EP4517153A1 - Method and system for simultaneously refueling a plurality of vehicles with hydrogen - Google Patents

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 a plurality of refueling cycles, hydrogen is obtained in at least some of the refueling paths and is simultaneously delivered to a plurality of connected vehicles (150).

Description

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.

Hydrogen, which is used as fuel for vehicles, for example, can be provided via so-called hydrogen filling stations. Two types of hydrogen filling 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, 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, two basic system areas can be distinguished in a hydrogen filling station. The first system area concerns the compression of the hydrogen, its storage, as well as its conditioning and cooling. The second system area includes a hydrogen dispenser and the associated refueling equipment such as breakaway and refueling couplings and the refueling hose.

Due to the compression heat that is 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 significantly longer than actively cooled refuelings.

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

Against this background, the task is to make refueling vehicles with hydrogen as cost- and energy-efficient as possible, but also as quick as possible.

disclosure of the invention

This object is achieved by a method and a system for simultaneously refueling a large number of vehicles with hydrogen with 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

The invention deals with the refueling of vehicles with hydrogen as well as corresponding systems and their operation. As mentioned at the beginning, hydrogen filling stations in particular come into consideration as such systems.

As mentioned, two types of hydrogen filling stations can be distinguished. The first type uses liquid hydrogen as a source and compresses the hydrogen in liquid form. The second type, on the other hand, has a gaseous hydrogen source, ie receives the hydrogen in gaseous form, and compresses the hydrogen in gaseous form. The present invention deals with the second type of hydrogen filling stations or generally the compression, storage and provision of hydrogen.

At a second type of hydrogen filling station, hydrogen is usually compressed in several stages (typically intermediate stage and cylinder jacket cooled) to up to 1000 bar and stored in medium and/or high pressure banks at e.g. between 500 and 1000 bar. When refueling a vehicle at the hydrogen filling station dispenser, the hydrogen is usually specifically preconditioned in terms of pressure and mass flow using a so-called pressure ramp controller. In order to refuel hydrogen-powered vehicles with hydrogen in accordance with the current standards (e.g. SAE J2601, JPEC-S0003, Phryde protocol or CEP protocol), it is usually 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 heats up due to the negative Joule-Thomson effect in the course of isenthalpic relaxation.

Within the scope of the present invention, a possibility for simultaneously (i.e. simultaneously) refueling a large number of vehicles with hydrogen is proposed. For this purpose, hydrogen is obtained and compressed using a compression device. The compression device can in particular have an ionic 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.

The compressed hydrogen is then fed to a filling system with a plurality of refueling paths. In other words, hydrogen is simultaneously fed 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 (ie, to a tank of the vehicle in question) - in total, hydrogen is delivered to several connected vehicles at the same time. 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 on the other. It is not necessary for the same number of vehicles to be refueled in each refueling cycle. Each refueling path can have, for example, a changeover 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 is feasible, for example.

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 time, not in a cascade, but via a compressor unit, without exceeding the maximum final tank temperature of these vehicles. In particular, seven vehicles with a tank capacity of approx. 38 kg of hydrogen can be refueled at a pressure of approx. 350 bar within approx. 5 hours. The advantage is that the low enthalpy flow per vehicle tank means that the cooling capacity converges towards zero, but at the same time it is ensured that as many vehicles as possible can be fully refueled as quickly as possible. This can also be done fully automatically.

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.

In one embodiment, the hydrogen, after it has been compressed by means of the compression device, is fed at least partially to a medium-pressure storage system if required. From the medium-pressure storage system, the hydrogen is then fed (again) to the compression device if required (internal bypass, so 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 in order to mitigate tank overheating and simultaneously to fully refuel as many vehicles as possible in a limited period of time. For example, during a predetermined period of time in which no vehicle is to be refueled (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 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.

