JPH0547402A - Fuel cell power generation apparatus - Google Patents

Abstract

PURPOSE:To make a phosphoric acid-type fuel cell power generation device of small size and make it possible to set the device in a small installation space. CONSTITUTION:All of a fuel cell I, which is a main component apparatus of a phosphoric acid-type fuel cell power generation apparatus, a reforming apparatus 5, a heat-exchanger 7, and a shift converter 6 are so made as to have a plate structure. The reforming apparatus 5, the heat-exchanger 7, a shift converter 6, and a fuel cell are stacked in the same pile to make the stacked body like one package. Since each component apparatus I, 5, 6, 7 neighbor each other by stacking, piping work to connect them mutually becomes easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation device for a phosphoric acid fuel cell, which uses an aqueous phosphoric acid solution as an electrolyte, among fuel cells used in the energy sector for directly converting chemical energy of fuel into electric energy. is there.

[0002]

2. Description of the Related Art A phosphoric acid fuel cell has been researched and developed as a first-generation fuel cell, and has come into practical use.

In this phosphoric acid fuel cell, as shown schematically in FIG. 5, an electrolyte plate 1 impregnated with a phosphoric acid aqueous solution as an electrolyte is sandwiched between an air electrode 2 and a fuel electrode 3 from both sides to form a cell. A large number of cells are stacked via a separator 4 to form a stack, and the air electrode 2 and the fuel electrode 3 are further stacked.
When the hydrogen gas H ₂ is supplied to the fuel electrode 3 as the fuel gas FG, the catalyst is dispersed and supported on the fuel electrode 3
On the side, the reaction of H ₂ → 2H ⁺ + 2e ⁻ is carried out, hydrogen releases electrons and becomes hydrogen ions, and the hydrogen ions 2H ⁺ pass through the electrolyte plate 1 and the air electrode 2
And the electron 2e ⁻ moves to the cathode 2 through the external circuit. On the other hand, in the air electrode 2, the oxygen supplied to the air electrode 2 receives the electron 2e ⁻ and reacts with the hydrogen ion 2H ⁺ , that is, the reaction of 2e ⁻ +1/2 O ₂ + 2H ⁺ → H ₂ O occurs. It becomes water H ₂ O, and the air electrode 2 and the fuel electrode 3
DC electricity is generated between them.

Conventionally, as a power generation system using the phosphoric acid fuel cell, there is a system configuration as shown in FIG. Since carbon monoxide CO is a poisoning substance for the catalyst supported on the fuel electrode 3 of the phosphoric acid fuel cell I, a shift converter (carbon monoxide transformer) for reducing CO in the fuel gas to 1% or less. ) 6 is installed on the upstream side of the fuel electrode 3 of the fuel cell I. Further, as shown in the relationship between the outlet temperature of the gas transformed by the shift converter 6 and the amount of CO in FIG. Since it is necessary to lower the gas outlet temperature of the shift converter 6 to 250 ° C. or lower in order to suppress the temperature to below, the temperature (700 ° C.) obtained in the reformer 5 is lowered to the shift converter operating temperature of 250 ° C. or lower. Is installed between the reformer 5 downstream side and the shift converter 6 upstream side, for example, when city gas TG is used as fuel, the city gas TG is used as the heat exchanger. Preheated at 7, When the heat is taken by the shift converter 6 and introduced into the reforming chamber of the reformer 5, the high-temperature fuel gas FG which is reformed and reformed here is converted by the heat exchanger 7 into the shift converter 6. After the temperature is lowered to the operating temperature, it is introduced into the shift converter 6, and the CO concentration is suppressed to 1% or less and supplied to the inlet of the fuel electrode 3 of the fuel cell I. The gas discharged from the fuel electrode 3 is
The gas sent from the air electrode 3 is sent to the combustion chamber of the reformer 5 and burned in the combustion chamber.
Is discharged to the atmosphere together with the combustion exhaust gas discharged from the combustion chamber of the fuel cell I. Further, in the cooling unit 8 of the fuel cell I, a steam separator 9, a cooling water circulation pump 10, and a heat treatment heat exchanger 11 are provided on the way. The cooling water circulation line 12 is provided so that the water H ₂ O treated by the water treatment device 13 can be supplied to the cooling water circulation line 12 by the water supply pump 14, and a part of the circulating cooling water is heated by the heat. The gas component separated by the steam / water separator 9 is returned to the steam / water separator 9 through the lower side of the exchanger 7, and the gas component separated by the steam / water separator 9 is converted from the steam superheater on the upper side of the heat exchanger 7 into steam by the steam line 15. It can be supplied to the upstream side of the reformer 5. Reference numeral 16 is a refrigerant circulation line for supplying a refrigerant to the heat treatment heat exchanger 11, and is provided with a refrigerant circulation pump 17, a water recovery condenser 18, an exhaust heat recovery heat exchanger 19, a dry cooling tower facility 20, and the like. Reference numeral 21 is a water tank for storing the water in the exhaust gas condensed by the water recovery condenser 18 and guiding it to the water treatment device 13. Reference numeral 22 is a direct current generated between the fuel electrode 3 and the air electrode 2 of the fuel cell I. It is an inverter that outputs electricity as an alternating current.

