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In-Situ Automotive Gaseous Fuel System Leak Check Method

IP.com Disclosure Number: IPCOM000124730D
Publication Date: 2005-May-04
Document File: 1 page(s) / 27K

Publishing Venue

The IP.com Prior Art Database

Abstract

This invention addresses the need to assure that there are no undetected leaks in an automotive gaseous fuel system, which includes the compressed gas fuel tank 1 and the fuel line 2 from the fuel tank to a fuel cell stack or internal combustion engine 3. This method could be used as a system integrity diagnostic tool invoked by a repair technician or this method could be initiated as part of the shutdown procedure of a vehicle.

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In-Situ Automotive Gaseous Fuel System Leak Check Method

This invention addresses the need to assure that there are no undetected leaks in an automotive gaseous fuel system, which includes the compressed gas fuel tank 1 and the fuel line 2 from the fuel tank to a fuel cell stack or internal combustion engine 3.  This method could be used as a system integrity diagnostic tool invoked by a repair technician or this method could be initiated as part of the shutdown procedure of a vehicle. 

 Figure 1. Schematic Diagram of the Leak Testing System

The invention method is to simply (i) pressurize the fuel line 2 or tank 1, (ii) isolate the fuel line 1 or tank 2, and (iii) measure the pressure drop in the fuel line 1 or tank 2 over an arbitrary period of time. 

Referring to Figure 1, the method is summarized as follows:

 

  1. Close the solenoid valves 4,5.
  2. Log the pressure and temperature readings from the temperature sensor 6 and pressure sensor 7.
  3. Measure the change in pressure (DP) over an arbitrary period of time.
  4. Calculate the DP due to temperature changes only.  If the measured DP from #3 does not equal the calculated DP due to temperature changes only within some arbitrary value, a significant leak must be present.

Because most of the valves 4,5 and sensors 6,7 are already in use on a vehicle, very little, if any, additional hardware will be required for implementation.  Although this invention was originally intended for hydrogen fuel specifically, the technique is equally a...