Method and system for simultaneously refueling a plurality of vehicles with hydrogen

Abstract

The invention relates to a method for simultaneously refueling a plurality of vehicles (150) with hydrogen, wherein hydrogen (a) is obtained and compressed by means of a compression device (130), wherein the compressed hydrogen (b) is simultaneously supplied to a plurality of refueling paths (140.1, 140.2, 140.3, 140.4, 140.5, 140.6, 140.7) of a filling system (140), wherein in each of several refueling cycles hydrogen is obtained in at least some of the refueling paths and simultaneously supplied to several connected vehicles (150).

Description

[0001] The invention relates to a method for simultaneously refueling a plurality of vehicles with hydrogen, as well as a system for this purpose, e.g. a hydrogen filling station.

[0002] Hydrogen, which is used as a fuel for vehicles, for example, can be made available via so-called hydrogen filling stations. There are two types of hydrogen filling stations. The first type uses liquid hydrogen as a source and compresses the hydrogen into a liquid, i.e. in liquid form. The second type, on the other hand, has a gaseous hydrogen source and compresses the hydrogen into a gaseous state, i.e. the hydrogen is at least initially obtained in gaseous form and is also compressed into a gaseous state. In addition, there are two basic system areas in a hydrogen filling station. The first system area concerns the compression of the hydrogen, its storage, conditioning and cooling. The second system area comprises a hydrogen dispenser and the associated refueling equipment such as a breakaway and refueling coupling and the refueling hose.

[0003] Due to the compression heat generated when filling hydrogen vehicles with hydrogen, as well as the negative Joule Thompson effect of hydrogen, which occurs during overflow refueling, it is usually necessary to pre-cool the hydrogen to be refueled to as low as -40 °C. For safety reasons, the tank temperature in the vehicle must not exceed a certain temperature on the inside of the tank, usually 85 °C. This must be taken into account for both cascaded filling and direct filling, or a mixture of these two filling methods. Pre-cooling of the hydrogen can be omitted for slow refueling, but these uncooled refuelings take considerably longer than actively cooled refuelings.

[0004] Not only operators or owners of so-called back-to-base hydrogen refueling stations, for example, for municipal hydrogen vehicles such as public buses or service vehicles, strive to implement very cost-effective refueling of hydrogen vehicles. Since up to a third of the costs of a hydrogen refueling station are due to hydrogen pre-cooling, and cascade storage systems also represent a significant cost driver, it is desirable to minimize these two factors as much as possible. However, uncooled hydrogen refueling without cascade storage systems takes too long to realize techno-economically and logistically viable refueling processes, especially for vehicle fleets. Due to their low performance, the attractiveness of hydrogen-powered systems is reduced compared to gasoline, diesel, or battery-powered vehicles.

[0005] Against this background, the task is to make refueling vehicles with hydrogen as cost- and energy-efficient as possible, but also as fast as possible. Disclosure of the invention

[0006] This object is achieved by a method and a system for simultaneously refueling a plurality of vehicles with hydrogen, having the features of the independent patent claims. Preferred embodiments are the subject of the dependent patent claims and the following description. Advantages of the invention

[0007] The invention concerns the refueling of vehicles with hydrogen, as well as corresponding systems and their operation. As mentioned at the beginning, hydrogen filling stations are particularly suitable as such systems.

[0008] As mentioned, two types of hydrogen refueling stations can be distinguished. The first type uses liquid hydrogen as a source and compresses the hydrogen into a liquid state, i.e., in liquid form. The second type, however, uses a gaseous hydrogen source, i.e., it receives the hydrogen in gaseous form and compresses it into a gaseous state. The present invention deals with the second type of hydrogen refueling station, or more generally, with the compression, optional storage, and provision of hydrogen.

[0009] At a second type of hydrogen refueling station, hydrogen is usually compressed in several stages (typically interstage and cylinder jacket cooled) to up to 1000 bar and stored in medium and / or high pressure banks at, for example, between 500 and 1000 bar. When refueling a vehicle at the hydrogen refueling station's dispenser, the hydrogen is usually specifically preconditioned with regard to pressure and mass flow using a so-called pressure ramp controller. In order to refuel hydrogen-powered vehicles with hydrogen in accordance with current standards (e.g. SAE J2601, JPEC-S0003, Phryde Protocol or CEP Protocol), it is generally necessary to pre-cool the hydrogen to temperatures of up to 233.15 K (or -40 °C) before refueling. In the relevant temperature ranges, gaseous hydrogen warms up as a result of isenthalpic expansion due to the negative Joule-Thomson effect.

