System for draining and refilling cryogenic fuel in a vehicle tank

1. A tool for draining and refilling a vehicle tank for cryogenic fuel, wherein the tool when in position for use has a vertical direction and comprises a heat exchanger and a cooling tank, the cooling tank having an upper portion and a lower portion as viewed in the vertical direction of the tool and comprising a fuel outlet on the cooling tank having at least one outlet valve, the fuel outlet on the cooling tank being connected to a fuel outlet conduit, wherein the fuel outlet conduit comprises a first connector for connecting the fuel outlet on the cooling tank to an inlet on the heat exchanger, and wherein the fuel outlet conduit comprises a second connector for connecting the fuel outlet on the cooling tank to an inlet on the vehicle tank, and the cooling tank further comprises a cooling tank inlet, the cooling tank inlet being connected to a fuel inlet conduit via a check valve, and the fuel inlet conduit comprises a third connector for connecting the cooling tank inlet to an outlet of the heat exchanger, or to an outlet of the vehicle tank, and the outlet of the heat exchanger comprises a fourth connector for connecting to the inlet on the vehicle tank, wherein the heat exchanger is provided with a fifth connector for connecting the inlet on the heat exchanger to a fuel outlet on the vehicle tank such that the cryogenic fuel from the vehicle tank can be conducted to said heat exchanger and returned to the vehicle tank.

2. The tool according to claim 1 , wherein the at least one outlet valve is disposed on the fuel outlet conduit, and wherein the fuel outlet conduit divides into a first fuel conduit and a second fuel conduit downstream of the at least one outlet valve, as viewed in a direction from the fuel outlet on the cooling tank.

3. The tool according to claim 1 , wherein the check valve is adapted to open at a back pressure from the cooling tank from 12 to 24 bars.

4. The tool according to claim 1 , wherein the cooling tank inlet to the cooling tank is placed above the fuel outlet from the cooling tank in the vertical direction of the tool.

5. The tool according to claim 3 , wherein a spraying device is connected to the cooling tank inlet of the cooling tank inside the cooling tank, the spraying device being adapted for spraying the cryogenic fuel into the upper portion of the cooling tank.

6. The tool according to claim 1 , wherein a gas outlet is disposed in the upper portion of the cooling tank.

7. The tool according to claim 6 , wherein the gas outlet is connected via one or several valves to one or several gas outlet conduits.

8. The tool according to claim 6 , wherein one gas outlet conduit is provided with a safety valve, which is adapted to open automatically at an outlet pressure of 24 bars.

9. The tool according to claim 6 , wherein one gas outlet conduit is provided with an outlet valve, which is adapted to be opened and closed manually.

10. The tool according to claim 1 , wherein the tool is portable.