DE10201930A1 - Parallel hybrid motor vehicle has combined combustion engine and fuel cell system with a common fuel tank - Google Patents

Abstract

The motor vehicle comprises a combustion engine (1) driving one axle (14.1) and an electric motor (3) powered by a fuel cell (2) and driving a second axle (14.2). Both the fuel cell and combustion engine are connected to a common fuel tank.

Description

The invention relates to a vehicle with an internal combustion engine and an electric machine according to the preamble of Patent claim 1.

From DE 39 40 172 is a generic vehicle with two Axes known. On the one axis acts to drive a Internal combustion engine. The other axis is using a electric motor driven. The vehicle becomes alternative only with the internal combustion engine or only with the electric Motor operated.

From EP 1 038 713 A2 is a vehicle with a Internal combustion engine and an electric motor known, wherein the electric motor of a fuel cell system with Energy is supplied. The internal combustion engine and the electric motor are connected to a common drive train coupled.

The invention is based on the object, a flexible to create an operable hybrid vehicle.

This task is performed by a vehicle with the characteristics of Patent claim 1 solved.

A fuel cell system faces energy storage an alternative to the power supply of an electrical Machine and thus indirectly to drive a vehicle axle While energy storage typically by means of in electrical energy converted rotational energy of the Internal combustion engine can be charged, the electric Machine thanks to the fuel cell system independent of the Internal combustion engine can be used.

Is hydrogen as a fuel for both the Internal combustion engine as well as for the fuel cell system used, the emission of pollutants can be low hold.

Further advantages and embodiments of the invention will be apparent the further claims and the description.

The invention is described below with reference to drawings described. Show it:

Fig. 1 is a schematic representation of a preferred embodiment of a vehicle according to the invention,

Fig. 2 is a schematic view of another preferred embodiment of a vehicle according to the invention with an additional electric machine,

Fig. 3 is a schematic diagram of a supply of oxygen-rich gas for a vehicle according to the invention,

Fig. 4 is a schematic diagram of a cooling circuit of a vehicle according to the invention and

Fig. 5 is a schematic representation of another preferred embodiment of a vehicle according to the invention with a further electric machine.

FIG. 1 shows a vehicle according to the invention with an internal combustion engine 1 and an electric machine 3 . The internal combustion engine 1 is connected via a gear 5 and a shaft 13 with an axle 6 . The transmission 5 is usually associated with a clutch, not shown. The axle drive 6 usually includes an axle drive, not shown, and an axle differential (not shown). The axle 6 is connected via an axle 14.1 with two wheels 8.1 and 8.2 . The internal combustion engine 1 can thus drive the wheels 8.1 and 8.2 via the transmission 5 , the shaft 13 , the axle gear 6 and the axle 14.1 .

The electric machine 3 is connected via a shaft 12 with a further axle drive 7 . Between the electric machine 3 and the axle 7 , a further not shown gear and / or a clutch, not shown, may be provided. Also, the axle drive 7 typically includes a final drive, not shown, and an axle differential, not shown. The axle drive 7 is connected via a further axle 14.2 with two further wheels 8.3 and 8.4 . The electric machine 3 can therefore be used as an electric motor for driving the axle 14.2 or the wheels 8.3 and 8.4 .

The axle 14.1 is preferably a front axle, while the axle 14.2 is preferably a rear axle. However, it is also possible to use the axle 14.1 as the rear axle and the axle 14.2 as the front axle.

The electric machine 3 is supplied with electrical energy, for example in the form of power or current, via an electrical line 11 from a fuel cell system 2 . In the fuel cell system 2 , electric energy and heat energy are generated by means of a fuel cell unit (not shown) made of hydrogen or hydrogen-rich gas and oxygen or oxygen-rich gas. The fuel cell unit may comprise, for example, PEM fuel cells or also SOFC fuel cells. An optionally integrated in the vehicle energy storage 9 can also be powered by the fuel cell system 2 via an electrical line 15 with electrical energy. The energy store 9 can be designed, for example, as an accumulator or as a supercapacitor. The electric machine 3 can also draw electrical energy from the energy store 9 via an electrical line 21 . If the electric machine 3 is operated as a generator, for example during the braking process, electrical energy can be fed into the energy store 9 via the line 21 . This is commonly referred to as recuperation. If the fuel cell system 2 is operated, for example, during or before starting with an excess of hydrogen-rich gas or hydrogen, the energy generated in this way can be stored as electrical energy in the energy store 9 .

