JPH0896827A - Solid electrolytic fuel cell module - Google Patents

Abstract

PURPOSE: To provide a solid electrolytic fuel cell module with excellent power generating and high durability by supplying air in series to each cell tube separated with a separation wall through a regenerative heat exchanger. CONSTITUTION: A power generating chamber 3 is divided into power generating chambers 3a, 3b, 3c by separation walls 9 each separates two cell tubes 4. Air 7 introduced into a regenerative heat exchanger 10c through a supply pipe 11 from the outside is heated by high temperature exhaust air 8 exhausted from an exhaust pipe 6 of the power generating chamber 3c and introduced into a regenerative heat exchanger 10b. Similarly, the air 7 heated by the regenerative heat exchanger 10b is further heated by the regenerative heat exchanger 10a, and introduced into the power generating chamber 3a. The air introduced into the power generating chamber 3a rises along the outer circumferential surface of a cell tube 4, supplied to an air electrode, and unused supply air 7 is heated, then exhausted from the power generating chamber 3a through the exhaust pipe 6 as the exhaust air 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is installed in a power generation room,
The present invention relates to a solid oxide fuel cell module having an air supply structure in which air supplied to the air electrodes of a plurality of cell tubes forming a solid oxide fuel cell (SOFC) is made to flow in series (cascade).

[0002]

2. Description of the Related Art FIG. 2 is a schematic structural diagram of a conventional solid oxide fuel cell module. In the figure, 01 is an outer wall that constitutes a solid oxide fuel cell module, 02 is a heat insulating material stretched inside the outer wall 01, 03 is a cell tube that forms an SOFC, and each element is combined with a ceramic thin film to form a concentric circle. Fuel electrode inside and outside the tube
An electrolyte and an air electrode are provided, and a fuel passage and an air passage 011 (not shown) are provided in the fuel electrode and the air electrode.
It is hung inside 4.

Reference numeral 05 denotes an exhaust pipe vertically provided between a plurality of suspended cell tubes 03. Of the supply air 07 supplied to the air electrode arranged outside the cell tube 03, unused supply air is supplied. 07 absorbs the high temperature generated by the cell tube 03, becomes exhaust air 08, and is discharged from the power generation chamber 04. Reference numeral 06 denotes an air-side regenerative heat exchanger, which has an inlet communicating with an air pipe 09 for supplying air from the outside and a cell tube 0.
3, an air flow path having an outlet communicating with an air passage 011 outside, an inlet communicating with an exhaust pipe 05, and an exhaust air pipe 01
An exhaust passage having an outlet communicating with 0, an air passage 0
Heat exchange is performed between the supply air 07 flowing into 11 and the exhaust air 08 passing through the exhaust passage.

In the power generation chamber 04 of such a self-supporting solid oxide fuel cell module, when the fuel in the cell tube 03 reacts with the supply air 09 to generate power, the self-heating causes an operation of about 1000 ° C. Hold at temperature. In addition, the supply air 0 preheated in the air side regeneration heat exchanger 06
Not only 7 is used for the reaction with the fuel, but the unused supply air 07 that is not used for the reaction removes heat from the cell tube 03 inside the power generation chamber 04, thereby overheating the cell tube 03. To prevent. Further, the exhaust air 08 heated by the power generation unit 04 is supplied to the power generation unit 04 by the exhaust pipe 05.
After being exhausted from the exhaust gas, the regenerative heat exchanger 06 cools the supply air 07 by preheating, and then the exhaust air pipe 010 discharges it to the outside. The thermal energy contained in the exhaust air 08 from the exhaust air pipe 010 is used as a heat source in the exhaust heat recovery cycle.

However, in the solid oxide fuel cell module configured as described above, heat exchange is performed in one pass of the air side regenerative heat exchanger 06, so it is difficult to control the flow rate of the supply air supplied to the air electrode. There's a problem. That is, the supply air 07 supplied from the air pipe 09 is divided into three parts, and 1/3 of the supply amount is preheated by the regenerative heat exchanger 06 and supplied to the outer peripheral surface of the cell tube 03. , It is difficult to distribute evenly because of the difference in arrangement. On the other hand, when the flow rate of the supply air 07 from the air pipe 09 is small in the solid oxide fuel cell module, the temperature rise of the exhaust air 08 in the power generation unit 04 becomes large, and the temperature of the exhaust air 08 rises, so that the downstream portion There is a problem that the temperature of the cell tube 03 rises and is overheated more than necessary. Since the overheating of the cell tube 03 affects the performance and durability of the device including the cell tube 03, it is necessary to increase the flow rate of the supply air 07 in order to suppress the air temperature on the downstream side.

