Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of the invention:
[0001] The present invention relates to an algorithm to detect air in a diesel fuel line, and more particularly to an algorithm to detect air in a diesel fuel line upstream on a high pressure fuel pump.

Background of the invention:
[0002] JP 2008210705 A2 describes an air bubble removing system for fuel cell and fuel cell system equipped for removing air bubbles. The fuel cell system comprises a hollow fiber filter is installed on a passage of a coolant for cooling the fuel cell. A light detection sensor detects the amount of air bubbles in the coolant is furthermore installed, and when the amount of air bubbles detected with the light detection sensor reaches the prescribed amount, on-off valves are controlled, and the coolant may be passed through the hollow fiber filter.

Brief description of the accompanying drawings:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawing:

[0004] FIG. 1 illustrates an algorithm to detect air in a diesel fuel line upstream of a high-pressure fuel pump.

Detailed description of the embodiments:
[0005] FIG. 1 illustrates an algorithm 100 to detect air in a diesel fuel line upstream of a high-pressure fuel pump. The algorithm 100 comprises passing 110 monochromatic light in a transparent glass tube of a fuel line downstream of a high-pressure fuel pump, detecting 120 an amplitude of light intensity of air bubbles by means of a photodiode in the fuel line downstream of the high-pressure fuel pump, and transmitting 130 the amplitude of light intensity of air bubbles from the photodiode to an engine control unit. The algorithm 100 further comprises comparing 140 the amplitude of light intensity of air bubbles from the photodiode with a standard amplitude of light intensity of air bubbles in an engine control unit, transmitting 150 an output signal that is below a threshold amplitude from the engine control unit if there are no air bubbles in the fuel line downstream of the high-pressure fuel pump, and transmitting 160 an output signal that is above the threshold amplitude from the engine control unit if there are air bubbles in the fuel line downstream of the high-pressure fuel pump.

[0006] Figure 1 illustrates an algorithm 100 to detect air in diesel fuel that is upstream of a high-pressure fuel pump. The algorithm 100 comprises passing 110 monochromatic light through a transparent glass tube of a fuel line downstream of a high-pressure fuel pump. Once the monochromatic light passes through the transparent glass tube of the fuel line that is downstream of the high-pressure fuel pump, it is received by a detector that is positioned downstream of the high-pressure fuel pump and detects the monochromatic light. The algorithm further comprises detecting 120 an amplitude of light intensity of air bubbles by means of a photodiode in the fuel line downstream of the high-pressure fuel pump. Once the amplitude of light intensity of air bubbles is detected by means of the photodiode in the fuel line downstream of the high-pressure fuel pump, the amplitude of light intensity of air bubbles from the photodiode is transmitted 130 an engine control unit. The algorithm further comprises comparing 140 the amplitude of light intensity of air bubbles from the photodiode with a standard amplitude of light intensity of air bubbles in an engine control unit to determine whether the amplitude of light intensity of air bubbles from the photodiode is lesser than a threshold amplitude of light intensity of air bubbles or greater than the threshold amplitude of light intensity of air bubbles in the engine control unit. Therein, the algorithm comprises transmitting 150 an output signal that is below the threshold amplitude from the engine control unit if there are no air bubbles in the fuel line downstream of the high-pressure fuel pump. Alternatively, the algorithm comprises transmitting 160 an output signal that is above the threshold amplitude from the engine control unit if there are air bubbles in the fuel line downstream of the high-pressure fuel pump.

[0007] Therefore, based on the amplitude of light intensity of air bubbles from the photodiode that is received in the engine control unit, the engine control unit determines if there are bubbles in the fuel line downstream of the high-pressure fuel pump or if there are no bubbles in the fuel line downstream of the high-pressure fuel pump.

[0008] It should be understood that the embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.

, Claims:We claim:

1. An algorithm (100) to detect air in a diesel fuel line, the algorithm (100) comprising:
passing (110) monochromatic light in a transparent glass tube of a fuel line downstream of a high-pressure fuel pump;
detecting (120) an amplitude of light intensity of air bubbles by means of a photodiode in the fuel line downstream of the high-pressure fuel pump;
transmitting (130) the amplitude of light intensity of air bubbles from the photodiode to an engine control unit;
comparing (140) the amplitude of light intensity of air bubbles from the photodiode with a standard amplitude of light intensity of air bubbles in an engine control unit;
transmitting (150) an output signal that is below a threshold amplitude from the engine control unit if there are no air bubbles in the fuel line downstream of the high-pressure fuel pump; and
transmitting (160) an output signal that is above the threshold amplitude from the engine control unit if there are air bubbles in the fuel line downstream of the high-pressure fuel pump.