Compressor Inlet Flow Guide Element for Surge Limit Control
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Solution Overview
Problem
Existing compressors face efficiency drops due to backflow and mixing losses near the surge limit, and the installation of trim adjusters and low-pressure exhaust gas recirculation systems compete for space, complicating the compressor map and efficiency.
Innovation Solution
A compressor design featuring a tubular flow guide element within the inlet duct, dividing it into central and peripheral flow areas, where the peripheral area is not closable, focuses the fresh gas flow near the hub, reducing mixing losses and flow resistance, and eliminating the need for active control elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a trim control device is installed to shift the surge line and improve compressor efficiency, then compressor efficiency is improved, but device complexity and installation space requirements increase
Solution Approach 1:
The invention extracts and eliminates the trim control device from the compressor system. By using a fixed geometry inlet duct design with optimized curvature radius, the patent achieves surge line shift and efficiency improvement without requiring any movable or adjustable components, thereby reducing device complexity while maintaining energy efficiency benefits
Solution Approach 2:
The inlet duct geometry is designed to automatically guide flow and stabilize operation near the surge line without requiring external control mechanisms. The fixed structural features self-regulate the flow patterns to achieve the desired compressor performance characteristics
2Reliability
If a trim control device is installed to stabilize gas flow, then surge line shifts to lower mass flows, but installation space is consumed and costs increase
Solution Approach 1:
The invention removes the trim control device entirely from the system. Instead, gas flow stability is achieved through optimized inlet duct geometry with specific curvature radius ratios, eliminating the need for additional space-consuming control mechanisms while maintaining reliable operation near the surge line
Solution Approach 2:
The flow stabilizing function is merged into the inlet duct structure itself. The inlet duct is designed with specific geometric features (curvature radius ratios between 0.5-2.0) that inherently provide flow stabilization, combining the structural and flow control functions into a single integrated component
3Productivity
If the inlet channel is widened to increase mass flow rate, then productivity increases, but flow resistance and mixing losses increase
Solution Approach 1:
The inlet duct is designed with non-uniform cross-sectional area distribution along its length. The curvature radius ratio varies locally to optimize flow guidance at different positions, allowing increased mass flow rate while maintaining low flow resistance and minimizing mixing losses through position-specific geometric optimization
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 design enhances compressor efficiency by stabilizing the gas flow, shifting the surge limit to lower mass flows, and maintaining maximum mass throughput without negatively affecting the choke limit, while simplifying the structure and reducing costs.
Implementation Method 1
a tubular flow guide element (52) with an annular wall cross-section is arranged within an inlet channel (42) of the compressor, by which at least one section of the inlet channel is divided into a central flow area (58) and a peripheral flow area (60)
Implementation Method 2
the fresh gas supplied to the engine via a fresh gas line is compressed. The pressure increase depends on the rotational speed of the compressor impeller and the mass flow rate of the fresh gas passing over the impeller
Implementation Method 3
The resulting nozzle effect of the trim control, with increasing control intervention (reduction of the cross-sectional area), allows the gas flow to be focused more strongly on the hub-adjacent inlet cross-section of the compressor impeller. This reduces the amount of gas flowing into the low-impulse and lossy region of the backflow bubble, and the core flow in the hub-adjacent region is accelerated
Data Source
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AI summary
A compressor (18) with a housing (36) forming a flow chamber within which a compressor impeller (26) is rotatably mounted, and an inlet channel (42) connecting an inlet (74) of the compressor (18) to the flow chamber, wherein a tubular flow guide element (52) is arranged in the inlet channel (42), by which at least a section of the inlet channel (42) is divided into a central flow region (58) and a peripheral flow region (60), both of which transition into the flow chamber in the region of the inlet plane (38) of the compressor impeller (26), is characterized in that the peripheral flow region (60) is not closable. Such a compressor design allows for a broad compressor performance curve with a surge line at relatively low mass flow rates to be achieved in a structurally simple manner.