JP3282695B2 - Fuel cell power generation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten carbonate fuel cell power generation system.

[0002]

2. Description of the Related Art A conventional molten carbonate fuel cell power generation system has, for example, a configuration as shown in FIG.
In FIG. 4, 31 is a fuel cell, 32 is a fuel pressurizing blower, 33 is a fuel preheater, 34 is a reformer, 35 is an exhaust gas turbine, 36 is an air compressor, 37 is a high-temperature blower, 38 is a carbon dioxide gas recycle blower, 39 is a cathode exhaust gas line, 40 is a cathode gas recycle line, 41 is a cathode inlet line, 42 is an anode exhaust gas line, 43 is an anode inlet line, 44 is a fuel supply line, and 45 is a reformer vapor supply line.

That is, in the molten carbonate fuel cell power generation system, the high temperature blower 37 is
It is an indispensable component device for controlling the temperature and supplying carbon dioxide necessary for the battery reaction.

[0004]

However, the high-temperature blower 37 of the fuel cell power generation system shown in FIG. 4 has a special design because it handles high-temperature gas at 600 to 700 ° C., thereby increasing the plant cost. In addition, there is a problem that an air source or an inert gas supply source for the shaft seal is required, and the power thereof reduces the plant efficiency.

[0005] The present invention is to solve the above problems. That is, the present invention can use a commercially available blower by lowering the temperature of the high-temperature blower, which is a factor of high plant cost and low plant efficiency, and eliminates the need for the power of the shaft seal. It is an object of the present invention to provide a fuel cell power generation facility that exhibits high efficiency at a low cost.

[0006]

In order to achieve the above object, the present invention relates to a molten carbonate fuel cell power generation facility, comprising an air preheater for lowering the temperature of a high-temperature cathode exhaust gas, and A low-temperature blower that feeds the gas , whose temperature has been lowered by the heater, to the air preheater in order to raise the temperature again in the air preheater and recycle the gas as a cathode inlet gas , between the exhaust gas outlet of the cathode and the air preheater. To
Having a reformer and discharged from an exhaust gas outlet of the cathode electrode.
Hot cathode exhaust gas discharged from the combustion chamber of the reformer
After reducing the temperature of the exhaust gas with the cathode preheater
The pipes are joined so as to be joined and guided to the inlet side of the low-temperature blower.
It was assumed. Or with the cathode exhaust gas outlet
A reformer is provided between the air preheaters to exhaust the cathode.
Hot cathode exhaust gas and anode discharged from the outlet
The anode exhaust gas discharged from the exhaust gas outlet of the
After mixing in a mixer, it is led to the combustion chamber of the reformer,
The cathode exhaust gas discharged from the combustion chamber of the reformer is supplied to the air preheater.
So that it is guided to the inlet side of the low-temperature blower
It was assumed that it was plumbed .

[0007]

According to the present invention, in a molten carbonate fuel cell power generation facility, an air preheater for lowering the temperature of a high-temperature cathode exhaust gas is provided, and the gas cooled by the air preheater is supplied to the air preheater. in by high temperature re cathode inlet gas comprising a Kyusuru cold blower feeding the air preheater in order to recycle as, for cathode waste gas outlet and the air preheater
With a reformer between the reactor and exhaust gas outlet of the cathode
High temperature cathode exhaust gas discharged from the furnace and combustion of the reformer
The cathode exhaust gas discharged from the chamber is cooled down by the air preheater.
So that it joins and leads to the inlet side of the low-temperature blower.
Plumbing or exhaust gas outlet at cathode
A reformer between the air preheater and the
The hot cathode exhaust gas discharged from the gas outlet and the anode
The anode exhaust gas discharged from the exhaust
After mixing with a gas mixer, the mixture is led to the combustion chamber of the reformer,
The cathode exhaust gas discharged from the combustion chamber of the reformer is preheated to the air.
So that it is guided to the inlet of the low-temperature blower
The blower handles low-temperature gas, so that it is not necessary to use an expensive specially designed blower, thereby achieving a reduction in plant cost and an increase in efficiency. In addition, since the cathode inlet gas is recycled after being heated to a high temperature, a decrease in power generation efficiency can be avoided.

[0008]

FIG. 1 shows an embodiment of the present invention. FIG.
1, 1 is a fuel cell having a cathode C and an anode A, etc., 2 is an air preheater such as a plate-type exchanger, 3 is a low-temperature blower described below, 4 is a condenser, 5 is a steam separator, 6 is A carbon dioxide recycle blower, 7 a heater for starting, 8 a fuel pressurizing blower, 9 a fuel preheater, 10 a reformer having a reforming chamber Re and a combustion chamber Co, 11
Is an exhaust gas turbine, 12 is an air compressor, 13 is an electric blower, 14 is a startup hot air supply line, 15 is a fuel supply line, 16 is a reforming steam supply line, 17 is a cathode exhaust gas line, 18 is an anode exhaust gas line, 19 Is a cathode inlet line, 20 is an anode inlet line, 21 is a first branch line of cathode exhaust gas, 22 is a second branch line of cathode exhaust gas, 23 is a gas outlet line of a reformer combustion chamber, 24 is a turbine exhaust line, and 25 is an air line. , 26 denotes a first low-temperature gas line, 27 denotes a second low-temperature gas line, 28 denotes an air supply line, and 29 denotes a third low-temperature gas line.

