Balancing power in split mixed refrigerant liquefaction system

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Solution Overview

Problem

Existing liquefaction systems face inefficiencies due to imbalanced power usage between propane and high-pressure MR compressors, particularly in varying ambient temperatures, leading to reduced LNG production during warmer or colder months.

Innovation Solution

A split MR liquefaction system that adjusts the characteristics of the high-pressure MR compressor to require less power in warmer temperatures and more power in cooler temperatures, using methods such as suction throttle valves, adjustable inlet guide vanes, or variable speed gearboxes to balance power distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single gas turbine drives both propane compressor and high-pressure MR compressor, then device complexity is reduced, but power availability becomes insufficient when both compressors need to operate at design point capacity

Engineering Contradiction:
Improvenumber of gas turbinesVSAvoidpower availability
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent divides the single gas turbine into two separate gas turbines: a first gas turbine driving the propane compressor and a second gas turbine driving the high-pressure MR compressor. This segmentation allows each compressor to have dedicated power sources, eliminating power availability constraints while maintaining operational flexibility.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the high-pressure MR compressor is designed for maximum capacity, then LNG production efficiency is maximized, but power consumption increases and requires larger gas turbines

Engineering Contradiction:
ImproveLNG production efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The patent implements variable speed drives on both the propane compressor and high-pressure MR compressor, allowing their operating speeds to be dynamically adjusted based on available power from gas turbines and actual LNG production requirements. This dynamic operation enables the system to optimize between productivity and power consumption in real-time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the compressors by introducing variable speed control, allowing the compressors to operate at different speeds and power levels rather than being fixed at design point capacity. This enables flexible adaptation to varying power availability and production demands.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If the propane compressor and high-pressure MR compressor operate at fixed design point capacity, then system stability is improved, but adaptability to varying power availability and production demands decreases

Engineering Contradiction:
Improvesystem stabilityVSAvoidadaptability to power availability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent transforms the fixed-capacity compressor system into a dynamic system with variable speed drives that can continuously adjust operating parameters. This allows the system to adapt to varying power availability from gas turbines and changing LNG production demands while maintaining stable operation through controlled adjustments.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements control systems that monitor power availability from gas turbines and adjust compressor speeds accordingly. This feedback mechanism ensures the system adapts to changing conditions while maintaining operational stability and optimizing LNG production efficiency.

Inventive Principle:
Principle #23Feedback

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

Enhances LNG production efficiency by optimizing power utilization across different ambient temperatures, ensuring maximum use of available power from gas turbines.

Implementation Method 1

A split MR liquefaction system, where LP and MP MR compressors are driven by a first gas turbine and a propane compressor and a HP MR compressor is driven by a second gas turbine

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

gas turbine

Methodology Applied
Scientific EffectHeat engine cycle: Heat Engine

Implementation Method 3

LP and MP MR compressors are driven by a first gas turbine and a propane compressor and a HP MR compressor is driven by a second gas turbine

Methodology Applied
Scientific EffectMechanical compression: Compression

Data Source

PatentEP3604993B1Balancing power in split mixed refrigerant liquefaction system
Publication Date: 2026.04.29 HERCULES PROJECT CO LLC
  • EP3604993B1 patent drawingFigure 1
  • EP3604993B1 patent drawingFigure 2
  • EP3604993B1 patent drawingFigure 3

AI summary

A split mixed refrigerant ("MR") natural gas liquefication system, where low-pressure ("LP") and medium pressure ("MP") MR compressors are driven by a first gas turbine and a propane compressor and a high-pressure ("HP") MR compressor is driven by a second gas turbine, is disclosed. The split MR liquefication system is configured to adjust the characteristics of the HP MR compressor to require less power when less power is available and more power when more power is available compared to the system's design point. Such adjustments allow for shifting the balance of power between the propane compressor and the HP MR compressor to improve LNG production efficiency.