[0001] 1. Field of the Invention
[0002] The present invention relates generally to a vehicle fueling system and specifically to an improved method and system to fuel a vehicle using a fuel line with a double block and bleed.
[0003] 2. Discussion of the Prior Art
[0004] In an effort to find alternative energy sources for automobiles, hydrogen can be used in an electrochemical reaction to generate electricity. Generally, the reaction takes place in fuel cells. Fuel cells are known in the prior art for directly converting chemical energy of a fuel to electrical energy. Fuel cell advantages include low emissions, high fuel energy conversion efficiencies, and low noise and vibrations (U.S. Pat. No. 5,248,566 to Kumar et al.) Despite fuel cell advantages, various design challenges are presented by existing technology.
[0005] Fuel cell systems are typically fueled with hydrogen. Hydrogen fuel is highly volatile. When a hydrogen vehicle receives fuel, the vehicle physically connects to a hydrogen-dispensing nozzle. It is known that aircraft, marine vessels and ground vessels such as automobiles can accumulate significant electrostatic charges during transport. For a hydrogen-fueled vehicle, improper vehicle grounding or lack of grounding of the vehicle prior to connecting to the hydrogen fueling station could result in inadvertent igniting of any hydrogen present in or around the fueling line if an electrostatic discharge occurs.
[0006] Ways to reduce risks associated with the transfers of fuels are known in the prior art. For example, U.S. Pat. No. 4,091,848 to Phillips discloses a warning system for a liquefied petroleum (“LP”) gas transport vehicle. The system informs a vehicle's operator of a hose connection extending between a vehicle's gas tank and a second remote main supply.
[0007] U.S. Pat. No. 5,156,198 to Hall discloses a pump lock fuel system. The patent describes a fuel lock and dispensing system where data from a vehicle computer is used to identify the vehicle, to transfer data to and from the vehicle computer to a fuel pump computer and to unlock the fuel pump. The system will only allow fueling after a fuel nozzle is inserted and a vehicle identified. Although this patent provides an element of safety, its primary function is vehicle identification.
[0008] Automatic refueling systems are also known in the prior art. For example, U.S. Pat. No. 5,383,500 to Dwars et al. discloses an automatic refueling system that allows the driver to interrupt or modify refueling without leaving the vehicle. See also, U.S. Pat. No. 4,608,830 to Peschka et al. and U.S. Pat. No. 3,502,117 to Nebelsiek et al.
[0009] Vehicle grounding systems or other means to discharge electrostatic charges also exist in the prior art. See generally, U.S. Pat. No. 5,159,523 to Claassen et al. This system has a first and second grounding means and a detection circuit to verify proper grounding configuration before fueling is allowed. While Claassen et al. reduces accidental and untimely discharge of accumulated electrostatic discharges in the proximity of volatile fuels, it requires three complicated system components and does nothing to reduce the amount of volatile fuels present in and around a vehicle fuel line.
[0010] A simple and inexpensive system to eliminate or reduce inadvertent fuel ignition in and around a vehicle fuel line during fueling is needed.
[0011] Accordingly, the present invention provides an improved system and method to fuel a vehicle, particularly a hydrogen-fueled vehicle, by eliminating or reducing inadvertent fuel ignition in and around a vehicle fuel line during fueling.
[0012] The present invention has a receptacle to mechanically receive a fuel fill nozzle from a fueling station, a fuel line connected to the receptacle, and a storage tank connected to the fuel line; a plurality of check valves in the fuel lines; a system to vent the fuel line between the 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 (such as a fuel fill door is opened) and a second switch to indicate that the receptacle is not attached to a fuel source. The switches can be electrical or mechanical.
[0013] The invention can be configured to be activated when the first switch indicates fueling is imminent and the second switch indicates that the fuel fill nozzle has been connected and a slight amount of fuel flow has started. In the preferred embodiment, when the fuel door opens, but before a fill station's fuel fill nozzle is attached, a mechanical or electrical 3-way solenoid valve activates and vents any hydrogen in the fuel line adjacent to the receptacle to a vent to the atmosphere. When the fuel fill nozzle is attached to the receptacle, a “puff” of hydrogen can be sent from the fueling station to flush any fuel line air from the vent cycle. The “puff” also activates the second switch to deactivate the 3-way solenoid valve. This ends the venting and allows hydrogen to flow into the vehicle tank. The venting system can be also be configured to deactivate if the first switch indicates fueling is not imminent (such as when the fuel door is closed).
[0014] The invention can add 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.
[0015] The vented area of the fuel line in the preferred embodiment lies between the two check valves closest to the receptacle. This area should not be greater than six inches. Further, the closest check valve to the receptacle and the receptacle should be separated by a minimal distance or even adjacent to each other.
[0016] Other objects of the present invention will become more apparent to persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying figures.
[0017] The foregoing objects, advantages, and features, as well as other objects and advantages, will become apparent with reference to the description and figures below, in which like numerals represent like elements and in which:
[0018]
[0019]
[0020] The present invention relates to fuel transfer and specifically to an improved method and system to fuel a vehicle that eliminates or reduces inadvertent fuel ignition in and around a vehicle fuel line during fueling. Although the illustrated embodiment of the present invention is particularly suited to hydrogen fueling, the present invention itself can be adapted to many types of fueling strategies by someone of ordinary skill in the art.
[0021]
[0022] The fueling system illustrated in
[0023] The present invention illustrated in
[0024] In
[0025] The present invention adds one of many possible venting systems to the fuel line
[0026] Fuel line
[0027] When the fuel line
[0028] In short, the present invention vents a small portion of the fuel line
[0029] The above-described embodiment of the invention is provided purely for purposes of example. Many other variations, modifications, catalysts, and applications of the invention may be made.