DE102016217743A1 - Hybrid system for an internal combustion engine - Google Patents

Abstract

Hybrid system (1) for an internal combustion engine (110), in particular for an internal combustion engine (110) of a vehicle. The hybrid system (1) includes a waste heat recovery system (100) and a recuperation system (120). The waste heat recovery system (100) comprises a circulation medium (100a) carrying a working medium. The circuit (100a) comprises, in the direction of flow of the working medium, a feed fluid pump (102), an evaporator (103), an expansion machine (104) and a condenser (105). The expansion machine (104) is mechanically connected to a generator (106). The recuperation system (120) has an electrical machine (122). The electric machine (122) can be connected to a crankshaft (121) of the internal combustion engine (110) by means of a transmission element (123). The generator (106) and the electric machine (122) are electrically connected to a common energy store (10), preferably a 48V battery. The waste heat recovery system (100) and the recuperation system (120) have common control logic.

Description

The present invention relates to a hybrid system for an internal combustion engine, in particular for an internal combustion engine for a vehicle, for the efficient use of energy.

State of the art

Vehicles with an internal combustion engine or an internal combustion engine can be equipped with a recuperation system which, in conjunction with an electrical accumulator (battery), allows recovery of excess kinetic energy. For this purpose, an electric machine is operated as a generator when operating the brake pedal, so that kinetic energy of the vehicle is converted into electrical energy and stored in the battery. Such Rekuperationssystem is from the published patent application
DE 10 2012 208 845 A1 known.

Furthermore, waste heat recovery systems for internal combustion engines are known from the prior art, for example from the published patent application DE 10 2014 218 485 A1 ,

Both recuperation system and waste heat recovery system are the subject of constant development to increase the efficiency and thus ultimately to reduce the fuel consumption of the internal combustion engine, especially when used in vehicles.

Disclosure of the invention

The hybrid system according to the invention for an internal combustion engine, in particular for an internal combustion engine of a vehicle, has the advantage that it uses actual energy losses of the internal combustion engine particularly efficiently. In this case, a waste heat recovery system and a recuperation system are brought together, whereby synergies used, components saved and parameters for the common control or regulation are combined advantageously.

For this purpose, the hybrid system comprises a waste heat recovery system and a recuperation system. The waste heat recovery system comprises a Clausius Rankine cycle leading to a working medium with an expansion machine. The expansion machine is mechanically connected to a generator. The recuperation system has an electric machine. The electric machine is connected by means of a transmission element with an output of the internal combustion engine, for example with a crankshaft. The generator and the electric machine are electrically connected to a common energy storage, preferably a 48V battery. Preferably, the Rankine cycle in the flow direction of the working medium comprises a feed fluid pump, an evaporator, an expansion machine and a condenser.

The energy storage is thus - depending on the operating points of the internal combustion engine and the hybrid system - charged both via the waste heat recovery system and the recuperation system. Accordingly, the energy storage device can also provide electrical energy for a relatively long period of time for various consumers, but in particular for the internal combustion engine.

Advantageously, the waste heat recovery system and the recuperation system have a common control logic. The common control logic of the waste heat recovery system and recuperation system results in improved control algorithms for both systems. For example, the state of charge of the energy store can thus be used for controlling or regulating both systems. Likewise, the energy states of the two systems can be coordinated. In addition, an energy demand for various consumers can be determined. So it can be tuned with the energy demand energy supply. Ideally, the energy is provided very efficiently over the shortest possible efficiency chain.

In advantageous embodiments, communicating control units, preferably a common control unit, regulate the waste heat recovery system and the recuperation system by means of the common control logic. The hybrid system is thus component-saving controlled by only one control unit, which includes the common control logic of the two systems or generated from this control logic drive signal for both systems. Alternatively, several communicating ECUs can be used for this purpose. By using only one controller or multiple communicating controllers, synergies and algorithms can be used for the control logic that take into account interactions between the waste heat recovery system and the recuperation system, thereby creating synergies in the hybrid system. The control logic is preferably subdivided such that an energy storage manager for the state of charge of the energy storage device handles relevant input and output data and that a waste heat recovery coordinator handles the data relevant to the control of the waste heat recovery system. The energy storage manager preferably takes into account the range of services and the demand for power as well as the charging states of the battery Energy storage and optional further energy storage in the vehicle.

Advantageously, the electric machine with respect to the internal combustion engine is operable both as a generator and as a motor. When the electric machine is running as an engine, for example, the electric machine supplies the crankshaft of the internal combustion engine with an additional torque, which ultimately is also obtained from the waste heat recovery system. If the electric machine runs as a generator, it acts as an engine brake, ie as a brake for the internal combustion engine, by applying torque to the crankshaft, which counteracts the torque of the internal combustion engine. In this regenerative state, the electric machine feeds energy into the energy store.

By sharing the energy storage with superordinate control logic, the energy efficiency of the two systems waste heat recovery system and recuperation system is optimized. As a result, the fuel consumption of the internal combustion engine is ultimately reduced. In this case, actual energy losses of the internal combustion engine, such as heat energy of the exhaust gas and braking energy of the wheels of a vehicle, used to provide them to the energy storage available.

Advantageously, the energy store serves as an intermediate buffer to enable energy flow optimization between the waste heat recovery system and the recuperation system. Through the storage capacity of the energy storage, energy supply and energy demand can be coordinated with each other in a proactive way.

In advantageous developments, additional consumers are attached to the energy store besides the internal combustion engine, for example a vehicle electrical system of a vehicle. This opens up the possibility of providing the required energy more efficiently, in the best case fuel neutral. As a result, components which today have the task of providing electrical energy from fuel, for example an alternator, can be relieved or even eliminated.

