Daily Archives: July 23, 2022

Advancements in Hybrid Thermal Management

Over the past few decades, the fastest-growing electronic industries have been power and energy. These include fuel cell and battery technologies, and power inversion, conversion, and rectification.

With form factors getting smaller, power electronic systems are becoming increasingly complex, while, at the same time, performing at higher power ranges. That makes heat generated within the system the greatest limiting factor to its functioning. To dissipate the amount of power the system generates, it is necessary for the designer to optimize and enlarge air cooling systems to remove the heat effectively. In some cases, size is the limiting factor for systems using forced convection. Where the weight or size of the air-cooled solution becomes impractical, engineers prefer to use liquid cooling as an alternative method.

However, it is not easy to switch quickly from an air-cooled system to a liquid one. Designers must consider several factors and possibilities for improving thermal management for handling higher heat loads. Although the market is trending towards full liquid cooling as the industry standard for cooling power electronic systems in the future, engineers can also consider various hybrid solutions. That helps to apply the benefits of hybrid systems as the system evolves or upgrades.

Engineers use liquid cooling systems, making them complementary to existing air-cooled solutions. That allows them to expand it gradually to replace the air-cooled system. They do this with a focus on the electronic systems that benefit from liquid cooling. For this, they employ fluid couplings, dependable pump systems, and compact heat exchangers. The system transfers heat from airflow to liquid flow that transports it elsewhere to manage it. If this is not possible, engineers have the option of fully replacing the air-cooled system with a liquid-cooled one, thereby enabling higher power outputs while optimizing the thermal performance.

Engineers must consider numerous key determining factors for improving the performance of any power electronic devices and facilities while switching to liquid cooling. They must consider the thermal performance requirements in addition to the size and weight requirements. They must also look into further optimizing the present air cooling system and whether it will still remain a viable thermal option. Furthermore, they must also look into any limitations on the availability of the liquid cooling system. As cost is always a huge factor in any project, the engineer must also look into the return on efficiency and performance when investing in liquid cooling. Also, they must look into the downtime necessary for the conversion and the easiest way of implementing the changeover.

Both forced, and natural thermal management has limitations. The total surface area necessary to dissipate heat limits natural thermal management systems, necessitating heavy and large, but impractical solutions.

On the other hand, pressure drop limits solutions using forced convection. Heat sinks require large surface areas in viable volumes. This creates high amounts of air resistance. But this also hinders the amount of airflow, thereby limiting the heat transfer from a fan. This, in turn, requires larger or more fans, and this increases the amount of noise in the system.