阅读说明：本技术 燃料添加系统 (Fuel addition system ) 是由 理查德·米尔斯 于 2019-08-02 设计创作，主要内容包括：燃料添加系统包括燃料管道、用于控制离开管道的燃料的流量的可变位置阀以及控制器。控制器构造成从传感器装置接收由该系统添加燃料的燃料箱中的静电状况的测量结果。控制器构造成至少部分地基于从传感器装置接收的测量结果来控制可变位置阀从而控制燃料的流量。(The fuel addition system includes a fuel conduit, a variable position valve for controlling the flow of fuel exiting the conduit, and a controller. The controller is configured to receive from the sensor device a measurement of an electrostatic condition in a fuel tank fueled by the system. The controller is configured to control the variable position valve to control the flow of fuel based at least in part on measurements received from the sensor device.)

1. A fuel addition system, the system comprising:

a fuel conduit;

a variable position valve for controlling the flow of fuel exiting the conduit; and

a controller; wherein the content of the first and second substances,

the controller is configured to receive a measurement of an electrostatic condition in a fuel tank fueled by the system from a sensor device, and the controller is configured to control the variable position valve to control a flow of the fuel based at least in part on the measurement received from the sensor device.

2. The fuel addition system of claim 1, wherein the variable position valve is a shutter valve defining an opening of variable size arranged to flow fuel therethrough, and wherein the controller is configured to control the size of the opening defined by the shutter valve, thereby controlling the flow rate of the fuel.

3. The fuel addition system according to claim 1 or 2, wherein the measurement of the electrostatic condition in the fuel tank is based on a measurement of an electric field.

4. The fuel addition system according to any one of claims 1 to 3, wherein the measurement of the electrostatic condition in the fuel tank is based on a measurement of a flowing current.

5. The fuel addition system according to any preceding claim, wherein the controller is configured to receive a determination of a fuel level in the fuel tank, and wherein the controller is configured to control the variable position valve based on a measurement of an electrostatic condition in the fuel tank and based on the determined fuel level in the fuel tank.

6. The fuel addition system of claim 5, wherein the controller is configured to control the variable position valve to prevent an overpressure condition in the fuel tank in response to the determined fuel level in the fuel tank.

7. The fuel addition system of any of the preceding claims, further comprising a second valve in the conduit to selectively start or stop the flow of the fuel through the conduit.

8. The fuel addition system of claim 7, wherein the second valve is configured to stop the flow of fuel through the conduit in response to a detected overpressure condition in the fuel tank.

9. The fuel addition system according to any of the preceding claims, wherein the variable position valve is configured to default to a closed position in response to a failure of the fuel addition system.

10. Fuel addition system according to any of the preceding claims, wherein the controller is configured to collect data relating to fuel addition of a fuel tank, wherein the data relates to the static condition of the fuel tank measured throughout the fuel addition of the fuel tank and one or more other factors relating to the fuel addition of the fuel tank, such as a flow curve throughout the fuel addition, or the type of fuel used, or properties of the fuel tank, or the fuel level in the fuel tank.

11. A fuel addition system for an aircraft, the system being configured to supply fuel to a fuel tank at a variable flow rate, wherein the flow rate is varied by controlling a variable position valve based on a measurement of an amount of electrostatic charge contacting the fuel tank.

12. A method of refueling a fuel tank, the method comprising:

measuring an electrostatic condition associated with the fuel tank using a sensor device;

determining, using a controller, a flow rate of fuel to be supplied to the fuel tank based at least on the measured electrostatic condition associated with the fuel tank; and

controlling a variable position valve using the controller to supply fuel to the fuel tank at the determined flow rate.

13. The method of claim 12, comprising determining a fuel level in the fuel tank, and wherein the flow rate of fuel to be supplied to the fuel tank is determined based on the measured electrostatic condition associated with the fuel tank and the determined fuel level in the fuel tank.

14. The method of claim 12 or 13, wherein determining the flow rate of the fuel comprises:

determining a level of electrostatic threat from the measured electrostatic condition, and wherein the determined flow rate of the fuel is a maximum flow rate that maintains the level of electrostatic threat at or below a predetermined level.

15. The method of claim 14, wherein determining the flow rate of the fuel comprises determining a threat of overpressure of the fuel tank, and wherein the determined flow rate of the fuel is a maximum flow rate that maintains the threat of overpressure of the fuel tank below a predetermined level.

16. Method according to any one of claims 12 to 15, being a method of refueling a fuel tank on board an aircraft.

17. A vehicle, comprising: the fuel addition system according to any one of claims 1 to 11; and a sensor arrangement configured to measure an electrostatic condition in a fuel tank refueled by the system.

