Method for operating a tank system, and control unit

Abstract

The invention relates to a method for operating a mobile tank system (1) for a fuel gas, in particular for hydrogen or natural gas, comprising: at least one pressurised gas vessel (2) in which the fuel gas is stored under pressure; and a control unit (3) by means of which sensor data from at least one sensor (4) installed in the tank system (1) are read out and evaluated. According to the invention, during phases in which the tank system (1) is not in operation, the control unit (3) is activated intermittently via an implemented wake-up function and is used to perform a leak test. The invention also relates to a control unit (3) for a mobile fuel-gas tank system (1).

Description

[0001] R.415613

[0002] - 1 -

[0003] Description

[0004] Method for operating a tank system and control unit

[0005] The invention relates to a method for operating a tank system for a fuel gas, in particular for hydrogen or natural gas. The tank system comprises at least one pressurized gas container in which the fuel gas is stored under high pressure, and a control unit for controlling the withdrawal of fuel gas from the at least one pressurized gas container.

[0006] Preferred areas of application are mobile applications, in particular fuel cell vehicles or vehicles with a gas engine.

[0007] State of the art

[0008] In mobile applications, the required fuel gas must be carried by the vehicles. For this purpose, the fuel gas is stored under high pressure in one or more tanks. Large commercial vehicles, such as trucks, trains, or ships, often have more than two tanks. This allows for flexible and space-saving placement of the tanks within the vehicle and also increases the vehicle's range. These multiple tanks or pressurized gas containers, along with other components, form a fuel system.

[0009] The other components may include, in particular, valves for extracting fuel gas from the pressurized gas cylinders and / or for filling the pressurized gas cylinders with fuel gas. With multiple pressurized gas cylinders, extraction and / or filling can be carried out via a central distribution system. Furthermore, sensors, especially temperature, pressure, and / or gas sensors, are usually provided to monitor the processes. Such a tank system is typically controlled by an R.415613.

[0010] - 2 -

[0011] Control unit. In particular, the control unit can be used to control the valves and / or read the sensors.

[0012] During vehicle operation, the fuel system is monitored for leaks using existing sensors, such as a fuel gas concentration sensor. The leak can be either external or internal. The sensors are installed in the vehicle and transmit their information to the control unit. If a leak is detected, the driver / owner is notified so they can stop the vehicle or take countermeasures.

[0013] The present invention is concerned with the objective of enabling the detection of an external or internal leakage of fuel gas in a fuel gas tank system of a vehicle that is temporarily switched off or parked.

[0014] To solve the problem, the method with the features of claim 1 is proposed. Advantageous embodiments of the invention are described in the dependent claims. Furthermore, a control unit for a mobile fuel gas tank system is proposed.

[0015] Disclosure of the invention

[0016] A method for operating a mobile tank system for a fuel gas, in particular for hydrogen or natural gas, is proposed, comprising at least one pressurized gas container in which the fuel gas is stored under pressure, and a control unit with which sensor data from at least one sensor installed in the tank system is read and evaluated. According to the invention, during phases in which the tank system is out of operation, the control unit is temporarily activated via an implemented wake-up function and used to perform a leak test.

[0017] Using the proposed method, any external or internal leaks can be detected even when the tank system is out of service, for example, when the vehicle is parked or switched off. This increases the operational safety of the tank system. In the event of a leak, fuel gas escapes, which—especially if the fuel gas is hydrogen (R.415613)—can cause serious contamination.

[0018] - 3 - acts - in combination with oxygen, it can form an explosive gas mixture. Early detection of a leak therefore helps to prevent the formation of an explosive gas mixture.

[0019] Preferably, the control unit is activated cyclically via the implemented wake-up function. This cyclical activation ensures that any leaks are detected even during extended periods when the tank system is out of service. Since these periods can vary in length and duration, the cycle duration is preferably adjustable. Advantageously, the cycle duration is set based on the vehicle's standstill time.

[0020] Activating the control unit using the wake-up function at variably predefined intervals ensures early detection of any leakage when the vehicle is parked, as the intervals can be chosen to be sufficiently short.

[0021] According to a preferred embodiment of the invention, for leak detection, the sensor data from at least one sensor installed in the tank system, in particular a concentration sensor, a pressure sensor, and / or a temperature sensor, are read and evaluated by the control unit. The concentration sensor detects the concentration of a specific gas, for example, hydrogen, in the tank system. For this purpose, the concentration sensor can be integrated into a gas line of the tank system. In this way, internal leaks, for example, due to leaking shut-off valves, can be detected using the concentration sensor. If the sensor data from a pressure and / or temperature sensor is read and evaluated for leak detection, these sensors can be integrated into the pressure gas container(s).A change in pressure and / or temperature within the pressurized gas container during a period when the tank system is out of service also indicates a leak. The leak could be a faulty tank valve or a leaking container itself, thus enabling the detection of both internal and external leaks. For example, the container leak could be due to a faulty end cap, which is typically located at the end of the pressurized gas container opposite the tank valve. R.415613.

[0022] - 4 -

[0023] Preferably, when an external or internal leak is detected by the control unit, a corresponding message is transmitted to a warning system. The vehicle user or operator can then be directly informed of the detected leak via the warning system, enabling them to take countermeasures and / or alternative measures. This is particularly important if the leak prevents the commissioning and thus the further operation of the fuel system, resulting in vehicle downtime. In this case, a replacement vehicle can be arranged in a timely manner.

