JP5892466B2 - Fuel cell device - Google Patents

Description

  The present invention relates to a fuel cell device that generates power using a fuel gas and an oxidant gas.

  A plurality of fuel cells that can obtain power using fuel gas and power generation air (oxidant gas) are housed in a casing, and fuel gas and power generation air are supplied to the plurality of fuel cells. Various fuel cell devices that generate electricity have been proposed. In such a fuel cell device, it is required that the temperature is quickly raised at a low temperature such as at the initial stage of startup and the power generation state is shifted as soon as possible. In order to meet the demand, there is known a fuel cell device that burns fuel gas and power generation air and raises the temperature of the fuel cell using the combustion heat. One of them is a fuel cell device disclosed in Patent Document 1.

The fuel cell device disclosed in Patent Literature 1 ignites above the tip of one fuel cell located on one end of a fuel cell assembly in which a large number of cylindrical fuel cells are arranged in a row. Plug is in place. The fuel gas discharged from the front end of the fuel cell via the fuel gas flow path inside the one fuel cell is ignited by a spark emitted from the ignition plug, and the one fuel cell generated by the ignition The combustion flame at the tip of the cell ignites (fires) the fuel gas discharged from the tip of the adjacent fuel cell, sequentially from one end to the other end of the upper part of the fuel cell assembly. Combustion occurs at the tip of all fuel cells.

JP 2010-67547 A

However, in the above configuration, the shape of the fuel gas discharge part of a part of the fuel cells constituting the fuel cell assembly is poor, and the fuel gas supplied to the fuel cell assembly and the power generation air are dispersed. Due to a defect or the like, the fuel gas discharged from some of the fuel cells is not discharged in a desired direction or in a desired amount, whereby in some of the fuel cells constituting the fuel cell assembly, In some cases, the fuel gas discharged from the fuel cell cannot come into contact with the nearby combustion flame, and the combustion flame generated by the contact may not be ignited. Similarly, ignition may not occur in some fuel cells constituting the fuel cell assembly due to variations in the installation angle of the fuel cells and the pitch between the fuel cells. . The fact that ignition does not occur means that the fire transfer stops in the middle, and if the fire transfer stops in the middle, the unburned fuel discharged from the fuel cell that does not burn at the tip. Since the gases are released to the outside of the fuel cell device, these fuel gases are wasted. Also, if the fire transfer stops in the middle, there is a fuel cell that does not burn at the tip, so the amount of heat applied to the fuel cell assembly is reduced, and the temperature of the fuel cell device is increased. The speed will drop. Therefore, the time until the fuel cell device reaches a temperature at which power can be generated becomes longer. This is very inconvenient for the user.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a fuel cell device capable of improving the transferability of a combustion flame during an ignition operation.

The fuel cell device according to the present invention comprises a fuel cell that discharges fuel gas from one end and a plurality of the fuel cells, so that the fuel gas is discharged in substantially the same direction from substantially the same plane. A fuel cell assembly arranged side by side, a casing covering the fuel cell assembly, a fuel gas supply means for supplying fuel gas to the fuel cell, and an oxidant gas to the outer periphery of the fuel cell An oxidant gas supply means, and a fuel in the fuel gas discharge direction side of the fuel cell so that the oxidant gas passing through the outer periphery of the fuel cell and the fuel gas discharged from the fuel cell are burned. Ignition in a fuel cell having a combustion chamber provided adjacent to a battery cell assembly and ignition means for generating a spark to ignite fuel gas discharged from the fuel cell During ignition operation to generate a spark by stage, than before the ignition operation and having a turbulence amplifying means for disturbing the flow of the combustion chamber of the gas.

In the present invention configured as described above, the gas flow in the combustion chamber is generated by disturbing the gas flow in the combustion chamber more than before the ignition operation in which the fuel gas and the oxidant gas are supplied to the combustion chamber at a predetermined supply amount. The combustion flame at the tip of the fuel cell is greatly shaken forward, backward, left, and right, and the fuel gas discharged from the fuel cell that does not burn at the tip is more diffused around the fuel cell. It can be made easier. As a result, the combustion flame at the tip of the fuel battery cell and the fuel gas discharged from the fuel battery cell adjacent to the fuel battery cell are more likely to come into contact with each other than before the ignition operation. Accordingly, the combustion flame is apt to be ignited sequentially to the unburned fuel gas discharged from the fuel cell in which no combustion occurs at the tip, so that the fire transfer property of the combustion flame during the ignition operation can be improved. .

  In the present invention, preferably, the turbulence amplification means is composed of a fuel gas supply means and an oxidant gas supply means, and a control means for controlling the supply amounts of the fuel gas supply means and the oxidant gas supply means. During the ignition operation by the ignition means, the flow of gas in the combustion chamber is disturbed by changing the amount of gas supplied from at least one of the fuel gas supply means and the oxidant gas supply means.

In the present invention configured as described above, at the time of the ignition operation, the flow rate of the gas flowing into the combustion chamber is changed by changing the supply amount of at least one of the fuel gas and the oxidant gas. Disturb gas flow. Therefore, it is only necessary to change the supply amount of fuel gas and oxidant gas essential for power generation, and it is not necessary to separately provide a device for disturbing the flow of gas, without increasing the equipment cost, Easily improve fire transfer.

