Sizing charts of helical capillary tubes used in refrigeration and air conditioning

Abstract

This paper presents new selection and correction factor charts for the sizing of adiabatic helical capillary tubes operating with alternative refrigerants. The mathematical model is based on the conservation of mass, energy, and momentum of fluids in capillary tubes. In the two-phase flow region, the developed model is based on the homogenous flow assumption. It is verified by the accuracy of the results of comparison between simulation results and experimental data in open literature. After the developed model is validated, selection and correction charts that include the important parameters are proposed for sizing adiabatic helical capillary tube. The present charts are proposed for R-134a, R-404A, R-407B, R-407C, and R-410A, and a wide range of operation. These newly developed selection and correction charts can be used to select helical capillary tube size from flow conditions and the mass flow rate or to predict the mass flow rate from capillary tube size and flow condition.

Additional information

Funding

The authors acknowledge the support provided by the “Research Chair Grant” National Science and Technology Development Agency (NSTDA), the Thailand Research Fund (TRF), and King Mongkut’s University of Technology Thonburi through the “KMUTT 55^th Anniversary Commemorative Fund.”