[0010] Within the scope of the present invention, a possibility for the simultaneous (i.e., simultaneous) refueling of a plurality of vehicles with hydrogen is proposed. For this purpose, hydrogen is obtained and compressed by means of a compression device. The compression device can, in particular, comprise an ionic compressor or compressor or be designed as such. In one embodiment, the hydrogen is obtained from one or more electrolysis units (or an electrolysis plant, in particular on an industrial scale). However, it is also conceivable to obtain the hydrogen from one or more tank vehicles or via pipelines. Mixed forms of these are also conceivable.

[0011] The compressed hydrogen is then fed to a filling system with a plurality of refueling paths. In other words, hydrogen is supplied simultaneously to the plurality of refueling paths, in particular to each refueling path. In at least some of the refueling paths, or even in all of them, hydrogen is obtained and delivered to a connected vehicle (i.e., to a tank of the vehicle in question) - in total, hydrogen is delivered to several connected vehicles simultaneously. This delivery of hydrogen to vehicles takes place in each of several refueling cycles, i.e., simultaneous refueling is carried out on the one hand, but also sequential refueling is carried out on the other. It is not necessarily necessary for the same number of vehicles to be refueled in each refueling cycle. Each refueling path can, for example,a switching valve, a mass flow-controlled pressure regulator, and a coupling device for connection to a vehicle. In one embodiment, each refueling path can be cooled, in particular by means of a water / glycol-air heat exchanger. Cooling to 10°C, for example, is feasible.

[0012] In this way, it is possible to refuel a large number of vehicles simultaneously and without cooling (or at most with minimal cooling, as mentioned) in a relatively short period of time. This is done not in a cascaded manner, but via a compressor or compressor unit, without exceeding the maximum final tank temperature of these vehicles. In particular, for example, seven vehicles with a tank capacity of approximately 38 kg of hydrogen can be refueled at a pressure of approximately 350 bar within approximately five hours. The advantage is that, firstly, the low enthalpy flow per vehicle tank converges the cooling capacity towards zero, but at the same time ensures that as many vehicles as possible can be fully refueled as quickly as possible. This can also be done fully automatically.

[0013] The energy required for optional ambient cooling is very low, as only electrical energy is needed for a small water pump, for example, to maintain the flow.

[0014] In one embodiment, the hydrogen, after being compressed by the compression device, is fed, if required, at least partially to a medium-pressure storage system. From the medium-pressure storage system, the hydrogen is then fed (again) to the compression device if required (internal bypass, thus a partial overflow into the tank system without compression is possible) and then fed to the plurality of refueling paths. This is done in particular in such a way that an enthalpy flow into the respective vehicles or their vehicle tanks has a sufficient minimum to mitigate tank overheating and to simultaneously refuel as many vehicles as possible within a limited period of time. For example, during a predetermined period in which no refueling of a vehicle is to take place (e.g.During a predetermined period of time (e.g. during the day when the vehicles are in use), the hydrogen is at least partially fed to the medium-pressure storage system, and during a predetermined period of time in which the large number of vehicles are to be refueled (e.g. at night), hydrogen is then fed to the compression device and then to the large number of refueling paths so that the vehicles are refueled. The gas (hydrogen) can be bypassed within the compressor system so that the pressure gradient between the vehicle tank and the medium-pressure storage tank can be used for partial overflow refueling. Only when the vehicle tank is sufficiently high and overflow is no longer possible are the respective vehicles fully filled using what is known as compressor refueling.

[0015] Such a medium-pressure storage system can, for example, be designed for a pressure of approximately 200 bar (or a value between 150 bar and 250 bar) and serves as intermediate storage. In this respect, the use of the medium-pressure storage system is particularly useful for obtaining hydrogen from electrolysis units; however, it is also conceivable to use the medium-pressure storage system for obtaining hydrogen from other sources, if necessary or appropriate.

[0016] In one embodiment, the mass flow of the hydrogen compressed by the compression device and supplied to the filling system is limited depending on a predetermined maximum hydrogen temperature. For example, the maximum permissible average mass flow at an ambient temperature of 45°C can be approximately 6.3 kg / h for the assumed tank system volume. This prevents overheating.