In the present invention, it is preferable that the control means keeps the supply amount of the fuel gas supplied by the fuel gas supply means constant during the ignition operation, and the supply amount of the oxidant gas supplied by the oxidant gas supply means. Fluctuate.

In the present invention configured as described above, the discharge flow rate of the fuel gas discharged from the fuel cells is stabilized by keeping the supply amount of the fuel gas, which is an ignition object, constant. Therefore, even if a large fluctuation is generated in the combustion flame, it is difficult to misfire, so that it is possible to improve the fire transfer property more reliably. Further, since only the supply amount of the oxidant gas is changed, the supply amount of the fuel gas, which is more expensive than the oxidant gas, can be suppressed to the minimum supply amount necessary for combustion, which is economical.

In the present invention, preferably, the control means supplies the oxidant gas supplied by the oxidant gas supply means during the ignition operation within a range equal to or less than a predetermined supply amount supplied by the oxidant gas supply means before the ignition operation. Vary the amount.

In the present invention configured as described above, since the supply amount of the oxidant gas is varied within a predetermined supply amount before the ignition operation, the supply amount of the oxidant gas may be larger than that before the ignition operation. Absent. Accordingly, misfire of the combustion flame generated by increasing the supply amount can be prevented, and the fire transfer property can be improved more reliably.

In the present invention, preferably, the control means alternately changes the supply amount of the oxidant gas supplied by the oxidant gas supply means to two different supply amounts.

In the present invention configured as described above, it is only necessary to alternately change the supply amount of the oxidant gas supplied by the oxidant gas supply means to two different supply amounts. Can be improved.

In the present invention, preferably, the oxidant gas supply means supplies the oxidant gas in a direction in which the oxidant gas collides with an outer peripheral surface of a cell constituting the fuel cell assembly.
.

In the present invention configured as above, the oxidant gas whose flow is disturbed by colliding with the outer peripheral surface of the fuel cell constituting the fuel cell assembly is directed to the combustion chamber. The flow can be further disturbed, and the fire transfer property can be further improved.

In the present invention, preferably, the combustion chamber is provided with temperature detection means for detecting the temperature in the combustion chamber, and the control means is based on the temperature detected by the temperature detection means, and the ignition state is a fuel cell assembly. The supply amount of the oxidant gas is continuously changed by the oxidant gas supply means until it is determined that a complete ignition state in which combustion occurs at the front end of the fuel gas discharge side of all the fuel cells constituting the fuel cell.

In the present invention configured as described above, the flow of gas in the combustion chamber continues to be disturbed until combustion occurs at the discharge-side tips of all the fuel cells constituting the fuel cell assembly. It is possible to transfer to the fuel gas discharged from the battery cell.

In the present invention, preferably, the control means fluctuates the supply amount of the oxidant gas by the oxidant gas supply means only when it is not determined that the ignition state has reached the complete ignition state within a predetermined time from the start of the ignition operation. Let

In the present invention configured as described above, only when the ignition state is not a complete ignition state, the flow of the oxidant gas is changed by the oxidant gas supply means to disturb the gas flow in the combustion chamber. It is possible to efficiently improve the fire transfer property without imposing a load more than necessary on the gas supply means.

  According to the fuel cell device of the present invention, it is possible to improve the fire transfer property during the ignition operation.

1 is an overall configuration diagram showing a fuel cell device 1 according to an embodiment of the present invention. It is a perspective view which shows the external appearance of the fuel cell module 2 which concerns on embodiment of this invention. It is sectional drawing in the center vicinity of FIG. 2, Comprising: It is sectional drawing which shows the cross section seen from the A direction of FIG. It is sectional drawing in the center vicinity of FIG. 2, Comprising: It is sectional drawing which shows the cross section seen from the B direction of FIG. It is a perspective view which shows the state which removed some outer plates from the casing 56 of FIG. FIG. 4 is a schematic diagram corresponding to FIG. 3, and is a schematic diagram showing flows of power generation air and combustion gas. FIG. 5 is a schematic diagram corresponding to FIG. 4, and is a schematic diagram showing flows of power generation air and combustion gas. It is a fragmentary sectional view which shows the fuel cell unit 16 used for embodiment of this invention. It is a perspective view which shows the structure of the fuel cell stack 14 which concerns on embodiment of this invention. It is a top view which shows the arrangement position of the igniter 42 and the temperature sensor 48 which concern on embodiment of this invention. 2 is a block diagram showing an electrical configuration around a control unit 10 and a functional configuration of the control unit 10 according to an embodiment of the present invention. FIG. It is a flowchart which shows the control content of the fuel cell apparatus which concerns on embodiment of this invention. It is a time chart which shows the control content of the fuel cell apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the mode at the time of ignition of the fuel cell apparatus which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  FIG. 1 is an overall configuration diagram of a fuel cell device according to an embodiment of the present invention. As shown in FIG. 1, a fuel cell device 1 according to an embodiment of the present invention includes a fuel cell module 2 and an auxiliary unit 4.

