Frequency Variable Fuel Vapor Recovery Control System And Method For Fuel Dispenser With Self-Calibrated Vapor Liquid Ratio

Abstract

A fuel vapor recovery control system includes a controller, a recovery electrical motor, a fuel vapor switching valve, a fuel vapor recovery pump, a fuel tank, a fueling pump, a fuel gun, and a temperature sensor connected in sequence. A fueling flowmeter is arranged on a fueling pipeline, in signal connection with the controller, the recovery electrical motor and the fuel vapor recovery pump in sequence. The temperature sensor is in signal connection with the controller for controling the recovery electrical motor and the fuel vapor recovery pump by temperature signals. The fuel vapor recovery control system includes a fuel vapor flowmeter for measuring the fuel vapor recovery amount, in signal connection with the controller for controling the recovery electrical motor and the fuel vapor recovery pump by fuel vapor recovery amount signals. The fuel vapor recovery ratio is between 1-1.4. A method of adopting the system is provided herein.

Claims

1. A variable-frequency fuel vapor recovery control system for a fuel dispenser including a self-calibrated vapor liquid ratio comprising, a fuel vapor switching valve; a fuel vapor recovery pump disposed in fluid communication with said fuel vapor switching valve; a fuel tank disposed in fluid communication with said fuel vapor recovery pump; a fueling pump disposed in fluid communication with said fuel tank; a fuel gun disposed in fluid communication with said fueling pump; a fueling pipeline extending between said fuel gun and said fueling pump to connect said fuel gun with said fueling pump; a temperature sensor disposed in connection with said fuel gun; a fueling flowmeter disposed on said fueling pipelines; a controller disposed in signal connection with said fueling flowmeter; a recovery electrical motor disposed in connection said vapor fuel recovery pump; said temperature sensor being disposed in signal connection with said controller for generating temperature signals to control said recovery electrical motor and said vapor fuel recovery pump; and a fuel vapor flowmeter disposed in signal connection with said controller for measuring a fuel vapor recovery amount and generating a fuel vapor recovery amount signal to control said recovery electrical motor and said fuel gas recovery pump.

2. The variable-frequency fuel vapor recovery control system for a fuel dispenser including a self-calibrated vapor liquid ratio according to claim 1 further including a fuel vapor recovery pipeline connecting said fuel vapor switching valve and said fuel gas recovery pump with said fuel vapor flowmeter being attached on said oil gas recovery pipeline.

3. The variable-frequency fuel vapor recovery control system for a fuel dispenser including a self-calibrated vapor liquid ratio according to claim 1 further including a display device connected to said controller for displaying a vapor liquid ratio in real time whereby said vapor liquid ratio is a ratio of fuel vapor recovery amount to fueling amount.

4. The variable-frequency fuel vapor recovery control system for a fuel dispenser including a self-calibrated vapor liquid ratio according to claim 1 wherein said controller is provided with more than two signal positions, and each of said signal positions corresponds to a temperature sensing range with each of said temperature sensing ranges corresponds to one fuel vapor recovery ratio.

5. The variable-frequency fuel vapor recovery control system for a fuel dispenser including a self-calibrated vapor liquid ratio according to claim 4 wherein said temperature sensing ranges are defined in ascending order: (1) T≦0° C.; (2) 0° C.<T≦20° C.; (3) 20° C.<T≦30° C.; (4) T>30° C. and said signal positions increase progressively or decrease progressively and respectively correspond to said temperature sensing ranges with T being temperature sensed by said temperature sensor.

6. The variable-frequency fuel vapor recovery control system for a fuel dispenser including with a self-calibrated vapor liquid ratio according to claim 1 wherein said fuel vapor recovery pump is a fuel vapor recovery vacuum pump, said controller is a frequency convertor controller, and said fuel vapor flowmeter is a VFM oil gas flowmeter.

7. The variable-frequency fuel vapor recovery control system for a fuel dispenser including a self-calibrated vapor liquid ratio according to claim 2 wherein said fuel vapor switching valve is arranged at a muzzle of said fuel gun and further includes fuel vapor filter and a steady flow tank disposed on said fuel vapor recovery pipeline between said fuel vapor switching valve and said fuel vapor flowmeter, whereby said fuel vapor switching valve, said fuel vapor filter, said steady flow tank, said fuel vapor flowmeter, said fuel vapor recovery pump and said fuel tank are connected in sequence.

8. A variable-frequency fuel vapor recovery control method for a fuel dispenser including a self-calibrated vapor liquid ratio, said method including the steps of, utilizing a combination of a temperature signal and a fueling amount signal to control a recovery electrical motor speed to provide a preliminary adjustment of a fuel vapor recovery ratio; utilizing a fuel vapor recovery amount signal and the fueling amount signal to determine a real-time vapor liquid ratio, and adopting the real-time gas liquid ratio as an output feedback signal of a recovery control system to form a closed-loop recovery control system, and providing a self-adaptive adjustment of the fuel vapor recovery ratio with the real-time vapor liquid ratio being defined as a ratio of a fuel vapor recovery amount to a fueling amount.

