Chinese Scientists Break Cooling Efficiency Barrier with Novel Salt-Based System

A breakthrough in cooling technology could revolutionize refrigeration and data center cooling, addressing both environmental concerns and the growing thermal demands of artificial intelligence infrastructure. Chinese researchers have developed a novel cooling system that achieves exceptional efficiency while producing zero carbon emissions.

The Environmental Challenge of Cooling

Traditional vapor-compression cooling systems consume massive amounts of energy and contribute significantly to global carbon emissions. According to recent data, these systems account for nearly 15% of electricity consumption in China and over 7.8% of global carbon emissions. As global cooling demand is projected to triple by 2050, finding sustainable alternatives has become increasingly urgent.

The "Impossible Triangle" Solved

For years, researchers have struggled with what they call the "impossible triangle" of cooling technology: achieving high cooling capacity, efficient heat transfer, and zero-carbon emissions simultaneously. Solid-state caloric materials offered a low-emission alternative but suffered from poor heat transfer capabilities that limited their practical application.

A research team led by Prof. Li Bing at the Institute of Metal Research, Chinese Academy of Sciences, has now cracked this challenge by developing a novel dissolution barocaloric effect system. Their work, published in the journal Nature, introduces a cooling method that combines the thermal benefits of solid coolants with the rapid flow capabilities of liquids.

How the Technology Works

The system uses an ammonium thiocyanate (NH4SCN) salt solution as its core component. The cooling cycle operates through a simple yet effective sequence:

Pressurization Phase: When pressure is applied, the solid salt precipitates out of the solution, releasing heat in the process.

Depressurization Phase: When pressure is removed, the salt rapidly dissolves back into the water, absorbing a massive amount of heat and causing the temperature to drop dramatically.

This approach transforms the coolant into a pumpable fluid that responds instantly to pressure changes, eliminating the heat-transfer bottlenecks that plague traditional solid boundaries.

Performance Results

During laboratory testing at room temperature, the fluid's temperature plummeted by nearly 30 kelvins (approximately 30°C) in just 20 seconds. The cooling span reached as high as 54 kelvins at elevated temperatures, demonstrating the system's effectiveness across different operating conditions.

Most impressively, simulations of a prototype four-step cycle showed an energy efficiency approaching 77% and a cooling capacity of 67 joules per gram. This performance significantly exceeds many existing cooling technologies while maintaining zero carbon emissions.

Applications and Future Impact

The technology's exceptional high-temperature performance makes it particularly suited for managing the intense thermal loads of next-generation artificial intelligence computing centers. As AI systems become more powerful and generate more heat, efficient cooling solutions will be critical for their operation and sustainability.

Beyond data centers, this stable and reversible technology paves the way for commercial, zero-emission refrigeration systems that could dramatically reduce the environmental impact of cooling in homes, businesses, and industrial applications.

The research represents a significant step forward in sustainable cooling technology, potentially addressing one of the most pressing environmental challenges of our time while meeting the growing demand for efficient thermal management in advanced computing systems.

Source: Nature via China Daily, MDPI, and Nature (2)