Device and method for temporarily increasing power

1. A device for temporarily increasing the power of at least a first turbine engine, the device comprising:

a tank of coolant liquid; and

a first injection circuit connected to said tank and leading to at least one injection nozzle suitable for being installed upstream from at least one compressor stage of the first turbine engine;

wherein the first injection circuit includes at least a first flow valve configured to open when pressure upstream from said first flow valve exceeds downstream pressure from at least one compressor stage of a second turbine engine by an amount greater than a predetermined threshold, so as to allow the coolant liquid to flow towards said injection nozzle of the first injection circuit, and wherein said device further includes at least one pressurization circuit suitable for being connected to at least one compressor stage of the first turbine engine to pressurize said tank with compressed air from the at least one compressor stage and including a check valve to avoid depressurizing the tank.

2. The device according to claim 1 , further including a second injection circuit connected to said tank, leading to at least one injection nozzle, and including at least one flow valve configured to open when pressure exceeds a predetermined threshold relative to a downstream pressure from at least one compressor stage, to enable the coolant liquid to flow towards said injection nozzle of the second injection circuit.

3. The device according to claim 1 , wherein at least said first injection circuit further includes at least one second flow valve connected in parallel with the first flow valve of said first injection circuit and configured to open when pressure exceeds a predetermined threshold relative to a downstream pressure from a compressor stage of a third turbine engine so as to enable the coolant liquid to flow towards said injection nozzle of the first injection circuit.

4. The device according to claim 1 , wherein each injection circuit further includes an additional valve upstream from the at least one flow valve.

5. A power plant including at least a first turbine engine, a second turbine engine, and a device according to claim 1 , wherein said injection nozzle of the first injection circuit is installed upstream from said at least one compressor stage of the first turbine engine, and the first flow valve of the first injection circuit is connected to a compressor of the second turbine engine in order to control said first flow valve.

6. An aircraft including a power plant according to claim 5 .

7. A method of temporarily increasing power of a first turbine engine, wherein a first flow valve of a first injection circuit connected to a tank of coolant liquid and leading to at least one injection nozzle upstream from at least one compressor stage of the first turbine engine opens when pressure upstream from said first flow valve is greater than downstream pressure from at least one compressor stage of a second turbine engine by an amount that exceeds a predetermined threshold so as to enable coolant liquid to flow through the first injection circuit and be injected by said injection nozzle upstream from at least one compressor stage of the first turbine engine, said tank being pressurized with compressed air by at least one pressurization circuit connected to at least one compressor stage of the first turbine engine and including a check valve in order to avoid depressurizing the tank.