Integrated Stirling Cryocooler Layout to Cut Thermal Conductance Loss
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Solution Overview
Problem
Conventional Sterling cryocoolers with a slip-on structure suffer from thermal conductance losses due to temperature gradients, leading to reduced refrigeration capacity, and their large size and weight are not suitable for compact applications.
Innovation Solution
An integrated Sterling cryocooler design where the expander is embedded within the compressor, forming a compact whole, with a groove in the compressor to house the expander and an orifice for communication between the compression cavity and the expander, eliminating the need for an outer sleeve and enhancing thermal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a slip-on structure with an outer sleeve is used for the displacer, then the cryocooler can maintain structural integrity and contactless movement, but thermal conductance loss occurs due to temperature gradient in the sleeve wall, reducing effective refrigeration capacity
Solution Approach 1:
The invention removes the outer sleeve component from the displacer structure, extracting the source of thermal conductance loss. The displacer operates directly within the cylinder bore without the intermediate sleeve, eliminating the thermal bridge that caused energy loss while maintaining the necessary clearance for contactless movement.
Solution Approach 2:
The invention merges the displacer and cylinder assembly into a more integrated configuration where the displacer operates directly in the cylinder without a separate outer sleeve. This consolidation eliminates the thermal interface between sleeve and cylinder, reducing heat leakage while maintaining structural integrity through precise clearance design.
2Reliability
If conventional separate-type or slip-on structure is used, then the cryocooler can ensure reliable operation, but the system becomes larger and heavier, reducing compactness
Solution Approach 1:
The invention merges the compressor and expander into a single integrated assembly where the expander is positioned within the compressor housing. This consolidation eliminates separate mounting structures and reduces overall system volume while maintaining reliable operation through unified structural support and shared components.
Solution Approach 2:
The invention nests the expander components within the compressor structure, placing the expander piston and associated mechanisms inside the compressor housing. This nested arrangement充分利用 the available space, reducing the external dimensions of the cryocooler while maintaining all necessary functional clearances and structural integrity.
3Reliability
If conventional separate-type structure is used, then the cryocooler can ensure independent closed system operation, but the device complexity and size increase
Solution Approach 1:
The invention merges the compressor and expander into a single integrated assembly where the expander is positioned within the compressor housing. This consolidation eliminates separate mounting structures and reduces overall system volume while maintaining unified structural support and shared components, thereby reducing device complexity.
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 design results in a more compact, smaller-sized cryocooler with improved thermal efficiency, reducing size and weight, making it suitable for applications requiring reduced dimensions and enhanced performance.
Implementation Method 1
the coil and the magnet are respectively fixed between the bracket and the support, an electromagnetic force is generated between the coil and the magnet to drive the piston into reciprocating movement
Implementation Method 2
compressed gas pushes the heat regenerator on the small piston into reciprocating movement between the pneumatic chamber and the expansion chamber
Implementation Method 3
the heat regenerator is in a clearance labyrinth sealing with a cold finger
Data Source
AI summary
An integrated Stirling refrigerator is composed of two parts: a compressor and an expander. The compressor is composed of a shell (1), a piston (4), a leaf spring (8), a magnet (9), a coil (10), a bracket (14) and a support shelf (15). The shell (1) of the compressor includes two cylinders (11, 12), one of which is set inside the other to form a compression chamber (3). The piston (4) is connected with the leaf spring (8). The coil (10) is fixed between the inside of the shell (1) and the bracket (14), and the magnet (9) is fixed between the bracket (14) and the support shelf (15), wherein the bracket (14) and the support shelf (15) are respectively connected with the shell (1). The inside of the expander is divided into two chambers by a small piston and a regenerator (7) fixed together, that is, an expansion chamber (6) and a pneumatic chamber, and a cylindrical spring (16) is provided on the bottom of the expander. The center of the compressor is designed as a groove, and the expander is inserted into the groove of the compressor. There is a small hole designed on the bottom of the expander, which is communicated with the compression chamber (3) of the compressor. The Stirling refrigerator has the advantages of compact structure and small volume, and hence it can be widely used.