If the waste heat recovery system supplies the electric machine with drive power via the energy store, which is coupled into the output of the internal combustion engine as additional torque, then there is direct electrical utilization of the hybrid system. As a result, the hybrid system can be operated as an electric transmission between the waste heat recovery system and the recuperation system; In the corresponding operating states, an additional torque is thus coupled indirectly from the waste heat recovery system in the output of the internal combustion engine. This operation is advantageous if currently no indirect use of electrical energy is possible and an assistance of the internal combustion engine from an energy point of view seems more useful than a storage of energy in the energy storage.

If the waste heat recovery system supplies further electric consumers of the vehicle with electrical energy without intermediate storage in the energy store, then there is indirect electrical use of the hybrid system. Furthermore, there is an indirect use when the available energy is cached in an energy storage.

An exclusively indirect electrical utilization of the power output by the waste heat recovery system or by the recuperation system alone would not be energy efficient without the merger into a hybrid system described here due to the high output power of the waste heat recovery system or the recuperation system in relation to the energy requirements of today's vehicle electrical systems. Only the combination of the two systems to the hybrid system opens up the possibility to release the generated energy again by choosing between direct and indirect use as needed. The efficiency of the two individual systems is thus improved only by the summary of the hybrid system.

Furthermore, opens up the possibility of significantly more auxiliary consumers to electrify than currently possible, for example, a water pump, a compressor, an air compressor, a steering assistance, or other comfort functions due to the increased energy through the waste heat recovery system in the electrical system of the vehicle. In particular, it should be noted that the waste heat recovery system provides the additional electrical energy fuel neutral, as it is based on the waste heat of the internal combustion engine, ie a loss energy. Although an alternator or the electric machine would also be able to apply the additional energy for electrified secondary consumers, but this would increase the additional load of the alternator fuel consumption and the system efficiency would be worse due to the longer loss chain.

In further embodiments, the evaporator of the waste heat recovery system is arranged in an exhaust pipe of the internal combustion engine. As a result, the heat energy of the exhaust gas of the internal combustion engine with the lowest possible Transmission losses fed into the cycle of the waste heat recovery system.

In advantageous developments, an exhaust gas bypass is connected in parallel to the evaporator in the exhaust pipe. An exhaust bypass door is disposed in the exhaust passage and divides the exhaust gas mass flow of the internal combustion engine into the evaporator and the exhaust gas bypass. Thereby, overheating of the cycle of the waste heat recovery system can be prevented. Preferably, the exhaust gas bypass valve can divide the exhaust gas mass flow proportionally. A complete closing of the entrances in the evaporator or in the exhaust gas bypass is possible.

In advantageous uses, the hybrid systems described above are used in vehicles. In particular, the synergy effects through the common control logic lead to fuel savings, which is very advantageous, especially in mobile applications. By increasing the efficiency of the internal combustion engine and pollutants are reduced, for example, the CO ₂ emissions is reduced.

In further applications, the energy storage of the hybrid system is connected to other consumers of the vehicle, for example with an electrical system, preferably via a DC-DC converter. As a result, auxiliary consumers in the vehicle, such as car radio, low beam, etc., can be supplied with electrical energy via the hybrid system.

In the following, methods according to the invention for operating the above-described hybrid system are set forth:
For this purpose, the hybrid system has a control logic which regulates both the recuperation system and the waste heat recovery system. In a method according to the invention, the control logic implements an energy flow optimization between the waste heat recovery system, the recuperation system and an energy requirement of the vehicle. By synergistic effects already described above, for example, the energy requirements of other auxiliary consumers of the vehicle can ideally be operated fuel neutral.

In an advantageous development, the control logic determines a state of charge of the energy store, an energy requirement of the vehicle and an energy supply of the hybrid system. The state of charge is a central variable for controlling the hybrid system, which is optimized with knowledge of energy supply and energy demand or energy demand. The state of charge determines, especially for the comparatively slow waste heat recovery system, the regulation or control of the components and serves as an intermediate buffer to compensate for short-term fluctuations in energy supply and / or energy demand.

In an advantageous embodiment of the method, the control unit or the control logic determines a maximum permitted output power of the generator as a function of the state of charge, the energy supply and the energy requirement. As a result, an overload of the energy storage is prevented.

In advantageous developments, the control unit or the control logic for determining the change in the state of charge takes into account the future energy requirement of the vehicle, in particular of secondary consumers. Preferably, the control logic can control or regulate the operation of the auxiliary consumers. Such auxiliary consumers may be, for example: a vehicle electrical system, a water pump, an air-conditioning compressor, a steering assistance, a compressor or comfort functions of a vehicle. As a result, the control unit can control the waste heat recovery system and its components as well as the secondary consumers in a predictive manner, which is particularly advantageous because the waste heat recovery system reacts relatively slowly. Preferably, the energy storage manager actively controls the auxiliary consumers according to the energy supply of the hybrid system.

In advantageous embodiments, the control logic predicts the development of the waste heat of the internal combustion engine and the development of the energy requirement of the secondary consumers. As a result, future energy supply and future energy demand can be better calculated. This allows a more efficient regulation between energy supply and energy demand.

In advantageous embodiments, the waste heat recovery system has a parallel to the expansion machine switched bypass line. A bypass valve divides the mass flow of the working medium into the expansion machine and into the bypass line. The bypass valve can also completely prevent the inflow of the working medium in the expansion machine or in the bypass line. When the maximum output power is exceeded, the control unit controls the bypass valve in such a way that the mass flow of the working medium into the expansion machine is reduced. As a result, the rotational energy supplied to the generator also decreases, so that the output of the waste heat recovery system is reduced. An overload of the energy storage is thus avoided.

In advantageous embodiments, the waste heat recovery system has a parallel to the evaporator connected exhaust gas bypass. An exhaust bypass door divides the exhaust gas mass flow of the internal combustion engine into the evaporator and into the exhaust gas bypass. The exhaust gas bypass flap can also completely prevent the inflow of the exhaust gas into the evaporator or into the exhaust gas bypass. When the maximum output power is exceeded, the control unit controls the exhaust gas bypass flap in such a way that the mass flow of the exhaust gas into the evaporator is reduced. As a result, the heat energy provided to the circuit also decreases, so that the output of the waste heat recovery system is reduced. An overload of the energy storage is thus avoided.