In the fuel cell power generation system configured as shown in FIG. 1, the air preheater 2 and the low-temperature blower 3 will be mainly described.
Of the cathode exhaust gas from the reactor enters the combustion chamber Co of the reformer 10 through the cathode exhaust gas first branch line 21,
Air preheater 2 through reformer combustion chamber gas outlet line 23
Will be introduced. The temperature of the introduced gas is 750 ° C., the heat is taken off by the air preheater 2, the temperature is reduced to 110 ° C., and the gas reaches the first low-temperature gas line 26.

A part of the cathode exhaust gas from the cathode exhaust gas line 17 is supplied to the cathode exhaust gas second branch line 2.
2 to the air preheater 2. The temperature of the introduced gas is 700 ° C., the heat is taken off by the air preheater 2, the temperature is reduced to 110 ° C., and the gas reaches the second low-temperature gas line 27. The gas whose temperature has been lowered in this manner is mixed with air from the air supply line 28, carbon dioxide from the carbon dioxide gas recycle blower 6, and the like, and further cooled to 80 ° C., and the low temperature blower 3 uses the mixed gas at 80 ° C. as an air preheater. Send to 2. Then, the mixed gas in the air preheater 2 is 570 ° C.
, And is recycled to the cathode C of the fuel cell 1 through the cathode inlet line 19.

In this way, a low-temperature blower 3 such as a commercial product can be used without using an expensive specially designed high-temperature blower, thereby reducing plant cost, making the plant more compact, and increasing the efficiency of the plant. Can be achieved.

FIG. 2 shows a second embodiment of the present invention.
2, 1 to 5, 7 to 21, and 23 to 25 are the same as those in FIG. Reference numeral 30 denotes a gas mixer for mixing the gas from the cathode exhaust gas first branch line 21 and the gas from the anode exhaust gas line 18, and the premixed gas can stabilize the catalytic combustion in the reformer 10. That is, the mixture is maintained within the explosion limit due to the presence of a large amount of cathode gas.

In this second embodiment, the cathode exhaust gas
The branch line 22 is eliminated, and the gas of 700 ° C. flows into the air preheater 2 from the reformer combustion chamber gas outlet line 23,
It is cooled down to 110 ° C. and reaches the second low-temperature gas line 27. The low-temperature blower 3 handles gas at 80 ° C., and the gas is heated to 570 ° C. by the air preheater 2 and recycled to the cathode C of the fuel cell 1.

Therefore, also in the second embodiment,
Functions and effects similar to those of the first embodiment are provided.

FIG. 3 shows a third embodiment of the present invention.
The third embodiment differs from the above-described second embodiment only in a part of the configuration, and there is no particular difference. Therefore, detailed description is omitted.

[0016]

As described above, according to the present invention,
In the molten carbonate fuel cell power generation equipment, an air preheater for lowering the temperature of the high-temperature cathode exhaust gas is provided, and the gas cooled at the air preheater is heated again at the air preheater to form a cathode inlet gas. A low-temperature blower that feeds the air preheater for recycling, so that the blower handles cold gases,
It is not necessary to use an expensive specially designed blower, so that plant cost can be reduced and the size can be reduced, and high efficiency can be achieved. In addition, since the cathode inlet gas is recycled after being heated to a high temperature, a decrease in power generation efficiency can be avoided.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing a second embodiment of the present invention.

FIG. 3 is an overall configuration diagram showing a third embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an example of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Air preheater 3 Low temperature blower 10 Reformer 17 Cathode exhaust gas line 19 Cathode inlet line

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 8/04 H01M 8/06

Claims (2)

(57) [Claims] 1. An apparatus for generating electricity from a molten carbonate fuel cell, comprising an air preheater for lowering the temperature of a high-temperature cathode exhaust gas, and raising the temperature of the gas cooled by the air preheater again by the air preheater. A low-temperature blower is supplied to the air preheater to be recycled as a cathode inlet gas, and a reformer is provided between the exhaust gas outlet of the cathode and the air preheater.
High temperature discharged from the exhaust gas outlet of the cathode electrode
Cathode exhaust gas and cathode from the combustion chamber of the reformer
After the exhaust gas and the air preheater are cooled down,
A fuel cell power generation facility, which is piped so as to lead to the inlet of the low-temperature blower . 2. A molten carbonate fuel cell power generation facility,
Equipped with an air preheater that lowers the temperature of the hot cathode exhaust gas,
The gas cooled by the air preheater is supplied to the air preheater.
The temperature is raised again by a heater and recycled as cathode inlet gas.
A low-temperature blower that feeds the air preheater to
Equipped with a reformer between the exhaust gas outlet of the cathode and the air preheater.
High temperature discharged from the exhaust gas outlet of the cathode electrode
Exhausted from cathode exhaust gas and anode exhaust gas outlet
After mixing the exhaust gas with the anode exhaust gas with a gas mixer.
Cascade from the combustion chamber of the reformer
After the exhaust gas is cooled to a low temperature by the air preheater,
It is characterized by being piped to lead to the inlet side of the blower
Fuel cell power plant to be.