JPH04324254A - Generating unit provided with differential pressure adjusting device - Google Patents

Abstract

PURPOSE:To suppress leakage of oxidizing gas from a sealing gasket of a fuel cell by adjusting a position of a partitioning plate, provided in a residual fuel duct, through a partitioning plate driving gear by a drive control unit so that a pressure of fuel gas in the fuel duct can be increased to the pressure suited for a pressure in an oxidizing gas flow passage. CONSTITUTION:Detection signals, respectively output from a fuel gas pressure detector 55 arranged in an oxidizing gas flow passage 41a and an oxidizing gas pressure detector 56 arranged in a fuel duct 12, are input to a drive control unit 54 which feeds a pressure of liquid to a gate valve driving gear 53 through a switching valve. The gate valve driving gear 53, which drives a partitioning plate 51 for opening/closing a residual fuel gas duct 52, adjusts a position of the gate valve 51, so that a pressure of the fuel gas pressure detector 55 is generated equal to a pressure of the oxidizing gas pressure detector 56, to minimize leakage to the fuel duct 12 of oxidizing gas 4 from a sealing gasket 8 of a fuel cell 9. In this way, a fuel gas pressure in the fuel duct can be increased to a value suited for a pressure of the oxidizing gas flow passage.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generating apparatus equipped with a differential pressure regulating device to which a flat solid electrolyte fuel cell using hydrogen gas, natural gas, etc. is applied.

0002

[Prior Art] As a power generation device using a flat solid electrolyte battery, a patent application related to an earlier application by one of the present applicants (application number: 1990 Patent Application No. 083864, title of invention:
There is a "power generation device").

[0003] A flat solid electrolyte fuel cell 9 used in a power generation device according to a patent application filed by one of the present applicants has an interconnector 11 which is an upper passage wall, as shown in FIGS. 3 and 4.
The fuel gas passage 2 is formed between the fuel gas passage 2 and the voltage generator support frame 10, which is a lower passage wall. Reference numeral 7 in the figure indicates an oxidizing gas passage, which is formed between the voltage generator support frame 10, which is the upper wall, and the interconnector 11, which is the lower passage wall. The interconnector 11 and the voltage generator support frame 10 are stacked. Joint flanges 34 to which the oxidizing gas conduit 5 and residual oxidizing gas conduit 36 are fixed are attached to both the upper and lower surfaces. The voltage generator support frame 10
, the interconnector 11 and the joint flange 34 are shielded by a sealing gasket 8. An oxidizing gas manifold 6 is provided between the oxidizing gas conduit 5 and the oxidizing gas passage 7 for distributing the oxidizing gas 4 to each oxidizing gas passage 7.
Oxidizing gas manifolds 6 for collecting the distributed oxidizing gas 18 remaining after the cell reaction are formed between them.

[0004] The heat insulating members, refractory materials, etc. of the above-mentioned power generation device are all made of ceramics so that they can withstand high temperatures of 1000°C or more, and the fuel cell 9
The solid electrolyte of is also formed from ceramics.

An example of a power generation device incorporating the fuel cell 9 will be explained below with reference to FIG. In Figure 5,
31 is an exhaust gas chamber partitioned by upper and lower heat insulating members (or fireproof materials) and fireproof materials on the sides. A fuel cell storage chamber 35 is arranged in the exhaust gas chamber 31 via an airtight partition wall 32c. A plate-shaped refractory material 32d is arranged on the side of the fuel cell storage chamber 35, and the airtight partition wall 32c is interposed between the plate-shaped refractory material 32d and the plate-shaped refractory material 32d. A residual fuel gas duct 52 is formed in the intermediate portion of the plate-shaped refractory material 32d.

[0006] An afterburner 16 is installed on the plate-shaped refractory material 32d on the side of the exhaust gas chamber 31 in the fuel cell storage chamber 35, and a fuel gas conduit 14 is installed on the refractory material on the opposite side of the afterburner 16. ing. Airtight bulkhead 32a~
An air-cooled pipe (or water-cooled pipe) 40 is disposed outside or on both sides of the fuel cell 9, and a seal gasket weight 20 is placed on the fuel cell 9. Note that 12 in the figure is a fuel duct. A plurality of oxidizing gas flow passages 41 made of non-conductive ceramics for supplying oxidizing gas to the fuel cell 9 are inserted into each of the seal gasket weights 20 . A residual oxidant gas conduit 36 extending to the residual gas duct 30 passes through each of the fuel cells 9 .