  First, the main configuration of the fuel cell module 2 will be described. The fuel cell module 2 includes a casing 56, and a fuel cell assembly 12 that performs a power generation reaction with fuel gas and power generation air (oxidant gas) is disposed in the power generation chamber 6 below the casing 56. Yes. Above the power generation chamber 6 is provided a combustion chamber 18 in which fuel gas not used in the power generation reaction and power generation air (oxidant gas) are combusted, and combustion gas is generated by combustion in the combustion chamber 18. It is supposed to be. A reformer 20 that reforms the fuel gas is disposed above the combustion chamber 18, and reaches a temperature at which the reformer 20 can undergo a reforming reaction by the combustion heat of combustion in the combustion chamber 18. So that it is heated. Further, a heat exchanger 22 for heating the power generation air passing through the interior by combustion heat is disposed above the reformer 20.

Next, the auxiliary machine unit 4 will be described. The auxiliary unit 4 adjusts the flow rate of the water supplied from the pure water tank 28 to the fuel cell module 2 by storing the water from the water supply source 26 such as tap water and making it pure water with a filter. A water flow rate adjusting unit 30 (such as a “water pump” driven by a motor) is provided. The auxiliary unit 4 is a fuel flow rate adjustment unit 34 (corresponding to fuel gas supply means) that adjusts the flow rate of the fuel gas supplied from the fuel supply source 32 such as city gas to the fuel cell module 2, and is a motor. A “fuel pump” to be driven) and a power generation air flow rate adjustment unit 38 (corresponding to an oxidant gas supply means) for adjusting the flow rate of air for power generation reaction supplied from the air supply source 36 to the fuel cell module 2 An air blower driven by a motor, etc.) and a reforming air flow rate adjustment unit 40 (with a motor) for adjusting the flow rate of the reforming reaction air supplied from the air supply source 36 to the fuel cell module 2. Driven "air blower" etc.). Further, the auxiliary unit 4 is provided with a control unit 10 which is a control means for controlling the supply amount of fuel gas and power generation air.

Next, based on FIGS. 2-5, the structure of the fuel cell module 2 in this embodiment is demonstrated in detail. FIG. 2 is a perspective view of the fuel cell module 2 in the present embodiment, and the height direction of the fuel cell module 2 is the y-axis direction. The x axis and the z axis are defined along a plane perpendicular to the y axis, the direction along the short direction of the fuel cell module 2 is defined as the x axis direction, and the direction along the longitudinal direction of the fuel cell module 2 is defined as z. Axial direction. The x-axis, y-axis, and z-axis described in FIG. 3 and thereafter are based on the x-axis, y-axis, and z-axis in FIG. Further, the direction along the negative direction of the z axis is the A direction, and the direction along the positive direction of the x axis is the B direction. 3 is a cross-sectional view of the fuel cell module 2 as viewed from the direction A in FIG. 2 in the vicinity of the center thereof. 4 is a cross-sectional view of the fuel cell module 2 as viewed from the direction B in FIG. 2 in the vicinity of the center thereof. FIG. 5 is a perspective view showing a state where a part of the casing 56 covering the fuel cell assembly 12 is removed from the fuel cell module 2 shown in FIG.

  As described above, the fuel cell module 2 includes the casing 56 that houses the fuel cell assembly 12 and the heat exchanger 22 that is provided on the upper portion of the casing 56. An igniter insertion port 44 is formed on one long side surface of the casing 56, and an igniter 42 (ignition means) that generates a spark to induce combustion in the combustion chamber 18 in the igniter insertion port 44. Inserted and installed.

A temperature sensor insertion port 46 is formed on the other long side surface, and a temperature sensor 48 (temperature detection means) such as a thermocouple for detecting the temperature inside the combustion chamber 18 is inserted into the temperature sensor insertion port 46. Is installed. In addition, a fuel gas / reforming air supply pipe 60 and a water supply pipe 62 are connected to the casing 56. On the other hand, a power generation air introduction pipe 74 and a combustion gas discharge pipe 82 are connected to the heat exchanger 22.

  The fuel gas / reforming air supply pipe 60 is a pipe for supplying fuel gas (reformed gas for reforming such as city gas) into the casing 56 and air used when reforming the fuel gas. The upstream end is connected to the fuel flow rate adjustment unit 34 and the reforming air flow rate adjustment unit 40. The water supply pipe 62 is a pipe for supplying water used when reforming the fuel gas, and the upstream end is connected to the water flow rate adjustment unit 30. The combustion gas discharge pipe 82 is a pipe line for discharging the combustion gas generated as a result of burning the remaining fuel gas not used in the power generation reaction and the power generation air. The power generation air introduction pipe 74 is a conduit for supplying power generation air for causing a power generation reaction with the reformed fuel gas, and the upstream end is connected to the power generation air flow rate adjustment unit 38.

  In the present embodiment, an evaporating mixer (not explicitly shown) for evaporating the water supplied from the water supply pipe 62 is provided inside the reformer 20. The evaporative mixer is heated by the combustion gas to convert water into water vapor and to mix the water vapor, fuel gas (reformed gas) and air.

