Going one step further to the cooling sector decarbonization.
The HYDROCOOL project will develop and test a novel CO₂ hydraulic cooling cycle concept to deliver cooling at any environmental conditions, meaning that it can work above the CO₂ critical temperature (>31ºC) via a reversible cycle capable of operating in both subcritical and transcritical conditions.
4 specific objectives to develop, characterize and assess the energy efficiency performance and operational conditions of a low footprint cooling system.
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Prove system flexibility and interchangeability between both subcritical (Tout <31ºC) and transcritical CO₂ cycles (Tout >31 ºC) depending on operating conditions and application.
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Achieve high system reliability and efficiency through design and operation improvements
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Demonstrate the affordability and reduced footprint of HYDROCOOL compared with conventional cooling solutions.
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Maximize the future use and impact of the project by defining the appropriate scale-up and communication strategy.
The project will develop 3 specific innovations that will go beyond the state of the art to improve the refrigeration systems performance.
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Using a liquid piston compressor that replace the mechanical compressor found in conventional cooling systems to enable a near-perfect isothermal CO2 compression to increase COP, along with reduced friction and avoided lubricants, extending component lifespan, and reducing maintenance costs.
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Develop a liquid piston fluid able to work at negative temperatures. The challenge is not only to achieve the system operability at freezing temperatures (up to -40ºC) but also overcome the challenge of its potential interaction with CO2 what would narrows the applicability of the system.
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The CO2 expander enables energy to be recovered: firstly, enabling the CO2 to expand in a quasi-isentropic manner which results in reduced vapor fraction in comparison to conventional expansion valve and, secondly, helping drive the next compression cycle converting this expansion into hydraulic pressure, enabling significant gains in COP (up to 10.2).
The ambition is to advance scientific knowledge and technological development on novel, clean, and efficient cooling generation, and supply displacing existing technologies.
Using CO2 as base refrigerant which, unlike the highly polluting CFC and HFC refrigerants, does not damage the ozone layer and has a minimal impact on global warming.
Reducing the footprint thanks to the high expected performance of the system, combined with the elimination of lubricant use and the circular design approach, enables up to a 55% reduction in the system’s carbon footprint compared to conventional systems.
Being a climate change adaptation tool as the system can operate in hotter climates and semi-desert regions where demand for cooling is expected to increase due to the need to ensure human-safe environmental conditions in the face of climate change. This thanks to the flexibility to work in both subcritical and transcritical mode (Tout>31ºC) thus allowing CO2 systems to operate in any environmental conditions.
Reducing the operational cost up to 95% (where 99% comes from the electricity cost) thanks to the increased system performance. Thus, significantly improving the cost-efficiency of the cooling sector, increasing the EU technological leadership in strategic productive fields strongly linked to cold production.
