LNG Loading System Cooling Unit for Evaporation Reduction
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Solution Overview
Problem
Existing LNG loading systems generate a significant amount of natural gas in gaseous form due to temperature differences, leading to increased evaporation and the need for bulky, expensive, and energy-intensive processing units to recirculate liquefied gas.
Innovation Solution
A loading system that cools cryogenic fluid using the cold generated from evaporated LNG, reducing the temperature of the fluid before transfer and minimizing evaporation, thereby reducing the capacity requirements of processing units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the liquid natural gas is transferred from the storage vessel to the receiving vessel using conventional loading systems, then the natural gas is transferred efficiently, but a significant portion of the natural gas evaporates due to temperature differences and heating during pumping
Solution Approach 1:
The patent applies preliminary action by pre-cooling the liquid natural gas in the flow element before it enters the receiving vessel. The cooling unit is positioned upstream in the transfer line to lower the temperature of the LNG beforehand, preventing temperature-induced evaporation when the gas enters the receiving vessel. This advance cooling action directly addresses the evaporation problem by preparing the fluid in advance rather than treating the symptom after evaporation occurs.
Solution Approach 2:
The patent converts the harmful effect of evaporation into a beneficial cooling source. The evaporated natural gas is captured and redirected through a heat exchanger where it cools the liquid natural gas in the flow element. The previously harmful evaporated gas now serves as a refrigerant, creating a closed-loop system where evaporation is harnessed to prevent further evaporation and maintain low temperatures throughout the transfer process.
2Reliability
If the processing and/or consumption unit is dimensioned to process the considerable volume of evaporated natural gas, then all evaporated gas can be handled, but the unit becomes bulky, expensive and energy intensive
Solution Approach 1:
The patent transforms the harmful evaporated gas into a useful cooling resource by routing it through a heat exchanger that contacts the liquid natural gas in the flow element. This converts the waste heat from evaporation into a refrigeration effect, reducing the temperature of the transferred LNG and minimizing further evaporation. Consequently, the volume of gas requiring processing is dramatically reduced, allowing for a smaller, less expensive processing unit.
Solution Approach 2:
The patent changes the temperature parameter of the liquid natural gas by introducing a cooling unit that lowers its temperature before transfer. This parameter change reduces the temperature differential between the LNG and the receiving vessel, thereby reducing the rate of evaporation. By controlling the temperature parameter proactively, the system minimizes the volume of evaporated gas that would otherwise require extensive processing capacity.
3Speed
If the liquid natural gas is heated during pumping or by thermal infiltration, then the natural gas moves through the supply line, but it becomes more likely to evaporate when entering the receiving vessel
Solution Approach 1:
The patent captures the heat generated during pumping and thermal infiltration by routing the evaporated gas through a heat exchanger that contacts the liquid natural gas. The evaporated gas, which carries the heat energy from pumping and environmental infiltration, serves to cool the liquid phase. This converts the harmful thermal energy into a useful cooling effect, counteracting the temperature increase caused by pumping and thermal infiltration.
Solution Approach 2:
The patent utilizes phase transitions by allowing liquid natural gas to evaporate into gas phase during pumping, then using that gas phase material in a heat exchanger to cool the remaining liquid. The phase change from liquid to gas absorbs heat (latent heat of vaporization), which counteracts the heating from pumping and thermal infiltration. This cyclic phase transition mechanism effectively maintains the temperature of the transferred LNG.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively limits the evaporation of cryogenic fluid during transfer, allowing for smaller processing units and reducing the quantity of gaseous natural gas generated, thus optimizing the capacity and efficiency of LNG loading operations.
Implementation Method 1
the cold generated by the cooling unit resulting from the evaporation of the cryogenic fluid coming from the storage vessel
Implementation Method 2
a portion of this cryogenic fluid is expanded, i.e., the pressure of this portion of cryogenic fluid is lowered, such that it lowers the temperature of the cryogenic fluid flowing through the additional supply line
Data Source
AI summary
The present invention primarily relates to a loading system (1) configured to transfer a cryogenic fluid (3) from a storage vessel (2) into a receiving vessel (4), the loading system (1) comprising at least one element (17) for circulating the cryogenic fluid (3) in the liquid state which connects the storage vessel (2) to the receiving vessel (4), a processing and/or consumption unit (26) of the cryogenic fluid (3) in the gaseous state originating at least from the receiving vessel (4) and a return line (28) of the cryogenic fluid in the gaseous state which connects the receiving vessel (4) with the processing and/or consumption unit (26), characterised in that the loading system (1) comprises at least one cooling unit (36) of the cryogenic fluid (3) circulating towards the receiving vessel (4) in the circulation element (17), the cold generated by the cooling unit (36) resulting from an evaporation of the cryogenic fluid (3) coming from the storage vessel (2).