Variable-Profile Screw Rotors for Low-Leakage Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary screw compressors face inefficiencies due to fixed rotor profiles that lead to increased leakage, higher radial loads, and suboptimal compression performance, particularly at higher speeds.
Innovation Solution
Implementing rotors with variable profiles, such as conical, ogive, or complex curved configurations, along with variable helix patterns and double helix designs, to optimize the outer diameter and helical lead along the axial length, reducing leakage and enhancing compression efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If constant rotor profiles and diameters are used, then manufacturing is simpler, but compression efficiency and performance are limited
Solution Approach 1:
The patent applies dynamics by transitioning from static constant-profile rotors to dynamic variable-profile rotors where the helix angle and outer diameter change along the axial length. This allows the rotor geometry to adapt during rotation, optimizing compression efficiency at different positions along the rotor while maintaining manufacturability through systematic variation patterns.
Solution Approach 2:
The patent implements parameter changes by varying the helix angle and outer diameter parameters along the axial length of the rotors. Specifically, the helix angle transitions from an initial value to a final value, and the outer diameter varies according to defined functions, thereby optimizing compression performance without excessive manufacturing complexity.
2Device complexity
If constant rotor profiles are used, then structural simplicity is maintained, but radial leakage is increased
Solution Approach 1:
The patent applies local quality by making different axial sections of the rotor have different properties - specifically, varying helix angles and outer diameters at different positions along the axial length. This localized variation optimizes the sealing characteristics at each section, reducing radial leakage while maintaining overall structural coherence.
3Productivity
If variable helical profiles and outer diameters are used, then compression efficiency is enhanced, but rotor design and manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the rotor into multiple axial sections, each with specific helix angle and outer diameter characteristics. The rotor is segmented into regions with different compression requirements, allowing optimized performance in each section while managing overall design complexity through modular variation patterns.
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 variable profiles and helix designs result in lower radial leakage, faster compression, higher efficiency, and improved performance at higher speeds, with reduced port losses and increased internal pressure ratios.
Implementation Method 1
The variable profiles and helix designs result in lower radial leakage
Implementation Method 2
During rotation, the intermeshing male and female rotors form cells of varying sizes to first receive the inlet fluid and then compress, thus increasing the pressure of, the fluid as it moves toward the outlet
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A screw compressor or expander is provided, comprising: a male rotor (210) having a first axial length extending from an inlet portion to an outlet portion and a set of lobes (212) with a variable profile extending along the first axial length; and a female rotor (214) having a second axial length extending from the inlet portion to the outlet portion and a set of grooves (216) with a variable profile extending along the second axial length, the set of grooves mating with the set of lobes. At least a portion of the male rotor (210) and the female rotor (212) each have a non-cylindrical configuration with a non-constant outer diameter, and the male rotor and the female rotor have an ogive configuration where the outer diameter of each respective rotor decreases in an arc along at least a portion of the respective axial length from the inlet portion to the outlet portion.