EP3747829A1

EP3747829A1 - Additive explosion risk

Info

Publication number: EP3747829A1
Application number: EP20171775.8A
Authority: EP
Inventors: Bengt I Larsson; Mattias Mårtensson
Original assignee: Wayne Fueling Systems Sweden AB
Current assignee: Wayne Fueling Systems Sweden AB
Priority date: 2019-06-05
Filing date: 2020-04-28
Publication date: 2020-12-09
Anticipated expiration: 2040-04-28
Also published as: EP3747829B1; PT3747829T; SE1950672A1; SE543664C2

Abstract

The invention relates to a fuel dispensing unit (1) for refueling vehicles. The fuel dispensing unit (1) comprises an underground tank for holding fuel, a fuel conduit (15) for transporting the fuel, the fuel conduit (15) extending between the underground tank (7) and a hose connection (11), a pump (8) arranged on the fuel conduit (13), the pump (8) having a suction side (S) and a pressure side (P), an additive tank (14) for holding additive, and an additive conduit (15) for transporting the additive, the additive conduit (15) extending between the additive tank (14) and the fuel conduit (13). The invention also relates to a method for handling a fuel dispensing unit (1).

Description

Technical field

The invention relates to a fuel dispensing unit for refueling vehicles and to a method for handling a fuel dispensing unit.

Background art

Safety aspects in and around areas containing fuel dispensing units is today a highly debated field and new technology is constantly developed with the intention to increase the safety within such areas. It is well-known that fuel, such as petrol or diesel, is a highly inflammable substance that must be handled with extreme care. An inherent property of fuel, that increases the risks of its handling, is its high volatility. For the above reasons, safety standards such as the UL standards for safety in North America, the ATEX directive in the EU or the European standard EN 13617 pertaining to petrol filling stations have been created for fuel handling to reduce the thereby induced risks.
According to those standards, electromechanical devices, such as the motor or the above mentioned switching device, must be enclosed in explosion-proof housings or isolated through the use of intrinsically safe circuitry in order to protect against the hazards of a spark igniting fuel vapors.
Although serious measures have been taken to ensure the safety it is always a concern when highly inflammable substances are handled around fuel dispensing units.
In today's conventional fuel dispensing units it is common that an additive is added to the fuel of the fuel dispensing unit for various reasons. The additive constitutes a highly inflammable substance and is normally held in a container which is placed in connection to the fuel dispensing unit and is connected thereto.
The additive is pumped into the fuel at a pressure side of a fuel pump inside the fuel dispensing unit. The additive itself is pumped by means of a pump driven by a motor.
A problem with this solution is that new regulations states that the additive is no longer allowed to be pressurized in concentrated form due to the risk of explosion.

