FUEL DISPENSING UNIT WITH ON-BOARD REFUELING VAPOR RECOVERY DETECTION

• US 20080092983A1
• Filed: 09/26/2007
• Published: 04/24/2008
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: Wayne Fueling Systems LLC (Dover Corporation)
• Original Assignee: Dresser Incorporated (Nagano Keiki Company Limited)
• Inventors: Larsson, Bengt, Hakansson, Marie, Karlsson, Richard
• Granted Patent: US 7,647,951 B2
• Time in Patent Office: Days
• US Class Current: 141/7
• CPC Class Codes: B67D 7/048 Vapour flow control means, e.g. valves, pumps
• CPC Class Codes: G01F 1/3227 using fluidic oscillators fluidic oscillators per se F15C1/00

Abstract

A vapor recovery system is configured to recover fuel vapor and comprises a vapor recovery line for transporting a stream of fuel vapor from a vehicle tank. A flow meter is arranged in the vapor recovery line for indicating the flow rate of the stream of fuel vapor, and a heated element is arranged in the vapor recovery line. Control means are configured to: detect a cooling exerted on the heated element by the stream of fuel vapor, determine a correction for the detected cooling by weighting said cooling with the flow rate, and decrease or stop the stream of fuel vapor, if the detected cooling is smaller than a predetermined level.

Claims

1. A vapor recovery system for recovering fuel vapor from a vehicle tank during dispensing of fuel into the vehicle tank, said vapor recovery system comprising a vapor recovery line for transporting a stream of fuel vapor, and control means for controlling the stream of fuel vapor, wherein a flow meter is arranged for indicating the flow rate of the stream of fuel vapor, a heated element is arranged in the vapor recovery line, and the control means are configured to:

detect a cooling exerted on the heated element by the stream of fuel vapor,

determine a correction for the detected cooling by weighting said cooling with the flow rate, and

decrease or stop the stream of fuel vapor, if the detected cooling is smaller than a predetermined level.

2. A vapor recovery system according claim 1, wherein the correction for the detected cooling comprises increasing said predetermined level as the flow rate increases.

3. A vapor recovery system according to claim 1, further comprising a temperature sensor operatively connected to the control means and arranged to measure the temperature of the stream of fuel vapor, the control means being configured to determine a correction for the detected cooling by weighting said cooling with the measured temperature.

4. A vapor recovery system according to claim 3, wherein the correction for the detected cooling comprises decreasing said predetermined level as the temperature increases.

5. A vapor recovery system according to claim 1, wherein the flow meter is arranged in the vapor recovery line and comprises a fluid oscillator for providing an oscillation of at least a part of the stream of fuel vapor.

6. A vapor recovery system according to claim 5, wherein the fluid oscillator is configured to provide a frequency oscillation which increases with an increased vapor flow.

7. A vapor recovery system according to claim 5, wherein the heated element is arranged at least partly in the oscillating part of the stream of fuel vapor.

8. A vapor recovery system according to claim 1, wherein the heated element is supplied with an electrical current for providing the heating of the heated element, said cooling being determined by the voltage across, and electrical current through, the heated element.

9. A vapor recovery system according to claim 1, wherein the control means are configured to estimate any of the density and the hydrocarbon content of the stream of fuel vapor, based on the cooling exerted on the heated element.

10. A fuel dispensing unit comprising a vapor recovery system according to claim 1.

11. A method of regulating a vapor recovery system when recovering fuel vapor from a vehicle tank during dispensing of fuel into the vehicle tank, said method comprising the steps of:

transporting a stream of fuel vapor through a vapor recovery line,

detecting the flow rate of the stream of fuel vapor,

detecting a cooling exerted on a heated element by the stream of fuel vapor,

determining a correction for the detected cooling by weighting said cooling with the flow rate, and

decreasing or stopping the stream of fuel vapor, if the detected cooling is smaller than a predetermined level.