Exhaust gas system

Patent metadata

Field	Value
Publication number	US-2017138221-A1
Application number	US-201415319765-A
Country	US
Kind code	A1
Filing date	Jun 26, 2014
Priority date	Jun 26, 2014
Publication date	May 18, 2017
Grant date	—

Abstract

An exhaust gas system includes an arrangement for conveying an exhaust gas stream and a thermodynamic engine connected to the exhaust gas stream conveying arrangement for recovery of heat from the exhaust gas stream. The thermodynamic engine includes a working fluid circulation circuit. The exhaust gas system includes at least one working fluid release arrangement which is connected between the working fluid circulation circuit and the exhaust, gas conveying arrangement for releasing the working fluid from the working fluid circulation circuit to the exhaust: gas conveying arrangement. The exhaust gas stream conveying arrangement includes at least one exhaust gas treatment unit. Further, the working fluid release arrangement is connected upstream of or directly to the exhaust gas treatment unit.

First claim

1 . Exhaust gas system ( 100 ; 200 ) comprising an arrangement ( 17 ) for conveying an exhaust gas stream ( 80 ) and a thermodynamic engine ( 1 ) connected to the exhaust gas stream conveying arrangement ( 17 ) for recovery of heat from the exhaust gas stream ( 80 ), wherein the thermodynamic engine ( 1 ) comprises a working fluid circulation circuit ( 11 ), wherein the exhaust gas system comprises at least one working fluid release means ( 24 ; 25 ; 27 ), which is connected between the working fluid circulation circuit ( 11 ) and the exhaust gas conveying arrangement ( 17 ) for releasing the working fluid from the working fluid circulation circuit ( 11 ) to the exhaust gas conveying arrangement ( 17 ), characterized in that the exhaust gas stream conveying arrangement ( 17 ) comprises at least one exhaust gas treatment unit ( 20 ) and that the working fluid release means ( 24 ; 25 ; 33 ) is connected upstream of or directly to the exhaust gas treatment unit ( 20 ).

2 . Exhaust gas system ( 100 ; 200 ) according to claim 1 , characterized in that the exhaust gas treatment unit ( 20 ) is formed by a selective catalytic reduction unit (SCR) using ammonia for reducing a NOx amount of the exhaust gas.

3 . Exhaust gas system ( 200 ) according to claim 1 or 2 , characterized in that the thermodynamic engine ( 1 ) comprises a condensation device ( 10 ) positioned in the working fluid circulation circuit ( 11 ) and that the working fluid release means ( 25 ; 27 ) is connected to the condensation device ( 10 ) at a gas side thereof.

4 . Exhaust gas system ( 100 ; 200 ) according to any preceding claim, characterized in that the thermodynamic engine ( 1 ) further comprises a heating device ( 4 ; 6 ) for heating the working fluid and thereby converting a liquid working fluid to the gaseous phase working fluid.

5 . Exhaust gas system ( 100 ; 200 ) according to claim 4 , characterized in that the heating device ( 4 ; 6 ) of the thermodynamic engine ( 1 ) is formed by a heat exchanger positioned in the exhaust gas stream ( 80 ) for exchanging heat between the exhaust gas stream and the working fluid of the thermodynamic engine ( 1 ).

6 . Exhaust gas system ( 100 ; 200 ) according to claim 4 or 5 , characterized in that the heating device ( 4 ) of the thermodynamic engine ( 1 ) is arranged downstream of the exhaust gas treatment unit ( 20 ) in the exhaust gas stream.

7 . Exhaust gas system ( 100 ; 200 ) according to claim 3 and any one of claims 4 - 6 , characterized in that the working fluid release means ( 24 ; 25 ; 27 ) is connected to the working fluid circuit ( 11 ) downstream of the heating device ( 6 ) and upstream of a gas-liquid interface in the condensation device ( 10 ).

8 . Exhaust gas system ( 100 ; 200 ) according to claim 3 and any one of claims 4 - 7 , characterized in that the thermodynamic engine ( 1 ) further comprises a pump device ( 2 ) for circulating the working fluid; an expander device ( 8 ) for converting thermal energy of the gaseous phase working fluid into kinetic energy; and that the condensation device ( 10 ) is arranged downstream of the expander device ( 8 ) for cooling and thereby converting the gaseous phase working fluid into the liquid phase.

9 . Exhaust gas system ( 100 ; 200 ) according to any one of the preceding claims, characterized in that the working fluid release means ( 24 ; 25 ; 27 ) comprises a connecting duct ( 28 ; 29 ; 31 ) and at least one release valve ( 26 ; 27 ; 33 ) for controlling opening and/or closing of the connecting duct ( 28 ; 29 ; 31 ).

