Patent ID: 12203602

DESCRIPTION OF EMBODIMENTS

The following describes a hydrogen supply system according to an embodiment of the present invention with reference to the accompanying drawings. Note that, constituent components in the embodiment described below include those easily replaceable by the skilled person in the art or those identical in effect.

(Hydrogen Supply System)

The following first describes the hydrogen supply system according to the present embodiment with reference toFIG.1. The hydrogen supply system is a system for supplying hydrogen to an FC forklift5as a fuel-cell vehicle by using a receptacle4for hydrogen transport. The hydrogen supply system includes a management device1, a hydrogen filling device2, a transport vehicle3, the receptacle4, and the FC forklift5operated at a business facility.

Note that, the above-described “business facility” is, for example, a distribution warehouse or a factory. Furthermore, there may be a plurality of business facilities. Moreover, there may be a plurality of FC forklifts5operated at each business facility.

The management device1, the hydrogen filling device2, each receptacle4, and each FC forklift5can perform mutual communication through a network NW. The network NW is constituted by, for example, the Internet network, a cellular-phone network, and the like.

(Management Device)

The following describes the management device (management unit)1. The management device1is provided at a management center. The management device1includes a control unit11, a communication unit12, and a storage unit13. Specifically, the control unit11includes a processor constituted by a central processing unit (CPU), a digital signal processor (DSP), or a field-programmable gate array (FPGA), and a memory (main storage unit) constituted by a random access memory (RAM) or a read only memory (ROM) (neither illustrated).

The control unit11loads a computer program stored in the storage unit13onto a work area of the main storage unit, executes the computer program, and controls each component or the like through the execution of the computer program, thereby achieving a function matching a predetermined purpose. The control unit11functions as a remaining amount prediction unit111and a transport timing calculation unit112through the execution of the computer program. Note that, details of the remaining amount prediction unit111and the transport timing calculation unit112will be described later.

The communication unit12is constituted by, for example, a local area network (LAN) interface board, a wireless communication circuit for wireless communication, and the like. The communication unit12is connected to the network NW such as the Internet as a public communication network. In addition, the communication unit12performs communication with the hydrogen filling device2, each receptacle4, and each FC forklift5by connecting to the network NW.

The storage unit13is constituted by a recording medium such as an erasable programmable ROM (EPROM), a hard disk drive (HDD), or a removable media. The removable media is, for example, a universal serial bus (USB) memory or a disk recording medium such as a compact disc (CD), a digital versatile disc (DVD), or a Blu-ray (registered trademark) disc (BD). Furthermore, an operating system (OS), various computer programs, various tables, various databases, and the like can be stored in the storage unit13. For example, hydrogen remaining amount data periodically transmitted from each receptacle4and each FC forklift5and data such as a result of calculation by the control unit11are stored in the storage unit13.

(Hydrogen Filling Device)

The following describes the hydrogen filling device (filling unit)2. The hydrogen filling device2is a device for filling, with hydrogen, a receptacle4transported by the transport vehicle3and is provided at a hydrogen filling facility. The hydrogen filling facility is, for example, a hydrogen generation source configured to generate by-product hydrogen by petroleum refinement and waste plastic generation. The hydrogen filling device2includes a non-illustrated compressor, compresses the hydrogen generated at the hydrogen filling facility, and then fills, with the hydrogen, the receptacle4collected or transported by the transport vehicle3.

(Transport Vehicle)

The transport vehicle (transport unit)3is a general-purpose vehicle such as a typical truck and transports the receptacle4between the hydrogen filling facility and the business facility. The transport vehicle3transports a hydrogen-filled receptacle4that is filled with hydrogen at the hydrogen filling facility to the business facility. Then, the transport vehicle3collects a receptacle4disposed in the business facility and having a decreased hydrogen storage amount and transports the collected receptacle4to the hydrogen filling facility.

Specifically, when collecting the receptacle4having a decreased hydrogen storage amount, the transport vehicle3transports another hydrogen-filled receptacle4to the business facility. Note that, the “receptacle4having a decreased hydrogen storage amount” means, for example, a receptacle4having a hydrogen storage pressure decreased to “20 MPa” approximately when the receptacle4initially has a hydrogen storage pressure of “45 MPa”.

