Two-Phase Flow in Adiabatic Capillary Tube for R-134a Cycles



In a CCOT system, an orifice tube converts hot, high pressure liquid from the condenser into cold, low pressure, two-phase flow before entering the evaporator. The main characteristic of a CCOT system is that there are no moving parts in the expansion device, lowering the manufacturing cost and simplifying the maintenance. In the current research, the orifice tube is replaced by a capillary tube with larger inner diameter and greater length. There are two reasons for doing this. First, it ensures the same pressure drop as was created using the orifice tube. Second, the longer tube provides more surface area, which allows it to function as a heat exchanger in the new device. For analysis, capillaries can be divided into two types: adiabatic and nonadiabatic. This chapter discusses the capillary flow characteristics of adiabatic cases.


Pressure Drop Root Mean Square Mass Flow Rate Capillary Length Slip Ratio 
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© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Department of Mechanical and Aerospace EngineeringCarleton UniversityOttawaCanada
  2. 2.Atomic Energy of Canada LimitedDeep RiverCanada
  3. 3.ENN Intelligent Energy Co., LtdENN GroupLangfangPeople’s Republic of China

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