Heat Pump System with R 22/R 114 Mixtures as Working Fluids: (2nd Report, Experiment on Double-Tube Evaporator and Condenser with Grooved Tubes)

Hiroshi Takamatsu, Shigeru Koyama, Yasuyuki Ikegami, Tomoyasu Yara, Minoru Kitamura, Tetsu Fujii

Research output: Contribution to journalArticle


The performance of a vapor compression heat pump system is tested using R22/R114 mixtures as the working fluid. Double pipe heat exchangers, where the refrigerant flows inside the inner tube with grooved internal surface and water flows countercurrently in the outer annulus, are used for the condenser and evaporator. Experimental results are compared with those for the same system with a smooth tube condenser and the evaporator presented before. The effect of the superheating of the refrigerant at the exit of the evaporator on COP is also discussed. A trial calculation based on the experimental results shows that the COP of the mixture becomes larger than that of the pure refrigerant in the case of a large change in the water temperature only if the heat transfer surface area is large enough and the superheating of the refrigerant is quite small at the exit of the evaporator.

Original languageEnglish
Pages (from-to)2377-2382
Number of pages6
JournalTransactions of the Japan Society of Mechanical Engineers Series B
Issue number539
Publication statusPublished - Jan 1 1991


All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering

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