Experimental and numerical investigation of metastable flow of refrigerant R-22 through capillary tube

الملخص EN

This study presents an experimental investigation of metastable region take place for refrigerant flow through adiabatic and non-adiabatic capillary tube of window type air conditioner.

Large numbers of experiments are carried out to explain the effect of length of straight and helical capillary tube on metastable region under adiabatic and non-adiabatic conditions.

for the case of adiabatic capillary tube, three different length are selected (70,100 and 150) cm and two helical capillary tube, the length of each tube is 100 cm with two coil diameters (2 and 6) cm.

For the non-adiabatic capillary tube, the straight capillary tube suction line is 150 cm while the length of non-adiabatic helical capillary tube is 200 cm with 8 cm coil diameter.

The results show that the length is the most influence parameters on beginning of metastable region.

In addition the helical coil tube effect on the beginning of metastable region.

As well as for the adiabatic and non-adiabatic capillary tube it is concluded that mass flow rate is the main parameters on beginning of metastable region.

Also effect of length and coiling on both pressure drop and mass flow rate are discussed.

The CFD commercial code, ANSYS CFX 16.1 based on finite volume method using Kturbulence model considering the homogeneous flow between phases applied to straight capillary tube.

The present numerical data has been validated with the present work experimental data and with other researchers.

A good agreement is obtained which can be lead to use ANSYS CFX 16.1 in the design and optimization of capillary tube in airconditioner.