Multipoint fuel injection system for a turbomachine and associated regulation method

A fuel system for a turbine engine, adapted to inject fuel into a combustion chamber of the turbine engine, comprising:

• a pilot circuit, adapted to inject fuel into the combustion chamber,
• a main circuit, adapted to inject fuel into the combustion chamber, and
• a flow rate regulator, adapted to regulate the fuel flow rate in the pilot circuit and in the main circuit as a function of the speed of the turbine engine, said flow rate regulator comprising a mobile spool between a first configuration, in which the main circuit is blocked and the pilot circuit is passing, and a second configuration in which at the same time the main circuit and the pilot circuit are passing,
• a pressure regulator downstream of the flow rate regulator,
• the fuel system being characterized in that it further comprises:
• a fuel tank,
• a high-pressure pump, adapted to pressurise the fuel at the outlet of the fuel tank, and
• a purge tank, connected on one side via a first port selectively to the fuel tank such that the pressure at the first port is equal to the pressure of the fuel tank, or to the high-pressure pump such that the pressure at the first port is equal to the pressure at an outlet of the high-pressure pump, and the purge tank being connected on another side at a purge port to the main circuit, said purge tank being adapted to suction, store and purge fuel in the main circuit through the purge port as a function of the pressure difference between the main circuit and the fuel tank or the high-pressure pump to which it is connected;
• wherein the purge tank is connected to the main circuit downstream of the pressure regulator.