[0005]

However, although it is expected that the fuel cell power generation device will be installed in towns such as hotels, hospitals, and apartment houses in the future, the conventional phosphoric acid fuel cell described above is used. In the case of a power generation system, since the fuel cell I, the reformer 5, the heat exchanger 7, and the shift converter 6 are separately installed, a wide space is required at the installation location and the above-mentioned components There are problems such as complicated piping for connecting the two and a large amount of heat dissipation loss.

[0006] Therefore, the present invention aims to provide a phosphoric acid fuel cell power generator in which the components which have been separately installed conventionally are compactly put together and the piping is easy and the heat radiation loss is small.

[0007]

In order to solve the above problems, the present invention is formed by filling a reforming chamber formed by filling a reforming catalyst on a plate and a combustion catalyst on a plate. The combustion chamber is superposed and integrated, the air supply port and the fuel introduction part are provided in the combustion chamber, the combustion exhaust gas outlet is provided, and the reforming source gas inlet and the fuel gas outlet are provided in the reforming chamber. A plate-type reformer provided, a plate-type shift converter having a shift reaction section filled with a shift reaction catalyst and a gas preheating section for cooling the shift reaction section, and a separator for separating the high-temperature fluid passage and the low-temperature fluid passage from each other. The plate-type heat exchanger and the plate heat exchanger, which are stacked alternately, are laminated in the same pile, and the reforming chamber inlet of the reformer and the low temperature side outlet of the heat exchanger, the reforming chamber outlet and the high temperature side inlet, the shift converter shift The reaction part inlet and the high temperature side outlet of the heat exchanger, Gas preheating portion of the shift converter and reformer combustion chamber inlet and the respectively connected, a configuration in which the outlet of the shift reaction unit was connected to the fuel electrode inlet of the fuel cell. In addition, a fuel cell having a structure in which an electrolyte plate is sandwiched between a fuel electrode and an air electrode from both sides and cells including a cooling unit are stacked to form a stack, and the fuel electrode of the fuel cell and a shift converter are connected Then, the whole is put in a container.

[0008]

The reformer, the heat exchanger, and the shift converter are all plate-shaped so that they can be easily stacked, and they are stacked and packaged in the same pile, so that compactness can be achieved. Since the devices are adjacent to each other by stacking, the piping is easy and the heat radiation loss can be reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which the reformer 5, the heat exchanger 7 and the shift converter 6 are each formed in a plate shape so that they can be stacked easily and the heat transfer area per unit volume is large. Change to a larger device and stack them on the same pile. That is, as in the case of FIG. 6, a fuel having a configuration in which cells, which are sandwiched between an electrolyte plate 1 impregnated with a phosphoric acid aqueous solution and an air electrode 2 and a fuel electrode 3 in a sandwich form, are stacked in multiple layers via a separator to form a stack. In the power generator using the battery I, since the reformer 5, the heat exchanger 7, and the shift converter 6 have a plate structure, the reformer 5 is provided with the reforming catalyst 23.
To form a plate type reformer having a structure in which a reforming chamber 5a formed by filling the plate with a combustion catalyst 24 and a combustion chamber 5b formed by filling the plate with the combustion catalyst 24 are laminated to form a reforming chamber 5a. The raw material gas can be supplied, the air and the fuel can be supplied to the combustion chamber 5b, and the reforming raw material gas is reformed by the endothermic reaction and discharged from the reforming chamber 5a.
Exhaust gas shall be emitted from.

