采用多级压缩，可以通过在级间设置中间冷却器的方法，使被压缩气体在经过一级压缩后，先进行等压冷却，以降低温度，再进入下一级气缸。温度降低、密度增大，这样易于进一步压缩，较之一次压缩可以大大节省耗功量。
By means of multi-stage compression, the compressed gas can be cooled isobarically after first stage compression by setting an intercooler between stages, so as to lower the temperature and enter the next stage of cylinder. As the temperature decreases and the density increases, it is easy to compress further, and the power consumption can be greatly saved compared with the first compression.
因此在相同的压力下多级压缩做功的面积就比单级压缩要少。级数越多省的功耗就越多越接近于等温压缩。
Therefore, under the same pressure, the area of work done by multi-stage compression is less than that by single-stage compression. The more series, the more power consumption, the closer to isothermal compression.