System for enhancing the efficiency of high pressure storage tanks for compressed natural gas or hydrogen

In a vehicle having a bank of on board tanks connected in series for storage of gas under high pressure, an apparatus wherein refuel gas is received within a first on board tank and compression heat of refueling is absorbed by a heat exchanger within an interior of the first tank and heat thereby absorbed is radiated to an external environment through an external heat exchanger exterior to the tank, whereupon, after the first tank is filled with gas, an inlet to the first tank is closed, an inlet to a second tank is opened and the sequence of fuel gas receipt, heat absorption, heat radiation, and the return of fuel gas with respect to the second tank is repeated, and the inlet to the second tank is closed, and the circulation sequence of the gas is repeated for the remaining tanks in the bank, wherein each tank includes a continuous conduit extending in the tank interior from the tank gas inlet, through the internal heat exchanger, into the heat exchanger exterior to the tank, and therefrom back into the tank interior, whereupon, with regard to a first tank in the series, a conduit extends in the tank interior from the gas inlet of the first tank, through the internal heat exchanger of the first tank, into the heat exchanger exterior to the tank, and therefrom back to the interior of the first tank whereupon, after the first tank is filled with gas, the inlet to the first tank is closed, the inlet to the second tank is opened and a conduit extending in the interior of the second tank from the gas inlet of the second tank, directs gas flow through the internal heat exchanger of the second tank into the heat exchanger exterior to the tank, and therefrom back to the interior of the second tank, and the sequence of closing the inlet, opening the inlet to a next tank and directing gas flow in the conduit through the internal heat exchanger of the next tank, into the heat exchanger exterior to the next tank, and therefrom back to the interior of the next tank is repeated for the remaining tanks in the bank.

Apparatus in a vehicle having an on board tank for the storage of fuel gas under high pressure wherein refuel gas flows within a conduit connectable to a fuel depot, the conduit comprising:

• an internal heat exchanger inside the tank;
• an external heat exchanger outside of the tank;
• a volume for the storage of gas inside of the tank;
• and
• an inlet for directing gas into the inside volume of the tank;
• wherein:
• 1) refuel gas introduced into the conduit from the fuel depot flows through the internal heat exchanger to the external heat exchanger and then into the inside of the tank via the inlet,
• 2) as the gas in the tank is compressed, heat from the compressed gas is absorbed by the refuel gas flowing through the internal heat exchanger, and
• 3) heat absorbed by the gas in the internal heat exchanger is transferred to and radiated to an exterior environment through the external heat exchanger.