10 . Exhaust gas system ( 100 ; 200 ) according to claim 9 , characterized in that the exhaust gas system ( 100 ; 200 ) comprises a control unit ( 110 ), which is operatively connected to the release valve ( 26 , 27 ) for opening and/or closing the valve ( 26 , 27 ).

11 . Exhaust gas system ( 100 ; 200 ) according to claim 10 , characterized in that the exhaust gas system ( 100 ; 200 ) comprises at least one pressure detector ( 102 ) arranged in the working fluid circuit ( 11 ) and that the control unit ( 110 ) is operatively connected to the pressure detector ( 102 ) for controlling the opening and/or closing of the release valve ( 26 , 27 ) in dependence on a detected pressure.

12 . Exhaust gas system ( 100 ; 200 ) according to claims 2 , 4 and 11 , characterized in that the pressure detector ( 102 ) is arranged downstream of the heating device ( 6 ) and upstream of a gas-liquid interface in the condensation device ( 10 ).

13 . Exhaust gas system ( 100 ; 200 ) according to claim 11 or 12 , characterized in that the control unit ( 110 ) is configured to open the release valve ( 26 , 27 ) if a pressure exceeding a pressure threshold is detected by means of the pressure detector ( 102 ).

14 . Exhaust gas system ( 100 ; 200 ) according to any one of claims 10 to 13 , characterized in that the exhaust gas system ( 100 ) comprises at least one air sensor ( 104 ) for detecting air in the working fluid circuit ( 11 ), that the control unit ( 110 ) is operatively connected to the air sensor ( 104 ) for opening the valve ( 26 , 27 ) upon detection of air accumulation in the working fluid circuit ( 11 ).

15 . Exhaust gas system ( 100 ; 200 ) according to any one of claims 10 to 14 , characterized in that the exhaust gas system ( 100 ) comprises a manually operable means ( 106 ), which is connected to the control unit ( 100 ) for manually controlling opening and/or closing of the valve ( 26 , 27 ).

16 . Exhaust gas system ( 100 ; 200 ) according to any one of the preceding claims, characterized in that the exhaust gas system ( 100 ) comprises a working fluid storage tank ( 30 , 40 ) fluidly connected to the working fluid circuit ( 11 ) for storing liquid working fluid.

17 . Exhaust gas system ( 100 ; 200 ) according to claim 16 , characterized in that the working fluid storage tank ( 30 , 40 ) is fluidly connected to a low pressure side of the working fluid circuit ( 11 ).

18 . Exhaust gas system ( 100 ; 200 ) according to claim 17 , characterized in that the thermodynamic engine ( 1 ) comprises a condensation device ( 10 ) positioned in the working fluid circulation circuit ( 11 ) and that the working fluid storage tank ( 30 ) is connected to the working fluid circuit ( 11 ) downstream of the condensation device ( 10 ) and upstream of the heating device ( 4 ).

19 . Exhaust gas system ( 100 ; 200 ) according to claim 16 , characterized in that the working fluid storage tank ( 40 ) is fluidly connected to a high pressure side of the working fluid circuit ( 11 ).

20 . Exhaust gas system ( 100 ; 200 ) according to any one of claims 16 - 19 , characterized in that the exhaust gas system ( 100 ; 200 ) comprises a working fluid storage tank valve ( 33 , 35 ; 42 ; 46 ) configured to control working fluid flow between the working fluid storage tank ( 30 ; 40 ) and the working fluid circuit ( 11 ).

21 . Exhaust gas system ( 100 ; 200 ) according to claim 20 , characterized in that the exhaust gas system ( 100 ; 200 ) comprises a control unit ( 120 ) and that the working fluid storage tank valve ( 33 , 35 ; 42 ; 46 ) is connected to the control unit ( 120 ) in order to open if a pressure below ambient air pressure is detected in the working fluid circuit ( 11 ).

22 . Exhaust gas system ( 100 ; 200 ) according to any one of the preceding claims, characterized in that the working fluid comprises an antifreeze component, such as ammonia and/or alcoho

Assignees

• Volvo Truck Corp

Inventors

• Andersson Lennart
• Andersson Arne
• Mårdberg Peter

Classifications

• F02G5/02

  Profiting from waste heat of exhaust gases · CPC title

• F01N3/0205

  using heat exchangers · CPC title

• F01K23/065

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

• F01N3/2066 Primary

  Selective catalytic reduction [SCR] · CPC title

• F01K5/00

  Plants characterised by use of means for storing steam in an alkali to increase steam pressure, e.g. of Honigmann or Koenemann type · CPC title