Experimental Study Of The Single Stage Pulse Tube Cooler At 20K Range

The pulse tube cooler (PTC) is a new type of refrigerator, which can make the cool power by using the principle of adiabatic expanse. Unlike the Stirling or Gifford-McMahon refrigerators, the pulse tube cooler has no moving parts at the cold head. The lack of cold moving parts has allowed it to have some advantages of low mechanical vibration, high reliability, long lifetime, low electromagnetic noise and so on, so it is usually used in many fields, such as space science, superconductivity technology, cryoelectricity, etc. However, its efficiency is still lower than that of the traditional cryocoolers, which is one of the barriers to further development of this refrigeration method. To insure a commercial success of the PTC by replacement of conventional coolers in most of their applications, it is of major importance to optimize the PTC and to demonstrate performances and efficiencies as close as possible to those known for the conventional cryocoolers. After a detailed review on the recent development of the pulse tube cooler, the aim of the cooling power 7W at 20K is presented. The present work focuses on the following objects:Firstly I calculate the Cooling power of the single-stage PTC. I calculate the theoretic cooling power by using Radebaugh enthalpy phasic theory. Then I subtract all kinds of energy loss from the last result. So I get the genuine cool power of the single stage pulse tube cooler that is 6.8W at 20K.Secondly I build the experiment platform of the single-stage PTC. The experiment platform of the single-tage PTC includes three parts of the cooler system, the measure system and the vacuum system, which has advantages of high precision, agility operation, stable capability and so on. This experiment platform is the base of getting good result.Lastly I test the capability of the single stage PTC. I experiment by changing the conditions of the long neck tube, the double-inlet tube, the regenerator's padding and the charging pressure. After a series of experiments, I get the best result of the PTC's capability that the lowest attainable no-load refrigeration temperature of the cold end of PTC is19.8 K and the cooling capacity is 21W at 39K.