Method for refueling a tank with a liquefied gas

Abstract

The invention relates to a method for refueling a tank with a liquefied gas, wherein a temperature (T) of a seal at a tank nozzle of the tank and / or its surroundings is monitored by means of at least one sensor, wherein the temperature (T) of the seal and / or its surroundings is, if necessary, raised to an upper nominal temperature (T) by means of a heater. ON ) is brought into play, whereby if a predetermined threshold (T) is exceeded, the process is initiated. SW ) defined required minimum operating temperature is not reached, a refueling process is interrupted and when the specified threshold (T) is reached SW ) will be continued.

Description

[0001] The invention relates to a method for refueling a tank with a liquefied gas according to the preamble of claim 1 and to a vehicle according to the preamble of claim 8.

[0002] Seals on tank nozzles for liquefied, processed gases, such as LNG or hydrogen, lose their sealing properties at temperatures outside a specified standard range, especially at low temperatures. When refueling liquefied, processed gases, such as LNG, the temperature is approximately -163°C. For liquid hydrogen, the temperature is approximately -250°C. In these cases, seals may be damaged or impaired in their function.

[0003] DE 10 2017 123 654 A1 describes a temperature-controlled sealing arrangement for sealing a space between two machine elements that either rotate around a common axis or are movable along this axis. The sealing arrangement comprises a radial shaft seal that is non-rotatably mounted on one machine element and sealingly engages the other machine element. A temperature control element made of a polymer and containing electrical contact elements and conductive material is attached to the seal. By applying an electrical voltage to the terminals of the temperature control element, the element is heated, which in turn heats the seal and ensures its elasticity even at low temperatures.

[0004] DE 10 2020 212 080 A1 discloses a method for keeping ice-free or thawing surfaces of a tank interface formed on a fuel nozzle and / or a fuel tank nozzle of a hydrogen-powered vehicle that are at risk of freezing. During or after a refueling process, the surface at risk of freezing is heated to prevent it from freezing solid.

[0005] CN 218883668 U describes a vehicle-mounted liquid hydrogen supply system, wherein a liquid hydrogen filling port of a vehicle-mounted liquid hydrogen cylinder is equipped with a liquid hydrogen filling line and a liquid hydrogen outlet of the vehicle-mounted liquid hydrogen. The cylinder is equipped with a liquid hydrogen supply line, and a gas phase port of the vehicle-mounted liquid hydrogen cylinder is equipped with a gas return line. One end of the liquid hydrogen filling line is configured as an opening end for the addition of low-temperature liquid, and the other end of the liquid hydrogen filling line sealingly penetrates a liquid hydrogen filling with a low-temperature check valve and then extends into the vehicle-mounted liquid hydrogen cylinder.The liquid hydrogen filling line between the low-temperature check valve and the liquid hydrogen filling port is connected to a pressure line and a first safety relief line with a first safety valve, respectively. The pressure line is hermetically connected to a gas outlet of the supply valve of the high-pressure hydrogen tank. A pressure reducing and regulating valve and a first pressure gauge are sequentially mounted on the pressure line in the direction from the outlet of the gas supply valve to the junction of the pressure line and the liquid hydrogen filling line.

[0006] The present invention has for its object to provide a novel method for refueling a tank with a liquefied gas and a novel vehicle.

[0007] The object is achieved according to the invention by a method for refueling a tank with a liquefied gas having the features of claim 1 and by a vehicle having the features of claim 8.

[0008] Advantageous embodiments of the invention are the subject of the subclaims.

[0009] A method for refueling a tank with a liquefied gas, for example, LNG or hydrogen, is proposed. According to the invention, the temperature of a seal on a tank nozzle of the tank and / or its surroundings is monitored by means of at least one temperature sensor or an indirect temperature detection device. If necessary, the temperature of the seal and / or its surroundings is brought to an upper nominal temperature by a heater. If a required minimum operating temperature defined by a predetermined threshold is not reached, a refueling process is interrupted and continued when the predetermined threshold is reached.

[0010] In one embodiment, heating occurs during the refueling process and / or before the refueling process.

[0011] In one embodiment, a refueling process is started or continued when the temperature is greater than or equal to the predetermined threshold value, wherein otherwise the refueling process is interrupted or the start of the refueling process is prevented and the seal and / or its surroundings are heated by means of the heater in order to bring the temperature to an upper nominal temperature which is greater than the predetermined threshold value, wherein, if the temperature is greater than or equal to the upper nominal temperature, the heater is switched off until the temperature falls below the predetermined threshold value.

[0012] In one embodiment, the temperature is measured before the start of a refueling process or is determined indirectly.

[0013] In one embodiment, the temperature is measured continuously or randomly or determined indirectly.

[0014] In one embodiment, the method is carried out in a vehicle, wherein the measured or indirectly determined temperatures and heating processes are logged and stored in the vehicle and / or in a backend connected to the vehicle.