18. The vehicle of claim 17, wherein the sensor device comprises one or more sensors located at the fuel tank.

19. The vehicle of claim 18, wherein one of the sensors located at the fuel tank is an electric field sensor.

20. A vehicle according to any of claims 17 to 19 wherein the sensor means comprises one or more sensors located at the fuel conduit or the variable position valve.

21. The vehicle of claim 20, wherein one of the sensors at the fuel line or the variable position valve is a flowing current sensor.

22. The vehicle of any of claims 17-21, wherein the vehicle is an aircraft.

Technical Field

The invention relates to a fuel addition system and a method for adding fuel to a fuel tank.

Background

The aircraft may add a certain amount of fuel between flights. It is desirable to maximize the flight time of an aircraft and therefore minimize the time spent on the ground between flights. The time taken to refuel may increase the time required between flights and therefore it is desirable to minimize the time taken to refuel an aircraft.

When refueling an aircraft, an accumulation of electrostatic charge may occur, which may pose a threat to the safety of nearby aircraft and personnel. The accumulation of charge may be due to ionic impurities in the fuel, or may be due to shear effects in the fuel as it is forced through filters, valves, and by changes in flow direction during fuel addition. The amount of static buildup generally increases along with the fuel flow provided to the aircraft. Therefore, in order to reduce the threat of electrostatic charge accumulation, it may be mandatory to specify (improsed) a maximum flow rate of the additional fuel. The flow rate may be controlled by the size of the fuel line or by using an orifice plate with a specifically sized orifice. Similarly, the build-up of potentially dangerous electrostatic charges may occur in addition to fuel tanks for aircraft, for example at fuel addition stations.

The maximum flow rate may be based on a "worst case scenario" assumption, and it may be assumed that there are no factors for reducing the risk of electrostatic charge build-up, such as antistatic additives in the fuel. The maximum flow rate can also be set in inverse proportion to the risk of overpressure of the tank. The risk of overpressure may only arise when the fuel tank reaches the upper capacity limit. In this way, such a mandatory provision of maximum flow rate throughout the refuelling operation may determine a minimum value for the time required for refuelling of the fuel tank, even when there is no threat from electrostatic build-up or overpressure. It would be advantageous to reduce the time required to refuel a fuel tank, such as an aircraft fuel tank, while safely doing so.

Disclosure of Invention

According to a first aspect of the present invention, there is provided a fuel addition system comprising: a fuel conduit, a variable position valve for controlling the flow of fuel exiting the conduit, and a controller, wherein the controller is configured to receive measurements of an electrostatic condition in a fuel tank being refueled by the system from the sensor device, and the controller is configured to control the variable position valve to control the flow of fuel based at least in part on the measurements received from the sensor device.

Optionally, the variable position valve is a shutter valve defining a variable sized opening through which fuel flows, and the controller is configured to control the size of the opening defined by the shutter valve to control the fuel flow rate.

Alternatively, the measurement of the electrostatic condition in the fuel tank is based on a measurement of the electric field.

Alternatively, the measurement of the electrostatic condition in the fuel tank is based on a measurement of the flowing current.

Optionally, the controller is configured to receive a determination of a fuel level in the fuel tank, and the controller is configured to control the variable position valve based on a measurement of an electrostatic condition in the fuel tank and based on the determined fuel level in the fuel tank.

Optionally, the controller is configured to control the variable position valve to prevent an overpressure condition in the fuel tank in response to a determined fuel level in the fuel tank.

Optionally, the fuel addition system includes a second valve in the conduit to selectively start or stop the flow of fuel through the conduit.

Optionally, the second valve is configured to stop the flow of fuel through the conduit in response to a detected overflow condition in the fuel tank.

Optionally, the variable position valve is configured to default to a closed position in response to a failure of the fuel addition system.

Optionally, the controller is configured to collect data relating to refueling of the fuel tank, wherein the data relates to the electrostatic condition of the fuel tank measured throughout refueling of the fuel tank and one or more other factors related to refueling of the fuel tank.

Optionally, the one or more other factors related to the addition of fuel to the fuel tank include one or more of a flow profile throughout the addition of fuel, or a type of fuel used, or a performance of the fuel tank, or a level of fuel in the fuel tank.

According to a second aspect of the present invention, there is provided a fuel addition system for an aircraft, the system being configured to supply fuel to a fuel tank at a variable flow rate, wherein the flow rate is varied by controlling a variable position valve, the variable position valve being controlled based on a measurement of an amount of electrostatic charge contacting the fuel tank.