9. The variable-frequency fuel vapor recovery control method for a fuel dispenser including a self-calibrated vapor liquid ratio according to claim 8 further including the steps of: Step 1: as the fuel dispenser operates, setting a fuel vapor recovery ratio δ according to a temperature signal monitored in real time, determining an initial fuel vapor recovery amount V.sub.fuel vapor=δV.sub.fuel, and controlling the speed of the recovery electrical motor according to the initial fuel vapor recovery amount V.sub.fuel vapor to implement the preliminary adjustment of the V.sub.fuel vapor recovery ratio with V.sub.fuel being the fueling amount monitored in real time; Step 2: determining a real-time vapor liquid ratio $\frac{A}{L}=\frac{V_{\mathrm{fuel}.Math..Math.\mathrm{vapor}}^{\prime }}{V_{\mathrm{fuel}.Math.}},$ with V′.sub.fuel vapor being the fuel vapor recovery amount monitored in real time; Step 3: referencing the real-time vapor liquid ratio A/L with the fuel vapor recovery ratio δ in said Step 1 and carrying out error correction on the real-time vapor liquid ratio A/L and controlling the speed of the recovery electrical motor in response to the corrected real-time vapor liquid ratio A/L to implement the self-adaptive adjustment of fuel vapor recovery ratio.

10. The variable-frequency fuel vapor recovery control method for a fuel dispenser including a self-calibrated vapor liquid ratio according to claim 9 wherein setting the fuel vapor recovery ratio δ according to a temperature signal monitored in real time of said Step 1 is further defined as corresponding each temperature signal with a set temperature sensing range; corresponding each temperature sensing range with one fuel vapor recovery ratio, and selecting and setting fuel vapor recovery ratio δ according to a temperature signal monitored in real time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0045] FIG. 1 is a schematic view of a variable-frequency fuel vapor recovery control system for a fuel dispenser with a self-calibrated vapor liquid ratio in accordance with the present invention; and

[0046] FIG. 2 is a schematic view of a control principle of a variable-frequency fuel vapor recovery control method for a fuel dispenser with a self-calibrated vapor liquid ratio in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0047] Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, a variable-frequency fuel vapor recovery control system is shown in FIG. 1. The present invention is further described in detail below in reference to the drawings and a specific embodiment.

[0048] The structural schematic diagram of a variable-frequency fuel vapor recovery control system for a fuel dispenser with a self-calibrated vapor liquid ratio of the present invention is generally shown in FIG. 1. The recovery control system comprises a frequency convertor controller 8, a recovery electrical motor 7, a fuel vapor switching valve 1, a fuel vapor recovery vacuum pump 5, a fuel tank 6, a fueling pump 10, a fuel gun 13, a temperature sensor 9 and a fueling flowmeter 11 for measuring the fueling amount, wherein the fuel vapor switching valve 1, the fuel vapor recovery pump 5, the fuel tank 6, the fueling pump 10, the fuel gun 13 and the temperature sensor 9 are connected in sequence, the fueling flowmeter 11 is arranged on a fueling pipeline, and the fueling flowmeter 11 is in signal connection with the frequency convertor controller 8, the recovery electrical motor 7 and the fuel vapor recovery pump 5 in sequence. The temperature sensor 9 of the present invention is in signal connection with the frequency convertor controller 8, and is used to control the recovery electrical motor 7 and the fuel vapor recovery vacuum pump 5 by temperature signals. The present invention further comprises a VFM fuel vapor flowmeter 4 for measuring the fuel vapor recovery amount, wherein the VFM fuel vapor flowmeter 4 is in signal connection with the frequency convertor controller 8, and is used to control the recovery electrical motor 7 and the fuel vapor recovery vacuum pump 5 by fuel vapor recovery amount signals. The fuel vapor switching valve 1 is arranged at the muzzle of the fuel gun 13; the present invention further comprises an a fuel vapor filter 2 and a steady flow tank 3 which are arranged on a fuel vapor recovery pipeline between the fuel vapor switching valve 1 and the VFM fuel vapor flowmeter 4, wherein the fuel vapor switching valve 1, the fuel vapor filter 2, the steady flow tank 3, the VFM fuel vapor flowmeter 4, the fuel vapor recovery vacuum pump 5 and the fuel tank 6 are connected in sequence.

[0049] The VFM fuel vapor flowmeter 4 of the present invention is installed on a fuel vapor recovery pipeline between the steady flow tank 3 and the fuel vapor recovery vacuum pump 5, so that the effect of measuring the fuel vapor recovery amount can be increased. In order to more visually know the working condition of the system, the present invention further comprises a display device 12 for displaying a vapor liquid ratio in real time, wherein the display device 12 is connected to a frequency convertor controller 8. The present invention has a real-time vapor liquid ratio display function, which is favorable for system maintenance.

