JP2005078997A - Fuel cell apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure for fitting a fuel cell apparatus in which prevention of stay of condensed water and layout flexibility are attained together. <P>SOLUTION: In a fuel cell apparatus, a fuel cell inlet and a fuel cell outlet are arranged side by side in the horizontal direction on the same side, water content adjusting means and a second circulation means are arranged between the fuel cell inlet and the fuel cell outlet, a first gas outlet is arranged in the direction substantially perpendicular to a first gas suction inlet, a second gas suction inlet and a second gas exhausting outlet are arranged in the same height, a first circulation flow channel is constructed so that the inside of the flow channel is connected between the first gas suction inlet and the first gas exhausting outlet, and a shut-off valve for shutting off the gas is fitted in the second circulation channel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a fuel cell device, and more particularly to a fuel cell module mounting structure.

The conventional fuel cell module mounting structure is such that the gas-liquid separator on the discharge side from the fuel cell is laid out at the lowest point with respect to devices such as fuel cells, the circulation device is above the gas-liquid separator, and the valve is piping Condensed water is prevented from staying by laying out a higher position than each connected device (circulation device etc.). (See Patent Document 1.)
JP 2002-231294 A (pages 4-7, Fig. 4)

  However, in the conventional fuel cell module mounting structure, condensate can be prevented from staying, but the height direction becomes larger because the circulation device is higher than the gas-liquid separator and the valve is arranged higher than the circulation device. Further, if the height direction is to be suppressed, the circulation device is disposed near the lateral direction of the gas-liquid separator, and the lateral direction becomes larger. And if it is going to suppress a height direction and a horizontal direction, a flow path will have many bending or an acute angle | corner, and a pressure loss will become large. Accordingly, it has been impossible to achieve both prevention of condensate water retention and layout.

  The fuel cell supply port and the fuel cell discharge port are arranged side by side on the same side of the fuel cell, the moisture adjusting means and the second circulation means are arranged between the fuel cell supply port and the fuel cell discharge port, The gas discharge port is arranged in the substantially vertical direction of the first gas suction port, the second gas suction port and the second exhaust gas discharge port are arranged at the same height, and the first circulation passage is stopped by the fuel cell. Sometimes the inside of the flow channel communicates, and a shutoff valve capable of shutting off the gas is attached to the second circulation flow channel.

The first gas discharge port is arranged in a substantially vertical direction of the first gas suction port, and the first circulation channel is structured to communicate with the inside of the channel when the fuel cell is stopped. By attaching a shut-off valve that can be shut off, the first circulation flow path can be made substantially straight, and a flow path that can prevent the condensate from staying can be secured, so that the fuel cell can be started. Since it can be made to flow only to the first circulation flow path at the time of activation without flowing to the second circulation flow path, the fuel cell can be efficiently activated. Further, the moisture adjusting means and the second circulation means are disposed between the fuel cell supply port and the fuel cell discharge port, and the first gas discharge port is disposed in a substantially vertical direction of the first gas suction port. Thus, layout is possible even in a limited space. The fuel cell supply port and the fuel cell discharge port are arranged side by side on the same side of the fuel cell, the moisture adjusting means and the second circulation means are arranged between the fuel cell supply port and the fuel cell discharge port, The second gas suction port and the second exhaust gas discharge port are arranged at the same height, so that the second circulation channel, the pipe connecting the fuel cell discharge port and the moisture adjusting means inlet, and the second circulation Since the piping connecting the circulating gas discharge port for discharging the gas from the means and the fuel cell supply port can be made substantially straight, it is possible to suppress the pressure loss. Therefore, with such an arrangement, it is possible to achieve both prevention of condensate retention and layout.

(Example 1)
The configuration of this embodiment will be described with reference to FIG. Fuel cell 1, fuel gas supply port 1b (fuel cell supply port), fuel gas discharge port 1a (fuel cell discharge port), circulation devices 3 and 4, shutoff valves 5 and 6, gas-liquid separator 2 (moisture adjustment means) It consists of In addition, a pipe connecting the fuel supply device (not shown) to the circulation device 4 (first circulation means) is a fuel gas supply piping 11 (first supply gas flow path), branched from the fuel gas supply piping 11, and the circulation device 3 ( The piping connecting the second circulation means) is the high-load fuel gas supply piping 12 (second supply gas passage), and the piping connecting the gas-liquid separator 2 and the circulation device 4 is the circulation piping 13 (first piping). And a pipe connecting the gas-liquid separator 2 and the circulation device 3 is a high-load circulation pipe 14 (second circulation path). The high load fuel gas supply pipe 12 is provided with a supply gas cutoff valve 5 (second valve), and the high load circulation pipe 14 is provided with a circulation gas cutoff valve 6 (first valve). The circulation pipe 13 has a structure in which no valve is provided. Moreover, the piping which connects each apparatus uses a linear thing. In addition, the linear form used here includes those having a gentle curved portion (obtuse angle).

