Double-Inlet Pulse Tube Refrigerator Bypass Layout for Secondary Flow
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Solution Overview
Problem
Double inlet type pulse tube refrigerators face reduced cooling capacity due to secondary flow generation, which decreases heat transfer efficiency and cooling capacity, primarily caused by an imbalance in coolant gas flow through the double inlet valve, leading to circulation in closed circuits.
Innovation Solution
Incorporating a second low pressure side pipe with a flow path resistance member and an additional opening and closing valve between the buffer tank and the compressor, which controls the flow to prevent secondary flow circulation by managing pressure waves and coolant gas distribution effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a double inlet valve is used to supply coolant gas to the pulse tube through two paths, then cooling efficiency is improved, but secondary flow is generated due to flow imbalance, reducing heat transfer and cooling capacity
Solution Approach 1:
A flow path resistance member (orifice) is introduced as an intermediary element in one of the coolant supply paths. This orifice acts as a flow regulator that balances the coolant gas distribution between the two inlet paths, preventing secondary flow while maintaining the benefits of dual-path cooling supply
Solution Approach 2:
The flow path resistance (via orifice) is adjusted to optimize the balance of coolant gas flow between the two inlet paths. By changing the resistance parameter, the system achieves balanced flow distribution that eliminates secondary flow generation while preserving high cooling efficiency
2Device complexity
If the coolant flow paths are simplified, then device complexity is reduced, but flow imbalance occurs leading to secondary flow generation
Solution Approach 1:
The orifice serves as a simple intermediary component that provides flow balance control without adding complex control systems. This maintains device simplicity while ensuring reliable flow distribution
Solution Approach 2:
The flow path resistance member creates a self-regulating system where the pressure differential automatically balances the flow between the two inlet paths, eliminating the need for active control mechanisms
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 effectively prevents secondary flow generation, maintaining high cooling efficiency and capacity by optimizing the flow paths and resistance within the pulse tube refrigerator system.
Implementation Method 1
Compression and expansion are repeated in the pulse tube 50 so that a cryogenic state is formed
Implementation Method 2
a cryogenic state is formed at low temperature ends of a regenerator and a pulse tube
Implementation Method 3
by placing a cooling subject in thermal contact with these low temperature ends, it is possible to remove heat from the cooling subject
Implementation Method 4
a first pipe having a first orifice, and a second pipe having a second orifice
Data Source
AI summary
A double inlet type pulse tube refrigerator includes a regenerator having a high temperature end and a low temperature end; a pulse tube having a high temperature end and a low temperature end connected to the low temperature end of the regenerator; a compressor having a high pressure supplying side and low pressure receiving side for a coolant, a bypass pipe having a double inlet valve, the bypass pipe being configured to connect the high temperature end of the pulse tube and the high temperature end of the regenerator; a buffer tank connected to the high temperature end of the pulse tube via a first pipe having a first flow path resistance member; and a second pipe having a second flow path resistance member including a third opening and closing valve.