How Alibaba’s Immersion Liquid‑Cooled Servers Achieve Near‑Perfect PUE

Alibaba Rebuilds Liquid‑Cooled Servers, Promoting Through Alibaba Cloud

On April 5, Alibaba Technology posted photos on its official Weibo confirming the “Kylin” project, which is actually one of the industry’s first immersion liquid‑cooling server clusters. The system uses liquid cooling instead of traditional air cooling, achieving a Power Usage Effectiveness (PUE) close to 1.0, a world‑leading figure.

The Weibo post described the “black‑technology” product as creating multiple industry records and supporting Alibaba’s “NASA” initiative. Photos show black metal boxes with the Alibaba logo placed on a rooftop container, and inside a transparent glass case the cables, copper tubes and high‑density server nodes.

According to senior server product expert Chi Ping, the “Kylin” plan mentioned on April 1 (April Fool’s Day) was a small side story after successful R&D; the real hardware is an immersion liquid‑cooling server cluster with PUE approaching 1.0.

PUE Nearing the Theoretical Limit

Immersion liquid cooling has attracted industry attention in recent years, especially after the SC14 Global Supercomputing Conference where many vendors showcased liquid‑cooling products. However, due to technical difficulty, most companies are still at single‑node testing or demonstration stages, with no large‑scale cluster deployments yet.

Deploying immersion liquid‑cooling clusters requires a complete redesign of server‑to‑data‑center architecture. Alibaba has conducted research on new cooling materials, server architecture, and full‑data‑center solutions, creating original design concepts and quickly building a full‑stack immersion‑cooled server solution for cluster practice.

In addition to hardware, Alibaba has developed a monitoring and management system tailored for immersion cooling. The technology will first be applied to Alibaba Cloud data centers, offering the solution as a public service. Immersion‑cooled servers are expected to excel in high‑frequency computing, significantly reducing energy consumption and enabling greener computing.

The servers use 3M fluorinated liquid, providing fan‑less, vibration‑free operation, superior heat dissipation, and improved component reliability by eliminating air, moisture, dust, and fan‑induced vibration.

Alibaba’s ongoing green data‑center innovations include a 2015 East China center using deep lake water cooling (average PUE < 1.3) and a North China center employing natural air and water‑side cooling (average PUE < 1.25). The new immersion‑cooled solution pushes PUE toward the theoretical limit of 1.0, inspiring the industry’s vision for future green data centers.