Fluent material handling – with receiver or receiver coacting mea – Automatic control of flow cutoff or diversion
Utility Patent
1999-09-01
2001-01-02
Douglas, Steven O. (Department: 3751)
Fluent material handling, with receiver or receiver coacting mea
Automatic control of flow cutoff or diversion
C141S059000, C141S083000
Utility Patent
active
06167923
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of fuel dispenser vapor recovery, and, more particularly to the diagnostic monitoring of such systems to ensure that they are operating properly.
2. Description of the Prior Art
During a conventional or standard automobile fueling operation, incoming fuel displaces fuel vapor from the head space of the automobile fuel tank and out through the filler pipe if not contained and recovered. The air pollution resulting from this situation is undesirable and has been the subject of considerable regulatory action.
Increasingly, environmental protection regulations require that fuel dispensers used for fueling automobiles recover vapors generated during the fueling process. These regulations typically require that a high percentage, typically 95%, of the generated vapors be recovered. The systems designed to do so include the “balance” system and the more commonly used “vacuum assist” system. Each of these systems returns the recovered vapors to the underground storage tanks at the fueling location. The equipment involved in this vapor recovery process has evolved to a high state of sophistication. For example the systems disclosed in U.S. Pat. Nos. 5,040,577 to Pope; 5,156,199 to Hartsell et al.; and 5,355,915 provide for the monitoring of the volume of liquid dispensed and the correlation of that volume to an expected vapor flow volume so that these volumes may be equalized or otherwise adjusted to maximize the recovery of fueling-generated vapors.
The need to meet increasingly strict air quality standards has led to the development of automobile-based vapor management systems. In this regard, onboard, or vehicle carried, fuel vapor recovery and storage systems (commonly referred to as onboard recovery vapor recovery or ORVR) have been developed in which the head space in the vehicle fuel tank is vented through an activated charcoal-filled canister so that the vapor is adsorbed by the activated charcoal. Subsequently, the fuel vapor is withdrawn from the canister into the engine intake manifold for mixture and combustion with the normal fuel and air mixture. The fuel tank head space must be vented to enable fuel to be withdrawn from the tank during vehicle operation.
In typical ORVR systems, a canister outlet is connected to the intake manifold of the vehicle engine through a normally closed purge valve. The canister is intermittently subjected to the intake manifold vacuum with the opening and closing of the purge valve between the canister and intake manifold. A computer which monitors various vehicle operating conditions controls the opening and closing of the purge valve to assure that the fuel mixture established by the fuel injection system is not overly enriched by the addition of fuel vapor from the canister to the mixture.
Fuel dispensing systems having vacuum assisted vapor recovery capability which are unable to detect ORVR systems will continue to operate at full capacity even though there is likely no need to do so. This situation can cause the vacuum assist systems to ingest excessive air into the underground storage tank. The tanks can then experience an excessive pressure buildup due to the expanded volume of hydrocarbon saturated air. Recognizing an ORVR system and adjusting the fuel dispenser's vapor recovery system accordingly eliminates the redundancy associated with operating two vapor recovery systems for a given fueling operation. Thus, a number of systems have been devised to detect the presence of ORVR vehicles during a fueling operation and to adjust the operation of the vacuum assist systems accordingly. One such system is disclosed in U.S. Pat. No. 5,782,275, the content of which is incorporated herein by reference. This patent discloses a system using a hydrocarbon sensor to detect hydrocarbon concentrations in the vapor path in order to determine the presence of an ORVR-equipped vehicle. Other systems may monitor pressure levels in the vapor return line, receive information directly from the vehicle, or read information on the vehicle to determine whether or not the vehicle is equipped with an ORVR system. Regardless of the type of detection system used, there is a need to determine whether or not these detection systems are working properly or if any part of these detection systems have failed. This is especially true for ORVR detection systems incorporating various types of sensors or communication electronics that could fail and provide no warning to the station operator.
SUMMARY OF THE INVENTION
The present invention relates to a system and method for monitoring the operation of a vacuum assist vapor recovery system used in conjunction with the fueling of ORVR and non-ORVR equipped vehicles. In particular, the present invention compares a value dependent on the number of ORVR fueling operations at a given fueling position with a reference value to predict whether or not there is a problem in a system used to detect an ORVR equipped vehicle. There are numerous ways to monitor the number of ORVR fueling operations and compare them to a reference. For example, the performance of any given fueling position may be compared to another fueling position, such as a fueling position on the opposite side of the dispenser. Alternatively, a comparison could be made to the performance of other fueling positions throughout the fueling environment or any group of dispensers therein. Further, the reference group may or may not include the fueling position being monitored.
Various types of comparisons are possible. For example, comparisons could include simply the number of fueling operations in which an ORVR equipped vehicle was detected. This number could be a running total or a total over a specific period. The period may have just ended or be one taken as a historical record. The comparison may be made with the ratio of fueling operations where an ORVR vehicle was detected to the number of fueling operations where an ORVR vehicle was not detected. Like the above, these comparisons may be made to a historical analysis at any given fueling position, to another fueling position, or to an average of a group of fueling positions.
Accordingly, an exemplary method of carrying out the invention includes establishing an expected number of ORVR fueling operations for a fuel dispenser during a given time interval; counting the actual number of ORVR fueling operations during said given time interval; comparing the actual number of fueling operations to the expected number of fueling operations; and permitting fueling operations to continue if the actual number is substantially equal to the expected number. In a preferred embodiment an error signal is generated if the actual number of ORVR fueling operations is not substantially equal to the expected number of ORVR fueling operations. Fueling operations are stopped or an alarm or signal status is generated if the actual number of ORVR fueling operations is not substantially equal to the expected number of ORVR fueling operations.
REFERENCES:
patent: 5484000 (1996-01-01), Hasselmann
patent: 5605182 (1997-02-01), Oberrecht et al.
patent: 5620031 (1997-04-01), Dalhart et al.
patent: 5636667 (1997-06-01), Young et al.
patent: 5671785 (1997-09-01), Andersson
patent: 5676181 (1997-10-01), Healy
patent: 5765603 (1998-06-01), Healy
patent: 5782275 (1998-07-01), Hartsell, Jr. et al.
Coats & Bennett P.L.L.C.
Douglas Steven O.
Marconi Commerce Systems Inc.
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