As data centers continue to expand, traditional air cooling technologies increasingly struggle to meet the thermal demands of high-density computing equipment. Liquid cooling, with its superior thermal conductivity efficiency, has emerged as a popular choice for data center cooling. The Cooling Distribution Unit (CDU), a core component of liquid cooling systems, manages and distributes coolant to ensure stable operation of data center equipment within optimal temperature ranges. So how should a CDU be installed and managed? This article details the key installation and management considerations for CDUs when deploying liquid cooling in data centers.
How a CDU Works
A coolant distribution unit (CDU) achieves strict coolant management by creating a secondary cooling loop isolated from the chilled water supply system (FWS), precisely controlling the cooling system's temperature, pressure, and flow rate. Its core components include pumps, heat exchangers, piping systems, and control systems. The primary side connects to the external cooling system, using electric regulating valve to regulate coolant flow into the CDU, thereby indirectly adjusting secondary-side temperatures. The secondary side connects directly to servers, with variable-speed pumps modulating circulation flow to ensure optimal heat dissipation efficiency.
CDU Installation
1. Pre-Installation Inspection
Before installing the CDU, conduct a thorough inspection to ensure compliance with data center specifications. First, verify the CDU's power requirements and confirm the data center possesses the necessary power capacity and type. Next, assess the CDU's feed type (top-fed or bottom-fed) and determine specific connection requirements, including pipe dimensions and fitting types. Additionally, understand the connection types needed for monitoring and integration with the data center's monitoring system.
2. Installation Location
The CDU's installation location significantly impacts its performance and maintenance accessibility. CDU equipment should ideally be installed outdoors, isolated from the main equipment room. If installed indoors, a waterproof containment barrier must be provided. Front and rear maintenance clearance should not be less than 800mm, while main equipment maintenance clearance should not be less than 1000mm.
3. Piping Connections
Within the data center, cold liquid pipes should preferably be routed under the floor, with adequate waterproofing, leak detection, and drainage measures implemented, along with corresponding alarm functions. When routing primary cooling loop pipes under the floor, the clear height under the raised floor should not be less than 600mm. When routing pipes above the floor, the clear height above the cabinet top should not be less than 600mm.
4. Refrigerant Charging and Commissioning
Before charging refrigerant and commissioning the liquid circuit, complete pressure testing of the primary cooling loop liquid cooling system, inspect valve statuses, and finalize CDU electrical connections. Use a funnel during refrigerant charging to prevent spills, and assign personnel to monitor the liquid cooling system for leaks during replenishment. After reaching the specified pressure, maintain CDU operation for over 24 hours to observe the liquid level in the CDU reservoir.
CDU Management
1. Real-Time Monitoring and Alarms
The CDU is equipped with integrated leak detection, intelligent flow monitoring, and alarm functions to ensure the safe operation of data center equipment. Through the real-time monitoring system, the CDU's operational status can be continuously tracked. Upon detecting anomalies such as signal loss or increased interference, the system immediately triggers an alarm to notify maintenance personnel for prompt resolution.
2. Regular Maintenance
To ensure long-term stable operation of the CDU, regular maintenance is essential. Periodically inspect the equipment's operational status and promptly replace aged or damaged components. For example, the CDU's filter (typically 50 microns) requires regular replacement to maintain coolant cleanliness and prevent contaminants or debris from compromising the integrity and performance of the server cold plate.
30 Energy Efficiency Optimization
With dynamic scalability and hot-swap design, the CDU easily adapts to cooling demands ranging from small server cabinets to hyperscale data centers. Each heat exchange module's 100kW capacity, combined with the plate heat exchanger's efficient thermal conductivity, significantly enhances cooling efficiency for high-power-density scenarios. Additionally, the constant-pressure module works in tandem with motorized ball valves to allocate cooling resources on demand, reducing energy consumption and improving the data center's Power Usage Effectiveness (PUE).
When deploying liquid cooling in data centers, CDU installation and management are critical to ensuring stable system operation. Through scientifically sound practices—including optimal placement, piping connections, refrigerant charging, and commissioning—alongside real-time monitoring, regular maintenance, and energy efficiency optimization, CDU performance and reliability can be substantially enhanced. Looking ahead, as technology continues to advance, CDUs will play increasingly vital roles across broader applications, providing robust safeguards for the secure and stable operation of data centers.