[0017] The proposed method of simultaneous refueling of vehicles makes it possible, for example, to fill seven vehicles with a so-called Type 4 tank system (the tank system volume used in the calculation here is 1.56 m3) in tranches simultaneously and uncooled with up to 30 kg of hydrogen each within a period of five hours without causing the tanks to overheat. This is made possible by the fact that the compressor system used (e.g. ionic compressor) can provide a mass flow of up to 52 kg / h, with a mass flow control system, for example controlled by a frequency converter, limiting the maximum permitted mass flows in order to comply with the temperature limits of the respective tank systems. For example, the maximum permitted average mass flow at an ambient temperature of 45 °C is around 6.3 kg / h for the underlying tank system volume.In particular, no human personnel are required to successfully complete the refueling process, which offers technological, economic, and safety advantages. A pressure surge to determine the starting pressure and a leak test can be performed after the vehicles have been coupled as part of a fully automated sequence of steps. Sequential batch processing allows for shorter waiting times, for example, to prepare municipal bus fleets for the next shift.

[0018] For this purpose, no medium-pressure cascade is required and refueling is carried out online, for example, by the compression device or a compressor whose flow control can be kept very simple (e.g. piston compressor with frequency converter-controlled speed control).

[0019] Given the data mentioned, it is also practical, for example, if the filling system is configured for seven or a multiple of seven vehicles that can be coupled. This way, for example, seven vehicles can be refueled first; as soon as these are fully refueled, the next seven vehicles can be refueled immediately. However, it should be noted that depending on the type of vehicle and its tank size, as well as the time available for refueling, a different number of vehicles can also be refueled simultaneously.

[0020] The invention is illustrated schematically in the drawing using exemplary embodiments and is described below with reference to the drawing. Short description of the drawing

[0021] Figure 1 schematically shows a system according to the invention in a preferred embodiment. Figure 2 schematically shows a system according to the invention in another preferred embodiment. Detailed description of the drawing

[0022] In Figure 1 A system 100 according to the invention is schematically shown in a preferred embodiment, by means of which a method according to the invention can also be carried out. This is a simplified process diagram. In particular, a concrete example of a system 100 designed as a hydrogen filling station with an ionic compressor as the compression device 130 and a filling system 140 is shown. The system 100 serves to simultaneously refuel a plurality of vehicles with hydrogen, although only one vehicle 150 is shown as an example.

[0023] In the Figure 1The example shown shows an electrolysis device 110, from which hydrogen a is obtained and fed to the compression device 130. For this purpose, the valve 112 can be opened. The electrolysis device 110 can be part of the system 100, but it does not have to be; for example, the hydrogen can also be transported via a pipeline from the electrolysis device 110 to the system 100 or there to the compression device 130.

[0024] Hydrogen, referred to here as stream b, can be supplied from the compression device 130 to the filling system 140. In one embodiment, the system 100 also has a medium-pressure storage system 120. The medium-pressure storage system 120 can, for example, comprise one or more storage tanks or storage banks in which hydrogen can be stored at approximately 200 bar. After it has been compressed by the compression device 130, the hydrogen can, if required, be at least partially supplied to the medium-pressure storage system 130; this is shown as stream d. For this purpose, the valve 122 can be opened. Likewise, the hydrogen, shown here as stream d, can be supplied from the medium-pressure storage system 120 to the compression device 130 if required and then, like stream b, to the filling system 104. For this purpose, the valve 124 can be opened.

[0025] The filling system 140 has, for example, seven refueling paths 140.1, 140.2, 140.3, 140.4, 140.5, 140.6, 140.7, to each of which hydrogen can be or is supplied from the compression device 130. For example, the refueling path 140.1 has a changeover valve 142.1, a mass flow-controlled pressure regulator 144.1, a heat exchanger 146.1, and a coupling device 148.1 for connection to the vehicle 150, which can then be refueled with hydrogen, here electricity e. The heat exchanger 146.1 can be, for example, a water or glycol-air heat exchanger.

[0026] The coupling device 148.1 can include components such as a flow transmitter, refueling hose, breakaway device, and refueling coupling, as well as other required sensors in the actual dispenser unit. The additional refueling paths 140.2, 140.3, 140.4, 140.5, 140.6, and 140.7 can be constructed similarly, with a vehicle or its tank also being connectable there, although this is not shown for the sake of clarity.