  Next, the layout of each device will be described. The fuel cell 1 has an air electrode and a fuel electrode, and is provided with a fuel electrode exhaust port 1a and a fuel electrode supply port 1b at the same height. Fuel electrode exhaust 1a, gas-liquid separator 2 intake 2c (exhaust gas inlet), gas-liquid separator 2 exhaust 2a (second exhaust gas exhaust), and circulation device 3 intake 3a (second gas intake port) and the fuel electrode supply port 1b are arranged at the same height. The high load circulation 4 and the gas-liquid separator 2 are disposed between the fuel cell exhaust port 1a and the fuel cell supply port 1b. An intake port 4a (first gas intake port) of the circulation device 4 is disposed on the vertical direction of the exhaust port 2b of the gas-liquid separator 2. In addition, the height described here means the height in the vertical direction from the ground.

  Next, the operation of this embodiment will be described.

  First, a case where the fuel cell 1 is operated at a low load will be described. The fuel gas supplied from the fuel supply device flows through the fuel gas supply pipe 11, passes through the circulation device 3, and is sent to the fuel electrode supply port 1b. At this time, the supply gas cutoff valve 5 is closed. The fuel gas supplied to the fuel cell 1 passes through the fuel cell 1 and is discharged from the fuel electrode exhaust port 1a. The discharged gas removes (or humidifies) moisture contained in the gas by the gas-liquid separator 2, flows through the circulation pipe 13, and is sent to the circulation device 4. At this time, the circulating gas cutoff valve 6 is closed. Thereafter, the fuel gas supplied from the fuel supply device is mixed with the circulation device 4 and sent again to the fuel electrode supply port 1b.

  Next, a case where the fuel cell 1 is operated at a high load will be described. The fuel gas supplied from the fuel supply device flows through the high load fuel gas supply piping 12 and the fuel gas supply piping 11, passes through the circulation device 3 and the circulation device 4, and is sent to the fuel electrode supply port 1b. The fuel gas supplied to the fuel cell 1 passes through the fuel cell 1 and is discharged from the fuel electrode exhaust port 1a. The discharged gas removes (or humidifies) moisture contained in the gas by the gas-liquid separator 2, flows through the high-load circulation pipe 14 and the circulation pipe 13, and is sent to the circulation device 3 and the circulation device 4. Thereafter, the fuel gas supplied from the fuel supply device is mixed with the circulation device 3 and the circulation device 4 and sent again to the fuel electrode supply port 1b.

  In the following, the circulation device 3 that is mainly used during high-load operation is referred to as a high-load circulation device, and the circulation device 4 that is mainly used during low-load operation and high-load operation or when the fuel cell 1 is started is referred to as low-load circulation device. Collectively.

  Thus, in the present embodiment, the following effects are obtained by the above configuration.

  By arranging the exhaust port 2b of the gas-liquid separator 2 in the vertical direction of the intake port 4a of the low load circulation device 4, the circulation pipe 13 can be made substantially straight, and the circulation pipe 13 is provided with a valve. By having a structure that does not have any, at least one can secure a flow path that can prevent the condensate from staying, so that the fuel cell 1 can be started and circulated without flowing through the high-load circulation pipe 14. The fuel cell 1 can be efficiently started up because it can flow only to the pipe 13 at the time of startup. Further, the gas-liquid separator 2, the high-load circulation device 3, and the low-load circulation device 4 are disposed between the fuel cell supply port 1b and the fuel cell discharge port 1a, and the gas-liquid separator 2 exhaust port 2b. By arranging the intake port 4a of the circulation device 4 in the vertical direction, layout is possible even in a limited space. The fuel cell supply port 1b and the fuel cell discharge port 1a are arranged side by side on the same side surface of the fuel cell 1, and the gas-liquid separator 2 and the high-load circulation device 3 are connected to the fuel cell supply port 1b and the fuel cell discharge port. By arranging it between 1a, the circulation piping 14, the piping connecting the fuel cell discharge port 1a and the gas-liquid separator 2, and the piping connecting the circulation device 3 and the fuel cell supply port 1b can be straightened. In addition, by arranging the intake port 3a of the fuel cell 1 circulation device 3 and the exhaust port 2a of the gas-liquid separator 2 at the same height, each device can be connected at the same height, particularly when operating at high loads. It becomes possible to suppress the pressure loss of the flow path. Therefore, with such an arrangement, it is possible to achieve both prevention of condensate retention and layout. In addition, after starting, the operation | movement by a high load is also attained by heating the flow path for high loads with the heat which generate | occur | produces in a system, or the electric power generated with the fuel cell.