  The fuel gas / reforming air supply pipe 60 and the water supply pipe 62 are both led to the inside of the casing 56 and then connected to the reformer 20. More specifically, as shown in FIG. 4, the reformer 20 is connected to an end on the right side in the drawing, which is an upstream end of the reformer 20.

  The reformer 20 is disposed further above the combustion chamber 18 formed above the fuel cell assembly 12. Therefore, the reformer 20 is heated by the combustion heat generated by the fuel gas and the power generation air, and is configured to serve as an evaporating mixer and as a reformer 20 that causes a reforming reaction. .

  The upper end of the fuel supply pipe 66 is connected to the downstream end (the left end in FIG. 4) of the reformer 20. The lower end side 66 a of the fuel supply pipe 66 is disposed so as to enter the fuel gas tank 68.

  As shown in FIGS. 3 to 5, the fuel gas tank 68 is provided directly below the fuel cell assembly 12. A plurality of small holes (not shown) are formed along the longitudinal direction (A direction) on the outer periphery of the lower end side 66 a of the fuel supply pipe 66 inserted into the fuel gas tank 68. The fuel gas passing through the reformer 20 is uniformly supplied in the longitudinal direction into the fuel gas tank 68 through the plurality of small holes (not shown). The fuel gas supplied to the fuel gas tank 68 is supplied into a fuel gas flow path 88 (described later in detail) inside each fuel cell unit 16 constituting the fuel cell assembly 12, and the fuel cell unit. The inside of 16 is raised to reach the combustion chamber 18.

  Next, a structure for supplying power generation air to the inside of the fuel cell module 2 will be described with reference to FIGS. 3 to 5, 6, and 7. FIG. 6 is a schematic diagram corresponding to FIG. 3 and shows the flow of power generation air and combustion gas. FIG. 7 is a schematic diagram corresponding to FIG. 4, and similarly shows the flow of power generation air and combustion gas. As shown in these drawings, a heat exchanger 22 is provided above the reformer 20. The heat exchanger 22 is provided with a plurality of combustion gas pipes 70 and a power generation air flow path 72 formed around the combustion gas pipes 70.

  A power generation air introduction pipe 74 is attached to one end side (the right end in FIG. 4) of the upper surface of the heat exchanger 22. The power generation air is introduced into the heat exchanger 22 from the power generation air flow rate adjustment unit 38 by the power generation air introduction pipe 74.

As shown in FIG. 3, a pair of outlet ports 76 a of the power generation air flow path 72 is formed on the other end side (the left end in FIG. 4) on the upper side of the heat exchanger 22. The outlet port 76a is connected to a pair of communication channels 76. Further, power generation air supply passages 77 are formed on the outer sides of both sides of the casing 56 of the fuel cell module 2 in the width direction (B direction: short side surface direction).

Therefore, power generation air is supplied to the power generation air supply path 77 from the outlet port 76 a of the power generation air flow path 72 and the communication flow path 76. The power generation air supply path 77 is formed along the longitudinal direction of the fuel cell assembly 12. Furthermore, in order to blow out the air for power generation toward each fuel cell unit 16 of the fuel cell assembly 12 in the power generation chamber 6 at a position corresponding to the lower side of the fuel cell assembly 12. A plurality of outlets 78a and 78b are formed. The power generation air blown out from these air outlets 78 a and 78 b flows from the lower side to the upper side along the outer surface of each fuel cell unit 16.

Subsequently, a structure for discharging combustion gas generated by combustion of fuel gas and power generation air will be described. In the combustion chamber 18 above the fuel cell unit 16, combustion gas is generated by burning the fuel gas that has not been used for the power generation reaction and the power generation air. The combustion gas rises in the combustion chamber 18 and reaches the combustion gas collecting portion 21. As shown in FIG. 7, the combustion gas collecting portion 21 is provided with an opening 21a, and the combustion gas is guided into the opening 21a. The combustion gas that has passed through the opening 21 a reaches the other end side of the heat exchanger 22. In the heat exchanger 22, a plurality of combustion gas pipes 70 (combustion gas passages) for discharging combustion gas are provided. A combustion gas discharge pipe 82 is connected to the downstream end side of these combustion gas pipes 70 so that the combustion gas is discharged to the outside.

Next, the fuel cell unit 16 will be described with reference to FIG. FIG. 8 is a partial cross-sectional view showing the fuel cell unit 16 of the present embodiment. As shown in FIG. 8, the fuel cell unit 16 includes a fuel cell 84 and inner electrode terminals 86 respectively connected to the end portions in the vertical direction of the fuel cell 84.

The fuel cell 84 is a tubular structure extending in the vertical direction, and includes a cylindrical inner electrode layer 90 that forms a fuel gas flow path 88 therein, a cylindrical outer electrode layer 92, an inner electrode layer 90, and an outer side. An electrolyte layer 94 is provided between the electrode layer 92 and the electrode layer 92. The inner electrode layer 90 is a fuel electrode through which fuel gas passes and becomes a (−) electrode, while the outer electrode layer 92 is an air electrode in contact with air and becomes a (+) electrode.