A meandering oxidizing gas preheating heat exchanger 17 is disposed within the exhaust gas chamber 31. This heat exchanger 1
One end of 7 is connected to an oxidizing gas introduction pipe (not shown). Between the heat exchanger 17 and the burner 16,
A refractory material 26 is provided. The other end of the heat exchanger 17 passes near the upper wall of the exhaust gas chamber 31, penetrates the airtight partition wall, and terminates in the oxidizing gas flow passage 41. Near the other end of the flow passages 41, there are flow passages 4 branched from these flow passages 41.
1 to constitute an oxidizing gas conduit. A starting burner 22 is connected to the other end of the flow path 41 . Note that the starting burner 22 is covered with a heat insulating material. The starting burner 22 is provided with an ignition device 22a, a fuel gas supply pipe 22c, and an oxidizing gas supply pipe 22b. An exhaust gas pipe 37 connected to a chimney is provided on the left wall of the heat insulating material that partitions the exhaust gas chamber 31.

[0008] Next, the operation of the power generating apparatus having the above-mentioned configuration will be explained separately during startup operation and during steady operation.

During start-up operation, the fuel gas introduction pipe 1
Fuel gas 1 (H2 gas or natural gas) introduced from 4
is supplied to each flat solid electrolyte fuel cell 9 through the fuel duct 12. On the other hand, oxidizing gas 4 (air) supplied from an oxidizing gas introduction pipe (not shown) led to the exhaust gas chamber 31 is supplied to each fuel cell through the oxidizing gas preheating heat exchanger 17 and the oxidizing gas flow path 41, Power is generated by the action described below.

After power generation, the oxidizing gas 4 becomes a residual oxidizing gas 18 and is transferred to a residual oxidizing gas conduit 36 and a residual oxidizing gas duct 30.
through which it flows into the exhaust gas chamber 31 and is guided upwards by the refractory material 26. On the other hand, the remaining fuel gas 15 flows into the exhaust gas chamber 31 through the remaining fuel gas duct 52. Here, the residual fuel gas 15 and the residual oxidant gas 18 are re-combusted by the afterburner 16 to heat the meandering oxidant gas preheating heat exchanger 17 disposed in the exhaust gas chamber 31. The oxidizing gas 4 passing through is preheated. The reburned gas 38 passes through the exhaust gas pipe 37 and is discharged from the chimney.

[0011] At the time of starting up the above-mentioned power generation device, 10
It takes time to reach a reaction temperature as high as 00°C. Therefore, by heating the oxidizing gas 4 supplied to the plurality of oxidizing gas flow passages 41 by the starting burner 22 and causing the fuel gas 1 to react with the oxidizing gas 4, each of the flat solid electrolyte fuel cells 9 reaches the rated temperature. let At this time, the residual fuel gas 15 and the residual oxidant gas 18 are re-combusted by the afterburner 16 as described above, so that the meandering oxidant gas preheating heat exchanger 1 disposed in the exhaust gas chamber 31
7 is heated to preheat the oxidizing gas 4 passing through the heat exchanger 17, and supplying the preheated oxidizing gas 4 to each fuel cell 9 through the oxidizing gas flow path 41, thereby increasing the reaction rate of the fuel cell 9. It is possible to promote this and shorten the startup time.

During steady operation, when the reaction temperature reaches the rated temperature, the starting burner 22 is stopped, and thereafter the oxidizing gas 4 and the fuel gas 1 are continuously supplied, thereby operating as an independent power generating device. do.

Next, the above-mentioned flat plate solid electrolyte fuel cell 9
The operation will be explained with reference to FIGS. 3 to 5.

The fuel gas 1 introduced through the fuel duct 12 is supplied to the fuel gas passage 2 and flows on the upper surface of the voltage generator support frame 10 . On the other hand, the oxidizing gas 4 introduced from the oxidizing gas flow passage 41 is distributed to each oxidizing gas passage 7 by the oxidizing gas internal manifold 6 and flows under the voltage generator support frame 10, at which time a current flows. This current is taken out from the current lead 21 connected to the upper and lower joint flanges 34.

