Conceptual design of a cryocooler and investigation of the effect of design parameters on cryocooler performance

Pulse tube cryocooler has low vibration and high reliability because of the lack of displacer in the cold area. This advantage cause development of these cryocoolers. In some applications such as MRI systems which need cryocoolers for cooling magnet, using them will improve the imaging quality. In this article, the steps of designing a pulse tube cryocooler which is able to be installed in MRI systems will be introduced. As conceptual design is a vital section of any design project, this part has been totally studied; Necessary data has been gathered and developed in order to have best function in the pulse tube system. Preliminary design with help of two analyses (Phasor and Isotherm analysis) is introduced to designers and important parameters are obtained. Then investigation of the effect of some design parameters like valve timing, reservoir volume and pressure ratio using isothermal analysis has been done on cryocooler performance.