Hello you professionals.

​

I wish to replace the 2 channel temperature controller
 with a Logo PLC.
​The thermostat controls the oil burner with two nozzles.
(boost)

So sometimes there is one nozzle in the flame 
and sometimes both - It depends on the need for heat
​My wish would be to calculate the oil consumption 
from both nozzles in total. The main nozzle burns Q1 22 
liters per hour and the booster nozzle burns Q2 8.8 liters per hour.
​The tank capacity is 3000 liters
 and it would be great to calculate and get
 an alert when the oil is low.

I already have the thermostat program ready,
 but I didn't know how to count the two different consumptions. 
​

A mechanical Overheat thermostat is included 
in the connection for safety.
​I know the counter isn't accurate, but it's good enough for me.



I would be grateful if someone could answer 
if the program is possible.

 I will buy a TD screen if I can get this to work

The best way to control the level tank is with analogic sensor, and set a low level alarm.

Thanks for the quick reply

Hello AutoGen,

what options do you have left ? With a flow meter in the inlet and one in the return per burner nozzle (i.e. 4 flow meters) you could definitely do it. However, such meters, which are also approved for fuels, are very, very expensive.

The affordable and possibly more accurate alternative is and remains the tank level measurement.

Regards Ella_68

Thank you for noticing my problem-

The problem of calculating the volume of a lying tank was already a topic in the German part of the forum. User Betel has already written some great posts about it.

Another option would be to access the switching information from the burner valves. You measure the switching time and multiply this by the determined consumption value (22 l/h and 8.8 l/h). However, this only works if the burners are running at the same power level.

Regards Ella_68

Wow.

Hello AutoGen_3987486,

I have implemented my last suggestion. But this cannot be an exact measurement, as there are inaccuracies in the quantity and rounding in the arithmetic.

The program consists of two groups of counters. The first counter in a group records the quantity per second (22/3600=0.00611). The second counter records the quantity per hour. After 3600 seconds, the second counter is triggered and the first is reset. This is not a problem in terms of quantity, as after an hour the quantity of the first counter corresponds to the quantity of the second counter when there is a pulse.

A total is now created for the liter quantity and the milliliter quantity from both groups of counters. The problem of whole liters in the milliliter count remains. To do this, I use a division with a remainder value, which comes from the formula collection of the user "Scorp" in the German part of the forum. I add the whole number of the division to the liter value and the remainder corresponds to the milliliters of the total.

This is a rough estimate, but perhaps it can help you.

Regards Ella_68

(translated with Google)