[0050] The controller 8 is provided with more than two signal positions, each signal position corresponds to a certain temperature sensing range, and each temperature sensing range corresponds to one fuel vapor recovery ratio. Because each signal position corresponds to one fuel vapor recovery ratio, the variation of the fuel vapor recovery ratio can be adapted. More specifically, the signal positions include four positions which increase progressively in sequence or decrease progressively in sequence; the four signal positions respectively correspond to the following temperature sensing ranges in ascending order: (1) T≦0° C.; (2) 0° C.<T≦20° C.; (3) 20° C.<T≦30° C.; (4) T>30° C.; with T being the temperature sensed by the temperature sensor. In this way, the controller only needs to determine the temperature signal positions for the temperature T fed back by the temperature sensor 9.

[0051] A diagram of a control principle of the variable-frequency fuel vapor recovery control system for a fuel dispenser with a self-calibrated vapor liquid ratio of the present invention is shown in FIG. 2. The fuel vapor recovery control method utilizes the combination of a temperature signal and a fueling amount signal to control the speed of the recovery electrical motor, so that the preliminary adjustment of the fuel vapor recovery ratio is implemented; then utilizing a fuel vapor recovery amount signal and the fueling amount signal to calculate the real-time fuel vapor liquid ratio, and adopting the real-time fuel vapor liquid ratio as an output feedback signal of the recovery control system, so that the recovery control system is formed into a closed-loop recovery control system, realizing the self-adaptive adjustment of the fuel vapor recovery ratio; and the fuel vapor liquid ratio refers to a ratio of the fuel vapor recovery amount to the fueling amount.

[0052] More specifically, the recovery control method of the present invention includes the following steps:

[0053] Step 1: When a fuel dispenser operates, setting a fuel vapor recovery ratio δ according to a temperature signal monitored in real time, calculating an initial fuel vapor recovery amount V.sub.fuel vapor=δV.sub.fuel, and controlling the speed of the recovery electrical motor according to the initial fuel vapor recovery amount V.sub.fuel vapor, so that the preliminary adjustment of the fuel vapor recovery ratio is implemented, wherein V.sub.fuel is the fueling amount monitored in real time;

[00003]$\frac{A}{L}=\frac{V_{\mathrm{fuel}.Math..Math.\mathrm{vapor}}^{\prime }}{V_{\mathrm{fuel}.Math.}},$

[0054] Step 2: Calculating a real-time vapor liquid ratio wherein V′.sub.fuel vapor is the fuel vapor recovery amount monitored in real time;

[0055] Step 3: Comparing the vapor liquid ratio A/L with the fuel vapor recovery ratio δ set in Step 1, carrying out error correction on the vapor liquid ratio A/L, and controlling the speed of the recovery electrical motor according to the corrected vapor liquid ratio A/L, so that the self-adaptive adjustment of the fuel vapor recovery ratio is implemented.

[0056] In Step 1, setting fuel vapor recovery ratio δ according to a temperature signal monitored in real time means: each temperature signal corresponding to a set temperature sensing range; each temperature sensing range corresponding to one fuel vapor recovery ratio, and selecting and setting the fuel vapor recovery ratio δ according to a temperature signal monitored in real time.

[0057] The control principle of the variable-frequency fuel vapor recovery control system for a fuel dispenser with a self-calibrated vapor liquid ratio of the present invention is as follows: an appropriate fuel vapor recovery ratio δ is selected and set by utilizing a temperature signal, it is calculated in real time that the needed initial fuel vapor recovery amount V.sub.fuel vapor=δV.sub.fuel in combination with the fueling amount V.sub.fuel, and then the output frequency is adjusted by the frequency convertor controller according to the fuel vapor recovery capability of the fuel vapor recovery system, thereby controlling the speed of the recovery electrical motor. In the process of operation, fuel vapor recovery amount V′.sub.fuel vapor is fed back by the VFM fuel vapor flowmeter, a real-time vapor liquid ratio

[00004]$\frac{A}{L}=\frac{V_{\mathrm{fuel}.Math..Math.\mathrm{vapor}}^{\prime }}{V_{\mathrm{fuel}.Math.}}$

is calculated in combination with the fueling amount V.sub.fuel, error correction is performed on the vapor liquid ratio A/L by the frequency convertor controller, the speed of the recovery electrical motor is controlled according to the corrected vapor liquid ratio A/L, so that the self-adaptive adjustment of the fuel vapor recovery ratio is implemented, and the vapor liquid ratio A/L is displayed on a display screen in real time.

[0058] The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiment, and any other alterations, modifications, replacements, combinations and simplifications which are made without departing from the spirit and principle of the present invention should all be equivalent replacement patterns, and should all be included in the protection scope of the present invention.