Experimental investigation of displacer type pulse tube refrigerator with inertance tube or orifice

Displacer type pulse tube refrigerator (DPTR) can get high efficiency with strong phase shifting and acoustic work recovery to advantages. However, the optimal match of gas driving displacer can only be reached at one point, while the linear motor driving displacer has a complex structure. And for two-stage DPTR, more parameters need to be optimized such as step ratio. A well-matched displacer costs a lot and asks high quality manufacturing. In this work, an orifice and an inertance tube were added to the single-stage DPTR and two-stage DPTR as an additional adjustment parameter. For single stage DPTR, the experimental results indicate that the lowest temperature decreases from 44.7 K to 42.1 K after a suitable inertance tube was added. The cooling power can be increased with almost same efficiency by adding an orifice with appropriate opening turn. After adding an additional inertance tube of the two-stage DPTR, the lowest temperature of 15.6 K was achieved, while the lowest temperature of 15.7 K was achieved by installing an orifice to the two-stage DPTR.