This disclosure relates to detecting compositions in hydrocarbon-based fuels.
An internal combustions (IC) engine, such as an IC engine for an automobile or other vehicle may operate on different blends of fuel during its lifetime. Different fuels may include different concentrations of ethanol or other additives or ingredients. Some IC engines are designed to operate under a wide range of ethanol concentrations in gasoline-ethanol blends, such as from 0-85 percent ethanol. Automobiles designed to operate with high-level gasoline-ethanol blends of between 60-85 percent ethanol are commonly referred to as flexible-fuel vehicles (FFVs). In many areas, low-level gasoline-ethanol blends with ethanol concentrations of up to 10 percent are either available or even legally mandated for use in automobiles. For this reason, substantially all IC engines for automobiles should be able to operate with gasoline-ethanol blends of between 0-10 ethanol. Different gasoline-ethanol blends provide different energy concentrations, emissions and octane ratings (a measure of a fuel's resistance to pre-ignition or engine “knock”).
In general, this disclosure relates to detecting concentrations of ethanol and water in gasoline-ethanol blends. In one example, concentrations of ethanol and water in gasoline-ethanol blends used to operate an IC engine may be monitored during the operation of the IC engine and used to actively adjust operational parameters of the IC engine. Actively adjusting operational parameters of the IC engine and/or associated emissions systems based on monitored concentrations of ethanol and/or water may facilitate reducing the emissions level and improvement in the overall performance of the IC, such as, efficiency, and/or reliability.
In one example, a device comprises a fuel line that carries a combustible fuel including gasoline, a first optical channel that evaluates a degree of absorption at a first wavelength spectrum of light transmitted through the combustible fuel within the fuel line, and a second optical channel that evaluates a degree of absorption at a second wavelength spectrum of light transmitted through the combustible fuel within the fuel line. The first and second wavelength spectrums each consists of wavelengths of between about 800 nanometers (nm) and about 1200 nm. The device further comprises a controller configured to receive inputs from the first and second optical channels representing the degree of absorption at the first wavelength spectrum and the degree of absorption at the second wavelength spectrum, correlate the degree of absorption at the first wavelength spectrum and the degree of absorption at the second wavelength spectrum with a proportion of ethanol in the combustible fuel and a proportion of water in the combustible fuel, and output data corresponding to the proportions of ethanol and water in the combustible fuel to a controller.
In another example, a method comprises evaluating a degree of absorption at a first wavelength spectrum of light transmitted through a combustible fuel including gasoline, evaluating a degree of absorption at a second wavelength spectrum of light transmitted through the combustible fuel, correlating the degree of absorption at the first wavelength spectrum and the degree of absorption at the second wavelength spectrum with a proportion of ethanol in the combustible fuel and a proportion of water in the combustible fuel; and outputting data corresponding to the proportions of ethanol and water in the combustible fuel to a controller of a combustion engine fed with the combustible fuel. The first and second wavelength spectrums consists of wavelengths of between about 800 nanometers (nm) and about 1200 nm.
In another example, a vehicle comprises a fuel tank that stores a combustible fuel including gasoline, an internal combustion engine that propels the vehicle, the internal combustion engine including a controller, a fuel line that carries the combustible fuel from the fuel tank to the internal combustion engine, a device positioned in-line with the fuel line. The device comprises a first optical channel that evaluates a degree of absorption at a first wavelength spectrum of light transmitted through the combustible fuel within the fuel line, and a second optical channel that evaluates a degree of absorption at a second wavelength spectrum of light transmitted through the combustible fuel within the fuel line. The first and second wavelength spectrums each consists of wavelengths of between about 800 nanometers (nm) and about 1200 nm. The device further comprises a controller configured to receive inputs from the first and second optical channels representing the degree of absorption at the first wavelength spectrum and the degree of absorption at the second wavelength spectrum, correlate the degree of absorption at the first wavelength spectrum and the degree of absorption at the second wavelength spectrum with a proportion of ethanol in the combustible fuel and a proportion of water in the combustible fuel, and output data corresponding to the proportions of ethanol and water in the combustible fuel to a controller of a combustion engine fed with the combustible fuel.
The details of one or more aspects of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages this disclosure will be apparent from the description and drawings, and from the claims.
