Rotary Compressor Bypass Device for Rapid Pressure Equalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotary compressors with fixed motor speeds at 50 Hz or 60 Hz experience frequent start-stop cycles due to room temperature control, leading to unsatisfactory comfort and degradation of Air-Conditioning Performance Factor (APF) due to mismatched housing and suction pressures.
Innovation Solution
Incorporation of a bypass device with a bypass hole and valve in the rotary compressor, which equalizes pressure by allowing gas from the housing to flow into the suction pipe when the motor is stopped, utilizing a spring-actuated mechanism to open the bypass hole based on pressure differences, thereby reducing restarting time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the motor is stopped frequently for room temperature control, then the air conditioner can maintain comfortable temperatures, but the housing pressure cannot equalize with suction pressure quickly enough, causing motor startup failure and degrading APF
Solution Approach 1:
The bypass valve opens automatically when the motor stops, allowing housing high-pressure gas to flow through the bypass hole to the suction pipe before the motor needs to restart. This preliminary pressure equalization action ensures that when the motor attempts to restart, the housing pressure has already equalized with suction pressure, preventing startup failure and reducing restart time to 30% of conventional systems
Solution Approach 2:
The bypass device acts as an intermediary pressure equalization pathway between the housing high-pressure side and the suction pipe low-pressure side. The bypass valve and bypass hole create a dedicated channel that mediates the pressure difference, allowing controlled flow of high-pressure gas to equalize pressures without affecting the main compression and discharge pathways
2Loss of time
If the bypass hole is always open to equalize pressure, then the restarting time is shortened, but the compression efficiency decreases due to pressure leakage
Solution Approach 1:
The bypass valve is designed to dynamically open and close based on operating conditions. During motor operation, the bypass valve remains closed to maintain compression efficiency and prevent pressure leakage. When the motor stops and the pressure difference between housing and suction pipe decreases, the bypass valve automatically opens to equalize pressures. This dynamic control ensures the bypass hole is open only when needed, reducing restart time while maintaining compression efficiency during operation
Solution Approach 2:
The bypass valve responds to changes in pressure difference parameters between the housing and suction pipe. When the pressure difference exceeds a threshold during operation, the valve closes to maintain efficiency. When the motor stops and pressure difference decreases below the threshold, the valve opens to enable rapid equalization. This parameter-based control allows the system to adapt between efficiency and restart speed requirements
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
The solution significantly shortens the compressor's restarting time, improving the APF and maintaining comfortable air conditioner temperatures by rapidly equalizing pressures, reducing the time to 30% of conventional systems.
Implementation Method 1
a bypass valve opening and closing the bypass hole due to pressure difference between the housing and the suction pipe
Implementation Method 2
a spring enabling the bypass valve to move in a direction of opening the bypass hole
Data Source
AI summary
A rotary compressor and a refrigeration cycle device are provided. The rotary compressor includes a housing, an exhaust pipe and a suction pipe. The housing accommodates a motor and a compression mechanism. The exhaust pipe is communicated with a high-pressure side of the refrigeration cycle device and coupled to the housing. The suction pipe is communicated with a low-pressure side of the refrigeration cycle device and coupled to the compression mechanism. The compression mechanism has a bypass device. When the motor is stopped, gas of the housing flows into the suction pipe or a low-pressure circuit communicated with the suction pipe.