Expander system

Abstract

An expander system for recovering waste heat, a waste heat recovery system including such an expander system, a vehicle including such a waste heat recovery system and a method for manufacturing such an expander system. The expander system includes a shaft and a coupling portion including a first sealing unit and a second sealing unit. The shaft is inserted through the coupling portion to an expanding unit. The first sealing unit and the second sealing unit are arranged facing one another along the shaft. The first sealing unit and the second sealing unit are configured to seal the shaft in an axial direction relative to the shaft.

Claims

1. An expander system for recovering waste heat, comprising: a shaft; and a coupling portion comprising a first sealing unit and a second sealing unit, the shaft being inserted through the coupling portion to an expanding unit, the first sealing unit and the second sealing unit being arranged facing one another along the shaft, the first sealing unit and the second sealing unit being configured to seal the shaft in an axial direction relative to the shaft, and the coupling portion comprising a through-hole arranged in a perpendicular direction relative to the shaft between the first sealing unit and the second sealing unit, the through-hole being fluidly connected to a pressure inlet of the expanding unit via a channel.

2. The expander system according to claim 1, the through-hole connecting an interior of the first sealing unit and an interior of the second sealing unit.

3. The expander system according to claim 1, the expanding unit further comprising a pressure outlet.

4. The expander system according to claim 1, the pressure inlet of the expanding unit being configured to allow a medium to enter, which has a higher pressure than atmospheric pressure.

5. The expander system according to claim 1, the expanding unit further comprising more than one channel connecting the pressure inlet and the through-hole.

6. The expander system according to claim 5, the channels being arranged to circulate a medium between the pressure inlet and the through-hole of the coupling portion substantially without a pressure drop.

7. The expander system according to claim 1, the first and/or second sealing unit comprising a lip seal.

8. The expander system according to claim 1, the first and/or second sealing unit comprising a labyrinth seal.

9. The expander system according to claim 1, the expanding unit further comprising a piston expander.

10. The expander system according to claim 4, the medium being ethanol.

11. A waste heat recovery system, comprising: an expander system comprising a shaft and a coupling portion comprising a first sealing unit and a second sealing unit, the shaft being inserted through the coupling portion to an expanding unit, the first sealing unit and the second sealing unit being arranged facing one another along the shaft, the first sealing unit and the second sealing unit being configured to seal the shaft in an axial direction relative to the shaft, and the coupling portion comprising a through-hole arranged in a perpendicular direction relative to the shaft between the first sealing unit and the second sealing unit, the through-hole being fluidly connected to a pressure inlet of the expanding unit via a channel; and a generator, the shaft of the expander system being configured to be connected to the generator, and the generator being configured to convert an energy transferred from the shaft to a mechanical and/or electrical energy.

12. The waste heat recovery system according to claim 11, being an organic Rankine system.

13. A vehicle, comprising the waste heat recovery system according to claim 11.

14. A method for manufacturing an expander system for recovering waste heat, comprising the following steps: providing a shaft; providing a coupling portion comprising a first sealing unit and a second sealing unit; inserting the shaft through the coupling portion to an expanding unit; and arranging the first sealing unit and the second sealing unit facing one another along the shaft, the first sealing unit and the second sealing unit being configured to seal the coupling portion in an axial direction relative to the shaft, and the coupling portion comprising a through-hole arranged in a perpendicular direction relative to the shaft between the first sealing unit and the second sealing unit, the through-hole being fluidly connected to a pressure inlet of the expanding unit via a channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the disclosure will be described in the following with reference to the following drawings:

(2) FIG. 1 shows schematically and exemplarily an embodiment of a waste heat recovery system according to the present disclosure.

(3) FIG. 2 shows schematically and exemplarily an embodiment of an expander system according to the present disclosure.

(4) FIG. 3 shows schematically and exemplarily an embodiment of a coupling portion of an expander system according to the present disclosure.

DESCRIPTION OF EMBODIMENTS

(5) FIG. 1 shows a waste heat recovery system 1, which may be integrated in a vehicle including a diesel internal combustion engine (ICE) or a petrol ICE 50. The waste heat recovery system 1 includes an expander system 10 and a generator 20. The waste heat recovery system 1 further includes a condenser 30 and a heat exchanger 40 for transferring heat from or to a working medium respectively, which circulates in the waste heat recovery system 1. The waste heat recovery system 1 may be an organic Rankine system and the working medium may be an organic fluid such as ethanol.

(6) As shown in FIG. 2, the expander system 10 includes an expanding unit 13, which is connected to the generator 20 via a shaft 11. The generator 20 is configured to convert a mechanical work of the expanding unit 13 for propelling the vehicle or collecting an electrical energy in a battery system. The shaft 11 is inserted to the expanding unit 13 through a coupling portion 12, which may be arranged directly at the expanding unit 13.

(7) The coupling portion 12 includes a first sealing unit 16 and a second sealing unit 17, which face each other along a longitudinal axis of the shaft 11. In other words, the first sealing unit 16 and the second sealing unit 17 are arranged around the shaft 11. The first sealing unit 16 and the second sealing unit 17 are configured to seal the coupling portion 12 in an axial direction relative to the shaft 11. The first and/or the second sealing unit 16, 17 may be a lip seal or a labyrinth seal.

(8) The coupling portion 12 includes a through-hole 18 arranged in a perpendicular direction relative to the shaft 11 between the first sealing unit 16 and the second sealing unit 17. The through-hole 18 connects an interior of the first sealing unit 16 and an interior of the second sealing unit 17 (see also FIG. 3).

(9) The expanding unit 13 includes a pressure inlet 14 for receiving a compressed working medium and a pressure outlet 15 for releasing the expanded working medium. Accordingly, the working medium entering in the expanding unit 13 has a higher pressure than the working medium exiting the expanding unit 13. The pressure of the working medium entering through the pressure inlet 14 may be preferably higher than atmospheric pressure.

(10) The through-hole 18 arranged in the coupling portion 12 is connected to the pressure inlet 14 of the expanding unit 13 via a channel. The channel is configured to circulate the pressurised medium between the pressure inlet 14 and the through-hole 18 substantially without any pressure drop. Accordingly, the first sealing unit 16 and the second sealing unit 17 are pressed outwardly from a centre of the coupling portion 12. In other words, the first sealing unit 16 and the second sealing unit 17 exert a sealing force outwardly from a centre of the coupling portion 12 along a longitudinal axis of the shaft 11. Hence, the coupling portion 12 may be hermetically sealed and an intrusion of air in to the expanding unit 13 along the shaft 11 may be prevented.

(11) The expanding unit 13 further includes a piston expander. The piston expander is configured to generate a sub-atmospheric pressure at least at the pressure outlet 15. Accordingly, a performance of the expander can be improved as the sub-atmospheric pressure would cause a suction force on the piston expander. Hence, an efficiency of the expander system 10 may be increased.

(12) It has to be noted that embodiments of the disclosure are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments are described with reference to the device type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application. However, all features can be combined providing synergetic effects that are more than the simple summation of the features.

(13) While the disclosure has been illustrated and described in detail in the drawings and description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The disclosure is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed disclosure, from a study of the drawings, the disclosure, and the dependent claims.

(14) In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.