HEAT RECOVERY SYSTEM FOR AN INTERNAL COMBUSTION ENGINE

• US 20150013334A1
• Filed: 07/10/2014
• Published: 01/15/2015
• Est. Priority Date: 07/11/2013
• Status: Active Grant

• Current Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Original Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Inventors: Elsaesser, Alfred, Mueller, Rolf, Maisch, Christian, Wieske, Peter
• Granted Patent: US 9,528,395 B2
• Time in Patent Office: Days
• US Class Current: 60/616
• CPC Class Codes: F01K 13/006 Auxiliaries or details not otherwise provided for
• CPC Class Codes: F01K 23/065 the combustion taking place in an internal combustion piston engine, e.g. a diesel engine
• CPC Class Codes: F01K 23/10 with exhaust fluid of one cycle heating the fluid in another cycle F01K17/025 takes precedence
• CPC Class Codes: F01K 5/02 used in regenerative installation
• CPC Class Codes: F01N 2240/02 a heat exchanger
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: F02G 5/02 Profiting from waste heat of exhaust gases
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A heat recovery system for an internal combustion engine may include a heat exchanger, through which a fluid heat-transfer medium flows, for transferring heat from an exhaust gas system to the heat-transfer medium. A heat engine, through which the heat-transfer medium flows, may be included for converting the heat transferred to the heat-transfer medium into mechanical output work. A cyclically closed line system may be included for connecting the heat exchanger to the heat engine. The system may include a positive displacement pump for conveying the heat-transfer medium through the line system in a predefined flow direction via mechanical drive work. The system may include a drive, which is hermetically sealed off from the heat-transfer medium, for feeding the drive work to the positive displacement pump, and an output, which is hermetically sealed off from the heat-transfer medium, for discharging the output work from the heat engine.

Claims

1. A heat recovery system for an internal combustion engine, having comprising:

a heat exchanger, through which a fluid heat-transfer medium flows, for transferring heat from an exhaust system to the heat-transfer medium,

a heat engine, through which the heat-transfer medium flows, for converting the heat transferred to the heat-transfer medium into mechanical output work,

a cyclically closed line system for connecting the heat exchanger to the heat engine,

a positive displacement pump for conveying the heat-transfer medium through the line system in a predefined flow direction via mechanical drive work,

a drive, which is hermetically sealed off from the heat-transfer medium, for feeding the drive work to the positive displacement pump, and

an output, which is hermetically sealed off from the heat-transfer medium, for discharging the output work from the heat engine.

2. The heat recovery system according to claim 1, wherein the positive displacement pump has a fluid-tight separating diaphragm, which hermetically seals off the drive from the heat-transfer medium.

3. The heat recovery system according to claim 2, wherein the separating diaphragm includes a metal.

4. The heat recovery system according to claim 2, wherein the separating diaphragm includes a polymer.

5. The heat recovery system according to claim 2, wherein the separating diaphragm includes a layer of coating.

6. The heat recovery system according to claim 2, further comprising a plurality of separating diaphragms, which are connected in a substantially stack-like manner to the separating diaphragm to form a bellows.

7. The heat recovery system according to claim 6, wherein the drive comprises a hydraulic liquid which substantially fills the bellows, and a lifting piston, which is movably mounted in the hydraulic liquid, so that a lifting movement of the lifting piston hydromechanically unfolds the bellows via the hydraulic liquid.

8. The heat recovery system according to claim 1, wherein the heat engine has a fluid-tight wall, which hermetically seals off the output from the heat-transfer medium.

9. The heat recovery system according to claim 8, further comprising a contactless magnetic coupling arranged between the heat engine and the output for transferring the output work through the wall.

10. The heat recovery system according to claim 1, further comprising an equalisation tank, which is in fluid connection to the line system, for equalising a pressure of the heat-transfer medium.

11. The heat recovery system according to claim 10, wherein the equalisation tank has a filling valve for filling the line system with the heat-transfer medium.

12. The heat recovery system according to claim 11, further comprising a pressure sensor, connected to the filling valve for detecting the pressure of the heat-transfer medium.

13. The heat recovery system according to claim 1, further comprising a bypass valve, which is embedded in the line system and is arranged upstream of the heat engine in the flow direction, for diverting the heat-transfer medium around the heat engine.

14. The heat recovery system according to claim 1, further comprising a control unit in communication with the positive displacement pump for controlling the positive displacement pump.

16. The heat recovery system according to claim 1, wherein the heat engine is an expansion engine.

17. The heat recovery system according to claim 7, wherein the heat engine has a fluid-tight wall hermetically sealing the output from the heat-transfer medium.

18. The heat recovery system according to claim 17, further comprising a contactless magnetic coupling arranged between the heat engine and the output for transferring the output work through the wall.

19. The heat recovery system according to claim 18, further comprising an equalisation tank fluidly connected to the line system for equalising a pressure of the heat-transfer medium, wherein the equalisation tank has a filling valve for filling the line system with the heat-transfer medium, and a pressure sensor in communication with the filling valve for detecting the pressure of the heat-transfer medium.

20. The heat recovery system according to claim 18, further comprising at least one of (i) a bypass valve integrated in the line system and arranged upstream of the heat engine in the flow direction, and (ii) a control unit in communication with the positive displacement pump for controlling the positive displacement pump.

15. An internal combustion engine, comprising:

a combustion chamber for burning a fuel,

an exhaust system, which is fluid-connected to the combustion chamber, for discharging a combustion waste gas from the combustion chamber, and

a heat recovery system thermally connected to the exhaust system, the heat recovery system including;

a heat exchanger for transferring heat from an exhaust system to a fluid heat-transfer medium;

a heat engine for converting the heat transferred to the heat-transfer medium into mechanical output work, the heat engine including an output hermetically sealed from the heat-transfer medium for discharging the output work;

a closed line system for connecting the heat exchanger to the heat engine;

a positive displacement pump for conveying the heat-transfer medium through the line system in a predefined flow direction via mechanical drive work, the pump including a drive hermetically sealed from the heat-transfer medium for generating the drive work;

wherein the drive includes a bellows filled at least in part with a hydraulic liquid, and a lifting piston movably mounted in the hydraulic liquid, wherein movement of the lifting piston hydromechanically expands the bellows via the hydraulic liquid.