EP2117992B1 - Installation and method for storing alcohol-based fuel - Google Patents

Abstract

The installation has a fuel tank (1) including a decanting unit decanting fuel e.g. E85 bioethanol based fuel. A vent conduit (3) communicating with a gas collector (5) is communicated with vents of other fuel storage tanks and a tank of a loading lorry. An exchanger (4) dehumidifying the gas passing through the vent conduit and includes a refrigeration exchanger that freezes the water and condenses fuel vapor or condensates. A distributing unit (113) distributes the de-icing water and condensates. A valve (112) de-ices and collects the de-icing water. An independent claim is also included for a method for distributing bioethanol based fuel.

Description

The present invention relates to the distribution of alcohol-based fuel, including ethanol, bioethanol, butanol, methanol and mixtures thereof, for example with hydrocarbons.

The arrival on the market of bioethanol fuels, on the one hand to fight against greenhouse gases, and on the other hand in order to put on the market an alternative fuel to fossil fuels, showed some difficulties .

Indeed ethanol, organic or not, is an alcohol. The alcohol has the particularity of being completely miscible in water. Essences of fossil origin are immiscible, or very little, and their density is different from water.

• détérioration des moteurs ayant été alimentés par un produit non conforme à son cahier des charges.
• obligation de destruction de la quantité de produit restant dans les cuves.
• coût générés par des accidents pris en charge par les assurances.
• immobilisation des véhicules ayant subit un problème dû aux ravitaillement du carburant impropre.

To dispense fuel containing a high proportion of alcohol, care must be taken to preserve the nature of the alcohol and its concentration in the fuel sold. Accidental water addition would be dramatic for many reasons, for example:

• deterioration of the engines having been supplied by a product not complying with its specifications.
• obligation to destroy the quantity of product remaining in the tanks.
• cost generated by accidents covered by insurance.
• immobilization of the vehicles having a problem due to the refueling of the improper fuel.

• ■ Le produit livré contient déjà de l'eau, le problème se situe entre le dépôt et la station.
• ■ le produit livré est conforme, mais de l'eau se mélange au carburant par une infiltration entre le sol et l'intérieur de la cuve.
• ■ La condensation de l'eau de l'air ambiant contenu dans la cuve de bioéthanol provoque un mélange d'eau et de carburant.

However, we can identify several causes of addition of water in ethanol:

• ■ The delivered product already contains water, the problem is between the depot and the station.
• ■ the delivered product is compliant, but water is mixed with the fuel by infiltration between the soil and the inside of the tank.
• ■ Condensation of the ambient air in the bioethanol tank causes a mixture of water and fuel.

If the first two causes can be solved by appropriate implementation for the transport or manufacture of the tanks, there is no known solution to control the condensation of water in the circuits in communication with the bioethanol tank , particularly in the field of automotive fuel distribution.

The document US 5,367,882 A describes an installation according to the preamble of claim 1.

Thus, the present invention relates to a fuel storage installation comprising at least one alcohol-based fuel tank, for example E85, said tank comprising at least fuel withdrawal means, filling means, and a conduit. in communication with a gas manifold that can be in communication with the vents of other fuel storage tanks and the tank of a loading truck. The installation comprises means for dehumidifying the gases passing through the vent pipe of the alcohol-based fuel tank, in particular bioethanol, comprising: a refrigerating exchanger intended to freeze the water and to condense the vapors of fuel, or condensates; - Condensate collection means; - Defrosting means and collection of defrost water.

The dehumidification means may comprise a condensate and defrosting water receiving tank from said exchanger, and two distribution valves for discharging the condensates separately from the water.

The de-icing means may comprise means for controlling the valves so as to close the condensate discharge valve before defrosting while opening the water discharge valve.

A gas collection duct can connect the dispensing gun to a fuel tank.

All vent lines in each fuel cell can pass through a refrigeration exchanger to condense the fuel vapors.

The vent lines of the diesel fuel tank and the alcohol fuel tank may be in communication.

• on déshumidifie des gaz passant par le conduit d'évent de la cuve de carburant à base d'alcool, par exemple du bioéthanol, en les faisant traverser un échangeur frigorifique destiné à geler l'eau et à condenser les vapeurs de carburant, ou condensats;
• on collecte lesdits condensats que l'on déverse dans une cuve de carburant essence,
• on effectue un dégivrage de l'échangeur frigorifique et on collecte de l'eau de dégivrage pour la déverser hors des cuves.

