Oil-balancing system for a multiple compressor sytem

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Solution Overview

Problem

Tandem compressor systems face challenges in balancing lubricant oil levels between compressors, leading to potential oil starvation and operational instability, which existing methods fail to address effectively.

Innovation Solution

An oil balancing system with an oil equalization line, valves, and a module that monitors and adjusts compressor operations to balance oil levels, includes self-learning and leak detection capabilities to prevent imbalances and isolate faulty compressors, utilizing signals from oil level detection systems to apply corrective actions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a carefully designed and calibrated orifice in the suction manifold is used to achieve a desired pressure differential for fluid flow, then oil levels can be balanced, but the system complexity increases and requires precise calibration

Engineering Contradiction:
Improveoil level balancingVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs feedback mechanisms through sensors that continuously monitor oil levels in each compressor and automatically adjust the equalization process. The control system receives oil level signals from multiple compressors and dynamically controls valve operations to maintain balanced oil levels, eliminating the need for manual calibration of orifices while ensuring reliable oil distribution.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system enables self-service through automatic oil equalization where the control system autonomously monitors oil levels and operates equalization valves without external intervention. The compressors themselves participate in the equalization process by allowing oil to flow from higher to lower level compressors under controlled conditions, making the system self-regulating and eliminating complex calibrated orifices.

Inventive Principle:
Principle #25Self-service

2Reliability

If oil levels are not properly balanced between compressors, then operational stability is maintained, but oil starvation occurs leading to adverse effects

Engineering Contradiction:
Improveoperational stabilityVSAvoidoil starvation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by proactively equalizing oil levels before critical imbalances occur. The control system continuously monitors oil levels and initiates equalization operations when minor imbalances are detected, preventing oil starvation conditions before they affect compressor operation. This preventive approach maintains operational stability by ensuring adequate oil levels are preserved in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The feedback mechanism continuously monitors oil levels in each compressor and automatically triggers equalization operations when imbalances are detected. The system receives real-time oil level signals and dynamically adjusts valve operations to prevent oil starvation, ensuring that adverse effects are avoided through continuous monitoring and automatic corrective action.

Inventive Principle:
Principle #23Feedback

3Device complexity

If manual monitoring and adjustment of oil levels is performed, then system complexity is reduced, but productivity and response time decrease

Engineering Contradiction:
Improvesystem complexityVSAvoidresponse time
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system implements self-service through automatic oil level monitoring and equalization. Sensors continuously track oil levels in each compressor, and the control system autonomously operates equalization valves without requiring manual intervention. This automation maintains simple system architecture while dramatically improving response time and productivity by instantly detecting and correcting oil imbalances as they occur.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical monitoring and adjustment operations with automated electronic sensing and control systems. Optical or electrical sensors substitute for manual visual inspection, and electronic control valves replace manual valve adjustment. This substitution maintains low system complexity while enhancing productivity through faster, more precise response to oil level variations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3334940B1Oil-balancing system for a multiple compressor sytem
Publication Date: 2020.06.24 EMERSON CLIMATE TECHNOLOGIES INC
  • EP3334940B1 patent drawingFigure 1
  • EP3334940B1 patent drawingFigure 2
  • EP3334940B1 patent drawingFigure 3

AI summary

An oil balancing system for a multiple compressor system is provided. The oil balancing system includes an oil equalization line disposed between a first compressor and a second compressor. A first solenoid valve is provided in the oil equalization line. A first signal corresponds to a first oil level in the first compressor. A second signal corresponds to a second oil level in the second compressor. An oil balancing module uses the first signal and the second signal to diagnose an oil imbalance between the first compressor and the second compressor, and applies corrective action, whereby the corrective action includes sending control signals to operate at least one of the first compressor, the second compressor, or the first solenoid valve in a way that eliminates the oil imbalance.