Experimental Research And Optimization Of A Single Stage G-M Type Pulse Tube Cryocooler

Compared with the traditional cryocoolers, the pulse tube cryocooler has no moving part in the cold end, resulting in lower electromagnetic interference, lower vibration and higher reliability. Due to these advantages, the G-M type pulse tube cryocooler has attracted more and more attention all over the world. It has been widely used in many fields such as super-conducting magnet cooling, cryo-pump, space exploration and medical treatment. With the improvement of the storage technology of the liquefied hydrogen , helium and the development of the high temperature superconducting materials, the G-M type pulse tube cryocooler is supposed to get more application. In recent years, great progress has been made in both theoretical and experimental researches on the G-M type pulse tube cryocooler. Many new theoretical analyses and experimental optimizations have been proposed. So far, the lowest cooling temperature has reached to 10K. However, no integrated evaluation and universality of these optimizations have been made. Integrated evaluation and universality of the optimizations are included in the paper as well as how the double inlet structure has impact on the performance. Based on the theoretical analyses and calculations, a single stage G-M type pulse tube cryocooler has been designed and constructed for experimental test.(1)The theoretical analyses and calculations were conducted. Based on the initial design, the thermodynamic calculation of the prototype was carried out. The theoretical cooling capacity and different kinds of thermal losses were obtained. These provided an effective guide for the optimal design. (2)A single stage G-M type pulse tube cryocooler was designed and constructed for experimental tests. Many optimizations can be realized. The mutual influence of two different optimization measures can also be shown. A measurement system with high accuracy was built for data acquisition and process.(3)A series of experiments were carried out to study the effects of orifice, double inlet on the Cooling performance. According to the experimental results, the double inlet has a positive impact on the system with an obvious improvement in certain case. The lowest temperature obtained by the single stage G-M pulse tube cryocooler was 28.7K with the cooling capacity of 32W at 80K.