Scroll compressor technology development for next generation refrigerants: Experimental and numerical model development
The imperative to mitigate climate change is driving the HVAC&R industry to transition to low-Global Warming Potential (GWP) refrigerants like R-290 and R-454C, as mandated by global protocols such as Kigali Amendment (2016) and F-Gas Regulation (2024). This study presents experimental evaluations and modelling efforts to support the development of high efficiency scroll compressors tailored for these next generation working fluids. Drop-in tests are performed for R-290 and R-454C using a Hydrochlorofluorocarbon (HCFC)- based scroll compressor, along with tests on a commercially available R-290 compressor and an R-410A baseline compressor. The tests demonstrated that R-290 offers high overall isentropic and volumetric efficiency potential. However, the lower volumetric capacity of these alternative refrigerants limits their delivered capacity compared to R-410A. This highlights the need for a comprehensive compressor redesign that goes beyond simple displacement scaling, as the interaction between refrigerant thermophysical properties and compressor geometry is highly coupled and non-linear. To support this, a high-fidelity, physics-based mechanistic scroll compressor model was developed incorporating detailed geometric features, leakage paths, and motor characteristics. The model was validated against R-410A experimental data, achieving mean absolute percentage errors (MAPE) of 2.4 %, 1.18 % and 2.12 % for mass flow rate, power consumption, and overall isentropic efficiency, respectively, and a mean absolute error (MAE) of 1.74 °C for discharge temperature. This developed model serves as an essential tool for further soft optimization studies to isolate loss mechanisms and define the necessary geometric modifications (e.g. scroll height, volume ratio) to maximize performance for R- 290 and R-454C. This combined experimental and modeling approach supports the development of high efficiency compressors for next-generation refrigerants.