Hydrogen tank remaining capacity prediction method, hydrogen tank remaining capacity prediction device, and power generation system

Abstract

The method for predicting the remaining amount of hydrogen in a hydrogen tank disclosed herein is a method for predicting the remaining amount of hydrogen in a hydrogen tank used in a fuel cell device including at least one fuel cell unit, and comprises the steps of predicting a time when the remaining amount of hydrogen in the hydrogen tank will be below a first threshold value based on the amount of hydrogen in the hydrogen tank used in a first period spanning multiple days, and notifying a display device of said time, and when the amount of hydrogen in the hydrogen tank used in a second period spanning multiple days within the first period is below a second threshold value, the time is predicted based on the amount of hydrogen in the hydrogen tank used in a period of the first period excluding the second period.

Description

[Technical field]

[0001] The present disclosure relates to a method for predicting remaining hydrogen tank capacity, a device for predicting remaining hydrogen tank capacity, and a power generation system. [Background technology]

[0002] Patent Document 1 discloses an apparatus that generates an operation plan for a hydrogen production system equipped with a hydrogen generation device, the apparatus comprising: a demand prediction unit that generates a predicted demand for each of multiple types of hydrogen whose production has different environmental loads during the period covered by the operation plan; and an operation planning unit that generates an operation plan for generating multiple types of hydrogen whose production has different environmental loads using the hydrogen generation device based on the predicted hydrogen demand for each of the multiple types of hydrogen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 203520 Summary of the Invention [Problem to be solved by the invention]

[0004] An objective of the present disclosure is to provide, as an example, a method for predicting remaining hydrogen in a hydrogen tank, a device for predicting remaining hydrogen in a hydrogen tank used in a fuel cell device, and a power generation system that can predict more accurately than conventional methods when the remaining hydrogen in the hydrogen tank used in the fuel cell device will fall below a predetermined amount. [Means for solving the problem]

[0005] In order to solve the above problems, one aspect of the present disclosure is a method for predicting the remaining amount of hydrogen in a hydrogen tank used in a fuel cell device including at least one fuel cell unit, comprising the steps of predicting a time when the remaining amount of hydrogen in the hydrogen tank will be below a first threshold based on the amount of hydrogen in the hydrogen tank used in a first period spanning multiple days, and notifying a display device of the time, wherein when the amount of hydrogen in the hydrogen tank used in a second period spanning multiple days within the first period is below a second threshold, the time is predicted based on the amount of hydrogen in the hydrogen tank used in a period of the first period excluding the second period.

[0006] Moreover, one aspect of the present disclosure is a hydrogen tank remaining amount prediction device used in a fuel cell apparatus including at least one fuel cell unit, comprising: a controller that predicts when the remaining amount of hydrogen in the hydrogen tank will be below a first threshold amount based on the amount of hydrogen in the hydrogen tank used during a first period spanning multiple days; and a communicator controlled by the controller that notifies a display device of the time, wherein when the amount of hydrogen in the hydrogen tank used during a second period spanning multiple days within the first period is below a second threshold amount, the controller predicts the time based on the amount of hydrogen in the hydrogen tank used during a period of the first period excluding the second period.

[0007] Moreover, a power generation system according to an aspect of the present disclosure includes a fuel cell device including at least one fuel cell unit, and the hydrogen tank remaining amount prediction device described above. Effect of the Invention

[0008] The hydrogen tank remaining amount prediction method, hydrogen tank remaining amount prediction device, and power generation system of one embodiment of the present disclosure have the effect of being able to predict more accurately than conventional methods when the remaining hydrogen amount in a hydrogen tank used in a fuel cell device will fall below a predetermined amount. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a power generation system according to a first embodiment. [Figure 2A] FIG. 2A is a diagram showing an example of a sensor for calculating the remaining amount of hydrogen in a hydrogen tank. [Figure 2B] FIG. 2B is a diagram showing an example of a sensor for calculating the remaining amount of hydrogen in a hydrogen tank. [Figure 2C] FIG. 2C is a diagram showing an example of a sensor for calculating the remaining amount of hydrogen in a hydrogen tank. [Diagram 3] FIG. 3 is a flow chart showing an example of the operation of the hydrogen tank remaining amount predicting device (hydrogen tank remaining amount predicting method) in the first embodiment. [Figure 4] FIG. 4 is a flow chart showing an example of the operation of the hydrogen tank remaining amount predicting device (hydrogen tank remaining amount predicting method) in the first example of the first embodiment. [Diagram 5] FIG. 5 is a diagram illustrating an example of a power generation system according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present inventors conducted extensive research into predicting when the remaining hydrogen level in a hydrogen tank used in a fuel cell device will fall below a predetermined threshold level, and as a result discovered that excluding data from periods when the amount of hydrogen usage in the hydrogen tank is irregularly low compared to normal hydrogen usage over multiple days when calculating the amount of hydrogen usage in the hydrogen tank can result in a more appropriate calculation of the amount of hydrogen usage than if this is not done, and thus came up with the following aspect of the present disclosure.

