JP2021038121A - Hydrogen utilization system - Google Patents

Abstract

To provide a hydrogen utilization system capable of maintaining heat quantity supplied to a hydrogen utilization device at a required value.SOLUTION: A hydrogen utilization system 1 comprises a reformer 4 for reforming ammonia gas to produce a reformed gas containing hydrogen, a hydrogen utilization device 5 for utilizing hydrogen contained in the reformed gas produced by the reformer 4, a bypass flow passage 13 arranged between an ammonia gas supply source 2 and the hydrogen utilization device 5 so as to bypass the reformer 4, a flow rate adjustment valve 8 for adjusting a flow rate of ammonia gas flowing through an ammonia gas flow passage 6 from the ammonia gas supply source 2 toward the reformer 4, a flow rate adjustment valve 9 for adjusting a flow rate of air flowing through the air flow passage 7 from an air supply source 3 toward the reformer 4, a flow rate adjustment valve 14 for adjusting a flow rate of ammonia gas flowing through the bypass flow passage 13, and a reformer controller 16 for controlling flow regulating valves 8, 9, 14 in accordance with a heat quantity required by the hydrogen utilization device 5.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hydrogen utilization system.

As a conventional hydrogen utilization system, for example, a cogeneration system as described in Patent Document 1 is known. The cogeneration system described in Patent Document 1 contains hydrogen by mixing and reforming an ammonia tank, a vaporizer that vaporizes ammonia supplied from the ammonia tank, and fuel and air from this vaporizer. It is equipped with a reformer that produces the reformed gas and an engine that is driven by the reformed gas.

Japanese Unexamined Patent Publication No. 2013-238356

By the way, in the above-mentioned prior art, when the reforming gas is supplied from the reformer to the engine (hydrogen utilization device), the calorific value (energy amount) of the reforming gas is supplied to the hydrogen utilization device. Here, even when the amount of heat required by the hydrogen utilization device changes or the performance of the reformer deteriorates, it is necessary to maintain the amount of heat supplied to the hydrogen utilization device at the required value. However, in the above-mentioned prior art, since the calorific value of the reforming gas supplied from the reformer to the hydrogen utilization apparatus is not adjusted, the calorific value supplied to the hydrogen utilization apparatus cannot be maintained at the required value.

An object of the present invention is to provide a hydrogen utilization system capable of maintaining the amount of heat supplied to the hydrogen utilization apparatus at a required value.

The hydrogen utilization system according to one aspect of the present invention includes a reformer that generates a reformed gas containing hydrogen by reforming the fuel gas by utilizing the heat generated by burning the fuel gas, and a fuel. From the fuel gas supply source that supplies the gas, the oxidizing gas supply source that supplies the oxidizing gas, the fuel gas flow path through which the fuel gas flows from the fuel gas supply source to the reformer, and the oxidizing gas supply source. An oxidizing gas flow path through which an oxidizing gas flows toward the reformer, a hydrogen utilization device that uses hydrogen contained in the reforming gas generated by the reformer, and a hydrogen utilization device from the reformer to the hydrogen utilization device. It is arranged between the reformed gas flow path through which the reformed gas flows and the fuel gas supply source and the hydrogen utilization device so as to bypass the reformer, and the fuel gas flows from the fuel gas supply source toward the hydrogen utilization device. A bypass flow path, a first flow rate adjusting unit that adjusts the flow rate of fuel gas flowing through the fuel gas flow path, a second flow rate adjusting unit that adjusts the flow rate of oxidizing gas flowing through the oxidizing gas flow path, and a bypass flow path. A third flow rate adjusting unit that adjusts the flow rate of the fuel gas flowing through the gas, and a control unit that controls the first flow rate adjusting unit, the second flow rate adjusting unit, and the third flow rate adjusting unit according to the amount of heat required by the hydrogen utilization device. To be equipped with.

In such a hydrogen utilization system, between the fuel gas supply source and the hydrogen utilization device, a bypass flow path through which the fuel gas flows from the fuel gas supply source to the hydrogen utilization device bypasses the reformer. Have been placed. Then, the first flow rate adjusting unit that adjusts the flow rate of the fuel gas supplied to the reformer and the second flow rate of the oxidizing gas supplied to the reformer are adjusted according to the amount of heat required by the hydrogen utilization device. The flow rate adjusting unit and the third flow rate adjusting unit that adjusts the flow rate of the fuel gas directly supplied to the hydrogen utilization device are controlled. As a result, even when the amount of heat required by the hydrogen utilization device changes or the performance of the reformer deteriorates, the amount of heat supplied to the hydrogen utilization device can be maintained at the required value.

The hydrogen utilization system further includes a deterioration detection unit that detects the deterioration of the reformer, and the control unit discharges the fuel gas flowing through the fuel gas flow path when the deterioration of the reformer is detected by the deterioration detection unit. The first flow rate adjusting unit may be controlled so that the flow rate of the first flow rate adjusting unit is increased, and the second flow rate adjusting unit may be controlled so that the flow rate of the oxidizing gas flowing through the oxidizing gas flow path is increased. When the reformer deteriorates, the flow rate of hydrogen contained in the reforming gas generated by the reformer decreases. Therefore, when the deterioration detection unit detects the deterioration of the reformer, the first flow rate adjusting unit is controlled so that the flow rate of the fuel gas supplied to the reformer increases, and the fuel gas is supplied to the reformer. The second flow rate adjusting unit is controlled so that the flow rate of the oxidizing gas increases. Therefore, the flow rate of hydrogen contained in the reforming gas generated by the reformer increases. As a result, even when the reformer deteriorates, the required flow rate of hydrogen is supplied to the hydrogen utilization device.