However, when the flow rate of the supplied air 07 from the air tube 09 is large, the self-heating amount of the cell tube 03 is constant (when the power generation efficiency is constant), so the heating temperature by the regenerative heat exchanger 06 becomes small and the upstream The temperature of the supply air supplied to the air electrode of the side cell tube 03 is lowered, and the power generation performance is deteriorated.

Further, an increase in the air flow rate causes an increase in auxiliary machine power and air exhaust heat, resulting in a problem that the system efficiency is lowered. Further, when the solid oxide fuel cell module becomes large in size, a large number of heat exchangers 06 and exhaust air pipes 01 are provided in order to make the air flow in the power generation chamber 05 uniform.
If 0 is provided and the uneven distribution of air flowing in the power generation chamber 05 is not corrected, a local temperature distribution is generated in the power generation chamber 04, which adversely affects power generation characteristics and durability.

[0008]

Therefore, according to the present invention, the total amount of supply air flowing through the plurality of cell tubes installed in the power generation section is the same, and the flow rate through each cell tube is large and even. An object of the present invention is to provide a solid oxide fuel cell module having excellent power generation characteristics and durability by reducing the temperature change of supply air while flowing through a cell tube.

[0009]

Therefore, the solid oxide fuel cell module of the present invention has the following means. A solid oxide fuel cell module is configured, a partition wall for partitioning the cell tubes is provided in a power generation chamber in which a plurality of cell tubes are installed, and an air-side regenerative heat exchanger is provided in each of the partitioned power generation chambers. The supply air supplied to each cell tube is made to flow in a cascade through a plurality of cell tubes. Incidentally, the partition may partition a single cell tube, or may partition two cell tubes sharing an exhaust pipe as shown in the embodiment, and further,
It may be provided so as to divide many cell tubes.

[0010]

The supply air is heated by the cell tube in the divided power generation chamber. The air-side regenerative heat exchanger attached to each power generation chamber cools the supply air at the outlet of the power generation chamber by heat exchange with the supply air to equalize the temperature of the supply air at the inlet of each power generation chamber. As a result, the supply air having a temperature that improves the power generation efficiency of the cell tube is supplied to the air electrode of the cell tube and does not become overheated supply air that impairs durability. In addition, since the temperature distribution in the power generation section is made uniform, uniform power generation is performed efficiently in each cell tube, and a highly efficient solid oxide fuel cell module is obtained.

[0011]

EXAMPLES The solid oxide fuel cell module of the present invention will be described below based on examples. FIG. 1 is a schematic structural diagram showing one embodiment of the solid oxide fuel cell module of the present invention. In the figure, 1 is an outer wall constituting a solid oxide fuel cell module, 2 is a heat insulating material attached inside the outer wall 1, and 3 is a power generation chamber defined inside the outer wall 1. The power generation chamber 3 is divided into power generation chambers 3a, 3b, 3c by a partition wall 9 that partitions two cell tubes 4 described later. A cylindrical cell tube 4 is provided so as to hang down from the top of each power generation chamber 3a, 3b, 3c. On the outer periphery of each cell tube 4, the outer peripheral surface of the cell tube 4 is provided with electronically conductive ceramics LaCoO 2.
₃ , an air passage 5 of supply air 7 to be supplied to the air electrode is formed of a thin film of LaMnO ₃ or the like.

In addition, an exhaust pipe 6 having an opening at the upper end of the suspended cell tube 4, that is, the wake end is vertically provided in each of the power generation chambers 3a, 3b, 3c, and extends from the lower end of the cell tube 4. Introduced, the air passage 5 on the outer peripheral surface of the cell tube 4
The unused exhaust air 8 that does not react in the cell tube 4 is discharged from the power generation chambers 3a, 3b, 3c among the supply air 7 rising.

