JP2874923B2 - Control device for fuel cell device and fuel cell device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device and a fuel cell device for a fuel cell device, and more particularly, to starting and temperature characteristics of a fuel reforming device as a hydrogen production means in a fuel cell system. The present invention relates to a control device of a fuel cell device and a fuel cell device suitable for controlling the fuel cell device.

2. Description of the Related Art A conventional burner device has a triple port structure in which fuel is ejected from a port provided around an air nozzle and air is ejected from an outer peripheral port thereof, as described in, for example, JP-A-56-127108. Nozzle.

The fuel reformer, which is a means for producing hydrogen in the fuel electronic system, includes a burner and a reaction tube, and supplies the fuel to the reaction tube in the fuel reformer until the fuel reformer generates hydrogen. The temperature in the system from the control means for controlling the flow rates of the natural gas and steam to be supplied to the reaction tube is increased, and the anode exhaust gas, which is a mixed gas of hydrogen, carbon dioxide, steam and the like, remaining in the fuel cell body, is subjected to the above-mentioned modification. The temperature in the system for supplying to the burner in the heating apparatus was raised by nitrogen. For this reason, it took time to raise the temperature in the system. In addition, nitrogen for temperature rise is released to the atmosphere, and no consideration is given to reusing nitrogen gas.

[Problems to be Solved by the Invention] Fuel switching of a burner in a conventional fuel reforming apparatus is performed by burning two types of fuel, that is, natural gas combustion when the system is started, and anode exhaust gas which is fuel remaining in the fuel cell body during operation. However, when switching from natural gas combustion to anode exhaust gas fuel of the fuel remaining in the fuel cell main body, after the temperature in the fuel supply system from the fuel cell main body to the burner is increased, if the fuel is not supplied, the fuel cell will perform the above-described operation. Water vapor contained in the anode exhaust gas fuel, which is the fuel supplied to the burner, may be drained in the system and cause a burner that has been burning with natural gas and combustion air to go out. Therefore, a complicated fuel supply system is required because high-temperature flammable gas flows into the system and then inert gas such as nitrogen and carbon dioxide gas flows to remove the flammable gas from the system. In addition, there has been a problem that complicated control is required accordingly.

The burner in the fuel reformer is a burner having a plurality of nozzles having a concentric triple port structure. When the system is started, natural gas is supplied from the first port, combustion air is supplied from the third port, and system operation is performed. At times, the anode exhaust gas and the combustion air are ejected from the second port and the third port, respectively, to burn the burner.

In a conventional burner having a triple port structure, for example,
In the combustion state by natural gas and combustion air at the time of starting the system, no gas flows through the second port, so that unburned gas by natural gas circulates in the second port via the second port header. When the burner is misfired and the flame length becomes uneven, the stable combustion range is as small as about 1 air ratio, and it cannot be used as a fuel reforming burner for fuel cells and hydrogen production. Further, in switching from natural gas combustion at the time of system startup to anode exhaust gas combustion at the time of system operation, if an inert gas flows into the second port in the natural gas combustion state, the burner of the natural gas combustion misfires and the anode exhaust gas is discharged. There is a problem that it is difficult to switch between them. In addition, when used in a system with severe load fluctuation such as an on-site type fuel cell or hydrogen production device,
Due to a sudden change in load, the supply pressure of fuel or air fluctuates, and unstable combustion and misfire are likely to occur. In particular, when operating at partial load, the amount of fuel supplied to the fuel nozzle and the amount of air supplied to the air nozzle decrease, so that these flow rates decrease and deviate from the design point, causing unstable combustion and misfire phenomena. There is a problem that it is easy to invite.

Furthermore, in fuel cells, the composition,
It is basically not suitable because the calorific value is completely different as shown below.

Startup fuel ... Natural gas (CH _4, other) 9,000~11,000Kcal / Nm ³ operated at the fuel ... cell waste gas also ^{_{600~800Kcal / Nm 3 (CO 2,}} CO, H 2 gas containing H ₂ O), normal In the burner, a special partition is provided so as to enable uniform heating, so that the combustion chamber becomes large, and the size cannot be reduced.

As a method of responding to the type of fuel, there is a method of dividing the nozzle into a natural gas nozzle and a battery exhaust gas nozzle. However, there is no particular problem in a small-capacity fuel reformer, but in a large-capacity reformer, it is difficult to flow gas uniformly without increasing the number of nozzles and increasing the fuel header. . Further, in such a nozzle type burner, when the frequency of the combustion system and the combustion frequency are close to each other, combustion vibration occurs, so that there is a problem that unstable combustion and misfire are likely to occur.

The present invention has been made to solve the above-mentioned problems of the prior art.

A first object of the present invention is to shorten a heating time in a fuel supply system in a fuel reforming apparatus related to a hydrogen production apparatus and to make effective use of the heating fuel, and to start up a heating operation of the system. An object of the present invention is to provide a highly efficient control device for a fuel cell device in which time is reduced.

Further, a second object of the present invention is to provide a control device for a fuel cell device in which two types of supplied fuel of a burner of a fuel reformer can be easily switched, and the device can be simplified and control reliability can be improved. To provide.

