Flow Characteristics in an Adiabatic Capillary Tube of Carbon Dioxide

$CO_2$ 단열 모세관내 유동 특성

  • Roh, Geon-Sang (Department of Refrigeration and Air-conditioning Engineering, Tong Myong Univ.) ;
  • Son, Chang-Hyo (School of Mechanical Engineering, Pukyong National Univ.)
  • 노건상 (동명대학교 냉동공조공학과) ;
  • 손창효 (부경대학교 기계공학부)
  • Published : 2008.12.30

Abstract

In this paper, flow characteristics of an adiabatic capillary tube in a transcritical $CO_2$ have been investigated employing the homogeneous model. The model is based on fundamental equations of mass, energy and momentum which are solved simultaneously. Two friction factors(Churchill) and viscosity(McAdams) are comparatively used to investigate the flow characteristics. Supercritical and subcritical thermodynamic and transport properties of $CO_2$ are calculated employing EES property code. Flow characteristics analysis of $CO_2$ adiabatic capillary tube is presented to offer the basic design data for the operating parameters. The operating parameters considered in this study include inlet temperature and pressure of an adiabatic capillary tube, evaporating temperature and inner diameter tube. The main results were summarized as follows : inlet temperature and pressure of an adiabatic capillary tube, evaporating temperature, mass flowrate and inner diameter of $CO_2$ adiabatic capillary tube have an effect on length of an adiabatic capillary tube.

Keywords

Adiabatic capillary tube;$CO_2$;Transcritical cycel;Vapor compression system

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