Liquid natural gas cooling on the fly
View Patent ↗Described herein are systems and methods for cryogenic fluid delivery to achieve the lowest reasonable saturation pressure while dispensing a cryogenic fluid such as liquefied natural gas to a holding tank on a use device. The systems and methods utilize a liquid nitrogen component and a liquefaction engine, very cold liquefied natural gas and a liquefaction engine, or a combination of both very cold liquefied natural gas and a liquid nitrogen component to deliver LNG to a holding tank on a use device.
1. A system for delivering a cryogenic fluid fuel at a predetermined saturation pressure to a fuel tank, the system comprising:
a source tank with a top portion and a second portion, the source tank containing a fuel, the fuel comprising a gas portion and a liquid portion;
a pump fluidly connected to the top portion of the source tank by a vapor line and the bottom portion of the source tank by a liquid line, the pump configured to pump the fuel from the source tank towards a vehicle fuel tank;
a cooling component comprising a second tank containing a cooling cryogenic fluid, the cooling component fluidly connected to a liquefaction engine, the pump, and a controlled inlet line, the controlled inlet line fluidly connected to the vehicle fuel tank;
a cooling line connecting the pump to the cooling component, the cooling line having a first end connected to the outlet of the pump and a second end connected to a vapor inlet of the second tank of the cooling component;
an ambient temperature line with a first end connected to the outlet of the pump and a second end connected to the controlled inlet line;
a low pressure output line that connects a liquid portion of the second tank to the controlled inlet line;
a dispenser tank fluidly connected to the controlled inlet line and to the vehicle fuel tank;
a direct input line with a first end fluidly connected to the source tank and a second end fluidly connected to the dispenser tank;
a vapor relief line having a first end connected to a vapor inlet of the second tank of the cooling component and a second end connected to the source tank, the vapor relief line configured to convey the vapor portion of the fuel from the source tank to the second tank of the cooling component; and
a temperature sensing valve controller connected to:
a cold fuel control valve at the second end of the cooling line;
a warm fuel control valve at the second end of the ambient temperature line; and
the controlled inlet line,
the temperature sensing valve controller configured to measure a temperature of the fuel in the controlled inlet line and control the flow of fuel through the cold fuel control valve and warm fuel control valve to maintain the temperature of the fuel in the controlled inlet line within a predetermined temperature range, wherein the fuel comprises liquefied natural gas at a first pressure and the cooling cryogenic fluid comprises liquefied natural gas at a second pressure, the first pressure lower than the second pressure;
and wherein when the temperature sensing valve controller detects need for an increase of cold fuel to the use device, the temperature sensing control valve activates the cold fuel control valve to cause cold fuel to be pumped from the source tank into the second tank through the cooling line, thereby cooling the second tank and forcing cryogenic fluid in the second tank to flow out of the second tank through the low pressure output line to the controlled inlet line and toward the use device;
and wherein when a predetermined amount of cryogenic fluid accumulates in the second tank, cryogenic fluid flows out of the second tank of the cooling component, through the dispenser tank, and into the source tank via the direct input line.
2. The system of claim 1 , wherein the liquefaction engine is configured to remove heat from the cooling cryogenic fluid using electrical energy.
3. The system of claim 1 , wherein the liquefaction engine comprises heat removing lines through which a heat removing fluid flows, the heat removing lines connected to a separate source of heat removing fluid, the flow of heat removing fluid controlled by one or more liquefaction engine valves to maintain a pressure of the cooling cryogenic fluid in the cooling component.
4. The system of claim 1 , wherein activation of the cold fuel control valve by the temperature sensing valve controller causes the cooling cryogenic fluid in the second tank to flow through low pressure outlet line to the controlled inlet line.