The invention relates to fueling systems and methods.
Modulation may be described as the process of varying a periodic waveform in order to use that signal to convey a message. Analog modulation uses a high-frequency sinusoid waveform as its carrier signal. Certain parameters of that sine wave, e.g., amplitude, phase and frequency, may be modified in accordance with a low frequency information signal to obtain the modulated signal. Digital modulation also uses a high-frequency sine wave as its carrier signal. The wave parameters, however, are modified in a discrete manner.
A device that performs modulation may be referred to as a modulator and a device that performs the inverse operation of modulation may be referred to as a demodulator. A device that can do both operations may be referred to as a modem.
A fuel storage system includes a fuel tank, a fueling receptacle in fluid communication with the tank, and a coil adjacent the fueling receptacle. The system also includes a controller configured to determine information about a state of fuel in the tank and to cause a modulated current to be driven into the coil to generate an electromagnetic field. The modulated current represents the information about the state of fuel in the tank.
An automotive fuel storage system includes a tank, a fueling port in fluid communication with the tank, a coil wrapped around the fueling port and a sensor configured to sense a condition of fuel in the tank. The fuel storage system also includes a controller configured to drive a modulated current into the coil based on the condition of the fuel to generate an electromagnetic field.
A method for refueling an automotive vehicle includes, while receiving fuel into a fueling receptacle in fluid communication with a tank, (i) determining information about a state of fuel in the tank and (ii) driving a modulated current into a coil surrounding the fueling receptacle based on the information to generate an electromagnetic field.
BRIEF DESCRIPTION OF THE DRAWING
While example embodiments in accordance with the invention are illustrated and disclosed, such disclosure should not be construed to limit the invention. It is anticipated that various modifications and alternative designs may be made without departing from the scope of the invention.
FIG. 1 is a schematic diagram of an embodiment of an automotive fueling system.
To minimize refueling times associated with a fuel cell vehicle, it may be desirable to quickly fill the vehicle's on-board fuel storage vessel. The time it takes to fill the storage vessel depends on the flow rate at which fuel is provided to the storage vessel (and the amount of fuel already in the vessel at the time of refueling).
It is known that a temperature of the fuel in the storage vessel during refueling is related to a flow rate (and duration) at which fuel is provided to the storage vessel. It is also known that certain storage vessels are rated for certain recommended maximum temperatures. For example, a storage vessel may be designed to provide pressurized storage of a gaseous fuel at maximum storage vessel temperatures less than 85 degrees Celsius.
The temperature at which fuel is provided to a storage vessel is typically less than the rated temperature of the storage vessel. The rated temperature of the storage vessel may thus limit the flow rate at which fuel is provided to the storage vessel.
During certain refueling operations, the temperature of the fuel inside the storage vessel may exceed the temperature of the storage vessel itself (provided the temperature of the storage vessel itself is less than its temperature rated limit.) For example, if the temperature of the storage vessel is 30 degrees Celsius before a refueling operation, the fuel may be provided to the storage vessel at relatively high flow rates to minimize refueling times and thus yield fuel temperatures inside the storage vessel significantly greater than 30 degrees Celsius. Such refueling strategies may require the fuel temperature, flow rate, etc., to be monitored to prevent exceeding the storage vessel rated temperature. This information may be communicated to a fueling station so that the fueling station may provide the fuel under conditions that minimize refueling times and avoid exceeding the storage vessel rated temperature.
Referring now to FIG. 1, a hydrogen fuel cell vehicle 10 includes a hydrogen storage tank 12, hydrogen port 14 and coil 16. The tank 12 and port 14 are fluidly connected via a fuel line 18. In the embodiment of FIG. 1, the coil 16, e.g., 30-gauge enameled copper magnet wire, is wrapped 50 times around the port 14. Of course, any suitable wire and/or winding scheme may be used. In other embodiments, the coil 16 may surround the port 14 and reside within/on a port housing (not shown). For example, the coil 16 may be wrapped around a sleeve (not shown) that is fitted over the port 14. Other configurations are also possible. For example, the coil 16 may be disposed on a plate (not shown) adjacent the port 14, etc.