Brief description of the drawings

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Show it:

1 1 schematically shows a hybrid system for an internal combustion engine of a vehicle, wherein only the essential areas are shown,

2 schematically a hybrid system with control unit and control signals,

3 schematically a control logic of a hybrid system with input and output signals.

Embodiments of the invention

1 shows a schematic hybrid system 1 for an internal combustion engine 110 a vehicle, with only the essential areas are shown. The hybrid system 1 includes a waste heat recovery system 100 and a recuperation system 120 , The internal combustion engine 110 gets oxygen through an air supply 112 supplied; the exhaust gas emitted after the combustion process is passed through an exhaust pipe 111 from the internal combustion engine 110 dissipated.

The internal combustion engine 110 is about a clutch 119 mechanically separable with a gearbox 115 connected to the vehicle. The gear 115 includes several courses 116 that can be selected during operation of the vehicle. The gears determine a gear ratio. About the drive shaft and the wheels 117 This is done by the internal combustion engine 110 generated torque transferred to the road.

The waste heat recovery system 100 has a working medium leading Clausius Rankine cycle 100a on, in the flow direction of the working medium, a feed fluid pump 102 , an evaporator 103 , an expansion machine 104 and a capacitor 105 includes. Parallel to the expansion machine 104 is a bypass line 108a with a bypass valve 108 switched, so that the working medium operating point-dependent by the expansion machine 104 guided or at this by the bypass line 108a can be bypassed. The working medium can continue as needed via a spur line from a sump 101 and a valve unit 101 in the cycle 100a be fed. The collection container 101 can alternatively also into the cycle 100a to be involved.

The evaporator 103 is to the exhaust pipe 111 the internal combustion engine 110 connected, so uses the heat energy of the exhaust gas of the internal combustion engine 110 , Parallel to the evaporator 103 is an exhaust gas bypass 113 switched, with an exhaust bypass door 114 so in the exhaust pipe 111 is arranged that the exhaust gas mass flow to the evaporator 103 and on the exhaust bypass 113 can be divided as required. This allows the circulation 100a For example, be protected from overheating.

The expansion machine 104 is via an output shaft 104a with a generator 106 connected, so that in the expansion machine 104 generated rotational energy is converted into electrical energy. The expansion machine 104 may for example be a turbine, and in the execution of 1 are the expansion machine 104 , the bypass valve 108 , the output shaft 104a and the generator 106 to a turbine-generator unit 107 summarized. In further education can between the expansion machine 104 and the generator 106 also be a gearbox interposed.

The operation of the waste heat recovery system 100 is as follows:
Liquid working fluid is passed through the feed fluid pump 102 , if necessary, from the collection container 101 , in the evaporator 103 promoted and there by the heat energy of the exhaust gas of the internal combustion engine 110 evaporated. The vaporized working medium is then in the turbine or expansion machine 104 while giving mechanical energy to the generator 106 relaxed. Subsequently, the working medium in the condenser 105 liquefied again and in the collection container 101 returned or the feed fluid pump 102 fed.

The recuperation system 120 the internal combustion engine 110 includes an electric machine 122 and a transmission element 123 , The electric machine 122 can be operated both as a generator and as a motor. The electric machine 122 , For example, a claw-pole machine, is on the mechanical transmission element 123 , For example, a belt drive, with a crankshaft 121 the internal combustion engine 110 connected. Alternatively, any mechanical connection between the internal combustion engine would be 110 and the electric machine 122 possible. Here is the arrangement of the transmission element 123 also between the internal combustion engine 110 and the transmission 115 possible.

The internal combustion engine 110 is a heat engine that converts the chemical energy of a fuel into mechanical work through combustion. The combustion takes place in a combustion chamber in which a mixture of fuel and ambient air is ignited. The thermal expansion of the hot gas is used to move a piston.

The recuperation system 120 recovers kinetic energy as electric energy when braking. This is achieved as a rule by the fact that the electric machine 122 is operated as a generator (regenerative). Due to the mechanical power consumption of the electric machine 122 becomes a braking effect transmitted through the crankshaft 121 , while at the same time recovering electrical energy.

The output or the crankshaft 121 the internal combustion engine 110 can from the electric machine 122 both accelerated and braked, depending on whether the electric machine 122 is operated as a generator or motor. This is the electrical machine 122 with an electrical energy storage 10 , such as a 48V battery. The electric machine 122 is thus capable of reducing the speed of the crankshaft 121 both in regenerative mode to reduce as well as to increase in engine operation.

The energy storage 10 serves both for driving the electric machine 122 as well as for storing electrical energy from the electric machine 122 is produced. In addition, the energy storage 10 via a DC / DC converter (DC-DC converter) 20 with a wiring system 30 , For example, a 12V or 24V electrical system, be connected to a starter battery and other electrical consumers. The optional DC / DC converter 20 of the hybrid system 1 is used for the waste heat recovery system 100 provided electric power for the conventional auxiliary consumers, such as 24V secondary consumers, to provide what the electric machine 122 relieved. Optionally, 48V high-power consumers can also be used directly via the waste heat recovery system 100 be supplied.

According to the invention, the energy storage 10 also with the generator 106 the waste heat recovery system 100 connected. The energy storage 10 So will energy from the waste heat recovery system 100 and from the recuperation system 120 fed.

