Compressor Oil Balancing Control in Multi-Unit Air Conditioners
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Solution Overview
Problem
In air conditioners with multiple compressors, oil imbalance occurs due to varying refrigerant discharge amounts, leading to inefficient oil collection and potential system malfunction.
Innovation Solution
An air conditioner system that includes oil level sensors to detect oil levels in each compressor and actively controls the oil return passages to balance oil distribution between compressors, using solenoid or electronic expansion valves to adjust refrigerant flow and facilitate quicker oil collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple compressors with different capacities are used to discharge different amounts of refrigerant, then the cooling/heating capacity is improved, but the oil distribution becomes imbalanced leading to compressor breakdown
Solution Approach 1:
The patent employs oil level sensors to continuously monitor oil levels in each compressor and uses control units to adjust the operation of opening/closing valves based on the detected oil levels. This feedback mechanism ensures that oil is dynamically redistributed to maintain balanced oil levels across all compressors, preventing breakdown while allowing different compressors to operate at different capacities.
Solution Approach 2:
The system enables compressors to self-regulate their oil levels through the control unit that automatically adjusts valve operations based on real-time oil level detection. Each compressor effectively serves itself by having its oil level independently monitored and adjusted, eliminating the need for manual intervention and ensuring continuous reliable operation.
2Reliability
If oil separators are connected to each compressor outlet to collect oil, then oil separation is improved, but the oil amount in each compressor becomes non-uniform
Solution Approach 1:
The patent merges the oil collection functions of multiple oil separators into a unified oil redistribution system. The control unit coordinates the opening and closing of valves to allow oil to flow between compressors through shared piping, effectively combining the separate oil collection efforts into a collaborative system that achieves both separation and uniform distribution.
Solution Approach 2:
The system applies local quality control by allowing different oil flow conditions in different parts of the system. The control unit selectively opens or closes specific valves based on the oil level status of each individual compressor, creating localized oil flow paths that adapt to the specific needs of each compressor while maintaining overall system balance.
3Device complexity
If conventional oil collection methods are used without active control, then the system complexity is reduced, but the oil balance control speed is slow and insufficient
Solution Approach 1:
The patent replaces passive mechanical oil collection mechanisms with an actively controlled system using electronic sensors and solenoid valves. The oil level sensors continuously detect oil levels and transmit signals to the control unit, which then electronically actuates the valves to adjust oil flow. This substitution of mechanical passive systems with sensor-controlled active systems dramatically increases the speed and precision of oil balance control.
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 enables active and rapid oil balance control, improving compressor operation reliability by ensuring uniform oil levels across compressors, thus preventing system malfunctions.
Implementation Method 1
Each of a uniform oil pipe and the third compressor is provided with oil level sensors for use in sensing an oil surface level of each of the compressors
Implementation Method 2
the solenoid or electronic expansion valves to adjust refrigerant flow and facilitate quicker oil collection
Implementation Method 3
the solenoid or electronic expansion valves to adjust refrigerant flow and facilitate quicker oil collection
Data Source
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AI summary
An air conditioner and a method of controlling the same are provided. An air conditioner includes a compressor, a main suction passage guiding suction of a refrigerant into the compressor, an oil separator connected to the compressor, the oil separator separating oil from the refrigerant discharged from the compressor, an oil level sensor disposed in the compressor to detect whether the compressor lacks oil, a return passage for collecting the oil separated from the oil separator into the compressor, a distribution return passage branched from the return passage, the distribution return passage being connected to the main suction passage, and a valve disposed in each of the return passage and the distribution return passage.