Summary of the invention

It is an objective of the present invention to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solve at least the above mentioned problems.
According to a first aspect of the invention, these and other objects are achieved, in full or at least in part, by a fuel dispensing unit for refueling vehicles. The fuel dispensing unit comprises an underground tank for holding fuel, a fuel conduit for transporting the fuel, the fuel conduit extending between the underground tank and a hose connection, a pump arranged on the fuel conduit, the pump having a suction side and a pressure side, an additive tank for holding additive, and an additive conduit for transporting the additive. The additive conduit extends between the additive tank and the fuel conduit. The fuel dispensing unit is characterized in that the additive conduit is connected to the fuel conduit on the suction side of the pump.
Since the additive enters the fuel conduit at the suction side of the pump, it is no longer pressurized in concentrated form. In other words, the additive is mixed into the fuel present in the fuel conduit before being pressurized by means of the pump.
This is advantageous in that the risk of explosion is eliminated. Another advantage is that the need for an additional pump and motor for pumping the additive in the fuel dispensing unit is removed.
The fuel dispensing unit may further comprise a flow meter and a control valve arranged in series in the additive conduit.
The fuel dispensing unit may further comprise a control unit connected to the flow meter and a control valve.
The control unit may be adapted to control the control valve based on the volume of fuel present in a fuel flow path of the fuel dispensing unit when a refuelling process is initiated to compensate for lack of additive in that volume of fuel.
The volume of fuel present between the nozzle of the fuel dispensing unit and the additive injection point of the system, i.e. where the additive conduit connects with the fuel conduit, is known. In one embodiment, the control valve in the additive conduit is set to distribute a higher level of additive for the first 5 litres of fuel to compensate for the lack of additive in the fuel present in the system when the refuelling process is initiated. If the preceding refuelling process in the system included additive, no such compensation will be necessary.
The fuel dispensing unit may further comprise a flow meter arranged in the fuel conduit at the suction side of the pump, wherein the control unit is connected to the flow meter arranged in the fuel conduit.
The control unit may be adapted to control the control valve based on information from the flow meter arranged in the additive conduit and from the flow meter arranged in the fuel conduit.
The fuel dispensing unit may further comprise bypass channel extending between the pressure side and the suction side of the pump on the fuel conduit, the bypass channel comprising a control valve.
The pump and the flow meter arranged in the fuel conduit may be arranged in a hydraulics compartment of the fuel dispensing unit.
The additive tank, and the flow meter and the control valve arranged in the additive conduit, may be arranged in an additive compartment.
The additive compartment may be arranged in an opposite side to the hydraulics compartment of the fuel dispensing.
The fuel dispensing unit may further comprise a nozzle connected to the hose connection via a hose.
According to a second aspect of the invention, these and other objects, and/or advantages that will be apparent from the following description of embodiments, are achieved, in full or at least in part, by a method for handling a fuel pump unit for a fuel dispensing unit. The fuel dispensing unit comprises an underground tank for holding fuel, a fuel conduit for transporting fuel, the fuel conduit extending between the underground tank and a hose connection, a pump arranged on the fuel conduit, the pump having a suction side and a pressure side, an additive tank for holding additive, an additive conduit for transporting additive. The additive conduit extending between the additive tank and the fuel conduit. The method is characterized by the step of connecting the additive conduit to the fuel conduit at the suction side (S) of the pump.
The method may further comprise the step of controlling the control valve arranged in the additive conduit based on the volume of fuel present in the fuel flow path of the fuel dispensing unit when a refuelling process is initiated to compensate for lack of additive in that volume of fuel.
The method may further comprise the step of controlling a control valve arranged in the additive conduit based on information from a flow meter arranged in the additive conduit and information from a flow meter arranged in the fuel conduit.
Effects and features of the second aspect of the present invention are largely analogous to those described above in connection with the first aspect of the inventive concept. Embodiments mentioned in relation to the first aspect of the present invention are largely compatible with the further aspects of the invention.
Other objectives, features and advantages of the present invention will appear from the following detailed disclosure, from the attached claims, as well as from the drawings. It is noted that the invention relates to all possible combinations of features.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [element, device, component, means, step, etc.]" are to be interpreted openly as referring to at least one instance of the element, device, component, means, step, etc., unless explicitly stated otherwise.
As used herein, the term "comprising" and variations of that term are not intended to exclude other additives, components, integers or steps.
The term "hose connection" is the part, portion or section connecting the fuel conduit with the hose in the fuel dispensing unit. It may for example be constituted by a normal connection means, or by a part or portion of a conduit.

Brief description of the drawings

The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings, where the same reference numerals may be used for similar elements, and wherein:

Fig. 1 is a perspective view of one exemplary embodiment of a fuel dispensing unit for refueling vehicles according to a first aspect of the invention.
Fig. 2 is another perspective view of one exemplary embodiment of the fuel dispensing unit for refueling vehicles according to the first aspect of the invention.

