Estimation device and estimation system
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-07
- Publication Date
- 2026-08-13
Smart Images
Figure JP2025004077_13082026_PF_FP_ABST
Abstract
Description
Estimation Device and Estimation System
[0001] The present disclosure relates to an estimation device and an estimation system.
[0002] In recent years, research and development on fuel cells that contribute to energy efficiency has been carried out in order to ensure access to affordable, reliable, sustainable, and modern energy for more people. International Publication No. 2013 / 187514 discloses a fuel cell system that controls the cathode gas flow rate according to the operating state.
[0003] There may be room to suppress the supply amount of the cathode gas supplied from the cathode gas supply device that supplies the cathode gas necessary for the fuel cell to generate electricity.
[0004] The present disclosure aims to solve the above-described problems and thus contributes to energy efficiency.
[0005] A first aspect of the present disclosure is a first estimation unit that estimates a first required amount of cathode gas required for dilution of exhaust gas discharged from a first fuel cell that generates electricity by receiving the supply of cathode gas from a first cathode gas supply device, an acquisition unit that acquires an inflow amount of cathode gas that flows into an exhaust flow path through which the exhaust gas flows and communicates with the atmosphere from a second cathode gas supply device different from the first cathode gas supply device, and a second estimation unit that estimates the supply amount of the cathode gas supplied from the first cathode gas supply device based on the first required amount and the inflow amount.
[0006] A second aspect of the present disclosure is an estimation system including the estimation device according to the first aspect and a plurality of fuel cell systems. The plurality of fuel cell systems include a first fuel cell system, a second fuel cell system, and the exhaust flow path. The first fuel cell system includes the first cathode gas supply device and the first fuel cell. The second fuel cell system includes a second fuel cell capable of generating electricity by receiving the supply of cathode gas from the second cathode gas supply device. Fluids flowing through a first cathode gas exhaust flow path and a second cathode gas exhaust flow path merge in the exhaust flow path and flow through the exhaust flow path.
[0007] According to this disclosure, the amount of cathode gas supplied from a cathode gas supply device that supplies the cathode gas necessary for fuel cells to generate electricity can be reduced.
[0008] Figure 1 is a diagram illustrating an estimation system having an estimation device according to one embodiment. Figure 2 is a block diagram illustrating the configuration of the estimation device. Figure 3 is a flowchart illustrating a processing procedure for estimating the supply amount of cathode gas and controlling the supply of cathode gas.
[0009] Large vehicles may be equipped with multiple fuel cells. When large vehicles are traveling at low speeds, the power requirements are not high. To meet such power requirements, it is not always necessary for all fuel cells to generate electricity. In that case, some of the fuel cells will generate electricity, while the others will not. The power output of the fuel cells that do generate electricity is fixed, for example, 4 kWh per unit.
[0010] Therefore, the power generated by the fuel cell is greater than the required power as described above. For example, if the required power is 1 kWh, a fuel cell that outputs 4 kWh of power will generate surplus power of 3 kWh, corresponding to the difference between the generated power and the required power. This surplus power is consumed by some load for the purpose of waste power disposal. The surplus power may also be used to operate a cathode gas supply device that can supply cathode gas to the fuel cell. The operation of the cathode gas supply device is carried out according to the estimation of the amount of cathode gas supplied from the cathode gas supply device.
[0011] Figure 1 illustrates an estimation system 12 having an estimation device 10 according to one embodiment. The estimation system 12 comprises the estimation device 10 and a plurality of fuel cell systems 14. In this embodiment, the plurality of fuel cell systems 14 comprises a first fuel cell system 16 and a second fuel cell system 18. However, the plurality of fuel cell systems 14 may comprise three or more fuel cell systems. The first fuel cell system 16 comprises a first cathode gas supply device 20, a first cathode gas supply channel 22, and a first fuel cell 24. The estimation device 10 estimates the amount of cathode gas supplied from the first cathode gas supply device 20.