Detector 4 is located opposite LEDs 1, 2, 3, on an opposing side of detection chamber 6 and detects light emitted by LEDs 1, 2, 3 after the light passes through the combustible fuel in chamber 6. Detector 4 measures light intensity over a wavelength spectrum that includes the wavelength spectrums of light transmitted by LEDs 1, 2, 3. For example, detector 4 may measures light intensity over a wavelength spectrum within the NIR (near infra-red) range, such as a wavelength spectrum range from about 800 nm to about 1200 nm, a wavelength spectrum from about 800 nm to about 1100 nm, a wavelength spectrum from about 1100 nm to about 1200 nm or another wavelength spectrum. Notably, detectors and LEDs in the NIR range are generally less expensive than detectors and LEDs in the far infra-red range.
The distance between detector 4 and LEDs 1, 2, 3 affects the light intensity measured by detector 4. A greater distance means than more light is absorbed by the combustible fuel within chamber 6. The distance between detector 4 and LEDs 1, 2, 3 may be selected to provide sufficient sensitivity in order to determine proportions of ethanol and water in the fuel. In one example, such a distance may be between about 30 millimeters (mm) and about 80 mm. Other distances may also be used. The distance that provides the most desirable sensitivity may depend on the wavelength spectrums of LEDs 1, 2, 3 as well as the intensity of light emitted by LEDs 1, 2, 3.
When switch 8 turns on one of LEDs 1, 2, 3, light from the activated LED passes through detection chamber 6 and through liquid fuel located within chamber 6 before reaching detector 4. Because gasoline-ethanol blends with different proportions of ethanol and water absorb light differently, light intensities measured by detector 4 for each of LEDs 1, 2, 3 facilitate determining proportions of ethanol and water in a combustible fuel including gasoline located within chamber 6.
Controller 7 controls switch 8 and receives inputs from detector 4 corresponding to the measured light intensities from detector 4 to determine proportions of ethanol and water in the liquid fuel. Each of LEDs 1, 2, 3 provides a different wavelength spectrum. LEDs 1, 2, 3 combine with detector 4 to provide three distinct optical channels that evaluates a degree of absorption of the combustible fuel. For example, LEDs 2 and 3 may combine with detector 4 to provide first and second optical channels, whereas LED 1 may combine with detector 4 to provide a third optical channel. Each optical channel facilitates evaluation of a degree of absorption at a particular wavelength spectrum of light transmitted through the combustible fuel within fuel line 5.
In other examples, a device may provide optical channels using different techniques. For example, one or more of LEDs 1, 2, 3 may be replaced with laser light sources. Laser light sources can be configured to emit light in a more narrow wavelength spectrum than LEDs 1, 2, 3, which may provide for more precise determinations of the proportions of ethanol and water in the combustible fuel. As another example, a broad wavelength spectrum light source may be used in combination with optical filters or a prism to isolate particular wavelength spectrums to provide different optical channels. As yet another example, a device may include multiple detectors, each detector detecting a particular wavelength spectrum to provide different optical channels. In this manner, device 10 is merely exemplary, and other techniques for providing distinct optical channels are also within the spirit of this disclosure.
Controller 7 receives inputs from the optical channels representing the degree of absorption at wavelength spectrums provided by LEDs 1, 2, 3. Controller 7 then correlates the degree of absorption at wavelength spectrums provided by LEDs 1, 2, 3 with a proportion of ethanol in the combustible fuel and a proportion of water in the combustible fuel. Finally, controller 7 outputs data corresponding to the proportions of ethanol and water in the combustible fuel to a controller, such as a controller of a combustion engine fed with the combustible fuel.
The wavelength spectrums of LEDs 1, 2, 3 are selected to facilitate calculation of the proportions of ethanol and water in a combustible fuel including gasoline located within chamber 6. Water detection LED 3 emits light at a wavelength spectrum selected to facilitate determination of the proportion of water in the combustible fuel. For example, as shown in
Ethanol detection LED 2 emits light at a wavelength spectrum selected to facilitate determination of the proportion of ethanol in the combustible fuel. For example, as shown in
As another example, as shown in
Likewise, at wavelengths between about 920 nm to about 1020, discussed above with respect to water detection LED 3, the degree of absorption of the combustible fuel is significantly affected by both the proportion of ethanol and the proportion of water in the combustible fuel. For this reason, the proportions of water within the combustible fuel may be more precisely determined if the light intensity detected from a water detection LED 3 that emits light within a wavelength spectrum centered within the range of about 920 nm to about 1020, is combined with the light intensity detected for ethanol detection LED 2.
