Liquid nitrogen refrigerating system, liquid nitrogen flow control method and related equipment

The invention relates to the technical field of low-temperature storage. The invention provides a liquid nitrogen refrigerating system, a liquid nitrogen flow control method and related equipment. The liquid nitrogen refrigerating system comprises a liquid nitrogen siphon tank, a heat exchanger, a liquid nitrogen storage tank and a control unit; the heat exchanger comprises a first heat exchange pipeline and a second heat exchange pipeline which are used for heat exchange, an outlet of the liquid nitrogen siphon tank is connected with the first heat exchange pipeline through a liquid nitrogen siphon pipeline so as to supply liquid nitrogen into the first heat exchange pipeline, and the second heat exchange pipeline is configured to enable a medium to be cooled to flow through; an inlet of the liquid nitrogen siphon tank is connected to the liquid nitrogen storage tank through a liquid nitrogen filling pipeline, a first adjusting valve is arranged on the liquid nitrogen filling pipeline, and a second adjusting