[Stoves] Interesting World Bank Report featuring stoves (a Christmas present)

[Crispin Pemberton-Pigott]

Dear Michael and All

 

Anyone know much about this affair at Brookhaven Labs on Long Island last
month?

http://forgreenheat.blogspot.com/2014_11_01_archive.html

 

In the past Brookhaven was more likely to be involved in radiation problems
here.

 

This link below is very interesting and describes an effort that is sort of
being run in parallel to the EPA's attempts to bring more science to the
fireplace. 

 

The linked article (which is very long) mentions many of the things people
are looking at including novel test methods.

 

Near the bottom of the article is a photo of Prof Philip Hopke from Clarkson
University in Potsdam NY, one of the well-known figures in the field of PM
measurement.

 

Previously mentioned here was the work of Alexander Batsulin in Russia who
Yury helped me find and contact. That in turn led to a contact with Alex
Chernov in Ontario who visited Waterloo for a fun-filled day.

 

The Alliance for Green Heat and the Masonry Stove Builders Association are
related but not entirely congruent in purpose or approach.  Both are
innovating. The technologies you can see at the website so I won't worry
about them.

 

Their common ground is the disagreement with the EPA over methods of
calculating performance, the targets set and the conditions which prevail
when measurements are made. Different methods given significantly different
results and ratings. 

 

Alexander Batsulin observes there are problems with the way Testo calculates
efficiency, and this has occupied many minds for a while. The EPA method is
different, and Batsulin disagrees with that too. The critical element of the
calculation is the determination of the total volume of air by various means
including fuel chemistry, velocity measurements, dilution (using differing
formulae) and PM sampling conditions.

 

The method described in the linked article is constantly under discussion.
Hundreds of submissions have been made to the EPA which is seeking to
regulate the sector. There are all sorts of problems with approving
fireplaces built one by one. Stand-alone space heating stoves are much
easier to regulate because they are shipped as a whole product.

 

The method used in Ulaanbaatar (HTP for space heating) was developed with
thinking along the lines that Batsulin uses - he having independently found
the same errors with popular methods and proposes a 'solution for
dilution'). The approach of both is a chemically balanced calculation though
Batsulin doesn't go as far (in part because of a lack of equipment). The HTP
attempts to make the efficiency calculation based on what was burned during
a test portion. Ultimately the goal is to determine it 'per measurement' (10
seconds).

 

Unless you are really interested in what these calculations involve I won't
bore anyone with them here. Conceptually they get a PM mass measured over
some time interval under certain conditions, then calculate the volume of
gases that contained that total mass of PM and calculate an emissions rate.
Unfortunately this is usually expressed by the EPA 'per unit mass of fuel
burned' though everyone else is moving to emissions per MJ delivered. This
is happening because the sector is unregulated and they can do what is
thought sensible at the time.

 

There is a device shown in a picture near the bottom of the web page - wa-ay
down. It is called a Condar and is a Canadian invention that many would find
useful. It is a sampling device with a large diameter filter. It is
connected to a vacuum source (like a vacuum cleaner) which is regulated in a
way such that the pressure in the sample tube is held to a certain value.
This gives a certain mass flow which with the PM mass gain on the filter,
can then be interpreted to give a total PM during the sample period. A
Condar is pretty cheap. 

 

Norbert Senf wrote:

http://heatkit.com/docs/OMNIcourse.pdf
<http://heatkit.com/research/lopezq.htm> 

has a transcript I did of Skip Barnett describing the Condar and how it
works and what it does, starting around page 21

The only actual document by Skip is the Condar operating guide, which is on
the Lopez Archive page:
http://heatkit.com/docs/condar.PDF

 

Using an O2 and CO cell (or whatever else you have) the volume of gases
passing through the chimney can be estimated. Batsulin's complaint is how
that number is calculated. Using that number and the temperature, the heat
loss from the stack can be calculated giving the system efficiency as a
space heater. There are several (big) problems with this. One is that the
fire might have a low burn rate but a low excess air flow and later that
changes, while the sample of PM is drawn constantly. Without knowing how
much fuel was burned and what was in it, the PM total mass is basically
unknowable. 

 

With heating efficiency, which is a ratio, it is easier, but again the
efficiency varies over time and averaging 'efficiencies' is not a valid
step. It may have been 75% efficient at a low power and 60% efficient at
high power, for different lengths of time. So Batsulin objects to as well
(which he should) to averaging all the efficiency numbers. Unless the fuel
burn rate was constant all the time (like in a power station from which the
method comes) the answer is wrong - all the time.  

 

So the cooking stove community and the heating stove community and the
fireplace community have some common issues to discuss.  Some are as simple
as this:

 

"The Mulciber was also tested with unseasoned, 50% moisture content wood and
performed quite well."

 

That is 50% on a dry weight basis, while we would normally say 33% WWB.  

 

"For decades, manufacturers have been building stoves to pass that test, but
not necessarily to burn cleanly in homes."

 

Yeah, well, we have that problem too. Getting a 'good rating' on a badly
calculated metric is not going to impress the cooks at the other end.
That's why we need to talk.

 

Regards

Crispin

 

 

 

Anyone know much about this affair at Brookhaven Labs on Long Island last
month?

http://forgreenheat.blogspot.com/2014_11_01_archive.html

 

In the past Brookhaven was more likely to be involved in radiation problems
here.

 

Michael N Trevor

Marshall Islands

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20141229/77de4d3c/attachment.html>