Fuel cell electricity generating device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a fuel cell power generation device that generates electricity using a fuel cell, and more particularly to a temperature control of a fuel generator that produces fuel mainly composed of hydrogen.

【0002】

[Conventional technology]

FIG. 4 is a configuration diagram of a conventional fuel cell power generation device. A fuel cell 1 that generates power using fuel gas and an oxidizing agent, a fuel generator 2 that generates hydrogen-rich fuel gas by adding water to a power generation material such as city gas 13A and reforming it, and fuel generation. A power generation material regulator 3 that regulates the amount of power generation material and water supplied to the vessel 2, a combustor 4 that burns a combustion material such as city gas 13A and a residual fuel gas discharged from the fuel cell 1, and a combustor. Combustion raw material that adjusts the flow rate of the combustion raw material supplied to 4 to maintain the temperature of the fuel generator 2 at the temperature required to generate fuel from the power generation raw material (about 700 ° C when using a Ru-based catalyst). The controller 5 and the combustion fan 6 that supplies combustion air to the combustor 4 according to the amount of combustion raw material and residual fuel gas so that complete combustion is performed in the combustor 4, and air as an oxidizing agent are used as fuel. It has a blower 8 to supply to the battery 1.

【0003】

The power generation raw material regulator 3 has a predetermined ratio of the power generation raw material and water, that is, in the configuration of the fuel cell power generation device, and when city gas 13A is used as the power generation raw material, the standard state city gas 13A, 1L / min ( = 1.67 × 10^-5m³/ sec) (Hereinafter, "N" is added to the amount of gas in the standard state. That is, 1NL / min here) is 3 g / min (= 5.0 × 10).^-5The amount of power generation raw material (city gas 13A) and water supplied to the fuel generator 2 is adjusted so that the amount of fuel gas required for power generation of the fuel cell 1 can be generated by adding water of about kg / sec). Adjust.

【0004】

The residual hydrogen estimator 10 in the air supply amount regulator 7 calculates the amount of hydrogen generated by the fuel generator 2 from the flow rate of the city gas 13A, which is the power generation raw material set by the power generation raw material regulator 3, and also calculates the current. The amount of hydrogen consumed by the fuel cell 1 is calculated from the generated current of the fuel cell 1 detected by the detector 9, and the amount of hydrogen contained in the residual fuel gas supplied to the combustor 4 is calculated from the calculation results of both. ..

【0005】

The air-fuel ratio setting device 11 simply burns the amount of hydrogen in the residual fuel gas calculated by the residual hydrogen estimator 10 and the city gas 13A which is the combustion raw material set by the combustion raw material regulator 5. The amount of air containing oxygen is calculated, and the rotation speed of the combustion fan 6 is set so as to supply air having a predetermined air-fuel ratio (for example, air-fuel ratio 1.5) to the combustor 4 with respect to the calculated air amount.

【0006】

In the fuel cell power generation device as in the above conventional example, in the case of normal operation, only the residual fuel gas is burned to maintain the temperature of the fuel generator 2 at the temperature required for producing fuel. Then, the amount of heat is insufficient, and the combustion raw material is separately supplied to maintain the temperature of the fuel generator 2.

【0007】

Then, when the temperature of the fuel generator 2 becomes higher than the temperature required to generate the fuel, for example, the generated power becomes small and the amount of heat of the residual fuel gas temporarily increases, and at the same time, the fuel generator 2 becomes When the amount of fuel gas produced is small, or when the environmental temperature is high and the amount of heat released from the fuel generator 2 is small, the combustion material regulator 5 reduces the amount of combustion material sent to the combustor 4 or stops the supply. By doing so, the calorific value of the combustor 4 is adjusted and the temperature of the fuel generator 2 is controlled.

【0008】

However, in this configuration, since the means for lowering the temperature of the fuel generator 2 is not particularly equipped, it takes time to lower the temperature, and the temperature of the fuel generator 2 is higher than the temperature required to generate the fuel. Even if the temperature drops, the temperature must be raised by gradually increasing the supply of combustion raw materials so that the temperature does not rise too much. The temperature of the fuel generator 2 can be increased only by controlling the supply of combustion raw materials with the fuel raw material regulator 5. There was a problem that it was difficult to ensure stability.