  Fuel cell outlet 1b, inlet 2c of gas-liquid separator 2, exhaust outlet 2a of gas-liquid separator 2, circulating gas outlet 3b (circulating gas outlet) of circulation device 3 for high load, fuel Since the battery supply port 1a is arranged at the same height, the flow path used during high load operation can further suppress pressure loss.

In the present embodiment, the circulation pipe 13 has a structure in which no valve is provided, but the structure may be such that the flow path is not blocked when the fuel cell 1 is started (particularly at the time of starting below freezing point) (for example, normally open). A valve may be provided). Further, although the high-load circulation pipe 14 is a straight pipe, it may be structured to have a small pressure loss (for example, a pipe having an obtuse angle bend). Moreover, although the fuel electrode was demonstrated, the same effect is acquired by making it the same structure also in an air electrode.
(Example 2)
The configuration of this embodiment will be described with reference to FIG. In this embodiment, the flow meter 7 (flow rate measuring means), the pressure adjustment valve 9, the pressure gauge 8, the purge valve 10 (third valve), and a control unit (not shown) are attached to the configuration used in the first embodiment. It is. Further, an exhaust pipe 15 (exhaust flow path) provided with a purge valve 10 is attached from the gas-liquid separator 2 to the outside so that the gas discharged from the fuel cell can be discharged out of the system.

  Next, the layout and function of each device will be described. The pressure gauge 7 is attached to the fuel electrode supply port 1b and measures the pressure of the fuel gas flowing into the fuel electrode supply port 1b. The pressure adjustment valve 8 is attached upstream of the branch point between the fuel gas supply pipe 11 and the high load fuel gas supply pipe 12 in the fuel gas flow direction, and adjusts the pressure of the fuel gas supplied to the fuel cell 1. The flow meter 7 is attached upstream from the pressure regulating valve 8 in the fuel gas flow direction, and measures the flow rate of the fuel gas supplied by the fuel supply device. The control unit performs opening / closing control of each valve based on the result of each instrument.

  Next, the operation of this embodiment will be described.

  When the fuel cell is operated, a phenomenon may occur in which nitrogen on the air electrode side passes through the polymer film and crosses over to the fuel electrode. In such a case, since the fuel gas partial pressure of the fuel electrode is lowered and the power generation efficiency is lowered, there is a case where a predetermined amount of gas in the fuel electrode is discharged to increase the fuel gas concentration. Control performed at that time (control method of the purge valve 10) will be described with reference to FIG. This system flowchart is repeatedly executed every set time (for example, 10 ms) after the fuel cell 1 is started.

  In step 100, the system flowchart is started.

  In step 101, it is determined whether or not the flag FP is 1. When the flag FP is 1, the routine proceeds to step 109.

  In step 102, the user's required load L (for example, an accelerator sensor) is read into the control unit.

  In step 103, the nitrogen gas mixing amount N2 per unit time at the required load L read in step 102 is obtained from a table (for example, FIG. 3 (3a)) obtained in advance through experiments or the like.

  In step 104, the total nitrogen gas amount SN2 in the fuel electrode is calculated from the value obtained in step 103. At this time, when this system flowchart is executed for a certain period of time, integration is performed, and when it is executed at irregular intervals, a product with the interval is integrated.

  In step 105, it is determined whether the total nitrogen gas amount SN2 calculated in step 104 exceeds a predetermined total nitrogen gas amount SLSN2. If it is less than or equal to the predetermined total nitrogen gas amount SLSN2, the routine proceeds to step 112.