The invention also relates to a method for dispensing fuel from a fuel storage installation comprising at least one alcohol-based fuel tank, said tank comprising at least fuel withdrawal means, filling means , and a vent pipe in communication with a gas manifold that can be in communication with the vents of other fuel storage tanks and the tank of a cargo truck. According to the method, the following steps are carried out:

• dehumidifies gases passing through the vent pipe of the alcohol-based fuel tank, for example bioethanol, by passing them through a cooling exchanger intended to freeze the water and to condense the fuel vapors, or condensates ;
• these condensates are collected and poured into a gasoline fuel tank,
• defrosting of the refrigerating exchanger is carried out and deicing water is collected to discharge it out of the tanks.

The invention combines the condensation of fuel vapors, hydrocarbon or alcohol-based, for example ethanol, bioethanol, butanol, methanol, their mixtures, for example with hydrocarbons, with the drying of air by the cold.

For this we lower the temperature of the air entering the tank to turn the water into frost.

• la figure 1 montre une cuve de bioéthanol et ses circuits de remplissage et de vidage;
• la figure 2 est une vue représentant une station service en cours de remplissage de ses cuves, dont une cuve de bioéthanol.
• la figure 3 représente une partie de l'installation de la figure 2 en cours de vidage de ses cuves.

The present invention will be better understood and its advantages will appear more clearly on reading the following description of exemplary embodiments, in no way limiting, and illustrated by the appended figures, among which:

• the figure 1 shows a bioethanol tank and its filling and emptying circuits;
• the figure 2 is a view of a service station in the process of filling its tanks, including a bioethanol tank.
• the figure 3 represents a part of the installation of the figure 2 during emptying of his tanks.

It is clear that the following embodiment, described for bioethanol, is not limited to this fuel, and extends to any alcohol-based fuel, such as those mentioned above.

On the figure 1 , the tank 1 is intended to contain a fuel based on bioethanol. For its filling, it has a pipe 2 which connects to the loading hose of a tanker truck.

In order to expel the air contained in the tank, it is equipped with a vent pipe 3 equipped with an exchanger 4.

In order to comply with the regulations, the vent gases are collected by means of a manifold 5, an output of which allows to connect a pipe 7 which brings these gases to the tank of the supply truck.

For safety reasons the vent pipe 3 is surmounted by a safety valve 6 for controlling the pressure of the gases in the tank.

Indeed, when the tank is filled, it is necessary to let air into the tank to compensate for the volume of liquid delivered to the pump to prevent depression of the tank.

Also, when the empty tank is in supply, it should be able to evacuate the air (gases) contained (s) in the tank. This volume of gas is normally taken up by the truck through line 7. Thus, an overpressure in the tank is not possible. The safety valve 6 operates in both directions of overpressure or depression in the tank.

• Lors d'une livraison d'un carburant à base de bioéthanol par vidage gravitationnel du produit par la canalisation 2, la cuve 1 se remplit en chassant le volume équivalent de gaz par le conduit d'évent 3. Ces gaz traversent un échangeur 4 dont la zone froide est fournie par un compresseur du type frigorifique, non décrit ici car à la portée de l'homme du métier.

According to the method and system of the present invention, the implementation is as follows:

• When a bioethanol-based fuel is delivered by gravitational emptying of the product via line 2, the tank 1 fills up by expelling the equivalent volume of gas through the vent pipe 3. These gases pass through a heat exchanger 4 of which the cold zone is provided by a compressor of the refrigerating type, not described here because within the reach of the skilled person.

By crossing this exchanger, the fuel molecules contained in the gas are condensed. The condensate is sent into a container 8. For example, this container can operate on the same principle as a flush. When the liquid reaches a determined level, a valve 111 opens to evacuate these fuel condensates to a suitable tank via the conduit 110.

At the same time, the passage of the gases in the exchanger transformed the water particles, for example due to the humidity of the ambient air, into frost on the walls of the exchanger 4.