Further, a third object of the present invention is to prevent a misfire or a non-uniform flame length due to circulation of unburned gas into the second port during conventional natural gas combustion, and to reduce a flame length in anode exhaust gas combustion. It is an object of the present invention to provide a fuel cell device provided with a burner device of a hydrogen production device that shortens the flame, ensures a wide combustion range, and generates combustion gas with a small temperature distribution deviation.

Furthermore, a fourth object of the present invention is to provide a fuel cell device provided with a burner device capable of obtaining stable combustion performance even with load fluctuation or partial load operation in which combustion oscillation is likely to occur and enabling uniform heating. Is to do.

Means for Solving the Problems In order to achieve the first object, a first invention according to a control device for a fuel cell device of the present invention comprises: a fuel cell main body; and supplying hydrogen to the fuel cell. A steam supply means for supplying steam, a steam heating means, a system for supplying natural gas, and a system for supplying combustion air to the hydrogen production apparatus. Supply switching means for switching each system for supplying the steam and the hydrogen fuel to the burner in the fuel cell and the hydrogen production apparatus, and means for controlling flow rates of the natural gas and the steam supplied to the hydrogen production apparatus. In the control device of the fuel cell device, a temperature sensor is provided at an inlet of the hydrogen production device on a path leading from the steam supply means to the hydrogen production device, and detects a temperature of the heated steam supply system. And a controller that controls the flow rates of natural gas and water vapor supplied to the hydrogen production device according to the temperature detected by the temperature detector, and controls the supply switching unit. Things.

In order to achieve the second object, a second invention according to a control device for a fuel cell device of the present invention comprises a fuel cell main body, a burner and a reaction tube, and supplies hydrogen to the fuel cell. A hydrogen producing apparatus for supplying the hydrogen producing apparatus, a steam supplying means for supplying steam, a steam heating means, a system for supplying natural gas, and a system for supplying combustion air to the hydrogen producing apparatus; A supply switching unit for switching each path for supplying the steam and the hydrogen fuel to the burner in the fuel cell and the hydrogen production device; and a unit for controlling flow rates of natural gas and water vapor supplied to the hydrogen production device. In the control device for a fuel cell device, a temperature provided at an inlet of the hydrogen production device in a path leading from the water vapor supply means to the hydrogen production device, and detecting a temperature of the heated steam supply system. A detector, a burner of the hydrogen production apparatus, a combustible gas detector provided at the burner inlet of a supply system for supplying the remaining fuel in the fuel cell body, and electrically connected to the temperature detector and the combustible gas detector. A controller connected thereto, the controller controls a flow rate of natural gas and water vapor supplied to the hydrogen production device in accordance with a temperature detected by the temperature detector, and In addition to controlling the switching means, in response to a signal detected by the combustible gas detector, the natural gas control valve is shut off when the fuel cell device is started, and fuel switching for burner combustion of the hydrogen production device is performed. Is a control circuit.

Further, in order to achieve the third object, the configuration of the fuel cell device according to the present invention comprises a fuel cell body, a burner and a reaction tube, and a hydrogen production device for supplying hydrogen to the fuel cell. A steam supply means for supplying steam, a steam heating means, a system for supplying natural gas, and a system for supplying combustion air to the hydrogen production apparatus, and steam and hydrogen fuel sent from the hydrogen production apparatus. The fuel cell device, comprising: a supply switching unit that switches each of the paths that supply to the burner in the fuel cell and the hydrogen production device; and a unit that controls a flow rate of natural gas and steam supplied to the hydrogen production device. The burner device of the manufacturing apparatus is formed by a first port formed by a first port wall, a second port wall surrounding the first port wall, and the first port wall. A nozzle having a triple port structure including a second port, and a third port formed by the third port wall surrounding the second port wall and the second port wall; A burner device, comprising: a plate for closing an outlet end face of a second port; and a slot-like notch formed on the circumference of the outlet end of the second port.

Still further, the fourth object is that the nozzle of the burner for the fuel reformer is connected to the nozzle for air, the nozzle for starting fuel and auxiliary fuel, the nozzle for exhaust gas remaining in the battery body or the nozzle for purifier exhaust gas. This is achieved by dividing the nozzle into three parts and restricting at least one of the nozzles.

[Operation] A fuel cell device, that is, a fuel cell system, includes a steam drum constituting a steam temperature increasing means, a burner in a fuel reformer related to a hydrogen production device, a reaction tube, a temperature detector provided at an inlet of the reaction tube, A three-way switching valve for switching the fuel supply system that has exited the reaction tube, the fuel cell body, a cooling water tank for cooling the fuel cell body, and a combustible gas provided at the burner fuel inlet of the system that supplies fuel remaining in the fuel cell to the burner A detector, an ejector that supplies water vapor and natural gas to the reaction tube,
It comprises a natural gas flow control valve for burning the burner when the system is started.

When the system is started, the burner is burning with natural gas and combustion air, and the temperature in the system up to the reaction tube is raised by the steam in the steam drum. The steam whose temperature has been raised in the system is supplied with thermal energy from the burner section in the reaction tube section.

The steam supplied with the thermal energy is supplied by a three-way switching valve to a fuel system supplied to the burner from the fuel cell main body, and the temperature in the system up to the burner is increased. The steam drained in the middle of the system is collected in a cooling water tank and used as cooling water for the fuel cell body.

