Liquid nitrogen washing system with flash vapor recovery device

The utility model provides a liquid nitrogen washing system with a flash steam recovery device. The liquid nitrogen washing system comprises an adsorber, a hydrogen separator, a nitrogen washing tower, a medium-pressure nitrogen cooler, a first feed gas cooler, a second feed gas cooler, a regenerated nitrogen heater, a regenerated nitrogen cooler, a mixer and a flash steam compressor, a bottom outlet of the hydrogen separator is sequentially communicated with a second refrigerant inlet of the No.2 feed gas cooler, a second refrigerant inlet of the No.1 feed gas cooler, a second refrigerant inlet of the medium-pressure nitrogen cooler and the methanol washer; an outlet in the top of the hydrogen separator is sequentially communicated with a third refrigerant inlet of the second feed gas cooler, a third refrigerant inlet of the first feed gas cooler and a third refrigerant inlet of the medium-pressure nitrogen cooler, and a third refrigerant outlet of the medium-pressure nitrogen cooler is respectively communic