Vehicle fueling system using double block and bleed fuel line

Abstract

The invention is an improved method and system to fuel a vehicle such as a hydrogen-powered vehicle. The present invention vents air into a fuel fill line within the vehicle from a fuel fill receptacle to the vehicle's fuel storage tank. The invention eliminates or reduces inadvertent fuel ignition from electrostatic discharge in and around a vehicle fuel line during fueling. Just prior to fueling, the invention vents the fuel line in between two of a plurality of fuel line check valves closest to the receptacle. The invention can be configured to activate the vent system where a first switch indicates vehicle fueling is imminent (such as a fuel fill door is opened) and a second switch indicates that the receptacle is not attached to a fuel source. The system can also be configured to deactivate if the first switch indicates fueling is not imminent (the fuel door is closed), or the second switch indicates that the receptacle is attached to the fuel source. Additional features can include a calibratable timer to assure enough time has lapsed to assure proper fuel venting has occurred; a disable feature to disable the vent system when the vehicle is powered off; and indicators for the vehicle operator that the venting system is functioning.

We claim:  
     
         1 . An improved vehicle fuel transfer system configured to interact with a fueling station, comprising: 
 a vehicle comprising a receptacle to mechanically receive a fuel fill nozzle from the fueling station, a fuel line connected to the receptacle, and an on-board storage tank connected to the fuel line;    the vehicle fuel line further comprising a plurality of check valves;    a system to vent the fuel line between two check valves closest to the receptacle; and    a system to activate and deactivate the vent system comprising a first switch to indicate vehicle fueling is imminent and a second switch to indicate that the receptacle is not attached to a fuel source.    
     
     
         2 . The system of  claim 1  wherein vehicle fueling is imminent when a fuel fill door is opened.  
     
     
         3 . The system of  claim 1  wherein the system to activate the vent system comprises a requirement that the first switch indicates fueling is imminent and the second switch indicates that the receptacle is not attached to the fuel source.  
     
     
         4 . The system of  claim 1  wherein the distance between the two check valves closest to the receptacle is no greater than six inches.  
     
     
         5 . The system of  claim 1  wherein the system to deactivate the vent system comprises a requirement that the first switch indicates fueling is not imminent.  
     
     
         6 . The system of  claim 1  wherein the system to deactivate the vent system comprises a requirement that the second switch indicates that the receptacle is attached to the fuel source.  
     
     
         7 . The system of  claim 1  wherein the system to activate the vent system further comprises a calibrated timer.  
     
     
         8 . The system of  claim 1  wherein the first switch is mechanical.  
     
     
         9 . The system of  claim 1  wherein the first switch is electrical.  
     
     
         10 . The system of  claim 1  wherein the second switch is mechanical.  
     
     
         11 . The system of  claim 1  wherein the second switch is electrical.  
     
     
         12 . The system of  claim 1  further comprising a system to disable the system to activate and deactivate the vent system when the vehicle is powered off.  
     
     
         13 . The system of  claim 1  further comprising indicators that let an operator know the vent system is functioning.  
     
     
         14 . The system of  claim 1  wherein the venting system comprises a 3-way solenoid valve and a vent.  
     
     
         15 . The system of  claim 14  wherein the 3-way solenoid valve is electrical.  
     
     
         16 . The system of  claim 14  wherein the 3-way solenoid valve is mechanical.  
     
     
         17 . An improved vehicle fuel transfer method configured to interact with a fueling station, comprising the steps of: 
 venting a fuel line comprising a plurality of check valves disposed between a vehicle fuel storage tank and a receptacle to mechanically receive a fuel fill nozzle from the fueling station, the venting occurring between two check valves closest to the receptacle; and    activating and deactivating the venting comprising the steps of indicating vehicle fueling is imminent and indicating the receptacle is not attached to a fuel source.    
     
     
         18 . The method of  claim 17  wherein the step of indicating vehicle fueling is imminent occurs when a fuel fill door is opened.  
     
     
         19 . The method of  claim 17  wherein the step of activating venting comprises the steps of indicating fueling is imminent and indicating the receptacle is not attached to the fuel source.  
     
     
         20 . The method of  claim 17  wherein the step of deactivating venting comprises the steps of indicating fueling is not imminent.  
     
     
         21 . The method of  claim 17  wherein the step of deactivating venting comprises the step of indicating that the receptacle is attached to the fuel source.  
     
     
         22 . The method of  claim 17  wherein the step of activating venting further comprises the step of timing the venting.  
     
     
         23 . The method of  claim 17  further comprising the step of disabling venting when the vehicle is powered off.  
     
     
         24 . The method of  claim 17  further comprising the step of indicating to the operator that the venting is functioning.  
     
     
         25 . The method of  claim 17  wherein the distance between the two check valves closest to the receptacle is no greater than six inches.  
     
     
         26 . The method of  claim 17  wherein the check valve closest to the receptacle is adjacent to the receptacle.