Since the inner electrode terminals 86 attached to the upper end side and the lower end side of the fuel cell unit 16 have the same structure, the inner electrode terminal 86 attached to the upper end side will be specifically described here. The upper portion 90 a of the inner electrode layer 90 includes an outer peripheral surface 90 b and an upper end surface 90 c exposed to the electrolyte layer 94 and the outer electrode layer 92. The inner electrode terminal 86 is connected to the outer peripheral surface 90b of the inner electrode layer 90 through a conductive sealing material 96, and is further in direct contact with the upper end surface 90c of the inner electrode layer 90, thereby Electrically connected. A communication channel 98 that communicates with the fuel gas channel 88 of the inner electrode layer 90 is formed at the center of the inner electrode terminal 86.

Next, the fuel cell stack 14 will be described with reference to FIG. FIG. 9 is a perspective view showing the fuel cell stack 14 in the present embodiment.

As shown in FIG. 9, the fuel cell stack 14 includes 16 fuel cell units 16, and a lower end side and an upper end side of these fuel cell units 16 are respectively made of ceramic fuel gas tank upper plate 68 a and It is supported by the upper support plate 100. The fuel gas tank upper plate 68a and the upper support plate 100 are formed with through holes through which the inner electrode terminal 86 can pass.

Further, a current collector 102 is attached to the fuel cell unit 16. The current collector 102 electrically connects the inner electrode terminal 86 attached to the inner electrode layer 90 that is a fuel electrode and the outer peripheral surface of the outer electrode layer 92 that is the air electrode of the adjacent fuel cell unit 16. As a result, the fuel cell units 16 are all connected in series.

FIG. 10 is a plan view for explaining the arrangement positions of the igniter 42 and the temperature sensor 48 above the fuel cell assembly 12. As shown in FIG. 10, the igniter 42 is disposed on the A direction end side. The igniter 42 has an ignition plug 43 made up of an anode 43a and a cathode (ground electrode) 43b at its tip, and a high voltage is applied between these electrodes from a power source (not shown) to thereby connect the tip of the anode 43a and the tip of the cathode 43b. Spark discharge is generated in the gap, and the fuel gas discharged from the discharge port 99 of the fuel cell unit 16 at the end in the A direction is ignited by the spark generated at this time.

In the present embodiment, the igniter 42 is arranged so as to ignite the fuel gas discharged from the discharge port 99 of the fuel cell unit 16 arranged in the second row from the end in the A direction and in the second row from the base end in the B direction. Has been. Note that the combustion flame generated at the tip of the fuel cell unit 16 by this ignition sequentially ignites the fuel gas discharged from the adjacent cells, so that combustion occurs in the entire upper part of the fuel cell assembly 12. It is like that.

On the other hand, the temperature sensor 48 is disposed on the base end side in the A direction and detects the temperature above the fuel cell assembly 12 on the base end side in the A direction. In the present embodiment, the temperature sensor 48 detects the temperature. The measured temperature is considered to be equivalent to the temperature in the combustion chamber 18.

Next, the control unit 10 will be described with reference to FIG. FIG. 11 is a block diagram showing an electrical configuration around the control unit 10 and a functional configuration of the control unit 10 in the present embodiment. As shown in FIG. 11, a plurality of sensors are connected to the control unit 10. The power generation air flow rate detection sensor 108 is for detecting the flow rate of power generation air supplied to the power generation chamber 6, and is provided in the power generation air flow rate adjustment unit 38. The reforming air flow rate sensor 110 is for detecting the flow rate of the reforming air supplied to the reformer 20, and is provided in the reforming air flow rate adjustment unit 40. The fuel flow rate sensor 112 is for detecting the flow rate of the fuel gas supplied to the reformer 20, and is provided in the fuel flow rate adjustment unit 34. The water flow rate sensor 114 is for detecting the flow rate of pure water (steam) supplied to the reformer 20, and is provided in the water flow rate adjustment unit 30. Further, as described above, the temperature sensor 48 detects the temperature above the fuel cell assembly 12 on the base end side in the A direction.

The control unit 10 incorporates a CPU, ROM, RAM, timer, and the like (not shown), and the CPU captures the results detected by various sensors as data and stores them in various programs and RAM stored in the ROM. Various processes and controls described later are performed based on the data and the like.

When the control unit 10 in the present embodiment grasps this functionally, as shown in FIG. 11, the flow rate comparison processing unit 10a, the power generation air flow rate control unit 10b, the reforming air flow rate control unit 10c, The fuel flow control unit 10d, the water flow control unit 10e, the ignition state determination processing unit 10f, and the ignition control unit 10g are provided. The flow rate comparison processing unit 10a compares the detection results of the various flow rate sensors (108, 110, 112, 114) with the target supply amount of each supply stored in advance in the RAM, and compares the difference between them. It outputs to the control part (10b, 10c, 10d, 10e) corresponding to various flow volume adjustment units (30, 34, 38, 40).