[0011] In other words, a first aspect of the present disclosure is a method for predicting the remaining amount of hydrogen in a hydrogen tank used in a fuel cell device including at least one fuel cell unit, comprising the steps of predicting a time when the remaining amount of hydrogen in the hydrogen tank will be below a first threshold based on the amount of hydrogen in the hydrogen tank used in a first period spanning multiple days, and notifying a display device of the time, wherein when the amount of hydrogen in the hydrogen tank used in a second period spanning multiple days within the first period is below the second threshold, the time is predicted based on the amount of hydrogen in the hydrogen tank used in a period of the first period excluding the second period.

[0012] According to the above, the method for predicting the remaining amount of hydrogen in a hydrogen tank of this aspect can predict the time when the remaining amount of hydrogen in a hydrogen tank used in a fuel cell device will fall below the first threshold value more accurately than ever before.

[0013] Specifically, excluding data from the second period during which the amount of hydrogen used in the hydrogen tank is irregularly low over a number of days compared to normal hydrogen usage, can more appropriately calculate the amount of hydrogen used than if this data were not included. Therefore, the hydrogen tank remaining amount prediction method of this embodiment predicts when the amount of hydrogen remaining in the hydrogen tank will be equal to or less than the first threshold based on the amount of hydrogen used in the hydrogen tank during the first period excluding the second period, thereby improving the accuracy of the prediction compared to when no exclusion period is set in the calculation of the amount of hydrogen used. This allows the user to refill the hydrogen tank with hydrogen or replace the hydrogen tank in use with a new one in a timely manner.

[0014] Furthermore, in the hydrogen tank remaining amount prediction method of this embodiment, by setting each of the first period and the second period over multiple days, the prediction of when the hydrogen remaining amount in the hydrogen tank will be equal to or less than the first threshold amount is less affected by fluctuations in the amount of hydrogen used in daily activities. For example, the amount of hydrogen used on specific days such as holidays is generally less than on weekdays, but in the hydrogen tank remaining amount prediction method of this embodiment, by setting the first period and the second period as described above, the influence of daily fluctuations in the amount of hydrogen used in the prediction of when the hydrogen remaining amount in the hydrogen tank will be equal to or less than the first threshold amount is reduced.

[0015] A second aspect of the present disclosure is a method for predicting remaining hydrogen in a hydrogen tank, in which, in the first aspect of the method for predicting remaining hydrogen in a hydrogen tank, when the first period and the second period are the same, it is not necessary to update the time when the remaining hydrogen in the hydrogen tank will be below the first threshold value.

[0016] Here, "the first period and the second period are the same" means that the amount of hydrogen used in the hydrogen tank is irregularly low compared to the normal amount of hydrogen used during the entire first period. Therefore, when the first period and the second period are the same, the hydrogen tank remaining amount prediction method of this embodiment does not update the time when the remaining hydrogen amount in the hydrogen tank used in the fuel cell device will be equal to or less than the first threshold, thereby making it possible to efficiently predict the time.

[0017] A third aspect of the present disclosure is a method for predicting remaining hydrogen in a hydrogen tank, which is a method for predicting remaining hydrogen in a hydrogen tank of the first or second aspect, and which predicts when the remaining hydrogen in the hydrogen tank will be below a first threshold value based on a difference between the remaining hydrogen in the hydrogen tank and a first threshold value divided by the average amount of hydrogen used per day during a period of the first period excluding the second period.

[0018] As described above, the present method for predicting the remaining amount of hydrogen in a hydrogen tank predicts the time when the remaining amount of hydrogen in the hydrogen tank will be below the first threshold value based on the difference between the remaining amount of hydrogen in the hydrogen tank and a first threshold value divided by the average amount of hydrogen used per day during the first period excluding the second period, thereby improving the accuracy of the prediction compared to a case where no exclusion period is set in calculating the amount of hydrogen usage.

[0019] A fourth aspect of the present disclosure is a method for predicting remaining capacity in a hydrogen tank, wherein, in any one of the first to third aspects, the first period may be one week or multiple weeks, and the second period may be a number of weeks shorter than the first period.

[0020] As described above, the hydrogen tank remaining amount prediction method of this embodiment sets the first period and the second period to one week or multiple weeks, and the number of weeks equal to or less than the first period, respectively, so that prediction of when the hydrogen remaining amount in the hydrogen tank will be equal to or less than the first threshold amount is less affected by fluctuations in the amount of hydrogen used in daily activities. For example, the amount of hydrogen used during a specific period of the week (e.g., Saturday and Sunday such as the weekend) is generally less than during weekdays, but by setting the first period and the second period as described above, the hydrogen tank remaining amount prediction method of this embodiment reduces the influence of daily fluctuations in the amount of hydrogen used that occur over a week in prediction of when the hydrogen remaining amount in the hydrogen tank will be equal to or less than the first threshold amount.

