METHOD FOR KEEPING FREE OF ICE OR THAWING AT LEAST ONE ICE-PROBLEM SURFACE OF A TANK INTERFACE, TANK INTERFACE

Description

[0001] The invention relates to a method for keeping ice-free or thawing at least one surface of a tank interface that is at risk of icing according to the preamble of claim 1. The invention further relates to a tank interface with at least one surface that is at risk of icing, which is formed on a fuel nozzle and / or on a tank nozzle of a hydrogen-powered vehicle. State of the art

[0002] Hydrogen-powered fuel cell systems are said to have great potential to play a significant role in the energy and transport transition. Initial series applications are already available on the market.

[0003] In mobile applications, hydrogen must be carried in a storage tank or tank. Hydrogen can generally be stored at low temperature in a so-called cryogenic tank or under pressure in a pressure tank. For mobile applications and those where continuous hydrogen withdrawal is not guaranteed, pressure tanks are the preferred solution. The storage pressure in these pressure tanks can reach up to 700 bar.

[0004] Once the stored hydrogen has been used up, the tanks must be refilled. A hydrogen-powered vehicle drives to a hydrogen filling station for this purpose. Refueling is carried out using a fuel nozzle and a corresponding fuel nozzle on the vehicle. This interface is internationally standardized, with the standard being defined in the SAE J2601 protocol. Since hydrogen heats up during refueling due to its thermodynamic properties, it is stored in the filling station at around -40°C. When refueling a vehicle, the areas through which the cold hydrogen flows, in particular valves, pipes and / or connections, can therefore cool down so much that they freeze. In addition, ambient moisture can condense on the fuel nozzle, which then freezes. This can lead to the fuel nozzle freezing to the fuel nozzle during refueling.The risk of freezing is particularly high when refueling the vehicle in a warm, humid environment. Rapid refueling operations also increase the risk, as the fuel nozzle does not have time to warm up. US 2018 / 266633 A1 and US 2013 / 061983 A1 each describe a vehicle and a method for filling fuel gas with a heating device for the fuel nozzle. US 2004 / 016240 A1 describes a fuel nozzle with a protective cap made of PTFE.

[0005] Since freezing of the fuel nozzle on the fuel tank nozzle leads to extended refueling times, the object of the present invention is to prevent or at least make it more difficult for the fuel nozzle to freeze.

[0006] To achieve this objective, the method having the features of claim 1 and the tank interface having the features of claim 4 are specified. Advantageous developments of the invention are set forth in the respective subclaims. Furthermore, a hydrogen-powered vehicle having a tank interface according to the invention is specified. Disclosure of the invention

[0007] A method is proposed for keeping ice-free or thawing at least one surface of a tank interface at risk of icing. The at least one surface at risk of icing is formed on a fuel nozzle and / or on a fuel tank nozzle of a hydrogen-powered vehicle. According to the invention, the at least one surface at risk of icing is heated during and / or after a refueling process.

[0008] By heating at least one surface at risk of icing, icing at the tank interface can be actively counteracted, so that icing either prevents it from occurring in the first place or, if it does, the icy area can be quickly thawed. If the at least one surface at risk of icing is heated during the refueling process, the fuel nozzle can be prevented from freezing to the fuel nozzle. Alternatively or additionally, heating can also be carried out after the refueling process, so that the formation of condensate, particularly on the fuel nozzle, is counteracted. In this way, the fuel nozzle can be prevented from freezing to the fuel nozzle of the following vehicle during rapid refueling processes.

[0009] The fuel nozzle forms the interface at the filling station for refueling a vehicle with hydrogen. The fuel nozzle forms the corresponding interface on the vehicle. The term "fuel interface" can therefore refer to the fuel nozzle and / or the fuel nozzle.

[0010] When refueling a hydrogen-powered vehicle, cold hydrogen flows into the vehicle's tank via the fuel nozzle and the fuel filler neck. Both the fuel nozzle and the fuel filler neck can thus form at least one surface at risk of icing. The method according to the invention can thus be used to keep the fuel nozzle and / or the fuel filler neck free of ice.

[0011] According to a preferred embodiment of the invention, the at least one surface at risk of icing is heated using a heating cartridge or a heating sleeve. These heating devices require little installation space and can therefore be installed even in confined spaces. Furthermore, they are very robust. The heating sleeve is particularly suitable for heating an outer or inner circumferential surface of the fuel nozzle and / or the fuel nozzle.

