WO2018046371A1

WO2018046371A1 - Heat recovery device

Info

Publication number: WO2018046371A1
Application number: PCT/EP2017/071771
Authority: WO
Inventors: Michael Bucher; Herbert Clemens; Jörg COLLISI; Michael HÖTGER
Original assignee: Mahle International Gmbh
Priority date: 2016-09-12
Filing date: 2017-08-30
Publication date: 2018-03-15
Also published as: DE102016217352A1

Abstract

The invention relates to a heat recovery device (1) having a housing (2) in which are arranged at least the following components: – an exhaust gas duct (3) having an inlet (4) and an outlet (5) and an evaporator (6) arranged therebetween, – a heat recovery circuit (7) in which a working medium flows and in which are arranged the evaporator (6), an expander (8), and air-cooled or coolant-cooled condenser (9) and a conveying device (10) for conveying the working medium, – a generator (12), connected to the expander (8), for generating electrical power, – a working medium reservoir (11), – a control device (13), and wherein there is arranged on the housing (2) an electrical interface (14) for transferring electrical power.

Description

heat recovery device

The present invention relates to a heat recovery device. The invention also relates to a motor vehicle with an internal combustion engine and such a heat recovery device.

Heat recovery facilities, such as. Waste heat utilization facilities, are increasingly used in motor vehicles with internal combustion engines, for example, to use the ejected from the engine and hot exhaust gases additionally thermally. This is done

usually via an integrated in a waste heat recovery circuit

Expander, for example. An axial piston machine or a turbine, which is driven by a working medium, for example. Steam and directly or indirectly

is mechanically connected to the internal combustion engine. The steam required for operating the expander is usually generated by the hot exhaust gases originating from the internal combustion engine.

The disadvantage here, however, is that a direct mechanical involvement of the heat recovery device is relatively expensive and therefore expensive and in no case readily retrofittable.

The present invention therefore addresses the problem of providing an improved or at least one alternative embodiment for a heat recovery device.

This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject of the dependent claims. The present invention is based on the general idea to dispense with a mechanical power input in a heat recovery device and instead of this only to choose an electrical power input and also all the components of the

Heat recovery device in a common housing and thus compact and inexpensive to order. In addition, the simplest possible control or control should be selected in order to be able to additionally reduce the costs of the heat recovery device according to the invention. The heat recovery device according to the invention in this case has a housing in which at least the following components are arranged: An exhaust duct with an input and an output and an evaporator, a heat recovery circuit in which a working fluid flows and the evaporator, an expander, for example. An axial piston or a turbine , an air-cooled or coolant-cooled condenser and a conveyor for conveying the working medium are arranged, a generator connected to the expander for generating electrical energy and a

Control device and a reservoir for the working medium. To the

Housing itself is additionally arranged an electrical interface for transferring the electrical energy generated by the generator or stored in the housing energy storage stored. On the housing of course, the input and the output of the exhaust passage are arranged, for example, even with a corresponding coupling. With the

Heat recovery device according to the invention, it is thus possible for the first time to offer a compact and thus small and above all inexpensive heat recovery device in which all components are combined and arranged in the housing. By example. The

According to the invention air-cooled condenser, it is also possible to

Heat recovery device according to the invention completely self-sufficient, that is in particular independent of a cooling circuit of a Operating motor vehicle, which is a great advantage in particular because the heat recovery device according to the invention can also be operated when a cooling system of the motor vehicle already at its power limit, eg. When driving uphill works.

Alternatively, an independent of the cooling system of the motor vehicle cooling circuit with its own radiator integrated into a suitable place in the vehicle and a coolant-cooled condenser can be used. Thus, the heat recovery device remains self-sufficient. The control device is extremely simple and has no or only a minimal

Information exchange with, for example, an engine control unit a

Internal combustion engine of a motor vehicle. The control device should primarily control the exhaust gas flow in the exhaust duct, for example via a

corresponding valve device, in particular an exhaust valve, and indirectly about the performance of the heat recovery device. Of particular advantage in the heat recovery device according to the invention is also that this can be installed as a retrofit kit and comparatively simple finished motor vehicles, especially since a mechanical load coupling does not take place.

In an advantageous development of the solution according to the invention, an electrical energy store connected to the generator is arranged in the housing. Such an electrical energy storage can, for example. As

Capacitor or be designed as an accumulator. As a result, it is, for example.

it is possible to store the electrical energy generated by the generator and to return it according to a demand. For example, it is conceivable that given an uphill drive power from the energy storage and stored in a downhill performance in this. In a purely mechanically coupled heat recovery device often the power generated by this heat in a hilly route can not be used optimally, since due to thermal inertias only the maximum power of the heat recovery device is ready when the vehicle is already downhill again. As a result, at least a certain part of the power is always lost. In the inventive

However, heat recovery device is exclusively an electrical energy transfer to electrical consumers, such as. Electric motors, these electric motors can be used even when driving downhill as a generator and thereby additionally reduce the conventionally available to be put energy demand of the motor vehicle and the electrical energy is available immediately , By means of the possibility to store the electrical energy, the power of one with the inventive

Heat recovery device connected electric motor can be chosen significantly larger than, for example, the power of the generator, so that this example. Maximum 10kW, in particular a maximum of 7kW, has power, while the associated electric motor, for example. 20kW can have power.