The fuel cell system 2 can be used to supply additional electrical consumers, for example a vehicle electrical system, an air conditioning system, an electrohydraulic brake. The fuel cell system 2 can also be used to supply electric components of the internal combustion engine, for example an electromagnetic valve controller, with electrical energy.

The fuel cell system 2 and the internal combustion engine 1 can be supplied with the same fuel. Advantageously, hydrogen-rich gas or hydrogen is used as the fuel. By using hydrogen or hydrogen-rich as fuel pollutant emissions can be kept low. The hydrogen or the hydrogen-rich gas is stored, preferably in liquid form, in a fuel tank 4 and fed via a supply line 22 into the internal combustion engine and via a supply line 23 into the fuel cell system 2 . The fuel tank 4 is usually formed as a double-walled steel tank in which the hydrogen is stored cryogenically, that is cryogenic and liquid. Other combustible cryogenic fuels, such as liquid natural gas, may alternatively be employed as fuel and in and stored in the fuel tank 4 . Unillustrated safety valves provide for excessively high pressure for a controlled venting. When using hydrogen as fuel, the internal combustion engine 1 usually has additional injection valves, not shown, for the hydrogen. Combustion generally takes place with excess air. The additional air in the combustion chamber of the internal combustion engine 1 reduces the flame temperature. This leads to a reduced formation of nitrogen oxides. The lines for the supply of oxygen-rich gas or air are not shown for simplicity.

The hydrogen-rich gas required as fuel can also with the help of a gas generating unit in the vehicle from a appropriate medium, such as methanol, gasoline, Diesel, natural gas, be generated.

The vehicle 1 has a control and evaluation unit 10 , which is preferably integrated in a control unit, not shown. The functionalities of the control and evaluation unit 10 can also be distributed to a plurality of control and evaluation units or control units. The control and evaluation unit 10 are transmitted via lines, usually signal lines, information about operating conditions, operating parameters, characteristics of vehicle components or vehicle systems. The information may, for example, be in the form of measured values that are determined with the aid of sensors that are assigned to the vehicle components. The control and evaluation unit 10 receives information about the fuel tank 4 (eg fill level, temperature, pressure) via the line 20, information about the electrical machine 3 (eg speed, torque, direction of rotation) via the line 17 , information about the fuel cell system (eg output power, output current, temperature, hydrogen mass flow, mass flow of oxygen-rich gas) via the line 16, information about the energy store 9 (eg state of charge, discharge state, temperature) via the line 19 and over the Line 18 Information about the internal combustion engine (eg., Speed, exhaust gas composition, air mass flow, hydrogen mass flow) supplied.

Preferably, the control and evaluation unit 10 additionally receives information about the driver's desired driving operation or the driving request. For example, the control and evaluation unit 10 receives information about the accelerator pedal position and / or accelerator pedal movement.

From this information, the control and evaluation unit 10 can determine the optimum mode of operation of the components, for example the internal combustion engine 1 , the fuel cell system 2 , the electric machine 3 and the energy store 9 . The determination is preferably carried out as a function of the driving request. Here, the efficiencies of the components internal combustion engine 1 , fuel cell system 2 , electrical machine 3 and energy storage 9 are preferably taken into account. The control and evaluation unit 10 can generate actuating signals or controlled variables for the respective components. Via the line 16 , the control and evaluation unit 10 transmits, for example, a power setpoint to the fuel cell system 2 . Via the line 17 , the control and evaluation unit 10 outputs, for example, a desired speed and / or a desired operating state (motor or generator) to the electric machine 3 . Via the line 18 , the control and evaluation unit 10 transmits, for example, a Ventilansteuersignal to the internal combustion engine. 1 Via the line 19 , the control and evaluation unit 10 gives the energy storage device 9, for example, an operating state (charging or discharging). The specification of the control signals or controlled variables can also be done via additional lines not shown.

Depending on requirements, the vehicle can either be driven only by the internal combustion engine 1 or only by the electric machine 3 . In addition, the vehicle can also be simultaneously driven by the internal combustion engine 1 and the electric machine 3 (four-wheel drive). If the vehicle is still in the starting phase and the warming up of the fuel cell system has not yet been completed, then operation with only the internal combustion engine 1 is advantageous. A combination of engine 1 and fuel cell system 2 facilitates cold start and freezer capability of the vehicle. Alternatively, the electric machine 3 can also be supplied with energy from the energy store 9 . Through the use of multiple drive systems, namely the internal combustion engine 1 and the electric motor 3 , which can be powered by the fuel cell system 2 and / or the energy storage 9 with energy, redundancy and emergency running properties of the vehicle are ensured and increases the life of the vehicle.

