JPS63128564A - Power generation process of solid electrolyte fuel battery module - Google Patents

Abstract

PURPOSE:To prevent hydrogen leakage to outside using a compact module by providing a low temperature air preheater outside the module as well as controlling the module internal pressure at the same atmospheric pressure or less, supplying hydrogen mixed with inert gas to the module, and dosing an oxidant to an intermediate stage of cells. CONSTITUTION:Hydrogen 5 mixed with inert gas 4 is introduced into a cell 2 and oxidant air is sent by a fan 7 to both of a low temperature air preheater 6 and a high temperature air preheater 3, where heat exchange of waste gas 11 is carried out. The hydrogen concentration around the cell 2 and the temperature atmosphere are controlled at optimum conditions using the inert gas 4, and the oxygen concentration around the cell 2 is controlled using air (or oxygen) 12 dosed among cells, in order to keep sufficient and uniform output of each cell 2. Furthermore, waste gas 11, so-called gas generated by the power generation reaction, is led to the fan 9 after heat exchange with air and blown off through a vent 10 to the atmosphere, controlling the internal pressure of module 1' at the same atmospheric pressure or less. By the arrangement, the hydrogen leakage to outside the module is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of generating electricity using a solid electrolyte fuel cell module.

[Prior Art and Problems] As is well known, solid oxide fuel cells (hereinafter referred to as 5OFC) are generally different from other fuel cells (first generation...phosphoric acid type PAFC, second generation molten carbonate type MCFC). In comparison, it is considered a third-generation fuel cell, and the technology is expected to be established in about 20 to 30 years. Therefore, there are many technologies that have not yet been established.

The present invention presents a basic idea regarding unestablished technology such as systems and processing of fuel hydrogen, air, exhaust gas, etc. of the 5OFG module, and the technical problems listed below are posed.

(5) Since oxygen and unreacted hydrogen exist within the OFG module, this may leak to the outside of the module and create an explosive atmosphere, which must be prevented.

■The gas temperature inside the module is approximately 9% due to the performance of the power generation cell.
The temperature is controlled at 00-1000°C. However, although an air preheater is installed inside the module to raise the temperature of the air, which is an oxidizer, in order to recover heat from exhaust gas, the gas temperature at the outlet of the air preheater is as high as several 100'C. Therefore, even more exhaust gas heat recovery is required. One possible solution is to increase the capacity of the air preheater inside the module, but this would make the module larger and lose the purpose of making the module more compact. This requires the use of a large amount of high-quality materials that can withstand high temperatures, which is economically disadvantageous.

■5OFC output depends on fuel hydrogen concentration and ambient temperature around the cell. However, it is relatively easy to control these separately; for example, to adjust the hydrogen concentration, inert gas is added, and to adjust the ambient temperature, heat is input by a heater, air,
Cooling the module using hydrogen could be considered, but this would lead to an increase in the size of the equipment.

■5OFG output also depends on the oxygen concentration around the cell,
When air flows perpendicular to the cells in the module, the cells on the upstream side have a high oxygen concentration and can produce high output, while the downstream cells have low oxygen concentration and can only produce a small output. An imbalance occurs.

The present invention was made in view of the above circumstances, and aims to prevent hydrogen leakage to the outside of the module, make the module more compact, and equalize the output of each cell, and simultaneously control the hydrogen concentration and ambient temperature around the cells. The present invention aims to provide a method for generating electricity using a solid electrolyte fuel cell module.

[Means for Solving the Problems] The present invention provides a method for generating electricity using a solid oxide fuel cell module in which a plurality of cells and a high-temperature air preheater are disposed, in which a low-temperature air preheater is disposed outside the module. , controlling the internal pressure of the module to be equal to or lower than atmospheric pressure,
The gist of this method is to feed hydrogen mixed with an inert gas into the module, and to inject an oxidizing agent between the cells.

[Function] According to the present invention, (1) Hydrogen leakage to the outside of the module can be prevented by the parallel ventilation method.

