2015. április 26., vasárnap

Thermoacoustic refrigeration part 2.

Hi folks!

This is the second step of my huge project of thermoacoustic refrigeration.
Today I'll show you my new engine's parts also the first test run and I'll draw the conclusions.

The engine is a standing wave type refrigerator.
Base parts:
- loudspeaker driver
- heat exchangers
- stack
- resonator
- amplifier
- PC, program
- digital thermometers
That's all!

My 180/120 W SAL XPRO 2060 loudspeaker is working in a closed
20 litres 250 mm diameter orange PVC tube box.

The other PVC tubes are 50 mm outside diameter.
The fittings and other parts dedicated for this diameter.
Easy to use them.

The heat exchangers from 0,4 mm holes, 0,063 mm wire, 75% relative open area copper mesh.
I stick together these with neutral silicon on a sticky tape base.
Layer by layer, nearly hole on hole.
That was a horrible slow and riski work.

The stack was a rolled, parallel plate style stack with 0,4 mm gap. Length: 83 mm
Plastic sheet's 0,08 mm thick.

I used a new tech for spacing!
Sorry, I don't need to show it yet!
I hope you understand! :)
But this  technique is so different as sticked fishing line spacer.
It has more open area. :)

Amplifier is a KÖNIG 6000, 2x170W on 4 ohm.

Thermometers are HQ FT-10 stainless steel pin food thermometer,
the range of this thermometer is -50 to 300 C degrees.

The working frequency was 108 Hz,
sinus shaped wave
what I made with a small Hungarian language program they call it Jelgen.
So simple to use on any PC.

Resonator length was λ/2: 1,6 m

Experiment start at 22.7 degrees room temperature.
The hot side is going up pretty quikly, but after the cold side start to drop.
The cold side was loaded from the room across the copper heat exchanger,
 so the 17 degrees is good for first run.
The hot side hasn't enough cooling capacity, so there was a big temperature different.
Here is my video about this experiment,
Dont forget to vote it, and share it with your friends on your community sites please!

Much better performance with a new parallel plate stack:


The cooling capacity isn't enough on the hot side, so I'll change the heat exchanger soon for a better one.
After I want to reach the magic 0 degrees celsius!
The stack performance was pretty good, but I need to change the length of it, 
also I need to change it for my new type parallel and pin array stack, 
and I need to check the differents in this atmospheric engine.

Last performance on 27.05.2015. was only one degrees yet:

Later on...
A need to build a "Bellow Bounce" type refrigerator too, but not the infold version as Ben and Jerry's refrigerator.
My engine will be straight and I'll use a simple rubber boots accordion for bouncer.
It has lower frequency and the resonator length should be 1/50th of the wavelength!
Unbelievable thesis!

See You Soon!