Comparative analysis of HFO-1234ze(E) and R-515B as low GWP alternatives to HFC-134a in moderately high temperature heat pumps

• Published in: International journal of refrigeration 2021-04, Vol.124, p.197-206
• Main Authors: Mateu-Royo, Carlos, Mota-Babiloni, Adrián, Navarro-Esbrí, Joaquín, Barragán-Cervera, Ángel
• Format: Article
• Language: English
• Subjects: Alternative au HFC-134a; Analyse énergétique et environnementale; Energy and environmental analysis; Flammability; Footprint analysis; Heat exchangers; Heat of vaporization; Heat pump; Heat pumps; Heat transfer; Heating; Heating capacity; HFC-134a alternative refrigerants; High temperature; Hydrofluorocarbons; Hydrofluorolefin (HFO); Hydrofluoroléfine (HFO); Latent heat; Low temperature; Natural gas; Pompe à chaleur; Puissance de chauffage; Pumps; Radiators; Refrigerants; Space heating; Studies; Suction; Temperature
• ISSN: 0140-7007; 1879-2081
• DOI: 10.1016/j.ijrefrig.2020.12.023

•HFO-1234ze(E) and R-515B are evaluated as low-GWP alternatives to HFC-134a.•An internal heat exchanger singularly benefits heating applications.•Heating production temperatures up to 90 °C are considered.•The alternative low-GWP refrigerants significantly reduces carbon emissions.•R-515B becomes a promising non-flammable alternative (A1) for heat pumps. This article provides a theoretical energy performance and carbon footprint analysis of the hydrofluoroolefin HFO-1234ze(E) and the mixture R-515B as low global warming potential (GWP) refrigerants to replace the hydrofluorocarbon HFC-134a in different heat pump applications. The reference configuration is a single-stage cycle with an internal heat exchanger (IHX). In this way, the impact of the IHX on medium and moderately high temperature heating applications has been investigated. HFO-1234ze(E) and R-515B result in approx. 25% lower heating capacity than HFC-134a due to a diminution of the latent heat of vaporisation and suction density. The heating capacity difference between HFO-1234ze(E) and R-515B remains below 2%. The heating coefficient of performance (COP) of the alternative low GWP refrigerants is comparable to that of the HFC-134a at the proposed conditions. The environmental analysis illustrates that HFO-1234ze(E) and R-515B can reduce down to 18% and 15%, respectively, the equivalent CO2 emissions compared to HFC-134a in low-temperature space heating applications. In addition, this reduction arrive at 78% when compared to a natural gas boiler, considered as the conventional heating technology in moderately high temperature applications (domestic hot water, industrial processes, and radiators). Although HFO-1234ze(E) and R-515B present comparable energy and environmental performance, the latter refrigerant has an advantage in regard to installation safety requirements as a non-flammable refrigerant (A1).