Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
  • B67D—DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
  • B67D7/00—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
  • B67D7/04—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes for transferring fuels, lubricants or mixed fuels and lubricants
  • B67D7/0476—Vapour recovery systems
  • B67D7/0478—Vapour recovery systems constructional features or components
  • B67D7/048—Vapour flow control means, e.g. valves, pumps
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B67—OPENING, CLOSING OR CLEANING BOTTLES, JARS OR SIMILAR CONTAINERS; LIQUID HANDLING
  • B67D—DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR
  • B67D7/00—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes
  • B67D7/04—Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes for transferring fuels, lubricants or mixed fuels and lubricants
  • B67D7/0476—Vapour recovery systems
  • B67D7/0478—Vapour recovery systems constructional features or components
  • B67D7/048—Vapour flow control means, e.g. valves, pumps
  • B67D7/0482—Vapour flow control means, e.g. valves, pumps using pumps driven at different flow rates
  • B67D7/0486—Pumps driven in response to electric signals indicative of pressure, temperature or liquid flow

Definitions

• the present invention relates to a process for recovering vapor emitted in a liquid distribution installation during the distribution of said liquid inside a tank.
• the invention finds a particularly advantageous application in the field of fuel distribution for motor vehicles for example, in order to recover the hydrocarbon vapors escaping from the tank of said vehicles as the latter fills with liquid fuel.
• a liquid dispensing installation such as fuel for motor vehicles generally comprises means for dispensing said liquid essentially constituted by pressure meters fitted with pumps capable of circulating the fuel with a liquid flow rate QL between a tank storage and tank vehicles.
• the meters also include a liquid meter connected to a pulse generator allowing a computer to establish the volume and the price of the fuel delivered, which appear in clear on a display with which the meters are equipped.
• said recovery means are constituted by a pump sucking the vapors from the tank to discharge them into the hydrocarbon storage tank.
• the characteristic magnitude G is then the speed w of rotation of said pump, which is controlled by the pulse generator of the distribution means.
• the operating conditions can be very different from one installation to another by: the pressure losses on the recovery pipe, upstream and downstream of the pump, - the possible presence of calibrated valves at the recovery tank which can generate in it a pressure different from atmospheric pressure and corresponding to an additional hydraulic resistance on the recovery pipe, - the internal leakage of the recovery pump, depending on the pressure difference upstream-downstream, which affects its effectiveness.
• the pressure losses on the recovery pipe can change over time due to: a gradual partial sealing by dust, the change in section of the elastomer pipes with the prolonged presence of hydrocarbons.
• the internal leakage of the pump can evolve due to wear, as in vane pumps for example, the density of the vapors is variable with the hydrocarbons and the temperature of the tanks of the vehicles, which modifies the influence of the losses of upstream and downstream load.
• the vapor pressure in the recovery tank can also vary with the hydrocarbons and the temperature.
• the technical problem to be solved by the object of the present invention is to propose a method for recovering vapor emitted in a liquid distribution installation during the distribution of said liquid inside a tank, said installation comprising : means for distributing liquid capable of circulating said liquid with a liquid flow rate Q L between a tank and said tank, means of vapor recovery capable of circulating said vapor with a vapor flow rate Qy along a pipeline, between said tank and a recovery tank, said vapor flow Qy being controlled by a quantity G characteristic of said recovery means, a process which, taking into account the slow evolution of the parameters characteristic of the circulation of vapor along the pipeline recovery, would allow a delayed recalibration of the characteristic quantity G as a function of the vapor flow rate eur Qv-
• the solution to the technical problem posed consists, according to the present invention, in that said method comprises the steps consisting in: build a relationship
• G F (Q ⁇ , ⁇ ) connecting the quantity G to the vapor flow rate Qy and to parameters p ⁇ characteristic of the recovery means and said pipe, determine an initial value ⁇ p j ⁇ 0 of the parameters p j , at each liquid distribution k: measure the liquid flow rate Q ⁇ and determine a value G ⁇ of the quantity G to be imposed on the recovery means by the relation: determine a new value (p ⁇ ⁇ of the parameters p j to be used for the following distribution k + 1 of liquid.
• a value determined from parameters calculated during the previous distribution is used for the characteristic quantity G, and, on the other hand, at least one measurement is carried out making it possible to calculate new values for said parameters which will be used for the following distribution.
• the recovery means comprising a pump, said quantity G is the speed w of rotation of said pump.
• the recovery means comprising a pump and a solenoid valve
• said quantity G is the hydraulic resistance imposed by said solenoid valve, the speed w of rotation of the pump being constant.
• the different parameters pj characteristic of the recovery means and the pipeline will be considered to be independent of the vapor flow rate Qy. However, it may happen that some of these parameters vary with said vapor flow rate. This is particularly the case for the internal leakage coefficient ⁇ of vane pumps when the vane is not guided with precision. The method of the invention must then be adapted to this particular situation.
• Figure 1 is a general diagram of a liquid distribution installation implementing a vapor recovery process according to the invention.
• Figure 2 is a diagram of the vapor recovery circuit of Figure 1 in the case where the recovery pump has no internal leakage.
• Figure 3 is a diagram of the vapor recovery circuit of Figure 1 in the case where the recovery pump has a non-zero internal leak.
• Figure 4 is a diagram of the vapor recovery circuit of Figure 1 using two pressure regulators.
• FIG. 5 is a diagram of a vapor recovery circuit with two recovery channels delivering through a common pipe.
• Figure 6 is a diagram of the vapor recovery circuit of Figure 1 with an adjustment valve downstream of the recovery pump.
• FIG. 1 shows an installation for distributing liquid, for example fuel, inside the tank of a vehicle, not shown.
• This installation comprises fuel distribution means essentially constituted by a pump PL capable of circulating said fuel L with a liquid flow rate QL between a storage tank 100 and said tank along a pipe 110, up to a gun. 111 distribution.
• the liquid pump PL comprises a measurer 113 placed on the pipe 110 in series with the pump PL so that a pulse generator 114, coupled to said measurer
• the installation of FIG. 1 also includes means for recovering the vapor V emitted during the distribution of the liquid in the tank of the vehicle.
• said recovery means mainly consist of a pump Pv capable of circulating said vapor with a vapor flow rate Qv along a pipe 120 between the tank, passing through the gun 111 of distribution, and a recovery tank 100 which, in the case of FIG. 1, is none other than the storage tank for liquid fuel.
• the recovery method of the invention consists in imposing on a quantity G characteristic of the recovery means, the speed w of rotation of the pump Pv in the example of FIG. 1, a value such that the flow rate resulting vapor Qv is as close as possible to the liquid flow rate QL-
• the recovery process according to the invention is based on the idea of a deferred updating of the parameters governing the circulation of vapor in the recovery pipe 120.
• the systematic error inherent in the process remains negligible given the very slow drift in time of the parameters p which are essentially linked to the steam pump Pv and to the pressure drops in the pipe 120.
• FIG. 2 A first example of application of the method of the invention is given in FIG. 2.
• the recovery means comprise the steam pump Pv whose speed w of rotation constitutes the quantity G controlling the vapor flow rate Qv-
• the VQ parameter is constant and can be measured once and for all at the factory.
• the initial value R'o of the parameter R ' is determined by means of the relation (2) by imposing any speed w of rotation on the pump Pv and by measuring the pressure F using a pressure sensor 122 and optionally a flow meter, not shown, which supplies the corresponding vapor flow rate Qv. After this initialization phase, the flow meter is deleted.
• the values of VQ and R'o are stored in a memory of the circuit 121 for controlling the motor Mv of the pump Pv-
• R ' ⁇ will be used during the second distribution, and so on.
• the diagram in FIG. 3 relates to a steam pump Py having a coefficient of non-zero internal leakage ⁇ .
• R being the downstream hydraulic resistance of the recovery line 120.
• This operation is carried out automatically by the circuit 121 for controlling the motor Mv which, in addition to the liquid flow information QL, also receives P 'and Q ⁇ u .
• the pressure inside the recovery tank 100 is not equal to atmospheric pressure PA and has a pressure difference ⁇ Po, positive or negative, due for example to the presence of a valve 130 shown in Figure 1.
• FIG. 5 shows the diagram of an installation where two steam pumps Pva, Pvb deliver in a common pipe 12 of small diameter. This is particularly the case in fuel distribution stations where, to limit the costs associated with the installation for recovering hydrocarbon vapors, a flexible tube is slid into the suction pipe for the return of the vapors to the recovery tank 100. This tube is generally common to two pumps, and has a common hydraulic resistance R c which can be significant.
• W a Qlua / VQa + ⁇ a ( R a + Rc) QVa + ⁇ * a * c (QVb + 2Q V a Qv ⁇ )
• the first two terms correspond to a simple path of hydraulic resistance R a + R c and the third term is a corrective term related to channel b.
• FIG. 6 illustrates a variant implementation of the vapor recovery process, object of the invention.
• the circulation of steam in the recovery pipe 120 is ensured by a pump Pv at speed w 0 of fixed rotation, controlled by a motor Mv-
• the vapor flow rate Qy is adjusted by a solenoid valve 126 disposed downstream of the pump Pv and having a variable hydraulic resistance Rx, the value of which is imposed by a control circuit 121.
• the parameters pj to be determined are VQ, R ', R and ⁇ . Apart from VQ, constant and measured in the factory, the other three parameters can be calculated from the measurements of the flow meter 123, and the pressures F and P "given by the sensors 122 and 126. We have indeed:

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Loading And Unloading Of Fuel Tanks Or Ships (AREA)
• Control Of Positive-Displacement Pumps (AREA)
• Measuring Volume Flow (AREA)
• Control Of Steam Boilers And Waste-Gas Boilers (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
• Flow Control (AREA)
• Gas Separation By Absorption (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9481912

Family Applications (1)

Country Status (8)

Families Citing this family (20)

Family Cites Families (7)

• 1995
  • 1995-08-10 FR FR9509796A patent/FR2737717B1/fr not_active Expired - Lifetime
• 1996
  • 1996-07-29 EP EP96927121A patent/EP0843644B1/de not_active Expired - Lifetime
  • 1996-07-29 ES ES96927121T patent/ES2153969T3/es not_active Expired - Lifetime
  • 1996-07-29 US US09/000,416 patent/US6047745A/en not_active Expired - Lifetime
  • 1996-07-29 DE DE69610985T patent/DE69610985T2/de not_active Expired - Lifetime
  • 1996-07-29 WO PCT/FR1996/001217 patent/WO1997006095A1/fr active IP Right Grant
  • 1996-07-29 CA CA002227874A patent/CA2227874C/en not_active Expired - Lifetime
  • 1996-07-29 AT AT96927121T patent/ATE197586T1/de not_active IP Right Cessation

Non-Patent Citations (1)

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