Although a dedicated filling vehicle such as a mobile hydrogen station is used in the conventional mobile supply system, the transport vehicle3in the present embodiment may use any vehicle on which a receptacle4can be loaded. Furthermore, a plurality of receptacles4may be loaded on the transport vehicle3.

(Receptacle)

Each receptacle4is for supplying hydrogen to the FC forklift5at the business facility. The receptacle4is placed at a predetermined place in the business facility, and when hydrogen filling is needed, the FC forklift5travels to the above-described place to be filled with hydrogen. Note that, the hydrogen filling from the receptacle4to the FC forklift5is directly performed by the driver of the FC forklift5. Furthermore, the hydrogen filling from the receptacle4to the FC forklift5is completed in several minutes (for example, three minutes approximately).

The receptacle4includes a plurality of hydrogen storage containers41. Each hydrogen storage container41is a composite structure container made of a steel liner (steel pipe) and a carbon-fiber-reinforced plastic. The hydrogen storage container41has a structure in which a sheet of the carbon-fiber-reinforced plastic is wound around the steel liner. The carbon-fiber-reinforced plastic used for the hydrogen storage container41preferably has a longitudinal elastic modulus equal to or larger than 230 GPa. It is possible to achieve both weight reduction and high rigidity of the hydrogen storage container41by using the carbon-fiber-reinforced plastic having the above-described elastic modulus. More preferably, the elastic modulus is equal to or larger than 350 GPa.

Each hydrogen storage container41is preferably designed, for example, as described below. Note that, the hydrogen storage pressures of hydrogen storage containers41in one receptacle4may be all the same (for example, 45 MPa at three receptacles) or may be partially different (for example, 45 MPa at two receptacles and 30 MPa at one receptacle).(1) Maximum hydrogen storage pressure (maximum storage pressure): 40 MPa or higher(2) Hydrogen storage amount: preferably less than 300 N·m3(3) Container capacity: 200 L per container(4) Container weight: 0.7 t per container(5) The number of containers: three

Although omitted from illustrations inFIG.1, each receptacle4includes a communication unit, a dispenser unit, a sprinkler unit, a protection barrier, and a fork pocket. The communication unit is a unit for periodically transmitting the hydrogen remaining amount data on each hydrogen storage container41to the management device1through the network NW.

The dispenser unit is a unit for supplying hydrogen to the FC forklift5and has at least a function to prevent abrupt temperature increase of the hydrogen storage containers41at hydrogen filling. Furthermore, the dispenser unit may include a control valve configured to automatically control a flow rate of hydrogen, and a rapid filling software application configured to perform hydrogen filling while switching a plurality of hydrogen storage containers41. In addition, the dispenser unit may include an orifice for controlling the flow rate of hydrogen.

Furthermore, the sprinkler unit is a unit for cooling the hydrogen storage containers41by sprinkling and provided to prevent exceedance of, for example, a use temperature upper limit set by “High Pressure Gas Safety Act”. Furthermore, the protection barrier is a wall provided so that the hydrogen storage containers41is not exposed to direct sunlight. Furthermore, the fork pocket is a guide hole into which the FC forklift5inserts a click when transporting the receptacle4being loaded on the transport vehicle3.

Each receptacle is preferably designed to have a total weight of, for example, 2.5 t or lower including the above-described plurality of hydrogen storage containers41, the dispenser unit, the sprinkler unit, and the protection barrier, and the like. With the total weight of 2.5 t or lower, the receptacle4can be lifted by the FC forklift5and easily loaded onto the general-purpose vehicle.

(FC Forklift)

Each FC forklift5is an industrial fuel-cell vehicle operated in the business facility and travels on a non-public road. Although omitted from illustrations inFIG.1, the FC forklift5includes a hydrogen tank (fuel tank) and a communication unit. The communication unit periodically transmits the hydrogen remaining amount data on the hydrogen tank to the management device1through the network NW.

