System and apparatus for reducing liquid water emissions in the exhaust of a hydrogen engine

Abstract

A system for reducing the volume of liquid water emitted from an exhaust pipe of a hydrogen-fueled engine is described. A vaporizer unit has a main body portion, a spraying assembly and a vapor port. The main body portion surrounds at least a portion of an exhaust manifold of the engine. The vapor port couples the vaporizer unit to the exhaust pipe of the engine via a vapor pipe. The spraying assembly is configured to spray liquid water over at least a portion of the exhaust manifold. The apparatus also includes a liquid-vapor separator placed inline in the exhaust pipe of the engine, and a sump coupled to the exhaust pipe. The sump collects liquid water recovered by the liquid-vapor separator. Finally, the apparatus includes a pump coupled to the sump and to the spraying assembly and configured to provide the collected liquid water to the vaporizer unit.

1 . A method to reduce the volume of liquid water ultimately emitted from an exhaust pipe of a hydrogen fueled engine comprising: 
 collecting liquid water from the exhaust pipe;    vaporizing the liquid water using waste heat from the engine; and    emitting the vaporized liquid water to the atmosphere.    
   
   
       2 . The method of  claim 1  further comprising pumping the collected liquid water to a vaporizer unit wherein the vaporizing is performed.  
   
   
       3 . The method of  claim 1  wherein the vaporized liquid water is emitted to the atmosphere via the exhaust pipe.  
   
   
       4 . The method of  claim 1  wherein the vaporized liquid water is emitted to the atmosphere via a separate pipe.  
   
   
       5 . The method of  claim 2  further comprising filtering the collected liquid water prior to the pumping.  
   
   
       6 . The method of  claim 1  wherein vaporizing the liquid water using waste heat from the engine comprises: 
 providing the collected liquid water to a vaporizer unit, the vaporizer unit comprising at least one spray nozzle disposed within a jacket that is formed at least partially around an exhaust manifold of the engine; and    spraying the collected liquid over the exhaust manifold with the spray nozzles, wherein the sprayed liquid water is contained within the jacket.    
   
   
       7 . The method of  claim 6  further comprising pre-heating the collected liquid water with recovered waste heat from at least a portion of the exhaust pipe.  
   
   
       8 . The method of  claim 1  wherein emitting the vaporized liquid water to the atmosphere via the exhaust pipe comprises directing the vaporized liquid water to a vapor port that is in fluid communication with the exhaust pipe.  
   
   
       9 . The method of  claim 6  further comprising making the jacket liquid-tight around the exhaust manifold of the engine.  
   
   
       10 . An apparatus to reduce the volume of liquid water emitted from an exhaust pipe of a hydrogen-fueled engine, comprising: 
 a vaporizer unit comprising a main body portion, a spraying assembly and a vapor port portion, and wherein: 
 the main body portion surrounds at least a portion of an exhaust manifold of the engine;  
 the main body portion is defined by an inner surface and an outer surface;  
 the inner surface is defined in part by at least a portion of the exhaust manifold;  
 the vapor port portion is defined by an opening in the vaporizer unit;  
 the spraying assembly comprises at least one spray nozzle supported by the main body portion and configured to spray liquid water over at least a portion of the exhaust manifold;  
   a sump coupled to the exhaust pipe wherein the sump is configured to collect liquid water recovered from the exhaust pipe; and    a pump coupled to the sump and to the spraying assembly and configured to provide the collected liquid water to the vaporizer unit.    
   
   
       11 . The apparatus of  claim 10  further comprising a liquid-vapor separator placed inline in the exhaust pipe of the engine, and wherein the sump is configured to collect liquid water from the liquid-vapor separator.  
   
   
       12 . The apparatus of  claim 10  further comprising a liquid return line that couples the pump to the vaporizer unit.  
   
   
       13 . The apparatus of  claim 12  wherein the liquid return line is at least partially disposed proximate to a portion of the exhaust pipe that is between the pump and the exhaust manifold.  
   
