Recent content by jwseifed

hacksaw What's the theory behind that? From my understanding, a counterflow system is more thermally efficient.

brtueblood I shouldn't comment on the application of this technology, but the industry is definitely "hyper" competitive. [wink] It seeming more and more to me that frost is a problem we have to live with. Insulating or heating the surface would reduce frost but also reduce heat transfer, which...

A closed-loop control of the surface temperature is very interesting. Decreasing LN2 flow rates would increase the surface temp but it would also decrease heat transfer rates, and thus our outlet air temperature would increase, and we want to decrease it as much as possible. Trying to decrease...

Thanks I'll look into that. I think LittleInch is right in that it is mainly just extra resistance due to fouling. These particles stick pretty good, have to open up our HX and see.

The np material is boron carbide. In the previous successful test referenced, the material was aluminum oxide.

Yea I'm guessing it is LittleInch. I agree there aren't really any confirmed findings with nanos. We are going based off of previous experiments, albeit much smaller scale ones, which showed some heat transfer enhancement of fluid after nanoparticles were introduced compared to before. The...

Thanks for replying IRstuff. Our hypothesis was based on previous experiments which showed an increase in heat transfer, based on increased delta_T, of air passing over a hot wire after nanoparticles were injected. However that was for a CROSS FLOW configuration, and ours is essentially...

Hey guys. I have a counterflow heat exchanger which passes liquid nitrogen through tubes and hot exhaust gas over them externally. At the same time, we are injecting nanoparticles into our inlet pipe so that it mixes with the exhaust gas prior to entering the heat exchanger. The purpose of this...