The FC forklift5functions as a disposition unit configured to dispose the hydrogen-filled receptacle4at a predetermined place in the business facility when the transport vehicle3has arrived at the business facility. In this case, the FC forklift5inserts the click into the fork pocket provided to the receptacle4loaded on the transport vehicle3and transports the receptacle4. Note that, the above-described “predetermined place” means a place to which the FC forklift5is capable of freely accessing to have a refill of hydrogen in the business facility and around which an explosion-proof electric facility is disposed.

(Hydrogen Supply Method)

The following describes a method of hydrogen supply by the hydrogen supply system with reference toFIG.2. First, the hydrogen filling device2fills the receptacle4with hydrogen (step S1). Subsequently, the hydrogen-filled receptacle4is loaded onto a cargo bed of the transport vehicle3by using a non-illustrated loading unit (for example, a forklift) (step S2).

Subsequently, residual pressures of the receptacle4and the FC forklift5are measured by using a pressure meter and a thermometer, and the hydrogen remaining amount data is acquired from temperatures and pressures thus obtained. Thereafter, the hydrogen remaining amount data is periodically transmitted to the management device1(steps S3and S4). Subsequently, the remaining amount prediction unit111of the management device1measures the residual pressures of the receptacle4and the FC forklift5by using the pressure meter and thermometer provided to each of the receptacle4and the FC forklift5, and acquires the hydrogen remaining amount data from temperatures and pressures thus obtained. Then, the remaining amount prediction unit111predicts the remaining amount of hydrogen that can be used at the business facility in future based on these remaining amount data (step S5).

Note that, the above-described temperatures do not necessarily need to be obtained by directly measuring the temperatures of the containers, and for example, an environmental temperature such as outside temperature of an environment in which the containers are used may be used. Furthermore, at step S5, the remaining amount of hydrogen that can be used the business facility in future can be predicted by using, for example, Expression (1) below.

R⁡(T)=∑i=0nαi(t)⁢Ci-∑i=0m{FCi⁢{1-βi(t)}+Xi}(1)

Symbols in Expression (1) above denote as follows.R (T): Remaining amount of hydrogen that can be used at the business facility T hours afterαi(t): correction ratio of the hydrogen remaining amount of the i-th receptacle4, which is periodically received by the remaining amount prediction unit111Ci: hydrogen stored amount of the i-th receptacle4FCi: hydrogen stored amount of the i-th FC forklift5βi(t): correction ratio of the hydrogen remaining amount of the i-th FC forklift5, which is periodically received by the remaining amount prediction unit111Xi: consumed hydrogen amount of the i-th FC forklift5per unit time

The following describes exemplary calculation (exemplary prediction) of a hydrogen remaining amount in future by using Expression (1) above. In this example, at a business facility owns and operates one receptacle4and two FC forklifts5, and a remaining amount of hydrogen that can be used at the business facility in future one hour after is predicted for a case in which values received by the remaining amount prediction unit111at time t are as follows.αi(t): correction ratio of the hydrogen remaining amount of the first receptacle4, which is received by the remaining amount prediction unit111at time t=0.8
Ci: hydrogen stored amount of the first receptacle4=10 kg
FC1: hydrogen stored amount of the first FC forklift5=1 kg
FC2: hydrogen stored amount of the second FC forklift5=1 kg
β1(t): correction ratio of the hydrogen remaining amount of the first FC forklift5, which is received by the remaining amount prediction unit111at time t=0.2
β2(t): correction ratio of the hydrogen remaining amount of the second FC forklift5, which is received by the remaining amount prediction unit111at time t=0.5
X1: consumed hydrogen amount of the first FC forklift5per one hour=0.2 kg/h
X2: consumed hydrogen amount of the second FC forklift5per one hour=0.4 kg/h

In this case, the remaining amount prediction unit111calculates the remaining amount of hydrogen that can be used at the business facility in future one hour after by using Expression (1) above as described below.
R(1)=0.8×10 kg−{1 kg(1−0.2)+0.2 kg}−1 kg{1 kg(1−0.5)+0.4 kg}=8 kg−1 kg−0.9 kg=6.1 kg

In Expression (1) above, Xiis preferably calculated from an operation record at each business facility or the like by computational science using IoT or the like. Furthermore, the remaining amount prediction unit111may predict the number of FC forklifts5that can be filled with hydrogen remaining in a receptacle4. Hereinafter, description of step S6or later inFIG.2will be continued.