FIG. 2 shows an external manifold type as an example of the plate-shaped reformer 5, in which a reforming source gas supply port and a reforming gas discharge port are cut out on a plate member 25. The mask frame 26 is installed in the periphery, and a partition member 27 having a large number of concavities and convexities continuously formed on the upper and lower surfaces is integrally attached to opposite sides, and the plate member 25 has the same height as the mask frame 26. The small columnar spacer member 28 is attached, and the reforming catalyst 23 is filled between the partition members 27 to form the reforming chamber 5a. Similarly, the mask frame 26 is installed by cutting out the air supply port and the exhaust gas discharge port around the plate member 25, and the partition member 27 and the spacer 28 similar to the above are integrally mounted, and further,
A large number of dispersion holes 29 are formed in the plate member 25 between the partition members 27.
And is filled with the combustion catalyst 24 to form the combustion chamber 5b. Further, a fuel frame 30 having a mask frame 26 notched only at the fuel introduction port is attached to the periphery of the plate member 25, partition members 27 similar to the above are installed on both sides, and a spacer 28 is further installed. Are formed, the combustion chamber 5b is polymerized on the fuel introducing chamber 30, the reforming chamber 5a is polymerized on the combustion chamber 5b, and the fuel introducing chamber 30 is polymerized on the reforming chamber 5a. Then, after that, the combustion chamber 5b and the reforming chamber 5a are stacked in this order, the chambers 5a, 5b and 30 are joined and laminated, and the upper plate 31 and the lower plate 32 are superposed on and under each other.
A reforming raw material gas supply manifold 33 is attached to the reforming raw material supply port of each stage of the reforming chamber 5a, and a fuel gas exhausting manifold 34 is attached to the reforming gas exhaust port. An air supply manifold 35 is attached to the air supply port of the combustion chamber 5b, a combustion exhaust gas manifold 36 is attached to the combustion exhaust gas outlet of the combustion chamber 5b, and a fuel introduction manifold 3 is attached to the fuel introduction port of the fuel introduction chamber 30.
7 is attached.

The heat exchanger 7 includes a high temperature section 7a and a low temperature section 7
b is laminated via a separator plate 7c, and heat is exchanged by flowing a high temperature side fluid and a low temperature side fluid with the separator plate 7c interposed therebetween. As an example, a plate fin type as shown in FIG. And In the plate fin heat exchanger shown in FIG. 3, a high temperature side fluid passage 39 and a low temperature side fluid passage 40, each having a fin 38 for promoting heat transfer in the fluid passage, are alternately stacked to form a high temperature side fluid H and a low temperature side fluid C. And are designed to be countercurrent.

Further, in the shift converter 6, an air preheating section 6b for preheating air and an exhaust gas preheating section 6c for preheating exhaust gas from the fuel electrode 3 are laminated on the shift reaction section 6a filled with the shift reaction catalyst 41. The heat generated by the exothermic reaction in the shift reaction section 6a is reduced.

The plate-shaped reformer 5 as described above,
The heat exchanger 7 and the shift converter 6 are stacked in the same pile, packaged, and housed in the container 42. The reformer 5 and the heat exchanger 7 are connected to the reforming source gas line 43 at a low temperature with the inlet of the reforming chamber 5a. The outlet of the portion 7b is connected, the outlet of the reforming chamber 5b and the inlet of the high temperature portion 7a are connected by the fuel gas line 44a, and the heat exchanger 7 and the shift converter 6 are connected to the outlet of the high temperature portion 7a and the shift reaction. The fuel gas line 4 with the inlet of the portion 6a
4b, and further the reformer 5 and the shift converter 6
Means that the inlet of the combustion chamber 5b and the outlet of the air preheating section 6b are connected by the air line 45, and the inlet of the combustion chamber 5b and the outlet of the exhaust gas preheating section 6c are connected by the exhaust gas line 46, and the shift converter 6 shifts. The fuel gas emitted from the reaction section 6a is supplied to the fuel electrode 3 of the separately placed fuel cell I, and the exhaust gas discharged from the outlet of the fuel electrode 3 is introduced into the exhaust gas preheating section 6b of the shift converter 6. .. In addition,
Since the reformer 5, the heat exchanger 7, and the shift converter 6 have different operating temperatures, a heat insulating material is required between these devices at the time of stacking.

In the case of the system system shown in FIG. 1, as the reforming raw material gas, for example, city gas TG is preheated through the low temperature portion 7b of the heat exchanger 7, and then the reforming chamber 5a of the reformer 5 is used.
The fuel gas FG which has been reformed by an endothermic reaction and has been reformed therein is flowed to the high temperature portion 7a of the heat exchanger 7 to lower the operating temperature of the shift converter 6 by heat exchange. Next, the temperature-reduced fuel gas is introduced into the shift reaction unit 6a of the shift converter 6, and CO in the fuel gas is discharged to 1% or less by the shift reaction so as to be discharged to the fuel electrode of the fuel cell. To do. On the other hand, the combustion chamber 5b of the reformer 5 is supplied with the air preheated by the air preheating unit 6b of the shift converter 6 and the exhaust gas preheated by the exhaust gas preheating unit 6c to burn combustible components in the exhaust gas. The combustion heat is used to perform the reforming by the endothermic reaction in the reforming chamber 5a.