[0015] In one embodiment, the end of the service life of the seal is determined in the vehicle and / or in the backend based on the temperature changes, their duration and a thermal load profile and signaled by an error code that is output via an interface, for example to recommend a replacement of the seal to a driver or a workshop.

[0016] According to one aspect of the present invention, a vehicle with a drive system for operation with liquefied gas and a tank for liquefied gas is proposed, wherein the tank has a tank nozzle provided with at least one seal. According to the invention, a heater for heating the seal and / or its surroundings, at least one temperature sensor for monitoring a temperature of the seal and / or its surroundings, and a control unit configured to carry out the method described above are provided.

[0017] The solution according to the invention enables an increase in operational reliability, an increase in the service life of the seal and an increase in the availability of refueling processes.

[0018] Embodiments of the invention are explained in more detail below with reference to a drawing.

[0019] It shows: Fig. 1 a schematic view of a temperature profile of a seal and / or its environment over time during a process for refueling a tank with a liquefied gas.

[0020] The only Fig. 1 is a schematic view of a temperature T of a seal and / or its environment versus time t during a process for refueling a tank with a liquefied gas, for example hydrogen or methane.

[0021] The tank may be part of a vehicle having a propulsion system powered by the liquefied gas, optionally after evaporation of the liquefied gas.

[0022] The tank has a tank nozzle provided with at least one seal. The seal and / or its surroundings can be heated by means of a heater, for example an electric heater. Furthermore, at least one temperature sensor is provided for monitoring a temperature T of the seal and / or its surroundings.

[0023] In a method according to the invention, a temperature T of the seal and / or its environment is monitored by means of the temperature sensor or temperature observer.

[0024] Optionally, the temperature T can be measured or determined before the start of the refueling process and then measured or determined continuously or randomly.

[0025] It is checked whether the temperature T is less than a given threshold T SW or as an upper nominal temperature T ON which is greater than the specified threshold T SWIn this case, the seal and / or its surroundings can be heated by means of the heater to bring the temperature T to the upper nominal temperature T ON If heating does not reach the specified threshold T SW the refueling process can be interrupted or the start of the refueling process can be prevented. If the specified threshold value T SW is reached or exceeded, for example due to heating, then the refueling process can be started or continued. In particular, when the upper nominal temperature T ON the heating is switched off until the specified threshold T SW is exceeded.

[0026] The measured / determined temperatures T and heating processes can be logged and stored in the vehicle and / or in a backend connected to the vehicle.

[0027] In the vehicle and / or in the backend, the end of the seal's service life can be determined based on the temperature changes, their duration and a thermal load profile and signaled by an error code that can be issued to a driver and / or a workshop so that the seal can be replaced. List of reference symbols t time T Temperature T ON upper nominal temperature T SW Threshold Daimler Truck AG

Claims

[1] Method for filling a tank with a liquefied gas, characterized by that a temperature (T) of a seal on a tank nozzle of the tank and / or its surroundings is monitored or otherwise determined by means of at least one sensor, wherein the temperature (T) of the seal and / or its surroundings is heated, if necessary, to an upper nominal temperature (T ON ), whereby if a signal is detected by a predetermined threshold value (T SW ) required minimum operating temperature is not reached, a refueling process is interrupted and when the specified threshold value (T SW ) continues. [2] Method according to claim 1, characterized by that heating takes place during the refueling process and / or before the refueling process. [3] Method according to claim 1 or 2, characterized bythat a refueling process is started or continued when the temperature (T) is greater than or equal to the specified threshold value (T SW ), otherwise the refuelling process is interrupted or the start of the refuelling process is prevented and the seal and / or its surroundings are heated by means of the heater in order to reduce the temperature (T) to an upper nominal temperature (T ON ) that are greater than the specified threshold (T SW ), where if the temperature (T) is greater than or equal to the upper nominal temperature (T ON ), the heating is switched off until the specified threshold (T SW ) is exceeded. [4] Method according to one of the preceding claims, characterized by that the temperature (T) is measured or determined indirectly before the start of a refueling process. [5] Method according to one of the preceding claims, characterized bythat the temperature (T) is measured continuously or randomly or determined indirectly. [6] Method according to one of the preceding claims, characterized by that the method is carried out in a vehicle, wherein the measured temperatures (T) and heating processes are logged and stored in the vehicle and / or in a backend connected to the vehicle. [7] Method according to claim 6, characterized by that in the vehicle and / or in the backend, the end of the service life of the seal is determined based on the temperature changes, their duration and a thermal load profile and signaled by an error code that is output via an interface in order to recommend a replacement of the seal. [8] A vehicle with a propulsion system for operation with liquefied gas and a tank for liquefied gas, the tank having a tank nozzle provided with at least one seal, characterized bya heater for heating the seal and / or its surroundings, at least one temperature sensor for monitoring a temperature (T) of the seal and / or its surroundings and a control device configured to carry out the method according to one of the preceding claims.

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