Charge cooling basics
Charge cooling basics
First of all: the basic layout of the charge cooler.
In an ideal world, charge air & water are in a counter-flow. Meaning, cold water enters on the cold side of the chargecooler. Instinctively I would have done this the other way around. But the reason is simple and very much logical: if the warm coolant is on the cold side of the charge cooler, the temperatur of the air exiting the cooler may never fall below the coolant temperature. So; the coldest water enters at the coldest end of the chargecooler. On the "hot" side, warm water can still dissipate heat from the hotter charge air...!
So - if you then look at many of those eBay charge cooler kits, you'll notice that sometimes water inlet & exit are even on the same end of the core, side by side. This of course means water will not flow through the full core (principle of least resistance/shortest way). Apparently those cheap chargecoolers also make use of "reversed" intercooler (air/air) cores which in this application aparently are less efficient then a "real" chargecooler core which is of a little different design. And the cores are mostly very short, giving insufficient time for heat-exchange. They are basically just not efficient.
In short: counterflow of coolant & air, and cross-flow of coolant through an elongated core. I am most likely going to make my own charge-cooler, I've found suppliers of charge-cooler cores local-ish.
This is my - current - design for a charge cooler with a rather long-ish core to give the air time to give heat away. Water inlet & exit are across the core:
![[Image: chargecooler_layout.png]](http://jan-wulf.de/wp-content/uploads/2015/02/chargecooler_layout.png)
excuse the terrible picture quality, it's a photo of a quick drawing.
Then the radiator:
This should be of a low-temperature design and as large as possible to exchange as much heat as possible. Normal car radiators are designed for higher temperatures of coolant. The coolant should be as cold as possible when it enters the chargecooler. The bigger the differential in temperatures is, the better the heat exchange works. I wil possibly, if space allows, include fans for the chargecooler radiator. Why not?
Now comes the part with the questions!
What I'm still unsure about is the coolant pump. Or better flow rate of the coolant pump. since I'm guessing that too much flow wil not give enough time for heat transfer, and too little will lead to "heat soak". I'm still looking for a basic assumption/formula to calculate the best flow... And neither am I good at physics nor math
So any help here is muchly appreciated! I guess first I would need to know my rate of air-flow & air temperature for starters.It's rather obvious that a air-to-air intercooler is a much simpler thing... Though it's harder to find a space up front for a decently sized (thick) intercooler on a W124. And neither am I going to cut up the bonnet for a top-mount IC
But a long, tall and flat radiator I can probably fit much easyer across the front. So - against the easyer route to take I'm most likely going for a chargecooler.Just my thoughts about all this... If I'm talking boIIocks, educate me, yes? That's why I started this thread
Thank you!
DiseaselWeasel
02-13-2015, 01:27 PM #1Sooo... I've thought about charge- instead of intercooling my OM603.
First of all: the basic layout of the charge cooler.
In an ideal world, charge air & water are in a counter-flow. Meaning, cold water enters on the cold side of the chargecooler. Instinctively I would have done this the other way around. But the reason is simple and very much logical: if the warm coolant is on the cold side of the charge cooler, the temperatur of the air exiting the cooler may never fall below the coolant temperature. So; the coldest water enters at the coldest end of the chargecooler. On the "hot" side, warm water can still dissipate heat from the hotter charge air...!
So - if you then look at many of those eBay charge cooler kits, you'll notice that sometimes water inlet & exit are even on the same end of the core, side by side. This of course means water will not flow through the full core (principle of least resistance/shortest way). Apparently those cheap chargecoolers also make use of "reversed" intercooler (air/air) cores which in this application aparently are less efficient then a "real" chargecooler core which is of a little different design. And the cores are mostly very short, giving insufficient time for heat-exchange. They are basically just not efficient.
In short: counterflow of coolant & air, and cross-flow of coolant through an elongated core. I am most likely going to make my own charge-cooler, I've found suppliers of charge-cooler cores local-ish.