Depending on the state of the energy store 9 and the fuel cell system 2 , the electric machine 3 can be supplied with electrical energy either from the fuel cell system 2 or from the energy store 9 or from the fuel cell system 2 and the energy store 9 . If the charging or discharging state has reached or fallen below a lower limit value, the energy store 9 is charged by the fuel cell system 2 . If the vehicle is braked via the wheels 8.3 and 8.4 of the axle 14 , the electric machine 3 can be operated as a generator and the electrical energy generated by the generator can be stored in the energy store 9 .

In a further preferred embodiment, the electric machine 3 is coupled to the internal combustion engine 1 via an additional shaft (not shown ) .

In FIG. 2, another preferred embodiment is shown of a vehicle according to the invention. The same reference numerals as in Fig. 1 indicate the same. Components. In contrast to the embodiment shown in FIG. 1, the vehicle shown in FIG. 2 has a further electric machine 24 . The electric machine 24 is connected via a shaft 25 to the internal combustion engine 1 and via the shaft 13 to the axle 6 . Between engine 1 and electric machine 24 or between axle 6 and electric machine 24 can each be arranged in Fig. 2 not shown gear. These transmissions, not shown, can each be assigned a clutch. The electrical machine 24 can be supplied with electrical energy from the fuel cell system 2 via an electrical line 26 . Via an electrical line 27 , the electric machine can draw electrical energy from the energy storage 9 . The control and evaluation unit 10 receives information about the operating state or parameters of the electric machine 24 via a line 28 , preferably a signal line. Depending on the information which the control and evaluation unit 10 receives via the electric machine 24 , the control and evaluation unit 10 determines actuating signals or controlled variables for the electric machine 24 , that of the electric machine 24 via the line 28 and / or an additional not shown line to be transmitted. The control signals or controlled variables are preferably dependent on the states of the other vehicle components, in particular the internal combustion engine 1 , the fuel cell system 2 , the electric machine 3 and the energy storage device 9 and / or the driving request or by the accelerator pedal position / movement.

The electric machine 24 can be used in engine operation for starting the internal combustion engine 1 . During engine operation, the electric machine 24 can also be used for additional drive of the shaft 13 while the internal combustion engine 1 is running (boosting). The electrical machine 24 can also be used as a generator to convert, for example, braking energy and / or supplied by the engine kinetic energy into electrical energy and to feed in a not shown electrical system with consumers and / or the energy storage 9 via the line 27 . In the electrical system, not shown, further energy storage, not shown, may be included.

In Fig. 3, a preferred embodiment of the supply of the internal combustion engine 1 and the fuel cell system 2 is shown with oxygen-rich gas or air. Advantageously, the internal combustion engine 1 and the fuel cell system 2 is associated with a common air supply line 30 which divides into the air supply lines 31 and 32 . The air supply line 31 serves to supply air or oxygen-rich gas to the internal combustion engine 1 . The air supply line 31 is a first actuator 29 , preferably a valve, for. B. a timing valve assigned. The air supply line 32 is associated with a second actuator 29 . The metering quantity or the air mass flow can be controlled via the actuators 29 . The actuators 29 preferably receive their specifications from the control and evaluation unit 10 . The actuators 29 may also receive specifications from another control and evaluation unit, not shown. The specifications can be made of the driving request, z. B. the accelerator pedal position, movement, be dependent on the state of the battery 9 , operating conditions and operating parameters of the fuel cell system 2 and the internal combustion engine 1 . Advantageously, in the air supply lines 31 and 32 downstream of the actuators 29 each a sensor unit, not shown, which measures the metered quantity or the air mass flow and preferably the control and evaluation unit 10 is available, so that a regulation of the metering or the air mass flow possible is.

In addition, compressors may be arranged in the supply lines 30 , 31 and 32 . If z. Example, as a fuel cell system 2, a fuel cell system used, the air supply is carried out under high pressure by means of a compressor, not shown, the compressor can also be used, for example, as a turbocharger, for the air supply of the internal combustion engine. The compressor will then advantageously be placed in line 30 .

Is it in the used fuel cell system to a low-pressure system so can a not shown Compressor can be used as a fan.

