zeotropic refrigerant blends, natural refrigerants, heat pump tumble dryer
Hydrofluorocarbon (HFCs), due to their high global warming impact, are not considered a desirable solution for future household application. In accordance to the Kigali Amendment to the Montreal Protocol, numerous countries committed the significant face- down of the production and consumption of HFCs over the next two to three decades. Natural refrigerants as well as their blends are considered viable alternatives due to their low global warming potentials. Additionally, the use of non-azeotropic refrigerant blends can positively influence the cycle performance of refrigerators and heat pump tumble dryers. Moreover, the knowledge of the behaviour of the oil-refrigerant-mixture is a necessity to enable a more precise component design and dimensioning. While most pure refrigerants are experimentally well investigated, the properties of specific refrigerant blends and oil-refrigerant-mixtures need to be confirmed by measurements. This paper describes the experimental investigation of a mixture of a propane (R290) / iso-butane (R600a) refrigerant blend and a mineral oil (MO) for application within household appliances. Several test benches were built to investigate the properties of interest, such as vapour pressure, viscosity as well as densities of the mixtures. Furthermore, the experimentally investigated properties are used to validate previous component design calculations.