Experimental comparison of R1224yd(Z) and R1233zd(E) in a high temperature heat pump. 

Number: No 216



High temperature heat pumps (HTHP) with heat supply temperatures of 100 to 160 °C will increasingly become commercialized in the coming years, especially for drying, sterilization and evaporation processes in the food and chemical industries. There is significant research towards testing new environmental-friendly refrigerants with low GWP for use in HTHPs. Besides natural refrigerants, the synthetic hydrochlorofluoroolefins (HCFO) R1224yd(Z) and R1233zd(E) (GWP < 1) are suitable substitutes for the hydrofluorocarbons (HFC) R245fa and R365mfc (GWP > 800). This paper examines the experimental performance of R1224yd(Z) and R1233zd(E) as a drop-in test in a laboratory HTHP with 5 to 10 kW heating capacity. The developed heat pump is single-stage, operates with a variable speed piston compressor, and contains a continuously adjustable internal heat exchanger (IHX) for superheating control. The performance data were measured at 30, 50, and 70 K temperature lift (40 to 80 °C heat source, 80 to 150 °C heat supply). The integration of the IHX in the heat pump cycle significantly increased the efficiency and the heating capacity over the entire operating map. The experimental results with R1224yd(Z) at W60/W110 indicate a COP of 2.8 (basic cycle) and 3.2 with IHX integration (+14%). The drop-in test showed that the heating capacity of R1224yd(Z) was on average 9% higher than that of R1233zd(E). The measured COP data of R1224yd(Z) were comparable to R1233zd(E) in the whole operating map. The deviations were within the measurement uncertainty of ± 0.2 COP. Moreover, an increase in the temperature glide on the heat sink side from 5 to 25 K further increased the COP by +9%, which is promising in processes with low return temperatures. Overall, the experimental results are promising for use in HTHPs and the developed laboratory HTHP system allows testing alternative HCFO and HFO refrigerants in the future.

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Pages: 12 p.




  • Original title: Experimental comparison of R1224yd(Z) and R1233zd(E) in a high temperature heat pump. 
  • Record ID : 30030044
  • Languages: English
  • Subject: HFCs alternatives
  • Source: 13th IEA Heat Pump Conference 2021: Heat Pumps – Mission for the Green World. Conference proceedings [full papers]
  • Publication date: 2021/08/31


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