[0021] A fifth aspect of the present disclosure is a hydrogen tank remaining amount prediction device used in a fuel cell apparatus including at least one fuel cell unit, comprising: a controller that predicts when the remaining hydrogen amount in the hydrogen tank will be below a first threshold amount based on the amount of hydrogen in the hydrogen tank used in a first period spanning multiple days; and a communicator controlled by the controller that notifies a display device of the time, wherein when the amount of hydrogen in the hydrogen tank used in a second period spanning multiple days within the first period is below the second threshold amount, the controller predicts the above-mentioned time based on the amount of hydrogen in the hydrogen tank used in a period of the first period excluding the second period.

[0022] As described above, the hydrogen tank remaining amount prediction device of this embodiment can predict the time when the remaining hydrogen amount in a hydrogen tank used in a fuel cell device will be equal to or less than the first threshold more accurately than ever before. Note that the detailed effects of the hydrogen tank remaining amount prediction device of this embodiment are similar to those of the hydrogen tank remaining amount prediction method of the first embodiment, so a detailed explanation will be omitted.

[0023] A power generation system according to a sixth aspect of the present disclosure includes a fuel cell device including at least one fuel cell unit, and the hydrogen tank remaining amount prediction device according to the fifth aspect.

[0024] As described above, the power generation system of this aspect can predict the time when the remaining hydrogen level in the hydrogen tank used in the fuel cell device will be equal to or lower than the first threshold value more accurately than in the past. Note that the detailed effects of the power generation system of this aspect are similar to those of the hydrogen tank remaining level prediction method of the first aspect, and therefore will not be described here.

[0025] Hereinafter, specific examples of the above-mentioned aspects of the present disclosure will be described with reference to the accompanying drawings. The specific examples described below are all examples of the above-mentioned aspects of the present disclosure. Therefore, the shapes, numerical values, components, arrangement positions and connection forms of the components shown below do not limit the scope of the claims unless otherwise stated in the claims.

[0026] In addition, among the components described below, components that are not described in the independent claims showing the highest concept of the present disclosure are described as optional components. In addition, in the drawings, the description of components with the same reference numerals may be omitted. The drawings show each component diagrammatically to facilitate understanding, and the shapes and dimensional ratios may not be displayed accurately.

[0027] Furthermore, in the operation of the apparatus, the order of steps may be changed or known steps may be added as necessary.

[0028] (First embodiment) [Device configuration] FIG. 1 is a diagram illustrating an example of a power generation system according to a first embodiment.

[0029] As shown in FIG. 1, the power generation system 10 includes a fuel cell device 15 and a remaining amount prediction device 20 for a hydrogen tank 40 used in the fuel cell device 15.

[0030] The fuel cell device 15 includes at least one fuel cell unit that generates power using hydrogen from the hydrogen tank 40. Thus, the fuel cell device 15 may include a single fuel cell unit, or multiple fuel cell units. In the latter case, the power generation system 10 may be, for example, a system that supplies large amounts of power to a power grid. That is, in the latter case, the power generation system 10 includes a fuel cell unit group consisting of multiple fuel cell units including a fuel cell stack, and the fuel cell device 15 corresponds to each group obtained by dividing the fuel cell unit group. A detailed configuration of such a power generation system 10 will be described in the second embodiment.

[0031] As shown in FIG. 1, the remaining amount predicting device 20 for a hydrogen tank 40 includes a communication device 21 and a controller 23.

[0032] Controller 23 predicts when the remaining amount of hydrogen in hydrogen tank 40 will be below threshold value SA based on the amount of hydrogen in hydrogen tank 40 used over period A spanning multiple days. Furthermore, when the amount of hydrogen in the hydrogen tank used over period B spanning multiple days within period A is below threshold value SB, controller 23 predicts when the remaining amount of hydrogen in hydrogen tank 40 will be below threshold value SA based on the amount of hydrogen in the hydrogen tank used during the period of period A excluding period B. A specific example of a method for calculating "when the remaining amount of hydrogen in hydrogen tank 40 will be below threshold value SA" will be described in the first embodiment.

[0033] Here, the "multiple days" in "period A" may be a few days, but may also be an appropriate number of days selected from a longer period of one week (7 days) to several months. For example, "period A" may be a week selected from a period of about two weeks to about one month (4 weeks).

[0034] The "multiple days" in "period B" may be a few days, but may also be any number of days longer than this, selected from one week (7 days) to one month. For example, "period B" may be one week (7 days), but is at least a period shorter than "period A."

[0035] The "threshold SA" is an appropriate amount of hydrogen previously set by the user, and corresponds to a reference value for urging the user to refill hydrogen tank 40 when the amount of hydrogen remaining in hydrogen tank 40 is low, and for urging the user to replace the hydrogen tank 40 currently in use with a new hydrogen tank. The "threshold SA" may be set to an amount of hydrogen that is, for example, about 20% of the amount of hydrogen when hydrogen tank 40 is full, but is not limited to this.

[0036] "Threshold SB" is an appropriate amount of hydrogen preset by the user, and corresponds to a reference value assuming a situation in which the amount of hydrogen used in hydrogen tank 40 used during period B is irregularly small compared to the normal amount of hydrogen used. "Threshold SB" may be set to an amount of hydrogen that is, for example, about 10% of the amount of hydrogen when hydrogen tank 40 is full, but is not limited to this.

