LLK die 10te: Größen und Leistungsstufen | Posts 32+

bafische wrote:

You can probably identify the double-flow cooling lines in the documentation, which largely eliminates the need for T-fittings.

Hi Bavarian,

Unfortunately, the flow pattern is difficult to discern in the complex network of hoses and pipes .

Quote:

There are also many publications on this topic (MTZ, especially in the 20J TDI special issue)

.
Hmm, I'll try to get that sorted out... thanks for the tip!

Hello.

The flow pattern is actually quite simple if you have some basic knowledge of the thermal behavior of things like air, etc.

Single-point discharge is the best option for degassing.
1 LLK: Influential entry, but ambiguous exit.
Connecting pipes are best made of aluminum.
2. LLk, two-stage entry (clear), in a radial engine, single-stage exit.
Also here, if possible, use aluminum piping.

LLK systems should not only be evaluated based on their air intake area, but also on factors such as air exhaust routing, material of the filter and housings, air intake velocity, etc.


Best regards, Cosi.

Just a quick question: What's the actual difference between the 1Z/AHU and the AFN LLK engines in the Golf 3?
The AFN, as far as I know, has a different .
AFAIK, all G3 TDIs have the same engine oil, regardless of whether they are 90 or 110 horsepower.

The part number differentiates between two models.

3A0 145 805 A was only available in the 1Z.
3A0 145 805 B was available in the 1Z and in the AFN.

Hi.

Logs of intake air temperature, with the condition that the ambient temperature is 14°C.

The temperature differences are negligible: approximately 48°C compared to approximately 45°C.
Under constant full throttle, the differences should be more pronounced, but still not critical.

Best regards, Rainer.

Rainer K. wrote:

The temperature differences are negligible: ~48°C compared to ~45°C. At constant full throttle, the differences should be larger but still not critical.

I'm somehow not understanding it.
AHF mit 2,2 bar abs. = 0,2 bar über Serie fährt max. LLT at 34,000 feet above AT.

ASZ at 2.4 bar absolute pressure = 0.1 bar above standard, allows maximum LLT (low load torque) up to approximately 52,000 RPM above AT (automatic transmission).
By the way, it looks similar in the Golf 4 ASZ (from Roger).

As if the ASZ model came from the factory with a smaller LLK (liquid cooling system) than the AHF model.

@Rainer: By any chance, do you also have air mass readings around 4000 rpm with the tuning?
My average serum zinc level is approximately 1000 mg/L.

Hi Ulf,

"At 4000 rpm and 2.2 bar, I've always measured 1275mg/stroke, which is the maximum measurable value. It's possible that the mass airflow sensor is being overloaded here and measuring too much, or that the engine control unit simply takes the maximum value once a certain output voltage is reached."

Best regards, Rainer.

Rainer K. wrote:

Of course, it's possible that the mass airflow sensor

is being overloaded here and measuring too much, or that the control unit simply takes the maximum value when a certain output voltage is reached.
Hi Rainer,

It will probably be that way.

27% more cylinder filling at 0.2 bar less LD doesn't make sense - even if your LLT is actually 20K below mine (which would result in approximately 6% more air density:? at the same pressure).


Do I remember correctly that your LD and temperature sensor is located in the pipe behind the LLK (low-level coolant)? Julian's logs also show wonderfully low LLT values, and he has the sensor in the pipe.

My sensor is located in the inlet air duct of the LLK - but I haven't been able to fully understand that the measured temperature there should be at least 15 K higher than in the subsequent pipe. }

Hello Ulf,

Quote:

Am I correct in remembering that your LD and temperature sensor is located in the pipe behind the LLK?

Yes, but it's only a few centimeters from there to the LLK (likely referring to a specific anatomical landmark).

Best regards, Rainer.

