TheWill
Automotive
- Dec 22, 2006
- 2
Hey guys! I've got a design question. I've got an enclosed system of cooling air that tends to reach 100-130 C, and we're trying to develop a compact air to air heat exchanger system with minimal impact to flow efficiency and minimal size.
I had the thought to use a long, narrow array of heat pipes or heat columns, half exposed to the hot side, half exposed to the ambient air, which is expected to be significantly cooler, closer to 37 C, with around a 30 mph average speed.
What I'm finding difficult to locate are data points on the efficiency and thermal transfer rate of heat pipes/columns. What I do know is they tend to have their greatest efficiency at ~70 degree tilts (on groove wick types) utilizing gravity assist. I am using a seemingly accepted data point of 100W of energy transfer for a 100mm long, 8mm round copper heat pipe with DI water, though admittedly this is a number that I've seen three times on different websites, so I don't know how well I can trust it.
So what do you think about this system? Are heat pipes/columns acceptable for air to air heat transfer? Should they be freely exposed to the airlfow, or should I design a system of layered plates in the internal air system to separate the air into separate cavities to maximize surface contact? Any other thoughts?
And if anyone has more data on heat pipes and their efficiency, I'd love to hear it, as well as any other ideas you have.
Some more specifications: The cooling pipes that we can work with are a 3"-4" round pipe, and a 4"x4" squared off pipe sections.
Thanks!
Will
I had the thought to use a long, narrow array of heat pipes or heat columns, half exposed to the hot side, half exposed to the ambient air, which is expected to be significantly cooler, closer to 37 C, with around a 30 mph average speed.
What I'm finding difficult to locate are data points on the efficiency and thermal transfer rate of heat pipes/columns. What I do know is they tend to have their greatest efficiency at ~70 degree tilts (on groove wick types) utilizing gravity assist. I am using a seemingly accepted data point of 100W of energy transfer for a 100mm long, 8mm round copper heat pipe with DI water, though admittedly this is a number that I've seen three times on different websites, so I don't know how well I can trust it.
So what do you think about this system? Are heat pipes/columns acceptable for air to air heat transfer? Should they be freely exposed to the airlfow, or should I design a system of layered plates in the internal air system to separate the air into separate cavities to maximize surface contact? Any other thoughts?
And if anyone has more data on heat pipes and their efficiency, I'd love to hear it, as well as any other ideas you have.
Some more specifications: The cooling pipes that we can work with are a 3"-4" round pipe, and a 4"x4" squared off pipe sections.
Thanks!
Will
