Experimental and Numerical Modeling of the Refrigerant Flow through an Adiabatic Helical Capillary Tube

This paper presents an experimental investigation of R-۱۳۴a flow inside an adiabatic helical coiled capillary tube. The two-phase flow was developed by drift flux model for both straight and helical capillary tubes. The conservation equations of the mass, energy and momentum are numerically solved using the ۴th order Runge-Kutta method. This model is validated by previously published experimental and numerical results and also by present experimental results. The effect of various inlet conditions such as pressure, temperature, degrees of sub cooling, and geometric parameters such as tube diameter and length and also coil diameter were studied. Moreover, the pressure, vapor quality and void fraction variation along both straight and helical capillary were experimentally obtained using a closed loop experiment apparatus and numerical simulation. The results of our study show that in the same length and condition, mass flow rate through helical capillary tube with coil diameter of ۴۰ mm is ۱۱% less than that of straight capillary tube where helical type reduces the tube length by ۲۴%. The comparison between the present measured data and the present developed drift flux model results give an absolute error of ۷%. This developed model can be used as an effective tool for designing and optimizing air conditioning with helical capillary tube for various refrigerants.

کلیدواژه ها:

helical capillary tube ، experimental ، Adiabatic ، numerical