[0012] The first cathode gas supply device 20 is, for example, an air pump that compresses and discharges air. By controlling the rotational speed of the motor that drives the air pump with the estimation device 10, the air pump can supply a supply amount of cathode gas corresponding to the rotational speed of the motor. The cathode gas discharged from the outlet of the first cathode gas supply device 20 flows through the first cathode gas supply passage 22.
[0013] As shown in Figure 1, the cathode gas supplied from the first cathode gas supply device 20 flows through the first cathode gas supply channel 22 and then flows into the first fuel cell 24. The first fuel cell 24 has an electrolyte membrane 26 and a cathode 28 and an anode 30 facing each other across the electrolyte membrane 26. The cathode gas that has flowed into the first fuel cell 24 is supplied to the cathode 28.
[0014] The first fuel cell system 16 further includes a first fuel tank 32, a first anode gas supply channel 34, a first cathode gas discharge channel 36, a first anode gas discharge channel 38, and a first drainage channel 40. The first fuel tank 32 stores hydrogen as fuel. The anode gas supplied from the first fuel tank 32 flows out into the first anode gas supply channel 34 and is then injected by an injector (not shown) into the first fuel cell 24. The anode gas that has flowed into the first fuel cell 24 is supplied to the anode 30.
[0015] The first fuel cell 24 generates electricity by receiving cathode gas from the first cathode gas supply device 20 and anode gas from the first fuel tank 32. Specifically, the first fuel cell 24 generates electricity when the cathode gas supplied to the cathode 28 and the anode gas supplied to the anode 30 undergo an oxidation-reduction reaction. As a result of the power generation by the first fuel cell 24, the first fuel cell 24 outputs generated power P and also produces oxygen and water. In this embodiment, the generated power P of the first fuel cell 24 is greater than the required power as described above.
[0016] The oxygen generated by the power generation of the first fuel cell 24 flows out into the first cathode gas discharge channel 36 along with the unreacted cathode gas. The first cathode gas discharge channel 36 also contains anode gas that has leaked from the anode 30 to the cathode 28. The water generated by the power generation of the first fuel cell 24 flows out into the first anode gas discharge channel 38 along with the unreacted anode gas.
[0017] Most of the unreacted anode gas that flows out into the first anode gas discharge channel 38 is separated from water by a gas-liquid separator (not shown). The water flows out into the first drainage channel 40. The anode gas separated from the water flows back into the first fuel cell 24 via the first anode gas supply channel 34 by an ejector (not shown).
[0018] A portion of the unreacted anode gas that flows into the first anode gas discharge channel 38 is mixed with water without being separated and flows into the first drainage channel 40. The water and anode gas flowing through the first drainage channel 40 flow into the first cathode gas discharge channel 36. The anode gas that leaks from the anode 30 to the cathode 28 and flows into the first cathode gas discharge channel 36, and the anode gas that is mixed with water without being separated and flows into the first cathode gas discharge channel 36 are collectively called exhaust gas.
[0019] Multiple fuel cell systems 14 further have an exhaust channel 42 that leads to the atmosphere. A first cathode gas exhaust channel 36 communicates with the exhaust channel 42. Oxygen, cathode gas, water, and exhaust gas flowing through the first cathode gas exhaust channel 36 are discharged into the atmosphere through the exhaust channel 42. Therefore, the exhaust gas needs to be diluted. In accordance with the standard, the exhaust gas must be diluted to a hydrogen concentration of 4% or less.
[0020] The first fuel cell system 16 further includes a first bypass channel 44 and a first valve 46. In this embodiment, as shown in Figure 1, the first bypass channel 44 connects the first cathode gas supply channel 22 and the first cathode gas discharge channel 36. The first valve 46 is provided in the first bypass channel 44, which allows a portion of the cathode gas supplied from the first cathode gas supply device 20 to flow into the discharge channel 42 without being supplied to the first fuel cell 24.
[0021] When the first fuel cell 24 is generating electricity, the estimation device 10 controls and opens the first valve 46, causing a portion of the cathode gas supplied from the first cathode gas supply device 20 to flow through the first bypass passage 44 and flow into the discharge passage 42 via the first cathode gas discharge passage 36 without being supplied to the first fuel cell 24. In other words, the cathode gas supplied from the first cathode gas supply device 20, which is originally intended to supply the cathode gas necessary for the first fuel cell 24 to generate electricity, flows through the first bypass passage 44 and into the discharge passage 42. This allows the exhaust gas flowing through the first cathode gas discharge passage 36 to be diluted.
