Fuel cell system for a vehicle

Abstract

Hydrogen-powered fuel cell system (1) comprising at least one fuel cell (B) for a vehicle, comprising a water tank (3) for storing the water produced by the fuel cell process, wherein the system (1) is provided with a de-icing device and / or a de-icing arrangement for the water of the water tank (3), wherein the de-icing device and / or de-icing arrangement is designed to prevent the water in the water tank (3) from freezing, and wherein in the de-icing arrangement the water tank (3) or a part of the tank (3) is arranged near the fuel cell (B) so that thermal coupling takes place between the water tank (3) and the fuel cell (B), characterized by the fact that the water tank is designed in two parts and has a main tank (3a) and a heat coupling tank (3b), wherein the heat coupling tank (3b) surrounds the fuel cell (B) and forms a water jacket.

Description

[0001] The invention relates to a hydrogen-powered fuel cell system for a vehicle, with a water tank that is provided for storing the water produced by the fuel cell process.

[0002] In very cold weather, the water produced by the fuel cell process in fuel cell vehicles causes problems. If this water is simply directed onto the road, it can freeze and become a hazard to others.

[0003] Document US 2006 / 0 068 240 A1 describes a vehicle that has a water tank as a buffer to prevent the unintentional release of water onto the roadway.

[0004] US Patent 9,054,354 B2 discloses a fuel cell-powered vehicle with an automatic water tank emptying system. This water tank collects the water produced during the fuel cell process. A common valve device, similar to a dispensing nozzle, is provided for automatically emptying the water tank during hydrogen refueling. This device has a first valve for the hydrogen, which is connected to a hydrogen tank via a hose. A second valve on the dispensing device allows for the emptying of the water tank. This second valve is connected to the water tank via a second hose. A sensor detects the hydrogen supply and automatically controls the water valve. The water tank is emptied by a pumping system.

[0005] US Standard 2008 / 0299432A1 describes how oxygen and drinking water can be supplied to an aircraft using a fuel cell. Oxygen is necessary at high altitudes. The drinking water can be used for the toilets and galley, as well as for a drinking water dispenser. The water produced during the fuel cell process is stored in a water tank. This saves weight during takeoff and subsequent flight operations. The water tank is connected to a heat exchanger via a condenser. The heat exchanger cools the fuel cell and heats the water in the tank. An additional heat exchanger prevents the water tank from freezing.

[0006] US Patent 7,040,430 B2 concerns a vehicle with a mobile living unit that incorporates a fuel cell. The water produced by the fuel cell is treated in a condenser and stored in a tank. This allows the water to be used for heating a kitchen or bathroom, or as drinking water.

[0007] From DE 603 ​​03 684 T2, a fuel cell arrangement for a vehicle is known in which a water storage tank is provided for humidifying the oxygen supplied to the fuel cell stack and for storing the water produced by the fuel cell stack. The fuel cell stack is cooled by means of a cooling circuit containing an antifreeze solution. The cooling circuit also passes by the water storage tank and can thus thaw the water in the tank at temperatures below freezing.

[0008] From DE 200 10 497 U1 a water storage tank for a fuel cell system is provided, which can be electrically heated as frost protection.

[0009] From EP 1 520 312 B1 a water storage tank for a fuel cell system is also known, which can be electrically heated as frost protection, with a special, energy-saving heating strategy being proposed.

[0010] From DE 603 ​​20 229 T2, a fuel cell system for a vehicle is known, in which an inner water tank is arranged within an inner container or vessel that also houses the fuel cell stack, and an outer water tank are provided. Both tanks can be heated as needed. In the inner tank, the water is protected from freezing by continuous heating, even during periods of inactivity, while in the outer tank, freezing of the water is intentionally accepted, with the water in the outer tank being thawed upon restarting. These two antifreeze measures are activated alternately by a control system depending on the specific situation.

[0011] From DE 10 2006 002 470 A1 it is known to use the water obtained from a fuel cell system in a vehicle for drinking water purposes.

[0012] The invention is based on the objective of improving a hydrogen-powered fuel cell system so that it is suitable for use even in very cold weather with minimal effort.

[0013] This problem is solved by a system with the features of claim 1.

[0014] Advantageous embodiments of the invention are described in the dependent patent claims.

[0015] The solution according to the invention ensures that the vehicle's water tank, which acts as a storage and buffer, remains operational even at very low temperatures. Freezing of the water in the tank would prevent further travel, as emptying the tank in a frozen state would be impossible. Furthermore, there is a risk of damage to the water tank from the expanding ice.

[0016] The solution according to the invention allows the water to be kept liquid in winter, even if the vehicle is parked for a certain period of time. This can be achieved by automatic intermediate operation of the cell, by electric heating and / or by suitable thermal insulation of the water tank.

[0017] In an advantageous embodiment of the solution according to the invention, the water tank is coupled to or equipped with a drinking water treatment device. This is advantageous because bacteria can multiply rapidly during water storage, particularly at temperatures between 30° and 50°C. These bacteria can be eliminated or rendered harmless by a drinking water treatment device. The drinking water treatment device need not be limited to disinfection. It can also aim to improve the taste or reduce other substances, such as chemical compounds, as is possible, for example, with an activated carbon filter.

