Direct-Coupled Steam Turbine Compression Train to Eliminate Gearbox
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Solution Overview
Problem
Current ethylene charge gas compression trains are bulky, costly, and unreliable due to the presence of a gearbox, which affects the overall system's footprint and reliability.
Innovation Solution
Directly coupling a steam turbine to a group of low-pressure compressors and integrating them in a common casing, eliminating the need for a gearbox and optimizing compressor design with unshrouded and shrouded impellers for higher rotational speeds, thereby reducing the footprint and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a gearbox is used to couple the steam turbine to the compressors, then the rotation speed can be increased to 5000 RPM, but the footprint, cost, and reliability of the system deteriorate
Solution Approach 1:
The patent removes the gearbox from the system entirely, directly coupling the steam turbine to the compressors. This extraction of the intermediate mechanical transmission component eliminates the associated footprint, cost, and reliability issues while maintaining the high rotation speed capability through direct drive design
Solution Approach 2:
The patent eliminates the gearbox as an intermediary mechanical component between the steam turbine and compressors. By removing this intermediate element, the system achieves direct coupling that reduces complexity and improves reliability while maintaining rotational speed through optimized compressor blade design
2Speed
If a gearbox is used to transmit rotation to compressors, then the rotation speed can be increased, but the reliability of the system deteriorates
Solution Approach 1:
The gearbox is completely removed from the power transmission chain. The steam turbine is directly coupled to the compressor rotors, eliminating the gearbox's potential failure points and reducing maintenance requirements, thereby improving overall system reliability while achieving high rotation speeds through direct drive
Solution Approach 2:
The mechanical gearbox transmission system is replaced with a direct mechanical coupling system. This substitution eliminates the complex gear meshing and lubrication systems that compromise reliability, while maintaining high rotation speed capability through optimized rotor and blade design
3Productivity
If a double flow compressor and two-section compressors are used, then the compression requirements are met, but the footprint of the system increases
Solution Approach 1:
The patent merges multiple compression functions into a single integrated compressor unit with a common casing. The first compressor and the two-section compressor (second and third compressors) are combined in one housing, sharing common structural elements and reducing the overall footprint while maintaining the required compression capabilities across all stages
4Productivity
If unshrouded and shrouded impellers are used, then the rotational efficiency is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent applies different impeller designs (unshrouded and shrouded) to different compressor stages based on local performance requirements. Unshrouded impellers are used where maximum efficiency is needed, while shrouded impellers are applied where structural stability and ease of manufacturing are prioritized, optimizing the balance between performance and manufacturability
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 solution results in a more compact, reliable, and cost-effective ethylene charge gas compression train with improved rotational efficiency and reduced space consumption, eliminating the need for a gearbox and enhancing system reliability.
Implementation Method 1
a steam turbine (2), a first compressor (60), a second compressor (40) and a third compressor (50) on the same shaft line
Implementation Method 2
The first compressor (60) receives an input gas flow at a first input pressure (e.g., 1.5-2 bar) and outputs a first output flow at a first output pressure (e.g., 2.5-4 bar)
Data Source
Figure 1~2
AI summary
A charge gas compression train (1) for ethylene,comprising on the same shaft line a steam turbine (2) and a first compressor (60) comprising a first group of compression stages(3), a second group of compression stages(4) and a third group of compression stages(5), the first group of compression stages(3) comprising an outlet (3B) configured to be connected to a first intercooler inlet (10A), the second group of compression stages(4) comprising a second compressor inlet (4A) configured to be connected to a first intercooler outlet (10B), the second group of compression stages (4) comprising a second compressor outlet (4B) configured to be connected to a second intercooler inlet (11A), the third group of compression stages(5) comprising a third compressor inlet (5A) configured to be connected to a second intercooler outlet (11B);the first (3), the second (4) and the third group of compression stages(5) being integrated in a first common casing (20) and operating at the same rotation speed of the steam turbine (2);the first compressor (60) comprising a plurality of unshrouded and shrouded impellers, wherein at least an unshrouded impeller (50) is positioned upstream to at least a shrouded impeller (51).