Development of rotary compressor for high-efficiency CO2 heat-pump hot-water supply system.

Number: pap. 1434

Author(s) : CHINEN T., KATO H., ICHIHARA M., et al.


In Japan, there has been an increase in the use of domestic heat-pump hot-water supply systems in which the refrigerant is CO2, which does not cause ozone layer depletion and has a low global-warming potential. In addition, in recent years, there has been an increase in the number of examples in which CO2 is employed as a refrigerant for showcase refrigerators, freezers etc. Therefore, in the future, it is expected that there will be an increasing demand for CO2 compressors with greater efficiency and lower noise. In the case of domestic heat-pump hot-water supply systems, in order to increase the annual performance factor (APF) of a product, it is effective to enhance the coefficient of performance (COP) in an intermediate capacity range. Here, we report the development of a high-APF rotary compressor achieved by optimizing the design specifications of a motor and a discharge pathway from a discharge chamber, for operation in the intermediate capacity range. In the optimization process, in order to cope with the high operating pressure of the CO2 water-heating cycle, we performed analysis using the finite element method (FEM) for evaluating the stiffness around the discharge port. In addition, we used an FEM model of the entire compressor in a modal analysis, and, in analyzing the radiation surfaces of the rotary compressor, we used an acoustic particle velocity probe that is capable of measuring the intensity at an intermediate portion between the accumulator and the compressor main unit, where it has been difficult to take measurements in the past. We also discuss an example in which noise reduction was confirmed when the specifications of the accumulator were changed based on the results of these analyses.

Available documents

Format PDF

Pages: 8 p.


  • Public price

    20 €

  • Member price*

    15 €

* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).


  • Original title: Development of rotary compressor for high-efficiency CO2 heat-pump hot-water supply system.
  • Record ID : 30014229
  • Languages: English
  • Source: 2014 Purdue Conferences. 22nd International Compressor Engineering Conference at Purdue.
  • Publication date: 2014/07/14


See other articles from the proceedings (138)
See the conference proceedings