The energy storage 10 of the hybrid system 1 is, in addition to the buffering of electrical energy from the Rekuperationsbetrieb the Rekuperationssystems 120 , also for temporary storage by the waste heat recovery system 100 generated electrical energy used when the condition of electrical system 30 , Hybrid system 1 and internal combustion engine 110 a direct coupling of the energy via the electric machine 122 in the crankshaft 121 or a use for secondary consumers such as the electrical system 30 does not allow. Will the energy from the energy storage 10 to the crankshaft 121 delivered, this is a direct electrical use. Will the energy to the electrical system 30 delivered, this is an indirect electrical use.

• – Gemeinsame Nutzung der elektrischen Maschine 122: über die elektrische Maschine 122 wird der Energiespeicher 10 elektrisch aufgeladen, wenn die elektrische Maschine 122 im Generatorbetrieb läuft. Läuft die elektrische Maschine 122 im Motorbetrieb, so wird der Kurbelwelle 121 Energie aus dem Energiespeicher 10 zugeführt. Der Energiespeicher 10 wird dabei betriebspunktabhängig sowohl von dem Generator 106 des Abwärmerückgewinnungssystems 100 als auch von der elektrischen Maschine 122 des Rekuperationssystems 120 mit Energie befüllt.
• – Gemeinsame Nutzung des Energiespeichers 10 als Zwischenspeicher; vorzugsweise ist der Zwischenspeicher 10 dabei als 48V-Batterie ausgeführt.
• – Gemeinsame Nutzung des DC/DC Wandlers 20 zur Versorgung von konventionellen Nebenverbrauchern, beispielsweise zur Versorgung des Bordnetzes 30 mit einer Spannung von 24V.
• – Möglichkeit zur Verwendung eines gemeinsamen Steuergeräts für das Abwärmerückgewinnungssystem 100 und das Rekuperationssystem 120.
• – Möglichkeit der Optimierung von Komponenten des Hybridsystems 1. Beispielsweise kann die elektrische Maschine 122 durch das Abwärmerückgewinnungssystem 100 entlastet und damit auch kleiner dimensioniert werden.

This allows the following advantages for the hybrid system 1 an internal combustion engine 110 for a vehicle, such as a passenger car or a lorry, achieve:

• - sharing the electric machine 122 : over the electric machine 122 becomes the energy store 10 electrically charged when the electric machine 122 in generator mode is running. Is the electric machine running? 122 in engine operation, so will the crankshaft 121 Energy from the energy storage 10 fed. The energy storage 10 becomes operating point dependent both from the generator 106 the waste heat recovery system 100 as well as from the electric machine 122 of the recuperation system 120 filled with energy.
• - Sharing the energy storage 10 as a cache; Preferably, the cache is 10 it is designed as a 48V battery.
• - Sharing the DC / DC converter 20 for the supply of conventional secondary consumers, for example for the supply of the electrical system 30 with a voltage of 24V.
• Possibility to use a common control unit for the waste heat recovery system 100 and the recuperation system 120 ,
• - Possibility of optimizing components of the hybrid system 1 , For example, the electric machine 122 through the waste heat recovery system 100 relieved and thus smaller dimensions.

Furthermore, there are the following advantages with regard to the electrical secondary consumers or the entire vehicle electrical system:
An indirect electrical use of the waste heat recovery system 100 output without the integration described here with the hybrid system 1 , due to the energy requirements of today's Bordnetze 30 high output of the waste heat recovery system 100 , not optimized. Only the combination of the two systems waste heat recovery system 100 and recuperation system 120 to the hybrid system 1 opens up the possibility to release the generated energy by choosing between direct and indirect use as needed.

Because of the waste heat recovery system 100 increased energy supply in the energy storage 10 and therefore also in the electrical system 30 opens up the possibility to electrify significantly more secondary consumers than is currently possible. Such auxiliary consumers may be, for example, a water pump, an air-conditioning compressor, a steering assistance, a compressor or comfort functions. In particular, it is important that the waste heat recovery system 100 the additional fuel energy fuel neutral provides, as they are from the waste heat of the engine or the internal combustion engine 110 is referred, so usually is completely loss energy.

The 2 shows a hybrid system 1 , like in the 1 described. In addition, however, now is the control of the hybrid system 1 outlined. For this purpose, the hybrid system has a control unit 50 on. The control unit 50 receives input signals from the internal combustion engine 110 , the generator 106 and the electric machine 122 , Preferably, the controller receives 50 even more signals, for example from in the circuit 100a arranged temperature and pressure sensors. For simplicity, the illustration refers to only one controller 50 , In principle, it is also possible to distribute the functionalities to several control units which communicate with one another.

The control unit 50 sends signals to the internal combustion engine 110 , the generator 106 , the electric machine 122 , the exhaust bypass door 114 , the bypass valve 108 , the feed pump 102 and the valve unit 101 , In addition, the control unit 50 Receive signals from other components or send signals to them, for example, the electrical system 30 with the control unit 50 and / or with the DC-DC converter 20 communicate.

The 3 shows schematically a control logic with input and output signals. In the execution of 3 is the control logic in a common controller 50 arranged, but could alternatively be distributed to several control units. The control unit 50 is part of a hybrid system 1 for an internal combustion engine 110 of a vehicle, as in 2 outlined. The control logic includes an energy storage manager 51 , a waste heat recovery coordinator 52 , a moment coordinator 53 and a vehicle coordinator 54 , Furthermore, the control logic comprises a generator controller 55 , a pump regulator 56 , a tank controller 57 and a safety controller 58 , However, this subdivision of the control logic on individual coordinators or controllers is to be understood in the software, physically the controller 50 form a unit.

The generator controller 55 controls or controls the generator 106 , Preferably via a speed control or speed control of the output shaft 104a , The pump regulator 56 controls or controls the feed fluid pump 102 with respect to the mass flow of the working medium; the regulation or control of the feed fluid pump 102 takes place advantageously as a pressure and / or temperature control or control of the working fluid in the circulation 100a between feed fluid pump 102 and capacitor 105 , For example, for sensor signals of a temperature sensor between evaporator 103 and expansion machine 104 be used. The tank controller 57 regulates or controls a pressure in the low-pressure area of the circuit 100a that is, between the expansion machine 104 and fluid pump 102 , This can be done, for example, by activating the valve unit 101 respectively. The safety controller 58 controls or controls the bypass valve 108 and the exhaust bypass door 114 , This will overheat the circuit 100a and / or damage to the expansion machine 104 avoided.

