Circulation system and granary

The utility model belongs to the technical field of granary equipment, and particularly relates to a circulation system and a granary, the circulation system comprises an air inlet pipeline, an air return pipeline and a circulation assembly; the air inlet pipelines comprise air inlet main pipelines arranged on the two sides of the bottom of the bin body and air inlet branch pipelines perpendicular to the air inlet main pipelines, and the air inlet branch pipelines are located between the air inlet main pipelines on the two sides; the air return pipeline comprises an air return main pipeline arranged at the top of the bin body and an air return branch pipeline connected with the air return main pipeline; the air return branch pipelines form a radial structure and are correspondingly arranged in the middle of the air inlet pipeline. The circulation system can enable the gas to uniformly enter the bin body, so that the gas can be diffused more uniformly; and the gas can form approximately vertically upward airfl