[0018] In the system according to the invention, the water tank, or part of the tank, is arranged near the fuel cell in the defrosting arrangement, so that thermal coupling occurs between the water tank and the fuel cell. This provides simple yet effective protection against icing. The tank can be in two parts, with one part enclosing the cell. A passive heat exchanger made of metal or a paste, or an active heat exchanger with a coolant and pump, can readily be used.

[0019] To achieve independence from battery operation, in another advantageous embodiment of the system the defrosting device is designed as an electric heating device. Battery operation also prevents the water in the tank from freezing when the vehicle is parked.

[0020] Another preferred solution is characterized in that the drinking water treatment device comprises a disinfection filter, an activated carbon filter, and / or a UV disinfection lamp, wherein the drinking water treatment device is preferably coupled to the de-icing device and / or the de-icing assembly or provided with an additional de-icing device. Suitable disinfection filters include known ceramic filters or other filters with a pore size capable of effectively filtering out bacteria. Additionally or alternatively, a suitable UV lamp can be used that can render even the smallest viruses harmless.

[0021] In another advantageous embodiment of the solution according to the invention, the drinking water treatment device is connected to an electric water pump. This allows the water to be conveniently forced through the filter by the pump, after which it can be drunk directly.

[0022] A very simple yet extremely effective measure for maintaining temperature is to insulate the water tank. The insulation can be created using suitable plastic materials, air gaps or a vacuum, or other insulating substances.

[0023] Furthermore, it is advantageous if the water tank is connected to an automatic emptying device designed to automatically empty at least part of the water tank during hydrogen refueling. The user then does not need to worry about emptying the water tank. An electric water pump and / or an electric valve are advantageous for this purpose.

[0024] It is very convenient if the emptying device is connected to a common tank head or nozzle for simultaneous hydrogen refueling and emptying of the water tank. The water tank is then automatically emptied during refueling.

[0025] Exemplary embodiments of the system according to the invention are described below with reference to the drawings.

[0026] They show: Fig. 1 a schematic representation of a fuel cell system according to the invention for a vehicle with automatic water tank emptying, Fig. 2 a schematic representation of the fuel cell system according to the invention with a two-part water tank, and Fig. 3 a further schematic representation of the fuel cell system according to the invention with drinking water treatment.

[0027] Fig. Figure 1 shows a fuel cell system 1 for a vehicle. This can be a car, truck, bus, motorhome, or similar vehicle. The fuel cell system 1 comprises a fuel cell B, which is operated with hydrogen (H2) in a known manner and releases water (H2O) and oxygen (O2) as condensed water during the cell process. The cell B generates electricity, among other things, to power an electric motor.

[0028] The vehicle can be refueled at a hydrogen station. The hydrogen for operating cell B is stored in hydrogen tank 2 within the vehicle. Also located in the vehicle is a water tank 3 for the water supplied by cell B. Water tank 3 is connected to cell B via line 4. Hydrogen tank 2 is connected to cell B via line 5. The water tank is connected to line 6 for emptying.

[0029] This hydrogen-powered fuel cell system, thanks to the water tank designed to store the water produced by the fuel cell process, prevents the water from being released onto the road or street and thus avoids ice formation at temperatures below 0°C.

[0030] How Fig. As illustrated in Figure 1, the water tank 3 in the exemplary embodiment is thermally coupled to cell B. This coupling is illustrated by line 7. System 1 is equipped with a de-icing device and / or de-icing arrangement for the water in water tank 3, the de-icing device and / or de-icing arrangement being designed to prevent the water in water tank 3 from freezing.

[0031] In the defrosting arrangement, water tank 3, or part of the tank, is located near fuel cell B. This allows for thermal coupling between water tank 3 and fuel cell B. A dual-tank solution is described below using the following example: Fig. 2 discussed.

[0032] The defrosting device is designed as an electric heating device 8, as further explained below. Fig. 3 will be explained in more detail.

[0033] Fig. Figure 1 shows that the water tank 3 is connected to an automatic emptying device. The water tank 3 is connected to a head 9 via line 6. The hydrogen tank 2 is also connected to this head 9 via line 10 for refueling. The automatic emptying device uses a sensor, e.g., a flow sensor, which sends a signal as soon as hydrogen refueling takes place. This signal activates a pump and / or a valve 20 (not shown). Fig. 3) controlled for the water, so that water tank 3 can be emptied simultaneously during hydrogen refueling. Thus, system 1 is designed in such a way that it automatically empties the water tank, at least partially, during hydrogen refueling. The in Fig. The emptying device shown in Figure 1 is therefore equipped with a common tank head or tank nozzle 9 for receiving a fuel nozzle for simultaneous hydrogen refueling and emptying of the water tank.

