EV cooling efficiency increases 4x with new electricity-free heat pipe tech

Researchers in Japan have developed a groundbreaking loop heat pipe (LHP) that achieves unprecedented heat transport capabilities without electricity.

The group’s loop heat pipe, detailed in the International Journal of Heat and Mass Transfer , is intended to enhance energy savings and carbon neutrality in industrial waste heat recovery, solar heat utilization, electric vehicle thermal management, and data center cooling.

This LHP outperforms the previous largest model thanks to improvements in the evaporator structure, resulting in an 18% size reduction, a 1.6 times increase in heat transport capacity, and a fourfold boost in heat transfer efficiency. LHPs are used in manned space flights, electric vehicles, meteorological satellites, and home appliances.

According to Professor Hosei Nagano, a senior researcher involved in the project, the LHP achieves unprecedented heat transport capabilities without electricity, marking the world’s largest non-electric heat transport.

It eliminates the need for electricity previously required by conventional mechanical pumps, allowing for near-perpetual heat transport without power.

Companies seek LHPs for cooling solutions to cut EV carbon footprints

The EV industry is increasingly seeking energy-efficient cooling solutions as companies become more aware of their carbon footprint. Loop heat pipes (LHPs) enhance EV efficiency by providing cooling without using electricity, thus lowering power consumption.

For electric vehicles, maintaining inverter temperature is crucial for optimal performance. Traditional cooling methods require energy, but the new LHP manages temperature without electricity, enhancing efficiency and handling high heat loads effectively.

In an LHP, heat is transported efficiently over long distances using a working fluid and a porous wick. The wick draws the fluid to its surface through capillary action. When heat is applied, the fluid turns into vapor, which travels to the condenser, releases heat, and condenses back into liquid. The liquid then returns to the wick, which draws it back to the surface, restarting the cooling cycle.

Optimized wick design and enhanced heat transport channels

The group improved the LHP by making the wick thinner, longer, and wider while maintaining its porous quality. They also enhanced heat transport by narrowing the vapor escape channels and adding more channels on the sides.

As Nagano explains, the loop heat pipe (LHP) stands out due to the shape, quality, and size of its wick and its overall performance. Typically, increasing wick size leads to reduced quality, but this wick maintains the high quality of smaller wicks. Its design includes cores that reduce thickness, resulting in lower pressure drop and operating temperatures.

Furthermore, the newly developed LHP achieved a heat transfer efficiency more than four times greater than existing models during testing. Its design allowed it to transport waste heat over 2.5 meters without power, utilizing the capillary force of the wick, setting a new record for non-powered heat transport.