Thus, the invention allows, in combination, to recover in liquid form the fuel vapors and to remove the water contained in the gas in contact with a miscible fuel in water.

When the delivery operation is completed, a defrost cycle of the machine is started. The defrost cycle consists of operating the machine producing cold upside down, following the same principle as reversible air conditioning. Ice in the form of frost melts and flows into the container 8. A valve 112 on a specific water discharge conduit 9 opens to discharge the water to a tank, for example the settling tank from the service station. In order not to re-dissolve the condensates collected in the container 8 with the defrosting water, the defrosting step can begin with the complete evacuation of the condensates via the duct 110.

At the end of the defrosting, the valve 112 is closed.

It is noted that during the first delivery if the tank of the station is filled correctly, the gaseous sky is of a very limited volume, so the volume of moist air is low. It is considered that the rate of water in contact with the bioethanol fuel will be low and negligible.

When the tank is emptied by motorists refueling, outside air comes to replace the volume of product withdrawn, conveyed by the vent 3, either by the air inlet provided by the valve 6, or by the collector 5 existing on a station delivering other products, type essence.

This air to replace the volume sold must pass through the exchanger 4 kept cold by the appropriate refrigerant circuit. Incoming air, possibly charged with humidity, is freed from water by forming frost. Dry air is therefore conveyed into the tank, so there can be no natural condensation in the tank, and therefore little miscibility of water in the bioethanol fuel.

The system includes programmed periodic defrost cycles, combined with the operation of the exhaust valves 111 and 112.

The figure 2 shows a variant in which the system according to the invention is integrated in a set of tanks of gasoline and diesel fuel C1 to C4.

On the figure 2 is represented a service station S comprising four tanks C1, C2, C3, C4, and a bioethanol tank 1, a storage facility I, each intended to contain a fuel intended to be dispensed from volumetric pumps or "pumps , Of which only one, referenced P, is represented. Tanks C1, C2 and C3 are intended to contain light fuels, namely "gasoline 98", "gasoline 95". The tank C4 is, for its part, intended to contain a heavy fuel, namely diesel, which differs from the light fuels of tanks C1, C2, C3 by its lower volatility. The tank 1, according to figure 1 contains a fuel based on ethanol.

In the configuration shown in figure 2 , the tank C1 is being filled from a tank 10 of a delivery truck, as represented by the arrows F1. In known manner, a discharge pipe 11 connects the tank 10 to the tank C1 in which is arranged for example a not shown gauge. A vent pipe 12 has its inlet 12a disposed in the upper part of the tank C1 to collect the vent gas resulting from the filling operation. The circulation of these vent gases is represented by arrows F2.

The vent duct 12 is provided, in its current part, with a condenser 13 and is connected, at its outlet orifice 12b, to a manifold 14 provided with a safety valve 15 for venting free the manifold in case of overpressure or gas vacuum. The outlet 14A of the manifold 14 is connected by a recycling duct 19 to a gas distribution network 16 inside the tank 10 (more particularly visible on the figure 3 ), so that the condenser 13 is integrated in a collection line of the vents of the tank C1 towards the tank, this line being formed by the meeting of the vent pipe 12, the collector 14, the pipe 19 and the network 16.

As explained in detail in WO-A-03/006358 , the vent gases flowing in the pipe 12 are cooled in the condenser 13 and are thus discharged from their fuel particles which condense and flow to the tank C1 as represented by the arrows F3. To reach this tank, the condensates circulate in a specific evacuation duct 17 shown in phantom, or, alternatively, flow into the vent duct 12, in particular by means of a capillary, either by simple gravity , or forcibly by means of a pump not shown. In a variant not shown, the exhaust duct 17 is connected to the discharge pipe 11 so as to promote the flow of condensates by Venturi effect caused by the flow of fuel removed from the tank 10.

The tanks C1, C2, C3 and C4 of the installation I are each equipped with a vent duct 22, 32, 42 opening at the outlet into the manifold 14 which is therefore common to all the vent ducts 12, 22 , 32 and 42, in the sense that gases can pass from any duct to another via this manifold. The collector 14 is preferably equipped with gas distribution means passing therethrough, sensitive to the gas pressure prevailing in the various vent pipes 12, 22, 32 and 42: if the pressure prevailing in one of these vent pipes is greater than those prevailing in other conduits, these distribution means balance these gas pressures by allowing a portion of the gas duct pressure to pass into the ducts of lower pressure. The vent duct 3 of the tank 1 is connected to the vent duct 42 of the diesel fuel tank.

