The invention discloses a double-storage-tank
nitrogen sealing
system suitable for fused salt heat storage, which comprises a
nitrogen making device, a
nitrogen storage tank, a low-temperature tank and a high-temperature tank, the nitrogen making device is connected with a main valve, a nitrogen analyzer and a
discharge pipe are arranged between the nitrogen making device and the main valve, a
discharge valve is arranged on the
discharge pipe, and the nitrogen
storage tank is connected with the low-temperature tank. The inlet end of each nitrogen
storage tank is connected with the outlet of the main valve through a respective gas inlet stop valve; the outlet end of each nitrogen storage tank is connected with an inlet of a self-operated nitrogen-sealed valve through a corresponding exhaust stop valve, an outlet of the self-operated nitrogen-sealed valve is connected with the middle of a communicating
pipe through an electric quick-closing valve and a connecting pipe, and the two ends of the communicating pipe are connected with the
gas phase area of the low-temperature tank and the
gas phase area of the high-temperature tank respectively. The low-temperature tank and the high-temperature tank are each provided with a pressure
transmitter and a first-stage
breather valve, the pressure transmitters are connected with a controller of the electric quick-closing valve, and a pressure guide pipe of the self-operated nitrogen-sealed valve is connected with the
gas phase area of the low-temperature tank and the gas phase area of the high-temperature tank. The nitrogen consumption can be reduced, failure of the nitrogen-sealed valve under the high-temperature working condition can be prevented, multi-stage pressure protection of the storage tank is achieved, and long-term stable and
safe operation of the storage tank is guaranteed.