[0012] According to the invention, at least one surface at risk of icing is heated inductively. This type of heating is suitable because the fuel nozzle and / or the fuel nozzle are usually made of metal in the area of ​​their surfaces at risk of icing, and thus of an electrically conductive material. An inductive heating device also requires little space and can be implemented easily and cost-effectively.

[0013] Several heating methods can also be combined, especially if several surfaces at risk of icing on the fuel nozzle and / or the fuel tank nozzle are heated.

[0014] The tank interface further proposed to solve the aforementioned problem has at least one surface susceptible to icing, which is formed on a fuel nozzle and / or on a fuel nozzle of a hydrogen-powered vehicle. The term "tank interface" can, in turn, refer to the fuel nozzle as the filling station-side interface and / or to the fuel nozzle as the vehicle-side interface. According to the invention, the at least one surface susceptible to icing can be heated by means of a heating device and / or is designed such that water is specifically drained, absorbed, or adsorbed.

[0015] The heating device can be used to heat at least one surface at risk of icing, if necessary, preventing the fuel nozzle from freezing to the fuel nozzle or thawing ice that has already formed in the area of ​​the fuel interface. Furthermore, the heating device, especially when used to heat the fuel nozzle, can counteract the formation of condensate. This also helps minimize the risk of freezing to a fuel nozzle.

[0016] The heating device can be, for example, a heating cartridge or a heating sleeve. The heating sleeve can be used, in particular, to heat an outer or inner peripheral surface of the fuel nozzle and / or the fuel nozzle. Alternatively or additionally, it is proposed that the heating device be an inductive heater.

[0017] If a heating device is provided, the method according to the invention described above can be carried out using the proposed tank interface. However, the tank interface according to the invention does not necessarily have to include a heating device.

[0018] The alternative or additional measure proposed provides for a special condition for at least one surface at risk of icing. This is characterized by the fact that it removes water, especially condensate, from the area at risk of icing. The removal of water is achieved passively, i.e., solely through the condition of the surface. The risk of icing is thus also minimized.

[0019] Water removal can be achieved, in particular, with a hydrophilic or hydrophobic surface. To create a hydrophilic surface that absorbs water, the surface can contain capillaries. The water absorbed via the capillaries can then be released at a non-critical location. To create a hydrophobic surface that repels water, the surface can either be hydrophobic itself or have a hydrophobic coating.

[0020] According to the invention, the at least one surface at risk of icing has a hydrophobic coating, for example, made of polytetrafluoroethylene (PTFE). PTFE, also known under the brand name "Teflon," has a low surface tension, so water doesn't stick to the surface but "beads off." The contact angle with water is 126°.

[0021] In addition, it is proposed that at least one surface at risk of icing be coated with a nanocoating. Such a coating can also significantly reduce the wettability of the surface.

[0022] Furthermore, the at least one surface at risk of icing can additionally have a zeolite layer that adsorbs water in an exothermic reaction. This removes the water from the surface, and the exothermic reaction generates heat, which counteracts icing.

[0023] The proposed measures for influencing the condition of at least one surface at risk of icing can be implemented individually or in various combinations. This is particularly true since, as a rule, multiple surfaces at a tank interface are at risk of icing. The multiple surfaces can therefore have the same or different surface conditions.

[0024] The at least one surface susceptible to icing can be located, in particular, on the front and / or outer circumference of the fuel inlet. The front surface and / or outer circumference of the fuel inlet generally form the contact surface(s) with the fuel nozzle during a refueling process, so the proposed measures against the fuel nozzle freezing to the fuel inlet are particularly effective here.

[0025] Alternatively or additionally, it is proposed that the at least one surface susceptible to icing be formed on the front and / or inner circumference of the fuel nozzle. The front and / or inner circumference of the fuel nozzle generally comes into contact with the fuel nozzle.

[0026] The at least one surface at risk of icing does not necessarily have to be flat. In the case of an outer or inner peripheral surface, it can be curved or circular. It can also have grooves and / or fits. The surface can be chamfered or rounded at the edges.

[0027] Since the preferred field of application of the tank nozzle of the tank interface according to the invention is a hydrogen-operated vehicle, such a vehicle with a tank interface according to the invention is further proposed.