The control unit may control the third flow rate adjusting unit so that the flow rate of the fuel gas flowing through the bypass flow path is reduced. When the flow rate of fuel gas and oxidizing gas supplied to the reformer increases, not only the flow rate of hydrogen produced by reforming the fuel gas by the reformer increases, but also the flow rate of hydrogen produced by the reformer increases. The flow of unreformed fuel gas also increases. Therefore, by controlling the third flow rate adjusting unit so that the flow rate of the fuel gas directly supplied to the hydrogen utilization device via the bypass flow path decreases, the total flow rate of the fuel gas supplied to the hydrogen utilization device is increased. You don't have to let it. Therefore, even when the reformer is deteriorated but the amount of heat required by the hydrogen utilization device has not changed, the amount of heat supplied to the hydrogen utilization device can be maintained at the required value.

The hydrogen utilization system further includes a first temperature detection unit that detects the temperature of the reformed gas, and the deterioration detection unit may detect the deterioration of the reformer by using the detection value of the first temperature detection unit. .. When the reformer deteriorates, the temperature of the reforming gas generated by the reformer tends to rise. Therefore, by detecting the temperature of the reforming gas, deterioration of the reformer can be easily detected.

The hydrogen utilization system detects the temperature of the second temperature detector that detects the temperature of the mixed gas of the fuel gas flowing through the fuel gas flow path and the oxidizing gas flowing through the oxidizing gas flow path, and the temperature of the reformer housing. The deterioration detection unit further includes a third temperature detection unit, and the deterioration detection unit is based on the detection values of the first temperature detection unit, the second temperature detection unit, and the third temperature detection unit, and the actual flow rate of hydrogen contained in the reforming gas. The amount of deterioration of the reformer is estimated from the difference between the actual flow rate of hydrogen and the predetermined target flow rate of hydrogen, and the control unit determines the fuel gas for the reformer based on the deterioration amount of the reformer. And the supply flow rate of the oxidizing gas may be determined, the first flow rate adjusting unit may be controlled according to the supply flow rate of the fuel gas, and the second flow rate adjusting unit may be controlled according to the supply flow rate of the oxidizing gas. In such a configuration, the temperature of the reforming gas generated by the reformer, the temperature of the mixed gas of the fuel gas and the oxidizing gas supplied to the reformer, and the temperature of the housing of the reformer are set. By detecting, the amount of deterioration of the reformer can be easily estimated. Then, the flow rates of the fuel gas and the oxidizing gas supplied to the reformer are determined based on the amount of deterioration of the reformer, and the first flow rate adjusting unit and the second flow rate adjusting unit are controlled according to the flow rates. By doing so, it is possible to generate hydrogen at an appropriate flow rate according to the amount of deterioration of the reformer.

The fuel gas may be ammonia gas. Ammonia gas is hard to burn, but hydrogen is easy to burn. Therefore, when the hydrogen utilization device burns ammonia gas, it is effective to supply the hydrogen generated by the reformer to the hydrogen utilization device.

According to the present invention, the amount of heat supplied to the hydrogen utilization device can be maintained at the required value.

It is a schematic block diagram which shows the hydrogen utilization system which concerns on 1st Embodiment of this invention. It is a flowchart which shows the procedure of the control process executed by the reformer controller shown in FIG. It is a schematic block diagram which shows the hydrogen utilization system which concerns on 2nd Embodiment of this invention. It is a functional block diagram of the reformer controller shown in FIG. It is a flowchart which shows the procedure of the control process executed by the reformer controller shown in FIG. It is a conceptual diagram which shows the relationship of the amount of heat generated in a reformer. It is a figure which shows the image which changes the flow rate of ammonia gas supplied to a reformer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 1 is a schematic configuration diagram showing a hydrogen utilization system according to the first embodiment of the present invention. In FIG. 1, the hydrogen utilization system 1 of the present embodiment includes an ammonia gas supply source 2, an air supply source 3, a reformer 4, and a hydrogen utilization device 5.

Ammonia gas supply source 2, a fuel gas supply source for supplying ammonia gas (NH ₃ gas) as a fuel gas. Although not particularly shown, the ammonia gas supply source 2 includes an ammonia tank that stores ammonia in a liquid state and a vaporizer that vaporizes the liquid ammonia to generate ammonia gas.

The air supply source 3 is an oxidizing gas supply source that supplies air, which is an oxidizing gas. As the air supply source 3, for example, a blower or the like is used.

The reformer 4 is connected to the ammonia gas supply source 2 via the ammonia gas flow path 6. The ammonia gas flow path 6 is a fuel gas flow path through which ammonia gas flows from the ammonia gas supply source 2 toward the reformer 4. One end of the ammonia gas flow path 6 is connected to the ammonia gas supply source 2. The other end of the ammonia gas flow path 6 is connected to the inlet portion 4a of the reformer 4.