The vehicle 10 also includes a controller 20, modulator 22 and sensors 24, 26. The modulator 22 of FIG. 1 is integrated with the controller 20. In other embodiments, however, the modulator 22 may be separate from the controller 20. The controller 20 is in communication with the sensors 24, 26. The modulator 22 is electrically connected with the coil 16. (Of course, the elements of FIG. 1 need not be located in the vehicle 10 and may, for example, comprise a stand alone fuel system.)
The sensors 24, 26 illustrated in FIG. 1 detect, respectively, a pressure and temperature of fuel within the tank 12. Other and/or different sensors, however, may be used. The controller 20 may read the sensors 24, 26 to determine the pressure and temperature of the fuel in the tank 12. Based on these readings, the controller 20 may transmit information regarding the temperature and pressure of the fuel to the modulator 22. The modulator 22 may vary current flowing into the coil 16 according to the information. As apparent to those of ordinary skill, this modulated current flow through the coil 16 will generate an electromagnetic field that is concentrated by the port 14 (provided the port 14 is made of material with magnetic permeability).
A hydrogen fueling station 28 includes a hydrogen storage tank 30, hydrogen nozzle 32 and coil 34. The tank 30 and nozzle 32 are fluidly connected via a fuel line 36. The coil 34, e.g., 30-gauge enameled copper magnet wire, illustrated in FIG. 1 is wrapped 50-times around an end portion 38 of the nozzle 32. (The coils 16, 34 of FIG. 1 are wound so as to share the same axis.) Any suitable wire and/or winding configuration/position, however, may be used.
The station 28 also includes a controller 40 and demodulator 42. The controller 40 is configured to control a valve 44 in the fuel line 36. The demodulator is electrically connected with the coil 34 and in communication with the controller 40.
During a refueling operation, the end portion 38 of the nozzle 32 may be placed over (and secured to) the port 14 to establish a fluid pathway between the tank 30 of the station 28 and the tank 12 of the vehicle 10. As discussed above, the controller 20 may continuously, periodically, etc. read the temperature, pressure, capacity, etc. of fuel in the tank 12 and encode this information into a current driven into the coil 16. With the end portion 38 in contact with the port 14, the electromagnetic field generated from the current flow through the coil 16 may permeate into the end portion 38 of the nozzle 32 (provided the end portion 38 is made of material with magnetic permeability).
As discussed above, the flow of current within the coil 16 generates an electromagnetic field. A change in this electromagnetic field may induce current flow in the coil 34. Without another change in the electromagnetic field, however, the current flow in the coil 34 will eventually decay due to the coil's internal resistance. Thus, to continue to induce current flow in the coil 34, the current in the coil 16 should change repeatedly to generate a changing electromagnetic field. By changing the current in the coil 16 according to, for example, a periodic waveform and modulating this waveform with encoded information, the coil 34 may be induced with current having a similar waveform. Demodulating the waveform may reproduce the encoded information.
Pulse modulation may be used in conjunction with the embodiment of FIG. 1. Any suitable modulation scheme, however, may be used. The pulses may be shaped similar to impulse responses of a slightly over-damped system. This may help reduce electromagnetic energy from radiating further than intended—thus avoiding turning port 14, for example, into a directional radio transmitter.
With information encoded in a stream of digital data, every transition from ‘0’ to ‘1’ generates an ‘up’ or positive pulse and every transition from ‘1’ to ‘0’ generates a ‘down’ or negative pulse. The ‘up’ pulse and ‘down’ pulse may be identical in shape but of opposite polarity—a mirror image along the time axis.
As discussed above, a change in the electromagnetic field experienced by the end portion 38 induces current flow in the coil 34. The demodulator 42 may translate the current flow through the coil 34 into information to be decoded by the controller 40. Based on the decoded information, e.g., temperature, pressure, capacity, etc. regarding the fuel in the tank 12, the controller 40 may control, for example, the flow rate of the hydrogen dispensed from the tank 30, via the valve 44, to minimize refueling time and avoid exceeding a rated temperature of the tank 12.
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.