Feasibility of alpha configuration for miniature stirling cycle coolers

摘要

Stirling coolers are classified in many ways. One of the criterion is whether the machine uses two pistons or a piston and a displacer and are accordingly called Alpha and Beta or Gamma configurations. Thermodynamically, Alpha configuration has some clear advantages. Gamma configuration is generally used in the miniature coolers because of the convenience of having an easy drive arrangement. In the Alpha configuration it may be possible to use equal and large strokes for the compressor and expander pistons. A computer program is developed using the Second Order Analysis and the refrigeration losses are calculated for Alpha and Gamma configurations. The ideal refrigeration capacity with Alpha configuration increases substantially but the total refrigeration losses increase only marginally, leading to improvement in the net refrigeration effect. Increase in the power input is also observed but the C.O.P. for the Alpha configuration is still much higher than that for the Gamma configuration, thus showing the superiority of the Alpha configuration.