EP3649075B1 - Fuel dispenser with two-speed motor and method of operation therefor - Google Patents

Description

Technical area

The present invention relates to a fuel dispenser comprising a two-speed engine and its operating method.

Prior art

In general, the fuel dispensers found in service stations include a pumping unit intended to suck the fuel into a storage tank.

The pumping unit comprises a pump driven by an electric motor and is connected in most cases to two distribution lines. Each distribution line comprises a fuel flow meter measuring the volume of fuel delivered and a flexible hose fitted with a dispensing gun actuated by the user to fill the tank of his vehicle.

The pump is a gear or vane type suction pump and usually operates at a constant speed.

It provides an average flow rate of 80 l / min which is necessary to provide a flow rate of 40 l / min in each of the two distribution lines when two guns are unhooked and activated at full flow to fill two respective vehicle tanks arranged on each side. side of the fuel dispenser.

However, when only one gun of a pumping unit is activated, the distribution line must continue to deliver a maximum flow rate of 40 l / min to comply with the standards in force.

For this, the pumping unit comprises a bypass circuit called bypass circuit comprising a bypass valve in which the excess flow not used is rolled in a closed circuit to relieve the pumping unit of this excessively high flow. The primary function of this bypass circuit is to protect the pump from overpressure that can destroy the pump.

As a result, the electric energy consumption of the motor is maximum during the entire operation of the pump while the actual flow rate is required is often much less when only one gun is activated. 50% of the speed is then only useful. This lower requirement represents more than 80% of the pump's operating time.

There are solutions consisting of using a frequency converter to control the rotational speed of the electric motor as a function of the required fuel flow. It is possible to adjust the fuel flow by adjusting the engine frequency.

When a single gun is unhooked, a control system transmits a frequency reference to the frequency converter so that the latter rotates the electric motor at a frequency allowing a flow rate of approximately 40 l / min to be obtained.

When two guns are unhooked, the control system transmits a frequency reference to the frequency converter so that the latter rotates the electric motor at a higher frequency allowing a flow rate of approximately 80 l / min to be obtained.

However, this solution only makes it possible to achieve partial energy savings (around 10%). This is due to a loss of efficiency of the frequency converter. In addition, frequency converters are very expensive.

The object of the present invention is to remedy this drawback by proposing a fuel dispenser consuming less electrical energy than those of the prior art.

A fuel dispenser according to the preamble of claim is known from document EP 0 440 845 A1 .

Disclosure of the invention

To this end, the invention relates to a fuel dispenser comprising a pumping unit comprising an electric motor driving a pump intended to suck fuel from a fuel tank.

The pumping unit is connected to two fuel distribution lines each comprising a flow meter connected to a flexible pipe equipped with a gun intended to deliver fuel into a vehicle tank.

According to the invention, the electric motor is a motor with two predetermined speeds providing the pump with two rotational speeds, including a low speed V1 intended to provide a small flow of fuel D1 at the outlet of the pumping unit when a single gun delivers fuel and high speed V2 intended to provide a large flow of fuel D2 at the outlet of the pumping unit when two guns deliver fuel.

The two speeds V1 t V2 are therefore fixed and predetermined.

The two-speed motor is electrically connected to a controller controlling the speed of the electric motor according to the number of guns activated.

According to one possible embodiment, the two-speed motor is an asynchronous motor operating with a variable number of poles. The fuel distributor comprises a switching means controlled by the controller and making it possible to switch from a number of X poles to a number of Y poles.

According to one possible embodiment, the two-speed motor operates in 4 poles or 8 poles so as to obtain the fixed speeds V2 or V1 respectively.

The invention thus provides a fuel dispenser consuming 30% less electrical energy per electric motor than conventional fuel dispensers for approximately more than 80% of the operating time of the fuel dispenser.

By comparison, using a frequency controller can reduce electrical energy consumption by at best 10%. In addition, this solution is more expensive than that of the invention.

It is also possible to reduce the demand on the bypass circuit, reducing fuel heating.

