Liquid cooling plate

Liquid cooling plates are the core components of liquid cooling systems, efficiently removing heat through the circulation of coolant. They are widely used in data centers, electric vehicles, high-performance computing, and other fields, offering advantages such as high heat dissipation efficiency, uniform temperature distribution, compact space requirements, and low noise levels. Their design requires comprehensive consideration of factors such as materials, flow channels, manufacturing processes, and condensation prevention. Below is a detailed introduction to liquid cooling plates:

I. Core Functions and Principles of Liquid Cooling Plates
Liquid cooling plates transfer heat generated by heat-generating components (such as chips, battery modules, and IGBT modules) to a radiator and dissipate it into the environment through the circulation of internal coolant (e.g., water, ethylene glycol mixtures, fluoride-based coolants). Their working principle can be divided into three steps:

1. Heat Source Contact and Conduction: Heat-generating components are closely attached to the surface of the liquid cooling plate using thermal interface materials (such as thermal grease and pads).

2. Solid Wall Conduction: Heat is transferred from high-temperature areas through the metal material of the liquid cooling plate (e.g., copper, aluminum alloy) to the inner wall of the flow channels.

3. Convective Heat Transfer: The coolant, driven by a pump, flows through the flow channels, disrupting the laminar boundary layer through forced convection (especially in turbulent flow conditions) to achieve efficient heat exchange.

II. Core Advantages of Liquid Cooling Plates

1. High Heat Dissipation Efficiency: The specific heat capacity of liquids is much higher than that of air (water is approximately four times that of air), and the convective heat transfer coefficient can be dozens of times higher than that of air, resulting in stronger heat-carrying capacity per unit volume.

2. Excellent Temperature Uniformity: Optimized flow channel designs (such as serpentine and multi-branch configurations) can prevent localized overheating and ensure stable equipment operation.

3. Compact Space Requirements: Liquid cooling systems have a smaller volume, making them suitable for high-density equipment arrangements.

4. Low Noise Levels: Relying on liquid circulation for heat dissipation eliminates the need for high-speed fans, making them suitable for quiet environments.

5. Flexible Customization: Dimensions, shapes, and flow channel designs can be customized according to specific needs to meet special application scenarios.

III. Key Design Elements of Liquid Cooling Plates

1. Material Selection:

   • Copper: With a thermal conductivity of approximately 400 W/m·K, copper offers excellent heat dissipation performance but is costly. It is commonly used in high heat flux density scenarios (such as CPUs and GPUs).

   • Aluminum Alloy: With a thermal conductivity of approximately 235 W/m·K, aluminum alloy is cost-effective, lightweight, and highly corrosion-resistant, making it the mainstream choice (e.g., for electric vehicle battery packs and energy storage systems).

   
   

2. Flow Channel Design:

   • Straight Flow Channels: Simple in structure and low in flow resistance, but may result in uneven temperature distribution.

   • Serpentine Flow Channels: Extend the coolant path, improve heat transfer efficiency, and enhance temperature uniformity, but with higher flow resistance.

   • Multi-Branch/Zoned Flow Channels: Optimize flow distribution to meet the needs of different heat source areas.

   
   

3. Manufacturing Processes:

   • Brazed: Flexible flow channel design, low thermal resistance, and high pressure resistance make brazing the most mainstream method.

   • Embedded Tube: Simple in structure and low in cost, but with a longer heat conduction path and higher thermal resistance.

   • Skived Fin/Folded Fin: Fins are integrally formed with the base plate, resulting in extremely low thermal resistance and suitable for high heat flux density heat dissipation, but at a higher cost.

   • Friction Stir Welding: Used for manufacturing large, complex, or irregularly shaped liquid cooling plates (such as the base plate of new energy vehicle battery packs).

   • Blow-Formed: Low in cost and suitable for simple shapes and high-volume production (such as home appliances), but with limited flow channel design options.

   • 3D Printing: Offers extremely high design freedom and enables topological optimization of flow channels, but currently at a high cost.

   
   

IV. Typical Application Scenarios of Liquid Cooling Plates

1. Data Centers and High-Performance Computing:

   • Server CPU/GPU Heat Dissipation: Ensures stability during long-term high-load operation and improves energy efficiency.

   • Supercomputer Heat Dissipation: Solves heat dissipation challenges under extremely high heat flux density conditions.

   
   

2. Electric Vehicles:

   • Battery Management System (BMS) Heat Dissipation: Ensures uniform battery temperature under various operating conditions and prevents thermal runaway.

   • Motor Controller Heat Dissipation: Improves equipment efficiency and lifespan.

   
   

3. Energy Storage Systems:

   • Battery Pack Heat Dissipation: Ensures temperature stability during battery charging and discharging processes and extends battery lifespan.

   
   

4. Laser Equipment:

   • Laser Cutting/Welding Equipment Heat Dissipation: Improves equipment accuracy and lifespan.

   
   

V. Condensation Prevention Design for Liquid Cooling Plates
Liquid cooling plates may produce condensation on their surfaces in low-temperature, high-humidity environments when the surface temperature drops below the air dew point, leading to equipment failures. Condensation prevention design requires comprehensive consideration of the following measures:

1. Thermal Insulation Materials: Cover the surface of the liquid cooling plate with low-thermal-conductivity materials such as foam and expanded rubber to reduce heat loss caused by thermal conduction and prevent the surface temperature from rapidly dropping below the dew point.

2. Precise Temperature Control:

   • Dew Point Sensing and Feedback Control: Install dew point sensors to monitor environmental temperature and humidity in real-time, calculate the dew point temperature, and automatically adjust the coolant temperature when it approaches or drops below the dew point.

   • Coolant Temperature Regulation System: Use heat exchangers or heaters to raise the coolant temperature and ensure it remains above the dew point.

   
   

3. Sealing and Isolation Design:

   • Use waterproof seals and sealants to ensure tight waterproofing at the connection points between the cooling plate and electronic equipment.

   • Establish airtight isolation zones inside and outside the cooling system to block high-humidity environments.

   
   

4. Humidity Control and Dehumidification Equipment:

   • Install dehumidification devices (such as condensation-type dehumidifiers or moisture-absorbing materials) inside the equipment or around the cooling system to reduce air humidity and thus lower the dew point temperature.

   
   

5. Condensate Management and Drainage System:

   • Set up drainage structures or guide channels on the surface of the liquid cooling plate to collect and drain condensed water out of the equipment.

   • Install a condensate recovery system to pump the water to an evaporation unit or external treatment device through a circulation pump.