  The control units (10b, 10c, 10d, 10e) corresponding to the various flow rate adjustment units (30, 34, 38, 40) are based on the output from the flow rate comparison processing unit 10a, and the various flow rate adjustment units (30, 34, 38). , 40) to output a control signal to control the supply amount in these flow rate adjusting units. For example, when the power generation air flow rate adjustment unit 38 is configured by an air blower, the power generation air flow rate control unit 10b controls the rotation speed of the air blower based on the output from the flow rate comparison processing unit 10a. Similarly, when the fuel flow rate adjustment unit 34 is configured by a fuel pump, the fuel control unit 10d controls the rotation speed of the fuel pump based on the output from the flow rate comparison processing unit 10a.

  When the detection result of the temperature sensor 48 is equal to or higher than a predetermined temperature stored in advance in the RAM, the ignition state determination processing unit 10f is attached to the tip of all the fuel cell units 16 constituting the fuel cell assembly 12. It is determined that combustion is occurring (complete ignition state), and the determination result is output to the ignition control unit 10g. On the other hand, when the detection result of the temperature sensor 48 is lower than a predetermined temperature stored in the RAM in advance, it is determined that the ignition state is not complete, and the determination result is output to the power generation air flow rate control unit 10b.

  Upon receiving the output from the ignition state determination processing unit 10f, the ignition control unit 10g turns the igniter 42 to the OFF state. On the other hand, the power generation air flow rate control unit 10b that has received the output from the ignition state determination processing unit 10f controls the power generation air flow rate adjustment unit 38 so that the supply amount of power generation air varies.

Next, the control content at the time of starting of the fuel cell apparatus 1 according to the present embodiment will be described. The fuel cell device 1 according to the present embodiment, when starting, starts a combustion operation that ignites the fuel gas, a partial oxidation reforming reaction (POX), an autothermal reforming reaction (ATR), and a steam reforming reaction (SR). However, in the following description, only the control content from the start of start to the completion of the ignition operation, which is directly related to the gist of the present invention, will be taken up, and the other control content will be described. Will not be described.

FIG. 12 is a flowchart showing the contents of control from the start of startup of the fuel cell device 1 in this embodiment to the completion of the ignition operation.

Step 131 is a step of starting the fuel cell device 1. When the fuel cell is started, the control unit 10 uses the reforming air flow rate adjusting unit 40 to supply fuel for reforming air at a predetermined supply amount. Supply to the battery module 2 is started (S132). Subsequently, the power generation air flow rate adjustment unit 38 starts supplying the power generation air to the fuel cell module 2 with a predetermined supply amount (S133). Next, supply of fuel gas to the fuel cell module 2 at a predetermined supply amount is started by the fuel flow rate adjusting unit 34 (S134).

When preparation for combustion in the combustion chamber 18 is completed by completing these steps (S131 to S133), the igniter 42 is then turned on (S135), and an ignition operation is started. Thus, ignition of the fuel gas discharged from the discharge port 99 of the predetermined fuel cell unit 16 of the fuel cell assembly 12 is started. After starting the ignition operation, an operation of a timer built in the control unit 10 is started, and an elapsed time from the start of the ignition operation is measured. Thereafter, it is determined whether or not the elapsed time measured by the timer has exceeded a predetermined time (S136). If the predetermined time has not been exceeded (NO in S136), the determination of whether or not the predetermined time has been exceeded is repeated. If the predetermined time has been exceeded (YES in S136), the temperature is detected based on the temperature detected by the temperature sensor 48. It is determined whether the ignition state is a complete ignition state (S137).

If it is determined that the ignition is complete (YES in S137), the igniter 42 is turned off (S140), and the ignition operation is terminated (S141). On the other hand, if it is determined that the ignition state is not complete (NO in S137), the power generation air supply amount fluctuation control described later is started to disturb the gas flow in the combustion chamber 18 (S138). Then, after starting the power generation air supply amount variation control, it is determined again whether or not the ignition state is the complete ignition state (S139). If it is determined that the ignition state is not complete (NO in S139), the same determination is repeated. If it is determined that the ignition is complete (YES in S139), the igniter 42 is turned off (S140), The process ends (S141).

  Next, the control content will be described based on the time chart shown in FIG. Note that the control content described below is based on a specific example, and the timing at which the control unit 10 determines that the ignition is complete is naturally different at each activation.

  When the start of the fuel cell device 1 is started at time t0 in FIG. 13, first, supply of reforming air and power generation air is started by the reforming air flow rate adjustment unit 40 and the power generation air flow rate adjustment unit 38. . In this embodiment, the supply amounts of reforming air and power generation air at this time are set to 5 L / min and 65 L / min, respectively.

Next, supply of fuel gas to the reformer 20 is started by the fuel flow rate adjustment unit 34 at time t1. The fuel gas and reforming air sent into each fuel cell unit 16 flow out from the upper end of each fuel cell unit 16, respectively. In the present embodiment, the supply amount of the fuel gas to be supplied at time t1 is set to 4 L / min.

