Operating Method for a Cryopressure Tank

摘要

An operating method is provided for a cryopressure tank in which cryogenic hydrogen for supplying a motor vehicle fuel cell can be stored under supercritical pressure at 13 bar or more. In order to compensate the pressure drop resulting from removal of hydrogen from the cryopressure tank, either a heat transfer medium is supplied to a heat exchanger provided in the cryopressure tank via a control valve over a period of time which significantly exceeds the cycle times of a conventional cycle valve or the heat transfer medium is not supplied to the heat exchanger. Depending on the fill level of the cryopressure tank, the control valve is actuated with respect o a desired temperature or a desired pressure of the hydrogen in the cryopressure tank. As long as there is a risk of liquefaction of the residual hydrogen in the cryopressure tank, as is the case when the temperature falls below the critical temperature of 33 K if the pressure drops below the critical pressure of approximately 13 bar, during the removal of cryogenic hydrogen from the cryopressure tank, the temperature is adjusted such that it does not drop below the critical temperature of 33 Kelvin. If the fill state in the cryopressure tank drops further, the pressure in the cryopressure tank is adjusted when there is no longer a risk of liquefaction such that the pressure does not drop below a minimum pressure value which the hydrogen that is removed from the cryopressure tank must have in order to be usable in the consumer without restricting the function thereof.

主权项

1. An operating method for a cryopressure tank in which cryogenic hydrogen for supplying a consumer, is storable under supercritical pressure at 13 bar or more, the method comprising the acts of:
for compensating a pressure drop resulting from removal of the hydrogen from the cryopressure tank, either supplying a heat transfer medium to a heat exchanger provided in the cryopressure tank via a control valve, or not supplying the heat transfer medium into said heat exchanger depending on the fill level of the cryopressure tank, actuating the control valve with respect to a desired temperature or a desired pressure of the hydrogen in the cryopressure tank, wherein:
in a case of a higher filling level and as long as there is a risk of liquefaction of residual hydrogen in the cryopressure tank during removal of cryogenic hydrogen from the cryopressure tank, adjusting the temperature of the hydrogen located in the tank such that it does not drop below the critical temperature, andin a case of a low fill level, when there is no longer the risk of liquefaction during the removal of cryogenic hydrogen and as long as this is possible with the residual amount of hydrogen contained in the cryopressure tank, adjusting the pressure in the cryopressure tank such that it does not drop below a minimum pressure value which the hydrogen removed from the cryopressure tank must have to be usable in the consumer without limiting the function thereof