Heat recovery system for an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9528395-B2
Application number	US-201414328648-A
Country	US
Kind code	B2
Filing date	Jul 10, 2014
Priority date	Jul 11, 2013
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

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.

First claim

The invention claimed is:

1. A heat recovery system for an internal combustion engine, 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;
wherein the heat engine includes an input operatively connected to the output for transmitting the output work to the output, and wherein the heat engine has a fluid-tight wall separating the input from the output, the wall hermetically sealing off the output from the heat-transfer medium.

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 , further comprising a contactless magnetic coupling connecting the input to the output for transferring the output work through the wall without penetrating the wall.

9. 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.

10. The heat recovery system according to claim 9 , wherein the equalisation tank has a filling valve for filling the line system with the heat-transfer medium.

11. The heat recovery system according to claim 10 , further comprising a pressure sensor connected to the filling valve for detecting the pressure of the heat-transfer medium.

12. 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.

13. 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.

14. 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 the 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 input, an output and a fluid-tight wall separating the input from the output, wherein the input is operatively connected to the output without penetrating the wall via a contactless magnetic coupling and the output is hermetically sealed from the heat-transfer medium;
a closed line system for connecting the heat exchanger to the heat engine; and
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 fillable 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.

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

16. The internal combustion engine according to claim 14 , 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.

17. The internal combustion engine according to claim 14 , 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.

18. The internal combustion engine according to claim 14 , wherein the bellows is composed of a plastic material.

Assignees

• Mahle Int Gmbh

Inventors

• Elsaesser Alfred
• Maisch Christian
• Mueller Rolf
• Wieske Peter

Classifications

• F01K5/02

  used in regenerative installation · CPC title

• F01K23/10

  with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) · CPC title

• F01K23/065 Primary

  the combustion taking place in an internal combustion piston engine, e.g. a diesel engine · CPC title

• F02G5/02

  Profiting from waste heat of exhaust gases · CPC title

• Y02T10/166

  Cross-Sectional Technologies · mapped topic