Patent ID: 9546645
Date: 2017-01-17
CPC Classifications: F04B

Claim:
1. A device for pumping a cryogenic fluid, comprising: a storage tank for storing a cryogenic fluid containing cryogenic liquid; a cryogenic pump for pumping the cryogenic liquid from the storage tank, the cryogenic pump having an inlet head loss; a suction line connecting the tank to the pump allowing the cryogenic liquid to be pumped from the storage tank; a temperature sensor adapted to measure a temperature of the cryogenic liquid in the storage tank; a computation unit adapted to receive the measured temperature of the cryogenic liquid in the storage tank from the temperature sensor and calculate a saturation pressure of the cryogenic liquid in the storage tank; a pressure sensor adapted to measure a pressure in the storage tank; and a pressure control system comprising a first pipe connecting a liquid outlet of the pump to the tank, the first pipe comprising an expansion valve adapted to expand the cryogenic liquid in the first pipe, the pressure control system being adapted to receive the calculated saturation pressure from the computation unit and the measured pressure from the pressure sensor and selectively keep the pressure in the tank at least equal to the sum of the saturation pressure of the cryogenic fluid stored and the inlet head loss of the cryogenic pump by selectively activating the expansion valve to allow any cryogenic liquid and vaporized cryogenic liquid from said activation to be injected into the tank based upon the measured pressure, the inlet head loss, and the calculated saturation pressure.