  In step 106, the purge valve 10 is opened.

  In step 107, timer A is started.

  In step 108, the flag FP is set to 1. Proceed to step 112.

  In step 109, it is determined whether the timer A has exceeded the set time T. If it is less than or equal to the set time T, the process proceeds to step 112.

  In step 110, the purge valve is closed.

  In step 111, the flag FP and the predetermined total nitrogen gas amount SLSN2 are set to 0, and the timer A is stopped and reset.

  In step 112, the system flowchart ends.

  Next, a pressure loss diagnosis method (pressure loss detection means) for the fuel gas flow path (high load flow path) that flows only at high loads will be described with reference to FIG. This system flowchart is executed only once when FP = 1 (that is, the purge valve 10 is opened).

  In step 200, the system flowchart is started.

  In step 201, it is determined whether the flag FP is 1. When the flag P is not 1, the routine proceeds to step 214.

  In step 202, it is determined whether the supply gas cutoff valve 5 and the circulation gas cutoff valve 6 are closed. If it is closed, the process proceeds to step 207.

  In step 203, the supply gas cutoff valve 5 and the circulation gas cutoff valve 6 are opened.

  In step 204, the flow meter 7 reads the fuel gas flow rate QO into the control unit.

  In step 205, the supply gas cutoff valve 5 and the circulation gas cutoff valve 6 are closed.

  In step 206, the flow rate QC of the fuel gas is read into the control unit by the flow meter 7. Proceed to step 211.

  In step 207, the supply gas cutoff valve 5 and the circulation gas cutoff valve 6 are closed.

  In step 208, the flow rate QC of the fuel gas is read into the control unit by the flow meter 7.

  In step 209, the supply gas cutoff valve 5 and the circulation gas cutoff valve 6 are opened.

  In Step 210, the flow meter 7 reads the fuel gas flow rate QO into the control unit.

  In step 211, a value obtained by subtracting the flow rate QC when the supply gas cutoff valve 5 and the circulation gas cutoff valve 6 are closed from the flow rate QO when the supply gas cutoff valve 5 and the circulation gas cutoff valve 6 are opened is a predetermined value. Determine if the flow rate SLDP is exceeded. If the flow rate is equal to or lower than the predetermined flow rate SLDP, the process proceeds to step 213.

  In step 212, the flag FDP is set to 0. Proceed to step 214.

  In step 213, the flag FDP is set to 1.

  In step 214, this system flowchart ends.

  Moreover, the high load driving | running | working prohibition method is demonstrated using FIG. This system flowchart is repeatedly executed every set time (for example, 10 ms) after the system flowchart of FIG. 4 is completed.

  In step 300, the system flowchart is started.

  In step 301, the user's required load L (for example, an accelerator sensor) is read into the control unit.

  In step 302, it is determined whether the required load L read in step 301 exceeds a predetermined load SLL. If the load is equal to or less than the predetermined load SLL, the process proceeds to step 305.

  In step 303, it is determined whether the flag FPD is 0. If the flag FPD is not 0, the process proceeds to step 305.

  In step 304, high-load operation is prohibited (for example, a warning sound or warning lamp is notified to the user).

  In step 305, this system flowchart ends.

  Thus, in the present embodiment, the following effects are obtained by performing the above control.

   If the pressure loss of the high-load flow path is greater than or equal to a predetermined value, the fuel cell system can be stably operated without causing a poor circulation of the fuel gas at the time of high load by performing control to prohibit high-load operation. It becomes possible. Specifically, when a poor circulation occurs, hydrogen may not be supplied to some of the cells of the fuel cell, which may result in a failure mode in which the cell deteriorates. In the present invention, this mode is avoided. It becomes an effective means. Also, if it is assumed that the pressure loss of the high load flow path is abnormal immediately after starting, that is, if the FDP = 1 is programmed with the key ON, the pressure loss of the high load flow path is normal from the start. The high-load operation can be prohibited until the determination is made, and the high-load operation can be avoided when the high-load flow path becomes a high pressure loss due to freezing or the like at the time of starting below freezing.

  It is possible to determine the pressure loss of the flow path for the high load from the reading value of the flow meter 7 without adding a special device, and it is possible to avoid reducing the efficiency such as fuel efficiency for the pressure loss measurement. Further, since the high load operation can be prohibited based on the determination result, it is possible to avoid the deterioration of the fuel cell due to the excessive high load operation under the condition that the accurate circulation amount cannot be secured.