The sound level of the gas station is also controlled by reducing the speed of the pump and therefore the maximum fuel flow during critical periods (night or high heat).

In addition, frequency converters take up space because of the radiators on the thyristors. The use of double-coil motors makes it possible to reduce the size inside the hydraulic compartment, to produce less calories and less electrical interference.

According to another variant, the fuel dispenser comprises a pump state detector connected to the controller. The pump condition detector transmits a signal to the controller informing it if a cavitation condition or a no-prime condition of the pump is detected. The controller transmits by means of switching a reference signal to switch the two-speed motor to high speed V2 if its initial speed was V1.

According to another variant, the state detector of the pump is an ammeter measuring the current consumed by the two-speed motor.

When the initial motor speed is V1 and the measured current is below a threshold value, the controller transmits to the switching means a reference signal to switch the speed to V2.

An increase in the speed of the two-speed engine at a higher speed makes it possible to limit the phenomenon of cavitation.

More generally, an increase in the speed of the two-speed motor makes it possible to optimize suction operation under high pressure and temperature conditions. This allows the highest possible fuel flow to be maintained when a fuel delivery line is used.

When the pump is not primed, a higher rotational speed will speed up the priming of the pump. The pump priming time is therefore also optimized.

In fact, when there is a pocket of gas in the pipe, the fact of increasing the speed of rotation of the pump makes it possible to suck this pocket of gas more quickly until the fuel reaches the pump.

The invention also relates to a method of operating a fuel dispenser as described above and comprising a step of releasing a first gun to deliver fuel to a first vehicle.

• commutation du moteur à deux vitesses à un nombre de Y pôles par le moyen de commutation pour démarrer le moteur à deux vitesses à une petite vitesse de rotation V1 afin de fournir un premier débit de carburant D1 en sortie de l'unité de pompage,
• commutation du moteur à deux vitesses à un nombre de X pôles par le moyen de commutation pour fournir une vitesse de rotation V2, plus grande que V1, lorsqu'un deuxième pistolet est décroché pour délivrer du carburant dans un deuxième véhicule de façon à obtenir un deuxième débit de carburant D2, supérieur à D1, en sortie de l'unité de pompage.

According to the invention, the method comprises the following steps:

• switching of the two-speed motor at a number of Y poles by the switching means to start the two-speed motor at a low speed of rotation V1 in order to provide a first flow of fuel D1 at the outlet of the pumping unit,
• switching of the two-speed motor at a number of X poles by the switching means to provide a speed of rotation V2, greater than V1, when a second gun is unhooked to deliver fuel to a second vehicle so as to obtain a second fuel flow D2, greater than D1, at the outlet of the pumping unit.

The rotation speeds V1 and V2 are fixed and predetermined.

• mesure de l'intensité du courant consommé par le moteur à deux vitesses,
• commutation du moteur à deux vitesses à un nombre de X pôles par le moyen de commutation fournissant une vitesse de rotation V2, plus grande que V1, si un seul pistolet est décroché, si la vitesse de rotation du moteur à deux vitesses est initialement à V1 et si l'intensité du courant consommé par le moteur à deux vitesses est inférieure à une valeur seuil,
• commutation du moteur à deux vitesses à un nombre de X pôles par le moyen de commutation fournissant la vitesse de rotation V1 si un seul pistolet est décroché et si l'intensité du courant consommé par le moteur à deux vitesses est supérieure ou égale à la valeur seuil.

According to one variant, the operating method comprises the following steps:

• measurement of the intensity of the current consumed by the two-speed motor,
• switching of the two-speed motor at a number of X poles by the switching means providing a speed of rotation V2, greater than V1, if only one gun is unhooked, if the speed of rotation of the two-speed motor is initially at V1 and if the intensity of the current consumed by the two-speed motor is less than a threshold value,
• switching of the two-speed motor at a number of X poles by the switching means supplying the speed of rotation V1 if only one gun is unhooked and if the intensity of the current consumed by the two-speed motor is greater than or equal to the value threshold.

