アコースティッククーリング技術の紹介
Hello everyone, SCIEN-SPOT is a podcast that shines a spotlight on the latest scientific
technology from Japan. Your host is REN from SCIEN-TALK. Today, I'm going to talk about
the cooling things with sound, known as acoustic cooling. Do you know what typically powers
the cooling devices we use every day, like refrigerators and air conditioners? Most commonly,
they use a method called vapor compression, which relies on the refrigerant, like from
gas. However, some of these refrigerants are greenhouse gases that contribute to global
warming, raising concerns about their environmental impact. This topic is the topic I talked about
in the previous episodes. But a new and environmentally friendly cooling technology that gains significant
attention is what we're discussing today, acoustic cooling. As the name suggests,
this is technology that uses sound waves to move heat, literally cooling with sound. So
how exactly does it cool? Imagine pumping air into a bicycle tire very quickly. The
nozzle often feels warm. That's because compressing air generates heat. Conversely,
音響冷却の原理
if you quickly release air from a tire, it feels cold because the expanding air absorbs
heat. Acoustic cooling works on this very same principle. When sound waves, for instance,
move through a gas like air or an insert gas, they cause the gas to rapidly expand and compress.
During this process, the gas absorbs and releases heat from its surroundings, a phenomenon
called adiabatic expansion and compression. Specifically, when this gas passes through
a porous material called a stack, an efficient heat exchange occurs between the gas and the
solid walls. This causes the heat to move in one direction, creating a cooling effect.
This entire process is highly efficient, described as the reversible cycle with high energy conversion
efficacy. An advantage of acoustic cooling is it's environmentally friendly. A major
advantage is that it doesn't use refrigerant like CFCs, which contributes to global warming,
making it environmentally friendly. And easy maintenance. With fewer moving parts,
it's less prone to breakdowns and are relatively easy to maintain. And quiet operation. It operates
アコースティック冷却技術の進展
much more quietly compared to traditional compressor-based cooling systems. This
acoustic cooling technology has made remarkable progresses in recent years, particularly with the
travelling wave type efficiencies that defy conventional wisdom have been reported.
In Japan, efforts to commercialize this technology are well underway.
Chuo Seiki Corporation and Tohkai University have jointly developed a thermal acoustic
cooling system that utilizes waste heat from factories, and they have successfully implemented
it on a production line for the first time in Japan. This system can operate using factory waste
heat at 250 degrees Celsius and generates cooling down to minus 30 degrees Celsius.
This is a truly groundbreaking step because it effectively utilizes previously wasted
industrial heat and contributes to reducing carbon dioxide emissions.
The research team aims to apply this technology to a wider range of fields.
Beyond general factory cooling and freezers, the possibilities are vast, from power to
音響冷却技術の応用
generation and cooling using waste heat from ship engines, to home generators,
air conditioning, and refrigerators powered by solar heat. Especially promising its application
in the car air conditioning system using engine waste heat, which is expected to
significantly improve fuel efficiency and reduce environmental impact. Furthermore,
thanks to its characteristics of low vibration, long lifespan, and maintenance-free operation,
acoustic cooling is also gathering attention as a cryo-cooling technology in military or space
applications. So, as we have seen, acoustic cooling is an incredibly environmentally friendly
technology because it can cool using only air without the need for front or other refrigerants.
Of course, there are still challenges for commercialization such as further improving
power consumption efficiency and addressing noise issues inherent in using sounds,
but advancements like optimizing stack and their resonance tube designs and the evolution of
cutting-edge noise reduction technology like active noise control systems are helping to
持続可能な冷却技術の未来
overcome these hurdles. While acoustic cooling still has some technologically immature aspects,
its low environmental impact and the potential to utilize untapped waste heat make it a
highly anticipated future cooling technology that can contribute to achieving a sustainable society.
So that's all for today's SciencePod. Today, let me chat a bit this time. Now, I'm planning a
driving trip to Cornwall in the UK soon, so I'm recording this series on refrigerators once or twice.
My apologies if the audio isn't great, but I hear Cornwall has beautiful resort-like scenery, so I'm
hoping to film some videos and share my thoughts about it later.
So that's all today's SciencePod. This podcast is broadcasted daily on weekday morning in both
Japanese and English. I'd love for you to listen to the podcast and post your
thoughts with hashtag SciencePod. See you next time!