  Next, at time t2, the igniter 42 is turned on and an ignition operation is started. If it is determined that the ignition state is not a complete ignition state at time t3 when a predetermined time has elapsed from the start of the ignition operation, the supply amount of power generation air is reduced to 55 L / min. Thereafter, at a time t4 when the predetermined time ta has elapsed, the supply amount of power generation air is returned to 65 L / min. Further, at the time t5 when the predetermined time tb has passed again, the supply amount of the power generation air is reduced again to 55 L / min, and at the time t6 when the predetermined time ta has passed, the supply amount of the power generation air is again reduced to 65 L / min. Return to min. Thereafter, the same operation is repeated until it is determined that the ignition state has reached the complete ignition state. Then, at time t9 when it is determined that the complete ignition state has been reached, the igniter 42 is turned off and the ignition operation is terminated.

In the fuel cell device 1 according to the present embodiment, the control unit 10 varies the supply amount of power generation air from time t3 to the complete ignition state (time t9) in the time chart shown in FIG. It is periodically changed to two supply amounts (65 L / min and 55 L / min). (In this specification, such control for changing the power generation air supply amount to two different supply amounts is referred to as “power generation air supply amount fluctuation control”.)

As a result, the flow rate of the power generation air flowing into the combustion chamber 18 changes periodically, so that the flow of gas in the combustion chamber 18 changes the reforming air at a predetermined supply amount necessary for combustion. It is more disturbed than before the ignition operation for supplying power generation air and fuel gas. Therefore, the combustion flame generated in the upper part of the fuel cell assembly 12 due to this disturbance greatly fluctuates front and rear, left and right before the ignition operation, and the fuel discharged from the fuel cell unit 16 in which no combustion occurs at the tip. Gas is likely to diffuse around. Therefore, since the combustion flame of the fuel cell unit 16 in which combustion has occurred at the tip and the fuel gas discharged from the adjacent fuel cell unit in which combustion has not occurred become easier to contact, the combustion flame is the fuel gas. This makes it easy to ignite, thereby improving the fire transfer property during the ignition operation.

More specifically, for example, in the time chart of FIG. 13, at time t <b> 3 when it is determined that the ignition state is not complete, a part of the many fuel cell units 16 constituting the fuel cell assembly 12 is included. Only the fuel cell unit 16 is in a state where combustion has occurred. Therefore, by performing power generation air supply amount fluctuation control from this state, as shown in FIG. 14, the fuel cell unit 16 (fuel cell unit located in the center of FIG. 14) in which combustion has occurred at the tip, as shown in FIG. This combustion flame is more likely to come into contact with the fuel gas discharged from the fuel cell unit 16 (fuel cell unit located on the left and right in FIG. 14) where no combustion occurs at the tip. Therefore, even when the fuel gas discharge state is not the desired state, such as when the fuel gas discharge direction is different from the desired discharge direction or the discharge amount is different from the desired discharge amount, It is easy for the fuel gas to ignite, and the fire transfer property can be improved.

As described above, by controlling the power supply air supply amount fluctuation control, the fire transfer property at the time of the ignition operation is improved, so that the combustion flame of the fuel cell unit 16 in which the combustion is generated at the tip is the fuel cell in which the combustion is not generated. The fuel gas discharged from the cell unit 16 is sequentially ignited, and combustion can be generated at the tips of all the fuel cell units 16 constituting the fuel cell assembly 12.

Further, in the present embodiment, since the supply amount of the power generation air is changed only when it is determined that the ignition is not in the complete ignition state even after a predetermined time has elapsed after the igniter 42 is turned on, in the complete ignition state In spite of this, the supply amount of power generation air is not changed. Therefore, the power generation air flow rate adjusting unit 38 is not wastefully loaded and is efficient. Further, when the power generation air supply amount is varied, generally, the power supply air supply amount before the ignition operation, which is set to a supply amount that does not cause the combustion flame at the tip of the fuel cell unit 16 to be misfired, is within a range. Since the supply amount of power generation air is varied, there is no concern that the supply amount of power generation air becomes too large and misfires the combustion flame. In addition, since the control unit 10 continues the power generation air supply amount variation control until it is determined that the ignition state has reached the complete ignition state, all the fuel cells constituting the fuel cell assembly 12 are surely formed. Combustion can be caused at the tip of the unit 16.

In the present embodiment, the power generation air is supplied from the side wall of the casing 56 to the inside of the casing 56 so as to pass between the fuel cell units 16 constituting the fuel cell assembly 12. The power generation air supplied from the side walls 56 collides with the outer peripheral surface of the fuel cell unit 16 and reaches the combustion chamber 18 in a state where the flow is disturbed. Therefore, with this configuration, the gas flow in the combustion chamber 18 can be more greatly disturbed.

As described above, by improving the fire transfer property at the time of the ignition operation, the ignition state is more likely to reach the complete ignition state, which is caused by the decrease in the heating rate of the fuel cell assembly 12 and the reformer 20. It is possible to prevent a decrease in startup speed.