Further, the reformer 4 is connected to the air supply source 3 via an air flow path 7. The air flow path 7 is an oxidizing gas flow path through which air flows from the air supply source 3 toward the reformer 4. One end of the air flow path 7 is connected to the air supply source 3. The other end of the air flow path 7 is connected to the ammonia gas flow path 6. Therefore, a mixed gas of ammonia gas and air flows in the portion of the ammonia gas flow path 6 between the connection point with the air flow path 7 and the reformer 4. That is, it is introduced into the inlet portion 4a of the reformer 4 in a state where ammonia gas and air are mixed.

A flow rate adjusting valve 8 is provided in the ammonia gas flow path 6. The flow rate adjusting valve 8 is a first flow rate adjusting unit that adjusts the flow rate of the ammonia gas flowing through the ammonia gas flow path 6. A flow rate adjusting valve 9 is provided in the air flow path 7. The flow rate adjusting valve 9 is a second flow rate adjusting unit that adjusts the flow rate of air flowing through the air flow path 7.

The reformer 4 generates a reformed gas containing hydrogen by reforming the ammonia gas by utilizing the heat generated by burning the ammonia gas. The reformer 4 has a combustion catalyst 10 that burns ammonia and a reforming catalyst 11 that is arranged downstream of the combustion catalyst 10 and decomposes ammonia into hydrogen.

The combustion catalyst 10, for example, zeolites supported palladium and copper catalysts or _{CuO / 10Al 2 O 3 · 2B} 2 O 3 or the like is used. The combustion catalyst 10 burns ammonia in a temperature range of, for example, 200 ° C. to 400 ° C. As the reforming catalyst 11, for example, Ru / CeO ₂ , Ru / ZrO ₂ , Ru / MgO, Ru / Al ₂ O ₃ or Ru / SiO _{2 and the} like are used. The reforming catalyst 11 decomposes ammonia into hydrogen in a temperature range of, for example, 250 ° C. to 500 ° C.

The hydrogen utilization device 5 is connected to the reformer 4 via the reforming gas flow path 12. The reformed gas flow path 12 is a flow path through which the reformed gas generated by the reformer 4 flows. One end of the reforming gas flow path 12 is connected to the outlet portion 4b of the reformer 4. The other end of the reformed gas flow path 12 is connected to the hydrogen utilization device 5.

The hydrogen utilization device 5 is an apparatus that utilizes hydrogen contained in the reforming gas. Examples of the hydrogen utilization device 5 include a combustion device such as an ammonia engine or an ammonia gas turbine using ammonia as fuel, or a fuel cell that chemically reacts hydrogen with oxygen in the air to generate power. Ammonia gas is hard to burn, but hydrogen is easy to burn. Therefore, the hydrogen generated by the reformer 4 is supplied to the hydrogen utilization device 5.

Further, the hydrogen utilization system 1 includes a bypass flow path 13 arranged between the ammonia gas supply source 2 and the hydrogen utilization device 5 so as to bypass the reformer 4. The bypass flow path 13 is a flow path through which ammonia gas flows from the ammonia gas supply source 2 toward the hydrogen utilization device 5. One end of the bypass flow path 13 is connected to the ammonia gas flow path 6. The other end of the bypass flow path 13 is connected to the reforming gas flow path 12.

A flow rate adjusting valve 14 is provided in the bypass flow path 13. The flow rate adjusting valve 14 is a third flow rate adjusting unit that adjusts the flow rate of ammonia gas flowing through the bypass flow path 13.

Further, the hydrogen utilization system 1 includes a main controller 15 and a reformer controller 16. The main controller 15 and the reformer controller 16 are composed of a CPU, RAM, ROM, an input / output interface, and the like.

The main controller 15 controls the entire hydrogen utilization system 1 including the hydrogen utilization device 5, and monitors the state of the hydrogen utilization device 5. The main controller 15 determines the amount of heat (energy amount) required by the hydrogen utilization device 5 based on the state of the hydrogen utilization device 5, and outputs the heat amount information to the reformer controller 16.

The reformer controller 16 is a control unit that controls the flow rate adjusting valves 8, 9, and 14 according to the amount of heat required by the hydrogen utilization device 5. The reformer controller 16 acquires heat quantity information from the main controller 15 and controls the flow rate adjusting valves 8, 9, and 14 based on the heat quantity information.

FIG. 2 is a flowchart showing a procedure of control processing executed by the reformer controller 16. This process is executed when the hydrogen utilization system 1 is started.

In FIG. 2, the reformer controller 16 first acquires heat quantity information from the main controller 15 (procedure S101). Subsequently, the reformer controller 16 determines whether or not there is a change in the amount of heat required by the hydrogen utilization device 5 based on the amount of heat information from the main controller 15 (procedure S102). The change in the amount of heat includes the initial setting of the amount of heat by starting the hydrogen utilization system 1. When the reformer controller 16 determines that the amount of heat required by the hydrogen utilization device 5 has not changed, the reformer controller 16 re-executes the procedure S101.

