Fueling system vapor recovery and containment performance monitor and method of operation thereof
First Claim
1. A system for monitoring vapor recovery in a liquid fuel dispensing facility having at least one fuel dispensing point connected to a main fuel storage system by a means for supplying liquid fuel to the dispensing point and a means for returning vapor from the dispensing point, said monitoring system comprising:
- a vapor flow sensor operatively connected to the means for returning vapor and adapted to indicate the amount of vapor flow through the means for returning vapor;
a liquid fuel dispensing meter operatively connected to the means for supplying liquid fuel and adapted to indicate the amount of liquid fuel dispensed through the at least one fuel dispensing point; and
a central electronic control and diagnostic arrangement having, a means for determining a ratio of vapor flow to dispensed liquid fuel for the at least one fuel dispensing point, said determining means receiving dispensed liquid fuel amount information from the liquid fuel dispensing meter and receiving vapor flow amount information from the vapor flow sensor, wherein the acceptability of vapor recovery for the fuel dispensing point is determined by said ratio of vapor flow to dispensed liquid fuel.
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Accused Products
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.
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Citations
85 Claims
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1. A system for monitoring vapor recovery in a liquid fuel dispensing facility having at least one fuel dispensing point connected to a main fuel storage system by a means for supplying liquid fuel to the dispensing point and a means for returning vapor from the dispensing point, said monitoring system comprising:
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a vapor flow sensor operatively connected to the means for returning vapor and adapted to indicate the amount of vapor flow through the means for returning vapor;
a liquid fuel dispensing meter operatively connected to the means for supplying liquid fuel and adapted to indicate the amount of liquid fuel dispensed through the at least one fuel dispensing point; and
a central electronic control and diagnostic arrangement having, a means for determining a ratio of vapor flow to dispensed liquid fuel for the at least one fuel dispensing point, said determining means receiving dispensed liquid fuel amount information from the liquid fuel dispensing meter and receiving vapor flow amount information from the vapor flow sensor, wherein the acceptability of vapor recovery for the fuel dispensing point is determined by said ratio of vapor flow to dispensed liquid fuel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 51)
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12. A system for monitoring vapor recovery in a liquid fuel dispensing facility having at least two fuel dispensing points connected to a main fuel storage system by a vapor return pipeline, said monitoring system comprising:
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a vapor flow sensor operatively connected to the vapor return pipeline;
means for determining dispensed liquid fuel amount information for each fuel dispensing point; and
a means for determining a ratio of vapor flow to dispensed liquid fuel for the fuel dispensing points based on vapor flow sensor readings and dispensed liquid fuel amount information, wherein the acceptability of vapor recovery for the fuel dispensing points is determined by said ratio of vapor flow to dispensed liquid fuel. - View Dependent Claims (13)
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14. A method of monitoring vapor recovery in a liquid fuel dispensing facility having at least one fuel dispensing point connected to a main fuel storage system by a means for supplying liquid fuel to the dispensing point and a means for returning vapors from the dispensing point, said monitoring method comprising the steps of:
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determining at multiple times an amount of vapor flow through the means for returning vapors;
determining at multiple times an amount of liquid fuel dispensed through the means for supplying liquid fuel; and
determining a ratio of vapor flow to dispensed liquid fuel for the fuel dispensing point based on the amount of vapor flow through the means for returning vapors and the amount of liquid fuel dispensed through the means for supplying liquid fuel, wherein the acceptability of vapor recovery for the fuel dispensing point is determined by said ratio of vapor flow to dispensed liquid fuel. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 26, 27, 28)
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22. A system for monitoring vapor containment in a liquid fuel dispensing facility having a main fuel storage system connected by a vent pipe-pressure relief valve arrangement to atmosphere, said monitoring system comprising:
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a pressure sensor operatively connected to the vent pipe;
a vapor processor operatively connected to the vent pipe; and
means for determining the acceptability of vapor containment in the main fuel storage system, said determining means being operatively connected to the pressure sensor to receive pressure level information therefrom and being operatively connected to the vapor processor to selectively cause the vapor processor to draw a negative pressure in the main fuel storage system.