Another consumption advantage can be achieved by the

Dynamic demand of an internal combustion engine of the motor vehicle is reduced. By this is to be understood that even with journeys with constant

Speed on a flat track, the load of the internal combustion engine permanently varies, so that it is not in a constant operating point, but constantly changes in terms of their load. This leads, for example, to the fact that z. For example, an exhaust gas turbocharger constantly changes its speed and the injection quantity of fuel is constantly varied. This dynamic in turn leads to

Consumption disadvantages compared to a stationary operation. If those

Dynamics of the internal combustion engine can be reduced by a corresponding, needs-based power output of the heat recovery device via the electric motor, it can also be achieved directly from a consumption reduction. In an advantageous embodiment of the solution according to the invention, the exhaust passage to a bypassing the evaporator exhaust bypass channel, wherein in addition a valve means, for example. An exhaust valve, is provided, which is controllable by means of the control device and thereby one through the

Exhaust gas bypass duct and / or the evaporator flowing exhaust gas flow controls. The control device thus serves in this case to control the performance of the heat recovery device by simply taking effect on the evaporator performance via the exhaust valve. In the same or similar manner, of course, a more immediate the expander

Arbeitsmediumbypasskanal be provided, which also with a

corresponding valve device is controllable, so that additionally or alternatively, the control device is designed to control the performance of the expander.

The present invention is further based on the general idea to use the previously described heat recovery device in a motor vehicle with an internal combustion engine and an exhaust line, whose exhaust passage is communicatively connected to the exhaust line of the internal combustion engine. As a result, substantial consumption advantages in the operation of the motor vehicle can be achieved and in particular also create a comparatively technically simple and therefore cost-effective installation situation.

In an advantageous development of the motor vehicle according to the invention, at least one electrical load, for example an electric motor, a fan of an air conditioning system or an electrical air conditioning compressor, is provided which is coupled directly to the heat recovery device via the electrical interface. For example, it is conceivable that in particular an electric air conditioning compressor or a fan of the air conditioner permanently by the elektnsche energy of the heat recovery device is operated and thus does not need to be considered in the energy budget of the internal combustion engine. This can be a constant even in the long term

Achieve reduced consumption.

Suitably, the motor vehicle is designed as a commercial vehicle with a trailer or a semi-trailer and the electrical load as a wheel hub motor in the trailer or the semi-trailer. In this case, the heat recovery device according to the invention would thus be arranged in a towing vehicle, while at least one energy store coupled thereto is arranged in the semi-trailer or trailer. By loading the energy storage while driving, an automatic maneuvering is possible at least in certain areas when parking the trailer or the trailer without towing vehicle.

Of course, the at least one wheel hub motor of the trailer or of the trailer, in particular during downhill driving, can be used as a generator in order to generate electrical energy and thus to charge the energy accumulator arranged in the trailer or in the semitrailer.

In a further advantageous embodiment of the invention

Motor vehicle is between the electrical consumer and the

Heat recovery device an electric wave or a

Frequency converter (electric transmission) arranged. An electric wave can be achieved, for example, by a different number of poles of the generator and the associated electric machine. This is the cheapest and simplest variant. About an electrical coupling of a

Electric motor with the generator by means of a frequency converter, the speed of the electric motor can be freely selected in relation to the generator speed. This is in comparison to the previous alternative consuming but also much more effective. Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated

Description of the figures with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically,

1 shows a heat recovery device according to the invention,

Fig. 2 shows an inventive motor vehicle with such

Heat recovery device.

According to FIG. 1, an inventive

Heat recovery device 1, a housing 2, in which at least the following components are arranged: An exhaust passage 3 with an input 4 and an output 5 and a disposed between the input 4 and the output 5 evaporator 6. In addition, a heat recovery circuit is provided in the housing 2 7, in which a working medium flows and the evaporator 6, an expander 8, an air-cooled or coolant-cooled Condenser 9 and a conveyor 10 for conveying the working medium are arranged. The expander 8 can be designed, for example, as an axial piston machine or as a turbine. Also arranged in the housing 2 are still a working medium reservoir 1 1 and connected to the expander 8 generator 12 for generating electrical energy and a control device 13 is arranged on the housing 2 also has an electrical interface 14 for the transfer of electrical energy. The inventive

Heat recovery device 1 has all the necessary

Components that are compactly arranged in the housing 2.

