Recommended by the IIR / IIR document

Improvement of a railway car air conditioning unit by conversion to transcritical R744 technology.

Number: 1011

Author(s) : LAWRENCE N., ZHENG J., ELBEL S., HRNJAK P.

Summary

Recent years have seen an increased focus on finding and implementing replacement refrigerants for mass transit air-conditioning systems, with R744 (CO2) being of common interest. The major drawback of using R744 for air conditioning is its performance at elevated ambient temperatures. However, previous studies have shown that with integration of an internal heat exchanger, careful attention to gas cooler design to reduce approach temperature, and implementation of high-side pressure optimization, R744 systems can approach or exceed the performance of existing systems with conventional refrigerants. This paper presents the results of a study to convert an existing R407C system providing air conditioning to passenger rail cars with an R744 system. Significant reductions in unit volume of 13 % and unit weight of 5 % were achieved by the R744 unit compared to the baseline. Subsequent experimental investigations have shown that the R744 system can increase net capacity by 14 % and COP by 16 %.

Available documents

Format PDF

Pages: 6p.

Available

Free

Details

  • Original title: Improvement of a railway car air conditioning unit by conversion to transcritical R744 technology.
  • Record ID : 30027881
  • Languages: English
  • Subject: Technology, HFCs alternatives
  • Source: 14th IIR-Gustav Lorentzen Conference on Natural Refrigerants (GL2020). Proceedings. Kyoto, Japon, December 7-9th 2020.
  • Publication date: 2020/12/07
  • DOI: http://dx.doi.org/10.18462/iir.gl.2020.1011
  • Document available for consultation in the library of the IIR headquarters only.

Links


See other articles from the proceedings (120)
See the conference proceedings