The temperature detector in front of the reaction tube entrance in the fuel reformer,
When the temperature reaches a preset temperature at which the mixed gas of natural gas and steam can be converted to hydrogen gas inside the reaction tube, the steam supplied from the steam drum decreases, and the natural gas and steam are sent to the reaction tube section by an ejector. Supplied.
When the conversion of the mixed gas of natural gas and steam to hydrogen starts in the reaction tube, the three-way switching valve switches to the battery body side,
A fuel containing hydrogen gas as a main component is supplied to the fuel cell body.

In the fuel supply system from the fuel cell main body to the burner, the combustible gas detector at the burner fuel supply inlet detects the combustible gas at the start-up of the burner when the system starts up. By stopping the fuel cell by reducing the concentration and burning the anode exhaust gas from the fuel cell main body, the system startup time can be reduced, and the overall efficiency of the system can be increased.

The burner is constituted by a triple tube structure of a nozzle, and each port of the nozzle is formed concentrically, and the fuel at the time of startup is made of natural gas mainly composed of methane as in a fuel cell system. Under the condition that the fuel during operation is the anode exhaust gas containing hydrogen, and the flow rate is low in natural gas and the anode exhaust gas is large, natural gas is discharged from the center port and anode exhaust gas is discharged from the surrounding ports.
In addition, air is ejected from the outermost peripheral port. This is difficult in the flammability of natural gas, that is, the flame holding property from the combustion range and the burning speed, and it is necessary to prevent the vicinity of the nozzle of the natural gas jet flow from being excessively disturbed by the air jet flow to prevent the flame holding. As a preferable arrangement for relaxing, natural gas is spouted from the center port and air is spouted from the outermost port so as to increase the interval between the two jets.

Since the anode exhaust gas port outlet end face is closed by the plate, it is possible to prevent natural gas and unburned gas of air from flowing back to the anode exhaust gas port. On the other hand, the anode exhaust gas containing hydrogen has a good flame holding property because the combustion range is wide and the combustion speed is large, but the flame length tends to be long due to a large flow rate. Therefore, it is necessary to improve the mixing property with air as much as possible during the combustion of the anode exhaust gas, and the anode exhaust gas jet is preferably arranged so as to easily merge with the air jet. Spout to the side. At this time, the partition wall shape of the air port and the anode exhaust gas port is closed by a plate having a convex portion protruding inside the air port on the anode exhaust gas outlet end face, and a long hole is formed on the circumference of the wall at the lower end of the anode exhaust gas nozzle. The notch has a shape that opens to the air port side.

The burner in the fuel reformer includes three headers and nozzles for burning two types of fuel. By providing a throttle at the inlet of the nozzle, the fluid flows evenly. If the header portion is small, the drift becomes intense. Further, if the degree of throttle is changed for each nozzle in accordance with the direction of introduction of the fluid into the header, it is possible to make the nozzles flow evenly. Further, when combustion vibration is involved, if a pressure fluctuation value accompanying the vibration is grasped, a misfire can be prevented by generating a differential pressure equal to or larger than the fluctuation value in the throttle portion.

A burner with a so-called multi-nozzle structure consisting of multiple assemblies of these nozzles ensures a wide stable combustion area for heterogeneous fuels, switching from natural gas combustion to anode exhaust gas combustion, and combustion gas temperature distribution by flame dispersion. Alleviation of the deviation and shortening of the flame length are realized.

Embodiments Embodiments of the present invention will be described below with reference to FIGS. 1 to 8.

FIG. 1 is a system diagram showing a configuration of a fuel cell system according to one embodiment of the present invention, FIG. 2 is a sectional view of a fuel reformer in the fuel cell system of FIG. 1, and FIG. FIG. 4 is a sectional view of a burner portion of the fuel reformer shown in FIG. 2, FIG. 4 is a view taken along line AA of FIG. 3, and FIG. 5 is a partially cutaway perspective view showing details of a nozzle portion of the burner.

In FIG. 1, reference numeral 3 denotes a reaction tube portion containing a catalyst;
Is a burner section for raising the temperature of the reaction tube section 3, 5 is a fuel reforming apparatus relating to the hydrogen production apparatus, 6 is a three-way switching valve, and the three-way switching valve 6 is provided with steam discharged from the fuel reforming apparatus 5. And a means for switching each system path for supplying hydrogen fuel to the fuel cell and the burner.

Reference numeral 7 denotes a fuel cell main body, 8 denotes a cooling water pump, 9 denotes a water supply pump, 10 denotes a cooling water tank, and 11 denotes a steam drum relating to a steam temperature raising means.

Reference numeral 12 denotes a temperature detector for detecting the temperature of the heated steam supply system. The temperature detector 12 is provided in a reaction pipe section 3 of a steam pipe 21 which is a path leading from the steam supply means to the fuel reformer 5. Provided at the entrance.

Reference numeral 13 denotes a combustible gas detector provided at the burner 4 inlet of the fuel pipe 25 for supplying the fuel remaining in the fuel cell body 7.

14 is a blower for supplying combustion air 2 to the burner,
15 is to adjust the flow rates of the natural gas 1 and the steam to form the reaction tube 3
It is an ejector to supply to.