According to a third aspect of the invention, there is provided a method of refueling a fuel tank, the method comprising: measuring an electrostatic condition associated with the fuel tank using the sensor device; determining, using a controller, a fuel flow rate to be supplied to a fuel tank based at least on a measured electrostatic condition associated with the fuel tank; and controlling the variable position valve using the controller to supply the fuel to the fuel tank at the determined flow rate.

Optionally, the method comprises determining a fuel level in the fuel tank and determining a fuel flow to be supplied to the fuel tank based on the measured electrostatic condition associated with the fuel tank and the determined fuel level in the fuel tank.

Optionally, the determining of the fuel flow rate comprises: a static threat level is determined from the measured static condition, and the determined fuel flow rate is a maximum flow rate that maintains the static threat level at or below a predetermined level.

Optionally, the determining of the fuel flow rate comprises determining a threat of tank overpressure, and the determined fuel flow rate is a maximum flow rate that maintains the threat of tank overpressure below a predetermined level.

Optionally, the method is a method of refueling a fuel tank on an aircraft.

According to a fourth aspect of the present invention, there is provided a vehicle comprising: the fuel addition system according to the first aspect or according to the second aspect; and a sensor device configured to measure an electrostatic condition in a fuel tank fueled by the system.

Optionally, the sensor device comprises one or more sensors located at the fuel tank.

Optionally, one of the sensors located at the fuel tank is an electric field sensor.

Optionally, the sensor means comprises one or more sensors located at the fuel conduit or at the variable position valve.

Optionally, one of the sensors located at the fuel line or at the variable position valve is a flow current sensor.

Optionally, the vehicle is an aircraft.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic view of a fuel addition system according to examples described herein.

FIG. 2 shows a schematic view of another fuel addition system according to examples described herein.

3 a-3 c illustrate schematic axial views of examples of variable position valves and controllers of the example fuel addition systems described herein.

FIG. 4 illustrates a schematic diagram of an exemplary fuel addition system according to examples described herein.

FIG. 5 shows a flow chart depicting an example of a method of refueling a fuel tank.

FIG. 6 shows a flow chart depicting another example of a method of refueling a fuel tank.

Fig. 7 shows a schematic front view of an aircraft.

Detailed Description

Some known fuel addition systems, such as those used in aircraft, include valves, such as ball valves, for starting and stopping the flow of fuel through a fuel line to a fuel tank. In such an example, the ball valve provides a binary start-stop function, enabling or stopping the flow of fuel. Such fuel addition systems may also include a flow restrictor, such as an orifice plate having a specifically sized orifice, to restrict the flow of fuel to a specific rate. The size of the orifice is typically selected to meet certain safety constraints. For example, the size of the orifice plate may be selected to limit the flow of fuel to the following rates: this rate prevents over-pressurization of the fuel tank and limits the build-up of electrostatic charge to safe levels.

The orifice plate may enforce a maximum flow rate determined by a "worst case scenario" assumption that relates to the amount of static buildup that occurs at a particular flow rate. For example, the determined maximum flow rate may be based on the assumption that the fuel does not contain an antistatic additive, or may be based on a fuel tank filter or a bowser filterSome assumed properties of the device. In one example, the maximum flow for refueling an aircraft with kerosene fuel corresponds to approximately 7ms^-1This may specify fueling for an aircraft on the ground. In an example, a higher maximum flow rate may be specified for aircraft-to-aircraft fueling. The maximum rate may be significantly lower than the true safe fuel flow for a given fueling. For example, the fuel may include an antistatic additive, or the type of bowser filter may be such that: for a given flow rate, the amount of static buildup is lower than the assumed amount. Thus, by using an orifice plate, the fuel flow may be more unnecessarily restricted than a safe refueling, resulting in refueling times that are greater than technically required and thus causing potential operational and economic impacts on the passenger aircraft.

The example fueling systems described herein may be adapted to fuel an aircraft. Such a system may be configured to supply fuel to a fuel tank at a variable flow rate that is varied by controlling a variable position valve based on a measurement of the electrostatic environment within the fuel tank. Examples described herein provide a fuel addition system that controls fuel flow to a fuel tank based on the presence of an actual electrostatic threat. This is accomplished by measuring the electrostatic condition associated with the fueled fuel tank. Thus, the example methods described herein may avoid using a fixed maximum traffic based on pessimistic security assumptions. Measurement of the static condition of the fuel tank may also reduce or avoid the difficulties associated with making assumptions of the level of static buildup for a given flow rate. In examples of fueling an aircraft, examples described herein may provide for maintaining safe fuel flow rates under the following conditions: in such cases, changes in fuel standards or airport infrastructure affect the likelihood of dangerous build-up of electrostatic charge for a given fuel flow rate.