When the reformer controller 16 determines that there is a change in the amount of heat required by the hydrogen utilization device 5, the flow rate of ammonia gas and air to the reformer 4 is determined based on the amount of heat required by the hydrogen utilization device 5. The flow rate of ammonia gas supplied to the hydrogen utilization device 5 is determined (procedure S103). That is, the reformer controller 16 determines the flow rate of ammonia gas flowing through the ammonia gas flow path 6, the flow rate of air flowing through the air flow path 7, and the flow rate of ammonia gas flowing through the bypass flow path 13.

Here, when the gas is supplied to the hydrogen utilization device 5, the amount of heat (energy amount) of the gas is supplied to the hydrogen utilization device 5. The total calorific value of the gas supplied to the hydrogen utilization device 5 is the sum of the calorific value of hydrogen supplied to the hydrogen utilization device 5 and the calorific value of the ammonia gas supplied to the hydrogen utilization device 5. In addition, in order to obtain a desired amount of heat in the hydrogen utilization device 5, a certain amount of heat of hydrogen is required.

When the amount of heat supplied to the hydrogen utilization device 5 reaches a specified value, the flow rates of ammonia gas and air supplied to the reformer 4 are known in advance by experiments and the like. Therefore, the reformer controller 16 is a reformer based on the amount of heat required by the hydrogen utilization device 5 with reference to the flow rates of ammonia gas and air when the amount of heat supplied to the hydrogen utilization device 5 is a specified value. The supply flow rate of ammonia gas and air for 4 and the supply flow rate of ammonia gas for the hydrogen utilization device 5 are determined.

Further, the reformer controller 16 preliminarily sets the relationship between the amount of heat required by the hydrogen utilization device 5 and the supply flow rate of ammonia gas and air to the reformer 4 and the supply flow rate of ammonia gas to the hydrogen utilization device 5 as map data. Prepared, and using the map data, determine the supply flow rate of ammonia gas and air to the reformer 4 and the supply flow rate of ammonia gas to the hydrogen utilization device 5 based on the amount of heat required by the hydrogen utilization device 5. You may.

The reformer controller 16 increases the flow rates of ammonia gas and air supplied to the reformer 4 when the amount of heat required by the hydrogen utilization device 5 increases. At this time, the flow rate of the ammonia gas directly supplied to the hydrogen utilization device 5 is changed according to the amount of increase in the amount of heat required by the hydrogen utilization device 5. On the other hand, the reformer controller 16 reduces the flow rates of ammonia gas and air supplied to the reformer 4 when the amount of heat required by the hydrogen utilization device 5 decreases. At this time, the flow rate of the ammonia gas directly supplied to the hydrogen utilization device 5 is changed according to the amount of decrease in the amount of heat required by the hydrogen utilization device 5.

Specifically, for example, since the reformer 4 has an optimum operating range, the amount of heat supplied to the hydrogen utilization device 5 is only for controlling the flow rates of the ammonia gas and air supplied to the reformer 4. There are restrictions on adjustment. Therefore, when the reformer controller 16 is required to have a large amount of heat that is higher than the optimum operating range of the reformer 4, the reformer controller 16 only increases the flow rate of the ammonia gas supplied to the reformer 4. It also increases the flow rate of ammonia gas directly supplied to the hydrogen utilization device 5. On the other hand, when the reformer controller 16 is required to have a small amount of heat that is lower than the optimum operating range of the reformer 4, the reformer controller 16 only reduces the flow rate of the ammonia gas supplied to the reformer 4. It also reduces the flow rate of ammonia gas directly supplied to the hydrogen utilization device 5.

Then, the reformer controller 16 controls the flow rate adjusting valve 8 according to the supply flow rate of ammonia gas to the reformer 4, and controls the flow rate adjusting valve 9 according to the supply flow rate of air to the reformer 4. The flow rate adjusting valve 14 is controlled according to the supply flow rate of ammonia gas to the hydrogen utilization device 5 (procedure S104). Then, the reformer controller 16 executes the procedure S101 again.

When the hydrogen utilization system 1 as described above is activated, ammonia gas is supplied from the ammonia gas supply source 2 to the reformer 4, and air is supplied from the air supply source 3 to the reformer 4.

Then, when the reformer 4 is heated by a heater (not shown) or the like to raise the temperature of the reformer 4, and the temperature of the reformer 4 reaches the combustible temperature, the combustion catalyst 10 releases ammonia gas. Burn. Specifically, as shown in the following formula, a chemical reaction (oxidation reaction) occurs between a part of ammonia and oxygen in the air, so that a combustion reaction of ammonia occurs and combustion heat is generated. The oxidation reaction is a reaction accompanied by heat generation.
NH ₃ + 3/4O ₂ → 1 / 2N ₂ + 3 / 2H ₂ O + 317kJ / mol… (A)

Then, when the reformer 4 is further heated by the heat of combustion of the ammonia gas and the temperature of the reformer 4 reaches the reformable temperature, the ammonia gas is reformed by the reforming catalyst 11 and the reformer contains hydrogen. Quality gas is produced. Specifically, as shown in the following formula, a reforming reaction occurs in which ammonia is decomposed into hydrogen and nitrogen, and a reforming gas containing hydrogen, nitrogen and ammonia is generated. The reforming reaction is an endothermic reaction.
_{NH 3 → 3 / 2H 2 +} 1 / 2N 2 -46kJ / mol ... (B)

The reforming gas generated by the reformer 4 is supplied to the hydrogen utilization device 5, and the hydrogen contained in the reforming gas is used in the hydrogen utilization device 5. At this time, the temperature of the reforming gas output from the reformer 4 is determined by the balance between the oxidation reaction of the above formula (A) and the reforming reaction of the above formula (B).