In the present embodiment, the power supply air supply amount is varied in order to disturb the gas flow in the combustion chamber 18, but of course, the reforming air supply amount and the fuel gas supply amount are varied. Thus, the gas flow in the combustion chamber 18 can be disturbed. Further, in this embodiment, when performing the power generation air supply amount fluctuation control, the power supply air supply amount is periodically changed to two supply amounts, but the present invention is limited to this. Of course, the supply amount may be changed at an arbitrary timing. Thus, even if the supply amount is changed at an arbitrary timing, the same effect can be obtained.

In the present embodiment, the temperature sensor 48 detects the temperature in the combustion chamber 18 to determine the ignition state. However, the temperature sensor 48 detects the temperature of the reformer 20 or the heat exchanger 22 to determine the ignition state. It doesn't matter.

DESCRIPTION OF SYMBOLS 1 ... Fuel cell apparatus 2 ... Fuel cell module 4 ... Auxiliary machine unit 6 ... Power generation chamber 10 ... Control part 12 ... Fuel cell assembly 14 ... Fuel cell stack 16 ... Fuel cell unit 18 ... Combustion chamber 20 ... Reformation Unit 22 ... Heat exchanger 26 ... Water supply source 28 ... Pure water tank 30 ... Water flow rate adjustment unit 32 ... Fuel supply source 34 ... Fuel flow rate adjustment unit 36 ... Air supply source 38 ... Air flow rate adjustment unit 40 for power generation ... Reforming Air flow rate adjustment unit 42 ... igniter 43 ... ignition plug 43a ... anode 43b ... cathode 48 ... temperature sensor 56 ... casing 60 ... fuel gas / reforming air supply pipe 62 ... water supply pipe 66 ... fuel supply pipe 68 ... fuel gas tank 70 ... Combustion gas pipe 72 ... Power generation air flow path 74 ... Power generation air introduction pipe 76 ... Communication flow path 76a ... Outlet port 77 ... Power generation air supply paths 78a, 78b ... Outlet 82 ... Combustion gas discharge pipe 84 ... Fuel cell 86 ... Inner electrode terminal 88 ... Fuel gas channel 90 ... Inner electrode layer 92 ... Outer electrode layer 94 ... Electrolyte layer 98 ... Communication channel 99 ... Discharge port 108 ... For power generation Air flow rate sensor 110 ... reforming air flow rate sensor 112 ... fuel flow rate sensor 114 ... water flow rate sensor

Claims (8)

A fuel battery cell for discharging fuel gas from one end;
A plurality of fuel cells, and a fuel cell assembly in which the fuel cells are disposed side by side so that fuel gas is discharged in substantially the same direction from substantially the same plane;
A casing covering the fuel cell assembly;
Fuel gas supply means for supplying fuel gas to the fuel cells;
Oxidant gas supply means for supplying oxidant gas to the outer periphery of the fuel cell;
The fuel cell assembly is disposed on the fuel gas discharge direction side of the fuel cell so that the oxidant gas passing through the outer periphery of the fuel cell and the fuel gas discharged from the fuel cell are burned inside the casing. An adjacent combustion chamber;
And ignition means for igniting the fuel gas discharged from the fuel cell,
In a fuel cell having
Fuel cell system, characterized in that said at ignition operation by the ignition means and a turbulence amplifying means than before ignition operation disturb the flow in the combustion chamber of the gas. The turbulence amplification means is composed of the fuel gas supply means and the oxidant gas supply means, and a control means for controlling the supply amounts of the fuel gas supply means and the oxidant gas supply means,
The control means varies the amount of gas supplied from at least one of the fuel gas supply means and the oxidant gas supply means during the ignition operation by the ignition means, thereby changing the amount of gas in the combustion chamber. The fuel cell device according to claim 1, wherein the flow is disturbed. The control means keeps the supply amount of the fuel gas supplied by the fuel gas supply means constant during the ignition operation, and varies the supply amount of the oxidant gas supplied by the oxidant gas supply means. The fuel cell device according to claim 2, wherein the flow of gas in the combustion chamber is disturbed by this. The control means controls a supply amount of the oxidant gas supplied by the oxidant gas supply means during the ignition operation within a range equal to or less than a predetermined supply amount supplied by the oxidant gas supply means before the ignition operation. The fuel cell device according to claim 3, wherein the fuel cell device is varied. 5. The fuel cell device according to claim 4, wherein the control unit alternately changes the supply amount of the oxidant gas supplied by the oxidant gas supply unit to two different supply amounts. 6. The oxidant gas supply means supplies the oxidant gas in a direction in which the oxidant gas collides with an outer peripheral surface of a fuel cell constituting the fuel cell assembly. The fuel cell device according to claim 1. The combustion chamber is provided with temperature detecting means for detecting the temperature in the combustion chamber, and the control means constitutes the fuel cell assembly based on the temperature detected by the temperature detecting means. The supply amount of the oxidant gas is continuously changed by the oxidant gas supply means until it is determined that a complete ignition state in which combustion occurs at the front end of the fuel gas discharge side of all the fuel cells to be performed. The fuel cell device according to any one of claims 3 to 6. The control means varies the supply amount of the oxidant gas by the oxidant gas supply means only when it is not determined that the ignition state has reached the complete ignition state within a predetermined time from the start of the ignition operation. The fuel cell device according to claim 7.

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