Because the static condition of the fuel tank is measured during refueling in the examples described herein, in some examples, the refueling system may collect data related to static buildup and may correlate such data with factors that define the refueling operation. The collected data may be analyzed to improve understanding of how various factors affect the accumulation of electrostatic charge during fueling. For example, the static data measured during refueling of the aircraft may be related to the flow rate during refueling, or the geographic location, or the type of refueling truck or refueling truck filter used, or the type of fuel used. In an example, a trend of static electricity accumulation during a fueling operation may be correlated with data indicating at which airport the fueling operation occurred.

Some examples described herein provide for the use of variable position valves in place of ball valves and orifice plates. This may lead to savings in weight or space on board the aircraft, or an improvement in reliability or simplification of maintenance of the fuel addition system.

Referring to FIG. 1, a schematic diagram of a first example of a fuel addition system 100 is shown. The fuel addition system 100 is used to add fuel 70 to the fuel tank 50. The fuel tank 50 may be a fuel tank of an aircraft. In an example, the fuel addition system 100 is located on an aircraft (not shown) and may, for example, receive fuel from a fuel tanker or tanker (not shown). The fuel addition system 100 includes fuel conduits 101a, 101b for transporting the fuel 70 to the fuel tank 50. The fuel addition system 100 includes a variable position valve 102 for controlling the flow of fuel 70 to the fuel tank 50, and the piping includes a first section 101a for carrying the fuel 70 to the valve 102 and a second section 101b for carrying the fuel 70 from the valve 102 to the fuel tank 50. The fuel tank 50 may include means (not shown in fig. 1) for venting air from the fuel tank when fuel 70 is introduced from conduit 101 b.

The fuel addition system 100 is configured to receive measurements of electrostatic conditions associated with the fuel tank 50 from the sensor device. In the example of fig. 1, the sensor arrangement includes at least one sensor 103 located on the fuel tank 50 or in the fuel tank 50, which sensor 103 may be, for example, an electric field sensor that measures the magnitude or magnitude and direction of an electric field associated with the fuel tank 50. The sensor 103 is connected to the controller 104 via a wired or wireless connection to communicate data to the controller 104. As will be discussed below with reference to other examples, in other examples, the sensor arrangement may comprise a sensor located on the fuel pipe 101a, 101b or at the valve 102. In an example, the sensor arrangement comprises more than one sensor arranged to measure the electrostatic condition of the fuel tank 50, for example comprising one or more sensors located at the fuel tank 50 and/or one or more sensors located at the fuel pipes 101a, 101b or at the valve 102.

The measured electrostatic condition associated with the fuel tank 50 may include, for example, a measurement of an electric field at one or more locations of the fuel tank 50. The measured electrostatic condition associated with the fuel tank 50 may include a measurement of a flow current from the fuel flowing in the pipes 101a, 101 b. For example, the controller 104 may measure the flow current by measuring the current grounded through a resistor and determine the amount of electrostatic charge provided to the fuel tank 50 from the measured flow current.

The controller 104 is configured to control the variable position valve 102 to control the flow of fuel 70 to the fuel tank 50. For example, the controller 104 may control the valve 102 to control the flow of the fuel 70 by changing the size of the opening of the valve. In an example, the variable position valve 102 is a shutter valve (shutter valve) that defines a variable sized opening arranged for the fuel 70 to flow through. In such an example, the controller 104 may then control the shutter valve 102 to increase the size of the opening it defines in order to increase the flow of fuel 70 to the fuel tank 50. Conversely, the controller 104 may control the shutter valve 102 to decrease the size of the opening it defines in order to decrease the flow of the fuel 70. Thus, the controller 104 may monitor the measurements of the sensor 103 throughout the fuel addition operation and actively control the fuel flow by controlling the amount the variable position valve 102 is opened.

The controller 104 is configured to control the flow of fuel 70 to the fuel tank 50 based on the electrostatic condition of the fuel tank 50 measured by the sensor device, in this example based on the measurement made by the sensor 103. For example, the controller 104 may determine the level of electrostatic threat through measurements by the sensors 103. In the event that the controller 104 determines that there is no significant electrostatic threat, the controller 104 may, for example, control the valve 102 to supply fuel 70 to the fuel tank 50 at a maximum rate. In the case where the valve 102 is a shutter valve that supplies fuel 70 at a maximum rate, the controller causes the shutter valve to fully open to provide an opening of maximum size. In the event that the controller 104 determines from measurements by the sensor 103 that there is a static threat or that the level of the static threat is above a predetermined level, the controller 104 may control the valve 102 to reduce the flow of fuel 70 to the fuel tank 50. In this manner, the fuel addition system 100 is able to control the flow rate of the fuel 70 in response to the measured electrostatic condition of the fuel tank 50. In some examples, this may result in a reduction in the time required for fuel tank 50 because fuel flow is limited in response to the presence of a determined threat and is not limited without the presence of a threat.