[0022] When the estimation device 10 controls and closes the first valve 46, the cathode gas supplied from the first cathode gas supply device 20 does not flow through the first bypass channel 44 but is supplied to the first fuel cell 24.
[0023] The second fuel cell system 18 includes a second cathode gas supply device 50, a second cathode gas supply channel 52, and a second fuel cell 54. When the second fuel cell 54 generates electricity, these components are the same as those of the first cathode gas supply device 20, the first cathode gas supply channel 22, and the first fuel cell 24, respectively, so their description is omitted. The cathode gas discharged from the outlet of the second cathode gas supply device 50 flows through the second cathode gas supply channel 52. The second fuel cell 54 has an electrolyte membrane 56, a cathode 58, and an anode 60, similar to the electrolyte membrane 26, cathode 28, and anode 30 of the first fuel cell 24.
[0024] The second fuel cell system 18 further includes a second fuel tank 62, a second anode gas supply channel 64, a second cathode gas discharge channel 66, a second anode gas discharge channel 68, and a second drainage channel 70. When the second fuel cell 54 generates electricity, these are the same as the first fuel tank 32, the first anode gas supply channel 34, the first cathode gas discharge channel 36, the first anode gas discharge channel 38, and the first drainage channel 40, respectively, so their explanation is omitted.
[0025] The second cathode gas discharge channel 66, together with the first cathode gas discharge channel 36, communicates with the discharge channel 42 described above. That is, the fluid flowing through the first cathode gas discharge channel 36 and the fluid flowing through the second cathode gas discharge channel 66 merge in the discharge channel 42 and flow through the discharge channel 42. In other words, the first cathode gas discharge channel 36 and the second cathode gas discharge channel 66 are channels provided upstream of the discharge channel 42.
[0026] The second fuel cell system 18 further includes a second bypass passage 74 and a second valve 76. These are the same as the first bypass passage 44 and the first valve 46. That is, the second bypass passage 74 connects the second cathode gas supply passage 52 and the second cathode gas discharge passage 66. The second valve 76 is provided in the second bypass passage 74.
[0027] When the second fuel cell 54 generates electricity, it can generate electricity by receiving cathode gas from the second cathode gas supply device 50. However, in this embodiment, unlike the first fuel cell 24, the second fuel cell 54 does not generate electricity. In that case, the cathode 58 and anode 60 of the second fuel cell 54 are not supplied with cathode gas from the second cathode gas supply device 50 or anode gas from the second fuel tank 62.
[0028] At least a portion of the surplus power Pa corresponding to the difference between the power generated P of the first fuel cell 24 and the required power is used to operate the second cathode gas supply device 50 for the purpose of waste power. Therefore, the cathode gas supplied from the second cathode gas supply device 50 flows out into the second cathode gas supply channel 52.
[0029] When the estimation device 10 controls and opens the second valve 76, all of the cathode gas supplied from the second cathode gas supply device 50 can flow through the second bypass channel 74 via the second cathode gas supply channel 52 and into the discharge channel 42 via the second cathode gas discharge channel 66. In other words, the cathode gas supplied from the second cathode gas supply device 50 and flowing into the discharge channel 42 can dilute the exhaust gas flowing into the discharge channel 42 via the first cathode gas discharge channel 36.
[0030] Therefore, the amount of cathode gas supplied from the first cathode gas supply device 20 to dilute the exhaust gas, which flows through the first bypass channel 44 and into the discharge channel 42, can be reduced. At least a portion of the surplus power Pa corresponding to the difference between the power generated P of the first fuel cell 24 and the required power is used to operate the second cathode gas supply device 50. This allows the surplus power Pa to be used beneficially without being wasted.
[0031] Figure 2 is a block diagram illustrating the configuration of the estimation device 10. The estimation device 10 includes a calculation unit 90 and a storage unit 92. The calculation unit 90 is a computer and includes a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In other words, the calculation unit 90 includes processing circuitry.
