IIR document

Thermal conductivities of HFO and HFO+HFC mixtures at saturated liquid condition.

Number: pap. n. TP-033

Author(s) : MIYARA A., FUKUDA R., KURIYAMA T.

Summary

HFCs which have been used widely as refrigerants are designated as global warming gases in Kyoto Protocol and they are headed to be regulated. Because of the requirement of low GWP refrigerants, HFOs were developed which are expected to become promising future refrigerants. Although there are different kinds of HFOs, such as HFO-1234yf, -1234ze(E), and -1234ze(Z), it is difficult to replace all HFCs by HFOs due to limitations of thermophysical properties. In order to solve this problem, mixture refrigerants of HFOs and HFC-32 are considered. HFC-32 has relatively lower GWP than other HFCs and higher competence as a refrigerant. In the present study, thermal conductivities of saturated liquid of HFOs and mixture of HFOs+HFC-32 have been measured. The thermal conductivity was measured by a transient hot-wire method. Short and long platinum wires with diameter of 15 micro-m used as the line heat source. The platinum wires were attached in cylindrical copper cell and the copper cell is installed in a pressure vessel made of stainless steel. This pressure vessel was set in an isothermal bath. The measured temperature conditions were stably controlled at 10°C to 70°C every 10°C. In the thermal conductivity measurement by the hot-wire method, liquids with polarity such as HFC-32 prevent the accurate measurement due to electric influence. This problem could be reduced by using a polarization technique. Thermal conductivities of HFOs are lower than that of HFC-32. The thermal conductivity of mixture is between both pure refrigerants and it is slightly lower than linearly interpolated value.

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Pages: 7 p.

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Details

  • Original title: Thermal conductivities of HFO and HFO+HFC mixtures at saturated liquid condition.
  • Record ID : 30008108
  • Languages: English
  • Source: 4th IIR Conference on Thermophysical Properties and Transfer Processes of Refrigerants
  • Publication date: 2013/06/17

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