Thermopneumatic analysis of single stage gifford-mcmahon cryocooler

The thermodynamics, fluid mechanics, pneumatic and dynamic aspects of a single stage GM cryocooler is governed by a set of non-linear differential equations and have been solved to estimate the performance parameters by using finite volume method. The influence of waiting time of the rotary valve on the refrigeration power and COP has been investigated. Longer is the waiting time means both valves will be closed for a long period, this increases the irreversibility inside the expansion space and, thus, decreases its performance. It is observed that refrigeration capacity and COP attain its maximum value at about 20° and 80° of waiting time respectively. It is also found that the refrigeration power and COP of the straight-line shaped opening is higher than that of square opening. The results may be needful for the effective design of rotary valves of a GM cryocooler.