【0009】

Furthermore, if for some reason the temperature of the fuel generator 2 rises too high above the temperature required to generate fuel, the temperature of the fuel generator 2 must be lowered immediately or the fuel generator 2 will rapidly start. In addition to the deterioration of performance, in the worst case, the fuel generator 2 is damaged, but there is a problem that the means for preventing it is not equipped.

【0010】

[Problems to be Solved by the Invention]

An object of the present invention is to solve the problems of the above-mentioned prior art.

【0011】

[Means for solving problems]

In order to solve the above problems, the present invention is characterized in that the following fuel cell power generation device is configured.

【0012】

The first invention (corresponding to the present invention according to claim 1) is a fuel cell main body that generates power with a fuel and an oxidizing agent and discharges residual fuel gas containing hydrogen, and the fuel from the power generation raw material and water. A fuel generator that burns the residual fuel gas and a combustion raw material to heat the fuel generator, a residual hydrogen estimator that estimates the amount of hydrogen in the residual fuel gas, and the combustor. A combustion raw material regulator for setting the amount of the combustion raw material supplied to the combustor and an air supply device for supplying air to the combustor are provided, and the amount of the combustion raw material supplied to the combustor is more than a threshold value. When small, it is a fuel cell power generator that supplies excess air to the combustor.

【0013】

The second invention (corresponding to the present invention according to claim 2) is a fuel cell main body that generates power with a fuel and an oxidizing agent and discharges residual fuel gas containing hydrogen, and the fuel from the power generation raw material and water. A fuel generator that burns the residual fuel gas and a combustion raw material to heat the fuel generator, a residual hydrogen estimator that estimates the amount of hydrogen in the residual fuel gas, and the combustor. A combustion material regulator for setting the amount of the combustion material supplied to the fuel generator, a temperature detector for detecting the temperature of the fuel generator, and an air supply device for supplying air to the fuel generator are provided. When the amount of fuel raw material supplied to the fuel generator is smaller than the threshold value, the amount of air supplied to the fuel generator is adjusted so as to keep the temperature of the fuel generator detected by the temperature detector appropriate. It is a fuel cell power generation device characterized by.

【0014】

The third invention (corresponding to the present invention according to claim 3) is a fuel cell main body that generates power with a fuel and an oxidizing agent and discharges residual fuel gas containing hydrogen, and the fuel from the power generation raw material and water. A fuel generator that burns the residual fuel gas and a combustion raw material to heat the fuel generator, a residual hydrogen estimator that estimates the amount of hydrogen in the residual fuel gas, and the combustor. A combustion raw material regulator for setting the amount of the combustion raw material supplied to the fuel generator, a temperature detector for detecting the temperature of the fuel generator, and a water amount regulator for adjusting the amount of the water are provided to the combustor. When the amount of the fuel raw material to be supplied is smaller than the threshold value, the amount of water supplied to the fuel generator by the water amount controller so as to keep the temperature of the fuel generator detected by the temperature detector appropriate. It is a fuel cell power generation device characterized by adjusting.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

【0016】

(Embodiment 1) FIG. 1 is a configuration diagram of a fuel cell power generation device according to the first embodiment of the present invention. The same components as in the conventional example are assigned the same numbers, and the description thereof is omitted here.

【0017】

During normal operation, in order to maintain the temperature of the fuel generator 2 at the temperature required to generate fuel (700 ° C when using a Ru-based catalyst), a combustion raw material is separately used in addition to the residual fuel gas. We are supplying. However, if the amount of power generated by the fuel cell 1 suddenly decreases due to a sudden drop in power demand, the amount of hydrogen in the residual fuel gas increases. If this is burned in the combustor 4 as it is, the control to reduce the reaction amount of the fuel generator 2 also works at the same time to reduce hydrogen, so the amount of heat consumed by the fuel generator 2 is reduced, and as a result, the fuel generator The temperature of 2 can be higher than the temperature required to produce fuel. Therefore, by performing the following control, it is possible to prevent the temperature of the fuel generator 2 from becoming higher than the temperature required to generate fuel without separately providing a cooling device for the fuel generator 2.