The energy storage manager 51 receives an actual charging signal 511 from the energy store 10 , The actual charging signal 511 indicates the state of charge of the energy store 10 , so for example a 48V battery, on. Optionally, the energy storage manager receives 51 another actual charging signal 515 from another energy storage 15 if the vehicle such a further energy storage 15 having. In addition, the energy storage manager receives 51 a demand signal 513 from secondary consumers, such as from the electrical system 30 , The demand signal 513 indicates the energy demand of the secondary consumers.

The energy storage manager 51 further receives an actual recovery power signal 61 and / or a prediction recovery power signal 62 from the waste heat recovery coordinator 52 , The actual recovery power signal 61 indicates the current performance in the expansion machine 104 is generated, or the generator 106 to the energy storage 10 supplies. The prediction recovery power signal 62 indicates a predicted performance in the expansion engine 104 will be generated, or the generator 106 to the energy storage 10 will deliver. The predicted performance can also be a predicted time course of a performance. The prediction can be arbitrarily complex; For example, sensor data of the internal combustion engine or a planned route profile can be used.

The energy storage manager 51 sends a limit power signal 63 to the waste heat recovery coordinator 52 , The limit power signal 63 indicates the maximum allowable power in the expansion machine 104 may be generated, or the generator 106 to the energy storage 10 may deliver, so a maximum allowable output power of the generator 106 , The limit power signal 63 can also specify a time course for the future maximum permitted output power. The energy storage manager 51 sends a charge state signal 64 to the moment coordinator 53 , The charge status signal 64 indicates the state of charge of the energy store 10 on, so in the energy storage 10 stored energy. Furthermore, the state of charge signal 64 also indicate how the change of state of charge is, so whether the energy storage 10 is being filled or emptied.

Optionally, the energy storage manager 51 also a pitcher signal 512 to the DC-DC converter 20 send. The energy storage 10 supplied or discharged from him energy can be subject to high fluctuations. Through the controller signal 512 can be the DC-DC converter 20 for example, the on-board network 30 change the voltage provided. This may be necessary, for example, when switching between the supply of different secondary consumers.

The waste heat recovery coordinator 52 sends the actual recovery power signal 61 and / or the prediction recovery power signal 62 to the energy storage manager 51 and receives the marginal power signal 63 from the energy storage manager 51 , Furthermore, the waste heat recovery coordinator receives 52 a motor data signal 65 from the vehicle coordinator 54 , The motor data signal 65 includes engine data of the internal combustion engine 110 , For example, a speed of the crankshaft 121 or a torque of the crankshaft 121 , The motor data signal 65 but can also exhaust gas data of the internal combustion engine 110 include, for example, an exhaust gas temperature or an exhaust gas mass flow passing through the exhaust pipe 111 flows. The motor data signal 65 may also include data of the vehicle thermo management, for example, a maximum cooling water temperature of the internal combustion engine 110 ,

The waste heat recovery coordinator 52 sends a speed signal 521 to the generator controller 55 , The speed signal 521 gives a target speed for the generator 106 at. As a result, for example, in the generator 106 generated electrical voltage can be controlled. The waste heat recovery coordinator 52 sends a reference signal 522 to the pump regulator 56 , The target signal 522 indicates a desired temperature or a desired pressure, in particular as the inlet temperature or inlet pressure of the working medium in the expansion machine 104 , The waste heat recovery coordinator 52 sends a pressure signal 523 to the tank controller 57 , The pressure signal 523 gives a set pressure for the low pressure area of the circuit 100a on, with this pressure, for example via the valve unit 100a can be regulated. The waste heat recovery coordinator 52 sends a limit signal 524 to the safety controller 58 , The limit signal 524 gives a maximum pressure or temperature of the working fluid in the circuit 100a , in particular between evaporators 103 and expansion machine 104 , at. The limit value signal is in the safety controller 58 further processed and for the control of the bypass valve 108 and the exhaust bypass door 114 used.

The vehicle coordinator 54 receives a driver signal 541 , The driver signal 541 includes data transmitted by the driver of the vehicle: for example, these are the accelerator pedal position, the brake pedal position or the gear selection for the transmission 115 of the vehicle. In the end, the driver wants to control the speed and acceleration of the vehicle, which physically requires torque or braking torques.

The vehicle coordinator 54 sends the motor data signal 65 with the operating data of the internal combustion engine 110 to the waste heat recovery coordinator 52 , Further sends the vehicle coordinator 54 a vehicle condition signal 66 and a desired torque signal 67 to the moment coordinator 53 , The vehicle condition signal 66 includes the state of motion of the vehicle, in particular with regard to acceleration or deceleration and thus also with respect to the torque of the crankshaft 121 , The nominal torque signal 67 includes a driver desired torque on the wheels 117 and thus maintaining or changing the torque of the crankshaft 121 ,

The moment coordinator 53 receives the vehicle condition signal 66 and the desired torque signal 67 from the vehicle coordinator 54 and the state of charge signal 64 from the energy storage manager 51 , The moment coordinator determines from this 53 a desired torque signal 531 which he attached to the internal combustion engine 110 sends, and a moment signal 532 which he connected to the electric machine 122 sends. The desired torque signal 531 gives the internal combustion engine 110 a target torque before, which they in the crankshaft 121 should feed. And the moment signal 532 gives the electric machine 122 another target torque before, which is the electric machine 122 in the crankshaft 121 should feed. The further target torque can be a crankshaft 121 accelerating (boosting) torque or the crankshaft 121 delayed (recuperation) torque.

