Parallel Double Flow Compressor for LNG Refrigerant Debottlenecking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquefied natural gas (LNG) production is often limited by the capacity of refrigerant compressors, particularly when operating near surge or stonewall conditions, and by the available driver power, leading to suboptimal design and efficiency in LNG plants.
Innovation Solution
A double flow compressor is used in parallel with the primary compression circuit, featuring distinct compressor stages and impeller geometries to manage different pressure and flow conditions, allowing for efficient debottlenecking of the compression system and improved LNG production capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single dynamic compressor is used in the refrigerant compression system, then the system is simple in structure, but the LNG production rate is limited when the compressor operates near surge or stonewall conditions
Solution Approach 1:
The refrigerant compression system is segmented into multiple parallel compression circuits, each with its own dynamic compressor. This allows the system to handle higher total refrigerant flow rates while maintaining optimal operating conditions for each individual compressor, thereby increasing LNG production without excessive complexity
Solution Approach 2:
Multiple compression circuits are merged into a unified refrigeration system that shares common heat exchangers and process integration. This combining approach achieves high productivity through parallel compression while maintaining relative structural simplicity through shared components
2Stress or pressure
If an additional dynamic compressor is added at the discharge of the primary compressor to build more head, then the compressor head capability is improved, but the system complexity increases and the solution is limited when the compressor is operating close to stonewall
Solution Approach 1:
The compression system is divided into parallel circuits that independently provide head capability. Each compressor in the parallel arrangement can be optimized for specific head requirements, eliminating the need for complex series arrangements or additional compression stages
3Reliability
If the compressor operating point is maintained away from surge and stonewall conditions, then the compressor operates in a stable and efficient manner, but the LNG production rate is limited by the maximum head and flow rate capabilities
Solution Approach 1:
The refrigerant flow is divided into multiple parallel compression circuits, allowing each compressor to operate independently within its stable efficiency range while the aggregate system delivers high production rates. This segmentation enables both reliability and productivity simultaneously
Solution Approach 2:
The parallel compression system provides dynamic flexibility to adjust individual compressor operating points based on varying plant conditions, ensuring each compressor remains within its optimal stable operating range while adapting total capacity to meet production demands
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 configuration enhances LNG production capacity by up to 10% and improves system efficiency, reducing capital costs and operational complexity while accommodating varying operating conditions.
Implementation Method 1
a compression system comprising: a compressor configured to compress a low pressure refrigerant stream to a medium pressure to produce a medium pressure refrigerant stream
Implementation Method 2
at least one heat exchanger configured to cool the hydrocarbon fluid by indirect heat exchange against the refrigerant
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system and method is provided for increasing the capacity and efficiency of natural gas liquefaction processes by debottlenecking the refrigerant compression system. A secondary compression circuit comprising at least one double flow compressor is provided in parallel fluid flow communication with at least a portion of a primary compression circuit.