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23. A method of monitoring vapor containment in a liquid fuel dispensing facility having at least one main fuel storage tank connected by a vent pipe-pressure relief valve arrangement atmosphere, said monitoring method comprising the steps of:
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identifying the start of an idle period for the liquid fuel dispensing facility;
monitoring the liquid fuel dispensing facility to confirm maintenance of the idle period;
determining whether pressure in the main fuel storage tank is equal or below a minimum level;
selectively adjusting pressure in the main fuel storage tank to a preset lower level when the previously determined pressure is above the minimum level;
monitoring variation of the pressure in the main fuel storage tank during the remainder of the idle period;
determining the end of the idle period; and
determining the acceptability of vapor containment in the main fuel storage tank based on the variation of the pressure during the idle period. - View Dependent Claims (24, 25)
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29. A method of determining vapor recovery system failures associated with a single fuel dispensing point, said method comprising the steps of:
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determining the vapor flow to dispensed fuel ratios for a plurality of fuel dispensing points;
determining the number of vapor flow to dispensed fuel ratios that are below a preset minimum for each of the plurality of fuel dispensing points;
determining the average number of vapor flow to dispensed fuel ratios below the preset minimum for the plurality of fuel dispensing points; and
comparing the number vapor flow to dispensed fuel ratios below the preset minimum for each of the plurality of fuel dispensing points to the average number of vapor flow to dispensed fuel ratios below the present minimum to determine whether the vapor recovery system associated with each of the plurality of fuel dispensing has failed.
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30. A system for monitoring vapor recovery in a liquid fuel dispensing facility comprising:
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a fuel dispensing point;
a fuel storage tank;
means for supplying liquid fuel from the fuel storage tank to the fuel dispensing point;
means for returning vapor from the fuel dispensing point to the fuel storage tank;
a vapor flow sensor operatively connected to the means for returning vapor and adapted to indicate the amount of vapor flow through the means for returning vapor;
a liquid fuel dispensing meter operatively connected to the means for supplying liquid fuel and adapted to indicate the amount of liquid fuel dispensed through the fuel dispensing point; and
means for determining a ratio of vapor flow- to dispensed liquid fuel for the fuel dispensing point, said determining means receiving dispensed liquid fuel amount information from the liquid fuel dispensing meter and receiving vapor flow amount information from the vapor flow sensor.
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31. A vapor recovery monitoring system that monitors vapor recovered during refueling of a vehicle and returned back to an underground storage tank in a service station environment, comprising:
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a plurality of fuel dispensing points that deliver fuel from the underground storage tank to the vehicle, wherein said plurality of fuel dispensing points each include at least one meter that measures the amount of fuel flow delivered;
at least one vapor flow sensor operatively connected to a vapor return line to measure the amount of vapor flow being returned back to the underground storage tank from at least two of said plurality of fuel dispensing points, wherein the number of said at least one vapor flow sensors is less that the number of said plurality of fuel dispensing points;
a central electronic control that receives information relating to said amount of fuel flow delivered by said plurality of fuel dispensing points and receives information from said vapor flow sensor relating to said amount of vapor flow recovered by said plurality of fuel dispensing points, wherein said central electronic control is capable of determining a ratio of vapor flow to fuel flow for each of said fuel dispensing points. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 81)
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60. A method of monitoring a vapor recovery system that recovers vapors expelled from a vehicle during refueling and returns the vapors back to an underground storage tank in a service station environment, comprising:
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measuring the amount of fuel flow delivered to the vehicle at a plurality of fuel dispensing points;
measuring the amount of vapor flow recovered at said plurality of fuel dispensing points using at least one vapor flow sensor wherein the number of said at least one vapor flow sensors is less that the number of said plurality of fuel dispensing points;
calculating a ratio of said vapor flow to said fuel flow for each of said plurality fuel dispensing points; and
determining if said calculated ratio of said vapor flow to said fuel flow for each of said plurality of fuel dispensers is within an acceptable range. - View Dependent Claims (61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 82)
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83. A vapor recovery monitoring system that monitors vapor recovered during refueling of a vehicle and returned back to an underground storage tank in a service station environment, comprising:
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a fuel dispensing point that delivers fuel from the underground storage tank to the vehicle;
a vapor flow sensor operatively connected to a vapor return line of said fuel dispensing point to measure the amount of vapor flow captured by said fuel dispensing point to be returned back to the underground storage tank; and
a central electronic control that receives information from said vapor flow sensor relating to said amount of vapor flow recovered by said fuel dispensing point, wherein said central electronic control registers a leak in said fuel dispensing point if said vapor flow sensor registers a reverse vapor flow when said fuel dispensing point is idle. - View Dependent Claims (84, 85)
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Specification