HYDROCOOL · Novel advanced hydraulic CO2 refrigeration system for multiple sectors

The cooling production, coupled with renewable electricity generation, are considered a cornerstone technology to meet increasing global cooling demand whilst decarbonise various sectors. According to the International Energy Agency, only accounting the air-conditioning sector, consumes about 20% of the overall electricity used globally and is expected to be doubled by 2050. Improving the efficiency, reliability, affordability, and environmental performance of cooling systems is critical to maximum benefit for society and the environment. HydroCool project will develop a novel cooling production concept that can significantly improve the cooling system performance beyond the state-of-the-art. The solution is based on the hydraulic compression and expansion of CO2 in a reversible cycle capable of delivering cooling for a wide range of application such as food, data centres or air conditioning [-40ºC;+12ºC]. By switching from solid to fluid dynamics, HydroCool will enable both isothermal compression using liquid piston fluid and energy recovery between expander and compressor. Preliminary studies indicate a potential to nearly double the Coefficient of Performance through these two mechanisms. The hydraulic compression is also expected to lead to a significant improvement of the system lifespan, operating cost and reliability due to reduced friction and limited use of lubricants. Additionally, HydroCool offers an opportunity to accelerate the move in favour to CO2, displacing the use of environmentally harmful HFC and CFC refrigerants with high Global Warming Impact, that combined with the high system performance, improves considerably the cooling sector footprint by almost halving its impact. Thus, HydroCool will improve the affordability, performance, sustainability, and scalability of the CO2 based refrigeration system. In the project, a hydraulic CO2 cooling system will be engineered, implemented, and tested at 17.6kW scale to achieve TRL4.