According to one variant, the method of operating the fuel dispenser comprises a silent mode in which the speed of rotation of the two-speed engine is limited to the speed V1 for a predetermined period T regardless of the intensity of the current consumed by the engine. two-speed.

Brief description of the drawing

• la figure 1 représente schématiquement un distributeur de carburant selon l'invention.

The characteristics of the invention will be described in more detail with reference to the figure 1 non-limiting annexed:

• the figure 1 schematically shows a fuel dispenser according to the invention.

Ways of carrying out the invention

The figure 1 shows a fuel dispenser 1 comprising a pumping unit 2 comprising an electric motor 3 driving a pump 4 intended to suck fuel from a fuel tank.

In this example, the electric motor 3 drives the pump 4 via two pulleys 12 and a transmission belt 13. The transmission between the electric motor 3 and the pump 4 can also be direct.

The pump 4 can be a vane or gear pump.

The pumping unit 2 is connected to two fuel distribution lines 5 each comprising a flow meter 6 connected to a flexible pipe 7 equipped with a gun 8 intended to deliver fuel into a vehicle tank.

According to the invention, the electric motor 3 is a two-speed motor 3 providing the pump with two rotational speeds, including a low speed V1 intended to provide a small flow of fuel D1 at the outlet of the pumping unit 2 when only one gun 8 delivers fuel and a high speed V2 intended to provide a large flow of fuel D2 at the outlet of the pumping unit 2 when two guns 8 deliver fuel.

The two-speed motor 3 is electrically connected to a controller 9 controlling the speed of the electric motor 3 as a function of the number of guns 8 activated.

The controller 9 is preferably arranged in the electronic head 14 of the fuel distributor 1.

The two-speed motor 3 is an asynchronous motor operating with a variable number of poles.

The fuel distributor 1 comprises a switching means 10 controlled by the controller 9 and making it possible to switch from a number of X poles to a number of Y poles, X being less than Y. The switching means 10 is a contactor, for example. example.

Other types of electric motors with two fixed and predetermined speeds are also possible.

Preferably, the two-speed motor 3 operates in 4 poles or 8 poles so as to obtain respectively the fixed speeds V2 and V1, the speed V2 being greater than the speed V1. X is therefore equal to 4 and Y is equal to 8.

Alternatively, the two-speed motor 3 can be a 4/6 pole motor, X being equal to 4 and Y being equal to 6.

For example, it is possible to use an asynchronous two-speed motor 3 supplied with 250 volts.

When a single gun 8 is unhooked, this information is transmitted to the controller 9 which in turn transmits to the switching means 10 the 6-pole operating instruction.

The two-speed motor 3 having switched in 6 poles, its speed of rotation is about 900 revolutions / min.

The electric motor 3 drives the pump 4 of the pumping unit 2 which is configured to deliver a fuel flow of approximately 40 l / min.

The sound volume is then around 65 dB.

When a second gun 8 is unhooked, this information is transmitted to the controller 9 which transmits to the switching means 10 the operating instruction in 4 poles.

The two-speed motor 3 having switched in 4 poles, its speed of rotation is about 1500 revolutions / min.

The electric motor 3 drives the pump 4 of the pumping unit 2 which is configured to deliver a fuel flow rate of approximately 80 l / min, i.e. a flow rate of 40 l / min for each of the two fuel distribution lines 5 .

The sound volume is then approximately 75 dB.

The electrical energy consumption of the two-speed motor 3 is reduced by approximately 30% for more than 80% of the time for which a single gun 8 is activated.

The noise level of the gas station is also controlled by reducing the rotation speed of the two-speed motor 3.

As said before, the two speed motor 3 can be a 4/8 pole motor.

The best known is the three-phase asynchronous motor with Dahlander coupling named after its inventor. This motor has a 1 to 2 ratio. When switched to 4 poles, it provides a rotational speed of 1500 rpm. When switched to 8 poles, it provides a rotational speed of 750 rpm.

It can be supplied with a single voltage of 230V or 400V. It includes two windings per phase that can be coupled in parallel to obtain the maximum speed with 4 poles or in series to obtain a speed divided by two with 8 poles.