Detailed description of preferred embodiments of the invention

Fig. 1 illustrates an exemplary embodiment of a fuel dispensing unit 1 for refueling vehicles. The fuel dispensing unit 1 has hose storage spaces 2 on each opposing side of the fuel dispensing unit 1, an electrical compartment 3 containing all the electronics for the fuel dispensing unit 1, a hydraulic compartment 4 containing fuel dispensing means (not shown), e.g. fuel metering means, valves, vapour recovery system etc., and a column 5 extending vertically between and separating the electrical compartment 3 and the hydraulic compartment 4 from the hose storage spaces 2. The fuel dispensing unit 1 also has an additive compartment 6 which is arranged on an opposite side of the fuel dispensing unit 1 in relation to the hydraulics compartment 4.
When filling up the tank of a motor vehicle, the fuel is pumped from an underground tank 7 by means of a pump 8 which is located in the hydraulic compartment 4, and from there to the column 5 and out to a nozzle 9 via a hose connected 10 to the hose connection 11.
The fuel dispensing unit 1 has a nozzle boot 12 in which the nozzle 9 is arranged when not in use. The nozzle boot 12 preferably comprises a sensor (not shown) for detecting if the nozzle 9 is present in the nozzle boot 12. Further, the nozzle 9 is normally equipped with a flow meter (not shown) for measuring the fuel flow rate from the nozzle 9 upon refuelling.
Fig. 2 illustrates the fuel dispensing unit 1 from a see through perspective. The fuel dispensing unit 1 comprises the underground tank 7 for holding fuel and a fuel conduit 13 for transporting the fuel. The fuel conduit 13 extends between the underground tank 7 and the hose connection 11. The fuel dispensing unit 1 further comprises the pump 8 arranged on the fuel conduit 13, the pump having a suction side S and a pressure side P, an additive tank 14 for holding additive, and an additive conduit 15 for transporting the additive. The additive conduit 15 extends between the additive tank 14 and the fuel conduit 13 and is connected the fuel conduit 13 at the suction side S of the pump 8.
In this embodiment, a flow meter 16 and a control valve 17 are arranged in series in the additive conduit 15. The fuel dispensing unit 1 also comprises a control unit 18 which is connected to the flow meter 16 and the control valve 17. The control unit 18 is used to control the flow of additive through the additive conduit 15 by means of the control valve 17.
The control unit 18 may for example be adapted to control the control valve 17 based on the volume of fuel present in a fuel flow path of the fuel dispensing unit 1 when a refuelling process is initiated to compensate for lack of additive in that volume of fuel.
More specifically, since the volume of fuel present between a nozzle 9 of the fuel dispensing unit 1 and the additive injection point of the system, i.e. where the additive conduit connects with the fuel conduit 13, is known, the control valve 17 in the additive conduit 15 may be set to distribute a higher level of additive for a predetermined number litres of fuel to compensate for the lack of additive in the fuel present in the system when the refuelling process is initiated. If the preceding refuelling process in the system included additive, no such compensation is necessary. The predetermined number of litre is established based on the volume of fuel present in the system when the refuelling process is initiated.
Optionally, a flow meter 19 is arranged in the fuel conduit at the suction side S of the pump 8. In this case, the control unit 18 is connected to the flow meter 19 arranged in the fuel conduit 13. This way, the control unit 18 may be adapted to control the control valve 17 based on information from the flow meter 16 arranged in the additive conduit and from the flow meter 13 arranged in the fuel conduit. In other words, the control valve 17 in the additive conduit 15 may be set to distribute a level of additive which is based on the fuel flow rate detected by the flow meter in the fuel conduit 13.
Naturally, the control unit 18 may be adapted to combine the different solutions described above in order to give the best possible accuracy of the ratio blending. In other words, the control unit 18 may be adapted to control the control valve 17 based on information from both the flow meter 16 and the flow meter 19, as well as, simultaneously compensating for the potential for the lack of additive in the fuel volume present in the system when the refuelling process is initiated.
The fuel dispensing unit 1 may also further comprise a bypass channel 20 extending between the pressure side P and the suction side S of the pump 8 on the fuel conduit 13, wherein the bypass channel 20 comprises a control valve 21. During simultaneous fuelling, the control valve 21 in the bypass channel 20 is closed or open at a small opening degree. However, when the fuel dispensing unit 1 is used to deliver fuel from only one nozzle 9, a backpressure develops and causes the control valve 21 to open. Thereby, a portion of the pumped fuel is recirculated to the inlet of the pump 8.
The pump 8 and the flow meter 13 arranged in the fuel conduit are arranged in a hydraulics compartment 4 of the fuel dispensing unit 1, while the additive tank 14, and the flow meter 16 and the control valve 17 arranged in the additive conduit 15, are arranged in an additive compartment 6. The additive compartment 6 is in this embodiment arranged at an opposite side to the hydraulics compartment 4 of the fuel dispensing unit 1.
It is understood that other variations in the present invention are contemplated and in some instances, some features of the invention can be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly in a manner consistent with the scope of the invention.
For instance, the control valve 17 may be constituted by an on-off valve, a proportional valve, or another device for adjusting the additive flow rate in the additive conduit 15.
The pump 8 may be connected to a pump motor which drives the same but it may also include a pump motor in itself.

