Exhaust gas recirculation system

Abstract

An exhaust gas recirculation system comprises an exhaust gas cooler (1) downstream of which a condenser (2) is disposed through which flows fresh air (7).

Claims

1. An exhaust gas recirculation system comprising an exhaust gas cooler and a condenser positioned downstream from the exhaust gas cooler, wherein the exhaust gas cooler includes a plurality of separated pipes through which exhaust gas passes and an exhaust gas collector for collecting an exhaust gas passing through the plurality of separated pipes, and wherein the condenser is formed inside the exhaust gas collector for removing moisture contained in the exhaust gas collector; wherein the condenser is formed as a fresh air tube extending through the exhaust gas collector, and includes an outlet in communication with a tank; and wherein the outlet of the condenser is discharging condensed water formed by condensing the moisture contained in the exhaust gas inside the exhaust gas collector to the tank; wherein the condenser is formed inside the exhaust gas collector for removing moisture contained in the exhaust gas collector; wherein the condenser is formed as a fresh air tube extending through the exhaust gas collector, and includes an outlet in communication with a tank; and wherein the outlet of the condenser is discharging condensed water formed by condensing the moisture contained in the exhaust gas inside the exhaust gas collector to the tank.

2. The exhaust gas recirculation system with the exhaust gas cooler according to claim 1, wherein a tube axis of the fresh air tube extends substantially perpendicularly to a direction of flow of the exhaust gas.

3. The exhaust gas recirculation system with the exhaust gas cooler according to claim 1, wherein the fresh air tube comprises ribs.

4. An exhaust gas recirculation system comprising an exhaust gas cooler, and a condenser positioned downstream from the exhaust gas cooler, and an exhaust gas collector for collecting an exhaust gas passing through the exhaust gas cooler; wherein the condenser includes an outlet leading to a tank, wherein the tank is connected to a combustion chamber and to an exhaust gas outlet of a combustion engine, wherein the condensate condensed by the condenser is collected in the tank through the outlet, and the condensate collected in the tank is guided to the combustion chamber, the exhaust gas outlet of the combustion engine, or both the combustion chamber and the exhaust as outlet; and wherein the condenser is formed inside the exhaust gas collector for removing moisture contained in the exhaust gas collector; wherein the condenser is formed as fresh air tube extending through the exhaust gas collector, and includes an outlet in communication with a tank; and wherein the outlet of the condenser is discharging condensed water formed by condensing the moisture contained in the exhaust gas inside the exhaust gas collector the tank.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the following an embodiment example of the invention will be explained in greater detail with reference to the Figures. In the drawing depict:

(2) FIG. 1 a schematic side view of the exhaust gas cooler according to the invention;

(3) FIG. 2 a schematic bottom view of the exhaust gas cooler according to the invention;

(4) FIG. 3 a schematic diagram in a first operating state and

(5) FIG. 4 a schematic diagram in a second operating state.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT EXAMPLE OF THE INVENTION

(6) As can be seen in FIG. 1, the exhaust gas 9 to be recirculated flows first through the exhaust gas cooler 1 and subsequently through the condenser 2. In the depicted case the latter is essentially formed by a volume encompassed by a housing through which extends a fresh air tube 3 whose diameter is only insignificantly less than the dimension of the described condenser housing. At its bottom is located an outlet 4 for the condensate. By 5 is designated an exhaust gas recirculation valve, disposed downstream of condenser 2, that regulates the flow rate of the exhaust gas now freed of the water vapor and consequently dried. Said housing may be the housing of an exhaust gas collector downstream of the exhaust gas cooler 1. The exhaust gas cooler 1 may in particular comprise numerous separate tubes or channels through which the exhaust gas flows, wherein the individual exhaust gas flows are combined in the region of the described exhaust gas collector.

(7) In the bottom view of FIG. 2 ribs 8 are supplementarily indicated which can be developed on the fresh air tube 3 such that they completely encircle it and/or extend parallel to the direction of flow of the exhaust gas. In the bottom view of FIG. 2 can be seen further that the fresh air tube 3 extends fully through the housing of the condenser [2]. The fresh air flow is denoted by 7. It can be seen that a preferred configuration is depicted in which the fresh air flow 7 is substantially perpendicular to the exhaust gas flow.

(8) In FIG. 3 a tank 11 is additionally depicted which is connected to an outlet 4 of the condenser 2 such that across a duct 10 the condensate can be collected in the tank 11. As shown in FIG. 3, the condensate can be recirculated from this tank 11 into the combustion chamber. FIG. 3 further indicates that the engine can comprise an exhaust turbocharger 12 disposed, in the direction of flow, upstream of a catalyst 13.

(9) After the fresh air to be charged, as indicated in FIG. 3, contains recirculated exhaust gas, the condenser [2], disposed according to the invention downstream of the exhaust gas cooler [1], notably deploys its effect since the recirculated exhaust gas has been dried and the water vapor, originally contained therein, cannot do any damage to the compressor wheel of the exhaust gas turbocharger.

(10) In FIG. 4 is depicted an alternative diagram in which the condensate is also collected in a tank 11 from which, however, is it evaporated and mixed to the exhaust gas discharged from the motor vehicle. The architectural execution corresponds otherwise to that of FIG. 3.