Reference numeral 16 denotes a controller, which is, as shown by a broken line,
It is electrically connected to a temperature detector 12, a combustible gas detector 13, an ejector 15, a three-way switching valve 6, a natural gas control valve 17, a drain valve 18, and a natural gas shut-off valve 31.

Reference numeral 19 denotes a condenser, and reference numerals 20 and 21 denote steam pipes for raising the temperature of the system up to the reaction tube 3 by the steam in the steam drum 11. The systems 22, 23, 24, and 25 are fuel pipes for raising the temperature of the fuel supplied from the fuel cell main body 7 to the burner unit 4. Two
The systems 7, 24 and 25 are fuel pipes for supplying the fuel remaining in the fuel cell main body 7 to the burner unit 4.

A more detailed function and operation of such a fuel cell system will be described.

Controller 16 inputs the detection signal T detected by the temperature detector 12, which predefined reaction tube inlet temperature signal T ₀ and compares the magnitude relation, and, depending on this comparison result When the detected temperature T reaches the specified temperature T ₀ , the valve opening of the ejector 15 is adjusted to reduce the flow rate of steam from the steam drum 11, the shutoff valve 31 is opened, and natural gas flows through the pipe 34, and the ejector 15 Thus, the natural gas 1 and the flow rate of steam supplied to the reaction tube section 3 in the fuel reformer 5 are controlled.

The combustible gas detector 13 outputs the detection signal K to the controller 16. The detection signal K input to the controller 16 is compared with a predetermined combustible gas signal K _0, and the input signal K is changed to K _0.
When the control value matches, the control valve 17 adjusts the valve opening and decreases the flow rate of the natural gas 1 supplied to the burner unit 4.

The controller 16 compares the combustible gas concentration with K ₁ , K ₂ , and K ₃ defined in the controller 16 based on the output signal K output from the combustible gas detector 13, and compares it with the output signal K. Control valve
17 controls, when the combustible gas output signal K is consistent with the K _3, stop the regulating valve 17, performs control to stop the supply of the natural gas fuel to the burner unit 4.

Specifically, when starting the system,
The combustion gas 2 is supplied to the burner section 4 in the fuel reformer 5 by the natural gas 1 and the blower 14, and the burner section 4 performs natural gas combustion.

At this time, the steam in the steam drum 11 raises the temperature of the steam pipes 20 and 21 and the pipe system up to the reaction pipe section 3 in the fuel reformer 5. The supply steam flow rate is
Controlled by 15. The steam that has been heated in the piping system of the steam pipes 20 and 21 is supplied with thermal energy by the burner unit 4 in the reaction tube unit 3 to increase the temperature in the piping system of the fuel piping 22, 23, 24 and 25. At this time, the three-way switching valve 6
It is switched so that steam is supplied to the 23 side.

When the steam that is raising the temperature in the piping system of the fuel pipes 22, 23, 24, and 25 is drained, it is turned into water in the condenser 19 through the drain valve 18 through the drain pipe 32, and cooled through the water pipe 33. Collected in the water tank 10. The collected water is used as cooling water for the fuel cell main body 7 by a water supply pump 9 and a cooling water pump 8.

The steam whose temperature has been raised in the piping system of the fuel pipes 22, 23, 24, 25 is supplied to the burner unit 4 and burned in the natural gas 1 and the fuel air 2.

The temperature detector 12 attached to the inlet of the reaction tube section 3 detects the temperature in the steam pipe 21 and outputs a detection signal T to the controller 16. The temperature T _{0 at} which the mixed gas of natural gas and water vapor is converted to hydrogen in the reaction tube section 3 containing the catalyst is specified in the controller 16 in advance, so that the detection signal T sent from the temperature detector 12 and The magnitude relationship of T ₀ is compared and examined. When T is equal to T ₀ , the temperature-raising steam from the steam drum 11 is reduced by the ejector 15 and supplied to the reaction tube section 3. The shut-off valve 31 for the natural gas 1 is opened, and the natural gas 1 and the steam flow rate in the steam drum 11 are controlled by the controller 16 to control the ejector 15 to supply fuel to the reaction tube section 3.

When a specified time has passed since the natural gas 1 and steam were supplied by the ejector 15 and the temperature T and T ₀ of the temperature detector 12 in the inlet system of the reaction tube 3 coincided, the three-way switching valve 6 was controlled by the controller 16 to The hydrogen gas is supplied to the fuel cell main body 7 by switching to the pipe 26 side of the fuel cell main body 7 side.

A hydrogen mixed gas (hereinafter, referred to as anode exhaust gas) containing water vapor, carbon dioxide gas, and the like remaining in the fuel cell main body 7 is supplied to the burner unit 4 through a piping system of fuel piping 27, 24, and 25 and is supplied as fuel. used.

When the combustible gas detector 13 detects combustible gas, the controller
A detection signal K is output to the controller 16, and a comparison is made between the detection signal K ₀ preset in the controller 16 and the detection signal K. If the detection signal K matches K ₀ , the natural gas fuel supplied to the burner unit 4 is adjusted. The natural gas fuel 1 is decreased by adjusting the valve opening of the control valve 17, and when the predetermined signal K ₃ in the controller 16 matches the combustible gas detector output signal K, the control valve 17 is stopped. The supply of the natural gas fuel to the burner unit 4 is stopped, and the burner unit 4 performs anode exhaust gas combustion by the return fuel, the anode exhaust gas, and the combustion air 2 from the fuel cell body 7.

