Turbo Compressor Check Valve Layout for Refrigerant Backflow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In turbo compressors, refrigerant backflow through the pressure equalization pipe to the oil tank occurs during operation stop, leading to increased inlet pressure and lubricant oil leakage, which reduces oil tank levels and causes refrigerant leakage.
Innovation Solution
Incorporating a check valve in the pressure equalization pipe that allows fluid flow only from the oil tank to the compressor side, and a suction capacity adjusting portion with a relay space connected to the pressure equalization pipe, ensuring the oil tank maintains low pressure and preventing backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only a pressure equalization pipe is disposed to release refrigerant gas from the oil tank, then the refrigerant gas can be released to the inlet side of the compressor during operation, but when the compressor is stopped, the refrigerant flows backward from the condenser into the compressor inlet, increasing the inlet pressure, which causes the refrigerant to flow backward from the pressure equalization pipe into the oil tank, leading to oil leakage and reduced oil tank level
Solution Approach 1:
A check valve is introduced as an intermediary component in the pressure equalization pipe between the oil tank and compressor inlet. This check valve acts as a mediator that allows refrigerant gas to flow from the oil tank to the compressor inlet during operation, but prevents backward flow from the compressor inlet to the oil tank when the compressor is stopped, thus solving the backflow problem without requiring complete system redesign
Solution Approach 2:
The check valve is pre-installed in the pressure equalization pipe to provide preliminary protection against refrigerant backflow. By having this anti-backflow mechanism in place before the stoppage occurs, the system proactively prevents the harmful backflow effect rather than reacting to it after it occurs, maintaining oil tank level and preventing oil leakage
2Use of energy by moving object
If the compressor operates frequently ON/OFF for energy saving, then energy consumption is reduced, but during operation stop, refrigerant backflow occurs through the pressure equalization pipe, causing oil leakage and reducing oil tank levels
Solution Approach 1:
The check valve serves as a protective intermediary that remains functional regardless of compressor operation status. During ON/OFF cycling, it allows normal refrigerant flow during ON periods and blocks backflow during OFF periods, ensuring oil tank level maintenance is not compromised by the energy-saving operation pattern
Solution Approach 2:
The check valve automatically responds to pressure differential changes caused by ON/OFF operation without requiring external control. When the compressor stops and inlet pressure rises, the check valve self-actuates to close and prevent backflow, and when the compressor starts and creates suction, it self-actuates to open and allow refrigerant flow, making the system self-regulating during frequent cycling
3Reliability
If a check valve is added to the pressure equalization pipe to prevent refrigerant backflow, then refrigerant backflow is blocked, but the device complexity increases
Solution Approach 1:
A simple check valve, which is a relatively inexpensive and straightforward component, is added to the pressure equalization pipe. This check valve is a mature, off-the-shelf component that provides reliable backflow prevention without requiring complex mechanisms, advanced materials, or sophisticated control systems, thus minimizing the increase in device complexity while achieving the desired reliability improvement
4Area of stationary object
If the check valve is built into the case, then the air-tightness of the overall case is secured and space is saved, but the manufacturing complexity increases
Solution Approach 1:
The check valve is integrated into the case structure itself rather than being a separate external component. The case is designed with a built-in check valve mechanism that combines the housing and valve functions into a single integrated structure, eliminating the need for additional mounting space and external piping while maintaining air-tightness. This merging approach saves space and improves apearance without requiring excessively complex manufacturing processes
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
Effectively suppresses refrigerant backflow to the oil tank, preventing lubricant oil leakage and maintaining oil tank levels, while ensuring air-tightness and space efficiency in the compressor design.
Implementation Method 1
a check valve which allows only the movement of the fluid from the oil tank side to the compression stage side in the pressure equalization pipe
Implementation Method 2
a pressure equalization pipe which connects the oil tank with the vicinity of the inlet of the compression stages
Data Source
AI summary
A turbo compressor includes a case; compression stages which are disposed in a plural number in a rotatable manner with respect to the case via a sliding part; an oil tank in which a lubricant oil to be supplied to the sliding part is stored; a pressure equalization pipe which communicates the oil tank with the vicinity of the inlet of the compression stage; and a check valve which allows only the movement of the fluid from the oil tank side to the compression stage side in the pressure equalization pipe.