In the above description, the reformer 5, the heat exchanger 7, and the shift converter 6 all have a plate structure, so they are easy to stack, and the above-mentioned respective constituent devices 5, 6, 7 are adjacent to each other by stacking. Therefore, it becomes possible to easily perform piping for connecting these constituent devices.

Next, FIG. 4 shows another embodiment of the present invention. The reformer 5, the heat exchanger 7, and the shift converter 6 having a plate structure with the fuel cell I separately provided in the above embodiment. The fuel cell I including the fuel cell I is laminated on the same pile as the reformer 5 and the like, and the outlet of the shift reaction portion 5a of the shift converter 6 and the inlet of the fuel electrode 3 of the fuel cell I are fueled. The gas line 44c is connected to connect the outlet of the fuel electrode 3 and the exhaust gas preheating section 6c of the shift converter 6 to each other.

In this embodiment, the above four constituent devices I,
Since 5, 6, and 7 are laminated on the same pile, there is an advantage that piping between each device becomes easier and a space can be effectively used.

It is needless to say that the shift converter 6 may be prepared for two types, one for high temperature and the other for low temperature, and may be variously modified without departing from the scope of the present invention.

[0020]

As described above, according to the fuel cell power generator of the present invention, the reformer for reforming the reforming raw material gas and the catalyst carried on the electrode of the phosphoric acid fuel cell are poisonous substances. Shift converter for suppressing carbon monoxide to 1% or less, and heat exchanger for lowering the reformer outlet temperature to the operating temperature of the shift converter, both having a plate structure and having the same pile shape. Since it is stacked and packaged, the whole can be made compact and easy to install in hotels, hospitals, etc. Also, since each component device is adjacent, piping is easy and heat dissipation loss is small. Further, by stacking the fuel cell and the reformer, heat exchanger, shift converter, and the like on the same pile, further compactification can be achieved, which is advantageous.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a fuel cell power generator of the present invention.

FIG. 2 is a partially cutaway perspective view showing an example of a plate-type reformer used in the fuel cell power generator of the present invention.

FIG. 3 is a perspective view showing an example of a plate fin heat exchanger used in the fuel cell power generator of the present invention.

FIG. 4 is a schematic diagram showing another embodiment of the fuel cell power generator of the present invention.

FIG. 5 is a perspective view showing a configuration example of a conventional phosphoric acid fuel cell.

FIG. 6 is a system diagram showing an example of a conventional fuel cell power generation system.

FIG. 7 is a diagram showing a relationship between a reformed gas outlet temperature and a VOL% of carbon monoxide in a shift converter.

[Explanation of symbols]

 I Fuel cell 1 Electrolyte plate 2 Air electrode 3 Fuel electrode 5 Reformer 5a Reforming chamber 5b Combustion chamber 6 Shift converter 6a Shift reaction part 6b Air preheating part 6c Exhaust gas preheating part 7 Heat exchanger 7a High temperature part 7b Low temperature part 7c Isolation Plate 8 Cooling unit 23 Reforming catalyst 24 Combustion catalyst 41 Shift reaction catalyst 43 Reforming raw material gas line (pipe) 44a, 44b, 44c Fuel gas line (pipe)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Mizusawa 3-15-15 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toni Technical Center

Claims (2)

[Claims] 1. A reforming source gas is reformed into a fuel gas by stacking a reforming chamber formed by filling a plate with a reforming catalyst and a combustion chamber formed by filling a plate with a combustion catalyst. Plate-type reformer, a plate-type shift converter having a shift reaction section filled with a shift reaction catalyst and a gas preheating section for reducing the heat generated in the shift reaction section, and a high-temperature portion and a low-temperature fluid passing therethrough A plate type heat exchanger in which low temperature parts are alternately laminated via partition plates is laminated on the same pile, and the fuel gas reformed in the reforming chamber of the reformer is passed through the heat exchanger. A fuel cell power generator characterized in that it is connected by a pipe so as to lead to a shift reaction section of a shift converter and is configured to supply the fuel gas exiting the shift reaction section to a fuel electrode inlet of a fuel cell. 2. An electrolyte plate impregnated with a phosphoric acid aqueous solution is sandwiched between an air electrode and a fuel electrode from both sides, and air is supplied to the air electrode.
In addition, a fuel cell is formed by stacking cells that can supply fuel gas to the fuel electrode via a separator, and stacking the fuel cell on the same pile as the plate-type reformer, heat exchanger, and shift converter. The fuel cell power generator according to claim 1, which is integrated.