Tank For A Reducing Agent, Motor Vehicle Having A Tank For A Reducing Agent And Method For Operating An SCR System Of A Motor Vehicle

Abstract

A tank for a reducing agent which forms ammonia or which includes ammonia, has a planar first tank volume and at least one elongate second tank volume. A motor vehicle has an internal combustion engine, an exhaust system with an SCR catalytic converter and a reducing agent metering device and a body with a roof. A tank with a planar first tank volume for the reducing agent is provided on the roof. A method for operating an SCR system of a motor vehicle which has at least two tank volumes, a reducing agent metering device and an SCR catalytic converter, is also provided.

1 . A tank for a reducing agent forming ammonia or including ammonia, the tank comprising:
 a planar first tank volume having a first height, a first mean base area and a first ratio of said first mean base area to said first height of greater than 500 cm; and   at least one elongate second tank volume having a second height and a second mean base area, said at least one elongate second tank volume projecting relative to said planar first tank volume.   
   
   
       2 . The tank according to  claim 1 , wherein a second ratio of said second mean base area to said second height is smaller than 2 cm. 
   
   
       3 . The tank according to  claim 1 , wherein said first tank volume has an edge region, and said at least one second tank volume is disposed directly in said edge region of said first tank volume. 
   
   
       4 . The tank according to  claim 1 , wherein said first tank volume has a first volume of at least 90 liters for holding the reducing agent, and said at least one elongate second tank volume has a second volume encompassing at most 10% of said first volume. 
   
   
       5 . The tank according to  claim 1 , which further comprises a third tank volume, and a connecting line connected between said third tank volume and at least one of said first tank volume or said at least one second tank volume. 
   
   
       6 . The tank according to  claim 5 , wherein at least one of said at least one second tank volume or said third tank volume includes a heater. 
   
   
       7 . The tank according to  claim 1 , wherein at least said first tank volume has a housing composed of plastic. 
   
   
       8 . The tank according to  claim 1 , wherein at least said first tank volume has heat insulation. 
   
   
       9 . A motor vehicle, comprising:
 an internal combustion engine;   an exhaust system communicating with said internal combustion engine and having an SCR catalytic converter and a reducing agent metering device;   a body with a roof; and   a tank disposed on said roof, communicating with said exhaust system and having a planar first tank volume for a reducing agent.   
   
   
       10 . The motor vehicle according to  claim 9 , wherein said body has a roof beam, and said tank has at least one elongate second tank volume, said at least one elongate second tank volume being disposed along said roof beam and projecting relative to said planar first tank volume. 
   
   
       11 . The motor vehicle according to  claim 10 , which further comprises a third tank volume, and a connecting line connected between said third tank volume and at least one of said at least one second tank volume or said first tank volume, at least said first tank volume being connected through said third tank volume to said reducing agent metering device. 
   
   
       12 . The motor vehicle according to  claim 10 , wherein said reducing agent metering device is connected to said at least one second tank volume which can be filled under gravitational force. 
   
   
       13 . The motor vehicle according to  claim 11 , wherein said reducing agent metering device is connected to said third tank volume which can be filled under gravitational force. 
   
   
       14 . The motor vehicle according to  claim 9 , which further comprises a roof region having heat insulation, at least said first tank volume of said tank being at least partially insulated by said heat insulation. 
   
   
       15 . A method for operating an SCR system of a motor vehicle having at least two tank volumes, a reducing agent metering device and an SCR catalytic converter, the method comprising the following steps:
 storing a reducing agent for the SCR system in one of the tank volumes;   during operation of the motor vehicle, automatically filling at least one further of the tank volumes with the reducing agent from the one tank volume; and   forming a reservoir for the reducing agent metering device with the at least one further tank volume.