[0027] The filling system 140 can also comprise further refueling paths, e.g., a further seven or fourteen refueling paths, or generally 7 n refueling paths with n being a number greater than or equal to 1 and, e.g., a maximum of 49. The filling system 140 can be configured to switch from the seven refueling paths 140.1, 140.2, 140.3, 140.4, 140.5, 140.6, 140.7 shown to other seven refueling paths in order to refuel vehicles connected there, e.g., in a subsequent refueling cycle.

[0028] The operation of the system 100 will be explained in more detail below. Hydrogen is generated by the electrolysis device 110, for example, at 36 kg / h, compressed by the compression device 130, and fed into the medium-pressure storage system 120 at approximately 200 bar. This takes place, for example, during a time of day when no vehicle is to be refueled. If, in the example shown, more than seven vehicles, e.g. an entire vehicle fleet, need to be refueled simultaneously, this can be done in batches of seven vehicles each. In this case, the compression device 130 can, for example, refuel seven vehicles each with up to approximately 30 kg of hydrogen, even at elevated ambient temperatures of more than 39 °C. The compression device 130 extracts the required amount of hydrogen from the medium-pressure storage system 120, which serves as a buffer storage here. As part of the refueling process for the first vehicle batch of, for example,seven vehicles are coupled to the filling system 140, a so-called header dispenser, which can accordingly comprise seven filling points (the coupling devices mentioned).

[0029] Refueling can be carried out completely independently. The aforementioned switchover valves of the filling system 140 enable the respective refueling processes of the vehicle tranches (here consisting of seven vehicles). After filling the seven vehicles, the system can switch to the next seven vehicles by switching the relevant switchover valves.

[0030] Optionally, the filling system 140 can also be cooled to, for example, 10 °C or at least approximately ambient temperature using the aforementioned cooling or heat exchangers. The energy required for this ambient cooling is very low, since only a small water pump requires electrical energy to maintain the flow.

[0031] In Figure 2 A system 200 according to the invention is schematically shown in a further preferred embodiment, by means of which a method according to the invention can also be carried out. This is a simplified process diagram. In particular, a concrete example of a system 200 designed as a hydrogen filling station with an ionic compressor as the compression device 130 and a filling system 140 is shown. The system 100 serves to simultaneously refuel a plurality of vehicles with hydrogen, although only one vehicle 150 is shown as an example.

[0032] In the following, only the difference to Annex 100 according to Figure 1 be explained, otherwise you can refer to the explanations on Figure 1The plant 100, for example, does not have an electrolysis plant; instead, the hydrogen, stream a, is obtained from a tank vehicle 210 (which is only shown very schematically here) and fed to the compression device 130 and then to the filling system 140. For this purpose, the valve 212 (e.g. on the tank vehicle and / or on the compression device 130) can be opened, whereby the tank vehicle is to be coupled accordingly. Several tank vehicles can also be provided in parallel or one after the other. For example, no medium-pressure storage system is provided here either, since the tank vehicles themselves form a storage system for the hydrogen anyway.

[0033] With the proposed approach - this applies both to the design of the Figure 1 as well as the design of the Figure 2or a mixture thereof - within approximately five hours, seven vehicles with a so-called Type 4 tank system (the tank system volume used in the calculation is 1.56 m3<) can be filled simultaneously and uncooled with up to 30 kg of hydrogen each in batches without causing tank overheating. This is made possible by the fact that the compression device 130 used (ionic compressor) can provide a mass flow of up to 52 kg / h, with a frequency converter-controlled mass flow control, for example, limiting the maximum permitted mass flows in order to comply with the temperature limits of the respective tank systems.

[0034] For example, the maximum permitted average mass flow at an ambient temperature of 45 °C is approximately 6.3 kg / h for the underlying tank system volume. No human personnel are required to successfully complete the refueling process, as the process can be fully automated. Only the coupling and uncoupling of the vehicles can be carried out by human personnel. The pressure surge to determine the starting pressure, as well as the leak test, can be carried out after the vehicles have been coupled as part of a fully automated step sequence. Sequential tranche processing enables shortened waiting times, for example to prepare municipal bus fleets for the next shift. No medium-pressure cascade is required, and refueling takes place online via the compression device, whose flow control can be kept very simple (e.g., a piston compressor with frequency converter-controlled speed control).