When a first gun 8 is unhooked and actuated, the two-speed motor 3 operates with 8 poles. The speed of rotation of the two-speed motor 3 is of the order of 750 revolutions / min, corresponding to the speed V1. The pumping unit 2 can then deliver a maximum fuel flow D1 of approximately 40 l / min into the tank of a first vehicle.

When a second gun 8 is unhooked and actuated, the two-speed motor 3 operates with 4 poles. The speed of rotation of the two-speed motor 3 is of the order of 15,000 revolutions / min, corresponding to the speed V2. The pumping unit 2 can then deliver a maximum fuel flow D2 of approximately 80 l / min resulting in a flow rate of 40 l / min for each fuel distribution line 5. Each tank of the two vehicles arranged on both sides. other of the fuel dispenser 1 can be filled with a maximum fuel flow of 40 l / min.

The detection of the number of unhooked guns is carried out by known means such as a magnetic detector placed in the gun rest (bag) which is fixed on the fuel distributor, for example. A magnet positioned on the gun allows the magnetic detector to detect the presence or absence of the gun in the gun rest. This information is transmitted to controller 9.

The electrical energy consumption of the two-speed motor 3 is reduced by approximately 50% for more than 80% of the time for which a single gun 8 is activated.

The two rotational speeds of the two-speed motor 3 V1 and V2 are fixed and predetermined in advance.

Under conditions of high temperature and / or high altitude, fuel evaporation may occur in the suction duct connecting the fuel storage tank and the pumping unit 2, generating a vapor / liquid fuel mixture. rich in fuel vapors.

This vapor / liquid mixture rich in fuel vapors causes a loss of flow, an increase in the sound volume of the pump 4 as well as vibrations. These phenomena are amplified because of the heating of pump 4 due to the bypass circuit. Indeed, when only one gun is activated, the fuel circulates in a loop in the pumping unit 2, causing it to heat up.

When the vapor pressure is too high in the vapor / liquid mixture, gas pockets form in the suction duct causing pump 4 to be deactivated.

To solve these problems, it is proposed to increase the speed of the two-speed motor 3 to the speed V2 when the initial speed is V1.

Increasing the speed of the two-speed motor 3 at a higher speed makes it possible to limit these effects.

More generally, an increase in the speed of the two-speed motor 3 makes it possible to optimize suction operation under high pressure and temperature conditions. This makes it possible to maintain the highest possible fuel flow when a fuel delivery line 5 is used.

The increase in the speed of rotation of the pump 4 has the effect of reducing the phenomenon of cavitation. The gas-rich phase is sucked in more quickly.

When pump 4 is not primed, a higher rotational speed also allows better priming of pump 4.

When a gas pocket is present in the pipe, a higher rotational speed makes it possible to increase the suction speed to evacuate the gas pocket.

The fuel dispenser 1 comprises a pump state detector 11 connected to the controller 9. The pump state detector 11 detects whether the pump has a cavitation problem or if it is not primed when it is started. .

The state detector of the pump 11 transmits a signal to the controller 9 informing it if a state of cavitation or a state of non-priming of the pump 4 is detected. In general, the state of cavitation also includes the presence of gas pockets.

When one of these states is detected, the controller 9 transmits to the switching means 10 a reference signal for switching the two-speed motor 3 to high speed V2 if its initial speed was V1.

The state detector of the pump 11 measures the current consumed by the two-speed motor 3. When the initial speed of the motor is V1 and the measured current is below a threshold value, the controller 9 transmits by means of switching 10 a setpoint signal to switch the speed to V2.

The state detector of the pump 11 may be an ammeter. The state detector of the pump 11 can comprise an ammeter associated with a voltmeter so as to measure a consumed electric power.

The threshold value of the intensity may correspond to an average of the intensity measured when the pumping unit 2 is operating normally, without cavitation and with a pump 4 primed.