[0024] The warning system can include a communication interface for communicating with an external server, to which the message about a detected leak is then transmitted. In this way, for example, a transport company can be informed early about a vehicle breakdown and take appropriate countermeasures. For example, a repair order can be placed, a replacement vehicle ordered, or a ventilation system activated. Alternatively or additionally, it is proposed that the warning system have a web application through which the message can be forwarded to a mobile device of the vehicle user or operator.

[0025] Furthermore, the notification of a leak detection is preferably displayed via the warning system. The warning system can include a display device, such as a screen or a display. This display device can warn people in the vicinity of the mobile tank system or the vehicle.

[0026] If a leak is detected, the control unit will preferably block the tank system from being started. This measure further increases operational safety.

[0027] Furthermore, a control unit for a mobile fuel gas tank system is proposed, wherein the control unit is configured to execute process steps of a method according to the invention. Preferably, a wake-up function is implemented in the control unit, by means of which the control unit can be activated when the tank system is out of operation. Furthermore, preferably, with the aid of R.415613

[0028] - 5 -

[0029] A leakage test can be performed by the control unit by reading and evaluating sensor data from at least one sensor installed in the tank system.

[0030] A preferred embodiment of the invention is explained in more detail below with reference to the accompanying drawings. These show:

[0031] Fig. 1 shows a schematic representation of a fuel gas tank system and

[0032] Fig. 2 is a flowchart illustrating a preferred process flow.

[0033] Detailed description of the drawings

[0034] Figure 1 shows a mobile fuel gas tank system 1 with two cylindrical pressure gas containers for a fuel gas, in this case hydrogen (H2). Each pressure gas container 2 is connected to a distribution block 9 via a tank valve 8 and a gas line 11. Fuel gas or hydrogen is drawn from the pressure gas containers 2, and the containers 2 are refueled, via this distribution block. The tank valves 8 are connected to a control unit s via control lines 12. Several valves 4 are integrated into each pressure gas container 2, each comprising a pressure sensor 6 and several temperature sensors 7. The type, number, and position of the sensors 4 shown in Figure 1 are for illustrative purposes only. Concentration sensors 5 are also provided. A first concentration sensor 5 is integrated into a gas line 11 that leads from the distribution block 9 to a pressure regulator 10 with an upstream valve 14.A second concentration sensor 5 is arranged in a gas line 11, through which fuel gas or hydrogen can be supplied to the pressurized gas containers 2 during refueling. The tank system 1 has a tank connection 13 for refueling.

[0035] The mobile tank system 1 shown can be the tank system of a fuel cell vehicle powered by flammable gas or the tank system of a vehicle with a gas engine. Since flammable gas, especially hydrogen, can form an explosive gas mixture with oxygen, the tightness of the tank system is continuously monitored during operation. The various sensors 4 can be used individually or in combination for this monitoring. The sensor data can be read and evaluated using the control unit 3. R.415613

[0036] - 6 -

[0037] When the vehicle or tank system 1 is switched off, monitoring is not normally carried out, as the tank system 1, including its components, is out of service. However, a leak can still occur even when the vehicle is switched off, and this will only be detected when the tank system is restarted. This can pose a safety risk.

[0038] To increase operational reliability, the method according to the invention is proposed. A preferred execution of the method is explained below by way of example with reference to Figure 2.

[0039] When a vehicle 1, which has a fuel system 1 as shown in Figure 1, is switched off, the state of the fuel system 1 is first determined in step S1. In step S2, a wake-up time for the control unit 3 is then set during the shutdown phase. In step S3, it is accepted that the control unit 3 "goes to sleep". In step S4, the control unit 3 is then woken up at the previously set wake-up time, and in step S5, a leakage test is then carried out using the control unit 3. If the test reveals that a leak has occurred (",,+"), measures are taken against it in step S6, for example, blocking the restart of the fuel system 1 or the vehicle. In a further step S7, a corresponding message is also transmitted to a warning system 15, which indicates the detection of a leak centrally and / or decentrally, for example, via a mobile device 16 of the driver.The test in step S5 shows that there is no leakage. In step S8, the state of tank system 1 is determined again in order to return to step S2 and set another wake-up time for control unit 3. Steps S3 to S5 are then repeated until the shutdown phase is complete.

Claims

R.415613 - 7 - Claims 1. Method for operating a mobile tank system (1) for a fuel gas, in particular for hydrogen or natural gas, comprising at least one pressure gas container (2) in which the fuel gas is stored under pressure, and a control unit (3) with the aid of which sensor data from at least one sensor (4) installed in the tank system (1) are read and evaluated, characterized in that in phases in which the tank system (1) is out of operation, the control unit (3) is temporarily activated via an implemented wake-up function and used to carry out a leakage test.

2. Method according to claim 1, characterized in that the control unit (3) is cyclically activated via the implemented wake-up function, wherein the cycle duration is preferably variably adjustable.

3. Method according to claim 1 or 2, characterized in that, for leak testing, the sensor data of at least one sensor (4) installed in the tank system (1), in particular a concentration sensor (5), a pressure sensor (6) and / or a temperature sensor (7), are read out and evaluated using the control unit (3).

4. Method according to one of the preceding claims, characterized in that, upon detection of an external or internal leakage, a corresponding message is transmitted to a warning system (15) using the control unit (3), preferably the message being displayed via the warning system (15).

5. Method according to one of the preceding claims, characterized in that, upon detection of a leak by the control unit (3), commissioning of the tank system (1) is blocked. R.415613 - 8 - 6. Control unit (3) for a mobile fuel gas tank system (1), wherein the control unit (3) is configured to perform process steps of a method according to one of the preceding claims.

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