[0032] The storage unit 92 is a recording medium that can be read by a computer. The storage unit 92 includes volatile memory such as RAM (Random Access Memory) and non-volatile memory such as ROM (Read Only Memory) or flash memory. The volatile memory is used as the working memory of the processor. The non-volatile memory stores the computer program executed by the processor and other necessary data.
[0033] Computer programs (computer software) executed by a processor can also be called computer program products. Computer program products are not limited to computer programs stored on recording media, but also include computer programs transmitted, distributed, or downloaded via the internet, etc.
[0034] The calculation unit 90 includes a first estimation unit 100, an acquisition unit 102, a second estimation unit 104, a third estimation unit 106, a supply control unit 108, a valve control unit 110, and a power control unit 112. The calculation unit 90 executes a computer program stored in the storage unit 92 to realize the first estimation unit 100, the acquisition unit 102, the second estimation unit 104, the third estimation unit 106, the supply control unit 108, the valve control unit 110, and the power control unit 112.
[0035] At least a portion of the first estimation unit 100, the acquisition unit 102, the second estimation unit 104, the third estimation unit 106, the supply control unit 108, the valve control unit 110, and the power control unit 112 may be implemented by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or by an electronic circuit including discrete devices.
[0036] The first estimation unit 100 estimates the first required amount of cathode gas needed to dilute the exhaust gas of the anode gas discharged from the first fuel cell 24, which generates electricity by receiving cathode gas from the first cathode gas supply device 20. The amount of exhaust gas of the anode gas discharged from the first fuel cell 24 can be calculated, for example, based on the command value of the amount of anode gas injected from the injector described above for power generation and the measured value of the current flowing from the first fuel cell 24 that outputs generated power P.
[0037] Based on the amount of anode gas exhaust gas calculated in this way, the first estimation unit 100 can estimate the first required amount of cathode gas needed to dilute the anode gas exhaust gas.
[0038] The acquisition unit 102 acquires the amount of cathode gas flowing from the second cathode gas supply device 50, which is different from the first cathode gas supply device 20, into the exhaust flow path 42 through which the exhaust gas flows. As described above, at least a portion of the surplus electricity Pa from the first fuel cell 24 is used to operate the second cathode gas supply device 50. Based on the electricity supplied to the second cathode gas supply device 50 in this way, the acquisition unit 102 can estimate the amount of cathode gas flowing from the second cathode gas supply device 50 into the exhaust flow path 42 via the second bypass flow path 74.
[0039] As described above, the acquisition unit 102 acquires the cathode gas inflow rate by estimating it based on the power supplied to the second cathode gas supply device 50, but is not limited to this. The acquisition unit 102 may acquire the flow rate of cathode gas discharged from the outlet of the second cathode gas supply device 50 as the cathode gas inflow rate described above. The acquisition unit 102 may acquire the flow rate of cathode gas supplied from the second cathode gas supply device 50 and flowing through the second cathode gas discharge channel 66 as the cathode gas inflow rate described above.
[0040] Furthermore, the acquisition unit 102 may acquire the detected value from a sensor that detects the flow rate of cathode gas as the cathode gas inflow amount described above. In that case, for example, the sensor may be provided in the second cathode gas discharge channel 66. The sensor that detects the flow rate of cathode gas may be provided in the discharge channel 42 provided downstream of the second cathode gas discharge channel 66. In that case, the acquisition unit 102 acquires the cathode gas inflow amount described above by estimating it based on the detected value from the sensor and the first required amount of cathode gas determined by the first estimation unit 100.
[0041] The second estimation unit 104 estimates the amount of cathode gas to be supplied from the first cathode gas supply device 20 based on the first required amount of cathode gas estimated by the first estimation unit 100 and the amount of cathode gas inflow estimated by the acquisition unit 102. The second estimation unit 104 estimates the supply amount based on the difference between the first required amount and the amount of inflow. Specifically, the second estimation unit 104 estimates the supply amount to be the larger of the difference and the second required amount of cathode gas estimated by the third estimation unit 106, which will be described later.
