Lambda controls vs baseline; fault-mode fallback, etc.

[TCaldwell]

Brian, i see this unit has a o2 sensor but displays a co2 value, what is the reason for this. I am to assume this is a calculated value based on the fuel factor and a given moisture content. The stiometeric residual o2 in the fluestream is approx 7% and a corresponding co2 of 13.25% for 20% mc. According to the video it shows a approx setpoint of 7%o2. On a typical start of burn, how high of a co2 reading do you see, and how long does it take to get back to setpoint, does this differ with different types of wood. What sort of damper outputs in percentage do you see for the initial stage of burn. once the burn has stabilized with no appearant disturbances, does the process value oscilate or stray from setpoint. Is the draft inducer a single speed or does it modulate. if it modulates is that controlled by flue temp. what is the control signal to the stepper motors, voltage or current. What sort of parameter indicators or alarms are offered with the controller and what parameters can you manipulate. These are questions as to the viability or flexibility for use on other boilers. i called early this morning, left a message hoping to talk to you, figured you must be busy, but since you offered on a prior post, these questions maybe could be answered once here than to each email.
thanks tom

 

[EffectaBoilerUser (USA)]

Tom,

The effecta lambda boilers use a CO2 sensor which is located in the base of the chimney. This sensor monitors the CO2% of the smoke leaving the boiler and with the help of the motherboard, opens and closes the primary and secondary drafts using the stepper motors. The motors move in 10 degree increments and always move as a pair, in opposite directions. Thus, if the CO% gets higher than the preset setting (usually 13%) the primary draft will close 10% and the secondary draft will open 10%. If it still continues to rise they will keep closing/opening until 13% is reached. 13% is the normal setting for 20% MC wood. However, if the wood is a little less seasoned it can be set to a higher value which results in more air being added to the primary chamber and less to the secondary chamber. If it is a little dryer, the opposite is true.

The effecta boiler uses a fixed speed fan located at the rear of the boiler, thus resulting in a negative draft system.

The control on the effecta lambda motherboard is such that the boiler is not allowed to cycle/idle during a burn cycle (as we all know, when a boiler which is originally designed for an induced draft fan is allowed to sit idle, with the fan off, it has no other option than to burn very inefficiently and with dirty/high emissions). In all actuality, when the fan is off the boiler cannot gasify at the normally high temperatures and becomes an expensive OWB. I used to own an EKO40 and any one who has one of these knows the problems that idling causes with the boiler.

In Sweden (who has some of the world's most stringent emissions requirement's) it is against the law to manufacture a gasification boiler that is allowed to cycle on/off during a burn. Thus, this forces the home owner to have a good amount of storage (1,000 gallons) for most size homes. Currently I have a customer with a 5,000 sq. ft home with lots of windows who is heating very well with an effecta lambda 35 with 1,000 gallons of propane tank storage.

I look forward to answering any other questions you may have.

EBU

 

[TCaldwell]

Brian, so the draft inducer runs a one speed for the burn? how high of a co2% do you see at the onset of burn for average wood, and how long to recover to setpoint and how tightly is setpoint maintained without a disturbance. thanks for the prior post. are you able to datalog co2 for a burn and post it, that would really be great!
tom