By the air-cooled (directly cooled) or coolant-cooled (indirectly cooled) condenser 9, it is also possible, the inventive

Heat recovery device 1 regardless of, for example, a

To operate vehicle cooling system. Between the evaporator 6 and the

Generator 12, condenser 9 or working medium reservoir 1 1 can also be provided a partition 25 to "warm" components, e.g. the evaporator 6 and the exhaust duct 3 of "cool" components, e.g. the capacitor 9 and the generator 12 to thermally separate. The cool components can also be cooled via an air duct with inlet and outlet at the condenser 9.

In addition, a collecting trough and / or at least one absorption device, in particular on the walls, can be provided in the housing 2 in order to collect escaping medium. Additionally or alternatively, in

Capacitor 9, a filter device 26 may be arranged to filter gases.

The conveyor 10 may be driven by an expander shaft 27, whereby the maximum load of the expander 8 directly depends on the speed of the expander 8 itself and thus reduced to the characteristic Material loading is achieved. As a result, the expander 8 can be designed for lower loads.

In addition, an electric fan 28 may be provided for cooling the condenser 9, which offers the advantage that in a detection of

Media outlet of the fan 28 at high speed can prevent an explosive mixture.

If, for example, such an electric fan 28 for cooling the

Condenser 9 is provided, it can variably according to a

Cooling requirement are controlled in terms of its speed, and / or run at maximum speed on detection of media leakage, that is operated at maximum speed.

Can be used, the inventive

Heat recovery device 1, for example, in a motor vehicle 15 (see Fig. 2), wherein in a particular variant of the invention

Heat recovery device 1 in the housing 2 additionally connected to the generator 12, electrical energy storage 16 may be arranged. In theory, of course, the energy storage 16 can also be arranged separately from the heat recovery device 1, as shown in Fig. 2. The electrical energy store 16 can be designed as a rechargeable accumulator or as an electrical capacitor.

If one looks closer to FIG. 1, it can be seen that the exhaust gas channel 3 has an exhaust gas bypass channel 17 surrounding the evaporator 6. At the entrance of the exhaust gas bypass channel 17, a valve device 18, for example. An exhaust valve may be provided, which is controllable with this control device 13 and the one flowing through the exhaust gas bypass passage 17 Exhaust gas flow controls. It is conceivable that, depending on the desired electrical power of the heat recovery device 1 more or less hot exhaust gas flows through the evaporator 6 and thereby to the operation of the

Expanders vaporized 8 required working medium. The control of the power of the heat recovery device 1 is thus comparatively easy via a position of the exhaust valve or the valve device 18 conceivable. Additionally or alternatively, also the expander 8 bypassing

Arbeitsmediumbypasskanal 19 may be provided which is controllable via a corresponding valve means 18 '. The valve device 18 'is also controllable by the control device 13, so that even without the

Valve means 18, the amount of vaporized working fluid provided by the evaporator 6 can bypass the expander 8 without doing any mechanical work.

The expander 8, which is designed, for example, as an axial piston machine or as a turbine, preferably has a maximum power of 10 kW, in particular of not more than 7 kW.

In this case, the motor vehicle 15 has an internal combustion engine 20 (cf., FIG. 2) with an exhaust gas line 21, in which the heat recovery device 1 described above with reference to FIG. The exhaust duct 3 of the heat recovery device 1 is communicating with the

Exhaust line 21 connected.

The motor vehicle 15 may also have at least one electrical

Consumer 22, such as, for example, an electric motor 23, a fan of an air conditioner or an electric air conditioning compressor, which is coupled via the electrical interface 14 directly to the heat recovery device 1. Between the electrical load 22 and the Heat recovery device 1 can also be an electrical or a frequency converter 24, arranged in the manner of an electrical transmission.

With the heat recovery device 1 according to the invention can be a compact and thus small and above all inexpensive system for waste heat use create, all the necessary components are arranged in a common housing 2, so that the heat recovery device 1 according to the invention comparatively free and flexible on

Motor vehicle 15 can be attached and no mechanical

Power coupling is required. In addition, the heat recovery device 1 according to the invention opens up the possibility to expand hybrid functions and in particular to achieve consumption advantages in the real driving operation of a commercial vehicle. The heat recovery device 1 can be comparatively easy with a valve device 18, 18 'activated or

be deactivated, wherein the electric power generated by the generator 12 regardless of the installation location of the heat recovery device 1 in

Motor vehicle 15 can be used.

In this case, use can be achieved, for example, via a direct electrical coupling of the heat recovery device 1 with an electric motor 23, with an over or under reduction ratio being determined by a different one

Polzahl of the generator 12 and the electric motor 23 can be achieved. This represents the simplest and at the same time the most cost-effective variant.

