RE: Stove testing? need help.

[Peter Verhaart <verhaarp@janus.cqu.edu.au>]

Years ago at the Eindhoven Woodburning Stove Group we tested a large number 
of kerosene cookstoves.
For cooking (boiling) you need a power rating appropriate for the amount of 
food cooked to bring the pan and its contents quickly to the boil.
After that you need just enough heating power to keep the pan and its 
contents at boiling point. This is the so-called simmering stage.
To compare the stoves you weigh the stove, containing enough fuel for the 
test, before lighting it.
The stove is lit and a pan with a known mass of water of known temperature 
is placed upon it. The stove is turned up to full power. As soon as the 
water in the pan has reached boiling point, the stove is extinguished and 
weighed.
The pan is also weighed.
The heat transfer efficiency = (Mws * (100 - ts)*Cw +(Mws - Mwe)*He)/((Mks 
- Mke)*Bk)

where:  Mws     mass of water at start
         Mwe     mass of water at the end
         ts      temperature of water at start in C
         Cw      specific heat capacity of water
         He      enthalpy  of evaporation of water
         Mks     mass of stove at start
         Mke     mass of stove at the end
         Bk      heating value of kerosene.

It tells us how much of the heat produced by burning the calculated amount 
of fuel has been transferred to the pan and its contents. If I memory 
serves, quite a number of the multi wick stoves we tested reached 50 %.

During the simmering stage the stove should ideally be capable of burning 
at such a low rate that the pan and its contents are just kept at boiling 
point without producing any steam.
In this regard it is important that the stove can be turned down sufficiently.

Peter Verhaart

> > -----Original Message-----
> > From: owner-stoves@crest.org [mailto:owner-stoves@crest.org]On Behalf Of
> > Jn-Gilles, Emile
> > Sent: Thursday, January 18, 2001 4:44 PM
> > To: stoves@crest.org
> > Subject: Stove testing? need help.
> >
> >
> > Hi stovers,
> > I am wondering what type of answers Adam Sebitt has received from his mail
> > on Stove testing. They would be really helpful to me.  I have
> > just bought 3
> > different size of kerosene stoves (made in Haiti, where I am living) and I
> > would like to do some testing by myself. They are gravity models,
> > noisy but
> > 2 with good flame and good heat.
> >
> > How can I test the efficiency ? What are the procedures ? Do I
> > need a water
> > boiling test or another type of test?

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