The smaller, the better? What can we benefit from using mini/micro channel heat exchangers in refrigeration and air-conditioning systems? Any thoughts shared here will be much appreciated. The following are my bits for your comments.
1. Compact from high heat transfer area-to-volume ratio (e.g., the ratio ~ 1/d for a cylindrical flow channel while d is the channel diameter)
2. Reducing refrigerant charge from small refrigerant-side volume with small OD tubes
3. Maximising capacity/COP with trade-off between decreasing pressure drop and increasing heat transfer coefficient by effective refrigerant flow distributing/circuiting
4. Air-side heat transfer coefficient increase from enhanced air flow disturbance with small OD tubes and narrow spacing tube banks
5. Low air flow pressure drop from using small OD tubes so both fan power and noise may be decreased
The smaller, the better for heat exchanger fluid flow channel size? This is one of the hot topics with users of our Refriglab cloud eTools ( www.refriglab.com being available for free trials). For developers and designers, an interesting question is how we can benefit more from a single mini/micro channel air coil design.
This post is a follow-up to my previous ones at LinkedIn:
https://lnkd.in/g68uaJW
https://lnkd.in/gsC9xWU
https://lnkd.in/g4kRSq8
https://lnkd.in/gPbb8E7
https://lnkd.in/eBNvrYF
Dear,
Due to the higher surface / volume ratio of the fluid, the exchanger can respond faster to capacity changes ...
it is possible to exchange heat between multiple media for certain types of HE
Negative - pressure drop may be higher for micro channels
Negative - possibly clogged microchannel if the fluid is not clean
...
I mean
due to the higher surface / volume ratio (better heat transfer coefficient, small amount of fluid), the exchanger can respond faster to temperature changes of heating/cooling fluid (examples in food industry ...)
Some of the advantages gained by the use of mini and micro channel heat exchangers are as following:
1- Increase of the exchange surface.
2- Minimization of the quantity of working fluid.
3- Minimization of the heat exchanger dimensions.
4- Increasing its thermal efficiency.
5- Possibility of using the capillary effect if it reinforces the movement and heat transfer in the heat exchanger.
Dear Jeff,
Couple of advantages of Mini and microchannel heat exchangers over conventional heat exchangers are there which can be counted. Micro channel heat exchangers are applied to residential and commercial heat pump airconditioning systems
Advantages
1. Higher surface contact area than conventional heat exchanger,
2. Higher heat transfer rate,
3. high thermal performance
4. Uses less refrigerant charge, refrigerant charge can be reduced by 51% at most.
5. For same cooling effect require less space,
6. System become lighter, weight can become lighter by 45% reduction.
7. Have the potential to provide energy efficient systems.
8. Characteristics of compactness, small size and lesser weight have attracted widespread applications.
9. Capacity and efficiency can be increased by almost 4%- 6%.
10. The distribution of refrigerant becomes more uniform by distribution optimization.
Ashish
- Badges
- Science method