When the amount of heat required by the hydrogen utilization device 5 changes during the operation of the reformer 4, the flow rate adjusting valves 8, 9, and 14 are controlled according to the amount of heat required by the hydrogen utilization device 5, thereby controlling the reformer. The operating conditions of 4 are changed. As a result, the amount of heat supplied to the hydrogen utilization device 5 is appropriately adjusted.

In the present embodiment as described above, between the ammonia gas supply source 2 and the hydrogen utilization device 5, there is a bypass flow path 13 in which ammonia gas flows from the ammonia gas supply source 2 toward the hydrogen utilization device 5. It is arranged so as to bypass the reformer 4. Then, the flow rate adjusting valve 8 for adjusting the flow rate of the ammonia gas supplied to the reformer 4 and the flow rate adjusting for adjusting the flow rate of the air supplied to the reformer 4 according to the amount of heat required by the hydrogen utilization device 5. The flow rate adjusting valve 14 for adjusting the flow rate of the ammonia gas directly supplied to the valve 9 and the hydrogen utilization device 5 is controlled. As a result, even when the amount of heat required by the hydrogen utilization device 5 changes, the amount of heat supplied to the hydrogen utilization device 5 can be maintained at the required value.

FIG. 3 is a schematic configuration diagram showing a hydrogen utilization system according to a second embodiment of the present invention. In FIG. 3, the hydrogen utilization system 1A of the present embodiment includes temperature sensors 21 to 23 in addition to the configuration of the first embodiment described above.

The temperature sensor 21 is arranged in the reformed gas flow path 12. The temperature sensor 21 is a first temperature detection unit that detects the temperature of the reformed gas. The temperature sensor 22 is arranged on the downstream side of the connection point with the air flow path 7 in the ammonia gas flow path 6. The temperature sensor 22 is a second temperature detection unit that detects the temperature of a mixed gas of ammonia gas and air. The temperature sensor 23 is arranged in the housing 4c of the reformer 4. The temperature sensor 23 is a third temperature detection unit that detects the temperature of the housing 4c of the reformer 4.

Further, the hydrogen utilization system 1 includes a reformer controller 16A instead of the reformer controller 16 in the first embodiment described above. As shown in FIG. 4, the reformer controller 16A has a valve control unit 24 for changing the amount of heat, a deterioration detection unit 25, and a valve control unit 26 for deterioration.

The heat amount changing valve control unit 24 is a control unit that controls the flow rate adjusting valves 8, 9 and 14 according to the heat amount required by the hydrogen utilization device 5. The valve control unit 24 at the time of changing the amount of heat has the same function as the reformer controller 16 described above.

The deterioration detection unit 25 detects the deterioration of the reformer 4 by using the detection values of the temperature sensors 21 to 23. At this time, the deterioration detection unit 25 obtains the actual flow rate of hydrogen contained in the reformed gas flowing through the reformed gas flow path 12 based on the detected values of the temperature sensors 21 to 23, and determines the actual flow rate of hydrogen in advance. The amount of deterioration of the reformer 4 is estimated from the difference from the target flow rate of hydrogen.

The deterioration valve control unit 26 is a control unit that controls the flow rate adjusting valves 8, 9 and 14 according to the amount of heat required by the hydrogen utilization device 5. Further, the deterioration valve control unit 26 controls the flow rate adjusting valve 8 so that the flow rate of the ammonia gas flowing through the ammonia gas flow path 6 increases when the deterioration detection unit 25 detects the deterioration of the reformer 4. Then, the flow rate adjusting valve 9 is controlled so that the flow rate of the air flowing through the air flow path 7 increases, and the flow rate adjusting valve 14 is controlled so that the flow rate of the ammonia gas flowing through the bypass flow path 13 decreases.

FIG. 5 is a flowchart showing a processing procedure executed by the reformer controller 16A. In this process, the process executed by the deterioration detection unit 25 and the valve control unit 26 at the time of deterioration is shown, and the process executed by the valve control unit 24 at the time of changing the amount of heat is omitted. That is, in this treatment, it is premised that the amount of heat required by the hydrogen utilization device 5 is not changed.

In FIG. 5, the reformer controller 16A first acquires the detected values of the temperature sensors 21 to 23 (procedure S111). Subsequently, the reformer controller 16A calculates the total flow rate of the reformed gas flowing through the reformed gas flow path 12 based on the detected values of the temperature sensors 21 to 23 (procedure S112). The total flow rate of the reformed gas is calculated as follows.

That is, in the reformer 4, the reforming catalyst 11 is more likely to deteriorate than the combustion catalyst 10. When the reforming catalyst 11 deteriorates, the amount of heat absorbed by the reforming catalyst 11 decreases, so that the temperature of the reforming gas output from the outlet portion 4b of the reformer 4 rises.