[0034] Based on the Fig. Section 2 now explains in more detail a possible thermal coupling between the water tank 3 and the fuel cell B. The water tank 3 is essentially two-part and comprises a main tank 3a and a thermal coupling device or thermal coupling tank 3b. A water pipe arrangement or similar can be used instead of tank 3b. The thermal coupling tank 3b surrounds the fuel cell B and forms a water jacket. The inner wall of tank 3b can be the outer wall of cell B. The thermal coupling tank 3b and cell B are provided with common insulation 11 to store the thermal energy of tank 3b. Tank 3b is connected to the main tank 3a by pipes 12 and 13, which form a water circuit. The main tank 3a is also thermally enclosed by further insulation 14. To prevent overheating of cell B in summer, it is equipped with an active cooling system comprising cooling circuit pipes 15 and 16.

[0035] System 1 further includes a drinking water treatment system 17. The drinking water treatment system 17 is best described by the Fig. 3 described. Fig. Figure 3 also shows the tank head 9. Fig. Figure 3 shows the water valve 20, which is controlled by a control unit 19 for the automatic emptying of the water tank during hydrogen refueling. The electric heating device 8 is controlled by an anti-icing control unit 18.

[0036] The drinking water treatment device includes a disinfection filter 21, which is designed as a ceramic filter 21 with a carbon filter. Alternatively, a UV light disinfection lamp can be used. A pump 22 provides the filter pressure. The drinking water treatment device is therefore connected to an electric water pump 22.

[0037] To prevent filter 21 from freezing in winter, the drinking water treatment device can be coupled with the de-icing device and / or the de-icing arrangement, or equipped with an additional de-icing device (not shown). This may include a further electric heating device.

[0038] The in Fig. The water drainage device shown in Figure 3 includes an electric water pump (not shown) and an electric valve 20.

[0039] Water tank 3 should be sized to account for the fact that 1 kg of hydrogen per 100 km yields 9 kg of water per 100 km. The water tank should be approximately 20% (10% - 30%) larger than necessary to provide a water reserve. A tank size of 50 liters, or 30 to 80 liters, is sufficient for most passenger car applications. Therefore, the volume of the water tank is larger than the volume of water produced by a hydrogen fill-up.

[0040] Water purification is very useful in summer and offers advantages for camping. The collected water can be used for camping cooking, washing, or similar purposes.

[0041] Other heat coupling systems connecting water tank 3 to cell B can also be used. For example, Peltier elements can be employed, which can be powered by the current from cell B. This cools cell B.

[0042] The invention is not limited to a vehicle powered by fuel cells. It can, for example, also be applied to a motorhome with an internal combustion engine, where only the power supply to the motorhome is provided by system 1.

[0043] The described water management system can also be combined with direct water discharge onto the road. During rain and temperatures above freezing, the condensed water from cell B can be safely discharged onto the road. This also allows for the integration of additional sensors such as temperature sensors, rain sensors, or similar devices.

[0044] System 1 can include one or more fuel cells B. Reference symbol list 1 Fuel cell system 2 hydrogen tanks 3 water tanks 4 first line 5 second line 6 third line 7 Thermal coupling 8 Heating device 9 Tank head / tank neck 10 fourth line 11 first isolation 12 fifth line 13 sixth line 14 second isolation 15 seventh line 16 eighth line 17 Drinking water treatment (-device) 18 Anti-Ice Control 19 Control unit 20 valve 21 filters 22 Pump

Claims

[1] Hydrogen-powered fuel cell system (1) comprising at least one fuel cell (B) for a vehicle, comprising a water tank (3) for storing the water produced by the fuel cell process, wherein the system (1) is provided with a de-icing device and / or a de-icing arrangement for the water of the water tank (3), wherein the de-icing device and / or de-icing arrangement is designed to prevent the water in the water tank (3) from freezing, and wherein in the de-icing arrangement the water tank (3) or a part of the tank (3) is arranged near the fuel cell (B) so that thermal coupling takes place between the water tank (3) and the fuel cell (B), characterized by , that the water tank is designed in two parts and has a main tank (3a) and a heat coupling tank (3b), wherein the heat coupling tank (3b) surrounds the fuel cell (B) and forms a water jacket. [2] Fuel cell system according to claim 1, characterized by that the water tank (3) is coupled to or equipped with a drinking water treatment device (17). [3] Fuel cell system according to claim 1 or 2, characterized by , that the de-icing device is designed as an electric heating device (8). [4] Device according to claim 2 or 3, characterized by , that the drinking water treatment device (17) comprises a disinfection filter (21), a carbon filter and / or a UV disinfection lamp, wherein the drinking water treatment device (17) is preferably coupled with the de-icing device and / or the de-icing arrangement or is provided with an additional de-icing device. [5] Device according to claim 4, characterized by that the drinking water treatment device (17) is connected to an electric water pump (22). [6] Device according to any one of the preceding claims, characterized by , that the water tank (3) is provided with at least one layer of thermal insulation (11, 14). [7] Device according to any one of the preceding claims, characterized by , that the water tank (3) is connected to an automatic emptying device designed to automatically empty the water tank at least partially when refueling with hydrogen. [8] Device according to claim 7, characterized by , that the draining device includes an electric water pump and / or an electric valve (20). [9] Device according to one of the preceding claims 7 or 8, characterized by, that the emptying device is connected to a common tank head (9) or tank nozzle for simultaneous hydrogen refueling and emptying of the water tank (3).

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