【0018】

The residual hydrogen estimator 10 in the air supply amount regulator 7 calculates the amount of hydrogen generated by the fuel generator 2 from the flow rate of the city gas 13A, which is the power generation raw material set by the power generation raw material regulator 3, and also calculates the current. The amount of hydrogen consumed by the fuel cell 1 is calculated from the generated current of the fuel cell 1 detected by the detector 9, and the amount of hydrogen contained in the residual fuel gas supplied to the combustor 4 is calculated from the calculation results of both. .. The second air-fuel ratio setter 12 just burns the amount of hydrogen in the residual fuel gas calculated by the residual hydrogen estimator 10 and the city gas 13A which is the combustion raw material set by the combustion raw material regulator 5. Calculate the amount of air containing enough oxygen to make it. Then, the amount of air multiplied by the air-fuel ratio λ calculated by (Equation 1) according to the supply amount Go [NL / min] of the city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is burned. The rotation speed of the combustion fan 6 is set so as to be supplied to the combustor 4, and the combustion fan 6 supplies the amount of air multiplied by the air-fuel ratio λ to the combustor 4. When Go is larger than the threshold x, the operation is in the normal mode, but when Go is smaller than the threshold x, the operation is in the cooling mode. At this time, since the amount of exhaust gas discharged from the combustor 4 through the fuel generator 2 increases, the amount of heat carried to the exhaust gas increases, and the amount of heat transferred to the fuel generator 2 decreases accordingly. Therefore, the temperature of the fuel generator 2 becomes relatively lower than when the air-fuel ratio λ is constant (λ = a), and the rate of decrease of the temperature of the fuel generator 2 can be increased.

【0019】

[Number 1]

<img file="JP2002158019A_D0001.tif" />【0020】

The threshold value x is a value that indirectly indicates a guideline for the relative start of hydrogen in the residual fuel gas. In such a case, the control for lowering the reaction amount of the fuel generator 2 also works, so nothing Otherwise, the temperature of the fuel generator 2 may rise abnormally. By setting the threshold value x, it is possible to predict the temperature rise of the fuel generator 2 and gradually increase the amount of heat that escapes to the exhaust gas before the supply amount of the combustion raw material becomes 0. The rate of temperature decrease can be increased, and an abnormal increase in the temperature of the fuel generator 2 can be prevented in a wide range.

【0021】

As described above, when the generated power is reduced and the residual fuel gas is increased, the environmental temperature is high and the heat dissipation loss of the fuel generator 2 is small, or the temperature of the fuel generator 2 is the fuel for some reason. According to the configuration of the present embodiment, even if the temperature becomes higher than the temperature required for generation, the temperature of the fuel generator 2 can be lowered quickly, so that the temperature stability of the fuel generator 2 is stable. It becomes easy to secure.

【0022】

Also, if the temperature of the fuel generator 2 is too low than the temperature required to generate fuel, increase the supply of city gas 13A, which is the combustion raw material of the combustion raw material regulator 5, to secure the temperature. Although control works, in the configuration of the present embodiment, the increment of the supply amount of the combustion raw material can be increased to increase the rate of temperature rise. Even if the temperature rises too much due to overshoot, first, the control to reduce the supply amount of the combustion raw material works, and then the control according to (Equation 1) is performed, so the temperature decrease rate of the fuel generator 2 is fast and the fuel The temperature of the generator 2 can be easily controlled to the temperature required to generate the fuel, and it becomes easy to ensure the temperature stability of the fuel generator 2.

【0023】

When the threshold value x is increased, the operation state in which the air-fuel ratio is large is quickly shifted, and the thermal efficiency transferred to the fuel generator 2 is lowered. On the contrary, when the threshold value x is made small, the transition to the operating state having a large air-fuel ratio is delayed, and it becomes difficult to obtain the effect of the present invention that it becomes easy to secure the temperature stability of the fuel generator 2. Therefore, the threshold value x may be set appropriately in consideration of the configuration of the power generation device. Further, the values of the air-fuel ratio a in the steady state and the air-fuel ratio b in the cooling mode may be selected as appropriate values in consideration of the configuration of the power generation device. For example, in a fuel cell power generation device with a rated output of 5 kw that uses city gas 13A as the power generation raw material and the combustion raw material, in (Equation 1), the air-fuel ratio in the steady state is a = 1.5, and the air-fuel ratio in the cooling mode is b = 2.0. When the air-fuel ratio λ is set by the value of the supply amount Go [NL / min] of the city gas 13A when the threshold value x is set to x = 1.0 [NL / min] (Equation 2), the temperature stability of the fuel generator is improved. We were able to configure a fuel cell power generator that can be easily secured.