Claims

A fuel dispensing unit (1) for refueling vehicles, comprising:
an underground tank (7) for holding fuel,

a fuel conduit (13) for transporting the fuel, the fuel conduit (13) extending between the underground tank (7) and a hose connection (11),

a pump (8) arranged on the fuel conduit (13), the pump (8) having a suction side (S) and a pressure side (P),

an additive tank (14) for holding additive, and

an additive conduit (15) for transporting the additive, the additive conduit (15) extending between the additive tank (14) and the fuel conduit (13),

characterized in that the additive conduit (15) is connected to the fuel conduit (13) at the suction side (S) of the pump (8).
The fuel dispensing unit (1) according to claim 1, further comprising a flow meter (16) and a control valve (17) arranged in series in the additive conduit (15).
The fuel dispensing (1) unit according to claim 2, further comprising a control unit (18) connected to the flow meter (16) and a control valve (17) in the additive conduit (15).
The fuel dispensing unit (1) according to claim 3, wherein the control unit (18) is adapted to control the control valve (17) based on the volume of fuel present in a fuel flow path of the fuel dispensing unit (1) when a refuelling process is initiated to compensate for lack of additive in that volume of fuel.
The fuel dispensing unit (1) according to any one of the preceding claims, further comprising a flow meter (19) arranged in the fuel conduit (13) at the suction side (S) of the pump (8), wherein the control unit (18) is connected to the flow meter (19) arranged in the fuel conduit (13).
The fuel dispensing unit (1) according to claim 5, wherein the control unit (18) is adapted to control the control valve (17) based on information from the flow meter (16) arranged in the additive conduit (15) and from the flow meter (19) arranged in the fuel conduit (13).
The fuel dispensing unit (1) according to any one of the preceding claims, further comprising a bypass channel (20) extending between the pressure side (P) and the suction side (S) of the pump (8) on the fuel conduit (13), the bypass channel (20) comprising a control valve (21).
The fuel dispensing unit (1) according to any one of the preceding claims, wherein the pump (8) and the flow meter (19) arranged in the fuel conduit (13) are arranged in a hydraulics compartment (4) of the fuel dispensing unit (1).
The fuel dispensing unit (1) according to claim 9, wherein the additive tank (14), and the flow meter (16) and the control valve (17) arranged in the additive conduit (15), are arranged in an additive compartment (6), the additive compartment (6) being arranged in an opposite side to the hydraulics compartment (6) of the fuel dispensing unit (1).
The fuel dispensing unit (1) according to any one of the preceding claims, further comprising a nozzle (9) connected to the hose connection (11) via a hose (10).
A method of handling a fuel dispensing unit (1), the fuel dispensing unit (1) comprising:
an underground tank (7) for holding fuel,

a fuel conduit (13) for transporting fuel, the fuel conduit (13) extending between the underground tank (7) and a hose connection (11),

a pump (8) arranged on the fuel conduit (13), the pump (8) having a suction side (S) and a pressure side (P),

an additive tank (14) for holding additive,

an additive conduit (15) for transporting additive, the additive conduit (15) extending between the additive tank (14) and the fuel conduit (13),

characterized by the step of:
connecting the additive conduit (15) to the fuel conduit (13) at the suction side (S) of the pump (8).
The method according to claim 11, further comprising the steps of:
controlling if the preceding refuelling process included fuel containing additive,

if no, controlling the control valve (17) arranged in the additive conduit (15) based on the volume of fuel present a fuel flow path of the fuel dispensing unit (1) when a new refuelling process is initiated to compensate for lack of additive in that volume of fuel.
The method according to claim 11 or 12, further comprising the step of controlling a control valve (17) arranged in the additive conduit (15) based on information from a flow meter (16) arranged in the additive conduit (15) and information from a flow meter (19) arranged in the fuel conduit (13).