Chimney Flue Temperature Control

Using Arduino Motors, Mechanics, Power and CNC
1

This would be used to control a DC induction fan on a wood-fired boiler.

A K-type thermocouple is installed in the chimney flue; it measures the temperature of the exhaust gasses.

The goal is to maintain a flue gas temperature of 450 degrees Fahrenheit (programmable) when the fan is operating.

I presently use a PID, but it does not allow fan modulation based on temperature.

The desired operating parameters would be:
Below 400 degrees F, induction fan would operate at 100%.
Between 400 F and 450 F, the speed of the fan would be reduced from 100% to 10% in a linear fashion.
Temperatures above 450 F would maintain a fan speed of 10% (or whatever the minimum speed of the fan is.)

Suggestions appreciated.

Regards.

2

Please read and follow the directions in the "How to use this forum" post.

3

Kntryhart:
I presently use a PID, but it does not allow fan modulation based on temperature.

Post your program and tell us in detail what it DOES do.

And tell us what you think may be the problem.

...R

4

Doesn’t this come into the safety critical envelope . If you alter the motor speed you will alter the draw on the woodburner affecting combustion. If the fan stops running, will products be forced out of the burner and will CO from the burner then kill the room occupants ??

I’m out

5

Good grief hopefully he is not using a wood fired boiler in a living space....

please tell me this is a backyard moonshine still or something..