IIR document

Investigation of low pressure accumulators in CO2 refrigeration cycles.

Author(s) : STRUPP C., LEMKE N., TEGETHOFF W., et al.


Usually, automotive R-744 HVAC units make use of a low pressure accumulator. A top-performing accumulator is crucial for a reliable operation of the system on the one hand and a good COP on the other. Regarding the design of the accumulator a main objective is to allow a proper separation and at the same time to avoid packaging problems due to unnecessary excess volume. In addition, an appropriate oil bleed hole has to be integrated to allow both oil return and a good performance of the accumulator. In order to improve the accumulator design and to allow computer modeling a profound knowledge of the functioning inside the accumulator is crucial. To meet these goals, a glass accumulator was designed. The paper presents this accumulator and the experimental results. The experiments conducted for two different separation mechanisms show a dependency of accumulator behaviour on liquid level, mass flow rate and oil bleed hole diameter. Based on the measurement data a physical based MODELICA model is presented. Furthermore, experiments conducted to study the influence of the refrigerant cycle oil concentration on the accumulator flow pattern and performance are presented.

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Pages: ICR07-E1-1480


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  • Original title: Investigation of low pressure accumulators in CO2 refrigeration cycles.
  • Record ID : 2008-0365
  • Languages: English
  • Source: ICR 2007. Refrigeration Creates the Future. Proceedings of the 22nd IIR International Congress of Refrigeration.
  • Publication date: 2007/08/21


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