Thursday August 29, 2019 from 10:40 to 12:00
High temperature heat pump using HFO and HCFO refrigerants – system design and experimental results
Cordin Arpagaus1, Ralph Kuster1, Frédéric Bless1, Manuel Prinzing1, Michael Uhlmann1, Elias Büchel1, Stefan Frei1, Jürg Schiffmann2, Stefan S. Bertsch1.
1NTB University of Applied Sciences of Technology Buchs, Institute for Energy Systems, Buchs, Switzerland; 2Ecole Polytechnique Fédérale de Lausanne, Laboratory for Applied Mechanical Design, Neuchâtel, Switzerland
High temperature heat pumps (HTHP) with heat sink temperatures of 100 to 160 °C will increasingly become commercialized in the coming years, especially for industrial drying, sterilization and evaporation processes. In particular, the HFO R1336mzz(Z) and the HCFOs R1233zd(E) & R1224yd(Z) are low GWP replacement refrigerants for R245fa and R365mfc. This study examines the experimental performance of R1336mzz(Z) and R1233zd(E) 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 sink). At W60/W110, the experimental results with R1233zd(E) showed a COP of 2.8 (basic cycle) and 3.1 with IHX integration (+15%). For R1336mzz(Z) a COP of 2.4 and 3.0 was reached (+24%). By increasing the heat sink temperature glide from 5 to 30 K, a further 15% COP increase was achieved.