[0015] In the above, an example has been described in which the oxidizing gas preheating heat exchanger 17 for preheating the oxidizing gas 4 and the starting burner 22 are provided in the oxidizing gas conduit.
A heat exchanger 17 for preheating the oxidizing gas and a heat exchanger for preheating the fuel gas for preheating the fuel gas are provided in the oxidizing gas conduit, and instead of providing the starting burner 22 in the oxidizing gas conduit, a starting burner for starting up is provided in the fuel gas introduction pipe 14. The effect is the same even if . Further, the heat exchanger for preheating the oxidizing gas and the fuel gas may be a finned tube.

[0016]

In the power generation device according to the earlier application of one of the present applicants, as shown in FIG.
It flows through the oxidizing gas passage 7 and the residual oxidizing gas conduit 36 . On the other hand, the fuel gas 1 only passes through the fuel gas passage 2 as shown in FIG.

Generally, it is necessary to flow the oxidizing gas 4 in a larger amount than the fuel gas 1, and furthermore, since the oxidizing gas passage is curved as described above, the pressure drop in the flow is large. Therefore, in the power generating apparatus shown in FIG. 5 incorporating the fuel cell, the pressure in the oxidizing gas flow path 41 is higher than the pressure in the fuel duct 12 by several tens to hundreds of mmAg.

The pressure difference between the two gases becomes the differential pressure between the oxidizing gas passage 7 and the fuel gas passage 2 and the differential pressure between the fuel duct 12 (or fuel cell storage chamber 35) and the oxidizing gas passage 7,
There is a possibility that the oxidizing gas 4 leaks from the sealing gasket 8 to the fuel gas side, and an improvement has been desired.

The present invention aims to solve the above problems.

[0020]

[Means for Solving the Problems] In the power generation device equipped with the differential pressure adjustment device of the present invention, the fuel duct and the oxidizing gas flow passage are connected to the residual fuel gas duct, and the voltage generation part support frame and the interconnector are used for sealing. In a power generation device equipped with fuel cells stacked through gaskets, a partition plate provided in the residual fuel gas duct to open and close the duct, and a fuel gas pressure detection device provided in the fuel duct and the oxidizing gas flow path, respectively. a drive control device that inputs pressure signals from the respective pressure detectors and outputs control signals, and a partition plate drive device that inputs control signals from the control device to drive the partition plate. It is characterized by having the following.

[0021]

[Operation] In the above, the fuel gas pressure detector and the oxidant gas pressure detector detect the pressure in the fuel duct and the oxidant gas flow path, respectively, and output pressure signals. The pressure signal is input to the drive control device, and the control device drives the partition plate via the partition plate drive device so that the pressure in the fuel duct and the oxidant gas flow path are equal, and determines the position of the partition plate. Adjust.

[0022] Due to this adjustment, the pressure of the fuel gas increases,
Since the pressure is approximately equal to the pressure of the oxidizing gas, leakage of the oxidizing gas to the fuel duct via the sealing gasket provided in the fuel cell is suppressed.

[0023] As a result of the above, it has become possible to increase the pressure of the fuel gas in the fuel duct to a pressure commensurate with the pressure in the oxidant gas flow path, thereby suppressing leakage of oxidant gas from the sealing gasket of the fuel cell. becomes possible.

[0024]

[Embodiment] An embodiment of the present invention will be explained with reference to FIGS. 1 and 2. In addition, in this embodiment, since the parts other than the differential pressure adjusting device are the same as the device according to the prior application described in the section of the prior art, the explanation thereof will be omitted.

