TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Fuel Injection System: The fuel injection system further comprises at least one fuel injection element (2) for injecting hydrocarbon fuel into the fuel reformer, characterized in that the fuel injection system comprises a valve (10) with at least two ports (P; C), where the first port (C) of the valve (10) is connected to the at least one fuel injecting element (2) and the second port (P) of the valve (10) is adapted to receive hydrocarbon fuel from a fuel supply system (4, 6, 8) and where the valve (10) is adapted to provide a hydrocarbon fuel stream having a pulsating pressure. Then fuel injection system (1) further comprises at least one fuel stream stopping element (12), preferably a check valve, which is adapted to stop the supply of the hydrocarbon fuel stream to the at least one fuel injection element (2), if the pressure of the fuel stream supplied at the at least one fuel injection element (2) falls below a predetermined threshold pressure value. At least one fuel stream stopping element (12) is arranged between the first port (C) of the valve (10) and the at least one fuel injection element (2), and where preferably the at least one fuel stream stopping element (12) and the at least one fuel injection element (2) are co-designed to form at least one fuel injection nozzle (2) with a built-in fuel stream stopping element (12). The fuel injection system (1) comprises a fuel supply system (4, 6, 8) comprising a fuel tank (4) for containing the liquid hydrocarbon fuel, which is connected via a fuel supply line (p) with the valve (10), and a pump (6) for pressurizing the hydrocarbon fuel contained in the fuel supply line (p), where the fuel in the fuel tank (4) is preferably on a substantially constant or only slightly varying pressure level, preferably at a pressure level substantially equal to the actual atmospheric pressure the fuel injection system (1) is exposed to. The fuel supply system (4, 6, 8) further comprises a reduction valve (8), preferably a back pressure type reduction valve (8), which is in connection with the fuel tank (4) and the fuel supply line (p), for preventing the fuel in the fuel supply line (p) from developing an overpressure and/or for keeping the fuel in the fuel supply line (p) on a substantially constant or only slightly varying pressure level. The valve (10) is a 3-way valve with three ports, a fuel supply port (P), a pressure relief port (R) and a fuel injection element connection port (C), where the fuel supply port (P) and the pressure relief port (R) are in connection with the fuel tank (4) via the fuel supply line (p) and via a pressure relief line (r), respectively, and the fuel injection element connection port (C) is in connection with the at least one fuel injection element (2) via a fuel injection element connection line (c). The 3-way valve (10) in its non-activated state is closed to the pressurized fuel supply. line (p), whereas the fuel injection element connection port (C) is operably connected to the pressure relief line (r) via the pressure relief port (R), and in that the 3-way valve (10) in its activated state is closed to the pressure relief line (r), whereas fuel injection element connection port (C) is operably connected to the fuel supply line (p) via pressurized fuel supply port (P), where the 3-way valve (10) is preferably electrically actuated. The fuel injection system (1) further comprises a gas accumulator (14) for reducing fluctuations in the hydrocarbon fuel stream pressure, where the gas accumulator (14) is preferably arranged close to the valve (10). The valve (10) is operated at a low frequency, preferably with a frequency of less than circa 50 Hz, and more preferred with a frequency of less than circa 20 Hz. The pressure of the hydrocarbon fuel in the fuel supply line (p) supplied to the valve (10) is circa 8 to circa 15 bar, preferably circa 10 to circa 12 bar, above atmospheric pressure. Preferred Method: In the method for injecting hydrocarbon fuel into a fuel reformer for generating hydrogen rich gas from hydrocarbon fuel, injecting is provided by means of a fuel injection element (2), and the method further comprises the step of providing a hydrocarbon fuel stream with a pulsating pressure at the at least one fuel injection element (2). The hydrocarbon fuel stream pressure pulsates with a low frequency, preferably with a frequency of less than circa 50 Hz and more preferred with a frequency of less than circa 20 Hz. The method is performed by a fuel injection system (1) above.