[0037] Note that "a situation in which the amount of hydrogen used in the hydrogen tank during period B is irregularly small compared to the normal amount of hydrogen used" can occur due to various factors. For example, the above situation can occur due to some unusual behavior by the user. In addition, the above situation can occur when the amount of hydrogen used in the hydrogen tank 40 cannot be measured normally. In addition, the above situation can occur when the power generation system 10 cannot generate power normally.

[0038] As described above, the above situation is an irregularly small amount of hydrogen compared to the normal amount of hydrogen usage, and does not include a case where the operation of the power generation system 10 is periodically suspended for multiple days. For example, the above situation does not include a case where the operation of the power generation system 10 is suspended on Saturdays and Sundays every week. In such a case, period B is set to include the suspension period and to be longer than the suspension period (for example, one week), and a threshold value SB is set for this period B to determine whether or not the above situation applies.

[0039] The controller 23 may have any control function, and includes an arithmetic processing unit (not shown) and a storage unit that stores a control program. The arithmetic processing unit reads out and executes the control program stored in the storage unit, whereby the controller 23 performs a predetermined control. An example of the arithmetic processing unit is a microprocessor. An example of the storage unit is a memory. The controller 23 may directly control the operation of the fuel cell unit in the fuel cell device 15, including the output. In addition, if a control device (not shown) that controls the operation of the fuel cell unit itself is provided in the fuel cell unit, the controller 23 may indirectly control the operation of the fuel cell unit in the fuel cell device 15, including the output, via the control device.

[0040] The communication device 21 is a transmitter that is controlled by the controller 23 and notifies the display device 50 of information indicating the time when the remaining amount of hydrogen in the hydrogen tank 40 will be equal to or less than the threshold value SA. An example of the display device 50 may be, but is not limited to, an information terminal of a user who receives the service of supplying electric power generated by the power generation system 10.

[0041] Here, the amount of hydrogen remaining in hydrogen tank 40 may be measured, for example, by an appropriate sensor. Such sensor measurement is performed at predetermined time intervals by the calculation processing unit of controller 23, and the sensor measurement data is successively stored in the memory unit of controller 23. This "predetermined time" may be, for example, about 30 seconds, but is not limited to this.

[0042] For example, as shown in FIG. 2A, a liquid hydrogen tank 40A for refilling hydrogen and a hydrogen gas tank 41 for storing the liquid hydrogen in the liquid hydrogen tank 40A as low-pressure hydrogen gas may be provided as hydrogen supply sources for the fuel cell device 15. In this case, since the liquid hydrogen tank 40A corresponds to the "hydrogen tank" of the present disclosure, the remaining amount of hydrogen in the liquid hydrogen tank 40A may be calculated by the controller 23 from measurement data of a liquid level sensor 42 provided in the liquid hydrogen tank 40A. The remaining amount of hydrogen in the liquid hydrogen tank 40A may also be calculated by the controller 23 from measurement data of a flow meter 43 provided in a hydrogen gas path for supplying hydrogen gas from the hydrogen gas tank 41 to the fuel cell device 15. The measurement data of the liquid level sensor 42 or the flow meter 43 may be transmitted to the controller 23 via a controller (not shown) provided in the fuel cell device 15, or may be transmitted directly to the controller 23. The controller (not shown) provided in the fuel cell device 15 corresponds to a control device 30A, etc., which will be described later.

[0043] 2B, a hydrogen gas tank 40B for storing high-pressure hydrogen gas for hydrogen replenishment and a hydrogen gas tank 41 for storing the high-pressure hydrogen gas in the hydrogen gas tank 40B as low-pressure hydrogen gas may be provided as hydrogen supply sources for the fuel cell device 15. In this case, the hydrogen gas tank 40B corresponds to the "hydrogen tank" of the present disclosure, so the remaining amount of hydrogen in the hydrogen gas tank 40B may be calculated by the controller 23 from measurement data of a pressure gauge 44 provided in the hydrogen gas tank 40B. The remaining amount of hydrogen in the hydrogen gas tank 40B may be calculated by the controller 23 from measurement data of a flow meter 43 provided in a hydrogen gas path for supplying hydrogen gas from the hydrogen gas tank 41 to the fuel cell device 15. The measurement data of the pressure gauge 44 or the flow meter 43 may be transmitted to the controller 23 via a controller (not shown) provided in the fuel cell device 15, or may be transmitted directly to the controller 23. The controller (not shown) provided in the fuel cell device 15 corresponds to a control device 30A, etc., which will be described later.

[0044] 2C, a hydrogen gas tank 40C for storing low-pressure hydrogen gas for hydrogen replenishment may be provided as a hydrogen supply source for the fuel cell device 15. In this case, the hydrogen gas tank 40C corresponds to the "hydrogen tank" of the present disclosure, and the remaining amount of hydrogen in the hydrogen gas tank 40C may be calculated by the controller 23 from measurement data of a pressure gauge 44 provided in the hydrogen gas tank 40C. The remaining amount of hydrogen in the hydrogen gas tank 40C may be calculated by the controller 23 from measurement data of a flow meter 43 provided in a hydrogen gas path for supplying hydrogen gas from the hydrogen gas tank 40C to the fuel cell device 15. The measurement data of the pressure gauge 44 or the flow meter 43 may be transmitted to the controller 23 via a controller (not shown) provided in the fuel cell device 15, or may be transmitted directly to the controller 23. The controller (not shown) provided in the fuel cell device 15 corresponds to a control device 30A, etc., which will be described later.

