IIR document

Performance assessment of residential heat pumps operating in extreme cold climates using zeotropic mixtures.

Author(s) : MAZER M. F. P., DA ROSA O. C., DA SILVA A. K.

Type of article: IJR article

Summary

Extremely cold climates subject residential heat pumps to significant temperature differences between the heat source and the ambient being heated, which may lead to system failure and reduced compressor performance. The present study considers the possibility of improving the performance of heat pump systems that are simultaneously used for residential space and domestic water heating while subjected to climates varying from -25 °C to 5 °C by exploring the use of zeotropic mixtures. CO2-based binary mixtures composed of low-GWP (global warming potential) refrigerants are considered – R32, R1234yf, and R290 – aiming to benefit from environmentally friendly and flame suppressants characteristics of CO2, as well as the improved thermal efficiency granted by the addition of a secondary refrigerant. A thermodynamic model was developed for a standard vapor-compression heat pump cycle and used to maximize the coefficient of performance limited by the minimum pinch point in the heat exchangers. Our analysis explores the effect of several parameters, such as, the mixture components, mass fractions, space and water heating demands, and heat source temperature on the heat pump's performance. For cold climates, the mixture of R32 (90%)/CO2 (10%) yields the highest COP and CO2-rich mixtures exhibit the lowest. However, by increasing the mass fraction of CO2 within the zeotropic mixture, the pressure ratio of the heat pump was improved. When considering combined performance criteria, such as the volumetric heating effect and the total heat delivered related to heat pump size, CO2-rich mixtures tend to allow more compact systems, especially in colder climates.

Available documents

Format PDF

Pages: 220-229

Available

  • Public price

    20 €

  • Member price*

    Free

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

Details

  • Original title: Performance assessment of residential heat pumps operating in extreme cold climates using zeotropic mixtures.
  • Record ID : 30032855
  • Languages: French, English
  • Source: International Journal of Refrigeration - Revue Internationale du Froid - vol. 168
  • Publication date: 2024/12
  • DOI: http://dx.doi.org/10.1016/j.ijrefrig.2024.08.018

Links


See other articles in this issue (63)
See the source