Two-Section Centrifugal Compressor Axial Scroll Layout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing two-section centrifugal compressors face challenges in reducing the rotor bearing span while maintaining aerodynamic performance, leading to increased compressor weight, cost, and manageability issues due to the need for larger outer casing diameters.
Innovation Solution
The discharge duct of the first section is positioned at an end of the compressor, with the second section's discharge duct adjacent to the first section's inlet, allowing the first discharge scroll to be placed axially, thereby reducing the external casing diameter without increasing the bearing span.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the discharge scroll is placed circumferentially outside the return channel u-bend to maintain short rotor bearing span, then rotordynamic behavior is improved, but the outer casing diameter increases leading to increased weight and cost
Solution Approach 1:
The patent repositions the first discharge scroll from a circumferential location outside the return channel u-bend to an axial location at the end of the compressor. This dimensional change in scroll placement allows the bearing span to remain short while reducing the outer casing diameter, thereby decreasing compressor weight without compromising rotordynamic behavior
2Productivity
If the discharge scroll size is increased to maintain aerodynamic performance, then aerodynamic performance is improved, but the outer casing diameter increases leading to increased weight and cost
Solution Approach 1:
By relocating the first discharge scroll axially to the compressor end rather than circumferentially, the patent achieves the required aerodynamic performance with a smaller outer casing diameter. This spatial reconfiguration maintains scroll functionality while reducing overall compressor dimensions and weight
3Length of moving object
If the outer casing diameter is increased to accommodate the discharge scroll, then the bearing span can be reduced, but the compressor weight and cost increase
Solution Approach 1:
The patent resolves this contradiction by placing the first discharge scroll at an axial position at the compressor end rather than requiring increased circumferential space. This allows the bearing span to be kept short while the outer casing diameter is reduced, achieving both compact dimensions and low weight
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 significantly reduces the external casing diameter, enhances compressor manageability, and decreases weight and cost while maintaining acceptable rotordynamic behavior.
Implementation Method 1
Each section comprises at least an impeller with a plurality of blades... the working fluid is compressed by each impeller in a sequence
Data Source
Figure 1
Figure 1a
Figure 2~3
AI summary
A multi-section centrifugal compressor (1) comprises at least a first (2) and a second section (3); each section (2, 3) has an inlet duct (7, 8) and a discharge duct (9, 10), the discharge duct (9) of the first section (2) is placed in fluid communication with the inlet duct (8) of the second section (3), the second section (3) is configured to compress a fluid compressed by the first section (2); the discharge duct (10) of the second section (3) is adjacent to the inlet duct (7) of the first section (2).