In known manner, the vent pipes 22 and 32 associated with tanks C2 and C3 of light fuel are each equipped with a condenser 23 and 33 substantially similar to the condenser 13. Each condenser 23 and 33 is connected to an evacuation pipe of condensates 27 and 37, similar to the conduit 17 associated with the condenser 13 and adapted to direct the condensed vapors at the outlet of each condenser respectively to the tanks C2 and C3.

Unlike known installations, the vent duct 42 associated with the diesel fuel tank C4 is also equipped with a condenser 43. This condenser 43 is implanted in a similar manner to that of the condenser 13 of the duct 12, but is different from this condenser 13 by its dimensioning. More specifically, the cooling capacity of the condenser 43 is significantly lower than that of the condensers 13, 23 and 33. The vent duct 3 being connected upstream of the condenser 43, all the gases of the tank 1 pass through said condenser 43 .

Like the other condensers 13, 23 and 33, the condenser 43 is connected to a condensate discharge duct 47 which, unlike the ducts 17, 27 and 37, does not direct the condensates towards the tank from which the condensates originate. gas vents treated in the condenser (tank C4), but to one of the tanks of light fuels, namely, for example, tanks C1, C2, C3, or tank 1, on the figure 1 . However, according to the present invention, means for distributing defrost water and condensates 113 are placed on the evacuation line 47.

The vent pipe 42 of the diesel fuel tank C4 is provided with a valve 20 disposed between the condenser 43 and the manifold 14. This valve is preferably calibrated more weakly than the valve 15, for example at -5 mbar instead of -15 mbar, so as to allow the introduction of ambient air into the tank C4 as soon as a depression is formed therein in particular when dispensing fuel from the tank C4 to the pump P .

According to the regulations, the vent pipe 3 also comprises a valve 6. However, its calibration must not allow the introduction of ambient air, but priority is given to the valve 20 so that the air introduced into the tank 1, and C4 passes through an exchanger, for example that referenced 43.

Although not shown in detail, the condensers 13, 23, 33 and 43 are for example adapted to be supplied with a heat transfer fluid from a cooling unit of this fluid, the latter being selected according to environmental standards in force. This unit comprises for example one or more compressors able to cool the fluid supplying the condensers at a temperature between -55 ° C and -25 ° C, preferably between about -45 ° C and -40 ° C. Details of embodiment of the condensers of this type are for example given in WO-A-03/006358 .

The installation 1 further comprises a suction duct 18 opening, at one of its ends, in the tank C1 and, at its opposite end, in a gas collection network of the flow meter P. In a preferred embodiment, the meter is equipped with fuel dispensing guns, respectively provided, for the light fuel dispensing guns, with a suction nozzle for the fuel vapors released during the filling of the tank of a motor vehicle. These suction nozzles collect the gases resulting from the filling of this tank and send them into the conduit 18 so that these vapors are not released into the atmosphere but returned to the tank C1. The conduit 18 and the collection network of the meter P thus form means for recovering the gases released during the filling of these tanks, able to meet certain environmental standards. It should be noted that these recovery gases can not reach the tank 1 of bioethanol fuel without passing through at least one exchanger, which guarantees dehumidification of the gases and prohibits an increase in the possible rate of water in the fuel. based on bioethanol stored in the tank 1.

The operation of the installation I will be more precisely described with regard to the figure 3 .