[0042] The third estimation unit 106 receives cathode gas from the first cathode gas supply device 20 and estimates the second required amount of cathode gas necessary for the first fuel cell 24 to generate electricity. As described above, the power generation P output by the fuel cell is a fixed value, for example, 4 kW. Therefore, the third estimation unit 106 estimates the second required amount of cathode gas necessary for the first fuel cell 24 to generate electricity, which outputs power generation P of this fixed value.
[0043] The second required amount indicates the minimum supply amount of cathode gas supplied from the first cathode gas supply device 20. Therefore, as described above, the second estimation unit 104 estimates the larger of the second required amount and the difference amount as the supply amount of cathode gas supplied from the first cathode gas supply device 20. The difference amount is, as described above, the difference between the first required amount of cathode gas required to dilute the exhaust gas of the anode gas discharged from the first fuel cell 24 and the amount of cathode gas flowing from the second cathode gas supply device 50 into the discharge flow path 42.
[0044] The supply control unit 108 controls the first cathode gas supply device 20 to supply the amount of cathode gas estimated by the second estimation unit 104. If the first cathode gas supply device 20 is an air pump, the supply control unit 108 sets the rotational speed of the motor driving the air pump to a value corresponding to the amount of cathode gas supplied estimated by the second estimation unit 104. Similarly, the supply control unit 108 controls the second cathode gas supply device 50 to supply the amount of cathode gas estimated by the acquisition unit 102.
[0045] The valve control unit 110 controls a first valve 46 provided in a first bypass passage 44 for allowing a part of the cathode gas supplied from the first cathode gas supply device 20 to flow into the discharge passage 42. When the first fuel cell 24 is generating power, if the valve control unit 110 controls the first valve 46 to open, a part of the cathode gas supplied from the first cathode gas supply device 20 flows into the discharge passage 42 via the first bypass passage 44.
[0046] When the above-described difference amount is larger than the second required amount, the valve control unit 110 controls the first valve 46 to circulate the cathode gas having a bypass flow rate corresponding to the difference between the difference amount and the second required amount through the first bypass passage 44 without supplying it to the first fuel cell 24.
[0047] When the valve control unit 110 controls the first valve 46 to close, the cathode gas supplied from the first cathode gas supply device 20 is not passed through the first bypass passage 44 and is all supplied to the first fuel cell 24.
[0048] The power control unit 112 supplies a part of the power generated by the first fuel cell 24 to the second cathode gas supply device 50. Specifically, as described above, at least a part of the surplus power Pa corresponding to the difference between the generated power P of the first fuel cell 24 and the required power is used for operating the second cathode gas supply device 50 for the purpose of waste power. The power control unit 112 supplies power from the first fuel cell 24 to the second cathode gas supply device 50 by controlling circuit elements constituting a power supply circuit (not shown).
[0049] FIG. 3 is a flowchart illustrating a processing procedure for estimating the supply amount of the cathode gas and controlling the supply of the cathode gas. This processing procedure is performed when the second fuel cell 54 stops while the first fuel cell 24 is generating power. This processing procedure is performed by the arithmetic unit 90 executing a computer program stored in the storage unit 92 of the estimation device 10.
[0050] When this processing procedure is started, in step S1, the first estimation unit 100 estimates the first required amount of cathode gas needed to dilute the exhaust gas of the anode gas discharged from the first fuel cell 24, which generates electricity by receiving cathode gas from the first cathode gas supply device 20. In step S2, the acquisition unit 102 acquires the amount of cathode gas flowing into the exhaust flow path 42 through which the exhaust gas flows from a second cathode gas supply device 50, which is different from the first cathode gas supply device 20.
[0051] In step S3, the second estimation unit 104 calculates the difference between the first required amount of cathode gas estimated in step S1 and the amount of cathode gas flowing in estimated in step S2. In step S4, the third estimation unit 106 estimates the second required amount of cathode gas necessary for the first fuel cell 24 to generate electricity by receiving cathode gas from the first cathode gas supply device 20.
