EXHAUST SYSTEM FOR AN INTERNAL COMBUSTION ENGINE AND METHOD FOR OPERATING AN EXHAUST SYSTEM

• US 20170198621A1
• Filed: 01/10/2017
• Published: 07/13/2017
• Est. Priority Date: 01/11/2016
• Status: Active Grant

• Current Assignee: Purem GmbH Formerly Eberspacher Exhaust Technology Gesellschaft mbH
• Original Assignee: Eberspacher Exhaust Technology GmbH & Co. KG (Eberspächer Gruppe GmbH & Co. KG)
• Inventors: GAISER, Gerd, FROBENIUS, Fabian, WELLER, Bernd
• Granted Patent: US 10,502,111 B2
• Time in Patent Office: Days
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/10 the substance being heated, e.g. by heating tank or supply line of the added substance
• CPC Class Codes: F01N 2610/105 Control thereof
• CPC Class Codes: F01N 2610/107 using glow plug heating elements
• CPC Class Codes: F01N 2610/14 Arrangements for the supply of substances, e.g. conduits
• CPC Class Codes: F01N 2610/144 Control thereof
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 2610/146 Control thereof, e.g. control of injectors or injection valves
• CPC Class Codes: F01N 2900/1808 Pressure
• CPC Class Codes: F01N 2900/1811 Temperature
• CPC Class Codes: F01N 3/0205 using heat exchangers
• CPC Class Codes: F01N 3/2026 directly electrifying the catalyst substrate, i.e. heating the electrically conductive catalyst substrate by joule effect
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: F01N 5/02 the devices using heat
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An exhaust system for an internal combustion engine, especially for a vehicle, includes an exhaust gas-carrying pipe (12) and a reactant release unit (14) for releasing reactant (R) into exhaust gas (A) flowing in the exhaust gas-carrying pipe (12). The reactant release unit (14) includes a reactant injection unit (20), a reactant delivery unit (18) delivering reactant (R) from a reactant reservoir to the reactant injection unit (20) and a heating unit (24) for heating reactant (R) being delivered to the reactant injection unit (20). The heating unit (24) includes an exhaust gas/reactant heat exchanger unit (26) for transferring heat, being transported in the exhaust gas (A), to the reactant (R).

Claims

1. An exhaust system for an internal combustion engine, the exhaust system comprising:

an exhaust gas-carrying pipe; and

a reactant release unit releasing reactant into exhaust gas flowing in the exhaust gas-carrying pipe, the reactant release unit comprising;

a reactant injection unit;

a reactant delivery unit delivering reactant from a reactant reservoir to the reactant injection unit; and

a heating unit heating reactant being delivered to the reactant injection unit, the heating unit comprising an exhaust gas/reactant heat exchanger unit transferring heat, being transported in the exhaust gas, to the reactant.

2. An exhaust system in accordance with claim 1, wherein the exhaust gas/reactant heat exchanger unit comprises a heat exchanger line area in a reactant line sending reactant to the reactant injection unit.

3. An exhaust system in accordance with claim 2, wherein the heat exchanger line area extends, in at least some sections, essentially completely in an interior of the exhaust gas-carrying pipe.

4. An exhaust system in accordance with claim 3, wherein the heat exchanger line area which extends in the interior of the exhaust gas-carrying pipe with a winding or a helical portion or a spiral or a meander or any combination of winding, a helical portion, a spiral and a meander.

5. An exhaust system in accordance with claim 3, wherein the heat exchanger line area extends adjacent to an inner surface of the exhaust gas-carrying pipe or in contact with an inner surface of the exhaust gas-carrying pipe or extends both adjacent to an inner surface of the exhaust gas-carrying pipe and in contact with an inner surface of the exhaust gas-carrying pipe.

6. An exhaust system in accordance with claim 3, wherein the heat exchanger line area comprises at least one heat transfer rib with heat transfer surfaces extending essentially parallel to an exhaust gas flow direction.

7. An exhaust system in accordance with claim 2, wherein the heat exchanger line area extends, in at least some sections, essentially completely outside the exhaust gas-carrying pipe.

8. An exhaust system in accordance with claim 7, wherein the heat exchanger line area extends adjacent to an outer surface of the exhaust gas-carrying pipe or in contact with an outer surface of the exhaust gas-carrying pipe or extends adjacent to an outer surface of the exhaust gas-carrying pipe and in contact with an outer surface of the exhaust gas-carrying pipe and the heat exchanger line area extends helically with respect to the exhaust gas-carrying pipe or meanders with respect to the exhaust gas-carrying pipe or both extends helically with respect to the exhaust gas-carrying pipe or meanders with respect to the exhaust gas-carrying pipe.

9. An exhaust system in accordance with claim 7, further comprising insulating material, wherein the exhaust gas-carrying pipe is surrounded, in at least some sections, by the insulating material at least in a length area interacting with the heat exchanger line area.

10. An exhaust system in accordance with claim 1, wherein the heating unit further comprises an electrically operable heater.

