System and method of de-bottlenecking LNG trains
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Solution Overview
Problem
LNG production is limited in existing trains operating at or above nameplate capacity, necessitating high capital expenditures for additional trains to increase production, while there is a need to enhance profitability and efficiency in LNG projects.
Innovation Solution
Configuring multiple LNG trains with a sub-cooling unit to liquefy natural gas streams in different operating modes, generating warm and cold streams, which increases the combined flow rate of cold streams without the need for new train construction, utilizing existing excess feed gas capacity and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If additional LNG trains are constructed to increase production capacity, then LNG output increases, but capital expenditures increase significantly
Solution Approach 1:
The patent combines multiple LNG trains with a shared subcooling unit, allowing the trains to operate in parallel while sharing common infrastructure. This merging approach increases total production capacity without requiring each train to have its own complete subcooling system, thereby reducing capital expenditures on duplicate equipment
Solution Approach 2:
The subcooling unit is designed to serve multiple LNG trains simultaneously, making it a multi-functional asset. This universal equipment can process streams from different trains and operate in various modes (first operating mode for subcooling, second operating mode for direct cooling), maximizing its utility and reducing the need for additional specialized equipment
2Productivity
If LNG trains operate at nameplate capacity, then existing infrastructure is utilized efficiently, but additional production capacity cannot be achieved
Solution Approach 1:
The system implements dynamic operational modes where LNG trains can switch between first operating mode (with subcooling for maximum capacity) and second operating mode (without subcooling or with reduced subcooling). This dynamic flexibility allows the plant to adapt production capacity to market demands while utilizing existing infrastructure at different utilization levels
Solution Approach 2:
The patent changes operational parameters by adjusting the temperature and flow rate of LNG streams through the subcooling unit. By controlling the degree of subcooling and the distribution of gas streams between different trains, the system can vary output capacity continuously without physical modifications to the trains themselves
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
This approach enhances LNG production capacity while minimizing new construction costs, offering a cost-effective and efficient method to increase output without building additional trains, leveraging existing infrastructure and reducing capital expenditures.
Implementation Method 1
A sub-cooling unit is configured to, in the first operating mode, sub-cool the first warm LNG stream and the second warm LNG stream to generate a first cold LNG stream in the first operating mode and a second cold LNG stream in the first operating mode
Implementation Method 2
A first LNG train is configured to liquefy a first portion of the natural gas stream to generate a first warm LNG stream
Data Source
AI summary
A system and method for producing liquefied natural gas (LNG) from a natural gas stream. Each of a plurality of LNG trains liquefies a portion of the natural gas stream to generate a warm LNG stream in a first operating mode, and a cold LNG stream in a second operating mode. A sub-cooling unit is configured to, in the first operating mode, sub-cool the warm LNG streams generated by each of the plurality of LNG trains to thereby generate a plurality of cold LNG streams. The warm LNG streams have a higher temperature than a temperature of the cold LNG streams in the second operating mode and the plurality of cold LNG streams. The combined flow rate of the plurality of cold LNG streams has, in the first operating mode, a higher flow rate than the combined flow rate of the cold LNG streams in the second operating mode.