When the pump 4 operates normally, it consumes more electrical energy than in the case where it is cavity or if it is not primed. The intensity consumed is therefore higher in normal operation.

Indeed, when the 4-cavity pump, the gas content in the fuel is higher, resulting in a lower pressure. The pump 4 provides less effort to suck gas instead of liquid.

Likewise, when the pump 4 is not primed, it sucks in gas and provides less effort to turn.

The state detector of the pump 11 can alternatively be a spectral analyzer analyzing the spectrum of the power or of the intensity consumed by the two-speed motor 3. The measured spectrum is compared with a reference spectrum corresponding to an operation. normal, without cavitation and with a pump 4 primed.

The state detector of the pump 11 may as a variant be a pressure sensor or a sound sensor detecting vibration frequencies specific to cavitation. The phenomenon of cavitation in fact causes additional vibrations.

Speed V2 is maintained as long as the measured intensity does not rise above the threshold value. When it rises above this value, the controller 9 transmits to the switching means 10 a reference signal for switching the two-speed 3 to 8-pole motor supplying the speed V1, if only one gun 8 is activated.

For about 80% of the operating time of a fuel dispenser 1, only one gun 8 is activated. The fact of limiting the speed of the pump to V1 during this time makes it possible to greatly limit the phenomenon of cavitation and to limit noise, while reducing the electrical consumption of the motor.

A method of operating the fuel dispenser 1 is described below.

When a gun 8 is unhooked, the two-speed motor 3 starts at low speed V1. It therefore works with 8 poles or 6 poles depending on the choice of two-speed motor 3.

The measurement of the current by the state detector of the pump 11 makes it possible to check whether the pump 4 is primed or not.

If the pump 4 is not primed, the controller 9 transmits to the switching means 10 a reference signal for switching the 4-pole motor (speed V2) until priming. This makes it possible to speed up the priming operation and to maintain the highest possible dry vacuum.

The operating method comprises a silent mode in which the speed of rotation of the two-speed motor 3 is limited to the speed V1 for a predetermined period T regardless of the intensity of the current consumed by the two-speed motor 3.

This duration may correspond to a time slot corresponding to the night in the city center during which the noise from the fuel dispenser 1 must be minimized.

The duration T can alternatively be programmed during the summer during periods of high heat during the day, limiting the risk of cavitation.

The duration T can be programmed directly in the fuel dispenser 1 or in the central control station of the filling station.

The silent mode is maintained even if the two pistols 8 are unhooked.

If the silent mode is not activated, the V2 speed is maintained after priming when the 2 guns 8 are activated.

If pump 4 is primed at start-up and only one gun is activated, the speed is maintained at V1.

Regardless of the number of guns 8 released, if the detection of the cavitation mode is triggered (low intensity measured during the engine operating phase), the change to 4 poles (speed V2) is automatic.

Thus, the invention makes it possible to reduce the electrical energy consumption of the motor by around 30% if a 4/6 pole motor is used or by 50% for a 4/8 pole motor for more than 80% of the time. operating mode of the fuel dispenser 1.

By comparison, using a frequency controller can reduce electrical power consumption by at best 10% while being more expensive.

It is also possible to reduce the demand on the bypass circuit, reducing fuel heating.

The sound level of the gas station is also controlled by reducing the speed of the pump and therefore the maximum fuel flow during critical periods (night in the city center or high heat).

The priming time of pump 4 is also optimized.

The maximum fuel flow from the service station remains optimal under the conditions which allow it (daytime or normal temperature).

