Analysis on size of capillary tube in cascade refrigeration system operated with R-508B gas

Although low temperature cascade refrigeration machines have various areas of use, those cannot be produced in our country. This state is due to not having sufficient knowledge in literature about thermodynamic properties and system analysis of low temperature gas.This study comprises the calculation of capillary tube size applicable for various pressures and temperatures according to gas quantity and diameter of capillary tube via macros prepared by Visual Basic based Microsoft Excel for cascade refrigeration systems having fluid R-508B as an alternative refrigerant within its low temperature part.