Next, FIG. 2 shows a fuel reformer of the fuel cell system of the present invention, FIG. 3 shows a cross-sectional view of a burner portion in the fuel reformer, and FIG. 4 shows a front view of a burner nozzle. The burner device according to the invention will be described.

FIG. 2 shows a burner section for fuel reforming and a fuel reforming section.

A mixed gas of natural gas and steam enters from the fuel inlet 36 and is supplied to the reaction tube 3. In the reaction tube section 3, heat energy is applied from the burner section 4, and when the temperature of the catalyst section rises to 600 ° C. or more by the fuel reforming catalyst 37, the mixed gas of natural gas and steam becomes a flammable gas containing hydrogen as a main component. The fuel is supplied from the reformed gas outlet 39 through the inside of the reaction tube 38 to the fuel cell body 7.

 The burner section 4 will be described in detail with reference to FIG.

FIG. 3 is a partial cross section of the burner 51 including an axial cross section of the nozzle 52 of FIG. 4, and FIG. 5 is a detailed view of a nozzle portion of the burner.

In FIG. 3, 55 is a nozzle tube constituting a first port wall, 54 is a nozzle tube constituting a second port wall surrounding the first port wall, and 53 is a nozzle tube constituting the second port wall. It is a nozzle tube which constitutes the surrounding third port wall.

67 is a natural gas port related to the first port, 66
Is the anode exhaust gas port related to the second port, 65 is
This is an air port according to the third port.

The nozzle 52 has a triple pipe configuration including the concentric nozzle pipes 53, 54, 55, and has a nozzle pipe having the same outer diameter as the outer diameter of the nozzle pipe 54.
A plate 75 having an inner diameter that is 0.1 to 0.2 mm larger than the outer diameter of 55 is fitted to the nozzle tube 55 and is joined to one end of the nozzle tube 54. Notches of long holes 78 are opened in the air port 65 at three places on the end circumference of the nozzle tube 54 on the side where the plate 75 is joined.

The lower ends of the nozzle tubes 53 and 55 shown in FIG. 3 and the lower surface of the plate 75 are flush with each other, but project from the other end of the nozzle tube 54 provided inside the nozzle tube 53 further into the burner 51. Nozzle tube 53 located inside burner 51
Is joined to a partition wall 56, and one end of the nozzle tube 54 is connected to a partition wall 57.
, And one end of the nozzle tube 55 is joined to the partition wall 58. The partition wall 59 at a position separated from the partition wall 58 by some distance,
It is vertically joined to the inner peripheral side of a body plate 61 having a flange 60. Similarly, the partition walls 56, 57, 58 are also vertically joined to the inner peripheral side of the body plate 61. Therefore, the air manifold 62 is formed by the partition walls 56 and 57 and the body plate 61, and the partition walls 57 and 58 and the body plate 6 are formed.
1 forms an anode exhaust gas manifold 63, and the partition walls 58, 59 and the body plate 61 form a natural gas manifold 64. The nozzle tube 53 and the partition 56 are joined so that the air port 65 formed between the nozzle tubes 53 and 54 is in fluid communication with the air manifold 62.
Similarly, the anode exhaust gas port 66 formed between the nozzle tubes 54 and 55 is joined to the nozzle tube 54 and the partition wall 57 so as to be in fluid communication with the anode exhaust gas manifold 63, and the inside of the nozzle tube 55 Formed natural gas port
The nozzle pipe 55 and the partition wall 58 are joined so that 67 is fluidly connected to the natural gas manifold 64.

An air supply pipe 68 is joined to the outer peripheral side of the body plate 61 so as to fluidly communicate with the air manifold 62. Similarly, body plate
An anode exhaust gas supply pipe 69 that is to be in fluid communication with the anode exhaust gas manifold 63 is joined to the outer peripheral side of 61, and the natural gas supply pipe 69 is in fluid communication with the natural gas manifold 64.
70 are joined.

A heat insulating material 71 is attached to the partition wall 56 between the wall surface of the partition wall 56 on the flame forming side and the position of the plane where one end of the nozzle pipes 53, 54, 55 is present on the same plane.

Thus, the structure centering on the nozzle 52 is combined to form the burner 51 of FIG.

The ignition device is provided at an appropriate position on the furnace wall.

 Next, the operation of this embodiment will be described.

In the process of activating the fuel cell system and bringing it to an operating state, air 72 flows from the air supply pipe 68 into the air manifold 62, blows out from the air port 65 into the furnace, and natural gas 73 flows into the natural gas supply pipe 70. Then, the gas flows into the natural gas manifold 64, and is discharged from the natural gas port 67 into the furnace to perform combustion, thereby heating the object to be heated and increasing its temperature.

At this time, the formation of the flame starts from the lower surface of the plate 75 near the inner periphery of the nozzle tube 54 where the stagnation of the natural gas 73 and the air 72 occurs. In order to secure flame holding, it is necessary to allow some space between the natural gas port 67 and the air port 65,
It is necessary to secure the flow velocity of the 73 jets to some extent.