As shown in FIG. 6, the calorific value of the mixed gas of ammonia gas and air flowing in from the inlet portion 4a of the reformer 4 is Q1, and the calorific value of the reforming gas released from the outlet portion 4b of the reformer 4 is defined as Q1. Is Q2, and the amount of heat released from the housing 4c of the reformer 4 is Q3, the following relational expression holds.
Q1 = Q2 + Q3
Q1 = mixed gas flow rate (set value) x mixed gas temperature (measured value)
Q2 = total flow rate of reformed gas (unknown value) x reformed gas temperature (measured value)
Q3 = Natural convection heat transfer coefficient (theoretical value) x housing surface area (known) x housing temperature (measured value)

The temperature of the mixed gas is obtained from the detected value of the temperature sensor 22. The temperature of the reforming gas is obtained from the detected value of the temperature sensor 21. The temperature of the housing 4c is obtained from the detected value of the temperature sensor 23. The flow rate of the mixed gas, the natural convection heat transfer coefficient and the surface area of the housing are known in advance. Therefore, the total flow rate of the reformed gas can be obtained by the above formula.

Subsequently, the reformer controller 16A calculates the actual flow rate of hydrogen contained in the reforming gas (procedure S113). The actual flow rate of hydrogen is the actual flow rate of hydrogen. The ratio of hydrogen, nitrogen, ammonia and water in the reformed gas is known in advance. Therefore, the actual flow rate of hydrogen can be obtained from the total flow rate of the reformed gas.

Subsequently, the reformer controller 16A calculates the difference between the target flow rate of hydrogen and the actual flow rate of hydrogen (procedure S114). The target flow rate of hydrogen is predetermined. The flow rates of ammonia gas and air supplied to the reformer 4 are determined by the target flow rate of hydrogen.

Subsequently, the reformer controller 16A determines whether or not the difference between the target flow rate of hydrogen and the actual flow rate of hydrogen is equal to or higher than the specified value (procedure S115). The specified value is appropriately determined according to the characteristics, specifications, operating conditions, etc. of the reformer 4. When the reformer controller 16A determines that the difference between the target flow rate of hydrogen and the actual flow rate of hydrogen is smaller than the specified value, it determines that the reformer 4 has not deteriorated, and executes step S111 again. ..

When the reformer controller 16A determines that the difference between the target flow rate of hydrogen and the actual flow rate of hydrogen is equal to or higher than the specified value, it determines that the reformer 4 has deteriorated, and the reformer controller 16A determines from the difference. The amount of deterioration of 4 is estimated (procedure S116). Here, the difference itself between the target flow rate of hydrogen and the actual flow rate of hydrogen is taken as the amount of deterioration of the reformer 4.

Subsequently, the reformer controller 16A determines the supply flow rate of ammonia gas and air to the reformer 4 and the supply flow rate of ammonia gas to the hydrogen utilization device 5 based on the amount of deterioration of the reformer 4 (procedure). S117).

At this time, the reformer controller 16A increases the supply flow rate of ammonia gas and air to the reformer 4 by the amount corresponding to the amount of deterioration of the reformer 4. Further, the reformer controller 16A uses hydrogen by the amount corresponding to the increase in the supply flow rate of the ammonia gas to the reformer 4 so that the total flow rate of the ammonia gas supplied to the hydrogen utilization device 5 is offset. The supply flow rate of ammonia gas to the device 5 is reduced.

Then, the reformer controller 16A controls the flow rate adjusting valve 8 according to the supply flow rate of ammonia gas to the reformer 4, and controls the flow rate adjusting valve 9 according to the supply flow rate of air to the reformer 4. The flow rate adjusting valve 14 is controlled according to the supply flow rate of ammonia gas to the hydrogen utilization device 5 (procedure S118). Then, the reformer controller 16A executes the procedure S111 again.

In the above, steps S111 to 116 are executed by the deterioration detection unit 25. Procedures S117 and 118 are executed by the deterioration valve control unit 26.

For example, as shown in FIG. 7, when the flow rate of ammonia gas supplied to the reformer 4 is 100, the target reformed ammonia gas flow rate (target hydrogen flow rate) is 60, and the target residual ammonia gas flow rate is 60. It is assumed to be 40. In this case, when the actual reformed ammonia gas flow rate (actual hydrogen flow rate) is 50 and the actual residual ammonia gas flow rate is 50, the difference between the target hydrogen flow rate and the actual hydrogen flow rate is 10.

Therefore, the flow rate of the ammonia gas supplied to the reformer 4 is increased by twice the difference between the target hydrogen flow rate and the actual hydrogen flow rate. That is, the flow rate of the ammonia gas supplied to the reformer 4 is 120. Then, the actual reformed ammonia gas flow rate (actual hydrogen flow rate) becomes 60, which is equal to the target reformed ammonia gas flow rate (target hydrogen flow rate).

However, the actual residual ammonia gas flow rate is also 60, which is 20 more than the target residual ammonia gas flow rate. Therefore, the flow rate of the ammonia gas directly supplied to the hydrogen utilization device 5 is reduced by 20. Therefore, the total of the actual residual ammonia gas flow rate supplied from the reformer 4 to the hydrogen utilization device 5 and the flow rate of the ammonia gas directly supplied from the ammonia gas supply source 2 to the hydrogen utilization device 5 does not change. As a result, the amount of heat required by the hydrogen utilization device 5 can be obtained.