In the event that the degree of absorption of the combustible fuel is significantly affected by both the proportion of ethanol and the proportion of water in the combustible fuel for the wavelength spectrums provided by either one or both of ethanol detection LED 2 and water detection LED 3, controller 7 may use the detected intensities of light transmitted by ethanol detection LED 2 and water detection LED 3 in combination to determine either the proportion of ethanol and/or the proportion of water in the combustible fuel. In some examples, controller 7 may first use the detected intensity of light transmitted by water detection LED 3 to separately determine the proportion of water in the combustible fuel before determining the proportion of ethanol in the combustible fuel. In other examples, controller 7 may simultaneously determine the proportion of ethanol in the combustible fuel and the proportion of water in the combustible fuel using a look-up table or equations representing the degree of absorption of the combustible fuel according to proportions of ethanol and water in the combustible fuel.
In summary, the two data points provided by ethanol detection LED 2 and water detection LED 3 may be used to simultaneously determine two unknowns, e.g., the proportion of ethanol in the combustible fuel and the proportion of water in the combustible fuel, even if the degree of absorption of the combustible fuel at the wavelength spectrum provided by ethanol detection LED 2 is dependent on both the proportion of ethanol in the combustible fuel and the proportion of water in the combustible fuel and if the degree of absorption of the combustible fuel at the wavelength spectrum provided by water detection LED 3 is also dependent on both the proportion of ethanol in the combustible fuel and the proportion of water in the combustible fuel. For this reason, it is not necessary that the degree of absorption at the wavelength spectrum provided by ethanol detection LED 2 be solely or even predominately affected by the proportion of ethanol in the combustible fuel and relatively less affected by the proportion of water in the combustible fuel. Nor is it necessary that the degree of absorption at the wavelength spectrum provided by water detection LED 3 be solely or even predominately affected by the proportion of water in the combustible fuel and relatively less affected by the proportion of ethanol in the combustible fuel.
Reference LED 1 emits light at a wavelength spectrum selected such that proportions of water and ethanol do not significantly affect the degree of absorption of a combustible fuel including gasoline located within chamber 6. For example, as shown in
Reference LED 1 may be suitable to calibrate detector 4 to determine the degree of absorption for light emitted by ethanol detection LED 2 and water detection LED 3. For example, variations in the temperature of the combustible fuel within chamber 6 can affect the degree of absorption for light emitted by ethanol detection LED 2 and water detection LED 3. Temperature variations can affect the measured degree of absorption up to five percent of the detected light transmission. To improve accuracy of device 10, the changes in degree of absorption due to temperature variation can be compensated by used of a third optical channel as provided by reference LED 1 and detector 4. As another example, the transparency of chamber 6 can be reduced over time, e.g., due to the flow of the combustible fuel, which also affects an intensity of light measured by detector 4. By emitting light within a wavelength spectrum having the same degree of absorption for any combustible fuel, reference LED 1 allows controller 7 to calibrate detector 4 for variations in the degree of absorption for combustible fuels at different temperatures temperature as well as variations in device that can occur over time, including but not limited to, changes in the translucence of chamber 6. In this manner, reference LED 1, allows controller 7 to more precisely determine the proportions of water and ethanol of a combustible fuel within chamber 6.
Controller 7 can be configured to output data corresponding to the proportions of ethanol and water in the combustible fuel to a controller of an IC engine. For example, as shown in
In other examples, device 10 can be used to determine proportions of ethanol and water in any combustible fuel, such as a combustible fuel within a storage tank, pipeline or other location.
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First, controller 7 evaluates a degree of absorption at a first wavelength spectrum of light transmitted through a combustible fuel including gasoline (32). The first wavelength spectrum consists of wavelengths of between about 800 nm and about 1200 nm. Then controller 7 evaluates a degree of absorption at a second wavelength spectrum of light transmitted through the combustible fuel (34). The first wavelength spectrum consists of wavelengths of between about 800 nm and about 1200 nm.
Controller 7 correlates the degree of absorption at the first wavelength spectrum and the degree of absorption at the second wavelength spectrum with a proportion of ethanol in the combustible fuel and a proportion of water in the combustible fuel (36, 38). Controller 7 then outputs data corresponding to the proportions of ethanol and water in the combustible fuel to a controller, such as IC engine controller 14 (39).
The techniques described in this disclosure, such as techniques relating to controller 7 and IC controller 14, may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various examples of the techniques may be implemented within one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components, embodied in programmers, such as physician or patient programmers, stimulators, or other devices. The term “controller” may generally refer to any of the foregoing processors or logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry.
When implemented in software, the functionality ascribed to the systems and devices described in this disclosure may be embodied as instructions on a computer-readable storage medium such as random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), FLASH memory, magnetic media, optical media, or the like. The instructions may be executed to cause one or more processors to support one or more examples of the functionality described in this disclosure.
Various aspects of the disclosure have been described. These and other aspects are within the scope of the following claims.