Energy recovery device of air separation plant and air separation plant

The invention provides an energy recovery device of an air separation plant and the air separation plant, and the energy recovery device of the air separation plant comprises a plurality of high-pressure nitrogen pipelines; the low-pressure nitrogen pipelines and the high-pressure nitrogen pipeline are arranged at intervals; a plurality of first connecting pipelines, wherein each first connecting pipeline is provided with a throttle valve; a plurality of second connection lines; the plurality of expanders are arranged on the plurality of second connecting pipelines in a one-to-one correspondence manner; the condenser is arranged on the multiple second connecting pipelines, and each expansion machine is located between the condenser and the high-pressure nitrogen pipeline; the evaporator is communicated with the condenser through a communicating pipeline; the water inlet pipe and the first water outlet pipe are communicated with the evaporator at intervals; the air cooling tower is arranged at an outlet of the