In FIG. 4, a common cooling circuit for the internal combustion engine 1 and the fuel cell system 2 is schematically illustrated. The vehicle has a cooling unit 33 , which is usually associated with a fan 34 . Via the line 37 , the coolant to the internal combustion engine 1 and the fuel cell system 2 is passed . The line 37 divides into the lines 38 and 39 . Via a line 41 , the coolant dissipates the heat energy of the internal combustion engine 1 . The heat energy of the fuel cell system 2 is dissipated via a line 42 . Via a line 40 can advantageously coolant, which has been heated by the released heat energy of the fuel cell system, are fed from line 42 into line 39 and used for cooling / heating of the internal combustion engine 1 . The lines 41 and 42 combine to line 43 , in which the coolant is supplied to the cooling unit 33 again. In line 43 , a pump 35 is arranged to convey the coolant. In the lines 38 , 39 , 40 , 41 and 42 actuators 36 , preferably valves, for example, timing valves, arranged for coolant metering. Depending on the temperature or cooling demand of the internal combustion engine 1 and the fuel cell system 2 or less coolant of the internal combustion engine 1 and / or the fuel cell system can be made available 2 so via the activation of which is arranged in the lines 38 and 39, actuators 36 more.

The fuel cell system 2 and the internal combustion engine 1 can be cooled either in parallel or in series or individually. In a serial cooling arranged in the line 39 actuator 36 is closed and there is only a cooling of the fuel cell system 2 and then via the line 40, a cooling of the internal combustion engine 1 when the arranged in the line 40 actuator 36 is opened.

If the arrangement of the internal combustion engine 1 and of the fuel cell system 2 in the cooling circuit is reversed, cooling of the internal combustion engine 1 and then cooling of the fuel cell system 2 take place in the case of serial cooling. If only the internal combustion engine 1 is cooled, then the actuator 36 , which is located in the line 38 , closed. If, however, only the fuel cell system 2 is cooled, then the actuator 36 , which is located in the line 39 is closed.

The coolant has an initial temperature T ₀ when exiting the cooler. When leaving the internal combustion engine 1 , the coolant has the temperature T ₁ and at the outlet from the fuel cell system 2 , the coolant has the temperature T ₂ . When coolant is supplied to the internal combustion engine 1 , the coolant can thus, depending on the state of the actuators 36 arranged in the lines 39 and 40 , have the temperatures T ₀ , T ₁ , or a temperature T which lies between the temperatures T ₀ and T ₁ . The recirculated in the conduit 43 has coolant, depending on the position of the arranged in the lines 41 and 42 actuators 36, the temperature T ₁ , the temperature T ₂ or a temperature T, which is between the temperatures T ₁ and T ₂ .

The control of the actuators 36 is preferably carried out by the control and evaluation unit 10 , but can also be done by another control and evaluation unit, not shown. The control is preferably carried out as a function of the operating conditions or operating parameters of the fuel cell system 2 and the internal combustion engine 1 , from the coolant temperatures T ₀ , T ₁ , T ₂ , and / or the driving request (accelerator pedal position and / or accelerator pedal movement).

In a common cooling circuit for internal combustion engine 1 and fuel cell system 2 less cooling power is required than when the fuel cell system 2 is assigned a separate cooling circuit. Advantageously, a shutdown system (internal combustion engine 1 or fuel cell system 2 ) can be heated by the waste heat of the other system. As a result, freezer capability and cold start capability of the fuel cell system 2 can be increased.

In the cooling circuit, further components can be advantageously integrated, such as the energy storage 9 , the electric machines 3 , 24 , 44th

In a further embodiment, the internal combustion engine 1 and the fuel cell system have a common Abgasabführleitung or a common exhaust system. Advantageously, the exhaust system is associated with an exhaust gas purification unit.

In order to keep the lines for the supply of the oxygen-rich gas, for the coolant, and for the exhaust gas removal as short as possible, the fuel cell system 2 and the internal combustion engine 1 are arranged as close to each other in the vehicle.

In FIG. 5, a further preferred embodiment is shown of a vehicle according to the invention. The same reference numerals as in FIGS. 1-4 designate the same components. In contrast to the embodiments illustrated in FIGS. 1 and 2, the embodiment illustrated in FIG. 5 has one or more further electrical machines 44 , which are preferably linear motors. The linear motors 44 are operatively connected to pistons, not shown, of the internal combustion engine 1 , wherein preferably a so-called Stelzer engine is used as the internal combustion engine 1 , as it is also known from DE 30 29 287 C2. The Stelzer engine is usually characterized by piston extended beyond the cylinder space. The Stelzer engine housing typically has two combustion chambers and two precompression chambers where the piston reciprocates and clears and closes inlet and outlet slots and overflow channels. The Stelzer engine is characterized by simplicity and hardly any wearing parts that make a long operating function possible without maintenance. Instead of the Stelzer engine and a corresponding 4-stroke engine can be used.

