Rotary Compressor Solenoid Valve for Pressure Equalization and Restart
Solution Overview
Problem
High-side compressors, such as rotary compressors, face difficulties in starting when there is a significant pressure differential between the discharge and suction sides, leading to potential failure in restarting due to unequalized pressure.
Innovation Solution
A solenoid valve is electrically coupled in series with an overload-protection switch to interrupt power, allowing pressure equalization between the suction and discharge sides by opening when an overload occurs, ensuring the compressor can restart once the pressure differential is reduced.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the compressor operates with high pressure differential between discharge and suction sides, then the compressor can maintain high discharge pressure for effective cooling, but the compressor cannot restart when the pressure differential exceeds the starting capability
Solution Approach 1:
The solenoid valve is configured to automatically open when the compressor stops running, equalizing pressure between discharge and suction sides before restart. This preliminary pressure equalization action prevents the pressure differential from blocking compressor restart, thereby maintaining reliability while allowing high discharge pressure operation.
2Reliability
If a pressure equalization valve is added to enable restart, then the compressor can restart after shutdown, but the system complexity increases with additional components
Solution Approach 1:
The solenoid valve is integrated into the existing compressor assembly, combining the pressure equalization function with the existing motor and electrical circuitry. The solenoid valve shares the same housing and electrical power source as the compressor motor, reducing overall system complexity while maintaining restart capability.
Solution Approach 2:
The solenoid valve serves multiple functions: it acts as a pressure equalization valve during shutdown and as a normal flow valve during operation. This multi-functionality reduces the need for separate dedicated pressure equalization components, thereby reducing system complexity while maintaining reliability.
3Productivity
If the solenoid valve remains closed during operation, then compressed fluid can be discharged effectively, but pressure cannot equalize if the compressor stops
Solution Approach 1:
The solenoid valve transitions from a static closed position during operation to an open position during shutdown. This dynamic behavior allows the valve to maintain discharge efficiency during operation while enabling pressure equalization and restart capability when the compressor stops, resolving the contradiction between productivity and reliability.
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 the compressor to safely shut down and restart by equalizing pressure, preventing damage and ensuring reliable operation by reducing the pressure differential, thus overcoming the challenge of high initial pressure differentials.
Implementation Method 1
A solenoid valve is fluidly coupled between the compression chamber and a location upstream of the suction side
Data Source
AI summary
A rotary compressor system includes a compressor housing that includes a compressor motor that draws in fluid from a suction side. The fluid is compressed within a compression chamber and discharged through a discharge side. The compression chamber is disposed between the suction side and the discharge side. An overload-protection switch is electrically coupled in series with the compressor motor and is adapted to cut power to the compressor motor responsive to an overload event. A solenoid valve is fluidly coupled between the compression chamber and a location upstream of the suction side and is electrically coupled in series with the overload-protection switch. An interruption of electrical current to the compressor motor also interrupts electrical current to the solenoid valve, which opens the solenoid valve to equalize pressure between the suction side and the discharge side.