■The module can be made more compact by using a low-temperature air preheater outside the module to exchange heat with air, which is an oxidizing agent.

■ By using a method of mixing inert gas with hydrogen, the hydrogen concentration and ambient temperature around the cell can be controlled simultaneously.

- By introducing an oxidizing agent between the cells, it is possible to equalize the main power of each cell.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

The figure is an explanatory diagram of the 5OFC module. 1 in the figure is a gas flow orthogonal type 5OFC module in which a plurality of cells 2 . . . and a high-temperature air preheater 3 are arranged. Said cell 2
... is introduced with hydrogen 5 mixed with a reactive inert gas (for example, nitrogen) 4. Outside the module 1,
A cold air preheater 6 is provided. Further, a forced draft fan 7 is provided outside the module 1, and the oxidizer air is guided from the fan 7 into the cell 2 through the low temperature air preheater 6 and the high temperature air preheater 3. Furthermore, an induced draft fan 9 and a chimney 10 connected to the module 1 via an inlet damper 8 are provided outside the module 1, respectively.

In this example, using such a 5OFC module, hydrogen 5 mixed with reaction inert gas 4 was first introduced into the cell 2.
to be introduced inside. On the other hand, the oxidant air is sent to the low temperature air preheater 6 and the high temperature air preheater 3 by the fan 7,
Here, heat exchange is performed with the exhaust gas 11. Furthermore, the hydrogen and air introduced into the module 1 are used in the cell 2 for a power generation reaction. At this time, the cell 2 is
The surrounding hydrogen concentration and temperature atmosphere are optimally controlled, and the oxygen concentration around the cells 2 is controlled by the air (or oxygen) 12 injected between the cells 2, so that the output of each cell 2 is sufficient and uniform. controlled in a similar manner. Furthermore, the gas produced by the power generation reaction, so-called exhaust gas 11, is guided to the fan 9 after heat exchange with the air, and is discharged into the atmosphere from the chimney 10. At this time, the internal pressure of the Modumil 1 is controlled to be equal to or lower than atmospheric pressure by operating the inlet damper 8 and changing the discharge pressure of the fan 9.

According to the above embodiment, the effects listed below are obtained.

(2) By adopting a parallel ventilation system that controls the internal pressure of the module 1 to be equal to or lower than atmospheric pressure, leakage of hydrogen to the outside of the module 1 can be prevented.

(2) The module 1 can be made more compact because a low-temperature air preheater 6 is installed outside the module 1 to exchange heat with air, which is an oxidizing agent.

(2) Since the inert gas 4 is mixed into the hydrogen 5, the hydrogen concentration and ambient temperature around the cell 1 can be controlled at the same time.

■Since the oxidizing agent (air, oxygen) is injected between the two cells, the output of the cells can be made uniform.

[Effects of the Invention] As detailed above, according to the present invention, hydrogen leakage to the outside of the module is prevented, the module is made compact, the output of each cell is made uniform, and the hydrogen concentration atmosphere temperature around the cells is simultaneously adjusted. We propose a controllable power generation method using a solid electrolyte fuel cell module, □4゜, 4゜

[Brief explanation of the drawing]

The figure is an explanatory diagram of a solid electrolyte fuel cell module according to the present invention. 1...5 OFC module, 2... cell, 3...
High temperature air preheater, 4... Reactive inert gas, 5... Hydrogen, 6... Low temperature air preheater, 7... Forced draft fan, 8... Inlet damper, 9... Induced draft fan, 10
...Chimney, 11...Exhaust gas, 12...Air (or oxygen).

Claims (1)

[Claims] In a method for generating electricity using a solid electrolyte fuel cell module equipped with a plurality of cells and a high-temperature air preheater, a low-temperature air preheater is disposed outside the module, and the internal pressure of the module is controlled to be equal to or lower than atmospheric pressure. A power generation method using a solid electrolyte fuel cell module, which adopts a parallel ventilation system, supplies hydrogen mixed with an inert gas into the module, and injects an oxidizing agent between the cells.