The controller 104 may control the valve 102 based on measurements provided to the controller 104 by the sensor device according to any suitable method. For example, the controller 104 may receive data from the sensor 103 indicative of an electrostatic measurement associated with the fuel tank 50, and the controller 104 may determine an optimal fuel flow rate based on the data. For example, the controller 104 may receive data from the sensor 103 indicative of the magnitude of the electric field in the fuel tank 50, and the controller 104 may determine the optimal flow rate based on the magnitude of the electric field, the fuel volume, the fuel tank geometry, and the like. In some examples, the sensor arrangement may include a flow current sensor that measures the flow current of the fuel 70 in the conduits 101a, 101 b. In such an example, the flow current sensor may be placed anywhere on the pipe 101a, 101 b. The controller 104 may receive data from the flow current sensor and use the data to determine the level of electrostatic threat. In other examples, the controller may receive the flow current measurements and the electric field measurements from the sensor device and may use these measurements to determine the level of electrostatic threat, for example, by determining the total amount of electrostatic charge added to fuel tank 50 by the fueling operation. The controller 104 may determine an optimal flow rate to minimize the fueling time while maintaining the determined electrostatic threat below a predetermined level.

Fig. 2 shows a schematic view of a second example of a fuel addition system 200, in this example the fuel addition system 200 is for an aircraft. Some features of the fuel addition system 200 are the same as those of the fuel addition system 100 shown in fig. 1, and those features have the same reference numerals as in fig. 1.

In the example shown in FIG. 2, the fuel tank 60 may be an aircraft wing fuel tank. In other examples, fuel tank 60 may be located at any suitable location in the aircraft and may be any suitable type of fuel tank. For example, the fuel tank may be a center fuel tank, a rear center fuel tank, an additional center fuel tank (ACT), a trim fuel tank, or any other type of fuel tank. In the example of fig. 2, the controller 104 of the fuel addition system 200 receives measurements of the electrostatic condition of the fuel tank 60 to which fuel is added from a sensor arrangement that includes a first sensor 203a and a second sensor 203 b. The first sensor 203a is an electric field sensor for measuring the magnitude or direction of an electric field in the fuel tank 60. The second sensor 203b is a flowing current sensor for measuring flowing current from the fuel passing through the pipes 201a, 201 b. The controller 104 may receive measurement data from the sensors 203a, 203b and any other sensors present via a wired or wireless connection.

In the example shown in fig. 2, the fuel tank 60 includes a first section 60a and a second section 60b connected by a vent 61. The first section 60a is for containing fuel 70 and the second section 60b is for receiving air that is exhausted from the first section 60a via the exhaust port 61 when the fuel 70 is introduced into the first section 60 a. The conduit 101a in fig. 2 includes a connector 210, such as a solenoid connector, for coupling to the fuel supply conduit 90. In an example, the solenoid connector is configured to open and close to start and stop the flow of fuel into the fuel addition system 200. The fuel supply conduit 90 may supply fuel from a fuel reservoir in a fuel tanker or tanker (not shown), which may include suitable filters and pumping mechanisms to supply fuel to the fuel addition system 200.

In the example shown in FIG. 2, except for the slave packageIn addition to the sensor arrangement including sensors 203a, 203b receiving measurements for measuring the electrostatic condition of fuel tank 60, controller 104 also receives data from sensor 205 indicative of the level of fuel 70. The controller 104 controls the flow of fuel 70 through the control valve 202 based on data received by the sensors 203a, 203b and the sensor 205. The controller 104 may, for example, control the valve 202 to prevent over-pressurization of the fuel tank 60 by the addition of fuel 70. The controller 104 may, for example, reduce the flow of fuel 70 to the fuel tank 60 when the level of fuel 70 in the fuel tank 60 is near a maximum value that can be tolerated to prevent over-pressurization of the fuel tank 60. In one example, the controller 104 is configured to limit the fuel flow to a predetermined flow when the level sensor 205 indicates that the level of fuel 70 in the fuel tank 60 reaches a predetermined level. For example, the controller 104 may be configured to limit the flow of the fuel flow 70 to a predetermined rate when the level sensor 205 indicates to the controller 104 that the level of the fuel 70 in the fuel tank 60 is near a specified level. For example, in a given fueling operation, fuel may be added to the fuel tank to a specified level that is less than the maximum allowable level for the fuel tank, or the specified level may be the maximum allowable level for the fuel tank. In an example, the controller 104 may be configured to limit the fuel flow when the level reaches 90% of a particular value. The predetermined rate may be a maximum allowable safe rate determined according to a standard for preventing overpressure. Reducing the flow rate can improve the accuracy of the fuel adding operation. For example, the fuel 70 may be kerosene and the predetermined rate may correspond to 5 to 10ms^-1Of between, e.g. about 7ms^-1。

