Liquid Cooling at Huaxin: What the Published 45 kW Rack Design Included

The Huaxin project is interesting because the published design does not stop at a liquid-cooled rack. It also has to move that heat into a room-side cooling loop. The source page identifies the work as a Zhejiang Science and Technology Department “Jianbing Lingyan” research project and describes a joint full-liquid-cooling solution for a data center.

What the project record lists

The public project description says the scope used two 45 kW liquid-cooled racks and four water-to-water dual-coil in-row air conditioners. The design is described as a hybrid active and passive cooling system, with air and liquid paths working in the same installation.

That combination matters at the interface between the rack loop and the room loop. A liquid-cooled rack can remove a large share of the heat close to the source, but the remaining air-side heat still has to be handled. The in-row units are the published room-side element in this project.

Engineering questions the page leaves open

The source does not publish the cooling-water temperatures, flow rates, pressure-drop limits, leak-detection arrangement, redundancy level or commissioning acceptance criteria. Those details should not be inferred from the equipment list. For a live project, they belong in the hydraulic calculation, control narrative and commissioning record.

The useful planning lesson is narrower and more reliable: a high-density liquid-cooling project needs a clearly defined boundary between rack-side and room-side heat removal. Equipment names alone do not show whether that boundary has been designed well.