Rotary Compressor Pre-Start Gas Bypass for Low Start-Up Torque
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Solution Overview
Problem
Existing rotary compressors face start-up failures due to excessive mass flow rate of refrigerant oil or liquid refrigerant during startup, leading to increased motor start-up torque and reduced energy efficiency.
Innovation Solution
Incorporation of a high-pressure chamber communication unit with a solenoid valve and connecting tubes to divert low-density refrigerant gas to the compression chamber before startup, reducing the mass flow and pressure difference, and using a low-torque motor to enhance efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the compressor directly sucks in refrigerant oil or liquid refrigerant during startup, then the mass flow rate is loaded by the compressor, but the motor's start-up torque becomes insufficient and energy efficiency deteriorates
Solution Approach 1:
The patent applies preliminary action by introducing low-density refrigerant gas into the compression chamber before the motor starts rotating. The solenoid valve opens prior to startup to fill the compression chamber with refrigerant gas, reducing the mass flow rate that the motor must handle during startup. This preliminary preparation eliminates the harmful effect of direct liquid refrigerant suction while maintaining productivity.
Solution Approach 2:
The patent uses low-density refrigerant gas as an intermediary substance between the suction source and the compression chamber during startup. Instead of directly compressing high-density liquid refrigerant or refrigerant oil, the system introduces refrigerant gas through the solenoid valve and bypass port, which acts as a mediator to reduce the load on the motor during startup while still enabling the compression function.
2Reliability
If the motor's start-up torque is increased to handle direct suction of refrigerant, then the compressor can start reliably, but the energy efficiency of the compressor deteriorates
Solution Approach 1:
The patent applies parameter changes by altering the density parameter of the refrigerant in the compression chamber during startup. By introducing low-density refrigerant gas instead of high-density liquid refrigerant or oil, the mass flow rate is reduced, which directly reduces the torque requirement of the motor. This parameter change enables reliable startup with a low-torque motor while improving energy efficiency.
3Use of energy by moving object
If a low-torque motor is used to improve energy efficiency, then the compressor operates more efficiently, but the motor cannot handle the mass flow rate during startup
Solution Approach 1:
The patent uses preliminary action to prepare the compression chamber before startup by introducing low-density refrigerant gas through the solenoid valve. This preliminary step reduces the mass flow rate that the low-torque motor must handle during startup, enabling the motor to start reliably without requiring high start-up torque, thus maintaining energy efficiency while ensuring productive operation.
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 reduces start-up torque requirements, ensuring smooth operation and improved energy efficiency by minimizing refrigerant mass and pressure differences during the startup phase.
Implementation Method 1
the solenoid valve and two connecting tubes, so as to transfer the refrigerant gas in the housing to the bypass port to enter into the compression chamber
Implementation Method 2
when the compressor is energized, the stator generates a magnetic field, which rotates the rotor, drives the crankshaft
Implementation Method 3
the stator generates a magnetic field, which rotates the rotor
Implementation Method 4
drives the crankshaft, and causes the rings to move eccentrically in the cylinder, thus compressing the low-temperature and low-pressure gas
Implementation Method 5
compressing the low-temperature and low-pressure gas into a high-temperature and high-pressure gas
Data Source
AI summary
A rotary compressor comprises a housing, a motor, a compression pump located within the housing and a high-pressure chamber communication unit located on one side of the housing. When the rotary compressor is not in the start-up state, a solenoid valve of the high-pressure chamber communication unit is activated, so that the low-density refrigerant gas in the housing of the rotary compressor will be transferred to the bypass port through the connecting tube located in the inner space of the housing and enters the compression chamber of the cylinder of the compression pump 0˜180 seconds prior to the start-up time, which reduces the quality of the refrigerant in the suction-compression-exhaust cycle, and at the same time reduces the high and low pressure difference during the start-up period. The solenoid valve is then closed to reduce the start-up and maximum torque required during this period.