When the temperature of the entire fuel cell system is increased and the fuel reformer 5 operates to generate hydrogen, the hydrogen is supplied to the anode of the fuel cell, and the anode exhaust gas 74 containing unreacted hydrogen is discharged from the anode. You. This anode exhaust gas 74
Instead of being supplied to the burner 51, the flow rate of the natural gas 73 is reduced, and the combustion in the burner 51 shifts from combustion of the natural gas 73 to combustion of the anode exhaust gas 74. The anode exhaust gas 74 flows from the anode exhaust gas supply pipe 69 into the anode exhaust gas manifold 63, passes through the anode exhaust gas port 66, and is ejected from the elongated hole 78 of the nozzle tube 54 into the air port 65 into the furnace. Until the anode exhaust gas flows into the anode exhaust gas supply pipe 69, the anode exhaust manifold 63, and the anode exhaust gas port 66, the steam 77 flows through the anode exhaust gas port.

At the same time that the anode exhaust gas 74 is ejected from the cutout of the long hole 78 of the nozzle tube 54 through the air port 65 into the furnace,
While controlling the flow rate of 72, it is adjusted so that the flame length does not become too long. At this time, the formation of the flame depends on the anode exhaust gas.
It starts from the cutout of the elongated hole 78 of the nozzle tube 54 where the air 74 and the air 72 start to join. When the anode exhaust gas 74 is burned, the flame length is maximized at the maximum rating of the system.Therefore, each port diameter and the oblong hole of the nozzle 54 are adjusted so that the balance between the flow rate of the anode exhaust gas 74 and the flow rate of the air 72 can be adjusted. Select a size of 78.

According to the present embodiment, the backflow of unburned gas to the anode exhaust gas port during natural gas combustion can be prevented, so that burner misfire can be prevented, and stable combustion and uniform combustion can be achieved over a wide range of excess air ratio λ = 5 or more. Since the flame length can be obtained, there is an effect that a combustion gas with a small temperature distribution deviation can be generated.

In addition, the triple port structure having a common air port enables combustion without increasing the number of nozzles and the diameter of the nozzles, and has the effect of improving manufacturability and economic efficiency.

In addition, the provision of the elongated hole cutout in the anode exhaust gas nozzle has the effect that the flame length is shortened and the combustion range can be expanded.

A restrictor 82 is attached to the natural gas port 67 inlet, a restrictor 81 is attached to the anode exhaust gas port 55 inlet, and a restrictor 80 is attached to the air port 65 inlet.

The natural gas 73 as a fuel flows from the outer peripheral side of the natural gas header 85 toward the center of the natural gas manifold 64 and flows out of the natural gas port 67.

The anode exhaust gas 74 and the air 72 also flow from the anode exhaust gas header 84 and the air header 83 to the center of the anode exhaust gas manifold 63 and the air manifold 62, respectively, and flow out of the anode exhaust gas port 66 and the air port 65, similarly to the flow of the natural gas. I do.

Within each manifold, throttle 8 to natural gas port 67 inlet
2, Anode exhaust port 66, throttle 81 at inlet, air port 6
5. Since the throttle 80 is attached to the inlet, even if combustion vibration occurs, the pressure loss generated in the throttle portion is larger than the pressure fluctuation value due to the vibration, so that the burner does not misfire.

In addition, by reducing the diameter of the throttle attached to the central portion of the throttle at the inlet of each nozzle from the diameter of the throttle attached to the outer peripheral side of the manifold, the flow rate of gas flowing through the ports of each nozzle becomes more uniform. Thus, the flame length during combustion can be made uniform.

As described above, according to this embodiment, the following effects can be obtained.

The fuel reformer is composed of a burner section and a reaction tube section. When the system starts, the burner section burns with natural gas and combustion air. The temperature is raised by steam in a process fuel line system that converts a mixed gas of the above into hydrogen into hydrogen, and the heated steam is supplied with heat energy from a burner in a reaction tube system.

As the control device of the present embodiment, a temperature detector for detecting the temperature in the reaction tube inlet system, and a detected temperature signal detected by the temperature detector are input, and a magnitude relationship with a predetermined temperature signal is obtained. A controller for controlling the amount of natural gas and water vapor supplied to the process fuel line by adjusting the amount of water vapor supplied to the process fuel line according to the comparison result, and an anode from the fuel cell body to the burner section. A detector for detecting flammable gas in a burner inlet system of a line for supplying exhaust gas fuel, and a detection signal detected by the flammable gas detector are input, and the magnitude of the signal is compared with a predetermined flammable gas signal. After a comparative study, a controller that controls the flow rate of natural gas supplied to the burner section and a burner device that does not misfire even when steam is introduced are added to the system according to the comparison result. As hereinbefore, it is possible to greatly shorten the heating time in the fuel supply system.

Next, according to the burner device of the present embodiment, natural gas is caused to flow to the center port of the burner nozzle having a triple port structure, anode exhaust gas is caused to flow to the surrounding ports, and air is caused to flow further to the outermost periphery. A burner for a fuel reforming device such as a hydrogen production device and a fuel cell system has an effect that even different types of fuel can be stably burned.

In addition, since a burner is formed by assembling a plurality of the above nozzles, there is an effect that a combustion gas having a small temperature distribution deviation can be obtained. Since the gas can be prevented from circulating in the anode exhaust gas port, there is an effect that the flame length can be averaged and an effect that it is difficult to cause a misfire.