This includes the moment signal 532 also an information, if the electric machine 122 should work as a generator or as a motor.

The common control logic for a waste heat recovery system 100 and a recuperation system 120 can work on multiple controllers 50 be distributed or alternatively in a control unit 50 be integrated. What matters is that information of the waste heat recovery system 100 and the recuperation system 120 run together and be shared.

• • Direkte elektrische Nutzung der gewonnenen Leistung aus dem Abwärmerückgewinnungssystem 100 im Antriebsstrang.
• • Indirekte elektrische Nutzung der gewonnenen Leistung aus dem Abwärmerückgewinnungssystem 100 durch Nebenverbraucher, beispielsweise durch das Bordnetz 30.
• • Indirekte elektrische Nutzung der gewonnenen Leistung bzw. Energie aus dem Abwärmerückgewinnungssystem 100 durch Zwischenspeicherung in dem Energiespeicher 10.

This common control logic allows not only the known functionalities of a recuperation system 120 - namely supply secondary consumers, energy storage 10 charge (recuperation) and torque in the crankshaft 121 feed (boost) -
further new additional functionalities:

• • Direct electrical use of the recovered power from the waste heat recovery system 100 in the drive train.
• • Indirect electrical utilization of the recovered power from the waste heat recovery system 100 by auxiliary consumers, for example by the electrical system 30 ,
• • Indirect electrical utilization of the recovered power or energy from the waste heat recovery system 100 by intermediate storage in the energy storage 10 ,

The waste heat recovery system 100 has a parent coordinator, the waste heat recovery coordinator 52 , which the waste heat recovery system 100 depending on the condition of the internal combustion engine 110 or the vehicle state controls. The waste heat recovery coordinator 52 is for it with the vehicle coordinator 54 connected and receives information about the current state of the internal combustion engine 110 , in particular engine torque and engine speed, as well as information about the current exhaust gas data, in particular exhaust gas temperatures and exhaust gas mass flow, which for thermal control / control of the waste heat recovery system 100 be used.

In addition, the vehicle coordinator has 54 about the possibility requirements to the waste heat recovery coordinator 52 to provide, from the thermal management of the vehicle or the internal combustion engine 110 result. For example, at high ambient temperature, the thermal performance of the waste heat recovery system 100 be reduced in order to relieve the vehicle cooling system and limit the use of the vehicle fan, which has a positive effect on the fuel demand due to the high power requirement of the vehicle fan.

• • Drehzahlregelung bzw. -steuerung durch den Generatorregler 55, die eine Kommunikationsschnittstelle zum Generator 106 hat, der mit der Expansionsmaschine 104 gekoppelt ist.
• • Hochdruck- und/oder Temperaturregelung bzw. -steuerung durch den Pumpenregler 56, die der Speisefluidpumpe 102 eine Drehzahl, einen Massen- oder einen Volumenstrom vorgibt, und damit den Hochdruck bzw. die Temperatur in Abhängigkeit der verfügbaren Abgasexergie regelt.
• • Niederdruckregelung bzw. -steuerung (optional) durch den Tankregler 57, welche über den Sammelbehälter 101 den Niederdruckbereich des Abwärmerückgewinnungssystems 100 zwecks Energieoptimierung führt.
• • Begrenzungs- bzw. Sicherheitsfunktionen durch den Sicherheitsregler 58, die über das Bypassventil 108 und/oder die Abgasbypassklappe 114 die Einhaltung der zulässigen Betriebsparameter des Kreislaufs 100a sicherstellen. Das Bypassventil 108 und die Abgasbypassklappe 114 und die zugehörige Ansteuerung können dabei beispielsweise als Proportionalventile ausgeführt sein.

The waste heat recovery coordinator 52 further determines the setpoint values for the lower-level control systems / controls of the waste heat recovery system 100 :

• • Speed control or control by the generator controller 55 , which is a communication interface to the generator 106 has that with the expansion machine 104 is coupled.
• • High pressure and / or temperature control by the pump regulator 56 that of the feed fluid pump 102 specifies a speed, a mass flow or a volume flow, and thus regulates the high pressure or the temperature as a function of the available exhaust gas energy.
• • Low pressure control (optional) through the tank controller 57 which over the collecting container 101 the low pressure area of the waste heat recovery system 100 for the purpose of optimizing energy.
• • Limiting or safety functions through the safety controller 58 passing the bypass valve 108 and / or the exhaust bypass door 114 compliance with the permissible operating parameters of the circuit 100a to ensure. The bypass valve 108 and the exhaust bypass door 114 and the associated control can be carried out for example as proportional valves.

The energy storage manager 51 controls the energy flows of the functions supply auxiliary consumers, recuperation and boosting. By integrating the waste heat recovery system 100 into the hybrid system 1 receives the energy storage manager 51 In addition, the functions described above for the direct and indirect use of the waste heat recovery system 100 gained power or energy. In particular, the energy storage manager 51 provided with the possibility to switch between direct and indirect electrical use as needed. Simultaneous direct and indirect use is also possible.

To the energy flows of the entire hybrid system 1 Optimal to control, has the waste heat recovery coordinator 52 also about the possibility of the energy storage manager 51 Information about the current and future electrical output of the waste heat recovery system 100 or of the generator 106 to provide. Conversely, the energy storage manager has 51 about possibility to the waste heat recovery coordinator 52 To convey information about the state of the electrical system, in particular the maximum permitted electrical output power of the generator 106 ,

The energy storage manager 51 has the possibility of the state of charge of any conventional batteries or other energy storage 15 of the vehicle and the energy storage 10 Among other things, these data are used to determine the performance of the waste heat recovery system 100 limit if, for example, the maximum state of charge of the batteries (energy storage 10 , another energy storage 15 etc.).

For the purpose of feedforward control or for reasons of stability of the electrical system 30 For high-energy consumers, the energy storage manager has 51 on the possibility of considering the current and / or future needs of secondary consumers.

