Method for controlling the temperature of gases fed into the engine of a motor vehicle exchanger and device for controllig the temperature of said gases

Abstract

According to the method, the gases are circulated in a liquid/gas heat exchanger ( 2, 12 ) prior to their entering the internal combustion engine ( 58 ) and a high temperature liquid and/or a low temperature liquid is circulated in the liquid/gas heat exchanger ( 2, 12 ) in order to heat and/or cool the gases ( 84 ) as required. The liquid/gas heat exchanger may comprise a single stage or two stages, that is a high temperature stage and a low temperature stage. It can also be used to cool the recirculating exhaust gases prior to their entering the engine.

1 . A method for controlling the temperature of the gases entering an internal combustion engine ( 58 ), particularly of an automotive vehicle, characterized in that the gases are circulated in a liquid/gas heat exchanger ( 2 ,  12 ,  22 ,  34 ,  44 ) prior to entering the internal combustion heat engine ( 58 ), and in that a high temperature liquid and/or a low temperature liquid is circulated in the liquid/gas heat exchanger in order to heat and/or cool the gases ( 84 ) as required.  
   
   
       2 . A liquid/gas heat exchanger for use in the method of  claim 1 , characterized in that the heat exchanger is a single-stage heat exchanger ( 2 ,  12 ) and in that valve means ( 4 ) are provided to circulate either a low temperature liquid, or a high temperature liquid, or a mixture of both liquids, in the heat exchanger ( 2 ,  12 ).  
   
   
       3 . The liquid/gas heat exchanger as claimed in  claim 2 , characterized in that it comprises a section ( 14 ) through which the engine intake air ( 15 ) passes and a section ( 16 ) through which a recirculated fraction of the exhaust gases ( 18 ) passes.  
   
   
       4 . A liquid/gas heat exchanger for use in the method as claimed in  claim 1 , characterized in that it comprises a high temperature stage ( 24 ,  36 ) in which a high temperature liquid can circulate, and a low temperature stage ( 26 ,  38 ) in which the low temperature liquid can circulate, interconnecting means ( 76 ,  86 ,  106 ) for controlling the circulation of the high temperature and low temperature liquids as required.  
   
   
       5 . The heat exchanger as claimed in  claim 4 , characterized in that the high temperature stage ( 36 ) comprises a section ( 40 ) through which the engine intake air ( 41 ) passes and a section ( 42 ) through which a recirculated fraction ( 43 ) of the exhaust gases passes.  
   
   
       6 . The liquid/gas heat exchanger as claimed in  claim 5 , characterized in that the low temperature stage ( 38 ) also comprises a section ( 42 ) through which a recirculated fraction ( 43 ) of the exhaust gases passes.  
   
   
       7 . A device for managing the temperature of the gases entering a heat engine ( 58 ), particularly of an automotive vehicle, comprising a main loop ( 52 ) equipped with a main pump ( 60 ) for circulating a heat transfer fluid between the heat engine ( 58 ) and a main radiator ( 64 ) for cooling at high temperature, characterized in that it comprises a secondary loop ( 54 ) including a secondary low temperature radiator ( 78 ), the device further comprising a liquid/gas radiator ( 2 ,  12 ,  22 ,  34 ,  44 ) as claimed in one of  claims 2  to  6 , and interconnecting means ( 76 ,  86 ,  106 ) for circulating the heat transfer fluid in the liquid/gas heat exchanger as required to heat and/or cool the gases ( 84 ) entering the engine ( 58 ).  
   
   
       8 . The management device as claimed in  claim 7 , characterized in that it comprises a single-stage heat exchanger ( 2 ,  12 ) and a three-way valve ( 76 ) for circulating either the hot heat transfer fluid directly leaving the internal combustion engine ( 58 ) in the heat exchanger, or a cold heat transfer fluid leaving the low temperature radiator ( 78 ), or an adequate mixture of both fluids.  
   
   
       9 . The management device as claimed in  claim 7 , characterized in that it comprises a single-stage heat exchanger ( 2 ,  12 ) and a branch on the high temperature fluid circuit equipped with an additional circulating pump ( 86 ), a valve ( 76 ) for circulating either the hot heat transfer fluid directly leaving the heat engine ( 58 ), or the cold heat transfer fluid cooled in the low temperature radiator ( 78 ), or a mixture of both fluids.  
   
   
       10 . The management device as claimed in  claim 7 , characterized in that it comprises a two-stage heat exchanger ( 22 ,  34 ,  44 ), a three-way valve ( 76 ) for circulating the hot heat transfer fluid leaving the internal combustion engine ( 58 ) in the high temperature stage, and a cold heat transfer fluid cooled in the low temperature radiator ( 68 ). in the low temperature stage of the heat exchanger.  
   
   
       11 . The management device as claimed in  claim 7 , characterized in that it comprises a two-stage heat exchanger ( 22 ,  34 ,  44 ), a two-way valve ( 106 ) for circulating the hot heat transfer fluid directly leaving the internal combustion engine ( 58 ) in the high temperature stage of the heat exchanger ( 22 ,  34 ,  44 ), an additional loop equipped with a circulating pump ( 86 ) for circulating the cold heat transfer fluid cooled in the low temperature radiator ( 78 ) in the low temperature stage of the heat exchanger ( 22 ,  34 ,  44 ).