【0024】

[Number 2]

<img file="JP2002158019A_D0002.tif" />【0025】

(Embodiment 2) FIG. 2 is a configuration diagram of a fuel cell power generation device according to a second embodiment of the present invention. The same components as those of the conventional example and the first embodiment are assigned the same numbers, and the description thereof will be omitted here.

【0026】

The residual hydrogen estimator 10 in the air supply amount regulator 7 calculates the amount of hydrogen generated by the fuel generator 2 from the flow rate of the city gas 13A, which is the power generation raw material set by the power generation raw material regulator 3, and also calculates the current. The amount of hydrogen consumed by the fuel cell 1 is calculated from the generated current of the fuel cell 1 detected by the detector 9, and the amount of hydrogen contained in the residual fuel gas supplied to the combustor 4 is calculated from the calculation results of both. ..

【0027】

The air amount calculator 13 simply burns the hydrogen in the residual fuel gas of the amount calculated by the residual hydrogen estimator 10 and the city gas 13A which is the combustion raw material set by the combustion raw material regulator 5. Calculate the amount of air containing oxygen. Then, when the supply amount of the city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is equal to or higher than the threshold value, the air having the air-fuel ratio at the steady state is used in the combustor 4 with respect to the calculated air amount. Set the rotation speed of the combustion fan 6 so as to supply to.

【0028】

On the other hand, when the supply amount of the city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is smaller than the threshold value, the fuel is based on the temperature detector 14 that detects the temperature of the fuel generator 2. The amount of air is controlled by adjusting the rotation speed of the combustion fan 6 so that the temperature of the generator 2 is kept at an appropriate temperature (the temperature required to generate fuel). A large amount of air increases the amount of heat that escapes to the exhaust gas from the combustor 4, resulting in a decrease in the temperature of the fuel generator 2, and a small amount of air reduces the amount of heat that escapes to the exhaust gas from the combustor 4, resulting in fuel. The temperature of generator 2 rises. At this time, the air amount calculator 13 just picks up the hydrogen in the residual fuel gas of the amount calculated by the residual hydrogen estimator 10 and the city gas 13A which is the combustion raw material set by the combustion raw material regulator 5. The amount of air containing enough oxygen to burn is calculated, and the air-fuel ratio is at least 1 or more even when the amount of air is small. If the supply amount of city gas 13A, which is the combustion raw material set by the combustion raw material controller 5, is smaller than the threshold value, the residual hydrogen is large and the temperature detected by the temperature detector 14 is high. However, according to the configuration of this embodiment, the supply amount of city gas 13A, which is a combustion raw material, is limited in advance. Since it is detected that it becomes smaller than the value, the amount of air supplied to the combustor 4 is increased by increasing the rotation speed of the combustion fan 6 more than usual, and the amount of heat escaping to the exhaust gas is increased to increase the temperature of the fuel generator 2. The rise is less likely to occur, and the temperature stability of the fuel generator 2 can be easily ensured.

【0029】

If for some reason the temperature of the fuel generator 2 rises abnormally above the temperature required to generate fuel, the combustion material regulator 5 reduces the supply of city gas 13A, which is the combustion material, to fuel. The heating amount of the generator 2 is reduced, and when the supply amount of the city gas 13A, which is a combustion raw material, becomes smaller than the threshold value x, the temperature of the fuel generator 2 is appropriate (fuel is generated). If the temperature is not (high), the temperature detector 14 detects it, and by increasing the rotation speed of the combustion fan 6 above normal, the amount of air supplied to the combustor 4 is increased, and the exhaust gas is discharged. By increasing the amount of heat that escapes to the fuel generator 2, the temperature of the fuel generator 2 is rapidly lowered to prevent abnormal temperature rise. If the temperature of the fuel generator 2 is too low, the temperature detector 14 detects it and burns. By lowering the rotation speed of the fan 6, the amount of air supplied to the combustor 4 is reduced, the amount of heat escaping to the exhaust gas is reduced, and the temperature of the fuel generator 2 is raised, so that the temperature of the fuel generator 2 is adjusted appropriately. It is something to keep.