Furthermore, in order to improve the mixing property between the anode exhaust gas and the air, a notch of a long hole is provided on the circumference of the lower end of the anode exhaust gas nozzle, and by opening to the air port side, the effect that the flame length is shortened, Due to the anode exhaust gas nozzle shape, there is an effect that even if steam is introduced during natural gas combustion, no misfire occurs and switching to anode exhaust gas combustion is easy.

In addition, as another effect of this embodiment, by providing a throttle at the inlet of each port of the triple-port structure nozzle,
Even if combustion oscillation occurs, there is an effect that a misfire does not occur and stable combustion can be performed with a uniform flame length.

Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a sectional view of a nozzle tube of a burner portion according to another embodiment of the present invention.

The embodiment shown in FIG. 6 is different from the embodiment shown in FIG. 3 in that a portion where the throttle and the nozzle at the nozzle entrance are integrated is different from the embodiment shown in FIG. 3, and each part of the burner device not shown is the same as that shown in FIG. is there.

That is, the throttle 80A is integrated with the nozzle pipe 53 constituting the air port 65, and the throttle 81A is
And the throttle 82A is formed integrally with the nozzle tube 55 forming the natural gas port 67.

By integrating the nozzle and the throttle, there is an effect that assembly and maintenance of the nozzle portion of the burner can be easily performed.

Next, FIG. 7 is a partially cutaway perspective view showing a nozzle portion of a burner device according to still another embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 5 denote the same parts, and a description thereof will be omitted.

The embodiment shown in FIG.
The difference is that a support plate 76 joined to 75A is provided. The support plate 76 may be in contact with the inside of the nozzle tube 53. In this embodiment, three support plates 76 are provided one by one around the nozzle tube 54 at three equally divided positions. These support plates 76 act as beams between the nozzle tubes 53 and 54 to prevent eccentricity when the nozzle tubes 54 are eccentric with respect to other nozzle tubes 53 due to fluctuations due to thermal effects. do.

According to the embodiment of FIG. 7, in addition to the effect of the embodiment of FIG.
The eccentricity between the nozzles can be prevented, and the reliability of the burner is improved. In addition, it is also possible to use these support plates as vanes for the swirling of air, increasing the mixability of natural gas and air during natural gas combustion,
There is also an effect that the flame length can be shortened.

Next, FIG. 8 is a partially cutaway perspective view showing a nozzle portion of a burner device according to still another embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 5 denote the same parts, and a description thereof will be omitted.

The embodiment shown in FIG.
The difference is that three protruding flame holding plates 79 in contact with 75B are provided. The flame holding plate 79 does not contact the inside of the nozzle 53, but protrudes to the center of the air port 65 and has a width. In this example, the flame holding plate 79 is a plate
It is provided at a position equally divided into the outer circumference of 75A.

According to the embodiment of FIG. 8, in addition to the effects of the embodiment of FIG. 3, the provision of the flame holding plate 79 in the air port allows the air flow ejected from the air port to collide with the flame holding plate. Since turbulence occurs in the place, there is an effect that the mixing property between natural gas and air is further improved.

[Effects of the Invention] As described in detail above, the present invention has the following effects.

1) High efficiency by shortening the heating time in the fuel supply system of the fuel reformer related to the hydrogen production device, and by effectively using the fuel for heating, and by shortening the startup time of the heating of the system. And a control device for the fuel cell device.

2) It is possible to provide a control device for a fuel cell device in which two types of supply fuel of a burner of a fuel reforming device can be easily switched, and the device can be simplified and control reliability can be improved.

3) The conventional method prevents natural gas from igniting due to circulation of natural gas into the port during combustion, or non-uniform flame length, shortens flame length in anode exhaust gas combustion, and secures a wide combustion range. It is possible to provide a burner device of a hydrogen production device that generates a combustion gas having a small temperature distribution deviation.

4) It is possible to provide a burner device capable of obtaining stable combustion performance even with load fluctuation and partial load operation in which combustion oscillation is likely to occur and enabling uniform heating.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration of a fuel cell system according to one embodiment of the present invention, FIG. 2 is a sectional view of a fuel reformer in the fuel cell system of FIG. 1, and FIG. FIG. 4 is a cross-sectional view of a burner portion of the fuel reformer shown in FIG. 2, FIG. 4 is a view taken along line AA of FIG. 3, FIG. FIG. 7 is a sectional view of a nozzle tube of a burner unit according to another embodiment of the present invention. FIG. 7 is a partially cutaway perspective view showing a nozzle unit of a burner device according to still another embodiment of the present invention. FIG. 8 is a partially cutaway perspective view showing a nozzle portion of a burner device according to still another embodiment of the present invention. 3 ... reaction tube section, 4 ... burner section, 5 ... fuel reformer, 6 ... 3-way switching valve, 7 ... fuel cell body, 8 ... cooling water pump, 9 ... water supply pump, 10 ... ... water tank for cooling, 11 ... steam drum, 12 ... temperature detector, 13 ...
Combustible gas detector, 14 …… Blower, 15 …… Ejector,
16 ... Controller, 17 ... Control valve, 20,21 ... Steam piping, 2
2,23,24,25,26,27 …… Fuel piping, 31 …… Shutoff valve, 51 ……
Burner, 53, 54, 55 …… Nozzle tube, 65 …… Air port, 66
…… Anode exhaust gas port, 67 …… Natural gas port, 7
5,75A, 75B …… Plate, 76 …… Support plate, 78 …… Long hole, 7
9 …… flame holding plate, 80,80A, 81,81A, 82,82A …… aperture.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadashi Oshima 603, Kandate-cho, Tsuchiura-shi, Ibaraki Pref.Hitachi, Ltd. (72) Inventor ▲ Ie ▼ Isao Hata 603, Kandamachi, Tsuchiura-shi, Ibaraki Prefecture Inside the Tsuchiura Plant, Hitachi, Ltd. ) Inventor Kazuhito Koyama 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (56) References JP-A-63-48771 (JP, A) JP-A-63-230503 (JP, A) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) H01M 8/00-8/24 C01B 3/32-3/48

