The restrictions on the use of hydrofluorocarbons with a high global warming potential (GWP) are increasing on a global scale. They can be cost-driven or politically enforced. In Europe, the EU regulation 517/2014 restricts the refrigerants currently used in household appliances, such as R-134a, so new systems and working fluids must be investigated as replacements. The trend in domestic appliances with heat pumps, such as tumble dryers, is towards using propane as a refrigerant.
This paper presents an experimental comparison of different refrigerants in a heat pump tumble dryer test rig. The original working fluid is R-134a, and the tests performed investigate a zeotropic refrigerant blend. The retrofit of the system for each new refrigerant is minimized. Modifications made to the system focus on adapting the throttling device to create a stable operating point.
The cycle performance is evaluated using various parameters such as refrigerant mass flow, compressor input power, energy consumption and the duration of a standard drying cycle.