[0052] In step S5, the second estimation unit 104 estimates the larger of the difference amount calculated in step S3 and the second required amount estimated in step S4 as the amount of cathode gas to be supplied from the first cathode gas supply device 20. This makes it possible to reduce the amount of cathode gas supplied from the first cathode gas supply device 20, which supplies the cathode gas necessary for the first fuel cell 24 to generate electricity. At the same time, it is possible to secure the cathode gas necessary for the first fuel cell 24 to generate electricity.
[0053] In step S6, the supply control unit 108 controls the first cathode gas supply device 20 to supply the amount of cathode gas estimated by the second estimation unit 104.
[0054] In step S7, the second estimation unit 104 determines whether the difference calculated in step S3 is estimated to be the amount of cathode gas supplied from the first cathode gas supply device 20. If the answer in step S7 is YES, the process proceeds to step S8. If the answer in step S7 is NO, the process ends. In step S8, the power control unit 112 supplies a portion of the electricity generated by the first fuel cell 24 to the second cathode gas supply device 50. This allows the surplus electricity Pa of the first fuel cell 24 to be used effectively without being wasted.
[0055] In step S9, the supply control unit 108 controls the second cathode gas supply device 50 to supply the cathode gas inflow amount estimated in step S2. In step S10, the valve control unit 110 controls the first valve 46 to allow the cathode gas in a bypass flow rate corresponding to the difference between the difference amount and the second required amount to flow through the first bypass flow path 44 instead of supplying it to the first fuel cell 24. Once the processing in step S10 is completed, this processing procedure is finished.
[0056] The embodiments described above may be modified as follows. In the following modifications, explanations that overlap with the embodiments described above will be omitted.
[0057] (Modified Version) In the above-described embodiment, the multiple fuel cell systems 14 include a first fuel cell system 16 and a second fuel cell system 18. In the first fuel cell system 16, the first fuel cell 24 generates electricity by receiving cathode gas from the first cathode gas supply device 20. In the second fuel cell system 18, unlike the first fuel cell 24, the second fuel cell 54 does not generate electricity. When the second fuel cell 54 generates electricity, the second cathode gas supply device 50, which can supply cathode gas to the second fuel cell 54, uses the surplus power Pa of the first fuel cell 24 to supply cathode gas to dilute the exhaust gas flowing into the discharge channel 42.
[0058] However, the multiple fuel cell systems 14 may further include other fuel cell systems having fuel cells that do not generate electricity, such as the second fuel cell 54. These other fuel cell systems include a fuel cell that does not generate electricity and a cathode gas supply device that can supply cathode gas to the fuel cell when it generates electricity. In this modified example, the other fuel cell system is described as a single fuel cell system, but it may include two or more fuel cell systems.
[0059] The cathode gas supply device of the other fuel cell system, similar to the second cathode gas supply device 50, uses the surplus power Pa of the first fuel cell 24 to supply cathode gas to dilute the exhaust gas flowing into the discharge channel 42. In this way, the cathode gas supplied from the cathode gas supply device and flowing into the discharge channel 42 can also dilute the exhaust gas flowing into the discharge channel 42 via the first cathode gas discharge channel 36.
[0060] The acquisition unit 102 of the estimation device 10 similarly acquires the amount of cathode gas flowing into the discharge channel 42 from cathode gas supply devices of the other fuel cell system, in addition to the second cathode gas supply device 50. The second estimation unit 104 of the estimation device 10 estimates the amount of cathode gas supplied from the first cathode gas supply device 20 based on the acquired amount of cathode gas flowing in. According to this modified example, the amount of cathode gas supplied from the first cathode gas supply device 20 to dilute the exhaust gas and flowing through the first bypass channel 44 into the discharge channel 42 can be further reduced.
[0061] At least a portion of the surplus electricity Pa of the first fuel cell 24 is used to operate the second cathode gas supply device 50 and the cathode gas supply devices of the other fuel cell system. This allows the surplus electricity Pa to be used more effectively without being wasted.
