Resulting design criteria
With regard to system technology, experience gained from the use of propane can widely be applied to propylene. However, component dimensions have to be altered due to higher volumetric refrigerating capacity (Comparison of performance data). The compressor displacement is correspondingly lower, as are the suction and high pressure volume flows. Because of higher vapour density, however, the mass flow is almost the same as for R290. As liquid density is nearly identical, the same applies to the liquid volume in circulation.
As with R290, an internal heat exchanger between suction and liquid lines is of advantage. However, due to the higher discharge gas temperature of R1270, restrictions are partly necessary at high pressure ratios.