Results 1 to 14 of 14
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14-11-2009, 07:07 AM #1
Parallel Flow vs Serpentine Evaporators
Hello,
I have two different evaporator types, they are both the same size and fit the same application, just the design of the core is different. Since both can fit I am wondering which one would provide better efficiency.
One is Parallel flow and the other is a Serpentine Type.
Thankyou.
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14-11-2009, 08:36 AM #2
Re: Parallel Flow vs Serpentine Evaporators
I should say that with parallel flow you have as many times superheat in the tubes as you have flows while with a serpentine you only have some tubes, not necessarily as many feet or meters lost in your coil to create superheat.
It's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.
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14-11-2009, 10:30 AM #3
Re: Parallel Flow vs Serpentine Evaporators
It depends what you call a 'parallel flow' evaporator - there are different types - some work & others don't.
Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
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14-11-2009, 10:39 AM #4
Re: Parallel Flow vs Serpentine Evaporators
In my parallel flow evaporator, the gas enters the evaporator through one long tube. The long tube has many tubes branching off it that flow parallel to eachover, they join up again into a common tube at the exit.
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14-11-2009, 11:31 AM #5
Re: Parallel Flow vs Serpentine Evaporators
Put up a picture, if you can - it will make it easier.
To qualify - if its is made in aluminium, the comments below will be appropriate:
It sounds like a parallel flow condenser, you have on hand.
If it is indeed a parallel flow evaporator, then it will be fairly new technology. Sounds like an automotive device.
If made in copper - conventional technology - then, again, please post a picture.Last edited by desA; 14-11-2009 at 11:35 AM.
Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
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14-11-2009, 04:29 PM #6
Re: Parallel Flow vs Serpentine Evaporators
I'll get some pictures tommorow, I have the cores outside so I'll take some pictures.
They are 20 year old cores made by Denso from a Toyota Soarer.
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15-11-2009, 03:13 AM #7
Re: Parallel Flow vs Serpentine Evaporators
^ Excellent. We'll get to it when we see the pics.
Good stuff.Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
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15-11-2009, 08:32 AM #8
Re: Parallel Flow vs Serpentine Evaporators
Big coils have a distributor and refrigerant is injected parallel to each other. There are as many flows as there are injections on the distributor. small coils without a distributor only have one flow. It all depends on the max allowable length/circuit.
Or he's having a liquid overfeed evaporatorIt's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.
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15-11-2009, 12:25 PM #9
Re: Parallel Flow vs Serpentine Evaporators
Hi,
Here are the pictures of the two cores :
http://img21.imageshack.us/img21/102/evapss.jpg
Also I have noticed they have different Thermal expansion valve part numbers.
The Serpentine Core has a Denso 047500-0480 and the Parallel flow has a Denso 047500-0770, I Wonder what the differences are in the Expansion valves and why they are different.
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15-11-2009, 12:51 PM #10
Re: Parallel Flow vs Serpentine Evaporators
^ Evaps, for sure.
The parallel flow evap (not truly // flow, though, since has multi-pass plates), has a lower fin height, giving improved heat-transfer. These are generally more modern than the serpentines.
The evap efficiency drops off as the air passes over the serpentine flat tube, leaving the heat-transfer in the last multi-port a fair bit lower than the port closest to the airside.
I'd clean up the plate unit. It should have a higher W/m3 than the serpentine.Last edited by desA; 15-11-2009 at 12:56 PM.
Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
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15-11-2009, 01:20 PM #11
Re: Parallel Flow vs Serpentine Evaporators
Do you have any idea of the refrigeration capacity of each unit?
Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
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15-11-2009, 03:03 PM #12
Re: Parallel Flow vs Serpentine Evaporators
hi
those evaporators look like a car a/c and one of them bigger than the other 0ne so maybe that the difference in exp valves
i am leaning toparallel flow as others mention
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16-11-2009, 11:27 AM #13
Re: Parallel Flow vs Serpentine Evaporators
When put side by side they are almost the same, But if the internal volume is different (total volume of the tubes), i'd assume that would mean a different expansion valve that has a larger orifice inside would be used.
I'm paranoid about evaporator cracks, so I'd prefer to use one that is less likely to leak, I was thinking that the Serpentine core would be less likely to leak as it has less points that it can leak from compared to the plate type.
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16-11-2009, 11:42 AM #14
Re: Parallel Flow vs Serpentine Evaporators
The serpentine tubes suffer from 'grain popout' on the large radii at the ends. Aluminium really doesn't like to be bent too much, due to the large grain sizes.
The corrosion life of the serpentine evap is probably les than a well-made plate evap.Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
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