This is my - current - design for a charge cooler with a rather long-ish core to give the air time to give heat away. Water inlet & exit are across the core:
excuse the terrible picture quality, it's a photo of a quick drawing.
Then the radiator:
This should be of a low-temperature design and as large as possible to exchange as much heat as possible. Normal car radiators are designed for higher temperatures of coolant. The coolant should be as cold as possible when it enters the chargecooler. The bigger the differential in temperatures is, the better the heat exchange works. I wil possibly, if space allows, include fans for the chargecooler radiator. Why not?
Now comes the part with the questions!
What I'm still unsure about is the coolant pump. Or better flow rate of the coolant pump. since I'm guessing that too much flow wil not give enough time for heat transfer, and too little will lead to "heat soak". I'm still looking for a basic assumption/formula to calculate the best flow... And neither am I good at physics nor math So any help here is muchly appreciated! I guess first I would need to know my rate of air-flow & air temperature for starters.
It's rather obvious that a air-to-air intercooler is a much simpler thing... Though it's harder to find a space up front for a decently sized (thick) intercooler on a W124. And neither am I going to cut up the bonnet for a top-mount IC But a long, tall and flat radiator I can probably fit much easyer across the front. So - against the easyer route to take I'm most likely going for a chargecooler.
Just my thoughts about all this... If I'm talking boIIocks, educate me, yes? That's why I started this thread Thank you!
I'll be using an electric water pump from a w202. I still haven't decided on the actual charge cooler yet. I'm a long way off from completion (in fact I haven't even started lol) so if you want to be the guinea pig then be my guest
With regards to the flow speed, I dont think it will impact negatively if you have a high flow rate. In fact I think it would be better. The molecules in contact with the heat exchanging surfaces have less time to transfer the energy, but it will still be faster as there are more molecules to transfer the energy in a given time.
I'm no physicist but it makes sense to me. Damn I'll probably end up spending the rest of my evening researching fluid dynamics...
I've been thinking along the same lines. There won't be enough space in my w201 to use a A/A intercooler whilst keeping the stock look. So I was thinking of using a chargecooler with an A/C rad from a w210 as they're quite large and slim.
I'll be using an electric water pump from a w202. I still haven't decided on the actual charge cooler yet. I'm a long way off from completion (in fact I haven't even started lol) so if you want to be the guinea pig then be my guest
With regards to the flow speed, I dont think it will impact negatively if you have a high flow rate. In fact I think it would be better. The molecules in contact with the heat exchanging surfaces have less time to transfer the energy, but it will still be faster as there are more molecules to transfer the energy in a given time.
I'm no physicist but it makes sense to me. Damn I'll probably end up spending the rest of my evening researching fluid dynamics...
As far as intercooler pumps, apparently tons of flow is what you want. If you get an off the shelf cooler, mind your fitting size. The ZL1 motor is using 19mm tubing. This link shows some exhausting performance testing of modern intercooler coolant pumps. Be prepared for sticker shock. http://www.lingenfelter.com/LPEforumfile...ng-results
raysorenson
02-13-2015, 04:56 PM #3I was looking to A/W intercool my 603 W124. I found a transmission cooler with 13mm barb fittings that pretty much filled out the entire radiator opening in the chassis sheet metal. It's the "26 row" cooler found on the Ford 6.0l diesels. There may be more efficient designs, but it doesn't let any air get around it and it's a low restriction design. Do an image search for it, you'll see what I'm talking about. I'll measure it's dimensions when I get home.
As far as intercooler pumps, apparently tons of flow is what you want. If you get an off the shelf cooler, mind your fitting size. The ZL1 motor is using 19mm tubing. This link shows some exhausting performance testing of modern intercooler coolant pumps. Be prepared for sticker shock. http://www.lingenfelter.com/LPEforumfile...ng-results
raysorenson
02-13-2015, 08:13 PM #4The Ford 26 row trans cooler is 1.25"X23"X17", the barbs extend 1.5" past 17". These measurements don't include the brackets, which can be cut off or bent or whatever.