Claims (8)

(57) [Claims] 1. A fuel cell main body, a hydrogen producing apparatus for supplying hydrogen to the fuel cell, a steam supplying means for supplying steam, a steam heating means, a system for supplying natural gas to the hydrogen producing apparatus, And a system for supplying combustion air; a supply switching unit for switching each system for supplying steam and hydrogen fuel sent from the hydrogen production device to a burner in the fuel cell and the hydrogen production device; and a hydrogen production device. A control device for a fuel cell device, comprising: means for controlling the flow rate of natural gas and steam supplied to the fuel cell device. The control device is provided at an inlet of the hydrogen production device in a path leading from the steam supply device to the hydrogen production device, and is heated. A temperature detector for detecting the temperature in the steam supply system, and a natural gas and a steam supplied to the hydrogen production apparatus in accordance with the detected temperature detected by the temperature detector. To control the amount, and the control apparatus for a fuel cell system, characterized by a controller for controlling the supply switching means comprises a. 2. A hydrogen production apparatus comprising a fuel cell main body, a burner and a reaction tube, for supplying hydrogen to the fuel cell, a steam supply means for supplying steam to the hydrogen production apparatus, and a steam heating means. , A system for supplying natural gas, and a system for supplying combustion air; and a supply for switching each system for supplying steam and hydrogen fuel sent from the hydrogen production device to a burner in the fuel cell and the hydrogen production device. A control device for a fuel cell device, comprising: a switching unit; and a unit that controls a flow rate of natural gas and steam supplied to the hydrogen production device. The hydrogen production device entrance of a path leading from the steam supply device to the hydrogen production device A temperature detector for detecting the temperature of the increased temperature of the steam supply system, and a supply system for supplying the fuel remaining in the fuel cell body to the burner of the hydrogen production apparatus. A flammable gas detector provided at the burner inlet; and a controller electrically connected to the temperature detector and the flammable gas detector. The controller adjusts the detected temperature detected by the temperature detector. Accordingly, the flow rate of natural gas and water vapor supplied to the hydrogen production device is controlled, and the supply switching means is controlled. In response to a signal detected by the combustible gas detector, a fuel cell power generator A control device for a fuel cell device, characterized in that a control circuit is configured to shut off a natural gas control valve that is open at the time of start-up, and to perform combustion switching of burner combustion of the hydrogen production device. 3. A hydrogen production apparatus comprising a fuel cell main body, a burner and a reaction tube, for supplying hydrogen to the fuel cell, a steam supply means for supplying steam to the hydrogen production apparatus, and a steam heating means. , A system for supplying natural gas, and a system for supplying combustion air; and a supply for switching each system for supplying steam and hydrogen fuel sent from the hydrogen production device to a burner in the fuel cell and the hydrogen production device. In a fuel cell device comprising switching means and means for controlling the flow rates of natural gas and steam supplied to the hydrogen production device, the burner device of the hydrogen production device has a first port wall formed by a first port wall. A second port formed by a port, a second port wall surrounding the first port wall, and the first port wall;
A third port wall surrounding the first port wall and a third port formed by the second port wall, the burner device having a nozzle having a triple port structure, A fuel cell device, comprising: a plate for closing an outlet end face of a port; and a notch on an elongated hole formed on the circumference of the outlet end of the second port. 4. A burner device of the hydrogen production apparatus, wherein a fuel containing hydrocarbon as a main component flows through a first port, a fuel containing hydrogen as a main component flows through a second port, and a fuel flows through a third port. 4. The fuel cell device according to claim 3, wherein air is made to flow. 5. The burner device of the hydrogen production apparatus, wherein a support portion is provided in the third port, the support portion being joined to the third port wall and the second port wall. 3. The fuel cell device according to 3. 6. The burner device of the hydrogen production apparatus according to claim 3, wherein the plate that closes the outlet end face of the second port is provided with a projection projecting into the second port. Fuel cell device. 7. The fuel according to claim 3, wherein the burner device of the hydrogen production device is a burner device having a nozzle having a triple port structure, wherein a throttle portion is provided in at least one place of the triple structure. Battery device. 8. The fuel cell device according to claim 7, wherein the burner device of the hydrogen production device comprises at least two or more nozzles, and the diameter of the throttle portion is different.