【0030】

As described above, in the fuel cell power generation device, when the supply amount of the city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is smaller than the threshold value, the rotation speed of the combustion fan 6 is adjusted. By controlling the temperature of the fuel generator 2 to an appropriate temperature, the generated power is reduced and the residual fuel gas is increased, the environmental temperature is high and the heat dissipation loss of the fuel generator 2 is small, or somehow. Even if the temperature of the fuel generator 2 becomes higher than the temperature required to generate fuel due to the cause, the temperature of the fuel generator 2 can be lowered quickly, so that the fuel generator 2 can be used. It becomes easy to ensure temperature stability.

【0031】

(Embodiment 3) FIG. 3 is a configuration diagram of a fuel cell power generation device according to a third embodiment of the present invention, in which the same components as those shown in the conventional example are assigned the same numbers. The description of is omitted.

【0032】

When the supply amount of city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is equal to or higher than the threshold value, the second power generation raw material regulator 15 divides the power generation raw material and water into a predetermined ratio (this). In the configuration of the fuel cell power generation device, the city gas 13A, which is the raw material for power generation, is supplied to the fuel generator 2 at a ratio of about 3 g / min of water to 1 NL / min of supply).

【0033】

On the other hand, when the supply amount of city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is smaller than the threshold value, it is based on the detection value of the temperature detector 14 that detects the temperature of the fuel generator 2. Therefore, the second power generation raw material regulator 15 controls the amount of water supplied to the fuel generator 2 so that the temperature of the fuel generator 2 is maintained at an appropriate temperature (the temperature required to generate the fuel). At this time, the ratio of the amount of water supplied is not significantly lower than the predetermined ratio, for example, the ratio of 3 g / min of water to the supply amount of 1 NL / min of city gas 13A which is a raw material for power generation.

【0034】

If the detection value of the temperature detector 14 is higher than the appropriate value, water is supplied in excess of the predetermined ratio, and if water is supplied in excess of the predetermined ratio, heat is taken away in excess, so that the fuel generator 2 The temperature drops. In such a state, the supply amount of city gas 13A, which is a combustion raw material supplied to the combustor 4, is smaller than the threshold value, so the amount of hydrogen generated in the fuel generator 2 is the fuel cell. It is in a situation where it is generated in excess of the amount of hydrogen used in 1, and even if the amount of water vapor in the fuel gas increases slightly, the effect on power generation in the fuel cell 1 is small.

【0035】

If the detection value of the temperature detector 14 is lower than the appropriate value, water is supplied less than the predetermined ratio, and if the water is supplied less than the predetermined ratio, the heat is excessive and the temperature of the fuel generator 2 is increased. To rise. In such a state, the supply amount of city gas 13A, which is the combustion raw material supplied to the combustor 4, is smaller than the threshold value, so the amount of hydrogen generated in the fuel generator 2 is the fuel cell. It is in a situation where it is generated in excess of the amount of hydrogen used in 1, and even if the amount of water vapor in the fuel gas is slightly reduced, the effect on power generation in the fuel cell 1 is small.

【0036】

In this way, when the supply amount of city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is smaller than the threshold value, the second power generation raw material adjustment is performed based on the detection value of the temperature detector 14. By controlling the amount of water supplied by the vessel 15 to the fuel generator 2, the temperature of the fuel generator 2 is adjusted to be maintained appropriately.

【0037】

If for some reason the temperature of the fuel generator 2 rises abnormally above the temperature required to generate fuel, the combustion material regulator 5 reduces the supply of city gas 13A, which is the combustion material, to fuel. The heating amount of the generator 2 is reduced, and when the supply amount of the city gas 13A, which is a combustion raw material, becomes smaller than the threshold value x, the temperature of the fuel generator 2 is appropriate (fuel is generated). If it is not (high), it is detected by the temperature detector 14, the amount of water supplied by the second power generation raw material regulator 15 to the fuel generator 2 is increased, and the fuel generator 2 is used. By increasing the amount of heat carried as water vapor from the fuel generator 2, the temperature of the fuel generator 2 is rapidly lowered to prevent abnormal temperature rise, and when the temperature of the fuel generator 2 is lowered, the amount of water is reduced and the fuel generator is used. By increasing the temperature of the fuel generator 2 by reducing the amount of heat carried as steam from 2, the temperature of the fuel generator 2 is maintained at an appropriate level.