Rainer K. wrote:

Do I remember correctly that your LD and temperature sensor is located in the pipe behind the LLK? Quote: Yes, but it's only a few centimeters from there to the LLK. Hmm, I'm starting to understand something. Donalexo had written something about the temperature profile in laminar flow. Only the air directly in contact with the inner surface of the pipe cools down, while the temperature in the center of the airflow is higher. The pipe sensors measure the flow close to the pipe wall, which is naturally cooled further along the length of the pipe (depending on the temperature outside the pipe). If the NTC sensor were placed further towards the center of the tube, the logged LLT (local liquid temperature) would likely be higher. However, the airflow in the LLK air chamber is still turbulent (as the flows from the individual LL channels mix together), which means that measurements taken there are likely to be more "accurate" than those taken in the suction pipes. In other words, the logic values of the intake manifold sensors would be more or less skewed downwards...? Alex, please come

.

Hi Ulf,

I don't think that makes a significant difference. My intercooler already has an opening at the top for the boost pressure sensor (now: a blind plug for mechanical LDA measurement), so I could, just for fun, swap the mounting locations. However, I haven't checked whether the intercooler I have is the original type that was installed. It was actually replaced once during a warranty repair.

Best regards, Rainer.

Rainer K. wrote:

My oil cooler already has a hole at the top for the boost pressure sensor (now: a blind plug for mechanical LDA measurement), so I could, just for fun, swap the mounting locations.

Wow, that's the perfect research subject!

If you could do that, I would be very interested in the results!

Quote:

I haven't checked whether the LLK (Linearity Loss Kernel) I have is the original type that was installed

. That doesn't matter, because it's only about the measured LLT (Linearity Loss Threshold) differences depending on the measurement point. And even a faulty LLK should still work fine for that.

Hello Ulf,

In my opinion, Donalexo prioritizes the maximization of 'heat transfer,' i.e., the maximum heat flow (= energy per unit of time), and therefore I can only agree with his statements.

However, for the optimal performance of the air dryer, it's not the maximum heat flow that's crucial, but rather minimizing the inlet temperature (T1) of the compressed air as much as possible, thereby achieving a correspondingly low outlet temperature (T2).

This can be achieved in two ways:

Make sure the length of the section to be traversed is sufficient.

or

to keep the flow rate as low as possible.

In both cases, the residence time in the heat exchanger is extended, and the temperature difference between T1 and T2 is maximized.

TAW wrote:

to keep the flow rate as low as possible. In both cases, the residence time in the LLk is extended, and the temperature difference between T1 and T2 is maximized.

According to this, a parallel connection of two liquid-liquid heat exchangers would also be effective: The volumetric flow rate would be divided, and the flow cross-section in the cooling network would be doubled (in the case of two identical heat exchangers), which would halve the flow velocity and double the residence time again.

This also roughly corresponds to my logs in terms of flow rate.
At full load in 6th gear at 2000 rpm, the low-temperature coolant (LTC) temperature at the LTC outlet is slightly more than half the temperature at 4000 rpm.

If the mass flow rate is also taken into account as a correction factor (2000 rpm: approximately 1100 mg/cycle, 4000 rpm: approximately 1000 mg), the results fit even better.

Unfortunately, it seems like I won't be able to do that with two parallel LLMs.
The narrower water cooler from the 100 horsepower gasoline engine cools insufficiently (approximately 2/3 of the cooling system volume, but only about 50% of the cooling capacity of the standard cooler) .

Hello Ulf.

I'm not sure how different the Fabia's front end is from the Polo's, but take a look:
http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=0013&product=FMINTFAB
(But don't look at the price ).

Best regards!

R.M. wrote:

I don't know to what extent the Fabia's front end differs from the Polo's, but take a look . . .

Thank you, but unfortunately, the front ends are so different that something like that won't fit in the Polo .

Quote:

In both cases, the residence time within the LLk is extended

.
You must free yourselves from the idea that this convective heat transfer has anything to do with time! You are looking at (quasi-)stationary processes, not processes of equalization: I put an ice cube in a glass and wait for it to dissolve, or I fill air into the cooling system and wait for it to cool down...
If you want to calculate the performance of your liquid cooling system, I recommend using the VDI Heat Atlas. However, you will need some technical data for the individual liquid cooling components used.
If you can't obtain those values, you can initially assume some default values and see whether a series or parallel configuration is more advantageous under the specific conditions of our TDIs.
Stay cheerful.
OlBe.