11. An exhaust system in accordance with claim 10, wherein:

the exhaust gas/reactant heat exchanger unit comprises a heat exchanger line area in a reactant line sending reactant to the reactant injection unit; and

the electrically operable heater is arranged upstream in relation to the heat exchanger line area in the direction of flow of the reactant.

12. An exhaust system in accordance with claim 10, wherein:

the exhaust gas/reactant heat exchanger unit comprises a heat exchanger line area in a reactant line sending reactant to the reactant injection unit; and

the electrically operable heater is arranged downstream in relation to the heat exchanger line area with respect to a direction of flow of the reactant.

13. An exhaust system in accordance with claim 1, wherein the reactant delivery unit is arranged upstream of the heating unit in a direction of flow of the reactant.

14. An exhaust system in accordance with claim 1, further comprising an actuating unit configured to actuate the reactant delivery unit or configured to actuate an electrically operable heating unit of the heating unit or configured to actuate the reactant release unit or any combination of configured to actuate the reactant delivery unit, configured to actuate an electrically operable heating unit of the heating unit and configured to actuate the reactant release unit.

15. An exhaust system in accordance with claim 14, further comprising:

at least one reactant pressure sensor provided in the flow path of the reactant between the reactant delivery unit and the reactant injection unit, wherein the actuating unit is configured to actuate the reactant delivery unit or the electrically operable heating unit or the reactant release unit or any combination of the reactant delivery unit, the electrically operable heating unit and the reactant release unit based on a reactant pressure detected by the reactant pressure sensor;

or

at least one reactant temperature sensor provided in the flow path of the reactant between the heating unit and the reactant injection unit, wherein the actuating unit is configured to actuate the reactant delivery unit or the electrically operable heating unit or the reactant release unit or any combination of the reactant delivery unit, the electrically operable heating unit and the reactant release unit based on a reactant temperature detected by the reactant temperature sensor;

or

at least one reactant pressure sensor provided in the flow path of the reactant between the reactant delivery unit and the reactant injection unit and at least one reactant temperature sensor provided in the flow path of the reactant between the heating unit and the reactant injection unit, wherein the actuating unit is configured to actuate the reactant delivery unit or the electrically operable heating unit or the reactant release unit or any combination of the reactant delivery unit, the electrically operable heating unit and the reactant release unit based on a reactant pressure detected by the reactant pressure sensor and based on a reactant temperature detected by the reactant temperature sensor.

16. A method for operating an exhaust system, the method comprising the steps of:

providing the exhaust system with an exhaust gas-carrying pipe and a reactant release unit releasing reactant into exhaust gas flowing in the exhaust gas-carrying pipe, wherein the reactant release unit comprises a reactant injection unit, a reactant delivery unit and a heating unit comprising an exhaust gas/reactant heat exchanger unit;

delivering reactant from a reactant reservoir to the reactant injection unit; and

heating reactant being delivered to the reactant injection unit by transferring heat, being transported in the exhaust gas, with the heat exchanger unit, to the reactant.

17. A method in accordance with claim 16, further comprising providing an actuating unit configured to actuate the reactant delivery unit or configured to actuate an electrically operable heating unit of the heating unit or configured to actuate the reactant release unit or any combination of configured to actuate the reactant delivery unit, configured to actuate an electrically operable heating unit of the heating unit and configured to actuate the reactant release unit.

18. A method in accordance with claim 16, further comprising:

providing at least one reactant pressure sensor in the flow path of the reactant between the reactant delivery unit and the reactant injection unit, wherein the actuating unit is configured to actuate the reactant delivery unit or the electrically operable heating unit or the reactant release unit or any combination of the reactant delivery unit, the electrically operable heating unit and the reactant release unit based on a reactant pressure detected by the reactant pressure sensor;

or

providing at least one reactant temperature sensor in the flow path of the reactant between the heating unit and the reactant injection unit, wherein the actuating unit is configured to actuate the reactant delivery unit or the electrically operable heating unit or the reactant release unit or any combination of the reactant delivery unit, the electrically operable heating unit and the reactant release unit based on a reactant temperature detected by the reactant temperature sensor;

or

providing at least one reactant pressure sensor in the flow path of the reactant between the reactant delivery unit and the reactant injection unit and at least one reactant temperature sensor provided in the flow path of the reactant between the heating unit and the reactant injection unit, wherein the actuating unit is configured to actuate the reactant delivery unit or the electrically operable heating unit or the reactant release unit or any combination of the reactant delivery unit, the electrically operable heating unit and the reactant release unit based on a reactant pressure detected by the reactant pressure sensor and based on a reactant temperature detected by the reactant temperature sensor.

19. A method in accordance with claim 18, wherein the actuating unit actuates the reactant delivery unit such that the reactant pressure is above the vapor pressure of the reactant heated by the heating unit.

20. A method in accordance with claim 19, wherein the actuating unit actuates the electrically operable heater such that the reactant heated by the heater is brought into a superheated state, such that the reactant temperature is in the range of a desired superheated temperature.