  A purge unit that discharges the circulating fuel gas to the outside of the system under a predetermined condition is performed, and the pressure loss diagnosis method is executed while the purge unit is being executed. Therefore, the fuel gas is not thrown away only for the determination, and the fuel consumption is not deteriorated. It is possible to determine the pressure loss of the high load fuel gas flow path.

It is a block diagram concerning 1st embodiment. It is a block diagram concerning 2nd embodiment. It is a system flowchart concerning a second embodiment. It is a system flowchart concerning a second embodiment. It is a system flowchart concerning a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Gas-liquid separator 3 High load circulation device 4 Low load circulation device 5 Supply gas cutoff valve 6 Circulation gas cutoff valve 7 Flow meter 8 Pressure gauge 9 Pressure adjustment valve 10 Purge valve 11 Fuel gas supply piping 12 High Fuel gas supply piping for load 13 Circulation piping 14 Circulation piping for high load 15 Exhaust piping

Claims (7)

A fuel cell having a fuel cell supply port for supplying gas and a fuel cell discharge port for discharging;
First and second supply gas passages for supplying gas to the fuel cell;
Moisture adjusting means for adjusting the amount of moisture contained in the exhaust gas discharged from the fuel cell;
A first circulation means for sending the exhaust gas after passing through the moisture adjusting means to the first supply gas flow path; and a second circulation means for sending to the second supply gas flow path,
The moisture adjusting means has an exhaust gas inlet through which exhaust gas flows, and first and second exhaust gas outlets for discharging a gas whose moisture in the exhaust gas is adjusted,
The first and second circulation means have first and second gas suction ports for sucking gases discharged from the first and second exhaust gas discharge ports, respectively.
The fuel cell supply port and the fuel cell discharge port are arranged side by side on the same side surface of the fuel cell,
The moisture adjusting means and the second circulation means are disposed between the fuel cell supply port and the fuel cell discharge port,
The first gas discharge port is disposed in a substantially vertical direction of the first gas suction port,
The second gas suction port and the second exhaust gas discharge port are arranged at the same height,
The first circulation channel connecting the first gas inlet and the first gas exhaust port has a structure in which the inside of the channel communicates when the fuel cell is stopped,
A second circulation passage connecting the second gas suction port and the second gas discharge port, a pipe connecting the fuel cell discharge port and the moisture adjusting means inlet, and gas from the second circulation means A pipe connecting the circulating gas discharge port for discharging the fuel cell and the fuel cell supply port,
The fuel cell device, wherein the second circulation channel is provided with a shut-off valve capable of shutting off gas. The fuel cell device according to claim 1, wherein
The fuel cell, the exhaust gas inlet, the second exhaust gas outlet, the circulating gas outlet, and the fuel cell supply port are arranged at the same height. apparatus. In the fuel cell device of claim 1 or claim 2,
The first circulation device is used at the time of low load operation of the fuel cell and at the start of the fuel cell,
The fuel cell device according to claim 1, wherein the second circulation device is used during high-load operation of the fuel cell. In the fuel cell device according to claim 1 to claim 3,
The first circulation device is used at the time of low load operation of the fuel cell and at the start of the fuel cell,
The fuel cell device according to claim 1, wherein the second circulation device is used during high-load operation of the fuel cell. In the fuel cell device according to claim 1 to claim 4,
The fuel cell device, wherein the use of the second circulation device is prohibited if the pressure loss of the flow path through which the gas flows only when the second circulation device of the fuel cell is used is a predetermined value or more. The fuel cell device according to claim 5,
Flow rate measuring means for measuring the flow rate of gas flowing into the fuel cell;
An exhaust passage for discharging the gas discharged from the fuel cell out of the system;
A second circulation passage connecting the second circulation means and the moisture adjusting means, and a first valve and a second valve for shutting off gas in the second gas supply passage;
While keeping the pressure of the gas supplied to the fuel cell constant,
Open when the first and second valves are closed, close when open,
A fuel cell device comprising pressure loss detecting means for judging the pressure loss based on a difference between measured values at the flow rate measuring means before and after opening and closing of the first and second valves. The fuel cell device according to claim 6,
The exhaust flow path has a third valve for blocking gas,
The pressure loss detection means includes
The fuel cell device is executed when the third valve is open.

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