Further, below the respective power generating chambers 3a, 3b, 3c, there are provided a flow path for the supply air 7 and a flow path for the exhaust air 8, respectively, and when rising along the outer peripheral surface of the cell tube 4,
Regeneration heat exchanger 10 for preheating supply air 7 with exhaust air 8 overheated by self-heating of cell tube 4.
a, 10b, 10c are provided. Supply air 7 introduced into the regenerative heat exchanger 10c through a supply pipe 11 from the outside
Is heated by the high temperature exhaust air 8 discharged from the exhaust pipe 6 of the power generation chamber 3c and introduced into the regenerative heat exchanger 10b. Similarly, the supply air 7 heated by the regenerative heat exchanger 10b is further heated by the regenerative heat exchanger 10a, and is supplied to the power generation chamber 3
It is introduced into a.

The supply air 7 introduced into the power generation chamber 3a rises on the outer peripheral surface of the cell tube 4 to supply the supply air 7 to the air electrode, and the unused supply air 7 is heated and exhausted air 8 Is discharged from the power generation chamber 3a by the exhaust pipe 6 and introduced into the exhaust passage of the regenerative heat exchanger 10a. Exhaust air 8 is regenerated heat exchanger 10a, as described above,
The supply air 7 is cooled by preheating the supply air 7
Then, it is introduced into the power generation room 3b. Heating in the same way,
The cooling is repeated, and the cell tube 4 reacts with the fuel to generate electricity. Even if the exhaust air 8 that has not passed through the outer peripheral surface of the cell tube 4 installed in the power generation chamber 3c passes from the exhaust pipe 6 to the regenerative heat exchanger 10c to preheat the supply air 7, the solid electrolyte It is discharged from the fuel cell module to the outside and used for the power required for the plant.

As described above, in this embodiment, the power generation chamber 3 has three
It is divided into paths. Therefore, the flow rate of the air flowing through each path is three times that in the case without division. In addition, power generation room 3
The exhaust air 8 from a is cooled by the regenerative heat exchanger 10a and then supplied as supply air 7 to the power generation chamber 3b. The same applies to the power generation chambers 3b and 3c. FIG. 3 shows temperature profiles of the supply air 7 and the exhaust air 8. As shown in the figure, in this embodiment, 1
The rise in the air temperature in the power generation chamber 3 can be suppressed to about 1/3 of the rise in the temperature during the pass.

Further, each regenerative heat exchanger 10a, 10b, 1
0c and each of the power generation chambers 3a, 3b, 3c are connected in series, and no flow rate imbalance occurs. Further, the temperature of the exhaust air 8 from the regenerative heat exchanger 10c after the regenerative heat recovery is higher than that in the case of one pass, and the efficiency of the exhaust heat recovery cycle installed in the downstream of the exhaust air pipe 12 is increased. Is possible.

[0017]

As described above, according to the solid oxide fuel cell module of the present invention, the air having a temperature that improves the power generation efficiency of the cell tube is the air of the cell tube due to the configuration described in the claims. The air is supplied to the entire pole and does not become overheated air that impairs the durability of the cell tube or the like. In addition, since the temperature distribution in the power generation unit is made uniform, uniform and efficient power generation can be performed in each cell tube.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram showing an embodiment of a solid oxide fuel cell module of the present invention,

FIG. 2 is a schematic structural diagram showing a conventional solid oxide fuel cell module,

FIG. 3 is a diagram showing a temperature profile of air in the embodiment shown in FIG.

[Explanation of symbols]

 1 Outer Wall 2 Heat Insulating Materials 3, 3a, 3b, 3c Power Generation Chamber 4 Cell Tube 5 Air Passage 6 Exhaust Pipe 7 Supply Air 8 Exhaust Air 9 Partition Walls 10a, 10b, 10c Regenerative Heat Exchanger 11 Supply Pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Nagata 1-1, Atsunouramachi, Nagasaki City Mitsubishi Heavy Industries Ltd. Nagasaki Shipyard Co., Ltd.

Claims (1)

[Claims] 1. A solid oxide fuel cell module for maintaining an operating temperature by self-heating of a cell tube installed in a power generation chamber for generating power, wherein a partition wall for partitioning the plurality of cell tubes installed in the power generation chamber is provided. The solid electrolyte fuel cell module is characterized in that the supply air supplied to the cell tubes flows in cascade to each of the cell tubes separated by the partition wall via a regenerative heat exchanger.