[0045] The above-described configuration of the hydrogen supply source of the fuel cell device 15 is merely an example and is not limited to this example. The hydrogen supply source may be configured, for example, to timely replace a hydrogen gas tank with a low hydrogen amount with a new hydrogen gas tank.

[0046] [Operation] 3 is a flow chart showing an example of the operation of the hydrogen tank remaining amount prediction device (hydrogen tank remaining amount prediction method) in the first embodiment. The following operations may be performed, for example, by the calculation processing unit of controller 23 reading out a control program from the memory unit of controller 23. However, it is not essential that the following operations are performed by controller 23. An operator may perform some of the operations. In the following example, a case where the operations are controlled by controller 23 will be described.

[0047] First, at a predetermined timing, a setting file stored in advance in the memory unit of the controller 23 is read into the calculation processing unit of the controller 23. The "predetermined timing" may be set, for example, at least once a week, but is not limited to this. The "setting file" stores, for example, period A and period B set in advance by the user, and the type of hydrogen tank 40 (e.g., hydrogen gas tank, liquid hydrogen tank), etc. Then, data such as the amount of hydrogen used in the hydrogen tank 40 during each of period A and period B is acquired from the memory unit of the controller 23.

[0048] When the above-mentioned operations are performed, in step S1, it is determined whether the amount of hydrogen in the hydrogen tank 40 used during a period B spanning multiple days within a period A spanning multiple days is equal to or less than a threshold value SB.

[0049] The determination in step S1 of "whether the amount of hydrogen used in hydrogen tank 40 during period B is equal to or less than threshold value SB" is not limited to being made by comparing the total amount of hydrogen used in hydrogen tank 40 during period B with threshold value SB. For example, the "determination" in step S1 may be made by comparing an average amount of hydrogen used in hydrogen tank 40 during period B (e.g., average amount of hydrogen used per day) with threshold value SB set for the average amount of hydrogen used in hydrogen tank 40 during period B. Furthermore, the "determination" in step S1 may be made by comparing an average power generation output of the fuel cell unit, which indirectly correlates with the amount of hydrogen used in hydrogen tank 40 during period B, with threshold value SB set for the average power generation power of the fuel cell unit during period B.

[0050] Here, if the amount of hydrogen used in the hydrogen tank 40 during period B within period A is below threshold value SB (``Yes'' in step S1), in step S2, the time when the remaining hydrogen amount in the hydrogen tank will be below threshold value SA is predicted based on the amount of hydrogen used in the hydrogen tank 40 during the period A excluding period B.

[0051] Next, in step S3, information indicating the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA, as predicted in step S2, is notified to the display device 50 by the communication device 21. The time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA may be provided to the user as, for example, information on the year, month, and day on a calendar displayed on the display device 50. Furthermore, if the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA is stored in the memory section of the controller 23, the stored time may be updated to new data. Thereafter, the operations from step S1 onwards are executed again at the next specified timing.

[0052] On the other hand, if the amount of hydrogen used in the hydrogen tank 40 during period B within period A exceeds threshold value SB ("No" in step S1), in step S4, the time when the remaining hydrogen amount in the hydrogen tank will fall below threshold value SA is predicted based on the amount of hydrogen used in the hydrogen tank during period A.

[0053] Next, in step S5, information indicating the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA, as predicted in step S4, is notified to the display device 50 by the communication device 21. The time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA may be provided to the user as, for example, information on the year, month, and day on a calendar displayed on the display device 50. Furthermore, if the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA is stored in the memory section of the controller 23, the stored time may be updated to new data. Thereafter, the operations from step S1 onwards are executed again at the next specified timing.

[0054] According to the present embodiment described above, it is possible to predict the time when the remaining amount of hydrogen in the hydrogen tank 40 used in the fuel cell device 15 will fall below the threshold value SA more accurately than ever before.

[0055] Specifically, excluding data from period B, during which the amount of hydrogen used in the hydrogen tank 40 is irregularly low over a number of days compared to normal hydrogen usage, from the calculation of the amount of hydrogen used can result in a more appropriate calculation of the amount of hydrogen used than if this were not done. Therefore, in this embodiment, by predicting the time when the remaining amount of hydrogen in the hydrogen tank 40 will be equal to or less than the threshold value SA based on the amount of hydrogen used in the hydrogen tank 40 during period A excluding period B, the accuracy of the prediction can be improved compared to the case where no exclusion period is set in the calculation of the amount of hydrogen used. This allows the user to refill the hydrogen tank 40 with hydrogen or replace the hydrogen tank 40 in use with a new hydrogen tank in a timely manner.

