STORAGE SYSTEM FOR FUELS
A condensation system for a reservoir, which stores fuel cryogenically, is disclosed. A portion of the fuel exists as a boil-off gas with a first vapor quality. The condensation system includes an absorption unit coupled to the reservoir and is configured to receive and mix the boil-off gas with a refrigerant, forming a liquid solution. A distillation unit is coupled to the absorption unit to receive the liquid solution at a supplemented pressure, and is configured to separate the fuel to a gaseous state from the liquid solution. Further, a cooling circuit is configured to receive the fuel in the gaseous state from the distillation unit at the supplemented pressure and a supplemented temperature, and deliver the fuel to the reservoir at a lower pressure and a temperature, with a vapor quality lower than the first vapor quality.
1 . A condensation system for a reservoir configured to store a fuel cryogenically, a portion of the fuel existing as a boil-off gas in the reservoir with a first vapor quality, the condensation system comprising:
an absorption unit fluidly coupled to the reservoir, the absorption unit configured to receive a refrigerant and the boil-off gas and facilitate a mixing therebetween to form a liquid solution;
a distillation unit fluidly coupled to the absorption unit to receive the liquid solution at a supplemented pressure, and configured to separate the fuel to a gaseous state from the liquid solution; and
a cooling circuit fluidly coupled between the distillation unit and the reservoir, and configured to receive the fuel in the gaseous state from the distillation unit at the supplemented pressure and a supplemented temperature, and deliver the fuel to the reservoir at a pressure and a temperature respectively lower than the supplemented pressure and the supplemented temperature, and with a vapor quality lower than the first vapor quality.
2 . The condensation system of claim 1 , wherein the cooling circuit includes:
a condenser fluidly coupled to the distillation unit and configured to receive the fuel and attain the temperature; and
an expansion valve fluidly coupled to the condenser and configured to receive the fuel and attain the pressure, before a delivery of the fuel into the reservoir.
3 . The condensation system of claim 1 further comprising a pump fluidly connected between the absorption unit and the distillation unit to pressurize the liquid solution to the supplemented pressure.
4 . The condensation system of claim 3 , wherein the pump is adapted to selectively pump and deliver the fuel to an engine.
5 . The condensation system of claim 1 further including a supplementary expansion valve to receive the boil-off gas from the reservoir, at a pressure prevalent within the reservoir, and deliver the fuel in the gaseous state at a reduced pressure to the absorption unit.
6 . The condensation system of claim 5 , wherein the supplementary expansion valve is positioned within the reservoir.
7 . The condensation system of claim 5 further including a heat exchanging section arranged downstream to the supplementary expansion valve, along a flow direction of the boil-off gas to the absorption unit, the heat exchanging section being positioned within the reservoir.
8 . The condensation system of claim 1 , wherein the fuel is Liquefied Natural Gas (LNG).
9 . The condensation system of claim 1 , wherein the refrigerant is Propane.
10 . A storage system for a fuel, the system comprising:
a reservoir to store the fuel cryogenically, wherein a portion of the fuel exists as a boil-off gas in the reservoir with a first vapor quality;
an absorption unit fluidly coupled to the reservoir, the absorption unit configured to receive a refrigerant and the boil-off gas and facilitate a mixing therebetween to form a liquid solution;
a distillation unit fluidly coupled to the absorption unit to receive the liquid solution at a supplemented pressure, and configured to separate the fuel to a gaseous state from the liquid solution; and
a cooling circuit fluidly coupled between the distillation unit and the reservoir, and configured to receive the fuel in the gaseous state from the distillation unit at the supplemented pressure and a supplemented temperature, and deliver the fuel to the reservoir at a pressure and a temperature respectively lower than the supplemented pressure and the supplemented temperature, and with a vapor quality lower than the first vapor quality.
11 . The storage system of claim 10 , wherein the cooling circuit includes:
a condenser fluidly coupled to the distillation unit and configured to receive the fuel and attain the temperature; and
an expansion valve fluidly coupled to the condenser and configured to receive the fuel and attain the pressure, before a delivery of the fuel into the reservoir.
12 . The storage system of claim 10 further comprising a pump fluidly connected between the absorption unit and the distillation unit to pressurize the liquid solution to the supplemented pressure.
13 . The storage system of claim 12 , wherein the pump is adapted to selectively pump and deliver the fuel to an engine.
14 . The storage system of claim 10 further including a supplementary expansion valve to receive the boil-off gas from the reservoir, at a pressure prevalent within the reservoir, and deliver the boil-off gas at a reduced pressure to the absorption unit.
15 . The storage system of claim 14 , wherein the supplementary expansion valve is positioned within the reservoir.
16 . The storage system of claim 14 further including a heat exchanging section arranged downstream to the supplementary expansion valve, along a flow direction of the boil-off gas to the absorption unit, the heat exchanging section being positioned within the reservoir.
17 . The storage system of claim 10 , wherein the fuel is Liquefied Natural Gas (LNG) and the refrigerant is Propane.
18 . A method for condensing a fuel, cryogenically stored in a reservoir, the method comprising:
upon a presence of a portion of the fuel as a boil-off gas with a first vapor quality in the reservoir,
extracting the boil-off gas to an absorption unit;
mixing the boil-off gas with a refrigerant in the absorption unit to form a liquid solution;
pressurizing the liquid solution to a supplemented pressure by a pump;
separating the fuel into a gaseous state from the liquid solution, at a supplemented temperature, in a distillation unit;
lowering the supplemented temperature and the supplemented pressure of the fuel in the gaseous state by a cooling circuit; and
delivering the fuel to the reservoir at a pressure and a temperature respectively lower than the supplemented pressure and the supplemented temperature, and with a vapor quality lower than the first vapor quality.
19 . The method of claim 18 further comprising, during extracting, reducing a pressure and temperature of the boil-off gas by passing the boil-off gas through an expansion valve, thereby forming a low temperature stream.
20 . The method of claim 19 further comprising condensing at least a portion of the fuel in the gaseous state in the cooling circuit by receiving refrigeration from the low temperature stream.