Air handling system constructions with externally-assisted boosting for turbocharged opposed-piston engines

Abstract

The air handling system of an opposed-piston engine is equipped with an externally-assisted pumping element such as an electrically-assisted compressor, an electrically-assisted supercharger, or an electrically-assisted turbocharger.

1 . An air handling system for an opposed-piston engine, including at least one cylinder with piston-controlled exhaust and intake ports, comprising:
 a charge air channel coupled to provide charge air to at least one intake port of the opposed-piston engine;   an exhaust channel coupled to transport exhaust gas from at least one exhaust port of the opposed-piston engine;   a turbocharger with a turbine in the exhaust channel and a first compressor in the charge air channel; and,   an electrically-assisted compressor in the charge air channel upstream of the first compressor, between a fresh air inlet of the charge air channel and an inlet of the first compressor.   
     
     
         2 . The air handling system of  claim 1 , further including an EGR loop including an inlet coupled to the exhaust channel, downstream of an outlet of the turbine, and an outlet coupled to the charge air channel, upstream of the electrically-assisted compressor. 
     
     
         3 . The air handling system of  claim 2 , further including a charge air cooler in the charge air channel between an outlet of the electrically-assisted compressor and the inlet of the first compressor. 
     
     
         4 . The air handling system of  claim 2 , further including an aftertreatment device in the exhaust channel, between an outlet of the turbine and the EGR loop inlet. 
     
     
         5 . (canceled) 
     
     
         6 . The air handling system of  claims 1 - 4 , in which the charge air channel includes first and second branches downstream of the first compressor, the first and second branches have a common input coupled to an outlet of the first compressor, and each branch includes a respective charge air cooler. 
     
     
         7 . The air handling system of  claim 1 , without an EGR loop. 
     
     
         8 . The air handling system of  claim 7 , further comprising:
 a valve-controlled bypass loop including an inlet in the charge air channel, between the fresh air inlet and an inlet of the electrically-assisted compressor, and an outlet in the charge air channel, between the outlet of the electrically-assisted compressor and the inlet of the first compressor; and   a back pressure valve in the exhaust channel, downstream of the turbine.   
     
     
         9 . An air handling system for an opposed-piston engine including at least one cylinder with piston-controlled exhaust and intake ports, comprising:
 a charge air channel coupled to provide charge air to at least one intake port of the opposed-piston engine;   an exhaust channel coupled to transport exhaust gas from at least one exhaust port of the opposed-piston engine;   a turbocharger with a turbine in the exhaust channel and a first compressor in the charge air channel; and,   an electrically-assisted compressor in the charge air channel downstream of the first compressor, between an outlet of the first compressor and the at least one intake port.   
     
     
         10 . The air handling system of  claim 9 , without an EGR loop. 
     
     
         11 . The air handling system of  claim 10 , further comprising at least one charge air cooler in the charge air channel, downstream of the first compressor. 
     
     
         12 . The air handling system of  claim 11 , in which the at least one charge air cooler is in a portion of the charge air channel between the outlet of the first compressor and an Inlet of the electrically-assisted compressor. 
     
     
         13 . The air handling system of  claim 10 , further comprising a valve-controlled back flow prevention loop including an inlet in the charge air channel, in common with an intake of the electrically-assisted compressor, and an outlet in the charge air channel, in common with the outlet of the electrically-assisted compressor. 
     
     
         14 . An air handling system for an opposed-piston engine including at least one cylinder with piston-controlled exhaust and intake ports, comprising:
 a charge air channel coupled to provide charge air to at least one intake port of the opposed-piston engine;   an exhaust channel coupled to transport exhaust gas from at least one exhaust port of the opposed-piston engine;   a turbocharger with a turbine in the exhaust channel and a compressor in the charge air channel;   an electrically-assisted supercharger in the charge air channel downstream of the compressor, between an outlet of the compressor and the at least one intake port; and,   an EGR loop including an inlet coupled to an exhaust port manifold in direct fluid communication with at least one exhaust port and an outlet coupled to the charge air channel, upstream of the electrically-assisted supercharger.   
     
     
         15 . The air handling system of  claim 14 , in which the charge air channel includes first and second branches downstream of the electrically-assisted supercharger, the first and second branches have a common input coupled to an outlet of the electrically-assisted supercharger, and each branch includes a respective charge air cooler. 
     
     
         16 . An air handling system for an opposed-piston engine, in which the engine has no supercharger and includes at least one cylinder with piston-controlled exhaust and intake ports, the air handling system comprising:
 a charge air channel coupled to provide charge air to at least one intake port of the opposed-piston engine;   art exhaust channel coupled to transport exhaust gas from at least one exhaust port of the opposed-piston engine;   an electrically-assisted turbocharger with a turbine in the exhaust channel and a compressor in the charge air channel;   at least one charge air cooler in the charge air channel, downstream of the compressor.   
     
     
         17 . The air handling system of  claim 16 , further comprising a back pressure valve in the exhaust channel, downstream of the turbine. 
     
     
         18 . The air handling system of  claim 17 , further including an EGR loop including an inlet coupled to the exhaust channel, between the back pressure valve and an outlet of the turbine, and an outlet coupled to the charge air channel, upstream of the compressor. 
     
     
         19 . The air handling system of  claim 18 , in which the turbine is a variable geometry turbine. 
     
     
         20 . The air handling system of  claim 18 , in which the charge air channel includes first and second branches downstream of the compressor, the first and second branches have a common input coupled to an outlet of the compressor, and each branch includes a respective charge air cooler. 
     
     
         21 . The air handling system of  claim 16 , without an EGR loop.