Direct drive refrigerant screw compressor with refrigerant lubricated bearings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional refrigeration systems using oil lubrication in screw compressors face issues with reduced oil viscosity when mixed with refrigerant, leading to increased wear on moving components, inefficient heat transfer, and the need for additional equipment for oil separation, which complicates the system and reduces capacity.
Innovation Solution
The system employs pure refrigerant as a lubricant, injected directly into the compressor's bearing chambers and rotors, eliminating the need for oil separation equipment by using refrigerant lubrication ports and flow control orifices to distribute and drain the refrigerant effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oil lubrication is used in screw compressors, then bearing lubrication is effective, but oil viscosity decreases when mixed with refrigerant causing increased wear and requiring additional separation equipment
Solution Approach 1:
The patent changes the lubricant parameter from oil to refrigerant, fundamentally altering the lubrication approach. The refrigerant is injected into bearing chambers at controlled rates through injection ports, maintaining lubrication effectiveness while eliminating the need for oil separation equipment since the refrigerant circulates naturally through the system
Solution Approach 2:
The patent extracts and eliminates the oil separation equipment from the system by removing oil as the lubricant entirely. By using refrigerant as the lubricant instead, the system no longer requires separate oil separation components, simplifying the overall system architecture
2Ease of operation
If oil is used for bearing lubrication, then lubrication is provided, but additional equipment for oil separation is required which complicates the system
Solution Approach 1:
The refrigerant serves multiple functions simultaneously: it acts as both the working fluid for heat transfer and the lubricant for bearing protection. This multi-functionality eliminates the need for separate oil lubrication systems and oil separation equipment, reducing system complexity while maintaining ease of operation
Solution Approach 2:
The patent merges the lubrication function with the refrigeration cycle by using the same refrigerant fluid for both purposes. The refrigerant is injected into bearing chambers and then returns to the refrigeration cycle, combining what were previously separate systems into one integrated approach
3Reliability
If oil lubrication is used, then bearing support is provided, but heat transfer efficiency decreases and wear increases
Solution Approach 1:
The patent changes the lubricant parameter from oil to refrigerant, which fundamentally improves heat transfer efficiency. The refrigerant, being the working fluid of the system, has superior heat transfer properties compared to oil, eliminating the energy loss associated with oil lubrication while still providing adequate component protection through controlled injection
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 reduces wear on components, enhances heat transfer efficiency, and simplifies the system by eliminating the need for oil separation equipment, resulting in improved performance and reduced costs.
Implementation Method 1
a working fluid disposed within each of the plurality of bearing chambers for providing lubrication to the plurality of bearing packs
Implementation Method 2
a plurality of bearing lubrication ports extending through the housing and into each of the plurality of bearing chambers, and configured for injecting the working fluid into each of the plurality of bearing chambers
Data Source
AI summary
Disclosed is a direct-drive refrigerant screw compressor, having: a housing; a compression chamber in the housing; a pair of rotors, each rotor of the pair of rotors being rotationally disposed in the compression chamber and including an outer surface with a screw-geared profile; wherein, for each rotor, the compressor includes: a plurality of bearing packs disposed within a respective plurality of bearing chambers; a working fluid disposed within each of the plurality of bearing chambers, the working fluid providing oil-free lubrication to the plurality of bearing packs; a plurality of bearing lubrication ports extending through the housing and into each of the plurality of bearing chambers, and configured for injecting the working fluid into each of the plurality of bearing chambers when the compressor is running.