Systems and methods for monitoring a fuel system

1. A system comprising:

a tank containing fuel;

a pump that is electronically controlled and configured to pressurize the fuel and provide pressurized fuel to an engine;

an electro-mechanical valve disposed downstream from the pump and configured to control flow of the pressurized fuel to the engine; and

a controller configured to perform operations prior to turning on the engine, the operations comprising:

with the pump and the electro-mechanical valve being turned-off, receiving, from a pressure sensor, pressure information indicative of a pressure level of the pressurized fuel between the electro-mechanical valve and the engine,

based on the pressure level being below a first threshold pressure, sending a first signal to open the electro-mechanical valve,

determining, based on the pressure information, that the pressure level is increasing upon sending the first signal,

in response to the pressure level increasing, sending a second signal to activate the pump,

determining that the pressure level has increased to a second threshold pressure, and

providing information indicating that the engine is ready for operation.

2. The system of claim 1 , wherein the electro-mechanical valve is a supply electro-mechanical valve, the system further comprising:

a return electro-mechanical valve disposed downstream from the engine, between the engine and the tank, wherein the operations further comprise:

prior to providing information indicating that the engine is ready for operation, sending a third signal to open the return electro-mechanical valve, while the pump is activated and the supply electro-mechanical valve is turned on, for a predetermined amount of time, so as to purge plumbing lines that fluidly couple the pump to the engine and the engine to the tank.

3. The system of claim 1 , further comprising:

a mechanical shut-off valve disposed between the pump and the electro-mechanical valve, wherein the mechanical shut-off valve is normally-open and is configured to close to shut-off the flow of the pressurized fuel when a pressure difference thereacross exceeds a threshold pressure difference, and wherein the operations further comprise:

after sending the second signal to activate the pump, determining that the pressure level has increased to a pressure value below the second threshold pressure;

based on the pressure level increasing to the pressure value below the second threshold pressure, determining that the mechanical shut-off valve closed; and

in response to determining that the mechanical shut-off valve is closed: (i) deactivating the pump, and (ii) sending a cyclic signal to the electro-mechanical valve.

4. The system of claim 3 , wherein the operations further comprise:

after sending the cyclic signal, determining, based on the pressure information, that the pressure level is within a threshold pressure value from a respective pressure level of fuel in the tank; and

determining whether the pressure level is stable, wherein providing the information indicating that the engine is ready for operation is based on whether the pressure level is stable.

5. The system of claim 4 , wherein the operations further comprise:

determining that the pressure level is stable;

in response to determining that the pressure level is stable, sending respective signals to reactivate the pump and open the electro-mechanical valve; and

determining that the pressure level has reached the second threshold pressure, wherein providing the information indicating that the engine is ready for operation is based on the pressure level reaching the second threshold pressure.

6. The system of claim 4 , wherein the operations further comprise:

estimating a rate of change of the pressure level with respect to time, wherein determining whether the pressure level is stable is based on a comparison between the estimated rate of change and a predetermined threshold rate of change.

7. The system of claim 4 , further comprising:

a fuel sensor configured to provide fuel quality information indicative of chemical composition of the fuel, wherein the operations further comprise:

receiving temperature information indicative a temperature of the fuel downstream from the electro-mechanical valve; and

determining, based on the temperature information and the fuel quality information, the respective pressure level of fuel in the tank, wherein determining whether the pressure level is stable is based on a comparison between the pressure level and the respective pressure level during a given amount of time.

8. The system of claim 7 , wherein the electro-mechanical valve is a supply electro-mechanical valve, the system further comprising:

a return electro-mechanical valve disposed downstream from the engine, between the engine and the tank, wherein the operations further comprise:

determining that the pressure level is stable based on the pressure level being with the threshold pressure value from the respective pressure level during the given amount of time; and

prior to providing information indicating that the engine is ready for operation, sending a third signal to open the return electro-mechanical valve, while the pump is activated and the supply electro-mechanical valve is turned on, so as to purge plumbing lines that fluidly couple the pump to the engine and the engine to the tank.

9. The system of claim 3 , wherein the cyclic signal has a predetermined frequency and lasts for a predetermined amount of time.

10. The system of claim 3 , wherein the cyclic signal comprises a predetermined number of cycles.

11. The system of claim 1 , wherein sending the second signal to activate the pump is based on determining that the pressure level has increased until the pressure level is within a threshold pressure value from a respective pressure level of fuel in the tank.