Also in the present embodiment as described above, it is supplied to the flow rate adjusting valve 8 and the reformer 4 that adjust the flow rate of the ammonia gas supplied to the reformer 4 according to the amount of heat required by the hydrogen utilization device 5. The flow rate adjusting valve 9 for adjusting the flow rate of air and the flow rate adjusting valve 14 for adjusting the flow rate of ammonia gas directly supplied to the hydrogen utilization device 5 are controlled. As a result, even when the performance of the reformer 4 deteriorates, the amount of heat supplied to the hydrogen utilization device 5 can be maintained at the required value.

Further, in the present embodiment, when deterioration of the reformer 4 is detected, the flow rate adjusting valve 8 is controlled so that the flow rate of the ammonia gas supplied to the reformer 4 increases, and the reformer 4 receives it. Since the flow rate adjusting valve 9 is controlled so that the flow rate of the supplied air increases, the flow rate of hydrogen contained in the reforming gas generated by the reformer 4 increases. As a result, even when the reformer 4 deteriorates, the required flow rate of hydrogen is supplied to the hydrogen utilization device 5.

Further, in the present embodiment, even if the flow rate of the ammonia gas and air supplied to the reformer 4 increases and the flow rate of the ammonia gas remaining in the reformer 4 also increases, the flow rate of the ammonia gas remaining in the reformer 4 also increases, via the bypass flow path 13. The flow rate adjusting valve 14 is controlled so that the flow rate of the ammonia gas directly supplied to the hydrogen utilization device 5 is reduced. Therefore, it is not necessary to increase the total flow rate of the ammonia gas supplied to the hydrogen utilization device 5. Therefore, even when the reformer 4 is deteriorated but the amount of heat required by the hydrogen utilization device 5 has not changed, the amount of heat supplied to the hydrogen utilization device 5 can be maintained at the required value.

Further, in the present embodiment, the temperature of the reforming gas generated by the reformer 4 tends to rise due to the deterioration of the reformer 4, but the reforming is performed by detecting the temperature of the reforming gas. Deterioration of the vessel 4 can be easily detected.

Further, in the present embodiment, the temperature of the reforming gas generated by the reformer 4, the temperature of the mixed gas of ammonia gas and air supplied to the reformer 4, and the housing 4c of the reformer 4 By detecting the temperature, the amount of deterioration of the reformer 4 can be easily estimated. Then, based on the amount of deterioration of the reformer 4, the flow rates of ammonia gas and air supplied to the reformer 4 are determined, and the flow rate adjusting valves 8 and 9 are controlled according to the flow rates to reform. It is possible to generate hydrogen at an appropriate flow rate according to the amount of deterioration of the vessel 4.

In the present embodiment, the reformer controller 16A executes the control process when the amount of heat required by the hydrogen utilization device 5 changes and the control process when the reformer 4 deteriorates in separate flows. However, the form is not particularly limited, and the control process when the amount of heat required by the hydrogen utilization device 5 changes and the control process when the reformer 4 deteriorates may be executed in one flow.

For example, when the amount of heat required by the hydrogen utilization device 5 increases and the reformer 4 deteriorates, the flow rates of ammonia gas and air supplied to the reformer 4 increase. At this time, the flow rate of the ammonia gas directly supplied to the hydrogen utilization device 5 may or may not be changed, and is determined according to the amount of increase in the amount of heat required by the hydrogen utilization device 5. ..

Although some embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the above-mentioned second embodiment, the deterioration of the reformer 4 is detected by the reformer 4 itself based on the temperature sensors 21 to 23, but the present invention is not particularly limited to that form, and the reformer 4 is cumulative. Deterioration of the reformer 4 may be detected based on the operating time, or deterioration of the reformer 4 may be detected based on the amount of change in the state of the hydrogen utilization device 5.

Further, in the above-mentioned second embodiment, the influence of pressure is not considered, but the reforming performance of the reformer 4 may change depending on the pressure. Therefore, when detecting the deterioration of the reformer 4, the pressure of the reformer 4 may also be taken into consideration.

Further, in the above embodiment, the flow rate adjusting valves 8, 9 and 14, which are the first flow rate adjusting unit to the third flow rate adjusting unit, are arranged in the ammonia gas flow path 6, the air flow path 7 and the bypass flow path 13, respectively. However, the first flow rate adjusting unit to the third flow rate adjusting unit are not particularly limited to such a flow rate adjusting valve. For example, a three-way valve type flow rate adjusting valve for adjusting the distribution ratio of ammonia gas flowing to the reformer 4 and the hydrogen utilization device 5 is provided at the confluence of the ammonia gas flow path 6 and the bypass flow path 13. May be good. In this case, the three-way valve type flow rate adjusting valve also serves as the first flow rate adjusting unit and the third flow rate adjusting unit. Further, the first flow rate adjusting unit to the third flow rate adjusting unit may be a compressor, a pump, or the like.

