Maisotsenko cycle

[Lc_shi]

I read an article about Maisotsenko cycle refer to below link:


http://www.idalex.com/technology/how...erspective.htm

i can't grasp the keypoint, who know it more in depth?

regards
lichuan

[chemi-cool]

Look here and see if it is what you want to know/

Chemi

[frank]

Look here and see if it is what you want to know/

Obviously Chemi with no link attached I think old age is catching up on you

[chemi-cool]

Ok, sorry,

http://www.munters.com/

Chemi

[coolman]

The munters principel works with desicant dryers with is complety different from the Maisotsenko cycle.

Desicant dryers do have a desicant (a sort of salt) witch absorbs moisture from the air.
Bij heating the desicant the moisture is expeled from the desicant.
This kind of drying is very usefull if you need extreem low humidity leves or you need to remove moisture from the air at very low ambient temperatures.

the Maisotsenko cycle is basicly what happens in a evaporator but more optimized to remove moisture from the air en give a fridge dehumidifier a beter performance to extract water from the air.
If you use a refrigeration dryer ith the purpose of removing moisture but no cooling effect from the room, you first need to remove the sensible heat from the air.
After that, the latend heat is removed from the air and the dewpoint is reached and moisture is release out of the air.
The more latend heat is removed, the dewpoint gets lower and more moisture is removed.
So in fact a fridge dryer uses most of its compressor capacitie to remove the sensible heat.

the Maisotsenko cycle has basicly a adapted airflow where actually the sensible heat is withdraw (the dry channel, the high temp channel) before the latend heat is removed with happens in the wet channel.

PS you dont need a fridge system to obtain low temps, any sort of cold medium can be used.

Victor

[Lc_shi]

thanks for your ideas.
Have you used the products manufactured according to the M-cycle--the coolerado cooler? I believe it's one kind of indirect evaperative cooler and the supplied air is near to ambient air dew point.It doesn't have dehumidifying capability.

rgds
lichuan

[Darshi]

yes ,it is an indirect evaporative cooling unit.
Only difference seems to be the effectiveness.
Normal IDEC systems have sensible cooling effectiveness
nomally within 60 to 70% ,whereas it claims
slightly more.

[Dan]

I don't quite grasp it either, Li, but the parts that I follow seem to be legitimate design. I am thinking that the heat exchanger design is extremely important in making this cycle effective.

Direct evaporative cooling should approach a wet bulb condition, and it is ideal in dry climates where the wet bulb temperature is significantly lower than the dry bulb temperature.

If I understand the concept of "Indirect Evaporative Cooling" correctly, it uses an evaporative cooler to keep the working fluid (water) near the wet bulb temperature, and then uses a heat exchanger to cool the air without mixing the working fluid (water) with the product fluid (air). Thus you are delivering a less humid cool air, but also less cool... after a large initial heat exchanger cost.

The Maisotsenko cycle somehow, with the working fluid, is taking advantage of counterflow heat exchange and incremental exhaust, to gain greater efficiency. That is where I become overwhelmed in my understanding. Marc or others could probably run the numbers and put it into words that I understand. But incremental cooling makes sense to me when I think of liquid subcooling to increase refrigeration efficiency, and counterflow makes sense with any sensible heat exchange mechanism.

I am intrigued by the design of the heat exchanger. My instincts are that this is not foolishness. Glad you shared this, Li

[Dan]

The dew point temperature is always the coldest of the three temperatures.

This was mentioned in the article, comparing dry bulb, wet bulb, and dew point temperatures right after talking about saturated conditions such as fog. I thought they would all be the same under such circumstances.

[Darshi]

Hi
It is another name for Indirect Direct evaporative cooling. The only difference is the counter current heat exchanger use in stead of a cross flow heat exchanger used by most of the designs in Indirect Direct Evaporative Cooling (IDEC) or Indirect Evaporative Air conditioning (IDAC) as it is called some times. IDEC The cycle is well known in elementary evaporative cooling cycle. In late 80s, when I started working on IDEC system design, I named it as ambiator cycle .These names are given for commercial reasons.
One of the good points of Colorado cooler is its hydrophilic coating on the Heat exchanger plate surface .The coating eliminates the use of a water pump as the water is constantly replenished by capillary action of the coating.

The plastic plate heat exchanger does the sensible cooling and can have effectiveness closer to 90% or better. In real life situations of IDEC/IEAC design ,efficiency above 80% does not make any appreciable difference in costs or performance of the system.

[williamk]

Theoretically the Maisotsenko cycle can approach the dew point. Inderect systems can't. The secret is how the stream of air is redirected to cool both the wet air and dry air incrementally. Imagine cooling air one step at a time, on each step you cool cooler air, as simple as that! this is a gret design.

[CHilly1]

During my Second semester teaching at Southern Nevada Community College a company asked the HVAC/R program for the use of it's facillities for application and effeciency testing, the unit was equal to a 5 ton AC unit with 5% to 13% entering air into the wet-cycle side @ 100F Indoor temp The Dry (Indoor) side had an entering temp of 79F and a supply temp of 64F with an Indoo RH of 25%, The thing about this system is a dry air evaporative cooler, great idea as long as the RH outside remains low. THe Cooler did not work until they added a soap solution to the rez to get full wetting inside the plastic HX.