[0056] Furthermore, according to this embodiment, by setting each of period A and period B over multiple days, the prediction of when the remaining hydrogen level in hydrogen tank 40 will fall below threshold SA is less affected by fluctuations in the amount of hydrogen used in daily activities. For example, the amount of hydrogen used on specific days such as holidays is generally less than on weekdays, but in this embodiment, by setting period A and period B as described above, the prediction of when the remaining hydrogen level in hydrogen tank 40 will fall below threshold SA is less affected by fluctuations in the amount of hydrogen used on a daily basis.

[0057] (First embodiment) FIG. 4 is a flow chart showing an example of the operation of the hydrogen tank remaining amount prediction device (hydrogen tank remaining amount prediction method) in the first example of the first embodiment. The following operations may be performed, for example, by the calculation processing unit of controller 23 reading out a control program from the memory unit of controller 23. However, it is not essential that the following operations are performed by controller 23. An operator may perform some of the operations. In the following example, a case where the operations are controlled by controller 23 will be described.

[0058] It should be noted that step S1 in FIG. 4 is similar to step S1 in FIG. 3, and therefore a detailed description thereof will be omitted.

[0059] If the amount of hydrogen used in hydrogen tank 40 during period B within period A is less than or equal to threshold value SB ("Yes" in step S1), in step S2A, the time when the remaining amount of hydrogen in hydrogen tank 40 will be less than or equal to threshold value SA is predicted based on the difference between the remaining amount of hydrogen in hydrogen tank 40 and threshold value SA divided by the average amount of hydrogen used per day during period A excluding period B.

[0060] For example, the average amount of hydrogen used per day q1 during the period A excluding period B (hereinafter, average amount of hydrogen used q1) is calculated using the following formula (1). q1 [Nm 3 (Normal hydrogen consumption / day) = (total amount of hydrogen used during period A excluding period B) / (number of days in period A - number of days in period B) (1)

[0061] Further, the difference Q1 between the amount of hydrogen present in the hydrogen tank 40 and the amount of hydrogen corresponding to the threshold value SA can be obtained, for example, from the measurement data of the pressure gauge 44 using the following formula (2). Q1 [Nm 3 ] = (current measurement data of pressure gauge 44 [MPa] - threshold value SA [MPa]) × "predetermined coefficient" (2)

[0062] Here, the "predetermined coefficient" is a numerical value that is proportional to the size (volume) of the hydrogen tank 40 and is preset by the user, and is an appropriate value for converting the sensor's counting data into the remaining amount of hydrogen in the hydrogen tank 40 (normal lube).

[0063] Then, the number of days T1 until the remaining amount of hydrogen in the hydrogen tank 40 is predicted to reach the threshold value SA is obtained from the following formula (3). T1 [days] = Q1 / q1 (3)

[0064] From the above, the time when the remaining amount of hydrogen in the hydrogen tank 40 will be equal to or less than the threshold value SA can be predicted from the number of days T1.

[0065] Next, in step S3A, information indicating the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA, as predicted in step S2A, is notified to the display device 50 by the communication device 21. The time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA may be provided to the user, for example, as information in the form of a date on a calendar displayed on the display device 50. Furthermore, if the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA is stored in the memory section of the controller 23, the stored time may be updated to new data. Thereafter, the operations from step S1 onwards are executed again at the next specified timing.

[0066] On the other hand, if the amount of hydrogen used in hydrogen tank 40 during period B within period A exceeds threshold value SB ("No" in step S1), in step S4A, the time when the amount of hydrogen remaining in hydrogen tank 40 will fall below threshold value SA is predicted based on the difference between the remaining hydrogen amount in hydrogen tank 40 and threshold value SA divided by the average amount of hydrogen used per day during period A.

[0067] For example, the average amount of hydrogen used per day in period A, q2 (hereinafter, average amount of hydrogen used, q2) is calculated by the following formula (4). q2 [Nm 3 (Normal hydrogen consumption / day) = (total amount of hydrogen used in period A) / (number of days in period A) (4)

[0068] Further, the difference Q2 between the amount of hydrogen present in the hydrogen tank 40 and the amount of hydrogen corresponding to the threshold value SA can be obtained, for example, from the measurement data of the pressure gauge 44 using the following formula (5). Q2 [Nm 3 ] = (current measurement data of pressure gauge 44 [MPa] - threshold value SA [MPa]) × "predetermined coefficient" (5)

[0069] Here, the "predetermined coefficient" is a numerical value that is proportional to the size (volume) of the hydrogen tank 40 and is preset by the user, and is an appropriate value for converting the sensor's counting data into the remaining amount of hydrogen in the hydrogen tank 40 (normal lube).

[0070] Then, the number of days T2 until the remaining amount of hydrogen in the hydrogen tank 40 is predicted to reach the threshold value SA is obtained from the following equation (6). T2 [days] = Q2 / q2 (6)

[0071] From the above, the time when the remaining amount of hydrogen in the hydrogen tank 40 will be equal to or less than the threshold value SA can be predicted from the number of days T2.