In the present embodiment shown in FIGS. 1 and 2, an exhaust gas chamber 31 and a fuel cell storage chamber 35 are divided into left and right sides by a plate-shaped fireproof member 32d having a residual fuel gas duct 52 in the center having an afterburner 16 at its tip. , as shown in FIGS. 3 and 4, a voltage generator support frame 10 and an interconnector 11 are stacked with a sealing gasket 8 in between, and a fuel gas passage 2 and an oxygen gas passage 7 are provided between the support frame 10 and the interconnector 11. A plurality of fuel cells 9 in which a plurality of fuel cells 9 are formed are arranged in the fuel duct 12 in the fuel cell storage chamber 35, and a seal gasket weight 20 having an oxidizing gas flow passage 41a is provided on the upper surface of the fuel cell 9. In the power generation device, a cylinder and a piston are provided in a guide groove provided in the plate-shaped fireproof member 32d and penetrating from the upper part to the fuel duct 12, and a partition plate drive device 53 having a drive section in the upper part; a partition plate 51 provided at the lower end of the piston; a fuel gas pressure detector 5 provided within the fuel duct 12;
5. Oxidizing gas pressure detector 5 disposed within the oxidizing gas flow passage 41a provided in the seal gasket weight 20
6, and the partition plate driving device 5 in which the fuel gas pressure detector 55 and the oxidizing gas pressure detector 56 are connected by an electric wire.
A drive control device 54 is provided to control the motor.

In the above, the detection signals outputted by the fuel gas pressure detector 55 disposed in the oxidizing gas flow path 41a and the oxidizing gas pressure detector 56 disposed in the fuel duct 12 are sent to the drive control device 54. The drive control device 54 inputs the hydraulic pressure to the gate valve drive device 5 via the switching valve.
Send to 3.

The gate valve driving device 53 that drives the partition plate 51 that opens and closes the residual fuel gas duct 52 controls the partition plate 51 so that the pressure of the fuel gas pressure detector 55 is equal to the pressure of the oxidizing gas pressure detector 56. The position is adjusted to minimize leakage of oxidizing gas 4 from sealing gasket 8 of fuel cell 9 into fuel duct 12 (or fuel cell storage chamber 4).

[0028] As a result of the above, it is possible to increase the pressure of the fuel gas in the fuel duct to a pressure commensurate with the pressure in the oxidant gas flow path, thereby suppressing the leakage of oxidant gas from the sealing gasket of the fuel cell. became possible.

[0029]

Effects of the Invention In the power generation device equipped with the differential pressure adjustment device of the present invention, the fuel gas pressure detector and the oxidant gas pressure detector detect the pressures in the fuel duct and the oxidant gas flow path, respectively, and adjust the pressure accordingly. A signal is input to the drive control device, and the control device adjusts the position of the partition plate provided in the remaining fuel duct via the partition plate drive device, thereby adjusting the pressure of the fuel gas in the fuel duct to the oxidizing gas flow path. Since it is now possible to increase the pressure to a value commensurate with the pressure of the fuel cell, it becomes possible to suppress leakage of oxidizing gas from the sealing gasket of the fuel cell.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a power generation device according to an embodiment of the present invention.

FIG. 2 is a view taken along the line A-A in FIG. 1;

FIG. 3 is a perspective view of a flat plate solid electrolyte fuel cell.

FIG. 4 is a view taken along the line BB in FIG. 3;

FIG. 5 is an explanatory diagram of a power generation device according to a prior application.

[Explanation of symbols]

1 Fuel gas 4 Oxidizing gas 8 Seal gasket 9
Fuel cell 10 Voltage generator support frame 11 Interconnector 12 Fuel duct 15 Residual fuel gas 16 Afterburner 31 Exhaust gas chamber 32d Plate fireproof member 35 Fuel cell storage chamber 51 Partition plate 52 Residual fuel gas duct 53 Partition plate drive device 54 Drive control device 55 Fuel gas pressure detector 56 Oxidizing gas pressure detector

Claims (1)

[Claims] Claim 1. A power generation device comprising a fuel cell in which a fuel duct and an oxidizing gas flow passage are connected to a residual fuel gas duct, and a voltage generating part support frame and an interconnector are stacked via a sealing gasket. A partition plate installed in the fuel gas duct to open and close the duct, a fuel gas pressure detector and an oxidant gas pressure detector installed in the fuel duct and the oxidant gas flow path, respectively, and a pressure signal is received from each pressure detector. What is claimed is: 1. A power generation device equipped with a differential pressure adjustment device, comprising: a drive control device that inputs a control signal and outputs a control signal; and a partition plate drive device that inputs a control signal from the control device and drives the partition plate.