If the linear motors 44 are operated as generators, then they convert the kinetic energy of the pistons, not shown, of the internal combustion engine 1 or of the Stelzer engine into electrical energy. For example, when starting the internal combustion engine 1 piston movements can be brought about by the linear motors 44 , ie an additional starter or starter is not needed. Alternatively, the piston movement can also be effected mechanically, for example by means of a corresponding lever mechanism. By the same or an additional mechanical lever mechanism not shown valves or injectors of the internal combustion engine 1 can be controlled.

Linear motors are due to their simple structure very robust and hardly susceptible to interference, since mechanical transmission elements, such as gear and linkage, are not needed. Because of the non-contact power transmission, the transferable forces are not limited by the static friction. Therefore, a wear and maintenance-free operation is possible (basics of electrical machines, H. Eckhardt, Teubner study books electrical engineering / mechanical engineering, Stuttgart 1982 ).

The use of the linear motors 44 in combination with a Stelzer engine as the internal combustion engine 1 can lead to a reduction in the total weight of the vehicle, since components such as crankshaft, transmission (including clutch or converter), propeller shaft can be saved. In addition, the robustness and maintenance requirements are decreasing.

The linear motors 44 are connected via one or more lines 51 to the control and evaluation unit 10 .

Advantageously, the control and evaluation unit 10 evaluates operating parameters / characteristics of the linear motors 44 , which are determined, for example, by calculation and / or measurement, and controls the linear electric motors 44 via the lines 51 and / or via further lines, not shown. The control of the linear motors 44 advantageously takes place as a function of the driving requirement, the operating states or operating parameters of the further electrical consumers and components, such as the electric drive motors 3 and 24 , and the electric energy storage. 9 Alternatively, it is also possible to use an additional control and evaluation unit (not shown) for controlling the linear motors 44 .

The valves or injection nozzles, not shown, can be electrically controlled, as for example in the case of the electromagnetic valve control. The electrical energy required for the control can be supplied, for example, from the fuel cell system 2 , from the electrical energy store 9 and / or from one of the vehicle-mounted electrical machines 3 , 24 , 44 , which is operated as a generator. From which component the electrical energy is ultimately delivered depends on the operating state or on the operating parameters of the respective component. The operating states or operating parameters are preferably evaluated by the control and evaluation unit 10 or by an alternative control unit. Likewise, the control of the components or valves and / or the piston movement takes place via the control and evaluation unit 10 or via an alternative control unit. The electrical machines 3 , 24 , 44 , the energy storage 9 and the fuel cell system 2 are advantageously connected via lines 46 , 47 , 48 , 49 , 50 to a power bus 45 . The power bus 45 serves to transport electrical energy that can be supplied and accessed by the components connected to the power bus 45 .

Claims (10)

1. vehicle with an internal combustion engine ( 1 ) and an electric machine ( 2 ), wherein the internal combustion engine ( 1 ) for driving a first axis ( 14.1 ) and the electric machine ( 3 ) for driving a second axis ( 14.2 ) is provided thereby in that the electric machine ( 3 ) for energy supply is assigned a fuel cell system ( 2 ), and in that the internal combustion engine ( 1 ) and the fuel cell system ( 2 ) are connected to a common fuel tank ( 4 ). 2. Vehicle according to claim 1, characterized in that the fuel tank ( 4 ) contains a hydrogen-rich gas and / or a combustible Kryokraftstoff. 3. Vehicle according to claim 1, characterized in that the internal combustion engine ( 1 ) and the fuel cell system ( 2 ) have a common cooling. 4. Vehicle according to claim 1, characterized in that the internal combustion engine ( 1 ) and the fuel cell system ( 2 ) have a common supply ( 30 ) of oxygen-rich gas. 5. Vehicle according to claim 1, characterized in that the internal combustion engine ( 1 ) and the fuel cell system ( 2 ) have a common exhaust system. 6. Vehicle according to claim 1, characterized in that the fuel cell system ( 2 ) is used to supply energy to other electrical consumers. 7. Vehicle according to claim 1, characterized in that the internal combustion engine ( 1 ) is associated with an electric machine ( 44 ) which converts the piston movement of the internal combustion engine ( 1 ) directly into electrical energy. 8. Vehicle according to claim 7, characterized in that the internal combustion engine ( 1 ) is a so-called Stelzer engine or a corresponding 4-stroke engine. 9. Vehicle according to claim 7, characterized in that the electrical machine ( 44 ) is a linear motor. 10. Vehicle according to claim 1, characterized in that an evaluation and control unit ( 10 ) is provided, the control of operating conditions of the internal combustion engine ( 1 ) and the fuel cell system ( 2 ) in dependence on operating parameters and / or parameters and / or measured values serves.