Heat pump and refrigeration cycle

HVAC

Gas compressor

Engineering

Ecology

Biology

Condenser (optics)

Global-warming potential

Waste heat

Materials science

Isentropic process

Power (physics)

Rankine cycle

Working fluid

Heat exchanger

Waste management

Mechanical engineering

Degree Rankine

Thermodynamics

Physics

Greenhouse gas

Optics

Process engineering

Environmental science

Chemistry

Meteorology

Heat pump

Light source

Refrigeration

Refrigerant

Organic Rankine cycle

ASHRAE 90.1

Air conditioning

Renewable and Sustainable Energy Reviews

Hydrofluorocarbons (HFCs), one of the most used working fluids in HVAC&R and ORC applications, are being phased down rapidly because of their high global warming potential (GWP). Consequently, this sector is looking for suitable eco-friendly low-GWP alternatives to the most representative 3rd generation HFC refrigerants (R-134a, R-404A, R-410A, and R-245fa). This article reviews the publicly available investigations regarding thermodynamic and transport properties and system performance of several low-GWP molecules. First, working fluids added to the ANSI/ASHRAE Standard 34 since 2015 (R-1130(E), R-1336mzz(Z), R-1336mzz(E), R-1233zd(E), R-1224yd(Z), R-13I1, and R-1132a) are considered. Then, other molecules identified in recent studies but not been added yet to that standard (R-1123, R-1243zf, R-1225ye(Z), R-1132(E), R-1252ye, R-1261ze, and R-1141) are investigated. The thermodynamic properties of R-1233zd(E) and R-1224yd(Z) are well described, and their suitability in high-temperature heat pump (HTHP) and Organic Rankine cycle (ORC) systems is experimentally confirmed. R-1336mzz(Z) and R-1336mzz(E), and R-1132a are considered promising working fluids in HTHP and ORC systems, and ULT applications, respectively. R-13I1 is used as a flame suppressant in recently developed blends, such as R-466A. Properties of R-1123, R-1243zf, and R-1225ye(Z) have been well studied, and they are not considered single compound working fluids due to their safety concerns. Therefore, further studies regarding their properties and system performance are needed to confirm their suitability. R-1130(E), R-1132(E), R-1252ye, R-1261ze, and R-1141 are recently identified as potential molecules, so scarce property data is available, and no conclusions can be extracted about them.

Novel molecules as working fluids for refrigeration, heat pump and organic Rankine cycle systems