Large-flow low-pressure online gas supply system

The invention relates to a high-flow low-pressure online gas supply system, and belongs to the field of industrial nitrogen production. The online gas supply system comprises a liquid nitrogen output source, a first vacuum stop valve, a filter, a third vacuum stop valve and an online gas supply structure, and the online gas supply structure comprises a fourth vacuum stop valve, a P1 pressure sensor, a gasification channel composed of a seventh vacuum stop valve, a gasifier, a T2 temperature sensor and a P2 pressure sensor, a gasification channel composed of a sixth vacuum stop valve, a gasifier, a T3 temperature sensor and a P3 pressure sensor, a P4 pressure sensor, a flowmeter, a ninth vacuum stop valve, an external gas source port and a replacement target. The online gas supply system is large in gasification amount, low in pressure and high in temperature, sufficient heat exchange between nitrogen and air is guaranteed, adjustment and control are convenient, and safety is higher. 本发明涉及一种大流量低压在线供气系统，属于工业制氮领