초록 ▼

Systems and methods for detecting a failure in a Stage II fuel vapor recovery system are disclosed. An exemplary failure is a restriction in the vapor recovery system. In one detection system dispensing points may be flagged if it is determined that there has been a series of detected A/L ratios at

Systems and methods for detecting a failure in a Stage II fuel vapor recovery system are disclosed. An exemplary failure is a restriction in the vapor recovery system. In one detection system dispensing points may be flagged if it is determined that there has been a series of detected A/L ratios at the respective dispensing point below a first threshold. Further, an estimated ORVR penetration percentage may be determined for each dispensing point. In a second detection system an average A/L ratio for each dispensing point may be determined. The average A/L ratio may be an approximation of the average A/L ratio for non-ORVR transactions.

대표청구항 ▼

1. For a fuel dispensing system for dispensing fuel from a dispensing nozzle into ORVR and non-ORVR equipped vehicles, the fuel dispensing system including a vapor recovery system, a method for monitoring for a restriction in the vapor recovery system comprising: for each fueling transaction, determ

1. For a fuel dispensing system for dispensing fuel from a dispensing nozzle into ORVR and non-ORVR equipped vehicles, the fuel dispensing system including a vapor recovery system, a method for monitoring for a restriction in the vapor recovery system comprising: for each fueling transaction, determining over a period of time an average of the A/L ratio for each fueling transaction either below a lower threshold or above an upper threshold, the upper threshold being greater than the lower threshold;determining whether a number of sequential fueling transactions having A/L ratios falling between the lower and upper thresholds exceed a threshold number;including fueling transactions having A/L ratios falling between the lower and upper thresholds in the average of the A/L ratios if the number of sequential fueling transactions having A/L ratios falling between the upper and lower thresholds exceed the threshold number, such inclusion to continue until a fueling transaction having an A/L ratio below the lower threshold or above the upper threshold is determined;comparing the determined average of the A/L ratios to a first lower test threshold and to a first upper test threshold; andproviding an indication if the determined average of the A/L ratios is below the first lower test threshold or above the first upper test threshold. 2. The method of claim 1 wherein the threshold number of sequential fueling transactions having A/L ratios falling between the upper and lower thresholds is eleven. 3. The method of claim 1 wherein the period of time is a day. 4. The method of claim 1 comprising: determining a weekly ORVR average as an average of seven consecutive daily averages;comparing the determined average of the A/L ratios to a second lower test threshold and to a second upper test threshold; andproviding an indication if the determined average of the A/L ratios is below the second lower test threshold or above the second upper test threshold. 5. For a fuel dispensing system for dispensing fuel from a dispensing nozzle into ORVR and non-ORVR equipped vehicles, the fuel dispensing system including a vapor recovery system, a system for monitoring for a restriction in the vapor recovery system comprising: a controller, wherein the controller: for each fueling transaction, determines over a period of time an average of the A/L ratio for each fueling transaction either below a lower threshold or above an upper threshold, the upper threshold being greater than the lower threshold;determines whether a number of sequential fueling transactions having A/L ratios falling between the lower and upper thresholds exceed a threshold number;includes fueling transactions having A/L ratios falling between the lower and upper thresholds in the average of the A/L ratios if the number of sequential fueling transactions having A/L ratios falling between the upper and lower thresholds exceed the threshold number, such inclusion to continue until a fueling transaction having an A/L ratio below the lower threshold or above the upper threshold is determined;compares the determined average of the A/L ratios to a first lower test threshold and to a first upper test threshold; andprovides an indication if the determined average of the A/L ratios is below the first lower test threshold or above the first upper test threshold. 6. The system of claim 5 wherein the threshold number of sequential fueling transactions having A/L ratios falling between the upper and lower thresholds is eleven. 7. The system of claim 5 wherein the period of time is a day. 8. The system of claim 5 wherein the controller: determines a weekly ORVR average as an average of seven consecutive daily averages;compares the determined average of the A/L ratios to a second lower test threshold and to a second upper test threshold; andprovides an indication if the determined average of the A/L ratios is below the second lower test threshold or above the second upper test threshold. 9. A fuel dispensing system for dispensing fuel from a plurality of dispensing nozzles into vehicles, the fuel dispensing system including a vapor recovery system, a system for monitoring for a restriction in the vapor recovery system comprising: a controller, wherein the controller: determines over a period of time, for each dispensing nozzle, a plurality of A/L ratios, each A/L ratio being associated with a respective dispensing transaction of the dispensing nozzle; andflags one of the dispensing nozzles if it is determined that there has been a consecutive series of dispensing transactions of the dispensing nozzle wherein the respective A/L ratios of the consecutive series of dispensing transactions are below a first threshold.