[0072] Next, in step S5A, information indicating the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA, as predicted in step S4A, is notified to the display device 50 by the communication device 21. The time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA may be provided to the user, for example, as information in the form of a date on a calendar displayed on the display device 50. Furthermore, if the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA is stored in the memory section of the controller 23, the stored time may be updated to new data. Thereafter, the operations from step S1 onwards are executed again at the next specified timing.

[0073] According to the present embodiment described above, by predicting the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below the threshold value SA based on the difference between the remaining amount of hydrogen in the hydrogen tank 40 and the threshold value SA divided by the average amount of hydrogen used per day during the period A excluding period B, the accuracy of the prediction can be improved compared to the case where no exclusion period is set in calculating the amount of hydrogen used.

[0074] The method for predicting the remaining amount of hydrogen in the hydrogen tank 40, the device 20 for predicting the remaining amount of hydrogen in the hydrogen tank 40, and the power generation system 10 of this embodiment may be similar to those of the first embodiment, except for the above-mentioned features.

[0075] (Second Example) The method for predicting the remaining amount of hydrogen in the hydrogen tank 40 in the second example of the first embodiment is similar to the method for predicting the remaining amount of hydrogen in the hydrogen tank 40 in the first embodiment, except that period A is one week or more weeks and period B is a number of weeks less than period A.

[0076] According to the present embodiment described above, by setting period A and period B to one week or multiple weeks, and a number of weeks equal to or less than the first period, respectively, the prediction of when the remaining amount of hydrogen in hydrogen tank 40 will fall below threshold SA is less susceptible to the influence of fluctuations in the amount of hydrogen used in daily activities. For example, the amount of hydrogen used during a specific period of the week (e.g., Saturday and Sunday such as weekends) is generally less than that used during weekdays, but according to the present embodiment, by setting period A and period B as described above, the influence of daily fluctuations in the amount of hydrogen used that occur over a week is reduced in the prediction of when the remaining amount of hydrogen in hydrogen tank 40 will fall below threshold SA.

[0077] Other than the above-mentioned features, the method for predicting remaining amount of hydrogen tank 40, device 20 for predicting remaining amount of hydrogen tank 40, and power generation system 10 of this embodiment may be similar to those of the first embodiment or the first example of the first embodiment.

[0078] (Modification) The method for predicting the remaining amount of hydrogen in the hydrogen tank 40 in the modified example of the first embodiment is similar to the method for predicting the remaining amount of hydrogen in the hydrogen tank 40 in the first embodiment, except that when periods A and B are the same, the time when the remaining amount of hydrogen in the hydrogen tank 40 will fall below threshold value SA is not updated.

[0079] Here, "period A and period B are the same" means that the amount of hydrogen used in hydrogen tank 40 is irregularly less than the normal amount of hydrogen used during the entire period A. Therefore, according to this modified example described above, when period A and period B are the same, the time when the remaining amount of hydrogen in hydrogen tank 40 used by fuel cell device 15 will be equal to or less than threshold value SA is not updated, thereby making it possible to efficiently predict the time.

[0080] Other than the above-mentioned features, the method for predicting remaining amount of hydrogen tank 40, the device 20 for predicting remaining amount of hydrogen tank 40, and the power generation system 10 of this modified example may be similar to any of the first embodiment and the first to second examples of the first embodiment.

[0081] Second embodiment Fig. 5 is a diagram showing an example of a power generation system according to the second embodiment. For convenience, the hydrogen tank 40 and the display device 50 in the first embodiment (Fig. 1) are omitted from Fig. 5. In addition, the internal configuration of the remaining amount prediction device 20 for the hydrogen tank 40 is similar to that in the first embodiment, and therefore a detailed description thereof will be omitted.

[0082] 5, the power generation system 10 of this embodiment includes groups 15A-15E obtained by dividing a fuel cell unit group corresponding to the fuel cell device 15 (see FIG. 1), a remaining amount prediction device 20 for a hydrogen tank 40, and control devices 30A-30E. In other words, the power generation system 10 includes a fuel cell unit group consisting of a plurality of fuel cell units.

[0083] Although not shown in the figure, each of these fuel cell units is composed of a fuel cell stack, an AC-AC conversion device for converting the DC power generated by the fuel cell stack into AC power and outputting it to the power grid, and a control device for controlling the operation of these devices.

[0084] 5, the fuel cell unit groups are divided into fuel cell units a1-an belonging to group 15A, fuel cell units b1-bn belonging to group 15B, fuel cell units c1-cn belonging to group 15C, fuel cell units d1-dn belonging to group 15D, and fuel cell units e1-en belonging to group 15E. All the fuel cell units belonging to one group are also referred to simply as "fuel cell units in the group."

[0085] However, the above configuration of the fuel cell unit group is merely an example and is not limited to this example. For example, the fuel cell unit group may be grouped by a single group of fuel cell units. Also, the number of fuel cell units in a group may be one.

[0086] Control devices 30A to 30E are provided for fuel cell units a1 to an in group 15A, fuel cell units b1 to bn in group 15B, fuel cell units c1 to cn in group 15C, fuel cell units d1 to dn in group 15D, and fuel cell units e1 to en in group 15E, respectively, and control the operation of each of the fuel cell units within the group.