   
       14 . The apparatus of  claim 13  wherein the liquid return line is covered with a heat-retaining insulation.  
   
   
       15 . The apparatus of  claim 14  wherein the heat retaining insulation material is selected from the group consisting of graphite composite, fiberglass, mylar, aluminum and ceramic.  
   
   
       16 . The apparatus of  claim 10  wherein at least a portion of the exhaust pipe is covered with a heat-retaining insulation to increase the transfer of heat to the liquid return line.  
   
   
       17 . The apparatus of  claim 12  wherein the liquid-vapor separator comprises a separator housing that defines an enclosed space interior to the separator housing, and wherein the enclosed space includes a medium to cause a separation of liquid water from water vapor.  
   
   
       18 . The apparatus of  claim 17  wherein the medium is a surface area enhancing material selected from the group consisting of plastic beads, glass beads, ceramic beads, metal wool, fiberglass wool, and expanded metal.  
   
   
       19 . The apparatus of  claim 10  wherein: 
 the exhaust manifold comprises a plurality of separate outlet pipes and a header that is connected to the plurality of outlet pipes, and wherein the exhaust pipe is connected to the header;    the main body portion is further defined by a front face, and four side faces, and wherein: 
 the front face is substantially rectangular and defined by one or more openings for the one or more output pipes;  
 the four side faces extend generally perpendicularly from an edge of each of the four sides of the front face to define an open sided box defining an interior space; and  
   wherein the main body portion is positioned on the exhaust manifold such that each of the side faces are affixed to the exhaust manifold, and the one or more output pipes traverse the interior space of the main body portion and exit the one or more openings on the front face of the main body portion.    
   
   
       20 . The apparatus of  claim 10  wherein the main body portion is composed of a material selected from the group consisting of plastic, graphite composite, aluminum, steel and ceramic.  
   
   
       21 . The apparatus of  claim 10  further comprising a drain channel disposed in the exhaust pipe between the liquid-vapor separator and an ambient exhaust point of the exhaust pipe, and wherein the drain channel is drained into the sump.  
   
   
       22 . The apparatus of  claim 21  further comprising a filter screen positioned between the exhaust pipe and the drain channel.  
   
   
       23 . The apparatus of  claim 10  further comprising a fluid deflector disposed within the exhaust pipe to prevent water from the sump from re-entering the exhaust pipe as exhaust gasses flow through the liquid-vapor separator.  
   
   
       24 . The apparatus of  claim 10  wherein the spraying assembly comprises two nozzles supported by the main body portion and configured to spray liquid water over at least a portion of the exhaust manifold.  
   
   
       25 . The apparatus of  claim 10  wherein the inner surface is coated with a sealant.  
   
   
       26 . The apparatus of  claim 25  wherein the sealant is a high temperature silicone.  
   
   
       27 . The apparatus of  claim 10  wherein the opening in the vaporizer unit is coupled to the exhaust pipe via a vapor pipe.  
   
   
       28 . The apparatus of  claim 10  wherein the opening in the vaporizer unit is vented directly to atmosphere outside of the body portion.  
   
   
       29 . The apparatus of  claim 10  wherein the opening in the vaporizer unit is vented to the liquid-vapor separator via a secondary pipe.  
   
   
       30 . The apparatus of  claim 29  wherein the secondary pipe encases the exhaust pipe.  
   
   
       31 . A system to reduce the volume of liquid water emitted from the tailpipe of a hydrogen fueled engine, comprising: 
 means for collecting liquid water that condenses in the tailpipe from exhaust gasses emitted by the engine;    means for vaporizing the liquid water using waste heat from the engine; and    means for returning the vaporized collected water to the atmosphere via the tailpipe.    
   
   
       32 . An apparatus comprising: 
 a jacket configured to cover at least a portion of an exhaust manifold of an engine;    a liquid collector configured to collect liquids within an exhaust pipe connected to the exhaust manifold;    a pump configured to pump liquids from the liquid collector to the jacket; and    a spray assembly configured to spray liquids from the pump over the portion of the exhaust manifold covered by the jacket.