Multiple-Compressor Oil Distribution Using Variable Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multiple-compressor systems, maintaining a sufficient oil level across compressors is challenging due to variations in compressor sizes and piping configurations, making equal oil distribution difficult.
Innovation Solution
The method involves supplying refrigerant gas and oil through a common supply line to compressors connected in series, with an oil flow conduit between adjacent compressors to facilitate oil distribution by regulating compressor speeds to maintain pressure differentials, and using inlet supply lines to create pressure differentials that allow oil to flow from higher-pressure to lower-pressure compressors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If compressors are connected in parallel with common supply line, then system capacity is increased, but oil distribution becomes uneven due to variations in compressor sizes and piping configurations
Solution Approach 1:
The patent applies local quality by providing each compressor with individually sized inlet supply lines that are specifically dimensioned to compensate for that compressor's unique characteristics (size, location, piping configuration). This ensures each compressor receives the appropriate amount of oil despite variations in the parallel arrangement, rather than using a uniform distribution approach.
2Reliability
If oil is distributed from one compressor to another, then oil level is maintained in receiving compressor, but oil availability at supplying compressor decreases
Solution Approach 1:
The patent segments the oil supply system by providing separate inlet supply lines from the common supply line to each compressor. This segmentation allows each compressor to independently receive oil directly from the common supply, eliminating the need for inter-compressor oil transfer and ensuring that oil distribution does not compromise the supplying compressor's oil availability.
3Ease of operation
If compressor speeds are varied to control pressure differentials, then oil flow direction is controlled, but system complexity increases
Solution Approach 1:
The patent utilizes parameter changes by varying the operating speeds of compressors to control pressure differentials, which in turn controls oil flow directions. By adjusting speed parameters, the system can dynamically control whether compressors operate as oil suppliers or receivers, providing flexible oil distribution control through a relatively simple mechanism.
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 ensures consistent oil distribution across compressors by controlling compressor speeds and pressure differentials, maintaining a higher oil sump pressure in lead compressors to facilitate oil flow to non-lead compressors, thereby addressing the challenge of varying compressor configurations.
Implementation Method 1
The oil flow conduit is configured to move oil from a compressor with a relatively higher pressure to a compressor with a relatively lower pressure
Implementation Method 2
supplying, via a common supply line, refrigerant gas and oil to a plurality of compressors coupled in series
Data Source
AI summary
A method of operating a multiple-compressor refrigeration system is provided. This method includes the steps of supplying, via a common supply line, refrigerant gas and oil to a plurality of compressors coupled in series, and attaching an oil flow conduit between adjacent compressors of the plurality of compressors. The oil flow conduit is configured to move oil from a compressor with a relatively higher pressure to a compressor with a relatively lower pressure. The method further includes controlling the pressure for each of the plurality of compressors by regulating a speed at which each of the plurality of compressors operates in order to maintain a pressure differential between the adjacent compressors to facilitate the flow of oil from the compressor with the relatively higher pressure to the compressor with the relatively lower pressure.