[0062] Furthermore, the other fuel cell system that receives cathode gas from the cathode gas supply device using the surplus power Pa of the first fuel cell 24 can be selected at a predetermined timing from among fuel cell systems whose fuel cells are currently stopped. The predetermined timing is, for example, the timing when the operating time of the cathode gas supply device that supplies cathode gas using the surplus power Pa of the first fuel cell 24 reaches a predetermined time or longer.
[0063] Furthermore, the predetermined timing may also be the timing when a fuel cell generating power enters a new shutdown state based on fluctuations in the required load. By setting the predetermined timing, the durability of each cathode gas supply device is improved, and the operating time of the fuel cell can be extended.
[0064] With regard to the embodiments and modifications described above, the following additional information is disclosed.
[0065] (Note 1) The estimation device (10) of this disclosure includes: a first estimation unit (100) that estimates a first required amount of cathode gas required to dilute the exhaust gas discharged from a first fuel cell (24) that generates electricity by receiving cathode gas from a first cathode gas supply device (20); an acquisition unit (102) that acquires the amount of cathode gas flowing in from a second cathode gas supply device (50), which is different from the first cathode gas supply device, into an exhaust channel (42) through which the exhaust gas flows and is connected to the atmosphere; and a second estimation unit (104) that estimates the amount of cathode gas supplied from the first cathode gas supply device based on the first required amount and the amount of flow. With this configuration, the amount of cathode gas supplied from the first cathode gas supply device that supplies the cathode gas necessary for the first fuel cell to generate electricity can be reduced.
[0066] (Note 2) In the estimation device described in Note 1, the second estimation unit may estimate the supply amount based on the difference amount, which is the difference between the first required amount and the inflow amount. With such a configuration, the supply amount of cathode gas supplied from the first cathode gas supply device that supplies the cathode gas necessary for the first fuel cell to generate electricity can be reduced.
[0067] (Note 3) The estimation device described in Note 2 further comprises a third estimation unit (106) that estimates a second required amount of cathode gas necessary for the first fuel cell to generate electricity by receiving a supply of cathode gas from the first cathode gas supply device, and the second estimation unit may estimate the larger of the difference amount and the second required amount as the supply amount. With such a configuration, the supply amount of cathode gas supplied from the first cathode gas supply device that supplies the cathode gas necessary for the first fuel cell to generate electricity can be reduced. In addition, the cathode gas necessary for the first fuel cell to generate electricity can also be secured.
[0068] (Note 4) The estimation device described in Note 3 further comprises a valve control unit (110) that controls a valve (46) provided in a bypass channel (44) for allowing a portion of the cathode gas supplied from the first cathode gas supply device to flow into the discharge channel instead of being supplied to the first fuel cell, and if the difference amount is greater than the second required amount, the valve control unit may control the valve to allow a bypass flow rate of cathode gas corresponding to the difference between the difference amount and the second required amount to flow through the bypass channel instead of being supplied to the first fuel cell. With such a configuration, the amount of cathode gas supplied from the first cathode gas supply device that supplies the cathode gas necessary for the first fuel cell to generate electricity can be reduced.
[0069] (Note 5) In the estimation device described in Note 1, the acquisition unit may acquire the inflow amount based on at least one of the following: the flow rate of cathode gas discharged from the outlet of the second cathode gas supply device, the flow rate of cathode gas flowing through the discharge channel, and the flow rate of cathode gas supplied from the second cathode gas supply device and flowing through the second cathode gas discharge channel (66) provided upstream of the discharge channel. With such a configuration, the amount of cathode gas supplied from the first cathode gas supply device, which supplies the cathode gas necessary for the first fuel cell to generate electricity, can be reduced.
[0070] (Note 6) The estimation device described in any one of Notes 1 to 5 may further include a power control unit (112) that supplies a portion of the electricity (P) generated by the first fuel cell to the second cathode gas supply device. With such a configuration, the surplus electricity of the first fuel cell can be utilized beneficially without being wasted.