The energy storage manager has direct electrical usage 51 (or optionally, the waste heat recovery coordinator 52 ) via an interface to the torque coordinator 53 , about the torque of the internal combustion engine 110 can be lowered if additional power by the electric machine 122 in the drive train or in the crankshaft 121 is coupled. Depending on the performance of the transmission element 123 this is necessary for reasons of driving comfort or for safety reasons.

The controller has an extended version 50 via prediction functions, which starting from the current operating point of the internal combustion engine 110 the development of the waste heat and thus the electrical output of the waste heat recovery system 100 predict. As described above, such information may be the energy storage manager 51 for energy flow optimization. Is the internal combustion engine 110 For example, in a high-load operating point, it is anticipated that the available waste heat output will increase. This information can be found in the Energy Storage Manager 51 purposefully used to anticipate the state of charge of the energy storage 10 lower capacity for the following thermal peak performance.

• – Erst durch die gemeinsame Steuerungslogik wird ein bedarfsgerechter Wechsel zwischen direkter und indirekter elektrischer Nutzung der Leistung aus dem Abwärmerückgewinnungssystem 100 möglich. Dadurch kann, abhängig vom Energiebedarf des elektrischen Bordnetzes 30 bzw. des Fahrzeugs, die Leistung des Abwärmerückgewinnungssystems 100 entweder für den Antriebsstrang – also für die Kurbelwelle 121 – oder für die Nebenverbraucher bzw. für das Bordnetz 30 genutzt werden oder in dem Energiespeicher 10 zwischengespeichert werden, was die Energieeffizienz des Abwärmerückgewinnungssystems 100 erhöht und damit den Kraftstoffverbrauch des Fahrzeugs reduziert.
• – Ein weiterer Vorteil ergibt sich aus den unterschiedlichen Dynamiken von Rekuperationssystem 120 und Abwärmerückgewinnungssystem 100. Während die Leistung der elektrischen Maschine 122 des Rekuperationssystems 120 schnell variieren kann, hat das Abwärmerückgewinnungssystem 100 eine hohe thermische Trägheit, wodurch die abgegebene elektrische Leistung des Generators 106 über längere Zeit vergleichsweise konstant ist. Der Gesamtleistungsbedarf für die direkte und indirekte Nutzung bzw. zum Laden des Energiespeichers 10 kann somit in einen Grund- und einen Spitzenlastanteil zerlegt werden, wobei nur noch letzterer durch die elektrische Maschine 122 oder einen weiteren Generator bzw. einen weiteren Energiespeicher 15 abgedeckt werden muss. Zum einen ermöglicht dies eine Optimierung der Wirkungsgradketten der Energieerzeugung, zum anderen kann die elektrische Maschine 122 und/oder der weitere Generator kleiner dimensioniert werden, was wiederum Kosten und Gewicht spart.
• – Weiterhin eröffnet sich die Möglichkeit durch prädiktive Funktionen die verhältnismäßig dynamische elektrische Energiebilanz des Rekuperationssystems 120 sowie die verhältnismäßig träge verfügbare thermische Energie des Abwärmerückgewinnungssystems 100 in die Zukunft zu extrapolieren und im Energiemanagement zu berücksichtigen. Beispielweise ist zu Beginn von Volllastphasen der Brennkraftmaschine 110 eine Erhöhung der Abgasabwärme im Bereich einiger Minuten in die Zukunft abzusehen. Wird in solchen Situationen der Ladezustand des Energiespeichers 10 gesenkt, steht mehr Speicherkapazität zum Speichern der folgenden thermischen Leistungsspitze zur Verfügung. Nutzt man innerhalb der gemeinsamen Steuerungslogik also auch die Prädiktionsfunktionen zur Vorhersage der Betriebspunkte von Brennkraftmaschine 110 und Abwärmerückgewinnungssystem 100, so lässt sich die elektrische Energieproduktion und der Bedarf (speziell die indirekte Nutzung) auch über längere Zeiträume besser anpassen, was eine weitere Erhöhung der Effizienz zur Folge hat und damit eine Verringerung des Kraftstoffverbrauchs ermöglicht.

Through the common control logic of the hybrid system 1 via the components of the control unit described above 50 There are the following advantages:

• - Only through the common control logic is a demand-driven change between direct and indirect electrical use of the power from the waste heat recovery system 100 possible. This can, depending on the energy requirements of the electrical system 30 or the vehicle, the performance of the waste heat recovery system 100 either for the powertrain - so for the crankshaft 121 - or for the secondary consumers or for the electrical system 30 be used or in the energy storage 10 cached, reflecting the energy efficiency of the waste heat recovery system 100 increases and thus reduces the fuel consumption of the vehicle.
• - Another advantage arises from the different dynamics of recuperation system 120 and waste heat recovery system 100 , While the power of the electric machine 122 of the recuperation system 120 can vary quickly, has the waste heat recovery system 100 a high thermal inertia, reducing the output electric power of the generator 106 is relatively constant over a long period of time. The total power requirement for the direct and indirect use or for charging the energy storage 10 can thus be broken down into a basic and a peak load, with only the latter by the electric machine 122 or another generator or a further energy store 15 must be covered. On the one hand, this allows an optimization of the energy efficiency chains, on the other hand, the electric machine 122 and / or the further generator are dimensioned smaller, which in turn saves costs and weight.
• - Furthermore, the possibility opens up by predictive functions, the relatively dynamic electrical energy balance of the recuperation 120 and the relatively slow available thermal energy of the waste heat recovery system 100 to extrapolate into the future and to consider in energy management. For example, at the beginning of full-load phases of the internal combustion engine 110 a Increase the exhaust heat in the range of a few minutes in the future. In such situations, the state of charge of the energy storage 10 lowered, more storage capacity is available for storing the following thermal performance peak. Within the common control logic, therefore, one also uses the prediction functions for the prediction of the operating points of the internal combustion engine 110 and waste heat recovery system 100 Thus, electrical energy production and demand (especially indirect use) can be better adapted over longer periods of time, resulting in a further increase in efficiency and thus a reduction in fuel consumption.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 102012208845 A1 [0002]
• DE 102014218485 A1 [0003]

