Abstract : Cryogenic refrigerators,配套 with infrared detectors, are high-tech products urgently needed for military applications. Domestic research and development has approached international advanced levels, with key technologies such as miniaturization, low vibration, long lifespan, fine square enameled wire fabrication, gap sealing, and electromagnetic interference elimination basically mastered. This paper introduces the main technical performance of the developed linear motor resonant compressor. It is hoped that all parties involved—including management, users, researchers, and manufacturers—will work together to achieve the industrialization of China's cryogenic refrigerators through application and improvement.
Keywords : low temperature; refrigerator; linear motor; compressor
1 Introduction
The Gulf War, the Kosovo War, and the Bosnian War in recent years have demonstrated the power of modern weaponry, particularly the astonishing accuracy of missiles. The secret to this lies in the application of infrared imaging guided missiles. The practical application of infrared imaging systems in target search, tracking, aiming, and guidance under nighttime or adverse weather conditions enables all-weather operations. Furthermore, infrared imaging guidance possesses strong anti-jamming capabilities and is a major development direction for guidance technology. Airborne detectors have a range of tens of kilometers, while spacecraft and satellites can detect targets at ranges of hundreds of kilometers. Therefore, infrared imaging systems based on infrared focal plane arrays are widely used in the military, such as in spaceborne early warning systems, low-altitude air defense, reconnaissance, search and tracking, border patrol, security, nighttime navigation, missile guidance, real-time precision strikes, strike effect estimation, and target search in complex backgrounds, changing sea and sky conditions, and at night. Whoever has stronger night vision capabilities holds more initiative in modern warfare; night vision capability is one of the hallmarks of modern national defense. A temperature difference of only 3°C between the target and the background is sufficient for a detection range exceeding 18km. However, the infrared detector must be cooled to below -196°C to function properly. Cryogenic refrigerators are a high-tech field developed with the rise of infrared remote sensing and high-temperature superconductivity technologies. They provide the necessary low-temperature environment for infrared detectors and high-temperature superconducting devices in space satellite remote sensing prediction, satellite early warning, and military night vision devices. Therefore, cryogenic refrigerators are a key product for military modernization.
2. Basic Principles of Cryogenic Refrigerators
A cryogenic cooler is a device that pumps heat from the cold end to the hot end; cryogenic temperature generally refers to below 120K. Currently, most miniature cryogenic coolers employ valveless closed-loop refrigeration systems, known as Stirling cycle coolers. These coolers are compact, efficient, and small in size, making them ideal for use as cooling sources in vehicle-mounted, shipborne, and airborne military infrared systems. The efficiency of this type of cooler is subject to the Carnot limit; a typical Stirling cooler can be used at 77K. For even lower requirements, such as 30K, a two-stage expander cooling system is necessary. To reach 4K, an additional Joule-Thompson cycle cooling stage is required.
For details, please click: Advances in Infrared Remote Sensing Cryogenic Coolers