Such a medium-pressure storage system can, for example, be designed for a pressure of around 200 bar (or a value between 150 bar and 250 bar) and is used for intermediate storage. In this respect, the use of the medium-pressure storage system is particularly useful when obtaining hydrogen from electrolysis units, but it is also conceivable to use the medium-pressure storage system when obtaining hydrogen from other sources, if necessary or expedient.

In one embodiment, a mass flow of the hydrogen compressed by the compression device and supplied to the filling system is limited depending on a predetermined maximum temperature of the hydrogen. For example, the maximum permitted average mass flow at an ambient temperature of 45 °C can be approximately 6.3 kg/h for the underlying tank system volume. In this way, overheating is avoided.

The proposed method of simultaneously refueling vehicles allows, for example, seven vehicles with a so-called Type 4 tank system (the tank system volume used in the calculation is 1.56 m ³ ) to be filled in batches simultaneously and uncooled with up to 30 kg of hydrogen each within five hours without causing the tank 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 controlled, for example, by means of a frequency converter, limiting the maximum permitted mass flows in order to comply with the temperature limits of the respective tank systems. The maximum permitted average mass flow at 45 °C is Environment, for example, around 6.3 kg/h for the underlying tank system volume. In order to successfully complete the refueling, no human personnel are required, which has technological, economic and safety advantages. A pressure surge to determine the starting pressure and a leak check can be carried out after the vehicles have been coupled as part of a fully automated controlled step chain. The sequential tranche processing enables a shortened waiting time, for example to get municipal bus fleets ready for the next shift.

No medium-pressure cascade is required for this and refueling takes place online, for example, through the compression device or a compressor whose flow control can be kept very simple (e.g. piston compressor with frequency converter-controlled speed control).

With the data mentioned, it is also useful, for example, if the filling system is set up for seven or a multiple of seven vehicles that can be connected. For example, seven vehicles can be filled up first, and as soon as these are fully filled up, the next seven vehicles can be filled up immediately. However, it should be noted that depending on the type of vehicle and its tank size, as well as the time available for filling up, other numbers of vehicles can also be filled up at the same time.

The invention is illustrated schematically in the drawing using embodiments and is described below with reference to the drawing.

Short description of the drawing

Figure 1

shows schematically a system according to the invention in a preferred embodiment.

Figure 2

shows schematically a system according to the invention in a further preferred embodiment.

Detailed description of the drawing

In Figure 1 a system 100 according to the invention is shown schematically 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 a compression device 130 and a filling system 140 is shown. The system 100 serves to simultaneously fill a large number of vehicles with hydrogen, although only one vehicle 150 is shown as an example.

In the Figure 1 In the example shown, an electrolysis device 110 is shown, 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.

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 means of the compression device 130, the hydrogen can be supplied at least partially to the medium-pressure storage system 130 if required; this is shown with 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.

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 switching 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 then can be fueled with hydrogen, here electricity e The heat exchanger 146.1 can be, for example, a water or glycol-air heat exchanger.

The coupling device 148.1 can, for example, include components such as a flow transmitter, refueling hose, tear-off device, and refueling coupling, as well as other required sensors in the actual dispenser unit. The other refueling paths 140.2, 140.3, 140.4, 140.5, 140.6, 140.7 can be constructed in a similar way, whereby a vehicle or its tank can also be connected there, although this is not shown for the sake of clarity.

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 set up 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.

The operation of the system 100 will be explained in more detail below. The electrolysis device 110 produces hydrogen at 36 kg/h, for example, which is compressed using the compression device 130 and fed into the medium-pressure storage system 120 at around 200 bar. This takes place, for example, at a time of day when no vehicle needs to be refueled. If, in the example shown, more than seven vehicles, e.g. an entire vehicle fleet, have to be refueled simultaneously, this can be done in batches of seven vehicles each. The compression device 130 can be used to simultaneously refuel seven vehicles, each with up to approx. 30 kg of hydrogen, even at elevated ambient temperatures of more than 39 °C. The compression device 130 takes 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 of the first vehicle tranche of, for example, seven vehicles, these are coupled to the filling system 140, a so-called header dispenser, which can accordingly comprise seven filling points (the coupling devices mentioned).

