Cryocooler On-Off Valve Design to Reduce Temperature Rising Load
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Solution Overview
Problem
The existing cryocoolers face increased load on the reciprocating drive mechanism during the temperature rising operation due to pressure in the assist chamber, which hinders the movement of the displacer and increases power consumption.
Innovation Solution
Incorporating an on-off valve to control the connection between the assist chamber and the compressor, ensuring the assist chamber becomes a low-pressure state during the temperature rising operation, thereby reducing the load on the drive mechanism and minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the assist chamber is connected to the discharge side of the compressor during temperature rising operation, then the pressure in the assist chamber assists the movement of the rod and displacer, but the load applied to the reciprocating drive mechanism increases
Solution Approach 1:
The patent applies dynamics by making the connection state of the assist chamber dynamic rather than fixed. The switch valve dynamically switches the assist chamber between connection to the discharge side (during cooling operation) and connection to the suction side (during temperature rising operation). This dynamic switching allows the system to adapt to different operational modes, reducing the load on the reciprocating drive mechanism during temperature rising while maintaining assist force during cooling operation.
2Ease of operation
If the assist chamber maintains high pressure to assist displacer movement, then the drive mechanism load is reduced, but the motor experiences overload during reverse rotation
Solution Approach 1:
The switch valve dynamically changes the pressure state of the assist chamber based on operational mode. During temperature rising operation (reverse rotation), the switch valve connects the assist chamber to the suction side, reducing its pressure and thereby reducing the load on the motor during reverse rotation. During normal cooling operation, the assist chamber is connected to the discharge side to provide assist force. This dynamic pressure control prevents motor overload while maintaining ease of operation.
3Adaptability or versatility
If the switch valve switches between different connection states, then the operational flexibility is improved, but the device complexity increases
Solution Approach 1:
The switch valve is designed to perform multiple functions: it controls the connection of the assist chamber to either the discharge side or suction side of the compressor, and it also controls the connection of the expansion space to the appropriate side. This multi-functionality reduces the need for separate valves for each function, thereby limiting the increase in device complexity while maintaining high operational flexibility.
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 configuration reduces the load on the Scotch yoke mechanism and motor, decreasing power consumption and preventing motor overload during reverse rotation, thus enhancing the efficiency of the cryocooler's temperature rising operation.
Implementation Method 1
high-pressure refrigerant gas is expanded to generate coldness
Implementation Method 2
a reversible motor configured to drive the switch valve
Data Source
AI summary
A cryocooler includes a displacer, a cylinder that forms an expansion space, a Scotch yoke mechanism configured to drive the displacer in a reciprocating manner, a first rod that extends from the Scotch yoke mechanism, a housing that includes an assist chamber, a rotary valve configured to switch between a state in which the expansion space and a discharge side of a compressor are connected and the assist chamber and a suction side of the compressor are connected and a state in which the expansion space and the suction side of the compressor are connected and the assist chamber and the discharge side of the compressor are connected, a motor configured to drive the Scotch yoke mechanism and the rotary valve, and an on-off valve configured to open and close a gas flow path through which the rotary valve and the assist chamber are connected.