In some examples, the controller 104 may receive further data, such as an indication of the fuel quality in the fuel tank 60, and use this data in conjunction with a measurement of the electrostatic condition of the fuel tank 60 to control the fuel flow. The controller 104 may use a suitable algorithm to determine the optimal flow rate based on data received from the sensors 203a, 203b and any other sensors present.

In the example shown in FIG. 2, controller 104 provides data to data lake 20. The data sent to the data lake 20 can then be stored and/or analyzed. For example, the controller 104 can provide data to the data lake 20 regarding measurements of the electrostatic condition of the fuel tank 60 made by the sensors 203a, 203 b. The controller 104 may also send data indicative of the flow rate of the fuel 70 and the following data throughout the fueling period: the data identifies any one or more types of aircraft being fueled, or the type of fuel used, or the temperature or pressure of the fueling environment, or the location where the fueling is occurring. Analysis of these data may allow for the determination of trends related to the accumulation of electrostatic charge in various environments and situations.

Fig. 3a, 3b, and 3c show schematic axial views of an example of a variable position valve 202, which variable position valve 202 may be used in the fuel addition system of fig. 2 and may be used as the valve 102 in the example of fig. 1. In this example, the variable position valve 202 is a fast gate valve. In use, the gate valve 202 is connected between a first portion and a second portion of a fuel line of the fuel addition system. The gate valve 202 is connected to the controller 104 to be controlled by the controller 104 in response to data received from a sensor arrangement (not shown in fig. 3a, 3b or 3 c) as described with reference to fig. 2 or 1. The shutter valve 202 includes a driving unit 322 and movable shutter plates 320a, 320b, 320c, which movable shutter plates 320a, 320b, 320c can be retracted into a housing 323 of the shutter valve 202. In the example of fig. 3 a-3 c, the shutter valve 202 includes three shutter plates, it being understood that in other examples, the shutter valves used in the fuel addition systems described herein may include any suitable number of shutter plates. The position of the shutter plates 320a, 320b, 320c defines the size of the opening 321 through which fuel flows in use. The driving unit 322 is controlled by the controller 104 to position the shutter plates 320a to 320c so as to configure the opening 321 to a specific size. The size of the opening 321 is adjustable to adjust the flow of fuel through the opening 321 and thereby adjust the flow of fuel to the tank to which the fuel is added. The controller 104 may provide power to the drive unit 322, or in some examples, the drive unit 322 may provide power separately to the controller 104. In some examples, the drive unit 322 and the controller 104 may be in a wired connection, or in some examples, the drive unit 322 may include a receiver (not shown) and the controller 104 may include a transmitter (not shown), and the drive unit 322 may be controlled by the controller 104 through wireless communication between the transmitter and the receiver.

Fig. 3a shows the shutter valve 202 in a first configuration, in which the shutter plates 320a, 320b, 320c are not fully retracted into the housing 323, but in which the opening 321 is defined. Thus, the first configuration shown in fig. 3a is a configuration that provides the following flow rates: the flow is non-zero but not the maximum flow that can be provided by the fast gate valve 202.

Fig. 3b shows the shutter valve 202 in a second configuration, in which the shutter plates 320 a-320 c are fully retracted into the housing 323 and the opening 321 is at its largest dimension. Thus, the second configuration shown in fig. 3b is a configuration that provides the maximum flow that can be provided by the shutter valve 202.

Fig. 3c shows the shutter valve 202 in a third configuration, in which the shutter plates 320 a-320 c extend completely from the housing 323 such that there are no openings through which fuel flows. Thus, the third configuration shows the following shutter valve 202: the shutter valve is in its closed configuration not allowing fuel flow.