【0038】

As described above, in the fuel cell power generation device, when the supply amount of the city gas 13A, which is the combustion raw material set by the combustion raw material regulator 5, is smaller than the threshold value, the water supplied to the fuel generator 2 is supplied. When the amount is increased and the temperature of the fuel generator 2 is controlled to an appropriate temperature to reduce the generated power and increase the residual fuel gas, or when the environmental temperature is high and the heat dissipation loss of the fuel generator 2 is small. Alternatively, even if the temperature of the fuel generator 2 becomes higher than the temperature required to generate the fuel for some reason, the temperature of the fuel generator 2 can be lowered quickly, so that the fuel can be generated. It becomes easy to secure the temperature stability of the vessel 2.

【0039】

In the first and second embodiments, if the amount of air supplied to the combustor 4 is large and the air-fuel ratio is extremely large, or if the speed of the gas in the combustor 4 is extremely high, a misfire will occur. There is a possibility, but it is natural to configure the combustor 4 and the like to avoid such a situation and set an upper limit of the air-fuel ratio.

【0040】

Further, even if the first embodiment and the third embodiment are configured, or the second embodiment and the third embodiment are combined, the effect of the present invention is not impaired at all.

【0041】

Further, in the first to third embodiments, the threshold value is a guideline for the relative surplus hydrogen in the residual fuel gas. In such a case, in a normal fuel cell power generation device, the fuel generator 2 Since the control to reduce the reaction amount also works, the temperature of the fuel generator 2 will rise abnormally if nothing is done. This threshold value may be set to a value fixed by the supply amount of the combustion raw material set by the combustion raw material regulator 5, or corresponds to the detection result of the flame detector such as the frame rod attached to the combustor 4. A threshold value may be set for a value that fluctuates.

【0042】

Further, in the first to third embodiments, it has been described that the power generation raw material and the combustion raw material are city gas 13A, but the present invention is not limited to this, and the power generation raw material can be sent to a fuel generator to generate hydrogen-rich fuel gas. And the combustion raw material, for example, other urban gas species mainly composed of hydrocarbons, LP gas, liquid fuel (kerosene, gasoline, methanol, dimethyl ether, etc.) may be used, or the power generation raw material and the combustion raw material may be different.

【0043】

Then, in the first to third embodiments, it was explained that the supply amount of the combustion raw material and the threshold value are compared, but even if the output of the combustion raw material regulator 5 and the threshold value are compared, the combustor Since it can be determined that the amount of combustion raw material supplied to 4 is smaller than the threshold value, it is clear that the same effect can be obtained.

【0044】

[Effect of the invention]

As is clear from the above description, according to the configuration of the present invention, the temperature of the fuel generator can be quickly lowered, the temperature of the fuel generator can be easily controlled, and the fuel generator 2 The abnormally high temperature state can be prevented while maintaining the operating state, and a stable and highly reliable fuel cell power generation device can be provided.

[Simple explanation of drawings]

[Figure 1]

Configuration diagram of the fuel cell power generation device according to the first embodiment of the present invention [Figure 2]

Configuration diagram of the fuel cell power generation device according to the second embodiment of the present invention [Fig. 3]

Configuration diagram of the fuel cell power generation device according to the third embodiment of the present invention [Fig. 4]

Configuration diagram of a conventional fuel cell power generator [Explanation of symbols]

1 Fuel cell 2 fuel generator 3 Power generation material regulator 4 Combustor 5 Combustion material regulator 6 Combustion fan 7 Air supply controller 8 blower 9 Current detector 10 Residual hydrogen estimator 11 Air-fuel ratio setting device 12 2nd air-fuel ratio setting device 13 Air volume calculator 14 Temperature detector 15 2nd power generation raw material regulator