In the case corresponding to a fuel distribution by emptying the tanks of the installation I, it is considered, as represented on the figure 3 , that, through the meter P, a motorist withdraws gasoline 98 from the tank C1 to fill the tank of his vehicle. When filling the tank, the dispensing gun delivers the gasoline 98 and sucks at the same time the gaseous phase present in the tank, in particular to limit gaseous escaping harmful to the environment. The aspirated gases, represented by the arrows F4 are, via the suction duct 18, sent to the tank C1 in practice, the volume of gas sucked is at least 10% greater than the volume of fuel emptied, which causes the increase internal gas pressure to this tank. At the same time, it is considered that another motorist withdraws diesel fuel from the tank C4 through another unrepresented pump unloading the tank C4 causes the lowering of the internal gas pressure to this tank. In practice, in a country like France, the distribution of diesel represents generally more than half of the total fuel distribution for the service station S. Via the collector 14, a portion of the gases contained in the tank C1 is then sent through the vent pipe 42 into the tank C4 so that the pressure in these tanks is substantially equal. In doing so, a stream of gas laden with light fuel vapors then passes through, as indicated by the arrow F5, the condenser 43 associated with the tank C4, which causes the condensation of at least a portion of these vapors, the condensates being directed via the conduit 47 to the tank C1. The remaining cooled gases, essentially free of their light fuel particles, are sent to the tank C4. The vent duct 3 of the tank 1 being connected to the duct 42, any return of gas passes through the exchanger 43, according to the present invention and therefore no moisture reaches the bioethanol tank 1. The description of the means 113 is consistent with the description of the figure 1 .

Thus, more generally, the fumes of light fuels passing through the common manifold 14, one of the tanks 1, C1, C2 and / or C3 to the tank C4, are at least partly recovered, by means of condenser 43, in the form of condensates discharged to the tank C1 being understood that these condensates could be evacuated to any tank of light fuel installation. This passage of fuel vapors is even more marked than the diesel tank is frequently solicited compared to tanks of light fuels. In addition, according to the present invention, the gases that can return to the tank 1 are dehumidified by icing.

Furthermore, the return of the condensates in one of the tanks of light fuel, namely in the tank C1 in the example in the figures, and the concomitant return of cooled gases, removed from most of their light fuel particles , in the tank C4 and, where appropriate, in the tanks C1, C2 and C3 make it possible to avoid sending light fuels into the tank of heavy fuel C4 and to cool the internal gas atmosphere of the tanks, which limits evaporation of fuels in the tanks.

Claims (7)

1. A fuel storage facility comprising at least one alcohol-based fuel tank (1), said tank comprising at least fuel withdrawal means, filling means (2), and a vent pipe (3) communicating with a gas collector (5) that can be communicated with the vent pipes of other fuel storage tanks and of the tank of a loading truck, and means (4) for dehumidifying the gases passing through vent pipe (3) of the alcohol-based fuel tank, and comprising: - a refrigerating exchanger (4) for freezing the water and for condensing the fuel vapours, or condensates; - and condensate collecting means (113), characterized in that said dehumidifying means (4) furthermore comprise means (8, 9) for defrosting and collecting the defrosted water.
2. A facility as claimed in claim 1, wherein the dehumidifying means comprise a drum (8) receiving condensate and defrosted water fluids from said exchanger (4), and two distribution valves (111, 112) for discharging the condensates separately from the water.
3. A facility as claimed in claim 2, wherein the defrosting means comprise valve control means (111, 112) for closing condensate discharge valve (111) prior to defrosting while opening water discharge valve (112).
4. A facility as claimed in any one of the previous claims, wherein a gas collecting line (5) connects the delivery nozzle to a gasoline fuel tank (C1, C2, C3).
5. A facility as claimed in any one of the previous claims, wherein all the vent pipes (12, 22, 32, 42) of each fuel tank (C1, C2, C3, C4) run through a refrigerating exchanger (13, 23, 33, 43) so as to condense the fuel vapours.
6. A facility as claimed in any one of the previous claims, wherein the vent pipes (42, 3) of diesel fuel tank (4) and of alcohol-based fuel tank (1) communicate with one another.
7. A method of distributing fuel from a fuel storage facility comprising at least one alcohol-based fuel tank, said tank comprising at least fuel withdrawal means, filling means and a vent pipe communicating with a gas collector that can be communicated with the vent pipes of other fuel storage tanks and of the tank of a loading truck, a method wherein the following stages are carried out:

   - dehumidifying gases passing through the vent pipe of the alcohol-based fuel tank by sending them through a refrigerating exchanger for freezing the water and for condensing the fuel vapours, or condensates,

   - collecting said condensates that are discharged into a gasoline fuel tank,

   - defrosting the refrigerating exchanger and collecting defrosted water so as to discharge it out of the tanks.

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