In some examples, the variable position valves used in the fuel addition systems described herein may be configured to default into a predetermined position in response to a failure of the fuel addition system, such as a failure of a controller or variable position valve, or a failure of a sensor device. In examples where the variable position valves are shutter valves, the shutter plates 320 a-320 c of the shutter valve 202 may be configured to move to predetermined positions in response to a failure of the fuel addition system. Examples of a failure of the shutter valve 202 may include a loss of power to the drive unit 322, a detected state in which the drive unit 322 is unable to move the shutter plates 320 a-320 c, or a loss of communication with the controller 104. The plates 320 a-320 c may be biased to automatically move to a predetermined position when a fault is detected. The predetermined positions of the shutter plates 320 a-320 c may define a closed configuration, such as the closed configuration shown in fig. 3c, such that the flow of fuel is stopped in response to a failure of the fuel addition system.

FIG. 4 illustrates another example of a fuel addition system 400, in which the fuel addition system 400 is again used in an aircraft. Some features of the fuel addition system 400 are the same as those of the fuel addition system 200 shown in fig. 2, and those features have the same reference numerals as in fig. 2.

The fuel addition system 400 of fig. 4 includes a connector 410 that functions as a second valve. For example, the connector may include a solenoid valve for connecting the fuel addition system 400 to the fuel supply apparatus 90. In this example, the controller 104 is a first controller and the second valve 410 is connected to the second controller 406. The fuel addition system 400 also receives data from an overflow sensor 405, in this example, the overflow sensor 405 is located at a wall between the first section 60a of the fuel tank and the second section 60b of the fuel tank. The second valve 410 allows the flow of fuel 70 through the conduit 101a to be selectively activated or deactivated. In the event that the overflow sensor 405 detects an overflow condition in the fuel tank 60, the second valve 410 may stop the flow of fuel 70 to the fuel tank 60. For example, the second valve 410 may close in response to an overflow condition occurring due to a failure of the variable position valve 202 or in response to control of the valve 202. In the example of fig. 4, the second valve 410 is controlled by the second controller 406. Additionally or alternatively, the second valve 410 may be manually controllable by a user. In another example, the fuel addition system may not include the second controller 406, and the second valve may be controlled by the first controller 104. However, it may be advantageous to provide a second controller 406 or otherwise allow control of the second valve 410 independent of the variable position valve 202, thereby minimizing the possibility that both the variable position valve 202 and the second valve 410 fail to respond to the same event, such as a failure of the controller 104. In an example, as described above, the second valve 410 is a solenoid valve that is controlled in response to the overflow sensor 405 and independently of the variable position valve 202. In the example of fig. 4, second controller 406 is connected to data lake 20 and can provide data obtained from overflow sensor 405 or second valve 410 to data lake 20.

As described above, in some examples, variable position valve 202 is configured to default to pre-entry in the event of a failure of fuel addition system 400And (5) fixing the structure. In some examples, the predetermined configuration may be a configuration in which the valve 202 is closed and the flow of fuel is stopped. In another example, the predetermined configuration may be a configuration that allows a predetermined flow rate of fuel, which may be a non-zero flow rate. For example, where the fuel is kerosene, the valve 202 may be configured to provide a default setting corresponding to 5 to 10ms^-1For example, about 7ms in between^-1The flow rate of (2). In this manner, the variable position valve may provide an equivalent flow restriction function for a fixed size orifice plate when a fault occurs in the fuel addition system 400. Therefore, a safe maximum flow rate can be ensured even when the fuel addition system 400 malfunctions. The valve 202 may be a shutter valve, such as the shutter valve 202 shown in fig. 3 a-3 c, and may default to a configuration such as that shown in fig. 3 a. In an example, the second valve 410 may then be used to selectively start or stop the flow of fuel 70.

FIG. 5 illustrates a diagram of an exemplary method 500 of refueling a fuel tank, such as with the exemplary fuel addition system described above. The method 500 includes measuring an electrostatic condition associated with a fuel tank with a sensor device at block 501. Measuring the static condition associated with the fuel tank may be accomplished using a sensor arrangement as described above with respect to the exemplary fuel addition system. At block 502, the method 500 includes determining, with a controller, a flow rate of fuel to be supplied to a fuel tank based at least on a measured electrostatic condition associated with the fuel tank. At block 503, the method 500 includes controlling, with the controller, the variable position valve to supply fuel to the fuel tank at the determined flow rate.

FIG. 6 illustrates a diagram of another exemplary method 600 of refueling a fuel tank. The method includes measuring an electrostatic condition associated with a fuel tank at block 601. At block 601, the method may include any of the features described with respect to block 501 with reference to FIG. 5 and with reference to the example fuel addition system described above.

