Parallel Scroll Compressors With Mixed Volume Indexes for Seasonal Efficiency
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Solution Overview
Problem
Fixed volume index compressors, such as scroll and screw compressors, face efficiency challenges due to fixed efficiency curves that do not adapt well to varying operating temperatures or part load conditions, especially across seasonal changes.
Innovation Solution
A compressor arrangement with multiple compressors of different volume indexes, optimized for either air cooling or water cooling, is used, where a controller selectively operates these compressors based on temperature ranges to maximize isentropic efficiency and Seasonal Energy Efficiency Ratio (SEER) and Integrated Part Load Value (IPLV) by determining the most efficient compressors to use based on demand load and condensing temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single fixed volume index compressor is used, then the device complexity is reduced, but the isentropic efficiency deteriorates under varying temperature and load conditions
Solution Approach 1:
The compressor system is segmented into multiple compressors with different volume indexes (e.g., first compressor with higher volume index, second compressor with lower volume index). Each compressor is optimized for specific operating conditions, allowing the system to segment the operating range and select the appropriate compressor for current temperature and load conditions, thereby maintaining high isentropic efficiency without excessive complexity
Solution Approach 2:
The system dynamically selects which compressor to operate based on real-time operating conditions such as condensing temperature and load demand. The controller adjusts the operating state by switching between compressors with different volume indexes, making the system adaptable to varying conditions while maintaining optimal efficiency
2Loss of energy
If variable geometry compressors are used to adapt to different operating conditions, then the isentropic efficiency is improved, but the device complexity and cost increase due to additional parts
Solution Approach 1:
Instead of making a single compressor variable geometry, the system segments the compression function across multiple fixed-volume-index compressors. Each compressor maintains a simple, fixed structure optimized for a specific volume index, while the system achieves adaptability by selecting among these segmented components based on operating conditions
Solution Approach 2:
The system uses multiple copies of compressors with different volume indexes rather than modifying a single compressor design. This approach achieves the effect of variable geometry through parallel fixed designs, avoiding the complexity of actuators and adjustment mechanisms while maintaining the ability to adapt to different operating conditions
3Adaptability or versatility
If compressors with different volume indexes are used, then the adaptability to different temperature ranges is improved, but the device complexity increases
Solution Approach 1:
Each compressor in the system has a specific local quality optimized for a particular volume index and corresponding temperature range. The first compressor is optimized for higher volume index operations, while the second compressor is optimized for lower volume index operations, allowing each component to have specialized characteristics matched to its intended operating conditions
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 approach enhances efficiency by using the most efficient compressors for specific temperature conditions, resulting in improved performance across varying loads and seasons, outperforming systems with uniformly optimized compressors.
Implementation Method 1
Such compressors trap a fixed volume of fluid (e.g. typically a pure gas state) on the suction side and increase the pressure by reducing the volume occupied by the fluid in a compression chamber, thereby raising the fluid pressure on the discharge side.
Implementation Method 2
The volume index is the ratio of the volume of suction gas in the compression chamber cavity (when it closes) to the volume of gas in the compressor chamber cavity (when it opens). This Volume index (Vi) provides for the internal pressure ratio for the compressor.
Data Source
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AI summary
A plurality of scroll compressors with different fixed volume indexes are connected in fluid parallel circuit and configured to selectively operate to maximize isentropic efficiency at different condensing temperatures. Different quantities of scroll compressors of different volume indexes may be selected based upon typical climate or geographic location environmental conditions to attempt to maximize efficiency. A controller may selectively operate different combinations of the compressors of different volume indexes bases up load demands and condensing temperature conditions, which may be determined in a variety of ways.