Variable Orifice Refrigerant Flow Control for Compressor Motor Cooling
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Solution Overview
Problem
Current compressor systems face inefficiencies due to recirculation and windage losses caused by fixed-size holes allowing compressed gas to cool compressor motor components, which vary with operation speed and pressure, leading to inadequate cooling demands.
Innovation Solution
A variable flow control device is implemented between the volute housing and the compressor motor housing to meter refrigerant flow based on compressor motor needs, reducing recirculation and windage losses while meeting cooling requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fixed-size holes are used to allow compressed gas to cool compressor components, then cooling is provided to motor and bearings, but recirculation and windage losses increase reducing efficiency
Solution Approach 1:
The patent applies the dynamics principle by replacing fixed-size holes with a variable flow control device that can dynamically adjust the flow area. This allows the system to adapt the cooling gas flow rate to match actual cooling demands at different operating conditions, preventing excessive flow that causes recirculation and windage losses while ensuring adequate cooling when needed.
Solution Approach 2:
The patent implements parameter changes by modifying the flow area parameter of the cooling gas passage from a fixed value to a variable value. The variable flow control device changes the flow area based on operating parameters such as compressor speed and discharge pressure, optimizing the balance between cooling effectiveness and energy efficiency.
2Device complexity
If fixed-size holes are used for cooling, then simple structure is maintained, but cooling demands varying with speed and pressure cannot be met
Solution Approach 1:
The variable flow control device introduces dynamic adjustability to the cooling system, allowing it to respond to varying cooling demands caused by changes in compressor speed and discharge pressure. This dynamic capability enables the system to adapt to different operating conditions while maintaining a relatively simple overall structure.
3Temperature
If compressed gas flow is increased to meet cooling demands, then cooling effectiveness improves, but recirculation losses increase reducing efficiency
Solution Approach 1:
The variable flow control device functions as a feedback-controlled system that adjusts the cooling gas flow rate based on actual cooling needs. By monitoring operating conditions and regulating flow accordingly, the system achieves effective cooling without excessive gas flow that would cause recirculation losses and reduce compressor efficiency.
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 improves compressor efficiency by dynamically controlling refrigerant flow, ensuring optimal cooling and reducing energy losses associated with recirculation and windage, thus enhancing overall system performance.
Implementation Method 1
A variable flow control device disposed between a volute housing and a compressor motor housing can improve compressor efficiency by metering the amount of coolant provided
Implementation Method 2
Compressor parts, particularly the motor, shaft, and bearings such as magnetic bearings require cooling while the compressor is in operation. The cooling may be provided, for example, by a flow of compressed gas discharged from the compressor.
Implementation Method 3
The cooling may be provided, for example, by a flow of compressed gas discharged from the compressor
Data Source
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Figure 3A
AI summary
A variable orifice flow device controls the flow of refrigerant into a compressor motor housing in a compressor. The variable orifice flow device may include, for example, an electronic expansion valve, a thermal expansion valve, or a shuttling valve controlling the flow of refrigerant into a compressor motor housing. One or more flows of refrigerant may be through a fixed orifice, a valve seat of the variable orifice flow device, or leakage through a seal of the compressor motor housing, providing a baseline refrigerant flow to the inside of the compressor motor housing in addition to the flow through the variable orifice flow device.