(02-13-2015, 01:27 PM)DiseaselWeasel since I'm guessing that too much flow wil not give enough time for heat transfer,
don't worry about it, it's a common myth from a long time ago,
Some engines needed the pressure differential across the thermostat opening to flow water through the block, people'd run their engines without the thermostat, then over heat because the water would only be going through the water pump and radiator, not circulating through the block. They thought it was because of 'too much coolant flow', and enough people parroted it until it was "fact"
In reality, more flow is better cooling, as it strips off the boundary layers of stagnant water off of surfaces.
(02-13-2015, 01:27 PM)DiseaselWeasel since I'm guessing that too much flow wil not give enough time for heat transfer,
don't worry about it, it's a common myth from a long time ago,
Some engines needed the pressure differential across the thermostat opening to flow water through the block, people'd run their engines without the thermostat, then over heat because the water would only be going through the water pump and radiator, not circulating through the block. They thought it was because of 'too much coolant flow', and enough people parroted it until it was "fact"
In reality, more flow is better cooling, as it strips off the boundary layers of stagnant water off of surfaces.
I will start with a std. Bosch pump as found in many Mercs (I have a steady supply of these). It's probably the easyest part to upgrade once the system is installed. Thanks for the pump-test link, I'll have a read through!!
Re: stock looking; the C30 CDI AMG charge-cooler looks beautifull! But it has a reputation of leaking water in the airstream. There's an official advisory from MB to not re-install the first version but to upgrade to a newer design. Most you find for sale are of the leaking version...
![[Image: c30_amg_CDI-1.jpg]](http://jan-wulf.de/wp-content/uploads/2015/02/c30_amg_CDI-1.jpg)
![[Image: c30_amg_CDI-2.jpg]](http://jan-wulf.de/wp-content/uploads/2015/02/c30_amg_CDI-2.jpg)
Plus I think it'll require re-welding to make a good fit to a OM603... But it's of a nice design and fairly large!
So far I have found these cars with stock A/W coolers:
- Mercedes C30 CDI AMG (rare, expensive and tends to leak...)
- Mercedes G270 CDI (rare - noone breaks these cars...)
- Jaguar XJR Supercharged (integrated into manifold, difficult to use)
- Mercedes 400 CDI (difficult to use, V engine, two inlets)
- Some Mercedes AMG V-engines (same issus as above)
- BMW X6M (one core for each bank, rather cheap)
- Toyota Celica GT4
- Subaru Legacy
- Lotus Carlton (twin entry, twin exist, twin-turbo setup)
- Lotus Esprit Turbo
- Peugeot 605 / Citröen XM 2.5TD http://projects.205gtidrivers.com/205mi32-ph8?page=6
- Smart Brabus Roadster (pretty smal...
)
DiseaselWeasel
02-14-2015, 05:02 AM #6Ok, this sort of makes sense! I will start with a std. Bosch pump as found in many Mercs (I have a steady supply of these). It's probably the easyest part to upgrade once the system is installed.
Thanks for the pump-test link, I'll have a read through!!
Re: stock looking; the C30 CDI AMG charge-cooler looks beautifull! But it has a reputation of leaking water in the airstream. There's an official advisory from MB to not re-install the first version but to upgrade to a newer design. Most you find for sale are of the leaking version...
Plus I think it'll require re-welding to make a good fit to a OM603... But it's of a nice design and fairly large!
So far I have found these cars with stock A/W coolers:
- Mercedes C30 CDI AMG (rare, expensive and tends to leak...)
- Mercedes G270 CDI (rare - noone breaks these cars...)
