Exhaust posttreatment arrangement with reducing agent reservoir, and method for posttreatment of exhaust gases

Abstract

Proposed are an exhaust gas posttreatment arrangement and a method for the reduction of pollutants, in particular for the selective catalytic reduction of nitrogen oxides. The arrangement has an exhaust line for conducting the exhaust gas of an internal combustion engine to a treatment unit for the reduction of the pollutants, and at least one reservoir for storing a reducing agent for use in the treatment unit. The reservoir is arranged in the region of the exhaust line and extends parallel to the exhaust line, and is in heat-conducting contact with the exhaust line and/or with the exhaust gas in the exhaust line.

1 - 25 . (canceled) 
     
     
         26 . An exhaust gas posttreatment arrangement for reducing pollutants contained in an exhaust gas of an internal combustion engine, in particular for selective catalytic reduction of nitrogen oxides, having
 an exhaust line for conducting the exhaust gas to a preparation unit for reducing the pollutants, and having   at least one reservoir for storing a reducing agent for use in the preparation unit, the reservoir being disposed in the vicinity of the exhaust line and extending parallel to the exhaust line and being in heat-conducting contact with the exhaust line and/or with the exhaust gas contained in the exhaust line, wherein   the exhaust line splits upstream of the preparation unit, in terms of the exhaust gas flow, into a first path and a second path, and the heat-conducting contact is effected via at least one of the first path and the second path.   
     
     
         27 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein the reservoir and the exhaust line are disposed such that the reservoir interacts in directly heat-conducting fashion with the exhaust line and/or the exhaust gas. 
     
     
         28 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein the heat-conducting contact is arranged for thermal release of the reducing agent from a reservoir substance of the reservoir, in particular for inducing a thermal desorption of the reducing agent out of the reservoir substance and/or for inducing an at least partially thermolytic decomposition of the reservoir substance, forming the reducing agent. 
     
     
         29 . The exhaust gas posttreatment arrangement as defined by  claim 27 , wherein the heat-conducting contact is arranged for thermal release of the reducing agent from a reservoir substance of the reservoir, in particular for inducing a thermal desorption of the reducing agent out of the reservoir substance and/or for inducing an at least partially thermolytic decomposition of the reservoir substance, forming the reducing agent. 
     
     
         30 . The exhaust gas posttreatment arrangement as defined by  claim 28 , wherein the reservoir substance is in the solid phase at room temperature. 
     
     
         31 . The exhaust gas posttreatment arrangement as defined by  claim 29 , wherein the reservoir substance is in the solid phase at room temperature. 
     
     
         32 . The exhaust gas posttreatment arrangement as defined by  claim 30 , wherein the reservoir substance is formed from at least one salt and/or at least sulfate of one or more alkaline earth elements and/or of one or more 3d subgroup elements and/or from at least one organic adsorber. 
     
     
         33 . The exhaust gas posttreatment arrangement as defined by  claim 31 , wherein the reservoir substance is formed from at least one salt and/or at least sulfate of one or more alkaline earth elements and/or of one or more 3d subgroup elements and/or from at least one organic adsorber. 
     
     
         34 . The exhaust gas posttreatment arrangement as defined by  claim 32 , wherein the salt is an ammonium salt. 
     
     
         35 . The exhaust gas posttreatment arrangement as defined by  claim 33 , wherein the salt is an ammonium salt. 
     
     
         36 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein a spatial dimension of the reservoir in a direction perpendicular to a flow direction of the exhaust gas is small in comparison to its spatial dimension in the flow direction of the exhaust gas. 
     
     
         37 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein the reservoir has a storage tank which extends along a wall of the exhaust line. 
     
     
         38 . The exhaust gas posttreatment arrangement as defined by  claim 37 , wherein the storage tank contacts and/or is secured to the wall of the exhaust line. 
     
     
         39 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein the reservoir has a replaceable cartridge. 
     
     
         40 . The exhaust gas posttreatment arrangement as defined by  claim 37 , wherein the storage tank is arranged for receiving a replaceable cartridge. 
     
     
         41 . The exhaust gas posttreatment arrangement as defined by  claim 38 , wherein the storage tank is arranged for receiving a replaceable cartridge. 
     
     
         42 . The exhaust gas posttreatment arrangement as defined by  claim 38 , wherein a replaceable cartridge is formed by the storage tank. 
     
     
         43 . The exhaust gas posttreatment arrangement as defined by  claim 38 , wherein a replaceable cartridge is formed by the storage tank. 
     
     
         44 . The exhaust gas posttreatment arrangement as defined by  claim 39 , wherein the replaceable cartridge is formed by a storage tank. 
     
     
         45 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein the reservoir is disposed inside the exhaust line. 
     
     
         46 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein both the first path and the second path discharge into the preparation unit. 
     
     
         47 . The exhaust gas posttreatment arrangement as defined by  claim 46 , wherein a switchable exhaust gas valve is provided, by way of which the first path and the second path are joined together upstream of the preparation unit. 
     
     
         48 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein switchable splitting exhaust gas valve is arranged for selectively introducing the exhaust gas into the first path or into the second path. 
     
     
         49 . The exhaust gas posttreatment arrangement as defined by  claim 48 , wherein the splitting exhaust gas valve is arranged for being able to assume an intermediate position as well, so that exhaust gas can be introduced into both the first path and the second path. 
     
     
         50 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein a heating element is provided for heating the reservoir independently of a heat derived from the exhaust gas. 
     
     
         51 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein the reservoir is disposed upstream of the preparation unit, in terms of the exhaust gas flow. 
     
     
         52 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein a cooling device is provided for cooling the reservoir. 
     
     
         53 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein an electrically triggerable metering valve is disposed on the reservoir. 
     
     
         54 . The exhaust gas posttreatment arrangement as defined by  claim 53 , wherein an electric control unit is provided for triggering the metering valve. 
     
     
         55 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein for intermediate storage of reducing agent that has already emerged from the reservoir before it is metered into the exhaust line, a buffer container is provided. 
     
     
         56 . The exhaust gas posttreatment arrangement as defined by  claim 26 , wherein the preparation unit has a catalytic converter, in particular a catalytic converter arranged for selective catalytic reduction. 
     
     
         57 . A method for exhaust gas posttreatment for reducing pollutants contained in an exhaust gas of an internal combustion engine, in particular for selective catalytic reduction of nitrogen oxides, comprising the steps of
 conducting the exhaust gas via an exhaust line from the engine to a preparation unit for reducing the pollutants;   storing a reducing agent for use in the preparation unit in a reservoir which is disposed in the vicinity of the exhaust line; and   extending the reservoir parallel to the exhaust line and having the reservoir contacting the exhaust line and/or the exhaust gas in heat-conducting contact, wherein the exhaust line splits upstream of the preparation unit, in terms of the exhaust gas flow, into a first path and a second path, and the heat-conducting contact is effected via at least one of the first path and the second path.