Low Pressure System: Tank Flow Rate (L/min)

I want to install a very precise metering device, and for that, I need a few flow meters.

But how many liters of liquid flow from the tank to the low-pressure section of the valve and back to the tank?
(Skoda Octavia 1.9 TDI / ALH)

Idling?
At full throttle / maximum RPM?

Best regards,
Jacob.

[Edit Admin]Hello Jakob, since the image you posted almost certainly violates copyright regulations, I have deleted it. Please be more careful about the images you post online in the future, because I could easily find the page in the book where the image originated.[/Edit]

Hi,

It's difficult to say exactly... Influences:

- Fuel viscosity/density (temperature-dependent).
- Pump speed
- Injection quantity

It's somewhere between 0 and over 100 liters per hour.

Generally speaking, you are correct.

Forward flow volume minus return flow volume (including leakage oil) = instantaneous consumption.
It is necessary to incorporate a temperature correction feature with a range of -30 to +120°C.

Regarding data acquisition/processing, Jochen145 recently wrote something about exhaust gas temperature. Perhaps he can help. However, such things are definitely not cheap (in the k€ range).

Best regards, Michael.

You can easily measure it.

My tractor consumes 0.6 liters per hour at idle when the engine is warm.

Okay, so you need to shut off the return flow and direct it into a measuring container. Start the timer, and you'll have the value.

From the gut: multiple times above the consumption value.

Our first PÖL (presumably a type of vacuum pump test) involved letting the T3 vacuum pump suck air from a container. It emptied the container, which held 0.5 to 1 liter, in just a few seconds (let's say a minute).

m;

Okay.

I need to try and check the values with a test case.

I believe that the maximum value of this measuring device is too low.
http://www.btflowmeter.com/Low-flow-flowmeter-FCH-m-POM.285.0.html?&L=0
(And yes, the initial value is not linearly related to the flow rate per minute, but that can be corrected with software.)


best regards
Jacob.

@jakobkoester: How do you evaluate the results? Using a microcontroller?

I'm planning something similar. However, I'll be taking the consumption signal from the control unit.

Best regards,

The consumption signal from the control unit is the same signal as that displayed in the instrument cluster.

'My consumption is 25% higher than the values shown on the combination instrument, and then I wanted to build a different consumption measuring device.'

No; not a microcontroller, but a PC.

jakobkoester wrote:

The consumption signal from the control unit is the same signal as in the combination instrument. "My consumption is 25% higher than the values shown on the combination instrument, and then I wanted to build a different consumption measuring device." No; not a microcontroller, but a PC.

Then, it might be more effective and cost-efficient to install a proper tuning system.

Then the display in the station wagon will fit.

If we roughly estimate the maximum consumption at 30 liters per minute, that would be 0.5 liters per minute. Since the low-pressure pump will likely not pump more than twice the consumption rate, 1 liter per minute should be sufficient. Unfortunately, there is no information about the accuracy of these figures.