Experimental and numerical investigation of a transcritical CO₂ air/water reversible heat pump: analysis of domestic hot water production

As a natural refrigerant, carbon dioxide is safe, economic and environmentally sustainable and can be
successfully utilized in heat pump and refrigeration systems operating according to transcritical cycles. This
paper describes the development of a CO₂ air/water reversible heat pump, specifically investigating the
domestic hot water (DHW) production operating mode. A dynamic model of the heat pump is developed with
the software Simcenter Amesim. After validation against experimental data, the numerical model is utilized to
predict the performance of the heat pump to a varying hot water demand, evaporator air inlet conditions and
high pressure value, leading to the discussion of the optimal control strategy.
Keywords: Transcritical heat pump, Carbon Dioxide, Numerical model, COP, DHW, Energy Efficiency.