Fuel recovery system

1. A fuel recovery system comprising:

a tank configured to store a liquid fuel;

an accumulator fluidly connected to the tank and configured to receive gaseous fuel formed in the tank;

a compressor fluidly connected to the accumulator and configured to compress the gaseous fuel;

a first control valve configured to selectively direct the gaseous fuel from the tank to the accumulator when a first pressure in the tank exceeds a first pressure threshold;

a second control valve configured to selectively direct the gaseous fuel from the accumulator to the compressor when a second pressure in the accumulator exceeds a second pressure threshold; and

a separator fluidly connected to the compressor and the tank and configured to:

receive the compressed gaseous fuel from the compressor,

separate the compressed gaseous fuel into a first flow of gaseous fuel at a first temperature and a second flow of gaseous fuel at a second temperature, and

direct the second flow to the tank.

2. The fuel recovery system of claim 1 , further including a heat exchanger fluidly connected to the accumulator and the compressor and configured to cool the compressed gaseous fuel exiting the compressor using the gaseous fuel received from the accumulator.

3. The fuel recovery system of claim 2 , wherein the second temperature is lower than the first temperature.

4. The fuel recovery system of claim 3 , wherein the separator is a Hilsch vortex generator.

5. The fuel recovery system of claim 4 , further including an engine configured to receive the first flow.

6. The fuel recovery system of claim 1 , further including:

a controller in communication with the first control valve and the second control valve, the controller being configured to selectively direct flows of the gaseous fuel from the tank and the accumulator.

7. The fuel recovery system of claim 6 , wherein the accumulator is a floating piston accumulator.

8. The fuel recovery system of claim 6 , wherein the engine drives the compressor.

9. The fuel recovery system of claim 6 , wherein the engine drives a refrigeration system configured to cool the liquid fuel in the tank.

10. A method of recovering gaseous fuel from a tank containing liquid fuel, comprising:

controlling a first control valve to selectively direct gaseous fuel from the tank to the accumulator when a first pressure in the tank exceeds a first threshold;

collecting the gaseous fuel from the tank in an accumulator;

controlling a second control valve to selectively direct the gaseous fuel from the accumulator to a compressor when a second pressure in the accumulator exceeds a second threshold;

compressing the gaseous fuel;

separating the compressed gaseous fuel into a first flow of gaseous fuel at a first temperature and a second flow of gaseous fuel at a second temperature; and

returning the second flow to the tank.

11. The method of claim 10 , further including:

circulating the gaseous fuel from the tank through a heat exchanger;

circulating the compressed gaseous fuel through the heat exchanger; and

cooling the compressed gaseous fuel using the gaseous fuel from the tank.

12. The method of claim 10 , wherein separating further includes:

injecting the compressed gaseous fuel into a Hilsch vortex generator;

removing the first flow from an outer periphery of the generator; and

removing the second flow from a center of the generator.

13. The method of claim 12 , wherein the second temperature is lower than a condensation temperature of the fuel at atmospheric pressure.

14. The method of claim 13 , further including:

supplying the first flow to an engine; and

combusting the first flow in the engine to generate power.

15. The method of claim 14 , further including using the power generated by the engine to drive the compressor.

16. The method of claim 15 , further including:

using the power generated by the engine to drive a refrigeration system; and

using the refrigeration system to cool the fuel in the tank.

17. A machine comprising:

a platform;

a plurality of wheels configured to support the platform;

a tank mounted on the platform and configured to store a liquid fuel;

an accumulator fluidly connected to the tank and configured to receive gaseous fuel from the tank;

a compressor fluidly connected to the accumulator and configured to compress the gaseous fuel;

a first control valve configured to selectively direct the gaseous fuel from the tank to the accumulator when a first pressure in the tank exceeds a first pressure threshold;

a second control valve configured to selectively direct the gaseous fuel from the accumulator to the compressor when a second pressure in the accumulator exceeds a second pressure threshold;

a heat exchanger fluidly connected to the compressor and configured to cool compressed gaseous fuel exiting the compressor;

an engine configured to drive the compressor; and

a Hilsch vortex generator fluidly connected to the compressor and the tank and configured to:

receive the compressed gaseous fuel from the compressor,

separate the compressed gaseous fuel into a first flow of gaseous fuel at a first temperature and a second flow of gaseous fuel at a second temperature lower than the first temperature,

direct the first flow to the engine, and

direct the second flow to the tank.

18. The machine of claim 17 , further including:

a controller in communication with the first control valve and the second control valve and configured to selectively direct flows of gaseous fuel from the tank and the accumulator.