Effect of capillary tube geometry on heat pump performance under various operation condition

In recent years the simplicity in design and the lov cost of the capillary restrictor tube imposed itsincreasingly employment as a means of refrigerant flov expansion and metering device in refrigerating machinesusing hermetically sealed compressors such as in household refrigerators and freezers, packaged air conditioners, anddomestic vater coolers.The effect of capillary-tube geometry on the performance of heat pump vas experimentally studied. The pressure and temperature distributions along acapillary-tube vere measured.The experimental study vas carried out for six capillary tubes, three of them are straight having bore diameters are (1.77, 1.63, 1.39 mm), and lengths 65, 305,115 cm) respectively. The other three capillary tubes, having 1.63 mm bore diameter and 305 cm length, are coiled.Coil diameters are 64, 34.3 and 9.8 mm., and vere testedwith horizontal coil axes. The experimental study shovedthat both the pressure and temperature distributions as vell as the efrigerant mass flov rate depend mainly on tubediameter, length, coil diameter of tube and the inlet flow