[0028] The invention is explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 a schematic plan view of a tank nozzle of a tank interface according to the invention, Fig. 2 a perspective view of the tank nozzle of the Fig. 1 and Fig. 3 a perspective view of a fuel nozzle of a tank interface according to the invention. Detailed description of the drawings

[0029] The Figures 1 and 2 show, by way of example, a fuel tank nozzle 4 of a hydrogen-powered vehicle (not shown). The fuel tank nozzle 4 is in the present case designed as a hollow cylinder. It has a flat end face 5 with a seal 8 and an outer circumferential surface 6. At least the outer circumferential surface 6 comes into contact with a fuel nozzle 3 during a refueling process. Such a fuel nozzle 3 is shown, by way of example, in Fig. 3 shown.

[0030] Again Fig. 3As can be seen, the fuel nozzle 3 has a type of nozzle which, for refueling a hydrogen-powered vehicle, is not inserted into but onto the fuel nozzle 4 of the vehicle, so that hydrogen can flow via the fuel nozzle 3 and the fuel nozzle 4 into a tank (not shown) of the vehicle.

[0031] When the fuel nozzle 3 is attached, an inner peripheral surface 7 of the fuel nozzle 3 comes into contact with the outer peripheral surface 6 of the fuel nozzle 4. These contact surfaces form surfaces 1 that are prone to icing, as they cool significantly when the vehicle is refueled with hydrogen. The temperature of hydrogen is approximately -40°C. If condensate also forms on the cooled surfaces, it can freeze. This can cause the fuel nozzle 3 to freeze to the fuel nozzle 4.

[0032] Even after refueling, condensation can form on cold surfaces, especially if the ambient air is warm and humid. If a refueling operation follows shortly thereafter, the fuel nozzle 3 can freeze to the fuel nozzle 4 of the other vehicle.

[0033] According to the method according to the invention, the at least one surface 1 of a tank interface 2 that is at risk of icing is heated. Heating can prevent excessive cooling of the surface, so that condensate does not form on it or at least does not freeze.

[0034] A tank interface 2 according to the invention therefore has a heating device (not shown) for carrying out the method according to the invention. Alternatively or additionally, the at least one surface 1 at risk of icing can have a property that drains away, absorbs, or adsorbs water. For example, water can be absorbed via capillaries present in the surface 1 and thus removed from the danger zone. A coating (not shown) can also be applied to the surface 1, which preferably has a hydrophobic effect, so that water simply beads up and rolls off the surface 1. The adsorption of water can be achieved by means of a zeolite layer in the surface 1. Adsorption by means of a zeolite layer has the advantage that this process is exothermic, i.e., it releases heat, which in turn can be used to heat the surface.

Claims

1. Method for keeping free of ice, or thawing, at least one surface (1) at risk of icing up of a tank interface (2), wherein the at least one surface (1) at risk of icing up is provided on a fuelling nozzle (3) and / or on a filler neck (4) of a hydrogen-operated vehicle, wherein the at least one surface (1) at risk of icing up is heated during a fuelling process and / or after a fuelling process, characterized in that the at least one surface (1) at risk of icing up is inductively heated.

2. Method according to Claim 1, characterized in that the at least one surface (1) at risk of icing up is heated using a heating cartridge or a heating sleeve.

3. Tank interface (2) having at least one surface (1) which is at risk of icing up and is provided on a fuelling nozzle (3) and / or on a filler neck (4) of a hydrogen-operated vehicle, wherein the at least one surface (1) at risk of icing up can be heated by means of a heating device and / or is provided in such a way that water is discharged, absorbed or adsorbed in controlled fashion, characterized in that the at least one surface (1) at risk of icing up has a hydrophobizing coating, for example of polytetrafluoroethylene (PTFE).

4. Tank interface (2) according to Claim 3, characterized in that the at least one surface (1) at risk of icing up has a nano-coating.

5. Tank interface (2) according to either of Claims 3 and 4, characterized in that the at least one surface (1) at risk of icing up has a zeolite layer, which adsorbs water in an exothermic reaction.

6. Tank interface (2) according to one of Claims 3 to 5, characterized in that the at least one surface (1) at risk of icing up is provided on the end face and / or around the outer circumference of the filler neck (4).

7. Tank interface (2) according to one of Claims 3 to 6, characterized in that the at least one surface (1) at risk of icing up is provided on the end face and / or around the inner circumference of the fuelling nozzle (3).

8. Hydrogen-operated vehicle comprising a tank interface (2) according to one of Claims 3 to 7.