How is immersion cooling deployed
History / Fluid / Cooling / Operation maintenance
Immersion cooling technology directly submerges electronic components in dielectric fluid to dissipate heat. This method efficiently absorbs heat and maintains the components within a safe operating temperature range. Dating back to the 19th century, people used dielectric fluids like insulating oil to cool high-voltage transformers, reflecting an early understanding of the superior thermal conductivity of liquids. In the 20th century, with increased processing power and heat density, immersion cooling regained attention in the fields of high-performance computing and data centers. Advances in technology and materials have made this cooling method more practical and efficient. Currently, immersion cooling is primarily categorized into two types: single-phase and two-phase. Single-Phase Immersion Cooling: This is the most common form, where the liquid remains in a liquid state and absorbs heat from the components through convection. It provides effective cooling for high-density components while reducing noise, improving reliability, and enhancing space efficiency. Two-Phase Immersion Cooling: A more efficient system, two-phase immersion cooling involves the liquid boiling and evaporating around the heat-generating components. Heat transfer occurs through the rise and condensation of vapor. However, this approach requires more complex cooling designs. Despite its advantages in efficient heat transfer, immersion cooling faces challenges such as higher initial costs, maintenance complexity, and scalability issues in large data centers. Nevertheless, there have been successful cases in newly established data centers and renovated buildings, offering benefits like reduced noise and energy pollution compared to traditional setups.
As high-performance computing demands increase and electronic component power densities rise, the complexity and heat management challenges of module parts have become significant. The market is currently balancing performance and maintenance considerations. Immersion cooling technology has rapidly evolved due to its exceptional heat management capabilities, particularly in the realm of two-phase immersion cooling. This technology has garnered attention in advanced semiconductor applications because of its superior heat dissipation capabilities. Additionally, advancements in cooling fluid materials have led to the development of new coolants that not only enhance thermal conductivity but also reduce flow losses. These developments address issues related to dielectric breakdown voltage, biodegradability, and environmental impact, promoting practical adoption and efficient maintenance. Innovations in water-cooling systems optimize fluid dynamics and heat efficiency. These improvements support integration with monitoring systems, further enhancing proactive maintenance and performance optimization. Direct liquid cooling (DLC) remains a primary cooling solution for high-performance computing systems and data centers, coexisting with existing infrastructure. High-end gaming PCs are also increasingly adopting DLC to achieve better heat management and overclocking potential.
The foundation for embracing these new technological applications lies in their ability to deliver high computational power while minimizing digital pollution. However, these advanced cooling techniques present challenges, including higher upfront costs compared to traditional air-cooling solutions. Implementing and maintaining liquid cooling systems require specialized knowledge. Collaborations between open computing consortia and hardware manufacturers are essential for refining standard specifications, product development, and warranty support. Expanding immersion cooling systems to large data centers also poses scalability challenges in terms of system reliability. To mitigate environmental impact, selecting appropriate coolants and responsible disposal methods is crucial. Ongoing research focuses on developing dielectric fluids compatible with a broader range of electronic components, addressing challenges related to material compatibility, aging, and validating bandwidth and latency performance.
When selecting a suitable fluid for direct liquid cooling (DLC) and immersion cooling systems, several critical factors come into play: performance, safety, and lifespan. Selecting the right coolant composition and additives depends on specific use cases. Enhancing corrosion resistance, biostability, and antifreeze protection is crucial. Compatibility between the fluid and system materials prevents leaks and corrosion. Regularly monitoring coolant quality (purity, corrosion inhibitor concentration, and particle count) is essential for maintaining system performance and longevity. Safety and environmental impact are also vital considerations. Opt for fluids that meet safety standards and allow responsible disposal.
In modern heat dissipation techniques, the development of direct liquid cooling and immersion cooling systems is increasingly crucial for improving performance, compatibility, and environmental responsibility. The fluids used in these systems must not only have high thermal conductivity for effective heat transfer but also adhere to environmental standards and be compatible with various materials. Deionized water (DI water) is widely used due to its high thermal conductivity and relative affordability. However, it requires regular maintenance to maintain purity and prevent metal ion corrosion. Ethylene glycol (EG) and propylene glycol (PG) mixtures offer corrosion inhibitors and convenient liquid maintenance while balancing performance. Dielectric Fluids (such as synthetic hydrocarbons) have good thermal conductivity but flammable with necessitates caution. Fluorinated Liquids provide excellent heat performance and non-flammable. Higher cost and potential environmental impact. Synthetic Esters are an environmentally friendly choice but may have limited thermal conductivity.
Additionally, proprietary mixtures often contain additives like corrosion inhibitors, biocides, and defoamers to enhance specific performance and extend component lifespans. Monitoring fluid quality through regular analysis (temperature, conductivity, particle count, and dielectric strength) helps identify potential degradation products and minimize system losses. Ensuring material compatibility prevents leaks and corrosion. Remember that maintaining fluid quality is challenging during operational maintenance. These measures collectively ensure efficient cooling system operation and long-term stability.
