Method for supercharging an engine with cold gases

The method involves compressing an inlet gas and expanding the compressed gas in a heat engine (26) to produce a work for generating electrical energy and for compressing a fluid, such that temperature of the compressed inlet gas is lowered. The compressed inlet gas is then injected into an internal combustion engine (10). The fluid is used to maintain a constant pressure variation with respect to the flow of the gas. An independent claim is also included for an installation of supercharging an internal combustion engine.