Claims (8)

1. Fuel dispenser (1) comprising a pumping unit (2) comprising an electric motor (3) that drives a pump (4), designed to draw fuel from a fuel tank, the pumping unit (2) being connected to two fuel dispensing lines (5) each comprising a flow rate measuring device (6) connected to a flexible hose (7) equipped with a nozzle (8), designed to deliver fuel to a vehicle tank, the electric motor (3) being a motor having two predetermined speeds (3), providing the pump (4) with two rotational speeds, to which a lower speed V1 that is intended to provide a small flow rate of fuel D1 at the outlet of the pumping unit (2) when only one nozzle (8) is delivering fuel, and a higher speed V2 that is intended to provide a large flow rate of fuel D2 at the outlet of the pumping unit (2) when two nozzles (8) are delivering fuel, the two-speed motor (3) being electrically connected to a controller (9) that controls the speed of the electric motor (3) depending on the activated number of nozzles (8), characterized in that the two-speed motor (3) is an asynchronous motor operating with a variable number of poles, the fuel dispenser (1) comprising a switching means (10) that is controlled by the controller (9) and serves to switch from a number X of poles to a number Y of poles.
2. Fuel dispenser (1) according to Claim 1, characterized in that the two-speed motor (3) operates in 4-pole operation or 8-pole operation so as to respectively obtain the fixed speeds V2 or V1.
3. Fuel dispenser (1) according to Claim 1 or 2, characterized in that it comprises a pump state detector (11) connected to the controller (9), said pump state detector (11) transmitting a signal to the controller (9) that informs the latter if a state of cavitation or a state of non-priming of the pump (4) is detected, said controller (9) transmitting to the switching means (10) a setpoint signal to switch the two-speed motor (3) to the higher speed V2 if its initial speed was V1.
4. Fuel dispenser according to Claim 3, characterized in that the pump state detector (11) is an ammeter measuring the current drawn by the two-speed motor (3), when the initial speed of the motor is V1 and the measured current is below a threshold value, the controller (9) transmits to the switching means (10) a setpoint signal to switch the speed to V2.
5. Operating method for a fuel dispenser (1) as defined by any one of Claims 1 to 4, said fuel dispenser (1) comprising a pumping unit (2) that comprises a two-speed motor (3) driving a pump (4) that is designed to draw fuel from a fuel tank, the pumping unit (2) being connected to two fuel dispensing lines (5), each comprising a flow rate measuring device (6) connected to a flexible hose (7) equipped with a nozzle (8) designed to deliver fuel to a vehicle tank, said two-speed motor (3) being an asynchronous motor operating with a variable number of poles, the fuel dispenser (1) comprising a switching means (10) controlled by the controller (9) and serving to switch from a number X of poles to a number Y of poles, X being smaller than Y, said method comprising a step of lifting a first nozzle (8) to deliver fuel to a first vehicle, characterized in that it comprises the following steps:

   - switching the two-speed motor (3) to a number Y of poles by means of the switching means (10) in order to start up the two-speed motor (3) at a lower rotational speed V1 so as to provide a first flow rate of fuel D1 at the outlet of the pumping unit (2),

   - switching the two-speed motor (3) to a number X of poles by means of the switching means (10) in order to provide a rotational speed V2, this being higher than V1, when a second nozzle (8) is lifted to deliver fuel to a second vehicle, so as to obtain a second flow rate of fuel D2, this being greater than D1, at the outlet of the pumping unit (2).
6. Operating method for a fuel dispenser (1) according to Claim 5, characterized in that the rotational speeds V1 and V2 are fixed and predetermined.
7. Operating method for a fuel dispenser (1) according to either one of Claims 5 and 6, characterized in that it comprises the following steps:

   - measuring the intensity of the current drawn by the two-speed motor (3),

   - switching the two-speed motor (3) to a number X of poles by means of the switching means (10) providing a rotational speed V2, this being greater than V1, if a single nozzle (8) is lifted, if the rotational speed of the two-speed motor (3) is initially V1 and if the intensity of the current drawn by the two-speed motor (3) is below a threshold value,

   - switching the two-speed motor (3) to a number X of poles by means of the switching means (10) providing the rotational speed V1 if a single nozzle (8) is lifted and if the intensity of the current drawn by the two-speed motor (3) is greater than or equal to the threshold value.
8. Operating method for a fuel dispenser (1) according to any one of Claims 5 to 7, characterized in that it comprises a silent mode in which the rotational speed of the two-speed motor (3) is limited to the speed V1 during a predetermined time T, whatever the intensity of the current drawn by the two-speed motor (3).

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