12. A system comprising:

a tank containing fuel;

a pump that is electronically controlled and configured to pressurize the fuel and provide pressurized fuel to an engine;

an electro-mechanical valve disposed downstream from the pump and configured to control flow of the pressurized fuel to the engine;

a mechanical shut-off valve disposed between the pump and the electro-mechanical valve, wherein the mechanical shut-off valve is normally-open and is configured to close to shut-off the flow of the pressurized fuel when a pressure difference thereacross exceeds a threshold pressure difference; and

a controller configured to perform operations prior to turning on the engine, the operations comprising:

with the pump and the electro-mechanical valve being turned-off, receiving, from a pressure sensor, pressure information indicative of a pressure level of the pressurized fuel between the electro-mechanical valve and the engine,

based on the pressure level being below a first threshold pressure, sending a first signal to open the electro-mechanical valve,

determining, based on the pressure information, that the pressure level has increased upon sending the first signal,

in response to determining that the pressure level has increased, sending a second signal to activate the pump,

after sending the second signal to activate the pump, determining that the pressure level has increased to a pressure value below a second threshold pressure,

based on the pressure level increasing to the pressure value below the second threshold pressure, determining that the mechanical shut-off valve is closed, and

in response to determining that the mechanical shut-off valve is closed: (i) deactivating the pump, and (ii) sending a cyclic signal to the electro-mechanical valve.

13. The system of claim 12 , wherein the operations further comprise:

after sending the cyclic signal, determining, based on the pressure information, that the pressure level is within a threshold pressure value from a respective pressure level of fuel in the tank;

determining whether the pressure level is stable; and

providing information indicating that the engine is ready for operation based at least on on whether the pressure level is stable.

14. The system of claim 13 , wherein the operations further comprise:

determining that the pressure level is stable;

in response to determining that the pressure level is stable, sending respective signals to reactivate the pump and open the electro-mechanical valve; and

determining that the pressure level has reached the second threshold pressure, wherein providing information indicating that the engine is ready for operation is based on the pressure level reaching the second threshold pressure.

15. The system of claim 13 , wherein the operations further comprise:

estimating a rate of change of the pressure level with respect to time, wherein determining whether the pressure level is stable is based on a comparison between the estimated rate of change and a predetermined threshold rate of change.

16. The system of claim 13 , wherein the electro-mechanical valve is a supply electro-mechanical valve, the system further comprising:

a return electro-mechanical valve disposed downstream from the engine, between the engine and the tank, wherein the operations further comprise:

determining that the pressure level is stable; and

prior to providing information indicating that the engine is ready for operation, sending a third signal to open the return electro-mechanical valve, while the pump is activated and the supply electro-mechanical valve is turned on, so as to purge plumbing lines that fluidly couple the pump to the engine and the engine to the tank.

17. The system of claim 12 , wherein the cyclic signal has a predetermined frequency and lasts for a predetermined amount of time.

18. The system of claim 12 , wherein the cyclic signal comprises a predetermined number of cycles.

19. A system comprising:

a tank containing fuel;

a pump that is electronically controlled and configured to pressurize the fuel and provide pressurized fuel to an engine;

an electro-mechanical valve disposed downstream from the pump and configured to control flow of the pressurized fuel to the engine;

a mechanical shut-off valve disposed between the pump and the electro-mechanical valve, wherein the mechanical shut-off valve is normally-open and is configured to close to shut-off the flow of the pressurized fuel when a pressure difference thereacross exceeds a threshold pressure difference; and

a controller configured to perform operations prior to turning on the engine, the operations comprising:

sending a signal to open the electro-mechanical valve,

receiving, from a pressure sensor, pressure information indicative of a pressure level of the pressurized fuel between the electro-mechanical valve and the engine,

determining, based on the pressure information, that the pressure level failed to increase upon sending the signal,

based on the pressure level failing to increase, determining that the mechanical shut-off valve is closed, and

in response to determining that the mechanical shut-off valve is closed, sending a cyclic signal to the electro-mechanical valve.

20. The system of claim 19 , wherein the electro-mechanical valve is a supply electro-mechanical valve, the system further comprising:

a return electro-mechanical valve disposed downstream from the engine, between the engine and the tank, wherein the operations further comprise:

after sending the cyclic signal, determining that the pressure level is stable;

sending a respective signal to open the return electro-mechanical valve, while the pump is activated and the supply electro-mechanical valve is turned on, so as to purge plumbing lines that fluidly couple the pump to the engine and the engine to the tank; and

providing information indicating that the engine is ready for operation.