Screw Compressor Bypass Port for Variable Volume Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Screw compressors in refrigeration systems face inefficiencies due to fixed volume ratios that do not adapt to varying load conditions or ambient temperatures, leading to suboptimal performance and energy inefficiency.
Innovation Solution
A system that adjusts the volume ratio of screw compressors using a valve to control vapor flow, allowing for part-load operation by enabling or disabling the flow of vapor through ports, thereby optimizing performance across different conditions without the need for costly slide valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed volume ratio compressor is used, then the compressor structure is simple and cost-effective, but the compressor efficiency deteriorates under varying load conditions and ambient temperatures
Solution Approach 1:
The patent applies the dynamics principle by introducing a variable volume ratio mechanism that allows the compressor to adapt its compression characteristics based on operating conditions. The volume ratio is varied by controlling the position of a discharge port relative to the rotating elements, enabling the compressor to optimize efficiency across different load conditions and ambient temperatures while maintaining a relatively simple overall structure.
2Loss of energy
If the volume ratio is reduced for part-load operation, then the energy efficiency improves, but the compression ratio control becomes more complex
Solution Approach 1:
The patent employs pneumatic principles to control the volume ratio variation. A bypass channel is introduced that allows a portion of the compressed gas to bypass the full compression cycle and mix with the main discharge flow. By controlling the bypass flow rate, the effective volume ratio is adjusted without requiring complex mechanical adjustments to the compression mechanism itself, thus improving energy efficiency with moderate complexity.
3Adaptability or versatility
If a bypass mechanism is added to vary volume ratio, then the adaptability to different operating conditions improves, but the device complexity increases
Solution Approach 1:
The patent merges the bypass mechanism with the existing compressor structure by integrating the bypass channel into the housing and combining it with the discharge port system. The bypass flow merges with the main compression discharge, allowing volume ratio variation without adding separate, independent control systems. This integration approach enhances adaptability to different operating conditions while minimizing the increase in overall device complexity.
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 solution improves energy efficiency by allowing the compressor to maintain optimal performance at part-load conditions, reducing energy consumption and extending the lifespan of the compressor.
Implementation Method 1
two tightly-meshing, rotating, helically lobed rotors that alternately draw gas into the threads and compress the gas to a higher pressure
Implementation Method 2
The valve is positionable using the pressure vapor entering the intake passage and the pressure of vapor discharged from the discharge passage
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system is provided for adjusting the volume ratio of a screw compressor. The system can use a port in a rotor cylinder to bypass vapor from the compression chamber to the discharge passage of the compressor. A valve can be used to open or close the port to obtain different volume ratios in the compressor.