ELECTRIC VEHICLE WITH ENERGY RECOVERY SYSTEM

Abstract

A vehicle may include an electromechanical energy recovery system and be configured to perform a method for its operation.

Claims

1. An electric vehicle, comprising a device for converting waste heat of at least one electrical machine and/or at least one energy accumulator of the electric vehicle into mechanical and/or electrical energy.

2. The electric vehicle according to claim 1, wherein the device for converting of waste heat into mechanical and/or electrical energy comprises a combi-generator, encompassing a gas-operated, pneumatic, mechanical linear motor and an electrical machine mechanically coupleable to the combi-generator.

3. The electric vehicle according to claim 2, wherein a piston rod of a linear piston of the gas-operated, pneumatic, mechanical linear motor is axially mounted in freewheels with guide curves, which convert a linear movement of the piston rod into a rotary movement of a rotor of the electrical machine.

4. The electric vehicle according to claim 1, wherein the at least one energy accumulator comprises at least one high-voltage battery.

5. The electric vehicle according to claim 1, wherein the at least one energy accumulator comprises at least one fuel cell.

6. The electric vehicle according to claim 1, wherein the device for converting of waste heat into mechanical and/or electrical energy comprises a circuit, in which a working medium circulates, which has a boiling point of not more than 80° C. at 1013.25 hPa.

7. The electric vehicle according to claim 6, wherein the working medium is carbon dioxide.

8. The electric vehicle according to claim 6, wherein the working medium is ethanol.

9. A method for operating an electric vehicle, comprising: converting waste heat of at least one electrical machine and/or at least one energy accumulator of the electric vehicle into mechanical energy, and utilizing the mechanical energy to drive the electric vehicle; and/or converting waste heat of the at least one electrical machine and/or the at least one energy accumulator of the electric vehicle into electrical energy, and supplying the electrical energy to at least one electrical machine and/or at least one energy accumulator of the electric vehicle.

10. The method according to claim 9, in which the waste heat is used to evaporate a working medium and the gaseous working medium drives a combi-generator or an expander.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0033] Embodiments of the invention are presented as examples with the aid of configurations in the enclosed drawings and will be further described with reference to the drawings.

[0034] FIG. 1 shows one embodiment of an electric vehicle.

[0035] FIG. 2 shows one embodiment of a combi-generator for converting thermal energy into mechanical and/or electrical energy.

DETAILED DESCRIPTION

[0036] FIG. 1 shows schematically one embodiment of the electric vehicle 1 according to an embodiment of the invention. The electric vehicle 1 comprises a combi-generator 10 for converting thermal energy into mechanical and/or electrical energy, being connected by pipelines of a circuit 40, in which an evaporable working medium circulates, to a heat exchanger/evaporator 20 and a condenser 30. The heat exchanger/evaporator 20 is connected to a heat transfer circuit 70, which takes heat away from a traction motor 50 and a HV battery 60 of the electric vehicle. In the heat exchanger/evaporator 20, the heat of the heat transfer agent circulating in the heat transfer circuit 70 is used to evaporate the working medium circulating in the circuit 40. The gaseous working medium is utilized in the combi-generator 10 to perform mechanical work and/or to generate electrical current. After the expansion work in the combi-generator 10, the working medium is again condensed in the condenser 30 and taken to the evaporator 20.

[0037] FIG. 2 shows schematically one embodiment of a combi-generator 10 for converting thermal energy into mechanical and/or electrical energy. The combi-generator 10 comprises a linear piston 110 having a piston rod 160, arranged movably in a pressure chamber 120. A regulating unit 200 regulates the current of the gaseous working medium into the pressure chamber 120 or out from this (symbolized by arrows in the drawing). A damping element 130, which may be for example a damping volume or a mechanical spring, creates a restoring force upon movement of the linear piston 110. Across the system connection 300, a linear or radial movement of the piston rod 160 can be utilized to perform mechanical work.

[0038] The combi-generator 10 furthermore comprises an electrical machine having a stator 180 and a rotor 190. The feeding or tapping of electrical energy 400 to and from the electrical machine (symbolized by arrows in the drawing) occurs across electrical contacts.

[0039] The piston rod 160 of the linear motor is mounted axially in freewheels 150, which have guide curves generating a rotary movement of the rotor 190 upon linear movement of the piston rod 160, when the friction clutch 140 connects the freewheel 150 to the housing.

[0040] The combi-generator 10 connects a mechanical linear motor (pressure chamber 120, piston 110, damping 130, piston rod 160) across a coupling 140 to an electrical machine (stator 180, rotor 190) and a common mounting with freewheels 150. The piston rod 160 is axially mounted in the freewheels 150 and guided by a guide curve. A rotary movement and a mechanical torque are generated by the stroke of the piston 110 and the angular momentum of the guide curve.

[0041] When the coupling 140 is open, a linear movement of the piston rod 160 can be mechanically tapped. The freewheel 150 cannot generate any torque, since there is no bracing against the housing. When the coupling 140 is closed, a rotary movement of the rotor 190 is generated. If the electrical machine is working in generator mode, the torque will be used to generate electrical current. In an alternative variant, the electrical machine is used additionally as a drive, and there will be a superimposing of the mechanical torques generated by the linear motor and the electrical machine.

[0042] The piston rod 160 may be hollow, for better cooling. The cavity 170 allows an active cooling in a separate cooling circuit, optionally with the E-machine, or a passive cooling via a sodium filling, etc.

[0043] Both the control of the required cooling circuits and the control of the combi-generators 10 are done through a computing unit, not represented. For this, the usual metered quantities of temperature, pressure, and rotary speed are determined and regulated by respective sensors.

[0044] German patent application no. 10 2021 114 792.1, filed Jun. 9, 2021, to which this application claims priority, is hereby incorporated herein by reference, in its entirety. Aspects of the various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.