At block 602, the method 600 includes determining a fuel level in a fuel tank. For example, the controller may receive data indicative of a fuel level in the fuel tank. The data indicative of the fuel level in the fuel tank may be obtained by a level sensor at the fuel tank, or may be obtained in other suitable ways, such as calculations involving measured values of the amount of fuel in the fuel tank and the amount of fuel supplied to the fuel tank at the beginning of the process of adding fuel.

At block 603, method 600 includes determining, with the controller, a flow rate of fuel to be supplied to the fuel tank. The flow rate of fuel supplied to the fuel tank may be determined by any suitable method. In this example, determining the flow rate of fuel to be supplied to the fuel tank is done by the controller based on the measured electrostatic condition associated with the fuel tank and based on the determined fuel level in the fuel tank. In some examples, the measured electrostatic condition associated with the fuel tank may be used to determine the presence of an electrostatic threat. For example, the magnitude of the electric field measured in the fuel tank may be correlated by the controller to the level of electrostatic threat. The maximum allowable static threat level threshold may be defined to correspond to a measured static condition. For example, the maximum allowable electrostatic threat level may correspond to a maximum allowable electric field magnitude. In other examples, the measured electrostatic condition may be a cumulative degree of electrostatic charge discharged to the fuel tank, as measured by a flowing current sensor, for example. The flow rate of the fuel that maintains the electrostatic threat at or below the predetermined level may then be determined by the controller. Determining the flow rate of fuel may take into account the rate of change of the measured quantity during the addition of fuel. For example, the controller may determine whether the electrostatic threat will exceed a maximum allowable level before fueling is complete if fueling continues at a particular rate. The controller may then adjust the fueling rate to prevent the electrostatic threat from exceeding the maximum allowable level.

At block 603, determining the rate of fuel to be supplied to the fuel tank further includes accounting for a threat of overpressure of the fuel tank. When the fuel tank reaches capacity and potentially reaches a flooding condition, the overpressure is a potential threat, so the controller may take into account the fuel level in the fuel tank and reduce the flow of fuel when the fuel level in the fuel tank reaches a predetermined level. As such, in exemplary method 600, the flow of fuel to the fuel tank may be controlled in response to the measured electrostatic condition of the fuel tank and the determined fuel level in the fuel tank. The flow rate of the fuel may be determined to minimize refueling time while maintaining electrostatic threats below a predetermined level and overpressure threats below a predetermined level.

Method 600 at block 604 includes controlling a variable position valve with a controller to supply fuel to a fuel tank at a determined flow rate. Accordingly, the controller controls the variable position valve to supply fuel to the fuel tank at the flow rate determined at block 603. As described above, the valve may be a shutter valve, and the controller may control the size of an opening defined by the shutter valve to control the flow rate of the fuel. The static condition of the fuel tank is measured and the fuel level in the fuel tank is determined throughout the fuel addition method. In this way, the controller can determine the flow rate of fuel supplied at each point in the process of adding fuel and adjust the flow rate accordingly by controlling the variable position valve.

Fig. 7 shows a view of an exemplary aircraft 800 from the front. Aircraft 800 includes a first wing section 801, a second wing section 802, a fuselage 803, a first engine 804, a second engine 805, and a Horizontal Tail (HTP) 806. In this example, the aircraft 800 includes a wing fuel tank 90 and a fuel addition system 700 mounted in a first wing 801. The fuel addition system 700 may have any of the features of the example fuel addition systems, including any of the features of the example variable position valves described herein. The fuel addition system 700 is for receiving fuel from a refueling truck or fuel tanker (not shown) for adding fuel to the fuel tank 90 of the aircraft 800. In some examples, the aircraft 800 may include more than one fuel addition system 700. For example, the aircraft 800 may include a second fuel addition system or more than one additional fuel addition system configured to supply one or more additional fuel tanks. Such fuel tanks may be located elsewhere on the aircraft 800, such as the fuselage 803, or the tailplane, or another wing portion 802.

While the described examples have described an aircraft fueling system, it should be understood that the fueling systems and methods described herein may also be applied in other environments where the accumulation of electrostatic charge may be a safety issue. For example, the systems and methods described herein may be applicable to refueling other vehicles, such as watercraft or land vehicles, or may be applicable to refueling such as fuel tanks in refueling stations. In one example, a refueling system such as described herein may be used to refuel a subsurface fuel tank of a refueling scenario.

It should be noted that the term "or" as used herein should be interpreted to mean "and/or" unless explicitly stated otherwise.

The above examples are to be understood as illustrative examples only. Any feature described in relation to any one example may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other example, or any combination of any other examples. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.