- Jaguar XJR Supercharged (integrated into manifold, difficult to use)
- Mercedes 400 CDI (difficult to use, V engine, two inlets)
- Some Mercedes AMG V-engines (same issus as above)
- BMW X6M (one core for each bank, rather cheap)
- Toyota Celica GT4
- Subaru Legacy
- Lotus Carlton (twin entry, twin exist, twin-turbo setup)
- Lotus Esprit Turbo
- Peugeot 605 / Citröen XM 2.5TD http://projects.205gtidrivers.com/205mi32-ph8?page=6
- Smart Brabus Roadster (pretty smal... )
at removing the heat.
In general I wouldn't really worry about it. You can always fit a restrictor at the pump outlet if you want to experiment. Never restrict the inlet.
It's somewhat easy to calculate how much cooling you need under steady state conditions. You just need to know the air mass flow and temperature along with how much cooling you're seeking.
Air temperature can be calculated from ambient temp if you know the boost pressure and turbo compressor adiabatic efficiency.
Baldur Gislason
There are no ill effects to having too much flow rate when it comes to chargecooler efficiency, in fact more is better but you will have a lower deltaT of the water meaning the radiator won't be as efficient
at removing the heat.
In general I wouldn't really worry about it. You can always fit a restrictor at the pump outlet if you want to experiment. Never restrict the inlet.
It's somewhat easy to calculate how much cooling you need under steady state conditions. You just need to know the air mass flow and temperature along with how much cooling you're seeking.
Air temperature can be calculated from ambient temp if you know the boost pressure and turbo compressor adiabatic efficiency.
Baldur Gislason
(02-13-2015, 01:27 PM)DiseaselWeasel Just a tip, read Heat and mass transfer of Frank P. Incropera and David P. DeWitt chapter 11, look at the NTU number for different type of heat exchangers there is some very useful information about the NTU method , NTU numbers for different kind of heat exchanger. Have in mind pressure losses in channels and pipes and a new world world will open up for you, I promise
Sooo... I've thought about charge- instead of intercooling my OM603.
First of all: the basic layout of the charge cooler.
In an ideal world, charge air & water are in a counter-flow. Meaning, cold water enters on the cold side of the chargecooler. Instinctively I would have done this the other way around. But the reason is simple and very much logical: if the warm coolant is on the cold side of the charge cooler, the temperatur of the air exiting the cooler may never fall below the coolant temperature. So; the coldest water enters at the coldest end of the chargecooler. On the "hot" side, warm water can still dissipate heat from the hotter charge air...!
So - if you then look at many of those eBay charge cooler kits, you'll notice that sometimes water inlet & exit are even on the same end of the core, side by side. This of course means water will not flow through the full core (principle of least resistance/shortest way). Apparently those cheap chargecoolers also make use of "reversed" intercooler (air/air) cores which in this application aparently are less efficient then a "real" chargecooler core which is of a little different design. And the cores are mostly very short, giving insufficient time for heat-exchange. They are basically just not efficient.
In short: counterflow of coolant & air, and cross-flow of coolant through an elongated core. I am most likely going to make my own charge-cooler, I've found suppliers of charge-cooler cores local-ish.
This is my - current - design for a charge cooler with a rather long-ish core to give the air time to give heat away. Water inlet & exit are across the core:
excuse the terrible picture quality, it's a photo of a quick drawing.
Then the radiator:
This should be of a low-temperature design and as large as possible to exchange as much heat as possible. Normal car radiators are designed for higher temperatures of coolant. The coolant should be as cold as possible when it enters the chargecooler. The bigger the differential in temperatures is, the better the heat exchange works. I wil possibly, if space allows, include fans for the chargecooler radiator. Why not?
Now comes the part with the questions!
What I'm still unsure about is the coolant pump. Or better flow rate of the coolant pump. since I'm guessing that too much flow wil not give enough time for heat transfer, and too little will lead to "heat soak". I'm still looking for a basic assumption/formula to calculate the best flow... And neither am I good at physics nor math
It's rather obvious that a air-to-air intercooler is a much simpler thing... Though it's harder to find a space up front for a decently sized (thick) intercooler on a W124. And neither am I going to cut up the bonnet for a top-mount IC
Just my thoughts about all this... If I'm talking boIIocks, educate me, yes? That's why I started this thread
(02-13-2015, 01:27 PM)DiseaselWeasel Just a tip, read Heat and mass transfer of Frank P. Incropera and David P. DeWitt chapter 11, look at the NTU number for different type of heat exchangers there is some very useful information about the NTU method , NTU numbers for different kind of heat exchanger. Have in mind pressure losses in channels and pipes and a new world world will open up for you, I promise
Sooo... I've thought about charge- instead of intercooling my OM603.