Subsequently, the transport timing calculation unit112of the management device1calculates, based on the hydrogen remaining amount of the receptacle4in future, which is predicted by the remaining amount prediction unit111, a transport timing at which a hydrogen-filled receptacle4is transported to the business facility (step S6). The transport timing calculation unit112calculates, as the transport timing, for example, a time point earlier than a time point at which the hydrogen remaining amount of the receptacle4disposed at the business facility runs out.

Note that, when calculating the transport timing, the transport timing calculation unit112may calculate the transport timing, with consideration on, for example, the degree of congestion of vehicles on a travel route of the transport vehicle3to the business facility, or the like. Alternatively, the transport timing calculated by the transport timing calculation unit112may be a time at which the transport vehicle3departs the hydrogen filling facility or may be a time at which the transport vehicle3arrives at the business facility.

Subsequently, the transport vehicle3transports a hydrogen-filled receptacle4to the business facility in accordance with the transport timing calculated by the transport timing calculation unit112(step S7). Specifically, when the above-described transport timing is the time of departure from the hydrogen filling facility, the transport vehicle3departs the hydrogen filling facility at the time, or when the above-described transport timing is the time of arrival at the business facility, the transport vehicle3arrives at the business facility in the time.

Furthermore, when having transported the hydrogen-filled receptacle4to the business facility, the transport vehicle3also collects a receptacle4having a decreased hydrogen storage amount (step S8). Then, the hydrogen filling device2refills, with hydrogen, the receptacle4having a decreased hydrogen storage amount and transported by the transport vehicle3(step S9). Thereafter, steps S2to S9are repeated.

With the hydrogen supply system according to the present embodiment as described above, it is possible to supply hydrogen to the FC forklift5at a desired timing by transporting a portable receptacle4to the business facility and keeping and using the receptacle at the business facility. In other words, with the hydrogen supply system according to the present embodiment, the timing of filling the FC forklift5with hydrogen can be determined by the user, which improves convenience at hydrogen supply.

Furthermore, with the hydrogen supply system according to the present embodiment, it is possible to transport the receptacle4to the business facility at an optimum timing, thereby preventing a situation in which hydrogen in the FC forklift5runs out before the receptacle4is transported.

The hydrogen supply system according to the present invention has been described in detail by means of the form of the invention and examples, but the scope of the present invention is not limited to these descriptions, and should be interpreted broadly based on the claims. In addition, it goes without saying that various changes and modifications based on these descriptions are also included in the scope of the present invention.

For example, the example in which the hydrogen supply system is applied to the FC forklift5as the industrial fuel-cell vehicle is described in the above-described embodiment, but the hydrogen supply system may be applied to a household fuel-cell vehicle. Furthermore, the hydrogen supply system is applicable not only to the fuel-cell vehicle but also to a mobile object such as a ship or a drone on which a fuel cell system is implemented.

Furthermore, in the above-described embodiment, the remaining amount prediction unit111of the management device1acquires the hydrogen remaining amount data on the receptacle4and the FC forklift5and predicts, based on these remaining amount data, the remaining amount of hydrogen that can be used at the business facility in future (refer to step S5inFIG.2), but the remaining amount prediction unit111may acquire only the hydrogen remaining amount data on the receptacle4. In this case, the remaining amount prediction unit111acquires the hydrogen remaining amount data on the receptacle4and predicts the hydrogen remaining amount of the receptacle4disposed at the business facility in future based on the remaining amount data. Note that, as in the above-described embodiment, by acquiring the hydrogen remaining amount data from both the receptacle4and the FC forklift5, the accuracy of prediction of the hydrogen remaining amount is improved as compared to a case of acquiring the hydrogen remaining amount data only from the receptacle4.

REFERENCE SIGNS LIST

1management device11control unit111remaining amount prediction unit112transport timing calculation unit12communication unit13storage unit2hydrogen filling device3transport vehicle4receptacle41hydrogen storage container5FC forkliftNW network