US 6,802,345 B1 · Fueling system vapor recovery and containment performance monitor and method of operation thereof

Abstract

A method and apparatus for monitoring and determining fuel vapor recovery performance is disclosed. The dispensing of liquid fuel into a tank by a conventional gas pump nozzle naturally displaces a mixture of air and fuel ullage vapor in the tank. These displaced vapors may be recovered at the dispensing point nozzle by a vapor recovery system. A properly functioning vapor recovery system recovers approximately one unit volume of vapor for every unit volume of dispensed liquid fuel. The ratio of recovered vapor to dispensed fuel is termed the A/L ratio, which should ideally be approximately equal to one (1). The A/L ratio, and thus the proper functioning of the vapor recovery system, may be determined by measuring liquid fuel flow and return vapor flow (using a vapor flow sensor) on a nozzle-by-nozzle basis. The disclosed methods and apparatus provide for the determination of A/L ratios for individual nozzles using a reduced number of vapor flow sensors. The disclosed methods and apparatus also provide for the determination of fuel dispensing system vapor containment integrity, and the differentiation of true vapor recovery failures as opposed to false failures resulting from the refueling of vehicles provided with onboard vapor recovery systems.

Claims32

Dependent claims

A method of detecting vapor recovery system failures associated with a fuel dispensing point, comprising:

a) determining an amount of fuel dispensed at each of a plurality of dispensing points at multiple times;
b) determining a composite amount of vapor recovered for said plurality of dispensing points at multiple times;
and
c) calculating a vapor recovered to fuel dispensed ratio for each of said plurality of fuel dispensing points by:
(1) forming a generalized equation for the relationship between said vapor recovered, said fuel dispensed, and a vapor recovered to fuel dispensed ratio, for each of the plurality of fuel dispensing points;
and
(2) solving said generalized equation for each of said vapor recovered to fuel dispensed ratios for each of the plurality of fuel dispensing points.

4 more elements

A system for detecting true vapor recovery failures in a fuel dispensing system capable of fueling non-ORVR and ORVR equipped vehicles, the system comprising:

a plurality of fuel dispensing points each coupled to a main fuel storage system by a fluid carrying conduit and a vapor carrying conduit;
one or more vapor flow sensors operatively connected to said vapor carrying conduit between the plurality of fuel dispensing points and said main fuel storage system;
a plurality of liquid dispensing meters each associated with one of said plurality of fuel dispensing points, each of said plurality of liquid dispensing meters operatively connected to said fluid carrying conduit between said one of said plurality of fuel dispensing points and the main fuel storage system;
and a central electronic and diagnostic system adapted to:
a) communicate with said one or more vapor flow sensors and said plurality of liquid dispensing meters;
b) calculate a plurality of vapor recovered to fuel dispensed ratios for each of said plurality of fuel dispensing points;
c) determine a first observed number of said ratios indicating a failure for each of said plurality of fuel dispensing points;
d) determine a second observed number of said ratios not indicating a failure for each of said plurality of fuel dispensing points;
e) determine a first expected number of vapor recovered to fuel dispensed ratios indicating a failure for each of said plurality of fuel dispensing points;
f) determine a second expected number of vapor recovered to fuel dispensed ratios not indicating a failure for each of said plurality of fuel dispensing points;
and
g) determine whether any of said plurality of fuel dispensing points has experienced a true vapor recovery failure based on a calculation that is a function of (1) said first observed number and said first expected number, and (2) said second observed number and said second expected number.

9 more elements

A system for detecting true vapor recovery failures in a fuel dispensing system capable of fueling non-ORVR and ORVR equipped vehicles, the system comprising:

a plurality of fuel dispensing points coupled to a main fuel storage system by a fluid carrying conduit and a vapor carrying conduit;
one or more vapor flow sensors operatively connected to said vapor carrying conduit between the plurality of fuel dispensing points and the main fuel storage system;
a plurality of liquid dispensing meters each associated with one of said plurality of fuel dispensing points, each of said plurality of liquid dispensing meters operatively connected to said fluid carrying conduit between said one of said plurality of fuel dispensing points and said main fuel storage system;
and
a central electronic and diagnostic system adapted to:
a) communicate with said one or more vapor flow sensors and said plurality of liquid dispensing meters;
b) calculate a plurality of vapor recovered to fuel dispensed ratios for each of said plurality of fuel dispensing points;
c) determine which of said ratios indicates a failure for each of said plurality of fuel dispensing points;
d) determine a proportion of said ratios indicating a failure for each of said plurality of fuel dispensing points;
e) determine an expected proportion of vapor recovered to fuel dispensed ratios indicating a failure derived from all of said plurality of fuel dispensing points;
and
f) compare said proportion to said expected proportion for each of said plurality of fuel dispensing points to generate a comparison;
and
g) determine which of said plurality of fuel dispensing points have experienced true vapor recovery failures based on said comparison.

11 more elements

Dependencies are inferred from the claim text.

Fueling system vapor recovery and containment performance monitor and method of operation thereof

Life of this patent

Fueling system vapor recovery and containment performance monitor and method of operation thereof

Life of this patent

Abstract

Claims32