System for recovering energy

A system for recovering energy,

• wherein the system has a main plant, during the operation of which a hot waste gas is produced,
• wherein the main plant has a discharge device, through which the waste gas flows and via which the waste gas is discharged from the main plant,
• wherein the system has a compressor arrangement having a number of compressors, by means of which air supplied to the compressor arrangement) and having an initial temperature is compressed from an initial pressure to a final pressure and an intermediate temperature,
• wherein the system has a heat exchanger arranged downstream of the compressor arrangement, through which the air compressed to the final pressure and the intermediate temperature flows and by means of which the heat of the waste gas flowing through the discharge device is supplied to the air flowing through the heat exchanger and thus the air is heated to a final temperature, and
• wherein the system has a compressed-air motor which is arranged downstream of the heat exchanger, to which the air heated to the final temperature and having the final pressure is supplied, which is operated with this air and from which the air is output at an output temperature and an output pressure.