First of all: the basic layout of the charge cooler.
In an ideal world, charge air & water are in a counter-flow. Meaning, cold water enters on the cold side of the chargecooler. Instinctively I would have done this the other way around. But the reason is simple and very much logical: if the warm coolant is on the cold side of the charge cooler, the temperatur of the air exiting the cooler may never fall below the coolant temperature. So; the coldest water enters at the coldest end of the chargecooler. On the "hot" side, warm water can still dissipate heat from the hotter charge air...!
So - if you then look at many of those eBay charge cooler kits, you'll notice that sometimes water inlet & exit are even on the same end of the core, side by side. This of course means water will not flow through the full core (principle of least resistance/shortest way). Apparently those cheap chargecoolers also make use of "reversed" intercooler (air/air) cores which in this application aparently are less efficient then a "real" chargecooler core which is of a little different design. And the cores are mostly very short, giving insufficient time for heat-exchange. They are basically just not efficient.
In short: counterflow of coolant & air, and cross-flow of coolant through an elongated core. I am most likely going to make my own charge-cooler, I've found suppliers of charge-cooler cores local-ish.
This is my - current - design for a charge cooler with a rather long-ish core to give the air time to give heat away. Water inlet & exit are across the core:
excuse the terrible picture quality, it's a photo of a quick drawing.
Then the radiator:
This should be of a low-temperature design and as large as possible to exchange as much heat as possible. Normal car radiators are designed for higher temperatures of coolant. The coolant should be as cold as possible when it enters the chargecooler. The bigger the differential in temperatures is, the better the heat exchange works. I wil possibly, if space allows, include fans for the chargecooler radiator. Why not?
Now comes the part with the questions!
What I'm still unsure about is the coolant pump. Or better flow rate of the coolant pump. since I'm guessing that too much flow wil not give enough time for heat transfer, and too little will lead to "heat soak". I'm still looking for a basic assumption/formula to calculate the best flow... And neither am I good at physics nor math
It's rather obvious that a air-to-air intercooler is a much simpler thing... Though it's harder to find a space up front for a decently sized (thick) intercooler on a W124. And neither am I going to cut up the bonnet for a top-mount IC
Just my thoughts about all this... If I'm talking boIIocks, educate me, yes? That's why I started this thread
https://search.yahoo.com/search?p=after+cooler
https://search.yahoo.com/search?p=charged+air+cooler
http://www.wisegeek.org/what-is-boyles-law.htm
https://search.yahoo.com/search?p=charged++cooler
https://search.yahoo.com/search?p=a%2Fw+intercooler
https://search.yahoo.com/search?p=a%2Fa+intercooler
2005 CDI heavily modified 1984 300TD - Myna pump/TMIC/enlarged PC's/HX30Super/W126 II front brakes/Vogtland springs/EGT +Boost gauges/H4 Hella's
https://search.yahoo.com/search?p=intercooler
https://search.yahoo.com/search?p=after+cooler
https://search.yahoo.com/search?p=charged+air+cooler
http://www.wisegeek.org/what-is-boyles-law.htm
https://search.yahoo.com/search?p=charged++cooler
https://search.yahoo.com/search?p=a%2Fw+intercooler
https://search.yahoo.com/search?p=a%2Fa+intercooler
2005 CDI heavily modified 1984 300TD - Myna pump/TMIC/enlarged PC's/HX30Super/W126 II front brakes/Vogtland springs/EGT +Boost gauges/H4 Hella's
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