【Frontiers in HaiChuan Chemical Technology】A new cooling mechanism has been discovered – the “dissolution pressure trapping effect”; Chinese research teams are poised to overcome the three major challenges in cooling technology at the same time

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Refrigeration technology affects the quality of life for everyone, and it may undergo a green transformation in the future. Researchers from institutions such as the Institute of Metal Research, Chinese Academy of Sciences, have discovered a completely new cooling mechanism – the \"dissolution pressure pinch effect\". This mechanism holds the potential to address the three major challenges faced by current cooling technologies: high carbon emissions, limited cooling capacity, and low heat transfer efficiency, thereby providing a new pathway for the development of next-generation efficient and environmentally friendly cooling technologies. The relevant research findings were published in the journal Nature on the 22nd. Most cooling devices we use in our daily lives, such as air conditioners and refrigerators, rely on gas compression for cooling. This refrigeration technology contributes about 2% to China’s GDP, yet it consumes nearly 20% of the country’s electricity and generates 7.8% of its carbon emissions. In recent years, scientists have begun to pay attention to solid-state phase change materials, which use external fields such as magnetic fields or pressure to achieve cooling, eliminating the need for greenhouse gases and thus being theoretically more environmentally friendly. However, due to issues such as slow heat transfer and high interfacial thermal resistance, solid-phase change cooling materials are difficult to be applied in high-power applications. In this study, the researchers observed in experiments that ammonium thiocyanate solutions exhibited extremely strong heat absorption and release phenomena under pressure changes: when pressure was applied, the salt precipitated and heat was released; when the pressure was reduced, the salt dissolved rapidly and heat was absorbed. “At room temperature, the temperature of an ammonium thiocyanate solution can drop by nearly 30°C within 20 seconds; the degree of temperature reduction is even greater in high-temperature environments, far exceeding the performance of known solid-phase change materials. We have named this phenomenon the ‘osmotic pressure card effect’. ”Li Bing, co-corresponding author of the paper and a researcher at the Institute of Metal Research, Chinese Academy of Sciences, told reporters. The breakthrough of this technology lies in combining the refrigerant with the heat transfer fluid; it utilizes the fluidity of the solution itself to achieve efficient heat transfer, and at the same time, the processes of dissolution and precipitation generate a large amount of cooling capacity. This approach effectively breaks the long-standing impossible triangle in the field of refrigeration materials – namely, the need for low carbon content, high cooling capacity, and efficient heat transfer. “Based on this effect, we designed a four-step cyclic system; simulation results show that each gram of solution can absorb 67 joules of heat per cycle, with a theoretical efficiency as high as 77%, indicating good potential for engineering application. ”Li Bing said, “This research not only proposes a completely new cooling mechanism but also lays a scientific foundation for the development of efficient and green cooling technologies for use in data centers and other applications.” ”