Molten salt heat storage and steam generation system with nitrogen preheating function

The utility model discloses a molten salt heat storage and steam generation system with a nitrogen preheating function. Comprising a tower type solar heat collector, a hot molten salt storage tank, a low-temperature molten salt storage tank, a steam generator, a molten salt pump, a first two-position three-way valve, a first pipeline, a preheating main backflow pipeline, a first preheating backflow pipeline, a first preheating valve, a heat storage pipeline, a first heat release pipeline, a first adjusting valve, a second heat release pipeline, a third two-position three-way valve and a first preheating pipe. A nitrogen salt heat exchange box, a fourth two-position three-way valve, a first preheating backflow pipeline, a first valve, a first spiral heat exchanger and a nitrogen circulation mechanism. The molten salt preheating device can comprehensively preheat pipelines through which most of molten salt flows, prevents the molten salt from being solidified and blocking the pipelines, and ensures that the mol