[0035] As mentioned, a mixed form of the embodiments according to Figure 1 and 2 be provided, whereby in the embodiment according to Figure 2 Optionally, it would also be possible to connect and consolidate multiple tankers simultaneously, for example, to allow for increased compressor inlet pressures and / or to include partial overflow refueling as an additional option. This would require simple bank control and, in some cases, the aforementioned ambient cooling.

[0036] In a further embodiment (regardless of the method of obtaining the hydrogen), the refueling ramps in the individual refueling paths can also be varied dynamically during the filling or refueling process.

Claims

1. A method for simultaneously refueling a plurality of vehicles (150) with hydrogen, wherein hydrogen (a) is obtained and compressed by means of a compression device (130), wherein the compressed hydrogen (b) is simultaneously supplied to a plurality of refueling paths (140.1, 140.2, 140.3, 140.4, 140.5, 140.6, 140.7) of a filling system (140), wherein in each of a plurality of refueling cycles, hydrogen is obtained in at least some of the refueling paths and is delivered to a plurality of connected vehicles (150) simultaneously.

2. The method according to claim 1, wherein the hydrogen (c), after being compressed by means of the compression device (130), is supplied at least partially to a medium-pressure storage system (120) as needed, and wherein the hydrogen (d) is supplied from the medium-pressure storage system to the compression device (130) as needed and then to the filling system (140).

3. The method according to claim 2, wherein the hydrogen (c), after it has been compressed by means of the compression device (130), is supplied at least partially to the medium-pressure storage system (120) during a predetermined period of time in which no refueling of a vehicle is to take place, and wherein the hydrogen (d) is supplied from the medium-pressure storage system (120) to the compression device (130) and then to the filling system (140) during a predetermined period of time in which refueling of the plurality of vehicles is to take place.

4. Method according to one of the preceding claims, wherein the hydrogen is obtained at least partially from one or more electrolysis devices (110) and fed to the compression device (130).

5. Method according to one of the preceding claims, wherein the hydrogen is at least partially obtained from one or more tank vehicles (210) and supplied to the compression device (130).

6. Method according to one of the preceding claims, wherein the hydrogen is obtained at least partially via one or more pipelines and fed to the compression device (130).

7. Method according to one of the preceding claims, wherein each refueling path has a switching valve, a mass flow controlled pressure regulator, and a coupling device for connection to a vehicle (150).

8. Method according to one of the preceding claims, wherein the hydrogen in the refueling path is cooled, in particular by means of a water and / or glycol-air heat exchanger.

9. Method according to one of the preceding claims, wherein a mass flow of the hydrogen (b) compressed by the compression device (130) and supplied to the filling system (140) is limited as a function of a predetermined maximum temperature of the hydrogen.

10. Method according to one of the preceding claims, wherein the hydrogen is provided to the vehicles (150) at a pressure of at least 300 bar, in particular at least 350 bar.

11. Method according to one of the preceding claims, wherein the compression device (130) comprises an ionic compressor.

12. A system (100, 200), in particular a hydrogen filling station, for the simultaneous refueling of a plurality of vehicles (150) with hydrogen, comprising a compression device (130) and a filling system (140) with a plurality of refueling paths, wherein a vehicle (150) can be connected to each refueling path, wherein the system (100, 200) is designed to receive hydrogen (a) and to compress it by means of the compression device (130), wherein the system (100, 200) is designed to supply compressed hydrogen (b) simultaneously to the plurality of refueling paths (140.1, 140.2, 140.3, 140.4, 140.5, 140.6, 140.7) and to deliver it simultaneously to at least some connected vehicles (150) in each of a plurality of refueling cycles.

13. The system according to claim 12, further comprising a medium-pressure storage system (120), wherein the system (100) is configured to supply the hydrogen, after it has been compressed by means of the compression device, at least partially to the medium-pressure storage system (120) as needed, and to supply the hydrogen from the medium-pressure storage system to the compression device and then to the filling system (140) as needed.

14. The system (100) according to claim 13, which is configured to supply the hydrogen, after it has been compressed by means of the compression device, at least partially to the medium-pressure storage system during a predetermined period of time in which no refueling of a vehicle is to take place, and to supply the hydrogen from the medium-pressure storage system to the compression device and then to the filling system (140) during a predetermined period of time in which refueling of the plurality of vehicles is to take place.

15. Plant (100, 200) according to one of claims 12 to 14, which is arranged to carry out a method according to one of claims 1 to 11.

Images