Thermorossi H2O 34 "No Temp Resis" error, improve combustion in the fireplace

[Christophe]

I will present the improvements I have made in terms of combustion chamber of an Idro Thermorossi H2O 34 28kW hydraulic pellet stove that I have been using since November 2017.

Originally, the concern comes from an error code "No Temp Resis" which means that the stove does not have time to reach its working temperature at the end of the ignition cycle and starts up. therefore in default.

The version I have is not working on a temperature delta but on a temperature to reach (which I think between 35 to 40 °). So if the stove is too cold on ignition, this temperature is not reached at the end of the start-up period and the error can occur quite often see photo below ...

Indeed, the regulation considers that the stove has not lit (which is wrong since there has been a rise in temperature ...) therefore stops everything ...

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So I tried 2 mechanical improvements which significantly reduce the defects (but ideally we would have to work on a delta). This subject presents the 1st improvement, that of the heart of the home

Improvement of the combustion stove on a Thermorossi sweeping stove

Thermorossi pellet stoves have a cleaning by mechanical sweep of the center of the hearth (reciprocating rotary movement on an angle of approximately 90-110 ° ...) this to evacuate the ashes. Problem with 1st generation stoves like mine: pellets can fall into the ashtray and the "flat" part of the fireplace is quickly invaded with ash (therefore lack of air), which requires regular cleaning (every 2- 3 days according to the instructions ... with what I put the cleaning of the fireplace is no longer necessary at all ...)

Thermorossi therefore quickly improved the crucible by increasing the height of the center of the hearth see diagram below. In addition, this new configuration makes it possible to provide secondary air for combustion (I saw small vortices forming on the left or on the right, which is very good for combustion).

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The first modification therefore consists in manufacturing 2 L-shaped parts with the small perforated part in order to imitate the new type of hearth (which, new, would cost 120 € ... in Italy I specify ...).

With the difference that I put a soft slope on the non-perforated part for a continuous evacuation of the ashes!

Original fireplace on the left and modified on the right:

Thermorossi pellet stove

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The part to be manufactured (a few euros):

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The quotes:

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It mounts slightly in force and is 100% removable if necessary, no modification of the original fireplace is necessary:

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Finish:

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Ignition:

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After a few minutes, it heats up well, the "brush" is cherry red:

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State of the sheets after a few hours of operation: no deformation or buckling:

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Any comments or suggestions are welcome

I obviously did not know how to estimate this impact on the stove's output (it must be low or almost zero and I am not equipped to measure this), it is especially that the rise in temperature is a bit more fast (concentration of pellets) and the cleaning gain is greatly appreciated.

After this improvement, I cleaned the hearth only 2 times during the season (and it was not really necessary) for about 400 kg of pellets consumed ...2 cleanings in 4 months instead of 2 times per week, it is not nothing like gain for the lazy (and I know that there is some on this forum huh lol).

I still had to empty the ashtrays 3 or 4 times ... (there are 3 but this I would talk about during improvement number 2 ...)

[Ahmed]

Beautiful and clever modification, probably very judicious, since resulting from attentive observations on your part!
A point of lexical detail: you write

State of the sheets after a few hours of operation: no deformation or buckling

I wonder about the meaning of the word underlined? What do you mean? No oxidation?

Does the "broom" resist this regime for a long time?

I see that the welds were made with a semi-auto, are they your work?

[Christophe]

Thank you Ahmed!

I was thinking about buckling by thermal expansion (it still heats up at this level) that's why I specified ... in addition to any other deformations (warping etc ...)

I did not specify that (but we can guess on the photos with the meter):
- the pierced sheet is 2 mm (it is sold in DIY for a few euros)
- the other 3 mm

No idea for the brush ... for the moment it holds ... Without this modification the temperature in the heart of the hearth was also high but I had never seen the brush blush. Expect more Thermorossi user reviews ...

Yes the welds are mine I'm starting to be less bad ...

The rest tomorrow

[Ahmed]

Buckling or, I prefer, buckling, is used rather in relation to a mechanical stress, hence my surprise ...

Yes, the welds are mine

It seems to me that your melting bath temperature is a little low, but as it is a part that is not in high demand ...
Are you still using the same station as when you built your turbine?

[Christophe]

If there is thermal expansion (I remind you that I mounted the parts in "light force" so reduced clearance), then there is a mechanical stress which can cause buckling (especially if the part is heated .. .) ... or blazing when it blazes in the hearth (with all these flames ... we stay in the subject! Hihi).

Notes that wiki equates the 2 terms: https://fr.wikipedia.org/wiki/Flambage

These are simple scores yes some are clearly not penetrating enough ...

I did this with an ESAB MIG / MAG (old but) pro in the evening classes (I have been following them since September ...).

I might be a subject on occasion to present my works to you ... but there are not many that are economical at the moment! Except maybe my electric paramotor that I have been studying for 18 months ... (hence taking welding lessons ... hum hum it's not a paramotor bike)

[Christophe]

As the subject interests you, I also carried out another test, I wanted the ash discharge plate (not pierced therefore) to be self-cleaning.

So I made 2 small deflectors (Ahmed, you who have the eye, you can observe the good penetration of the weld on this part) and made some air holes (4) near the right angle of the plate not pierced. The idea was that part of the air constantly created a slight breath on this plate ...

The idea was also, ideally, to create a double air vortex (clockwise to the left and anti-clockwise to the right of the flame) which would bring "tertiary" air to the combustion (if we consider the primary air. like the bottom of the hearth and the secondary like that of the sloped pierced plates).

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Problem: this does not work because a pellet stove operates in vacuum and it is not sufficient (despite the strength of the flame) to create a fairly powerful air flow. (or else I did not make enough holes but it would have been harmful to the air in the fireplace)

Those which operated in suppression, even partial, presented a risk of explosion, the technique therefore no longer exists: heating-insulation / stove-a-pellet-stove explosion-qui-t10934.html explodes

I still used the 2 deflectors to do air "flow" tests but without much success:

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[Ahmed]

On your first photo, it seems that there remains a scale, so a welding to the electrode?
The fact that the stove is under vacuum does not really change the gas dynamics, but probably it is too weak to fulfill the function you are looking for, at least with this calibration of holes ... But, you are right to be wary possible modifications to the household supply.

[Christophe]

Yes I am semi (or bow) in class and I work at home with a bow if necessary

I have a little telwin mig here but when we touched Esab ... uh how to say ... it's difficult to iron on amateur equipment (even if telwin it's not bad but good for the general public for Sunday what ...) ...

For the gas dynamics if it changes anyway: a blow gun at 1 bar does not blow much ... and it is infinitely easier to make +3 bars than -3 bars

[Ahmed]

For throttle dynamics, I was talking about the effects, not the "getting" aspect.
I see that you understand better these questions of quality of welding equipment that we talked about quite a while ago ...

[Christophe]

Of course, but given the configuration (I do not think that the depression exceeds 0,1 to 0,2 bars and yet ...) we are limited in capacity for "blowing" effect ...