In the field of cooling technologies within data centers, there are significant differences. Traditional air cooling systems rely on large amounts of water for evaporative cooling to achieve cooling water temperatures close to the wet bulb temperature. This can be problematic in water-scarce regions and is inefficient in hot and humid conditions, leading to increased energy consumption. In contrast, DLC and immersion cooling technologies have lower dependence on external climate conditions. They directly remove heat from electronic equipment without relying on air conditioning systems, allowing infrastructure to operate efficiently even at higher cooling water temperatures. This reduces the sensitivity of high loads to chiller performance and cooling water temperature, resulting in lower energy consumption and reduced water usage. These systems typically account for 30% to 50% of total data center water usage, which has decreased due to technological advancements but remains substantial. The goal is to make data center infrastructure fully compatible with dry coolers, reducing water dependency and environmental impact. Additionally, DLC and immersion cooling systems may allow for smaller chiller units or even eliminate the need for chillers in some cases. This helps reduce capital and operational expenses while minimizing greenhouse gas emissions, providing both economic and environmental advantages. Advances in cooling technology are crucial for data center operations, especially regarding water usage, regional climate adaptability, and cost-effectiveness.
Regarding regional climate impact, traditional air conditioning is highly sensitive to environmental temperatures, especially in hot and humid conditions where efficiency decreases, requiring more energy for air cooling, sometimes exceeding system capacity. In colder climates, additional heating is needed to maintain indoor temperatures, further increasing energy consumption. DLC and immersion cooling technologies focus on directly removing heat from electronic equipment, reducing reliance on external air temperatures, and allowing efficient operation even at higher ambient temperatures. Research indicates that these technologies can effectively cool data centers at temperatures ranging from 27°C to 30°C, compared to the traditional air conditioning system’s typical operating temperature of around 25°C, representing a 2°C to 5°C increase.
Dry coolers, in suitable climates such as cooler and drier regions, offer additional potential. These coolers use ambient air to cool the fluid loop without any water usage, reducing environmental impact and data center water consumption while implementing DLC or immersion cooling. Furthermore, dry coolers can eliminate 100% of data center cooling water usage compared to traditional air conditioning systems. Economically, while DLC and immersion cooling systems may have slightly higher upfront costs than traditional air conditioning, their potential for reducing chiller capacity cannot be overlooked. These systems may allow for smaller chiller units and piping systems, or even eliminate the need for chillers, potentially saving 10% to 20% in capital expenditures. Additionally, the use of dry coolers eliminates the need for water treatment facilities and related infrastructure, further reducing costs and saving 5% to 15% in capital expenditures. In terms of operational expenses, improving cooling efficiency significantly reduces energy costs. Studies show that DLC and immersion cooling can reduce energy consumption by 15% to 20% compared to traditional air conditioning. Additionally, minimizing water usage and related water treatment costs is expected to save 5% to 10% in operational costs.
DLC and immersion cooling systems provide efficient heat dissipation solutions for data centers, but they each have distinct maintenance and operational requirements. DLC systems typically involve direct contact between a liquid coolant and electronic components via cold plates. This design facilitates relatively straightforward maintenance with high repeatability. Regular checks for leaks or corrosion in the cold plates and pipes are essential. Monitoring the coolant level and adding coolant based on monitoring results is also part of DLC system maintenance. Filter replacement and monitoring coolant quality (including temperature, conductivity, and particle count) are critical components of DLC maintenance. However, disassembling and maintaining individual IT components connected to complex water-cooled plate systems can be more challenging. Immersion cooling fully submerges electronic components in a dielectric fluid. This approach requires maintenance similar to traditional air cooling and HVAC check. Tasks include continuous monitoring of fluid levels, regular analysis of dielectric fluid quality, and inspection for leaks or damage in the storage tanks. Immersion cooling maintenance can be more straightforward than DLC, especially for individual nodes within a rack.
Proper handling and disposal of coolant are crucial for environmental protection and worker safety. Compliance with regulations and best practices is essential. Leak monitoring and worker training are increasingly important. Operators need training on safe handling practices for specific coolant types and how to use leak detection systems effectively. Both systems have specified Mean Time Between Failures (MTBF) for components such as pumps, fans, and heat exchangers. DLC extra complex components require regular preventive maintenance based on MTBF guidelines helps extend equipment lifespan, while immersion remain similar to traditional IT maintenance without vendor locking. Regular monitoring of fluid quality is vital for both DLC and immersion cooling systems. Parameters include temperature, conductivity, particle count, and dielectric strength. Automated and real-time monitoring technologies track these parameters. Setting clear alarm thresholds helps identify issues promptly and enables preventive maintenance. Fluid analysis provides a comprehensive assessment of coolant health.