Further, in the above embodiment, the reformer 4 has a combustion catalyst 10 for burning ammonia gas and a reforming catalyst 11 for decomposing ammonia into hydrogen, but the catalyst used in the reformer 4 The form is not particularly limited, and for example, a combustion reforming catalyst that burns ammonia and decomposes ammonia into hydrogen may be used.

Further, in the above embodiment, the flow rate adjusting valves 8, 9 and 14 are controlled by the reformer controller 16, but the mode is not particularly limited, and for example, the main controller 15 controls the flow rate adjusting valves 8, 9 and 14. It may be controlled directly. In this case, the number of controllers can be minimized, and the output of heat quantity information to the reformer controller 16 becomes unnecessary.

Further, in the above embodiment, ammonia gas is used as the fuel gas, but the present invention can also be applied to a hydrogen utilization system using a hydrocarbon gas or the like as the fuel gas.

Further, in the above embodiment, air is used as the oxidizing gas, but the present invention is also applicable to a hydrogen utilization system using oxygen as the oxidizing gas.

1,1A ... Hydrogen utilization system, 2 ... Ammonia gas supply source (fuel gas supply source), 3 ... Air supply source (oxidizing gas supply source), 4 ... Reformer, 4c ... Housing, 5 ... Hydrogen utilization device , 6 ... Ammonia gas flow path (fuel gas flow path), 7 ... Air flow path (oxidizing gas flow path), 8 ... Flow rate adjusting valve (first flow rate adjusting section), 9 ... Flow rate adjusting valve (second flow rate adjusting) Section), 12 ... reforming gas flow path, 13 ... bypass flow path, 14 ... flow rate adjusting valve (third flow rate adjusting section), 16 ... reformer controller (control section), 21 ... temperature sensor (first temperature detection) Unit), 22 ... Temperature sensor (second temperature detection unit), 23 ... Temperature sensor (third temperature detection unit), 24 ... Valve control unit (control unit) when changing the amount of heat, 25 ... Deterioration detection unit, 26 ... Deterioration Valve control unit (control unit).

Claims (6)

A reformer that produces a reformed gas containing hydrogen by reforming the fuel gas using the heat generated by burning the fuel gas.
The fuel gas supply source that supplies the fuel gas and
Oxidizing gas supply source that supplies oxidizing gas and
A fuel gas flow path through which the fuel gas flows from the fuel gas supply source to the reformer, and
An oxidizing gas flow path through which the oxidizing gas flows from the oxidizing gas supply source to the reformer, and
A hydrogen utilization device that utilizes hydrogen contained in the reforming gas generated by the reformer, and a hydrogen utilization device.
A reformed gas flow path through which the reformed gas flows from the reformer toward the hydrogen utilization device, and
A bypass flow path arranged between the fuel gas supply source and the hydrogen utilization device so as to bypass the reformer, and the fuel gas flows from the fuel gas supply source to the hydrogen utilization device.
A first flow rate adjusting unit that adjusts the flow rate of the fuel gas flowing through the fuel gas flow path,
A second flow rate adjusting unit that adjusts the flow rate of the oxidizing gas flowing through the oxidizing gas flow path,
A third flow rate adjusting unit that adjusts the flow rate of the fuel gas flowing through the bypass flow path, and
A hydrogen utilization system including a first flow rate adjusting unit, a second flow rate adjusting unit, and a control unit that controls the third flow rate adjusting unit according to the amount of heat required by the hydrogen utilization device. Further equipped with a deterioration detection unit for detecting the deterioration of the reformer,
When the deterioration detection unit detects the deterioration of the reformer, the control unit controls the first flow rate adjusting unit so that the flow rate of the fuel gas flowing through the fuel gas flow path increases. The hydrogen utilization system according to claim 1, wherein the second flow rate adjusting unit is controlled so that the flow rate of the oxidizing gas flowing through the oxidizing gas flow path is increased. The hydrogen utilization system according to claim 2, wherein the control unit controls the third flow rate adjusting unit so that the flow rate of the fuel gas flowing through the bypass flow path is reduced. A first temperature detection unit for detecting the temperature of the reformed gas is further provided.
The hydrogen utilization system according to claim 2 or 3, wherein the deterioration detection unit detects deterioration of the reformer by using the detection value of the first temperature detection unit. A second temperature detection unit that detects the temperature of a mixed gas of the fuel gas flowing through the fuel gas flow path and the oxidizing gas flowing through the oxidizing gas flow path, and
Further provided with a third temperature detecting unit for detecting the temperature of the housing of the reformer.
The deterioration detection unit obtains the actual flow rate of hydrogen contained in the reforming gas based on the detection values of the first temperature detection unit, the second temperature detection unit, and the third temperature detection unit, and determines the actual flow rate of hydrogen contained in the reforming gas. The amount of deterioration of the reformer is estimated from the difference between the actual flow rate and the predetermined target flow rate of hydrogen.
The control unit determines the supply flow rates of the fuel gas and the oxidizing gas to the reformer based on the amount of deterioration of the reformer, and adjusts the first flow rate according to the supply flow rate of the fuel gas. The hydrogen utilization system according to claim 4, wherein the second flow rate adjusting unit is controlled according to the supply flow rate of the oxidizing gas. The hydrogen utilization system according to any one of claims 1 to 5, wherein the fuel gas is ammonia gas.

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