Claims (16)

Hybrid system ( 1 ) for an internal combustion engine ( 110 ), in particular for an internal combustion engine ( 110 ) of a vehicle, the hybrid system ( 1 ) a waste heat recovery system ( 100 ) and a recuperation system ( 120 ), wherein the waste heat recovery system ( 100 ) a leading a working medium Clausius Rankine cycle ( 100a ) with an expansion machine ( 104 ), wherein the expansion machine ( 104 ) mechanically with a generator ( 106 ), the recuperation system ( 120 ) an electric machine ( 122 ), wherein the electric machine ( 122 ) by means of a transmission element ( 123 ) with an output ( 121 ) of the internal combustion engine ( 110 ), characterized in that the generator ( 106 ) and the electric machine ( 122 ) electrically with a common energy storage ( 10 ), preferably a 48V battery. Hybrid system ( 1 ) according to claim 1, characterized in that the waste heat recovery system ( 100 ) and the recuperation system ( 120 ) have a common control logic. Hybrid system ( 1 ) according to claim 2, characterized in that communicating control devices, preferably a common control device ( 50 ), the waste heat recovery system ( 100 ) and the recuperation system ( 120 ) by means of the common control logic. Hybrid system ( 1 ) according to one of claims 1 to 3, characterized in that the electrical machine ( 122 ) with respect to the internal combustion engine ( 110 ) is operable both as a generator and as a motor. Hybrid system ( 1 ) according to one of claims 1 to 4, characterized in that the energy store ( 10 ) serves as an intermediate buffer to optimize energy flow between the waste heat recovery system ( 100 ) and the recuperation system ( 120 ). Hybrid system ( 1 ) according to one of claims 1 to 5, characterized in that the evaporator ( 103 ) in an exhaust pipe ( 111 ) of the internal combustion engine ( 110 ) is arranged. Hybrid system ( 1 ) according to claim 6, characterized in that in the exhaust pipe ( 111 ) parallel to the evaporator ( 103 ) an exhaust gas bypass ( 113 ), wherein an exhaust gas bypass flap ( 114 ) the exhaust gas mass flow of the internal combustion engine ( 110 ) in the evaporator ( 103 ) and in the exhaust gas bypass ( 113 ). Vehicle with an internal combustion engine ( 110 ) with a hybrid system ( 1 ) according to one of claims 1 to 7. Vehicle according to claim 8, characterized in that the energy store ( 10 ) is electrically connected to other consumers of the vehicle, for example with a vehicle electrical system ( 30 ). Method for controlling a hybrid system ( 1 ) for an internal combustion engine ( 110 ) of a vehicle, the hybrid system ( 1 ) a waste heat recovery system ( 100 ) and a recuperation system ( 120 ), wherein the waste heat recovery system ( 100 ) a leading a working medium Clausius Rankine cycle ( 100a ) with an expansion machine ( 104 ), wherein the expansion machine ( 104 ) mechanically with a generator ( 106 ), the recuperation system ( 120 ) an electric machine ( 122 ), wherein the electric machine ( 122 ) by means of a transmission element ( 123 ) with an output ( 121 ) of the internal combustion engine ( 110 ) is connectable, wherein the generator ( 106 ) and the electric machine ( 122 ) electrically with a common energy storage ( 10 ), the waste heat recovery system ( 100 ) and the recuperation system ( 120 ) have common control logic, characterized in that the control logic provides power flow optimization between the waste heat recovery system ( 100 ), the recuperation system ( 120 ) and an energy requirement of the vehicle. Method for controlling a hybrid system ( 1 ) according to claim 10, characterized in that the control logic has a state of charge of the energy store ( 10 ), an energy demand of the vehicle, in particular of secondary consumers, and an energy supply of the hybrid system ( 1 ). Method for controlling a hybrid system ( 1 ) according to claim 11, characterized in that the control logic has a maximum allowed output power of the generator ( 106 ) depending on the state of charge, the energy demand and the energy supply. Method for controlling a hybrid system ( 1 ) according to claim 11 or 12, characterized in that the control logic for determining the change in the state of charge takes into account the future energy needs of the vehicle, wherein the control logic can control the operation of the auxiliary consumers or regulate. Method for controlling a hybrid system ( 1 ) according to one of claims 11 to 13, characterized in that the control logic the development of the waste heat of the internal combustion engine ( 110 ) and predicts the evolution of the energy needs of secondary consumers. Method for controlling a hybrid system ( 1 ) according to one of claims 12 to 14, wherein the waste heat recovery system ( 100 ) one parallel to the expansion machine ( 104 ) bypass line ( 108a ), wherein a bypass valve ( 108 ) the mass flow of the working medium into the expansion machine ( 104 ) and in the bypass line ( 108a ), characterized in that the control logic in bypassing the maximum allowable output, the bypass valve ( 108 ) so that the mass flow of the working medium into the expansion machine ( 104 ) is reduced. Method for controlling a hybrid system ( 1 ) according to one of claims 12 to 15, wherein the waste heat recovery system ( 100 ) one parallel to the evaporator ( 103 ) switched exhaust gas bypass ( 113 ), wherein an exhaust gas bypass flap ( 114 ) the exhaust gas mass flow of the internal combustion engine ( 110 ) in the evaporator ( 103 ) and in the exhaust gas bypass ( 113 ), characterized in that the control logic in excess of the maximum allowable output power, the exhaust gas bypass door ( 114 ) so that the exhaust gas mass flow into the evaporator ( 103 ) is reduced.

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