[0087] For example, the control device 30A controls the output of each of the fuel cell units a1-an belonging to the group 15A via a communications network so as to enable efficient operation (eg, optimization of the life span) of these fuel cell units a1-an.

[0088] The control devices 30A to 30E may have any control function, and include a calculation processing unit (not shown), a storage unit that stores a control program, and a communication device. The calculation processing unit reads out and executes the control program stored in the storage unit, thereby performing predetermined control in the control devices 30A to 30E. An example of the calculation processing unit is a microprocessor. An example of the storage unit is a memory.

[0089] The above-described configuration of the power generation system 10 is merely an example, and the power generation system 10 is not limited to this example.

[0090] For example, the fuel cell units may not be provided with control devices, and the operations of the fuel cell units belonging to each group may be directly controlled by the control devices 30A to 30E.

[0091] Furthermore, the controller 23 (see FIG. 1) of the hydrogen tank 40 remaining amount prediction device 20 performs an operation to predict when the remaining amount of hydrogen in the hydrogen tank 40 will be equal to or less than the threshold value SA based on the amount of hydrogen in the hydrogen tank 40, but is not limited to this. A control device other than the controller 23 (e.g., control devices 30A-30E) may perform such an operation.

[0092] Furthermore, the remaining amount predicting device 20 for the hydrogen tank 40 may be integrated with the control devices 30A-30E, in other words, may be equipped with the control functions of the control devices 30A-30E, and may directly control the operation of each of the fuel cell units in the group.

[0093] Other than the above-mentioned features, the method for predicting the remaining amount of hydrogen in a hydrogen tank 40, the device 20 for predicting the remaining amount of hydrogen in a hydrogen tank 40, and the power generation system 10 of this embodiment may be similar to any of the first embodiment, the first to second examples of the first embodiment, and the modified example of the first embodiment.

[0094] The first embodiment, the first to second examples of the first embodiment, the modified example of the first embodiment, and the second embodiment may be combined with each other as long as they do not exclude each other. From the above description, many improvements and other embodiments of the present disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as merely illustrative and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. The details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present disclosure. [Industrial Applicability]

[0095] One aspect of the present disclosure can be used in a hydrogen tank remaining amount prediction method, a hydrogen tank remaining amount prediction device, and a power generation system, which can predict more accurately than conventional methods when the remaining hydrogen amount in a hydrogen tank used in a fuel cell device will fall below a specified amount. [Explanation of symbols]

[0096] 10: Power generation system 15:Fuel cell device 20: Remaining amount prediction device 21: Communication device 23: Controller 30A: Control device 30B: Control device 30C: Control device 30D: Control device 30E: Control device 40: Hydrogen tank 40A: Liquid hydrogen tank 40B: Hydrogen gas tank 40C: Hydrogen gas tank 41: Hydrogen gas tank 42: Liquid level sensor 43:Flow meter 44: Pressure gauge 50:Display device SA: Threshold SB: Threshold a1~an: fuel cell unit b1 to bn: fuel cell units c1~cn: fuel cell unit d1~dn: fuel cell unit e1~en: Fuel cell unit

Claims

1. 1. A method for predicting remaining capacity of a hydrogen tank used in a fuel cell device including at least one fuel cell unit, comprising: predicting when the remaining amount of hydrogen in the hydrogen tank will be equal to or less than a first threshold based on the amount of hydrogen used in the hydrogen tank during a first period spanning multiple days; and notifying a display device of the time. A method for predicting remaining capacity in a hydrogen tank, which predicts the time based on the amount of hydrogen used in the hydrogen tank during a period of the first period excluding the second period when the amount of hydrogen used in the hydrogen tank during a second period spanning multiple days within the first period is below a second threshold value.

2. 2. The method for predicting remaining amount of hydrogen in a hydrogen tank according to claim 1, wherein when the first period and the second period are the same, the time is not updated.

3. 2. The method for predicting remaining hydrogen in a hydrogen tank as described in claim 1, wherein the time is predicted based on a value obtained by dividing the difference between the remaining hydrogen amount in the hydrogen tank and a first threshold value by the average amount of hydrogen used per day during a period of the first period excluding the second period.

4. 2. The method for predicting remaining capacity of a hydrogen tank according to claim 1, wherein the first period is one week or more weeks, and the second period is a period of weeks equal to or less than the first period.

5. 1. A hydrogen tank remaining capacity prediction device for use in a fuel cell device including at least one fuel cell unit, comprising: a controller that predicts when the remaining amount of hydrogen in the hydrogen tank will be equal to or less than a first threshold based on the amount of hydrogen used in the hydrogen tank during a first period spanning multiple days; a communication device controlled by the controller to notify a display device of the time, The controller is a hydrogen tank remaining amount prediction device that predicts the time based on the amount of hydrogen in the hydrogen tank used during a period of the first period excluding the second period when the amount of hydrogen in the hydrogen tank used during a second period spanning multiple days within the first period is below a second threshold value.

6. a fuel cell device including at least one fuel cell unit; A power generation system comprising: the hydrogen tank remaining amount predicting device according to claim 5.

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