The refueling can be carried out completely independently. The aforementioned switching valves of the filling system 140 can enable the respective refueling processes of the vehicle tranches (here consisting of seven vehicles). After the seven vehicles have been filled, it is possible to switch to the next seven vehicles by switching the relevant switching valves.

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

In Figure 2 a system 200 according to the invention is shown schematically 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 compression device 130 and a filling system 140 is shown. The system 100 serves to simultaneously fill a large number of vehicles with hydrogen, although only one vehicle 150 is shown as an example.

In the following, only the difference to Annex 100 according to Figure 1 be explained, otherwise please refer to the explanations on Figure 1 The system 100 does not have an electrolysis system, for example, but instead the hydrogen, stream a, is received from a tanker 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 tanker and/or on the compression device 130) can be opened, with the tanker being coupled accordingly. Several tankers can also be provided in parallel or one after the other. For example, no medium-pressure storage system is provided here either, since the tankers themselves form a storage system for the hydrogen anyway.

With the proposed approach - this applies both to the design of the Figure 1 as well as the design of the Figure 2 or a mixture of these - let Within about five hours, seven vehicles with a so-called type 4 tank system (the tank system volume used in the calculation is 1.56 m ³ ) can be filled in batches simultaneously and uncooled with up to 30 kg of hydrogen each, without causing the tank to overheat. This is made possible by the fact that the compression device 130 (ionic compressor) used 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.

For example, the maximum permitted average mass flow at 45 °C ambient is around 6.3 kg/h for the underlying tank system volume. No human personnel is required to complete the refueling successfully, 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 and the leak check can be carried out after the vehicles have been coupled in the course of a fully automated controlled step chain. The sequential tranche processing enables a shortened waiting time, for example to get municipal bus fleets ready for the next shift. No medium-pressure cascade is required for this and the
Refueling is carried out online by the compression device, the flow control of which can be kept very simple (e.g. a piston compressor with frequency converter-controlled speed control).

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 several tank vehicles simultaneously and consolidate them, for example to enable increased compressor inlet pressures and/or to include partial overflow refueling as a further option. This would require simple bank control and, in some cases, the ambient cooling mentioned above.

In a further embodiment (independent 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 (15)

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 received in at least some of the refueling paths and is simultaneously delivered to a plurality of connected vehicles (150). Method according to claim 1, wherein the hydrogen (c), after it has been compressed by means of the compression device (130), is supplied at least partially to a medium-pressure storage system (120) as required, and wherein the hydrogen (d) from the medium-pressure storage system is supplied to the compression device (130) as required and is then supplied to the filling system (140). Method according to claim 2, wherein the hydrogen (c), after it has been compressed by means of the compression device (130), is at least partially supplied 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. Method according to one of the preceding claims, wherein the hydrogen is at least partially obtained from one or more electrolysis devices (110) and fed to the compression device (130). 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). Method according to one of the preceding claims, wherein the hydrogen is at least partially obtained via one or more pipelines and fed to the compression device (130). Method according to one of the preceding claims, wherein each refueling path has a changeover valve, a mass flow-controlled pressure regulator, and a coupling device for connection to a vehicle (150). 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. 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. 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. Method according to one of the preceding claims, wherein the compression device (130) comprises an ionic compressor. Installation (100, 200), in particular a hydrogen filling station, for simultaneously filling a plurality of vehicles (150) with hydrogen, comprising a compression device (130) and a filling system (140) with a plurality of filling paths, wherein a vehicle (150) can be connected to each filling path, wherein the plant (100, 200) is arranged to obtain hydrogen (a) and to compress it by means of the compression device (130), wherein the system (100, 200) is configured 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. 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) when required, and to supply the hydrogen from the medium-pressure storage system to the compression device and then to the filling system (140) when required. System (100) according to claim 13, which is arranged 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. 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.

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