device according to claim 12, wherein the fuel supply device supplies the hydrocarbon-based raw fuel under at least one of a start-up condition, a transient condition, and a high load condition. Power source system. 14. A power source system comprising: reformed gas generating means; and a solid oxide fuel cell for receiving the reformed gas generated by said means on a fuel electrode side, wherein The gas generating means generates reformed gas containing hydrogen and carbon monoxide as main components by combustion under excess fuel, and switches to combustion at a stoichiometric air-fuel ratio under predetermined conditions. Source system. 15. The power source system according to claim 14, wherein the predetermined condition is a time of a warm-up operation of the solid oxide fuel cell. 16. The apparatus according to claim 14, wherein said reformed gas generating means is a reciprocating reformer, and outputs rotational power by said reformer during said warm-up operation. Power source system. 17. In a normal state, a reformed gas containing hydrogen and carbon monoxide as main components is generated by combustion under excess fuel, and the generated reformed gas is supplied to a fuel electrode of a solid oxide fuel cell. On the other hand, a method for warming up a solid oxide fuel cell in a power generation system using the solid oxide fuel cell, wherein the combustion is controlled at a stoichiometric air-fuel ratio during the warm-up operation of the solid oxide fuel cell.