Mountainbeers
Well-Known Member
So I've been getting ready to go AG soon and I am amazed at the amount of water these chillers go through.
Yea yea I know what you're going to say..."Recycle your water!"..."Recirculate your water!" Well I'm willing to do that but only if I can't find an easier solution first.
I started trying to think of a design for a chiller using ice. The problem with ice baths now are that a) they melt too fast and b) the heat (energy) isn't taken away like it is in water in say an IC so it takes too long.
Now for the boring part. Hang in there.
The general heat transfer formula is:
1/UA = 1/h1*A1 + (dx/KA) + 1/h2*A2
U = the overall heat transfer coefficient (w/m^2k)
A = contact area (m^2)
k = thermal conductivity of material (w/mk)
h = individual convection heat transfer coefficient for each fluid (w/m^2k) (this depends on the type of fluid and the velocity at which it is moving)
dx = wall thickness (m)
So in general, in order to increase your heat transfer you want to:
1) Increase the amount of contact between the fluids. (A)
2) Decrease the thickness of your copper wall. (dx)
3) Increase the speed at which the fluids move by each other. (h)
4) Increase convection coeff. (h)
With the below design you would be keeping the same k and dx because you are using copper tubing. The only common material with a higher coeff. than copper is silver. And this obviously isn't practical. Ice would fill the cavity (which would be closed off on the ends) and melt down through the holes. The ice conducts heat about 4 times more than water.
Has anybody tried anything like this?
Yea yea I know what you're going to say..."Recycle your water!"..."Recirculate your water!" Well I'm willing to do that but only if I can't find an easier solution first.
I started trying to think of a design for a chiller using ice. The problem with ice baths now are that a) they melt too fast and b) the heat (energy) isn't taken away like it is in water in say an IC so it takes too long.
Now for the boring part. Hang in there.
The general heat transfer formula is:
1/UA = 1/h1*A1 + (dx/KA) + 1/h2*A2
U = the overall heat transfer coefficient (w/m^2k)
A = contact area (m^2)
k = thermal conductivity of material (w/mk)
h = individual convection heat transfer coefficient for each fluid (w/m^2k) (this depends on the type of fluid and the velocity at which it is moving)
dx = wall thickness (m)
So in general, in order to increase your heat transfer you want to:
1) Increase the amount of contact between the fluids. (A)
2) Decrease the thickness of your copper wall. (dx)
3) Increase the speed at which the fluids move by each other. (h)
4) Increase convection coeff. (h)
With the below design you would be keeping the same k and dx because you are using copper tubing. The only common material with a higher coeff. than copper is silver. And this obviously isn't practical. Ice would fill the cavity (which would be closed off on the ends) and melt down through the holes. The ice conducts heat about 4 times more than water.
Has anybody tried anything like this?