About an electrical coupling of the electric motor 23 with the generator 12 via the frequency converter 24, the speed of the electric motor 23 in

Relative to the generator speed can be freely selected. This is more complex but at the same time more effective than the previously described variant. About a in the housing 2 or externally on the motor vehicle 15 arranged battery (Energy storage 16) can also cached electrical power and discharged according to a need again. As a result, for example, a demand-based power delivery to auxiliary equipment, such as, for example, fans or hydraulic pumps, can be achieved. The inventive

Heat recovery device 1 is usually used after a so-called range extender. A permanent drive of electrical loads 22 in the motor vehicle 15 is by means of

Heat recovery device 1 and the energy storage 16 conceivable, thereby reducing a load on the engine 20 and resulting in consumption benefits.

Of particular advantage may also be provided that the motor vehicle 15 has a trailer or a semi-trailer and the electric motor 23 as

Hub motor is formed in the trailer or the semi-trailer. In this case, the electrical energy storage is also located in the trailer or in the semi-trailer and thus allows independent to towing vehicle maneuvering. While driving the designed as a commercial vehicle motor vehicle 15 with the trailer or semi-trailer, the wheel hub motor can be used at the same time as a generator for charging the energy storage 16.

Claims

claims

1 . Heat recovery device (1) with

a housing (2) in which at least the following components are arranged,

an exhaust duct (3) having an inlet (4) and an outlet (5) and an evaporator (6) arranged therebetween,

a heat recovery circuit (7) in which a working medium flows and the evaporator (6), an expander (8), an air-cooled or coolant-cooled condenser (9) and a conveyor (10) for conveying the working medium are arranged,

a generator (12) connected to the expander (8) for generating electrical energy,

- A working medium reservoir (1 1) and

a control device (13),

wherein on the housing (2) an electrical interface (14) is arranged for the transfer of electrical energy.

2. Heat recovery device according to claim 1,

characterized in that

in the housing (2) with the generator (12) connected, electrical energy storage (16) is arranged.

3. Heat recovery device according to claim 2,

characterized in that the electrical energy store (16) is an accumulator or an electrical capacitor.

4. Heat recovery device according to one of the preceding

Claims,

characterized in that

the exhaust duct (3) a the evaporator (6) bypassing

Exhaust gas bypass channel (17).

5. Heat recovery device according to claim 4,

characterized in that

a valve device (18), in particular an exhaust gas flap, is provided, which is controllable by means of the control device (13) and which controls an exhaust gas flow flowing through the exhaust gas bypass duct (17) and the evaporator (6).

6. Heat recovery device according to one of the preceding

Claims,

characterized in that

- A the expander (8) bypassing Arbeitsmediumbypasskanal (19) with a valve means (18 ') is provided, and / or

- The expander (8) is designed as an axial piston machine or as a turbine.

7. Heat recovery device according to one of the preceding

Claims,

characterized in that

the expander (8) has a maximum power of 10 kW, in particular a maximum of 7 kW.

8. Heat recovery device according to one of the preceding

Claims,

characterized,

in that a dividing wall (25) is provided between the evaporator (6) and cool components, such as the generator (12), the condenser (9) or the working medium reservoir (11).

9. Heat recovery device according to one of the preceding

Claims,

characterized,

- That in the housing (2) a collecting tray and / or at least one

Absorbing device, in particular on the walls, are / is provided to catch escaping medium, and / or

- That in the condenser (9) a filter device (26) is arranged to

To filter gases.

10. Heat recovery device according to one of the preceding

Claims,

characterized,

- That the conveyor (10) by an expander shaft (27) is driven and / or

- That an electric fan (28) for cooling the capacitor (9) is provided.

1 1. Motor vehicle (15) with an internal combustion engine (20), an exhaust line (21) and a heat recovery device (1) according to one of the preceding claims, whose exhaust passage (3) communicating with the exhaust line (21) is connected.

12. Motor vehicle according to claim 1 1,

characterized in that

at least one electrical load (22), such as a

Electric motor (23), a fan of an air conditioner or an electric air conditioning compressor, is provided, which is coupled via the electrical interface (14) directly to the heat recovery device (1).

13. Motor vehicle according to claim 12,

characterized in that

that the motor vehicle (15) is designed as a commercial vehicle with a trailer or a semi-trailer and the electrical consumer (22) as

Wheel hub motor is formed in the trailer or semitrailer.

14. Motor vehicle according to claim 12 or 13,

characterized in that

between the electrical load (22) and the

Heat recovery device (1) an electric wave or a frequency converter (24) is arranged.

15. A method for operating a heat recovery device (1) according to any one of claims 1 to 10, wherein additionally an electric fan (28) for cooling the capacitor (9) is provided and wherein

- The electric fan (28) is variably controlled in accordance with a cooling requirement in terms of its speed, and / or

- The electric fan (28) runs on detection of media leakage at maximum speed.