Where does the work output by a turbine expander take place?

Typically, an expander delivers kinetic energy outward through its rotor shaft; it has one shaft, with the expander impeller at one end and either a fan impeller or a compressor impeller at the other end, and in some cases it is used to drive a motor to generate electricity. . . . . . Currently, it is mostly used to drive a compressor for pressure enhancement, for reference only.

Take the steam turbine in a power plant as an example: high-temperature and high-pressure steam enters the turbine, where it passes through a series of grid-type impeller assemblies fixed to the main shaft, causing them to rotate and thereby driving the main shaft to spin at high speed. After passing through, the steam pressure and temperature drop, and the internal energy of the steam is converted into rotational kinetic energy of the turbine shaft. In a power plant, the turbine shaft drives the generator, converting kinetic energy into electrical energy. To improve power generation efficiency, it is necessary to keep the steam pressure and temperature at the lowest possible level, so as to ensure that more internal energy is converted into rotational kinetic energy of the shaft. Of course, this energy can also be used directly. For example, in a gas turbine, air is drawn in and burned; the high-temperature, high-pressure gas then expands within the turbine to generate power, with the exhaust gases being released as a result. This is how chemical energy is converted into kinetic energy. By varying the design of the gas turbine, the distribution of energy can be adjusted. If used for power generation, the main energy is converted into kinetic energy of the shaft; if used as a propulsion force for aircraft, the main energy is converted into heat, which causes the exhaust gases to be expelled.