[0071] (Note 7) The estimation system (12) of the present disclosure comprises the estimation device described in Note 1 and a plurality of fuel cell systems (14), wherein the plurality of fuel cell systems include a first fuel cell system (16), a second fuel cell system (18), and the discharge channel, the first fuel cell system includes the first cathode gas supply device and the first fuel cell, the second fuel cell system includes a second fuel cell (54) that can generate electricity by receiving cathode gas from the second cathode gas supply device, and a fluid flowing through the first cathode gas discharge channel (36) and a fluid flowing through the second cathode gas discharge channel merge in the discharge channel and flow through the discharge channel.
[0072] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the spirit of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values or mathematical formulas are used in the description of the embodiments described above.
[0073] 10... Estimation device 20... First cathode gas supply device 22... First cathode gas supply channel 24... First fuel cell 26, 56... Electrolyte membrane 28, 58... Cathode 30, 60... Anode 32... First fuel tank 34... First anode gas supply channel 36... First cathode gas discharge channel 38... First anode gas discharge channel 40... First drainage channel 42... Discharge channel 44... First bypass channel 46... First valve 50... Second cathode gas supply device 52... Second cathode gas supply channel 54... Second fuel cell 62... Second fuel tank 64... Second anode gas supply channel 66... Second cathode gas discharge channel 68... Second anode gas discharge channel 70... Second drainage channel 74... Second bypass channel 76... Second valve 90... Calculation unit 92... Memory unit 100...First estimation unit 102...Acquisition unit 104...Second estimation unit 106...Third estimation unit 108...Supply control unit 110...Valve control unit 112...Power control unit
Claims
1. An estimation device (10) comprising: a first estimation unit (100) that estimates a first required amount of cathode gas for diluting exhaust gas discharged from a first fuel cell (24) that generates electricity by receiving cathode gas from a first cathode gas supply device (20); an acquisition unit (102) that acquires the amount of cathode gas flowing in from a second cathode gas supply device (50) different from the first cathode gas supply device into an exhaust channel (42) through which the exhaust gas flows and is connected to the atmosphere; and a second estimation unit (104) that estimates the amount of cathode gas supplied from the first cathode gas supply device based on the first required amount and the amount of flow.
2. Estimation device according to claim 1, wherein the second estimation unit estimates the supply amount based on the difference amount which is the difference between the first required amount and the inflow amount.
3. Estimation device according to claim 2, further comprising a third estimation unit (106) that estimates a second required amount of cathode gas necessary for the first fuel cell to generate electricity by receiving a supply of cathode gas from the first cathode gas supply device, wherein the second estimation unit estimates the larger of the difference amount and the second required amount as the supply amount.
4. Estimation device according to claim 3, further comprising a valve control unit (110) that controls a valve (46) provided in a bypass channel (44) for allowing a portion of the cathode gas supplied from the first cathode gas supply device to flow into the discharge channel without being supplied to the first fuel cell, wherein if the difference amount is greater than the second required amount, the valve control unit controls the valve to allow cathode gas at a bypass flow rate corresponding to the difference between the difference amount and the second required amount to flow through the bypass channel without being supplied to the first fuel cell.
5. Estimation device according to claim 1, wherein the acquisition unit acquires the inflow amount based on at least one of the flow rate of cathode gas discharged from the outlet of the second cathode gas supply device, the flow rate of cathode gas flowing through the discharge channel, and the flow rate of cathode gas supplied from the second cathode gas supply device and flowing through a second cathode gas discharge channel (66) provided upstream of the discharge channel.
6. Estimation device according to any one of claims 1 to 5, further comprising a power control unit (112) that supplies a portion of the electricity (P) generated by the first fuel cell to the second cathode gas supply device.
7. Estimation system (12) comprising: the estimation device according to claim 1; and a plurality of fuel cell systems (14), wherein the plurality of fuel cell systems include a first fuel cell system (16), a second fuel cell system (18), and the discharge channel; the first fuel cell system includes a first cathode gas supply device and a first fuel cell; the second fuel cell system includes a second fuel cell (54) capable of generating electricity by receiving cathode gas from the second cathode gas supply device; and a fluid flowing through a first cathode gas discharge channel (36) and a fluid flowing through a second cathode gas discharge channel merge in the discharge channel and flow through the discharge channel.