Numerical Investigation on a 70Hz Pulse Tube Micro-cryocooler

In this paper, a 70 Hz pulse tube micro cryocooler (PTMC) driven by two opposite linear generators has been studied using linear theory of thermoacoustic. In contrast to conventional thermodynamic calculation method the results of a small-scale PTC as a thermoacoustic system were obtained. Numerical simulation was conducted to design the system and optimum structure parameters were obtained. With operating condition of 2.5 MPa mean pressure and 70 Hz operating frequency, a cooling power of 8 W at 77 K and a relative Carnot efficiency of 21% were achieved. In order to prove the applicability of numerical simulation using linear theory of thermoacoustic to such small-scale cooling system and to better understand the energy conversion characteristics of the system, distributions of key parameters such as acoustic work, exergy were presented and discussed.